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:
Aug. 14, 2001
Filed:
Feb. 03, 1999
Tadashi Yamada, Kariya, JP;
Hiroo Ito, Kariya, JP;
Kabushiki Kaisha Toyoda Jidoshokki Seisakusho, Kariya, JP;
Abstract
A method and an apparatus for preventing a solenoid from being heated by an exciting current. When a hydraulic cylinder is permitted to extend and retract, a controller commands a high-side driver to send a moving current to the solenoid such that a valve body of an electromagnetic valve is moved to a connection position. Subsequently, the controller commands the high side driver to send a maintaining current to the solenoid such that the valve body is maintained at the connection position. The moving current and the maintaining current are pulse waves. The duty ratio of the maintaining current is smaller than that of the moving current.