Method and apparatus for simultaneous dilution and dispensation

• US 4,327,595 A
• Filed: 07/07/1980
• Issued: 05/04/1982
• Est. Priority Date: 07/07/1980
• Status: Expired due to Term

• Current Assignee: Hamilton Company
• Original Assignee: Hamilton Company
• Inventors: Schultz, Harold R.
• Primary Examiner(s): Swisher, S. Clement
• Application Number:
  US06/166,141
• Time in Patent Office: 666 Days
• Field of Search: 73/864.12, 73/864.17, 222/383, 222/85, 422/100
• US Class Current: 73/864.12
• CPC Class Codes: B01L 3/0231 having several coaxial pistons
• CPC Class Codes: G01N 1/38 Diluting, dispersing or mixing samples

Abstract

A method and apparatus for achieving substantially simultaneous dilution or mixing and dispensing is disclosed wherein the diluent or carrier is supplied by a syringe including a relatively large diluent reservoir and a pipette including a replaceable tip for containing a specimen or concentrate, the syringe including a nozzle or tube extending into the interior of the replaceable tip to produce a jet of diluent directed toward an outlet opening formed by the replaceable tip, the specimen being intermixed with the diluent jet for substantially simultaneous dispensation. In a preferred embodiment of the syringe which may be employed by itself or within the above noted diluting dispenser, a replaceable cartridge provides a relatively large volume of the diluent or other material for delivery by the syringe.

Claims

1. A diluting dispenser for mixing a specimen with a diluent and substantially simultaneously dispensing the mixture, comprising

syringe means including a diluent chamber, and means for drawing a predetermined volume of the diluent into said diluent chamber and for expelling the diluent from said diluent chamber, and

pipette means including a dispensing tip, a specimen chamber and means for drawing a predetermined volume of the specimen into said specimen chamber,

said diluent expelling means including nozzle means directed toward said dispensing tip and arranged for interaction with said specimen chamber in order to draw said specimen into intimately mixed relation with a jet of diluent as it passes toward said dispensing tip so that the mixture of diluent and specimen is dispensed substantially simultaneously as it is mixed,

said syringe means further comprising a reservoir from which diluent is drawn into said diluent chamber, the means for drawing a predetermined volume of diluent into said diluent chamber comprising a first check valve communicating said diluent reservoir with said diluent chamber and a second check valve communicating said diluent chamber with said nozzle means, said means for drawing diluent into said diluent chamber and for expelling diluent from said diluent chamber comprising means for effectively expanding and contracting said diluent chamber.

2. The diluting dispenser of claim 1 further comprising vent means for said reservoir.

3. The diluting dispenser of claim 1 wherein said nozzle means comprises an elongated tube extending from said second check valve toward said dispensing tip.

4. The diluting dispenser of claim 1 wherein said means for drawing specimen into said specimen chamber comprises spring-loaded means forming an aspiration chamber in communication with said specimen chamber.

5. The diluting dispenser of claim 4 wherein said spring-loaded means is shifted in a direction to contract said aspirating chamber by said means for expelling diluent from said diluent chamber.

6. The diluting dispenser of claim 5 further comprising latch means for maintaining said spring-loaded member in said contracted position and means for selectively releasing said latch in order to permit movement of said spring-loaded member under its spring load in order to expand said aspirating chamber and thereby draw the specimen into said specimen chamber.

7. The diluting dispenser of claim 6 wherein said nozzle means comprises an elongated tube extending from said second check valve toward said dispensing tip, said aspirating chamber being annularly formed about said elongated tube.

10. The diluting dispenser of claim 1 wherein said diluent reservoir is formed by an element which is replaceably arranged within the diluting dispenser for communication with said first check valve.

11. The diluting dispenser of claim 10 wherein the diluting dispenser further comprises means for receiving the replaceable element and means for communicating said diluent reservoir formed by said replaceable element with said first check valve.

12. The diluting dispenser of claim 11 wherein said replaceable element is formed from a penetrable material, said means for communicating said diluent reservoir with said first check valve comprising a needle arranged for penetrating said replaceable element when it is mounted within said diluting dispenser.

13. The diluting dispenser of claim 12 further comprising additional means for venting said diluent reservoir.

8. A diluting dispenser for mixing a specimen with a diluent and substantially simultaneously dispensing the mixture, comprising

syringe means including a diluent chamber, and means for drawing a predetermined volume of the diluent into said diluent chamber and for expelling the diluent from said diluent chamber, and

pipette means including a dispensing tip, a specimen chamber and means for drawing a predetermined volume of the specimen into said specimen chamber,

said diluent expelling means including nozzle means directed toward said dispensing tip and arranged for interaction with said specimen chamber in order to draw said specimen into intimately mixed relation with a jet of diluent as it passes toward said dispensing tip so that the mixture of diluent and specimen is dispensed substantially simultaneously as it is mixed, said means for drawing specimen into said specimen chamber comprising spring-loaded means forming an aspiration chamber in communication with said specimen chamber, wherein said spring-loaded means is shifted in a direction to contract said aspirating chamber by said means for expelling diluent from said diluent chamber.

9. The diluting dispenser of claim 8 further comprising latch means for maintaining said spring-loaded member in said contracted position and means for selectively releasing said latch in order to permit movement of said spring-loaded member under its spring load in order to expand said aspirating chamber and thereby draw the specimen into said specimen chamber.

