Composite elastomer/PTFE seal, in particular for insertion between relatively rotating members subject to oscillation

1) A composite seal (1) insertable between two relatively rotating members (2, 3) to seal in fluidtight manner a cavity (4) defined between said members;

• the seal comprising a substantially rigid support (6) for connection to a first (3) of said members, and a flexible sealing element (8) carried integrally by said support (6) and comprising at least one annular sealing lip (10) cooperating in sliding contact with a sealing surface (11) of a second (2) of said members;
• said flexible sealing element (8) being made of a non-elastomeric, synthetic plastic resin;
• characterized in that said annular sealing lip (10) of the flexible sealing element (8) is substantially in the form of a cylindrical sleeve defined by a first lateral surface (18) cooperating, in use, with said sealing surface (11) of said second member (2), and by a second lateral surface (20) opposite the first and facing, in use, said first member (3);
• and by also comprising, in combination, an annular pressure element (21) made of an elastomer and carried integrally by said annular sealing lip (10) on said second lateral surface (20) of the annular sealing lip;
• and a radial toroidal pressure spring (22) carried by said elastomeric annular pressure element (21) and inserted in an annular seat (23) formed in the elastomeric annular pressure element (21), on the opposite side to said annular sealing lip (10).