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US4031352A Expired / Lapsed US ⏱️ 0.0 years remaining

Electric blanket

Assignee: C S OOSTERBERG Ltd Pty
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Filing: 1975-10-16
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Granted: 1977-06-21
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Expires: 1995-10-16
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Abstract

Abstract An electric blanket assembly having a blanket whose heating elements are supplied from a low voltage supply source and a control circuit assembly adapted both to regulate the heating of the blanket and to disconnect the supply source from the heating elements under conditions of malfunction of the assembly. The control circuit includes temperature sensitive elements suitably located in the blanket and associated circuitry arranged to generate a control voltage which is selectable and reference voltage generating means which is also selectable. The control circuit also includes means to compare the control voltage and the reference voltage and to control current flow through the heating elements.

Inventors

  • 👤 Cedric Siegfried Oosterberg

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 22:27
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/20; H05B3/34; H05B3/342; G; G05; G05D; G05D23/00; G05D23/19; G05D23/1906; G05D23/1909; G05D23/20; G05D23/24; H05B1/00; H05B1/02; H05B1/0227; H05B2203/00; H05B2203/035

Claims Analysis

Total Claims: 15
Claim 1
Independent Claim 119 words
An electric blanket assembly including a blanket having elements adapted to be heated from an electric supply source and a control circuit assembly adapted to control current through the elements to regulate the heating of the blanket and further adapted to disconnect the supply source from the heating elements under conditions of malfunction of the blanket, characterised in that the control circuit assembly includes temperature sensitive elements suitably located in the blanket and arranged to generate a control voltage, timing means adapted to generate a reference voltage and regulating means to compare the control voltage and the reference voltage and to trigger a solid state switching device which is adapted to control the current through the blanket heating elements.
Claim 2
Dependent Claim 119 words
An electric blanket assembly including a blanket having elements adapted to be heated from an electric supply source and a control circuit assembly adapted to control current through the elements to regulate the heating of the blanket and further adapted to disconnect the supply source from the heating elements under conditions of malfunction of the blanket, characterised in that the control circuit assembly includes temperature sensitive elements suitably located in the blanket and arranged to generate a control voltage, timing means adapted to generate a reference voltage and regulating means to compare the control voltage and the reference voltage and to trigger a solid state switching device which is adapted to control the current through the blanket heating elements.
Claim 3
Dependent Claim 26 words
The electric blanket assembly claimed in claim 1 wherein the regulating means includes differential amplifier circuitry, zero crossing detector amplifier circuitry and an output pluse circuit.
Claim 4
Dependent Claim 35 words
The electric blanket assembly claimed in claim 2 wherein the control voltage is applied to one input of the differential amplifier and the reference voltage is applied to the other input of the differential amplifier.
Claim 5
Dependent Claim 29 words
The electric blanket assembly claimed in claim 3 in which the output pulse circuit is connected to the solid state switching device and is adapted to trigger the latter.
Claim 6
Dependent Claim 18 words
The electric blanket assembly claim in claim 4 in which the solid state switching device is a triac.
Claim 7
Dependent Claim 30 words
The electric blanket assembly as claimed in claim 1 wherein the reference voltage is of a ramp like nature and is arranged to be cyclic with a preset time period.
Claim 8
Dependent Claim 19 words
The electric blanket assembly as claimed in claim 1 wherein the temperature sensitive elements are negative temperature coefficient thermistors.
Claim 9
Dependent Claim 76 words
The electric blanket assembly claimed in claim 1 wherein the control circuit assembly includes means to disconnect the supply source from the heating elements under conditions of malfunction of the blanket which is connected to the control voltage generated by the temperature sensitive elements and which is adapted to operate a relay to disconnect the supply from the heating elements, and further including differential amplifier circuitry, zero crossing detector amplifier circuitry and an output pulse circuit.
Claim 10
Dependent Claim 26 words
The electric blanket assembly claimed in claim 8 in which the output pulses from the output pulse circuit act to trigger a solid state switching device.
Claim 11
Dependent Claim 18 words
The electric blanket assembly claimed in claim 9 in which the solid state switching device is a triac.
Claim 12
Dependent Claim 18 words
The electric blanket assembly claimed in claim 1 in which the control circuit assembly includes a visible alarm.
Claim 13
Dependent Claim 16 words
The electric blanket assembly claimed in claim 11 in which the alarm is a visible alarm.
Claim 14
Dependent Claim 16 words
The electric blanket assembly claimed in claim 11 in which the alarm is visible and audible.
Claim 15
Dependent Claim 24 words
The electric blanket assembly claimed in claim 13 wherein the control circuit assembly includes delay circuitry to delay the triggering of the audible alarm.

References Cited (Backward Citations)

US3437792A Cited
US3549865A Cited
US3678247A Cited
US3946200A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1980-06-20 1980-12-20 1981-06-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1984-06-20 1984-12-20 1985-06-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1988-06-20 1988-12-20 1989-06-21 $7700.00 Window Closed / Lapsed

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