GB770833A - Improvements in or relating to adjustable tables - Google Patents

Abstract

770,833. Releasable fastenings. APPLICATIONS INDUSTRIELLES DU TUBE. June 15, 1955, No. 17318/55. Class 44. [Also in Group XIV] A table top 22 is supported by a tube 4 sliding inside a tube 1 attached to a base 23 and provided with internal threading or grooves 2, the tubes being releasably engaged by the engagement of ball. bearings 10, carried by a member 9 associated with the tube 4, with the threading or grooves 2, release being effected by the lowering of a tumbler 13 acted on by a strong spring 16 tending to lock the ball-bearings in position and a relatively weak spring 15 controlled by a lever 19, the spring 15 being of such strength that the tubes are still locked together if there is an appreciable weight on the table when lever 19 is operated. As shown in Fig. 1, a spring is welded to the inner wall of tube 1, thus forming the internal threading, while a bearing 5 is welded to the bottom of tube 4 and carries a rotatable cylinder 9 having holes formed therein along a line identical in pitch and direction'with the spring forming the threading 2, a ball. bearing 10 being loosely mounted in each hole. Radially resilient strips are formed in a sleeve 11 and urge the ball-bearings outwardly. A central rod 14 slides in tube 4 and extends below it carrying at its lower end a tumbler 13, normally, under the action of a spring 16, bearing against the resilient strips. When a lever 19, pivoted to the underside of table top 22, is operated, the action of the spring 16 is nullified and a weaker spring 15 releases the tumbler 13 from abutment of the resilient strips. This permits raising or lowering of the table top unless there is considerable weight on it, in which case the pressure on tube 4 is transmitted through the bearings 5 and radially through the resilient strips against the ball-bearings, preventing accidental displacement of the table top. A simpler form of the invention is shown in Fig. 4, in which the lever construction is modified and the internal grooves in the outer tube are simply circular recesses.