1964-04-02

Abstract of GB953910 953,910. Air cushion vehicles. VICKERSARMSTRONGS Ltd. July 6, 1962 [July 21, 1961], No. 26566/61. Heading B7K. A vehicle adapted to ride on a non-compartmented air cushion formed on the underside of the vehicle within means encircling the cushion and including a curtain arranged to be produced by air issuing from downwardly directed orifice means on the perimeter of the underside of the vehicle has means provided for stabilizing the vehicle against tipping including an orifice or orifices for introducing air into the cushion, the orifice or orifices each being of limited lateral extent so that air issuing therefrom cannot form a curtain compartmenting the cushion, the arrangement being such that in operation when the vehicle tips air from said orifice or orifices flows towards the side of the vehicle having the higher ground clearance, an increase of pressure occurring in the cushion towards the opposite side of the vehicle whereby the tipping is opposed. The vehicle comprises a peripheral orifice 2 which is enlarged at the positions marked 3-6, so that when the vehicle pitches so that, say, the ground clearance at location 3 increases and that at location 5 decreases, cross flows 8 and 10 from enlargements 4 and 6 result. This involves an increase in pressure on the convex sides of the flows so that the pressure in the zone 11 of the cushion 1 builds up to resist the tipping of the vehicle. Strokes may be formed on the base of the vehicle to direct the cross-flows. Alternative embodiments are described employing a single central orifice or a plurality of discrete slits or orifices arranged mutually at right angles in the base surface. Instead of a peripheral air curtain the cushion may be confined by sidewalls and end air curtains, or the peripheral curtain system may be constructed for recirculation.

9

1964-04-02

B60V1/00 ; B60V1/00

B60V1/00

GB19610026566 19610721

GB19610026566 19610721

1	Improvements in or relating to air cushion vehicles
	Inventor: BENNISON MICHAEL JEREMY	Applicant: VICKERS ARMSTRONGS LTD
	EC:B60V1/00	IPC: B60V1/00;B60V1/00
	Publication info: GB953910 A - 1964-04-02

WHAT WE CLAIM IS:- 105

1. A vehicle adapted to ride on a noncompartmented air cushion formed on the underside of the vehicle within means encircling the cushion and including a curtain arranged to be produced by air issuing from 110 downwardly directed orifice means on the perimeter of the underside of the vehicle, wherein means are provided for stabilising the vehicle against tipping, such means including an orifice or orifices for introducing 115 air into the cushion, the orifice or orifices each being of limited lateral extent so that air issuing therefrom cannot form a curtain compartmenting the cushion, the arrangement being such that in operation when the 120 vehicle tips air from said orifice or orifices flows towards the side of the vehicle having the higher ground clearance, an increase of pressure occurring in the cushion towards the opposite side of the vehicle 125 whereby the tipping is opposed.

2. A vehicle as claimed in Claim 1, wherein the orifice means are locally thickened, thereby forming said orifice or orifices.

perimeter of the underside of the vehicle for forming part of the means encircling the cushion, the remainder of which is arranged to be formed by air delivered by said orifice means.

8. A vehicle as claimed in Claim 7, wherein said solid members extend along the sides of the vehicle and the downwardly directed orifice means extend across the front and rear of the vehicle.

9. A vehicle adapted to ride on an air cushion formned on the underside of the vehicle, the vehicle being substantially as hereinbefore described with reference to Figures 1 and 2, or Figures 3 and 4 of the drawing accompanying the Provisional Specification, or with reference to any one of Figures 5 to 8 of the accompanying drawing.

HASELTINE, LAKE & CO., Chartered Patent Agents, 28 Southampton Buildings, Chancery Lane, London, W.C.2, Agents for the Applicants.

3. A vehicle as claimed in Claim 1, wherein said stabilising means comprise at seast one jet orifice connected to be supplied with air and arranged to introduce air into the cushion separately from the orifice means.

4. A vehicle as claimed in Claim 3, wherein the orifice or orifices is/are arranged for introducing air vertically into the cushion.

5. A vehicle as claimed in any one of' the preceding claims, wherein the underside of the vehicle is provided with horizontally extending members for directing said cross-flows.

6. A vehicle as claimed in any one of the preceding claims, wherein the downwardly directed orifice means extends around the whole of the perimeter of the underside of the vehicle whereby in operation of the vehicle the whole of the cushion is encircled by a curtain of air.

7. A vehicle as claimed in any one of Claims 1 to 5, and including solid members extending downwardly from part of the Abingdon: Printed for Her Majesty's Stationery Office, by Burgess & Son (Abingdon), Ltd.-1964.

Published at The Patent Office, 25 Southampton Buildings, London, W.C.2, from which copies may be obtained.

953,910

PATENT SPECIFICATION

DRAWINGS ATTACHED.

Inventor:-MICHAEL JEREMY BENNISON.

953t910 Date of filinq Complete Specification.: July 6, 1962.

Application Date: July 21, 1961. No. 26566/61.

Complete Specification Published: April 2, 1964.

Crown Copyright 1964.

Index at Acceptance:-B7 K.

International Classification:-B 64 c.

COMPLETE SPECIFICATION.

Improvements in or relating to Air Cushion Vehicles.

We, VICKERS-ARMsTRoNGs LIMITED, a British Company, of Vickers House, Broadway, Westminster, London, S.W.l, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: -

This invention relates to vehicles adapted to ride on an air cushion formed on the underside of the vehicle.

It is known to, improve the pitch and roll stability of such vehicles by dividing the air cushion, by means of vertical partitions, into two or more compartments.

The partitions between the compartments are formed either by solid membranes or by jets of fluid. Such solid membranes must be of a flexible nature and are heavy and costly. Partitions formed by jets require a considerable amount of power and increase the structure weight and cost.

