Double pump device for mixing two or more liquids with variable relative ratios and concentrations

• US 3,935,971 A
• Filed: 05/23/1974
• Issued: 02/03/1976
• Est. Priority Date: 05/30/1973
• Status: Expired due to Term

• Current Assignee: Consiglio Nazionale Delle Ricerche (Repubblica Italiana)
• Original Assignee: Consiglio Nazionale Delle Ricerche (Repubblica Italiana)
• Inventors: Guidarini, Dante, Papoff, Paolo, Fragale, Carlo
• Primary Examiner(s): Husar, C. J.
• Application Number:
  US05/472,848
• Time in Patent Office: 621 Days
• Field of Search: 417/426, 137/99, 318/678, 318/8, 222/26, 222/134
• US Class Current: 222/134
• CPC Class Codes: F04B 43/1292 Pumps specially adapted for several tubular flexible members
• CPC Class Codes: F04B 49/06 Control using electricity regulating by means of floats actuating electric switches F04B49/04
• CPC Class Codes: G05D 11/132 by controlling the flow of the individual components G05D11/133 takes precedence
• CPC Class Codes: G05D 11/138 by sensing the concentration of the mixture, e.g. measuring pH value
• CPC Class Codes: H03F 2203/45352 the AAC comprising a combination of a plurality of transistors, e.g. Darlington coupled transistors
• CPC Class Codes: H03F 2203/45591 the IC comprising one or more potentiometers
• CPC Class Codes: H03F 2203/45611 the IC comprising only one input signal connection lead for one phase of the signal
• CPC Class Codes: H03F 2203/45702 the LC comprising two resistors
• CPC Class Codes: H03F 2203/45712 the LC comprising a capacitor as shunt
• CPC Class Codes: H03F 2203/45722 the LC comprising one or more source followers, as post buffer or driver stages, in cascade in the LC
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/45085 Long tailed pairs H03F3/45112, H03F3/45139 take precedence

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.

Claims

1. 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.

2. 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.

3. 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.

4. 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.

5. 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.

6. 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.