Abstract: A pipette body extends along a longitudinal axis and a piston mounted in sliding fashion along this axis inside the said pipette body so as to define a chamber of variable volume emerging at a sampling orifice, said piston being driven over a limited distance of travel in the direction of the sampling orifice by means of pressure manually exerted on a push rod mounted in sliding fashion in the pipette body, and in the opposite direction by the reaction of elastic return means until it abuts against an axial extremity of a metal sheath extending along the said longitudinal axis in side the pipette body. The sheath has an external thread which works by engaging with a thread inside the pipette body in such a way as to move the sheath longitudinally when driven in rotations, in order to adjust the distance of travel of the piston in the opposite direction and the volume of the chamber.

Abstract: The present invention relates to a device for dispensing adjustable volumes of a liquid, comprising a stopper adaptable on the neck of a flask, which incorporates a device with valves; a calibrated cylinder which is mounted in the stopper and which comprises, near its free upper end, a fixed, outwardly projecting, annular stop; a calibrated cylindrical plunger adapted to cooperate with said calibrated cylinder; a body for actuating the calibrated plunger, internally defining a first cavity in which a threaded adjusting shaft is adapted to be housed, which shaft may modify the vertical position of a nut; a digital display system mounted in the upper part of the threaded shaft; a member for driving the shaft in rotation, and a connector is provided to connect the actuator body with the upper part of the calibrated plunger. The invention finds particular application in laboratory equipment.

Abstract: The invention provides an adjustable diluting device comprising a casing and a tapered tubular element or nose member, a volume-adjustment mechanism coupled with an indicator assembly, and a plunger unit movable in said casing; the plunger unit comprises a first piston having a central recess, a second piston adapted to slide in the recess with the interposition of a frictionally mounted joint, a sleeve for controlling the first piston, a shaft for controlling the second piston adapted to slide inside the sleeve, and a push button fixed to the upper end of the control shaft and adapted to cooperate with the upper end of the sleeve. The invention is particularly applied to the mixing of a determined volume of a liquid sample and of a determined volume of a liquid diluent.