EP0348612A2 - Pipette - Google Patents

Pipette Download PDF

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Publication number
EP0348612A2
EP0348612A2 EP89106634A EP89106634A EP0348612A2 EP 0348612 A2 EP0348612 A2 EP 0348612A2 EP 89106634 A EP89106634 A EP 89106634A EP 89106634 A EP89106634 A EP 89106634A EP 0348612 A2 EP0348612 A2 EP 0348612A2
Authority
EP
European Patent Office
Prior art keywords
plunger
arbor
casing
sleeve
flange
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Withdrawn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
EP89106634A
Other languages
German (de)
English (en)
Other versions
EP0348612A3 (fr
Inventor
Wojciech Sarna
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.)
Przedsiebiorstwo Polonijno Zagraniczne Plastomed
Original Assignee
Przedsiebiorstwo Polonijno Zagraniczne Plastomed
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 Przedsiebiorstwo Polonijno Zagraniczne Plastomed filed Critical Przedsiebiorstwo Polonijno Zagraniczne Plastomed
Publication of EP0348612A2 publication Critical patent/EP0348612A2/fr
Publication of EP0348612A3 publication Critical patent/EP0348612A3/fr
Withdrawn legal-status Critical Current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

Definitions

  • the subject of the invention is a plain pipette being a laboratory instrument and serving for drawing in, pipet­ting and dispensing the fluid of a strictly specified volume.
  • the up­per sleeve and the casing are provided with a co-operating groove/projection assembly, which prevents turning thereof but enables the movement of the sleeve along the piston rod, and thereby, after turning the push which defines the upper position of the piston, the sleeve can be displaced up and down relative to the piston rod, changing the pipette's vo­lume which is monitored on the scale in the casing.
  • a hand-held pipetting device comprising a slim, conical body, the upper portion whereof is a handle, while the lower portion is terminated with an outlet member projecting outside the body, whereon a replaceable working tip of the pipette is fitted.
  • a dispensing mechanism being activated by means of a push projecting over the upper portion of the body.
  • the mechanism of the pipette principally consists of a few ope­rating systems placed in tandem on a single axis running alongside the whole symmetry axis of the pipette. The up­per part of the mechanism constitutes the dosage measuring system.
  • the said system comprises a piston rod being termi­ nated with a push projecting over the body, a return spring being fitted on the piston rod and a limiter with a hole in its bottom, wherethrough there passes the end of the piston rod.
  • a piston rod being termi­ nated with a push projecting over the body
  • a return spring being fitted on the piston rod
  • a limiter with a hole in its bottom, wherethrough there passes the end of the piston rod.
  • a constant ring setting the upper basic position of the plunger and the whole mechanism In the body above the limiter, there is screwed a constant ring setting the upper
  • a pipette as disclosed in the US patent specification No. 4,009,611, has a cylindrical body being a handle and an outerly step-by-step slimmer cylinder, being an elong­ation thereof, with a correspondingly step-by-step slimmer ejector's sleeve, being mounted thereon. Inside the body there is placed a long piston rod also terminated with a long rod plunger embedded into the cylinder, and periphe­ rally sealed from the top of the system.
  • a sleeve is forced, the length whereof is determined by the plunger's one-­length stroke.
  • a movable ring threaded through the piston rod and held down from the bot­tom by means of a spiral spring in such a manner that a se­parable sleeve bottom is formed.
  • a return spring mounted on the piston rod, with its lower end resting upon the bottom of the body, whereas with its upper end resting upon a peripheral limiter, being fitted on the piston rod beneath the ring which forms the bottom of the upper sle­eve.
  • the upper end of the piston rod passes through the interior of the upper sleeve and projects above the body, where the piston rod is terminated with a push.
  • the said push is a right-angled triangle in cross-section with a rounded and profiled leg for better support of a thumb.
  • the said laboratory micro-pipette is characterized in that in the upper separable two-segment body, in the por­tion above the piston, there is a partition wall, whereunder there is placed a main spring co-operating with the piston.
  • auxiliary spring acting upon the sleeve, being centrically and movably placed inside the piston stroke control spring which is screwed in the aperture of the upper portion of the bo­dy, above the auxiliary spring.
  • a movable push rod of the piston provided with a push head.
  • the hitherto-known pipettes are of a quite complicated design as they comprise a great number of component parts.
  • the pressing movement is at length accompanied by the movement of a plunger.
  • the force barrier is car­ried out by a bending stop. It results in a risk of weaker or stronger pressing down to a stop because of a fear of exceeding the force barrier, and the steps of pressing movement are not properly differentiated, what makes it possible that a high repeatability of results in drawing in the fluid for examination is not entire­ly ensured.
  • the plain pipette as per the present invention is charac­teric by the fact that in the middle of the symmetry axis of the body of the casing, right under a push, there is a calibration unit.
  • the said calibration unit comprises a multi-step calibra­tion sleeve resting upon the inner projection of the body of the casing, the said sleeve being blocked from the top by means of a hold-down element being screwed into the body of the casing.
  • Inside the calibration sleeve there freely slides an arbor which is connected to a press means, being with a part of its flattened diameter placed inside a flat­tened oblong sleeve being a push rod, which from the top rests with its flange upon the face of a stop, being screwed into the internal thread of the calibration sleeve.
  • the plun­ger of the pipette comprises a two-step flange and a trunca­ted cone portion, being with its smaller diameter directed towards the oblong arbor of the plunger terminated with the other conical portion.
  • a plunger sea­ling unit comprising a nut with a flanged sleeve screwed into the internal thread thereof, being a hold-down element, which through the said sleeve presses down the ring and the sealing sleeve to the face of the main body.
  • a plunger comprises a two-step flange, a short cylindrical portion and then an oblong arbor and a thin plunger rod.
  • a plunger sealing unit comprising a nut, inside whereof a hold-down element is screwed, which through a spring exerts pressure upon a hold-down sleeve, which, being slid into the hole of the shank, presses down the ring and the sealing sleeve to the face of the shank.
  • the press means of the pipette is in the shape of a round, one end-closed sleeve, whereto from the inside an arbor is rigidly fitted. From the outside, it has a transparent plastics cover mounted thereon. At the top, around the periphery of the press means, there is a rectangular gro­ove, wherein an information strip is placed.
  • the pipette as per the present invention due to the application of a calibration unit, in the course of pressing down the press means, is capable of differentia­ting the three steps of movement and the two force bar­riers and of separating them, where only the first and the third step of pressing movement is accompanied by the mo­vement of the plunger.
  • the pipette performs an idle movement, which separates the draw-in cycle from the blow-out cyc­le.
  • the plain pipette which ser­ves for drawing in the fluid within the range of 100 - 1000 ⁇ l. It comprises a round body of a casing 1 , which is made of plastics material, simultaneously being a handle for the persons applying it.
  • a shank 3 is fitted through a round nut 2 being screwed into the end of the body of casing 1 , being in the shape of a step-by-step elongated sleeve.
  • a sealing unit of a plunger 4 which comprises a hold-down element 5 being in the shape of a flanged sleeve.
  • Hold-down element 5 being screwed inside the internal thread of nut 2 , through a sleeve 6 presses down a ring 7 and a sealing sleeve 8 to th face of shank 3 , which together seal the arbor of plunger 4 , which slides into the opening of shank 3 .
  • the free and of shank 3 is made in such a manner that it enables inser­ting therein a tip for drawing in the examined fluid, not being shown into the drawing.
  • Plunger 4 consists of a two-step flange 10 being connected to a conical portion 11 which is narrower towards the bottom, and then of a cylindrical portion being an arbor 21 , which is again at the bottom terminated with a conical portion 12 being narrower to­wards the bottom.
  • a cylindrical spring 13 lifting plunger 4 upwards.
  • flange 10 is pressed down by a push rod 14 provided with an arbor 15 , which has a press means 16 fitted upon its upper end, whereas the movement of push rod 14 and arbor 15 .
  • Arbor 15 is in the shape of a two-step round rod, having an un­dercut in the fitting place of pressing element 16 , and the other one in the fitting place of ring 17 , and of a step washer 18 .
  • a calibration unit serving to impart the particular sta­ges of movement to plunger 4 which comprises a multi-step calibration sleeve 19 , being inserted inside the body of casing 1 , inside whereof there is screwed a short step 20 being in the shape of a sleeve.
  • arbor 15 is placed with its bigger diameter in the middle of elongated push rod 14 , being in the shape of a step sleeve which is pressed down from the top to the flange of arbor 15 by means of a blow-out mechanism spring 22 .
  • the flange of push rod 14 being in the state of rest, rests upon the face of short stop 20 .
