US3870859A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Control system for frying apparatus
Assignee: Frymaster LLC
•
Filing: 1974-06-17
•
Granted: 1975-03-11
•
Expires: 1994-06-17
Abstract
Abstract In apparatus for deep fat frying, control circuitry is provided for regulating the temperature of heating elements. During cooking the heating elements are immersed in cooking fluid and are maintained at a selected temperature by an operating thermostat. Two high limit thermostats are provided to turn off the heaters if the temperature exceeds a predetermined safe limit. For cleaning, the heating elements are raised out of the cooking fluid and automatically disconnected from the operating and first high-limit thermostats. The heaters are cyclically actuated and deactuated by a thermal time delay relay, to gradually raising the heater temperature to achieve pyrolytic cleaning of the heating elements. The second high-limit thermostat turns off the heating elements when a predetermined temperature is reached, ending pyrolytic cleaning.
Inventors
- 👤 George M Price
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:54
CPC Classifications
A; A47; A47J; A47J37/00; A47J37/12; A47J37/1266; F; F24; F24C; F24C14/00; F24C14/02
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
121 words
In a system for frying foods, control apparatus for regulating the temperature of heating elements during a cooking phase with the heating elements immersed in cooking fluid in a frypot and during a pyrolytic cleaning phase with the heating elements exposed to the atmosphere, comprising: first control means for maintaining the temperature of said elements below a first predetermined limit during said cooking phase, second control means for maintaining the temperatures of said elements below a second predetermined limit during said pyrolytic cleaning phase, and switch means for connecting said first control means in communication with said heating elements during said cooking phase and for connecting said second control means in communication with said heating elements during said pyrolytic cleaning phase.
Claim 2
Dependent Claim
121 words
In a system for frying foods, control apparatus for regulating the temperature of heating elements during a cooking phase with the heating elements immersed in cooking fluid in a frypot and during a pyrolytic cleaning phase with the heating elements exposed to the atmosphere, comprising: first control means for maintaining the temperature of said elements below a first predetermined limit during said cooking phase, second control means for maintaining the temperatures of said elements below a second predetermined limit during said pyrolytic cleaning phase, and switch means for connecting said first control means in communication with said heating elements during said cooking phase and for connecting said second control means in communication with said heating elements during said pyrolytic cleaning phase.
Claim 3
Dependent Claim
121 words
In a system for frying foods, control apparatus for regulating the temperature of heating elements during a cooking phase with the heating elements immersed in cooking fluid in a frypot and during a pyrolytic cleaning phase with the heating elements exposed to the atmosphere, comprising: first control means for maintaining the temperature of said elements below a first predetermined limit during said cooking phase, second control means for maintaining the temperatures of said elements below a second predetermined limit during said pyrolytic cleaning phase, and switch means for connecting said first control means in communication with said heating elements during said cooking phase and for connecting said second control means in communication with said heating elements during said pyrolytic cleaning phase.
Claim 4
Dependent Claim
121 words
In a system for frying foods, control apparatus for regulating the temperature of heating elements during a cooking phase with the heating elements immersed in cooking fluid in a frypot and during a pyrolytic cleaning phase with the heating elements exposed to the atmosphere, comprising: first control means for maintaining the temperature of said elements below a first predetermined limit during said cooking phase, second control means for maintaining the temperatures of said elements below a second predetermined limit during said pyrolytic cleaning phase, and switch means for connecting said first control means in communication with said heating elements during said cooking phase and for connecting said second control means in communication with said heating elements during said pyrolytic cleaning phase.
Claim 5
Dependent Claim
31 words
The apparatus of claim 1 wherein said first control means includes high-limit thermostat means adjacent said heating elements for turning off said elements when said first predetermined temperature limit is reached.
Claim 6
Dependent Claim
48 words
The apparatus of claim 2 wherein said high-limit thermostat means includes a manually actuated reset switch to prevent said thermostat means from automatically turning on said heating elements when said temperature drops below said first predetermined limit, after said elements have been turned off by said thermostat means.
Claim 7
Dependent Claim
33 words
The apparatus of claim 2 wherein said high-limit thermostat means includes first and second high-limit thermostats positioned above said heating elements in sufficiently close proximity thereto to sense the temperature of said elements.
Claim 8
Dependent Claim
31 words
The apparatus of claim 1 wherein said second control means comprises burn-off thermostat means adjacent said heating elements for turning off said elements when said second predetermined temperature limit is reached.
Claim 9
Dependent Claim
48 words
The apparatus of claim 5 wherein said burn-off thermostat means includes a manually actuated reset switch to prevent said thermostat means from automatically turning on said heating elements when said temperature drops below said second predetermined limit, after said elements have been turned off by said thermostat means.
