Patent ID: 7273041

Claim:
A combination valve ( 15 ) for pressure control and venting in a fuel system for delivering fuel to an internal combustion engine, comprising a primary valve cone ( 25 ), which is supported so that it is displaceable between two limit positions in a cylinder bore ( 24 ) in a valve housing ( 23 ), against the action of a first spring element ( 26 ), the displacement of the valve cone from an inoperative limit position into an operative limit position leading to the opening of a connection between an inlet duct ( 32 ) and an outlet duct ( 33 ) in the valve housing, wherein the valve cone ( 25 ) is provided with an inner passage ( 27 ), which is designed to accommodate a secondary valve cone ( 28 ), which is displaceable between a support surface ( 29 ) and a valve seat ( 30 ) against the action of a second spring element ( 31 ) having a lower spring constant than the first spring element, displacement of the secondary valve cone against the action of the second spring element ( 31 ) leading to the opening of a connection between the inlet duct ( 32 ) and a venting duct ( 34 ), wherein the secondary valve cone ( 28 ) interacts with the valve seat ( 30 ) in such a way that a comparatively small partial flow can pass the valve cone when resting against the seat.