US4717902A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrical components incorporating a temperature responsive device
Assignee: DUBLILER PLC A CORP OF GREAT BRITAIN
•
Filing: 1985-10-21
•
Granted: 1988-01-05
•
Expires: 2005-10-21
Abstract
Abstract An electrical component comprising a temperature responsive device including an electrically conducting member (1) of spring temper in contact with a thin insulating coating (3) of a substance which decomposes on being subject to an elevated temperature thereby allowing the conducting member (1) to effect a short circuiting operation. Suitably the conducting member (1) is coated with a thin layer of polyurethane varnish which vaporizes at the elevated temperature, and the conducting member (1) is arranged to engage contacts (5,5) under spring tension. In one embodiment the conducting member (1) is a wire of phosphor bronze or beryllium copper formed as a loop (2) with spring arms, the loop (2) being positioned on a pin 4 centrally disposed between spaced contacts (5) engaged by the arms under spring tension.
Inventors
- 👤 Kenneth S. James
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:28
CPC Classifications
H; H01; H01H; H01H37/00; H01H37/74; H01H37/76; H01H37/767; H01T; H01T1/00; H01T1/14; H02; H02H; H02H7/00; H02H7/24; H02H9/00; H02H9/04; H02H9/043
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
An excess voltage arrestor comprising at least two spaced electrodes defining a spark gap arranged in a gas filled enclosure, and a protective temperature responsive device comprising an electrically conducting member of spring temper and a thin insulating coating of a substance which thermally decomposes on being subject to an elevated temperature, said temperature responsive device being urged by said spring temper into physical contact with said electrodes such that upon thermal decomposition of said insulating coating at an elevated temperature, said electrically conducting member effects a short circuit across said electrodes.
Claim 2
Dependent Claim
92 words
An excess voltage arrestor comprising at least two spaced electrodes defining a spark gap arranged in a gas filled enclosure, and a protective temperature responsive device comprising an electrically conducting member of spring temper and a thin insulating coating of a substance which thermally decomposes on being subject to an elevated temperature, said temperature responsive device being urged by said spring temper into physical contact with said electrodes such that upon thermal decomposition of said insulating coating at an elevated temperature, said electrically conducting member effects a short circuit across said electrodes.
Claim 3
Dependent Claim
32 words
An excess voltage arrestor as claimed in claim 1, in which the electrically conducting member of spring temper is of metal alloy chosen from the group comprising phosphor bronze and beryllium copper.
Claim 4
Dependent Claim
21 words
An excess voltage arrestor as claimed in claim 1, in which the electrically conducting member is a wire of spring temper.
Claim 5
Dependent Claim
19 words
An excess voltage arrestor as claimed in claim 1, in which the thermally decomposable coating is a polyurethane varnish.
Claim 6
Dependent Claim
24 words
An excess voltage arrestor as claimed in claim 4, in which the coating is of a thickness not exceeding a few tens of microns.
Claim 7
Dependent Claim
39 words
An excess voltage arrestor as claimed in claim 5, in which the coating is of a thickness within the range of 15 to 20 microns and is such that it decomposes within the range of 175° to 300° C.
Claim 8
Dependent Claim
35 words
An excess voltage arrestor as claimed in claim 1, in which the protective temperature responsive device comprises a metal wire of spring temper coated with a polyurethane varnish and engaging respective electrodes under spring tension.
Claim 9
Dependent Claim
22 words
An excess voltage arrestor as claimed in claim 7, in which an outer coating of nylon is provided on the polyurethane varnish.
Claim 10
Dependent Claim
48 words
An excess voltage arrestor as claimed in claim 1, comprising three spaced electrodes and having a metal wire of spring temper coated with a polyurethane varnish in contact with the central one of the three electrodes and also having its opposite ends respectively engaging the other two electrodes.
References Cited (Backward Citations)
BE676466A
Cited
CH309057A
Cited
US2992310A
Cited
US3046536A
Cited
US4212047A
Cited
GB2018028A
Cited
US4371911A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |