Chair with pivoting keyboard pad

Claim 1

In a chair having a base supported on casters for rolling movement, an upright elongated pedestal extending upwardly from said base, a seat structure mounted on said pedestal for swiveling movement about a vertical centerline of said pedestal, said seat structure having a front edge, a rear edge, two opposed side edges, an upper surface and a lower surface, and an upright back structure extending upwardly from said seat structure close to the rear edge thereof, the improvement which comprises: a substantially L-shaped support structure comprising (1) a lower, elongated, substantially horizontal arm having an inner end located below said seat structure and having an outer end extending beyond one of the side edges of said seat structure, and (2) an upper, elongated, substantially upright arm extending upwardly from said outer end of said horizontal arm and extending alongside said seat structure to a location above said seat structure, a first pivot mounting on the lower side of said seat structure and providing a first vertical pivot axis below said seat structure, the inner end of said horizontal arm being mounted on said first pivot mounting for pivotal movement about said first vertical pivot axis, said first vertical pivot axis being laterally offset from the vertical centerline of said pedestal, a vertical, elongated, first tube sleeved on an upper end portion of said upright arm for vertical sliding movement thereon and for pivotal movement about a longitudinal axis of said upright arm, means for releasably locking said first tube against vertical sliding movement and against pivotal movement with respect to said upright arm, a second pivot mount extending sidewardly from said first tube close to an upper end thereof and providing a horizontal pivot axis extending at a right angle to said upright arm at the upper end thereof, an enlarged pad member of substantially rectangular platelike configuration and having support surfaces on opposite sides thereof, one of said support surfaces having means for supporting a computer keyboard thereon and the other of said support surfaces being substantially planar so that it can be used as a writing surface, said pad member being supported on said second pivot mount for pivotal movement about said horizontal pivot axis between a first position in which one of said support surfaces faces upwardly and a second position in which the other of said support surfaces faces upwardly, said pad member being supported in centilevered fashion relative to said upright arm so that it can extend crosswise of said seat structure, said substantially L-shaped support structure being a second tube and said means for releasably locking said first tube against vertical sliding movement and against pivotal movement with respect to said upright arm comprising a tubular clamping sleeve vertically slidably disposed within the upper end portion of said upper arm, said tubular clamping sleeve having circumferentially spacedapart resilient clamping fingers at its inner end inside said upper arm and frictionally engageable with an inner surface of said upper arm, a vertically movable wedge member engageable with said clamping fingers for moving same outwardly into frictional engagement with the inner surface of said upper arm and a manually operable screw for moving said wedge member into and out of engagement with said clamping fingers.