US3260323A - Pleated jet skirting for ground effect machines - Google Patents

Description

July 12, 1966 J. HENRY 3,260,323

PLEATED JET SKIRTING FOR GROUND EFFECT MACHINES Filed July 29, 1963 5 Sheets-Sheet l INVENT OR JOHN HENRY BY 0 5mg y ATTORNEYS July 12, 1966 J. HENRY 3,2 23

PLEATED JET SKIRTING FOR GROUND EFFECT MACHINES Filed July 29, 1963 5 Sheets-Sheet 2 INVENTOR JOHN HENRY ATTOR NE'YS July 12, 1966 J. HENRY 3,2

PLEATED JET SKIRTING FOR GROUND EFFECT MACHINES Filed July 29, 1965 5 Sheets-Sheet :3

INVENTOR JOHN HENRY BY o rwl g ATTORNEYS United States Patent 3,260,323 PLEATED JET SKIRTING FOR GROUND EFFECT MACHINES Ilohn Henry, Cowes, Isle of Wight, England, assignor to Westland Aircraft Limited, Somerset, England Filed July 29, 1963, Ser. No. 298,382 9 Claims. (Cl. 180-7) This invention relates to ground eflect machines and is concerned with the construction of flexible jet base skirtings such as are proposed, for example, in British Patents 860,781, 925,425 and 929,671.

During the operation of such machines, and more particularly during overwater operations, I have found that flexible jet skirting, at and in the vicinity of the stern, is subjected to greater stresses than might be expected, due to forward movement of the machine. This occurs since the forward curvature of the skirting from the astern position to encompass the sides tends to dig in or scoop water instead of parting the water or flexing inwardly as at the bow or sides. Such extra stresses however, also occur on skirting positioned at what may be termed the trailing side of the bow, side or stern quarter when the forward movement of the machine has a crabwise attitude relative to the surface over which it is operating, as in running cross-seas or crosswinds, or when a banked turn is made and the trailing edge dips into the water.

Considering a skirting arranged to retard escape of the ground effect pressurised gaseous cushion, these extra stresses are applied outward from the cushion area. They are exerted to act upon the skirting in a direction against which flexing of the skirting is normally restrained to re sist the cushion pressure. The applied extra stresses are big enough to cause splitting of the skirting on many occasions.

The object in this invention is to provide a new or improved construction of flexible jet skirting for side, end

or peripheral applications, which can flex outwardly under stresses of the kind described, whilst remaining operative to retard escape of the gaseous ground-eflect cushion, and also being capable of otherwise flexing when struck by obstacles.

Accordingly this invention consists in a ground effect vehicle provided with a fluted, or pleated, fieXible jet skirting system, attached to suspend from the base structure of the machine in a normal fluted or pleated state and in which a degree of inherent rigidity resists outward flexing under the influence of the ground effect cushion pressure, and 'biasses the skirting to re-assume the fluted, or pleated state after flexing in any direction, the arrange ment being such that in addition to being able to flex when obstacles are struck, the skirting can flare outwardly from the bottom by flexing to unfold the flutes, or pleats, and relieve excessive pressures whilst maintaining retarding action to the escape of the gaseous ground effect cushion.

Further objects and advantages of the invention will become apparent from the following detailed description with reference to the accompanying drawings, which are by way of example only, wherein:

FIGURE 1 is an elevation in section through the base platform, ducting and flexible skirting according to the invention.

FIGURE 2 is a diagram of the flexible skirting according to the invention, sectioned along line IIII of FIG- URE 1.

FIGURE 3 is a diagram of the flexible skirting according to the invention, sectioned along line IIIIII of FIGURE 1.

FIGURE 4 is a perspective view of the flexible skirting according to the invention and as shown in FIGURES 1, 2 and 3.

FIGURE 5 is a diagram similar to FIGURE 3, showing the flutes or pleats extended, according to the invention.

FIGURE 6 is a diagram similar to FIGURE 3, but showing an alternative method of construction of the flexible skirting according to the invention.

FIGURE 7 is a diagram similar to FIGURES 3 and 6 but showing a further alternative method of construction of the flexible skirting according to the invention.

In carrying the invention into effect according to one convenient form, by way of example only with reference to FIGURES 1-5, the rigid base platform 1 of a peripheral jet type ground effect machine carries a rigid air or gas supply duct 2 around the periphery. The duct 2 conveys air drawn from atmosphere to peripheral pressure jet orifices 3, through which air is discharged downwardly.

The air is pressurised within the duct 2 by one or more centrifugal fans, not shown. The pressure air discharge from the jet orifices 3 generates the ground effect pressurised air cushion between the surface 4, over which the machine is operating, and the base platform 1.

The duct 2 is flexibly extended a predetermined distance beneath the platform 1 by a flexible skirting assembly generally indicated at 5, the flexible skirting assembly 5 being attached to the rigid walls 6 by any suitable method. It is made of rubber, plastic, rubberised or plasticised fabric, or any other flaccid or flexible hard wearing material made up to resist abrasion. The distance the flexible skirting assembly 5 extends the duct 2 below the platform 1 is predetermined in accordance with the operational role of the vehicle.

The flexible skirting assembly 5 comprises pleats, or flutes, preferably incorporated in the form of flexible folded webs 7 of U or V shape, the legs of the U or V connecting adjacent air or gas flexible ducts 8 arranged in side-by-side relationship in the form of tubular members, the fold in the webs 7 occurring centrally thereof in a substantially vertical plane and the ends of the legs being attached to the flexible ducts by any suitable means, such as stitching or staples. In the preferred embodiment illustrated, the air or gas flexible ducts 8 are funnel-shaped with the larger orifice 9 at the top for connection to the rigid air or gas supply duct 2 of the machine, and tapering towards the bottom to form the jet orifice 3, and may be constructed by attaching two portions together, the two portions being an inner wall 10 and an outer wall 11.

The attachment of the inner wall 10 to the outer wall 11 may be achieved conveniently, by using the same stitching and staples that attach the webs 7 to the flexible ducts 8 and could thus be performed in one operation. The jet orifice 3 may be inwardly inclined to impart an inward component to the jet discharge, so that each flexible duct 8 is rather like 21 Wellington boot with an open toe forming jet orifice 3. Such an arrangement utilises the inflationary pressure of the air or gas to provide an element of inherent rigidity maintaining and biassing the flexible skirting assembly 5 to assume or remain in the downwardly-extended position.

The pleats or flutes may alternatively be incorporated in the form illustrated in the FIGURES 6 and 7, wherein two legs 12 are attached to each other, by stitching, staples or any other suitable means of attachment, in a substantially vertical plane, the other ends of the legs 12 being attached to adjacent air or gas flexible ducts 8 in the manner already described. FIGURE 7 shows an alternative form of constructing the flexible ducts 8, wherein the outer wall comprises two portions 13 attached to each other, by stitching, staples or any other suitable means of attachment, in a substantially vertical plane.

The assembly of webs and ducts can be constructed to form a continuous flexible peripheral base skirting, side wall, end wall, bow or stem skirtings, or could be incor porated as part of a continuous skirting which varies in construction and configuration according to the part of the machine at which it is located. Where advantageous, the invention could be used for stability jet skirting or keels or cushion compartmentation divisions which extend flexibly from the base structure.

In the preferred construction, the webs 7 are attached to the air or gas ducts 8 in such a manner so that, when the flexible skirting assembly 5 flares out to unfold the pleats, or flutes, the webs 7 are located at the inner edge of the air or gas ducts 8, which consequently stand roud as ribs on the outside of the flexible skirting assembly 5, relatively to the machine. In this way the stretched webs 7, with the inner walls of the air or gas ducts 8, present a substantially smooth continuous skirt surface on the cushion side, against which any excessive pressures, as described, are exerted. To this end, it will be understood that the webs 7 normally lie as folded pleats or flutes between adjacent pairs of air or gas ducts 8.

This invention constitutes a development of the construction described in British Patent 929,671. It will be apparent to anyone skilled in the art that the flexible skirting assembly 5, comprising the webs 7 and the air or gas flexible ducts 8, may alternatively be moulded in one piece, such that the entire peripheral skirting assembly 5, may be constructed of one integral moulding or alternatively of an assembly of several sections, each section consisting of an integral moulding of several webs 7 and flexible ducts 8.

