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 04:27
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.
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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 |