Patent ID: 7673532
Filing Date: 2010-03-09
Classification: B01L

Abstract:
1. Pipetting device for metering liquids comprising a piston actuating rod ( 9 ), at least one receiver ( 17 ) for a piston head ( 38 ) arranged on one end of the piston actuating rod ( 9 ) and which is defined by an abutment surface ( 20 ) for the piston head ( 38 ) in the axial direction of the piston actuating rod ( 9 ), and comprises a through-opening ( 18 ) for a piston rod ( 36 ) opposing said piston head and a base ( 19 ) for supporting the piston head ( 38 ) surrounding the through-opening ( 18 ), at least one cylinder ( 27 ) with a hollow space ( 28 ), at least one seat ( 29 ) for holding a pipette tip, at least one through-channel ( 30 ) connecting the hollow space ( 28 ) of a cylinder ( 27 ) to a through-hole ( 31 ) in a seat ( 29 ) and at least one piston ( 36 ) arranged longitudinally displaceably in the hollow space ( 28 ) of a cylinder ( 27 ) with a piston rod ( 37 ) extending through the through-opening ( 18 ) of a receiver ( 17 ) and a piston head ( 38 ) at the end of the piston rod ( 37 ) arranged in the receiver ( 17 ), which is positioned on the base ( 19 ) with a lower face ( 41 ) facing the piston rod ( 37 ) and comprises a resilient body ( 47 ) projecting beyond an upper face ( 42 ) facing away from the piston rod ( 37 ), which does not bear against the abutment surface in an elastically compressed manner, or bears against the abutment surface ( 20 ) in a partially elastically compressed manner.