WO2014099684A1

WO2014099684A1 - Fastener

Info

Publication number: WO2014099684A1
Application number: PCT/US2013/075202
Authority: WO
Inventors: Tayebeh Alirezaee; David Charles Collinson
Original assignee: Illinois Tool Works Inc.
Priority date: 2012-12-19
Filing date: 2013-12-14
Publication date: 2014-06-26
Also published as: AU2013270644A1; AU2013270644B2

Abstract

A fastener 14 for fastening material to a structure, comprising a screw threaded fastener component and a sealing washer component, wherein the fastener component has a head 18 and a screw-threaded shank 20, the sealing washer component is mounted around the shank 20 to abut the head 18 for sealing between the head 18 and the material, wherein the shank 20 includes a portion of increased diameter 22 located to reside in a bore of the washer component when the fastener is tightened in place against said material.

Description

FASTENER

Field of the Invention The invention relates to a fastener for fixing material (for example, cladding material) to a structure and, more particularly, but not exclusively, to a fastener suitable for fixing roof and/or wall sheeting material to a structure.

Back2round of the Invention

It is known to secure sheeting to a structure by way of fasteners. More particularly, it is known to secure corrugated iron roof sheeting to a building by way of screw-threaded fasteners having deformable washers to prevent leakage of rainwater into the building. The applicant has identified that, at present, washers having a Shore A hardness of 75 to 85 are assembled to the majority of its roofing fasteners to provide sealing against leakage of water, and to prevent a metal-on-metal connection between the screw and the roof sheet to avoid the risk of corrosion.

However, the applicant has identified two major problems with existing cut washers in that they tend to "spew" out from underneath a head of the fastener, as shown in Figure 1 of the drawings. In other words, the washer tends to move sideways on round roofing profiles of the kind present in corrugated iron roofing sheets. In addition, there also exists a problem in that existing washers tend to tear when exposed to burr caused by driving the fastener into metal. Furthermore, because of these problems, the end users in many cases (especially in walling operations) opt to remove the deformable washer during assembly which will create metal-on-metal contact between a head of the fastener and the sheeting, ultimately causing corrosion and failure of the structure.

Exacerbating the problem is that existing washers tend to fall to one side of the rounded roofing profile so as to spew from beneath the fastener head, and the heads of existing fasteners have a corrosion resistant coating which must be separate to a metal roofing sheet otherwise corrosion is promoted. Examples of the invention seek to provide an improved fastener for mounting sheeting to a structure which overcomes or at least alleviates disadvantages associated with existing fasteners. Summary of the Invention

In accordance with one aspect of the present invention, there is provided a fastener for fastening material to a structure, comprising a screw threaded fastener component and a sealing washer component, wherein the fastener component has a head and a screw- threaded shank, the sealing washer component is mounted around the shank to abut the head for sealing between the head and the material, wherein the shank includes a portion of increased diameter located to reside in a bore of the washer component when the fastener is tightened in place against said material.

Preferably, said portion of increased diameter is stepped outwardly from a main portion of the shank. More preferably, the portion of increased diameter has a diameter which is approximately 0.4mm larger than a diameter of the main portion of the shank. In another form, the portion of increased diameter may be tapered outwardly from a main portion of the shank.

Preferably, the portion of increased diameter has a length substantially the same as a thickness dimension of the washer component. More preferably, the portion of increased diameter has a length of between 1.5mm and 3.5mm.

In a preferred form, the portion of increased diameter has a circular cross-section. More preferably, the portion of increased diameter is cylindrical.

Preferably, the portion of increased diameter is adjacent the head.

It is preferred that the portion of increased diameter is dimensioned to fit snugly inside the bore of the washer component. In a preferred form, the washer component has a Shore A hardness of 86 to 92, and even more preferably 88 to 92, International Rubber Hardness Degrees (IRHD).

Preferably, the washer component is made of EPDM rubber. More preferably, the EPDM rubber contains carbon.

In a preferred form, the washer component is non-conductive. More preferably, the washer component has an electrical resistivity of at least 2000 M ohms. Preferably, the head has a corrosion coating.

In accordance with another aspect of the present invention, there is provided a fastener for fastening material to a structure, comprising a screw threaded fastener component and a sealing washer component, wherein the fastener component has a head and a screw-threaded shank, the sealing washer component is mounted around the shank to abut the head for sealing between the head and the material, wherein the shank includes a portion located to reside in a bore of the washer component when the fastener is tightened in place against said material, and wherein the washer component has a Shore A hardness of 86 to 92 International Rubber Hardness Degrees (IRHD).

