Patent ID: 7234366
Filing Date: 2007-06-26
Classification: F16D

Abstract:
1. In a vehicle having a power source for producing rotational motion, a power take-off shaft for supplying rotational motion to at least one piece of equipment other than the vehicle, and a clutch including an input shaft coupled to the power source and an output shaft coupled to the PTO shaft, wherein the clutch transmits a maximum torque between the input and output shafts in response to a maximum clutch pressure and transmits a selectable torque between the input and output shafts in response to a selected clutch engagement pressure less than the maximum clutch engagement pressure, a power take-off control system comprising: a first transducer disposed to generate an input shaft speed signal representative of the rotational speed of the input shaft; a second transducer disposed to generate an output shaft speed signal representative of the rotational speed of the output shaft; a clutch control configured to effect engagement and disengagement by the clutch in response to engagement control signals applied thereto, the clutch transmitting a selectable torque between the input and output shafts dependent upon a clutch engagement pressure defined by said engagement control signals, wherein the clutch engagement pressure is variable up to the maximum engagement pressure; a controller coupled to the clutch control, the first transducer, and the second transducer, said controller operable to monitor the input shaft speed signals and the output shaft speed signals generated by said first and second transducers and to produce time-based engagement control signals dependent thereon, said engagement control signals each including a characteristic representative of an associated amount of clutch pressure to be applied, said controller operable to generate a first set of time-based engagement control signals during a time period between commencement of an engagement operation and the time at which an output shaft speed signal indicative of movement by the output shaft is detected by said controller, and a second set of engagement signals at times subsequent to said detection of movement by the output shaft, said controller operable, upon detection of movement of the output shaft, to determine whether the monitored input speed at such time has remained within an established deviation value from the nominal input speed prior to such time and to establish a first load status if the speed has remained within the established deviation value and to establish another load status if the speed has not remained within the established deviation value, said second set of time-based engagement signals including a subset of engagement control signals dependent, in part, upon the established load status and defining a flattened control curve relative to control curves that are established for loads of said another load status.