Patent ID: 7322804
Filing Date: 2008-01-29
Classification: F04B

Abstract:
1. A Metering pump device for a vehicle heater, comprising an inlet chamber ( 40 ), an outlet chamber ( 54 ), a first valve assembly ( 66 ) between the inlet chamber ( 40 ) and the outlet chamber ( 54 ), which permits fluid exchange substantially only from the inlet chamber ( 40 ) to the outlet chamber ( 54 ), a displacement piston element ( 12 ), which is movable to and fro in an opening ( 16 ) formed in a piston housing ( 14 ) between a first piston position, in which it minimizes the volume of the inlet chamber ( 40 ) and a second piston position, in which it minimizes the volume of the outlet chamber ( 54 ), a reduction (V 1 ) in the volume of the inlet chamber ( 40 ) being greater than an increase (V 2 ) in the volume of the outlet chamber ( 54 ) on movement of the displacement piston element ( 12 ) from the second piston position to the first piston position, wherein the opening ( the displacement piston element ( the displacement piston element ( the piston housing ( the displacement piston element ( a fluid feed line is provided in the displacement piston element (