US4223364A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pressure and temperature responsive protective devices
Assignee: Individual
•
Filing: 1978-05-25
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Granted: 1980-09-16
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Expires: 1998-05-25
Abstract
Abstract The dangers inherent in the failure of available sensors to protect against explosions of the tanks of oil filled transformers has been found to be due in part to failures of such sensors to compensate for the fact that the temperature-pressure relationship in tanks of oil filled transformers does not necessarily follow a single valued constant volume version of Boyle's Law. The construction of the apparatus is readily adaptable to pressure only or temperature only sensing, to contact make or break operation either inside or outside of the tank. Further difficulties arise particularly in stiff systems from failure of available protective systems to respond in a manner to prevent explosions in spite of a warning that conditions have reached the danger point. These dangers are further overcome by the use of a sensor which senses both temperture and pressure in the system to short circuit the high-voltage input conductor to the transformer to ground whereby a current limiting fuse or other overcurrent device is quickly opened thus causing the protective device immediately ahead of the transformer to clear the fault and prevent explosion of the transformer.
Inventors
- 👤 Harold L. Sangster
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 20:55
CPC Classifications
H; H02; H02H; H02H5/00; H02H5/04; H02H5/06; H02H5/08
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
133 words
A protection device comprising first sensor means producing a response to temperature which varies as a predetermined function of temperature, second sensor means producing a response to pressure which varies as a predeterminable function of pressure, a control means, means for setting said control means in a first control condition, said control means establishing a first electrical circuit condition when in said first control condition and establishing a second electrical circuit condition when in a second control condition, means for changing said control means from said first to said second condition upon detection of a predetermined condition, said condition being a function of the responses of said means for sensing over a continuous range from a minimum predetermined temperature and a maximum pressure to a minimum predetermined pressure to a maximum predetermined temperature.
Claim 2
Dependent Claim
133 words
A protection device comprising first sensor means producing a response to temperature which varies as a predetermined function of temperature, second sensor means producing a response to pressure which varies as a predeterminable function of pressure, a control means, means for setting said control means in a first control condition, said control means establishing a first electrical circuit condition when in said first control condition and establishing a second electrical circuit condition when in a second control condition, means for changing said control means from said first to said second condition upon detection of a predetermined condition, said condition being a function of the responses of said means for sensing over a continuous range from a minimum predetermined temperature and a maximum pressure to a minimum predetermined pressure to a maximum predetermined temperature.
Claim 3
Dependent Claim
38 words
The protection device of claim 1 wherein said means for changing includes an operating member, said operating member passing through a wall of said tank whereby to effect said change of electrical circuit condition exteriorly of said tank.
Claim 4
Dependent Claim
69 words
The protection device of claim 12 wherein said control means comprises, an operating member, said means for setting including means for retaining said operating member in a first position to establish said first electrical circuit condition, said means for changing including means biasing said operating member toward a second position and releasing said operating member to permit movement to said second position to establish said second electrical circuit condition.
Claim 5
Dependent Claim
36 words
The protection device of claim 3 wherein said protective device is mounted within a transformer tank, and means located external to said tank for moving said operating member from its second position to its first position.
Claim 6
Dependent Claim
64 words
A protection device of claim 3 wherein said operating member is a rod, said rod having conducting and nonconducting segments, a pair of coaxial and spaced conductive sleeves, said rod being slidably positioned within and in contact with said sleeves, said segments of said rod being positioned such that in said first position of said operating member said conductive segment bridges said conductive sleeves.
Claim 7
Dependent Claim
64 words
A protection device of claim 3 wherein said operating member is a rod, said rod having conducting and nonconducting segments, a pair of coaxial and spaced conductive sleeves, said rod being slidably positioned within and in contact with said sleeves, said segments of said rod being positioned such that in said first position of said operating member said non-conductive segment bridges said conductive sleeves.
Claim 8
Dependent Claim
14 words
The protection device of claim 3 wherein said means for biasing comprises a spring.
Claim 9
Dependent Claim
37 words
The protection device of claim 1 or claim 3 further comprising a tank partially filled with a fluid means for mounting said first and second sensor in said tank generally immediately below the level of said fluid.
Claim 10
Dependent Claim
27 words
The protection device of claim 1 or claim 3 further comprising means for selectively disabling response of said means for changing to one of said sensor means.
Claim 11
Dependent Claim
69 words
A protection device of claim 1 or claim 3 further comprising a closed tank, a high voltage cable, a transformer having a high voltage input terminal, and an overcurrent circuit interrupting device disposed between said high voltage cable and said input terminal, and an electrical ground, said second circuit condition of said control means establishing a short circuit to ground of said high voltage applied to said input terminal.
Claim 12
Dependent Claim
18 words
A protection device of claim 10 wherein said circuit interrupting device is a full range current limiting fuse.
Claim 13
Dependent Claim
38 words
The protection device of claim 1 or 3 further comprising a tank partially filled with liquid, and means for subjecting said sensor means to the temperature of the liquid lying immediately below the upper surface of said liquid.
Claim 14
Dependent Claim
38 words
The protection device of claim 1 or 3 further comprising a tank filled with liquid, and means subjecting said sensor means to the pressure and temperature of the liquid lying immediately below the upper surface of said liquid.
Claim 15
Dependent Claim
36 words
The protection device of claim 1 or 3 further comprising a tank, an electrical cable extending into said tank, a bushing supporting said cable means supporting said protective device on said cable interiorly of said tank.
Claim 16
Dependent Claim
24 words
The protection device of claim 1 or 3 further comprising means for varying the response of said means for changing to said sensor means.
Claim 17
Dependent Claim
24 words
The protection device of claim 15 wherein said means for varying includes means for varying the response to said sensor means to different extents.
Claim 18
Dependent Claim
23 words
The protection device of claim 1 or 3 including means for rendering said means for changing independently responsive to each said sensor means.
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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) | 1983-09-16 | 1984-03-17 | 1984-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-09-16 | 1988-03-17 | 1988-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-09-16 | 1992-03-17 | 1992-09-16 | $7700.00 | Window Closed / Lapsed |