(19)
(11) EP 0 348 612 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
12.09.1990 Bulletin 1990/37

(43) Date of publication A2:
03.01.1990 Bulletin 1990/01

(21) Application number: 89106634.2

(22) Date of filing: 13.04.1989
(51) International Patent Classification (IPC)5B01L 3/02
(84) Designated Contracting States:
DE FR GB

(30) Priority: 15.04.1988 PL 271845

(71) Applicant: PRZEDSIEBIORSTWO POLONIJNO ZAGRANICZNE PLASTOMED
PL-03-230 Warszawa (PL)

(72) Inventor:
  • Sarna, Wojciech
    PL-02-601 Warszawa (PL)

(74) Representative: Finck, Dieter, Dr.Ing. et al
Patentanwälte v. Füner, Ebbinghaus, Finck, Postfach 95 01 60
81517 München
81517 München (DE)


(56) References cited: : 
   
       


    (54) Pipette


    (57) The present invention solves the problem of working out a de­sign of a plain pipette which seves for drawing in, pipetting and dispensing the fluid of a strictly specified volume and which is characterized by a high repeatability of results.
    The said pipette consists of a round casing /1/ being simul­taneously a handle thereof, whereto, via a round nut /2/, there is fitted a multi-step shank /3/. Inside the body of casing /1/, there is a plunger /4/, being in the form of a multi-step rod,which is being displaced downwards with the aid of a press means /16/ and of a round arbor /15/, contrary to the force being exerted by a lift-up spring /13/ which makes plunger /4/ return to its initial position. Furthermore, inside the body of casing /1/, centrally in the symmetry axis of the pipette, directly under press means /16/, there is a calibration unit comprising a multi-step calibration sleeve /19/, which is blocked from the top by a hold-down element /24/, being screwed into the body of casing /1/, inside whereof there freely slides an arbor /15/ being connected to press means /16/.
    The end of arbor /15/ is placed inside an elongated sleeve being a push rod /14/, which from the top rests with its flange upon the face of a stop /20/ being screwed into the internal thread of calibration sleeve /19/.
    From the top, upon the flange of push rod /14/, the pres­sure is being simultaneously exerted by a blow-out mechanism spring /22/, which from the top rests upon a washer /18/ being blocked by a ring /17/. The lower part of push rod /14/ gets in contact with a plunger's flange /10/, whereas bet­ween plunger's flange /10/ and the end of arbor /15/ there is a narrow slot /23/.







    Search report