Adjustable volume pipette with improved volume adjustment lock mechanism

摘要

A volume adjustable pipette for aspirating and dispensing precise volumes of liquid comprising an elongated hollow hand-holdable housing supporting a plunger for turning and for axial movement within the housing the pipette including (i) an upper stop which is axially adjustable within the housing in response to a turning of the plunger to adjust the volume of liquid which may be drawn into a tip secured to a lower end of the housing upon upward axial movement of the plunger to the upper stop and (ii) a manually actuated lock mechanism for locking the plunger against rotation to set the volume adjustment for the pipette and comprising a hand-turnable knob for actuating and releasing the lock mechanism by virtue of two thumb and/or finger engageable wings extending outwardly from diametrically opposite sides of the hand-turnable knob a gripping member for fixedly securing the plunger against turning and being actuated by a turning of the hand-turnable knob to force a cam surface of the knob against a cam surface of the gripping member.