GB1580794A

GB1580794A - Aircushion vehicles

Info

Publication number: GB1580794A
Application number: GB492176A
Authority: GB
Original assignee: Individual
Current assignee: Individual
Priority date: 1976-02-09
Filing date: 1976-02-09
Publication date: 1980-12-03

Description

(54) IMPROVEMENTS IN AND RELATING TO AIR-CUSHION VEHICLES (71) I, DONALD RUSSELL ROB ERTSON, a British Subject of Flat 33, No. 5, Sloane Court East, London S.W.3.

do hereby declare the invention, for which I pray that a patent may be granted to me, and the method by which it is to be performed, to be particularly described in and by the following statement: The invention relates to air-cushion vehicles.

In an air-cushion vehicle, air is directed into a space beneath the hull of the vehicle, which space is generally bounded by a flexible wall or skirt system atached to the hull. The skirt system may itself take the form of an annular duct, the outer wall of which is formed by a so-called "outer loop" of arcuate section and the inner wall by a so-called "inner loop" or "apron". A number of flexible wall members or "segments" are attached both to the outer loop and to the apron and divide the ducts permitting the flow of air from the region between the outer loop and the apron to be directed inwardly and downwardly to the space beneath the vehicle. The lower edge or tips of the wall members contact the surface of the water or land. The air enclosed under pressure by the skirt system provides lift for the vehicle.

In use, the lower edges of the wall members sustain substantial wear and are also liable to damage caused by snagging on stakes or rocks. The wall members must therefore be replaced after a period of time. It has previously been proposed to bolt the wall members at their outermost edges to the outer loop, and attach their innermost edges. to the apron by bolting adjacent wall members to gether and using a chain to secure the bolt to the apron. On replacing a wall member, the bolts on the outermost edge are relatively accessible and easy to undo, but the fastenings at the innermost edges are much less readily accessible and hence cause difficulties during replacement.

The invention provides an air-cushion vehicle having a flexible wall comprising a plurality of flexible wall members depending adjacent to one another, each of which is of generally U-shaped section in a plane extending transversely of the vehicle, the arms of the U extending inwardly, the innermost ends of the arms of the member being provided with beading extending transversely between the arms, and linking portions being provided which extend between the beading and the arms, the vehicle also comprising a plurality of clips for securing the wall members thereto, each clip being secured to the remainder of the vehicle and having a tubular portion arranged to receive the beading and an axially-extending slot through which the linking portions extend the width of the slot being such that the beading cannot pass therethrough, the arrangement being such that the beading and the linking portions can be inserted into and removed from the clip only by sliding along the clip in an axial direction.

By securing the wall members at their innermost edges to the remainder of the vehicle by means of the beading and clips in accordance with the invention, it is possible for individual wall members to be released at their innermost edges simply by sliding the beading of the wall member out of the clip.

The beading of a new wall member can then be inserted in place of the old one. Accordingly it is possible for the replacement of a wall member to be made without the use of tools for the fastening of the innermost edges of the wall member. When the vehicle is in use, each wall member exerts an outward pull, thus drawing the beading against, and sealing, the axially-extending slot od the clip in which it rests preventing by friction any relative movement.

Advantageously, each wall member is secured to the remainder ob the vehicle by a different one of the clips, each of which is of a width substantially equal to the transverse width of the wall member, the clips being arranged adjacent to one another. With this arrangement it is possible for the beading of one wall member to abut against the beading of an adjacent wall member so that when under pressure the wall member cannot be disconnected. One or more additional retaining loops passing through each clip and the wall member received therein may, however, be provided to prevent relative displacement in use. Each clip is advantageously formed with a flange which is secured to the remainder of the vehicle, generally to the flexible apron, preferably by means of bolts or rivets.

To release a wall member from its clip, the clip can be strained out of alignment with its neighbour to such an extent that the tubular portion of the clip is moved clear of the neighbouring clip to allow the beading of the wall member to be removed by sliding out of the clip. The material of the apron is usually sufficiently flexible to allow this, but in those cases where the material of the apron is too heavy to stretch sufficiently, each clip may be provided with a further tubular portion and an axially-extending slot arranged to receive a beading provided on the outermost edge of the apron.

Each clip is advantageously made by extrusion from plastics or metal, for example, an alloy of aluminium.

The linking portions of each of the wall members are provided to distribute the load generated in the wall member in use over a length of the beading and along at least a portion of the arms rather than allow the load to be concentrated at a point such as a bolt hole as was previously the case. Each of the linking portions may be provided by a strip of flexible material secured to, or integral with, an arm of the wall member along at least a portion of its length and, preferably, along substantially the entire length of the arm. When the linking portions are formed by such separate strips, the beading of each wall member is preferably also in two sew arate portions, one secured to each strip, so that on connection of a wall member to the vehicle the portions of the beading can be inserted separately into the dip, one from each end.Each strip may he stitched or heatwelded onto the arm along its uppermost edge portion, or alternatively the wall member including its beading and linking portions may be formed as a one-piece moulding.

As an alternative to having the linking portions of a wall member in the form of separate strips, they may be provided by a single inner member extending across the wall member between the arms, the central portion of which is inclined away from the uppermost edge portion of the free ends of the arms towards the lowermost edge portion of the bight of the U. With this arrangement the beading of each wall member advantageously extends unbroken between the arms and is secured along its length to the inner member.

The inner member is preferably formed with a hole in the region of the bight of the U, the size of which can be varied to control the flow of air through the wall member.

Each wall member is advantageously formed from a woven material coated with polyvinyl chloride or neoprene, and is preferably formed from a generally triangular-shaped piece of the flexible woven material, in which the warp extends along the base of the triangle and the woof extends from the base towards the apex of the triangle, the material being folded along the woof to provide the arms of the U. The region of the apex of the triangle may be folded over to reinforce one or more bolt holes formed in this region of the wall member to permit attachment to the outerloop. Alternatively, the apex may be cut off and a separate reinforcing sleeve of material attached to the wall member, through which sleeve a small batten of, for example, plastics, may be inserted for additional strength.

Each of the linking portions may be formed from a flexible woven material secured to an arm of the wall member with the warp or the woof extending substantially parallel to the arm and normal to the beading. In such an arrangement the lines of force are along the warp or the woof and not at an angle to the lie of the weave. This avoids distortion of the material and alterations of the geometry of the wall member under load.

At certain positions on the air-cushioned vehicle, and especially at the stern, it is advantageous to provide a further wall member of generally U-shaped section in the trans- verse plane with the arms of the U extending outwardly around each of the first-mentioned wall members. The further wall members tend to prevent scooping of water by the first-mentioned wall members. With such an arrangement, the inner and outer wall members are preferably bolted together and are provided with beading for attachment to clips in accordance with the invention on both the apron and the outer loop.

An air-cushion vehicle constructed in accordance with the invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows diagrammatically a section through a portion of an air-cushion vehicle in accordance with the invention; Figure 2 is a view taken along the line X-X of a series of wall members of the vehicle shown in Figure 1; Figure 3 is a perspective view of a wall member as shown in Figure 2; Figure 4 is a section taken along the line Y-Y shown in Figure 2; Figure 5 is a view similar to that of Figure 2 of a series of modified wall members; Figure 6 is a perspective view of a wall member as shown in Figure 5; and Figure 7 is a section taken along the line Z-Z shown in Figure 5.

Referring to the accompanying drawings, and initially to Figure 1, an air-cushion vehicle indicated generally by the reference numeral 1, includes a hull 2 to which is attached a flexible wall indicated generally by the reference numeral 3. The flexible wall 3 is in the form of an annular duct arranged to direct the flow of air from an enginedriven fan (not shown) into, the space beneath the hull 2 to provide lift for the vehicle 1.

