Air cushion stability control device with adjustable plenum chamber volume

Claim 1

A GROUND EFFECT MACHINE DESIGNED TO MOVE ALONG A BEARING SURFACE AND HAVING A PLENUM CHAMBER AND CLOSURE SPACED FROM SAID SURFACE, AND WALL MEANS PROJECTING IN FLUIDTIGHT RELATION FROM SAID END CLOSURE TOWARD SAID SURFACE TO PARTIALLY BOUND THEREWITH A PLENUM CHAMBER IN WHICH A PRESSURE FLUID CUSHION MAY BE FORMED, SAID WALL MEANS ENDING IN A FREE END ADJACENT TO SAID SURFACE BUT SPACED THEREFROM BY AN AVERAGE DISTANCE WHICH VARIES DURING OPERATION OF THE MACHINE, SAID END CLOSURE DEFINING AN END WALL OF SAID PLENUM CHAMBER OPPOSITE TO SAID BEARING SURFACE, WHEREAS SAID PROJECTING WALL MEANS DEFINES A LATERAL WALL OF SAID PLENUM CHAMBER MEANS FOR INTRODUCING INTO SAID CHAMBER A FLUID UNDER PRESSURE, WHEREIN THE IMPROVEMENT COMPRISES A MOVABLE WALL MEMBER SEPARATE AND DISTINCT FROM SAID WALL MEANS BUT COOPERATING THEREWITH AND WITH SAID END CLOSURE IN DEFINING THE VOLUME OF SAID PLENUM CHAMBER WHEREBY DISPLACEMENT OF SAID MOVABLE WALL MEMBER CAUSES CORRESPONDING VARIATION IN THE PLENUM CHAMBER VOLUME, AND MEANS ASSOCIATED WITH AND MOVABLY SUPPORTING SAID WALL MEMBER IN SUBSTANTIALLY FLUIDTIGHT PLENUM CHAMBER BOUNDING RELATION THROUGHOUT THE EFFECTIVE RANGE OF DISPLACEMENT OF SAID WALL MEMBER TO VARY SAID PLENUM CHAMBER VOLUME WHEREBY SAID MOVABLE WALL MEMBER REMAINS IN FLUIDTIGHT, PLENUM CHAMBER VOLUME DEFINING CONDITION THROUGHOUT SAID EFFECTIVE RANGE OF DISPLACEMENT THEREOF.