DESK STRUCTURE

Abstract: Desk structure having a longitudinally extending beam (82, 82a) and a desk top (21a, 21b) supported on supports (22a, 22b, 22c) extending laterally of the beam (82, 82a) and resting on a floor. The supports (22a, 22b, 22c) connect slidably with the beam (82, 82a) to support the desk top (21a, 21b), and couplings (87) connect the supports (22a, 22b, 22c) to the beam (82, 82a) to be slidably adjustable along the beam (82, 82a). The support (22a, 22b, 22c) is a hollow casing (23) having a side panel (31) that is detachable to allow access to the interior of the casing (23), and a lower side (29) having an opening (36) so that the support (22a, 22b, 22c) can be positioned to receive wiring (37) and the like from floor outlets in order to conceal and confine such wiring (37).

Description: Desk Structure The present invention relates to desk structure especially although not exclusively useful for office furniture. In the current economic climate, there is considerable demand for furniture, especially office furniture, which can be manufactured relatively inexpensively from relatively low cost materials and which functionally is at least equal to and preferably superior to conventional designs. Frequently, the user of a desk needs to make electrical or telecommunications connections through cables, lines, and like wiring for work station equipment and with the known structures it is often difficult or impossible to adequately conceal such wiring which tends to produce an untidy and cluttered appearance at the workstation. Further, trailing wiring connecting to flow outlets and the like can be an electrical or physical hazard. A further area in which known designs tend to be deficient is in the difficulty of adjustment of the components of the desk structure relative to one another and relative to the surroundings. It may be desired, for example, to allow adjustment of the height of the desk top to suit it for use by disabled personnel, and most known structures are not adapted for such adjustment. Adjustment of the spacing or position of the desk top supports or of the position of the desk top may in any event be required by a variety of users whether able or disabled for the purpose of providing a satisfactorily ergonomically functioning work station. Known desk structures that are capable of adjustment in the manner described above tend to be more complex and expensive and more difficult to install and operate than may be considered desirable. The present invention provides desk structure having a longitudinally extending beam. Support members extend laterally of the beam and are adapted to rest on a floor and connect to and support the desk top. Coupling members serve to couple the support members to the beam to be slidably adjustable longitudinally along the beam. At least one of said support members comprises a hollow casing having a side panel which is detachable to allow access to the interior of the casing, and a lower floor engaging side having an opening therein. This structure is well adapted for use in an office or other environment where it is desired to provide a number of desks or workstations in proximity to one another. Usually, a number of sets of desk tops and associated support members will be coupled to a common beam. The structure can be manufactured relatively inexpensively from low cost materials. Many of the components can be formed as extrusions and others can be made from sheet metal using conventional bending and pressing operations. With the above arrangement, there is considerably greater flexibility of positioning of the workstation and of its components since the desk top can be positioned at any desired point relative to the beam as long as the beam is left adequately supported and balanced, and the positioning and spacing of the support members relative to the desk top may be varied considerably. In particular it is readily possible to position one or both support member casings over floor outlets or receptacles so that wiring for the work station and optionally for adjacent workstations can be introduced upwardly through the openings in the lower sides of the casings and can be fed upwardly to the desk top, and usually through openings in the casing toward the rear edge of the desk top. Further, the above structure is readily adaptable to provide for adjustment of the height of the desk top and, in the preferred form, the or each of the above-mentioned support members comprises vertically adjustable means whereby the height of the desk top can be adjusted. The desk structure of the invention will now be more fully described, by way of example only, with reference to the accompanying drawings. Figure 1 is a partial perspective view, with portions cut away to show interior detail, of one form of desk structure in accordance with the invention. Figure 2 is a transverse cross-section taken along the stepped line 2-2 in Figure 1. Figure 2A is a cross-section on an enlarged scale of the area circled at 2A in Figure 2. Figure 3 is an end view, with portions cut away showing interior detail, of one form of C-section leg indicated at 3 in Figure 1. Figure 4 is a partially cross-sectional view on an enlarged scale through the area indicated at 4-4 in Figure 2. Figure 5 is a cross-sectional view on an enlarged scale taken on the line 5-5 in Figure 2. Figure 6 is a partially transverse cross-sectional view of a privacy panel structure indicated at 6 in Figure 2. Figure 7 is a partially transverse cross-section of a further privacy panel structure employed in the desk structure of Figure 1. Figures 8 and 9 are, respectively, views on enlarged scales of the areas circled at 8 and 9 in Figure 3. Figure 10 is a view of a coupling member indicated generally at 10 in Figure 