Rainin Instrument Co., Inc.

Rainin Instrument, LLC

Steven T Nielsen

James S Petrek

Kenneth Rainin

Christopher F Kelly

A pipette tip and mounting shaft combination in an air displacement pipette, the combination comprising a pipette tip mounting shaft having a radially stepped exterior comprising adjacent substantially cylindrical portions of different diameter and an annular sealing zone including an annular edge seal at an outermost edge of a radially extending shaft transition, a pipette tip including an annular sealing region having an inner sealing surface on a sidewall of the tip which in the sealing region is sufficiently thin as to expand slightly and form an interference fit and air tight seal between the sealing surface and the sealing zone when the sealing zone penetrates the sealing region, and axial penetration limiting means for limiting penetration of the shaft into the tip to limit axial contact between the sealing region and the sealing zone to a narrow annular band comprising the annular edge seal.

Pipette with improved pipette tip and mounting shaft

An air displacement pipette having axially spaced annular sealing and substantially cylindrical lateral support zones on the outer surface of the pipette's mounting shaft for mating with axially spaced annular sealing and substantially cylindrical lateral support regions on the inner surface of a pipette tip, whereby the pipette tip is easily and firmly mountable on and easily ejectable from the pipette tip mounting shaft by the application of minimal axial mounting and ejection forces.

Pipette with improved pipette tip mounting shaft

Pipette tip

An air displacement pipette having axially spaced annular sealing and substantially cylindrical lateral support zones and regions on the pipette's mounting shaft and tip, respectively, in combination with structure for insuring uniform depth of mounting shaft penetration into the pipette tip to maintain uniform tip interference with the mounting shaft as successive tips are mounted on and ejected from the mounting shaft whereby the pipette tip is easily and firmly mountable on and easily ejectable from the pipette tip mounting shaft by the application of axial mounting and ejection forces of about two pounds and one pound, respectively.

Growing community of inventors

Los Gatos, CA, United States of America

Steven T Nielsen