Pneumatic control device for controlling drive piston for displacement device of Gifford-McMahon cooler, has control valve including control slide that connects control chambers opposite and alternative to high and low pressure ports

摘要

The control device (10) has a drive piston (12) conducted in a guide bushing (20) between control chambers (22, 24) that are connected with a high-pressure port (26) and a low-pressure port (28) for control gases, respectively. The control chambers are alternatively and oppositely moved by pressure, and a control valve (30) includes a control slide (32) that automatically connects the control chambers opposite and alternative to the high-pressure port and the low-pressure port, where the control chambers are arranged depending upon a position of the drive piston in the guide bushing.