Hydraulic shock absorber comprising an elastic piston

Claim 1

A HYDRAULIC SHOCK ABSORBER COMPRISING A CASING FORMING A CYLINDER, A PISTON HAVING A BODY MADE OF ELASTIC MATERIAL MOVABLY DISPOSED IN SAID CYLINDER, HYDRAULIC FLUID DISPOSED AT OPPOSITE SIDES OF SAID PISTON AND FILLING SAID CYLINDER, DUCTS FORMED IN SAID PISTON BODY FOR THE PASSAGE OF HYDRAULIC FLUID THERETHROUGH FROM ONE SIDE OF THE PISTON TO THE OTHER, BY MEANS OF WHICH FLUID FLOW THE SHOCK ABSORBER ACTION IS DERIVED, AND MEANS RESPONSIVE TO FLUCTUATIONS OF A LOAD, CONNECTED RESPECTIVELY TO SAID CASING AND SAID PISTON, FOR APPLYING TO SAID PISTON CENTRALLY THEREOF A FORCE SO AS TO MOVE SAID PISTON WITHIN AND RELATIVE TO SAID CYLINDER, SAID FORCE BEING EFFECTIVE TO AXIALLY DISPLACE THE INNER CENTRAL PORTION OF SAID PISTON WITH RESPECT TO THE OUTER PERIPHERAL PORTION THEREOF TO DISPLACE THE INNER SUPERFICIES OF THE PISTON WITH RESPECT TO THE OUTER SUPERFICIES THEREOF AND THEREBY EFFECT A CHANGE IN THE CROSSSECTIONAL AREAS OF SAID DUCTS FOR THE PURPOSE OF REGULATING THE PASSAGE OF HYDRAULIC FLUID THERETHROUGH DEPENDING UPON THE DIRECTION OF MOTION AND VELOCITY OF SAID PISTON, AND MEANS FORMING LIP-SHAPED EXTENSIONS TERMINATING SAID DUCTS.