This invention relates to conveyors for transporting suspended articles and in particlar to conveyors for transporting curtains and more particularly to powered curtains.

The need for powered curtains arises for a number of reasons. In Europe, America and Japan there is considerable interest in home automation. Home security is an important aspect of home automation and creating the illusion of occupation is considered an effective deterrent against unauthorised access. Powered curtains arranged to open or close automatically provide a means to create such an illusion.

Curtains may also be arranged to close automatically in bright sunlight to limit glare or for energy management purposes. Powered curtains would also be advantageous for windows that are out of reach and for use by handicapped or elderly persons.

In a conventional apparatus for powered curtains the curtains are operated by a series of pulleys and cords driven by an electrically powered winch. One problem arising from such a configuration is that the cords are prone to jamming or breaking, particularly when used to pull wide or heavy curtains. In addition the electric winch can be bulky and obtrusive and difficult to blend ψ \ with domestic decor.

In another example of the prior art, curtains suspended by a conventional rail are pulled by a drive unit, the drive unit being supported by either a fixed or

rotatable steel drive shaft adjacent the rail. Referring to Figure 1, the drive unit consists of three ball races 1, of which two are shown, with offset axes 2 that bear onto the shaft 3. The ball races are preloaded onto the shaft by a steel ring (not shown) . This ring bears onto cones 4 mounted on the outer ends of the three shafts carrying the ball races and has the effect of deflecting the ball races onto the drive shaft 3. When the ball races rotate a helical path is described over the surface of the shaft thereby imparting linear motion to the drive unit. In this apparatus either the ball races or the shaft or both may be driven. The device has been used for theatre curtains but is unsuitable for domestic and normal commercial applications because its design necessitates the use of a close tolerance, hardened steel shaft and precision engineered components within the drive. The cost of these is prohibitive. It is an object of this invention to provide an improved conveyor.

This invention provides a conveyor for transporting a suspended article comprising at least one carriage from which the article can be suspended, a rotary rod to support the carriage and any article suspended thereon, said carriage having at least a first wheel arranged to transfer at least part of the load of said carriage to said rod and so as to trace a helical path over the surface of the rod when the rod is rotated relative to the carriage whereby the carriage can be driven along the rod by frictional contact with the wheel.

An advantage of the present invention is that because the same rod can be used to both drive and support the load of the carriage the need for both pulleys and cords and additional support rails is eliminated and simultaneously because the force between the wheel of the

carriage and the rod required to produce the necessary traction to drive the carriage can be provided by gravity, other preloading arrangements are unnecessary, making redundant requirements of close tolerance machined components and especially hardened materials.

In a preferred embodiment the carriage has at least two wheels, one either side of the vertical through the central longitudinal axis of the rod and is adapted to have centre of mass below the axis of the rod. Thus, advantageously, additional stabiliser rails are unnecessary.

In a further embodiment, wherein the suspended article is suspended from a position other than below the rotational axis of the rod so that the centre of mass of the carriage plus suspended article is no longer acting between the wheels positioned either side of the vertical through the axis of the rod, a rail adjacent and parallel to the rod can be provided to stabilise the carriage.

In another embodiment the rod is rotated by an electric motor. Advantageously the electric motor can be controlled automatically. Beneficially, a preferred embodiment is suitable for long lengths and the rod can be adapted to conform to bends or curved surfaces.

Where the rod is required to conform to bends or curved surfaces, a preferred form of the rod comprises a flexible sleeve and a non-rotatably mounted core member extending through said sleeve and having an axis about which said sleeve is rotatable, said core member being capable of adopting a curve in a first plane containing said axis and being rigid in a second plane tangential to said axis and orthogonal to said first plane, said core member further having cooperating means arranged to

cooperate with the inner face of said sleeve so as to hold the sleeve coaxial with the axis of the core member as the sleeve rotates.

Preferably the cooperating means comprises a plurality of rollers.

