Pipette assembly, in a laboratory apparatus to deliver fluid doses, is a syringe with a drive for a hollow piston plunger in a cylinder and a further hollow piston within it and structured passage openings to give reduced dimensions

摘要

The pipette assembly has a drive (22) to operate a fluid displacement system (1) as a syringe. A cylinder (3) has a fluid passage opening (7) at the cylinder base (4), and a passage opening (10) at the opposite end to take a hollow sliding piston plunger (11) in a sealed fit around the piston base (12) circumference. The piston plunger slides within the cylinder together with a further cylinder (16) forming a hollow zone, with a passage opening (13) in the piston base, and a further cylinder base (15) at the opposite side of the piston base. A further hollow piston (24) slides within the first piston plunger, with its base (28) in a sealed fit through the passage opening, has an axial hollow zone (26) with openings at both ends.