Patent ID: 8186685

Claim:
An annular sealing element ( 12 ) for a downhole tool for providing a seal between a first ( 32 ) and a second surface, comprising: an inner sleeve ( 20 ) providing an inner deformable surface and arranged concentric with an outer sleeve ( 22 ) providing an outer deformable surface, each of the inner and outer sleeves being formed of a material liable to plastic deformation, the inner and outer sleeves being joined at respective junctions of opposed first ends ( 24 ) and second ends ( 26 ), providing a body defining an interior volume ( 30 ) entirely bounded by the said surfaces and said ends, and a deformable filler material ( 28 ) within said interior volume, wherein the filler material ( 28 ) is a plastic; wherein the inner and outer sleeves each comprise a plurality of fold lines; wherein the element ( 12 ) deforms in a predetermined manner when said first ends ( 24 ) are brought toward said second ends ( 26 ) by deformation of the inner and outer sleeves about their respective fold lines, to thereby seal between the first ( 32 ) and second surfaces, wherein the inner and outer sleeves ( 20 , 22 ) define a first shape containing said interior volume ( 30 ), and following deformation the inner and outer sleeves ( 20 , 22 ) define a second shape, which is a cantilever structure arranged longitudinally between the ends ( 24 , 26 ), and wherein the first and second shape are annular having a polygon in longitudinal cross-section.