3. Figure 11 shows on an enlarged scale the portion circled at 11 in Figure 1, and indicating in more detail the quarter turn connector used for connecting to the underside of the desk top. Figure 12 is a transverse cross-section taken on the line 12-12 in Figure 1, and showing a wiring storage bin. Figure 13 is a transverse cross-section through the fluted column employed in the present desk structure. Figure 14 is a partially exploded perspective view, with portions removed to show interior detail, of a desk structure in accordance with the invention having a modified drive for the vertically-adjustable column members. Figure 15 is a side elevational view on an enlarged scale of a support member taken in the direction of arrow XV in Figure 14. Figure 16 is a side view taken on the arrow XVI in Figure 15, showing a column member with portions cut away to show interior detail. Figure 17 shows views on an enlarged scale of the area circled at A and B, respectively, in Figure 16. Figure 18 is a cross-sectional view on an enlarged scale of a truss bearing used at the upper end of the column member of Figure 16. Figure 19 is a view on an enlarged scale of the drive arrangement used for connecting the upper ends of column members of adjacent support members. Referring to the drawings, wherein like references indicate like parts, Figure 1 shows a desk structure comprising a first main desk top portion 21a and a second desk top portion 2lb extending generally at right angles to portion 21a. The desk tops may be formed of any board-like sheet material providing adequate strength properties, and which is preferably readily machine using routing devices and the like, so that its edges can be readily shaped and profiled. Examples of suitable materials include wood, chip board and various other particle board and fibreboard materials well known to those of skill in the art, and typically formed from bonded wood or other cellulosic particle or fibre products. A preferred material is MDF (medium density fibreboard) . As seen in the drawings, preferably the front edge of each desk top 21a and 21b is downwardly forwardly bevelled. The rear edge of the desk top portion 21a is formed at right angles to the main desk top surface, while the rear edge of the desk top 21b is preferably downwardly rearwardly bevelled, as seen in Figure 1. In the example shown in Figure 1, the desk top 21a is supported at each end on a support member in the form of a generally rectangular gable 22a and 22b, respectively. As seen in more detail in Figure 2, the gables 22 comprise a generally tray-like pressing 23 formed from sheet metal. This pressing 23 comprises a main rectangular panel 24, a top lip 26, sides 27 and 28 and a lower side 29. Within the open side of the tray-like pressing 23 is received a sheet metal panel 31 which is a frictional fit within the open side of the pressing 23, so that the pressing 23 and panel 31 together form a closed rectangular casing. The lower side 29 is provided with a pair of levelling feet 32 each provided with a threaded stem 33 received in a fitting 34 spot welded to the lower side 29 of the member 23, so that, by rotation of the feet 32, the height of each is adjusted and levelling effected. The lower side 29 is cut away at 36, as may best be seen in Figure 1 for the gable 22c supporting the left-hand end of the desk top 21b, so that the lower side 29 is provided with an opening which can conveniently be positioned over floor outlets, receptacles or the like, whereby lines, cabling, or other wiring 37 can be conveniently led upwardly through the hollow casing 22c. The connections to the floor outlets can conveniently be made while panel 31 is removed. The main panel 24 is formed with two circular areas 38 adjacent each side of its upper end. These areas 38 may be punched-out holes or may be lines of weakness partially punched-out to form knockouts which can be removed by application of a circular punch to provide openings through which the wiring 37 may be passed, normally to be directed upwardly and rearwardly toward the rear edge of the desk top, for connection with telephones, other telecommunication equipment, computers or other electrical equipment to be used on the desk top. As best seen in Figure 2, in the preferred form each gable 22 is provided with a pair of vertically-adjustable column members 39 which support the desk top 21. Each member 39 is a length of an extrusion of the cross-section seen at 41 in Figure 13. Preferably, the extrusion 41 is fluted on its exterior, and has radially directed fins 42 in its interior. Between every, other pair of the fins 42, the wall material is somewhat thickened to provide openings of somewhat smaller width providing ports 43 into which self-tapping screws or the like may be threaded. The extrusion 41 may preferably be of aluminium, but may be of other materials of suitable strength, such as engineering plastics or the like. As seen in Figure 2, each column member 39 passes with a small clearance through openings formed in transverse bracing members 44, spot welded to the member 23. As seen in Figure 4, a bushing 46 comprising a tapped sleeve 47 is inserted into the lower end of each column member 39, and is held in place with screws 48 passed upwardly into the screw ports 43. The upper end of each column member 39 carries a rectangular plate 49, as seen in Figure 11, held on with screws 51 passed into the screw ports 43. As seen in Figure 2, each desk top 21 may be provided with two parallel longitudinally extending rails 52, seen in more detail in Figure 2A. Each rail 52 comprises a generally channel section extrusion formed with saw tooth gripping portions 53 on its outer channel sides, and re-entrant lower lip portions 54. Outwardly from the lip portions, the rail extends laterally on each side to form a relatively shallow and wide outer channel portion having outer channel edges 56. Conveniently, the rail 52 may be received in rectangular grooves routed in the underside of the desk top 21, and may then be either press fitted or glued in place. As illustrated in Figure 11, in assembling the desk top 21 to the columns 39, the rail 52 is placed over the rectangular plate 49, so that the narrower dimension of the plate 49 is received snugly between the channel sides 56, as seen in Figure 2A and a quarter turn connector 57 is passed upwardly through a key hole shaped slot 58 in the plate 49 to enter the channel recess of the rail 52, and the quarter turn connector 57 operated to engage its head 59 transversely on the upper sides of the lips 54 and retain the plate 49 in compression against the rail 52. The quarter turn connector 57 may be as described in applicant's copending application serial No. CA94/00624. Briefly, the connector 57 comprises a screw having a shaft 61 bearing the head 59 on one end, and passing through a circular washer 62 provided with arms 63. The opposite end of the shaft 61 is threaded within a knurled nut 64 and, in the assembled condition, shown in Figure 11, the action of a compression spring 66 between the washer 62 and the nut 64 maintains the head 59 lodged firmly on the ends of the arms 63. In use, the head 59, shaft 61 and arms 63 are passed through the key hole slot 58, the nut 64 turned a quarter turn to dislodge the head 59 from the arms 63 and to adopt the position shown in Figure 2A, and the nut 64 then tightened up to apply compression between the head 59 and the washer 62. As seen in Figure 2A, the outer end of the threaded shaft 61 carries a transverse indicator rib 67 indicating the position of the head 59. With less advantage, other quarter turn connector devices may be adapted for use in the present invention, for example those shown in U.S. patents 4,442,571 (Davis et al) and 4,801,232 (Hempel) . Alternatively, the plates 49 may have holes through which screws are passed upwardly into the underside of the desk top 21 to secure each column 39 to the desk top 21. As a result of the firm connection between the plate 49 and the desk top 21, the upper end of each column 39 is held non-rotatably relative to the desk top 21. The connection may be sufficiently stable that a desk top 21 may be supported on only one central axis such as along rail 52, but preferably as shown there are two points of connection between each gable 22 and the desk top, so that there is support along two parallel axes, e.g. using a two rail support employing rails 52 disposed parallel to and inset somewhat laterally from each longitudinal edge of the desk top 21. Referring again to Figure 4, a screw jack arrangement is used for raising and lowering column members 39 relative to the gable 22. The screw jack arrangement comprises a threaded shaft 68, the lower end of which, as seen in Figure 5 is supported on a bearing bushing 69 mounted within a lower brace portion 70 welded to the member 23, so that the shaft 68 is freely rotatable. Secured on the shaft 68 is a gear 71 keyed within a thumb wheel 72, a portion of the perimeter of which extends through a slot in an inwardly dished portion 73 of the rear panel 24 of the member 23. The wheel 72 can be rotated by hand to rotate the shaft 68 and raise or lower the bushing 46 together with column member 39 depending on the direction of rotation, and raise or lower the desk top 21. A drive interconnects the two column members 39 within each gable 22 so that the column members 39 are raised and lowered in unison. In the example illustrated, the drive comprises an endless toothed belt 74, for example a rubber timing belt of the like engaging around the gears 71 associated with each shaft 68. Other interconnecting drives could of course be used. The lower end of each shaft 68 is provided with a socket member 76. Adjacent the lower end of one shaft 68 is provided a support bracket 77, secured to the back panels 24, to which may be attached a motor, for example, an electrical motor 78 having a drive shaft 79 insertable within the socket and secured with a set screw or the like passed through an opening 81 in the side of the socket 76. The motor 78 and its associated control devices can be readily fitted if desired after installation of the desk structure, in order to convert from manual to powered desk top height adjustment. The gables 22 or other support members are interconnected by a beam 82, which, in the preferred form, is a length of an extrusion of the section 83, as seen in Figure 7, and is extruded from aluminium or other material of suitable strength, such as engineering plastic. As best seen in Figure 7, the extrusion 83 is of generally rectangular cross-section, having planar upper and lower sides and opposing side surfaces which are formed with a series of longitudinally extending channel section grooves 84. Each groove 84 has a pair of re-entrant lips 86. In the example illustrated, each side face of the extrusion 83 is provided with five grooves, which are uniformly vertically spaced. A clamping member such as the clamping member 87 shown in Figure 10 is used for connecting each gable 22 to the beam 82. Each laterally inner side panel 27 of the gable member 23 is formed with a pair of transverse slots 88 adjacent its upper end. Desirably for increased flexibility of construction, the laterally outer side panel 28 is likewise formed with a similar pair of slots 88 as seen in Figure 1. The spacing of these slots 88 is equal to the spacing between the upper most and lower most of the channels 84 in the side faces of the extrusion 83. As seen in Figure 10, each clamp member comprises similar upper and lower clamping portions 89 connected by a turn buckle arrangement 91. The turn buckle comprises upper and lower threaded members 92 and 93 having tool- engaging heads 93a which are counter sunk in recesses 94 in the portions 89. For example, the heads 93a may have a slotted formation to be engaged by a screwdriver. The turn buckle 91 may be housed in a resilient corrugated sleeve 96. Each portion 89 has laterally opposing hook portions 97 and 98. The portions 97 intended to engage the slots 88 are made somewhat shallower for ease of manipulation and engagement with the slots 88. In use, the hook portions 97 are engaged within the slots 88 and the hook portions 98 within a pair of channel grooves 84 in the beam 82, as seen in Figure 2, and tools are used to operate the turn buckle 91 and drawn the clamping portions 89 toward one another, thus firmly clamping the gable 22 to the beam 82, and providing a structure of increased rigidity and stability. When the tension in the turnbuckles 91 is released the gables 22 and clamps 87 may be slid longitudinally along the beam 82 for adjustment of the position or spacing of the gables 22. Further, by rotating the nuts 64 of the quarter turn connectors 57 to release the compression, longitudinal adjustment of the gables 22 relative to the rails 52 and the desk tops 21 is possible. As seen in Figures 2 and 10, each clamp portion 89 is formed with a deeply concave recess 99. The upper recess 99 serves as a guide and support for electrical lines, cabling and other wiring passed lengthwise along the beam 82. The recess 99 tends to retain the wiring well below the upper surfaces of the gabling 22 and desk tops 21, so that they are kept out of sight and are unobtrusive. At points where greater freedom of movement for the knees of the user of the workstation is desired, for example approximately half way along the desk top 21b in the arrangement of Figure 1, a generally C-section leg 101 may be employed as shown in more detail in Figure 3. The leg 101 comprises an elongated base 102 provided with levelling feet 32 similar to those described above in more detail with reference to Figure 2. An upright casing 103 is secured on the base. This comprises a vertical recess within which is reciprocable an upper leg portion 104 comprising an upper plate 105, a column member 106 similar to the column members 39, and secured with screws at its upper end to the plate 105 and a generally triangular plate 107 extending through a forward slot in the casing 103. Internally of the casing 103 are journalled guide wheels 108 which run on vertical flanges 109 provided on each side of the plate 107, and thus serve to guide the upper member 104 for vertical reciprocation relative to the casing 103. A screw jacking arrangement similar to that described above with reference to Figure 2 provides for vertical adjustment of the upper member 104 relative to the casing 103. A screw 68a reacting with a threaded bushing 47a secured to the lower end of the column member 106 is supported in a bearing bushing 70a supported at the lower end of the casing 103 and engages a gear 71a rotatable by means of a thumb wheel 72 passing through a slot 73 in a side surface of the casing 103, whereby manual adjustment of the leg can be made. Further, there is the option of attaching a motor 78a within the casing 103 to drive a socket 76a by means of its spindle 79a. The laterally inner side of the casing 103 is likewise formed with a pair of slots similar to the slots 88 in the gable side panels 27 and 28, whereby the leg member 101 may be secured to a beam section such as the beam section 82a shown in Figure 1 through use of a clamping member 87a similar to the clamping member 87 described above with reference to Figure 10. The plate 105 of the leg 101 may be provided with key hole slots similar to the slots 58 formed in the plate 59 described above with reference to Figure 11, or the plate 105 may have auxiliary plates connected transversely to it and the auxiliary plates provided with key hole slots similar to the slots 58, to enable connection of the plate 105 to the rails 52 provided in the underside of the desk top 21b, similar to those described above for the desk top 21a. One advantage of the arrangement described above is that the greatest transverse dimension of the beam 82 may be considerably smaller than the height of the gable 22 or leg 102. For example, typically, the ratio of the height of the gable 22 to the ratio of the height of the beam 82 will be of the order of about 3:1 to 4:1. This provides increased access to the underside of the desk, for example for ease of positioning of floor mounted equipment and the like. Moreover, it provides significant advantages in transportation of the components. As will be appreciated, normally the components of the desk structure are transported in knocked-down form, and are assembled in the office or other site where the desk structure is to be used. In the example shown in Figure 1, the desk top 21b is supported on the left hand gable 22c and the central C-leg 101. Connector plates (not shown) applied to the underside of the desk tops 2lb and 2la may be used to inter-connect them, for example using screws passed upwardly through such connector plates and into the material of the desk tops 21a and 21b. Similarly, a triangular filler piece 21c may be attached using similar underside-attached connector plates. Preferably, the right hand edge of the desk top 21b and the inner edges of the filler piece 21c are chamfered to match the bevel of the adjoining edges of the adjacent desk top portions. A desk top extension, such as the extension portions 2Id and 21e as shown in Figure 1 may be provided on the desk tops. These extension are supported on rigid, for example metal, support members 111 extending transversely on the underside of the desk top 21. The members 111 may be, for example, of channel section disposed with the channel facing downwardly, and the channel bottoms (adjacent the underside of the desk top 21) may be formed with key hole openings similar to the openings 58, enabling quarter turn connectors to be used to secure the members 111 to the rail 52 at points spaced between the points of connection of the column members 39. In the preferred form, the extensions 21e are connected to the rearward end of the support members 111 through hinges at a position such that there is a small gap between the forward edge of the extension 2le and the rearward edge of the main desk top 21, and enabling upward and rearward swinging of the extension 21e from the normal position shown in solid lines to the raised position shown in broken lines in Figure 2, enabling allowing access to connectors and the like interposed between the wiring normally running parallel to and adjacent to the beam 82 and electrical or electronic equipment to be supported on the main desk top 21. Preferably, the forward edge of the extension 21e is provided with a resilient sealing gasket 112 which, in the normal position bridges between the extension 2le and the main desk top 21 at approximately the level of the upper surface of the desk top 21 in order to effectively close off the gap, while allowing electrical lines, cables or other wiring to pass through. A further preferred feature of the present desk structure is a wiring storage bin 113 illustrated in Figures 1 and 12. This comprises an upwardly open generally channel section main portion 114, preferably having a vertical rear wall 116 formed with a hook shaped portion 117 at its upper end so that the bin can be simply hooked onto the side of the beam 82a as seen in Figure 2. An intermediate portion 118 of the bin, preferably of reduced length as compared with the main portion 114 comprises a platform portion 119 with an upwardly extending forward edge 121. The portion 119 is secured, for example by spot welding to the rear face 116 at a flange portion 122. Preferably, a front portion 123 of the bin 113 is upwardly and outwardly bevelled toward a front wall 124. This bin arrangement allows for storage of bundles of cable or other wiring which would otherwise tend to trail on the floor or occupy desk top space. A preferred form of the present invention includes privacy panel structure 125. Figure 7 illustrates one form of support structure 126 for the privacy panel structure 125. Preferably, a set of two of these support structures 126 supports each panel structure 125. The support structure 126 comprises a tubular casing 127 provided on one side with clamp structure for clamping on grooves 84 of the beam 82. The clamp structure comprises an upper hook portion 128 extending through a slot in an inner side wall of the casing 127 and a lower clamp portion 129 riding vertically in a vertically extending slot 131 in the lower portion of the inner face. A compression spring 132 acts between the portions 128 and 129, and is located on a threaded shaft 133 having an upper tool engaging head 134 engaging the upper clamp portion 128 and a nut 136 engaging non-rotatably on the lower portion 129. For example, the nut 136 may be square and may engage a planar side surface of the hook portion 129. A shaft 137 passes through the casing 127. At its lower end, the shaft 137 retains a cap portion 138 which may be, for example, threaded on the shaft 137, and engages a plate 139 secured in the lower end of the casing 127. At the upper end, the shaft 137 retains, for example threadedly, a cap 141 which retains a plate 142. The plate 142 is apertured at 143 to allow access to the tool for engaging portion 134 of the clamp structure in order to tighten or loosen the engagement of the portions 128 and 129 in the grooves 84 of the beam 82 for the purpose of securing the support structure 126 to the beam 82 or for removing it or the structure 125 moving along the beam. Secured on the plate 142, for example with screws 144, is a length 146 of the extrusion 41 of the cross-section shown in Figure 13. A preferred form of privacy panel, shown in Figure 6 comprises a rectangular frame formed by bending an extrusion, for example of aluminium, having the cross- sectional profile indicated at 147. In order to provide such rectangular frame, a length of the extrusion 147 is notched on its inner side at four portions, and the notched extrusion is then bent inwardly at 90° at each notch. A joining strip of a rectangular cross section, having been preinserted into one end of a generally rectangular channel section portion 148 of the extrusion may then be slid to bridge between the adjoining ends of the bent extrusion and may be secured in place, for example with screws to form a rigid rectangular frame structure. A pair of holes are then bored through one side of the rectangular frame, to provide entry for a pair of sleeve structures 149 comprising upper and lower sections 149a and 149b which clamp between them a flange portion 147a of the extrusion 147. Into each sleeve 149 is inserted a threaded rod 151, one end of which engages threadedly in a rectangular nut 152 pre-inserted in the rectangular channel section portion 148. A washer 153 and nut 154 are then applied over the free end of the rod 151, as seen in Figure 6, and tightened up in order to clamp the sleeve portions 149a and 149b compressively on flange 147a between the nuts 152 and 154. In assembly of the desk structure, the privacy panels 125 as shown in Figure 6, having a pair of the depending sleeves 149 are used together with a pair of the support structures 126 as shown in Figure 7. The tubes 149 are inserted into the open upper ends of the fluted columns 146, as shown in broken lines in Figure 6, so that the lower side of the extrusion 147 forming the frame of the privacy panel rests on the upper end of the column 146. As seen in Figure 6, panel elements 156 are supported on each side of the rectangular frame defined by the extrusion 147. Each panel element 156 has a hook section extrusion 157 secured on the lower side of its inner face, having a hook portion 158 which engages behind a lip 159 provided on the extrusion 147. A resilient retainer member 161 is secured to the rear face of each panel 156 adjacent its upper edge. The resilient retainer member 161 has a generally U-shaped rearwardly extending catch portion 162 which engages resiliently on the lip 159 in a manner generally similar to the U-section catches which are the subject of applicant's U.S. patent 4,905,428, dated March 6, 1990. In the case of the privacy panel structures shown in Figure 2, support structure 126a is employed, which is generally similar to the structure described above with reference to Figure 7, except the support plate 142a is of sufficient length to extend rearwardly to clear the rearward edge of the desk extension 21e. As will be appreciated, usually a number of sets of the desk top structures similar to the desk tops 21a and 2lb, together with gables such as the gables 22a, 22b and 22c with or without the C-section legs 101 will be connected in common to a single beam, especially in office environments where it is desired to provide a number of adjoining workstations or a number of workstations in proximity to one another. For example, the arrangement of Figure 1 may be modified in that the beam 82 and/or the beam 82a may extend continuously through a number of workstations. Two adjoining workstations are indicated partially at 21f and 21g in Figure 1. As seen in Fig. 7, the internal profile of the beam 82 includes upper and lower laterally extending grooves or pockets 166 and 167 adapted to receive rectangular connector plates which can be inserted end wise into the beams 82 to fit snugly in the pockets 166 or 167 in order to connect lengths of the beam extrusion 82 together. For example, using plane rectangular connector plates, two lengths of the extrusion 82 can be joined together in line, or by using T form or cruciform plates, three or four pieces can be joined at a T junction or four point connection. The connection may if desired be made more secure with screws passed through the upper or lower faces of the beam extrusions 82 to engage the connector plates. As a result various lengths and configurations of the beam structure 82 may be employed. As noted above, the gables 22 and legs 101 may be positioned at any point along the beam, and longitudinal adjustment along the beam 82 is readily possible, as well as longitudinal adjustment of the gables 22 at legs 101 relative to the desk tops 21 by virtue of the slidable connections with the beam 82 and with the rails 52. As will be appreciated therefore, the desk structure exhibits great versatility in its installation and configuration. In particular, in a given installation, it is relatively easy to position the gables 22, so that their lower openings 36 coincide with a floor outlet, receptacle or the like whereby wiring may be passed upwardly through the gables 22, so that the wiring is concealed neatly and confined within the gables 22. Figures 14 to 19 illustrate a modified form of drive whereby all the column members connected to a desk top rise and fall in unison. Figure 14 shows a generally L-shaped desk top 21c consisting of a main desk top portion 21d and an integral return 21e. The main portion 21d is supported on two parallel gables 22d and 22e, one adjacent each end of the main portion 21d, and the return portion is supported on a gable 22f adjacent its end remote from the main portion 21d, the gable 22f being disposed at right angles to the gables 22d and 22e. As with the embodiment described with reference to Figures 1 to 13, the gables 22d and 22e are connected to a beam 82b through clamps 87 engaging pairs of slots 88 on the side panels of the members 22d and 22e and engaging in channel section grooves 84 in the beam 82b. A cross beam 82c is connected transversely to beam 82b, for example using a connector element 87 engaging in the channel section grooves 84 in the lateral face of the beam 82b and in a pair of slots similar to the slots 88 formed in an end plate (not visible in Figure 14) of the cross beam 82c. The gable 22f similarly connects to the cross beam 82c through a clamp member 87 engaging in the channel section grooves 84 provided in the lateral face of beam 82c and in a pair of slots 88 formed on the inner side of the gable member 22f. In a typical installation, the beam 82b, for example, may be considerably longer than illustrated in Figure 14, and may have a series of desk tops similar to the desk top 21c connected to it at intervals. Along side each desk top may be provided a cross beam similar to cross beam 82c, or adjacent pairs of desk tops may be connected on opposite sides of common cross beams 82c, each cross beam 82c being connected to one or to a pair of return-supporting gables similar to the gable 22f. Each cross beam 82c may be connected to a main beam 82b through clamps similar to the clamp members 87. Alternatively, the main beam may be formed from sections joined together end to end through T-shaped connector plates as described above wherein a cross beam 82c is connected at each T branch. As shown in more detail in Figures 15 to 17, the vertical adjustment mechanism of the embodiment of Figures 14 to 19 comprises column members 39 supported on threaded shafts 168 similar to the shafts 68 described above. In this instance, however, the lower ends of the shafts 168 are fixed relative to the gable 22f, for example by being pinned through holes 169 passing through corresponding holes in socket members 171. The lower ends of the members 171 are pinned, for example through pins passed through holes 172 and into the gable structure adjacent the brace portions 173 on which the socket members and threaded shafts 168 are supported. The shaft 168 engages a tapped sleeve 47 secured in the lower end of the column 39, whereby rotation of the column 39 about the axis of the threaded shaft causes the column 39 to rise or fall along the axis of the shaft 168. A bushing or guide 174 is secured to the upper end of the shaft 168 and engages rotatably on the generally cylindrical inner surface of the column member 39 and maintains the column member 39 in axial alignment with the shaft 168 so that the threaded surface of the shaft 168 does not tend to rub or wear on the inner side of the column 39. The upper end of each column 39 connects through a bearing shaft 176 shown in more detail in Figure 18 to the underside of the desk top 21c. The bearing comprises a cylindrical shank 177 which is secured in the upper end of the column 39 to rotate as a unit with the column 39. For example, a pin may be passed transversely through a bore 178 in a lower end of the shank 177 and through corresponding bores formed through the side walls of the column member 39. Alternatively, the shank member 177 may be provided with a plastics material fitting which is itself press-fitted into the open upper end of the column member 39 and resists withdrawal of the shank 177 from the column member or rotation relative to the column member. The upper end of the shank 177 is provided with an annular race 179 on which balls 181 run. An upper portion 182 of the bearing runs on the balls 181. The lower and upper portions 179 and 182 are provided with cooperating annular shoulders 183 and 184 through which the lower and upper portions 179 and 182 are snap locked together, so that the upper portion 182 cannot be separated from the lower portion 179 except by destroying the integrity of the bearing. The upper portion 182 is generally circular, and is formed with a series of holes 184 adjacent its perimeter through which fasteners such as screws can be passed upwardly to fix the upper portion 182 to the underside of the desk top 21c. Each pair of column members 39 in a gable such as gable 22f are linked together by a non-slipping positive drive, such as a toothed timing belt 186, the teeth of which engage on the external grooves or flutes 187 of the fluted column members 39. A pair of grooves 188 are machined into the outer side of each column member 39 at a spacing approximately the width of the belt 186. A pair of O-rings 189 are fitted into these grooves to locate the belt 186 and prevent it creeping longitudinally of the column 39. The positioning of the pair of grooves 188 and O-rings 189 is the same on each column member 39, so that, throughout the system, the belts 186 extend horizontally parallel to one another. At least one of the column members of the system is adapted to be rotated by a crank or like tool 191 applied through an opening 192 formed through the desk top 21c. In the example illustrated, the opening 192 is provided in alignment with the column member 39 in the gable 22d spaced rearmost from the front edge of the desk portion 2Id, considering the front edge as the side adjacent the beam 82b. As seen in Figure 18, the shank portion 177 is formed internally with a hexagonal or other prismatic socket 193 accessible through an opening 194 in the upper or fixed bearing portion 182. The lower end of the crank tool 191 has an Allen key or like prismatic section keying with the socket 193, so that the column 39 can be rotated by engaging the crank 191 in the socket 193 and manually rotating the crank tool 191. The torque exerted by the tool 191 is transmitted progressively from the gable 22d to the gable 22e and in turn to the gable 22f through the belt 186 and through a series of chain and sprocket drives 169a and 169b which run along the outer side of the desk top 21c on the front or outer edges remote from the position normally occupied by the user on the inner or rear side of the desk. As seen in Figure 19, the drives 169a and 169b comprise sprockets 197 each secured to a shaft 198, the lower end 199 of which is secured to the shank portion 177 of a bearing 176 and to the upper end of a column 39, for example by means of pins passed transversely through bores 201 passing through the shaft 199, shank 177 and through the upper end of the column 39. An endless chain 202 passes around each adjacent pair of the sprockets 197. Desirably, the sprockets 197 and chains 202 constituting the drives 196a and 196b, respectively, are housed in elongated recesses 203 formed for example by routing in the underside of the desk top 21c, and desirably the sprockets 197 and 202 are isolated from the underside of the desk top 21c by elongated plate-like guards or covers interposed between the fixed or upper portion 182 of the bearing and the desk top 21c and secured to the underside of the desk top by means of the screws or other fasteners passed upwardly through the upper or fixed bearing portion 182. In operation, when the tool 191 is applied and rotated to turn the rearmost column member 39 in gable 22d, the belt 186 transmits the torque to the other column member 39 in gable 22d hence through the drive 196a to the forward column 39 in gable 22e, rearwardly through the belt 186 to the rear column 39 in gable 22e and hence through the drive 196b and belt 186 in gable 22f to the columns 39 in gable 22f, so that by rotation of the tool 191 all the columns 39, together with the desk top 21c can be caused to rise or fall in unison.

