US6207938B1
Expired / Lapsed
US
⏱️ 0.0 years remaining
Resistive heating track with bridge fuse
Assignee: Strix Ltd
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Filing: 1997-04-17
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Granted: 2001-03-27
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Expires: 2017-04-17
Abstract
Abstract An electrical resistance or heater includes an electrical resistive track provided on an insulating substrate. Two predetermined sections of the track have a predetermined current carrying capacity and are bridged by a glass, ceramic, or glass ceramic material. The configuration of the track and the glass material are such that at a predetermined temperature, the leakage current between the track sections rises to the extent that it causes a current to flow through one or both of the sections which is substantially above its current carrying capability, whereby one section fails.
Inventors
- 👤 John Crawshaw Taylor
- 👤 Keith Barrie Doyle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:19
CPC Classifications
H; H05; H05B; H05B1/00; H05B1/02; H05B1/0227; H05B1/0288; H05B1/0294; H05B3/00; H05B3/68; H05B3/74; H05B3/746; H05B3/78; H05B3/82
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
88 words
An electrical heater comprising an electrical resistive heating track provided on an insulating substrate, two predetermined sections of said track having a predetermined current carrying capacity being bridged by a glass material forming a glass bridge, the configuration of the track and the glass material being chosen such that at a predetermined temperature, a leakage current between the track sections rises to an extent that a current flows through one or both of said sections which is substantially above the current carrying capacity thereof, whereby said section fails.
Claim 2
Dependent Claim
88 words
An electrical heater comprising an electrical resistive heating track provided on an insulating substrate, two predetermined sections of said track having a predetermined current carrying capacity being bridged by a glass material forming a glass bridge, the configuration of the track and the glass material being chosen such that at a predetermined temperature, a leakage current between the track sections rises to an extent that a current flows through one or both of said sections which is substantially above the current carrying capacity thereof, whereby said section fails.
Claim 3
Dependent Claim
22 words
A heater as claimed in claim 1 wherein the glass material is arranged to form a discrete bridge between the track sections.
Claim 4
Dependent Claim
20 words
A heater as claimed in claim 1 wherein the glass material is applied as an overglaze to the track sections.
Claim 5
Dependent Claim
18 words
A heater as claimed in claim 3 wherein the overglaze extends over a substantial portion of the track.
Claim 6
Dependent Claim
21 words
A heater as claimed in claim 1 wherein the bridged sections of the track are respective end sections of the track.
Claim 7
Dependent Claim
23 words
A heater as claimed in claim 1 wherein the bridged sections of the track are most closely spaced apart sections of the track.
Claim 8
Dependent Claim
27 words
A heater as claimed in claim 1 wherein the track sections are configured to provide a maximum voltage gradient therebetween in a region of the glass bridge.
Claim 9
Dependent Claim
29 words
A heater as claimed in claim 1 wherein the track sections are configured and arranged to provide a localised maximum power density in a region of the glass bridge.
Claim 10
Dependent Claim
92 words
An electrical appliance comprising an electrical heater comprising an electrical resistive heating track provided on an insulating substrate, two predetermined sections of said track having a predetermined current carrying capacity being bridged by a glass material forming a glass bridge, the configuration of the track and the glass material being chosen such that at a predetermined temperature, a leakage current between the track sections rises to an extent that a current flows through one or both of said sections which is substantially above the current carrying capacity thereof whereby said section fails.
Claim 11
Dependent Claim
92 words
An electrical appliance comprising an electrical heater comprising an electrical resistive heating track provided on an insulating substrate, two predetermined sections of said track having a predetermined current carrying capacity being bridged by a glass material forming a glass bridge, the configuration of the track and the glass material being chosen such that at a predetermined temperature, a leakage current between the track sections rises to an extent that a current flows through one or both of said sections which is substantially above the current carrying capacity thereof whereby said section fails.
Claim 12
Dependent Claim
33 words
An appliance as claimed in claim 9 wherein said appliance is a liquid heating vessel, and said heater forms or is attached to at least a part of a base of the vessel.
Claim 13
Dependent Claim
77 words
An overheat protection means for an electrical heater, comprising an electrically insulating glass for bridging two sections of electrical resistive heating track, wherein electrical resistance of the insulating glass falls as a temperature thereof increases, said glass being arranged so as to bridge a fuse, and being chosen such that upon the temperature thereof rising above a given value, current in the fuse is caused to rise above a maximum rated value, causing the fuse to fail.
Claim 14
Dependent Claim
77 words
An overheat protection means for an electrical heater, comprising an electrically insulating glass for bridging two sections of electrical resistive heating track, wherein electrical resistance of the insulating glass falls as a temperature thereof increases, said glass being arranged so as to bridge a fuse, and being chosen such that upon the temperature thereof rising above a given value, current in the fuse is caused to rise above a maximum rated value, causing the fuse to fail.
Claim 15
Dependent Claim
70 words
A fuse for protecting an electrical heater from overheating comprising an electrical resistive heating conductor designed to carry a predetermined electrical current and having two sections bridged by an electrically insulating glass such that when the glass is heated above a predetermined temperature, the glass forms a conductive path between the sections, causing the current in the conductor to rise above a predetermined design value and the conductor to fail.
Claim 16
Dependent Claim
70 words
A fuse for protecting an electrical heater from overheating comprising an electrical resistive heating conductor designed to carry a predetermined electrical current and having two sections bridged by an electrically insulating glass such that when the glass is heated above a predetermined temperature, the glass forms a conductive path between the sections, causing the current in the conductor to rise above a predetermined design value and the conductor to fail.
Claim 17
Independent Claim
80 words
A method of manufacturing an electrical heater comprising an electrical resistive track provided on an insulating substrate, comprising providing a bridge of glass material between two selected sections of the track capable of carrying a maximum predetermined current, the position of said bridge being predetermined such that above a predetermined temperature, leakage current between said sections will rise such that the current flowing through said section of the track rises above a maximum predetermined current, causing said section to fail.
Claim 18
Independent Claim
80 words
A method of manufacturing an electrical heater comprising an electrical resistive track provided on an insulating substrate, comprising providing a bridge of glass material between two selected sections of the track capable of carrying a maximum predetermined current, the position of said bridge being predetermined such that above a predetermined temperature, leakage current between said sections will rise such that the current flowing through said section of the track rises above a maximum predetermined current, causing said section to fail.
Claim 19
Dependent Claim
50 words
An electrical heater comprising a resistive track laid down on an insulating substrate wherein a glass bridge is provided between two sections of the track in a position at which a voltage gradient between adjacent sections of the track and a local power density of the heater are a maximum.
Claim 20
Dependent Claim
50 words
An electrical heater comprising a resistive track laid down on an insulating substrate wherein a glass bridge is provided between two sections of the track in a position at which a voltage gradient between adjacent sections of the track and a local power density of the heater are a maximum.
Claim 21
Dependent Claim
82 words
An electrical resistance comprising an electrical resistive track provided on an insulating substrate, two predetermined sections of said track having a predetermined current carrying capacity being bridged by a glass material, a configuration of the track and the glass material being chosen such that at a predetermined temperature, a leakage current between the track sections rises to cause a current to flow through one or both of said sections which is substantially above a current carrying capacity thereof, whereby said section fails.
Claim 22
Dependent Claim
82 words
An electrical resistance comprising an electrical resistive track provided on an insulating substrate, two predetermined sections of said track having a predetermined current carrying capacity being bridged by a glass material, a configuration of the track and the glass material being chosen such that at a predetermined temperature, a leakage current between the track sections rises to cause a current to flow through one or both of said sections which is substantially above a current carrying capacity thereof, whereby said section fails.
Claim 23
Dependent Claim
39 words
A heater as claimed in claim 4 wherein the bridged sections of the track are closely adjacent and the track is configured to provide a maximum voltage gradient between adjacent track portions in a region of the glass bridge.
Claim 24
Dependent Claim
29 words
A heater as claimed in claim 16 wherein the track sections are configured and arranged to provide a localised maximum power density in the region of the glass bridge.
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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) | 2004-03-26 | 2004-09-25 | 2005-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-03-26 | 2008-09-25 | 2009-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-03-26 | 2012-09-25 | 2013-03-27 | $7700.00 | Window Closed / Lapsed |