Dynamic seal

Claim 1

A seal means for substantially preventing the flow of fluid between a pair of elements while functioning to maintain solid particles in suspension in the fluid and providing a reaction force on one of the pair of elements comprising: a longitudinally extending hollow member, a body member positioned within said hollow member, a plurality of skirtlike members positioned in spaced relationship about the circumference of said body member, each of said skirtlike members including an outer sharp-edged liplike portion, said liplike portion extending in a direction toward an associated fluid flow, said skirtlike members each being constructed to define a convex surface and a concave surface, said convex and concave surfaces joining to define said sharp-edged liplike portion of each skirtlike member, and a plurality of toroidal grooves defined by and positioned about the circumference of said body member, one of said grooves being positioned intermediate an adjacent pair of said skirtlike members, each of said toroidal grooves having a portion thereof forming at least a portion of said concave surfaces of said skirtlike members, said convex surfaces of said skirtlike members adjoining another portion of said toroidal grooves so as to define a smooth reverse-curve therebetween, whereby an associated fluid flowing past said skirtlike members is deflected by said liplike portion of said skirtlike members to circulate in said toroidal grooves thereby substantially preventing flow of fluid between said hollow member and said body member while maintaining particles in an associated fluid suspended therein by circulation of such an associated fluid in said toroidal grooves and providing a reaction force on said body member in a direction of flow of an associated fluid due to fluid flow reversal caused by said liplike portions and said toroidal grooves, said body member comprising at least a portion of a free floating piston assembly adapted to be moved in one direction by associated pressurized fluid directed toward said liplike portions of said skirtlike members, and moved in the opposite direction by at least the force of gravity when such associated pressurized fluid is removed, said hollow member comprising a first conduit means, a second conduit means concentrically spaced about said first conduit means to define a passageway therebetween, said first and second conduit means being closed at one end thereof, said first conduit means being provided with at least one aperture therein to provide fluid communication adjacent said closed end between said first conduit interior and said passageway, and means for selectively directing an associated pressurized fluid into the opposite end of said first conduit means or into said passageway for moving said piston assembly in opposite directions.