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:
Jun. 10, 1980
Filed:
Oct. 11, 1977
Tom Williams, Corona Del Mar, CA (US);
Thompson Manufacturing Co., Los Angeles, CA (US);
Abstract
A metering apparatus for controlling the rate of closure of a pressure-actuated valve of a type normally used in irrigation systems. When a pressure-actuated valve is closing, fluid from a supply line must flow into a pressure-actuating chamber, gradually filling it to force the valve's plug member against its seat. The metering apparatus is a compressible spring through which fluid must flow to enter this pressure-actuating chamber. As the valve closes, it compresses the spring through which the fluid must flow, thereby restricting the rate of flow into the pressure-actuating chamber. This reduction in flow reduces the rate at which the valve's plug member approaches its seat in an exponential manner, allowing rapid closure at first which is reduced considerably as the plug approaches its seat. Such a restricted closure rate prevents pressure shock in the supply line, otherwise known as hammering or chatter, which causes damage and excess wear and tear to the supply line, to the pressure-actuated valve and to other valves in the line.