TECHNICAL FIELD

The following relates generally to architectural opening coverings and, in particular, architectural opening coverings wherein a rail is moveable by a motor drive.

BACKGROUND

A variety of different architectural opening coverings are known having shades which may be extended across an architectural structure. Many types of architectural opening coverings are motorised, so that a user may perform an operation of opening or closing the covering without needing to manually open or close the covering, for example by manually pulling a cord.

Known coverings include those based on two rails attached to a shade material which spans the area between the rails to cover a whole, or part, of an architectural opening. These coverings are normally operated by a user manually and independently positioning the rails, so as to cover the opening or a part of the opening as desired. Motorising this type of covering is fairly recent and improvements may be made. It is an object to provide an improvement in this regard.

SUMMARY OF INVENTION

As described herein, there is provided an architectural opening covering including a first rail having an elongate extent. With the elongate extent of the first rail extending in a longitudinal direction, the first rail is configured to translate laterally in opposite first and second lateral directions. The first and second lateral directions are substantially perpendicular to the longitudinal direction. The architectural opening covering also includes a second rail having an elongate extent. With the elongate extent of the second rail extending in the longitudinal direction, the second rail is configured to translate laterally in the opposite first and second lateral directions. The architectural opening covering includes a shade material, which extends in the first lateral direction between the first and second rails. For example, the shade material may extend in the first lateral direction from a lateral side of the first rail to a lateral side of the second rail. The shade material may be configured to be extended by relative translation of the first and second rails away from each other, and to be retracted by relative translation of the first and second rails towards each other. The architectural opening covering includes a motor drive configured to translate only the first rail of the first and second rails selectively in the first and second lateral directions. The second rail is configured to be translated in the first and second lateral directions manually by a user. The second rail may be translated in the first lateral direction by the lateral side of the first rail pushing on the lateral side of the second rail. The motor drive and the first rail are together configured to translate the second rail in the first lateral direction by the first rail pushing the second rail in the first lateral direction, while the first rail is being translated in the first lateral direction by the motor drive. This may be, for example, by abutting the lateral side of the first rail against the lateral side of the second rail (directly or via the shade material) and pushing the second rail in the first lateral direction.

There is also provided herein an architectural opening covering installed in an architectural opening. The covering includes a first rail having an elongate extent in a horizontal (width) direction with respect to the opening. The first rail is configured to translate upwards and downwards with respect to the opening. The architectural opening covering also includes a second rail having an elongate extent in the horizontal direction. The second rail is configured to translate upwards and downwards. The architectural opening covering includes a shade material, which extends between the first and second rails (e.g. from a lower side of the first rail to an upper side of the second rail). The architectural opening covering includes a motor drive configured to translate only the first rail of the first and second rails selectively upwards and downwards. The second rail is configured to be translated upwards and downwards manually by a user. The second rail may be translated downwards by the lower side of the first rail pushing on the upper side of the second rail, either via the shade material or directly. The motor drive and the first rail are together configured to translate the second rail downwards by pushing the second rail downwards (e.g. by abutting the lower side of the first rail against the upper side of the second rail). A method of operating an architectural opening covering includes using a motor drive to translate a first rail in a first lateral direction, so as to push a second rail in the first lateral direction. Optionally, a lateral side of the first rail may abut against a lateral side of the second rail, so as to push the second rail. The lateral side of the first rail can abut against the lateral side of the second rail via a shade material, or directly. The first rail can also be translated in the first lateral direction without pushing the second rail, when the first and second rails are apart from one another. The first rail has an elongate extent in a longitudinal direction. The second rail has an elongate extent in the longitudinal direction. The longitudinal direction and the first lateral direction are substantially perpendicular.

A method of opening the architectural opening covering includes using the motor drive to translate the first rail, in the first lateral direction, so as to retract the shade material extending between the first and second rails. The method further includes translating the second rail in the first lateral direction by using the motor drive to translate the first rail in the first lateral direction, so as to push the second rail with the first rail. The first rail is moved directly by the motor drive. The second rail is moved indirectly by the motor drive by being pushed by the first rail which is directly moved by the motor drive.

A method of closing the architectural opening covering includes using the motor drive to translate the first rail, in the first lateral direction, so as to retract the shade material extending between the first and second rails. The method further includes translating the second rail in the first lateral direction by using the motor drive to translate the first rail in the first lateral direction, so as to push the second rail with the first rail. The method includes subsequently using the motor drive to translate the first rail in the second lateral direction, away from the second rail, so as to extend the shade material.

By independently moving the first and second rails in the first and/or second lateral direction, a user is able to cover any portion of an architectural opening with the shade material. For example, if the rails are oriented horizontally when the covering is installed, a user can cover a top part, a middle part, or a bottom part of the opening according to outside light conditions or privacy needs. The covering may be put into a fully open configuration by moving both rails close together, at either end of the opening in the first or second lateral direction. By moving the motorised rail only, a user can fully open the covering by using the first rail to push the second rail all of the way to a first end of the opening in the first lateral direction. Then the shade material is fully retracted between the two rails which are close together. Also by moving the motorised rail only, a user can fully close the covering, by first fully opening the covering by pushing the second rail in the first lateral direction towards the first end of the opening, and subsequently moving only the first rail in the (opposite) second lateral direction to the other (second) end of the opening. The functionality of fully opening the covering (with both first and second rails at the first end of the opening) and fully closing the covering (with the first rail at the second end of the opening and the second rail at the first end of the opening) can thus be achieved by using the motorised mechanism only, without the need to manually move one or both of the rails. At the same time, the user also has the versatility of being able to freely position both rails.

The motor drive could be provided inside the first rail. The motor drive is preferably provided outside of the first and second rails. This avoids the need for a motor drive to be included within or attached to the first rail. This could allow the first rail to be lighter and easier to move. This could also allow the first rail to be less bulky and more aesthetically pleasing. The motor drive could be configured to be fixed to a part of an architectural structure, such as a wall, adjacent the architectural opening. The architectural opening covering may include a third rail configured to be fixed adjacent the architectural opening, for example, to a wall above the architectural opening. When a third rail is provided, the motor drive is provided within the third rail. A third rail may house other components of the covering, for example components of a support assembly for supporting the rails. It may therefore be convenient from an aesthetic point of view to provide the motor drive within a third rail.

Generally, any motorised mechanism may be used to translate the first rail. For example, a known linear actuator based on a screw could be used. A motor could be used to rotate a screw, extending in the lateral direction, to which the first rail is coupled. Rotation of the screw in a first rotational direction would translate the first rail in the first lateral direction and rotation of the screw in the opposite rotational direction would translate the first rail in the second lateral direction. The motor drive may include a motor and a drive shaft configured to be rotated by the motor about an axis extending in an axial direction. The covering may include a first elongate flexible member. The first elongate flexible member may be coupled to the drive shaft and to the first rail, such that rotation of the drive shaft in a first rotational direction causes the first rail to translate in the first lateral direction. The motor drive may further include a second elongate flexible member. The second elongate flexible member may be coupled to the drive shaft and to the first rail, such that rotation of the drive shaft in a second rotational direction causes the first rail to translate in the second lateral direction. The second rotational direction is opposite to the first rotational direction. One or both elongate flexible members may be belts, chains, or, most preferably, cords.

A drive shaft and one or more elongate flexible members, coupled to both the first rail and the drive shaft, provides a means for transmitting power from the motor to the first rail, when the motor is provided at some distance away from the first rail (for example, adjacent an edge of the architectural opening). Elongate flexible members, such as cords, are visually discrete and do not obscure the architectural opening.

When a drive shaft is provided, the first and second elongate flexible members may be configured to wind around the drive shaft itself. Winding of elongate flexible members around the drive shaft provides a way of converting rotational movement of the motor into translational movement of the first rail to which the elongate flexible members are attached.

Preferably, the drive shaft includes thereon first and second spools which are configured to rotate with the drive shaft. The first elongate flexible member is coupled to the first spool and the second elongate flexible member is coupled to the second spool. The elongate flexible members are coupled to the spools in such a way that rotation of the drive shaft causes an elongate flexible member to wind around its respective spool. Winding of an elongate flexible member around its respective spool shortens the effective length of elongate flexible member between its spool and the first rail. In this way, the first rail is moved by the winding. Winding of the first and second elongate flexible members around their respective spools causes the first rail to move in the first and second lateral directions, respectively. A method of using a motor drive to translate the first rail in the first lateral direction to push the second rail may include rotating the drive shaft by the motor in the first rotational direction, such that the first elongate flexible member winds around the first spool provided on the drive shaft, and the second elongate flexible member simultaneously unwinds from around the second spool provided on the drive shaft. In this method, the first elongate flexible member is coupled to the first spool and to the first rail such that winding of the first elongate flexible member around the first spool pulls the first rail in the first lateral direction, and the second elongate flexible member is coupled to the second spool and to the first rail such that unwinding of the second elongate flexible member from around the second spool allows the first rail to translate in the first lateral direction.

By providing first and second spools on the same drive shaft, the motorised first rail is moved in both lateral directions, selectively, by the same operation, that is by rotating the drive shaft. By rotating the drive shaft in the first rotational direction, a portion of the first elongate flexible member is taken up by (wound around) the first spool so as to pull the first rail in the first lateral direction. A corresponding portion of the second elongate flexible member is simultaneously released from (unwound from around) its spool, so as to allow the first rail to move in the first lateral direction. When the drive shaft is rotated in the second lateral direction, a portion of the second elongate flexible member is wound around its spool to pull the first rail in the second lateral direction. A portion of the first elongate flexible member is unwound from around its spool, simultaneously, to allow the first rail to move in the second lateral direction.

Preferably, the covering further comprises third and fourth spools provided on the drive shaft so as to rotate with the drive shaft, wherein the first elongate flexible member is coupled to the third spool and the second elongate flexible member is coupled to the fourth spool. In such an arrangement, rotation of the drive shaft in the first rotational direction causes the first elongate flexible member to wind around the third spool and the second elongate flexible member to unwind from around the fourth spool, thereby translating the first rail in the first lateral direction. Rotation of the drive shaft in the second rotational direction causes the second elongate flexible member to wind around the fourth spool and the first elongate flexible member to unwind from around the third spool, thereby translating the first rail in the second lateral direction. Each of the spools may extend along the drive shaft in the axial direction. Each of the spools may have, in the axial direction, opposite first and second ends and a middle portion connecting the first and second opposite ends, respectively. Each spool may be substantially cylindrical.

