US3935971A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Double pump device for mixing two or more liquids with variable relative ratios and concentrations
Assignee: Consiglio Nazionale delle Richerche
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Filing: 1974-05-23
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Granted: 1976-02-03
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Expires: 1994-05-23
Abstract
Abstract A double pump device for mixing with variable ratios and concentrations two or more liquids, comprising in combination: a first peristaltic pump, and a second peristaltic pump, each of said pumps acting on a plurality of collapsible tubes, said pumps being operated by two electric motors, interdependant and preferably identical to each other, driven by an electronic circuit comprising as main elements a differential amplifier and circuitry means for adjusting the input voltage of the differential amplifier and for amplifying the output signals from the differential amplifier before their application to the two driving motors.
Inventors
- 👤 Paolo Papoff
- 👤 Dante Guidarini
- 👤 Carlo Fragale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:06
CPC Classifications
H; H03; H03F; H03F3/00; H03F3/45; H03F3/45071; H03F3/45076; H03F3/4508; H03F3/45085; F; F04; F04B; F04B43/00; F04B43/12; F04B43/1253; F04B43/1292; F04B49/00; F04B49/06; G; G05; G05D; G05D11/00; G05D11/02; G05D11/13; G05D11/131; G05D11/132; G05D11/135; G05D11/138; H03F3/20; H03F3/21; H03F3/211; H03F2203/00; H03F2203/45; H03F2203/45352; H03F2203/45591; H03F2203/45611; H03F2203/45702; H03F2203/45712; H03F2203/45722
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
A double pump device for mixing with variable ratios and concentrations two or more liquids, comprising in combination: a first peristaltic pump, and a second peristaltic pump, each of said pumps acting on a plurality of collapsible tubes, some of said tubes having a crosssectional area different from others of said tubes, said pumps being operated by two electric motors, driven by an electronic circuit comprising as main elements a differential amplifier and circuitry means for adjusting the input voltage of the differential amplifier and for amplifying the output signals from the differential amplifier before their application to the two driving motors so that the speeds of the motors vary inversely to each other.
Claim 2
Dependent Claim
114 words
A double pump device for mixing with variable ratios and concentrations two or more liquids, comprising in combination: a first peristaltic pump, and a second peristaltic pump, each of said pumps acting on a plurality of collapsible tubes, some of said tubes having a crosssectional area different from others of said tubes, said pumps being operated by two electric motors, driven by an electronic circuit comprising as main elements a differential amplifier and circuitry means for adjusting the input voltage of the differential amplifier and for amplifying the output signals from the differential amplifier before their application to the two driving motors so that the speeds of the motors vary inversely to each other.
Claim 3
Dependent Claim
53 words
A double pump device as claimed in claim 1 characterized in that said differential amplifier comprises a double transistor to one base of which a variable potential is applied, said variable potential being adjustable by said means for adjusting the input voltage, while to the second base, a fixed potential will be applied.
Claim 4
Dependent Claim
57 words
A double pump device as claimed in claim 2, characterized in that the input adjusting means for the differential amplifier include a first potentiometer, supplying the variable voltage to the first base of the double transistor, and a second trimming potentiometer in series with the first cited potentiometer; the two potentiometers being connected to a voltage generator.
Claim 5
Dependent Claim
53 words
A double pump device as claimed in claim 1, characterized in that for adjusting the operating point of the differential amplifier, a constant current generator is provided including a transistor with a potentiometer inserted into its base biassing circuit, said current generator being connected to the centre reference point of said differential amplifier.
Claim 6
Dependent Claim
36 words
A double pump device as claimed in claim 1 characterized in that the means for amplifying the output voltages of the differential amplifier before their application to the pump operating motors, consist of Darlington amplifier circuits.
Claim 7
Dependent Claim
37 words
A double pump device as claimed in claim 1 characterized in that means are provided for admixing liquid from at least one tube of one pump with liquid from at least one tube of the other pump.
References Cited (Backward Citations)
US3427520A
Cited
US3398689A
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US3559008A
Cited
US3565286A
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US3523228A
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US3771032A
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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) | 1979-02-02 | 1979-08-04 | 1980-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-02-02 | 1983-08-04 | 1984-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-02-02 | 1987-08-04 | 1988-02-03 | $7700.00 | Window Closed / Lapsed |