Claims: Claims 1. Desk structure comprising a longitudinally extending beam, a desk top, support members extending laterally of the beam and adapted to rest on a floor and connect with the desk top and to support the desk top thereon, and coupling members coupling the support members to the beam to be slidably adjustable longitudinally along the beam, and wherein at least one of the support members comprises a hollow casing having a side panel detachable to allow access to the interior of the casing, and a lower floor engaging side having an opening therein. 2. Desk structure as claimed in claim 1 wherein said at least one support member comprises vertically adjustable means whereby the height of the desk top can be adjusted, preferably in the form of a column member extending upwardly from said casing and including screw jack means within the casing for vertically extending and retracting said column member. 3. Desk structure as claimed in claim 2 wherein each casing has two of the column members each provided with screw jack means, and including a drive interconnecting said screw jack means whereby they extend and retract the column members in unison. 4. Desk structure as claimed in claim 3 wherein each screw jack means comprises a screw member fixed to the casing and engaging a threaded member connected to each said column member, and wherein each column member is connected through a bearing to the desk top, and the drive connects the column members. 5. Desk structure as claimed in claim 4 wherein an upper end of at least one of the column members comprises a tool- receiving socket, and the desk top comprises an aperture in register with the socket, whereby a tool may be applied to the socket to rotate the column members. 6. Desk structure as claimed in claim 3, 4 or 5 wherein the outer side of each column member comprises longitudinal grooves, and the drive comprises a toothed belt engaging positively with said grooves. 7. Desk structure as claimed in any of claims 3 to 6 wherein each support member comprises a hollow casing, and including secondary drives, preferably a sprocket and chain drive extending in a recess formed in an underside of the desk top, interconnecting progressively between column members of adjacent support members whereby all said column members connected to said desktop rotate in unison. 8. Desk structure as claimed in claim 2 wherein the screw jack means comprises a thumb wheel extending through an opening in a side panel of said casing whereby the jack means can be operated manually, and preferably including a motor for operating said screw jack means. 9. Desk structure as claimed in any preceding claim wherein the casing is generally rectangular. 10. Desk structure as claimed in any preceding claim wherein the desk top has on its underside a longitudinally extending rail of channel section with re-entrant sides, and including releasable connector members, preferably quarter turn connectors, connecting between the support members and said rail. 11. Desk structure as claimed in any preceding claim wherein one support member comprises a generally C-shaped leg comprising a laterally extending floor engaging portion and an upper desk top engaging portion vertically adjustable relative to the floor engaging portion. 12. Desk structure as claimed in any preceding claim wherein the beam has opposite side faces each provided with a plurality of vertically spaced longitudinally extending grooves of channel section of which the sides have re¬ entrant lips. 13. Desk structure as claimed in claim 12 including a wiring storage bin comprising an upwardly open channel section receptacle having a rearwardly directed hook portion adjacent an upper rear edge for engaging a groove of the beam. 14. Desk structure as claimed in claim 13 wherein the bin comprises an auxiliary support portion comprising a platform connected to a rear channel side and extending forwardly to an upstanding lip. 15. Desk structure as claimed in claim 12, 13 or 14 including clamp members, preferably having a concave recess in their vertically outer sides for receiving wiring, for attachment of structure to the beam, each clamp member having clamp portions having laterally projecting hook portions for engaging the slots and tensioning means for urging the clamp portions towards each other. 16. Desk structure as claimed in claim 15 wherein each support member comprises a lateral side having two vertically spaced slots therein and the clamp members constitute the coupling members and each clamp portion has two of said hook portions laterally opposed to one another for engaging said grooves of said beam and the slots of the support members respectively. 17. Desk structure as claimed in claim 15 or 16 including privacy panel structure adapted to be supported above and generally parallel to the beam and comprising a rectangular panel, a pair of the clamp members each supported in a tubular casing, whereby the tubular casings are attached to the beam, a plate connected to the upper end of each tubular casing, and a column member connected to and extending upwardly from each plate and supporting the panel thereon. 18. Desk structure as claimed in any preceding claim including a desk top extension portion parallel to and spaced from a rear edge of the desk top adjacent the beam and supported through hinge connections to transversely extending support members attached to the underside of the desk top, whereby the extension portions pivot upwardly rearwardly away from the desk top. 19. Desk structure as claimed in claim 18 including a resilient gasket attached to an upper forward edge of the extension portion and bridging the space between the upper surfaces of the desk top and extension.

Applicants: SYKES CHRISTOPHER C, SYKES, CHRISTOPHER, C.
Application year: 1995
Main classification: A47B13
IPC codes: A47B13, A47B17