AU2008219357A1 - Guardrail System - Google Patents

Description

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AUSTRALIA

_Patents Act 1990 Roofsafe-T-Systems Pty Limited COMPLETE SPECIFICATION Invention Title: Guardrail System The invention is described in the following statement: 00 Field of the Invention The present invention relates to guardrail systems and in particular, to roof Nguardrail systems for use on commercial or industrial buildings.

Backqround to the Invention Guardrail systems are installed along the edge of roofs of buildings to protect workers from falling over the edge. Typically, the guardrail system extends around the 0 perimeter of the roof and comprises a plurality of spaced vertical posts supporting horizontal rails via rail brackets. The posts are mounted to different parts of the building structure, such as purlins or walls, depending on the type of roof construction.

Different roof constructions require the posts to be mounted at different distances below the roof surface. However, the datum point for measuring the height of rails for safety standards is at the roof surface. This requires different length posts for different roof constructions. Custom made guardrail systems for each different roof construction is expensive and time consuming. Alternatively, extendable posts and/or adjustable rail brackets can compromise the strength and reliability of the guardrail system.

Rail brackets that are permanently fixed to the posts require the entire post to be replaced if the rail bracket fails or is faulty. Alternatively, rail clamping arrangements can be cumbersome to use when installing rails across multiple posts.

The present inventor has developed a new guardrail system adaptable for different roof types and construction.

Summary of the Invention Accordingly, in a first aspect, the present invention provides a multi-configuration post assembly adapted to support a rail in a guardrail system, the post assembly comprising: a support structure comprising a support bar mountable adjacent an edge of a building roof, such that an outer end of the support bar projects outwardly beyond the edge of the roof; a connector comprising an elongate connector sleeve, having open proximal and distal ends, and a connector bracket located nearer to the proximal end than the distal end, wherein the connector is adapted to be mounted on the support bar via the connector bracket in an upward configuration, in which the distal end projects above the 00 N support bar and/or a downward configuration, in which the distal end projects below the support bar; and a post having an upper portion adapted to support one or more rails and a lower portion telescopically receivable in either the proximal end or the distal end of the connector sleeve, wherein the lower portion of the post is securable in the sleeve.

Preferably the connector bracket comprises a clamping apparatus which includes a clamping zone adapted to receive the support bar. Preferably the clamping zone includes a clamping aperture between a movable clamping element and a fixed 0 clamping element. Preferably the fixed clamping element includes one ore more clamping stops. In one form the one or more clamping tops comprise an end wall of the clamping aperture. Preferably the clamping apparatus comprises a hollow body to retain the support bar, the hollow body including spaced apart walls wherein the end wall is disposed opposite a clamping wall. Preferably the clamping wall includes an extendible clamping member mounted therein and mounted so as in use to extend towards the end wall to clamp the support bar.

In one arrangement, the connector bracket comprises a pair of retainer bars mounted on opposite sides of the sleeve. In that arrangement, each retainer bar is a Ushaped bar having a central portion and a pair of perpendicular end portions, the end portions being mounted to the sleeve. This alternative arrangement includes a clamping device as part of the connector bracket comprising a housing mounted between the end portions of opposite U-shaped bars, a threaded shaft mounted in the housing and a clamping plate slidably mounted on the central portions of the two bars via a pair of holes.

The connector is preferably adapted to be mounted with the connector sleeve on either side of the support bar, in both the upward configuration or downward configuration.

In a preferred embodiment, the post assembly further comprises at least one detachable rail bracket mountable on the post. Preferably, the rail bracket, when mounted on the post, is resiliently biased towards an extended position for receiving one of the rails.

Further preferably, the rail bracket comprises: a rail retainer having a pair of parallel, threaded end portions, a nut fastenable on each end portion and a spring axially mounted on each end portion; an actuator comprising a main plate having a pair of holes adapted to receive the end portions of the rail retainer and a threaded handle mounted through the main plate 00 N via a central threaded hole; and a dispersion plate having a pair of holes adapted to receive the end portions of the rail retainer.

