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 with domestic decor.

Another example of the prior art as described in US2538755 provides a number of carriages supported on a rotatable rod in which each carriage has two wheels with their axes skewed with respect to the

rotational axis of _. the rod and which ride over the upper surface of the rod so that when the rod rotates the carriages are propelled along the rod.

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 being formed with a ridge-type formation 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 ridge-type formation.

Because the ridge-type formation does not rotate with respect to the carriage, the need for components such as axles, wheels and tyres is removed. Thus, the carriage can be manufactured in one operation from a wide range of materials.

In one emdodiment, the carriage may have an upper inner face with a single ridge formation formed thereon and arranged to engage the upper surface of said rod.

Preferably, the carriage comprises two groups of ridge formations arranged to transfer at least part of the load of the carriage to positions either side of the vertical through the rotational axis of the rod.

In a preferred embodiment, the surface of the rod comprises a compliant material which deforms at the positions of contact with the or each ridge-type formation. In one embodiment, the compliant material may be velvet-like. In other embodiments the compliant material may be any type of cloth, including carpet material. Alternatively the surface of the rod may have a bristled finish or the surface may be smooth and untextured. The rod may also be

covered with a non-Newtonian material that softens or liquefies under pressure and self heals when the pressure is removed, such as a thixotropic material.

In one embodiment the conveyor includes a plurality of carriages on said rod, said carriages being adapted to suspend at least one curtain.

In a preferred embodiment the conveyor includes means to limit the travel of the or each carriage when the rod is rotating. Preferably, the conveyor includes means to reduce the load transferred to the or each ridge-type formation when said carriage is at rest and the rod is rotating. In a preferred embodiment the means to reduce is provided by an edge of said carriage, wherein said edge is arranged to support part of the load of said carriage when said carriage is tilted with respect to the rotational axis of the rod. Preferably the edge is shaped so as to minimise the thrust along the rotational axis of the rod provided by the portion of the or each ridge-type formation which remains in contact with said rod when the or each carriage is tilted.

The carriage may be tilted by an external buffer means arranged to engage said carriage at a position below the point of contact between said ridge-type formations and said rod. Alternatively the carriage may be tilted by means operatively connected to said carriage at a position below the point of contact between said ridge-type formation and said rod and arranged to apply a force in a direction opposite to that of the thrust applied to said carriage by said rod.

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 co-operating means arranged to co-operate 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 co-operating 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 the frictional coupling between each carriage and the rod can be relatively small. Consequently the frictional force between each carriage 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 carriages slipping over the rod so that, conveniently, limit switches are not required.

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.

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.

This invention also provides a carriage for transporting a suspended article along a rotary rod, comprising a ridge-type formation 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.

The carriage may further include any of the preferred features mentioned above.

The invention also provides a rotary rod for transporting a carriage along the length thereof, said rod having a surface comprising a compliant material and further including means for rotating said rod and means for rotatably supporting said rod.

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

Figure 1 shows a part sectional perspective view of an embodiment of the invention;

Figure 2 shows a front view of an embodiment of the invention;

Figure 3 shows a side view of the embodiment shown in Figure 2;

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 a front view of an embodiment of the invention;

Figure 6 shows an arrangement for an end fitting;

Figure 7A shows a plan view of a cross-section through an intermediate support bracket and a curved rod section;

Figure 7B shows a section of the curved rod section shown in Figure 7A through AA, and

Figure 7C shows a section through the curved rod section shown in Figure 7A through BB.

Referring to Figures 1 to 3, a carriage 1 comprises two groups 2 and 3 of ridge formations 7 arranged so as to engage the upward facing surface of a circular rod 4, at positions either side of the vertical through the rotational 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 ridge formations 7 in contact with the surface of the rod at positions 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.

The ridge formations 7 in each group 2 and 3 are aligned parallel to one another and skewed at a predetermined angle relative to a line orthogonal to the rotational axis of the rod 4. The two groups 2 and 3 of ridge formations 7 will each have to be skewed oppositely with respect to this line.

Preferably the magnitude of the angle between the ridge formations and this line are equal so that equal amounts of thrust are imparted to each side of the carriage 1. The rod 4 is covered with a compliant material 9 which deforms at the positions of contact with the ridge formations 7. The leading edges 11 and 13 of the ridge formations 7 are curved to minimise friction between the ridge formations and the surface of the rod reducing the risk of the ridge formations jarring on the surface which would tend to cause the carriage to rotate with the rod.

When the rod 4 rotates with respect to the carriage 1, the ridge formations move over the surface of the rod in a direction in which the frictional force between the contact surfaces of the ridge formations and the surface of the rod is minimum. In the present case, the direction will be along the length of the ridge formations. By arranging the ridge formations to be skewed with respect to a line transverse to the rotational axis of the rod, the ridge formations will trace a helical path over the surface of the rod and the carriage will be driven along the rod. Because the surface of the rod is compliant, the impression of the ridge formations is momentarily imposed on the surface of the rod as the ridge formations move over the surface, thereby producing furrows which increase the frictional contact between the ridge formations and the rod.

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 rotates about a vertical axis,

tending to align the ridge formations with a line transverse to the rotational axis of the rod, with the effect that the thrust parallel to the rotational axis of the rod transmitted to the carriage is reduced.

The rod is generally supported by two brackets, one either end of the rod, the bracket being mounted on a wall or appropriate fixture. The carriage may also be adapted to clear intermediate brackets, by having a geometry similar to the carriage shown in Figures 1 to 3.

