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Title:
A SUPPORT DEVICE
Document Type and Number:
WIPO Patent Application WO/1998/040632
Kind Code:
A1
Abstract:
A support device (11) positionable to span a gap between two facing surfaces, comprises a body (12, 13, 14) having two opposite ends (16, 17) and a surface-contacting foot member (18, 19) carried at one said end and linked to the body (12, 13, 14) by interconnection means (44, 45; 47, 48) acting to convert a relative displacement between the body (12, 13, 14) and the foot member (18, 19) in a direction transverse a line joining the ends into a relative displacement between the body and the foot member in a direction parallel to the line joining the ends. The body (12, 13, 14) may be a rod, such as a curtain pole, a shelf or any other rigid structure capable of spanning two facing surfaces.

Inventors:
JAMES ALEC CAMPBELL (GB)
Application Number:
PCT/GB1998/000717
Publication Date:
September 17, 1998
Filing Date:
March 10, 1998
Export Citation:
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Assignee:
JAMES ALEC CAMPBELL (GB)
International Classes:
A47B45/00; A47B96/14; A47H1/022; (IPC1-7): F16B7/14
Domestic Patent References:
WO1998008422A11998-03-05
Foreign References:
DE9305495U11993-07-22
US3145669A1964-08-25
FR2329232A11977-05-27
Attorney, Agent or Firm:
Bryer, Kenneth Robert (7 Gay Street, Bath BA1 2PH, GB)
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Claims:
CLAIMS
1. A support device positionable to span a gap between two facing surfaces, comprising a body having two opposite ends and a surfacecontacting foot member carried at one said end and linked to the body by interconnection means acting to convert a relative displacement between the body and the foot member in a direction transverse a line joining the said ends into a relative displacement between the body and the foot member in a direction parallel to the said line joining the said ends.
2. A support device according to Claim 1, in which the displacement of the said interconnection means parallel to the line joining the ends of the body is smaller in magnitude than the relative displacement between the body and the foot member transverse the line joining the said ends.
3. A support device according to Claim 1 or Claim 2, in which there is provided a foot member at each said end of the body.
4. A support device according to any of Claims 1 to 3, in which the said interconnection means is or includes a lever mechanism.
5. A support device according to any of Claims 1 to 3, in which the said interconnection means is or includes a wedge mechanism.
6. A support device according to any preceding claim, in which the said body is adjustable in length parallel to the line joining the said two ends and is provided with adjustment means for effecting such adjustment.
7. A support device according to Claim 6, in which the body has two body parts relatively movable parallel to the line joining the said two ends whereby to adjust its length and the said adjustment means acts to lock the said body with the said two body parts in a selected relative position with respect to one another.
8. A support device according to any preceding claim, in which there are further provided means for resiliently biasing the or each foot with respect to the body or body part to which it is connected.
9. A support device according to any preceding claim, in which the said body is an elongate member such as a rod or the like.
10. A support device according to any of Claims 1 to 9, in which the body is a shelf or other such support member.
11. A support device according to any of Claims 6 to 10, in which the adjustment of the length of the body is lockable by means of a locking mechanism operating by frictionally engaging a rockable member on one of the two body parts against an elongate element fixed to the other of the two body parts.
12. A support device according to Claim 11, in which the said frictionally engageable locking mechanism is releasable by means of a lever acting directly or indirectly on the said rockable member.
13. A support device according to Claim 11, in which the said frictionally engageable locking mechanism is releasable by means of a relative twisting action of the two body parts.
14. A support device according to any of Claims 11 to 13, in which the said rockable member of the said frictionally engageable locking mechanism comprises an apertured plate pivotally fixed to one body part and the said elongate element of the said frictionally engageable locking mechanism comprises an elongate rod fixed to the other body part and passing through the aperture in the said apertured plate.
15. A support device according to Claim 14, in which the said elongate rod has two opposite parallel flats defining an oval crosssection and the rod and plate are each mounted on their respective body part in such a way as to be fixed in relation to rotation about an axis parallel to the length of the said rod. AMENDED CLAIMS [received by the International Bureau on 27 July 1998 (27.07.98); original claims 115 replaced by amended claims 118 (4 pages)] 1. A support device positionable to span a gap between two facing surfaces, comprising a body having two opposite ends and a surfacecontacting foot member carried at one said end and linked to the body by interconnection means acting to convert a relative displacement between the body and the foot member in any direction transverse a line joining the said ends into a relative displacement between the body and the foot member in a direction parallel to the said line joining the said ends so as to increase in use the contact force between the foot member and the surface.
16. 2 A support device according to Claim 1, in which the interconnection means acts to convert relative displacement in any transverse direction into a parallel force by means of a concavely curved surface.
17. 3 A support device according to Claim 2, in which the concavely curved surface is provided on the foot member.
18. 4 A support device according to Claim 1,2 or 3, in which there are further provided means for resiliently biasing the or each foot member with respect to the body or body part to which it is connected.
19. 5 A support device positionable to span a gap between two facing surfaces, comprising a body having two opposite ends and a surfacecontacting foot member carried at one said end and linked to the body by interconnection means acting to convert a relative displacement between the body and the foot member in a direction transverse a line joining the said ends into a relative displacement between the body and the foot member in a direction parallel to the said line joining the said ends, and in which there are further provided means for resiliently biasing the or each foot member with respect to the body or body part to which it is connected.
20. 6 A support device according to any preceding claim, in which the displacement of the said interconnection means parallel to the line joining the ends of the body is smaller in magnitude than the relative displacement between the body and the foot member transverse the line joining the said ends.
21. 7 A support device according to any preceding claim, in which there is provided a foot member at each said end of the body.
22. 8 A support device according to any preceding claim, in which the said interconnection means is or includes a lever mechanism.
23. 9 A support device according to any of Claims 1 to 7, in which the said interconnection means is or includes a wedge mechanism.
24. 10 A support device according to any preceding claim, in which the said body is adjustable in length parallel to the line joining the said two ends and is provided with adjustment means for effecting such adjustment.
25. 11 A support device according to Claim 10, in which the body has two body parts relatively movable parallel to the line joining the said two ends whereby to adjust its length and the said adjustment means acts to lock the said body with the said two body parts in a selected relative position with respect to one another.
26. 12 A support device according to any preceding claim, in which the said body is an elongate member such as a rod or the like.
27. 13 A support device according to any preceding claim, in which the body is a shelf or other such support member.
28. 14 A support device according to any of Claims 10 to 13, in which the adjustment of the length of the body is lockable by means of a locking mechanism operating by frictionally engaging a rockable member on one of the two body parts against an elongate element fixed to the other of the two body parts.
29. 15 A support device according to Claim 14, in which the said frictionally engageable locking mechanism is releasable by means of a lever acting directly or indirectly on the said rockable member.
30. A support device according to Claim 14, in which the said frictionally engageable locking mechanism is releasable by means of a relative twisting action of the two body parts.
31. A support device according to any of Claims 14 to 16, in which the said rockable member of the said frictionally engageable locking mechanism comprises an apertured plate pivotally fixed to one body part and the said elongate element of the said frictionally engageable locking mechanism comprises an elongate rod fixed to the other body part and passing through the aperture in the said apertured plate.
32. A support device according to Claim 17, in which the said elongate rod has two opposite parallel flats defining an oval crosssection and the rod and plate are each mounted on their respective body part in such a way as to be fixed in relation to rotation about an axis parallel to the length of the said rod.
Description:
A SUPPORT DEVICE The present invention relates generally to a support device and particularly to a support device capable of spanning a gap between two surfaces and providing frictional engagement with the surfaces to allow the device to support a load.

The present invention find particular utility in connection with the provision of a temporary load bearing device for intermitant use, for example where there may be a need to provide a support for a short time, such as when on holiday, or when subject to changing situations.

For example the load support device of the present invention may be applied as a temporary support for a shower curtain on camping sites, or as a hanging rail for clothes, as a shelf for supporting books or carrying other articles, as a fixing for a safety gate at the foot or head of a stair case to prevent children from falling down the stairs, or in a wide range of other circumstances where a temporary fitment may be required.

Such temporary support may also be needed for example, for a screen, such as a projection screen or a curtain or partition for dividing a room to provide separate living and/or working environments. Similarly, a temporary support may be required between a floor and ceiling to support lighting, loud speakers or decorative

accessories.

In certain. environments, such as in caravans or camping site facilities, there are few means by which to hang clothing, washing or other items and it could be of value to have available a support rod or rail for this purpose, even if only to span a small gap. In such cases, and in others, it is not always desirable or possible to insert fixings into walls either because the holes formed for or by fixings such as screws, nails or the like may not be permissible in the circumstances, or the means for effecting a permanent fitment may not be available.

The present invention seeks, therefore, to provide a support which can be used for a wide variety of purposes but which does not involve physical damage to the structures by which the support is carried.

Accordingly, there is provided a support device positionable to span a gap between two facing surfaces, comprising a body having two opposite ends and a surface- contacting foot member carried at one said end and linked to the body by interconnection means acting to convert a relative displacement between the body and the foot member in a direction transverse a line joining the said ends into a relative displacement between the body and the foot member in a direction parallel to the said line joining the said ends.

In a preferred embodiment of the invention the displacement of the said interconnection means parallel to the line joining the ends of the body is smaller in magnitude than the relative displacement between the body and the foot member transverse the line joining the said ends. This ensures that there is an adequate mechanical advantage in order to transfer a suitably high pressure to the contacting surfaces by the foot. Moreover, because the support device of the invention utilises friction between itself and the facing surfaces defining the gap spanned by the support device the surfaces themselves are not damaged by the device and it leaves no other damage (such as may be caused by the application of glue) when the device is removed.

Preferably there is provided a foot member at each said end of the body. Although in the minimum case only a single foil is required the presence of two feet, one at each end, makes the device more versatile.

The support device of the invention may be formed in a bar or rail but need not necessarily be of such a shape.

Embodiments may be formed as a shelf with a flat plate- like body, or as a more complex shown above such as a gat or gate frame, screen panel or other shape as required.

Whatever the form of the body it may be that the said interconnection means is or includes a lever mechanism,

although it is preferred that the said interconnection means is or includes a wedge mechanism.

The body is preferably extensible so that it can be extended from a collapsed condition to a length suitable for spanning a selected gap. The versatility and utility of such extensible support devices make them particularly useful. Preferably, therefore the said body is adjustable in length parallel to the line joining the said two ends and is provided with adjustment means for effecting such adjustment. To put this into effect, the body may have two body parts relatively movable parallel to the line joining the said two ends whereby to adjust its length and the said adjustment means acts to lock the said body with the said two body parts in a selected relative position with respect to one another.

There may also be further provided means for resiliently biasing the or each foot with respect to the body or body part to which it is connected. This assists in obtaining preliminary frictional engagement with the support surfaces but is not at present considered essential.

In longitudinally adjustable embodiments it is preferred that the adjustment of the length of the body is lockable by means of a locking mechanism operating by frictionally engaging a rockable member on one of the two body parts against an elongate element fixed to the other of the two

body parts. Other locking mechanisms may of course be envisaged, particularly one using a ratchet to allow ready extension to be effected. If, however, a frictionally engageable lock is used it is preferred that the said frictionally engageable locking mechanism is releasable by means of a lever acting directly or indirectly on the said rockable member. Alternatively the said frictionally engageable locking mechanism may be releasable by means of a relative twisting action of the two body parts.

In such a case it is of particularly convenient construction if the said rockable member of the said frictionally engageable locking mechanism comprises an apertured plate pivotally fixed to one body part and the said elongate element of the said frictionally engageable locking mechanism comprises an elongate rod fixed to the other body part and passing through the aperture in the said apertured plate. Disengagement of the locking mechanism by twisting can be achieved particularly felicitously if the said elongate rod has two opposite parallel flats defining an oval cross-section and the rod and plate are each mounted on their respective body part in such a way as to be fixed in relation to rotation about an axis parallel to the length of the said rod.

