Steiger Tractor Inc.

William E Martinson

Barry Douglas Batcheller

Michael A Tuchscherer

An environmental control system for an enclosed cab of an off-the-road vehicle such as a tractor includes a pressurization blower for pressurizing the cab to a positive pressure with respect to atmospheric pressure outside the cab, and a recirculation blower for recirculating air within the cab. The system includes a fresh air intake for taking in air from outside the cab, a recirculation air intake for taking in air from within the cab, and outlets through which the air from the blowers enters the cab. An air precleaner and a fresh air filter are provided between the pressurization blower and the fresh air intake. A control circuit automatically provides a speed control signal to the pressurization blower, and a manually selected speed control signal is provided to the recirculation blower. A speed sensor senses the speed of the pressurization blower, which varies for a given speed control signal as a function of air pressure within the cab and the condition of the fresh air filter. The control circuit varies the speed control signal to the pressurization blower as a function of the pressurization blower speed to provide essentially constant air flow from the pressurization blower despite changes in cab pressure and filter condition.

Environmental control for tractor cab

An electrical control provides output signals to a group of solenoid valves which control the gear ratio selected by a transmission. The electrical control receives input signals from a mode select lever, an upshift/downshift pulser lever, an engine RPM sensor, a ground speed sensor, a clutch position sensor switch, and a throttle control lever. The mode select lever has a neutral (N) position, a reverse (R) position, a forward manual (FM) position, and a forward automatic (FA) position. Movement of the mode select lever from N to FM causes the electronic control to actuate solenoid valves which select a first forward gear. Similarly, movement of the lever from N to R causes the control to actuate solenoid valves which provide a first reverse gear. Higher/lower gears are obtained by moving the upshift/downshift pulser lever from its normal position to either an upshift position or a downshift position. One upshift pulse causes the electronic control to actuate solenoid valves resulting in one gear shift upward. Holding the pulser lever forward in the upshift position gives sequential upshifts at predetermined time intervals. Pulsing or holding the pulser lever rearward in the downshift position has a reverse effect. When the forward automatic mode is desired, the operator first moves the mode select lever to FM and operates the pulser lever until the desired maximum gear has been attained. The operator then moves the mode select lever from the FM to the FA position. Thereafter the control upshifts and downshifts the transmission according to engine RPM and the desired throttle set point.

Electrical control for power shift transmission

An overhead instrument console for use in a tractor includes a panel spanning the driver's compartment. A hinge pivotally connects the panel to the ceiling such that the panel pivots to a down position permitting full access to the rear of instruments mounted on the panel and to such devices as windshield wiper motors, and pivots to an up position hiding from view the rear of the instruments mounted thereon. A latching mechanism is provided to keep the panel in the up position.

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Fargo, ND, United States of America

William E Martinson