| 摘要 |
<p>A two-speed power transmission having a gear box in which are mounted, for rotation about parallel axes, a power input shaft, an intermediate shaft and an output shaft. A first gear train interconnects the input and the intermediate shafts for driving the intermediate shaft into rotation. Within the gear box are also second and third gear trains, each having a first gear secured on the intermediate shaft for rotation therewith and a second gear in mesh with the first gear, these second gears being freely mounted on the output shaft so as to rotate independently, the second and third gear trains having different diameter ratios. A drive wheel is mounted on the output shaft, between the second gears, for rotation with it and for slidable displacement over it. The drive wheel and the second gears are provided with meshing parts permitting the drive wheel to mesh selectively with one of the two second gears to bring the output shaft into rotation. The space between the two second gears is sufficient to allow for a neutral position of the drive wheel and the latter is shifted toward either one of the two second gears by means of a manually operable oscillating shifting stirrup member.</p> |
