Patent ID: 6021680
Filing Date: 2000-02-08
Classification: B01L

Abstract:
A pipette comprising:a cylindrical casing;a cylinder formed at an inner tip end of said cylindrical casing;a first suction chamber which is formed in said cylinder and is open on an inward end surface of the cylinder;a nozzle part which is formed at an outward end of the cylinder t o ext end to the outside of the casing and has a suction passage in communication with the first suction chamber;a first piston which is reciprocatably inserted into the first suction chamber;a second suction chamber which is formed in said first piston and is open on both end surfaces of the first piston;a second piston which is reciprocatably inserted into the second suction chamber, said second piston comprising a small-diameter part which is insertable into said second suction chamber and a large-diameter part which is engagable with said first piston to push said first piston;a first resilient member which pushes said first piston in a direction of protruding from said cylinder;a second resilient member which pushes said second piston in a direction of protruding from said first piston, said second resilient member having less resiliency than said first resilient member; andan operating lever which is provided in the casing comes into contact at an inward end thereof with a top surface of the second piston, and operates the first and second pistons to switch between a small suction position where the second piston is embedded in the first piston and a large suction position where the first and second pistons are embedded in the cylinder and the first piston, respectively.