Abstract: A bed has movable upper body and knee support sections, and first and second coupling arrangements which each couple a respective drive arrangement to one of the upper body and knee support sections to effect movement thereof between inclined and horizontal positions. Each coupling arrangement includes two telescoping tubes and a locking mechanism for releasably holding the tubes against relative movement, the locking mechanisms of both coupling arrangements being released in response to manual operation of a release handle. Each locking mechanism includes a transverse cylindrical locking element rotatably supported on a first of the tubes for movement between a locking position in which a portion thereof engages a semicylindrical recess in the second tube, and a release position in which the tubes are free to move relative to each other with a portion of the second tube which extends lengthwise thereof sliding within a transverse recess in the locking element.