IE73279B1 - A support device for a chair - Google Patents

Abstract

A support device (1) for an office chair has a central body portion (2) for connection to an adjustment mechanism such as the adjustment box on a vertical spiggot (not shown). A pair of seat support members (10) extend to each side transversely and upwardly for support of a seat (32) figure 5 and for support of an armrest support (21) figure 6 (respectively, not shown). The seat support members (10) are channel-shaped and thus provide for a very high strength support and in addition because they extend upwardly and transversely, they are particularly strong in downward loading. The construction of the support device (1) is also provided with means such as bolt holes (14) to provide anchorage for armrest supports.

Description

A support device for a chair The invention relates to a support device for a chair, and more particularly for a chair of the office type which generally has a central support spindle.

Such chairs may include an adjustment mechanism supported on the spindle and mounted underneath the seat and which supports the seat. This mechanism generally has a boxshaped housing which supports the seat of the chair and there may be an L-shaped bracket at the front of the housing which may in turn be used for supporting an armrest of the chair. One problem with the presently available support devices is that they are often not capable of providing sufficient support to withstand the stresses which are involved in everyday use of a chair. For example, some of the standards compliance tests which are required of such chairs include, for example, a downwards static load of 1200 on an armrest.

The invention is directed towards providing a support device for a chair which has improved strength to withstand the stresses that are required of it.

Another object of the invention is that the support device be simple to manufacture, and simple to install when assembling a chair.

According to the invention, there is provided a support device for a chair, the device comprising :a pair of interconnected seat support members extending in opposed directions, each seat support member having a channel-shaped cross-sectional configuration for at least a substantial part of its length; - 2 73279 means on each seat support member for engaging the underside of a chair seat with the seat support members extending transversely with respect to the seat; and means on each seat support member for engaging an armrest support of the chair.

In one embodiment, the seat support members extend transversely and upwardly.

In another embodiment, the seat support members have an inverted channel-shaped cross-sectional configuration.

Preferably the seat support are supported on a central body portion.

In one embodiment, the central body portion comprises means for attachment to a chair adjustment mechanism.

Alternatively, the central body portion is formed from the housing of a chair adjustment mechanism.

Preferably, the means for engaging the chair seat comprises a boss.

In another embodiment, the means for engaging the armrest support comprises a plurality of bolt holes.

According to another aspect, the invention provides a chair adjustment mechanism incorporating a support device.

According to a still further aspect, the invention provides a chair support assembly comprising a support device connected to a pair of armrest supports.

The invention will be clearly understood from the following description of some preferred embodiments thereof, given by way of example only with reference to the accompanying drawings in which :Fig. 1 is a diagrammatic front view of a support device of the invention; Fig. 2 is a plan view from underneath of the support device; Fig. 3 is a front view of an armrest support which may be connected to the support device; Fig. 4 is a plan view of the armrest support; Fig. 5 is a diagrammatic rear view showing the support device, in use; Fig. 6 is a plan view from underneath showing portion of the support device, in use; Fig. 7 is a side view showing the support device, in use; and Fig. 8 is a diagrammatic rear view showing an alternative construction of support device, in use.

Referring to the drawings, and initially to Figs. 1 to 7 inclusive, a support device 1 for a chair is shown. As shown most clearly in Figs. 1 and 2, the support device 1 comprises a central body portion 2 which is for engagement with the end of the housing for an adjustment mechanism which is mounted underneath the seat of an office chair. The central body portion 2 comprises an upper plate 3 of rectangular shape in plan view and which has a socket for reception of a T-piece at the end of the spring-bias unit of an adjustment mechanism. Thus, when the support device of 1 is secured to the front of an adjustment mechanism, it forms an integral part of its operation. The central body of portion 2 also includes a downwardly depending flange 5 at its front end and it has an opening 6 at its rear end for reception of the adjustment mechanism housing.

The support device 1 further comprises a pair of seat support members which extend in opposed directions from the central body portion 2. These directions are transverse with respect to the direction by which the device 1 is connected to the underside of the seat and to the adjustment mechanism. Each seat support member 10 comprises an upper plate 11 which extends transversely and upwardly at a 9° angle from the central body portion 2. A pair of downwardly-depending flanges 12 extend from the upper plate 11 and the lower edge of the flanges 12 extend transversely and upwardly at an angle of 20°. Thus, each seat support member 10 is channel-shaped in cross-section, therefore providing very strong support·. The upper plate 11 of each seat support member 10 includes an upwardlyextending boss 13 having a central aperture for engagement with a seat of a chair. In addition, each upper plate 11 includes a pair of bolt holes 14 and corresponding weld nuts 15 which provide for engagement with armrest supports.