Preferably, a first end of the first elongate flexible member is coupled to the first end of the first spool. From here, the first elongate flexible member extends to the second end of the first spool. The first elongate flexible member is held adjacent the second end of the first spool by a first holding member which is stationary (i.e. does not rotate with the drive shaft). The second end of the first elongate flexible member is coupled to the first end of the third spool. The first elongate flexible member extends between the first and second ends of the third spool, and is held adjacent the second end of the third spool by the first holding member. The holding member holds a portion of elongate flexible member in such a way that the elongate flexible member can move in its longitudinal direction (the direction in which the elongate flexible member extends at that point). Thus, rotation of the first and third spools in the first rotational direction draws the first elongate flexible member through the first holding member. A portion of the first elongate flexible member near its first end winds around the first spool and a portion of the first elongate flexible member near its second end winds around the third spool.

Similarly, a first end of the second elongate flexible member is coupled to the first end of the second spool. From here, the second elongate flexible member extends to the second end of the second spool. The second elongate flexible member is held adjacent the second end of the second spool by a second stationary holding member. The second end of the second elongate flexible member is coupled to the first end of the fourth spool. The second elongate flexible member extends between the first and second ends of the fourth spool, and is held adjacent the second end of the fourth spool by the second holding member. The second holding member holds a portion of elongate flexible member in such a way as the elongate flexible member can move in its longitudinal direction. Thus, rotation of the second and fourth spools in the second rotational direction draws the second elongate flexible member through the second holding member. A portion of the second elongate flexible member near its first end winds around the second spool and a portion of the second elongate flexible member near its second end winds around the fourth spool.

This method of winding an elongate flexible member around a spool may avoid overlapping different sections of the elongate flexible member when the elongate flexible member is wound around the spool multiple times. By coupling an elongate flexible member to one end of a spool and drawing it from the opposite end, winding and unwinding take place in a controlled and smooth manner. In contrast, in the case of overlapping, the length of elongate flexible member which is wound around the spool for a rotation of the spool through a given angle may vary randomly. This may present a problem when the simultaneous winding and unwinding of elongate flexible members provides corresponding movement of the first rail. It is therefore desirable to wind the elongate flexible member around the spool such that sections of cord do not overlap one another.

In an alternative arrangement, only two spools are provided. In such arrangements, an intermediate portion (i.e. not an end) of the first elongate flexible member is coupled to the first spool at a first coupling position between the first and second ends of the first spool (optionally substantially in the middle of the first spool in the axial direction). The first elongate flexible member extends between the first and second ends of the first spool via the first coupling position. Adjacent the first and second ends of the first spool, the first elongate flexible member is held by stationary holding members, through which the first elongate flexible member may move in its longitudinal direction. Similarly, the second elongate flexible member is coupled to the second spool at a second coupling position between the first and second ends of the second spool (optionally substantially in the middle of the first spool in the axial direction). The second elongate flexible member extends between the first and second ends of the second spool via the second coupling position. Adjacent the first and second ends of the second spool, the second elongate flexible member is held by stationary holding members, through which the second elongate flexible member may move in its longitudinal direction. In this alternative arrangement, rotation of the first spool in the first rotational direction draws the first elongate flexible member through its holding members so as to wind the first elongate flexible member around the first spool, on both sides of the first coupling position. Rotation of the second spool in the second rotational direction draws the second elongate flexible member through its holding members so as to wind the second elongate flexible member around the second spool, on both sides of the second coupling position.

In arrangements in which only one elongate flexible member is coupled to each spool, both ends of the first elongate flexible member are coupled to the first rail, with an intermediate portion of the first elongate flexible member coupled to the first spool. Similarly, both ends of the second elongate flexible member are coupled to the first rail, with an intermediate portion of the second elongate flexible member coupled to the second spool.

This arrangement of coupling an elongate flexible member to a spool allows the elongate flexible member to be drawn inwards towards the spool in two directions. This allows two ends of the elongate flexible member to be coupled to the first rail in two locations on the rail, respectively. In this way, a single elongate flexible member can exert a pulling force on the first rail at two points on the first rail.

In such arrangements, the first and/or second spool may have a constant width/diameter along its axial length. Alternatively, the first and/or second spool may be wider (have a larger diameter perpendicular to its axis) at both ends and narrower in the middle in the axial direction. The elongate flexible member may be coupled to its spool at the narrow middle portion. Each of the first and second spools may have a shape which is frustoconical on either side of the middle portion where the respective elongate flexible members are coupled.

The architectural opening covering may include a guide member configured to guide the first elongate flexible member at an intermediate part of the first elongate flexible member between the drive shaft and the first rail, and to change a direction in which the first elongate flexible member extends. The guide member may be configured to be positioned at an end of the architectural opening in the first lateral direction, and configured to hold the intermediate part of the first elongate flexible member such that it can move through the guide member in its longitudinal (or axial) direction (i.e. the direction in which the elongate flexible member extends at any point). The guide member may include a pulley around which the first elongate flexible member is looped. For example, the drive shaft may be provided at one end of the architectural opening in the second lateral direction. Then, the guide member is provided at the opposite end of the architectural opening. The first elongate flexible member may extend from the drive shaft, to which it is coupled, to the guide member at the opposite end of the opening, change direction at the guide member, then extend from the guide member to the first rail, which is at a position between the drive shaft and the guide member. In this way, rotation of the drive shaft pulls a portion of the first elongate flexible member, between the drive shaft and the guide member, in the second lateral direction. This in turn pulls a portion of the first elongate flexible member, between the guide member and the first rail, in the first lateral direction, thereby translating the first rail in the first lateral direction.

A second guide member may also be provided. First and second guide members may be positioned at an end of the architectural opening in the first lateral direction. The first guide member is configured to hold a first part of the first elongate flexible member, between the part which is coupled to the drive shaft (e.g. the first end which is coupled to the first spool) and the part which is coupled to the first rail (e.g. an intermediate part). The second guide member is configured to hold a second part of the first elongate flexible member, between the part which is coupled to the drive shaft (e.g. the second end which is coupled to the third spool) and the part which is coupled to the first rail (the intermediate part). The first elongate flexible member changes direction at each respective guide member. The first elongate flexible member may slide or move through each respective guide member, in its longitudinal (or axial) direction.

For example, the drive shaft may be provided at one end of the architectural opening in the second lateral direction, with the first and second guide members provided at the opposite end. The first rail is then positioned between the drive shaft and the first and second guide members, in the first lateral direction. The first elongate flexible member may extend from the drive shaft in the first lateral direction to the first guide member, then change direction at the first guide member to extend in the second lateral direction to the first rail. The first elongate flexible member may subsequently extend along the first rail to the other side of the covering, and then extend in the first lateral direction from the first rail to the second guide member, change direction at the second guide member, then extend from the second guide member in the second lateral direction to the drive shaft. In this way, rotation of the drive shaft pulls the first elongate flexible member from both first and second guide members, in the second lateral direction. This in turn pulls portions of the first elongate flexible member, between the first guide member and the first rail and between the second guide member and the first rail, respectively, in the first lateral direction, thereby translating the first rail in the first lateral direction.

In an alternative arrangement, the first and second ends of the first elongate flexible member may be coupled to the first rail, with an intermediate part coupled to the first spool, as described above. Then, the first guide member may be configured to guide a first part of the first elongate flexible member between the intermediate part which is coupled to the drive shaft and the first end of the elongate flexible member, and change a direction in which the first part of the first elongate flexible member extends. The second guide member may be configured to guide a second part of the first elongate flexible member between the intermediate part which is coupled to the drive shaft and the second end of the elongate flexible member,, and change a direction in which the second part of the first elongate flexible member extends.

Each of the first and second guide members may include a pulley respectively. This reduces friction and provides for a smoother operation.

The architectural opening covering may include a support assembly configured to hold the second rail, and optionally the first rail. The support assembly may be configured to constrain movement of the second rail (and optionally the first rail) other than translation in the first and second lateral directions. The support assembly may be configured to hold the second rail, and optionally the first rail, at respective positions in the first lateral direction such that the second rail, and optionally the first rail, is translatable in the first and second lateral directions. For example, the second rail, and optionally the first rail, may be held at their respective positions in the first lateral direction by friction, and may be moveable in the first and second lateral directions by overcoming the friction force. The support assembly may be provided for the second rail only, with the first rail being held by friction between the first rail and the elongate flexible members, by virtue of the tension in the elongate flexible members. The support assembly could be upper and lower tracks along which a retractable screen/ door/ curtain may translate, for example.

The architectural opening covering may include a tension cord routing arrangement as a support assembly. The tension cord routing arrangement may include tension cords, along which the second rail, and optionally the first rail, is translatable in the first and second lateral directions.

When the architectural opening covering includes a tension cord routing arrangement, the tension cord routing arrangement includes tension cord mounts for receiving the tension cords. The tension cord mounts may be configured to be provided on the side of the second rail opposite to the side of the first rail, which may be at an end of the architectural opening in the first lateral direction. When the architectural opening covering also includes a guide member, the guide member may be provided in one of the tension cord mounts. When there are first and second guide members, each of the first and second guide members may be provided in one of the tension cord mounts, respectively.

The first rail could be moveable only by the motor. Preferably, a disengagement clutch is provided between the motor and the drive shaft, such that the first rail is moveable in the first and second directions by being moved manually when the motor and drive shaft are disengaged. This configuration provides further flexibility for a user, for example, a user would be able to move the first rail in the event of being unable to supply power to the motor.

The first elongate flexible member may be coupled to the first rail by a tensioning spring. The tensioning spring keeps the first elongate flexible member taut so that the first rail is stably held in position. The tensioning spring also takes up any variations/inconsistencies between the winding and unwinding of the first elongate flexible member around the first and third spools, respectively.

BRIEF DESCRIPTION OF THE DRAWINGS Implementations of the invention will be more clearly understood from the following description, given by way of example only, with reference to the accompanying drawings, in which:

Fig. 1 shows an architectural opening covering according to an illustrated example;

Fig. 2 shows an alternative example of an architectural opening covering;

Fig. 3 illustrates a retractable shade material extending between first and second rails according to the illustrated example (perspective view);

Fig. 4 shows a covering including a head rail, tension cords, and drive cords according to the illustrated example (perspective view);

Fig. 5 shows an exploded view of the arrangement of the head rail of Fig. 4;

Fig. 6 shows a configuration of a second drive cord wound around second and fourth spools according to the illustrated example (perspective view);

Fig. 7 shows a cross-sectional view of a motor drive according to the illustrated example;

Fig. 8 shows a perspective view of the covering of the illustrated example, showing components inside the headrail and the drive cords, with tension cords omitted;

Fig. 9 shows spool housings and drive cords according to the illustrated example (perspective view);

Fig. 10 shows a perspective view of the covering of the illustrated example, showing components inside the headrail and tension cords, with drive cords omitted;

Fig. 11 shows the same view as Figs. 8 and 10, with both drive cords and tension cords shown;

Figs. 12a and 12b show an adapted tension cord mount according to the illustrated example;

Fig. 13 shows a cord routing member according to the illustrated example; Fig. 14 shows a first rail end member and a second rail end member of the illustrated example;

Fig. 15 shows the routing of the first drive cord within the first rail according to the illustrated example;

Fig. 16 shows the routing of the second drive cord within the first rail according to the illustrated example;

Figs. 17a, 17b and 17c show example tension cord routing arrangements according to the illustrated example;

Fig. 18 shows an exploded perspective view of the covering of a second illustrated example, with the shade material omitted;

Figs. 19a and 19b show the winding and unwinding of drive cords on spools according to the second illustrated example;

Fig. 20 shows a cord routing member according to the second illustrated example.

DETAILED DESCRIPTION

An illustrated example of an architectural opening covering will now be described with reference to the drawings.

Fig. 1 shows an architectural opening covering 10 according to the illustrated example. The architectural opening covering (also referred to as a “covering”) includes a first elongate rail 21, a second elongate rail 22, and a shade material 30 extending between the first and second rails 21, 22. An alternative arrangement of an architectural opening covering 10 is illustrated in Fig. 2. In Figs. 1 and 2, the vertical and horizontal direction with respect to the architectural structure opening are the vertical and horizontal directions in the plane of the page, respectively. Unless specified otherwise, “horizontal” means in the width direction of the covering.

In the illustrated example, as shown in Fig. 1, the covering 10 is a top-down bottom-up blind. In a top-down bottom-up blind, the first and second rails 21, 22 extend substantially horizontally across an opening 100 with respect to which the covering 10 is installed (an example of a longitudinal direction). The first and second rails 21, 22 are translatable vertically upwards (an example of a second lateral direction) and downwards (an example of a first lateral direction) with respect to the opening 100. The first rail 21 is positioned vertically above the second rail 22. The first and second rails 21, 22 may also be referred to as upper and lower moveable rails, respectively. A shade material 30 extends between the first and second rails 21, 22, such that the blind may be (partially) opened by moving the top rail down and/or moving the bottom rail up. In particular, the covering 10 is a tensioned top-down bottom-up blind (as opposed to a free-hanging top-down bottom-up blind). In a tensioned top-down bottom-up blind, at least one of the moveable rails 21, 22 is supported by a tension cord arrangement, which will be described later.

In the alternative arrangement shown in Fig. 2, the covering 10 is a retractable door or privacy screen. In a retractable screen/door, the first and second rails 21, 22 extend substantially vertically across the opening 100. A shade material 30 (or screen) extends horizontally between the first and second rails 21, 22. The first and second rails 21, 22 are translatable in opposite horizontal directions, so as to extend or retract the shade material 30 across the opening 100.

The first and second rails 21, 22 have the same elongate extent. As illustrated in Figs. 1 and 2, when installed in situ, the first and second rails 21, 22 have an elongate extent which is designed to fit within the architectural opening 100. For example, an elongate extent of the first and second rails 21, 22 may be slightly smaller than the width or height of an architectural opening 100 in which the covering 10 is to be installed.

In the following description of the illustrated example, a “rear” side/direction with respect to the covering faces the architectural structure opening. A “front” side/direction faces an interior of a room, when the covering is installed in a window. Any references to left and right are as viewed from the front side, i.e. towards the rear side.

The architectural opening 100 has a first end 101 in a first lateral direction and a second end 102 in a second lateral direction. In the illustrated example, the first end 101 is a bottom end of the architectural opening and the second end 102 is a top end of the architectural opening. In the illustrated example, the first lateral direction is defined as vertically downwards, and the second lateral direction is defined as vertically upwards, as shown in Fig. 1. Generally, the first lateral direction is defined as a direction, perpendicular to the elongate extent of the first and second rails 21, 22, from the first rail 21 to the second rail 22.

When the covering 10 is installed in the architectural opening 100, the first rail 21 is configured to be moveable between any two positions between a position A and a position

C. The second rail 22 is configured to be moveable between any two positions between a position B and a position D. The positions A and B are close to the second end of the architectural opening 100, with the position A being closest to the second end of the architectural opening 100. The positions C and D are close to the first end of the architectural opening 100, with the position D being closest to the first end of the architectural opening 100. Examples of positions A, B, C and D are annotated in Figs. 1 and 2.

When the first rail 21 is located at position A and the second rail 22 is located at position

D, then the shade material 30 extends substantially between the ends of the architectural opening 100 (fully closed configuration). When the first rail 21 is located at position A and the second rail 22 is located at position B, or the first rail 21 is located at position C and the second rail 22 is located at position D, the shade material 30 is retracted (fully open configuration).

The first and second rails 21, 22 and shade material 30 according to the illustrated example will now be described with reference to Figs. 3 and 4. As shown in Fig. 3, the first rail 21 has a lateral side 212 and the second rail 22 has a lateral side 221. The “lateral sides” of the first and second rails 21, 22 are defined as the lateral sides which face one another when the covering 10 is installed in situ. The first and second rails also have other lateral sides which do not face each other.

The first rail 21 has a first end 213, a second end 214, an upper lateral side 211 and a lower lateral side 212. The second rail 22 has a first end 223, a second end 224, an upper lateral side 221 and a lower lateral side 222. The first ends of the first and second rails are on the left-hand side of the covering and the second ends of the first and second rails are on the right-hand side of the covering. The lower lateral side of the first rail faces the upper lateral side of the second rail when the covering 10 is installed. The shade material 30 extends between the lower lateral side 212 of the first rail 21 and the upper lateral side 221 of the second rail 22. In the illustrated example, the lateral side of the first rail 21 is the lower lateral side 212 and the lateral side of the second rail 22 is the upper lateral side 221. In alternative arrangements, for example in a retractable door, the lateral sides could be a right lateral side and a left lateral side which face each other.

The first and second rails 21, 22 are substantially rigid. The first and second rails 21, 22 may be made from any suitable material, for example a plastic, wood, or metal (for example aluminium). In the illustrated example, each of the first and second rails 21, 22 is hollow, including within it a space for housing other components, as will be described later.

The first and second rails 21, 22 are substantially straight. Generally, the first and second rails 21, 22 can have any elongate shape, provided that their shapes allow the lateral side of the first rail 21 to abut the lateral side of the second rail 22, in order that the first rail 21 can exert a force on the second rail 22 so as to push the second rail in the first lateral direction. It is not necessary that the whole of the lateral side of the first rail 21 abuts the whole of the lateral side of the second rail 22, in order that the first rail 21 can push the second rail 22 in the first lateral direction. For example, the first and second rails 21, 22 may be in direct contact only at certain points on their lateral sides. Furthermore, it is not necessary for the first and second rails 21, 22 to be in direct contact with one another. In the illustrated example, the lateral side of the first rail 21 abuts the lateral side of the second rail 22 via the retracted shade material 30.

As shown in Fig. 4, the first rail 21 includes an opening 216 at its first end 213 and an opening 216 at its second end 214. The second rail 22 includes an opening 226 at its first end 223 and an opening 226 at its second end 224. Each opening extends vertically from the upper lateral side 211, 221 to the lower lateral side 212, 222 of the rail. The openings communicate with the interiors of the first and second rails 21, 22, allowing cords (such as tension cords and elongate flexible members, which will be described later) to be partially located within the first and second rails 21, 22 and to exit the first and second rails through the openings at the ends of the first and second rails.

The shade material 30 extends in the first lateral direction from the lower lateral side 212 of the first rail 21 to the upper lateral side 221 of the second rail 22, as illustrated in Figs. 3 and 4. The shade material 30 is any suitable shade material for use in an architectural opening covering 10. The shade material 30 could be any time of stackable (i.e. not rollable) shade, for instance, Venetian blinds, Roman shades, pleated blinds or honeycomb/cellular blinds. When the shade material 30 is stackable, the first rail abuts the second rail via the retracted shade material.

The shade material 30 could alternatively be a rollable shade. In such an arrangement, the fabric of the roller blind is attached to the first rail 21 and the roller blind tube with an integrated spring motor is attached to the second rail 22. In such an arrangement, the first rail directly abuts the second rail to push the second rail, because the shade material can retract into the second rail (around the tube).

In the illustrated example, the shade material 30 is provided only between the first and second rails 21, 22 and not elsewhere. Alternatively, there may be a second shade material, usually between the upper moveable rail 21 and a fixed top rail (which will be described later). In that case, the second shade material usually has different opacity/view through.

In the illustrated example, the shade material 30 has an effective length from the lateral side 212 of the first rail 21 to the lateral side 221 of the second rail 22 in the first lateral direction. In the illustrated example, the shade material 30 is configured to be extended by relative translation of the first and second rails 21, 22 away from each other, and to be retracted by relative translation of the first and second rails 21, 22 towards each other. In other words, an effective length of the shade material 30 from the lateral side 212 of the first rail 21 to the lateral side 221 of the second rail 22 lengthens/shortens as the distance between the moveable rails 21, 22 increases/decreases. This could be achieved in numerous different ways, for example a pleated blind with pleats extending in the horizontal direction, as shown in Fig. 3, allows the shade material to extend and retract in the vertical direction. Similarly, the shade material 30 may have a cellular structure, the cells of the shade material being configured to open and close, with extension of the material and retraction of the material, respectively, as shown in Fig. 4. In a pleated or cellular shade, horizontal strips of the material stack on top of one another when the shade is retracted.

The covering 10 also includes a motor drive 40 (not shown in Figs. 1 to 4). The motor drive 40 is configured to translate only the first rail 21 of the first and second rails 21, 22. This means that the motor drive 40 is operatively connected to the first rail 21 so as to be able to translate the first rail 21. The motor drive 40 is configured to translate the first rail

21 selectively in the first and second lateral directions.

The motor drive 40 is configured to translate the first rail 21 by an operation of a user. The motor drive is provided with controls which allow a user to operate the motor drive 40 so as to move the first rail 21 in the first or second lateral direction. One or more buttons for operating the motor drive 40 may be provided on a remote control device, for example.

The second rail 22 is translatable in the first and second lateral directions manually by a user. The second rail 22 is provided with a handle 225 for a user to hold in order to move the second rail in the first or second lateral direction, as illustrated in Figs. 4 and 5. There is no motor drive provided for moving the second rail 22 only (the second rail 22 does not have a dedicated motor drive).

The second rail 22 cannot be directly moved by a motor drive. However, the second rail

22 is configured to be indirectly moved using the motor drive 40, because the second rail can be moved by being pushed by the first rail 21 when the first rail 21 is moved directly by the motor drive 40. In other words, the second rail 22 is not operatively connected to the motor drive 40, other than by abutting against the first rail 21, via the shade material 30, so as to be pushed by the first rail 21. The only way in which the second rail 22 can be moved by the motor drive 40 (or by any motor drive), is by being pushed by the first rail 21 when the first rail 21 is moved by the motor drive 40 in the first lateral direction, whilst the rails abut against one another, via the shade material 30 (or directly in alternative arrangements). In the illustrated example, the covering 10 is provided with a third rail 23 having an elongate extent, as shown in Fig. 4. The elongate extend of the third rail 23 is substantially the same as the elongate extent of the first and second rails 21, 22, as shown in Fig. 4. The third rail 23 is hollow, including within it space for housing the motor drive 40 and other components. In the illustrated embodiment, the third rail 23 has an upper lateral side 231, a lower lateral side 232, a first end 233 and a second end 234. In the illustrated example, the first end of the third rail is on the left-hand side of the covering and the second end of the third rail is on the right-hand side of the covering.

Unlike the first and second rails 21, 22, the third rail 23 is not configured to be moveable when the covering 10 is installed in situ. The third rail 23 is configured to be fixed to a part of the architectural structure, for example to a wall adjacent the opening 100. The third rail 23 may be configured to be fixed to a wall using any suitable means, such as brackets, bolts, and/or screws.

In the illustrated example, the third rail 23 is positioned at the second end 102 of the architectural opening 100, with an elongate extent of the third rail extending substantially in the longitudinal direction of the first and second rails. In the illustrated example, the third rail 23 is a head rail (an example of a third rail) which is configured to be oriented substantially horizontally with respect to the opening 100 and positioned near the top of the opening. In alternative arrangements, the third rail 23 could be oriented vertically and fixed to a wall adjacent a side of the opening 100 in the second lateral direction. Generally speaking, the third rail 23 may be provided in any position near the architectural opening 100.

Fig. 5 shows an exploded view of the head rail 23, containing the motor drive 40, of the illustrated example. A first end plate 241 is provided at the first end 233 of the head rail and a second end plate 242 is provided at the second end 234 of the head rail. The first and second end plates 241, 242 partially close the ends 233, 234 of the head rail. Gaps are provided between the lower lateral side 232 of the head rail and the first and second end plates 241, 242, respectively. The gaps allow cords (drive cords and tension cords, which will be described later) which are partially situated within the head rail 23 to exit the head rail. As shown in Fig. 5, the head rail 23 is provided with first and second brackets 26 for attaching the head rail to the architectural structure above the opening.

The motor drive 40 according to the illustrated example will be described with reference to Figs. 5 and 7. In the illustrated example, the motor drive 40 includes a drive shaft 50 configured to be rotated by a motor about an axis of the drive shaft extending in an axial direction. The drive shaft 50 has an elongate extent in the axial direction. The length of the elongate extent of the drive shaft 50 is smaller than the length of the first and second rails 21, 22. In the illustrated example, the axial direction is horizontal (parallel to the longitudinal direction of the first and second rails).

The motor drive 40 may include any type of motor 41 which is suitable for rotating the drive shaft 50 selectively in both rotational directions. In the illustrated example, the motor 41 is provided with one or more batteries 44. Alternatively or additionally, the motor 41 may be connected to the mains power. The motor 41 is provided with motor controls for controlling the operation of the motor and a radio transceiver for remotely operating the motor to move the first rail.

The motor drive, including the motor 41 and drive shaft 50, is configured to be provided at a predetermined position outside of the first and second rails 21, 22. In the illustrated example, the motor drive, including the motor 41 and drive shaft 50, are configured to be positioned at the second end of the architectural opening 100 (the top end of the opening), with the drive shaft axis extending substantially in the longitudinal direction of the first and second rails 21, 22 (horizontally). In the illustrated example, the drive shaft 50, motor 41, motor controls and batteries 44 are provided in the third rail 23 described above, as shown in Fig. 5.

Next, a description is given of how rotation of the drive shaft by the motor acts to move the first rail, selectively, in the first and second lateral directions, with reference to Fig. 8. In the illustrated example, the covering 10 includes a first drive cord 61 and a second drive cord 62. In Fig. 8, the first drive cord 61 is shown as a dashed line and the second drive cord 62 is shown as a solid line. A drive cord is an example of an elongate flexible member. Other examples of an elongate flexible member are flat tape-like members, wires, and cables. In the illustrated example, each drive cord 61, 62 has first and second ends connected by an intermediate portion. In alternative arrangements, an elongate flexible member may have no ends, for example a loop or a belt. The first and second drive cords 61, 62 are configured to be held under tension, when the covering 10 is installed in situ.

Where the following description refers to “a/the drive cord”, the description may apply equally to both of the first and second drive cords 61, 62, unless it is clear from the context which drive cord is being referred to.

The first and second ends of each respective drive cord 61, 62 are coupled to the drive shaft. The intermediate portion of each respective drive cord 61, 62 is coupled to the first rail 21. In an alternative arrangement, one end of a drive cord may be coupled to the drive shaft 50 and the other end may be coupled to the first rail 21. In another alternative arrangement, each end of a drive cord is coupled to the first rail 21, with the intermediate portion of the drive cord coupled to the drive shaft 50. In general, a drive cord may be coupled to the drive shaft 50 and the first rail 21 by any means, for example, by one or more clips/holes/grooves and/or by one of more knots in the drive cord.

In the illustrated example, the drive shaft 50 is housed within the third rail 23, as described above, and the first and second drive cords 61, 62 are partially located within the third rail, as shown in Fig. 8.

In alternative arrangements, first and second drive cords 61, 62 may be configured to wind directly onto the drive shaft 50. However, in the illustrated example, the drive shaft 50 is provided with first, second, third and fourth respective spools 51, 52, 53, 54. Where the following description refers to “a/the spool”, the description may apply equally to each of the first, second, third and fourth spools 51, 52, 53, 54 (unless it is clear from the context which spool is being referred to). The spools themselves are not visible in Fig. 8. The first and third spools 51, 53 are located within a first spool housing 91 and the second and fourth spools are located within a second spool housing 92, with the spool housings 91, 92 shown in Fig. 8. The first spool housing 91 is an example of a “first holding member” and the second spool housing 92 is an example of a “second holding member”. The first end of the first drive cord 61 is coupled to the first spool 51 and the second end of the first drive cord is coupled to the third spool 53. The first end of the second drive cord 62 is coupled to the second spool 52 and the second end of the second drive cord is coupled to the fourth spool 54. The first drive cord is a lowering cord which is configured to lower the first rail, i.e. to translate it in the first lateral direction. The second drive cord is a lift cord which is configured to raise the first rail, i.e. to translate it in the second lateral direction.

In alternative arrangements, four drive cords may be provided, with an end of each respective drive cord coupled to a respective spool, and the other end coupled to the first rail. However, with four drive cords, the system can be sensitive to skewness of the first rail in installation. With two drive cords each forming a loop in the first rail, as in the illustrated example, the horizontal orientation of the first rail can be easily corrected. Furthermore, the location of the first and third spools and the location of the second and fourth spools, respectively, within the headrail can be changed without affecting the position or orientation of the first rail (because the drive cords can be fed through the first rail in order to move the spools). Calculating the respective lengths of the first and second drive cords is also easier than calculating the lengths of four respective drive cords. The lengths of the first drive cord and the second drive cord are calculated according to the dimensions of the covering, such that each of the first and second drive cords forms a loop starting and ending at its spools (the drive cord routing is described in detail below). Partitioning the total length of a drive cord loop between two separate cords depends on the positions of the spools in the head rail and also on the orientation of the first rail (which could thus be adversely affected).

In the illustrated example, the first drive cord 61 is coupled to the first and third spools 51, 53 such that, when the first and third spools rotate in a first rotational direction, the first drive cord 61 winds around the first and third spools 51, 53. Specifically, a length of the first drive cord 61 adjacent its first end winds around the first spool 51 and a length of the first drive cord adjacent its second end winds around the third spool 53. When the first and third spools rotate in a second rotational direction, opposite to the first rotational direction, the portion of the first drive cord 61 which was wound around the first spool 51 unwinds from around the first spool 51, and the portion of the first drive cord 61 which was wound around the third spool 53 unwinds from around the third spool 53.

Similarly, the second drive cord 62 is coupled to the second and fourth spools 52, 54 such that the second drive cord winds around the second and fourth spools, when the second and fourth spools rotate in the second rotational direction. Specifically, a length of the second drive cord 62 adjacent its first end winds around the second spool 52 and a length of the second drive cord adjacent its second end winds around the fourth spool 54. When the second and fourth spools rotate in the first rotational direction, the portion which was wound around the second spool unwinds from around the second spool and the portion which was wound around the fourth spool unwinds from around the fourth spool.

Thus, rotation of the drive shaft 50, by the motor, in the first rotational direction causes portions of the first drive cord 61 to wind around the first and third spools 51, 53, and causes corresponding portions of the second drive cord 62 to unwind from around the second and fourth spools 52, 54. A portion of the first drive cord 61, which is not wound around the first spool 51 and which connects the first spool to the first rail 21, is thus shortened. Likewise, a portion of the first drive cord 61, which is not wound around the third spool 53 and which connects the third spool to the first rail 21, is shortened by the same amount. This has the result of moving the first rail 21 in the first lateral direction.

A portion of the second drive cord 62, which is not wound around the second spool 52 and which connects the second spool to the first rail 21, and a portion of the second drive cord 62, which is not wound around the fourth spool 54 and which connects the fourth spool to the first rail, are correspondingly lengthened. This extra length of the second drive cord 62 between the drive shaft and the first rail allows the first rail 21 to move in the first lateral direction.

When the drive shaft 50 is rotated by the motor 41 in the second rotational direction, the reverse operation takes place. The second drive cord 62 winds onto the second and fourth spools 52, 54 to move the first rail 21 in the second lateral direction, while the first drive cord 61 unwinds from around the first and third spools 51, 53, to allow the first rail 21 to move in the second lateral direction. A portion of the second drive cord 62, which is not wound around the second spool 52 and which connects the second spool to the first rail 21, is thus shortened. Likewise, a portion of the second drive cord 62, which is not wound around the fourth spool 54 and which connects the fourth spool to the first rail is shortened by the same amount. This has the result of moving the first rail 21 in the second lateral direction. A portion of the first drive cord 61, which is not wound around the first spool 51 and which connects the first spool 51 to the first rail 21, and a portion of the first drive cord 61, which is not wound around third spool 53 and which connects third spool 53 to the first rail, are correspondingly lengthened. This extra length in the portions of the first drive cord 61 which connect the drive shaft to the first rail allows the first rail 21 to move in the second lateral direction.

The first drive cord 61 winds around the spools 51, 53 in the opposite direction to the direction in which the second drive cords 62 winds around the spools 52, 54. This allows for simultaneous winding around the second and fourth spools 52, 54 and unwinding around the first and third spools 51, 53, and vice versa. In the illustrated example, the second drive cord 62 winds onto the lift spools 52, 54 when the drive shaft rotates clockwise (an example of a second rotational direction), as viewed from the first (left) end of the head rail.

When assembling the covering 10, firstly the second drive cord 62 is routed and attached to the second and fourth spools 52, 54. Then, the drive shaft is driven in the second rotational direction (optionally by the motor) for a predetermined number of rotations to wind the second drive cord 62 onto the second and fourth spools. Then the first drive cord 61 is routed and attached to the first and third spools 51, 53 and the drive shaft is rotated in the first rotational direction (optionally by the motor) to wind the first drive cord 61 onto the first and third spools 51, 53 (whilst simultaneously unwinding the second drive cord 62 from the second and fourth spools 52, 54). The assembly could be performed in the reverse order, i.e. by firstly winding the first drive cord onto the first and third spools, and subsequently winding the second drive cord onto the second and fourth spools. This is how the simultaneous winding and unwinding of the first and second drive cords respectively is obtained with the spools on a single drive shaft. The first drive cord (lowering cord) 61 is configured to exert a pulling force on the first rail 21 in the first lateral direction so as to translate the first rail in the first lateral direction, in order to lower the first rail. The second drive cord (lift cord) 62 is configured to exert a pulling force on the first rail 21 in the second lateral direction, in order to raise the first rail. Both the lift cord 62 and the lowering cord 61 are configured to exert said pulling force by being wound around spools 51, 52, 53, 54 on a single drive shaft 50. It is therefore necessary to configure a pathway of the first drive cord 61 between the drive shaft 50 and the first rail 21, so as to exert a pulling force in the first lateral direction. It is also necessary to configure a pathway of the second drive cord 62 between the drive shaft and the first rail 21, so as to exert a pulling force in the opposite second lateral direction.

In the illustrated example, the drive shaft 50 is positioned in the head rail 23 at the second end (top end) of the architectural opening 100, and the drive shaft axis extends in the longitudinal direction of the first and second rails 21, 22 (horizontally). The first end of the second drive cord 62 is coupled to the second spool 52 within the second spool housing 92. The second drive cord 62 exits the second spool housing 92, and then extends horizontally to a first end 233 of the head rail 23 (i.e. to a side of the covering 10). From here, the second drive cord 62 extends vertically downwards, along a side of the opening, to the first end of the first rail, as shown in Fig. 8. Then, the second drive cord 62 enters the first rail and extends horizontally through the interior of the first rail to the second end 214 of the first rail (i.e. to the other side of the covering 10). From here, the second drive cord exits the second end 214 of the first rail, and extends vertically upwards along a side of the opening to the second end of the head rail 23. From here, the second drive cord 62 enters the head rail 23 and extends horizontally to the second spool housing. The second drive cord 62 re-enters the second spool housing to be coupled to the fourth spool 64. Therefore, winding the second drive cord 62 around the second and fourth spools 52, 54 causes the first rail 21 to move in the second lateral direction towards the drive shaft 50.

In order to move the first rail 21 in the first lateral direction (away from the drive shaft 50), the first drive cord 61 is routed from the drive shaft 50 to a turning point beyond the first rail in the first lateral direction, at which the drive cord reverses direction so as to extend in the second lateral direction back to the first rail, as shown in Fig. 8. Specifically, the first end of the first drive cord 61 is coupled to the first spool 51 within the first spool housing 91. The first drive cord 61 exits the first spool housing 91 and, from here, extends horizontally to the first end 233 of the head rail. Then, the first drive cord 61 extends vertically downwards, along a side of the opening and alongside the shade material 30, to a first turning point at the bottom of the opening. Here, the first drive cord 61 is looped through a first guide member 71. From the first guide member 71 , the first drive cord 61 extends vertically upwards alongside the shade material 30 to the first end 213 of the first rail. The first drive cord enters the first rail and extends from the first end to the second end of the first rail, within the interior of the first rail (details of the routing of the first drive cord within the first rail will be described later). The first drive cord exits the second end of the first rail and extends vertically downwards, alongside the shade material, to a second turning point at the bottom of the covering 10. Here, the first drive cord 61 is looped through a second guide member 72, from which the first drive cord 61 extends vertically upwards to the second end of the head rail. Then the first drive cord 61 enters the head rail, and extends horizontally to the first spool housing, which it re-enters to be coupled to the third spool 53.

In this way, winding of the first drive cord 61 onto the first spool 51 pulls the section of cord extending between the head rail 23 and the first guide member 71 in the second lateral direction (towards the drive shaft 50), which in turn pulls the section of cord extending between the first guide member and the first rail 21 in the first lateral direction (towards the first guide member and away from the drive shaft 50). At the same time, winding of the first drive cord 61 onto the third spool 53 pulls the section of cord between the head rail 23 and the second guide member 72 towards the drive shaft, which in turn pulls the section of cord between the second guide member and the first rail 21 downwards. This allows rotation of the drive shaft which is located in the head rail to move the first rail downwards.

A configuration of the first, second, third and fourth spools 51, 52, 53, 54 and first and second spool housings 91, 92 according to the illustrated example will now be described with reference to Figs. 6, 7 and 9. Fig. 6 shows the second drive cord 62 wound around second and fourth spools 52, 54 within the second spool housing 92. The upper part of the spool housing 92 is absent from the drawing in order to show the spools. Taken in isolation, the first spool housing 91 containing the first and third spools 51, 53 is identical to the second spool housing 92 containing second and fourth spools 52, 54. When installed within the head rail, the first spool housing 91 is rotated through 180° around the vertical direction relative to the second spool housing 92. Therefore, Fig. 6 shows the second and fourth spools within the lower part of the second spool housing when viewed from the front of the covering, but also represents the first and third spools within the lower part of the first spool housing when viewed from the rear of the covering.

Each spool 51, 52, 53, 54 has a first end, a second end, an axis extending in an axial direction between the first and second ends, and an outer surface (also called a middle portion) extending around the axis and extending in the axial direction between the first and second ends. Each spool has a substantially cylindrical shape. In general, a spool may have any shape (e.g. having a curved outer surface) which allows a drive cord to be wound around the spool.

Each spool 51, 52, 53, 54 is a separate component which is fixedly attached to the drive shaft 50. Each spool has a through-hole extending from the first end of the spool to the second end of the spool along its axis, through which the drive shaft 50 extends, as shown in Fig. 7. The spools are keyed to the drive shaft 50, so that they cannot rotate relative to the shaft but rotate with the shaft. The spools are slid onto the shaft during assembly and then fixed to prevent sliding along the shaft during use.

All four of the spools 51, 52, 53, 54 share a rotational axis coincident with the rotational axis of the drive shaft 50 (which will be referred to as “the rotational axis”). When the drive shaft 50 rotates in a given rotational direction and at a given rotational speed, all of the spools 51, 52, 53, 54 rotate in the same rotational direction, on the same rotational axis, and at the same rotational speed.

In the illustrated example, the one or more batteries 44, motor 41 and drive shaft 50 are housed in the head rail 23, with the one or more batteries 44 nearest the second end 234 of the head rail, followed by the motor 41 (in the axial direction), and the drive shaft 50 nearest the first end 233 of the head rail, as shown in Fig. 7. In the illustrated example, the second spool 52 is provided at an end of the drive shaft 50 furthest from the motor, followed by the fourth spool 54, then the first spool 51, then the third spool 53, as shown in Fig. 7. In Fig. 8, the second spool housing is nearest to the first end of the head rail 23. This allows for easier assembly, by firstly assembling the first drive cord 61, which is located towards the rear of the head rail, onto the first and third spools and sliding those onto the drive shaft, and subsequently installing the second and fourth spools with the second drive cord. However, the positions of the spool housings in the axial direction may be reversed. The spool housings could also be located at the opposite end of the head rail (on the right hand side of the covering).

The first and second ends of the first drive cord 61 are coupled to the first end of the first spool 51 and the first end of the third spool 53, respectively. The first and second ends of the second drive cord 62 are coupled to the first end of the second spool 52 and the first end of the fourth spool 54, respectively. Each spool is substantially cylindrical and hollow. The first end of each spool includes a slot in the outer surface of the spool, extending part way along the length of the spool, in the axial direction. The first end of each spool is located adjacent an end face of the spool housing in which it is located. The second end of each spool is located at a position near the middle of the spool housing in which it is located.