The manner in which the foot or feet are interconnected to the body may be achieved in a variety of ways

especially in order to ensure that the two facing surfaces against which the feet engage do not have to be entirely parallel. Construction tolerances usually result in a degree of inclination in even supposedly parallel walls in buildings. For this reason the foot may, for example, be pivotally connected to the body or flexibly connected thereto.

In embodiments having resilient biasing means acting between relative movable parts of the body so as to urge the feet, which preferably have a high coefficient of friction, into contact with the said surfaces, the support body is preferably capable of being manipulated by one hand to locate it in a desired position. Any resilient biasing means operable to extend the support body should be sufficiently weak to allow this single- handed manipulation and need not be sufficiently strong to retain the support body in a position to which it is fitted without the additional assistance of the interconnection means.

The interconnection means could take the form of a pivoted arm carried by the support body and acting on a cam surface of the foot member, or vice versa.

Alternatively, and preferably, the interconnection means comprise an abutment member carried by the support body which cooperates with a wedge surface of the foot member, the two bodies being resiliently biased towards their

engaged portion: these positions could however be reversed. A manually operable retaining or locking member preferably keeps the biasing means in an inoperative position during the initial location of a support body in a selected position spanning a gap; the retaining member may then be operated to release the biasing means to urge the interconnection means and the foot member against each other and thereby press the end face of the foot member against its adjacent supporting surface. The biasing means are preferably considerably stronger than any resilient biasing means that operate to extend the support body when it is initially located to span a gap between two surfaces. Moreover, once the abutment member is urged against the cooperating wedge surface, any attempt to move the support body perpendicular to its longitudinal extent tends to move the abutment member along the wedge surface so as to increase the resilient biasing force and urge the end contact face of the foot member into greater pressure contact with the adjacent support surface so as to oppose the movement.

The wedge surface may be planar such that only movement in a certain direction causes jamming of the support member, movement in any other direction being allowed.

This would, in most cases, necessitate the support body being located in a specific orientation so as to prevent movement in a particular direction, normally downward, if

the support body extends horizontally. More conveniently, the wedge surface is curved, preferably with two degrees of curvature, that is part spherical curvature, being concave towards the interconnection means which latter include an abutment member having a curved surface for cooperating with the curved wedge surface. The wedging means are arranged such that, when the resilient biasing means are released, they operate to urge the abutment member into contact with a central portion of the concave wedge surface: relative movement of the abutment member and the wedge surface in any direction perpendicular to their line of contact will therefore wedge them tighter together.

Respective wedging mechanisms are provided on respective end foot members, one at each end of the support body.

Such mechanisms are effectively operable independently.

In preferred embodiments of the invention the support body is hollow and the various parts of its operating mechanisms are housed within it, apart from a control member, such as a push button, trigger or other such member, for operating the locking means.

The support body may comprise one or more tubes which may for example be of circular cross-section.

Various embodiments of the invention will now be more

particularly described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic sectional view of a first embodiment of the present invention formed as a hanging rail and shown in position between two facing walls; Figure 2 is an axial sectional view showing the interior structure of the embodiment of Figure 1; Figure 3 is a sectional view similar to Figure 2 showing the components of the embodiment of Figure 1 in a different operating position; Figure 4 is a view of a second embodiment of the invention in position between a wall and a ceiling; Figure 5 is an axial sectional view of a part of a third embodiment of the invention; Figure 6 is a schematic perspective view illustrating a further embodiment of the invention; Figures 7A and 7B are respectively a cross-section and an axial section of a part of the embodiment of Figure 6 shown in a first relative configuration; Figures 8A and 8B are respectively a cross-section and an axial sectional of the same part of the embodiment of Figure 6 as is shown in Figure 7, with the components in a second operating position; Figure 9 is a schematic perspective view of a further embodiment of the present invention formed as a shelf rather than a hanging rail; Figure 10 is an axial sectional view of a part of the embodiment of Figure 9;

Figure 11 is a partial perspective view of a further embodiment of the invention for a window alcove; and Figure 12 is an axial sectional view of a simplified embodiment for general use.

