Abstract: A multi-volume displacement pipette assembly has a tubular body with a first end for receiving a plunger assembly and a second mounting end for mounting a removable dispensing tip to the tubular body. A first cylindrical chamber extends through the tubular body for holding a first volume of fluid. The first cylindrical chamber opens through the second end of the tubular body. At least one second cylindrical chamber extends through the tubular body for holding a second volume of fluid. The such at least one cylindrical chamber is coaxially aligned with the first chamber and is open through the second end of the tubular body through a fluid pathway extending through the tubular body to the second end. A plunger assembly is coaxially positioned within the tubular body and operatively mounted therein for reciprocal, longitudinal movement.

Abstract: A hand-held manually operated pipette having an adjustable plunger stroke and calibrated electronic digital volumetric display draws-up and dispenses viscous, dense or high vapor pressure liquids by means of an easily replaced, disposable, integral, positive displacement type plunger tip and capillary assembly. The pipette in another form utilizes a disposable air displacement capillary. The plunger adjustably strokes to a first stop in a first mode for calibration or sample draw-up and dispensing with the volume of pipette liquid contents continuously displayed. In a second mode an over-travel arrangement enables the plunger shaft to stroke beyond the first stop to permit collet type attachment and ejection of the integral plunger tip and capillary for positive displacement service or to eject an air displacement capillary.

Abstract: An adjustable volume dispenser comprises a barrel assembly having an internally threaded tubular portion, an adjustable stop formed with external threads engaged with the internal threaded tubular portion of said assembly, and a sleeve coaxially mounted within the tubular portion and rotatable therein, said sleeve being connected to the adjustable stop for imparting rotation thereto but allowing said stop to move axially thereon. A finger engageable wheel connects to the sleeve for rotating the adjustable stop relative to the barrel assembly, a plurality of numbered wheels being coaxially connected to the finger engageable wheel for indicating the position of the stop and the volume of liquid to be dispensed. A plunger assembly is provided including a rod reciprocally removeable within the barrel assembly, said rod extending coaxially through the adjustable stop, the sleeve and said wheels.