Caterpillar Tractor Co.

Shairyl I Pearce

Sidney J Audiffred

Willis E Windish

Lowell E Johnson

Gerald B Ireland

Raymond N Erkkila

David W Bump

A safety valve includes a movable piston which functions to prevent actuation of fluid operated drive conditioning clutches of a vehicle transmission unless the selector valve means are passed through a neutral position. Such safety valve spool also acts as a load piston for a pressure modulating relief valve of the system.

Modulating relief valve with hydraulic safety

A compact combination of planetary gear sets together with a torque converter and drive conditioning clutches and brakes provides for a broad range of output speeds in either mechanical or converter drive with a nearly constant small step ratio between speeds and with a relatively small variation of transmitted power throughout a very broad range of output speeds.

Broad range fluid and mechanical power transmission for vehicles or the

A control system for a vehicular drive train including a slipping clutch for proportioning power from a prime mover to implements and a primary output shaft of the vehicle including a manual control conditioned by a manual selector to vary engagement of the slipping clutch through a regulating valve in a first mode of vehicle operation and to regulate acceleration of the prime mover in a second mode of vehicle operation. Additional elements of the control system include an adjustable wheel slip sensing mechanism preferably associated with the manual control, a bypass valve associated with the regulating valve and preferably with a hydraulically operable transmission in the drive train for maintaining at least limited engagement of the slipping clutch in order to prevent or limit reverse rotation of components within a torque converter coupled with the slipping clutch and an input valve also associated with the transmission to condition the slipping clutch for receiving a substantial portion of shock loading applied to the drive train.

Growing community of inventors

East Peoria, IL, United States of America

Shairyl I Pearce