The drive cords may be coupled to the spools in any way which results in the simultaneous winding and unwinding described above. In the illustrated example, each of the first and second ends of the first drive cord and each of the first and second ends of the second drive cord, respectively, include a respective knot for coupling to a spool. When the covering 10 is installed, each knot is located in the interior of a respective spool, and the drive cord passes through the slot to the outer surface of the spool, around which it can wind. The knot cannot pass through the slot and so the end of the drive cord is coupled to the spool. For example, the knot in the first end of the first drive cord 61 is located within the first spool 51 , and the first drive cord passes through the slot in the first spool to the outer surface of the spool, around which it can wind. Spool housings 91, 92 are illustrated in Fig. 9. In Fig. 9, the first drive cord 61 is dashed and the second drive cord 61 is solid. Each spool housing is substantially cylindrical and hollow. Each spool housing has opposite end faces in the axial direction through which the drive shaft extends. Each spool housing also includes two openings through which its drive cord exits and enters the spool housing. The openings are provided in an upper surface of the spool housing, near the middle of the spool housing in the axial direction.

Specifically, the first spool housing 91 includes an opening 911 located above the second end of the first spool 51 and towards the rear of the first spool housing 91, and an opening 912 located above the second end of the third spool 53 and towards the rear of the first spool housing 91. The second spool housing 92 includes an opening 921 located above the second end of the second spool 52 and towards the front of the spool housing 92, and an opening 922 located above the second end of the fourth spool 54 and towards the front of the spool housing 92.

Each drive cord extends from the first end of a spool, to which it is coupled by a knot, around the outer surface of the spool, to the second end of the spool. From the second end of the spool, the drive cord extends upwards to pass through one of the pair of openings in the spool housing. Each opening in the spool housing is configured to guide the drive cord from the spool housing to an end of the third rail. Within each opening there is a bearing wheel 93 with its axis along the front-rear direction of the covering 10. Each respective bearing wheel is has a respective shaft which slots into a recess in its spool housing. The drive cord bends around the outer curved surface of the bearing wheel 93 to be guided to an end of the third rail. The bearing wheels enable the drive cords to move smoothly between the interior and exterior of the spool housings by reducing friction. Each spool housing also includes guiding protrusions on the upper surface, one at the first end and one at the second end. The guiding protrusions guide the drive cord which has exited the spool housing from the spool housing to the ends of the head rail, respectively.

For example, the first end of the first drive cord 61 is coupled to the first end of the first spool 51 by a knot. Then the first drive cord 61 extends around the first spool 51 to the second end of the first spool 51. From here, the first drive cord 61 extends vertically upwards to exit the first spool housing via the opening 911 located above the second end of the first spool. The first drive cord 61 bends around the bearing wheel within the opening to be guided horizontally to the first end of the head rail, passing the first spool 51 around which it is wound. Above the first end of the first spool 51 , a guiding protrusion provided on the upper surface of the first spool housing 91 helps to guide the first drive cord 61 to the first end of the head rail.

The second end of the first drive cord 61 is coupled to the first end of the third spool by a knot. The first drive cord extends around the third spool to the second end of the third spool, from where it extends vertically upwards to exit via the opening 912 in the first spool housing located above the second end of the third spool. The first drive cord 61 bends around the bearing wheel to be guided horizontally to the second end of the head rail, passing over the third spool 53 along the way. Above the first end of the third spool, the first drive cord is guided by a guiding protrusion provided on the first spool housing 91.

The preceding two paragraphs also apply to the second drive cord, by replacing “first drive cord” with “second drive cord”, “first spool” by “second spool”, “third spool” by “fourth spool”, and “first spool housing” by “second spool housing”.

The first and second drive cords can move/slide through the openings in the spool housings and through the guiding protrusions on the spool housings, in the longitudinal/axial direction of the cord, in response to the spools being rotated on the drive shaft, to allow winding/unwinding to take place.

A mentioned above, the openings 911, 912 in the first spool housing 91 are positioned near the rear of the first spool housing when the spool housings are installed in the head rail. The openings 921, 922 in the second spool housing 92 are positioned near the front of the second spool housing. The spool housing 91, 92 are arranged in this way so that the first drive cord 61 extends horizontally between the first spool housing 91 and the ends of the head rail 233, 234 towards the rear of the head rail. The second drive cord 61 extends horizontally between the second spool housing 92 and the ends of the head rail 233, 234 towards the front of the head rail. In this way, the first and second drive cords to not interfere with one another within the head rail. At the first and second ends of the third rail 23, there are provided respective first and second cord routing members 251, 252 for routing both drive cords 61, 62 out of the third rail 23. The routing of the first and second drive cords 61, 62 between the drive shaft 50 and the first rail 21 is described above. The first cord routing member 251 is illustrated in Fig. 13.

The first cord routing member 251 is located at the first end 233 of the head rail 23. The first drive cord 61 enters the first cord routing member 251, from inside the head rail 23, in the axial direction, at a position near the rear of the head rail 23. The first cord routing member 251 is configured to guide the first drive cord 61 through the first cord routing member 251 , so as to exit the first cord routing member 251 at the lower side of the first cord routing member 251 , vertically. The first drive cord then extends vertically downwards alongside the shade material 30.

The second drive cord 62 enters the first cord routing member 251 , from inside the head rail, in the axial direction, at a position near the front of the head rail 23. The first cord routing member is configured to guide the second drive cord 62 through itself, such that the second drive cord exits the first cord routing member 251 vertically, at the lower side of the first cord routing member, in front of the first drive cord 61. Then, the second drive cord and the first drive cord extend vertically downwards along the side of the opening 100 between the head rail and the first rail, with the second drive cord in front of the first drive cord.

This routing of the first and second drive cords through the first and second cord routing members allows for minimal direction changes of the drive cords, which results in less friction between the cord routing members and the drive cords, providing a smoother operation for moving the first rail.

Where the first and second drive cords 61, 62 respectively enter the first cord routing member from within the head rail 23, there are provided respective bearing wheels 250. The first and second drive cords 61, 62 are guided around the outer curved surface of each respective bearing wheel. The first cord routing member includes walls which configure a pathway for the first drive cord and a pathway for the second drive cord. The first and second cord routing members are configured such that the first and second drive cords may slide/move through the first and second cord routing members, in their respective longitudinal/axial directions.

The preceding four paragraphs apply also to the second cord routing member 252, by replacing “first cord routing member 251” with “second cord routing member 252”, and “first end 233” with “second end 234”.

In addition to the first and second cord routing members 251, 252 at the ends of the third rail, there may be provided further routing members inside the third rail between the ends of the third rail, for example near to the motor/batteries, for guiding the first and second drive cords through the third rail in the axial direction.

First and second guide members 71, 72 are provided at first and second turning points, as described above. A guide member 71, 72 is any member which is configured to slidably guide the first drive cord 61 so as to change the direction of the drive cord. That is to say, the first drive cord 61 approaches the guide member 71, 72 in the first lateral direction and leaves the guide member in the second lateral direction. Each of the first and second guide members 71, 72 includes a bearing wheel 73 (an example of a “pulley”). In the illustrated example, the first guide member 71 is provided at the left-hand side of the covering, directly below the first end of the third rail, and the second guide member 71 is provided at the right-hand side of the covering, directly below the second end of the third rail.

In the illustrated example, as shown in Fig. 8, the first drive cord 61 extends from the first cord routing member 251 in the first lateral direction to the first guide member 71 , at the first end of the architectural opening 100. The first drive cord 61 runs alongside the shade material 30, near the rear of the covering 10. The first drive cord 61 enters through the top of the first guide member near the rear of the guide member, then loops around a bearing wheel therein. The axis of the bearing wheel extends in the width direction of the covering, such that the first drive cord 61 exits through the top of the first guide member 71 in front of where it entered. From the first guide member 71, the first drive cord 61 extends in the second lateral direction to the first end 213 of the first rail 21. The portion of the first drive cord 61 which connects the first guide member 71 to the first rail 21 runs alongside, and in front of, the portion of the first drive cord which connects the first guide member 71 to the head rail 23.

The preceding paragraph also applies to the routing of the first drive cord 61 between the second cord routing member and the second guide member, by replacing “first cord routing member 251” with “second cord routing member 252”, “first guide member 71” with “second guide member 72” , and “first end 213 of the first rail 21” with “second end 214 of the first rail 21”.

Next, the coupling of the first and second drive cords 61, 62 to the first rail 21 will be described with reference to Figs. 14, 15 and 16.

In general, the first and second drive cords 61, 62 may be coupled to the first rail 21 in any way which enables the first rail 21 to move by being pulled in the first lateral direction by the first drive cord 61, and to move by being pulled in the second lateral direction by the second drive cord 62. A drive cord 61, 62 may be coupled to the first rail 21 at any position along the elongate extent of the first rail.

Fig. 15 illustrates an exploded view of the first rail 21, showing the routing of the first drive cord 61, according to the illustrated example. The second drive cord 62 is omitted from Fig. 15. The first rail 21 includes a first rail end member 217 at each end of the first rail 21. The first rail end members 217 route the first and second drive cords between the interior and exterior of the first rail 21. The first rail end members 217 also route tension cords, which will be described later, between the interior and exterior of the first rail 21.

The first rail 21 also includes a tensioning spring assembly 27 within the interior of the first rail 21. The tensioning spring assembly includes a tensioning spring 271 , a spring block 272, and two adjustment blocks 273. The spring block 272 is a hollow elongate member which houses the tensioning spring 271. An upper side of the spring block 272 is open. The tensioning spring 271 and spring block 272 each extend in the longitudinal direction of the first rail. The spring block is fixed to the interior of the first rail 21, in a position in the centre of the first rail in the longitudinal direction (alternatively, the spring block could be positioned towards the first end or towards the second end of the first rail). The spring block 272 includes a channel which runs from one end to the other end of the spring block, in the longitudinal direction of the first rail. The tensioning spring 271 is located in the middle of the channel in the longitudinal direction. At each respective end of the tensioning spring 271, there is a respective spring end member 274, around which a portion of the first drive cord is looped. The spring end members are fixedly attached to the ends of the tensioning spring. The spring end members are configured to move along the channel in the longitudinal direction of the rail, so that the tensioning spring can extended under tension.

Each adjustment block 273 is located within the first rail, between an end of the first rail and the spring block. Each adjustment block includes a projection around which the first drive cord is looped.

