Power transmission device for four wheel drive vehicle having an improved differential motion limiting mechanism
Patent 4790211 Issued on December 13, 1988. Estimated Expiration Date: 
December 31, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
December 31, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 3612237 3650364 3894446 Four pinion differential Pneumatic actuation for disc brake assemblies Speed-sensitive differential mechanism Inter-axle differential transfer box unit for a four-wheel drive vehicle Constant four wheel drive vehicle transaxle Power transfer device for four wheel drive Patent #: 4643045 InventorsAssigneeApplicationNo. 06/948218 filed on 12/31/1986US Classes:475/86, By fluid operated mechanical clutch180/247, With manually operated means for disengaging drive to one or more, but fewer than all, of the four wheels475/221Differential or nondifferential planetary combined with differential (e.g., two differentials)ExaminersPrimary: Braun, Leslie A.Assistant: Diehl, Dwight G. Attorney, Agent or FirmInternational ClassesB60K 17/344 (20060101)B60K 17/346 (20060101) Foreign Application Priority Data1985-09-30 JPAbstractA power transmission device for a full-time four wheel drive vehicle has a differential motion limiting device composed of a hydraulic frictional clutch such as a wet multiple disc type clutch. The friction clutch is disposed between a diff-carrier constituting a front wheel differential gear and a ring gear mount casing covering the diff-carrier and arranged coaxially with the diff-carrier. The ring gear mount casing is associated with the diff-carrier in a center differential gear, and the diff-carrier of the front wheel differential gear is associated with the left hand side gear in the center differential gear. Thus, when the friction clutch is engaged, the ring gear mount casing and the diff-carrier of the front wheel differential gear are integrally coupled with each other so that the rotation of the ring gear is transmitted directly to the front wheel differential gear, while the two elements in the center differential gear are integrally coupled with each other to lock the center differential gear. | |
