P/00/011 Regulation 3.2 AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: Improvements to flat bed trailers The following statement is a full description of this invention, including the best method of performing it known to me: 3777635 2 IMPROVEMENTS TO FLAT BED TRAILERS This invention relates to flat bed trailers for transporting heavy machinery, and to kits of parts for retrofitting to same. 5 It is well known to transport items of heavy machinery, such as mechanical diggers and forklift devices, to a site of use using a flat bed trailer. Traditionally, the item of heavy machinery is positioned on the trailer and straps are used to secure it in place. Unfortunately, it is becoming increasingly apparent that the use of straps is less than desirable, since the item of heavy 10 machinery is often not secured in place very effectively. Indeed, the present inventors are aware that at least one fatality caused by an item of heavy machinery that fell from a flat bed trailer during transportation. The Applicant's International patent publication W02007/129054 (the entire contents of which are herein incorporated by reference) discloses flat bed 15 trailers having a convenient system for securely restraining an item of heavy machinery during transportation. The present invention concerns certain improvements to the general system disclosed in W02007/129054. According to an aspect of the invention there is provided a flat bed trailer for transporting heavy machinery including: a floor; a plurality of wheels suitable 20 for travel over roads; coupling means for coupling the trailer to a towing vehicle; one or more restraining bars disposable substantially laterally across the trailer to restrain an item of heavy machinery when positioned in the trailer; and at least one bar retaining means for releasably retaining a restraining bar in its restraining position; 3 in which at least one restraining bar is formed from metal cylindrical tubing. According to another aspect of the invention, there is provided a flat bed trailer for transporting heavy machinery including: a floor; a plurality of wheels 5 suitable for travel over roads; coupling means for coupling the trailer to a towing vehicle; and a heavy machinery restraining arrangement to restrain an item of heavy machinery when positioned in the trailer; the heavy machinery restraining arrangement including a bucket restraining portion for use in transporting an item of heavy machinery having a bucket, the bucket restraining portion acting, 10 in use, to restrain the bucket; in which the bucket restraining portion is formed from metal cylindrical tubing. The metal cylindrical tubing used in the present invention can be conveniently formed into the desired shapes by bending processes. In contract, 15 prior art systems utilise square tubing which cannot be bent for potential applications, and instead require expensive and time consuming art and weld producing techniques. Also, the tubing used in the present invention does not contain sharp edges. Typically, the cylindrical tubing is of circular cross sections. However, 20 cylindrical tubing having other curved cross sections, such as elliptical cross sections, might be utilised. Preferably, the heavy machinery restraining arrangement includes one or more restraining bars of the type disclosed herein. It is understood that flat bed trailers do not have high sided walls, 4 although the flat bed trailers of the invention have side walls, which are low walls, typically extending less than one metre and commonly less than 50 cm above the level of the trailer floor. Also, it is understood that the term "bucket" relates to the scoop of a 5 mechanical digger which is used for excavating purposes. The item of heavy machinery may be a plant hire item, such as a mechanical digger or forklift device. The item of heavy machinery might utilise caterpillar trackers, or might be a wheeled vehicle. Typically, the flat bed trailer includes two or more restraining bars. 10 Preferably, the bar retaining means releasably retain all of the restraining bars in their restraining positions. However, it may be possible to employ a bar of permanently fixed position as one of the restraining bars. Preferably, the flat bed trailer has a pair of spaced apart restraining bars. Most preferably the pair of restraining bars are spaced by at least 750mm. 15 One or more of the restraining bars may be fully detachable from the trailer. In preferred embodiments, all of the restraining bars are fully detachable from the trailer. One or more of the restraining bars may be permanently fixed to the trailer whilst being releasable from its restraining position. For example, a bar 20 may be swingable, pivotable or otherwise moveable with respect to a permanent fixture so that the bar can be brought into or out of its restraining position. The flat bed trailer may include one or more restraining bars which are fully detachable from the trailer and one or more restraining bars which are permanently fixed to the trailer whilst being releasable from its restraining 5 position. In a preferred embodiment of this kind the flat bed trailer includes one restraining bar which is fully detachable from the trailer and one restraining bar which is permanently fixed to the trailer whilst being releasable from its restraining position. 5 Advantageously, the bar retaining means include a plurality of bar receiving elements, such as collars and jaws. The flat bed trailer includes a pair of longitudinally extending side walls, and at least some of the bar retaining means may be disposed on the side walls. The trailer may further include at least a pair of brackets, each located on a side 10 wall, and at least some of the bar retaining means may be disposed on the brackets. In a preferred embodiment, each bracket is located on top of a side wall, and at least some of the bar retaining means are disposed on top of the brackets. Preferably, the brackets are releasably coupled to the side walls, most preferably by bolts. 15 Advantageously, the flat bed trailer further includes at least one of; i) a plurality of tracks disposed substantially longitudinally on the floor of the trailer for restraining the item of machinery when disposed in the trailer, the tracks being formed from metal cylindrical tubing; and ii) one or more upstanding projections which upstand from the floor of 20 the trailer to restrain the item of heavy machinery, the upstanding projections being formed from metal cylindrical tubing. The tracks provide restraint against sideways motion of the item of heavy machinery and aid in locating the item in the trailer. The upstanding projections provide restraint against forward motion of the item of heavy machinery.
6 According to yet another aspect of the present invention, there is provided a kit of parts for retrofitting to a flat bed trailer including: one or more restraining bars formed from metal cylindrical tubing; and at least one bar retaining means for releasably retaining a restraining bar, the bar retaining means being 5 coupleable to the flat bed trailer so that, when the kit is retrofitted, the restraining bar is disposed substantially laterally across the trailer. The kit of parts may further include a bucket restraining portion for use in transporting an item of heavy machinery having a bucket, the bucket restraining portion acting, in use, to restrain the bucket; in which the bucket restraining 10 portion is formed from metal cylindrical tubing. Whilst the invention has been described above, it extends to any inventive combination or sub-combination of the features set out above or in the following description or drawings or claims. Flat bed trailers and kits of parts in accordance with the invention will now 15 be described with reference to the accompanying drawings, in which; Figure 1 is a perspective view of a first embodiment of a flat bed trailer of the invention; Figure 2 is a side view of the first embodiment of flat bed trailer; Figure 3 is a side perspective view of the first embodiment of the flat bed 20 trailer with a mechanical digger positioned thereon; Figure 4 is a perspective view of a restraining bar of the first embodiment; Figure 5 is a side view of a second embodiment of a flat bed trailer of the invention; Figure 6 is a perspective view of a restraining bar of the second 7 embodiment; and Figure 7 is a perspective view of a structure for retaining the bucket of a mechanical digger. Figures 1 to 3 show a first embodiment of a flat bed trailer 10 of the 5 invention. Figure 3 shows the flat bed trailer 10 with a mechanical digger 12 positioned thereon. The main body of the flat bed trailer 10 is of conventional design, having road-engaging wheels 14, and low, parallel side walls 16, 18. The flat bed trailer 10 further comprises a releaseable back wall 20, permitting positioning of the mechanical digger 12 in the trailer 10, and a front coupling 10 section 22 enabling the flat bed trailer 10 to be coupled to a suitable transportation device such as a van or lorry. In addition to these standard features, the flat bed trailer 10 includes further components which are used to restrain the mechanical digger 12 during transportation. These additional components can be conveniently retrofitted to a flat bed trailer of conventional 15 design. The additional components include a pair of spaced apart restraining bars 24, 26 which extend sideways across the flat bed trailer 10 thereby acting to retain the mechanical digger 12 in place by way of restraining the caterpillar tread and cabin of the mechanical digger. Each restraining bar 24, 26 is releaseably mounted at either end thereof in spaced apart collars 28 and are 20 securely in place with pins. Each collar 28 is mounted on a bracket 30 which is secured to a side wall 16, 18 of the flat bed trailer 10. The constructional principles