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:
May. 26, 2026
Filed:
Oct. 19, 2022
Sumitomo (Shi) Cryogenics of America, Inc., Allentown, PA (US);
Eric F. Finlayson, Allentown, PA (US);
Qian Bao, Allentown, PA (US);
Mingyao Xu, Allentown, PA (US);
Ralph C. Longsworth, Mount Desert, ME (US);
SUMITOMO (SHI) CRYOGENIC OF AMERICA, INC., Allentown, PA (US);
Abstract
A Gifford McMahon (GM) cryogenic expander provides a structure configured to increase the life of the displacer and stem seals of the reciprocating displacer. The seal includes a ring that is relatively long and thin and uses the pressure difference across the seal, acting behind the ring, as the primary force to bring the ring into contact with the cylinder and stem walls. The pressure difference across the seal ring pushes the ring to one end of the groove, and the friction force pushes the ring in the same direction while it is moving. The sealing force is distributed over a larger area compared with a conventional backed 'O' ring thus reducing the wear rate and increasing the seal life.