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. 24, 1987
Filed:
Feb. 28, 1986
Masaki Nakano, Kawasaki, JP;
Sigeaki Yamamuro, Zushi, JP;
Hiroyuki Hirano, Yokohama, JP;
Keiju Abo, Yokosuka, JP;
Haruyoshi Kumura, Yokohama, JP;
Nissan Motor Co., Ltd., Yokohama, JP;
Abstract
A fluid pressure control valve for a hydraulic actuator has a valve body having a valve bore and a fluid port for discharging a fluid toward the hydraulic actuator, and a spool slidably received in the valve bore. The spool has a cylindrical spool section slidably fitted in the valve bore for closing the fluid port and a tapered spool section having a conical shape for opening the fluid port through annular open clearance of a variable area between the concial surface of the spool and the cylindrical surface of the valve bore. Between the cylindrical ad tapered spool sections, there is formed an annular groove or an annular face forming a step for preventing particles of dust suspended in the fluid from being bitten between the tapered spool section and the cylindrical surface of the valve bore by traping the particles. Furthermore, a radial groove is formed in a side wall of the fluid port in order to prevent a sudden change in the opening area which would be otherwise caused by an abrupt change of the spool contour due to the annular groove or the annular face.