Patent ID: 6345566
Filing Date: 2002-02-12
Classification: F15B

Abstract:
A pressure cylinder apparatus comprising:a hydraulic cylinder structure having a cylindrical wall defining a generally closed left end and a generally open right end; a piston movable axially within the hollow of the cylinder structure; a seal structure between the piston and the cylinder structure defining a fluid pressure chamber within the cylinder structure on the left side of the piston and an unpressurized chamber on the right side of the piston; a fluid pressure fitting communicating with the pressure chamber for connection to a fluid pressure conduit communicating with a coacting fluid pressure device; a piston rod extending through the open end of the cylinder structure and into the unpressurized chamber for connection to the right side of the piston; a piston contact carried by and fixedly secured to the piston at a location on the piston to the right of the seal structure and within the unpressurized chamber; a cylinder contact disposed at an interior surface of the cylinder structure within the unpressurized chamber for coaction with the piston contact in response to axial movement of the piston in the hollow of the cylinder structure; and an electrical lead connected to one of the piston and cylinder contacts and extending to a location external to the cylinder apparatus for providing an electrical control signal generated in response to engagement of the cylinder contact with the piston contact.