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:
Sep. 14, 1999
Filed:
Apr. 02, 1998
Mark R Nicewonger, Aptos, CA (US);
John W Clove, Santa Clara, CA (US);
Proteus Industries, Inc., Mountainview, CA (US);
Abstract
An apparatus detects an opening in a fluid flow passageway such as occurs when a resistance welding cap which is cooled by the fluid flow becomes accidently detached from a welding machine. Upon detection of an opening, an air-actuated pinch lever is activated to quickly pinch shut flexible fluid inlet and outlet hoses and thereby shut off the fluid flow. Inlet and outlet flow rate sensors provide periodic outputs to a digital computer which determines directions of inlet and outlet flow acceleration. If either the inlet or outlet acceleration changes direction, a baseline inlet or outlet flow rate is set equal to the corresponding current flow rate value to prevent erroneous opening detection due to normal flow fluctuations. If the inlet and outlet accelerations are in the same direction, the baseline values are similarly updated. If the inlet acceleration is positive and the outlet acceleration is negative, it indicates a probable opening. Another test is made to preclude an erroneous detection by determining if the inlet and outlet flow rates are different from the baseline values by more than a predetermined percentage. If so, a valid opening is indicated and the fluid flow is shut off.