Patent ID: 8115121

Claim:
A timer, comprising: a case, comprising a shaft rotatably and axially movably disposed in the case, and the shaft is axially movable between a setting position and a driving position; a cam wheel, pivoted on the shaft, wherein the cam wheel comprises a plurality of cam tracks on at least one side surface thereof and a plurality of first ratchets annularly disposed on a circular rim thereof; the cam wheel rotates along with the shaft when the shaft is located at the setting position; and the cam wheel separates from the shaft when the shaft is located at the driving position; a drive mechanism, selectively contacting the first ratchets of the cam wheel, for driving the cam wheel to rotate relative to the shaft; a plurality of switch blades, each comprising a plurality of cam actuating portions respectively, the cam actuating portions are actuated by a rotation motion of the cam wheel, so as to enable the corresponding switch blades to generate an electrical connection/disconnection; and an off-contact lever, pivoted in the case, and connected to the shaft; wherein when the shaft is located at the setting position, the off-contact lever presses at least a portion of the switch blades to free the cam actuating portions of the switch blades from the cam tracks of the cam wheel, and to move the drive mechanism away from contacting the cam wheel; and when the shaft is located at the driving position, the off-contact lever frees the cam actuating portions of the switch blades to contact the cam tracks of the cam wheel, and let the drive mechanism drive the cam wheel.