Heating blankets and the like
First Claim
1. An elongated heating element for an electric blanket comprising a first conductor means to provide heat for the blanket and extending lengthwise of the element, a second conductor means extending lengthwise of the element, and a meltdown layer between the first and second conductor means having a meltdown characteristic less than about 130°
- C., and an NTC, and including electronic control means set to detect a change in the resistance of the meltdown layer to provide a means of changing the power supply to the conductor means providing heat to the blanket to prevent destruction of the meltdown layer.
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Accused Products
Abstract
An elongated heating element for an electric blanket comprising a first conductor means to provide heat for the blanket and extending lengthwise of the element, a second conductor means extending lengthwise of the element, and a meltdown layer between the first and second conductor means which is selected, designed and constructed or otherwise formed so as to display an NTC, and including electronic controller set to detect a change in the resistance of the meltdown layer to provide a means of changing the power supply to the first conductor means (providing heat to the blanket), to prevent destruction of the melt down layer(.), the element further including a meltdown detection circuit for detecting meltdown of the meltdown layer and for terminating power to the first conductor means in the event that the control means fails and the meltdown layer heats up to a pre-determined degree.
77 Citations
18 Claims
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1. An elongated heating element for an electric blanket comprising a first conductor means to provide heat for the blanket and extending lengthwise of the element, a second conductor means extending lengthwise of the element, and a meltdown layer between the first and second conductor means having a meltdown characteristic less than about 130°
- C., and an NTC, and including electronic control means set to detect a change in the resistance of the meltdown layer to provide a means of changing the power supply to the conductor means providing heat to the blanket to prevent destruction of the meltdown layer.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
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14. An elongated heating element for an electric blanket comprising:
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a first conductor element to provide heat for the blanket and extending lengthwise of the heating element;
a second conductor element extending lengthwise of the heating element;
a meltdown layer between the first conductor element and the second conductor element, the meltdown layer having a meltdown characteristic less than about 130°
C., a resistance, and an NTC; and
an electronic control element adapted to detect a change in the resistance of the meltdown layer and to change a power to the heating element. - View Dependent Claims (15, 16, 17)
the detection conductor has a PTC, so that when the detection conductor heats up its resistance increases, and the electronic control element uses the PTC of the detection conductor to control the power to the heating element. -
17. The heating element of claim 14, in which the heating element comprises less than three conductor elements.
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18. An elongated heating element for an electric blanket consisting of:
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a first conductor element to provide heat for the blanket and extending lengthwise of the heating element;
a second conductor element extending lengthwise of the heating element;
a meltdown layer between the first conductor element and the second conductor element, the meltdown layer having a meltdown characteristic less than about 130°
C., a resistance, and an NTC; and
an electronic control element adapted to detect a change in the resistance of the meltdown layer and to change the power supply to the conductor elements providing heat to the blanket.
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Specification