Abstract: An automatic powershift vehicle transmission comprising an input shaft; an output shaft; first and second intermediate shafts parallel to the input shaft; a lay shaft parallel to the output shaft; gearing providing first, second, third and fourth forward driving paths from the input shaft to the output shaft; a first clutch and a second clutch between the ends of the input shaft to establish driving connections; a third clutch for establishing the first or third forward driving path when the first clutch is operative; and a fourth clutch for establishing the second or fourth forward driving path when the second clutch is operative.

Abstract: A method of controlling a vehicle transmission, the vehicle transmission including a power shift gearbox, the power shift gearbox having a power shift input shaft, a power shift output shaft, power shift input gearing and power shift output gearing, and a plurality of power shift clutches to drivingly connect the power shift input gearing and the power shift output gearing, and a master clutch operable to connect the power shift input shaft to a prime mover, the method comprising the steps of, disengaging the master clutch, and engaging at least two of the power shift clutches.

Abstract: A method of controlling a vehicle transmission during a gear change thereof, the method comprising operating a plurality of power shift clutches to disengage the power shift input gearing and the power shift output gearing, disengaging the driving connection between the range shift input shaft and the range shift output shaft by means of the range selection gearing, engaging at least two of the power shift clutches to vary the rotational speed of the power shift output shaft and hence the range shift input shaft, and operating the range selection gearing to establish a driving connection between the range shift input shaft and the range shift output shaft.

Abstract: A method of controlling a vehicle transmission, the vehicle transmission including a power shift gearbox, the power shift gearbox having a power shift input shaft, a power shift output shaft, power shift input gearing and power shift output gearing, and a plurality of power shift clutches to drivingly connect the power shift input gearing and the power shift output gearing, and a master clutch operable to connect the power shift input shaft to a prime mover, the method comprising the steps of, disengaging the master clutch, and engaging at least two of the power shift clutches.

Abstract: An automatic powershift vehicle transmission comprising an input shaft; an output shaft; first and second intermediate shafts parallel to the input shaft; a lay shaft parallel to the output shaft; gearing providing first, second, third and fourth forward driving paths from the input shaft to the output shaft; a first clutch and a second clutch between the ends of the input shaft to establish driving connections; a third clutch for establishing the first or third forward driving path when the first clutch is operative; and a fourth clutch for establishing the second or fourth forward driving path when the second clutch is operative.

Abstract: A method of controlling a vehicle transmission during a gear change thereof, the vehicle transmission including a power shift gearbox and a range shift gearbox, the power shift gearbox having a power shift input shaft, a power shift output shaft, power shift input gearing and power shift output gearing, and a plurality of power shift clutches to drivingly connect the power shift input gearing and the power shift output gearing, the range shift gearbox having a range shift input shaft drivingly connected to the power shaft output shaft, a range shift output shaft and range selection gearing to drivingly connect the range shift input shaft and range shift output shaft, the method comprising the steps of operating the plurality of power shift clutches to disengage the power shift input gearing and the power shift output gearing, disengaging the driving connection between the range shift input shaft and the range shift output shaft by means of the range selection gearing, engaging at least two of the power shift

Abstract: A method of controlling a vehicle transmission during a gear change thereof, the vehicle transmission including an input shaft, an output shaft, input gearing, output gearing, a first clutch for establishing a driving connection between the input shaft and the input gearing to drive the output shaft in a first direction, and a second clutch for establishing a driving connection between the input shaft and the input gearing to drive the output shaft in an opposite direction. The method comprising the steps of disengaging the driving connection between the input shaft and the input gearing by means of the first clutch, and subsequently establishing a driving connection between the input shaft and the input gearing by means of the second clutch to retard the rotational speed of the input gearing.

Abstract: A single shaft shifting mechanism (300) is provided having supports (310, 312), independent of the shift shaft (106), for supporting the weight of the shift forks (302, 304, 306) to minimize frictional contact between the shift shaft and the shift forks.

Abstract: An improved upshift brake (130) for a mechanical transmission (10) is provided. The upshift brake is provided with an axially clamped stator (138) and piston/cylinder assembly (148) to minimize cyclical axial loading and stress on the cantilevered end walls (134 and 136) of the upshift brake housing (132).