Oven with temperature limiting protection and indicating system

Claim 2

In an oven comprising an oven liner and a front-opening access door forming an oven cooking cavity, an oven control panel having a time clock, a clock motor for operating said time clock, heating means for cooking food placed within the cavity as well as for pyrolytically removing food soil from the inner wall surfaces of the oven cavity, oven thermostat means including oven temperature responsive switch means in power supply relationship with said heating means for controlling said heating means below a predetermined temperature limit, an oven vent in an upper wall of the oven liner, means communicating with the oven vent for degrading the hot oven gases before they are returned to the atmosphere, duct means connected to said degrading means for discharging the degraded hot oven gases to the atmosphere, an inner oven cabinet surrounding the oven liner, insulation between said oven liner and said inner oven cabinet encompassing said duct means, an outer oven cabinet surrounding the inner oven cabinet but spaced therefrom to form an air passageway therebetween, a transverse partition in the air passageway to form a plenum chamber, fan means mounted through the partition and adapted to blow cooling air through said air passageway, and an air outlet opening from the plenum chamber, the invention comprising an over-temperature protective means protecting against failure of said fan means and said oven thermostat means and an indicating means for indicating said failure, said protective means including a temperature limiting thermostatic switch means and a sensing means, said sensing means supporting said temperature limiting thermostatic switch means and extending through said inner oven cabinet and said insulation toward said duct means to define with said insulation a heat sensing chimney which conveys heat to said sensing means from the degrated hot oven gases in said duct means as a measure of the temperature of said oven cavity, said temperature limiting thermostatic switch means including a single limit switch only in series electrical supply relationship with said oven temperature responsive switch means and having a first limit switch actuating portion in temperature sensing relation with said sensing means to sense an over-temperature condition in said oven cavity and a second limit switch actuating portion in heat transfer with the cooling air blown by said fan means to sense a failure condition of said fan means to blow cooling air through said air passageway, thereby to terminate heating in said oven cavity by interrupting power supply to said heating means upon occurrence of either of said conditions, and said indicating means including said time clock and said clock motor, said single limit switch in series electrical supply relationship with said clock motor, thereby to stop said time clock simultaneously with the interruption of power supply to said heating means.

Claim 3

In an oven comprising an oven liner and a front-opening access door forming an oven cooking cavity, an oven control panel having a time clock including a clock timer switch, a clock motor for operating said time clock and said clock timer switch, heating means operated by said clock timer switch for cooking food placed within the cavity in accordance with a timed program as well as for pyrolytically removing food soil from the inner wall surfaces of the oven cavity, oven thermostat means including oven temperature responsive switch means in power supply relationship with said heating means for controlling said heating means below a predetermined temperature limit, an oven vent in an upper wall of the oven liner, a catalytic oxidation unit communicating with the oven vent for degrading the hot oven gases before they are returned to the atmosphere, duct means connected to the oxidation unit for discharging the degraded hot oven gases to the atmosphere, an inner oven cabinet surrounding the oven liner, insulation between said oven liner and said inner oven cabinet encompassing said duct means, an outer oven cabinet surrounding the inner oven cabinet but spaced therefrom to form an air passageway therebetween, a transverse partition in the air passageway to form a plenum chamber, fan means mounted through the partition and adapted to blow cooling air through said air passageway, and an air outlet opening from the plenum chamber, the invention comprising an over-temperature protective means protecting against failure of said fan means and said oven thermostat means and an indicating means for indicating said failure, said protective means including a temperature limiting thermostatic switch means and a sensing ferrule, said ferrule supporting said temperature limiting thermostatic switch means and extending through said inner oven cabinet and said insulation toward said duct means to define with said insulation a heat sensing chimney which conveys heat to said ferrule from the degraded hot oven gases in said duct means as a measure of the temperature of said oven cavity, said temperature limiting thermostatic switch means including a single limit switch only in series electrical supply relationship with said oven temperature responsive switch means and having a first limit switch actuating portion in temperature sensing relation with said ferrule to sense an over-temperature condition in said oven cavity and a second limit switch actuating portion in heat transfer with the cooling air blown by said fan means to sense a failure condition of said fan means to blow cooling air through said air passageway, thereby to terminate heating in said oven cavity by interrupting power supply to said heating means upon occurrence of either of said conditions, and said indicating means including said time clock and said clock motor, said single limit switch in series electrical supply relationship with said clock motor, thereby to stop said time clock simultaneously with the interruption of power supply to said heating means.

