WO1993003650A1

WO1993003650A1 - Desk mechanism

Info

Publication number: WO1993003650A1
Application number: PCT/AU1992/000446
Authority: WO
Inventors: Michael John Cotterill
Original assignee: Cotterill Michael J
Priority date: 1991-08-23
Filing date: 1992-08-24
Publication date: 1993-03-04

Abstract

An adjustable desk (1) includes a base (2) having a pair of generally parallel feet (3) joined by an intermediate cross member (4). A first hollow rectangular column (5) extends upwardly and away from member (4) and a second hollow rectangular column (6) is complementarily telescopically mounted within column (5) for movement between an extended and retracted configuration. Column (5) includes two inwardly opening parallel grooves (30, 31) which are semicircular in cross section and terminate at inner and outer lips (32, 33). These grooves at least partially co-extend with a corresponding number of outwardly opening grooves (38, 39) formed in column (6). Ball bearings are maintained within the passageway formed by the co-extension of these grooves to facilitate telescopic engagement between columns (5, 6). A spacer plate (45) maintains the ball bearings in a fixed spaced apart relationship.

Description

Title: "DESK MECHANISM"

TECHNICAL FIELD

This invention relates to a desk and in particular to an adjustable desk.

The invention has been developed primarily for supporting visual display units and keyboards associated with computers or word processors and will be described hereinafter with reference to that application. However, it will be appreciated that the invention is not limited to that particular field of use and it is also suitable for use with drafting desks, work desks or the like. BACKGROUND ART

Hitherto, desks, and especially larger desks have generally been fixed in height, or alternatively, have included awkward lifting mechanisms having an arrangement of leavers or crank handles to allow the desk height to be varied. Often the force required to adjust the height will be substantial due both to the weight of the desk itself and any items resting thereon.

The large weight to be supported also causes problems with wear of the lifting mechanism while also requiring the use of strengthened and expensive components.

Additionally, the leavers or knobs which are actuated to effect adjustment are often hard to access. In circumstances where tilt variation is required, such as with drawing desks, further adjustment mechanisms are needed, exacerbating the abovementioned problems.

A number of devices have been contemplated to overcome these disadvantages. However, they essentially involve the use of a number of separate supports extending to the working surface. Consequently, it is necessary to provide additional linkages to synchronise the movement of the supports. This further complicates any adjustment mechanism and introduces more friction to be overcome during an adjustment operation. DISCLOSURE OF THE INVENTION

It is an object of the present invention, at least in its preferred embodiment, to overcome or substantially ameliorate at least some of these deficiencies of the prior art.

According to a first aspect of the invention there is provided an adjustable desk including: a base ; a first column extending away from the base; a second column telescopically mounted to the first column for movement between an extended and retracted configuration; a support surface mounted to the second column; and locking means for selectively maintaining the support surface a predetermined distance from the base, wherein at least one of the columns includes a groove for retaining bearing means for reducing the frictional engagement between the columns.

Preferably, the first and second columns include opposed grooves and more preferably include a plurality of opposed grooves.

Preferably also, the first column is tubular and rectangular in cross-section, and has four inwardly opening grooves extending along its length, the grooves being disposed on the inner surface of the shorter sides of the column and being substantially maximally spaced apart.

In a preferred form the second column is complementarily telescopically mounted within the first column and includes four outwardly opening grooves disposed adjacent the inwardly opening grooves on the first column. More preferably, each pair of adjacent grooves collectively define a passageway along which the bearing means, in the form of a plurality of ball bearings, travel in response to telescopic movement between the columns.

Preferably, the grooves are shaped such that the ball bearings, when progressing therealong, rotate about an axis angularly displaced by substantially 45° from the side of the column in which those grooves extend. More preferably, the ball bearings in each passageway are maintained in a fixed spaced apart relationship by way of a spacer plate, the spacer plate being disposed intermediately between the first and second columns and including a plurality of apertures for complementarily receiving respective ball bearings.

According to a second aspect of the invention there is provided an adjustable desk including: a base; a first column extending away from the base; a second column telescopically mounted to the first column for movement between an extended and retracted configuration; a first support surface mounted to the second column; locking means for maintaining the support surface a predetermined distance from the base; and a third column telescopically mounted to said second column for movement between an extended and retracted configuration and supporting a second support surface. Preferably, the desk includes additional locking means for selectively maintaining the second support surface at a predetermined distance from the first support surface.

Preferably also, the first and second columns are interconnected by way of a lift mechanism for assisting and damping movement of the second column toward the extended and retracted configuration respectively. More preferably the second and third columns are similarly interconnected by way of a further independent lift mechanism.

According to a third aspect of the invention there is provided an adjustable desk including: a base; a first column extending away from the base; a second column telescopically mounted to the first column for movement between an extended and retracted configuration; a support surface rotatably mounted to the second column for relative angular displacement thereto; and locking means for selectively maintaining the support surface a predetermined distance from the base.

Preferably, the locking means also selectively maintains the support surface at one of a number of predetermined angularly displaced configurations.

Preferably also, the locking means includes a single actuating lever, wherein the lever is moved in one direction for allowing adjustment of the distance between the support surface and base, and in an opposite direction for allowing angular displacement of the support surface.

In a preferred form, the second column includes at its free end a mounting bracket which rotatably supports two opposed support brackets extending from the support surface. A locking bar, movable by the actuating lever, is selectively engagable with one pair of a plurality of spaced apart slot pairs formed in opposed support brackets to selectively maintain the support surface is one of a plurality of inclinations with respect to the second column. BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompany drawings in which:

Figure 1 is a front view of an adjustable desk according to the invention;

Figure 2 is a side view of Figure 1; Figure 3 is an exploded view of the columns of the desk of Figure 1 showing the locking mechanism;

Figure 4 is an enlarged top view of the first column of Figure 1;

Figure 5 is an enlarged view of the second column of the desk shown in Figure 1;

Figure 6 is the bearing plate used in the desk of Figure 1 ;

Figure 7 is an enlarged top view of a third column suitable for telescopic engagement within the column of Figure 5;

Figure 8 is an enlarged top view of a fourth column suitable for telescopic engagement within the column of Figure 6;

Figure 9 is an alternative arrangement of the desk shown in Figure 1;

Figure 10 is a perspective view of a tilt adjustment mechanism for use with either of the desks of Figure 1 or 9;

Figure 11 is an enlarged top view of the locking bar of Figure 10; and

Figure 12 is a sectional view of the desk of Figure 1. MODES FOR CARRYING OUT THE INVENTION

Referring in particular to Figures 1 and 2 an adjustable desk 1 includes a base 2 having a pair of generally parallel feet 3 joined by an intermediate cross-member 4. A first hollow rectangular column 5 extends upwardly and away from member 4 and a second hollow rectangular column 6 is complementarily telescopically mounted within column 5 for movement between an extended and retracted configuration. Column 6 is shown intermediate the extremities of the available range of movement. Disposed on the free end 7 of column 6 is a support surface 8 having a VDU 9 disposed thereon. Surface 8 is selectively maintained at a predetermined distance from base 2 by way of a locking mechanism extending between the two columns. A preferred locking mechanism 10 is illustrated in Figure 3 and takes the form of a slotted bar 11 hingedly mounted at one end 12 to the exterior surface 13 of column 6 and extending substantially along the length thereof. The spaced apart slots 14 in bar 11 are intended to selectively engage a complementarily formed protrusion 15 on the interior surface 16 of column 5. Bar 11 is able to be rotated in and out of engagement with the protrusion in order to effect locking and unlocking of the two columns. Free end 17 of bar 11 extends beyond end 7 of column 6 and is available for engagement by a suitable lever, as will be described below, for allowing easy operation of mechanism 10.

