Air cushion vehicle seal

Claim 2

In an air cushion vehicle an air cushion seal assembly comprising in combination, an inflatable bag attached to and extending downwardly from the vehicle hard structure to thereby provide a primary air-cell means, a flexible apertured partition device dividing said bag into two compartments and thereby providing a ''''two-stage stiffness'''' air cell system including a first cell and a second cell, and a flexible airtight apron device extending along the vehicle and attached along its upper edge to a perimetral portion of the hard structure of said vehicle and along its lower edge to the outer portion of said bag and having flexible airtight end closure means thereby defining in combination with the hard structure and said bag a third air cell.

Claim 3

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 1, wherein a secondary seal device is attached to depend below said bag.

Claim 4

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 1, wherein said apron device is disposed in a substantially vertical attitude.

Claim 5

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 3, whereby said apron device provides resistance against downward and inward deflection of said bag.

Claim 6

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 1, wherein the bow portion of the vehicle hard structure is of square ended planform.

Claim 7

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 1, wherein a valve is provided in conjunction with the apertured portion of said partition device, said valve being automatically operable to maintain the air within said second cell at a pressure at least as high as the pressure within said first cell.

Claim 8

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 1, wherein a control means is provided normally to maintain a supply of air within said third air cell at a pressure lower than the air pressure within said second cell.

Claim 9

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 7, wherein said control means comprises a one-way automatically operating check valve controlled air inlet for air from the outside atmosphere.

Claim 10

In an air cushion vehicle having an air cushion seal assembly as set forth in claim 8, wherein a secondary seal device is attached to depend below said bag.

Claim 11

In an air cushion vehicle having a body presenting marginally extending hard structure, in combination: air cushion confining means attached to said hard structure for forming a depending skirt circumscribing an air cushion beneath the Vehicle, said air cushion confining means including an inflatable, flexible bag extending lengthwise to form at least a portion of said skirt, a flexible partition device dividing said bag into lengthwise extending inner and outer air cells, said partition device including check valve means allowing air flow from said inner cell to said outer cell, and said inner cell having air discharge opening means along its bottom and inwardly of said partition to allow air escape into the air cushion space; means for supplying air under pressure into said inner cell whereby to inflate both said inner and said outer cell and create a two-stage stiffness effect for said air cushion confining means as between said inner and outer cells; said air cushion confining means also including a flexible airtight apron extending along the vehicle outwardly of said bag and attached respectively along its upper and lower edges to said vehicle and to said bag to define a third air cell inwardly of the apron and in cooperation with the outer surface of the vehicle and said bag; and means for maintaining said third air cell normally under internal pressure different from those air pressures in the inner and outer cells whereby to create a third stage stiffness effect for said air cushion confining means.

Claim 12

In an air cushion vehicle having a body presenting marginally extending hard structure, in combination: air cushion confining means attached to said hard structure for forming a depending skirt circumscribing an air cushion beneath the Vehicle, said air cushion confining means including an inflatable, flexible bag extending lengthwise to form at least a portion of said skirt, a flexible partition device dividing said bag into lengthwise extending inner and outer air cells, said partition device including check valve means allowing air flow from said inner cell to said outer cell, and said inner cell having air discharge opening means along its bottom and inwardly of said partition to allow air escape into the air cushion space; means for supplying air under pressure into said inner cell whereby to inflate both said inner and said outer cell and create a two-stage stiffness effect for said air cushion confining means as between said inner and outer cells; said air cushion confining means also including a flexible airtight apron extending along the vehicle outwardly of said bag and attached respectively along its upper and lower edges to said vehicle and to said bag to define a third air cell inwardly of the apron and in cooperation with the outer surface of the vehicle and said bag; and means for maintaining said third air cell normally under internal pressure different from those air pressures in the inner and outer cells whereby to create a third stage stiffness effect for said air cushion confining means.