Referring first to Figures 1 to 3 there is shown a hanging rail generally indicated 10 comprising two main body parts 11,12 which are telescopically slidable with respect to one another. The first body part 11 comprises two sections 13,14 fixed together end-to-end as illustrated in Figure 2 by a pin 15 such that the part 14 can slide telescopically within the body part 12.

At each free end of the main body parts 11,12 are respective end feet 16,17 having end pads 18,19 with high-friction layers 20,21 on their faces in contact with the two facing walls 8,9 between which the support device 10 of the invention is positioned.

The device 10 is adapted to exert a lateral force, parallel to its length, against the walls 8,9 when an applied load is exerted transverse the length of the body portions 11,12 as will be described in more detail below with reference to Figures 2 and 3.

Figure 2 illustrates the support device 10 in position between the two walls whilst Figure 3 illustrates the support device with the components in the relative

configuration which they would adopt as a user is fitting the device between the two walls. The two relatively telescopic portions 11,12 can be held fixed in relation to one another at any selected adjustment by means of a locking mechanism which comprises a centrally located interior locking rod 22 secured at one end 23 to a transverse plate 24 fixed to the free end 25 of the outer tubular body part 12. The telescopically inner tube 14 of the body part 11, which slides within the tubular part 12 has an end plate 26 and carries a pivoted locking plate 27 with a central hole 28 through which the locking rod 22 passes. The pivoted locking plate 27 is pivotally connected at 29 to a control rod 30 which is axially displaceable within the telescopically inner tube 14 and is carried on a fixed bracket 31 and resiliently urged to the left, as viewed in Figure 2, by a spring 32 compressed between the plate 31 and a fixing pin 33 carried by the control rod 30.

The hole 28 in the locking plate 27 is just larger than the diameter of the locking rod 22 such that when a telescopically collapsing force is exerted between the outer telescopic tube member 12 and the inner telescopic tube member 14 such that the locking rod 22 is urged to move to the left as viewed in Figure 2 with respect to the locking plate 27 (or, conversely, the locking plate 27 is urged to move towards the right as viewed in Figure 2 in relation to the locking rod 22) the engagement

between the hole 28 and the locking rod 22 tends to cause the locking plate 27 to turn clockwise as viewed in Figure 2 thereby increasing the frictional contact between the edges of the hole 28 and the rod 22 tightening the frictional engagement and causing the plate 27 to jam securely against the rod 22 preventing telescopic collapse of the body 10. Release of the locking plate 27 can be achieved readily, however, by displacing the control rod 30 to the right as viewed in Figure 2 causing the locking plate 27 to adopt a position in which its plane lies orthogonal to the length of the telescopic body 10 and in particular to the locking rod 22 such that the sides of the hole 28 lie parallel to the rod 22 so that free movement of the plate 27 and the rod 22 can take place in either direction.

Control of the movement of the control rod 30 is achieved by a trigger 34 pivotally mounted at 35 to the outer tubular member 13 of the first body part 11 and having a nose 36 which engages one arm 37 of a bell crank 38 the other arm 39 of which can contact the end of the control rod 30. As the trigger 34 is squeezed, therefore, as shown by the arrow A of Figure 2, the nose 36 engages the arm 37 of the bell crank 38 and the arm 39 of the bell crank 38 is pushed into engagement with the end of the control rod 30 displacing it to the left as viewed in Figure 2. The pin 33 carried by the control rod 30 is likewise moved to the left, compressing the spring 32 and

rocking the plate 27 through a small angle from its inclined position as shown in Figure 2 to a position in which is plane lies perpendicular to the locking rod 22.

This configuration is shown in Figure 3.

