Seal assembly

A two compression seal assembly, solely made up of two elements, for use between two closely spaced relatively reciprocable machine parts, the first of the machine parts having a radial groove comprising spaced sidewalls and a base between the sidewalls, the assembly comprising:

• an endless relatively soft annular spring element of yieldable material with memory and having a solid cross-sectional configuration;
• an endless annular sealing element comprising a house-shaped body of relatively hard wear resistant synthetic resinous material having a generally U-shaped cross-sectional configuration;
• said sealing element further comprising spaced radially directed elongated anti-extrusion and anti-roll legs, the length of said elongated legs being coextensive with substantially the entire adjacent sidewall, a thin separation existing between the end of each elongated leg and the base of the groove, the spring element being positioned between and extending radially beyond the ends of the elongated legs across said thin separation to compressively engage the base while preserving the thin separation thereby accommodating creation of a first static seal solely and directly between the extended part of the spring element and the base of the groove in the first machine part, the interior surface formed by and between the elongated legs being contiguous with in excess of fifty percent of the exterior surface of the spring element, a second static seal being formed solely and directly between one exterior elongated leg surface and substantially all of one sidewall of the groove so that at all times, when under pressure from one side or the other of the seal assembly, the elongated leg away from the pressure is caused to be contiguous with essentially the entire surface of the adjacent sidewall and at all times the elongated leg at one element only entirely prevents the other element in the form of said spring from reaching the sidewall of the groove;
• said house-shaped sealing element further comprising a delta-shaped projection having central disposed thin apex means, the projection extending radially away from said anti-extrusion and anti-roll legs and beyond said groove, the apex compressively engaging the surface of a second machine part in such a fashion so as to cause said apex to no more than slightly flattened solely at the tip region thereof and to create an annular line dynamic seal solely along the entirety of the 360 degrees of said slightly flattened tip region whereby a surprisingly high stable pressure resistance is developed in excess of any hydraulic or pneumatic pressure applied to the seal assembly;
• said delta-shaped projection extending radially and the tip portion thereof having an undulating surface when in an unstressed condition.