Patent ID: 7384246

Claim:
In a pump element for a piston pump ( 3 ) for generating high fuel pressure in fuel injection systems of internal combustion engines, with at least one piston ( 11 ), disposed in a cylinder bore ( 9 ), the piston ( 11 ) having a piston base ( 15 ) and a piston shaft ( 13 ), and with a plate ( 17 ), mounted on the piston base ( 15 ), for transmitting the pumping motion from a drive mechanism ( 5 ) to the piston ( 11 ), the piston base ( 15 ) having a bearing face ( 29 ) cooperating with an indentation ( 31 ) in the plate ( 17 ), the improvement wherein the bearing face ( 29 ) protrudes into the indentation ( 31 ) and rests on a bottom surface ( 33 ) of the indentation ( 31 ), the indentation ( 31 ) in the plate ( 17 ) being dimensioned such that the piston base ( 15 ) fits precisely into the indentation ( 31 ), and wherein the bearing face ( 29 ) and the bottom surface ( 33 ) of the indentation ( 31 ) form an essentially plane contact zone and the area of the essentially plane contact zone is larger than or equal to the cross-sectional area of the piston shaft ( 13 ).