Safety door latching system for self-cleaning oven having hydraulic thermostat with cam-actuated auxiliary switch

Claim 2

In a high temperature self-cleaning oven, a temperature responsive control device, said device comprising a housing, an expansible member adjustably mounted through one wall of the housing and furnished with a remote temperature sensor, said expansible member expanding and contracting according to the direction and extent of temperature change of the said temperature sensor, and manual settable means combined with the expansible member for selecting a predetermined control temperature, electrical switching means including a switch actuator in the form of a snap-acting spring mechanism governed by the expansion and contraction of the expansible member, said switching means being adapted to be connected in a power circuit that governs the heating means for a self-cleaning oven, and an auxiliary switch means associated with the said thermostat housing and adapted to be connected in either a cooking circuit or an oven door locking control circuit, whereby the temperature responsive control device has a variable ''''bake'''' position between about 150* F. and about 550* F. and a fixed ''''clean'''' position somewhere between about 750* F. and about 950* F., the variable ''''bake'''' position being for substantially a complete revolution of the manual settable means with the auxiliary switch being set in a cooking circuit, while the fixed ''''clean'''' position of the control device actuates the auxiliary switch into its second oven door locking control circuit, the said manual settable means including camming means for governing the position of the auxiliary switch as a function of the position of the manual settable means.

Claim 3

In a high temperature self-cleaning oven, a hydraulic thermostat comprising a housing supporting an expansible member with a remote temperature sensor, a manual settable shaft extending through one wall of the housing and engaging the expansible member on its innermost end, thermostat switching means adapted to be connected in the oven heating circuits, a snap-acting switching mechanism connected to the switching means and acted upon by the expansible member, and auxiliary switch means combined with the thermostat housing and adapted to be connected in the oven heating circuits, said auxiliary switch means having a cooking position and a cleaning position, the thermostat shaft having a variable cooking range of about one revolution over a temperature scale between about 150* F. and about 550* F., the thermostat shaft also having a ''''clean'''' position upon continued rotation thereof within the temperature scale above about 750* F., the thermostat shaft having camming means for governing the actuation of the auxiliary switch means so that the cooking and ''''clean'''' positions of the auxiliary switch means will coincide with the cooking and ''''clean'''' positions of the thermostat shaft, said camming means including a mechanism for effecting snap-action of the auxiliary switch means.

Claim 4

In a high temperature self-cleaning oven, a hydraulic thermostat comprising a housing supporting an expansible member with a remote temperature sensor, a manual settable shaft extending through one wall of the housing and engaging the expansible member on its innermost end, thermostat switching means adapted to be connected in the oven heating circuits, a snap-acting switching mechanism connected to the switching means and acted upon by the expansible member, and auxiliary switch means combined with the thermostat housing and adapted to be connected in the oven heating circuits, said auxiliary switch means having a cooking position and a cleaning position, the thermostat shaft having a variable cooking range of about one revolution over a temperature scale between about 150* F. and about 550* F., the thermostat shaft also having a ''''clean'''' position upon continued rotation thereof within the temperature scale above about 750* F., the thermostat shaft having camming means for governing the actuation of the auxiliary switch means so that the cooking and ''''clean'''' positions of the auxiliary switch means will coincide with the cooking and ''''clean'''' positions of the thermostat shaft, said camming means including a mechanism for effecting snap-action of the auxiliary switch means.

Claim 5

In a High temperature self-cleaning oven, a hydraulic thermostat as recited in claim 2 wherein the said camming means includes a rotatable finger mounted on the thermostat shaft and a rotatable cam supported by the housing and engageable by the said finger to actuate said auxiliary switch in the transition of both the thermostat and the auxiliary switch between the cooking and the ''''clean'''' positions, the auxiliary switch including a movable spring contact member biased against the said cam and movable thereby.

Claim 6

In a high temperature self-cleaning oven, a hydraulic thermostat as recited in claim 3 wherein the thermostat knob is furnished with a dial that includes the cooking temperatures marked thereon, the dial including an opening at the top of the cooking temperature scale, the thermostat housing supporting an arcuate cantilever, ''''clean'''' indicia blade which underlies the dial and is adapted to protrude through the said opening and overlie a portion of the dial when the thermostat knob is turned to its ''''clean'''' position.

