Patent US3653264A successfully refreshed from Google Patents.
US3653264A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for detecting a leak in a fluid pressure system
Assignee: Individual
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Filing: 1969-11-25
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Granted: 1972-04-04
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Expires: 1989-11-25
Abstract
Abstract A fluid-pressure differential cell wherein pressure is transmitted between the two sides of the cell internally thereof by means of a liquid medium. The liquid may be contained between spaced apart diaphragms so that pressure applied to one diaphragm is transmitted to the other. In a preferred cell of the present invention, providing an amplification of the signal produced by the pressure difference, the two diaphragms are bellows diaphragms, one of a greater cross-sectional area than the other, between which liquid passes on the development of a pressure difference between the two sides of the cell, so that the amplified signal is constituted by an expansion of the bellows diaphragm of narrower cross-section, over a greater axial distance than the other bellows diaphragm is contracted by that pressure difference. The bellows diaphragms may be separated by a chamber connecting the internal spaces of the two diaphragms, and the chamber may be formed with an access port for filling the chamber and the internal spaces of the bellows diaphragms with the liquid which, preferably, is a light oil.
Inventors
- 👤 Albert E Mills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:25
CPC Classifications
G; G01; G01L; G01L13/00; G01L13/02; G01M; G01M3/00; G01M3/02; G01M3/04; G01M3/20; G01M3/202
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
137 words
A leak detection system comprising a fluid pressure differential cell including a chamber having opposed sides and filled with a liquid, the cell being operable when differential pressures are transmitted to opposite sides of the liquid-filled chamber to produce a signal of the pressure difference; and means for providing an indication of the magnitude of the signal, said means including a transducer for converting the signal to an electrical signal, an electronic amplifier circuit for amplifying the electrical signal, said amplifier circuit including a first amplifier for directly amplifying the electrical signal for the transducer, and a comparator amplifier for receiving the output of the first amplifier and operable to produce an output signal when the output of the first amplifier exceeds a predetermined value, and an indicator for indicating the magnitude of the amplitude electrical signal.
Claim 2
Dependent Claim
137 words
A leak detection system comprising a fluid pressure differential cell including a chamber having opposed sides and filled with a liquid, the cell being operable when differential pressures are transmitted to opposite sides of the liquid-filled chamber to produce a signal of the pressure difference; and means for providing an indication of the magnitude of the signal, said means including a transducer for converting the signal to an electrical signal, an electronic amplifier circuit for amplifying the electrical signal, said amplifier circuit including a first amplifier for directly amplifying the electrical signal for the transducer, and a comparator amplifier for receiving the output of the first amplifier and operable to produce an output signal when the output of the first amplifier exceeds a predetermined value, and an indicator for indicating the magnitude of the amplitude electrical signal.
Claim 3
Dependent Claim
14 words
A system according to claim 1, wherein the transducer is a linear differential transformer.
Claim 4
Dependent Claim
26 words
A system according to claim 1, wherein the first amplifier comprises a feedback loop having a limiter therein to limit the output fed to the indicator.
Claim 5
Dependent Claim
95 words
A system according to claim 1, wherein the system further comprises an input to the first amplifier, having a potentiometer, a servo amplifier, a switch by means of which the output of the first amplifier can be switched to the servo amplifier and a servo motor driven by the servo amplifier and connected to the potentiometer so that when an output is obtained from the first amplifier and that amplifier is switched to the servo amplifier, the servo motor is driven to adjust the potentiometer so as to zero the output of the first amplifier.
Claim 6
Dependent Claim
112 words
A system according to claim 1, wherein the two sides of the cell are connected externally of the cell by a conduit having therein a leak-proof valve; and wherein the system comprises an electronic timing circuit such that when the two sides of the cell have been brought to test pressure and the timing circuit activated, the timing circuit automatically causes the leak-proof valve to close and the first amplifier output first to be switched to the servo amplifier and then to the comparator amplifier, and thereafter, following the lapse of a predetermined time intErval, the leak-proof valve to open and the first amplifier to be switched back from the comparator amplifier.
Claim 7
Dependent Claim
26 words
A system according to claim 5, wherein the timing circuit comprises a capacitor the discharging and charging of which effects the timing provided by the circuit.
Claim 8
Dependent Claim
89 words
A system according to claim 6, wherein the capacitor is employed to control, by the charge thereon, the conduction of a unijunction, and the unijunction is employed to control a transistor switch arrangement so that when the unijunction is rendered conducting, the transistor switch arrangement causes the leak-proof valve to close and the first amplifier to be switched first to the servo amplifier and then to the comparator amplifier, and so that when the unijunction is rendered non-conducting, the transistor switch arrangement is caused to open the leak-proof valve.
Claim 9
Dependent Claim
41 words
A system according to claim 5, wherein the fluid-pressure differential cell together with the transducer, amplifier circuit and timing circuit is provided in plurality; and wherein the plurality of timing circuits are formed together as parts of a single circuit entity.
Claim 10
Dependent Claim
13 words
A system according to claim 1, wherein the transducer is a strain-wire gauge.
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) | 1975-04-04 | 1975-10-04 | 1976-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-04 | 1979-10-04 | 1980-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-04 | 1983-10-04 | 1984-04-04 | $7700.00 | Window Closed / Lapsed |