GB2447852A

GB2447852A - Ground effect transport system

Info

Publication number: GB2447852A
Application number: GB0625262A
Authority: GB
Inventors: Jeremy Wilfred Fox
Original assignee: Kallista Properties Ltd
Current assignee: Kallista Properties Ltd
Priority date: 2006-12-19
Filing date: 2006-12-19
Publication date: 2008-10-01
Also published as: GB0625262D0

Abstract

A ground effect transport system, eg a semi-trailer, full trailer or other lorry, comprises a load carrying platform (21, figs. 2,4), a skirt 41 depending from the platform to form a plenum chamber and fan means 37 for supplying air to the plenum chamber. The platform may have ground wheels 23. The skirt 41 extends without a break around the plenum chamber and means, eg steel wire ties 75, 77, are provided which hold the skirt 41 in engagement with the ground against the force of the air in the plenum chamber. The angles between the ties 75 and 77 and the upright portion 67 of the skirt may be 60 and 68 degrees, respectively. The skirt 41 may be made of extruded polyurethane with a J-shaped cross-section the curved part 69 of which may have an exterior ceramic layer for protection as the skirt rubs on the ground or road. The skirt 41 may have three reinforcing ribs 61, 63, 65 one or more of which may have a steel strengthening rod 71.

Description

-1-2447852

GROUND EFFECT LOAD TRANSPORTATION

This invention relates to load transportation by means of vehicles using ground effect to support part of the load.

There have been a number of proposals for easing the load on goods vehicles by taking up a large part of the load using ground effect with a skirt. However, these have had problems due to excessive escape of air from underneath the lower edges of the skirt which has necessitated the use of excessive air supplies in order to maintain the air cushion and provide sufficient support for the load.

The present invention seeks to obviate or reduce these above disadvantages.

According to a first aspect of the invention, a ground effect transport system comprises a load carrying platform, a skirt depending from the load carrying platform to form a plenum chamber and fan means for supplying air to the plenum chamber, wherein the skirt extends without a break around the plenum chamber.

Preferably means are provided which hold the skirt in engagement with the ground against the force of the air in the plenum chamber.

According to a second aspect of the invention, a ground effect transport system comprises a load carrying platform, a skirt depending from the load carrying platform to form a plenum chamber and fan means for supplying air to the plenum chamber, wherein means are provided which hold the skirt in engagement with the ground against the force of the air in the plenum chamber.

The load carrying platform may have wheels for contact with the ground and the wheels may be located within the plenum chamber.

The skirt may extend in a forward direction such that it narrows towards the front thereof and the skirt may extend in a rearward direction such that it narrows towards the back thereof.

The skirt may be formed of two parallel sections extending along the outsides of the vehicle, the two parallel sections being connected together at the front and rear by a pair of sections which extend at an angle to the parallel sections towards each other so that the meet at a point at the rear and at the front of the skirt.

The angle at which the pair of sections meet may be 67 degrees.

Preferably the skirt is made from polyurethane.

The skirt may have a "J" shaped cross section with the shorter arm of the "J" facing inwards. The upright portion and the curved portion of thee UJfl may be provided with one or more strengthening ribs extending longitudinally of the skirt.

One or more of the strengthening ribs may have a longitudinally extending strengthening insert which may comprise a wire, rod or tube which may be of steel.

The skirt may be provided with a pair of ties, one extending from a middle portion * . of the upright portion of the "J" and the other extending from a middle portion of * the curved portion of the MJ" both ties extending inwardly from the skirt at predetermined angles and attached to the structure of the vehicle. I.

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The skirt may have three longitudinally extending strengthening ribs, two spaced **S.

*..,, apart on the upright portion of the "J" and one in the middle portion of the curved portion of the "J" with the ties being secured to the skirt at the location of the lower rib of the upright portion of the UJII and the rib of the curved portion of the UJU.

The ties may be secured to cross beams of the skirt supporting structure and may comprise steel wire.

The upper tie may extend at an angle to the upright portion of the "J" in the range of 50 to 70 degrees and the lower tie may extend at an angle to the upright portion of the"!' in the range of 55 to 80 degrees The upper tie may extend at an angle to the upright portion of the"!' in the range of 55 to 65 degrees and the lower tie may extend at an angle to the upright portion of the JW in the range of 60 to 75 degrees The upper tie may extend at an angle to the upright portion of the "! of 60 degrees and the lower tie may extend at an angle to the upright portion of the Jfl of 68 degrees The invention will now be described in greater detail by way of example; with reference to the drawings, in which:-Figure 1 is a general schematic side view of a vehicle in accordance with one * ** *, embodiment of the invention; **** * I * *, Figure 2 is a side view of the trailer of a semi-trailer for the vehicle shown in Figure 1 with the support framework for the skirt shown but the panelling and *** * skirt removed; I...

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Figure 3 is a view similar to figure 2 but showing the skirt in place.

