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. 04, 1990
Filed:
Mar. 31, 1989
Applicant:
Inventors:
Toshifumi Kakinuma, Sano, JP;
Kiyoshi Hayashi, Takebayashi, JP;
Assignee:
Tokyo Keiki Company Ltd., Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F15B / ;
U.S. Cl.
CPC ...
137554 ; 13762565 ; 25112915 ;
Abstract
A spool of a valve main body is switched and driven by exciting a solenoid coil by supplying a DC or AC voltage. An intensity of the magnetism generated by the excitation of the solenoid coil is detected by a magnetic sensor. When a predetermined sensor output is obtained, an indicator lamp is lit to indicate that the spool has operated correctly. The intensity of the magnetism due to the DC excitation is detected by magnetoresistive devices. The intensity of magnetism due to the AC excitation is detected by a pickup coil or a current transformer.