Switch with adjustable spring

A switch comprising:

• a base having an open top for a button being engaged therewith, three slots defined through a bottom of the base and three terminal plates respectively inserted in the slots, a groove defined in an inside of the base and an adjusting hole defined in the base and communicating with the groove, a first contact point connected to one of the terminal plates;
• a bimetal plate located in the base and a recess defined in a first end of the bimetal plate, an N-shaped spring having one end thereof engaged with the groove in the inside of the base, the other end of the N-shaped spring received in the recess in the bimetal plate;
• a swing member pivotally connected between two opposite insides of the base and a recess defined in a top of the swing member, a cone-shaped protrusion extending from a top of the swing member and located in the recess so as to define two notches separated by the protrusion, a connection plate connected between an end of the swing member and the first end of the bimetal plate;
• a pushing rod having an enlarged head at a top end of the pushing rod and a spring mounted to the pushing rod, the enlarged head contacting an underside of the button and a lower end of the pushing rod located in one of the two notches in the swing member, and
• an adjusting member movably engaged with the adjusting hole and an end of the adjusting member contacting the N-shaped spring in the groove.