Ford New Holland, Inc.

Shairyl I Pearce

Rudolf Beim

David John Rutkowski

John H Tanzer

Bradley A Nielsen

David G Sokol

Stephen J Churchill

Michael E Langford

In a transmission system, a solenoid controlled electro-hydraulically actuated creeper gear coupler permits selection of very low speeds and provision is made to prevent creeper gear engagement/disengagement unless conrolled by the operator and then only if specified conditions exist. Current flow through the solenoid which actuates the creeper gear is monitored at all times to provide a controlled engagement/disengagement of the creeper gear in the event the monitoried conditions are not within prescribed limits. The current is monitored as the creeper solenoid is energized to insure sufficient pull-in current and while it is energized to insure sufficient hold-in current. The solenoid current is also monitored when the solenoid is not energized. Short or open circuit conditions are detected before they can cause an unexpected engagement or disengagement of the creeper gear.

Creeper gear engagement/disengagement

In a transmission system having range shift levers mechanically linked to couplers and shiftable between first and second positions to select ranges of gears and electro-hydraulic powershift clutches for selecting a gear within the range selected by the range shift lever, the powershift clutches are located on each side of at least one of the couplers, between the input shaft and the coupler and between the output shaft and the coupler. A dump solenoid is controlled by operation of a clutch pedal to release fluid from the powershift clutches as the clutch pedal is depressed but before it reaches the fully depressed position so that the coupler is not being driven when coupler shifting takes place. A microprocessor is responsive to shifting of the range shift levers to control energization of the powershift clutches so that when one or more of the shift levers is shifted the lowest powershift gear is selected if the new lever positions will produced a higher gear range and the highest powershift gear is selected if the new lever positions select a lower gear range.

Driveline engagement/disengagement

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Lititz, PA, United States of America

Shairyl I Pearce