According to the present invention there is provided a vehicle adapted to ride on a non-compartmented air cushion formed on the underside of the vehicle within means encircling the cushion and including a curtain arranged to be produced by air issuing from downwardly directed orifice means on the perimeter of the underside of the vehicle, wherein means are provided for stabilising the vehicle against tipping, such means including an orifice or orifices for introducing air into the cushion, the orifice or orifices each being of limited lateral extent so that air issuing therefrom cannot form a curtain compartmenting the cushion, the arrangement being such that in operation when the vehicle tips air from said orifice or orifices flows towards the side of the vehicle having the higher ground clear[Price 4s. 6d.] ance, an increase of pressure occurring in the cushion towards the opposite side of the vehicle whereby the tipping is opposed.

For a better understanding of the invention and to show how the same may be carried into effect reference will now be made to the drawing accompanying the Provisional Specification and to the accompanying drawing. The figures of the drawing accompanying the Provisional Specification are numbered 1 to 4 and the figures of the accompanying drawing are numbered to 8. In the drawings:Figures 1 and 2 are diagrammatic underneath plan views of a first form of vehicle; Figures 3 and 4 are diagrammatic underneath plan views of the second form of vehicle; and 60 Figures 5 to 8 are diagrammatic underneath plan views of four further forms of vehicle.

The vehicle in Figures 1 and 2 rides on an air cushion 1 contained within an air 65 curtain discharged from a downwardly directed orifice 2 disposed around the underside of the periphery of the vehicle. The vehicle is thus of the kind known under the Registered Trade Mark "Hovercraft". The 70 orifice 2 is locally widened at 3, 4, 5 and 6, these locations being disposed mid-way along each of the four sides of the cushion 1. Thus the air cushion curtain is thicker at the locations 3 to 6 than it is around the 75 remainder of the curtain. Such an arrangement induces cross-flows 7 to 10 of air within the cushion 1. In the event that the vehicle tips such that, for example, the ground clearance at the location 3 increases 80 and that at the location 5 decreases, the cross-flows 8 and 10 are deflected in the 11f 953,910 way indicated in Figure 2. That is to say, they curve round to flow towards the part of the cushion 1 in which the ground clearance is greatest, Such curving of the crossflows 8 and 10 involves an increase of pressure on the convex sides thereof so that the pressure in the zone 11 of the cushion 1 which is on the side of the cushion where the ground clearance is least, builds up, the L0 tipping of the vehicle being opposed by this increase in pressure. The cross-flows 8 and thus have the effect of stabilising the vehicle for pitch and it will be readily understood that the cross-flows 7 and 9 have the effect of stabilising the vehicle for roll.

It will, of course, be understood that the local widening of the orifice 2 at the locations 3 to 6 can be regarded as providing orifices 3A, 4A, 5A and 6A in addition to the orifice 2. It will also be understood that local thickening of the orifice 2 may be employed at any number of locations and that furthermore local thinning of the jets may be used in conjunction with local thickening.

The vehicle of Figures 3 and 4 also rides on an air cushion 1 formed within an air curtain discharged from downwardly directed orifice 2 around the periphery of the underside of the vehicle. Air orifice 12 is arranged for introducing air vertically into the cushion 1 at the centre of the underside of the vehicle. The air so introduced flows outwardly in all directions towards the curtain such flows being diagrammatically illustrated at 13 to 16. Should the vehicle tip so that the ground clearance on the side 17 increases and that on the side 18 decreases, the flows 13 and 15 curve towards the side 17, the pressure increasing on the convex sides of these flows so that an increase in pressure occurs in the zone 19 of the cushion 1 which is on the side thereof where the ground clearance is least.

The increase in pressure in the zone 19 tends to lift the vehicle on this side whereby the tipping is opposed and the vehicle stabilised.

It will be appreciated that the stabilising arrangements of Figures 1 and 2, and 3 and 4, can be employed in one and the same vehicle.

If desired the underside of the vehicle may be provided with horizontally extending strakes or horizontally disposed downwardly open channel-shaped members for directing the cross-flows within the cushion 1 to ensure that such flows are favourable ones.

The vehicles of Figures 5 and 6 each ride on an air cushion 1 encircled by an air curtain produced by a downwardly directed jet orifice 2 around the periphery of the underside of the vehicle. Vertically directed elongated orifices 20 are provided for introducing air into the cushion 1. The air so introduced gives rise to cross-flows that serve for stabilising the vehicles of Figures and 6 in a manner similar to that describe-d in connected with the vehicles of 70 Figures 1 to 4.

The vehicles of Figures 7 and 8 each have straight side walls 21 extending from front to rear of the vehicle and depending from the underside of the vehicle. The side walls 75 21 are of solid material which may be flexible or non-flexible. Air curtains are formed across the front and rear of the vehicles by dlownwvardly directed jet orifices 22 at the front and rear of the vehicle and extending 80 from one side wall to the other side wall.

The vehicles of Figures 7 and 8 each ride on an air cushion 1 which is encircled around the perimeter of the underside of the vehicle by the side walls 21 and the air 85 curtains 22. A vertically directed orifice 23 in the case of Figure 7 and two vertically directed orifices 23 in the case of Figure 8 are provided for introducing air into the cushion 1 for giving rise to cross-flows of 90 air that stabilise the vehicles of Figures 7 and 8 in a similar way to that described in connection with the earlier figures.

It will, of course, be appreciated that the invention can be employed with vehicles 95 having curtain configurations other than those shown in Figures 1 to 8, for example, the invention can be used in conjunction with recirculated curtains.

It is to be noted that the orifices 3A to 100 6A, 12, 20, and 23 are each of limited lateral extent so that the air issuing therefrom cannot form a curtain compartmenting the cushion 1.