Brief Description of the Drawin2S

The invention is described, by way of non-limiting example only, with reference to the accompanying drawings, in which:

Figure 1 shows a washer of an existing fastener spewing from underneath a head of the fastener;

Figure 2 shows a trial of fasteners in accordance with an example of the present invention;

Figure 3 a shows a top view of a washer component in accordance with the present invention;

Figure 3b shows a side view of the washer component;

Figure 3c shows specifications of various models of washer components in accordance with various examples of the present invention; Figure 4a shows a proximal end view of a fastener in accordance with the present invention;

Figure 4b shows a side view of the fastener shown in Figure 4a;

Figure 4c shows a cross-sectional view of the fastener, taken along line A-A shown in Figure 4b;

Figure 4d shows a detailed cross-sectional view of the circled portion shown in Figure 4c;

Figure 5 a shows a profile of an existing fastener component for the purpose of comparison with Figure 5b which shows the profile of a fastener in accordance with an example of the present invention;

Figure 6a shows a proximal end view of a fastener in accordance with an example of the present invention;

Figure 6b shows a side view of the fastener of Figure 6a, with a washer component fitted to a shaft of the fastener; and

Figure 6c shows a distal end view of the fastener shown in Figures 6a and 6b.

Detailed Description

With reference to Figures 2 to 4d and 5b to 6c, there is shown a fastener 10 which is suitable for fastening roof sheeting, wall sheeting and/or other metal and polymer cladding materials to a structure for roofing or walling. Advantageously, the fastener 10 provides an improved tightness of fit between a fastener component and washer component of the fastener 10 so as to prevent spewing of the washer component from beneath a head of the fastener, to prevent tearing of the washer component, and to prevent corrosion of the sheeting. In particular, the applicant identified that the washer component of existing fasteners, as shown in Figure 1, float excessively around a shank of the fastener which leads to the problems which it identified.

In identifying these problems and deciding that it may be beneficial to improve a tightness of fit between the components, the applicant sought to reduce an inner diameter of the washer component so that the washer component would fit more tightly on the shank of the fastener component. However, in conducting research and trials, the applicant determined that a washer component having a reduced inner diameter would fit too tightly over a screw thread of the shank and would require changes in assembly machinery to fit the washer component. As a result, it was decided that it would not be a practical solution to reduce the inner diameter of the washer component, and that it may be more practical to include a stepped portion of increased diameter on the shank near a head of the fastener component so as to improve the tightness of fit between the components. In another form, rather than stepping the diameter, the portion of increased diameter may be tapered outwardly from a main portion of the shank.

Accordingly, the applicant determined that it would not be necessary to change the dimensions of the washer component, but that it may be advantageous to increase a hardness of the washer component so as to prevent the washer component from spewing and tearing. The applicant investigated polymers, but found that such materials may not withstand the process of painting the fasteners and, in particular, the heat applied to the fasteners during manufacture and use. In that regard, it was identified by the applicant that during use temperatures on roof sheeting may exceed 100 degrees Celsius.

The applicant also investigated the use of elastomers, however found that many elastomers would be too expensive. Silicon material was also investigated, however it was determined that it may be difficult or impossible to harden the silicon to the correct degree. Finally, the applicant investigated the use of EPDM rubber but found that the technology in this type of material is not sufficiently sophisticated. Carbon is used to increase the hardness of rubber, however the applicant determined that to solve the present problems it would be necessary to increase the hardness without increasing the carbon content in the material of the washer components to a level which would result in conductivity of the washer components which, in turn, would result in accelerated corrosion of the sheeting.

Accordingly, with reference to Figures 2 to 4d and 5b to 6c, the applicant has provided a fastener 10 for fastening a sheet 12 to a structure, comprising a screw threaded fastener component 14 and a sealing washer component 16. The fastener component 14 has a head 18 and a screw-threaded shank 20. The sealing washer component 16 is mounted around the shank 20 to abut the head 18 for sealing between the head 18 and the sheet 12. The shank 20 includes a portion 22 of increased diameter located to reside in a bore 24 of the washer component 16 when the fastener 10 is tightened in place against said sheet 12.

Figure 2 shows a trial installation of fasteners 10 in accordance with an example of the present invention used to fix a sheet 12 to a structure. Figures 3a and 3b show the general form of a washer component in accordance with an example of the present invention, and variations may be formed as per several models of washer components, as detailed in the table provided in Figure 3c. By changing tolerances of the washer, the applicant has been able to determine that reduction of rubber material enables spew of the washer to be reduced and possibly completely eliminated. In Figures 3a and 3b, the outside diameter of the washer component is labelled by reference letter "a", the bore diameter is labelled by reference letter "b", and the thickness is labelled by reference letter "c". Figures 4a to 4d show detail of the fastener component 14. In particular, Figure 4b shows that the portion 22 of increased diameter is stepped at a step 26, outwardly from a main portion 28 of the shank 20. The portion of increased diameter 22 has a diameter which is approximately 0.4mm larger than a diameter of the main portion 28 of the shank 20.

Figure 4c shows a cross-sectional view of the fastener, taken along line A-A shown in Figure 4b. With reference to Figure 4d, angle marked "d" is 30 degrees, dimension "e" is 1.75-2.25mm, and dimension "f" is 5.15-5.25mm. The portion of increased diameter 22 may have a length substantially the same as a thickness dimension of the washer component 16. In a preferred form, the portion of increased diameter 22 may have a length of between 1.5mm and 3.5mm.

For a purpose of comparison, Figures 5a and 5b show the profile of an existing fastener component (see Figure 5a) and the profile of the fastener component 14 of the present invention (see Figure 5b) having the portion of increased diameter 22. The portion of increased diameter 22 may have a circular cross-section, and may be cylindrical so as to have parallel edges in profile. The portion of increased diameter 22 may be adjacent to the head 18, as shown in the cross-sectional view in Figure 4d. Figures 6a to 6c show the fastener 10 with the washer component 16 fitted thereto.

The portion of increased diameter 22 may be dimensioned to fit snugly inside the bore 24 of the washer component 16. With reference to Figure 6a, diameter "g" may be a maximum of 14.7mm in the example shown, the drive formation "h" may be a 5/16 inch hex drive, and the fastener type "i" may be 6-030-33061C4, M6-11 x 50 Hi Grip Hex Washer Zips. Turning to Figure 6b, in the example shown, head height "j" may be a maximum of 6.3mm, dimension "k" may be 50mm, grip length "1" may be 15.3mm, feature "m" is an M6-11 Hi Grip Thread, reference "n" is an SG Feature, reference "o" is an M6-11 Thread, and reference "p" is a Zips Point. In Figure 6c, washer type "q" is 6- 989-0031-2 14g Sealing Washer.

The washer component may have a Shore A hardness of 86 to 92, and more preferably 88 to 92, International Rubber Hardness Degrees (IRHD). This is above the top end of hardness specification for current washers which is 85 Shore A. The washer component 16 may be made of EPDM rubber, and the EPDM rubber may contain carbon. The washer component 16 is to be non-conductive and preferably has an electrical resistivity of at least 2000 M ohms.

The head 18 of the fastener component 14 may have a corrosion-resistant coating. While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

The reference in this specification to any prior publication (or information derived from it), or to any matter which is known, is not, and should not be taken as an acknowledgment or admission or any form of suggestion that that prior publication (or information derived from it) or known matter forms part of the common general knowledge in the field of endeavour to which this specification relates. Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

Claims

THE CLAIMS DEFINING THE INVENTION ARE AS FOLLOWS:

1. A fastener for fastening material to a structure, comprising a screw threaded fastener component and a sealing washer component, wherein the fastener component has a head and a screw-threaded shank, the sealing washer component is mounted around the shank to abut the head for sealing between the head and the material, wherein the shank includes a portion of increased diameter located to reside in a bore of the washer component when the fastener is tightened in place against said material.

2. A fastener as claimed in claim 1, wherein said portion of increased diameter is stepped outwardly from a main portion of the shank.

3. A fastener as claimed in claim 1, wherein said portion of increased diameter is tapered outwardly from a main portion of the shank.

4. A fastener as claimed in any one of claims 1 to 3, wherein the portion of increased diameter has a length substantially the same as a thickness dimension of the washer component.

5. A fastener as claimed in claim 4, wherein the portion of increased diameter has a length of between 1.5mm and 3.5mm.

6. A fastener as claimed in any one of claims 1 to 5, wherein the portion of increased diameter has a circular cross-section.

7. A fastener as claimed in claim 6, wherein the portion of increased diameter is cylindrical.

8. A fastener as claimed in any one of claims 1 to 7, wherein the portion of increased diameter is adjacent the head.

9. A fastener as claimed in any one of claims 1 to 8, wherein the portion of increased diameter is dimensioned to fit snugly inside the bore of the washer component.

10. A fastener as claimed in claim 2, wherein the portion of increased diameter has a diameter which is approximately 0.4mm larger than a diameter of the main portion of the shank.

11. A fastener as claimed in any one of claims 1 to 10, wherein the washer component has a Shore A hardness of 86 to 92 International Rubber Hardness Degrees (IRHD).

12. A fastener as claimed in claim 11, wherein the washer component has a Shore A hardness of 88 to 92 International Rubber Hardness Degrees (IRHD).

13. A fastener as claimed in any one of claims 1 to 12, wherein the washer component is made of EPDM rubber.

14. A fastener as claimed in claim 13, wherein the EPDM rubber contains carbon.

15. A fastener as claimed in any one of claims 1 to 14, wherein the washer component is non-conductive.

16. A fastener as claimed in claim 15, wherein the washer component has an electrical resistivity of at least 2000 M ohms.

17. A fastener as claimed in any one of claims 1 to 16, wherein the head has a corrosion coating.

18. A fastener as claimed in any one of claims 1 to 17, wherein said material is cladding material.

19. A fastener as claimed in claim 18, wherein said material is a sheet. A fastener for fastening material to a structure, comprising a screw threaded fastener component and a sealing washer component, wherein the fastener component has a head and a screw-threaded shank, the sealing washer component is mounted around the shank to abut the head for sealing between the head and the material, wherein the shank includes a portion located to reside in a bore of the washer component when the fastener is tightened in place against said material, and wherein the washer component has a Shore A hardness of 86 to 92 International Rubber Hardness Degrees (IRHD).

A fastener substantially as hereinbefore described with reference to the accompanying drawings.