Preferably, the rail retainer is a U-shaped bar.

In one preferable embodiment, the support bar comprises an elongate V' rectangular beam and the post assembly further comprises two clamps adapted to clamp the support bar across two purlins of a building.

0 In another preferable embodiment, the post assembly comprises two of the 0 connectors and the support structure further comprises two spacer elements, each S 10 spacer element comprising an elongate sleeve portion and a perpendicular beam portion, wherein the clamps are adapted to clamp the beam portion of each spacer element to a purlin of a building and the sleeve portion of each spacer is adapted to telescopically receive the connector sleeve of one of the connectors, wherein the connector is securable in the spacer element.

In another preferable embodiment, the support bar comprises an end plate adapted to be bolted to a side of a building.

In another preferable embodiment, the support structure comprises a mounting clamp incorporating the support bar, the mounting clamp adapted to be clamped to a building projection.

In a second aspect, the present invention provides a guardrail system comprising rails supported by a plurality of post assemblies according to the first aspect of the present invention.

In a third aspect, the present invention provides a rail bracket for supporting a rail on a post, the rail bracket comprising: a rail retainer having a pair of parallel, threaded end portions, a nut fastenable on each end portion and a spring axially mounted on each end portion; an actuator comprising a main plate having a pair of holes adapted to receive the end portions of the rail retainer and a threaded handle mounted through the main plate via a central threaded hole; and a dispersion plate having a pair of holes adapted to receive the end portions of the rail retainer.

Preferably, the rail retainer is a U-shaped bar.

00 N In a fourth aspect, the present invention provides a method of providing a fall arrest system to a roof construction comprising providing a guardrail system according to the second aspect of the present invention to a building.

In a fifth aspect, the present invention provides a connector bracket suitable for connecting a guardrail support bar to a structural element of a roof, the connector bracket including: a main hollow body comprising upper and lower spaced-apart walls and left and right spaced apart walls; the left and right walls each including a bight extending from a front edge towards a rear edge so that at least one clamping region is 0 defined between upper and lower sides of the left and right spaced apart walls for receiving in use the roof structural element; the bight including at least. one notch formed on at least one bight wall and extending therefrom at an angle thereto, so as in use to receive a formation of corresponding shape extending from the structural element of the roof, wherein in use the roof structural element and the guardrail support bar extend through the main hollow body and are clamped against one another between the two clamping regions.

Preferably the side walls are adapted to receive the roof support so that when in use the roof support extends from one side wall to the other.

Preferably the main hollow body is open at the front and rear ends so that the support bar extends from the front end to the rear end and at an angle to the roof support.

Preferably the bight includes upper and lower notches extending towairds, respectively, the upper and lower walls so as to receive an angled return extending from the flange of the roof structural element, with the main hollow body in an inverted, upright, or left- or right-handed orientation.

Preferably the or each clamping region includes jaws which in one embodiment are fixed and include teeth so as to engage the roof structural member when clamped.

Preferably an extendible clamping member is associated with one or more of the spaced-apart walls and mounted so as in use to extend towards the other spaced-apart wall.

In accordance with yet another aspect of the present invention there is provided a corner connector bracket suitable for use in connecting guard rails disposed at an angle to one another, the corner connector bracket including: a peripheral frame comprising spaced-apart frame arms defining an aperture for receiving the connecting guard rails; a clamping device associated with one frame arm, the clamping device 00 ri including an advancing means and a clamping element adapted to advance under the influence of the advancing means; a stop adapted to cause the clamping element to pivot thereabout during advance.

Throughout this specification, unless the context requires otherwise, the word "comprise", or variations such as "comprises" or "comprising", will be understood to Iimply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

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0 Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is solely for the purpose of providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed in Australia before the priority date of each claim of this specification.

In order that the present invention may be more clearly understood, preferred embodiments will be described with reference to the following drawings and examples.

