The present invention relates to items of ftirniture which have panels, end slabs or other components which are capable of positional adjustment and preferably which may be readily assembled and disassembled. More particularly, the invention relates to items of furniture such as desks or other items of furniture having panels or other components which may be height adjusted according to the particular requirements of a user.

Although the invention will be principally described with reference to an adjustable desk it will be appreciated that the invention is also suitable for use in other items of ftirniture which utilise adjustable panels or slab components.

There are in existence desks which have adjustable tops which can be varied in height within predetermined ranges. Typically, these desks are adapted with mechanisms which enable the height adjustment of the desk top. One problem associated with desk having these mechanisms is that in use if an excessive or eccentric weight is placed on one end of the adjustable top as often occurs, the top sinks down affecting or even breaking the adjusting mechanism. To repair the mechanism can require major demolition of the desk.

A further problem is that known arrangements do not provide for the mechanism and indeed the desk to be disassembled when removal is required. These desks are generally known as ergonomic desks because of their adjustability. Due to the way the existing adjusting mechanisms are constructed the desks to which those mechanisms are fitted cannot be disassembled as the connections associated with the adjusting mechanisms are generally welded and are therefore permanent.

An object of the present invention is to alleviate one or more of the shortcomings of the prior art as hereinbefore described.

According to one aspect of the present invention there is provided an adjustment

assembly for an item of ftirniture, the furniture including a base component and at least one adjustable component, the adjustment assembly permitting adjustment of the position of the adjustable component relative to the base component and comprising at least two elevating mechanisms which, in an operative position, are operatively interconnected between the adjustable component and the base component, drive means operatively connected to one of said elevating mechanisms for causing operation thereof, and transmission means operatively connecting said one elevating mechanism to the other elevating mechanism so that when said drive means is activated to cause operation of said one elevating mechanism the other said elevating mechanism is caused to operate as a result of the operative connection via said transmission means.

The aforementioned one elevating mechanism may comprise two telescopically arranged members having co-operating threaded sections arranged such that relative rotation between the members causes extension or retraction of the members relative to each other, one of the members being rotatable by the drive means.

Preferably the other elevating mechanism comprises a rack and pinion assembly which are movable relative to one another as a result of rotation of that pinion. The transmission means may comprise a transmission rack and pinion assembly operatively connected to the aforementioned one elevating mechanism so that extension or retraction of the members causes rotation of the transmission pinion. The transmission means may further include a transmission rod operatively interconnecting the pinions so that rotation of the transmission pinion causes rotation of the elevating mechanism so that the two elevating mechanisms move together.

In a preferred form the base component of the ftirniture comprises at least two legs, these legs comprising two telescopically arranged parts one of each of the parts being fixed and the other being extendable or retractable relative to the fixed leg part. The other part is operatively connected to the adjustable component of the item of furniture, thee elevating mechanisms being associated with a respective one of the legs so as to cause extension or retraction of the parts thereof.

Preferably one of the members of the aforementioned one elevating mechanism

is mounted in fixed relation to the base component of the item of furniture and the other of the members is rotatable relative thereto in response to activation of the drive means.

The drive means may comprise a manually activatable rotatable drive shaft, and a worm gear assembly operatively connecting the drive shaft to the aforementioned one elevating mechanism so that rotation of the drive shaft causes rotation of the rotatable member of the elevating mechanism.

According to another aspect of the present invention there is provided an assembly for enabling adjustment of one or more panels of an item of furniture such that the panel/s is/are urged in a forward and reverse direction and supported during movement by the assembly, said assembly comprising; at least two elevating mechanisms, a manually operable handle, a first linkage rod having a first end on which said handle is placed and having on its second end a worm gear, a telescopic linkage rod having an anchorage at one end which engages with the ground or a foot component of an item of ftιrniture and at its opposite end a bearing and a key which key engages with a recess which connects directly or indirectly to a second gear which engages with the worm gear, said at least two elevating mechanisms each comprising telescopic tubular members the first of which members advances and retracts in response to rotation of said handle, the other of which maintains its position whilst the other advances and retracts, a first rack connected to the advancing tubular member which engages a first cog on one end of a third linkage rod which has connected to its opposite end a second cog which engages with a second rack on a second elevating mechanism, said third linkage rod connecting the two elevating mechanisms so that they advance in cooperation with each other, wherein, when the panel/s is/are to be adjusted the handle is rotated to raise or lower the panel, whereupon the first linkage rod also rotates causing the telescopic linkage rod to rotate by virtue of the engagement between said key and said recess, the telescopic linkage rod expanding or contracting depending upon which way the handle is turned causing movement of at least one panel in the desk.

According to yet another aspect of the present invention there is provided an assembly for enabling the adjustment of one or more panels of an item of furniture such that the panel s may be urged in a forward and reverse direction upon actuation of the assembly, the assembly comprising, at least two elevating mechanisms which are connected to panels of the item of ftirniture and manually operable by means of an adjustable handle which moves between an operable and inoperable position, a first linkage rod having a first end on which said handle is disposed and on its second end a worm gear, a telescopic linkage rod having an anchorage at one end which engages with the ground or a foot component of an item of furniture and at its opposite end a thrust bearing and a key, which key engages with a recess which connects directly or indirectly to a second gear which engages with a worm gear, the worm gear and second gear being contained within a gear housing, said at least elevating mechanisms each comprising telescopic tubular members a first of which members advances and retracts in response to rotation of the handle the other of which maintains its position whilst the other advances and retracts, the first member having said second linkage rod, a first rack connected to the advancing tubular member which engages a first cog on one end of a third linkage rod which has connected to its opposite end a second cog which engages with a second rack on a second elevating mechanism, said third linkage rod connecting the two elevating mechanisms so that they advance in cooperation with each other, wherein, when the panel/s is/are to be adjusted the handle is rotated to raise or lower the panel, whereupon the first linkage rod also rotates causing the telescopic linkage rod to rotate by virtue of the engagement between said key and said recess, the telescopic linkage rod expanding or contracting depending upon which way the handle is turned causing movement of at least one panel in the desk.

According to yet another aspect of the present invention there is provided an assembly for use with an item of furniture to adjust and re-adjust the position of at least one panel of the item of furniture, the assembly comprising at least two elevating mechanisms which operate in

association with two interconnected linkage rods the first of which is operable by means of a handle, the second of which is linked via gears to the first rod so that the second rod rotates in response to rotation of the first rod, the second rod being telescopic so that it advances and retracts in response to turning of the handle, the second rod working in cooperation with the elevating mechanisms to adjust said panel, said assembly adapted for disassembly.

Preferably the elevating mechanisms are linked by a third rod so that each elevates at the same rate. Preferably each of the telescopic adjusting mechanisms comprise inner and outer members each of which comprise a pair of spaced apart but linked tubes.

The present invention will now be described in more detail according to a preferred but non limiting embodiment and with reference to the accompanying illustrations wherein:

Figure 1 shows an isometric view of an ergonomic adjustable desk according to a preferred embodiment of the present invention.

Figure 2 shows an exploded isometric view of the adjusting mechanism according to a preferred embodiment. Figure 3 shows a front elevational view of the slab end fastening plate according to a preferred embodiment.

Figure 4 shows elevational views of the bearing case. Figure 5 shows various views of the handle assembly, and Figure 6 is an isometric view of a further form of desk according to the invention.

Referring to figure 1 there is shown as isometric view of a free standing desk 1 comprising a panel or slab '2 which forms a desk top. The slab 2 is supported by a support structure 3 which comprises a pair of feet 4 and 5, a supporting H frame 6 and two telescopic leg assemblies 7 and 8. The leg assemblies are operated by handle 9 which activates an elevating mechanism 10 (see figure 2 below).

Referring to figure 2 there is shown an exploded isometric view of an elevating mechanism 10 from an isometric view and removed from rod housings. The elevating

mechanism 10 works in elevating and lowering panel 2 in this way.

The rotatable handle 9 is connected to linkage rod 12. The handle 9 is adjustable so that it can be pulled up and folded down as required. The channel 13 of the handle 9 is adapted to slide in slot 14 at end 15 of rod 12. When the handle is to be used it is rotated upwards in the direction of arrow 16. Once it is rotated through approximately 90° it can then be slid along slot 14 until the handle engages its position for rotation. At the opposite end 17 of the rod 12 is a worm gear 18 which engages cog wheel 19. Both the worm gear 18 and cog wheel 19 are contained within gearbox housing 20. Base 21 has a recess 23 which engages with wings 24 which act as a key for rod 25 to enable transfer of rotation of rod 12 via worm gear 18 and cog 19 to rod 25. Rod 25 has fitted thereabout at end 26 a thrust bearing 27. The thrust bearing allows smooth rotation of rod 25 whilst under the load of the panel during elevating and lowering. Rod 25 is part of a telescopic arrangement whereby a helical thread 28 on rod 29 feeds inside the rod 25 enabling telescopic extension and retraction of rod 25 while rod 29 remains stationary. Rod 29 has connected to it at end 30 a base plate 31 which is fixed to foot 4 (see figure 1) of desk 1. On the inner wall 47 of desk side panel or slab 46 is a telescopic assembly 32 which comprises inner and outer sleeves 33 and 34 respectively. Telescopic rods 25 and 29 lie within the inner and outer sleeves 33 and 34. The telescopic assembly 32 also has disposed therein between sleeves 33 and 34 a bearing cage 35. Bearing cage 35 is adapted with an elongated slot 48 which engages with shaft 37 of drive cog 40 which limits the travel of inner sleeve 33 and eliminates any sloppiness between inner and outer sleeves 33 and 34 respectively. Attached to inner sleeve 33 is a rack 36. The purpose of this rack is to engage drive cog 40 of drive shaft 37.

On one end of drive shaft 37 the drive cog 40 engages with a rack 36. Connecting rod 38 joins at its opposite end to a corresponding drive shaft and rack arrangement. Connecting rod 38 may be made of any length but spans almost the length of the panel which is to be adjusted. The drive shafts by virtue of their interconnection by connecting rod 38 prevents any out of alignment travel of the panel during elevation and lowering. The rod 38 may be spot welded at either end to the respective drive shafts. Rod 38 may be removed by applying heat to the welds. Connecting rod 38 joins at its opposite end to a corresponding drive shaft and rack

arrangement.

The inner and outer sleeves 33 and 34 each comprise auxiliary sleeves. Inner sleeve 33 is formed from auxiliary tubes 42 and 43 and outer sleeve 34 is formed from auxiliary tubes 44 and 45.

Where the desk is to be removed the various elements of the elevating and lowering mechanism may be disassembled. This involved unbolting the elevating mechanisms and releasing the linkage rod therefrom. The rod 38 which spans between the drive shafts may be released by applying heat to the spot welds. Once the drive shafts are free and the side panels removed the drive shaft can be released from the telescopic elevating mechanism. Linkage rod 29 can be released from the inner sleeve and the first rod can then be uncoupled.

Referring to figure 3 there is shown a front elevational view of a slab end fastening plate 49 according to a preferred embodiment. This fastening plate enables fastening of each elevating assembly to a support panel of the ftirniture item. The panel may be fixed by conventional means such as bolting or screwing.

The present invention also provides a system for assembly and disassembly of ergonomic fnrniture items such as free standing desks split level workstations and other ' office fixtures. The system enables panel adjustment and disassembly of the associated adjusting mechanism.

Referring to figure 4 there is shown elevational views of the bearing cage 35. The cage fits between inner and outer sleeves 33 and 34 of the elevating mechanism.

Figure 5 shows the handle assembly from various views and in particular it shows the coupling arrangements which allow adjustability of the handle assembly.

It will be recognised by persons skilled in the art that numerous variations and modifications may be made to the invention as broadly described herein without departing from the overall spirit and scope of the invention.