Abstract: A telescopic supporting post (10) comprises two mutually displaceable telescope members (11, 12), each comprising an inner tubular portion (15, 17) of small diameter and an outer tubular portion (16, 18) of large diameter. Said inner portions (15, 17) are provided with cooperating bearing surfaces (15a, 17a) by which the two telescope members (11, 12) are mounted for axial displacement relatively to each other. Said outer portions (16, 18) are provided with cooperating interengagement means (19, 21) for holding the two telescope members (11, 12) against mutual rotation. In order to avoid the need for a separate turntable when it is desired to permit rotary movement of a chair supported by the post (10), said interengagement means (19, 21) are arranged for releasable engagement with each other, whereby the two telescope members may be rotated relatively to each other, utilizing said bearing surfaces also as rotary bearing surfaces, when said interengagement means are out of engagement with each other.

Abstract: A device for stepwise adjustment of the relative positions of two mutually displaceable members (10, 11) comprises a gear rack (13) formed in one (10) of said members, a pin gear (14) with two pin teeth (15) which is mounted for rotation and limited transversal displacement thereof in the other member (11), and means (23) for spring-biasing the pin gear (14) towards a locking position in which the two pin teeth (15) are located in meshing engagement in adjacent tooth gaps of the gear rack (13). Said spring-biasing means (23) are placed in front of the pin teeth (15), on the opposite side thereof with respect to the gear rack (13), and they include a spring-force applying member (23A) which bears resiliently against both pin teeth (15) when the pin gear (14) is in its locking position.