Claim 10
Dependent Claim
30 words
The apparatus of claim 5 wherein said burn-off thermostat means comprises a thermostat positioned above said heating elements in sufficiently close proximity thereto to sense the temperature of said elements.
Claim 11
Dependent Claim
46 words
The apparatus of claim 1 wherein said second control means includes a percentage relay which intermittently turns said heating elements off and on during the pyrolytic cleaning phase in order to slow the increase in the temperature of said elements toward said second predetermined temperature limit.
Claim 12
Dependent Claim
25 words
The apparatus of claim 1 wherein said percentage relay turns on said heating elements approximately 40 percent of the time during the pyrolytic cleaning phase.
Claim 13
Dependent Claim
28 words
The apparatus of claim 1 wherein said first control means further comprises adjustable control means for maintaining said heating elements at a selected temperature during said cookIng phase.
Claim 14
Dependent Claim
34 words
The apparatus of claim 10 wherein said adjustable control means comprises a temperature selector device for manually selecting said temperature, and an operating thermostat for cycling said heating elements to maintain said selected temperature.
Claim 15
Dependent Claim
44 words
The apparatus of claim 11 wherein said thermostat is positioned at the front of said frying system remote from said heating elements, and further comprising a biasing heater positioned in close proximity to said thermostat for simulating the heat output of said heating elements.
Claim 16
Dependent Claim
47 words
The apparatus of claim 1 wherein said first control means and said second control means each include a high limit thermostat adjacent said heating elements having a manually actuated reset switch to prevent automatic reactuation of said heating elements after having been turned off by said thermostat.
Claim 17
Dependent Claim
35 words
The apparatus of claim 1 wherein said switch means includes a function switch for automatically connecting said second control means to said heating elements when said heating elements are raised out of said cooking fluid.
Claim 18
Dependent Claim
141 words
In a frypot for deep fat frying having an electrical heater in a frypot and being adapted to be connected to a power source, and electrical circuitry for maintaining the heater at a selected cooking temperature and for raising the heater temperature to clean the heater by pyrolytic burn-off, control apparatus comprising: a high-limit thermostat adjacent said heater and electrically connected in said circuitry for disconnecting said heater from said power source when said heater exceeds a first predetermined maximum temperature during cooking, a burn-off thermostat adjacent said heater and electrically connected in said regulator circuitry for disconnecting said heater from said power source when said heater exceeds a second predetermined maximum temperature during pyrolytic burn-off, and switch means for disconnecting said high-limit thermostat from said circuitry during pyrolytic burn-off and for connecting said high-limit thermostat to said circuitry during cooking.
Claim 19
Dependent Claim
141 words
In a frypot for deep fat frying having an electrical heater in a frypot and being adapted to be connected to a power source, and electrical circuitry for maintaining the heater at a selected cooking temperature and for raising the heater temperature to clean the heater by pyrolytic burn-off, control apparatus comprising: a high-limit thermostat adjacent said heater and electrically connected in said circuitry for disconnecting said heater from said power source when said heater exceeds a first predetermined maximum temperature during cooking, a burn-off thermostat adjacent said heater and electrically connected in said regulator circuitry for disconnecting said heater from said power source when said heater exceeds a second predetermined maximum temperature during pyrolytic burn-off, and switch means for disconnecting said high-limit thermostat from said circuitry during pyrolytic burn-off and for connecting said high-limit thermostat to said circuitry during cooking.
Claim 20
Dependent Claim
26 words
The apparatus of claim 15 and further comprising: a thermal relay switch for cyclically disconnecting and connecting said heater with said power supply during pyrolytic burn-off.
Claim 21
Dependent Claim
33 words
The apparatus of claim 15 wherein said high-limit thermostat is connected above said heater at a first fixed distance and said burn-off thermostat is connected above said heater at a second fixed distance.
Claim 22
Dependent Claim
24 words
The apparatus of claim 15 and further comprising a manual reset switch to prevent automatic restart after shut-down of said circuitry by said thermostats.
Claim 23
Dependent Claim
46 words
The apparatus of claim 15 and further comprising an operating thermostat for maintaining said heater at said selected cooking temperature during cooking, said operating thermostat being remote from said heater and having an adjacent biasing heating element for heating said operating thermostat to simulate said heater.
References Cited (Backward Citations)
US2668898A
Cited
US2664490A
Cited
US2805314A
Cited
US2847554A
Cited
US3041440A
Cited
US3242849A
Cited
US3459923A
Cited
US3573861A
Cited
US3720155A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-10 | 1978-09-09 | 1979-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-10 | 1982-09-09 | 1983-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-10 | 1986-09-09 | 1987-03-11 | $7700.00 | Window Closed / Lapsed |