Abstract: A one-piece piston rod wiping seal member for cleaning reciprocating piston rods or plungers as the rod moves into the cylinder chamber for cleaning dust and other foreign matter from the surface of the rod to prevent the foreign matter from entering the working chamber and contaminating the interior thereof. The wiping seal member is of one-piece construction and includes an endless body portion of elastomeric material with a pair of lips projecting axially and radially with respect to an end wall of the body member. One of the lips is a rod engaging lip and projects radially inwardly to engage the surface of a piston rod. The other lip is a cylinder end cap engaging the lip for engaging the end cap of the cylinder. The body portion can be snap fitted into a groove in the end cap of the cylinder.

Abstract: A one-piece seal member of elastomeric material having an endless main body portion and a pair of leg portions projecting axially from the main body portion in side-by-side relation. The leg portions each have outer sealing surfaces and inner surfaces, and an endless, unobstructed narrow groove is formed between the leg portions. The groove has side walls that extend axially from a closed base to a normally open end at the juncture between the inner surfaces of the leg portions. The leg portions thus flex toward each other about the base of the groove from an unstressed position when the groove is open to provide relatively low resistance to movement of the sealing surfaces. The legs have an installed position relative to each other when the open end of the groove closes, whereupon the resistance to movement of sealing surfaces toward each other, and hence the sealing pressure exerted thereby, is abruptly increased.