AU715578B3

AU715578B3 - Fastener

Info

Publication number: AU715578B3
Application number: AU98212/98A
Authority: AU
Inventors: Raymond Gary Hollis
Original assignee: Individual
Current assignee: Individual
Priority date: 1998-12-24
Filing date: 1998-12-24
Publication date: 2000-02-03
Anticipated expiration: 2001-02-03

Description

-1- Regulation 3.2

AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A PETTY PATENT

(ORIGINAL)

Name of Applicant: Actual Inventors: Address for Service: Invention Title: Raymond Gary HOLLIS Raymond Gary HOLLIS DAVIES COLLISON CAVE, Patent Attorneys, 1 Little Collins Street, Melbourne, 3000.

FASTENER

The following statement is a full description of this invention, including the best method of performing it known to me: Q:\oPER\DH\FASENER.NPA. -2412/98 P:\OPER\DH\98212-98.RSI 6/9/99 -2-

FASTENER

FIELD OF THE INVENTION This invention relates to a fastener, particularly a cyclone screw for use in securing a roof against cyclone winds.

BACKGROUND OF THE INVENTION A number of fastener assemblies are known for securing a roof against cyclone wind.

Examples of such assemblies are shown in Figure 1. As can be seen, such assemblies all include a screw 1 which passes through roof sheeting 2 and is secured in a roof beam 3. A metal washer 4 is fitted on the screw 1 and abuts a head of the screw on one side thereof. A rubber washer 5 is also provided between the metal washer and the roof sheeting. Each metal washer includes downwardly directed wings 6 which are specifically designed to fit against respective flanks 7 of the associated sheeting profile. As such, substantially different washer configurations are required in order to accommodate the different roof sheeting profiles. For example, in Figure 1A the roof profile has relatively low aspect flanks and the metal washer is relatively wide with substantial length wings which engage directly with the roof sheeting.

The rubber washer 5 in this instance is in the form of a conical type washer, provided in a space between the washer 4 and the roof sheeting to seal the roof from ingress of water from between the sheeting and washer. The metal washers 4 shown in Figures 1B and 1C on the other hand are arranged to fit roof profiles with relatively steep flanks and the rubber washers are shaped in general conformity with the metal washers.

P:\OPER\DH\98212-98.RS 6/9/99 -3- Aside from the disadvantage of the washers being designed for use with one roof sheeting profile only, the winged shape requires the washer to be positioned in a particular orientation whilst the screw is fastened in place, which becomes both labour and time consuming, particularly when a substantial number of fasteners need to be fitted to a roof.

It is an object of the invention to provide a fastener which is easier to install and which may be used in combination with a plurality of different roof profiles.

SUMMARY OF THE INVENTION In accordance with the invention there is provided a cyclone screw including a shaft, a head portion with an outwardly divergent flange and a domed washer having a central opening arranged to resiliently engage the shaft, to mount the washer on the shaft, wherein the flange has a frustoconical profile so as to define a recessed region for abutment with a convex side of the washer and wherein the washer is formed of resilient material so that a lip thereof is adapted to seal against an object, through which the fastener is affixed, in a domed condition or in a substantially compressed condition and wherein the domed washer has a convex surface area larger than a surface area of the recessed region so that the lip of the washer extends beyond the flange when the washer is in the compressed condition, against the surface of the flange.

Preferably, the flange is integrally formed with the shaft.

Preferably, the flange has an outer diameter in the range 22-27mm and more ,oreferably in the range 24-25mm.

P:\OPER\DH\FASTENER.PRV 24/12/98 -4- Preferably, the washer is formed of EPDM material.

Preferably, the head portion includes a nut fixed to the flange, the nut being positioned at an end of the fastener and being provided with a substantially planar end surface.

BRIEF DESCRIPTION OF THE DRAWINGS The invention is described in more detail, by way of non-limiting example only, with reference to the accompanying drawings, in which: Figure 1 is a side view illustrating different prior art fastener assemblies.