Referring in particular to Figs. 3 to 7 inclusive, the manner in which the support device 1 is used is now described. In Figs. 3 and 4, an armrest support 20 is illustrated and this comprises a flat bar arm 21 having a pair of bolt holes 22 corresponding to the bolt holes 14. The outer extremity of the arm 21 is welded to a longitudinally-directed support bar 23 for an armrest. The view of Fig. 3 shows the angle at which the armrest support 20 is mounted, in use.

Referring in particular to Figs. 5 to 7, the support device 1 is shown connected to a chair adjustment mechanism 30 which has a lever 31 extending to one side for adjustment of the gas spindle of the chair. The support device 1 supports a seat 32 which rests on the bosses 13 and is secured to them by bolts, not shown. In addition, the armrest supports 21 are secured in place on to the lower surface of the upper plate 11 of each seat support member 10 and each of these supports an armrest 33. The manner in which this connection is made is shown most clearly in Fig. 6 and in Fig. 7. A backrest support 35 for the chair is also shown.

It will be appreciated that because of the manner in which the support device 1 is constructed, an extremely strong foundation is provided for withstanding the stresses arising out of forces which may be applied to an armrest. In addition, the support device provides for reliable support of a seat. This is achieved because of the crosssectional channel shape and the fact that the support members extend transversely. The fact that the seat support members extend upwardly in addition to transversely is also of help in providing additional strength. It will also be appreciated that the support device of the invention is of extremely simple construction and is thus inexpensive to produce.

The invention is not limited to the embodiments described. For example, as shown in Fig. 8, the seat support members need not necessarily be of inverted channel-shaped in cross-section. In Fig. 8, an alternative support device 40 of the invention is shown connected to an adjustment mechanism 41. The device 40 has a pair of seat support members 42 which have lower plates and upwardly-extending flanges and a boss 43 which extends from the lower plate. In this embodiment, the armrest support 21 is bent intermediate the ends so that it is secured in place against the lower plate of the seat support member 42. The support device of the invention need not necessarily include a central body portion. This may be provided by the adjustment mechanism, in which case the support device would comprise a pair of support members which are welded or secured in some other way to the adjustment mechanism. In practice, such a support device would be provided as an integral part of an adjustment mechanism. The support device may of course be provided in an assembly which includes the armrest supports, and indeed the armrest supports may be integral with the seat members.

Further, the seat support members need not necessarily have a channel-shaped cross-sectional configuration along their full length - a substantial part of the length sufficient to provide the necessary strength would suffice.

Claims (11)

1. A support device for a chair, the device comprising : a pair of interconnected seat support members extending in opposed directions, each seat support member having a channel-shaped cross-sectional configuration for at least a substantial part of its length; means on each seat support member for engaging the underside of a chair seat with the seat support members extending transversely with respect to the seat; and means on each seat support member for engaging an armrest support of the chair.

2. A support device as claimed in claim 1, wherein the seat support members extend transversely and upwardly.

3. A support device as claimed in claims 1 and 2, wherein the seat support members have an inverted channel-shaped cross-sectional configuration.

4. A support device as claimed in any preceding claim, wherein the seat support members are supported on a central body portion.

5. A support device as claimed in claim 4, wherein the central body portion comprises means for attachment to a chair adjustment mechanism.

6. A support device as claimed in claim 4, wherein the central body portion is formed from the housing of a chair adjustment mechanism. A support device as claimed in any preceding claim wherein the means for engaging the chair seat comprises a boss.

7. 8. A support device as claimed in any preceding claim, wherein the means for engaging the armrest support comprises a plurality of bolt holes. 10

8. 9 A chair adjustment mechanism incorporating a support device as claimed in any preceding claim.

9. 10. A chair support assembly comprising a support device as claimed in any preceding claim connected to a pair of armrest supports.

10. 15

11. A support device substantially as hereinbefore described, with reference to and as illustrated in the accompanying drawings. Dated this 23rd day of April 1993