Self-healing parallel heating tape
First Claim
1. A parallel heating tape, comprising:
- (a) two electrical power conductors extending generally alongside but spaced apart from one another;
(b) a plurality of heating elements extending between and being electrically connected to each of the two power conductors along the length of tape;
(c) the heating elements each being thinner and of higher resistance than the power conductors and providing a current path from one of the power conductors to the other whereby the heating elements dissipate heat;
(d) a temperature monitoring conductor extending alongside one of the power conductors but being separated from the respective power conductor by a substance which electrically insulates the temperature monitoring conductor from the power conductor when the temperature is below one of the specified temperatures and a temperature within a transition temperature range; and
(e) the substance providing a current path between the power conductor and the temperature monitoring conductor when the temperature is above the respective one of the specified temperature and a temperature within the transition temperature range, and the substance again insulating the power conductor from the temperature monitoring conductor when the temperature falls below the respective specified temperature or a temperature within the transition temperature range.
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Accused Products
Abstract
A parallel circuit heating tape (13) of the kind comprising two electrical power conductors (12,15) with low resistance relatively thin heating elements (16) between them which dissipate heat, the tape (13) comprising a temperature monitoring conductor (18,25) which extends alongside one of the power conductors (12,15), the temperature monitoring conductor (18,25) being separated from the one power conductor (18,25) by a substance (23,28) which insulates the two conductors (12,18; 15,25) from one another when the temperature is below a specified temperature or temperature within a transition temperature range, and provides a current path from one conductor (12,14) to the other (18,25) when the temperature is above the specified temperature or temperature within the transition temperature range.
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Citations
12 Claims
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1. A parallel heating tape, comprising:
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(a) two electrical power conductors extending generally alongside but spaced apart from one another; (b) a plurality of heating elements extending between and being electrically connected to each of the two power conductors along the length of tape; (c) the heating elements each being thinner and of higher resistance than the power conductors and providing a current path from one of the power conductors to the other whereby the heating elements dissipate heat; (d) a temperature monitoring conductor extending alongside one of the power conductors but being separated from the respective power conductor by a substance which electrically insulates the temperature monitoring conductor from the power conductor when the temperature is below one of the specified temperatures and a temperature within a transition temperature range; and (e) the substance providing a current path between the power conductor and the temperature monitoring conductor when the temperature is above the respective one of the specified temperature and a temperature within the transition temperature range, and the substance again insulating the power conductor from the temperature monitoring conductor when the temperature falls below the respective specified temperature or a temperature within the transition temperature range. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 10, 11, 12)
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9. A heating tape according to claim 9 wherein the temperature monitoring conductor is earthed and an earth leakage monitor is provided between the two power conductors.
Specification