Patent ID: 7134871

Claim:
A timer device for a gas stove comprising a housing, a disc-like wheel, a motor, a driving wheel, a microswitch and a timing circuit; wherein: the housing is mounted on a surface of the gas stove, an upper and a lower round holes are formed in an top surface and a bottom surface of the housing, respectively, for the passage of a rotary-knob switch, a plurality of locating holes is formed around the upper round hole for the insertion of locating wheels, each of the locating wheels is V-shaped in cross section for supporting the disc-like wheel, the disc-like wheel is mounted under the upper round hole, an oblong aperture is formed in the center of the disc-like wheel and a plurality of teeth is formed on a periphery of a bottom of the disc-like wheel for engaging with the driving wheel of the motor, a protrusion protrudes vertically from the disc-like wheel, the motor is disposed in the housing and is to be actuated by signals emitted from the timing circuit, the microswitch is a three-pole switch having a leaf spring employed to be contacted by the protrusion of the disc-like wheel, when the gas stove is turned on, the protrusion disengages from the leaf spring of the microswitch, and a normal close pole is switched on to turn on the timing circuit and make it start to count time, when the set time is reached and if the gas is not turned off, the motor will be actuated to drive the disc-like wheel to its original position, and the rotary-knob switch will turn the gas off, at the same time, the protrusion will touch the leaf spring of the microswitch to cut off the power, when the gas is turned off, the protrusion keeps touching the leaf spring of the microswitch, the normal close pole is disconnected from power.