The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 31, 1995
Filed:
Sep. 08, 1994
Sunpower, Inc., Athens, OH (US);
Abstract
A piston centering system for a free piston machine. The invention uses a centering passageway which is in communication between a work space and a second space which spaces are formed in a housing and are separated by a piston which reciprocates in a cylinder in the housing. The centering passageway has a valve, such as a spool valve formed in the piston and cylinder or a center post, the valve opening in response to the piston being near the center of the opposite limits of its reciprocation. The improvement is the inclusion of a pressure responsive, one way valve interposed in the passageway. The one way valve is oriented to permit the passage of the working gas through the passageway from one space to the other in a direction opposite to a net leakage flow from one space to the other through the annular gap between the piston and cylinder and to prevent substantial flow through the passageway in the reverse direction.