Patent US4889973A successfully refreshed from Google Patents.
US4889973A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aquarium heater
Assignee: Individual
•
Filing: 1988-10-12
•
Granted: 1989-12-26
•
Expires: 2008-10-12
Abstract
Abstract An aquarium heater which consists of a heater pad attached to the outside bottom surface of the aquarium. The heater pad uses an etched-foil heating element laminated between layers of insulating material. Normally, the heat is attached to the bottom of the tank using a pressure sensitive adhesive. The aquarium water temperature is maintained using a current limiting electronic controller and a thermistor for sensing temperature. The thermistor is located in the heater pad between the two layers of insulation.
Inventors
- 👤 Michael F. Farinacci
- 👤 William A. Rowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:15
CPC Classifications
A; A01; A01K; A01K63/00; A01K63/06; A01K63/065
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
103 words
An aquarium heater for mounting on the outside bottom surface of an aquarium tank or the like comprising; (a) a heating pad wherein said heating pad comprises an etched-foil heating element laminated between layers of insulating material, said etched-foil heating element being arranged to provide a clear space within said heating pad; (b) a thermistor for sensing the temperature of said heating pad wherein said thermistor is located within said clear space; and (c) an electronic circuit for controlling the temperature in said heating pad wherein said circuit operates to limit the current in the thermistor below the point at which self-heating occurs.
Claim 2
Dependent Claim
103 words
An aquarium heater for mounting on the outside bottom surface of an aquarium tank or the like comprising; (a) a heating pad wherein said heating pad comprises an etched-foil heating element laminated between layers of insulating material, said etched-foil heating element being arranged to provide a clear space within said heating pad; (b) a thermistor for sensing the temperature of said heating pad wherein said thermistor is located within said clear space; and (c) an electronic circuit for controlling the temperature in said heating pad wherein said circuit operates to limit the current in the thermistor below the point at which self-heating occurs.
Claim 3
Dependent Claim
28 words
An aquarium heater as in claim 1 wherein said heating pad is attached to the outside bottom surface of said aquarium tank by means of pressure sensitive adhesive.
Claim 4
Dependent Claim
24 words
An aquarium heater as in claim 1 wherein said electronic circuit controls said heating element to maintain said aquarium tank internal temperature substantially constant.
Claim 5
Dependent Claim
119 words
An aquarium heater for mounting on the outside bottom surface of an aquarium tank or the like comprising; (a) a heating pad wherein said heating pad comprises an etched-foil heating element laminated between layers of insulating material, said etched-foil heating element being arranged to provide a clear space within said heating pad; (b) a thermistor for sensing the temperature of said heating pad wherein said thermistor is located within said clear space; and (c) an electronic circuit for controlling the temperature in said heating pad wherein said circuit operates to limit the current in the thermistor below the point at which self-heating occurs and said circuit controls said heating element to maintain said aquarium tank internal temperature substantially constant.
Claim 6
Dependent Claim
119 words
An aquarium heater for mounting on the outside bottom surface of an aquarium tank or the like comprising; (a) a heating pad wherein said heating pad comprises an etched-foil heating element laminated between layers of insulating material, said etched-foil heating element being arranged to provide a clear space within said heating pad; (b) a thermistor for sensing the temperature of said heating pad wherein said thermistor is located within said clear space; and (c) an electronic circuit for controlling the temperature in said heating pad wherein said circuit operates to limit the current in the thermistor below the point at which self-heating occurs and said circuit controls said heating element to maintain said aquarium tank internal temperature substantially constant.
References Cited (Backward Citations)
US2805313A
Cited
US3842241A
Cited
US3890486A
Cited
WO1979000705A1
Cited
US4313048A
Cited
US4333626A
Cited
US4652726A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |