US3714828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluidic digital pneumotachometer
Assignee: Individual
•
Filing: 1970-10-26
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Granted: 1973-02-06
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Expires: 1990-10-26
Abstract
Abstract A device for measuring fluid flow comprises a fluid oscillator including a feedback path whose RC time constant may be varied in response to the flow being measured, such that the frequency of oscillation is proportional to the rate of flow. A proportional fluid amplifier has a power stream input and one output connected in the feedback path of a NOR-type oscillator, and the flow being measured is applied as a control input signal to the amplifier to effectively vary the RC time constant of the feedback path. The oscillator produces fluid output pulses at a rate proportional to the flow being measured, and these pulses are counted to provide a digital indication of the flow rate.
Inventors
- 👤 G Durkan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:12
CPC Classifications
F; F15; F15C; F15C1/00; F15C1/08; F15C1/10; F15C1/005; G; G01; G01F; G01F1/00; G01F1/05; G01F1/34; G01F1/36; Y; Y10; Y10S; Y10S73/00; Y10S73/08; Y10T; Y10T137/00; Y10T137/206; Y10T137/212; Y10T137/2125; Y10T137/2147; Y10T137/2158
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
119 words
Apparatus for measuring air flow comprising: a fluidic OR/NOR oscillator including an OR output port, and a feedback loop connected between a NOR output port of the oscillator and a control port thereof; a proportional fluid amplifier having a power stream input port connected to receive fluid from said feedback loop, an output port connected to supply fluid to said feedback loop, and a control port; and, means for applying the flow to be measured to said control port of said proportional amplifier to thereby effectively vary the RC feedback and time constant of said oscillator, whereby a pulsed output is obtained at the OR output port of said oscillator at a frequency proportional to the flow being measured.
Claim 2
Dependent Claim
119 words
Apparatus for measuring air flow comprising: a fluidic OR/NOR oscillator including an OR output port, and a feedback loop connected between a NOR output port of the oscillator and a control port thereof; a proportional fluid amplifier having a power stream input port connected to receive fluid from said feedback loop, an output port connected to supply fluid to said feedback loop, and a control port; and, means for applying the flow to be measured to said control port of said proportional amplifier to thereby effectively vary the RC feedback and time constant of said oscillator, whereby a pulsed output is obtained at the OR output port of said oscillator at a frequency proportional to the flow being measured.
Claim 3
Dependent Claim
119 words
Apparatus for measuring air flow comprising: a fluidic OR/NOR oscillator including an OR output port, and a feedback loop connected between a NOR output port of the oscillator and a control port thereof; a proportional fluid amplifier having a power stream input port connected to receive fluid from said feedback loop, an output port connected to supply fluid to said feedback loop, and a control port; and, means for applying the flow to be measured to said control port of said proportional amplifier to thereby effectively vary the RC feedback and time constant of said oscillator, whereby a pulsed output is obtained at the OR output port of said oscillator at a frequency proportional to the flow being measured.
Claim 4
Dependent Claim
119 words
Apparatus for measuring air flow comprising: a fluidic OR/NOR oscillator including an OR output port, and a feedback loop connected between a NOR output port of the oscillator and a control port thereof; a proportional fluid amplifier having a power stream input port connected to receive fluid from said feedback loop, an output port connected to supply fluid to said feedback loop, and a control port; and, means for applying the flow to be measured to said control port of said proportional amplifier to thereby effectively vary the RC feedback and time constant of said oscillator, whereby a pulsed output is obtained at the OR output port of said oscillator at a frequency proportional to the flow being measured.
Claim 5
Dependent Claim
185 words
Apparatus for measuring fluid flow comprising: oscillator means including fluid amplifier means and a feedback path for applying a fluid signal produced at an output of said amplifier means to a control signal input of said amplifier means; and means in said feedback path and responsive to the fluid flow being measured for applying to said control signal input a portion of the fluid signal from said output that varies in proportion to the magnitude of the flow being measured, whereby said oscillator means oscillates at a frequency proportional to said fluid flow, said means in said feedback path including second fluid amplifier means having power stream input means, control signal input means, and first and second output means, said feedback path including first fluid conduit means connecting the output of said fluid amplifier means to said power stream input means and second fluid conduit means connecting said second output means to said control signal input, said fluid flow being applied to said control signal input means to direct a portion of the fluid from said power stream input means to said second output means.
Claim 6
Dependent Claim
185 words
Apparatus for measuring fluid flow comprising: oscillator means including fluid amplifier means and a feedback path for applying a fluid signal produced at an output of said amplifier means to a control signal input of said amplifier means; and means in said feedback path and responsive to the fluid flow being measured for applying to said control signal input a portion of the fluid signal from said output that varies in proportion to the magnitude of the flow being measured, whereby said oscillator means oscillates at a frequency proportional to said fluid flow, said means in said feedback path including second fluid amplifier means having power stream input means, control signal input means, and first and second output means, said feedback path including first fluid conduit means connecting the output of said fluid amplifier means to said power stream input means and second fluid conduit means connecting said second output means to said control signal input, said fluid flow being applied to said control signal input means to direct a portion of the fluid from said power stream input means to said second output means.
Claim 7
Dependent Claim
16 words
Apparatus as claimed in claim 2 and further comprising counter means responsive to said oscillator means.
Claim 8
Dependent Claim
30 words
Apparatus as claimed in claim 2 wherein a Pitot tube is disposed to sample said fluid flow, the sample from said tube being applied to said control signal input means.
Claim 9
Dependent Claim
85 words
Apparatus as claimed in claim 2 wherein said second fluid amplifier means comprises two vortex amplifiers each having a power stream input connected to said first fluid conduit means, said fluid flow being applied to the control signal input means of the first vortex amplifier, said second fluid conduit means being connected to the second output means of said second vortex amplifier, and means connecting the second output means of said first vortex amplifier to the control signal input means of said second vortex amplifier.
Claim 10
Dependent Claim
200 words
Apparatus for measuring fluid flow comprising: oscillator means including fluid amplifier means and a feedback path for applying a fluid signal produced at an output of said amplifier means to a control signal input of said amplifier means; and means in said feedback path and responsive to the fluid flow being measured for applying to said control signal input a portion of the fluid signal from said output that varies in proportion to the magnitude of the flow being measured, whereby said oscillator means oscillates at a frequency proportional to said fluid flow, said means iN said feedback path including a second fluid amplifier having a power stream input, first and second control inputs, and first and second outputs, said feedback path including a first fluid conduit means connecting the output of said fluid amplifier means to said power stream input and second fluid conduit means connecting said second output to the control signal input of said fluid amplifier means, said apparatus including a venturi through which the measured fluid flows, first and second sensing means for sensing the pressures upstream and downstream of said venturi, and means for applying said sensed pressures to said first and second control inputs.
Claim 11
Dependent Claim
200 words
Apparatus for measuring fluid flow comprising: oscillator means including fluid amplifier means and a feedback path for applying a fluid signal produced at an output of said amplifier means to a control signal input of said amplifier means; and means in said feedback path and responsive to the fluid flow being measured for applying to said control signal input a portion of the fluid signal from said output that varies in proportion to the magnitude of the flow being measured, whereby said oscillator means oscillates at a frequency proportional to said fluid flow, said means iN said feedback path including a second fluid amplifier having a power stream input, first and second control inputs, and first and second outputs, said feedback path including a first fluid conduit means connecting the output of said fluid amplifier means to said power stream input and second fluid conduit means connecting said second output to the control signal input of said fluid amplifier means, said apparatus including a venturi through which the measured fluid flows, first and second sensing means for sensing the pressures upstream and downstream of said venturi, and means for applying said sensed pressures to said first and second control inputs.
Claim 12
Dependent Claim
94 words
Apparatus for measuring fluid flow comprising: oscillator means including fluid turbulence amplifier means and a feedback path for applying a fluid signal produced at an output of said amplifier means to a control signal input of said amplifier means; and means in said feedback path and responsive to the fluid flow being measured for applying to said control signal input a portion of the fluid signal from said output that varies in proportion to the magnitude of the flow being measured, whereby said oscillator means oscillates at a frequency proportional to said fluid flow.
Claim 13
Dependent Claim
94 words
Apparatus for measuring fluid flow comprising: oscillator means including fluid turbulence amplifier means and a feedback path for applying a fluid signal produced at an output of said amplifier means to a control signal input of said amplifier means; and means in said feedback path and responsive to the fluid flow being measured for applying to said control signal input a portion of the fluid signal from said output that varies in proportion to the magnitude of the flow being measured, whereby said oscillator means oscillates at a frequency proportional to said fluid flow.
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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) | 1976-02-06 | 1976-08-07 | 1977-02-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-02-06 | 1980-08-07 | 1981-02-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-02-06 | 1984-08-07 | 1985-02-06 | $7700.00 | Window Closed / Lapsed |