The flexible wall 3 comprises an outer loop 4 of arcuate section secured at its upper edge to the hull 2, and an apron 5 also secured to the hull. To the lower edges of the outer loop 4 and the apron 5 are secured a series of wall members, indicated generally by the reference numeral 6, which divide the annular duct into a series od smaller ducts. One form of wall members 6 is shown in greater detail in Figures 2 to 4, and a modified form in Figures 5 to 7.

Referring to Figures 2 to 4, each of the wall members 6 is formed from a generally triangular piece of woven nylon coated with polyvinyl chloride. The material is folded with the apex of the triangle extending up wardly so that the wall member 6 is of generally U-shaped section in a plane extending transversely of the vehicle 1, having arms 7 and 8, respectively, extending inwardly and the bight of the fold is inclined downwardly and inwardly to direct air from the region between the outer loop 4 and the apron 5 into the space beneath the hull 2. The warp of the weave of the material extends parallel to the base of the triangle and the woof extends normally from the base to the apex of the triangle.

At the innermost ends of the arms 7 and 8 of each wall member 6 two short lengths of wooden beading 9 are secured to linking portions 10 and 11, respectively, each of the linking portions being wrapped around one of the lengths of the beading and being secured to itself by stitching 12 to secure the beading to it. The linking portions 10 and 11 which are hemmed along their edges 10a and lla, respectively are secured to the arms 7 and 8 respectively by stitching 13. The linking portions 10 and 11 taper slightly in a direction towards the bight of the fold and extend approximately half way along the arms 7 and 8.The linking portions 10 and 11 are also formed from polyvinyl chloride coated nylon, and they are stitched to the arms 7 and 8 with the warp of the weave extending parallel to the uppermost edges of the arms, and normal to the beading 9, so that, in use, the lines of force are along the warp of the linking portions and not at an angle to the lie of the weave.

The beading 9 is held within a clip, indicated generally by the reference numeral 14, of the same length as the width of the wall member 6 having an open-ended tubular portion 15 for accommodating the beading and an axially-extending slot 16 through which the linking portions 10 and 11 extend. The slot 16 is not wide enough to allow the beading 9 to pass through and accordingly the wall member 6 can only be detached from the clip 14 by sliding the beading 9 and its linking portions 10 and 11 along the clip in an axial direction. The clip 14 has a flange 17 secured by rivets 18 to the apron 5, and the clip is formed from an aluminium alloy by extrusion.

The region 6a of the apex of each of the wall members 6, is folded over and stitched down by stitching 6b. Bolt holes 19 are formed along the straight edge so formed, the central hole passing through the region 6a, which reinforces the hole. These holes 19 are used to secure the wall member 6 in the outer loop 4. Instead of folding over the region 6a, the region may be cut off and a separate reinforcing sleeve of material extending over the edge on each side of the wall member 6 stitched on. All three bolt holes 19 can then be formed through the sleeve and a small plastics batten can be inserted through the sleeve to provide additional strength.

The wall members 6 depend adjacent to one another with adjacent arms 7 and 8 of adjacent members in contact so that when air is flowing through the wall members the adjacent arms are urged against each other.

The clips 14 are also arranged adjacent to one another so that the beading 9 of one wall member 6 abuts against the beading of an adjacent wall member and, under pressure, the wall members 6 cannot accidentally slide out of the clips 14. Two additional retaining loops (not shown) passing through the clip 14 and a different one of the linking portions 10 and 11, may also be provided to prevent relative displacement.

To detach a wall member 6 from the vehicle 1, the bolts 19 securing the member to the outer loop 4 are first unfastened. The retaining loop, if provided, is removed and the clip 14 connecting the wall member 6 to the apron 5 is straight out of alignment with its neighbours. The lengths of the beading 9 slide axially along the tubular portion 15 and either both out of the same open end or one out of each end. A fresh wall member 6 may then be attached to the vehicle by reversing this procedure. In use, with air flowing into the space beneath the hull 2, each wall member 6 exerts an outward pull and the beading 9 is drawn against the slot 16, sealing the slot and preventing by friction any relative movement.The load generated in the wall member 6 is distributed by the linking portions 10 and 11 over the length of the beading 9 and along the upper edges of the arms 7 and 8 and is not concentrated at a point, thus reducing the risk of distortion or tearing of the material.

