Device for controlling a working machine

In combination with a working machine of the type having a chuck body including a rotary chuck cylinder closed by a cylinder cover to define a substantially closed pressure space, and a chuck piston slidably disposed in the pressure space for displacement responsive to a fluid pressure in the pressure space, a source of fluid under pressure, and means for providing fluid communication between the source and the pressure space, an improved device for controlling the working machine, comprising:

• a pulse generator member axially guided within the chuck body in communication with the pressure space for movement responsive to the fluid pressure at a predetermined level and axially displaceable into an end position;
• switching means provided outside of the chuck body at a spaced location therefrom for switching the machine off;
• stop means connected to said pulse generator and engageable by the chuck piston near end position of the chuck piston so that said pulse generator is also responsive to chuck piston position;
• and a control member displaceably mounted in the chuck body operative to interconnect said pulse generator member and said switching means, whereby, the control member is displaceable upon movement of said pulse generator member into said end position to actuate said switching means to switch off the machine;
• said pulse generator member including piston means having a piston portion slidably guided in the cylinder cover operatively loaded by the fluid pressure in the pressure space and spring means for biasing said piston portion into an equilibrium position.