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. 16, 1991
Filed:
Sep. 21, 1989
Dane A Hoiberg, Irvine, CA (US);
Other;
Abstract
A battery-powered, liquid-detection alarm and shut-off system includes an elongated sensor, an electronic controller, and a spring biased shut-off valve assembly. The sensor comprises two partially exposed conductors separated by protruding ridges of insulation. The protruding-ridge configuration enables the sensor to detect small quantities of surface water and yet be insensitive to humidity. The electronic controller maximizes battery life and protects against false alarms caused by electrical interference. The shut-off valve assembly comprises a 1/4-turn ball valve and a valve-actuating assembly. The valve is set by being manually cocked to an open position, engaging a lever actuated cam and preloading a valve shut-off spring. The valve is then closed by momentarily passing an electrical current through a temperature-activated memory-shaped spring located on the valve assembly. The current is supplied by the electronic controller in response to detection of liquid by the sensor. The heating of the spring from the induced current causes the tension of the memory-shaped spring to increase, releasing the lever actuated cam and permitting the preloaded valve shut-off spring to close the valve.