GB2438925A

GB2438925A - Clamping plate for use in furniture leg raising apparatus

Info

Publication number: GB2438925A
Application number: GB0611220A
Authority: GB
Inventors: Philip Nixon
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-06-08
Filing date: 2006-06-08
Publication date: 2007-12-12
Also published as: GB0611220D0

Abstract

The clamp screw 41 of apparatus for raising the leg 46 of an item of furniture is provided with a clamp button 11,43 for contacting and clamping the leg against a wall 40 of the apparatus. The clamp button 11,43 can be recessed 16 to accommodate different forms of furniture leg or castor [see Figures 1-6]. The button 11 may include a central boss 14 from which radial webs 12 extend. The clamp screw is received within a cavity 17 of the boss. The furniture leg raising apparatus includes a clamp cup 40 which carries the clamp screw 41. A leg of the furniture is received and clamped with the cup.

Description

Furniture raiser Leg damp, button, and raiser

Field of the Invention

The invention relates to furniture raiser leg clamps; furniture raiser leg clamp buttons; the combination of a furniture raiser leg clamp and a furniture leg raiser clamp button; and furniture raisers.

In the context of this application the term "leg" is to be interpreted broadly to incorporate any portion detachable or fixed to a furniture piece onto which a furniture raiser can be clamped. The term "leg" wouLd therefore incorporate castors, integral legs, spigots, pads or similar furniture portions.

In the context of this application, the term "clamp cup" is to be interpreted broadly as the furniture raiser receptacle, in which the furniture leg is placed to enable clamping. The clamp cup may be for example fully or partially walled. The button discussed below may also be part of the cup wall itself such as a half of the cup.

Review of Art Known to the Applicant The closest prior art known to the applicant is the applicant's own prior UK patent GB 2323274A, for a Chair or Bed Raiser which comprises two end supports interconnected by a link. The link is adjustable in length with each end support having at its upper end a formation shaped to support or engage a portion of the chair or bed. The formation described in the prior art takes the form of a cylindrical cup into which a portion of the chair or bed is inserted. The cup incorporates a threaded hole to receive a thumbscrew which can be rotated to impact directly against a leg within the cup in order to clamp the leg in the cup to improve stability.

This prior art furniture raiser clamp has the following drawbacks: a) The clamp will not locate securely on the leg particularly when it is a castor and therefore the castor will tend to jump out of the cup when clamping pressure is applied; b) The end of the thumb screw causes surface damage; c) The screw causes distortion of the leg during clamping because the screw end applies a force over a small area; and d) The furniture raiser wilt need repeated adjustment after having been clamped.

The broad Problem to be solved The problem to be solved is how to improve the clamping of furniture legs to raisers by minimising wear to the legs.

Summary of the Invention

In its broadest independent aspect, the invention provides a furniture raiser leg clamp whose clamp screw end carries, in use, a button for contacting said leg as the screw is driven home to clamp the leg against the clamp cup wall.

This configuration is particularly advantageous because: a) it minimises wear to the surface of the leg; b) it requires less or no adjustment of the furniture raiser clamp once secured onto the leg; c) it applies a force over a greater area than the end of the thumb screw of the prior art; d) it prevents the leg jumping out of the cup when clamping pressure is applied and is therefore particularly advantageous when the leg is a castor.

In a subsidiary aspect in accordance with the invention's broadest independent aspect, the button incorporates a recessed portion shaped and configured to at least approximate the shape of the furniture leg surface against which, in use, the button is impacted by the clamp.

One particular advantage of incorporating a recess in the button is that it increases the effective clamping of the furniture raiser leg clamp onto furniture legs such as castors. The recess in the button can for example locate on the circumference surface of a castor and park the castor in position. The parking of the castor will prevent it from moving sideways when the furniture raiser leg clamp makes contact on the periphery of the castor.

In a further subsidiary aspect, the button incorporates both a flat outer most surface suitable for engaging the flat surface of a rectangular shaped leg and a recess portion for engaging a curved furniture leg.

This configuration allows a single button to have multiple functions in order to operate with a variety of different shaped legs such as a castor or a rectangular shaped leg.

In a further subsidiary aspect, the button incorporates a flat annular outermost surface suitable for engaging the fLat surface of a rectangular shaped leg and a recessed portion located within said annular surface for engaging a curved furniture leg.

The advantage of incorporating a flat outer surface, on the furniture raiser leg clamp button engaging face, is that the clamping pressure of the furniture raiser leg clamp button is dispersed over a larger contact area with the rectangular shaped furniture leg which reduces the possibility of surface damage to the furniture leg.

The recess in the button allows castors to be efficiently wedged in the recess by dispersing the clamping pressure over a larger contact area than in the prior art. This also contributes to reducing the possibility of damaging the castor. This advantage is particularly relevant to Shepherd castors which are relatively fragile and any distortion caused by the clamping pressure may cause the castor to fail.

In a further subsidiary aspect, the button is a relatively loose fit on the screw end.

The loosely fitted button on the screw end is advantageous because it enables the button to locate with precision on the circumference of the castor without requiring the screw to be flexible.

In a further subsidiary aspect, the button incorporates a front face with a recess portion and a rear face with a boss for engaging the member and webs extending between the boss and the button; whereby bending of the button, in use, is resisted.

The webs are particularly advantageous as they strengthen and reinforce the buttons functionality which wilt not lose its shape whilst being impacted by the screw member of the clamp.

The invention also provides a furniture raiser leg clamp button suitable for use with a furniture raiser leg clamp in accordance with the above aspects.

This would allow buttons to be retro-fitted on the existing furniture raisers in order to achieve the advantages mentioned above.

The invention also provides the combination of a furniture raiser leg clamp and a furniture leg raiser clamp button; the clamp being in accordance with the appropriate above aspects and the button being in accordance with the appropriate above aspects.

The invention also provides a furniture raiser incorporating the invention of any of the preceding aspects.

Brief Description of the Figures

Figure 1 shows a plan of the furniture raiser leg clamp button.

Figure 2 shows a side view of the furniture raiser leg clamp button.

Figure 3 shows a rear plan view of the furniture raiser leg clamp button incorporating webs.

Figure 4 shows a side view of the furniture raiser leg clamp button incorporating webs.

Figure 5 shows a side view of the furniture raiser leg clamp button which incorporates a deformable pad in the recess portion of the button.

Figure 6 shows a side view of the furniture raiser leg clamp button which incorporates an alternatively configured recess portion in the button.

Figure 7 shows a side view of the castor being positioned in a furniture raiser leg clamp cup.

Figure 8 shows a side view of the furniture leg being clamped in furniture raiser leg clamp cup.

Figure 9 shows a side view of the castor being positioned in furniture raiser leg clamp cup incorporating a high friction foam pad.

Detailed Description of the Figures

Figure 1 shows a furniture raiser leg clamp button 1 which incorporates a back plane 2 which incorporates a circumference plane 3. A boss 4 which is located centrally on the back plane 2 is perpendicular 8 to the back plane 2. The boss incorporates a cavity 5 in which the threaded member of the furniture raiser leg clamp locates itself in button 1 The cavity incorporates a closed bottom surface 6. The recessed portion 7 of the furniture raiser leg clamp button 1 is located centrally on the front plane of the button 1 and is represented by a broken line.

Figure 2 shows a side view of the furniture raiser leg clamp button 1. The boss 4 is mounted centrally and perpendicularly 8 on the back plane 2. The boss cavity 5 in which the threaded member of the furniture clamp locates itself in button 1. The cavity incorporates an enclosed bottom surface 6. The curvature of the recessed part in 7 is represented by a broken line 10 and is located centrally on the button front plane 9.

Figure 3 shows an alternative embodiment of the furniture raiser leg clamp button 11 which incorporates webs 12 in the button back plane 13. The webs 12 form elongated members that span outwards from the centrally mounted boss 14 that are perpendicular to the back plane 13, to the outer edge circumference 15. The boss incorporates a cavity 17 for locating the screw member of the furniture raiser leg clamp into button 11. The figure also shows the recessed portion 16 that is located centrally on the button front plane 57 and is represented by a broken line.

Figure 4 shows a side view of an alternative embodiment of the clamp button 11 which incorporates webs 12 in the button back plane 13. The webs span outwards from the centrally mounted boss 14 and are perpendicular to the back plane 13, to the outer edge circumference 15. The boss 14 incorporates a cavity 17 for locating the end of the thumbscrew of the furniture raiser leg clamp into button 11. The figure shows the recess portion 16 that is located centrally on the button front plane 57 which is an annular flat front face. The curvature of the recessed portion is represented by a broken line. The webs 12 are adjacent to the central boss 14. The webs 12 are perpendicular to the button back plane 13. The height of the webs 12 from the back plane is equal to the height of the central boss 14, but the webs height reduces linearly to the outer edge.

Figure 5 shows the side view of an alternative embodiment of the furniture raiser leg clamp button 20 which has a deformabte pad 21, which is inserted into the recess 22 located centrally on the button front 23. The thickness of the deformable pad 21 is detailed by the two broken lines 24 and 25. The back plane 26 is shown to have a central boss 27 mounted centrally, which is perpendicular to the back plane 26. The central boss 27 incorporates a cavity 28 in which the screw member of the furniture raiser leg clamp is located into button 20.

Figure 6 shows a side view of an alternative embodiment of the furniture raiser leg clamp button 30 which has a recess that is configured by linear surfaces 31 and 60, instead of a curvature as shown in previous embodiments. The back plane 26 is shown to have a central boss 32 mounted centrally, that is perpendicular to the back plane 33. The central boss 32 incorporates a cavity 34 in which the screw member of the furniture raiser Leg clamp is located into button 30.

Figure 7 shows the furniture raiser leg clamp cup 40 which has a screw member 41 which travels in the directions indicated 42. The furniture raiser leg clamp button 43 is attached loosely on the end of the screw member 41. The button's recessed portion 44 makes contact on the circumfural plane of the furniture castor 45 which forms part of the furniture leg 46. The screw member 41 is driven home into the button 43, which clamps the castor 45 to the inside wall of the furniture raiser leg clamp cup 40.

Figure 8 shows the furniture raiser leg clamp cup 40 which has a screw member 41 which travels in the directions indicated 42. The furniture raiser leg clamp button 43 is attached loosely on the end of the screw member 41. The button's flat outer most surface 47 which makes contact with the furniture Leg 46 is driven home into the button 43, which clamps the furniture leg to the inside wall of the furniture raiser leg clamp cup 40.

Figure 9 shows the furniture raiser Leg clamp cup 40 which has a screw member 41 which travels in the directions indicated 42. The furniture raiser leg clamp button 43 is attached Loosely on the end of the screw member 41. The button's recess portion 44 makes contact on the circumference plane of the furniture castor 45, which forms part of the furniture leg 46. The screw member 41 is driven home into the button 43, which clamps the castor 45 to the high friction pad 48, which is mounted on the inside wall of the furniture raiser leg clamp cup 40 to improve the efficiency of the clamp.

These embodiments of the invention make it clear that in the claims which now follow, the term "button" is used for convenience, not in any restrictive sense. In other words, it is not intended to cover only a conventionally and literally clothing button-like shape.

Claims

Claims 1. A furniture raiser leg clamp whose clamp screw end carries,

in use, a button for contacting said leg as the screw is driven home to clamp the leg against the clamp cup wall.

2. A clamp according to claim 1, wherein the button incorporates a recessed portion shaped and configured to at least approximate the shape of the furniture leg surface against which, in use, the button is impacted by the clamp.

3. A clamp according to either of claims 1 and 2, wherein the button incorporates both a flat outermost surface suitable for engaging the flat surface of a rectangular shaped leg and a recessed portion for engaging a curved furniture leg.

4. A clamp according to any of the preceding claims, wherein the button incorporates a flat annular outermost surface suitable for engaging the flat surface of a rectangular shaped leg and a recessed portion located within said annular surface for engaging a curved furniture Leg.

5. A clamp according to any of the preceding claims, wherein the button is a relatively Loose fit on the screw end.

6. A clamp according to any of the preceding claims, wherein the button incorporates a front face with a recessed portion and a rear face with a boss for engaging the member and webs extending between the boss and the button; whereby bending of the button, in use, is resisted.

7. A furniture raiser Leg clamp substantially as hereinbefore described with reference to and/or illustrated in any appropriate combination of the accompanying text and/or figures.

8. A furniture raiser Leg clamp button suitable for use with a furniture raiser leg clamp in accordance with any preceding claim.

9. A furniture raiser leg clamp button substantially as hereinbefore described with reference to and / or illustrated in any appropriate combination of the accompanying text and / or figures.

10. The combination of a furniture raiser leg clamp and a furniture leg raiser clamp button; the clamp being in accordance with any of the claims 1 to 7, and the button being in accordance with either of claims 8 and 9.

11. A furniture raiser incorporating the invention of any of claims 1 to 10.