Twin Disc Incorporated

Basil White

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.

Multi-speed reversible power transmission

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.

Multi-speed reversible transmission of countershaft construction

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. The output speed range clutch is then brought to increased 'brake mode' torque capacity. The output speed range clutch then functions as a brake to decelerate the vehicle. The static braking reaction torque is held by the locked up direction clutches. When the vehicle speed reaches a predetermined lower value (where it is almost stopped) that situation is sensed by the hydraulic control means and immediately thereafter and simultaneously the forward clutch is released and apply pressure on the braking (output speed range) clutch is permitted to increase to full value. The vehicle then accelerates in the opposite direction under the influence of the torque converter. This control system also provides means for quick and smooth full throttle shifts at and near vehicle stopped condition; that is for either a neutral into range shift or a directional shift.

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Rockford, IL, United States of America

Basil White