AU733546B2 - Gable end safety rail bracket support - Google Patents

Description

F/UU/U11 2a/5191 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged:

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Invention Title: GABLE END SAFETY RAIL BRACKET SUPPORT The following statement is a full description of this invention, including the best method of performing it known to us GABLE END SAFETY RAIL BRACKET SUPPORT BACKGROUND OF THE INVENTION This invention relates to a safety rail bracket support intended for use by roof workers during the construction or renovation of a building. In particular the present invention provides a solution to numerous problems associated with the provision of a safety barrier along the gable end of a roof.

Several problems must be overcome to provide a safety rail support bracket suitable for mounting at a gable end of a roof. One problem is that it is necessary to provide a bracket that, while capable of withstanding the considerable forces that may be applied to it when preventing a roof worker from falling, is also sufficiently lightweight to permit convenient mounting to a roof.

Another problem is that in order for a bracket to be suitable for use in different construction situations the means by which it is secured to the roof must be adjustable to accommodate dimensional variations in roof structure such as inter-rafter spacing. A further requirement is that the mounting bracket must remain securely mounted to the roof not only when in standard use but also during an emergency when extraordinary "emergency forces" will be applied to it. Such will be the case, for example, when a worker falls heavily against safety rails mounted to the bracket. In particular there must be very little likelihood of 20 the means for securing the bracket to the roof detaching from the body of the bracket during an emergency of the type described.

In the past there have been attempts made at addressing some of the above problems. For example Australian patent 652,609 to Mitchinson et al.

describes at pages 15 to 17, and depicts in Figure 12, a gable end safety hand S 25 rail mounting bracket.

The Mitchinson apparatus includes two support assemblies each of which is designed to engage a rafter. The support assemblies are each welded to slidable sleeves which locate around a connecting rod to which a safety rail support member is attached. While this method of mounting the bracket to the rafters is satisfactory when the bracket is in an unstressed state, doubts must exist as to its ability to withstand emergency forces. In the event of such forces being applied, the welded connection between the gable end sleeve and the remainder of the support assembly described in Mitchinson would be placed under considerable tension. In fact, welded connections between the sleeves and the support assemblies would be subjected to the entire force applied to the safety rail during an emergency. Should the welded connections between the sleeve and support assembly nearest the gable fail, due to the suddenly applied tension, then the result could well be catastrophic as the body of the bracket would then rotate away from the rafter adjacent the failed support assembly resulting in the collapse of the safety rail. Furthermore, the repeated stressing and un-stressing of any metal structure may cause metal fatigue so that such a failure might come to pass after an extended period of use.

Consequently, it would be advantageous if the forces that are applied to a safety rail mounting bracket during an emergency were not substantially directed to tensioning a critical connection between the means for engaging the bracket to the roof and the remainder of the bracket, as is the case in Mitchinson.

It is an object of the present invention that the means for engaging the bracket in relation to the supporting members are not subjected to tension forces during an emergency situation. Preferably not all of the emergency forces are applied to the engaging means. It is a further objective of the present invention "that the bracket be adapted so that upon force being applied to it during an emergency, the applied force will be directed to bring the bracket into harder contact with the supporting members rather than tending to remove the bracket S" from the supporting members.

~It is a further object of the present invention to provide a bracket which is relatively simple to make, interferes only minimally with roof workers and is compatible with standard roofing construction methods.

SUMMARY OF THE INVENTION According to the present invention, there is provided a safety rail bracket including; a) a hand rail support member b) an anchor member; c) a first engagement means, connected to the anchor member, for operatively engaging a first rafter; d) a second engagement means, connected to the anchor member, for operatively engaging a second rafter; wherein in use the anchor member transverses at least two roof rafters and is configured so that it lies across the top of the first rafter and the underside of the second rafter so that upon emergency forces being applied to the hand rail support member the anchor member will tend to rotate against both the first and second rafters.

The hand rail and the anchor member may be integral.

Preferably, the distance between the first and second engagement means is adjustable.

Preferably, the position of the hand rail support member relative to the anchor member is adjustable.

In an exemplary embodiment, a hand rail support bracket includes at least ~two engagement means and is constructed to extend transversely across and to engage at least two rafters. Importantly, in the embodiment, neither of said engaging means is substantially subjected to tension stresses upon the application of emergency forces as may occur where a roof worker falls or leans heavily against safety rails attached to the bracket. This property is achieved by shaping the bracket so that it lies across the top of the mounting rafter closest to S the gable and extends across the underside of the second mounting rafter. The bracket is provided with a means for fixing the bracket to the topside of one rafter by a first engagement means and to the underside of the other rafter by a second engagement means. As a result of this arrangement neither of the engagement means are substantially tensioned by emergency forces and so there is minimal tendency for either of the engagement means to become detached from the bracket.

Preferably the centre distance between the first and second engagement means is adjustable to accommodate different spacing of the rafters and to ensure a secure fitting to the rafters.

BRIEF DESCRIPTION OF DRAWING In order that the invention might be more fully understood, embodiments of the invention will be described in greater detail by way of example only with reference to the accompanying Figure 1 which shows a perspective view of a safety rail bracket support mounted to two of three rafters.

DESCRIPTION OF AN EMBODIMENT OF THE INVENTION With reference to Figure 1, there are depicted three rafters 10A, 10B, of a roofing frame. The rafters are usually equispaced, however inter-rafter spacing may vary both in a single roof as well as from one roof to another. Such variations are accommodated by the present invention as will be explained below.

