EP0041318A1 - Pipette - Google Patents

Pipette Download PDF

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Publication number
EP0041318A1
EP0041318A1 EP81301936A EP81301936A EP0041318A1 EP 0041318 A1 EP0041318 A1 EP 0041318A1 EP 81301936 A EP81301936 A EP 81301936A EP 81301936 A EP81301936 A EP 81301936A EP 0041318 A1 EP0041318 A1 EP 0041318A1
Authority
EP
European Patent Office
Prior art keywords
pipette
piston
piston rod
handle portion
adjustment device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP81301936A
Other languages
German (de)
French (fr)
Inventor
Osmo Suovaniemi
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Thermo Fisher Scientific Oy
Original Assignee
Labsystems Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Labsystems Oy filed Critical Labsystems Oy
Publication of EP0041318A1 publication Critical patent/EP0041318A1/en
Withdrawn legal-status Critical Current

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Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01L—CHEMICAL OR PHYSICAL LABORATORY APPARATUS FOR GENERAL USE
    • B01L3/00—Containers or dishes for laboratory use, e.g. laboratory glassware; Droppers
    • B01L3/02—Burettes; Pipettes
    • B01L3/021—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids
    • B01L3/0217—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids of the plunger pump type
    • B01L3/0224—Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids of the plunger pump type having mechanical means to set stroke length, e.g. movable stops

Definitions

  • the subject of the present invention is a pipette comprising a cylindrical handle portion, a frame portion connected to same, in whose cylinder space a piston is fitted for sucking liquid into, and removing liquid from, a tip connected to the lower end of the frame portion and functioning as a liquid container, and that the piston is provided with two piston rods fitted inside each other, each of them being at the upper end provided with a knob, and that out of the said piston rods, the stroke of the inner, secondary piston rod is longer than the stroke of the second piston rod, surrounding the first one, and that the piston rods are prevented from rotating in relation to the handle portion.
  • the invention is in particular concerned with a liquid dosage pipette, more specifically with its adjustment for different volumes and with its calibration.
  • the pipette in accordance with the invention is mainly characterized in that around the piston rod surrounding the secondary piston rod, a sleeve-shaped adjustment device has been fitted by means of a threaded joint for the purpose of calibration of the pipette, while the adjustment device is placed in the chamber space of the upper end of the handle portion and is supported by means of shoulders against the support portion of the handle portion and that the turning of the adjustement device in relation to the piston rod so as to adjust or calibrate the pipette has been arranged as taking place from outside the pipette by using the adjustment and calibration unit.. ;
  • a frame portion 2 is connected to a preferably cylindrically shaped handle portion 1, inside which frame portion 2 a piston portion 3 moves and to which it is possible to connect a pipette_tip 4 functioning as a liquid container.
  • the sealing between the frame portion 2 and the piston 3 takes place by means of an 0-ring 5, against which a spiral spring 7 presses by means of an 0-ring support 6.
  • a secondary piston rod 9 runs inside the piston rod 8, said secondary piston rod 9 being connected to the adjustment unit 10 by means of a threaded joint.
  • the piston rod 8 is by means of a threaded joint connected with the adjustment device 12, which is by means of shoulders supported against a support and scale portion 13 connected to the handle portion 1.
  • the knob 16 in the upper part of the piston rod,8 is pressed, which knob transfers the movement via the piston rod 8 and the adjustment; unit 10 located therein to the piston 3 by the intermedaiate of the flange 11.
  • the knob 16 is pressed the distance a to its lower position, and thereupon, while the pipette tip 4 is in the liquid, the piston 3 is allowed to rise the distance a to its upper position.
  • the knob 17 of the secondary piston rod 9 is depressed, whereby the secondary piston rod 9 goes down a total of the distances a and b.
  • the pipette may be calibrated to a certain volume at the manufacturing stage by means of an adjustment device'12to be operated from the outside of the pipette and connected to the mobile piston rod 8. Moreover, the distance passed by the secondary piston rod 9 inside the piston rod 8 can be adjusted by means of the adjustment unit 10.
  • Such scales may, if necessary, be provided with markings so as to indicate a certain volume and/or a certain mass for liquids of different specific gravities.
  • the scales concerned may also be used so that by their means a desired volume is adjusted for the pipette within a certain volume range.
  • the invention'described here is also suitable for so-called reverse pipetting method, wherein more liquid is taken into the pipette tip than is removed from it (Medical Laboratory Technology, 31, 213, 1974). Then the filling of the pipette tip 4 takes place so that the secondary knob 17 is depressed first into its lower position, whereby the piston 3 goes down the total distance of a and b, and then liquid is sucked into the tip 4 by allowing the piston 3 to pass to its upper position the distance a+b. At the stage of emptying of the pipette tip 4 the knob 16 is depressed into its lower position, whereby the piston 3 goes down the distance a. The volume of liquid corresponding the distance a of the piston 3 is removed from the pipette tip 4. In many cases the reverse pipetting method improves the precision and reproducibility of pipetting.