Where necessary, a bracket can be provided for rotatably supporting and transmitting torque between the neighbouring ends of two rod sections, wherein at least one of the rod sections is flexible comprising said flexible sleeve and said non-rotatably mounted core member, said bracket comprising a non-rotatable support member adapted for fixing to a suitable fixture, two cylindrical connector members coaxially mounted for rotation on said support member and adapted for connection with respective neighbouring ends of said two rod sections, said support member being accessible in at least one of said cylindrical connector members to retain non-rotatably said core member of the flexible rod section, and torque transmitting means comprising respective drive wheels engaging the two cylindrical connector members but having axes displaced from the common axis of said members and coupling means for transmitting torque between said drive wheels.

In another embodiment the conveyor comprises a plurality of carriages. Such a conveyor could be used for example to open and close curtains. An advantage of this particular embodiment, when applied to curtains is that thrust is imparted to each carriage which reduces the chance of rings becoming jammed.

Because the thrust required to pull the curtains is divided among the individual carriages and the number of carriages can be large and is further divided among the number of wheels driving each carriage and this number may also be large, the frictional coupling between each wheel and the rod can be small. Consequently the frictional force between each wheel and the rod may be overcome with ease, permitting manual operation. If attempts are made to automatically open or close the curtains when they have already acquired either state this will merely result in the wheels slipping over the rod so that, conveniently, limit switches are not required.

In another embodiment the conveyor includes means to reduce the thrust imparted to the carriage, when the carriage is at rest, by transferring part of the load of the carriage to other wheels or bearing surfaces ^* .

A significant advantage of this apparatus, as applied to curtains, over many conventional counterparts, is that a wide variety of materials can be used in its construction. By virtue of the fact that the carriages run on wheels, the ease with which the curtains move when operated automatically does not depend on the degree of smoothness of the contact surfaces between the rail and a ring. Thus using wheels increases the range of materials suitable for constructing the apparatus and simultaneously further reduces the risk of rings becoming jammed.

In another embodiment the electric motor can be incorporated into an end bracket as an integral part thereof or within the rod itself. This provides a means to conceal the motor to enhance the elegance of the apparatus lacking in a conventional system.

In another embodiment the rod could be illuminated from within to provide down lighting.

In some situations it may be preferable to include at least one further rotary rod, parallel to the first rod, the carriage having a corresponding further wheel to engage the further rod, to provide additional thrust and stability to the carriage.

It is envisaged that this apparatus is simple to manufacture, and by virtue of this and because of the wide range of materials which are suited to its construction, it can be made cheaply.

Examples of embodiments of the present invention will now be described with reference to the drawings, in which:-

Figure 1 shows a part sectional view of an example of the prior art;

Figures 2 and 3 show part sectional views of first and second embodiments of the invention;

Figure 4 shows the front view of an embodiment of the invention, with internal parts shown by dotted lines, wherein a plurality of carriages are used to suspend curtains;

Figure 5 shows an arrangement for an end fitting;

Figure 6A shows a plan view of a cross-section through an intermediate support bracket and a curved rod section;

Figure 6B shows a section of the curved rod section shown in Figure 6A through AA, and

Figure 6C shows a section through the curved rod section shown in Figure 6A through BB.

Referring to Figure 2, a carriage 1 comprises two wheels 2 and 3 in contact with the upward facing surface of a circular rod 4, the wheels positioned one either side of the vertical through the longitudinal axis of the rod. The carriage 1 is adapted to have centre of mass below the rotational axis of the rod thereby providing means to maintain the wheels in contact with the surface of the rod at positions one either side of the vertical. A hook or eye 5 is provided on the underside of the carriage to suspend an article vertically below the rotational axis of the rod. In this particular embodiment the axes of the wheels 2 and 3 are skewed to the axis of the rod, the axes being fixed to the carriage such that the wheels attain the desired offset when the wheels are sitting on the rod at their respective lowest points either side of the vertical. Thus any torque which may tend to rotate the carriage about a vertical axis, when the carriage is at its lowest position on the rod, will be counteracted by an opposing torque provided by the load of the carriage pulling the carriage to its lowest position. Should this mechanism prove inadequate to stabilize the carriage about its vertical axis, low friction bearing surfaces can be provided on the carriage either side of the rod. When the rod 4 rotates with respect to the carriage 1, the wheels trace a helical path along the rod, whereby the carriage is driven along the rod by frictional contact with each wheel. The frictional contact between the rod and a wheel can be increased by fitting the wheel with a rubber tyre. With continued rotation of the rod, the travel of the carriage can be limited by a suitable buffer or end stop which may be for example part of a bracket or another carriage. The carriage and end stop may be arranged to