Claim 7

In a self-cleaning oven comprising an insulated cabinet supplied with an oven liner and an access door to form an oven cooking cavity, electrical heating means for said oven cavity, a circuit network adapted to connect the heating means to an electrical power supply, a manual selector switch means for the circuit network to effect cooking operations having normal cooking temperatures between about 150* F. and about 550* F., and door latching means movable between open and closed positions for holding the door closed during a heat-cleaning cycle when the oven temperatures are above the normal cooking temperatures for removing food soils lodged on the walls of the oven cavity, and locking means and a latch interlock switch means operated when the door latching means is closed for deactivating the release means whenever the heat-cleaning cycle is initiated, the invention comprising a door latch ''''clean'''' switch for bypassing the manual selector switch when the latch is closed, a manually settable oven thermostat having switch contact means in the circuit network which are closed when the oven temperature is below the temperature preset on the thermostat and which contact means are opened when the oven temperature reaches the said preset temperature, said thermostat having a temperature scale which covers the full range of coking and heat-cleaning temperatures, and an auxiliary switch combined with the thermostat and connected in the circuit network to have a cooking position and a ''''clean'''' position, and camming means interposed between the thermostat and the auxiliary switch for coordinating them in the cooking position and in the ''''clean'''' position, whereby the thermostat must be reset to a cooking position and the oven temperature must drop into the cooking temperature range before the said electroresponsive release means is energized to unlock the door latching means.

Claim 8

In a self-cleaning oven comprising an insulated cabinet supplied with an oven liner and an access door to form an oven cooking cavity, electrical heating means for said oven cavity, a circuit network adapted to connect the heating means to an electrical power supply, a manual selector switch means for the circuit network to effect cooking operations having normal cooking temperatures between about 150* F. and about 550* F., and door latching means movable between open and closed positions for holding the door closed during a heat-cleaning cycle when the oven temperatures are above the normal cooking temperatures for removing food soils lodged on the walls of the oven cavity, and locking means and a latch interlock switch means operated when the door latching means is closed for deactivating the release means whenever the heat-cleaning cycle is initiated, the invention comprising a door latch ''''clean'''' switch for bypassing the manual selector switch when the latch is closed, a manually settable oven thermostat having switch contact means in the circuit network which are closed when the oven temperature is below the temperature preset on the thermostat and which contact means are opened when the oven temperature reaches the said preset temperature, said thermostat having a temperature scale which covers the full range of coking and heat-cleaning temperatures, and an auxiliary switch combined with the thermostat and connected in the circuit network to have a cooking position and a ''''clean'''' position, and camming means interposed between the thermostat and the auxiliary switch for coordinating them in the cooking position and in the ''''clean'''' position, whereby the thermostat must be reset to a cooking position and the oven temperature must drop into the cooking temperature range before the said electroresponsive release means is energized to unlock the door latching means.

Claim 9

In a self-cleaning oven as recited in claim 5 wherein the said manually settable thermostat has a knob with a variable cooking range of about one revolution over a temperature scale between about 150* F. and about 550* F., the thermostat knob also having a ''''clean'''' position upon continued rotation thereof to reach a maximum temperature setting of about 950* F., the said camming means being associated with the thermostat knob and including a toggle mechanism for effecting snap-action of the auxiliary switch means.

Claim 10

In a self-cleaning oven as recited in claim 6 wherein the said camming means includes a rotatable finger mounted to the thermostat knob and a rotatable cam that is engageable by the said finger in the transition of both the thermostat and the auxiliary switch between the cooking and the ''''clean'''' positions, the auxiliary switch including a movable spring contact member pressed against the said tumbler and movable thereby.

Claim 11

In a self-cleaning oveN as recited in claim 7 wherein the thermostat knob is furnished with a dial that indicates the range of cooking temperatures, the dial including an opening at the top of the cooking temperature scale, the thermostat including a housing that supports an arcuate cantilever ''''clean'''' indicia indicator which underlies the dial and is adapted to protrude through the said opening and overlie a portion of the dial when the thermostat knob is turned to its ''''clean'''' position.

