Patent ID: 6615703
Filing Date: 2003-09-09
Classification: F15B

Abstract:
A hydraulic or pneumatic cylinder including:a bore generally surrounding a chamber having opposite ends; a piston in said bore and co-operating therewith to divide said chamber into a first and a second sub-chamber; a piston rod fixed to and extending from said piston and extending beyond one of said ends; means closing said opposite ends; releasable locking means to retain said piston at a desired location within said bore, said locking means being releasable to permit movement of said piston upon delivery of a fluid under pressure to one of said sub-chambers; and duct means extending from the bore to provide for fluid flow from said second sub-chamber to said first sub-chamber when said locking means is engaged with said piston to retain said piston at said desired location, wherein said duct means is closed when said piston is displaced from said desired location.