co-operate to provide torque about a vertical axis of the carriage which opposes the torque provided by the load of the carriage, so that the carriage rides up the rod. The carriage and end stop may also be arranged so that the carriage assumes a position on the rod such that the axis of the wheels are parallel to the rotational axis of the rod, with the effect that thrust parallel to the rotational axis of the rod is removed from the carriage.

The ability to stop the carriages at positions between the ends of the rod without having to stop the rod rotating is an important feature of the conveyor where articles are to be removed from a carriage at a predetermined position along the rod. To achieve this, a buffer arm positioned at a desired location can be arranged to intercept a carriage at a particular instant of time depending on which particular carriage (if there is more than one) is to be stopped. The carriage may be designed such that by tilting the carriage relative to the longitudinal axis of the rod the frictional force between the wheels of the carriage and the surface of the rod is reduced to allow the wheels to slip. Various arrangements for achieving this are described below in relation to powered curtains, but the principle may be equally applied to other applications of the conveyor.

By arranging the buffer arm to interact with a position on the carriage below the rod, the carriage can be tilted in the desired manner. The buffer arm can be operated in such a way as to interrupt the motion of one carriage at a time, or interrupt the motion of more than one carriage at a time by intercepting the first carriage for a sufficient period of time so that others will queue behind.

The rod is supported by two brackets 6, one either end of the rod, the bracket being mounted on a wall or appropriate fixture 7. The carriage may also be adapted to clear intermediate brackets, by having a geometry similar to the carriage shown in Figure 2.

Figure 3 shows a second embodiment of the invention whereby the carriage is adapted to bear onto a support rail 8. Part of the load of the carriage is transferred onto the rail by a jockey wheel 9. The rail counteracts rotational torque applied clockwise to the carriage about the rotational axis of the rod due to either the carriage or a combination of the carriage and an article suspended from the hook or eye 5.

Figure 4 shows one application of the invention as applied to opening and closing curtains. Curtains 10A and 10B are suspended on a plurality of carriages 1 which are completely supported by a rod 4. The diagram shows the rod divided into two sections 4A and 4B, although more can be provided. One end of section 4A is supported and rotated by a motor 11. The opposite end of section 4A is supported by an intermediate support bracket 12. The support bracket 12 comprises a ring 13, having an outer diameter equal to that of the rod, and a smooth surface profile. Two bearings 14 are juxtaposed within the ring 13, each for receiving and rotatably supporting the ends of each adjacent rod section 4A and 4B. The ends of each rod section are suitably adapted to engage with each bearing. Bearings 14 can be, for example, self aligning ball races that can allow for a certain degree of mis-alignment between sections of the rod. The ring 13 of the intermediate support bracket 12 has an arm 15 extending

outwards to a plate (not shown) for mounting on a suitable wall or fixture. A connecting rod 16 of diameter equal to or less than the diameter of the bearing 14, passes through the ring 13 connecting rod sections 4A and 4B either side of the ring 13 for transmitting torque from rod section 4A to 4B. If required the connecting rod can be flexible. This may be preferable in applications where there is some mis-alignment between the rotational axis of adjacent rod sections.

In an alternative arrangement, the connecting rod 16 could be rotatably supported by the bracket so that the ends of adjacent rod sections are not directly supported on bearings within the ring 13.

Alternatively, the ends of adjacent rod sections could be adapted to engage and interlock so that a connecting rod 16 is not required. In this arrangement, only one bearing 14 need be disposed inside the ring 13 to support the end of only one of the adjacent rod sections directly.

