Abstract: A sealing arrangement is designed for sealing a space that extends between high and low pressure areas and that is defined between a first apparatus part and a cylindrical surface of a second apparatus part, the first and second apparatus parts being mutually moveable in a reciprocating manner along the axis of said cylindrical surface. The sealing arrangement includes an annular sealing member of resilient material having a radially outer peripheral surface extending between axially opposite first and second end surfaces facing the high and low pressure areas, respectively, and a radially inner peripheral surface for providing a sealing engagement with the cylindrical surface of the second apparatus part at a contact area, and for defining with the cylindrical surface a first space widening or diverging from the contact area toward the low pressure area.

Abstract: A piston or plunger is made by passing an annular sealing member blank around a piston body and by moving it towards a central outer cylindrical surface part of the piston body defined between first and second circular edges. The sealing member blank is deformed into tight engagement with the central outer cylindrical surface part and into grooves or depressions formed therein. In this manner, a tubular sealing member, which extends axially along the central outer surface part, and which has opposite first and second ends extending beyond the first and second circular edges, respectively, is formed. Thereby both of these opposite end portions of the tubular sealing member may function as sealing lips.

Abstract: A piston or plunger and a method for making the same A piston or plunger comprises a piston body and a sealing member. The piston body is preferably made from metal by moulding, such as casting or pressure moulding and sintering. The sealing member is made from a thermoplast, such as polytetrafluoroethylene (PTFE). The piston body has an outer or an inner peripheral surface part in which axially extending depressions or grooves are formed during moulding of the piston body. The axially extending grooves may be open at one or at opposite ends. An annular sealing member blank is applied to the peripheral surface part and is deformed and forced into tight engagement with the peripheral surface part and into the grooves or depressions formed therein. The sealing member formed is also exposed to a heat treatment. The piston or plunger having the sealing member applied to an outer peripheral surface part may, for example, be used in shock absorbers.

Abstract: For sealing between two opposed surfaces of two machine elements (1, 2) a combination seal is provided to be fitted into an open groove (3) in one of the machine elements (2). The seal comprises an electomeric expansion ring (4, 5) at the bottom of the groove (3), an intermediate ring (6) made of a viscous-elastic material, e.g. PTFE and having a sealing surface (6b) to contact the mating machine element (2), and an elastomeric outer ring (8) fitted into a separate groove (7) in the sealing surface (6b) of the intermediate ring.