US 4,231,578 AGranted

Seal assembly

AssigneeW. S. Shamban & Company

InventorHenry A. Traub

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Abstract

A sealing assembly, designed primarily for both very low and high pressure sealing of a rod while either stationary or reciprocating, comprising a first sealing ring having a generally Y-shaped cross-sectional configuration and a second sealing ring having a generally L-shaped cross-sectional configuration. One arm of the Y-shaped sealing ring seals in the static mode. The other arm seals in the static mode and also serves as a wiper arm wiping fluid off the surface of the reciprocating rod in the dynamic mode. This wiper arm is provided with a sharp wiping edge which in cooperation with the L-shaped sealing ring maintains both a higher loading per unit area and a high rate of pressure rise at the contact with the rod for maximum leakage control at both low pressure and high pressure. The L-shaped sealing ring also restricts and controls the deformation of the wiper arm so as to maintain an optimum contact area between the wiper and rod surface thereby minimizing friction and wear therebetween. The Y-shaped sealing ring is preferably made of a relatively flowable material such as rubber while the L-shaped sealing ring is preferably made of polytetrafluorethylene to provide good sealing characteristics and low friction at high pressures. The seal is designed to take advantage of the good characteristics of rubber and polytetrafluorethylene while retaining almost none of the disadvantages of either.

Claims9

Dependent claims

A seal assembly having a low pressure side and a high pressure side, said seal assembly comprising:

a first annular sealing ring having a substantially L-shaped cross-sectional configuration, the base portion of which has a first end and a second end and defines the low pressure side of said seal assembly, the arm portion of said L-shaped sealing ring extending axially from said first end of said base portion, said arm portion having a first side coplanar with said first end of said base portion and having a second side, the free end of said arm portion tapering to form an acute edge on said first side of said arm portion;
a second annular sealing ring having a substantially Y-shaped cross-sectional configuration, the body portion of which has a first side and a second side, the distance between which is greater than the distance between the second end of said base portion and the second side of said arm portion of said L-shaped annular sealing ring, said second annular sealing ring being seated concentrically upon said first annular sealing ring such that said second side of said body of said second annular sealing ring confronts said second side of said arm portion of said first annular sealing ring;
said second annular sealing ring having two arm portions each of which has an outermost corner, said corners spanning a distance greater than the distance between said first and second end of said base of said first annular sealing ring;
said two arm portions extending toward the high pressure side of said seal assembly, one of said two outermost corners extending just beyond the edge of said arm of said first annular sealing ring whereby substantially all the length of one of said two arms rests upon the tapered portion of the free end of the arm of said first annular sealing ring.

1 more element

Dependencies are inferred from the claim text.