US3593817A

US3593817A - Air cushion load-supporting devices

Info

Publication number: US3593817A
Application number: US790719A
Authority: US
Inventors: Clive A F Hawkins
Original assignee: British Hovercraft Corp Ltd
Current assignee: British Hovercraft Corp Ltd
Priority date: 1968-11-11
Filing date: 1969-01-13
Publication date: 1971-07-20
Anticipated expiration: 1988-07-20

Abstract

In an air cushion supported materials handling device of the type comprising a load-carrying platform carried by tubular support structure, part of which tubular structure also forms the handle for manual propulsion of the device, the platform has mounted on its underside a plurality of inflatable air pads, and the pressurized air is supplied to the inflatable air pads through the tubular support structure, and can be supplied also through the handle. Suitable control valves can be incorporated in the handle or in the tubular structure.

Description

United States Patent {72] Inventor Clive A. F. Hawkins Yeovll, Somerset. England [21] Appl No 790,7[9 [22] Filed Jan. [3, I969 [45] Patented July 20, 1971 [7 3] Assignce British Hovercraft Corporation Limited Yeovil, Somerset. England 32 Priority Nov. ll, 1968 [33] Great Britain |3l 55452/68 [54] AIR CUSHION LOAD-SUPPORTING DEVICES 1 Claim, 7 Drawing Pip.

[52] U.S.Cl l80/l2l, 180/1 16, ISO/I24, ISO/I25 5| lnt.Cl 560v 1/00, 860v Hill [50] FieldofSearch l80/l24, 125, 1 l6, I21

[56] References Cited UNITED STATES PATENTS 3,276,530 10/1966 Bomeman ISO/124 3,493,071 2/1970 Street et a1. 180/124 3,082.836 3/1963 Billman 180/124 3,161,247 12/1964 Mackie H 180/124 3,247,921 4/1966 Latimer-Needham et al 180/124 3,392,800 7/1968 Swamy ISO/I25 3,466,010 9/1969 lung 180/125 X FOREIGN PATENTS 782,892 4/1968 Canada 180/[25 Primary Examiner-A. Harry Levy AtI0rneyLars0n, Taylor 8:. Hinds ABSTRACT: In an air cushion supported materials handling device of the type comprising a load-carrying platform carried by tubular support structure, part of which tubular structure also forms the handle for manual propulsion of the device, the platform has mounted on its underside a plurality of inflatable air pads, and the pressurized air is supplied to the inflatable air pads through the tubular support structure, and can be supplied also through the handle, Suitable control valves can be incorporated in the handle or in the tubular structure.

PATENTEB JULZO :911 3593817 sum 1 OF 4 AIR CUSHION LOAD-SUPPORTING DEVICES This invention relates to devices for the movement of loads across a surface and utilizes pressurized air for support, being referred to as air cushion vehicles.

It is the object of the invention to provide an uncomplicated and robust load-moving device having very low frictional resistance to movement.

in accordance with the present invention, I provide an air cushion vehicle comprising a load bearing structure having on its undersurface one or more flexible inflatable elements each defining within its periphery a region which is closed at its upper part, bounded across its sides by the element and open at its lower part, and means for conveying a pressurized gaseous fluid to each region to form a cushion of fluid therein to support the vehicle above the surface across which it is to operate. The structure is formed partially by a tubular framework through which pressurized air is passed to form the cushion. it is to be understood by the term "elements" that these may be of any form where a chamber is provided that can have gaseous fluid introduced into it, and where at least part of the walls of the chamber can be distended.

