US3732434A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pipeline pigs
Assignee: Trans Canada Pipelines Ltd
•
Filing: 1972-03-02
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Granted: 1973-05-08
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Expires: 1992-03-02
Abstract
Abstract This invention provides a pipeline pig for transporting electrical circuitry through a pipeline. The pipeline pig includes a pressure-sensitive switch on the housing which is designed to electrically activate the electrical circuitry when the internal pipeline pressure exceeds a predetermined level. When the pressure does not exceed that level, the electrical circuitry remains inactive.
Inventors
- 👤 H French
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:04
CPC Classifications
B; B08; B08B; B08B9/00; B08B9/02; B08B9/027; B08B9/04; B08B9/053; B08B9/055; B08B9/0557; G; G01; G01M; G01M3/00; G01M3/005; G01M3/02; G01M3/26; G01M3/28; G01M3/2807; G01M3/2823
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
112 words
A pipeline pig for transporting electrical circuitry through a pipeline, the pipeline pig comprising: housing means supporting said electrical circuitry, means for supporting the housing means for translational movement within the pipeline, sealed chamber means maintaining an internal pressure lower than the working pressure of the pressurized pipeline, and a pressure-sensitive switch on the housing adapted to electrically activate said electrical circuitry when the pressure in the pipeline longitudinally adjacent the pig exceeds the pressure within said chamber means by at least a predetermined amount, and adapted to render the electrical circuitry inactive when the pipeline pressure does not exceed the pressure within said chamber means by at least said predetermined amount.
Claim 2
Dependent Claim
112 words
A pipeline pig for transporting electrical circuitry through a pipeline, the pipeline pig comprising: housing means supporting said electrical circuitry, means for supporting the housing means for translational movement within the pipeline, sealed chamber means maintaining an internal pressure lower than the working pressure of the pressurized pipeline, and a pressure-sensitive switch on the housing adapted to electrically activate said electrical circuitry when the pressure in the pipeline longitudinally adjacent the pig exceeds the pressure within said chamber means by at least a predetermined amount, and adapted to render the electrical circuitry inactive when the pipeline pressure does not exceed the pressure within said chamber means by at least said predetermined amount.
Claim 3
Dependent Claim
129 words
A pipeline pig for transporting battery means and electrical circuitry through a pressurized pipeline, the pipeline pig comprising: a pressure-tight housing containing said electrical circuitry, the pressure within said housing being lower than the working pressure of the pressurized pipeline, scraper-cup means for supporting the pressure-tight housing within the pipeline, and a pressure-sensitive switch on the housing adapted to electrically connect said battery means with said electrical circuitry when the pressure in the pipeline longitudinally adjacent the pig exceeds the pressure within said housing by at least a predetermined amount, and adapted to open the electrical connection between the battery means and the electrical circuitry when the pressure in the pipeline longitudinally adjacent the pig does not exceed the pressure within said housing by at least said predetermined amount.
Claim 4
Dependent Claim
129 words
A pipeline pig for transporting battery means and electrical circuitry through a pressurized pipeline, the pipeline pig comprising: a pressure-tight housing containing said electrical circuitry, the pressure within said housing being lower than the working pressure of the pressurized pipeline, scraper-cup means for supporting the pressure-tight housing within the pipeline, and a pressure-sensitive switch on the housing adapted to electrically connect said battery means with said electrical circuitry when the pressure in the pipeline longitudinally adjacent the pig exceeds the pressure within said housing by at least a predetermined amount, and adapted to open the electrical connection between the battery means and the electrical circuitry when the pressure in the pipeline longitudinally adjacent the pig does not exceed the pressure within said housing by at least said predetermined amount.
Claim 5
Dependent Claim
23 words
The invention claimed in claim 2, in which the housing has connector means by which it can be filled with an inert gas.
Claim 6
Dependent Claim
13 words
The invention claimed in claim 2, in which the housing contains low-pressure nitrogen.
Claim 7
Dependent Claim
19 words
The invention claimed in claim 2, in which some at least of the electrical circuitry is encapsulated in plastic.
Claim 8
Dependent Claim
22 words
The invention claimed in claim 2, in which the pressure-sensitive switch senses the pipeline pressure to the rear of the pipeline pig.
References Cited (Backward Citations)
US2951362A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-07 | 1976-11-06 | 1977-05-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-07 | 1980-11-06 | 1981-05-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-07 | 1984-11-06 | 1985-05-08 | $7700.00 | Window Closed / Lapsed |