| 摘要 |
Improved change speed gearing utilizing an improved blocker means for effecting engagement of the jaw clutch associated with the low speed gearing of a simple transmission, or with the low speed gearing of the main transmission section of a splitter type compound transmission. A transmission having an input shaft driven by a one-way prime mover, a main shaft and at least one countershaft, and including pairs of shiftable gears arranged on and cooperatively between said shafts, is provided with positive clutches, preferably spring loaded jaw clutches, for effecting connection to one of said shafts of a selected one gear of a selected one of said pairs of said gears upon the achievement of substantial synchronization between such gear and such shaft. Blockers are provided for protecting the positive clutch teeth from excessive wear during such shifting. One of said blockers, preferably that blocker associated with either the positive clutch for engaging the low speed pair of gears in a simple transmission, or that blocker associated with the positive clutch for engaging the low speed pair of gears in the main transmission section of a splitter type compound transmission, is effective to sense only one type of nonsynchronous condition, such as, that condition corresponding to one of the clutch members overspeeding the other clutch member in a given direction of rotation. |