Referring to Figures 5 to 7, the modified form of the wall member 6 is similar to that shown in Figures 2 to 4 (the same reference numerals being used for the same features where appropriate) except that instead of having linking portions 10 and 11 formed from separate strips of material, the linking portions are provided by a continuous inner member 20. This inner member 20 is sewn to the uppermost edges of the arms 7 and 8 and at the innermost ends of the arms is wrapped around a single length of wooden beading 21, the inner member 20 being stitched to itself at 22 and 23. The inner member 20 extends downwardly towards the bight of the fold and is formed with a hole 24 to control the rate of flow of air through the wall member 6. This form of the wall member is detached from the vehicle and replaced in a similar manner to that shown in Figures 2 to 4.

WHAT I CLAIM IS: 1. An air-cushioned vehicle having a flexible wall comprising a plurality of flexible wall members depending adjacent to one another, each of which is of generally U-shaped section in a plane extending transversely of the vehicle, the arms of the U extending inwardly, the innermost ends of the arms of the member being provided with beading extending transversely between the arms and linking portions being provided which extend between the beading and the arms, the vehicle also comprising a plurality of clips for securing the wall members thereto, each clip being secured to the remainder of the vehicle and having a tubular portion arranged to receive the beading and an axially-extending slot through which the linking portions extend, the width of the slot being such that the beading cannot pass therethrough, the arrangement being such that the beading and the linking portions can be inserted into and removed from the clip only by sliding along the clip in an axial direction.

2. An air-cushion vehicle as clamed in claim 1, wherein each wall member is secured to the remainder of the vehicle by a different one of the clips, each of which is of a width substantially equal to the transverse width of the wall member, the clips being arranged adjacent to one another.

3. An air-cushion vehicle as claimed in claim 1 or claim 2, wherein one or more retaining loops is or are arranged to pass through each clip and the wall member received therein to prevent relative displacement, in use.

4. An aireshion vehicle as claimed in any one of claims 1 to 3, wherin each clip is formed with a flange which is secured to the remainder of the vehicle.

5. An air-cushion vehicle as claimed in claim 4, wherein the flange is secured to the remainder of the vehicle by bolts or rivets.

6. An air-cushion vehicle as claimed in any one of claims 1 to 3, wherein, for securing the clip to the remainder of the vehicle, each clip is provided with a further tubular por tion and an axially-extending slot arranged to receive a further beading on the remainder of the vehicle.

7. An air-cushion vehicle as claimed in any one of claims 1 to 6, wherein each clip is made by extrusion.

8. An air-cushion vehicle as claimed in any one of claims 1 to 7, wherein each clip is made from a plastics material.

9. An airsushion vehicle as daimed in any one of claims 1 to 7, wherein each clip is made from a metal.

10. An air-cushion vehicle as claimed in any one of claims 1 to 9, wherein each of the linking portions is provided by a strip of flexible material secured to, or integral with, an arm of the wall member along at least a portion of its length.

11. An air-cushion vehicle as claimed in claim 10, wherein each strip of flexible material extends substantially the entire length of the arm.

12. An air-cushion vehicle as claimed in claim 10 or claim 11, wherein the beading of each wall member is in two separate por tisns, one secured to each strip.

13. An air-cushion vehicle as claimed in any one of claims 10 to 12, wherein each strip is stitched onto the arm of the wall member along its uppermost edge portion.

14. An air-cushion vehicle as claimed. in any one od claims 10 to 12, wherein each strip is heat-welded on to the arm of the wall member along its uppermost edge portion.

