Case Corporation

Bradley A Nielsen

Craig R Eike

An apparatus and method is disclosed for controlling engagement of a power take-off shaft (PTO) on a vehicle. The apparatus includes a clutch including an input shaft coupled to a power source and an output shaft coupled to the PTO. The apparatus also includes an input speed sensor for sensing a quantity related to the angular velocity of the input shaft, an output shaft speed sensor for sensing angular velocity of the output shaft, and a clutch controller for adjusting pressure of hydraulic fluid applied to the clutch in response to control signals. Torque transmitted between the input and output shafts is responsive to the control signals. The apparatus also includes a control circuit coupled to the speed sensors and the clutch controller. The control circuit is configured to receive signals from the speed sensors and to provide the control signals in response thereto. During engagement of the PTO, the control circuit continuously determines an actual acceleration of the PTO based upon the output shaft velocity, and generates the control signals using a desired acceleration and the actual acceleration. The control circuit may continuously determine the desired acceleration based upon the input speed signal. Alternatively, the control circuit may provide control signals to cause the torque transmitted through the clutch to increase at a rate depending upon the difference between the desired and actual accelerations when the actual acceleration is more than a threshold proportion of the desired acceleration, and to cause the torque to increase at a rate independent of the difference when the actual acceleration is less than the threshold proportion.

Power take-off engagement control system

An apparatus and method is disclosed for preventing the performance of an automatic sequence of operations of a work vehicle. The apparatus is a system that includes a databus, a plurality of input devices, a primary control unit coupled to the plurality of input devices and to the databus, a plurality of output devices and a plurality of secondary control units coupled to the databus, each of the secondary control units also being coupled to at least one of the output devices. The primary control unit directs the performance of the automatic sequence of operations by generating commands to be provided onto the databus. Each of the secondary control units directs an output function by the at least one output device coupled thereto in response to the commands on the databus. At least one of the secondary control units provides a status signal onto the databus indicative of a status of the at least one of the secondary control units or the respective output device, wherein the primary control unit prevents the performance of the automatic sequence of operations if the status signal is indicative of a system malfunction.

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Lisle, IL, United States of America

Bradley A Nielsen