AU632297B2

AU632297B2 - Desk height adjustment mechanism

Info

Publication number: AU632297B2
Application number: AU43798/89A
Authority: AU
Inventors: Antonino Schiavello
Original assignee: Schiavello Bros Vic Pty Ltd
Current assignee: Schiavello Bros Vic Pty Ltd
Priority date: 1986-11-19
Filing date: 1989-10-27
Publication date: 1992-12-24
Anticipated expiration: 2007-11-17
Also published as: NZ222589A; AU592681B2; AU8130687A; AU4379889A

Description

~A r P/00/Oil 4,6322 7 Form PATENTS ACT 1952-1973 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Class: Int. CI: Application Number: Lodged: Complete Specification-Lodged: Accepted: Published: Priority: *Related Art: TO BE COMPLETED BY APPLI CANT .Name of Applicant: A~ddress of Applicant: SCHIAVELLO BROS.

company, of Tulla Victoria 3043, Aust (VIC.) PTY. LTD., a Victorian marine Park Road, Tullamarine, ralia Acto'aI Inventor: ANTONINO SCHIAVELLO Care of: Address for Service:- COWE, CARTEI HENDY PATENT TRADEMARK AITORNEYS 71 QUEENS ROAD, MELBOURNE, 3004, AUSTRALIA Co. tplete Specification for the invention entitled' "DESK HEIGHT ADJUSTMENT MECHANISM" The following statement is a full description of this invention, including the best method of performing it kn~own to 'Note: The description is to bet,pedl in doublespacing. pica typeface, in an area notexceeding 250 mm in depth and 160 mm in width, oai tough white paper of good quality and it is to be inserted inside this form.

C~F~C-ICT

I- i X This invention relates to improvements in desks and relates particularly to a height adjustment mechanism for desks to enable the desk top height to be adjusted to suit the user.

Most desks are of a fixed height which may be suitable for some users but will not be suitable for other users. Various means have been proposed to enable the height of a desk to be adjustable, but all such means have tended to be relatively complicated and/or expensive and have not been successful.

It is therefore desirable to provide means to enable a desk top height to be adjustable.

It is also desirable to provide a desk height adjustment mechanism which is relatively simple to I construct and is easy to operate.

i It is also desirable to provide a height adjustment mechanism which is able to be used with a variety of desk constructions.

t is also desirable to provide a desk height ooo adjustment mechanism which is cheap and economical to produce and is easily transportable.

According to one aspect of the present invention there is provided a desk height adjustment mechanism comprising an elongated desk top member, a pair of leg members attached to the top member to extend substantially perpendicular thereto, each leg member e de having a first part fixed to the desk top member and a second part movable longitudinally relative to the 0. first paft, each first part having a rotatable screw r carried by bearings on the first part with a bevel 0 gear at its upper end, each respective second part including a nut engaged with the screw, a drive shaft extending between the first parts of the leg members, the drive shaft having a bevel gear on each end engaged with the screw bevel gear of a respective first part, a right-angle drive gearbox mounted on the drive shaft and slidable therealong, and handle means connected by drive means to the gearbox and which is rotatable to drive the shaft and the screws to cause relative 2j I 1 Z 'i ii i I- i 0 00

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0e0S 0* *0 0 0 oS *c 0 movement of the first and second parts of the leg members.

The mechanism of the present invention enables the height of a desk top to be adjusted readily and can be used with desks of various sizes and constructions.

The feature of the right-angle drive gearbox being slidable along the drive shaft is advantageous in that it allows the gearbox and the handle means to be located at various positions on the desk.

The drive means connecting the handle means to the right-angle drive gearbox preferably comprises a flexible drive cable. This arrangement allows further flexibility in the locations of the gearbox and the handle means.

Conveniently, the handle means comprises a folding drive handle mounted in a housing located in a recess in the desk top. This enables the handle to be folded into a concealed position when it is not being used to adjust the height of the desk top.

Preferably, complementary guide means are provided on the first and second leg parts of the leg members to facilitate the relative movement of the first and second pairts. In a preferred embodiment guide wheels are rotatably mounted on one of the leg parts for engagement with longitudinally extending runners on the other respective leg part.