The trigger 34 is itself biased towards the position shown in Figure 2 by a link 40 which is pivotally connected to the trigger 34 at one end and carried on a plunger 41 at the other. A spring 42 is compressed between the plunger 41 and a fixed abutment ring 43 which is secured to the tubular member 13. Squeezing the trigger 34 thus draws the plunger 41 to the right, compressing the spring 42 as shown in Figure 3.

The plunger 41 is generally cup-shape, and engages at its open end with a ball 44 pressed between the end of the plunger 41 and a facing surface 45 of the pad 18 of the foot 16. In this respect the ball 44 and plunger 41, together with the facing surface 45 of the pad 18, which is spherically curved and concave, constitutes the interconnection between the foot 16 and the tubular member 13. A similar configuration interconnecting the foot 17 with the tubular member 12 is found at the other end of the rod 10. Here, the telescopic tube 12 has a fixed cup 4 6 secured within its end adjacent the fixed plate 24, which cup engages a ball 47 which can roll on the concavely curved inner surface 48 of the pad 19.

In use of the embodiment illustrated in Figures 1 to 3, the trigger 34 is squeezed to turn the bell crank 38 and displace the control rod 30 to the right, thereby rocking the locking plate 27 to its release position in which, as described above, it lies perpendicular to the locking rod 22 allowing this free movement in either direction. A set of light compression springs 49a, 49b, 49c, separated by sliding washers 50a, 50b, the function of which will be explained below, act between the end plate 24 fixed to the free end of the outer telescopic tubular member 12 and the fixed plate 26 at the end of the inner telescopic tube 14 allowing telescopic extension of the device until the feet 16,17 come into contact with the walls 8,9.

This motion can be assisted by the use of the user's other hand, but such is not essential. Then, by holding the trigger end of the telescopic member firmly against the wall 8 and releasing the trigger 34 the control rod 30 is moved to the left, into the position shown in Figure 2, where the inclined locking plate 27 jams against the locking rod 22. When the force on the spring 42 is released, therefore, this exerts a force on the ball 44 via the cup 41 pressing the pad 18 of the foot 16 against the wall 8. The compressive force of the spring 42 is also transmitted via the annular stop member 43 to the tubular outer part 13 of the telescopic member 11 which, via its connection 15 to the inner telescopic tube 14 transmits the force to the locking plate 27 via its pivotal connection, tending to cause this to displace to

the right and increase the jamming interconnection between the plate 27 and the locking rod 22 which is therefore also urged to the right pressing the end plate 24 and the cup 46 towards the wall 9. This force is transmitted via the ball 47 and the pad 19 to the wall 9 so that the support device 10 is held in position by friction. Any tendency for the compressive force transmitted along the rod 22 to cause this to buckle is resisted by the washers 50 which hold this rod centrally within the tube 12.

Any load applied to the device 10, such as by hanging clothes or any other item thereon, will cause a slight displacement downwardly which results in a downward motion of the balls 44,47. These are made of a low friction material or coated in a suitable low friction material such as polytetrafluoroethylene allowing free, virtually frictionless motion between the balls 44,47 and the concave surfaces 45,48 of the pads 18,19. By contrast the high friction surfaces 20,21 of the pads 18,19 cause these to be engaged firmly with the walls 8, 9. Displacement of the balls 44,47 thus causes a wedging action increasing the contact force between the pads 18,19 and the walls 8,9. It has been found in practice that embodiments of the invention are capable in appropriate circumstances of supporting the weight of a person.

Figure 4 illustrates an alternative configuration in which the embodiment of Figures 1 to 3 is fitted between a floor and a ceiling to support a screen 50. Apart from the interconnection of the screen 50 to the telescopic tubular body the interior structure of the embodiment illustrated in Figure 4 may be the same as that of Figures 1 to 3.

An alternative configuration is shown in Figure 5, which constitutes a slight simplification. In this embodiment a telescopically outer tube 51 and telescopically inner tube 52 are relatively displaceable with respect to one another as illustrated by the arrows B, C. The outer tube 51 carries a locking rod 53 and the inner tube 52 carries a pivoted locking plate or disc 54 which act in the same manner as in the embodiment of Figures 1 to 3.

