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:
Apr. 28, 1992
Filed:
May. 29, 1991
Wayne A Hewitt, LaPorte, IN (US);
Allied-Signal Inc., Morristown, NJ (US);
Abstract
This invention relates to a check valve having a first port connected to a chamber, a second port connected to a source of vacuum having a first fluid pressure and a third port connected to a second fluid pressure. A wall which separates the second port from the third has a plurality of openings therein which allows communication from the first port to the second port. A poppet moves away from the plurality of openings to allow air to flow from the first port to the second port in response to the first fluid pressure. When the fluid pressure in the chamber substantially equals the first fluid pressure, a pressure differential between the first and second pressures moves the poppet toward the plurality of openings to allow the second fluid pressure to further evacuate air from the chamber.