Brief Description of the Drawinqs Figure 1 is an isometric view of a post assembly according to a first embodiment of the present invention mounted to a building; Figure 2 is an isometric view of the post assembly of Figure 1 with the building elements removed for clarity; Figure 3 depicts the support bar of the post assembly of Figure 2; Figures 4 to 6 depict the clamps of Figure 3, having an additional slot to provide the clamps with greater flexibility; Figures 7 to 9 depict a preferred embodiment of connector of the post assembly of Figure 2; Figures 10 to 12 depict the post of the post assembly of Figure 2; Figures 13 to 15 depict the rail brackets of the post assembly of Figure 2; Figure 16 is an isometric view of a post assembly in accordance with a second embodiment of the present invention mounted to a building; 00 C Figure 17 is an isometric view of the post assembly of Figure 16 with the building elements removed for clarity; CFigures 18 to 20 depict spacer elements of the post assembly of Figure 17; Figure 21 is an isometric view of a post assembly in accordance with a third and fourth embodiments of the present invention mounted to a building; C' Figure 22 depicts the post assembly of the third embodiment of Figure 21 with _the building removed from view for clarity; 00 Figure 23 depicts the post assembly of the fourth embodiment of Figure 21 with the building removed from view for clarity; Figures 24 26 show various views of another embodiment of the clamp shown in Figure 2; Figures 27 29 show various views of another embodiment of the connector shown in Figure 1; Figures 30 32 show various views of a corner connector bracket for connecting the rail as shown in other drawings around corners; Figures 33 35 show various view of the adjustable connector bracket, known as a dropper bracket, shown in Figure 23; Figures 36 38 show various views of a connector bracket suitable for use with a dropper bracket to provide more flexibility in adjustment; Figures 39 41 show various views of a dropper bracket shown with the connector bracket of Figures 36 38 so as to provide more flexibility in adjustment than that shown in Figure 23; Figure 42 shows an underside perspective view of the corner connector bracket of Figures 30 32 shown with a par of rails connected at a selected angle; Figure 43 is a front elevation view of the corner bracket of Figure 42 with the two rails connected at a selected angle.

Detailed Description of Preferred Embodiments of the Invention Although there are several separate and distinct aspects of the present invention, each one will be described in combination with each other.

Referring to Figure 1, a section of a guardrail system 10 is shown mounted to a building 12 and extending along the edge of a roof 14 having purlins 16. The guard rail 00 Cr system 10 comprises a plurality of horizontal rails 18 supported by a plurality of post assemblies 20 spaced along the edge of the roof 14 and mounted to the building 12. As shown in more detail in Figure 2, a first embodiment of the post assembly 20 comprises a rectangular support bar 22, a connector 24, a post 26, three rail brackets 28 and a pair of purlin clamps I"The support bar 22 and purlin clamps 30 are depicted separately in Figure 3.

t' The support bar 22 comprises an elongate rectangular hollow section beam. One of the purlin clamps 30 is depicted separately in Figures 4 to 6 and comprises a T-shaped oO threaded handle 32 mounted in a generally rectangular hollow section having a pair of side plates 34, a top plate 36, a bottom plate 38, an open front end 40 and an open rear end 42. The side plates 34 have corresponding bights or slots 44 formed in the side plates 34. The slots 44 extend rearwardly from the front end 40 of the clamp 30 and each have notches 46 at the end of the slot 44 and a recess 48 near the front of the slot 44, one notch extending towards the top plate 36 and the other notch extending away from the top plate 36. The handle 32 is mounted via a threaded hole 50 through the bottom plate 38.

In use the notches 46 and 47 receive the flange of the purlin and due to the notches being disposed on opposite sides of the slot or bight 44, the clamp 30 may be applied left-or-right handed, or upside down or sight-side up as required.