Figure 2 is a side view of the present invention; Figure 3 is a cross-sectional view of the fastener attached to a roof; and Figure 4 is a perspective view of the fastener attached to a roof with an alternative roof sheeting profile.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT The fastener 10 shown in Figure 2 includes a shank 11 with a thread form 12 formed at one end, a head portion 13 formed at the other end and a domed washer 14 which is preferably formed of rubber-like material such as EPDM. The head portion includes a nut affixed to a flange 16 which has a frustoconical profile so as to define a recessed region 17 for receipt of a convex side 18 of the washer 14.

The surface area of the convex side 18 is greater than the surface area of the associated recessed region 17 so that the washer 14, in its compressed state, has a diameter of greater P:\OPER\DH\FASTENER.PRV -2412/98 dimension than the flange 16. This is more clearly shown in Figure 3 where the fastener is shown secured in a roof 20 covered with roof sheeting 21. More particularly, the washer 14 is shown in a compressed condition such that an outer peripheral lip 22 thereof extends beyond the flange 16 so that there is no direct contact between the flange 16 and the sheeting 21. In the arrangement shown, the periphery of the flange 16 will provide a continuous support surface for preventing the sheeting 21 being lifted away from the roof 20 during, for example, cyclonic winds. The provision of the washer 14 between the periphery of the flange 16 and the sheeting 21 prevents any direct metal to metal contact which may otherwise cause tearing of the sheeting and failure of the fastening system so that the sheeting 21 lifts away from the roof The washer also has sufficient resilience so that a seal may still be effected when the roof is of a different profile, such as shown in Figure 4, wherein the flanks 23 of the profile are somewhat steeper. In this arrangement, the washer in part maintains a somewhat dome shaped configuration with portions 24 extending down side flanks of the roof sheeting profile whilst establishing a seal therebetween, without the need for the flange to fully compress the washer. The portions of the washer on a peak 25 of the profile are, however, once again fully compressed so as to project beyond the flange in a manner similar to that shown in Figure 3.

In addition to the advantage afforded by the washer 14, of being adapted to fit to varying roof profiles, the flange 16 is formed integrally with the shaft 11 so as to increase the ease with which the fastener may be secured in the roof. More particularly, forming the P:\OPER\DHT\ASTENER.PRV 24/12/98 -6flange as an integral component of the fastener avoids the need to separately feed both a metal and rubber washer onto the shank of the fastener, as required in the prior art, and the symmetric nature of the flange means that the fastener itself does not need to be orientated in any particular direction to effect secure and sealed fastening of the roof sheeting. The diameter of the flange is preferably in the order of 22 to 27 mm and more preferably in the range of 24 to 25 mm to make the fastener ideally dimensioned to fit with any of the conventional roof sheeting profiles represented in Figure 1.

Another feature of the fastener is that the nut 15 has a planar end surface, unlike conventional roofing screws, which have a recessed head prone to rusting.

As may be appreciated from the above, the fastener of the invention provides a number of advantages in that the flange is symmetrical in shape which provides for convenient and effective load bearing about the periphery of the flange and, combined with the structure of the washer, the fastener may be used in conjunction with roof sheeting of varying profile.

The fastener has been described by way of non-limiting example only, and many modifications and variations may be made thereto without departing from the spirit and scope of the invention as described.

Claims

1. A cyclone screw including a shaft, a head portion with an outwardly divergent flange and a domed washer having a central opening arranged to resiliently engage the shaft, to mount the washer on the shaft, wherein the flange has a frustoconical profile so as to define a recessed region for abutment with a convex side of the washer and wherein the washer is formed of resilient material so that a lip thereof is adapted to seal against an object, through which the fastener is affixed, in a domed condition or in a substantially compressed condition and wherein the domed washer has a convex surface area larger than a surface area of the recessed region so that the lip of the washer extends beyond the flange when the washer is in the compressed condition, against the surface of the flange.

2. A cyclone screw as claimed in claim 1, wherein the flange is integrally formed with the shaft.

3. A cyclone screw as claimed in claim 1 or 2, wherein the head portion includes a nut fixed to the flange, the nut being positioned at an end of the fastener and being provided with a substantially planar end surface. DATED this 6th day of September, 1999 RAYMOND GARY HOLLIS by his Patent Attorneys DAVIES COLLISON CAVE