GB2079684A - Bodies for curtain sided goods vehicle - Google Patents

Abstract

Front end billowing of the curtain 24 of a curtain-sided goods vehicle is reduced by forming the front-wall 32 with radiused lateral edges 36 to give a smooth rearward airflow at the leading edge of the curtain. <IMAGE>

Description

SPECIFICATION Bodies for curtain sided goods vehicle The present invention relates to a curtain-sided goods vehicle which may comprise a body on a rigid truck chassis or a semi-trailer or trailer goods vehicle.

Curtain sided vehicles for use on roads are becoming increasingly popular because the load is protected from the weather like a van but the curtain can be drawn aside to allow the vehicle to be on and off loaded from the side by means of fork lift trucks.

But these vehicles suffer from a long-standing problem because as the vehicle goes along the road the curtains are prone to billow which is both undesirable in itself and also obstructs the driver's rear vision through side mirrors. A remedy for the problem has been proposed by Boalloy Limited in U.K. Patent Specification Nos 1262879 and 1262880 by the provision of horizontal and vertical tensioning means for the curtain and virtually all curtain sided vehicles on the road have provision for curtain tensioning.

It has recently been proposed by York Trailer Holdings Limited in U.K. Patent Specification No.

1560381 that a van-type body can be given reduced air resistance and therefore lower fuel consumption by forming its front wall along the top edge and top side edges with a generally curved surface which is rounded to a radius of at least 6 inches. We believe, however, that the advantages in fuel economy obtainable by the use of this front wall structure are of marginal significance compared to a conventional van such as is sold by this company and which has an angular top front rail and radiused corner posts.

We have observed however, as a result of experimental trials that by fitting to the front wall of a curtain sided goods vehicle a fairing having radiused side edges and also preferably a radiused top edge, a smooth rearward flow of air can be produced at the leading portion of the curtain sides and the tendency to curtain billowing is significantly reduced. Without the fairing, our tests shown that there is a zone of air turbulence immediately behind the front wall which we believe is responsible in large measure for the observed curtain billowing.

Accordingly the invention provides a goods vehicle having a load platform bounded by lower side rails, a roof supported above the load platform and bounded by upper side rails, at least one side closed by means of a slidable curtain suspended at its upper end on a track located in or adjacent an upper side rail, and secured to the lower side rail at its lower end by a plurality of longitudinally spaced tensionable fastening members, a front wall extending between the roof and the load platform and forwardly of the leading edge of the curtain having upper portions of the side edges rearwardly bevelled or curved so as to produce a smooth rearward air flow at the leading edge of the curtain and thereby reduce billowing thereof. The top edge may be similarly bevelled or curved.

The side edges and preferably also the top edge of the front wall may be rearwardly curved with a radius of curvature of 10-100 cms, preferably about 30 cms. The front wall may comprise a generally planar bulkhead and a separately fabricated fairing secured to the front face of the bulkhead and having regions defining curved top and side edges of the front wall. The bottom edge of the fairing may be curved with the same radius of curvature as the top and side edges.

The goods vehicle may be a semi-trailer body to be drawn by a tractor vehicle having a lower roof than the semi-trailer body, the fairing being fastened over portion of the bulkhead above the roof of the tractor so as substantially fill the vertical space between the tractor roof level and the semi-trailer roof level. The distance downwards over which the side walls of the fairing need to be radiused as aforesaid will of course depend upon the cab height of the intended tractor vehicle and on whether the vehicle has a rigid body, is articulated or is a drawbar trailer (in which latter case the trailer body may be radiused down to floor level).

An embodiment of the invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure lisa rear perspective view of a curtain sided semi-trailer road vehicle according to the invention; Figure 2 is a front perspective view showing the front bulkhead of the vehicle; and Figure 3 is a view of the leading edge of the curtain while the vehicle is in motion.

In Figure 1, an articulated curtain sided vehicle comprises a tractor unit 10 having a cab roof 12 and a semi-trailer 14 pivotally connected thereto in conventional manner. The trailer 14 includes a chassis 16 supporting a load platform 18 bounded by lower side rails 19. There is provided above the load platform a roof 20 supported on central pillars and bonded by upper side raills 22 which are formed with internal curtain tracks. Curtains 24 are supported at their top edges on longitudinally spaced runners which fit the curtain tracks and at their lower edges are fastened along the lower side rail 19 when curtain is pulled closed by means of tensioning straps 26 which locate in anchorage points on the body and conventional means (not shown) is provided for longitudinal curtain tensioning.The front of the trailer body is closed off by means of a bulkhead 28 extending from roof to load platform and the rear of the body is closed off by means of a frame structure fitted with rear doors 30.

A front fairing 32 fitted to the frontwall bulkhead 28 extends vertically from the top edge of the bulkhead to a vertical position approximately level with the roof 12 of the tractor vehicle, although exact registration will often not be obtained because the trailer body may be drawn by different makes of tractor having different roof heights. The top edge 34 and lateral edges 36,37 of the fairing are rearwardly curved with a radius of about 30 cms as also is the lower edge 38.

Figure 3 is taken from a photograph of the sidewall of a prototype vehicle travelling around a test track.

Telltales 40 are all aligned approximately horizontal indicating a smooth rearward air flow. If the fairing 34 is removed, the telltales fly in all directions, indicating the pressure of a zone of turbulence and curtain billowing becomes more pronounced.

Claims (8)

1. A goods vehicle having a load platform bounded by lower side rails, a roof supported above the load platform and bounded by upper side rails, at least one side closed by means of a slideable curtain suspended at its upper end on a track located in or adjacent an upper side rail, and secured to the lower side rail at its lower end by a plurality of longitudinally spaced tensionable fastening members, a front wall extending between the roof and the load platform and forwardly of the leading edge of the curtain having upper portions of the side edges rearwardly bevelled or curved so as to produce a smooth rearward air flow at the leading edge of the curtain and thereby reduced billowing thereof.

2. A vehicle according to Claim 1, wherein the top edge of the front wall is also rearwardly curved.

3. A vehicle according to Claim 2, wherein the top and side edges of the front wall are rearwardly curved with a radius of curvature of from 10-100 cms.

4. A vehicle according to Claim 3, wherein the radius of curvature is about 30 cms.

5. Avehicle according to any of Claims 1 to 4, wherein the front wall comprises a generally planar bulkhead and a separately fabricated fairing secured to the front face of the bulkhead and having regions defining curved top and side edges of the front wall.

6. A vehicle according to Claim 5, wherein the bottom edge of the fairing is curved with the same radius of curvature as the top and side edges thereof.

7. A goods vehicle according to Claim 5 or 6, in which a tracorvehicle has a lower roof than that of the body or the semi-trailer drawn by it, the fairing being fastened over a portion of the bulkhead above the roof of the tractor so as substantially fill the vertical space between the tractor roof level and the semi-trailer roof level.

8. A curtain sided goods vehicle having a front wall substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.