| 摘要 |
An electromechanical timer (101) comprises a pair of switch contacts (109, 111), a rotary cam (115) determining the condition of the switch contacts, a snap-acting bimetal (124) arranged to move cyclically during operation of the timer, and first and second spring coils (129, 130) wound on the cam shaft (117) and arranged to unidirectionally couple the bimetal movements to the cam shaft so as to rotatably reset the cam and reset the switch contacts. The timer can be used with an electric toaster in which case the bimetal can be caused to cycle by being intermittently exposed to heat from the toaster by means of a shutter moved by the bimetal, and the rate of cycling of the bimetal can be adjusted to determine the time-out period of the timer by provision of a further shutter adjustably screening the bimetal from the heat of the toaster. |
