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:
Mar. 05, 1991
Filed:
Jun. 13, 1990
Kazunori Yoshino, Kobe, JP;
Naotaka Dohke, Akashi, JP;
Shin Caterpillar Mitsubishi Ltd., Tokyo, JP;
Abstract
A main poppet body of a logic valve receives inlet pressure at first and second ends. A flow-restricting orifice between the first and second ends produces a differential pressure between the two ends when inlet fluid is permitted to flow from the second end. The main poppet body is normally resiliently seated against a seat. A pilot poppet body, movable in the main poppet body, seats against a seat in the main poppet body. The pilot poppet body, when sealed to its seat, seals the fluid at the second end of the main poppet body from flowing. Thus, equal pressures exist at opposed ends of the main poppet body, and the main poppet body remains in its sealing position. An external source of controllable pilot pressure acts on the pilot poppet body to unseal it from its seat. This permits a flow of inlet fluid from the second end of the main poppet body, and produces a pressure reduction at the second end. The differential pressure between the first and second ends of the main poppet body tends to move the main poppet body out of its sealing position, and consequently to permit an inlet flow past the seat of the main poppet body. This inlet fluid flows to a drain. The position of the main poppet body varies in substantially linear relationship to the pilot pressure applied to the pilot poppet body.