The gable end safety rail bracket includes three components being hand rail support member 15, anchor member 17 and rafter securing clamp 12.

The handrail support member 15 may be constructed from square section hollow steel and configured in an L shape of sufficient dimensions to allow it to extend out to the periphery of the roof, from a point of attachment to the anchor member 17, and up to a height which allows for the suitable mounting of safety rail 26. In particular, roof safety rails are usually positioned 900mm to 1100mm e:i" above the roof working surface, and parallel to, the gable end. Welded, or otherwise connected, to the safety rail support member 15 is a rail bracket 23 for S receiving a safety rail 26. Preferably bracket 23 is adapted to enclose safety rail 26 so that there is no possibility of the rail shaking loose.

Anchor member 17 comprises a piece of square section steel incorporating a an angle 28. Angle 28 divides anchor member 17 into head section 11 and tail section 16. Head section 11 terminates in a square section connector 14 adapted to receive hand rail support member 15. Hand rail support member 15 can be inserted to varying extents through square section connector 14 thereby allowing for variation in size of the eaves on the outer edge of the roof. Once hand rail jTqF support member 15 is satisfactorily positioned, locking bolts 30, 32 are tightened to secure the handrail support member in place. Anchor member 17 is angled so that when head section 11 is located across the top of rafter lOB tail end 16 may be positioned to pass beneath and adjacent to rafter On the underside of head section 11, beneath square section connector 14, there is located a rafter fixing bracket 13. Bracket 13 is adapted to be bolted to the top of rafter lOB by means of coach screw 9. It is envisaged that during the mounting procedure a suitable hole will be drilled through rafter lOB to receive coach screw 9. It should be noted that preferably upon bolting fixing bracket 13 to the top of rafter lOB, the underside of head section 11 will be in contact with the upper right hand edge 29 of rafter lOB.

Rafter securing clamp 12 is positioned on tail section 16 of anchor member 17. The securing clamp includes contact plate 20 which fits over the top of rafter 10C and is held in place by a retaining strap 22. The position of securing clamp 12 may altered by sliding it along tail section 16 of anchor member 17 and then fixing it in a desired position by tightening locking bolt 18. Repositioning of the securing clamp may be necessary to facilitate matching of the distance between fixing bracket 13 and securing clamp 12 to variations in rafter spacing.

In a preferred form of the invention, the distance between the first and second engagement means is adjustable, however, in alternative embodiments (not illustrated) the hand rail support member and the anchor member may be formed integrally as one piece.

When mounted on the gable end of a roof as described, the safety rail mounting bracket is securely attached by means of fixing bracket. 13, coach screw 9, and securing clamp 12. In the event of a person falling outwards from the roof •coo onto safety rail 26, then by virtue of the connection of handrail support 15 to S° anchor member 17, a rotational moment will be generated about fixing bracket 13, and force will also be applied by the fixing bracket downwards onto rafter thereby forcing the anchor member 17 and fixing bracket 13 into harder contact with rafter 10B. Tail end 16 and securing clamp 12 will also be forced into harder contact with the underside of rafter 10C. Furthermore, the rotational moment will be opposed without stressing contact -plate 20 or retaining strap 22.

Consequently, because of its configuration the bracket is not susceptible to disengagement by emergency forces. It is observed that, rather than forcing the bracket away from the rafter, the application of typical emergency forces will actually bring the bracket into harder contact with the rafter. Furthermore, neither the fixing bracket 13 nor the securing clamp 12 are subjected to tension forces, a factor which greatly reduces their susceptibility to disengagement from anchor member 11.

While embodiments of the invention has been described by way of example only, other embodiments and variations are possible within the spirit and scope of the invention as defined by the appended claims.

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Claims (6)

1. A safety rail bracket including; a) a hand rail support member b) an anchor member; c) a first engagement means, connected to the anchor member, for operatively engaging a first rafter; d) a second engagement means, connected to the anchor member, for operatively engaging a second rafter; wherein in use the anchor member transverses at least two roof rafters and is configured so that it lies across the top of the first rafter and the underside of the second rafter so that upon emergency forces being applied to the hand rail support member the anchor member will tend to rotate against both the first and second rafters. S

2. A safety rail bracket according to claim 1 wherein the hand rail support member and the anchor member are integral.

3. A safety rail bracket according to claim 1 wherein the distance between the first and second engagement means is adjustable. a..

4. A safety rail bracket according to claim 1 or claim 3 wherein the position of oooo S.the hand rail support member relative to the anchor member is adjustable.

5. A safety rail bracket substantially as hereinbefore described and illustrated with reference to Figure 1 of the accompanying drawing. 8

6. Use of a safety rail bracket, the bracket being in accordance with any one of the preceding claims, wherein the bracket is used to support a hand rail on a roofing construction which includes spaced roofing rafters. DATED this 15 th day of March 2001 RICCARDO J A VERGAN. ANDY GALOVIC, NIKOLA GALOVIC WATERMARK PATENT TRADEMARK ATTORNEYS UNIT 1 THE VILLAGE RIVERSIDE CORPORATE PARK NORTH RYDE NSW 2113 AUSTRALIA PNF/RJS/MEH P7812AUOO.DOC C C...i C. o *oooo ov *oo