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:
Jan. 22, 2008
Filed:
Apr. 21, 2004
John Manhard, Durham, NC (US);
John Manhard, Durham, NC (US);
Medi-Physics, Inc., Princeton, NJ (US);
Abstract
The valve of the present invention provides a one-piece valve stem piston having a piston head and a piston stem. The piston head has a larger diameter than the piston stem. The stem incorporates only a single sliding O-ring in the area that seals the gas in the valve cylinder bore. The valve blocks gas flow by sealing against the positioning each O-ring over the gas flow port. This provides the valve with a low sliding friction upon piston movement. Pilot control air pressure is reduced because of the lower friction and due to the air operating on the larger surface area of the piston head. All materials in the construction of the valve are non-metallic.