Claim 4

In an oven comprising an oven liner and a front-opening access door forming an oven cooking cavity, an oven control panel having a time clock including a clock timer switch, a clock motor for operating said time clock and said clock timer switch, heating means operated by said clock timer switch for cooking food placed within the cavity in accordance with a timed program as well as for pyrolytically removing food soil from the inner wall surfaces of the oven cavity, oven thermostat means including oven temperature responsive switch means in power supply relationship with said heating means for controlling said heating means below a predetermined temperature limit, an oven vent in an upper wall of the oven liner, a catalytic oxidation unit communicating with the oven vent for degrading the hot oven gases before they are returned to the atmosphere, duct means connected to the oxidation unit for discharging the degraded hot oven gases to the atmosphere, an inner oven cabinet surrounding the oven liner, insulation between said oven liner and said inner oven cabinet encompassing said duct means, an outer oven cabinet surrounding the inner oven cabinet but spaced therefrom to form an air passageway therebetween, a transverse partition in the air passageway to form a plenum chamber, fan means mounted through the partition and adapted to blow cooling air through said air passageway, and an air outlet opening from the plenum chamber, the invention comprising an over-temperature protective means protecting against failure of said fan means and said oven thermostat means and an indicating means for indicating said failure, said protective means including a temperature limiting thermostatic switch means and a sensing ferrule, said ferrule supporting said temperature limiting thermostatic switch means and extending through said inner oven cabinet and said insulation toward said duct means to define with said insulation a heat sensing chimney which conveys heat to said ferrule from the degraded hot oven gases in said duct means as a measure of the temperature of said oven cavity, said temperature limiting thermostatic switch means including a single limit switch only in series electrical supply relationship with said oven temperature responsive switch means and having a first limit switch actuating portion in temperature sensing relation with said ferrule to sense an over-temperature condition in said oven cavity and a second limit switch actuating portion in heat transfer with the cooling air blown by said fan means to sense a failure condition of said fan means to blow cooling air through said air passageway, thereby to terminate heating in said oven cavity by interrupting power supply to said heating means upon occurrence of either of said conditions, and said indicating means including said time clock and said clock motor, said single limit switch in series electrical supply relationship with said clock motor, thereby to stop said time clock simultaneously with the interruption of power supply to said heating means.

Claim 5

In an oven comprising an oven liner and a front-opening access door forming an oven cooking cavity, an oven control panel having a time clock, a clock motor for operating said time clock, heating means for cooking food placed within the cavity, oven thermostat means including oven temperature responsive Switch means in power supply relationship with said heating means for controlling said heating means below a predetermined temperature limit, an oven vent in an upper wall of the oven liner, duct means connected to said oven vent for discharging hot oven gases to the atmosphere, an inner oven cabinet surrounding the oven liner, insulation between said oven liner and said inner oven cabinet encompassing said duct means, an outer oven cabinet surrounding the inner oven cabinet but spaced therefrom to form an air passageway therebetween, a transverse partition in the air passageway to form a plenum chamber, fan means mounted through the partition and adapted to blow cooling air through said air passageway, and an air outlet opening from the plenum chamber, the invention comprising an over-temperature protective means protecting against failure of said fan means and said oven thermostat means and an indicating means for indicating said failure, said protective means including a temperature limiting thermostatic switch means and means for sensing the heat of said oven gases, said sensing means supporting said temperature limiting thermostatic switch means and extending through said inner oven cabinet and said insulation into heat sensing relation with the oven gases in said duct means as a measure of the temperature of said oven cavity, said temperature limiting thermostatic switch means including a single limit switch only in series electrical supply relationship with said oven temperature responsive switch means and having a first limit switch actuating portion in temperature sensing relation with said sensing means to sense an over-temperature condition in said oven cavity and a second limit switch actuating portion in heat transfer with the cooling air blown by said fan means to sense a failure condition of said fan means to blow cooling air through said air passageway, thereby to terminate heating in said oven cavity by interrupting power supply to said heating means upon occurrence of either of said conditions, and said indicating means including said time clock and said clock motor, said single limit switch in series electrical supply relationship with said clock motor, thereby to stop said time clock simultaneously with the interruption of power supply to said heating means.

Claim 6

In an oven comprising an oven liner and a front-opening access door forming an oven cooking cavity, an oven control panel having a time clock, a clock motor for operating said time clock, heating means for cooking food placed within the cavity, oven thermostat means including oven temperature responsive Switch means in power supply relationship with said heating means for controlling said heating means below a predetermined temperature limit, an oven vent in an upper wall of the oven liner, duct means connected to said oven vent for discharging hot oven gases to the atmosphere, an inner oven cabinet surrounding the oven liner, insulation between said oven liner and said inner oven cabinet encompassing said duct means, an outer oven cabinet surrounding the inner oven cabinet but spaced therefrom to form an air passageway therebetween, a transverse partition in the air passageway to form a plenum chamber, fan means mounted through the partition and adapted to blow cooling air through said air passageway, and an air outlet opening from the plenum chamber, the invention comprising an over-temperature protective means protecting against failure of said fan means and said oven thermostat means and an indicating means for indicating said failure, said protective means including a temperature limiting thermostatic switch means and means for sensing the heat of said oven gases, said sensing means supporting said temperature limiting thermostatic switch means and extending through said inner oven cabinet and said insulation into heat sensing relation with the oven gases in said duct means as a measure of the temperature of said oven cavity, said temperature limiting thermostatic switch means including a single limit switch only in series electrical supply relationship with said oven temperature responsive switch means and having a first limit switch actuating portion in temperature sensing relation with said sensing means to sense an over-temperature condition in said oven cavity and a second limit switch actuating portion in heat transfer with the cooling air blown by said fan means to sense a failure condition of said fan means to blow cooling air through said air passageway, thereby to terminate heating in said oven cavity by interrupting power supply to said heating means upon occurrence of either of said conditions, and said indicating means including said time clock and said clock motor, said single limit switch in series electrical supply relationship with said clock motor, thereby to stop said time clock simultaneously with the interruption of power supply to said heating means.