Claim 12

A self-cleaning oven comprising walls defining an oven cavity, one wall of the cavity including a door for gaining access thereto, a source of electric power supply, a first ''''baking'''' circuit adapted to be completed to said power source, a second ''''broiling'''' circuit adapted to be completed to said power source, and a third ''''clean'''' circuit adapted to be completed to said power source, a manual selector switch having an ''''OFF'''' position, a ''''bake'''' position and a ''''broil'''' position, said manual selector switch in its ''''OFF'''' position interrupting both of said positions, said selector switch in its ''''bake'''' position preparing said first ''''bakig'''' circuit, said selector switch in its ''''broil'''' position preparing aid second ''''broiling'''' circuit, an adjustable oven thermostat having a variable ''''bake'''' position, a fixed ''''broil'''' position and a ''''clean'''' position, said thermostat in its variable ''''bake'''' position correspondingly presetting a variable ''''bake'''' temperature for said cooking cavity in the normal cooking temperature range extending from about 150* F. to about 550* F., said thermostat in its ''''broil'''' position correspondingly presetting a broil temperature substantially near 550* F., said thermostat in its ''''clean'''' position presetting a given heat-cleaning temperature for said cooking cavity in the temperature range above about 750* F., door latching means movable between open and closed positions for holding the door closed during the heat-cleaning operation, locking means for locking the door lathing means, an electroresponsive means for releasing the locking means, and a latch interlock switch means having a first open latch position and a second closed latch position, the thermostat including an auxiliary switch means having a first cooking switch position in series with the thermostat and selector switch means and a second ''''cleaning'''' switch position to be in circuit with the first open latch position of the latch interlock switch means and the electroresponsive means when the door latching means is in an open position, said electroresponsive means being in circuit with the second closed position of the latch interlock switch and the thermostat and first cooking position of the auxiliary switch means.

Claim 13

A self-cleaning oven comprising walls defining an oven cavity, one wall of the cavity including a door for gaining access thereto, a source of electric power supply, a first ''''baking'''' circuit adapted to be completed to said power source, a second ''''broiling'''' circuit adapted to be completed to said power source, and a third ''''clean'''' circuit adapted to be completed to said power source, a manual selector switch having an ''''OFF'''' position, a ''''bake'''' position and a ''''broil'''' position, said manual selector switch in its ''''OFF'''' position interrupting both of said positions, said selector switch in its ''''bake'''' position preparing said first ''''bakig'''' circuit, said selector switch in its ''''broil'''' position preparing aid second ''''broiling'''' circuit, an adjustable oven thermostat having a variable ''''bake'''' position, a fixed ''''broil'''' position and a ''''clean'''' position, said thermostat in its variable ''''bake'''' position correspondingly presetting a variable ''''bake'''' temperature for said cooking cavity in the normal cooking temperature range extending from about 150* F. to about 550* F., said thermostat in its ''''broil'''' position correspondingly presetting a broil temperature substantially near 550* F., said thermostat in its ''''clean'''' position presetting a given heat-cleaning temperature for said cooking cavity in the temperature range above about 750* F., door latching means movable between open and closed positions for holding the door closed during the heat-cleaning operation, locking means for locking the door lathing means, an electroresponsive means for releasing the locking means, and a latch interlock switch means having a first open latch position and a second closed latch position, the thermostat including an auxiliary switch means having a first cooking switch position in series with the thermostat and selector switch means and a second ''''cleaning'''' switch position to be in circuit with the first open latch position of the latch interlock switch means and the electroresponsive means when the door latching means is in an open position, said electroresponsive means being in circuit with the second closed position of the latch interlock switch and the thermostat and first cooking position of the auxiliary switch means.

Claim 14

In a high temperature oven comprising walls defining an oven cavity, one wall of the cavity including a door for gaining access thereto, heating means for supplying heat to the oven cavity for normal cooking temperatures between about 150* F. and 550* F. and a self-cleaning oven cycle with a maximum temperature above about 750* F., door latching means movable between an open and a closed position for holding the door closed during a high temperature operation above normal cooking temperatures, locking means for locking the door latching means in its closed position, and electroresponsive means for releasing the said locking means; the improvement comprising a manual control thermostat having thermally controlled switch contact means for governing power delivered to the heating means and auxiliary switch contact means settable into a cooking or a high temperature position as a function of the setting of the thermostat into a cooking or a high temperature position respectively, a latch interlock switch means having an unlatched and a latched position governed by the position oF the door latching means, and circuit means including said thermostat and said latch interlock switch for controlling the energization of said electroresponsive means thereby to allow latching and unlatching of said door, said circuit means having a first circuit actuated through said auxiliary switch contact means when said thermostat is set to the high temperature position to allow latching of the door, and a second circuit actuated through said auxiliary switch contact means and said thermally controlled switch contact means to allow unlatching of the door, said second circuit being closed only when said thermostat is reset into a cooking temperature position and the temperature in the oven cavity returns to the cooking temperature setting of the thermostat thereby to prevent opening of the door during high temperature operations.