The routing of the first drive cord 61 through the first rail will now be described, with reference to Fig. 15. Starting at the first end of the first rail 21, the first drive cord enters the first rail end member 217 from below (coming from the first guide member 71), and extends in the longitudinal direction to the spring end member 274 at the nearest end of the tensioning spring 271 to the first end of the first rail. The first drive cord is looped around the spring end member, then returns in the opposite longitudinal direction to the adjustment block 273 nearest the first end of the first rail. The first drive cord is looped around the adjustment block 273, then extends in the longitudinal direction, past the tensioning spring, to the adjustment block 274 nearest the second end of the first rail. The first drive cord is looped around this adjustment block 273, then extends in the opposite longitudinal direction to the spring end member 274 nearest the second end of the first rail. The first drive cord is looped around this spring end member 274, then extends in the longitudinal direction towards the second end of the first rail, where it exits the first rail via the first rail end member at the second end of the first rail (to then be routed to the second guide member 72).

Prior to assembling the covering 10, the adjustment blocks are moveable in the longitudinal direction of the first rail. When assembling the covering 10, the positions of the adjustment blocks are adjusted, which adjusts the amount of tension in the tensioning spring and thus in the first drive cord. Once the first drive cord is tensioned, the adjustment blocks are locked into place. The routing of the second drive cord 62 within the first rail is described with reference to Fig. 16. Fig. 16 shows an exploded view of the first rail 21, first rail end members 217, and the second drive cord 62. The first drive cord 61 is omitted in this drawing. The second drive cord 62 enters the first rail end member 217 at the first end of the first rail from above (coming from the drive shaft via the first end of the head rail). Then the second drive cord 62 exits the first rail end member inside the first rail 21, and extends in the longitudinal direction directly to the second end of the first rail 21. Here, the second drive cord 62 enters the first rail end member at the second end of the first rail from within the first rail, then exits the first rail end member outside of the first rail (and is then routed upwards to the second end of the head rail and on to the drive shaft).

There is no tensioning spring provided for the second drive cord 62. This makes the second drive cord quick to assemble, and allows the position of the first rail to be easily corrected to a horizontal orientation during assembly.

Within the first rail 21, the second drive cord 62 passes above the tensioning spring assembly of the first drive cord 61, so that the first and second drive cords do not interfere with one another within the first rail 21.

The covering 10 of the illustrated example includes a tension cord arrangement (an example of a support assembly). When the covering 10 is installed, the tension cord arrangement holds the first and second rails 21, 22 such that each extends in the longitudinal direction (horizontally). The tension cord arrangement allows translation of the first and second rails 21, 22 in the first and second lateral directions, relative to the architectural opening 100. The tension cord arrangement constrains translation in any other direction other than the first and second lateral directions and guides translation in the first and second lateral directions. The tension cord arrangement supports the first and second rails 21, 22 at respective positions in the first lateral direction (downwards) by friction. The first and second rails 21, 22 are moveable along tension cords, in the first and second lateral directions, by overcoming the friction force.

Examples of tension cord arrangements 81 that may be used with the covering 10 are shown in Figs. 17a- 17c. Figs. 17a- 17c illustrate the routing of tension cords through the shade material 30 and moveable rails. The routing of the tension cords between the upper moveable rail and the head rail and between the lower moveable rail and the first (lower) end of the covering 10 is illustrated in Fig. 10. In Fig. 10, the drive cords 61, 62 are omitted such that the tension cords are clearly identifiable. Fig. 11 shows the covering 10 with both the drive cords 61, 62 and the tension cords shown.

As shown in Figs. 17a-17c, the tension cord routing arrangement 81 includes at least a first tension cord 811 (shown as dashed) and a second tension cord 812 (shown as solid). The tension cords 811, 812 extend through the moveable first and second rails 21, 22 in the longitudinal direction, and run through the shade material 30 parallel to the sides of the architectural opening 100 (in the lateral directions). The tension cords run through the blind material 30 to give it structure, so that the blind material 30 does not escape the window (particularly when the blind is very wide). In contrast, the drive cords 61, 62 run alongside the sides of the opening 100 (with the first drive cord 61 also running alongside the sides of the shade material 30), not through the shade material.

The tension cords are tensioned by a spring to keep the tension cords taut. In the example arrangements of Figs. 17a-17c, the tension cords are tensioned by a tensioning spring provided only in the lower (manual) moveable rail. This allows more space within the upper (motorized) moveable rail for a spring assembly for tensioning the first drive cord 61. Further springs for tensioning the tension cords may be provided in either of the first and second rails, particularly in larger blinds with longer tension cords.

The tension cords exit the first and second ends of the first rail via the first rail end members, and exit the first and second ends of the second rail via second rail end members provided at the first and second ends of the second rail. From each of the first rail end members at the first and second ends of the first rail, at least one tension cord extends vertically upwards, alongside the drive cords 61, 62, to the head rail. From each of the second rail end members at the first and second ends of the second rail, at least one tension cord extends vertically downwards, alongside the first drive cord 61, to the bottom of the opening. In the example routings shown in Figs 17a- 17c, the second tension cord 812 extends from a position near the bottom-right of the opening, vertically upwards to the second end of the second rail, enters the second end of the second rail, then is routed through the shade material and the first rail 21. The second tension cord exits the first end of the first rail, extends vertically upwards to the first end of the third rail, forms a loop, then extends vertically downwards to re-enter the first end of the first rail. Then the second tension cord is routed through the shade material and the second rail, exits the second end of the second rail, and extends vertically downwards back to the position near the bottom-right of the opening. The first tension cord 811 is similarly routed. However the first tension cord is routed from a position near the botom-left of the covering 10, enters and exits the first end of the second rail and the second end of the first rail, and forms a loop at the second end of the third rail.

Between the head rail and the first rail, and adjacent the sides of the opening, the tension cords run vertically alongside the first and second drive cords. Here, the tension cords are positioned inside of the drive cords with respect to the width direction of the opening, and the second drive cord is positioned in front of the first drive cord. Between the second rail and the bottom of the opening, and adjacent the sides of the opening, the tension cords run vertically alongside the first drive cord. Here, the tension cords are positioned inside of the first drive cord with respect to the with direction of the opening.

The tension cords 811, 812 are coupled to a part of the architectural structure near the first (bottom) end of the architectural opening 100 by respective tension cord mounts. Tension cord mounts secure the tension cords 811, 812 to an edge of an architectural opening 100 and hold the tension cords under tension. At the second (top) end of the architectural opening, the tension cords 811, 812 are held by the first and second cord routing members 251, 252 described earlier.

In the illustrated example, an intermediate portion of the first tension cord 811 and an intermediate portion of the second tension cord 812 are held by the second cord routing member 252 and first cord routing member 251 , respectively. The ends of the first tension cord 811 are held by a first tension cord mount 821 provided near a botom-left comer of the architectural opening. Similarly, the ends of the second tension cord 812 are held by a second tension cord mount 822 provided near a bottom-right comer of the architectural opening. This configuration is illustrated in Fig. 10.

Each of the first and second cord routing members 251, 252 includes a projection 253 for holding at least one tension cord. As shown in Fig. 13, the intermediate portion of the second tension cord 812 is looped within the first cord routing member 251. In the example shown in Fig. 13, the second tension cord 812 includes two cords. The specific details of the tension cord arrangement depend on considerations such as the size of the blind. The intermediate portion of the second tension cord 812 forms a horizontally oriented loop around the protrusion 253 of the first cord routing member 251 which holds the loop in place. The intermediate portion of the second tension cord 812 exits the first cord routing member 251, at a position in the horizontal direction between the shade material 30 and the first and second drive cords 61, 62, to extend vertically downwards, as shown in Fig. 13. The second cord routing member 252 has substantially the same form and function as the first cord routing member 251.

The first and second guide members 71, 72, described above, may be provided in the first and second tension cord mounts 821, 822, respectively. Figs. 12a and 12b show a tension cord mount which is adapted for both holding a tension cord 811, 812 (of a tension cord routing arrangement 81) and guiding the first drive cord 61. The tension cord mount of Figs. 12a and 12b could be either the first tension cord mount 821 or the second tension cord mount 822. Fig. 12a shows a perspective view of the first tension cord mount 821 when viewed from the front side of the covering 10.

Fig. 12a shows the tension cord mount 821, 822 assembled with a tension cord 811, 812 and the first drive cord 61. Fig. 12b shows an exploded/unassembled view of the tension cord mount from an upper side, from which the tension cord 811, 812 and first drive cord 61 extend, when in situ. In the example tension cord mount of Figs. 12a and 12b, a bearing wheel 73 is provided for guiding the first drive cord 61.

The tension cord mount 821, 822 is formed from a base plate 823 and a top cover 824. The base plate 823 is configured to be mounted to a surround of the architectural opening, for example to a window ledge/shelf by a screw. The base plate 823 includes a hole for receiving a mounting screw. The base plate 823 and top cover 824 slot together to form the tension cord mount 821, 822. As shown in Figs. 12a and 12b, the first drive cord 61 enters the tension cord mount 821, 822 from above, through an opening in the top cover 824. Then the first drive cord 61 is looped around the cylindrical bearing wheel 73 (the rotational axis of the bearing wheel being parallel to the axis of the drive shaft), and then exits the tension cord mounting through the opening in the top cover 824.

A tension cord 811, 812 also enters the tension cord mount 821, 822 via the opening in the top cover 824. The tension cord 811, 812 may then form a horizontal loop through the top cover 824, being held in place by being looped around a protrusion inside the tension cord mount. Ends of the tension cord 811, 812 may be knotted within the tension cord mount, with the knot securing the tension cord. Whether ends of the tension cord are knotted within tension cord mount depends on the particular tension cord routing arrangement. Furthermore, there may be more than one tension cord held by each tension cord mount. The tension cord then exits through the opening in the top cover, at a position in the horizontal direction between the shade material and the first drive cord 61 . Each tension cord mount 821, 822 may include a magnet 825 for completely closing the blind without running the motor to move the first (motorised) rail all the way down.

As described above, the first rail 21 is provided with respective first rail end members 217 at its first and second ends, and the second rail 22 is provided with respective second rail end members 227 at its first and second ends. Fig. 14 shows the first rail end member 217 at the first end of the first rail 21 and the second rail end member 227 at the first end of the second rail 22.

