AU2008100475A4 - Side curtain for truck and trailer bodies - Google Patents

Description

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TRANSTECH RESEARCH PTY LTD

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT "SIDE CURTAIN FOR TRUCK AND TRAILER BODIES" The following statement is a full description of this invention, including the best method of performing it known to us:- 26/05/2008, PRS101817.spc, 1 -2o00 SIDE CURTAIN FOR TRUCK AND TRAILER BODIES TECHNICAL FIELD The present invention relates to curtain sided rigid type trucks and semi-trailers and more particularly to side curtains for such truck and trailer bodies.

In BACKGROUND ART Conventional side curtains on truck and trailer bodies are retained oo Salong the top edge on a rail system extending along the roof of the body in a manner whereby the curtain may be slid between the ends of the body. At one or both ends of the body the curtain is wrapped around a vertical pipe and the pipe is rotatable by a ratchet mechanism to tension the curtain in a horizontal direction. Along the bottom edge the curtain is tensioned in a vertical direction by a large number of closely spaced straps and buckles with hooks that engage underneath the coaming rail of the body. In the case of a foot long trailer there is as many as 24 such straps. These straps and buckles require a significant amount of time to attach and tension, considerably increasing the time to load and unload a curtain sided truck or trailer.

More recently transport vehicle regulations have become more stringent in relation to side load restraints, and the conventional side curtains are no longer acceptable as such load restraints. In fact it is now necessary to provide more substantial load restraints on the inside of the curtains, and the curtains now serve primarily as visual and environmental protection of the load.

As a consequence of the above it is an object of the present invention to provide a side curtain for truck and trailer bodies which provides means for tensioning the curtain in a vertical direction whilst avoiding the need for the conventional large number of closely spaced buckles and straps.

260512008, PRS101817.spc, 2 -3o00 DISCLOSURE OF THE INVENTION The invention therefore provides a side curtain for truck or trailer bodies, said curtain having a bottom edge in the shape of a series of intersecting arcuate curves, where the points of intersection (apexes) of adjoining curves are at or near the lowermost points of the side curtain and provide attachment points for tensioning the curtain in a vertical direction, In wherein the geometric centre of each arc is substantially below said bottom Sedge, and wherein a skirt is attached to the inside of said curtain adjacent said bottom edge to cover any gap between the edge curves, and the floor of o Sthe truck or trailer, when the curtain is in a closed condition.

SAs will be evident hereinafter by having the geometric centre of the arcs substantially below the bottom edge creates shallow arcs enabling the curtain to be tensioned with only a few attachment points. This greatly reduces the time and effort required to open or close the curtain.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more readily understood a particular embodiment will now be described with reference to the accompanying drawings wherein: Figure 1 is a perspective side view of a trailer showing a prior art side curtain in a closed position; Figure 2 is a view similar to Figure 1 showing a trailer with a side curtain according to the invention, in a closed position; and Figure 3 is an enlarged drawing of one attachment point for the side curtain shown in the circle of Figure 2.

MODES FOR CARRYING OUT THE INVENTION Referring to Figure 1 a large trailer 10 is shown with a conventional side curtain 11 which is tensioned horizontally and vertically in a known manner. Whilst horizontal tensioning cannot be clearly seen in Figure 1 it comprises a vertical pipe at one or both ends of the curtain and a ratchet 26/05/2008, PRS101817.spc, 3 -4- 00

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Smechanism for rotating the pipe. The curtain 11 wraps around the pipe and obtains horizontal tensioning as the pipe is rotated.

Vertical tensioning of the curtain is provided by a large number of closely spaced curtain straps and buckles 12. The bottom of the straps hook underneath a coaming rail of the trailer and fastening of the buckles provides a downward force on the curtain to tension it in a vertical direction.

Referring now to Figure 2 a side curtain 16 according to the present Sinvention is shown on a similar trailer 10. The attachment along the top edge 13 and vertical ends is the same as the conventional side curtain shown in 00 Figure 1 and is of the conventional construction described hereinabove.

However, the bottom edge of the curtain is made with a series of intersecting concave arcs 14 which in this embodiment comprise five in number. The geometrical centre of each arc is substantially below the bottom edge of the curtain 16 which results in shallow arcs. The bottom edge of the curtain, in the vicinity of the apexes 15 of adjoining arcs 14, is adjacent a rope rail 17 of the trailer body. The rope rail 17 is supported below a coaming rail 24 in a conventional manner. The uppermost part of the arcs 14 is above the coaming rail 24 (Figure 3).

A skirt 18 is attached on the inside of the curtain along the bottom edge for covering a gap which would otherwise occur between the bottom edge of the curtain and the coaming rail 24 at points between the apexes of the arcs 14. The skirt 18 ensures protection of the load from the external environment.

A rope or cable 21 (Figure 3) is enclosed in a pocket 22 along the bottom edge of the curtain 16. The cable or rope is exposed at eyelets or apertures 19 in the curtain bottom edge located at each apex 15. The apertures 19 are reinforced by additional fabric 20 sewn or welded into the curtain as shown. Also, the rope or cable has an outer sleeve (not shown) at the exposed portions to assist in wear prevention. The cable terminates at points 23 where it connects to the trailer frame at the respective trailer ends.

