P/00/012 Regulation 3.2 AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Invention Title: "AN EDGE PROTECTION SYSTEM AND METHOD OF ASSEMBLING AN EDGE PROTECTION SYSTEM " The following statement is a full description of this invention, including the best method of performing it known to me/us: 1 TITLE An Edge Protection System and Method of Assembling an Edge Protection System FIELD OF THE INVENTION 5 This invention relates to an edge protection system and a method of assembling an edge protection system and more particularly an edge protection system for roofs. BACKGROUND OF THE INVENTION Construction sites contain many hazards and one such hazard is 10 working at heights, especially on rooftops with unprotected edges. When working on such rooftops an edge protection system is installed to reduce the possibility of a worker falling from the rooftop. A prior art edge protection system comprises a support bar clamped to and more commonly clamped to an underside of one or more purlins 15 extending inside a building. The support bar extends towards an edge of the building such that when a barrier is secured to the support bar, the barrier provides some protection to workers working on the roof of the building. The barrier includes posts mounted to the support bar, with a top rail a mid rail and a bottom rail extending therebetween. Once the edge protection system 20 has been installed, workers may safely work on the roof. A disadvantage of the prior art edge protection system is that it prevents wall sheets from being installed concurrently as the support bars impede their installation. As a result, the roof must be completed first, then the edge protection system can be removed to allow the installation of the 2 wall sheets which were impeded by the support bars. In some cases, the edge protection system needs to be re-installed onto the new roof upon its removal from the underside in order that further work on the roof can take place. 5 A further disadvantage of the prior art edge protection system described, is that in some cases a two-step process is required to dismantle it. Firstly, the rails are removed followed by the posts leaving the support bars in place. The second step is to remove the support bars which can only be removed from inside of the building. 10 OBJECT OF THE INVENTION It is an object of the invention to overcome or alleviate one or more of the above disadvantages and/or to provide the consumer with a useful or commercial choice. SUMMARY OF THE INVENTION 15 In one form, although it need not be the only or indeed the broadest form, the invention resides in an edge protection system for a roof of a building including: a purlin; and a support bar, adapted to extend through an aperture formed in the 20 purlin. Preferably, the support bar includes a fastener to secure the support bar to the purlin. Preferably, the fastener includes a hook pivotally connected to the support bar, adapted to engage in an aperture formed in an outermost purlin 3 of the building. Alternatively, the fastener includes a flange coaxially connected to the support bar that, in use, is secured to an outside of the outermost purlin. In a further embodiment, the fastener includes a groove located towards an end of the support bar and in use, the groove frictionally 5 engages with an inside surface of an aperture formed in a purlin. Preferably, the support bar includes a circular sectioned tube coaxially mounted to a square sectioned tube. Ideally, the fastener is secured to the square sectioned tube. Optionally, an extension bar coaxially connects to the circular 10 sectioned tube. In another form, the invention resides in a method of assembling an edge protection system for a roof including the step of: passing a support bar through an aperture formed in at least one purlin. 15 Optionally, the method includes the step of securing the support bar to an outermost purlin of the at least one purlin. BRIEF DESCRIPTION OF THE DRAWINGS An embodiment of the invention, by way of example only, will be described with reference to the accompanying drawings in which: 20 Fig 1 is a perspective view of the support bar of Fig 1 according to a first embodiment of the present invention; Fig 2 is a close up perspective view of the support bar of Fig 1; Fig 3 is a perspective view of the support bar of Fig 1 installed as part of an edge protection system; 4 Fig 4 is a perspective view of a support bar according to a second embodiment of the present invention; Fig 5 is a perspective view of the support bar of Fig 4 installed as part of an edge protection system; 5 Figs 6A-D are perspective and plan views of a support bar according to a third embodiment of the present invention; Fig 7 is a perspective view of the support bar of Fig 6 installed as part of an edge protection system; and Fig 8 is a partial perspective view of a building when the edge protection 10 system has been removed from the building. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT In this specification, adjectives such as first and second, left and right, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual 15 such relationship or order. Words such as "comprises" or "includes" are intended to define a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a process, method, article, or 20 apparatus. Fig 1 shows a support bar 10 for use in an edge protection system for a roof in accordance with a first embodiment of the present invention. The support bar 10 is used to support posts and rails of the edge protection system to reduce the possibility of workers falling from the roof.
5 The support bar 10 includes a circular sectioned tube 11, coaxially mounted inside a square sectioned tube 12, a fastener 20 located towards an end of the support bar 10, and an extension bar 30. Each tube is made from metal or any other suitable material. The circular sectioned tube 11 may 5 be screwed or welded to the square sectioned tube 12 or secured using any other applicable mechanism. The square sectioned tube 12 is significantly shorter than the circular sectioned tube but long enough such that a bracket supporting posts may be coaxially connected to it without impeding access to the fastener 20. It should be noted that the support bar 10 may alternatively 10 be a single continuous length of tube with any suitable cross-section. Optionally, the extension bar 30 is telescopically mounted inside the circular sectioned tube 11. The extension bar 30 may be made from a solid metal bar or a tube and is of an appropriate cross-section. The extension bar 30 is secured to the circular sectioned tube 11 and square sectioned tube 12 15 using bolt 27. Bolt 27 is threadably connected through a side of the square sectioned tube 12 and the circular sectioned tube 11. Fig 2 shows a close up perspective view of the support bar of Fig 1. The fastener 20 is located towards an end of the support bar 10, adjacent a junction of the circular sectioned tube 11 and the square sectioned tube 12. 20 The fastener 20 includes a hook 21, rotatably connected to a pair of flanges 23, 24 with a pin 25. The flanges 23, 24 are welded, or using any other applicable joining method such as braising or gluing the flanges 23, 24, to opposite longitudinal edges of the square sectioned tube 22. The flanges 23, 24 extend away from the square sectioned tube 12 so that the flanges 23, 24 6 are parallel to one another. The flanges 23, 24 are positioned so that an engaging end 21a of the hook 21 extends past an end of the square sectioned tube 12. Additionally, a locking bolt 26 threadably connects to a flange 28. Flange 28 is welded transversely to the square sectioned tube 12 5 adjacent a proximal end 21b of the hook 21. When the locking bolt 26 presses against the proximal end 21b of the hook 31, the engaging end 21a of the hook 21 rotates around the pin 25 in a same direction to the proximal end 21b. Fig 3 shows a perspective view of an edge protection system 40 10 including the support bar 10 of Figs 1 and 2. The edge protection system 40 further includes brackets 41, posts 42, a lower rail 43 and an upper rail 44. Purlins 45, 46 are standard purlins used to support a roof with the exception that apertures 47, 48 have been drilled or punched into a vertical side of the purlins 45, 46 during manufacture. The diameter of the aperture 47 is of 15 sufficient diameter to allow the circular sectioned tube 11 and the engaging end 21a of the hook 21 to pass through the aperture 47. The diameter of the aperture 48 is a suitable diameter that complements the circular sectioned tube 11. In use, an end of the circular sectioned tube 11 is passed through the 20 aperture 47 in an outermost purlin 45 and through the aperture 48 formed in an inner purlin 46 until the engaging end 21a of the hook 21 protrudes through the aperture 47 in the outermost purlin 45. This is also the point where the square sectioned tube 12 abuts the vertical side of the outermost purlin 45. To secure the support bar 10 into position, the locking bolt 26 is 7 threaded towards the proximal end 21 b of the hook 21 until the engaging end 21b locates on an inside edge of the aperture 47. If the support bars 10 have been installed, brackets 41 coaxially connect to the ends of the square sectioned tube 12. The bracket 41 may 5 then be secured to the support bar 10 using bolt 41a and the posts 42 coaxially connect to the brackets 41. Finally, the lower rail 43 and upper rail 44 are mounted to the posts 42 as is known in the art. To dismantle the edge protection system 40, the upper rail 44 and the lower rail 43 are removed from the posts 42. Once the brackets 41 have 10 been removed, the locking bolt 26 is loosened and the engaging end 21a of the hook 21 lowers and the support bar 10 can then be removed from apertures 47, 48 from an outside of the building without having to perform any removal steps inside the building. Fig 4 shows a support bar 50 according to a further embodiment of 15 the invention. The support bar 50 includes a single square sectioned tube 51 and a fastener 60. The fastener 60 includes a flange 61, coaxially connected towards an end of the square sectioned tube 51. The position of the flange 61 is sufficient to allow a bracket of an edge protection system to coaxially connect to the support bar 50. The fastener 60 also includes a series of 20 holes 62 drilled into the flange 61 to secure the support bar 50 to a purlin. In an alternative embodiment of the support bar 50 of fig 4, the square sectioned tube 51 is divided into two parts. The first part is significantly longer and has a smaller cross section that the second part. This allows the first part to be telescopically mounted to the entire length of the inside of the 8 second part. The flange in this embodiment is coaxially connected to an end of the second part such that when first part is telescopically mounted to the second part the flange is positioned away from an end of the first part. The second part is secured to the first part with a bolt threadably connected to 5 the second part thus clamping to the first part. Fig 5 is a perspective view of the support bar 50 of Fig 4 installed as part of an edge protection system 40. Similarly to the first embodiment, the edge protection system 40 includes brackets 41, posts 42, a lower rail 43 and an upper rail 44 mounted to the support bar 50. Purlins 45, 46 are 10 standard purlins.used in the art with the exception that apertures 47, 48 may have been drilled or punched into a vertical side of the purlins 45, 46 during manufacture. In the present embodiment, the apertures 47, 48 are square to complement the square section of the support bar 50 and allow the support bar 50 to pass through each purlin 45, 46. The outermost purlin 45 includes 15 a series of holes that align with the holes 62 formed in the flange 61. Appropriate fasteners such as a nut and bolt arrangement, or screws can be used to secure the support bar 50 to the outermost purlin 45. When installed, the support bar 50 is passed through the apertures 47, 48 of purlins 45, 46 until the flange 61 abuts an outermost purlin 45. The 20 flange 61 is secured to the outermost purlin 45 using screws, bolts or any other applicable securing mechanism. Once the support bar 50 is secured to the outermost purlin 45, the bracket 41 can be secured to the end of the support bar 50 with bolt 41a.
