Patent ID: 7871251

Claim:
A high-pressure pump for feeding fuel to an internal combustion engine; the pump comprising: a pump housing; a fuel delivery duct; and a check valve, which extends along a longitudinal axis, is arranged along the delivery duct, and comprises a fuel chamber; a valve ball mobile within the fuel chamber; and a fastening member suitable for being fastened to the pump housing and sealing the chamber in a fluid-tight manner; a helical spring biasing the valve ball; and a bushing arranged about the helical spring in the fuel chamber in order to prevent bending of the helical spring, wherein the fastening member, the helical spring and the bushing can be assembled together so as to form a biasing and guiding assembly before inserting the biasing and guiding assembly in the fuel chamber, wherein the fastening member is fastened to the pump housing and comprises a first threaded cylindrical body portion and a second cylindrical body portion on which the bushing is fitted, wherein the fastening member comprises a third cylindrical body portion comprising a seat for fastening the helical spring, wherein the third cylindrical body portion has an annular protrusion, and wherein the helical spring comprises two end turns arranged respectively on the opposite ends of the helical spring, which end turns have a diameter that is smaller than the essentially constant diameter of the remaining turns, whereby one end turn is adapted to flex outwardly and then snappingly engage with the annular protrusion of the third cylindrical body portion so as to hold the spring to the third cylindrical body portion before insertion into the fuel chamber, and whereby the other end turn engages the valve ball, wherein the first threaded cylindrical body portion, the second cylindrical body portion and the third cylindrical body portion are formed integrally as a single element of structure.