摘要 |
<p>A piston end position limiter for a free piston machine of the type having a piston sealingly reciprocating in a cylinder and separating a work space bounded at one end of the piston from a second space bounded at the opposite end of the piston. The work space and the second space contain a working fluid having an average pressure. A first valve is connected in communication between a fluid reservoir and the work space and is adapted to open only when the working fluid pressure varies sufficiently in one direction from its average pressure. A second position responsive valve is connected between the reservoir and the second space and is operatively linked to the piston for opening in response to the piston reaching a selected end limit of its reciprocation.</p> |