TRANSTECH RESEARCH PTY LTD AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION INNOVATION PATENT "FLEXIBLE LOAD RESTRAINT" The following statement is a full description of this invention, including the best method of performing it known to us:- -2 FLEXIBLE LOAD RESTRAINT The present invention relates to load restraints and more particularly to a load restraint for curtain sided truck and trailer bodies. 5 Until recently side curtains for transport vehicles such as trucks and large trailers have not provided any significant restraint against side load movement. In other words the side curtains only provide protection from the external elements and although they may provide some lateral restraint for lighter loads they do not meet the Load Restraint Regulations now in force in Australia for 10 heavier loads. Therefore in the past it has been necessary to provide load restraints on the inside of the curtain in the form of gates or frames extending from support posts supporting the roof, or from the floor of the truck or trailer body. The gates or frames provide the primary restraint and are rated according to load 15 type, trailer design and intended use. The gates are manufactured primarily from steel or aluminium and are heavy and cumbersome and can cause Occupational Health & Safety Issues as well as a cost burden "accepted" as part of the overall transportation costs in using curtain sided trailers. The gates also add about 300kg in weight when 20 installed on a 45 foot trailer thus reducing the maximum pay-load. Manufacturers and operators have been constantly devising ways to lighten, alter or eliminate gates in curtain sided trailers. More recently Applicants have invented a side curtain having inherent load restraint characteristics (see Australian Patent Application 2008900452 for 25 example) which thus obviates the need for restraints inside the curtain. However there is still a need for additional restraints on the inside of the curtain in many situations. For example many operators have fleets of vehicles with existing non-load bearing side curtains. Other operators when purchasing a new truck or trailer body may opt for a non-load bearing curtain which is lighter 30 more flexible and thus easier to open and close because it suits the majority of their operations but they may require additional restraints on the inside of the curtain for a minority of operations with heavier loads. 24/02/2009, PRS102293.spc.doc, 2 -3 Accordingly it is an object of this invention to provide a load restraint for truck and trailer bodies which obviates the need for traditional heavy gates or frames or at least provides a useful alternative. The invention provides a load restraint comprising a series of spaced 5 horizontal and vertical interconnected straps forming a mesh wherein some of the vertical straps are attachment straps formed of flexible non-extensible material and the remainder on the vertical straps and the horizontal straps are a flexible webbing material, said attachment straps extending beyond said mesh at the top and being pivotally connected to individual roller assemblies for 10 running on a top rail and extending beyond said mesh at the bottom and having means for connecting to a bottom rail via a tensioning device for applying vertical tension to said attachment straps. In order that the invention may be more readily understood one particular embodiment will now be described in detail with reference to the accompanying 15 drawings wherein: FIG. 1 is a side elevation of part of a truck or trailer body shown in broken lines with a load restraint according to the invention mounted thereon; FIG. 2 is a sectional view of the restraint of FIG. 1; and 20 FIG. 3 is an enlarged sectional view of the restraint showing roof and coaming connection in greater detail. The load restraint 10 consists essentially of an open mesh formed from a series of vertical and horizontal webbing straps 11 and vertical attachment straps 12 as shown in FIG. 1. The attachment straps 12 alternate with vertical 25 webbing straps 11 and are pultruded fibreglass straps which extend vertically above and below the webbing straps 11. The horizontal and vertical webbing straps 11 are joined together at each intersection 13 by means of suitable stitching and the webbing straps are attached to the pultruded attachment straps 12 at each intersection by means of 30 rivets or bolts. The top of each attachment strap 12 is connected to a top roller assembly 14 by a pivotal connection. The top roller assembly runs on the 24102/2009, PRS102293.spc.doc, 3 -4 inside of a roof track 15 which extends along the side of a truck or trailer body. The roof track 15 also supports a sliding side curtain (not shown) which runs on the outside of the roof track 15. As is evident the roller assembly 14 comprises a pair of wheels 16 which run in an upwardly facing groove of the roof track 15 5 and a lower wheel 17 which runs on the under side of the roof track 15. The bottom end of each attachment strap 12 is connected to a curtain buckle 18 by suitable bolts or rivets (not shown). The curtain buckle 18 is a conventional over-centre buckle which is connected to a bottom strap 19 containing a rave hook 20 for connection to a bottom rail of the truck or trailer io body. The curtain buckle 18 provides tension to the attachment strap when it is in a closed position. The rave hook 20 may be attached to the under side of a coaming rail 21 or another suitable attachment point. The length of the load restraint 10 is generally such that it extends between spaced roof support posts (not shown) of a truck or trailer body and in 15 the case of large trailer bodies there may be three or more separate load restraints 10 along the side of the body. The spacing between vertical straps and horizontal straps is nominally 610mm respectively. The webbing straps 11 are nominally 40mm in width. As will be evident once all the attachment straps 12 are connected under 20 tension to the coaming rail 21 the load restraint provides a barrier against side way or lateral movement of a load. In other words the load restraint of this invention effectively provides a flexible gate which replaces the heavy steel or aluminium gates of the prior art. The load restraint meets the Load Restraint Regulations now in force in Australia and overcomes all the aforementioned 25 problems associated with steel or aluminium gates. It should be evident that the load restraint of this invention is effectively a flexible gate that is easily detached from the coaming rail by releasing the buckles 18 and the respective rave hooks. The restraint can then be slid to one side of the opening between roof support posts to thereby provide access to the 30 load. There is no lifting of heavy gates and therefore any issues of Occupational Health and Safety are obviated. To reattach the restraint the rave hook at one end is attached and the restraint -is pulled along the side of the body until the 24/02/2009, PRS102293.spc.doc, 4 -5 attachment straps 12 are evenly spaced and each rave hook is then reattached and the straps 12 tensioned by the respective buckles 18. Whilst particular materials and a particular construction has been described hereinabove it will be evident to those skilled in the art that variations 5 may be readily affected without departing from the scope of the invention. For example the pultruded fibreglass attachment straps 12 may be replaced by straps formed from thin steel or other suitable material. Also whilst polyester webbing has been used for the straps 11 other suitable material may produce similar results. Also the size and spacing of the straps may be varied according 1o to load restraint requirements. 24/02/2009, PRS102293.spc.doc, 5