Clark Equipment Compnay

Allied Corporation

Willard L Chichester

Howard C Hansen

Donald A Holtkamp

James J Bauer

Allen B Wright

George J Trusock

Dean E Davis

An air cleaner assembly includes a pair of molded housing members, each of which include four side walls and an open end. The opposite end of one of the members carries an outlet tube for connection to the air intake system of the vehicle, and the opposite end of the other member includes a lattice-work structure defining openings to admit air into the air cleaner assembly. The two housings snap together by receiving the side walls of the one member into the open end of the other member, and the members defining the lattice-work structure engage a panel cartridge filter assembly to force the latter into an adhesive carried in a groove extending around a flange defined on the one member.

Simplified air filter

A hydraulic system is disclosed for energizing the power steering and various work handling hydraulic load circuits of a lift truck. A single positive displacement pump supplies the requirements of the plural load circuits and is driven by a changeable speed prime mover. Manually actuable selector means are operatively connected with the load circuits and speed control means are provided for the prime mover. A priority demand valve is connected between the pump and the respective load circuits. When only the power steering circuit is selected, the prime mover is operated in a low speed range and the priority demand valve supplies the required flow to the power steering circuit. When the lift circuit is selected, the prime mover is operated in a high speed range and the priority demand valve supplies the flow requirements to the power steering circuit and to the lift circuit. When an auxiliary work handling circuit is selected, the prime mover is operated in an intermediate speed range and the flow requirements of the power steering circuit and the auxiliary load handling circuit are supplied. The prime mover may be either an electric motor or an internal combustion engine.

Vehicle hydraulic system with single pump

A lift truck is disclosed with a changeable speed electric motor for driving a single positive displacement pump to supply the power steering and various work handling hydraulic load circuits. Manually actuable selector means are operatively connected with the load circuits and a speed range control means is operatively connected with the selector means for energizing the electric motor in different speed ranges according to the actuation of the selector means. A priority demand valve is connected between the pump and the respective load circuits and supplies fluid to the load circuits, giving priority to the power steering circuit. The speed range control means includes speed regulating means for the electric motor. The motor is energized from the battery and the regulating means includes a pulsing circuit with a motor current feedback to vary the mark/space ratio of the pulses produced by the pulsing circuit.

Vehicle hydraulic system with pump speed control

An auxiliary release apparatus for use with a hydraulic pressure releasable brake having a principal source of hydraulic pressure which comprises an auxiliary source of hydraulic pressure selectively connectible to the brake for releasing the brake when the principal source of hydraulic pressure is not operating. The auxiliary release apparatus includes a manual pump device for interrupting communication between the normal pressure source and the pressure releasable brake when the pressure source, as a pump, is not operating, and for manually pumping through a by-pass circuit pressure fluid to the pressure releasable brake.

Auxiliary release device for a hydraulic pressure releasable brake

An air cleaner system for an internal combustion engine located in a vehicle engine compartment. The system includes a cubic air filter device located beside the engine in the engine compartment which is arranged to draw air from outside the vehicle, pass it through a filter cartridge in the air filter device, and through a flexible conduit connecting the air filter device with the carburetor.

Engine compartment and air cleaner

A method and device for purging air from the hydraulic brake system of vehicles wherein the master brake cylinder is connected hydraulically to a sump return conduit of a hydraulic component of the main hydraulic system which combines with a restriction associated with the master cylinder to cause a flow of pressure fluid from the return conduit through the brake system when air bleed valves in the brake system are open.

Method and means for bleeding hydraulic brakes

A power steering system, particularly advantageous for use on electric powered vehicles, in which the hydraulic pump operates only when steering commands are given. Torque applied to the steering shaft by rotation of the steering wheel is translated to axial stress on a thin walled tube, the direction and intensity of which depend on the direction and amount of steer angle change commanded. The axial stresses are detected by strain gages, and the motor which powers the hydraulic pump is activated only when stress is detected. Manual steering inputs enter the pump on one side, and the powered servo motor inputs enter on the opposite side, thus permitting the vehicle to be steered by manual input alone if the powered input fails. The components of the system are arranged in coaxial alignment, providing a compact system with improved heat dissipation qualities.

Power steering system

A hydrostatic transmission in which a hydraulic pump and motor are in a generally U-shaped arrangement with a fluid transfer manifold extending between the pump and the motor. The pump is driven on one side of the manifold by the drive motor of the vehicle on which the transmission is used, and a drive shaft from the motor extends through the manifold, to power the drive wheels on the other side of the manifold. A housing surrounds the pump, motor and manifold and contains hydraulic fluid for the operation of the transmission. Servo controls for the pump and motor are located on the outside of the housing, and a control cover has preloaded servo pistons which properly adjust the servo control when the cover is attached to the housing. A charge pump for the servo controls is in the manifold, and rigid tubular conduits extend between the charge pump and the control cover. The conduits are mounted between, and held in place by, the charge pump and control cover, and require no hydraulic fittings or connections to secure them therebetween.

Hydrostatic transmission

A hydraulic control circuit especially for use with multi-function hydraulic devices, such as for industrial lift truck attachments, in which a combination of valves are adapted to operate two or more hydraulic systems, the valve system being designed such that a minimum number of hydraulic conduits are required to connect the main hydraulic system to the hydraulic devices, as from a lift truck to an attachment supporting carriage on a lift truck upright, and no electric lines are required to be connected to switching devices between the hydraulic devices, such as to solenoid operated valves.

Hydraulic control system for operating multiple remote devices with a

A hydraulic control circuit especially for use with multi-function hydraulic devices, such as for industrial lift truck attachments, in which a combination of valve means are adapted to operate two or more hydraulic systems, the valve system being designed such that a minimum number of hydraulic conduits are required to connect the main hydraulic system to the hydraulic devices, as from a lift truck to an attachment supporting carriage on a lift truck upright, and no electric lines are required to be connected to switching devices between the hydraulic devices, such as to solenoid operated valves.

Hydraulic control system

A hydraulic circuit for operator pre-selection in one exemplary embodiment of the extension of a lift truck upright which utilizes a fixed displacement hydraulic motor operating to adjust either a rotary switch or a potentiometer which is connected to a valve for interrupting the flow to the lift cylinder of the upright at the pre-selected height. The adjusted position of an operator's lift height selector is coordinated with the rotary switch or potentiometer or to effect the selected extension of the upright.

Hydraulic cylinder extension control

A power steering system for electric vehicles in which an electric drive motor for the supply pump of a power steering system is controlled by a motor control which is in turn controlled by the steering demand of the operator. The motor and pump are operated only during steering operations and only at the power level required for any steering demand.

A closed recirculating hydrostatic transmission system suitable for driving a traction vehicle. The system includes a pair of hydrostatic engine driven variable displacement pumps either of different displacements or engine driven at different speed ratios and each pump being operative to drive hydrostatic motors at the various wheels and in separate closed loop drive circuits such that accurate flow division as between the circuits is effected for driving the vehicle in four-wheel drive or, at the operator's selection, for driving the motors in the one closed loop circuit at a higher speed in two-wheel drive by means of the pump of larger discharge volume. An operator's control operates both pumps together within the limits of the smaller discharge pump in four-wheel drive, and operates the larger discharge pump within the limits thereof while rendering ineffective the smaller discharge pump in two-wheel drive. Valve means enables smooth transition and shifting between two and four-wheel drive at any time. Flow divider-combiner means in each closed loop circuit adjusts fluid flow to each motor as a function of steering angle to assure positive traction at each driven wheel in either forward or reverse drive under all surface conditions, and to differentiate as required wheel speeds during vehicle steering operations. Braking may be effected by reversing pump flow at selected conditions of either decreasing, constant or increasing engine speed.

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Battle Creek, MI, United States of America

Willard L Chichester