According to another aspect of the present invention there is provided a height adjustment mechanism for a desk, said mechanism comprising two or more leg members each extending downwardly from a top member of the desk, each leg having a first part fixed to the desk top member and a second part movable longitudinally relative to the first part, each first part having a rotatable screw carried by bearings with a right-angle gearbox at its upper end, each second part including a nut engaged with the screw of the respective first part, the right-angle gearbox of each first part having at the upper end of the respective screw a bevel gear engageable with at least 3 r 1.

e~ one other bevel gear at the end of a rotatable shaft extending to another right-angle gearbox at the upper end of the screw of the first part of another leg member, a right-angle drive gearbox being mounted on and slidable along a drive shaft extending between the first parts of two of the leg members, and handle means connected to the drive gearbox by drive means and which is rotatable to drive each shaft and each screw through the drive gearbox to cause relative movement of the first and second parts of each leg member.

The height adjustment mechanism in accordance with the second aspect of the present invention may be used to adjust the height of a desk top member I: which is supported by, say, four or more leg members I with the interconnected right-angle gearboxes at each leg member ensuring that the legs are raised or lowered simultaneously The height adjustment mechanism in accordance with the second aspect of the present invention may be used to adjust the height of a desk top supported by, for instance, four or more legs with the rightangle gearboxes at the ends of the main drive shaft being arranged to drive at least one further rotatable shaft leading to another right angle gearbox at the 1 ~upper end of a screw of another leg member.

BIn a similar manner, the height of a desk return attached to a desk may be adjustable simultaneously S. a. with the main desk top by forming a leg of the desk *lo return in first and second relatively movable parts, providing a right-angle gearbox at the upper end of the first part of the desk return leg with a rotatable shaft extending to said gearbox from a right-angle gearbox mounted at one of the ends of the main drive shaft.

Two embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: -4r Figure 1 is a plan view of a desk height adjustmenii mechanism in accordance with the invention; Figure 2 is a part sectional view taken along the line 2-2 of Figure 1; Figure 3 is a part sectional view taken along the lines 3-3 of Figure 2; and Figure 4 is a view similar to Figure 1 of a modified desk height adjustment mechanism for a desk and for a desk return attached to the desk.

Referring to Figures 1 to 3 there is shown a first embodiment of the invention comprising opposed legs 47 each having an inner pprt 48 adapted to be fixed to a desk top member 16 -id respective outer parts 49 adapted to be fixed to desk end panels 21.

At the upper end of etch inner part 48 there o"is mounted a pair of bevel gears 51 and 52, the gear 52 driving a screw 53 the lower end of which is mounted in a bearing 54 at the lower end of the respective inner part 48.

The outer part 49 of each leg 47 has a nut 56 which engages with the respective screw 53. Thus, rotation of the screw 53 causes relative movement between the inner and outer parts 48 and 49 of each leg.

Extending between the bevelgears 51 of each leg 47 is a drive shaft 57 which is preferably of constant *000. cross-section throughout, more preferably of square cross-section. A right-angle drive gearbox 58 has opposed bevel gears 59 and a drive gear 61 mounted V'I therein. One of the bevel gears 59 is provided with

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an internal bore of a shape to receive the drive shaft 57 and be movable therealong. The opposed bevel gear 59 has a similarly shaped bore in a boss rotatable relative to the gear thus allowing the gear to rotate relative to the drive shaft 57.

The gearbox 58 is connected to a drive handle 62 mounted in a housing 63 which is located in a recess in the desk top 16. The handle 62 is of a multiple link type which enables the handle to be folded out to an operative position at which rotation thereof causes rotation of the drive shaft 57 and corresponding relative movement between the inner and outer parts 48 and 49 of each leg 47. Such relative movement is facilitated by guide wheels 64 rotatably mounted on the leg inner parts 48 and engaging with guide ribs 66 on each outer part 49.

The drive shaft 57 may be carried by supports (not shown) attached to the desk top 16 or constituting part of a top member 14 extending between the legs 47 as shown in Figure 3. With such an arrangement, the legs 47 may be pivoted to the top member 14.

With this embodiment, the height of the desk top 16 is infinitely adjustable between upper and lower limits defined by the relative position of the nuts 56 on the screws 53. The provision of the folding handle in a recess in the desk top ensures that the handle is not projecting and is not liable to be knocked by a user.

