Abstract: A multi-speed power transmission utilizing ten gears, seven clutches and four shafts provides eight forward speeds and four reverse speeds. The transmission is coaxial in that the input and the output shafts are on the same centerline. The transmission requires only a minimum number of gears, clutches and shafts for the large number of gear ratios provided, and at the same time it is relatively compact and has only three shaft centers. In this transmission there are always three clutches applied in any speed range. Of the seven shifts between forward speed ranges, four of them require the engagement of one different clutch only, two of them require two different clutches to engage simultaneously, and one shift requires engaging three different clutches. The clutches are of the type having multiple friction plates, and hydraulically applied force pistons which are spring load returned. The clutches include appropriate ball dump valves in the force pistons.

Abstract: A power transmission utilizing only eleven gears and four shafts to obtain six forward speeds, three reverse speeds, and an 19-inch drop from input to output shafts. Optionally, there may be provided an inbuilt power-take-off and brake uniquely located with an 8-inch drop from the input shaft. A power transmission further expanded to obtain twelve forward speeds and six reverse speeds with addition of (1) a low-range planetary system, and (2) a direct clutch, each connectable between a journalled output gear to the output shaft.

Abstract: A power transmission control system for vehicles where it is desired to reverse the vehicle direction at full throttle such as vehicles used in mining operations, off road application, or the like. The transmission includes selectively and hydraulically operated friction-type clutches and hydraulic control circuits for actuation thereof. The hydraulically operated output clutches are used to change speed range of the transmission while input clutches are used to change speed and/or direction of the vehicle. The control mechanism permits the vehicle in motion to be shifted to a reverse direction at full throttle and the arrangement is such that when the shift is made, the output speed range clutch disengages or optionally drops to residual torque capacity, the forward clutch remains fully engaged, and the reverse clutch comes on fully to brake the input. Then both forward and reverse clutches are engaged. The input is then locked.