| 摘要 |
A programmer/timer for an appliance of the type having a rotatable cam drum (12) advanced for sequential actuation and deactuation of a plurality of electrical switches (20). The drum is advanced or indexed intermittently by an oscillating advance pawl (26) engaging a ratchet wheel (25) and also continuously by a gear (44) driven by a common motor for oscillating the advance pawl. The ratchet wheel (25) has a hub (38) which is frictionally engaged (37) to drive the cam drum. The driven gear in turn is frictionally engaged (51) with the hub to also drive the ratchet wheel. When the advance pawl engages the ratchet wheel for intermittent drive, the driven gear slips on the ratchet hub. Upon user selection, a separate cam track (52) lifts the advance pawl to permit the driven gear to continuously drive the ratchet wheel. |
