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:
Apr. 27, 2004
Filed:
Apr. 24, 2002
James A. Krisher, Fort Wayne, IN (US);
John Allen Grogg, LaOtto, IN (US);
Torque-Traction Technologies, Inc., Maumee, OH (US);
Abstract
A hydraulically actuated torque-coupling device is provided for selectively actuating a secondary drive axle of an All-Wheel Drive motor vehicle when wheel slippage occurs with a primary axle. The torque-coupling device comprises a housing, an input shaft and an output shaft both rotatably supported within the housing, a selectively engageable friction clutch assembly for operatively coupling the input shaft to the output shaft, and hydraulic clutch actuator. The hydraulic actuator includes a hydraulic pump located within the housing and adapted to generate a hydraulic pressure to frictionally load the friction clutch assembly, and a variable pressure relief valve assembly fluidly communicating with the hydraulic pump to selectively control the hydraulic pressure generated by the pump. The variable pressure relief valve assembly includes an electro-magnetic actuator for selectively varying a release pressure of the pressure relief valve assembly based on a magnitude of an electric current applied thereto.