Patent attributes
A shaft for a sampling pipette includes a first cylindrical portion, a first annular shoulder, and a second annular shoulder. A first cross section of the first cylindrical portion has a first diameter. The first annular shoulder includes a first transition end adjacent the first cylindrical portion and a second cylindrical portion. A second cross section of the second cylindrical portion has a second diameter. The second annular shoulder includes a second transition end adjacent the first annular shoulder and a third cylindrical portion. A third cross section of the third cylindrical portion has a third diameter. The third diameter is greater than the second diameter which is greater than the first diameter. The second diameter and the third diameter are selected so that a pipette tip contacts the second cylindrical portion and the third cylindrical portion when the pipette tip is mounted on the shaft.
