Method and apparatus of controlling operation of range top heating elements for cooking

• US 6,246,033 B1
• Filed: 12/07/1999
• Issued: 06/12/2001
• Est. Priority Date: 12/07/1999
• Status: Expired due to Term

• Current Assignee: Pioneering Technology Corp
• Original Assignee: Reza H. Shah
• Inventors: Shah, Reza H.
• Primary Examiner(s): PAIK, SANG YEOP
• Application Number:
  US09/455,925
• Time in Patent Office: 553 Days
• Field of Search: 219/446.1, 219/447.1, 219/448.11, 219/448.12, 219/448.13, 219/493, 219/494, 219/509, 219/510
• US Class Current: 219/447.1
• CPC Class Codes: A47J 27/62 by devices for automatically controlling the heat supply by switching off heaters or for automatically lifting the cooking-vessels
• CPC Class Codes: H05B 2213/05 Heating plates with pan detection means
• CPC Class Codes: H05B 2213/07 Heating plates with temperature control means
• CPC Class Codes: H05B 3/68 Heating arrangements specially adapted for cooking plates or analogous hot-plates
• CPC Class Codes: H05B 3/746 Protection, e.g. overheat cutoff, hot plate indicator

Abstract

A method and device for controlling and limiting the cooking temperature of any selected utensil for cooking on a surface burner element of a range are shown. A temperature sensor is provided either on a heat transfer plate which is mounted to the burner element or in a remote-controlled unit mounted directly to the utensil. The actual temperature of the utensil is compared with the selected cooking temperature, and it is then adjusted to maintain the two temperatures close to each other. The device also automatically turns off the burner element in a potential runaway condition or in the absence of a utensil placed thereon.

Claims

1. A device for controlling the cooking temperature of a surface burner element of a cooking range having a heat control switch connected in series with said burner element for controlling energization of said burner element, comprising

a heat transfer metal plate removably mounted in a fixed position on top of said burner element, said metal plate having a uniformly flat top surface and a flat under surface, said top surface being adapted to contact with the entirety of a cooking base of a utensil placed on said metal plate whereby said metal plate and said cooking base have an identical temperature, and said under surface being always in contact with said top of said burner element,

a temperature sensing means mounted in contact with said under surface of said metal plate, said temperature sensing means having a predetermined opening temperature,

a relay means having switching contacts connected in series with said burner element and said heat control switch, and said relay means being connected in series with said temperature sensing means and adapted to open said switching contacts to de-energize said burner element when said temperature sensing means detects a temperature at said metal plate higher than said predetermined opening temperature of said temperature sensing means.

2. A device according to claim 1 wherein said temperature sensing means is a thermostat having a heat sensing surface abutting said under surface of said metal plate.

3. A device according to claim 2 wherein said relay means has a low voltage operating coil operated with a direct current input voltage.

4. A device according to claim 3 including a transformer means having a low input voltage secondary connected to said low voltage operating coil of said relay means and said thermostat.

5. A device according to claim 4 including a rectifier means connected to the secondary of said transformer means and said low voltage operating coil of said relay means, and being operative to energize said low voltage operating coil of said relay means to close said relay contacts when temperature of said metal plate is lower than said predetermined opening temperature of said thermostat.

6. A device for controlling the cooking temperature of a surface burner element of a cooking range having a heat control switch connected in series with said burner element for controlling energization of said burner element, comprising

a heat transfer metal plate removably mounted on top of said burner element, said metal plate having a uniform flat top surface and a flat under surface, said top surface being adapted to contact with the entirety of a bottom cooking base of a cooking utensil placed on said heat transfer metal plate whereby said heat transfer metal plate and said cooking base always have an identical temperature, and said under surface being in constant contact with said top of said burner element,

a thermocouple having a temperature sensing means mounted in contact with said under surface of said heat transfer metal plate,

a switching circuit means connected to said thermocouple, said switching circuit means operative to become open circuit when said temperature sensing means detecting temperature of said heat transfer metal plate rising above a predetermined temperature,

a relay means having electrical switching contacts connected in series with said burner element and said heat control switch, and having a low voltage energization coil connected in series with said switching circuit means,

a transformer means having a low voltage secondary output connected to said low voltage energization coil of said relay means and said switching circuit means, and being operative to energize said low voltage energization coil of said relay means to close said electrical switching contacts when temperature of said heat transfer metal plate is less than said predetermined temperature.

7. A device according to claim 6 wherein said temperature sensing means is a heat sensing junction mounted to a washer member, and said washer member is mounted to said metal plate with said heat sensing junction abutting said metal plate.

8. A device for controlling the cooking temperature of a surface burner element of a cooking range having a heat control switch connected in series with said burner element for controlling energization of said burner element, comprising

a heat transfer metal plate fixedly mounted on top of said burner element, said metal plate having a uniform flat top surface and a flat under surface, said top surface being adapted to contact with the entirety of a cooking base of a cooking utensil placed on said metal plate whereby said metal plate and said cooking base have an identical temperature, and said under surface being in constant contact with said top of said burner element,

a temperature sensing means operative to be mounted on said cooking utensil, said temperature sensing means including a thermocouple junction adapted to contact a side surface of said cooking utensil and operative to provide an electrical signal representative of temperature of said metal plate, and an electronic transmission means operative by said electrical signal to emit a transmission signal representative of said temperature of said metal plate,

an electronic receiver means mounted on said cooking range, said electronic receiver means including a relay means having switching contacts connected in series with said burner element and said heat control switch, and having a low voltage actuation coil connected to a switching means operative by said transmission signal, a transformer means having a low voltage secondary connected to said low voltage actuation coil of said relay means and adapted to energize said relay means to open said switching contact when said temperature sensing means detecting a temperature at said metal plate higher than a predetermined temperature.

9. A device according to claim 8 including a fail-safe means in said electronic receiver means operative to de-energize said burner element to prevent a runaway condition to occur in said burner element in absence of a cooking utensil placed on said metal plate.