The connector 24 is depicted separately in Figures 7 to 9 and comprises an elongate square connector sleeve 54 having a front face 56, a rear face 58, two side faces 60, a proximal end 62 and a distal end 64. Three pairs of coaxial mounting holes 52 are provided in the front and rear faces 56, 58 of the connector sleeve 54. The connector sleeve 54 further comprises a connector bracket 66 affixed by welding to the sleeve 54 nearer the proximal end 62 than the distal end 64 and a clamping device 68 associated with the connector bracket 66. The connector bracket 66 includes a clamping zone 69 adapted to receive the support bar 22. The clamping zone is disposed within a clamping aperture 71 which is defined by a hollow body comprising a plurality of spaced-apart walls 73, 75, 77, 79. The aperture 71 is a through aperture so that the connector bracket 66 may be disposed at a selected position along the support bar 22. The clamping zone 69 may be selectively closed by a clamping wall 73 which in use extends towards its oppositely-disposed wall 77. The connector bracket 66 may in one form not be welded but may be adjustably mounted at a selected position along the connector by use of a separate clamping bracket such as that shown in Figures 36 38.

00 Cr Another embodiment of connector bracket 66 is shown in Figs 27 29 and comprises a pair of U-shaped retainer bars 72, each U-shaped retainer bar 72 having a central portion 74 and two parallel end portions 76 extending at right angles to the _central portion 74. The retainer bars 72 are each mounted opposite one another on a side face .60 of the connector sleeve 54 via the end portions 76, with the central portion 74 extending parallel to and spaced forwardly of the connector sleeve 54. The clamping t' device 68 has a housing 78 mounted between two end portions 76 of opposite retainer bars 72, a threaded shaft 80 mounted in the housing 78 and a clamping plate 82 slidably 00 mounted on the central portions 74 of the two retainer bars 72 via holes 84.

0 The post 26, as depicted separately in Figures 10 to 12, is an elongate square beam. Six pairs of coaxial mounting holes 86 are provided in opposite front and rear faces 88 of an upper portion 92 of the post 26 and two pairs of coaxial mounting holes 94 are provided in opposite side faces 96 of a lower portion 98 of the post 26.

The rail brackets 28 are depicted separately in Figures 13 to 15 and comprise a rail retainer, in the form of a U-shaped bar, 100 with threaded end portions 102, an actuator 104 and a dispersion plate 106. A spring 108 is axially received on each of the end portions 102. The actuator 104 comprises a main plate 110 and a threaded Tshaped handle 112 mounted through the main plate 110 via a central threaded hole 114.

Both the main plate 110 and the dispersion plate 106 have a pair of holes 116 adapted to receive the threaded end portions 102 of the U-shaped bar 100.

Returning to Figure 1, the post assembly 20 is assembled by securing the support bar 22 beneath a roof 14, using two of the clamps. Each purlin clamp 30 is arranged on the support bar 22 by sliding the purlin clamp 30 over an end of the support bar 22 with the support bar 22 extending through the open front 40 and rear 42 ends of the purlin clamp 30. The support bar 22 is then arranged across a pair of purlins 16 so that an outer end of the support bar 22 projects beyond the edge of the roof 14. The purlin clamps 30 are arranged over a flange of the purlin 16, with the flange of the purlin 16 extending into the slot 44 of the purlin clamp 30. By tightening the handle 32 of the purlin clamp 30, the handle 32 pulls the purlin clamp 30 downwardly with respect to the purlin 16 and clamps the flange of the purlin 16 between the support bar 22 and the teeth 49 of the purlin clamp The connector 24 is then mounted on the outer end of the support bar 22 by inserting the end of the support bar 22 through the connector bracket 66, with the distal end of the connector sleeve 54 extending upwards. The clamping device 68 is then used to secure the connector 24 to the support bar 22, by screwing the threaded shaft 00 I ri 80 into the housing 78, to press the clamping plate 82 against the support bar 22. The post 26 is then telescopically received in the connector sleeve 54 such that one of the pairs of coaxial mounting holes 94 in the lower portion 98 of the post 26 are aligned with one of the pairs of coaxial mounting holes 52 of the connector sleeve 54. The post 26 is then secured in place with a bolt through the aligned mounting holes 52, 94.

