The article presents a development of new machine safety devices, which provide protection of operating elements from overload. Theoretical calculations have been made in order to determine the optimum design, kinematic and dynamic parameters of safety devices. A test bench has been developed and experimental investigations have been conducted in order to determine basic parameters of overload clutches.Keywords: safety devices; overload clutch; design and kinematic parameters; dynamic load; test bench; operating elements of machines. J -equivalent drive moment of inertia; 21 J -equivalent drive half coupling moment rtia; 22 J -equivalent driven half coupling moment of inertia; 3with a screw operating element drive has been developed ( Figure 3). This model is described by the following set of equations: