| 摘要 |
PURPOSE:To improve durability of a friction wheel or so in a vehicle provided with both a shift lever by which transmission gear ratio is changed in a plurality of gear positions and an operating lever by which a whole transmission gear ratio is changed to run the vehicle in a low speed range or a high speed range by allowing the shift lever to make no shift operation to the low speed range when the vehicle runs in the high speed range. CONSTITUTION:A vehicle such as a small-sized snow plow is provided with a speed change mechanism consisting of both a supplementary speed change gear which has a driving friction wheel and a main speed change gear which has a friction wheel making frictional engagement with the driving friction wheel perpendicularly therewith. In such snow plow 1, if it is driven forth at a speed higher than any speed within the third gear range F3, the operating lever 101 of the supplementary speed change mechanism is turned into a high speed range H and the shift lever 85 of the main speed change mechanism is thrown into an engagement groove 765. By the turning operation of the operating lever 101, a sliding member 111 is slided via pins 114 and slots 113 to have projections 112 and 112 close engagement grooves 763 and 764. Since the shift lever 85 is restricted to be thrown into the engagement grooves 763 and 764, the driving friction wheel may be prevented from making frictional engagement with the friction wheel in the vicinity of the rolling center and generation of resulting friction heat to be prevented. |