A control rod 55 is movable by a pivoted trigger 56 which, in this embodiment, has a trigger lever 57 projecting through a hole in the tubular member 52 sufficiently elongate to allow the trigger lever 57 to turn the trigger 56 about its pivotal connection with the tube 52 in a direction parallel to the length of the tube 52.

The trigger 56 engages a compression spring 58 which biases it to turn in a clockwise direction to move the locking disc 54 to its inclined locking position.

Displacement of the trigger lever 57 to the right as

viewed in Figure 5 will cause the locking disc 54 to be moved to its release position. A coil spring 59 is engaged between a fixed plate 60 (to which the trigger 56 is also pivoted) and a slidable bush 61 having a mushroom head 62 the curved surface of which is engageable with a concavely curved surface 63 of a pressure plate 64 in a manner similar to the relationship between the ball 44 and the corresponding concave surface 45 in the embodiment of Figures 1 to 3.

The bush 61 has an elongate slot 65 engaged by a pin 66 held on the tubular member 52 in order to determine the maximum displacement outwardly of the bush 61 urged by the spring 59. The maximum inward displacement of the bush 61 is determined by engagement of the mushroom head 62 against the end of the tubular member 52.

The embodiment of Figure 5 has the advantage over the embodiment of Figures 1 to 3 that the trigger lever 57 is moved by the user's hand in the same direction as the force applied to the tubular member 52 in order to fit the device between two walls. Indeed, as illustrated by the broken outline 67 in Figure 5, a tubular sleeve slidable on the tubular member 52 may be provided for displacing the trigger 57 which, in such a configuration, can be reduced in dimensions such that, when the device is fitted, there is no significant transverse projection from the rail.

The embodiment of Figures 6 to 8 likewise have the advantage of avoiding external projections for the trigger, this being achieved by so arranging the locking plate that it can be moved between a locking and a release position by relative rotation of the inner and outer tubular members. In this embodiment those components which are the same as or fulfill the same functions as corresponding components in the embodiment of Figure 5 have been indicated with the same reference numerals. In this case the locking rod 53 has an oval cross-section as can be seen in Figures 7A and 8A, and the locking plate or disc 54 has a hole 120 which has a circular portion 121 and two lateral enlargements 122, 123 such that, when the two telescopic tubes 51,52 are turned to a first relative orientation the rod 53, as shown in Figure 7A, engages the circular part 121 of the hole and can be locked when the plate is in the inclined position as illustrated in Figure 7B, whereas when the tubes are relatively rotated to the position shown in Figure 8A and 8B, the locking rod 53 enters the extensions 122,123 such that, even when the locking plate 54 is inclined, as illustrated in Figure 8B the two telescopic tubular members 51,52 can move axially with respect to one another. In order to facilitate this the extension spring 124 is engaged against a spacer 69 which engages a pressure ring 70 having an axial extension 71 which engages a radial projection 72 of the locking disc 54 which is limited in movement when projection 72

contacts the end of slot 73 (Figure 8B). This prevents contact between disc 54 and rod 53. The radial projection 72 slides in a slot 73 in the inner tube 52 to prevent relative rotation of the locking disc 54 and the tube 52 when the two telescopic tubes are rotated with respect to one another. A pivot pin 74 mounts the locking disc 54 to the inner telescopic tube 52.

Turning now to Figures 9 and 10, the alternative embodiment shown'comprises a shelf 80 which can be received in a mounting bracket 81 having an eccentric cam 82 by which the position of the bracket 81 in relation to the shelf 80 can be adjusted along two C-shape channel section arms 83,84 of the bracket. A lever 85 determines the angular orientation of the cam and therefore the position of the shelf 80.