I claim as my invention:

1. A ground effect vehicle provided with a fluted or pleated flexible jet skirting system through which air under pressure is discharged downwardly to build up and maintain the air pressure of the ground effect air cushion, the system forming also a flexible barrier to the dissipation of pressurised air constituting the ground effect air cushion associated with the barrier, and comprising an assembly of flexible tubular components formed of a flaccid impervious material so as to be flexible in all lateral directions and arranged in side by side relationship to depend downwardly from the base of the vehicle, said tubular components being open at both ends for passing pressurized air downwardly therethrough, adjacent pairs of flexible tubular components being connected by flexible folded webs, said flexible tubular components being funnel shaped with the larger orifice at the top and tapering toward the bottom to form a jet orifice, the jet orifice being inwardly inclined to impart an inward component to the jet discharge, the inflationary pressure of the air or gas flowing through said flexible tubular components providing an element of inherent rigidity maintaining and biasing said flexible jet skirting system to assume or remain in the downwardly extended position.

2. A ground effect vehicle provided with a fluted, or pleated, flexible jet skirting system as claimed in claim 1, wherein said flexible folded webs are of U or V shape, the legs of said U or V shaped flexible webs being attached to adjacent flexible tubular components.

3. A ground effect vehicle provided with a fluted or pleated flexible jet skirting system, as claimed in claim 2, wherein the fold in said flexible folded webs occurs substantially centrally thereof and has a vertical disposition.

4. A ground effect vehicle provided with a fluted or pleated flexible jet skirting system, as claimed in claim 1, wherein said flexible tubular components are formed by two portions, said two portions comprising an inner wall and an outer wall.

5. A ground effect vehicle provided with a fluted or pleated flexible jet skirting system as claimed in claim 4 wherein said inner wall, said outer wall and said flexible folded webs are mutually attached by stitching.

6. In a ground effect machine having an elongated duct opening to which pressurized fluid is passed, a flexible jet skirting system comprising: a plurality of hollow tubular members formed of a flaccid impervious material so as to be flexible in all lateral directions and disposed in side-by-side relationship, said tubular members being connected to the elongated duct opening at their upper ends for conducting pressurized fluid downwardly therefrom to issue from the lower ends of the tubular members to build up and maintain a supporting fluid cushion under the machine, and a plurality of folded webs of a flexible impervious material extending downwardly between adjacent tubular members and connected along their longitudinal edges to adjacent tubular members, said tubular components being substantially funnel shaped with the larger opening at the top and tapering downwardly to form a jet orifice at the lower end of each tubular component, said jet orifice being inwardly inclined toward the machine.

7. Apparatus as set forth in claim 6 wherein said folded webs are substantially of a U shape in cross-section.

8. Apparatus as set forth in claim 7 wherein said webs are connected to said tubular members along longitudinal lines which are disposed inwardly of the center lines of said flexible tubular members toward the underside of the machine such that when viewed in cross-section a greater portion of the perimeter of each tubular member is disposed outwardly of the machine between said longitudinal lines than is disposed inwardly of the machine between said lines, whereby the tubular members will stand proud as longitudinal ribs on the outer surface of the skirting system when the folded webs are extended laterally.

9. Apparatus as set forth in claim 8 wherein said tubular members each comprise two connected wall members, said wall members being connected along said longitudinal lines to each other and to an edge of one of said folded webs, the wall member which is disposed inwardly of the machine being of less circumferential length than the wall member which is disposed outwardly of the machine.

Fit

BENJAMIN HERSH, Primary Examiner.

A. HARRY LEVY, Examiner.

R. M. WOHLFARTH, M. s. SALES Assistant Examiners.

Claims (1)

1. A GROUND EFFECT VEHICLE PROVIDED WITH A FLUTED OR PLEATED FLEXIBLE JET SKIRTING SYSTEM THROUGH WHICH AIR UNDER PRESSURE IS DISCHARGED DOWNWARDLY TO BUILD UP AND MAINTAIN THE AIR PRESSURE OF THE GROUND EFFECT AIR CUSHION, THE SYSTEM FORMING ALSO A FLEXIBLE BARRIER TO THE DISSIPATION OF PRESSURIZED AIR CONSTITUTING THE GROUND EFFECT AIR CUSHION ASSOCIATED WITH THE BARRIER, AND COMPRISING AN ASSEMBLY OF FLEXIBLE TUBULAR COMPONENTS FORMED OF A FLACCID IMPERVIOUS MATERIAL SO AS TO BE FLEXIBLE IN ALL LATERAL DIRECTIONS AND ARRANGED IN SIDE BY SIDE RELATIONSHIP TO DEPEND DOWNWARDLY FROM THE BASE OF THE VEHICLE, SAID TUBULAR COMPONENTS BEING OPEN AT BOTH ENDS FOR PASSING PRESSURIZED AIR DOWNWARDLY THERETHROUGH, ADJACENT PAIRS OF FLEXIBLE

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