The three rail brackets 28 are then mounted on the post 26. The end portions of the U-shaped bar 100 are each inserted from the rear face of the post 26 through a pair of the coaxial mounting holes in the upper portion of the post 26, so that the end 0portions of the U-shaped bar 100 project from the front face of the post 26. The load

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dispersion plate 106 is mounted on the end portions 102 of the U-shaped bar 100, followed by the actuator 104. Nuts 118 are threaded onto the end portions 102 to secure the dispersion plate 106 and actuator 104 on the U-shaped bar 100.. The Tshaped handle 112 of the actuator 104 is then turned such that the T-shaped handle 112 presses the dispersion plate 106 against the post 26 and draws the U-shaped bar 100 towards the actuator 104. This action squares the U-shaped bar 100 with respect to the post 26 and compresses the springs 108, which bias the U-shaped bar 100 to project outwardly from the rear surface of the post 26. Rails 18 can then be mounted through the opening between the U-shaped bar 100 and the post 26.

Referring to Figure 16, a section of the guardrail system 10 incorporating a post assembly 20 in a second configuration is shown mounted to the building 12. As shown in more detail in Figure 17, the post assembly 20 further comprises a second connector 24 and two spacer elements 120.

One of the spacer elements 120 is depicted in isolation in Figures 18 to 20 and comprises a square sleeve portion 122 and two axially aligned, rectangular beam portions 124 extending perpendicularly to the sleeve portion 122. The sleeve portion 122 is provided with a pair of coaxial mounting holes 126.

Returning to Figures 16 and 17, one of the spacer elements 120 is mounted to each of the two purlins 16 using the purlin clamps 30 in the same way that the support bar 22 was mounted in the first embodiment. In the second embodiment, the purlin clamp 30 is mounted on one of the beam portions 124 of the spacer element 120 instead of on the support bar 22. The connector sleeve 54 of each connector 24 is then received telescopically within the sleeve portion 122 of a corresponding spacer element 120. The most distal pair of mounting holes 52 on the connector sleeve 54 are aligned with the pair of mounting holes 126 on the sleeve portion 122 of the spacer element 120 and a bolt is inserted and secured therethrough. The support bar 22 is mounted through 00 II

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N the connector brackets 66 of the two connectors 24 and secured by tightening the clamping devices 68 of each connector 24, which are arranged with the distal end 64 of C/ the connector sleeve 54 extending upwards. The post 26 can then be mounted in the

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outermost connector 24 and rail brackets 28 mounted on the post 26 as in the first embodiment.

Figure 21 shows third and fourth embodiments of the post assembly 20 attached to a building 12. The third embodiment is depicted in Figure 22 and comprises a support bar 22 having an end plate 128 adapted to be bolted to a cement surface of the 0 building 12. In this embodiment, as depicted, the distal end 64 of the connector sleeve

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54 extends downwards from the support bar 22. The fourth embodiment is depicted in Figure 23 and comprises a mounting apparatus 130 associated with the support bar 22 the mounting apparatus 130 being adapted to mount the support bar 22 from a projecting portion of a building 12. In this embodiment, as depicted, the distal end 64 of the connector sleeve 54 also extends downwards from the support bar 22.

The post assembly 20 of the present invention is readily adaptable to suit many different roof 14 constructions. Different configurations of the post assembly 20 are possible using the same components, as the connector 24 is able to be mounted to the support bar 22 in either an upward or downward configuration and on either side of the support bar 22 in each configuration. Further, the different components for mounting the support bar 22 allow the post assembly 20 to be used for different building configurations.

As the rail brackets 28 are resiliently biased by the springs 108 to project the Ushaped bar 100 outwards from the post 26, the task of aligning and mounting rails 18 through the rail brackets 28 is simplified. Further, if one of the rail brackets 28 fails, it can be replaced individually, without needing to replace an entire post assembly Turning to Figures 30 32, and 42 and 43, it can be seen that a rail corner connector bracket 25 is shown, which in use connects together rails 18 which are disposed at an angle to one another. The rail corner connector bracket 25 includes a peripheral frame 27 including spaced-apart frame arms 29 which define an aperture 31.

