Owatonna Manufacturing Company, Inc.

Figgie International, Inc.

Brian C Clark

Michael D Jines

Colin R Hart

Jon A Macht

An hydraulic drive system for driving a plurality of wheels of a vehicle. The drive system comprises an hydraulic fluid source, at least two motors for driving the vehicle wheels, a pump connected between the fluid source and the motors for drawing hydraulic fluid from the source and forcing the fluid to the motors, at least two flow restrictions, and at least two load-reaction compensators. Each of the motors drives at least one of the wheels at varying speeds in response to varying rates of fluid flow supplied to the motor from the fluid source. Each of the flow restrictions is positioned between the pump and at least one of the motors. Each restriction varies the rate of fluid flow to at least one of the motors in response to changes in fluid pressure upstream from the restriction. Each of the compensators is connected between the pump and at least one of the restrictions. Each compensator controls pressures upstream from at least one of the restrictions to thereby control the speed of the respective wheel. Each compensator maintains a first generally constant fluid pressure upstream from the respective restriction when fluid pressure downstream from the compensator is below a first predetermined value, and maintains a second generally constant fluid pressure upstream from the respective restriction when the downstream fluid pressure is above a second predetermined value.

Limited slip differential hydraulic drive system

An improved cooling system for a skid steer loader includes a swing-up radiator and oil cooler assembly (60) incorporating a pair of radiators (64, 88) supported for independent pivotal movement between raised and lowered positions to facilitate access to the radiators, as well as access to the engine and associated components for service, maintenance and the like. The lowermost radiator (64) serves as the hydraulic oil cooler, and is supported in a frame (62) pivotal about a generally longitudinal axis (78). The uppermost radiator (88) serves as the engine cooler and is mounted in another shelf (86) pivotal about a second longitudinal axis (104). A latch assembly (106, 108, 110, 112 and 114) is provided for releasably securing the entire radiator and oil cooler assembly (60) in a lowered position and at least the upper radiator (88) in a raised position.

Swing-up radiator and oil cooler assembly

The specification discloses a brake system (84) which is particularly adapted for vehicles such as skid steer loaders in which the wheels on each side of the vehicle are driven independently by separate transmissions. The brake system (84) includes a caliper assembly (86) overlying brake discs (66) which are mounted for rotation about a common axis but are individually connected to the transmissions. The brake pucks (98) are actuated by a manual lever (132) connected to a rotatable cam (112) associated with an axial plunger (120). The cam (112) is rotatable about an axis parallel to the bore (96) in the caliper assembly (86) containing the brake pucks (98) and plunger (120), to provide a wider range of motion in a more compact space.

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Owatonna, MN, United States of America

Brian C Clark