14. A diluting dispenser for mising a specimen with a diluent and substantially simultaneously dispensing the mixture, comprising

syringe means including a diluent chamber, and means for drawing a predetermined volume of the diluent from said diluent chamber, and

pipette means including a dispensing tip, a specimen chamber and means for drawing a predetermined volume of the specimen into said specimen chamber,

said diluent expelling means including nozzle means directed toward said dispensing tip and arranged for interaction with said specimen chamber in order to draw said specimen into intimately mixed relation with jet of diluent as it passes toward said dispensing tip so that the mixture of diluent and specimen is dispensed substantially simultaneously as it is mixed, said syringe means further comprising a reservoir from which diluent is drawn into said diluent chamber, wherein said diluent reservoir is formed by an element which is replaceably arranged within the diluting dispenser for communication with said means for drawing diluent into said diluent chamber.

15. The diluting dispenser of claim 14 wherein said diluting dispenser further comprises means for receiving the replaceable element and means for communicating said diluent reservoir formed by said replaceable element with said means for drawing diluent into said diluent chamber.

16. The diluting dispenser of claim 15 wherein said replaceable element is formed from a penetrable material, said means for communicating said diluent reservoir with said means for drawing diluent into said diluent chamber comprising a needle arranged for penetrating said replaceable element when it is mounted within the diluting dispenser.

17. The diluting dispenser of claim 16 further comprising additional means for venting said diluent reservoir.

18. A diluting dispenser for substantially simultaneously mixing a specimen with a diluent and dispensing the mixture, comprising a dispensing tip forming a restrictive opening for dispensing the mixture, means forming a specimen chamber in communication with said opening and means for directing a jet of the diluent into the specimen and toward said restrictive opening of the dispensing tip in order to draw the specimen into intermixed relation with the diluent jet for dispensation through said restrictive opening, the specimen being a liquid and said restrictive opening being sized to permit the specimen to be drawn into the specimen chamber and to permit passage of the jet of diluent and intermixed specimen, surface tension of the specimen normally preventing its passage through said restrictive opening, wherein an interior surface of said replaceable element tapers outwardly and longitudinally away from said restrictive opening to form said specimen chamber, said jet directing means comprising tubular means extending into the interior of said replaceable element in facing relation with said restrictive opening.

19. The diluting dispenser of claim 18 further comprising a housing including said jet directing means, said dispensing tip being a replaceable element secured to the housing, an interior portion of the replaceable element forming the specimen chamber.

20. The diluting dispenser of claim 18 wherein said restrictive opening includes means for normally preventing passage of said specimen therethrough while permitting passage of a jet of diluent and intermixed specimen.

21. The diluting dispenser of claim 18 wherein said tubular means is adapted for movement within said replaceable element toward said restrictive opening while directing the jet of diluent into the specimen so that a projecting end of said tubular means remains in closely spaced apart relation to specimen remaining within said specimen chamber.

22. The diluting dispenser of claim 18 wherein the tubular means is sized relative to the size of said restrictive opening and the tapered interior of said replaceable element to facilitate blending of the concentrate with the diluent and passage of the resulting mixture through said restrictive opening.

23. The diluting dispenser of claim 22 wherein the interior of said replaceable element is formed with a taper having a maximum enclosed angle of about 30°

.

24. The diluting dispenser of claim 23 wherein the interior of the replaceable element is tapered to form an included angle approximately within the range of 10°

-15°

.

25. The diluting dispenser of claim 18 wherein said jet directing means is sized relative to the size of said restrictive opening and configuration of said specimen chamber for facilitating intermixing of specimen with said diluent jet and for facilitating passage of said mixture through said restrictive opening.

26. In a method for mixing a specimen with a diluent and substantially simultaneously dispensing the mixture, the steps comprising

drawing a predetermined volume of the diluent into a diluent chamber formed by a syringe means,

drawing a predetermined volume of the specimen into a specimen chamber,

expelling the diluent from the diluent chamber and forming a diluent jet directed toward a dispensing tip while interacting the jet with the specimen in the specimen chamber in order to draw the specimen into intimately mixed relation with the diluent jet as it passes toward said dispensing tip so that the mixture of diluent and specimen is dispensed substantially simultaneously as it is mixed, and

further comprising the step of providing pipette means for drawing the predetermined volume of specimen into the specimen chamber, cocking the pipette into a latched condition and against a spring-load by action of the syringe means and subsequently unlatching the pipette in order to draw the predetemined volume of specimen into the specimen chamber.

27. The method of claim 26 further comprising the step of providing a replaceable tip on the pipette means, the replaceable tip forming a dispensing opening and an interior chamber for receiving the specimen.

28. In a method for substantially simultaneously mixing a specimen with a diluent and dispensing the mixture, the steps comprising

arranging a predetermined volume of the specimen in a specimen chamber in communication with a restrictive dispensing opening, and

directing a jet of the diluent into the specimen and toward said restrictive opening in order to draw the specimen into intermixed relation with the diluent jet for simultaneous dispensation through said restrictive dispensing opening, further comprising the step of introducing fluid into the specimen chamber along with the diluent jet to assist in expelling the specimen and diluent from the specimen chamber.

29. The method of claim 28 further comprising the step of introducing the diluent jet into the specimen chamber through a tube which is movable through the chamber to remain generally closely adjacent the specimen.

30. The method of claim 28 wherein the fluid is air.