Line force measurement appts. with overload protection for lifting unit - involves tractive tensions or loads continuously transmitted as pressure movement to electric contact unit which finally prevents overload in lifting device

The appts. monitors a load or force on a line, wire, or chain (3) which is located over two spaced wheels (1,2) provided with tracks. The line, wire or chain is tensioned at a fixture point (4) arranged between the racked wheels, the point incorporating a screw union (4c), clamp (4b) and drawbar (4a). The drawbar (4a) and the wheel (1,2) support plates are fixed by welding in a spring beam (5), in one end of which is fixed an extension arm (6) on which is mounted an electrical contact unit (7) and a cable (8). An adjustment screw (8) is fitted in the spring beam (5). The spring beam is provided with a weakening track (10).