9 If required, the support bar 50 may be extended by coaxially connecting an extension bar to an end of the support bar 50 and secured using a threadbly connected bolt in a similar manner described for the first embodiment. 5 Similarly to the first embodiment, the support bar 50 may be removed using the reverse steps to installation. Firstly bolts or screws securing the flange 61 to the outermost purlin 45 are removed and the support bar 50 is slid out from the apertures 47, 48 from an outside of the building. Figs 6A-6D show a support bar 70 according to a third embodiment of 10 the present invention. Fig 6A shows a sectional view of a distal end of support bar 70. Fig 6B shows a side view of the support bar 70. Fig 6C shows a sectional view of a proximal end of support bar 70. Fig 6D shows a perspective view of support bar 70. In this embodiment, the support bar 70 includes an ovular sectioned tube 71 and a square sectioned tube 72. The 15 ovular sectioned tube 71 is coaxially connected to the square sectioned tube 72 and welded or bolted in place. Similarly to the first embodiment, the square sectioned tube 72 is significantly shorter than the ovular sectioned tube 71 to allow a bracket of the edge protection system to be coaxially mounted to an end of the square sectioned tube 72. A groove 73 is formed 20 towards an end of the ovular section 71 coinciding with an end of the square sectioned tube 72. Fig 7 shows a perspective view of the support bar 70 of Fig 6 installed in an edge protection system 40. Further, the edge protection system 40 includes brackets 41, posts 42, a lower rail 43 and an upper rail 44. Purlins 10 45, 46 are standard purlins used in the art with the exception that oval apertures 47, 48 are drilled or punched into a vertical side of the purlins 45, 46 during manufacture. The apertures 47, 48 are ovular in shape and of appropriate dimensions to allow the support bar 70 to pass through each 5 purlin 45, 46. In use, an end of the ovular sectioned tube 71 is passed through apertures 47, 48 until an end of the square sectioned tube 72 abuts an outermost purlin 45. The support bar 71 is turned through substantially ninety degrees to secure the support bar 70 to the outermost purlin 45 so that the 10 groove 73 frictionally engages with an inside surface of aperture 47 in the outermost purlin 45. If required, the support bar 70 may be extended by coaxially connecting an extension bar to an end of the support bar 70 as previously described. 15 Fig 8 shows a partial perspective view of a building 80 to which an edge protection system according to the present invention has been installed. The building includes purlins 45, 46, a roof 81, wall sheets 82, a framework 83, gutter brackets 84 and a gutter 85. The wall sheets 82 are installed to a height just below the apertures 47 formed in purlin 45. As 20 shown in Fig 8, once the edge protection system has been removed, the apertures 47 may be visible from an outside of the building. To overcome this drawback, the gutter brackets 84 are mounted to the wall sheets 82 so that when the gutter 85 is mounted on the gutter brackets 84, the apertures 47 are hidden from view. Furthermore, the gutter 85 prevents moisture from 11 entering the building. Alternatively, caps may be used to seal outermost apertures 47, made from an appropriate material such as metal or plastic. An advantage of the edge protection system using support bars of the present invention is that the system can be installed and dismantled more 5 quickly. This is because the support bars are passed through apertures in the purlins rather than being clamped to an underneath of the purlin and also allows the edge protection system to be left in place whilst the wall sheets are installed. The time taken is further reduced due to the provision of single fastener at an end of the support bar requiring an installer to operate from a 10 single working position. Furthermore, the fastener is located on an outside of a building allowing the support bars to be removed, even when wall sheets have been installed impeding access to an inside of the building. The above description of an embodiment of the present invention is provided for purposes of description to one of ordinary skill in the related art. 15 It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or 20 relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.