| 摘要 |
A drive shaft (1) rotatably journalled in a stationary block (2) has keyed thereto a driving member (5), while a driven member (6) is rotatably mounted on the shaft. The driving member imparts to the shaft a positive intermittent rotation, for example by steps of one revolution or an integer fraction of one revolution. Co-axially mounted on the shaft is a disc (8) having a periphery with at least one keyway (108) if the intermittent rotation of the shaft is by one-revolution steps. The keyway-recessed disc cooperates with a latch (9) which is slidably but not rotatably mounted on the driven member and which is parallel to the axis of the shaft. The latch has a pronged end (109) which, in the dwell position of the intermittent motion of the shaft, is aligned with the head (110) of a rod (10) that is slidably mounted in the stationary block parallel to the shaft and that is driven by a pneumatic cylinder (12). The latch is spring-biassed against the disc in registry with the region of the keyway or keyways, while the cylinder is controlled to disengage the latch from the keyway or keyways on completion of each step of the transmitted intermittent motion, whereby the latch is moved backwards so as to lock the driven wheel in position until the next step is to be transmitted. |