15. An air-cushion vehicle as claimed in any one of claims 10 to 12, wherein each wall member is a one-piece moulding.

16. An air-cushion vehicle as claimed in any one of claims 1 to 9, wherein each of the linking portions of a wall member is pro vided by a single inner member extending across the wall member between the arms, and the central portion od which is inclined away from the uppermost edge portion of the free ends of the arms towards the lowermost edge portion of the bight of the U.

17. An air-cushion vehicle as claimed in claim 16, wherein the beading of each wall member extends unbroken between the arms and is secured along its length to the inner member.

18. An air-cushion vehicle as claimed in claim 16 or claim 17, wherein the inner member is formed with a hole in the region of the bight of the U.

19. An aircushion vehicle as claimed in any one of claims 1 to 18, wherein each wall member is formed of a woven material coated with polyvinyl chloride.

20. An air-cushion vehicle as claimed in any one of claims 1 to 18, wherein each wall member is formed of a woven material coated with neoprene.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. shown in Figures 2 to 4 (the same reference numerals being used for the same features where appropriate) except that instead of having linking portions 10 and 11 formed from separate strips of material, the linking portions are provided by a continuous inner member 20. This inner member 20 is sewn to the uppermost edges of the arms 7 and 8 and at the innermost ends of the arms is wrapped around a single length of wooden beading 21, the inner member 20 being stitched to itself at 22 and 23. The inner member 20 extends downwardly towards the bight of the fold and is formed with a hole 24 to control the rate of flow of air through the wall member 6. This form of the wall member is detached from the vehicle and replaced in a similar manner to that shown in Figures 2 to 4. WHAT I CLAIM IS:

1. An air-cushioned vehicle having a flexible wall comprising a plurality of flexible wall members depending adjacent to one another, each of which is of generally U-shaped section in a plane extending transversely of the vehicle, the arms of the U extending inwardly, the innermost ends of the arms of the member being provided with beading extending transversely between the arms and linking portions being provided which extend between the beading and the arms, the vehicle also comprising a plurality of clips for securing the wall members thereto, each clip being secured to the remainder of the vehicle and having a tubular portion arranged to receive the beading and an axially-extending slot through which the linking portions extend, the width of the slot being such that the beading cannot pass therethrough, the arrangement being such that the beading and the linking portions can be inserted into and removed from the clip only by sliding along the clip in an axial direction.

21. An air-cushion vehicle as claimed in

any one of claims 1 to 20, wherein each wall member is formed from a generally triangularshaped piece of flexible woven material in which the warp extends along the base of the triangle and the woof extends from the base towards the apex of the triangle, the material being folded along the woof to pre vide the arms of the U.

22. An air-cushion vehicle as claimed in claim 21, wherein the region of the apex of the triangle is folded over to reinforce one or more bolt holes formed in this region of the wall member to permit attachment to the outer loop.

23. An air-cushion vehicle as claimed in claim 21, wherein the apex is cat off and a separate reinforcing sleeve of material attached to the wall member, through which sleeve a batten is inserted one or more bolt holes being formed through the sleeve to permit attachment to the outer loop.

24. An air-cushion vehicle as claimed in any one of claims 1 to 23, wherein each of the linking portions is formed from flexible woven material secured to an arm of the wall member with the warp or the woof extending substantially parallel to the arm and normal to the beading.

25. An air-cushion vehicle as claimed in any one of claims 1 to 24, wherein there is provided one or more further outer wall members each of generally U-shaped section in the transverse plane with the arms of the U extending outwardly around a different one of the first-mentioned wall members.

26. An air-cushion vehicle as claimed in claim 25, wherein the inner and outer wall members are bolted together.

27. An air-cushion vehicle as claimed in claim 25, or claim 26, wherein beading extending transversely between the arms of the outer wall member is provided and a further clip for securing the outer wall member to the remainder of the vehicle.

28. An air-cushion vehicle substantially as hereinbefore described with reference to and as shown in the accompanying drawings.