US Patent 7896102 Pneumatic drive system

A pneumatic drive system (1) in which the movement of an output drive unit (7) of a pneumatic drive (2) is controlled by a control valve (25 and 26) which is connected with the working chambers (12 and 13) of the pneumatic drive (2). The control valve (25 and 26) comprises least one air economy setting (30) setting a choke cross section and a high power setting (29) defining a flow cross section larger than it. An actuator serves to ensure that the control valve is switched over, in a fashion dependent on the air pressure obtaining in the at least one working chamber (12 and 13) from the normally assumed air economy setting (30) into the high power setting (29), when the output drive unit (7) meets with an increased resistance to motion.