Landscapes

  • Health & Medical Sciences (AREA)
  • Clinical Laboratory Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Devices For Use In Laboratory Experiments (AREA)
  • Sampling And Sample Adjustment (AREA)

Abstract

The subject of the present invention is a pipette comprising a cylindrical handle portion (1), a frame portion (2) connected to same, in whose cylinder space a piston (3) is fitted for sucking liquid into, and removing liquid from, a tip (4) connected to the lower end of the frame portion (2) and functioning as a liquid container. The piston (3) is provided with two piston rods (8 and 9) fitted inside each other, each of them being at the upper end provided with a knob (16 and 17). Out of the said piston rods (8 and 9), the stroke of the inner, secondary piston rod (9) is longer than the stroke of the second piston rod (8), surrounding the first one. Moreover, the piston rods are prevented from rotating in relation to the handle portion (1). According to the invention, around the piston rod (9), a sleeve-shaped adjustment device (12) has been fitted by means of a threaded joint for the purpose of calibration of the pipette, while the adjustment device is placed in the chamber space of the upper end of the handle portion (1) and is supported by means of shoulders against the support portion (13) of the handle portion (1). The turning of the adjustment device (12) in relation to the piston rod (8) so as to adjust or calibrate the pipette has been arranged as taking place from outside the pipette by using the adjustment and calibration unit.

