| 摘要 |
In the illustrative embodiment of the invention, an electromechanical timer employs a manually operable actuator, a pawl and a control cam cooperatively arranged to provide a push to start capability. The control cam is carried on a shaft having a longitudinal bore formed therein. The actuator is slidably received in the bore for axial movement between a neutral position and an actuating position. One end of the actuator extends from the shaft for manual operation. The other end has an axial cam surface formed thereon. The pawl is mounted for pivotal movement between a rest position and a cocked position and spring biased to its rest position. A cam follower extends from the pawl into the path of the axial cam surface of the actuator for camming engagement between pawl and actuator. A ratchet tooth is formed on the control cam for engagement by the pawl. Manual movement of the actuator from its neutral position to its actuating position moves the pawl to its cocked position, thereby storing energy in the biasing spring. Movement of the actuator back to its neutral position releases the pawl. Energy stored in the spring is utilized to drive the pawl to its rest position. In moving from its cocked position to its rest position, the pawl drivingly engages the ratchet tooth formed on the control cam and moves the control cam from its idle position. In moving from its idle position the control cam closes a switch to initiate timer operation.
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