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. 11, 1993
Filed:
Jul. 29, 1992
Paul D Engdahl, Santa Ana, CA (US);
Roger P Engdahl, Costa Mesa, CA (US);
Other;
Abstract
A safey shutoff valve for insertion into a gas line or other fluid line, that closes in response to an electrical input pulse or to a seismic disturbance. A pivoted flapper arm is held in the open position by a permanent magnet embedded in it. When the magnetic attractive force is reduced enough, the arm swings down by gravity into the closed position and a primary flapper seal element seals the valve seat. Line pressure keeps it closed. The magnetic holding force may be reduced by means of an opposing electromagnet or by the mechanical displacement of a ferromagnetic ball. The valve is manually reset by turning a reset shaft to raise the flapper arm to the open position. The reset shaft also raises a secondary flapper to uncover a small bypass tube to bleed off any residual line pressure; this bypass is automatically closed when the valve closes. No standby power is required.