Column 5 also supports a fixed support surface 20 by way of brackets 21. In alternative embodiments this bracket is slidably mounted to column 5 to enable suitable height adjustment so that the keyboard 22 resting on surface 20 can be positioned at a suitable height.

Referring in particular to Figure 4 an enlarged partially cross-sectional view of column 5 is illustrated. It will be appreciated that the column is symmetrical about both axes 25 and 26. Column 5 includes broad and narrow sides 27 and 28 which collectively define interior and exterior surfaces 16 and 29. The interior 16 of side 28 is formed to include two inwardly opening parallel grooves 30 and 31 which extend along the length of column 5. These grooves are substantially semi-circular in cross-section and transversely terminate at inner and outer lips 32 and 33. The opposite narrow side (not shown in detail) also includes a corresponding pair of grooves.

Referring now to Figure 5 there is illustrated an expanded cross-sectional view of part of column 6. This column includes broad and narrow sides 35 and 36 for collectively defining interior and exterior surfaces 37 and 13 of column 6. The exterior surface of narrow end 36 is formed with two generally parallel outwardly opening grooves 38 and 39 which each terminate at inner and outer lips 40 and 41.

When column 5 and 6 are arranged in telescopic engagement grooves 30 and 31 respectively co-extend along at least a portion of grooves 38 and 39 to define a pair of substantially parallel generally cylindrical passageways. A similar pair of passageways is formed between the opposite narrow sides of the columns. It is within these passageways that ball bearings are mounted in order to facilitate the telescopic progression of the two columns. - lo ¬ in this preferred embodiment, each of the passageways retains a plurality of ball bearings which are fixed in a spaced apart configuration by way of a plate 45 which is illustrated in Figure 6. Plate 45 includes two generally parallel spaced apart rows 46 and 47 each including a number of apertures 48 for selectively maintaining the ball bearings in a spaced apart configuration within the passageway. As columns 5 and 6 are telescopically progressed plate 45 will also move by approximately half the relative displacement between the columns. Plate 45 ensures that a maximum number of ball bearings are maintained in engagement with both columns to facilitate both load sharing between those ball bearings and ease of movement between the columns.

The plate is constructed of a thin plastics or metal sheet and is nested between the interior of column 5 and the exterior of column 6 along their narrow sides. Two such plates are used, one being associated with each pair of passageways. However, in other embodiments the ball bearings in each passageway are held by a separate plate.

Columns 5 and 6 include on the exterior surface of each of their respective narrow sides T-shaped channels 50. A plurality of separate support surfaces are able to be fixedly or releasably attached to these channels and subsequently positioned along the columns. In some embodiments these surfaces are in the form of shelves. Referring again to Figure 5, column 6 includes on the interior of narrow side 36 two generally parallel inwardly facing grooves 51 and 52 which extend along the length of the column and transversely terminate in inner and outer lips 53 and 54. This allows alternative embodiments of desk 1 to include further telescopically nested columns. For example, support surface 7 is able to be configured to extend about column 6 such that a third column 60, as illustrated in Figure 7, can be telescopically engaged within column 6. Column 60 includes broad and narrow sides 61 and 62 which collectively define interior and exterior surfaces 63 and 64. The exterior surface of narrow sides 62 each include two outwardly facing grooves 65 and 66 for interacting with inwardly facing grooves 51 and 52 of column 6 to define two pairs of bearing passageways. Column 60 also includes inwardly facing grooves 67 and 68 to facilitate the telescopic mounting and progression of a fourth column 69, as illustrated in Figure 8, with column 60.

Column 69 includes broad and narrow sides 70 and 71, and outwardly facing grooves 72 and 73 in each of those narrow sides. The grooves are intended for at least partial co-extension with grooves 67 and 68 of column 60 to form bearing passageways similar to those described above. The passageways formed due to the co-extension of the grooves described above are each intended to retain a plurality of ball bearings which are all preferably maintained in a fixed spaced apart relationship by an appropriately dimensioned plate similar to that shown in Figure 6.