relating to the collars and brackets are similar to those described in the Applicant's earlier PCT publication W02007/129054. Figure 4 shows a restraining bar 40 of the first embodiment. As can be seen most clearly in 8 Figure 4 and Figure 2, the restraining bar is formed from cylindrical tubing, and consists of horizontal end sections 40a, a horizontal main section 40b, and intermediate sections 40c each of which extends between the main section 40b, and an end section 40a. In use, the main section 40b abuts or nearly abuts 5 against the mechanical digger 12. The end sections 40a are received in the collars 28. In the first embodiment, the intermediate sections 40c extend at an angle of approximately 450 to the end sections 40a and main section 40b. The frame 32 is coupled to the front of the flat bed trailer 10 using bolts. The frame 32 can be conveniently coupled to the front wall of the flat bed trailer 10 10 and also to a front plate 34. The main body of the frame 32 is formed from metal cylindrical tubing, and comprises two substantially vertical frame members each having a horizontal frame member projecting from the upper end thereof. The horizontal frame members are linked by a front portion formed from cylindrical tubing which, as shown, can be in the form of a lip structure allowing 15 installation and removal of the bucket of the mechanical digger 12 in the frame 32. The frame member 32 is shown in more detail in Figure 7. As best seen in Figure 1, the components for securing the mechanical digger 12 further includes a pair of tracks 36, 38 which are disposed substantially longitudinally on the floor of the flat bed trailer 10. The tracks 36, 20 38 provide restraint against sideways motion of the item of heavy machinery during transportation, and have an additional advantage in aiding location of the item of heavy machinery in the trailer. The above mentioned components further comprise end stops 42, 44, which are also best shown in Figure 1. Each end stop 42, 44 comprises a ground engaging portion which is secured to the 9 floor or the flat bed trailer by bolts, and an upstanding projection portion in connection with the ground engaging portion. As shown in Figure 1, the upstanding projection portion can be substantially in the shape of an inverted U. One end of the inverted U is in connection with a straight section which is 5 positioned substantially longitudinally in respect to the flat bed trailer 12. The tracks 36, 38, upstanding projection portion and straight portion of the end stops 42, 44 are all formed from cylindrical tubing. Figure 5 shows a second embodiment of a flat bed trailer of the invention which shares many of the features of the first embodiment. Identical numerals 10 are used to denote such features which are shared between the first and second embodiments. The principal difference associated with the second embodiment is that it includes a pair of restraining bars 52, 54 wherein the intermediate portions are substantially vertical so that the restraining bars 52, 54 upstand from the collars 28 to a greater degree than the restraining bars 24, 26 of the 15 first embodiment. Figure 6 shows a restraining bar 52 in more detail. The first and second embodiments can be used in connection with items of heavy machinery such as mechanical diggers of differing sizes and weights. The use of cylindrical metal tubing to form the portions of the flat bed trailer which act to restrain the item of heavy machinery is highly advantageous. 20 Prior art systems utilised square tubing which could not be bent, and required expensive and time consuming cut and weld production techniques. In contrast, the equivalent components of the present invention can be conveniently formed by bending processes. Furthermore, the restraining portions of these components do not contain any sharp edges, which are advantageous in respect 10 of minimising damage to the heavy machinery, the components themselves, and any users thereof. Additionally, the cylindrical tubing of the present invention provides a pleasing aesthetic appearance. It is highly convenient that flat bed trailers of the present invention can be 5 produced by way of retrofitting a kit of parts to a conventional flat bed trailer. The kit of parts used for this purpose also comprises part of the present invention. For the purposes of this invention, a kit of parts can be considered to consist of a plurality of any of the restraining components described herein, or any single component. The skilled reader will appreciate that many variations 10 and modifications of the designs and principles described herein are possible. For example, the restraining bars and the bucket restraining frame can be provided in a number of different designs using cylindrical tubing. As one possibility only, the bucket restraining frame might have a lower section which provides a floor for the bucket retaining receptacle defined by the frame.