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. 11, 2001
Filed:
Sep. 21, 2000
Louis C. Harms, Evanston, IL (US);
Zilek Liberfarb, Morton Grove, IL (US);
Parker-Hannifin Corporation, Cleveland, OH (US);
Abstract
The technical field of the invention generally concerns electronically controlled hydraulic valves adapted for use in electro-hydraulically controlled automotive transmissions. The proportional pressure control valve,includes a hollow cage,pierced by cage tank ports,, cage clutch ports,, and by cage pump ports,. The cage pump ports,receive fluid from a pump. The cage clutch ports,supply fluid to a hydraulic actuator, such as that for an automotive clutch. The cage clutch ports,. supply the fluid at a pressure that is proportional to an electrical control signal applied to a solenoid coil,of the valve,. The cage tank ports,return fluid from the valve,to a tank from which the fluid circulates back to the pump. Located in the cage,is a main spool,that is movable laterally relative to the cage,for controlling a flow of hydraulic fluid between the cage clutch ports,and either the cage pump ports,or the cage tank ports,. An electromagnetically operated pilot valve regulates a control pressure of fluid applied to a control pressure surface,at one end of the main spool,. A feedback pressure passage,, having a feedback restriction orifice,, couples the pressure of fluid in the cage clutch ports,to a feedback pressure surface,at the opposite end of the spool. The feedback restriction orifice,restrains the rate at which fluid may flow between the cage clutch ports,and the feedback pressure surface,. One embodiment of the valve,includes a pressure spike suppression check valve,for relieving any abnormally high pressure that occurs in the cage clutch ports,.