The speed regulator is a hydraulic closed circuit without any independent power source. It’s composed by a cylinder filled of oil, a rod and its piston, a control valve and a compensation tank. When the rod of the controller is coupled with an external organ and it moves, the piston moves too. In this way the internal unidirectional valve closes and the oil is constricted to move towards the tube to reach the control valve. The speed of the fluid is regulated by the external variable restriction. Bypassing the valve the oil reach another room which is separated by the piston. In the return movement the unidirectional valve opens and the oil comes out without any obstacles and this speeds up the movement. The tank which is located in line or parallel has the function of compensating the spill, the level of the rod and the minimal seepings. The tank rod measure the level of the oil. On request it’s possible to add control valves to the speed regulators: acceleration valves (SKIP) and stop valves (STOP) and the combination of these. These valves normally are opened and commended through air. Through the speed regulators it’s possible to stop or speed up the speed predefined by an handwheel externally located.