Antidrift mechanism for an air cushion vehicle

Claim 2

In an air cushion vehicle having downwardly extending means to confine air cushions thereunder, the improvement to oppose the tendency of the vehicle to skid sidewise because of lateral slope of the underlying support surfaces that the vehicle is traversing or because of a strong side wind when the vehicle is being operated comprising: a set of ground wheels on an axle structure; means connecting the axle structure to the vehicle with freedom for vertical movement of the axle structure relative to the vehicle to permit the ground wheels to track on the underlying support surface throughout a range of elevations of the vehicle from the underlying support surface, said connecting means including means to limit lateral movement of the vehicle relative to the axle structure.

Claim 3

AN improvement as set forth in claim 1 in which said connecting means comprises a pair of divergent arms pivotally connected to at least one of said vehicle and said axle structure and slidingly connected to the other of said vehicle and said axle structure.

Claim 4

An improvement as set forth in claim 2 which includes a pair of laterally spaced slide members on one of said vehicle and said axle structure, said divergent arms being pivotally connected to the slide members respectively.

Claim 5

An improvement as set forth in claim 3 in which the slides are sleeves on the axle structure.

Claim 6

An improvement as set forth in claim 1 which includes yielding means to urge the axle structure downward to keep the wheels in effective contact with the underlying support surface.

Claim 7

An improvement as set forth in claim 1 in which said connecting means comprises: a pair of downwardly divergent arms; pivot means connecting upper ends of the two arms respectively to the vehicle; stop means on the axle structure near the opposite ends respectively thereof; a pair of spaced slide members on the axle structure between the two stop means and movable along the axis of the axle structure to abut the two stop means alternatively; and pivot means connecting the lower ends of the two arms to the two slide members respectively, the axes of the pivot means at the upper and lower ends of the two arms being substantailly parallel to the longitudinal axis of the vehicle, each of said slide members being cooperative with the corresponding stop means to place the corresponding arm under axial compression at a limit position of the arm to limit the shift of the vehicle toward the corresponding end of the axle structure.

Claim 8

An improvement as set forth in claim 6 in which the angle of each arm relative to the axle structure at the limit position of the arm is such that the numerical ratio of the lateral force component to the downward force component of the load on the upper end of the arm is less than the coefficient of skidding friction of the ground wheels on the underlying support surface.

Claim 9

An improvement as set forth in claim 7 in which each of said arms is adjustable in length to vary said ratio and to permit periodic adjustment to compensate for wear on the wheels and on said air cushion confining means.

Claim 10

An improvement as set forth in claim 6 which includes means fixedly united with the vehicle between the two arms to keep the two arms from swinging to positions perpendicular to the axle structure.

Claim 11

An improvement as set forth in claim 6 which includes means to yieldingly urge the axle structure downward from the vehicle to keep the ground wheels in effective contact with the underlying support surface.

Claim 12

An improvement as set forth in claim 10 in which said urging means comprises tension spring means interconnecting the two slide members to urge the two slide members toward each other.

Claim 13

An improvement as set forth in claim 6 which includes means to releasably suspend the axle structure from the vehicle to keep the pair of ground wheels out of contact with the underlying support surface when desired.