The opposite end of section 4B is supported by a bearing 17 of end bracket 18. Carriages 1A and IB, either end of the rod 4, are fixed in order to limit the travel of the other carriages 1. Carriages 1 each have two wheels (partly shown) positioned either side of the vertical through the central longitudinal axis of the rod 4. The axes of the wheels are skewed with respect to the central longitudinal axis of the rod 4, so that when the rod 4 rotates with respect to the carriages motion is imparted to each carriage in accordance with the embodiments of Figures 2 and 3.

The axes of the wheels of the carriages for carrying curtain 10A are oppositely skewed (with respect to the central longitudinal axis of the rod 4) to the axes of the wheels of the carriages for carrying curtain 10B, so that the carriages for carrying curtain 10A travel in the opposite direction to the carriages for carrying curtain 10B when the rod 4 rotates. When a carriage sits over the ring 13 of an intermediate support bracket 12, because the outer surface of the ring is fixed, thrust is removed from the carriage. In order to traverse the width of the ring the carriage must be pulled or pushed by carriages either side of the ring. In order to minimise the number of carriages temporarily arrested by the ring at any one moment the thickness of the ring parallel to the rotational axis of the rod should be made as small as possible. If the axial thickness of the ring is less than the contact surface length between a wheel of the carriage and the rod, parallel to the rotational axis of the rod, and if the radial dimensions of the ring, at least where the bracket is to be traversed by a wheel, is less than the radius of the rod, then the wheel will continue to provide thrust as the bracket in traversed. Some applications may require a plurality of intermediate support brackets and rod sections. By the use of these brackets no restrictions are imposed on the length of the rod.

In opening or closing a curtain 10A or 10B, some carriages have less far- to travel than others. This can be accommodated by allowing each wheel to slip on the rod 4. Alternatively the axes of the wheels of individual carriages can be offset by different amounts so that each carriage travels a different distance along the rod 4 per rotation of the rod 4. This would reduce the number of

rotations that the wheel of an individual carriage would have to slip if at all, over the surface of the rod once this carriage had reached its final position, as limited by the tension between the fixed end of the curtain and that carriage.

A method to limit the frictional force opposing slip between wheels and rod when closing a curtain 10A or 10B is as follows. When a carriage reaches its final position on the rod 4, by virtue of a combination of thrust from the rod 4, and tension due to the curtain, which act in opposite directions, provided that the curtains are suspended below the vertical position of contact between the wheels and the rod, then the thrust and tension will act from different points on the vertical through the carriage, so as to apply torsion to the carriage, whereby the carriage would tilt at an angle to the vertical. At a predefined angle, a second set of wheels or a low friction bearing surface adjacent the skewed wheels, could be arranged to bear onto the rod, thereby reducing the load carried by the skewed wheels, the second set of wheels being arranged to have their axes of rotation parallel to the rotational axis of the rod in the horizontal plane of the axis, so that thrust of the carriage is reduced. As long as the frictional coupling between the combination of the skewed wheels and the second set of wheels and the rod is sufficient to prevent slip, the carriage will remain tilted about the pivot .position by virtue of the tension in the curtains.

Referring to Figure 5, an arrangement is shown for an end fitting 20 which incorporates a fixed final carriage 1A. The fixed carriage 1A has an armature 22 positioned below the rod 4 for causing the carriages 1 to tilt with

respect to the longitudinal axis of the rod 4. Thus, as the rod rotates so as to propel the carriages 1 in the direction of the end fitting 20, the armature 22 will act against the first carriage IC at a position on the carriage below the point of contact between the wheels and the carriage so that on continued rotation of the rod 4, the carriage IC tilts as shown. Then, on reaching carriage IC, the neighbouring carriage ID will co-operate with carriage IC and be tilted in a similar way. Likewise, each subsequent carriage 1 reaching its final destination as limited by the previous neighbouring carriage will also be tilted. As stated above, each of the carriages is suitably adapted so that when each carriage is tilted, the frictional force opposing slip between the. wheels of each carriage and the rod is reduced so as to reduce the opposing torque on the drive motor 11. The motor and a gearbox 11 are mounted at one end to the end fitting. The rod 4 is adapted to fit over the motor and gearbox 11 and the end of the rod 4 is supported on bearings 17 provided in the end fitting 20. The rod 4 is arranged to engage with a keyed output shaft 24 extending from the gearbox, as shown. The armature 22 may conveniently be provided with a hook or eye 5A.