  • push rod 14 through plunger flange 10 , is pressed from the bottom by lift up spring 13 , whereas there remains a narrow slot 23 between plunger flange 10 and the end of arbor 15 .
  • the inner flange of a calibration sleeve 19 forms a lower resistance point for push rod 14 sliding down together with arbor 15 .
  • the calibration unit is closed from the top by a hold-down element 24 which is screwed into the internal thread of the body of casing 1 , the said element being in the shape of a nut, which blocks cali­bration sleeve 19 from the top.
  • the blow-­out mechanism spring 22 rests upon step washer 18 , which slides down along arbor 15 , and is displaced relative to calibration sleeve 19 together arbor 15 .
  • Press means 16 serving for actuating the pipette, which slides along the body of casing 1 .
  • Press means 16 is in the form of a round sleeve, being closed from the top. From the outside, a transparent plastics cover 25 is put upon press means 16 .
  • press means 16 has a rectangular groove 26 , wherein information strip 27 is placed, showing the pipette's volume.
  • a plain pipette which serves for drawing in small volumes of fluid renging 5 + 50 ⁇ l, which is different by the design of plunger 4 , by the manner of sealing plunger 4 in handle 3 , and which is provided with stop 30 .
  • Plunger 4 is in the form of multi-step arbor, which consists of two-step flange 10 , whereon lift-up spring 13 is supported, and further of a short cylindrical portion 31 being terminated with an elongated arbor 32 , having a thin arbor of plunger 4 at its end, which slides in the opening of shank 3 .
  • a sealing unit of the arbor 21 comprising nut 6 being screwed onto the body of casing 1 , inside whereof hold-down element 5 is screwed being in the form of a sleeve with its flange turned down, whereon lift-up spring 13 is supported.
  • Hold-down element 5 through spring 33 , exerts pressure on hold-down sleeve 34 , which is slid inside the first opening of shank 3 and then it presses down a ring 35 and a sealing sleeve 36 to the face of shank 3 , the said elements sealing the arbor 21 of plun­ger 4 , which slides in the other opening of shank 3 .
  • the above disclosed plain pipette operates in the following manner: when the pressing element is being pressed down, the three steps of movement are differentiated, being se­parated therefrom by the two force barriers.
  • Fig. 6 is a calibration unit of the pipette in its state of rest, when press means 16 is extended and in Fig. 7 the first step of movement of press means 16 is shown.
  • the pre­ssing down movement of press means 16 is accompanied by the movement of push rod 14 .
  • the flange of push rod 14 is de­tached from the surface of stop 20 or 30 .
  • Push rod 14 ac­tuates plunger 4 causing lift-up spring 13 bend down.
  • the first step of movement is over when the flange of push rod 14 rests upon the projection of calibration sleeve 19 . Then the first force barrier is sensed.
  • the fluid is drawn in. Fig.
  • FIG. 8 shows the second step of movement of press means 16 .
  • press means 16 When press means 16 is being pressed down, the pretension of blow-out mechanisms spring 22 is to be overcome, the said spring causing the first force barrier.
  • the movement of press means 16 causes arbor 15 displace re­lative to immovable push rod 14 .
  • blow-out mechanism spring 22 of plunger 4 is bent down, whereas plunger 4 remains in the state of rest.
  • the second step of movement continues up to the moment of contact of the face of arbor 15 with plunger's flange 10 .
  • the second force barrier is sensed.
  • the second step of movement is separated by the first and the third force barrier. In this step of movement no operation of the pipette occurs; it is a protective step.
  • Fig. 9 is the third step of mo­vement of press means 16 .
  • the second force barrier is to be further overcome.
  • both springs lift-up spring 13 and blow-out mechanism spring 22 start to operate in a paral­lel system and not in a series system as before.
  • the ten­sion of lift-up spring 13 is added to the tension of blow-­out mechanism spring 22 .
  • arbor 15 drives plunger 4 up to the moment when press means 16 rests upon hold-down element 24 .
  • press means 16 rests upon hold-down element 24 .
  • the move­ment is terminated then.
  • This additional step of movement serves to exactly clean the pipette from the remaining fluid.
  • Only the first and the third step of movement of press means 16 is accompanied by the downward movement of plunger 4 . Therefore, when press means 16 is being pressed down, for drawing in the fluid the first force barrier is to be always crossed and press means 16 is to be stopped before reaching the second force barrier. It ensures obtaining a higher repeatability of results.
EP19890106634 1988-04-15 1989-04-13 Pipette Withdrawn EP0348612A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
PL27184588A PL155157B1 (en) 1988-04-15 1988-04-15 Simple pipette
PL271845 1988-04-15