Columns 60 and 69 also include T-shaped channels 74 and 75 respectively which centrally extend along the exterior of each of the narrow sides 62 and 71. These channels function similarly to the channel 50 of columns 5 and 6.

In some embodiments only the innermost column supports at its free end a support surface to enable a large degree of height adjustability, or alternatively, a number of spaced apart support surfaces are included.

In the embodiment shown in Figures 1 and 2 a single gas slider unit extends between columns 5 and 6 to respectively assist and dampen extensive and retractive progression between the columns. A suitable unit is illustrated in Figure 12 and includes a gas strut 110. If additional telescopic columns are included that slider unit is able to either connect between column 5 and the innermost column, or more preferably, separate slider units extend between adjacent columns to allow independent adjustment.

Referring in particular to Figures 4 and 5, it will be appreciated that the passageways defined by opposed grooves 30 and 51, and 31 and 52 retain the ball bearings therein to facilitate telescopic progression of columns 5 and 6. The grooves are configured such that the ball bearings rotate about an axis which is angularly spaced by 45° from axis 26. More preferably, the axis of rotation of the ball bearings disposed within the passageways defined by grooves 30 and 51 and 31 and 52 are angularly displaced by 45° in anti-clockwise and clockwise direction from axis 26. It has been found that this configuration is effective in preventing twisting between the columns and reducing the wear that results from forces causing that twisting. The opposed narrow side (not shown) is similarly configured and is a mirror image of those described above. Furthermore, the other grooves in the other columns are advantageously configured to enable a similar interaction with respective ball bearings.

It is also preferred to have a narrow portion of resilient material protruding into at least some of the grooves, for engagement with the ball bearings as they progress through respective passageways. The resilient material most preferably engages the ball bearings near their axis of rotation and prevents the bearings from moving within the passageway in absence of any telescopic progression between nested columns. A suitable material is a reasonably stiff foam, however, soft rubber compounds or the like are also used. Referring to Figure 9, an alternative embodiment of the desk 1 is shown. Column 5 extends vertically away from a base 2 and is secured to a cross beam 80 by way of flanges 81. Beam 80 is generally a part, or an extension of, other furniture, however, any support is able to be used.

Column 6 supports an adjustment mechanism 82 at its free end 7 for allowing tilt adjustment of a support surface attached thereto. Referring to Figure 10 a preferred adjustment mechanism 83 includes a bracket 84 which is intended for mounting to free end 7 of column 6. Bracket 84 rotatably supports two opposed brackets 85 and 86 by way of pins 73. Each of brackets 85 and 86 extends from the support surface and includes an arcuate aperture 87 each having a plurality of opposed spaced apart formations 88.

A locking bar 90 is slidably mounted to bracket 84 by way of slots 91 which engage upstanding pins 92 extending from bracket 84. Bar 90 is illustrated in greater detail in Figure 11.

Bar 90 extends between two ends 93 and 94 and includes at each of those ends a locking portion 95 and 96 for selectively engaging formations 88 in bracket 85 and 86 respectively. Leading from portions 95 and 96 are ramps 97 and 98 which extend to respective narrowed regions 99 and 100.

In use, portions 95 and 96 will be biased into engagement with respective formations 88. Upon movement of lever 101 in the direction of arrows 102, end 103 of lever 101 will engage a pin 104 of bar 90. Subsequently, bar 90 is progressively disengaged from formations 88, and narrowed regions 99 and 100 are thereafter disposed within apertures 87. The travel of bar 90 is limited by slots 91 and pins 92 to ensure that narrowed regions 99 and 100 are disposed within apertures 87 to allow rotation of brackets 85 and 86 about bracket 84. Subsequent release of bar 101 allows bar 90 to be progressed into a locked configuration under the influence of the bias to maintain the support surface at the selected inclination with respect to column 6.

