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:
Jun. 22, 1976
Filed:
May. 02, 1973
Richard G Grundman, Coopersville, MI (US);
General Motors Corporation, Detroit, MI (US);
Abstract
A system for controlling pressure of a fluid, specifically the pressure of servo oil delivered to a clutch which determines the torque transmitted by the clutch. The system includes a pump, a pressure regulating valve to provide servo oil at constant pressure from the pump, and a pilot valve controlled by a solenoid responsive to electric current to vary the pressure in a pilot fluid line supplied from the constant pressure line. The oil is delivered from the fixed pressure line to the clutch by a throttling flow control servo valve which can open for rapid filling of the clutch cylinder. This valve is biased to close by the delivered pressure and biased to open by the pilot pressure. It may also be biased to close by a spring, and in this case be restrained from completely closing, so that the valve assumes its minimum area when the delivered pressure is slightly less than the pilot pressure. The clutch supply line is connected to the pump inlet through a by-pass servo valve which opens when the delivered pressure exceeds the pilot pressure, thus equalizing the delivered pressure with the pilot pressure. This valve also provides for rapid emptying of the clutch cylinder.