A clamping device 33 is associated with one frame arm and includes a clamping element 39 disposed inside the aperture 31 which can be advanced into the aperture by advancing means 35 in the form of a threaded bar 37. The clamping element 39 pivotally advances into the aperture 31 due to one end 41 being retained by a retainer 43 in the form of a boss or ridge or bump 00 N Turning to Figures 24 26 there is shown purlin clamps 130 and in the drawings, like numerals denote parts like to those described above. The purlin clamps shown in these figures only have a single notch 46 so although they are stronger, their flexibility of application is slightly more limited than those described above and shown in Figures 4 6.

Figures 33 35 and Figures 39 41 show dropper brackets 149 which allow the support bar 122 to clear roof structural members such as those shown in Figures 16 and 17 as well as those in Figures 21 and 23. The first set of dropper brackets 149 are OO adjustable and have coarse and fine tuning. The coarse tuning is in the form of a

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plurality of adjustment holes 153 which can be selected by a pin 151, and the fine tuning is in the form of a threaded bar 155 which can be advanced to clamp the bracket 149 to a roof structural member such as shown in Figure 21. The dropper bracket 149 includes bearing bosses 157 so as to facilitate the clamping to the structural member.

A second form of dropper bracket 249 is shown in Figures 39 41 and can be more flexibly adjusted, as can the connector brackets 24, by using the clamping brackets shown in Figures 36 38. The adjustment is such that support bar 122 can be affixed at any selected location along bar 124.

It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the invention as shown in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive.

Claims (21)

1. A multi-configuration post assembly adapted to support a rail in a guardrail Isystem, the post assembly comprising: a support structure comprising a support bar mountable adjacent an edge of a building roof, such that an outer end of the support bar projects outwardly beyond the edge of the roof; 1a connector comprising an elongate connector sleeve, having open N proximal and distal ends, and a connector bracket located nearer to the proximal 00 OO 0 end than the distal end, wherein the connector is adapted to be mounted on the S 10 support bar via the connector bracket in an upward configuration, in which the distal end projects above the support bar and a downward configuration, in which the distal end projects below the support bar; and a post having an upper portion adapted to support one or more rails and a lower portion telescopically receivable in either the proximal end or the distal end of the connector sleeve, wherein the lower portion of the post is securable in the sleeve.

2. The multi post assembly of in claim 1 wherein the connector bracket comprises a clamping apparatus which includes a clamping zone adapted to receive the support bar.

3. The multi post assembly of in claim 2 wherein the clamping zone includes a movable clamping element and a fixed clamping element, and a clamping aperture disposed therebetween.

4. The multi post assembly of in claim 3 wherein the fixed clamping element includes one ore more clamping stops. The multi post assembly of in claim 4 wherein the one or more clamping stops comprise a side wall of the clamping aperture. O' 00 O r" 6. The multi post assembly of any one of claims 2 to 5 wherein the clamping apparatus comprises a hollow body to retain the support bar when in use, the hollow body including spaced apart walls.

7. The multi post assembly defined in claim 6 wherein the spaced apart walls I' include a clamping element with which is associated an extendible clamping 0member, the clamping element mounted so as in use to extend towards an ri opposed wall to clamp the support bar in the clamping zone. 00 OO O

8. The post assembly of claim 1, wherein the connector bracket comprises a pair of parallel retainer bars mounted on opposite sides of the sleeve.

9. The post assembly of claim 8, wherein the retainer bars are U-shaped bars having a central portion and a pair of perpendicular end portions, the end portions being mounted to the sleeve. The post assembly of claim 9, wherein the connector further comprises a clamping device comprising a housing mounted between end portions of opposite U-shaped bars, a threaded shaft mounted in the housing and a clamping plate slidably mounted on the central portions of the two bars via a pair of holes.

11. The post assembly of any one of claims 1 to 10, wherein the connector is adapted to be mounted with the connector sleeve on either side of the support bar, in both the upward configuration or downward configuration.

12. The post assembly of any one of claims 1 to 11, further comprising at least one detachable rail bracket mountable on the post.