Where the wall supporting the conveyor is curved or has sharp corners, the rod can be made to conform to the contours of the wall using flexible sections of rod in combination with a number of intermediate support brackets.

An arrangement for providing a curved section of the rod 4 is shown in Figures 6A to 6C. The rod 4 consists of a flexible sleeve 30, which may be made from any suitable material e.g. rubber, rubber compounds or plastics. The

radial strength or stiffness of the flexible sleeve 30 may be increased by, for example, helically wound wire or a wire matrix embedded within the sleeve. Each end of the flexible sleeve 30 is supported for rotation by a bracket 40 which will be described in detail below. The end of the sleeve is fitted over the end of a rotatably mounted adaptor 44. The rod has a core member 34 which extends along the length of the sleeve 30. The ends of the core member 34 are supported by a bracket 40 and are fixed so they cannot rotate. The core member 34 is designed to be capable of forming a curve in the horizontal plane and being rigid in the vertical plane. A suitable geometry which fulfills these requirements is that of a strip having a cross-section as shown in Figure 6C. A number of rollers 36 are rotatably mounted along the top and bottom of the core member 34 and engage with the inner face 31 of the flexible sleeve 30. The rollers 36 support the sleeve 30 and hold the sleeve 30 coaxial with the longitudinal curved axis 35 of the core member 34 as the sleeve rotates. Other forms of core members 34 are contemplated with various geometries depending on the application. For example if the flexible section is to support carriages carrying particularly heavy loads, the core member 34 may require a geometry which provides rollers to engage the inner face 31 of the flexible sleeve 30 at more than two positions on the circumference.

Referring to Figure 6A, an intermediate support bracket is shown which enables the transmission of torque from one rod section to another rod section. The embodiment shown is especially well suited for connecting a linear non-flexible rod section with a curved flexible rod section. The bracket 40 consists of a plate 41 for

mounting the bracket 40 to a wall or suitable fixture, an arm 43 extending from the plate and a specially formed support member 45. Each end of the support member 45 acts as a stub axle for two connector members 42 and 44. Preferably the arm 45 is connected to the specially formed support member 45 in such a way as to minimise the gap 47 between connector members 42 and 44. Furthermore, the support member preferably has a diameter at the gap equal to or less than the diameter of the connector members. The connector members 42 and 44, are rotatably mounted at either end of the support member 45 on bearings 46, 48 and 50, so as to rotate about a common longitudinal axis 51 of the support member. The connector members 42 and 44 are each in the form of a hollow cylinder and have suitably adapted end portions 53 and 55 to facilitate connection with the ends of the respective rod sections. The outer diameter of the rod sections and the connector members are preferably the same. One end of the support member 45 is provided with a slot 57 for receiving and retaining the end of the core member of the flexible rod section. Other arrangements for fixing the core member 34 to the support member 45 which prevent the core member 34 from rotating, are also contemplated.

Transmission of torque between the two rod sections is achieved by providing two gears 59 and 61 coaxially connected by a shaft 63 mounted for rotation about a second axis positioned parallel to and spaced from the first common longitudinal axis 51 of the support member 45. Complementary gear teeth are formed about the circumference of the inner face of a portion of each of the connector members 42 and 44 which engage with the respective gears 59 and 61. Alternatively the gears 59 and 61 may be replaced by rollers so that the torque is transmitted via the frictional force between the rollers and the inner face of the connector members.

The conveyor can be operated automatically by either a local or remote controller in response to, for example, real time, or changes in light intensity and temperature. A typical controller will comprise a timer, a real time clock, a photosensor, a thermometer, a reversible output drive and a programming interface. An auxiliary output can be included to control lighting, heating and other applicances. The controller can be powered directly by the electricity mains or by a battery with the addition of a solar powered recharger.

The rod can be made of a transparent material and adapted to embody an elongated lamp to provide down lighting.