Patent ID: 7464544

Claim:
A pressure device attached to an actuator and applying: pressure to an object to be pressurized, the device comprising: a cylinder body, to one end of which an attachment of said actuator is attached and at the other end of which an insertion hole communicating with a housing chamber formed therein is provided; a pressure rod axially reciprocably attached to said cylinder body and provided, at one end of the pressure rod, with a pressure end protruding from said insertion hole; a reciprocating body provided at the other end of said pressure rod and having a diameter smaller than that of an inner circumferential surface of said housing chamber, which is reciprocably housed in said housing chamber; an advance pressure diaphragm provided between said reciprocating body and said cylinder body and partitioning and forming an advance pressure chamber for applying a pressure thrust toward said object to be pressurized; a weight offset pressure diaphragm provided between said reciprocating body and said cylinder body and partitioning and forming a weight offset pressure chamber for applying a weight offset thrust in a direction opposite to said pressure thrust; and an offset adjusting diaphragm provided between said reciprocating body and said cylinder body, partitioning and forming said weight offset pressure chamber along with said weight offset pressure diaphram, and blocking off the weight offset pressure chamber and an ambient-air pressure chamber.