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Electric cooking apparatus with safety control

  • US 4,217,482 A
  • Filed: 05/16/1977
  • Issued: 08/12/1980
  • Est. Priority Date: 05/16/1977
  • Status: Expired due to Term
First Claim
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1. In a cooking appliance having electric heating means and separate operating and safety contactors, each of said contactors having separable contact means connected in series with the heating means and each of said contactors having coil means that when energized close the contact means, and further having an operating thermostat effective with the operating contactor to cycle the heating means on and off to maintain the desired cooking temperature and further having a safety thermostat effective with the safety contactor to render the appliance inoperable in the event of a malfunctioning overheat condition, and further having a manual start actuator having normally open contact means and stop and reset actuators having normally closed contact means, the improvement comprising the combination of a control having a normally open contact means and a normally closed contact means and an actuating coil that when energized shifts and holds the said contact means to and in the closed and open conditions respectively, a first circuit including the start actuator and the normally closed contact means of the control, said first circuit being operable to energize the safety contactor coil means and initially close the contact means of the safety contactor upon momentary closure of the normally open start actuator contact means;

  • a second circuit including the initially closed contact means of the safety contactor, the normally closed contact means of the control, and the normally closed contact means of the stop actuator, said second circuit being operable to maintain the safety contactor coil energized through the closed contact means of the safety contactor upon the initial closure of said safety contactor contact means by said first circuit;

    a third circuit including the safety thermostat contact means operable to energize the coil of the control and open the normally closed contact means of the control in said second circuit and deenergize the safety contactor coil to open the safety contactor contact means, said coil also closing the normally open contact means of the control; and

    a fourth circuit including the closed normally open contact means of the control and the normally closed contact means of the reset actuator operable to maintain the coil of the control energized.

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