Adjustment means (not shown) are provided to allow adjustment to compensate for stretching of the cable 21.

26/0512008, PRS101817.spc, 4 00

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0 Tensioning devices 25 are provided on the trailer body at the apexes of the curtain 16. A preferred form of tensioning device is disclosed in Applicant's Australian patent application number 2007902574 entitled I"Tensioning Device" and lodged on 15 May 2007. The device disclosed therein is mounted on the underside of the trailer floor and has a hook member 26 (Figure 3) that is able to be extended to project from the side of the trailer at a gap in the rope rail 17 so as to engage in an aperture 19.

Once engaged in an aperture 19 the hook member 26 is retracted, that is, Ocaused to move downwardly and slightly inwardly whereby it pulls on the 00 sleeved rope or cable 21 in the curtain bottom edge, and hence tensions the curtain in the vertical direction. The tensioning device is actuated by an actuating means (not shown) that is preferably power operated by electrical, hydraulic or pneumatic means. A tensioning device is located at each apex of the closed side curtain and the tensioning devices may be operated simultaneously by a common control or may be operated individually by a separate control on each tensioning device.

The tensioning devices may take various different forms. For example, a cable or strap (not shown) attached to each apex 15 may be wrapped over a pulley, roller or similar device that is affixed to the structure of the underside of the trailer. This cable or strap will then be tensioned by a vertical or horizontal force applied by a mechanical electrical hydraulic or air driven device underneath the trailer. The tensioning device may also be manually operated.

Horizontal tensioning of the curtain is performed in a conventional manner by winding on a vertical pole (not shown) at the forward and/or rear end of the curtain. When closing the curtain the horizontal tensioning is performed first and then the vertical tensioning follows.

The number of intersecting arcs along the bottom edge of the curtain 16 will depend upon the length of the trailer, the type of material of the curtain and other factors such as the amount of force applied by the tensioning device. It is important that sufficient tension is applied to the curtain in a vertical direction to main the curtain in position against the side of the trailer 26/05/2008, PRS101817.spc, -6oO 00 C body when the trailer is moving at high speed. In other words, there must be sufficient intersecting arcs and tensioning devices to ensure that the curtain does not flap outwardly away from the trailer body when the trailer is moving at high speed.

Whilst the preferred form of the invention has concave arcs along the bottom edge other curves or shapes could be utilized. It will be readily apparent however that the optimum result is achieved with uniform concave Oarcs insofar as applying a uniform vertical tension to the curtain.

In an alternative arrangement (not shown) a sliding cable may be 00 arranged entirely along the bottom edge of the curtain 16 so as to loop over brackets on the trailer body at the apexes 15 whereby tensioning of the cable in a horizontal direction at one or both ends of the trailer will provide the necessary vertical tension to the curtain 16. Other arrangements for tensioning the curtain may be readily appreciated by those skilled in the art.

The benefits of the novel side curtain according to this invention will be readily apparent to those skilled in the art. For example, the curtain will be faster to open and close because of the vastly reduced number of tensioning points along the bottom edge of the curtain. In the described embodiment a foot trailer has only four tensioning points as opposed to 24 with the prior art. This will reduce the time and cost of loading and unloading.

Furthermore, the curtain is likely to be less complex to operate and it lends itself to automation of the tensioning devices at the apexes of the arcs or at the body corner posts. This results in a reduced occupational health and safety issue associated with opening and tensioning curtains manually.

26/05/2008, PRS101817.spc, 6

Claims (4)

1. A side curtain for truck or trailer bodies, said curtain having a bottom edge in the shape of a series of intersecting arcuate curves, where the points of intersection (apexes) of adjoining curves are at or near the lowermost points of the side curtain and provide attachment points for O tensioning the curtain in a vertical direction, wherein the geometric centre of each arc is substantially below said bottom edge, and wherein a skirt is 00 Sattached to the inside of said curtain adjacent said bottom edge to cover any gap between the edge curves, and the floor of the truck or trailer, when the curtain is in a closed condition.

2. A side curtain as defined in claim 1, wherein said attachment points are arranged substantially at the level of a rope rail below a coaming rail of the body and each said attachment points comprise an aperture in the curtain edge at each apex, and a rope or cable is slidably enclosed in said curtain along said bottom edge and exposed at each aperture, whereby tensioning means at each apex is able to apply a downward force on said rope or cable and hence provide said tensioning in a vertical direction.

3. A side curtain as defined in claim 2, wherein said rope or cable terminates at the extreme ends of the respective end curves and is adapted for connection to said truck or trailer body.

4. A side curtain as defined in claim 3, wherein said side curtain is reinforced around each said aperture and said rope or cable has adjustment means to compensate for stretching of the rope or cable. A side curtain as defined in claim 4, wherein said tensioning means comprises a power actuated hook at each apex adapted to move outwardly to pass through said aperture and engage said rope or cable and 26/05/2008, PRS101817.spc, 7 -8- 00 O Sthen move downwardly and inwardly so as to tension said curtain in a vertical direction. INO N DATED this 26 t h day of May, 2008 t TRANSTECH RESEARCH PTY LTD O By Their Patent Attorneys EKM patent 00 OO> 0 ON M 26/05/2008, PRS101817.spc, 8