Patent ID: 7033543

Claim:
A pipette device, comprising: a pipette unit ( 201 ) having a pipette tip including a working surface ( 127 ) with a radially extending surface component; wherein the pipette unit ( 201 ) has a coupling stud ( 203 ) onto which the pipette tip can be mounted for coupling; wherein the coupling stud ( 203 ) comprises a counter-stop ( 219 ) and an adjustable prestress member ( 213 ), that can be adjusted into a prestress state and a release state via an actuation device which is provided in the coupling stud; wherein the pipette tip ( 101 ) has an axial stop ( 121 ) which interacts with said counter-stop ( 219 ) of the coupling stud ( 203 ) in an axial coupling position of the pipette tip ( 101 ) such that the prestress member ( 213 ) in the prestressed state, acts upon said surface component of said working surface ( 127 ) of the mounted pipette tip ( 101 ) in such a way that the prestress member abuts sealingly on the working surface, and prestresses the pipette tip ( 101 ) on the pipette unit ( 201 ) into the axial coupling position; and wherein the prestress member ( 213 ) in the release state, releases the working surface ( 127 ) of the pipette tip ( 101 ).