Abstract: Relative rotational movement is allowed between two longitudinally extending articulated members connected by a joint while at the same time longitudinal relative translation of the members is restrained. Each joint is composed of two substantially identical halves with each half having parallel semi-cylindrical slots provided therein cooperating with the semi-cylindrical slots of the opposite half to form cylindrical apertures for receiving the longitudinally extending articulated members. Each semi-cylindrical slot has a circumferential groove about its periphery. The grooves of cooperating semi-cylindrical slots meet to provide a complete circumferentially extending groove for receiving a pin inserted through the member received in that aperture. In this manner, rotary motion of the longitudinally extending member is allowed to a full 360.degree..