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 15. The opposite end of section 4A is supported by an intermediate support bracket 17. The support bracket 17 comprises a ring 19, having an outer diameter equal to that of the rod, and a smooth surface profile. Two bearings 21 are juxtaposed within the ring 19, 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 21 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 19 of the intermediate support bracket 17 has an arm 23 extending outwards to a plate (not shown) for mounting on a suitable wall or fixture. A connecting rod 25 of diameter equal to or less than the diameter of the bearing 21, passes through the ring 19 connecting rod sections 4A and 4B either side of the ring 19 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 25 could be rotatably supported by the bracket so that the ends of adjacent rod sections are not directly supported on bearings within the ring 19.

Alternatively, the ends of adjacent rod sections could be adapted to engage and interlock so that a connecting rod 25 is not required. In this arrangement, only one bearing 21 need be disposed inside the ring 19 to support the end of only one of the adjacent rod sections directly.

The opposite end of section 4B is supported by a bearing 27 of end bracket 29. Carriages IA and IB, either end of the rod 4, are fixed in order to limit the travel of the other carriages 1.

The ridge formations of the carriages for carrying curtain 10A are oppositely skewed (with respect to a line transverse to the rotational axis of the rod 4) to the ridge formations of the 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 19 of an intermediate support bracket 17, 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 19 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 group of ridge

formations 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 the ridge formations, is less than the radius of the rod, then the ridge formations 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 carriage to slip on the rod 4. Alternatively the ridge formations 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 so that all carriages reach their final position at more or less the same time. Because the friction between the ridge formations and the surface of the rod is appreciable when the carriages are stationary but the rod is rotating, there is considerable torque opposing the rotation of the rod.

A method to reduce the frictional force opposing slip between the ridge formations and rod when closing a curtain 10A or 10B is as follows. Referring to Figure 5, a curtain 10 is suspended below a number of carriages 1. When a carriage reaches its final position on the rod 4, the thrust from the rod 4 and tension due to the curtain each of which act from different points on the vertical through the carriage and in opposite directions, will cause the carriage to tilt at an angle to the vertical. At a pre-defined angle a low friction bearing surface 8, shown in Figures 1 to 3, bears on to the rod, thereby reducing the load transmitted by the ridge formations to the surface of the rod. The

thrust imparted to the carriage by the rod is therefore reduced. The residual thrust will be just sufficient to allow the carriage to remain tilted.

Referring to Figure 6, an arrangement is shown for an end fitting 31 which incorporates a fixed arm 33 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 l towards the end fitting 31, the arm 33 will act against the first carriage 1C at a position on the carriage below the point of contact between the ridge formations and the carriage so that on continued rotation of the rod 4, the carriage 1C tilts as shown. Then, on reaching carriage 1C, the neighbouring carriage ID will co-operate with carriage 1C 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 ridge formations of each carriage and the rod is reduced so as to reduce the opposing torque on the drive motor 15. The motor and a gearbox 15 are mounted at one end to the end fitting. The rod 4 is adapted to fit over the motor and gearbox 15 and the end of the rod 4 is supported on bearings 35 provided in the end fitting 31. The rod 4 is arranged to engage with a keyed output shaft 37 extending from the gearbox, as shown. The arm 33 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 7A to 7C. The rod 4 consists of a flexible sleeve 39, which may be made from any suitable material e.g. rubber, rubber compounds or plastics. The radial strength or stiffness of the flexible sleeve 39 may be increased by, for example, helically wound wire 32 or a wire matrix embedded within the sleeve. Each end of the flexible sleeve 39 is supported for rotation by a bracket 41 which will be described in detail below. The end of the sleeve is fitted over the end of a rotatably mounted adaptor 43. The rod has a core member 45 which extends along the length of the sleeve 39. The ends of the core member 45 are supported by a bracket 41 and are fixed so they cannot rotate. The core member 45 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 7C. A number of rollers 47 are rotatably mounted along the top and bottom of the core member 45 and engage with the inner face 49 of the flexible sleeve 39. The rollers 47 support the sleeve 39 and hold the sleeve 39 coaxial with the longitudinal curved axis 51 of the core member 45 as the sleeve rotates. Other forms of core members 45 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 45 may require a geometry which provides rollers to engage the inner face 49 of the flexible sleeve 39 at more than two positions on the circumference.

Referring to Figure 7A, 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 41 consists of a plate 53 for mounting the bracket 41 to a wall or suitable fixture, an arm 55 extending from the plate and a specially formed support member 57. Each end of the support member 57 acts as a stub axle for two connector members 42 and 43. Preferably the arm 55 is connected to the specially formed support member 57 in such a way as to minimise the gap 59 between connector members 42 and 43. 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 43, are rotatably mounted at either end of the support member 57 on bearings 46, 48 and 50, so as to rotate about a common longitudinal axis 61 of the support member. The connector members 42 and 43 are each in the form of a hollow cylinder and have suitably adapted end portions 63 and 65 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 57 is provided with a slot 67 for receiving and retaining the end of the core member of the flexible rod section. Other arrangements for fixing the core member 45 to the support member 57 which prevent the core member 45 from rotating, are also contemplated.

Transmission of torque between the two rod sections is achieved by providing two gears 69 and 71 coaxially connected by a shaft 73 mounted for rotation about a second axis positioned parallel to and spaced from the first common longitudinal axis 52 of the support member 57. Complementary gear teeth are formed about the circumference of the inner face of a portion of each of the connector members 42 and 43 which engage with the respective gears 69 and 71. Alternatively the gears 69 and 71 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 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 ridge formations of the carriage and the surface of the rod is reduced to allow the carriage to slip. Various arrangements for achieving this have been described above 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 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 compliant material covering the rod may be of any colour or combination of colours for example, to match or complement the curtains or the decor of the room.

The carriages can be made from a wide variety of materials such as plastics, metal, alloys, wood, porcelain and glass, or a combination of materials.