Low friction sealing means

Claim 1

In combination with a plurality of elements spaced by a therebetween space which at an end is exposed to fluid at a first pressure, sealing means for preventing flow of such fluid through said space, said sealing means comprising a seal defining a chamber and including a wall having a face remote from said chamber opposing one of said elements, said wall, when the sealing means is preventing such fluid flow, including portions adjacent opposite sides of the seal closer to said one of said elements than any therebetween part of said wall and intermediate said wall portions including a groove extending inwardly from said face through only a portion of the thickness of said wall, said wall also including a plurality of openings extending only partially through the thickness of said wall communicating said groove with said chamber, said face, when the sealing means is preventing such fluid flow, intermediate said wall portions defining a single concave arc to provide only a single cavity between said face and said one of said elements, and means for supplying fluid at a second pressure, higher than said first pressure, to said chamber whereby the fluid flows from said chamber through said openings and said groove to said cavity without deflecting said face from said concave configuration.