Push-to-start appliance program timer and method utilizing snap-action switch

A push-to-start appliance program timer for use with an appliance, comprising:

• a housing;
• a program cam stack defining at least one program cycle thereon;
• a plurality of switches responsive to the at least one program cycle operable to control operation of the appliance during the program cycle;
• a shaft in rotary driving engagement with the cam stack, the shaft being linearly translatable within the housing along an axis of the shaft through the cam stack, the shaft further having an actuation wheel integrated therewith;
• a snap-action start switch;
• an actuation lever positioned within the housing to translate linear movement of the shaft to actuate the snap-action switch;
• and
• wherein the snap-action start switch includes an actuation surface and a push button, and wherein the actuation lever translates the linear movement of the shaft to a normal direction by sliding along the actuation surface to actuate the push button.

A push-to-start appliance program timer for use with an appliance, comprising:

• a housing;
• a program cam stack defining at least one program cycle thereon;
• a plurality of switches responsive to the at least one program cycle operable to control operation of the appliance during the program cycle;
• a shaft in rotary driving engagement with the cam stack, the shaft being linearly translatable within the housing along an axis of the shaft through the cam stack, the shaft further having an actuation wheel integrated therewith;
• a snap-action start switch;
• an actuation lever positioned within the housing to translate linear movement of the shaft to actuate the snap-action switch;
• a bias means for returning the shaft to a quiescent position within the housing;
• and
• wherein the snap-action start switch includes an outwardly biased push button operably coupled through an actuation surface to the actuation lever.

An appliance program timer, comprising:

• a shaft configured to accommodate a user interface knob affixed on an end thereof;
• a program control mechanism responsive to a rotary position of the shaft to control operation of an appliance;
• a snap-action start switch responsive to a linear translation of the shaft to a first position to close electrical contacts therein to begin a selected program cycle and to a second position to open the electrical contacts therein;
• and
• wherein the first position and the second position are selected to provide linear positional hysteresis for the actuation of the snap-action start switch.

A method of providing a push-to-start function in an appliance program timer having a shaft that is rotatable to select a desired program cycle and linearly translatable from an outward biased position to an inward depressed position to start the program cycle, comprising the steps of:

• providing a snap-action start switch;
• actuating the snap-action start switch to close electrical contacts therein upon linear translation of the shaft to a first position;
• and
• actuating the snap-action start switch to open the electric contacts therein upon linear translation of the shaft to a second position.