Figure 4 is a view similar to figures 2 and 3 showing both the skirt an upper panelling in place; Figure 5 is a plan view of the skirt; Figure 6 is a cross sectional view of the skirt, and Figure 7 is a perspective view of a short section of the skirt.

Refemng firstly to figure 1, there is shown schematically a vehicle I to which the invention is applied. The vehicle shown is a semi-trailer which is a vehicle having a cab unit 3 which is self contained and is supported on the ground by two steerable front wheels 5 and four trailing wheels 7 at the rear. The trailer portion 9 in this case is, for transit purposes, supported at its rear by wheels (not shown in this figure) and by a plenum chamber defined in part by a skirt 11 and at its front end by the rear wheels 7 of the cab unit 3 over which the front end of the trailer extends.

The arrangements so far described are known. However, as has been mentioned above, the previous proposals have never been very satisfactory because of excessive escape of air from the plenum chamber due, to a large extent, to the construction of the plenum chamber and particularly of the skirt. * S. * e I * S.

*::::* The application of the invention to the above described semi-trailer vehicle will * * now be discussed in connection with figures 2 to 5. Looking first at figure 2, there is shown a side view of the trailer 9 of the semi-trailer 1. Thus, the trailer 9 S..

* comprises a load carrying platform 21 which is basically supported towards its rear end by six wheels 23 and at its forward end, when not connected to a cab **.

unit 3 (figure 1) by means of loading legs 25. When attachment is made to the cab unit the trailer 9 is connected to the cab unit 3 by means of a king pin 27. In this situation, the landing legs 25 are folded up towards the load supporting platform 21.

Attached to the loading platform 21 and depending therebeneath is a framework 29 on which the plenum chamber is built and the depending skirt is carried. To this end, the framework comprises vertical struts 31 attached at their upper ends to the load platform and braced by cross beam supports 33 extending across the vehicle from one side to the other. Towards the lower ends of the struts 31 is a skirt carrying beam 35 which extends around the whole of the plenum chamber.

Also shown in this figure is the fan 37 which feeds the plenum chamber and has an air inlet indicated at 39. This fan is either driven by an electric motor (not shown) located adjacent to the fan or by means of an hydraulic motor driven by the hydraulic system provided in the cab unit.

Figure 3 shows the skirt 41 attached to the skirt carrying beam 35 (figure 2). As can be seen. the skirt extends completely around the plenum chamber and is inclined to a point 43 at each end. The plan shape of the skirt 41 can be seen particularly from the plan view in figure 5. It is important to note that the skirt extends unbroken around the entire area of the plenum chamber.

Figure 4 shows the arrangement completed by the arrangement of metal panels which enclose the area above the skirt 41. At the front and rear ends, the panels extend transversely of the trailer leaving the front and rear points 43 of the *::: skirt free. At theses pointed ends, a roof portion 47 is provided to seal the plenum chamber.

* Figure 5 is a plan view of the skirt 41 from which it can be seen that the skirt has two parallel sides 51 and 53 on opposite sides of the vehicle, these two sides **** : being connected together by the pointed ends 43 each comprising two elements and 57 having a n apex angle of 67 degrees. All of the elements 51 to 57 being connected together to form a continuous skirt. It will be appreciated that the pointed ends provide for an increased area for the action of the air cushion and also provide an aerodynamic construction reducing the drag caused by the skirt.

Figures 6 and 7 show details of the skirt, figure 6 being a cross section while figure 7 is a perspective view of a short length of the skirt. The skirt 41 is made from extruded polyurethane. Preferable values for this material are Hardness 90 Shore Density 1,250 kg/rn3 As can be seen, the skirt 41 has a UJfl shaped section having three reinforcing ribs 61, 63, and 65, two of these ribs 61 and 63 being in the upright portion 67 of the aJn while the other rib 65 is on the inside of the curved part 69 of the "J". One or more of the ribs can have a strengthening rod, one of which is shown at 71, preferably made of a suitable metal such as steel. The curved part 69 is suitably provided with an exterior ceramic layer (not shown) to protect this part of the skirt as it rubs on the ground or road surface.

A pair of steel wire ties 75 and 77 extend at an angle upwardly and inwardly from 63 and 65 respectively. The purpose of these ties is to counter the air pressure within the plenum chamber which would otherwise cause the skirt to blow outwards and at the same time, maintain the skirt in contact with the ground or road surface. These ties 75 and 77 are attached a their other ends to the frame * * work supporting the skirt, for example, to the cross beams 33 (Figure 2). The angle between the ties 75 and 77 and the upright portion 67 of the skirt 41 must * lie in the range of 50 to 70 degrees for the upper tie 75, more preferably in the range of 55 to 65 degrees, and in the range of 55 to 80 degrees for the lower tie ***e 77, more preferably in the range of 60 to 75 degrees. For optimum results it has been determined that the best angle for the upper tie 75 is 60 degrees and for the lower tie 77 is 68 degrees. The ties should be located at a spacing of no more than 1,000 mm but for maximum effect, this spacing should be reduced.

