US3886794A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flowmeter apparatus and method
Assignee: Rosemount Inc
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Filing: 1974-03-11
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Granted: 1975-06-03
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Expires: 1994-03-11
Abstract
Abstract The flowmeter technique involves directing acoustic signals along separate acoustic paths through vortices created in a stream of fluid and combining the detected acoustic signals to enhance the modulation effect by the vortices thereby to facilitate detection of the characteristic frequency.
Inventors
- 👤 James L Mcshane
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 06:40
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/05; G01F1/20; G01F1/32; G01F1/325; G01F1/3282
Claims Analysis
Total Claims: 30
Claim 1
Independent Claim
150 words
The method of measuring the velocity of relative movement between a fluid and an object immersed therein, said object creating periodic fluid disturbances in a pattern along a direction of disturbances, said periodic disturbances being characteristic of said velocity, said method comprIsing the steps of: directing individual acoustic signals along at least two respective separate acoustic paths in the fluid at an angle to said direction of disturbances, and with at least one of said paths being through said disturbances; receiving said acoustic signals after traveling along said paths whereby at least one acoustic signal is modulated by said periodic disturbances thereby to provide a signal having a modulation envelope; combining the received acoustic signals into a combined signal of increased modulation index relative to the modulation index of the received acoustic signals; and deriving a representation of the modulation of said combined signal as an indication of said velocity.
Claim 2
Independent Claim
150 words
The method of measuring the velocity of relative movement between a fluid and an object immersed therein, said object creating periodic fluid disturbances in a pattern along a direction of disturbances, said periodic disturbances being characteristic of said velocity, said method comprIsing the steps of: directing individual acoustic signals along at least two respective separate acoustic paths in the fluid at an angle to said direction of disturbances, and with at least one of said paths being through said disturbances; receiving said acoustic signals after traveling along said paths whereby at least one acoustic signal is modulated by said periodic disturbances thereby to provide a signal having a modulation envelope; combining the received acoustic signals into a combined signal of increased modulation index relative to the modulation index of the received acoustic signals; and deriving a representation of the modulation of said combined signal as an indication of said velocity.
Claim 3
Independent Claim
150 words
The method of measuring the velocity of relative movement between a fluid and an object immersed therein, said object creating periodic fluid disturbances in a pattern along a direction of disturbances, said periodic disturbances being characteristic of said velocity, said method comprIsing the steps of: directing individual acoustic signals along at least two respective separate acoustic paths in the fluid at an angle to said direction of disturbances, and with at least one of said paths being through said disturbances; receiving said acoustic signals after traveling along said paths whereby at least one acoustic signal is modulated by said periodic disturbances thereby to provide a signal having a modulation envelope; combining the received acoustic signals into a combined signal of increased modulation index relative to the modulation index of the received acoustic signals; and deriving a representation of the modulation of said combined signal as an indication of said velocity.
Claim 4
Independent Claim
150 words
The method of measuring the velocity of relative movement between a fluid and an object immersed therein, said object creating periodic fluid disturbances in a pattern along a direction of disturbances, said periodic disturbances being characteristic of said velocity, said method comprIsing the steps of: directing individual acoustic signals along at least two respective separate acoustic paths in the fluid at an angle to said direction of disturbances, and with at least one of said paths being through said disturbances; receiving said acoustic signals after traveling along said paths whereby at least one acoustic signal is modulated by said periodic disturbances thereby to provide a signal having a modulation envelope; combining the received acoustic signals into a combined signal of increased modulation index relative to the modulation index of the received acoustic signals; and deriving a representation of the modulation of said combined signal as an indication of said velocity.
Claim 5
Dependent Claim
23 words
The method of claim 1 wherein said increased modulation index represents the sum of the modulation indexes of the respective said acoustic signals.
Claim 6
Dependent Claim
22 words
The method of claim 2 wherein said combined signal is obtained by subtracting the carrier portions of the respective said acoustic signals.
Claim 7
Dependent Claim
33 words
The method of claim 1 wherein said acoustic paths are both through said disturbances, said acoustic signals being equally affected by said fluid disturbances with a phase difference between the respective modulation envelope.
Claim 8
Dependent Claim
35 words
The method of claim 4 wherein said phase difference between said modulation envelopes is pi and carrier cancellation is effected, the detected modulation of said combined signal being twice the frequency of said modulation envelopes.
Claim 9
Dependent Claim
26 words
The method of claim 4 wherein said acoustic paths are selected to be in two parallel planes oriented at an angle to said direction of disturbances.
Claim 10
Dependent Claim
25 words
The method of claim 6 wherein the direction of disturbances is parallel to said velocity, the disturbances being in the wake of the immersed object.
Claim 11
Dependent Claim
24 words
The method of claim 6, wherein the direction of disturbances is transverse to said velocity, the disturbances being in front of said immersed object.
Claim 12
Dependent Claim
27 words
A method according to claim 1 wherein said individual acoustic signals are directed with a selected phase difference for adjusting the phase between said received acoustic signals.
Claim 13
Independent Claim
157 words
A system for measuring the velocity of relative movement between a fluid and an object immersed therein, said object creating periodic fluid disturbances in a pattern along a direction of disturbances, with the periodicity of said disturbances having a frequency that is characteristic of said velocity, said system comprising; means for directing acoustic signals along at least two respective separate acoustic paths in the fluid at an angle to said direction of disturbances, at least one of said paths being through said disturbances; means for receiving said acoustic signals after travel along said paths, whereby at least one acoustic signal is modulated by said disturbances thereby to provide a signal having a modulation envelope; means for combining the received acoustic signals into a combined signal of increased modulation index relative to modulation indexes of the received acoustic signals; and meawns for deriving a representation of the modulation of said combined signal as an indication of said velocity.
Claim 14
Independent Claim
157 words
A system for measuring the velocity of relative movement between a fluid and an object immersed therein, said object creating periodic fluid disturbances in a pattern along a direction of disturbances, with the periodicity of said disturbances having a frequency that is characteristic of said velocity, said system comprising; means for directing acoustic signals along at least two respective separate acoustic paths in the fluid at an angle to said direction of disturbances, at least one of said paths being through said disturbances; means for receiving said acoustic signals after travel along said paths, whereby at least one acoustic signal is modulated by said disturbances thereby to provide a signal having a modulation envelope; means for combining the received acoustic signals into a combined signal of increased modulation index relative to modulation indexes of the received acoustic signals; and meawns for deriving a representation of the modulation of said combined signal as an indication of said velocity.
Claim 15
Dependent Claim
53 words
A system according to claim 10 with said means for directing acoustic signals including first transmitting and receiving transducer means and second transmitting and receiving transducer means respectively associated with said separate acoustic paths, said means for combining said acoustic signals being responsive to the respective said first and second receiving transducer means.
Claim 16
Dependent Claim
43 words
A system according to claim 10 with said means for directing acoustic signals including first and second transmitting transducer means and with said means for combining said acoustic signals including receiving transducer means responsive to both said first and second transmitting transducer means.
Claim 17
Dependent Claim
53 words
A system according to claim 10 with said means for directing acoustic signals including transmitting transducer means, and first and seconD receiving transducer means respectively responsive to said acoustic signals along said separate acoustic paths, said means for combining said acoustic signals being responsive to the respective said first and second receiving transducers.
Claim 18
Dependent Claim
39 words
A system according to claim 13 with said first and second receiving transducer means comprising an acoustic transducer having a housing, two juxtapositioned transducer elements mounted in said housing, and two output connections respectively associated with said transducer elements.
Claim 19
Dependent Claim
19 words
A system according to claim 10 wherein said acoustic paths are defined by acoustic signals refracted by said disturbances.
Claim 20
Dependent Claim
33 words
A system according to claim 10 wherein means is provided for reflecting at least one of said acoustic signals, said means for receiving said acoustic signals being responsive to such reflected acoustic signal.
Claim 21
Dependent Claim
27 words
A system according to claim 10 with said means for combining said acoustic signals including means for subtracting the carrier portions of said acoustic signals after modulation.
Claim 22
Dependent Claim
25 words
A system according to claim 17 with said means for subtracting said carrier portions including differential amplifier means responsive to said acoustic signals after modulation.
Claim 23
Dependent Claim
43 words
A system according to claim 18 with said detecting means being responsive to said differential amplifier means for deriving a modulation signal, means being provided for deriving a signal characteristic of the frequency of said modulation signal as a representation of said velocity.
Claim 24
Dependent Claim
50 words
A system according to claim 19 with said acoustic signals directing means including signal transmitter means, transmitting transducer means responsive to said signal transmitter means, and receiving transducer means responsive to said acoustic signals along said separate acoustic paths, said differential amplifier means being responsive to said receiving transducer means.
Claim 25
Dependent Claim
28 words
A system according to claim 20 with phase shifting means being associated with at least one acoustic path to shift the phase between said acoustic signals after modulation.
Claim 26
Dependent Claim
37 words
A system according to claim 20 with means for adjusting the voltage inputs of said differential amplifier means, thereby to adjust the amplitude of the carrier portion in at least one of said acoustic signals after modulation.
Claim 27
Dependent Claim
27 words
A system according to claim 10 with said means for combining said acoustic signals including phase shifting means associated with at least one of said acoustic signals.
Claim 28
Dependent Claim
23 words
A system according to claim 10 wherein said acoustic paths are selected to be at pi phase difference in said pattern of disturbances.
Claim 29
Dependent Claim
25 words
A system according to claim 24 with said carrier portion being cancelled completely and with said detecting means being calibrated to detect twice said frequency.
Claim 30
Dependent Claim
74 words
A system according to claim 10 with said means for directing acoustic signals including first transmitting and receiving transducer means and second transmitting and receiving transducer means respectively associated with said separate acoustic paths, said means for combining said acoustic signal comprising said first and second receiving transducer means connected in series with opposite polarities, said means for deriving a representation of the increased modulation being responsive to said series connected receiving transducer means.
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) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |