| 摘要 |
A motor (12) has an output shaft (18). A transmission device (14) transmits rotary power, selectively, in any one of two drive modes from the shaft (18) to an output shaft (16) connected to a rotary load. The drive modes differ in respect of direction of rotation and/or speed ratio. Output pulleys (20/22) are respectively connected to intermediate pulleys (44/54) on the device (14). Auxiliary intermediate wheels (48/58), which are respectively co-axial with and connected to the pulleys (44/54), are drivingly connected respectively in accordance with the two drive modes by means of a drive element (51) to an output wheel (42) on the shaft (16). The device (14) is pivoted about the shaft (16) as shown at (36). Pivoting in one direction tightens a V-belt (50) transmitting drive to the pulley (44) and thence via the wheel (48) in a first drive mode to the shaft (16); while slackening a V-belt (60) to disconnect drive to the pulley (54). Pivoting in an opposite direction causes drive via the pulley (54) and wheel (58) to the shaft (16) in the other drive mode. <IMAGE> |
