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:
Oct. 25, 1988
Filed:
Mar. 09, 1987
William J Haley, Ithaca, NY (US);
Borg-Warner Automotive, Inc., Troy, MI (US);
Abstract
When a pulse width modulated electrical signal is employed to operate an electro-mechanical device, such as a solenoid valve, in a transmission to produce a controlled fluid pressure whose level is proportional to the signal's duty cycle, proper operation at cold temperatures is ensured by varying the frequency of the pulse width modulated signal directly with the temperature of the transmission fluid. By decreasing the operating frequency when the transmission fluid is cold (at which time the fluid may thicken and become heavy since its viscosity will increase), the solenoid valve will be actuated slowly enough to effect flow control through the valve and adequate regulation of the fluid pressure.