Description

  • The subject of the present invention is a pipette comprising a cylindrical handle portion, a frame portion connected to same, in whose cylinder space a piston is fitted for sucking liquid into, and removing liquid from, a tip connected to the lower end of the frame portion and functioning as a liquid container, and that the piston is provided with two piston rods fitted inside each other, each of them being at the upper end provided with a knob, and that out of the said piston rods, the stroke of the inner, secondary piston rod is longer than the stroke of the second piston rod, surrounding the first one, and that the piston rods are prevented from rotating in relation to the handle portion.
  • The invention is in particular concerned with a liquid dosage pipette, more specifically with its adjustment for different volumes and with its calibration.
  • In the pipette in accordance with the invention the adjustment of the pipette for different volumes and the calibration-can be performed by using the same adjustment and calibration unit. It is particularly characteristic of the invention that the calibration of the pipette can be performed from outside the pipette without opening it and that the calibration unit moves along in such a unit .as transfers the movement to the pipette piston or as is a part of the piston.
  • The pipette in accordance with the invention is mainly characterized in that around the piston rod surrounding the secondary piston rod, a sleeve-shaped adjustment device has been fitted by means of a threaded joint for the purpose of calibration of the pipette, while the adjustment device is placed in the chamber space of the upper end of the handle portion and is supported by means of shoulders against the support portion of the handle portion and that the turning of the adjustement device in relation to the piston rod so as to adjust or calibrate the pipette has been arranged as taking place from outside the pipette by using the adjustment and calibration unit.. ;
  • By applying the invention described herein to pipettes of different types, e.g. to adjustable or fixed-volume single-channel or multi-channel pipettes, remarkable advantages are achieved as compared with such pipettes in which the calibration nut of the pipette is fixed in the handle portion of the pipette or the calibration screw is placed inside the pipette, in which case, every time that it is desired to calibrate the pipette, the pipette must be opened.
  • The invention comes out more closely from the following description and from the attached drawing, which shows an exemplifying embodiment of a pipette in accordance with the invention as a side view in section.
  • In the pipette shown in Figure 1, a frame portion 2 is connected to a preferably cylindrically shaped handle portion 1, inside which frame portion 2 a piston portion 3 moves and to which it is possible to connect a pipette_tip 4 functioning as a liquid container. The sealing between the frame portion 2 and the piston 3 takes place by means of an 0-ring 5, against which a spiral spring 7 presses by means of an 0-ring support 6. A secondary piston rod 9 runs inside the piston rod 8, said secondary piston rod 9 being connected to the adjustment unit 10 by means of a threaded joint. A flange 11, constituting a support for the spiral spring 7, presses the piston 3 against the adjustment unit 10. The piston rod 8 is by means of a threaded joint connected with the adjustment device 12, which is by means of shoulders supported against a support and scale portion 13 connected to the handle portion 1.
  • Inside the handle portion 1 there are guides 14, which glide in the shaft 8 in guide grooves 15 parallel to the longitudinal axis.
  • When pipetting is performed by means of the pipette shown in Fig. 1, the knob 16 in the upper part of the piston rod,8 is pressed, which knob transfers the movement via the piston rod 8 and the adjustment; unit 10 located therein to the piston 3 by the intermedaiate of the flange 11. During the step of filling of the pipette tip 4, the knob 16 is pressed the distance a to its lower position, and thereupon, while the pipette tip 4 is in the liquid, the piston 3 is allowed to rise the distance a to its upper position. When the pipette tip 4 is emptied, the knob 17 of the secondary piston rod 9 is depressed, whereby the secondary piston rod 9 goes down a total of the distances a and b. Here the total movement (a+b) is transferred by means of the adjustment unit 10 to the piston by the intermediate of the flange 11, whereby the emptying movement of the piston 3 is longer than its filling movement, which again guarantees good emptying of the pipette tip 4 out of the liquid to be pipetted.
  • Below, some of the characteristics and advantages of the present invention will be presented.
  • The pipette may be calibrated to a certain volume at the manufacturing stage by means of an adjustment device'12to be operated from the outside of the pipette and connected to the mobile piston rod 8. Moreover, the distance passed by the secondary piston rod 9 inside the piston rod 8 can be adjusted by means of the adjustment unit 10.
  • .'When adjustment is performed by means of the adjustment device 12 by turning it either clockwise or anticlockwise, turning of the piston rod 8 along with the unit is prevented.by means of the guides 14 and guide grooves 15. These means also prevent rotation of the piston rod 8 during pipetting.
  • The adjustment device=12 and the scale portion 13 can be provided with scales in order to faciliate the calibration and/or to indicate a certain volume. Such scales may, if necessary, be provided with markings so as to indicate a certain volume and/or a certain mass for liquids of different specific gravities. The scales concerned may also be used so that by their means a desired volume is adjusted for the pipette within a certain volume range.
  • The invention'described here is also suitable for so-called reverse pipetting method, wherein more liquid is taken into the pipette tip than is removed from it (Medical Laboratory Technology, 31, 213, 1974). Then the filling of the pipette tip 4 takes place so that the secondary knob 17 is depressed first into its lower position, whereby the piston 3 goes down the total distance of a and b, and then liquid is sucked into the tip 4 by allowing the piston 3 to pass to its upper position the distance a+b. At the stage of emptying of the pipette tip 4 the knob 16 is depressed into its lower position, whereby the piston 3 goes down the distance a. The volume of liquid corresponding the distance a of the piston 3 is removed from the pipette tip 4. In many cases the reverse pipetting method improves the precision and reproducibility of pipetting.

Claims (1)

1. A pipette comprising a cylindrical handle portion (1), a frame portion (2) connected to same, in whose cylinder space a piston (3) is fitted for sucking liquid into, and removing liquid from, a tip (4) connected to the lower end of the frame portion (2) and functioning as a liquid container, and that the piston (3) is provided with two piston rods (8 and 9) fitted inside each other, each of them being at the upper end provided with a knob (16 and 17), and that out of the said piston rods (8 and 9), the stroke of the inner, secondary piston rod (9) is longer than the stroke of the second piston rod (8), surrounding the first one, and that the piston rods are prevented from rotating in-relation to the handle portion (1), characterized in that around the piston rod (8) surrounding the secondary piston rod (9), a sleeve-shaped adjustment device (12) has been fitted by means of a threaded joint for the purpose of calibration of the pipette, while the adjustment device is placed in the chamber space of the upper end of the handle portion (1) and is supported by means of shoulders against the support portion (13) of the handle portion (1) and that the turning of the adjustment device (12) in relation to the piston rod (8) so as to adjust or calibrate the pipette has been arranged as taking place from outside the pipette by using the adjustment and calibration unit.
EP81301936A 1980-06-02 1981-05-01 Pipette Withdrawn EP0041318A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FI801770A FI60359C (en) 1980-06-02 1980-06-02 pipette
FI801770 1980-06-02

Publications (1)

Publication Number Publication Date
EP0041318A1 true EP0041318A1 (en) 1981-12-09

Family

ID=8513531

Family Applications (1)

Application Number Title Priority Date Filing Date
EP81301936A Withdrawn EP0041318A1 (en) 1980-06-02 1981-05-01 Pipette

Country Status (4)

Country Link
EP (1) EP0041318A1 (en)
JP (1) JPS57174148A (en)
FI (1) FI60359C (en)
SU (1) SU1205751A3 (en)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2161398A (en) * 1984-07-11 1986-01-15 Scient Supplies M B Pipette
US5012682A (en) * 1988-10-21 1991-05-07 Firma Eppendorf-Netheler-Hinz Gmbh Pipetting device
EP0562358A2 (en) * 1992-03-25 1993-09-29 Eppendorf-Netheler-Hinz Gmbh Pipetting system
DE10013511A1 (en) * 2000-03-20 2001-10-11 Brand Gmbh & Co Kg Multiple channel pipetting arrangement used for microtitration plates has pipette shafts each having a sealing receiver on the upper end with a plunger seal arranged in it
WO2006103315A1 (en) * 2005-04-01 2006-10-05 Thermo Electron Oy Calibratable pipette
EP1708814A2 (en) * 2003-12-31 2006-10-11 Rainin Instrument LLC. Volume adjustable manual pipette with quick set volume adjustment
CN109939759A (en) * 2019-04-18 2019-06-28 马占龙 A kind of two-tube acid-base universal burette of high-precision

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FI64752C (en) * 1982-06-29 1984-01-10 Labsystems Oy VOLUME REGULATOR PIPETT

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4096751A (en) * 1977-06-15 1978-06-27 Oxford Laboratories Inc. Hand-held micropipettor with fluid transfer volume adjustment mechanism
US4128009A (en) * 1976-08-18 1978-12-05 Marteau D Autry Eric Adjustable diluting device
US4141250A (en) * 1976-05-10 1979-02-27 Marteau D Autry Eric Plural piston, adjustable diluting device having a volume indicator assembly
GB2029262A (en) * 1978-09-08 1980-03-19 Metsala S Pipette

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4141250A (en) * 1976-05-10 1979-02-27 Marteau D Autry Eric Plural piston, adjustable diluting device having a volume indicator assembly
US4128009A (en) * 1976-08-18 1978-12-05 Marteau D Autry Eric Adjustable diluting device
US4096751A (en) * 1977-06-15 1978-06-27 Oxford Laboratories Inc. Hand-held micropipettor with fluid transfer volume adjustment mechanism
GB2029262A (en) * 1978-09-08 1980-03-19 Metsala S Pipette

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB2161398A (en) * 1984-07-11 1986-01-15 Scient Supplies M B Pipette
US5012682A (en) * 1988-10-21 1991-05-07 Firma Eppendorf-Netheler-Hinz Gmbh Pipetting device
EP0562358A2 (en) * 1992-03-25 1993-09-29 Eppendorf-Netheler-Hinz Gmbh Pipetting system
EP0562358A3 (en) * 1992-03-25 1994-05-18 Eppendorf Geraetebau Netheler Pipetting system
US5481900A (en) * 1992-03-25 1996-01-09 Eppendorf-Netheler-Hinz Gmbh Pipette system
US6627160B2 (en) 2000-03-20 2003-09-30 Brand Gmbh + Co. Kg Multiple channel pipetting device
DE10013511A1 (en) * 2000-03-20 2001-10-11 Brand Gmbh & Co Kg Multiple channel pipetting arrangement used for microtitration plates has pipette shafts each having a sealing receiver on the upper end with a plunger seal arranged in it
EP1708814A2 (en) * 2003-12-31 2006-10-11 Rainin Instrument LLC. Volume adjustable manual pipette with quick set volume adjustment
EP1708814A4 (en) * 2003-12-31 2008-06-11 Rainin Instr Llc Volume adjustable manual pipette with quick set volume adjustment
WO2006103315A1 (en) * 2005-04-01 2006-10-05 Thermo Electron Oy Calibratable pipette
CN101296750B (en) * 2005-04-01 2011-08-03 恩姆菲舍尔科技公司 Calibratable pipette
US8631682B2 (en) 2005-04-01 2014-01-21 Thermo Fisher Scientific Oy Calibratable pipette
CN109939759A (en) * 2019-04-18 2019-06-28 马占龙 A kind of two-tube acid-base universal burette of high-precision

Also Published As

Publication number Publication date
JPS57174148A (en) 1982-10-26
FI60359B (en) 1981-09-30
SU1205751A3 (en) 1986-01-15
FI60359C (en) 1982-01-11

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PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

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Effective date: 19820218

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Inventor name: SUOVANIEMI, OSMO