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AssigneeFord New Holland, Inc.
InventorsMichael E. Langford, Stephen J. Churchill, Shairyl I. Pearce, Bradley A. Nielsen, David G. Sokol
Estimating the term…
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.
In a transmission system having a range shift lever movable between a first and a second position to shift a first coupler to select a low or a high range of gears to thereby select first and second ranges of output shaft speed relative to input shaft speed, at least one electro-hydraulic powershift clutch for selecting a particular gear within the selected range and fluid control means for controlling the flow of fluid to and from the powershift clutch, the improvement comprising:
In a transmission system having a non-synchronized solenoid actuated creeper gear mechanism including a non-synchronized coupler engageable to greatly reduce the ratio of output shaft speed to input shaft speed, at least one electro-hydraulic powershift clutch located between the input shaft and the creeper gear mechanism, a dump valve for controlling the flow of hydraulic fluid to, or the release of hydraulic fluid from the powershift clutch, and a microprocessor for controlling the system a method of controlling said creeper gear mechanism, said method comprising:
Dependencies are inferred from the claim text.