Claim 15

In a high temperature oven comprising walls defining an oven cavity, one wall of the cavity including a door for gaining access thereto, heating means for supplying heat to the oven cavity for normal cooking temperatures between about 150* F. and 550* F. and a self-cleaning oven cycle with a maximum temperature above about 750* F., door latching means movable between an open and a closed position for holding the door closed during a high temperature operation above normal cooking temperatures, locking means for locking the door latching means in its closed position, and electroresponsive means for releasing the said locking means; the improvement comprising a manual control thermostat having thermally controlled switch contact means for governing power delivered to the heating means and auxiliary switch contact means settable into a cooking or a high temperature position as a function of the setting of the thermostat into a cooking or a high temperature position respectively, a latch interlock switch means having an unlatched and a latched position governed by the position oF the door latching means, and circuit means including said thermostat and said latch interlock switch for controlling the energization of said electroresponsive means thereby to allow latching and unlatching of said door, said circuit means having a first circuit actuated through said auxiliary switch contact means when said thermostat is set to the high temperature position to allow latching of the door, and a second circuit actuated through said auxiliary switch contact means and said thermally controlled switch contact means to allow unlatching of the door, said second circuit being closed only when said thermostat is reset into a cooking temperature position and the temperature in the oven cavity returns to the cooking temperature setting of the thermostat thereby to prevent opening of the door during high temperature operations.

Claim 16

In a high temperature oven comprising walls defining an oven cavity, one wall of the cavity including a door for gaining access thereto, heating means for supplying heat to the oven cavity for normal cooking temperatures between about 150* F. and 550* F. and a self-cleaning oven cycle with a maximum temperature above about 750* F., door latching means movable between an open and a closed position for holding the door closed during a high temperature operation above normal cooking temperatures, locking means for locking the door latching means in its closed position, and electroresponsive means for releasing the said locking means; the improvement comprising a manual control thermostat having thermally controlled switch contact means for governing power delivered to the heating means and auxiliary switch contact means settable into a cooking or a high temperature position as a function of the setting of the thermostat into a cooking or a high temperature position respectively, a latch interlock switch means having an unlatched and a latched position governed by the position of the door latching means, and circuit means including said thermostat and said latch interlock switch for controlling the energization of said electroresponsive means to prevent opening of the door when the oven cavity is in a high temperature mode, said circuit means incorporating both the auxiliary switch contact means and the thermally controlled switch contact means of said thermostat and being arranged to disable the electroresponsive means after latching of the door unless the thermostat is set in its cooking position and the temperature of the oven cavity returns to the cooking temperature setting of the thermostat.

Claim 17

In a high temperature oven comprising walls defining an oven cavity, one wall of the cavity including a door for gaining access thereto, heating means for supplying heat to the oven cavity for normal cooking temperatures between about 150* F. and 550* F. and a self-cleaning oven cycle with a maximum temperature above about 750* F., door latching means movable between an open and a closed position for holding the door closed during a high temperature operation above normal cooking temperatures, locking means for locking the door latching means in its closed position, and electroresponsive means for releasing the said locking means; the improvement comprising a manual control thermostat having thermally controlled switch contact means for governing power delivered to the heating means and auxiliary switch contact means settable into a cooking or a high temperature position as a function of the setting of the thermostat into a cooking or a high temperature position respectively, a latch interlock switch means having an unlatched and a latched position governed by the position of the door latching means, and circuit means including said thermostat and said latch interlock switch for controlling the energization of said electroresponsive means to prevent opening of the door when the oven cavity is in a high temperature mode, said circuit means incorporating both the auxiliary switch contact means and the thermally controlled switch contact means of said thermostat and being arranged to disable the electroresponsive means after latching of the door unless the thermostat is set in its cooking position and the temperature of the oven cavity returns to the cooking temperature setting of the thermostat.

Claim 18

In a high temperature oven as recited in claim 10 with the addition of circuit means including an oven selector switch for governing variable heating rates of the said heating means during cooking, and a latch clean switch having a first normal cooking position in series with the oven selector switch and a second clean position that is set when the door latching means is closed for bypassing the said oven selector switch and setting up a high temperature heating circuit.