The first rail end members 217 slot into the ends of the first rail. The first rail end members 217 guide the first and second drive cords 61, 62 and the tension cords 80 between the interior of the first rail and outside of the first rail as described above with reference to Figs. 15, 16 and 17a-c. Each first rail end member 21 includes walls which form pathways through the first rail end member 21 to guide the drive cords and tension cords as described above. The first rail end members 217 also guide the portions of the first drive cord 61 which extend all of the way from the head rail to the guide members at the bottom of the architectural opening. Each first rail end member 217 includes a hole through which a portion of the first drive cord 61 passes, and can move/slide, as it extends from the head rail to the bottom of the architectural opening.

The second rail end members 227 slot into the ends of the second rail. The second rail end members 227 guide the tension cords 80 between the interior of the second rail and outside of the second rail as described above with reference to Figs. 17a-c. The second rail end members also guide the portions of the first drive cord 61 which extend between the ends of the first rail and the guide members at the bottom of the opening. Each second rail end member includes a hole for guiding the first drive cord 61 downwards from the first rail to a guide member, and a hole for guiding the first drive cord 61 upwards from the guide member to the first rail (the first drive cord 61 having been looped around the guide member). The sections of the first drive cord 61 which pass through the second rail end members may slide through the second rail end members (when the first and or second rail is moved).

The first and second rail end members 217, 227 can have substantially the same shape, with the second rail end members 227 being rotated 180° about the longitudinal direction of the rails relative to the first rail end members 221. The shapes of the first and second rail end members are configured such that they guide the first drive cord 61 vertically alongside the shade material with a clearance between the first drive cord 61 and the edges of the shade material, so that they do not interfere with one another.

A disengagement clutch may be provided between the motor 41 and the drive shaft 50. By disengaging the clutch, the first rail 21 is moveable by being pushed or pulled manually by a user in the first or second lateral direction. When no clutch is provided, any movement of the first rail 21 described herein is performed using the motor 40. When a clutch is provided, any movement of the first rail 21 described herein can be performed either by the motor when the clutch is engaged, or manually when the clutch is disengaged. The disengagement clutch may be provided between an output shaft of the motor 41 and the drive shaft 50 on which the spools 51, 52, 53, 54 are fixed. The disengagement clutch may be configured as described in WO2017/121875. In an alternative arrangement, a tension cord routing arrangement may be provided which supports the second (manual) rail only. The first (motorised) rail may be supported and held in place by the friction of the motor when not driven, when no clutch is provided. Even when a clutch is provided, it is possible for only the second (manual) rail to be tensioned by tension cords. This is because the integral friction of the system caused by the counter winding of the cords on the spools would hold the motorized rail in place.

The following method of operating an architectural opening covering 10 may be applied to the architectural opening covering 10 described herein. The method includes using a motor drive to translate a first rail in a first lateral direction. While the first rail is being translated by the motor drive, a lateral side of the first rail abuts against a lateral side of a second rail (usually via a shade material). In this way, the first rail pushes the second rail so as to move the second rail in the same direction (the first lateral direction) and at the same speed. In other words, the first and second rail are moved in synchrony, by using the motor drive to move the first rail.

The first rail can also be moved by the motor in the first lateral direction without pushing the second rail, when the first and second rails are not next to each other. The first rail only pushes the second rail when the a shade material between the first and second rails is fully retracted. If the first and second rails are separated in the lateral directions, i.e. the shade material 30 is at least partially extended, then translating the first rail in the first lateral direction will not cause the second rail to move. Rather it will cause the first rail to approach the second rail, and the shade material 30 to retract. Once the shade material is fully retracted, then moving the first rail in the first lateral direction also moves the second rail in the first lateral direction.

Second illustrated example

A second example will now be described with reference to Figs. 18 to 20. Only the differences from the illustrated example described above will be described. The same reference numerals are used for corresponding features.

The overall configuration of the covering 10 of the second illustrated example is shown in Fig. 18. The second drive cord 62 is dashed and the first drive cord 61 is solid in Fig. 18. In the second illustrated example, the ends of the drive cords 61, 62 are coupled to the first rail 21 and an intermediate portion of each drive cord 61, 62 is coupled to the drive shaft. In the second illustrated example, two spools are provided instead of four. The first drive cord 61 is coupled to the first spool 51 and the second drive cord is coupled to the second spool. The first drive cord is looped around a first guide member 71 near a botom-left corner of the architectural opening, and a second guide member 72 near a bottom-right corner of the architectural opening, similar to the illustrated example described above. In the second illustrated example, the ends of the first drive cord 61 enter each end of the first rail 21, respectively, and are coupled to the interior of the first rail. The ends of the second drive cord enter each end of the first rail, respectively, and are coupled to the interior of the first rail.

The coupling of the drive cords 61, 62 to the spools 51, 52 is illustrated in Figs. 19a and 19b. An intermediate section of a drive cord 61, 62 is coupled to a coupling position on the outer surface of its spool 51, 52, substantially in the middle of the spool in the axial direction, as shown in Figs. 19a and 19b. The drive cord 61, 62 is coupled to its spool 51, 52 in such a way that rotation of the spool causes a section of cord to wind around the spool on either side of the coupling position. The section of drive cord 61, 62 which is coupled to its spool 51, 52 extends substantially parallel to the axial direction of the spools/drive shaft, when not wound around its spool.

Each drive cord 61, 62 is coupled to its respective spool 51, 52 by a respective cord fixation member 513, 523 as shown in Figs. 19a and 19b. Each cord fixation member is a component fixedly attached to the spool or formed as part of the spool, so that they are driven to rotate with the spools by the motor. Each cord fixation member includes a groove, extending in the axial direction, for holding and pinching the section of drive cord 61, 62 which is configured to wind around the spool 51, 52. A drive cord may slide through the groove during assembly. However, when a drive cord is wound around its spool, the part of the drive cord which is pinched by the cord fixation member cannot move relative to the spool, due to the tension in the drive cord. Each cord fixation member 513, 523 is substantially ring shaped, extending around the middle of its spool in the axial direction, as shown in Figs. 19a and 19b. The spools 51, 52 and drive cords 61, 62 are configured so that a drive cord is drawn from both ends of the spool in order to wind around the spool, as illustrated in Figs. 19a and 19b. Each of the first and second spools 51, 52 is provided with a respective first spool end member 511, 521 and a respective second spool end member 512, 522 (examples of stationary holding members). The spool end members are bearing members which keep the spools centred within the head rail. The first spool end member 511, 521 is a separate component which holds a drive cord 61, 62 at a position near the first end of its spool 51, 52 (the end nearest the first end of the head rail). The second spool end member 512, 522 is a separate component which holds a drive cord 61, 62 at a position near the second end of its spool 51, 52 (nearest the second end of the head rail). The first and second spool end members are configured to be fixed within the third rail, and therefore not to move relative to the architectural structure opening 100.

Each of the spool end members 511, 512 of the first spool 51 has a hole or groove for holding the first drive cord 61 such that it may slide/move through the spool end members in the longitudinal direction of the cord (in the axial direction). Each of the spool end members 521, 522 of the second spool 52 has a hole or groove for holding the second drive cord 62 such that it may move through the spool end members in its longitudinal direction (in the axial direction). The section of drive cord which is held by a first/second spool end member extends in a direction substantially parallel to the axial direction of the spools/drive shaft.

Rotation of the spools 51, 52 in the first rotational direction draws the first drive cord 61 from both ends of the first spool 51, that is, from both first and second spool end members at the ends of the first spool 51 to wind around the first spool 51. Likewise, the second drive cord 62 is drawn from both ends of the second spool 52 when the spools rotate in the second rotational direction. Each part of a spool, on either side of its cord fixation member, causes each side of its drive cord to be spooled on/off the spool. This is because each drive cord is coupled to both ends of the first rail 21 at either side of the shade material, and exerts a pulling force on the first rail at both ends of the first rail. For example, if the rail is held at each end by a support assembly, then it may be easier to move the rail by pulling both ends of the rail simultaneously. Furthermore, this method of winding cord around a spool may avoid overlapping different sections of cord when the cord is wound around the spool multiple times.

In Fig. 19a, the second drive cord 62 is wound around the second spool 52. The first drive cord 61 is shown to be only partially drawn onto the first spool 51. This winding state corresponds to the first rail 21 being at a position close to the second end of the opening 100. In Fig. 19b, the first drive cord 61 is wound around the first spool 51, with the second drive cord 62 being fully unwound. This winding state corresponds to the first rail 21 being at a position close to the first end of the opening 100.

Each spool 51, 52 has a shape which is tapered towards the coupling position at which the cord is coupled. In other words, each spool 51, 52 is wider at an end from which the cord is drawn, and narrow at the part to which the cord is attached. This encourages the windings of cord to slide towards the narrower part of the spool so that the windings are spaced out and not all concentrated at the end of the spool, to avoid overlapping.

Each of the first and second spools 51, 52 has cylindrical symmetry (axisymmetry) about its axis. In the illustrated example, the diameter of the spool 51, 52 at the middle is narrower than the diameter of the spool at each end. The outer surface of each spool is frustoconical, being formed of two conical frustums 54 having the same axis as the drive shaft 50.

Each drive cord 61, 62 extends from the first end of its spool 51, 52 in the axial direction to a position substantially near a side of the covering 10 in the axial direction (the end closest to the first end of the spool). From the second end of its spool 51, 52, each drive cord 61, 62 extends in the axial direction to a position substantially near the other side of the covering 10 in the axial direction, as shown in Fig. 18.

Similarly to the illustrated example described above, in the second illustrated example, the drive cords 61, 62 are guided at the ends of the third rail by respective first and second cord routing members. Fig. 20 shows an alternative design of a first cord routing member 251. The first cord routing member 251 has an approximately cuboid shape. The second drive cord 62 enters the first cord routing member 251, from within the head rail 23, in the axial direction, near a front top-right comer of the first cord routing member 251. The second drive cord 62 then extends diagonally through the first cord routing member 251 to a position near a rear top-left corner of the first cord routing member 251. From here, the second drive cord 62 extends downwards in the first lateral direction. The first drive cord 61 enters the first cord routing member 251, from within the head rail 23, in the axial direction, near a front bottom-right comer of the first cord routing member 251. Then, the first drive cord 61 extends diagonally through the first cord routing member 251 towards a position near a rear botom-left comer of the first cord routing member 251. Then, the first drive cord 61 extends downwards, in front of the second drive cord 62. The first and second drive cords 61, 62 could of course swap positions in this arrangement. These and other features and advantages of the present disclosure will be readily apparent from the detailed description, the scope of the invention being set out in the appended claims.