| 摘要 |
A seed disk in a vacuum seed meter has a central mounting aperture in the form of a slot widening to a circular hole at its centre. When the disk is mounted on the hub of the seed meter a correspondingly shaped raised portion of the hub is received in the aperture to key the disk to the hub and a correspondingly shaped handle (24) passes through the aperture. The handle is retained rotatably on a shaft by a cap (56) and a coil spring under the cap urges the handle towards the hub. After the disk has been fitted, the handle is rotated as indicated by arrow (76) and the arms (60, 62) of the handle ride up ramps (34, 36) until the arms click into detent recesses (82, 80). |
