US3864577A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tank filling monitor
Assignee: BP PLC
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Filing: 1973-11-07
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Granted: 1975-02-04
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Expires: 1993-11-07
Abstract
Abstract Tank filling monitor based on the attenuation of a light signal transmitted by an isosceles prism with total internal reflection as the prism is progressively immersed in a liquid of differing refractive index from the atmosphere. Optical fibres of appropriate length may be used to convey the incident light from the source to the prism and from the prism to a light detector.
Inventors
- 👤 Jacques Pierre Pellett
- 👤 Henri Bernard Andre Baisan
- 👤 Jean Lievaux
- 👤 Georges Patchett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 11:18
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/22; G01F23/28; G01F23/284; G01F23/292; G01F23/2921; G01F23/2922; G01F23/2924
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
312 words
An apparatus for providing a desired liquid level during filling of a contaianer having a filler valve coupled thereto comprising: a first prism having a downwardly pointing apex, said first prism being totally internally reflecting in air and substantially transmitting when immersed in a container including liquid; light source meAns and first light detecting means positioned remote from said first prism; first optical fibers optically coupling said light source means, said first prism, and said first light detecting means, for transmitting light from said light source means into said first prism and for transmitting light which is totally internally reflected in said first prism to said first light detecting means, said first optical fibers including a portion common to the incident light and the reflected light from said first prism; said first light detecting means initiating closure of the filler valve when the light intensity received from said first prism falls below a predetermined threshold; a second prism having a downwardly pointing apex, said second prism being totally internally reflecting in air and substantially transmitting when immersed in a container including liquid, said second prism being positioned at a lower level than the desired liquid level which is determined by said first prism; a second light detecting means positioned remote from said second prism; second optical fibers optically coupling said light source means, said second prism, and said second light detecting means, for transmitting light from said light source means into said second prism and for transmitting light which is totally internally reflected in said second prism to said second light detecting means, said second optical fibers including a portion common to the incident light and the reflected light from said second prism; and said second light detecting means reducing the flow of liquid through the filler valve when the light intensity received from the second prism falls below a predetermined threshold.
Claim 2
Independent Claim
312 words
An apparatus for providing a desired liquid level during filling of a contaianer having a filler valve coupled thereto comprising: a first prism having a downwardly pointing apex, said first prism being totally internally reflecting in air and substantially transmitting when immersed in a container including liquid; light source meAns and first light detecting means positioned remote from said first prism; first optical fibers optically coupling said light source means, said first prism, and said first light detecting means, for transmitting light from said light source means into said first prism and for transmitting light which is totally internally reflected in said first prism to said first light detecting means, said first optical fibers including a portion common to the incident light and the reflected light from said first prism; said first light detecting means initiating closure of the filler valve when the light intensity received from said first prism falls below a predetermined threshold; a second prism having a downwardly pointing apex, said second prism being totally internally reflecting in air and substantially transmitting when immersed in a container including liquid, said second prism being positioned at a lower level than the desired liquid level which is determined by said first prism; a second light detecting means positioned remote from said second prism; second optical fibers optically coupling said light source means, said second prism, and said second light detecting means, for transmitting light from said light source means into said second prism and for transmitting light which is totally internally reflected in said second prism to said second light detecting means, said second optical fibers including a portion common to the incident light and the reflected light from said second prism; and said second light detecting means reducing the flow of liquid through the filler valve when the light intensity received from the second prism falls below a predetermined threshold.
Claim 3
Dependent Claim
44 words
An apparatus as claimed in claim 1 wherein: said light source means includes a pair of light sources, one of said light sources optically coupled to said first optical fibers and the other of said light sources optically coupled to said second optical fibers.
Claim 4
Dependent Claim
16 words
An apparatus as claimed in claim 1 wherein: said first and second prisms are isoceles prisms.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-02-03 | 1978-08-05 | 1979-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-03 | 1982-08-05 | 1983-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-03 | 1986-08-05 | 1987-02-04 | $7700.00 | Window Closed / Lapsed |