US3955417A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Grease thermoparticulating coating
Assignee: Westinghouse Electric Corp
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Filing: 1975-04-15
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Granted: 1976-05-11
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Expires: 1995-04-15
Abstract
Abstract A grease of a telomer of polytetrafluoroethylene and a perfluoroalkyl polyether is used to protect electrical apparatus from overheating. The grease is applied to a portion of an electrical apparatus which is exposed to a gas stream, particularly to portions subjected to operating temperatures of about 100 DEG to about 130 DEG C. When the coated portion of the electrical apparatus overheats the grease forms particles in the gas stream which are detected by a monitor. The apparatus can then be shut down or its load reduced.
Inventors
- 👤 James D. B. Smith
- 👤 David C. Phillips
- 👤 Kenneth W. Grossett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:51
CPC Classifications
G; G01; G01K; G01K11/00
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
73 words
A method of protecting electrical apparatus from damage due to overheating, said apparatus including a gas stream and a monitor for detecting particles in said gas stream and for emitting a signal when said particles are detected, comprising applying to said electrical apparatus at positions exposed to said gas stream a grease which comprises a telomer of polytetrafluoroethylene and a perfluoroalkyl polyether, and monitoring said gas stream for the presence of particles therein.
Claim 2
Independent Claim
73 words
A method of protecting electrical apparatus from damage due to overheating, said apparatus including a gas stream and a monitor for detecting particles in said gas stream and for emitting a signal when said particles are detected, comprising applying to said electrical apparatus at positions exposed to said gas stream a grease which comprises a telomer of polytetrafluoroethylene and a perfluoroalkyl polyether, and monitoring said gas stream for the presence of particles therein.
Claim 3
Dependent Claim
60 words
A method according to claim 1 wherein said telomer of polytetrafluoroethylene has the general formula CF 3 --CX 2 -- m CF 3 where each X in the formula as extended is independently selected from F and CF 3 , m is the number of repeating units, and the molecular weight of said telomer is about 10,000 to about 50,000.
Claim 4
Dependent Claim
19 words
A method according to claim 1 wherein the molecular weight of said telomer is about 15,000 to about 30,000.
Claim 5
Dependent Claim
63 words
A method according to claim 1 wherein said perfluoroalkyl polyether has the general formula CF 3 ----CX 2 -- n --O-- p CF 3 where each X in the formula as extended is independently selected from F and CF 3 , n and p are the number of repeating units and the molecular weight of said polyether is about 1000 to about 50,000.
Claim 6
Dependent Claim
28 words
A method according to claim 4 wherein the molecular weight of said polyether is about 2000 to about 7000 and n is an integer from 2 to 3.
Claim 7
Dependent Claim
26 words
A method according to claim 1 wherein said grease comprises about 10 to about 50% telomer of polytetrafluoroethylene and about 50 to about 90% perfluoroalkyl polyether.
Claim 8
Dependent Claim
26 words
A method according to claim 6 wherein said grease comprises about 20 to about 30% telomer of polytetrafluoroethylene and about 70 to about 80% perfluoroalkyl polyether.
Claim 9
Dependent Claim
27 words
A method according to claim 1 wherein said grease is applied to a position which is normally at an operating temperature of about 100° to about 130°C.
Claim 10
Dependent Claim
33 words
A method according to claim 8 wherein said apparatus is a generator and said position is the inner surfaces of gas-cooled parallel rings or bushings, the stator core, or the rotor hollow conductors.
Claim 11
Dependent Claim
23 words
A method according to claim 1 including the last steps of collecting said particles and analyzing them when said monitor emits a signal.
Claim 12
Dependent Claim
55 words
A thermal detection system for electrical apparatus cooled by a gas stream, comprising a coating on a portion of said electrical apparatus exposed to said gas stream and a monitor for detecting the presence of particles in said gas stream, said coating comprising a grease which comprises a telomer of polytetrafluoroethylene and a perfluoroalkyl polyether.
Claim 13
Dependent Claim
55 words
A thermal detection system for electrical apparatus cooled by a gas stream, comprising a coating on a portion of said electrical apparatus exposed to said gas stream and a monitor for detecting the presence of particles in said gas stream, said coating comprising a grease which comprises a telomer of polytetrafluoroethylene and a perfluoroalkyl polyether.
Claim 14
Dependent Claim
62 words
A thermal detection system according to claim 11 wherein said telomer of polytetrafluoroethylene has the general formula CF 3 --CX 2 -- m CF 3 where each X in the formula as extended is independently selected from F and CF 3 , m is the number of repeating units, and the molecular weight of said telomer is about 10,000 to about 50,000.
Claim 15
Dependent Claim
21 words
A thermal detection system according to claim 11 wherein the molecular weight of said telomer is about 15,000 to about 30,000.
Claim 16
Dependent Claim
65 words
A thermal detection system according to claim 11 wherein said perfluoroalkyl polyether has the general formula CF 3 ----CX 2 -- n --O-- p CF 3 where each X in the formula as extended is independently selected from F and CF 3 , n and p are the number of repeating units and the molecular weight of said polyether is about 1000 to about 50,000.
Claim 17
Dependent Claim
30 words
A thermal detection system according to claim 14 wherein the molecular weight of said polyether is about 2000 to about 7000 and n is an integer from 2 to 3.
Claim 18
Dependent Claim
28 words
A thermal detection system according to claim 11 wherein said grease comprises about 10 to about 50% telomer of polytetrafluoroethylene and about 50 to about 90% perfluoroalkyl polyether.
Claim 19
Dependent Claim
28 words
A thermal detection system according to claim 16 wherein said grease comprises about 20 to about 30% telomer of polytetrafluoroethylene and about 70 to about 80% perfluoralkyl polyether.
Claim 20
Dependent Claim
29 words
A thermal detection system according to claim 11 wherein said grease is applied to a position which is normally at an operating temperature of about 100° to about 130°C.
Claim 21
Dependent Claim
35 words
A thermal detection system according to claim 18 wherein said apparatus is a generator and said position is the inner surfaces of gas-cooled parallel rings or bushings, the stator core, or the rotor hollow conductors.
References Cited (Backward Citations)
US3427880A
Cited
US3807218A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |