Patent US3875801A successfully refreshed from Google Patents.
US3875801A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Scuba diver's time remaining gauge
Assignee: Individual
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Filing: 1973-08-27
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Granted: 1975-04-08
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Expires: 1993-08-27
Abstract
Abstract A sensing and indicating device for automatically indicating the time to depletion of a gas in any size pressure tank, comprising a sensor circuit continuously responsive to the instantaneous pressure in the tank, and the rate of depletion of gas in said tank, for developing signals indicative of the instantaneous pressure and a differentiator circuit for receiving the pressure signals and, in turn, for developing signals proportional to the rate of change of said instantaneous pressure. A divider circuit compares the pressure signals and rate of change signals, and develops signals proportional to the time remaining before depletion of the gas supply in said tank feeding the same into a receiving indicator connected to said divider circuit for continuously indicating the time to depletion of the gas supply in said tank.
Inventors
- 👤 Phillip C Bishaf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:33
CPC Classifications
G; G01; G01F; G01F9/00; G01F9/008
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
144 words
A sensing and indicating device for automatically indicating the time to depletion of a gas in a pressure tank, the device comprising: sensor means comprising a transducer continuously responsive to the instantaneous pressure and the rate of depletion of gas in said tank, for developing electrical signals indicative of said instantaneous pressure; an integrated circuit chip electrically connected to said transducer, said circuit chip comprising differentiator means for receiving said pressure signals and, in turn, for continuously developing signals proportional to the rate of change of said instantaneous pressure; electronic divider means for continuously comparing said pressure signals and said rate of change signals, and for developing signals proportional to the time remaining before depletion of the gas supply in said tank; and receiving means connected to said divider means for continuously indicating the time to depletion of the gas supply in said tank.
Claim 2
Dependent Claim
144 words
A sensing and indicating device for automatically indicating the time to depletion of a gas in a pressure tank, the device comprising: sensor means comprising a transducer continuously responsive to the instantaneous pressure and the rate of depletion of gas in said tank, for developing electrical signals indicative of said instantaneous pressure; an integrated circuit chip electrically connected to said transducer, said circuit chip comprising differentiator means for receiving said pressure signals and, in turn, for continuously developing signals proportional to the rate of change of said instantaneous pressure; electronic divider means for continuously comparing said pressure signals and said rate of change signals, and for developing signals proportional to the time remaining before depletion of the gas supply in said tank; and receiving means connected to said divider means for continuously indicating the time to depletion of the gas supply in said tank.
Claim 3
Dependent Claim
16 words
The device as claimed in claim 1 including battery means for electrically biasing said sensor means.
Claim 4
Dependent Claim
38 words
The device as claimed in claim 1 wherein said sensing means comprises a pressure transducer, and wherein said differentiator means comprises an R-C circuit in series with an integrated circuit operational amplifier deriving its input from said transducer.
Claim 5
Dependent Claim
36 words
The device as described in claim 1 wherein said divider means electronically divides a signal proportional to the instantaneous pressure in said tank by a signal proportional to the rate of change of said instantaneous pressure.
Claim 6
Dependent Claim
16 words
The device as claimed in claim 3 wherein said integrated circuit comprises dual matched operational amplifiers.
Claim 7
Dependent Claim
42 words
The device as claimed in claim 1 and further comprising a voltage follower amplifier receiving its input from said divider means and delivering its output to said receiving means; and wherein said receiving means is a gauge calibrated in a time scale.
Claim 8
Dependent Claim
13 words
The device as claimed in claim 6 wherein said gauge is a voltmeter.
Claim 9
Dependent Claim
13 words
The device as claimed in claim 6 wherein said gauge has digital readout.
Claim 10
Independent Claim
170 words
The device for electronically indicating the time to depletion of a gas supply in a pressure tank, comprising: pressure sensing means sensitive to instantaneous internal tank pressures for issuing first electrical signals indicative of such pressures; first operational amplifier means for receiving said first electrical signals and for issuing second amplified signals proportional to said first signals; second operational amplifier means for receiving said first electrical signals and for issuing third electrical signals proportional to the rate of change of said first electrical signals; third operational amplifier means for receiving said third electrical signals and for issuing fourth amplified signals proportional to said third electrical signals; and divider means adapted to receive and divide said second electrical signals by said fourth electrical signals, and for issuing fifth electrical signals proportional to such quotient; and sensing and display means for receiving said fifth electrical signals and for issuing a visual indication proportional to the strength thereof, and displaying the time remaining before the depletion of the gas supply in said tank.
Claim 11
Independent Claim
170 words
The device for electronically indicating the time to depletion of a gas supply in a pressure tank, comprising: pressure sensing means sensitive to instantaneous internal tank pressures for issuing first electrical signals indicative of such pressures; first operational amplifier means for receiving said first electrical signals and for issuing second amplified signals proportional to said first signals; second operational amplifier means for receiving said first electrical signals and for issuing third electrical signals proportional to the rate of change of said first electrical signals; third operational amplifier means for receiving said third electrical signals and for issuing fourth amplified signals proportional to said third electrical signals; and divider means adapted to receive and divide said second electrical signals by said fourth electrical signals, and for issuing fifth electrical signals proportional to such quotient; and sensing and display means for receiving said fifth electrical signals and for issuing a visual indication proportional to the strength thereof, and displaying the time remaining before the depletion of the gas supply in said tank.
Claim 12
Dependent Claim
28 words
The device recited in claim 9 wherein the first operational amplifier is connected in its non-inverting mode and said second operational amplifier is connected in its inverting mode.
Claim 13
Dependent Claim
26 words
The device recited in claim 10 and further comprising a voltage follower amplifier interposed in series between said divider means and said sensing and display means.
Claim 14
Independent Claim
172 words
The device for electronically indicating the time to depletion of a gas supply in a pressure tank, comprising: pressure sensing means sensitive to instantaneous internal tank pressures for issuing first electrical signals indicative of such pressures; first operational amplifier means for receiving said first electrical signals and for issuing second amplified signals proportional to said first signals; second operational amplifier means for receiving said first electrical signals and for issuing third electrical signals proportional to the rate of change of said first electrical signals; third operational amplifier means for receiving said third electrical signals and for issuing fourth amplifed signals proportional to said third electrical signals, and divider means adapted to receive and divide said second electrical signals by said fourth electrical signals; and for issuing fifth electrical signals digitally equivalent to such quotient; and sensing and display means for receiving said fifth electrical signals and for issuing a visual indication digitally equivalent to the strength thereof to display the time remaining before the depletion of the gas supply in said tank.
Claim 15
Independent Claim
172 words
The device for electronically indicating the time to depletion of a gas supply in a pressure tank, comprising: pressure sensing means sensitive to instantaneous internal tank pressures for issuing first electrical signals indicative of such pressures; first operational amplifier means for receiving said first electrical signals and for issuing second amplified signals proportional to said first signals; second operational amplifier means for receiving said first electrical signals and for issuing third electrical signals proportional to the rate of change of said first electrical signals; third operational amplifier means for receiving said third electrical signals and for issuing fourth amplifed signals proportional to said third electrical signals, and divider means adapted to receive and divide said second electrical signals by said fourth electrical signals; and for issuing fifth electrical signals digitally equivalent to such quotient; and sensing and display means for receiving said fifth electrical signals and for issuing a visual indication digitally equivalent to the strength thereof to display the time remaining before the depletion of the gas supply in said tank.
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) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |