Thermal switch

Claim 2

A multiple point, thermally-responsive switch assembly comprising: a base; a housing attached to said base; a plurality of switch means attached to said housing; rigid, motion-amplifier means hingedly attached to said base, said amplifier means operationally engaging said switch means; temperature responsive means attached to said base, said temperature responsive means having a driver; and a universal motion translator operatively coupled in tension said driver and said amplifier means to further effect opening and closing of said temperature responsive means being exposed to predetermined temperatures.

Claim 3

The invention of claim 1 wherein the temperature responsive means is a thermostat of the differential expansion type having an outer tube secured to the base and an inner driver secured to the tube at the free end thereof, the driver being formed of a material having a much lower coefficient of thermal expansion than that of the outer tube material.

Claim 4

The invention of claim 1 wherein the rigid amplifier means is a lever for transferring motion from said driver to said switch means to effect opening and closing thereof.

Claim 5

The invention of claim 1 wherein the universal motion translator is a ball and socket joint.

Claim 6

A double-point, thermally-responsive switch assembly comprising: a base; a housing attached to said base; a pair of switch means attached to said housing; a rigid, motion-amplifier lever hingedly attached to said base, the amplifier lever operationally engaging said switch means; a differential expansion thermostat having an outer tube secured to said base and an inner rod driver secured to the tube at the free end thereof; a motion translator of the ball and socket type operatively coupled in tension said lever with said driver for effecting the opening and closing of said switch upon said thermostat being exposed to predetermined temperatures; bias means for compressively maintaining said lever in positive contact with said motion translator ball; and calibration means located in said housing individually adjusting the temperature at which each of said switch means will be caused to be switched by said lever and, thereby, by said thermostat.

Claim 7

A double-point, thermally-responsive switch assembly comprising: a base; a housing attached to said base; a pair of switch means attached to said housing; a rigid, motion-amplifier lever hingedly attached to said base, the amplifier lever operationally engaging said switch means; a differential expansion thermostat having an outer tube secured to said base and an inner rod driver secured to the tube at the free end thereof; a motion translator of the ball and socket type operatively coupled in tension said lever with said driver for effecting the opening and closing of said switch upon said thermostat being exposed to predetermined temperatures; bias means for compressively maintaining said lever in positive contact with said motion translator ball; and calibration means located in said housing individually adjusting the temperature at which each of said switch means will be caused to be switched by said lever and, thereby, by said thermostat.

Claim 8

The invention of claim 5 wherein a first of said switch means is of the normally-closed, single-pole, single-throw type, and a second of said switch means is of the single-pole, double-throw type, adapted first to close a set of normally-open contacts at a calibratable predetermined temperature, then, after a short temperature dwell, to open a set of normally-closed contacts while still holding closed the normally-open contacts.

Claim 9

The invention of claim 5 wherein the calibration means is a threaded adjustment at the free end of the driver combined with a nut forming a part of the ball and socket motion translator, and a set screw adjustment for biasing the contacts of one of said switch means.

Claim 10

The invention of claim 5 wherein the thermostat driver is formed of a material having a much lower coefficient of thermal expansion than that of the material of the outer tube.

Claim 11

A double-point, thermally-responsive, control switch assembly for a self-cleaning electric oven comprising: an electrically-insulating housing; a metallic cover for said housing; a first switch of the normally-closed, single-pole, single-throw type, the switch being secured within said housing; a second switch of the single-pole, double-throw, rocker-arm type, the switch being secured within said housing and having first, normally-open contacts and second, normally-closed contacts; a rigid, metal, motion-amplifier lever hingedly attached at a point off-center thereof to said cover, the lever having an abutment of insulating material located at a free end of the lever further from the hinge point thereof and adapted to operationally engage said first and second switches; a differential expansion thermostat having an elongated outer tube secured to said base and an inner, rod driver secured to the tube at the free end thereof, the driver being formed of a material having a much lower coefficient of thermal expansion than that of the material of the outer tube, the thermostat being adapted to project within the oven to sense the temperature therewithin; a ball and socket joint motion translator operationally coupled in tension said lever at a free end nearer the hinge point thereof with the free end of said driver for effecting the opening of said first switch upon the thermostat being exposed to predetermined elevated temperatures, and closing of the normally-open contacts of said second switch, and after a short temperature dwell, the opening of the normally-closed contacts of said second switch while holding closed the normally-open contacts; compressive bias means disposed between said lever and said cover for maintaining said lever in positive contact with said motion translator ball; and calibration means for adjusting the temperature at which each of said switches will be caused to be switched by said lever and thereby, by said thermostat, including a threaded adjustment at the free end of said driver combined with a nut forming a part of said ball and socket motion translator, and a set-screw adjustment for biasing said normally-open contacts of said second switch.

Claim 12

A double-point, thermally-responsive, control switch assembly for a self-cleaning electric oven comprising: an electrically-insulating housing; a metallic cover for said housing; a first switch of the normally-closed, single-pole, single-throw type, the switch being secured within said housing; a second switch of the single-pole, double-throw, rocker-arm type, the switch being secured within said housing and having first, normally-open contacts and second, normally-closed contacts; a rigid, metal, motion-amplifier lever hingedly attached at a point off-center thereof to said cover, the lever having an abutment of insulating material located at a free end of the lever further from the hinge point thereof and adapted to operationally engage said first and second switches; a differential expansion thermostat having an elongated outer tube secured to said base and an inner, rod driver secured to the tube at the free end thereof, the driver being formed of a material having a much lower coefficient of thermal expansion than that of the material of the outer tube, the thermostat being adapted to project within the oven to sense the temperature therewithin; a ball and socket joint motion translator operationally coupled in tension said lever at a free end nearer the hinge point thereof with the free end of said driver for effecting the opening of said first switch upon the thermostat being exposed to predetermined elevated temperatures, and closing of the normally-open contacts of said second switch, and after a short temperature dwell, the opening of the normally-closed contacts of said second switch while holding closed the normally-open contacts; compressive bias means disposed between said lever and said cover for maintaining said lever in positive contact with said motion translator ball; and calibration means for adjusting the temperature at which each of said switches will be caused to be switched by said lever and thereby, by said thermostat, including a threaded adjustment at the free end of said driver combined with a nut forming a part of said ball and socket motion translator, and a set-screw adjustment for biasing said normally-open contacts of said second switch.

Claim 13

The invention of claim 9 wherein said first switch is of the high current, switch-blade type adapted to flex only at the hinge point to open the contacts, said switch further having compressive bias means for maintaining the contact points in tightly-closed engagement, and wherein said second switch has compressive bias means for maintaining said normally-closed contacts in tightly-closed engagement and for maintaining open the normally-open contacts.