US 4,576,386 A · Anti-extrusion back-up ring assembly

Abstract

A seal back-up assembly adapted for use in preventing the extrusion of the cap seal of an elastomer energized seal into the extrusion gap between two mating surfaces which are being sealed by the elastomer energized seal. One of the mating surfaces has a groove with side walls in which the elastomer energized seal is housed. The elastomer energized seal includes a cap seal and an elastomer energizer. The seal back-up assembly includes first and second back-up elements, which are located between the elastomer energized seal and the groove walls to sandwich the elastomer energized seal therebetween. Each of the back-up elements includes an outer member made from a relatively hard, non-resilient material which is sufficiently strong to prevent extrusion of the cap seal and an inner member made from a relatively soft plastic material which does not abrade or chafe the soft elastomer energizer. The outer member and inner member include mating perimeter surfaces which locate the two members together so that the outer member is positioned next to and adjacent against the cap seal portion of the elastomer energized seal, but does not contact the elastomer energizer, while the inner member is positioned against the expander element and partially overlapping the cap seal.

Claims21

Dependent claims

A seal back-up assembly adapted for use in preventing the extrusion of the cap seal of an elastomer energized seal between two mating surfaces being sealed by said elastomer energized seal, one of said surfaces having a groove with sidewalls in which said elastomer energized seal is housed for sealing contact with the other surface, said cap seal including a sealing surface for sealing contact with said other surface, first and second edges and a supporting surface, said elastomer energized seal further including a resilient expander element located below said cap seal in said groove and in contact with said supporting surface of said cap seal to bias said cap seal into sealing engagement with said other surface, said expander element including first and second edges, said seal back-up assembly comprising:

a first back-up ring located in said groove adjacent said cap seal first edge and a second back-up ring located in said groove adjacent said cap seal second edge, wherein each of said back-up rings includes:
an outer member made from a relatively hard, nonresilient material which is sufficiently strong to prevent extrusion of said cap seal;
an inner member made from a relatively soft elastic material which is sufficiently soft to prevent abrasion of said expander element;
and
means for connecting said inner member to said outer member so that said outer member is prevented from contacting said expander element to provide said back-up ring for use in preventing the extrusion of said elastomer energized seal between the two mating surfaces being sealed.

2 more elements

An elastomer energized seal assembly adapted for providing a seal between two mating surfaces, one of said surfaces having a groove with side walls in which said elastomer energized seal assembly is housed for sealing contact with the other surface, said elastomer energized seal assembly comprising:

a central elastomer energized seal including a cap seal, said cap seal having a sealing surface for sealing contact with said other surface, first and second edges and a supporting surface, said central elastomer energized seal further including a resilient expander element located below said cap seal in said groove and in contact with said supporting surface of said cap seal to bias said cap seal into sealing engagement with said other surface;
a frist back-up element located in said groove adjacent said cap seal first edge;
a second back-up element located in said groove adjacent said cap seal second edge wherein each of said back-up elements includes:
an outer member made from a relatively hard, non-resilient seal material which is sufficiently strong to prevent extrusion of said cap seal, said outer member having a first edge adapted to be positioned next to and adjacent against the edge of said cap seal but not against said expander element, and a second edge adapted to be positioned against the groove side wall;
an inner member made from a relatively soft material which is sufficiently soft to prevent abrasion of said expander element, said inner member having a first edge adapted to be positioned next to and adjacent against the edge of said expander element and overlapping said cap seal and a second edge adapted to be positioned against the groove side wall;
and
means for connecting said inner member to said outer member to provide said back-up element which is adapted to prevent the extrusion of the cap seal of said central elastomer energized seal in between the two mating surfaces being sealed while preventing abrasion of said expander element.

4 more elements

Dependencies are inferred from the claim text.

Anti-extrusion back-up ring assembly

Life of this patent

Anti-extrusion back-up ring assembly

Life of this patent

Abstract

Claims21