The invention now will be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 shows the underside of a known vehicle having four flexible inflflable elements, this being included only for purposes of explanation,

FIG. 3 diagrammatically illustrates a ducting and control valve arrangement that utilizes the handle and framework of a vehicle in accordance with one form of the invention,

FIGS. 4 and 5 illustrate alternative duct arrangements where the control valve is associated with the handle of the vehicle,

FIG. 6 shows a multiple duct and control valve arrangement for selective control of delivery of the air at a plurality of positions, and

FIG. 7 shows a fragmentary view of the framework of a vehicle that includes a ducting and valve arrangement and attachment for a separable handle. A load-bearing structure in the fonn of a rigid platform 10 has a plurality of separate flexible inflatable elements ll spaced symmetrically beneath it and sealed to it. The elements 11 are tubular, and for convenience are illustrated as being circular but can be of any suitable tubular shape and form. An air duct system 12 is secured to the underside of the platform 10, having a main duct l3 which provides connection with a source of pressurized air and branch ducts 14 which connect with the inlet of each inflatable element 11. The elements II have at least one outlet port 15 that opens into the region 16 bounded by the element. The total area of the outlet port or ports 15 in each element is less than the area of the inlet orifice 17. Each branch duct 14 can include an aspirator or injector 18.

In operation, a hose or airline from a pressurized air source, such as a factory compressed air system or separate air compressor, is connected to the main duct l3 whereby air is supplied through the branch ducts 14 to the interior of each flexible element ll which inflates and forms the region 16 into a plenum chamber. Air discharges into the plenum chambers from the flexible elements It by way of the outlet ports 15 and forms pressurized cushions of air capable of lifting the structure l0 and its load off the surface upon which it rests. The pressurized air supplied through the branch ducts 14 can, where necessary, entrain ambient air by way of the injectors 18, in order to provide improved mass flow of air to the cushion.

Referring now to FIG. 3, wherein the illustrated vehicle has an air duct system somewhat similar to that described above, but embodying one form of the present invention, the platform 31 comprises a tubular framework 32 having a peripheral tube 33 and transverse tubes 34, with an impermeable panel or sheet 35 and inflatable elements 36 attached beneath. A tubular handle 37 is conduitly secured to the peripheral tube 33 on a side where one end of the transverse tubes 34 are also secured. A hose connection 38 is fitted to the peripheral tube 33 near one junction of the handle 37 with the peripheral tube 33. Two of the transverse tubes 344 that cross above the inflatable elements 36 have outlet connections 39 thereto. COnduit communication is thereby provided between the hose connection 38 and the inflatable elements by way of the handle 37 and the tubular framework 32. The ensure that communication is confined to the most direct route plugs are positioned in the peripheral tube 33 at 40, 41, 42, and 43. A suitable manually operated valve, such as a twist-grip type 44, is provided in the handle 37 for controlling flow of pressurized air to the inflatable elements 36.

Two further embodiments of the invention shown in FIGS. 4 and 5 illustrate a simple means of construction incorporating strength with great utility. That shown in FIG. 4 comprises a single tubular frame 5| that is upturned at one end to form a handle 52, into which a l-shaped connection 53 incorporating a flow control valve is fitted for the attachment of a compressed air hose 54. A rigid platform 55 is supported between the level portions of the frame 51 and has four inflatable flexible elements 56 attached to its underside. The tubular frame 51 provides the main ducting for distribution of the compressed air to the elements 56, which are each connected thereto by smaller bore tubes 57, 572. The tubes 57 connect the two elements 56, that are nearer to the handle 52, with conveniently positioned connections on the tubular frame 51 at the side of the platform 55, whilst tubes 57a, connect the two elements 56, that are remote from the handle 52, with connections provided at the two ends of the tubular frame 51. Frame Sl can be conveniently closed to an endless configuration by joining the two ends together with a coupling having two connections for tubes 57a. Regulation of the air supply is made by means of the valve in the connection 53.

The embodiment shown in FIG. 5 is of similar general construction to that of HO. 4, but instead of using the framework as a ducting for distribution of compressed air to the inflatable flexible elements, the valved connection 6! is a cruciform having only a straight-through passageway connecting with a tube 62 that extends centrally between two of the flexible inflatable elements 63 beneath the platform 64, and terminates near the two elements 630 which are remotely disposed from the handle 65. A pair of smaller bore tubes 66a join elements 630 with a connector provided at the end of tube 62, whilst another similar pair of tubes 66 connect elements 63 with tube 62 at a suitably adjacent position.

Yet a further embodiment is illustrated in FIG. 6, wherein the tubular framework 7] of a platform 72 is adapted to allow separate control of compressed air to the interior of the flexible inflatable elements 73 and to the plenum chamber 74 formed in each of the elements 73. This form of element 73 has no outlet orifice and is inflated similarly to an inner tube of a motor vehicle s tire; deflation being by way of a bleed valve, referred to later. Elements 73 such as this provide buoyancy to vehicles where it is required, as, say, on canals and other waterways.

in this embodiment, the compressed air is conveyed by inlet tube 75 to the center of handle 76, where it is directed into two flow paths, each being outwardly through the handle 76 to the peripheral tube 77 and transverse tubes 78 of the framework 71. One flow path, indicated by solid arrows, is to the interior of elements 73 and the other flow path, indicated by hollow arrows, is to the plenum chambers 74. Plugs, suitably positioned in the framework 71 to maintain separation of the flow paths, are indicated at 79, and outlets to the interior of the elements 73 and plenum chambers 74 are indicated at 80 and 81 respectively. Regulation of the compressed air delivered through the two flow paths is achieved by means of manual

flow control valves

82, 83, provided in han dle 76. Provided on the downstream side of the valve 82, which controls the airflow to the interior of the elements 73, is a bleed valve 84 which permits deflation of the elements by venting the air from therein.

FIG. 7 shows a convenient arrangement of ducting, flow control valve and handle attachment of the framework of a vehicle which has a removable handle. The framework 91 is of tubular construction, and by the inclusion of suitable plugs 92 provides the main air ducting to the flexible inflatable elements (not shown). A compressed air inlet 93 and a conveniently positioned foot'operated flow control valve 94, disposed downstream of the inlet 93, are provided on the peripheral tube 95 of the framework 9i, adjacent to a bracket 96 that provides a socket for one of the spade ends 97 of a handle 98.

Many modifications and alternative embodiments can be made within the scope of the claims as indicated by the following examples.

The flexible inflatable elements need not be of unitary construction, but may be formed from, say, two sheets of impermeable material of which the upper sheet is flat and the under sheet is folded or preformed into a corrugation and the crest or crests thereof continuously sealed to the upper sheet, or alternatively the upper sheet may be substituted by the undersurface of the load supporting platform. Further, in a modification of the flexible elements of the type illustrated in FIGS. 1 and 2, they may have an impermeable membrane sealed across the top of each element, so as to form a plenum chamber in the element. Where a vehicle is moved by tug or tractor having air compressor means, it is advisable that the inlet connection of the air duct on the vehicle is fitted with a self-sealing device, or nonreturn valve.

A small wall or small feel may project from the underside of the platform structure sufficiently to limit the amount of crushing that the flexible elements will receive when a vehicle is at rest.

I claim as my invention:

l. in an air cushion supported materials handling device, a substantially rigid tubular support framework, said tubular support framework comprising a plurality of interconnected tubular members arranged in a horizontal expanse; an impermeable member extending across said horizontal expanse; means forming an upstanding handle from said framework for manual propulsion and control of the device, said handle comprising a tubular member connected to said tubular framework, with its hollow interior in conduit communication with the hollow interiors of said tubular framework; a plurality of inflatable air pads beneath said framework, said pads forming at least partial boundary means for at least one pressurizable cushion area beneath said framework; and means for passing pressurized air through said tubular handle into and through at least parts of the tubular framework and then separately to said inflatable pads and said cushion area; said tubular handle including separate control valve means for controlling the flow of pressurized air separately to said inflatable pads and to said cushion area.

Claims

1. In an air cushion supported materials handling device, a substantially rigid tubular support framework, said tubular support framework comprising a plurality of interconnected tubular members arranged in a horizontal expanse; an impermeable member extending across said horizontal expanse; means forming an upstanding handle from said framework for manual propulsion and control of the device, said handle comprising a tubular member connected to said tubular framework, with its hollow interior in conduit communication with the hollow interiors of said tubular framework; a plurality of inflatable air pads beneath said framework, said pads forming at least partial boundary means for at least one pressurizable cushion area beneath said framework; and means for passing pressurized air through said tubular handle into and through at least parts of the tubular framework and then separately to said inflatable pads and said cushion area; said tubular handle including separate control valve means for controlling the flow of pressurized air separately to said inflatable pads and to said cushion area.