Movement of lever 101 in the opposite direction results in the engagement and progression of free end 17 of bar 11 along slot 106 and the subsequent unlocking of the height adjustment mechanism as previously described. That is, both height and tilt adjustment are able to be easily effected through the use of a single hand operable lever 101.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

Claims

CLAIMS : -

1. An adjustable desk including: a base; a first column extending away from the base; a second column telescopically mounted to the first column for movement between an extended and retracted configuration; a support surface mounted to the second column; and locking means for selectively maintaining the support surface a predetermined distance from the base, wherein at least one of the columns includes a groove for retaining bearing means for reducing the frictional engagement between the column.

2. A desk according to claim 1 wherein said first column includes a plurality of grooves and said second column includes a corresponding number of grooves which at least partially co-extend with the grooves on said first column.

3. A desk according to claim 1 or claim 2 wherein said first column is tubular and has four inwardly opening grooves extending along its length, the grooves being disposed on the inner surface of the column and being substantially maximally spaced apart.

4. A desk according to claim 3 wherein said first column is rectangular in cross-section and the grooves extend along opposite edges of the narrow side of the colum .

5. A desk according to any one of claims 2 to 4 wherein said second column is complementarily telescopically mounted within said first column and includes four outwardly opening grooves disposed adjacent said inwardly opening grooves on said first column.

6. A desk according to claim 5 wherein each pair of adjacent grooves collectively define a passageway along which the bearing means, in the form of a plurality of ball bearings, travel in response to telescopic movement between the columns.

7. A desk according to claim 6 wherein said grooves are shaped such that the ball bearings, when progressing therealong, rotate about an axis angularly displaced by substantially 45° from the narrow side of the column.

8. A desk according to any one of the preceding claims wherein said bearing means includes a plurality of ball bearings maintained in a fixed spaced apart relationship.

9. A desk according to claim 8 wherein said bearing means includes a plate having a plurality of apertures for retaining a corresponding number of ball bearings in said spaced apart relationship, said plate being disposed between said first and second columns.

10. An adjustable desk including: a base; a first column extending away from the base; a second column telescopically mounted to the first column for movement between an extended and retracted configuration; a first support surface mounted to the second column; locking means for maintaining the support surface at a predetermined distance from the base; and a third column telescopically mounted to said second column for movement between an extended and retracted configuration and supporting a second support surface.

11. A desk according to claim 10 including additional locking means for selectively maintaining said second support surface at a predetermined distance from the first support surface.

12. A desk according to claim 10 or claim 11 wherein said first and second columns are interconnected by way of a lift mechanism for assisting and damping movement of the second column toward the extended and retracted configuration respectively.

13. A desk according to claim 12 wherein said second and third columns are interconnected by way of a second independent lift mechanism.

14. An adjustable desk including: a base; a first column extending away from the base; a second column telescopically mounted to the first column for movement between an extended and retracted configuration; a support surface rotatably mounted to the second column for relative angular displacement thereto; and locking means for selectively maintaining the support surface a predetermined distance from the base.

15. A desk according to claim 14 wherein said locking means also selectively maintains the support surface at one of a number of predetermined angularly displaced configurations.

16. A desk according to claim 14 or claim 15 wherein said locking means includes a single actuating lever, wherein the lever is moved in one direction for allowing adjustment of the distance between said support surface and base, and in an opposite direction for allowing angular displacement of the support surface.

17. A desk according to any one of claims 14 to 16 wherein said second column includes at its free end a mounting bracket which rotatably supports two opposed support brackets extending from the support surface.

18. A desk according to claim 17 wherein a locking bar being movable by said actuating lever, is selectively engagable with one pair of a plurality of spaced apart slot pairs formed in opposed support brackets to selectively maintain the support surface in one of a plurality of inclinations with respect to the second column.

19. An adjustable desk substantially as herein described with reference to the accompanying drawings.