13. The post assembly of claim 12, wherein the rail bracket, when mounted on the post, is resiliently biased towards an extended position for receiving one of the rails. 00 a 14. The post assembly of claim 13, wherein the rail bracket comprises: a rail retainer having a pair of parallel, threaded end portions, a nut fastenable on each end portion and a spring axially mounted on each end portion; In an actuator comprising a main plate having a pair of holes adapted to t' receive the end portions of the rail retainer and a threaded handle mounted through the main plate via a central threaded hole; and 00 a dispersion plate having a pair of holes adapted to receive the end portions of the rail retainer. The post assembly of claim 14, wherein the rail retainer is a U-shaped bar.

16. The post assembly of any one of claims 1 to 15, wherein the support bar comprises an elongate rectangular beam and the post assembly further comprises two clamps adapted to clamp the support bar across two purlins of a building.

17. The post assembly of claim 10, comprising two of the connectors and the support structure further comprising two spacer elements, each spacer element comprising an elongate sleeve portion and a perpendicular beam portion, wherein the clamps are adapted to clamp the beam portion of each spacer element to a purlin of a building and the sleeve portion of each spacer is adapted to telescopically receive the connector sleeve of one of the connectors, wherein the connector is securable in the spacer element.

18. The post assembly of any one of claims 1 to 9, wherein the support bar comprises an end plate adapted to be bolted to a side of a building.

19. The post assembly of any one of claims 1 to 9, wherein the support structure comprises a mounting clamp incorporating the support bar. 00 O O ri 20. A guardrail system comprising rails supported by a plurality of post assemblies of any one of claims 1 to 19.

21. a method of providing a fall arrest system to a roof construction comprising providing a guardrail system according to claim 20 to a building. A connector Sbracket suitable for connecting a guardrail support bar to a structural element of 1a roof, the connector bracket including: a main hollow body comprising upper N and lower spaced-apart side walls and left and right spaced apart walls, the left 00 O and right walls each including a bight extending from a front edge towards a rear edge so that at least one clamping region is defined between upper and lower sides of the left and right spaced apart side walls for receiving the roof structural element in use, the bight including at least one notch formed on at least one bight wall and extending therefrom at an angle thereto, so as in use to receive a formation of corresponding shape extending from the structural element of the roof, wherein in use the roof structural element and the guardrail support bar extend through the main hollow body and are clamped against one another between the two clamping regions.

22. The connector bracket of claim 21 wherein the side walls are adapted to receive the roof support so that when in use the roof support extends from one side wall to the other.

23. The connector bracket of claim 21 or 22 wherein the main hollow body is open at the front and rear ends so that the support bar extends from the front edge to the rear edge and at an angle to the roof support.

24. The connector bracket of claim 21, 22 or 23 wherein the bight includes upper and lower notches extending towards, respectively, the upper and lower walls so as to receive an angled return extending from the flange of the roof structural element, with the main hollow body in an inverted, upright, or left- or right- handed orientation. 00If O O N 25. The connector bracket of anyone of claims 21 to 24 wherein one or more of the clamping regions include fixed jaws which include teeth so as to engage the roof Cstructural member when clamped.

26. The connector bracket of any one of claims 21 to 25 wherein an extendible .clamping member is associated with one or more of the spaced-apart walls and T mounted so as in use to extend towards an opposed spaced-apart wall. 00 O O S27. A corner connector bracket suitable for use in connecting guard rails disposed at an angle to one another, the corner connector bracket including: a peripheral frame comprising spaced-apart frame arms defining an aperture for receiving the connecting guard rails; a clamping device associated with one frame arm, the clamping device including an advancing means and a clamping element adapted to advance under the influence of the advancing means; a stop adapted to cause the clamping element to pivot thereabout during advance.

28. A rail bracket for supporting a rail on a post, the rail bracket comprising: a rail retainer having a pair of parallel, threaded end portions, a nut fastenable on each end portion and a spring axially mounted on each end portion; an actuator comprising a main plate having a pair of holes adapted to receive the end portions of the rail retainer and a threaded handle mounted through the main plate via a central threaded hole; and a dispersion plate having a pair of holes adapted to receive the end portions of the rail retainer.

29. The rail bracket of claim 28, wherein the rail retainer is a U-shaped bar.