Abstract:
A height adjustable work table comprises a work surface and at least three adjustable leg arrangements supporting said work surface. Each leg arrangement comprises a curved leg supported in a leg bracket attached beneath the work surface. Each leg bracket is an open channel having predetermined support positions for engaging the curved leg with fasteners for releasably securing the leg in any of the support positions.

Description:
FIELD OF THE INVENTION 
     The present invention relates to adjustable height tables and in particular, relates to adjustable height tables for office desks, work tables and conference tables. 
     BACKGROUND OF THE INVENTION 
     There are many examples of height adjustable tables for use in association with a work station. Computer stations are, perhaps, the best examples of work surfaces which are height-adjustable and can include either a mechanical counter-balancing arrangement, electrical drive arrangements or hydraulic arrangements for controlling the height of the work surface. There are also many telescopic legs for providing variable heights. The present invention provides a simple mechanical arrangement for varying the height of a work surface, such as a table or mobile table, which is relatively inexpensive to use, and provides increased stability as the height of the table increases. 
     SUMMARY OF THE INVENTION 
     A height adjustable work table, according to the present invention, comprises a work surface and at least three adjustable leg arrangements supporting the work surface. Each leg arrangement comprises a curve leg supported in the leg bracket attached beneath the work surface. The leg bracket is an open channel having predetermined support positions for engaging the curved leg with means for releasably securing said leg in any of the support positions. 
     According to an aspect of the invention, the curved leg is angled outwardly at the top thereof and is integral with a generally vertical lower section which terminates within the downward projection of the work surface. 
     According to a further aspect of the invention, each leg arrangement increases the support base as the height of the table is increased. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the invention are shown in the drawings, wherein: 
     FIG. 1 is a perspective view of a height-adjustable table having two opposed leg pairs; 
     FIG. 2 is perspective in view of the table in FIG. 1; 
     FIG. 3 is an inside view of the table of FIG. 2; 
     FIG. 4 is a side view of the paired leg arrangement; 
     FIG. 5 shows details of the securement of the curved leg to the channel bracket; 
     FIG. 6 is a side view of a single leg arrangement; 
     FIG. 7 is an end view of the leg of FIG. 6; 
     FIG. 8 is a further side view of the single leg arrangement; 
     FIG. 9 is a front view of the single leg arrangement; 
     FIG. 10 shows the single leg arrangement secured to a generally triangular conference table; 
     FIG. 11 is a partial perspective view of the single leg arrangement; and 
     FIG. 12 is a side view of a single leg arrangement illustrating the increasing base as the height of the work surface increases. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The height-adjustable table and the paired leg arrangement shown in FIGS. 1 through 4, define a height-adjustable table 2 having work surface 4. At opposite ends of the work surface and positioned slightly inwardly of the edges thereof, are two opposed paired leg arrangements 10. Each paired leg arrangement includes two curved legs 12 with each leg having a curved transition 14, approximately one foot above the base of the leg, which transition joins the generally straight upper section 16 and the generally straight lower section 18. The straight upper section is at an angle relative to vertical and it is received in a similarly angled channel-shaped leg support bracket 30. The generally straight upper leg section 16 allows movement of the leg within the channel-shaped leg support bracket and is securable to this bracket at a number of points, as will subsequently be described. 
     As the leg is moved within the channel-shaped leg support bracket 30, the base of the table increases or decreases. For example, if the leg is moved downwardly the channel-shaped leg support bracket 30, the castor 31 associated with the leg is moved slightly outwardly, increasing the base of the table 2. This is desirable as the height of the table has increased, the base has increased and thus, the stability of the table has been appropriately adjusted. As shown in FIG. 12, the leg 12, even in the maximum height position, is located slightly inwardly of the edge of the work surface, such that the legs are still within the footprint of the work surface defined by the periphery of a downward projection of the work surface. 
     Each channel-shaped leg support bracket 30, as shown in FIGS. 5 and 12, has opposed sides 32 which support the side edges 13 of the leg 12 on the portion of the leg which overlaps with the channel-shaped leg support bracket. The leg 12 is secured to the channel 30 by means of screw fasteners 52 which pass through the rear of the channel-shaped leg support bracket and engage the leg 12. The actual shape of the channel 30 includes inwardly directed surfaces 34 which engage the back surface 15 of the leg with a further strengthening channel or differing recess 36 which extends inwardly of surfaces 34. This stiffens the channel-shaped leg support bracket. 
     As shown in FIGS. 7 and 11, the leg 12 is secured to the leg support bracket 30 at a number of different positions. The back surface 15 of the leg has ports 19 provided therein for cooperation with fasteners 52. These fasteners cooperate with a series of ports 54 provided in the strengthening channel 36. The channel-shaped leg support bracket 30 has a series of ports 54 for adjusting the height in fixed increments. 
     As can be appreciated from FIGS. 11 and 12, there may be a gap at the top of the channel-shaped leg support bracket 30, if the legs of the table 2 are above the minimum position. To provide a more pleasing appearance a cover 50 provides a finished extension for the leg support bracket 30 that conceals what would otherwise be the exposed channel 30 above the leg. The cover 50 is open on the back side and telescopes on the leg 12. The cover 50 is adjusted prior to final securement of the leg to the bracket 30 and the final securement of the leg locks the cover 50 in place. 
     The side view of the single leg embodiment of FIG. 6 and the exploded view of FIG. 11 illustrate securement of the leg 12 to the channel-shaped leg support bracket 30 by fasteners 52. If the leg is released from the channel 30 and adjusted to provide an increase in the height of the table, the leg moves slightly outwardly as indicated by arrow 23 (see FIG. 12). This increases the base of the table and the stability thereof. If the height of the table is decreased, the bottom of the leg moves slightly inwardly as indicated by arrow 21. The curved leg allows the leg support bracket 30 to be near the edge of the work surface with the leg angled outwardly. The curved transition 14 of the leg then joins with a vertical segment to maintain the base of the leg within the footprint of the work surface. 
     The single leg embodiment of FIGS. 6 through 12 includes a connecting strut or gusset 40 which is secured to the back of the channel-shaped leg support bracket 30 and is also fastened to the work surface support bracket 46 as shown in the preferred embodiment, the gusset 40 is a plate member. In the case of the paired leg arrangement 10 of FIGS. 1 through 4, the connecting strut or gusset 40 is continuous between the two channel-shaped leg support brackets. The connecting strut or gusset 40 includes an arched lower surface. 
     The embodiment, as shown in FIG. 1, illustrates a horizontal work surface 4, however, if desired, the rear legs of the table may be secured with a slightly different position increasing the height of the rear edge of the table, relative to the front edge of the table. This then defines an angled work surface which may be desirable for drafting or other applications. It can also be appreciated that the table could be angled upwardly or downwardly from end to end, if desired, by the appropriate setting of the legs 12. 
     The single leg design of FIGS. 6 through 9 is particularly advantageous with respect to tables which do not have a rectangular top surface. For example, the table as shown in FIG. 10, has three separate legs, each of which is disposed at a different angle, relative to the work surface. 
     The present invention provides a convenient cost effective structure for allowing the height of a table to be increased or decreased. It uses a simple mechanical design and it also allows for adjustment of the size of the base as the height of the table increases. The curved lower section of the leg also allows the table to generally stay within the footprint of the work surface and is unobtrusive. Also this design allows the support bracket atop the leg to be placed inwardly of the edge of the table reducing the likelihood of striking it during use. 
     Although various preferred embodiments of the present invention have been described herein in detail, it will be appreciated by those skilled in the art, that variations may be made thereto without departing from the spirit of the invention or the scope of the appended claims.