Publications (2)

Publication Number Publication Date
EP0348612A2 true EP0348612A2 (fr) 1990-01-03
EP0348612A3 EP0348612A3 (fr) 1990-09-12

Family

ID=20041629

Family Applications (1)

Application Number Title Priority Date Filing Date
EP19890106634 Withdrawn EP0348612A3 (fr) 1988-04-15 1989-04-13 Pipette

Country Status (8)

Country Link
EP (1) EP0348612A3 (fr)
CS (1) CS227189A3 (fr)
DD (1) DD283779A5 (fr)
HU (1) HUT53459A (fr)
LT (1) LTIP796A (fr)
LV (1) LV10400A (fr)
PL (1) PL155157B1 (fr)
RU (1) RU1836147C (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991012077A1 (fr) * 1990-02-07 1991-08-22 Spindler Joerg Pipette a canaux multiples
WO1993015837A1 (fr) * 1992-02-11 1993-08-19 Biohit Oy Pipette
EP1136127A2 (fr) * 2000-03-20 2001-09-26 Brand Gmbh + Co Kg Dispositif de pipetage à canaux multiples et tige de pipette associée
WO2005044452A1 (fr) * 2003-11-10 2005-05-19 Thermo Electron Oy Pipette à phases multiples
CN112206843A (zh) * 2019-07-12 2021-01-12 华大青兰生物科技(无锡)有限公司 一种转移液体的装置
CN112206842A (zh) * 2019-07-12 2021-01-12 华大青兰生物科技(无锡)有限公司 一种多通道移液器

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1209592A (fr) * 1958-08-14 1960-03-02 Dispositif permettant de doser exactement et de transférer de petites quantités de liquide
US4009611A (en) * 1976-05-13 1977-03-01 Oxford Laboratories Inc. Hand-held micropipettor with improved pipette tip ejector
US4096751A (en) * 1977-06-15 1978-06-27 Oxford Laboratories Inc. Hand-held micropipettor with fluid transfer volume adjustment mechanism
EP0181957A1 (fr) * 1984-11-20 1986-05-28 HTL High-Tech Lab Herstellung und Vertrieb medizinisch technischer Erzeugnisse GmbH Pipette à dose réglable

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1209592A (fr) * 1958-08-14 1960-03-02 Dispositif permettant de doser exactement et de transférer de petites quantités de liquide
US4009611A (en) * 1976-05-13 1977-03-01 Oxford Laboratories Inc. Hand-held micropipettor with improved pipette tip ejector
US4096751A (en) * 1977-06-15 1978-06-27 Oxford Laboratories Inc. Hand-held micropipettor with fluid transfer volume adjustment mechanism
EP0181957A1 (fr) * 1984-11-20 1986-05-28 HTL High-Tech Lab Herstellung und Vertrieb medizinisch technischer Erzeugnisse GmbH Pipette à dose réglable

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991012077A1 (fr) * 1990-02-07 1991-08-22 Spindler Joerg Pipette a canaux multiples
WO1993015837A1 (fr) * 1992-02-11 1993-08-19 Biohit Oy Pipette
EP1136127A2 (fr) * 2000-03-20 2001-09-26 Brand Gmbh + Co Kg Dispositif de pipetage à canaux multiples et tige de pipette associée
EP1136127A3 (fr) * 2000-03-20 2003-06-25 Brand Gmbh + Co Kg Dispositif de pipetage à canaux multiples et tige de pipette associée
US6627160B2 (en) 2000-03-20 2003-09-30 Brand Gmbh + Co. Kg Multiple channel pipetting device
WO2005044452A1 (fr) * 2003-11-10 2005-05-19 Thermo Electron Oy Pipette à phases multiples
CN112206843A (zh) * 2019-07-12 2021-01-12 华大青兰生物科技(无锡)有限公司 一种转移液体的装置
CN112206842A (zh) * 2019-07-12 2021-01-12 华大青兰生物科技(无锡)有限公司 一种多通道移液器

Also Published As

Publication number Publication date
HUT53459A (en) 1990-10-28
LV10400A (lv) 1995-02-20
PL271845A1 (en) 1990-01-08
PL155157B1 (en) 1991-10-31
RU1836147C (ru) 1993-08-23
CS227189A3 (en) 1992-06-17
DD283779A5 (de) 1990-10-24
EP0348612A3 (fr) 1990-09-12
LTIP796A (en) 1995-02-27

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