Surface effect devices with skirt height adjusting means

Claim 1

A FLUID CUSHION SKIRTING SYSTEM FOR A MOVABLE BODY OF THE GROUND EFFECT TYPE HAVING A SUPPORT FRAME SPACED FROM A BEARING SURFACE ALONG WHICH SAID BODY IS DESIGNED TO MOVE, AND A SKIRT FREE EDGE POSITIONED IN OPERATION ADJACENT TO BUT CLEAR OF SAID BEARING SURFACE TO DEFINE THEREWITH AN OPERATIVE LEAKAGE GAP BETWEEN AN INNER PRESSURE FLUID CUSHION AND AN OUTER LOWER PRESSURE FLUID MEDIUM AND FORMING THE PERIPHERY OF AN ORIFICE OPENING EXTENDING IN CLOSE PROXIMITY TO SAID BEARING SURFACE, WHEREIN THE IMPROVEMENT COMPRISES A SUPPLE FLUIDTIGHT SKIRT BODY PORTION CARRIED BY SAID SUPPORT FRAME AND LATERALLY BOUNDING A CAVITY FOR CONFINING SAID PRESSURE FLUID CUSHION AND EXTENDING FOR SUBSTANTIALLY ITS FULL LENGTH OUTWARDLY FROM SAID SUPPORT FRAME TOWARD SAID BEARING SURFACE AND TERMINATING IN SAID SKIRT FREE EDGE, SAID SKIRT BODY PORTION BEING AT LEAST PARTLY CONTRACTIBLE TOWARD AND EXPANSIBLE AWAY FROM SAID SUPPORT FRAME, AND SELECTIVELY OPERABLE, SKIRT BODY CONTROL MEANS FOR SELECTIVELY ADJUSTABLY CONTRACTING OR EXPANDING AT LEAST A PART OF SAID SKIRT BODY PORTION WHEREBY THE OPERATIVE LENGTH OF SAID PART IS ADAPTED TO BE VARIED TO PERMIT THE POSITION OF SAID SUPPORT FRAME RELATIVE TO SAID BEARING SURFACE TO BE VARIED WHILE KEEPING SAID SKIRT FREE EDGE IN PROXIMITY TO SAID BEARING SURFACE WHEREBY LEAKAGE FROM SAID CUSHION TO SAID OUTER FLUID MEDIUM IS MINIMIZED AND WHEREBY DAMAGE TO THE BODY STRUCTURE IS AVOIDED.