The bracket 81 is carried on a mounting plate 86 having a cylindrically concave engagement face 87 contacted by a corresponding cylindrically curved surface 88 of the bracket 81. The plate 86 has a flat face 89 with a coating of resilient high friction material such as rubber. As illustrated in Figure 10, the bracket 81 can be positioned against the pad 86, the shelf 80 introduced into the bracket through the channel section arms 83,84 and the lever 85 turned to apply pressure between the shelf 80 and the pressure pad 86. A corresponding element may be fitted at the other end of the shelf such

that, when weight is applied to the shelf 80, the relative displacement between the cylindrically curved surface 88 of the bracket 81, which has a relatively small radius of curvature, in relation to the relatively large radius of curvature of the contact surface 87 of the pad 86, causes a wedging action which increases the frictional contact between the rubber coated surface 89 and a wall 90 thereby retaining the shelf in position.

Referring now to Figure 11, there is shown a structure adapted for use in a window alcove or recess. Only one end of the structure is illustrated, it being appreciated that a corresponding structure at the other end would be formed as in the previous embodiments. This structure is adapted to engage a side face or"reveal"91 of a window opening to support a rod 92 such as a curtain rod. The rod 92 may, of course, be replaced by any other rigid elongate element such as a pelmet. In this embodiment the rod 92 is fixed securely to one limb 93 of an L-shape bracket 95 by means of a strap fixing 94. Other means for securing the rod 92 to the bracket 95 may, of course, be employed.

The other limb 96 of the L-shape bracket 95 has a threaded pin 97 passing through a threaded opening therein. The pin 97 has a rounded end 98 clad in low- friction material which engages the concave surface of a contact plate 99 pressed against the window reveal 91.

It will be appreciated that, in this embodiment, the covering boot which may be provided to interconnect the pin 97 and the plate 99, has been omitted for clarity.

The pin 97 has a head end 100 by means of which adjustment to the pressure applied to the plate 99 can be achieved. As in the previous embodiments, the concave face of the plate 99 acts to provide a wedging action such that, once the structure has been located in position and appropriate adjustments made, it is held in position by frictional engagement of the pad 99 with the window reveal 91 (and the corresponding configuration at the other end of the rod 92) whereas additional load on the rod 92 will cause an increase in the frictional contact between the pad 99 and the reveal 91 by wedging action.

In Figure 12 there is shown a simplified embodiment in which a rod 101 has a plain end 102 over which is fitted a cap 103 of low friction material with a rounded end engaging a concave surface 104 of a friction pad 105. At the other end the rod 101 has a clamping structure comprising an adjustable collar 106 in the form of a cup with a spring 107 compressed between the bottom of the cup 106 and the end of the rod 101. The cup 106 has an axially extending spigot 108 which is externally threaded and threadedly engaged to a cup-shape compressor nut 109 which can be contacted by a lock nut 110. The compressor nut 109 has a rounded end engaging a concave surface 111

of a friction pad 112 and held to the compressor nut 109 by a resilient boot 113 in the form of a flexible retainer. A similar flexible retainer 114 interconnects the pressure pad 105 and the end cap 103 at the plain end 102 of the rod 101. In this embodiment the rod 101 must be approximately the correct length for the distance between two facing walls, illustrated in Figure 12 as walls 115,116. If the rod 101 is too long it must be shortened, for example by cutting, or if too short must be replaced by a longer rod such that, when fitted with the structures described above at each end, it can be positioned between the two facing walls 113,116 with the spring 107 under compression to retain the pressure pads 105,112 in frictional engagement with the walls 115, 116. For this purpose the compressor nut 109 can be adjusted by screwing it one way or the other along the threaded spigot 108, whereupon it can be fixed in position along the spigot 108 by clamping with the lock nut 110. Introduction of the assembly between the two facing walls 115,116 then involves compressing the spring 107 by applying a compressive force between the rod 101 and the pressure pad 112. Alternatively, of course, the adjustment to the compressor nut 109 can be made with the rod 101 held in position between the two walls 115,116 until the spring 107 is suitably compressed, preferably totally compressed between the end of the rod 101 and the cup-shape member 106.