Patent Number: 6,305,266

Title: Piston or plunger and a method for making the same

Abstract: A piston or plunger and a method for making the sameA piston or plunger comprises a piston body and a sealing member. Thepiston body is preferably made from metal by moulding, such as casting orpressure moulding and sintering. The sealing member is made from athermoplast, such as polytetrafluoroethylene (PTFE). The piston body hasan outer or an inner peripheral surface part in which axially extendingdepressions or grooves are formed during moulding of the piston body. Theaxially extending grooves may be open at one or at opposite ends. Anannular sealing member blank is applied to the peripheral surface part andis deformed and forced into tight engagement with the peripheral surfacepart and into the grooves or depressions formed therein. The sealingmember formed is also exposed to a heat treatment.The piston or plunger having the sealing member applied to an outerperipheral surface part may, for example, be used in shock absorbers.Alternatively, the sealing member may be applied to an inner peripheralsurface part. In such case the piston or plunger may be used as astationary sealing device for encircling and sealingly guiding areciprocating shaft or a piston rod.

Inventors: Jensen; Leo (.ANG.lsg.ang.rde, DK), Tonndorff; Agge Jan (Virum, DK)

Assignee:

International Classification:

Expiration Date: 10/23/2013