Timer for a gas stove

Abstract

A timer for a gas stove has a housing to be mounted to a front panel of the gas stove. A controlling unit, a driving unit and a clutch unit are received in the housing. A switch is provided for ignition of gas and controlling of flames. The controlling unit can be set to a preferred period so that when the period has elapsed, the driving unit is activated to rotate the switch and shut off the gas stove automatically via the clutch unit. In addition, if the switch is turned by the user to ignite the gas or control the flames, the clutch unit is in a disengaged state so that unnecessary wear among components of the timer is prevented.

What is claimed is:  
     
         1 . A timer for a gas stove having an ignition device and a valve for starting and controlling flames, the timer comprising: 
 a housing to be mounted on the gas stove and to receive a battery, a sleeve pivotally connected to the housing and adapted to be coupled to the ignition device and the valve;    a switch having a shaft extending therefrom, the shaft further extending into and coupled to the sleeve so that a user is able to turn the switch for starting and controlling the flames;    a controlling unit to be supplied power by the battery, and having an electronic circuit to provide a timing function and multiple controlling buttons to set the controlling unit;    a driving unit mounted inside the housing and having a motor and a transmission coupled to the motor; and    a clutch unit having an axle extending from an inner surface of the housing, a barrel securely mounted around the axle and having a threaded outer surface formed thereon, the clutch unit also having a first gear and a second gear, the first gear coupled with the transmission and screwed on the barrel by mating a threaded bore defined through the first gear and the threaded outer surface of the barrel, a first toothed face formed on the first gear, the second gear coupled with the sleeve and mounted around the axle, a second toothed face formed on the second gear to mesh with the first toothed face, a spring mounted around the axle and compressed between the first gear and the second gear,    whereby a user is able to set the controlling unit to a preferred period so that once the period has elapsed, the controlling unit automatically activates the motor and thereby rotates the shaft to shut the gas stove off.    
     
     
         2 . The timer as claimed in  claim 1 , wherein the controlling unit further comprises a display mounted on the housing.  
     
     
         3 . The timer as claimed in  claim 1  wherein the sleeve has a gear portion formed thereon, and a toothed surface is formed on the second gear and meshed with the gear portion so as to couple the sleeve with the second gear.  
     
     
         4 . The timer as claimed in  claim 1 , wherein the barrel has an annular groove defined therearound, and a hair spring is mounted on the inner surface of the housing, a portion of the hair spring received in the annular groove and abutted to a surface defining the annular groove so as to secure the barrel with respect to the axle.  
     
     
         5 . The timer as claimed in claim  15  wherein the transmission comprises a set of secondary gears.  
     
     
         6 . The timer as claimed in  claim 1 , wherein the housing further has a case mounted therein, and an opening is defined in the housing and communicates with a hollow interior of the case so that the batteries is able to be fitted into the case via the opening.  
     
     
         7 . The timer as claimed in  claim 6  further comprising a cover detachably covering the opening.