Caterpillar Tractor Co.

David S Ohaver

James L Schmitt

Sidney J Audiffred

A hydraulic control system for a multi-directional multi-speed transmission for the power train of a vehicle includes means responsive to the directional shift of the transmission at a predetermined minimum speed to automatically apply the brakes of the vehicle during a shifting period.

Control system to apply vehicle brakes during a transmission directional

A hydraulically operated winch of the type adapted for logging or towing operations and having a rotatable winch drum about which a cable or line is entrained, a normally disengaged clutch being hydraulically operable to provide a coupling between a power input member and a winch drum drive shaft, a normally engaged friction brake normally securing the winch drum drive shaft against rotation while being hydraulically disengagable and a normally engaged clutch providing a selective coupling between the winch drum drive shaft and the winch drum. A modulating control valve for the winch includes a valve body having an inlet chamber in communication with a source of fluid under pressure, a single regulating spool in the valve being operable to selectively communicate fluid under pressure from the inlet chamber with respective actuating chambers for the brake and the two clutches, the valve also including a modulating valve responsive to the positioning of the regulating spool for modulating fluid pressure in the inlet chamber.

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Canton, IL, United States of America

David S Ohaver