Abstract: In order to improve the operational reliability of an extending system with at least four extending elements (10, 20, 30, 40, 50) which are disposed behind one another and can be moved relative to one another in a direction of extension (B) as well as a direction of insertion (A) opposed thereto between an inserted position and an extended position it is proposed that for coupling the motion of the individual extending elements (10, 20, 30, 40, 50) a coupling arrangement be used which has a coupling element (28) which runs round a return spindle (24, 26), wherein the said return spindle is fixed relative to the middle extending element (20) of a group of three extending elements (10, 20, 30) disposed behind one another and extends perpendicular to the direction of extension, and the said coupling element (28) is movable along a path which is fixed relative to the return spindle (24, 25) and runs round the latter, the coupling arrangement also having two entraining elements (12, 31) which on the one hand are c