With these tie angles, a suitable positioning of the tie attachments is 0.18 down of the free depth of the skirt for the upper tie and 0.93 for the lower tie.

It is important for a full satisfactory operation of the skirt and thus of the invention that the angles of the ties remain in these ranges. This will insure that air leakage is kept to a minimum so as to provide the desired lift to the vehicle with a minimum use of power to generate the necessary pressure in the plenum chamber.

It will be appreciated that various modifications of or additions to the above described embodiments may be made without departing from the scope of the invention. For example, while it is considered that two ties provide optimum support for the skirt, if desired, three or more ties could be used. The materials for the ties and the strengthening elements in skirt ribs may be varied, for example, in suitable situations, plastics of suitable strength and characteristics could be used. While three strengthening ribs have been shown, more or less strengthening ribs could be used as seems suitable to a particular application.

In addition to the air supply provided by the fan, additional air can be provided using a ram air intake facing forwards above the cab unit as indicated schematically in figure 1 at 81 * ** ** S * IS It will further be noted that while the invention has been described in connection * * with a semi-trailer, it could also be applied to both full trailers and articulated or other lorries. S.. S... a I...

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Claims

CLAIMS:- 1. A ground effect transport system comprising a load carrying

platform, a skirt depending from the load carrying platform to form a plenum chamber and fan means for supplying air to the plenum chamber, wherein the skirt extends without a break around the plenum chamber.
2 A system as claimed in claim 1, wherein means are provided which hold the skirt in engagement with the ground against the force of the air in the plenum chamber.
3. A ground effect transport system comprising a load carrying platform, a skirt depending from the load carrying platform to form a plenum chamber and fan means for supplying air to the plenum chamber, wherein means are provided which hold the skirt in engagement with the ground against the force of the air in the plenum chamber.
4. A system as claimed in claim 1, 2 or 3, wherein the load carrying platform has wheels for contact with the ground and the wheels are located within the plenum chamber.
5. A system as claimed in any one of claims I to 4, wherein the skirt extends in a forward direction such that it narrows towards the front thereof. * . S...

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6. A system as claimed in any preceding claim, wherein the skirt extends in a rearward direction such that it narrows towards the back thereof. *.*
7. A system as claimed in any preceding claim, wherein the skirt is formed of S..

two parallel sections extending along the outsides of the vehicle, the two parallel sections being connected together at the front and rear by a pair of sections which extend at an angle to the parallel sections towards each other so that the meet at a point at the rear and at the front of the skirt.
8. A system as claimed in claim 7, wherein the angle at which the pair of sections meet is 67 degrees.
9. A system as claimed in any preceding claim wherein the skirt is made from polyurethane.
10. A system as claimed in ant preceding claim, wherein the skirt has a UJP shaped cross section with the shorter arm of the "J" facing inwards.
11. A system as claimed in claim 10, wherein the upright portion and the curved portion of thee "J" are provided with one or more strengthening ribs extending longitudinally of the skirt.
12. A system as claimed in claim 11, wherein one or more of the strengthening ribs has a longitudinally extending strengthening insert.
13. A system as claimed in claim 12, wherein the strengthen insert comprises awire, rod ortube.
14. A system as claimed in claim 13, wherein the wire, rod or tube is of steel. * I I...

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15. A system as claimed in any one of claims 10 to 14, wherein the skirt is * : provided with a pair of ties, one extending from a middle portion of the upright I..

* portion of the "J and the other extending from a middle portion of the curved portion of the "J", both ties extending inwardly from the skirt at predetermined I...

angles and attached to the structure of the vehicle. -10-
16. A system as claimed in claim 15, wherein the skirt has three longitudinafly extending strengthening ribs, two spaced apart on the upright portion of the "J" and one in the middle portion of the curved portion of the IIJfl with the ties being secured to the skirt at the location of the tower rib of the upright portion of the UJIP and the rib of the curved portion of the "J".
17. A system as claimed in claim 16, wherein the ties are secured to cross beams of the skirt supporting structure.
18. A system as claimed in claim 16 or 17, wherein the ties comprise steel wire.
19. A system as claimed in claim 16, 17 or 18, wherein the upper tie extends at an angle to the upright portion of the "J" in the range of to degrees and the lower tie extends at an angle to the upright portion of the UJfl in the range of to degrees
20. A system as claimed in claim 16, 17 or 18, wherein the upper tie extends at an angle to the upright portion of the UJfl in the range of to degrees and the lower tie extends at an angle to the upright portion of the UJ in the range of to degrees *:*::*
21. A system as claimed in claim 16, 17 or 18, wherein the upper tie extends at an angle to the upright portion of the "J" of degrees and the lower tie extends at an angle to the upright portion of the of degrees * **

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22. A ground effect transport system substantially as described herein with reference to the drawings.

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