Patent ID: 6308613
Filing Date: 2001-10-30
Classification: F15B

Abstract:
A fluid pressure cylinder comprising:a cylinder body,a piston provided in said cylinder body and operated by a fluid pressure applied to said piston,a piston rod provided in said cylinder body and extended from said piston, anda lock mechanism provided in said cylinder body and configured to lock said piston rod in a predetermined operation position,wherein said lock mechanism includes an annular lock plate tiltably fitted to said piston rod for locking said piston rod by tilting movement, a fulcrum pin configured to support said lock plate tiltably on said cylinder body around one point of an outer periphery of said fulcrum pin, a biasing device configured to tilt said piston rod in its locking direction around said fulcrum pin, and a returning device configured to return said tilted lock plate in a lock-releasing direction by the fluid pressure applied thereto,wherein said returning device includes a pressure chamber configured to introduce a pressurized fluid and also includes a pressure receiving member having a single annular member operated by the fluid pressure introduced into said pressure chamber for returning said lock plate in said lock-releasing direction, andwherein said pressure receiving member is provided at an inner peripheral end and an outer peripheral end each respectively with a lip seal, and in a state where said lip seal of said inner peripheral end is abutted against an outer peripheral surface of a sleeve which fluid-tightly guides said piston rod and said lip seal of said outer peripheral end is abutted against an inner peripheral surface of said pressure chamber, said pressure receiving member is disposed so as to partition one side of said pressure chamber at a position adjacent said lock plate and is connected to an end surface of said lock plate.