Figure 4 of the drawings shows a height adjustment *go: mechanism similar to that of Figures 1 to 3 and corresponding numerals refer to corresponding parts. In Figure 4, a further leg member 47' is provided extending downwardly from a top member 67 of a desk return attached to the main desk. T1r leg member 47' is of substantially the same construction as the legs 47 of the main desk, having relatively movable inner and outer parts 48' ar.nd 49' respectively, and a right-angle gearbox 68' S at the upper end of a screw 53' mounted on the inner :3 part 48'. The leg member 47 of the main desk shown in Figure 4 differs from the leg members 47 of Figures 1 to 3 in that it has a right-angle gearbox 68 which includes three mutually engageable bevel gears 51, 52 and 69 rotatable about three axes at right-angles to each other. The third bevel gear 69 is connected0 to a rotatable shaft 70 which extends to the gearbox 68' of the desk return leg member 47' which also has three bevel gears 51', 52' and 69'. Thus when the main drive shaft 57 is rotated by the handle to adjust 6

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the height of the top member 16 of the main desk, the shaft 70 extending between the gearboxes 68 and 68' is also rotated to adjust the height of the top member 67 of the desk return by a similar amount.

It will be appreciated that by using right-angle gearboxes which have three or more bevel gears, such as those designated 68 and 68' in Figure 4, it is possible to provide a height adjustment mechanism in accordance with the invention for a desk having more than two legs, e.g. a four-legged or six-legged desk and which can be operated from a single handle means.

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Claims

1. i The claims defining the invention are as follows:- 1. A desk height adjustment mechanism comprising an elongated desk top member, a pair of leg members attached to the top member to extend substantially perpendicular thereto, each leg member having a first part fixed to the desk top member and a second part movable longitudinally relative to the first part, each first part having a rotatable screw carried by bearings on the first part with a bevel gear at its upper end, each respective second part including a nut engaged with the screw, a drive shaft extending between the first parts of the leg members, the drive shaft having a bevel gear on each end engaged with the screw bevel gear of a respective first part, a right-angle drive gearbox mounted on the drive shaft and slidable therealong, and handle means connected by drive means to the gearbox and which is rotatable to drive the shaft and the screws to cause relative movement of the first and second parts of the leg members. nool

2. A mechanism according to claim 1 wherein one of the leg parts of each leg member has guide wheels rotatably mounted thereon while the other of the e respective leg parts has longitudinally extending runners engaged with the guide wheels. *.o

3. A mechanism according to claim 1 or claim 2 wherein

06.. *o the drive means connecting the handle means to the 0 right-angle drive gearbox comprises a flexible drive 4 cable. 04 4. A mechanism accordinq to any one of claims 1 o to 3 wherein the handle means comprises a folding eb handle located in a recess in the desk top. A height adjustment mechanism for a desk, said mechanism comprising two or more leg members each extending downwardly from a top member of the desk, each leg having a first part fixed to the desk top member and a second part movable longitudinally relative to the first part, each first part having a rotatable screw carried by bearings with a right-anqgle gearbox 8 at its upper end, each second part including a nut engaged with the screw of the respective first part, the right-angle gearbox of each first part having at the upper end of the respective screw a bevel gear enageable with at least one other bevel gear at the end of a rotatable shaft extending to another right- angle gearbox at the upper end of the screw of the first part of another leg member, a right-angle drive gearbox being mounted on and slidable along a main drive shaft extending between the first parts of two of the leg members, and handle means connected to the drive gearbox by drive means and which is rotatable to drive each shaft and each screw through the drive gearbox to cause relative movement of the first and second parts of each leg member. 6, A height adjustment mechanism according to claim 5 comprising four or more leg members, an opposed pair of which have right-angle gearboxes connected togthner by said main drive shaft, each of the remaining leg members having a right-angle gearbox connected by a rotatable shaft to the gearbox of one of said opposed pair of leg members.

7. A height adjustment mechanism according to claim 00 0 5 for a desk having a desk return attached thereto, said mechanism comprising a pair of opposed leg members extending downwardly from the top member of said desk S* and at least one further leg member extending downwardly from a top member of the desk return, said opposed pair of leg members having right-angle gearboxes connected together by said main drive shaft, and said further leg member having a right-angle gearbox connected by a rotatable shaft to the gearbox of one of said opposed pair of leg members.

8. A desk including a desk height adjustment mechanism in accordance with any one of the preceding claims.

9. A desk height adjustment mechanism substantially as described herein with reference to the accompanying drawings. DATED this 23rd day of October, 1989. PAT NTs .TT.ORNYS 71 (QU ROAD, S MELBOURN, 3004, AUSTRALA SCHIAVELLO BROS. (VIC.) PTY. LTD. I M