AU749290B2 - Fastening system for structural framing elements - Google Patents

Description

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AUSTRALIA

PATENTS ACT 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT O RI GI NA L

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S S S. S Name of Applicant: Actual Inventor: IHERIBERT H A' N k-cj,41 P~y L 4-c ic. Herbert HAHN ADDRESS FOR S1

ALTERED

Address of Service: BAI=BWIN 91 E. STANWATERS MAR EET -1 4EY NSSW 2 c 4 cA*~SA ~ooo

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Invention Title: "FASTENING SYSTEM FOR STRUCTURAL FRAMING

ELEMENTS"

Details of Associated Provisional Application No. PP 0042 dated 27th October 1997 The following statement is a full description of this invention, including the best method of performing it known to me:- -2- The present invention relates generally to structural framing systems and more particularly to framing members adapted for interconnection with like members to form a structural frame.

The invention has been developed primarily for use in the building industry, for the construction of steel framed houses. The invention will therefore be described primarily with reference to this application. It will be appreciated, however, that the invention is not limited to this particular field of use.

In the past, houses have typically been constructed by first erecting a timber frame.

An internal lining material such as plasterboard is then applied to the interior of the 10 frame to form the internal walls. The external walls are typically formed from single or double brick or a suitable cladding material such as fibre reinforced cement (FRC) sheet, weatherboard, aluminium cladding, or the like.

S1: ~A major problem with this form of housing construction is that it requires substantial use of relatively skilled labour on site. In particular, builders and carpenters see.

15 are required to construct the frame, which is a time consuming and costly process. A further problem is that most of the framing work needs to be performed on site, following architectural plans. Accordingly, there is little scope for modular construction or prefabrication off site, whereby automated fabrication processes might otherwise lead to cost efficiencies. Moreover, as supplies of suitable timber begin to diminish, the cost of the raw materials are also increasing.

In an attempt to address some of these problems, it is also known to construct houses from steel frames. Typically, the structural framing members have comprised channels roll formed from galvanised steel. Such channels would typically have a web -3width of around 75 mm, a flange depth of around 32 mm and a metal thickness of around 1 mm and as such, are dimensioned to function in the same way as conventional wall studs, top plates, bottom plates, noggins, and the like. Whilst structural members of this type are themselves comparatively inexpensive to produce, it has been found that the individual framing members are difficult to join together in a reliable, secure and costeffective manner.

For example, it is known to join galvanised steel framing members together by means of spot welding. However, this requires the use of relatively heavy, cumbersome and expensive welding equipment on site. Such equipment is not always conveniently Se.

i: 10 available and in any event, involves additional cost. It is also reliant upon the e availability of electrical power. A further disadvantage with spot welding and other welding techniques is that the protective galvanised coating is destroyed in the heat affected areas, thereby rendering the frame vulnerable to corrosion in the vicinity of the joins.

15 It has also been known simply to join the steel framing members by means of nuts and bolts. However, this is a particularly time consuming assembly process and can only be used in situations where both sides of the channel flanges or webs are readily accessible. A further disadvantage is that either the nut or bolt head inevitably protrudes beyond the surrounding surface of the framing member. This creates additional difficulties where plasterboard or other lining or cladding materials must subsequently be fastened to the frame, as is usually the case.

Pop riveting has also been used as a fastening technique. However, it has been found that rivets typically possess inadequate load bearing capacity, whether subject to direct bearing loads or shear stress, unless used in relatively large numbers which adds considerably to the construction time and tends to off-set the benefit. Self-tapping screws have also been used. However, these have been found to suffer similar problems in terms of inadequate strength. In particular, the threads have been found to strip under relatively modest loads, making the technique unsafe in structural applications.

It is additionally know to join steel framing elements by means of clinching. This involves permanently deforming two overlapping portions of sheet metal, by means of an appropriately shaped pinch and die assembly, into an integral flared head formation, by virtue of which the sheets are mechanically interlocked. To date, however, clinching techniques have been unable to consistently and reliably produce the required "pullout" strength. For this reason, clinching has failed to gain widespread acceptance in the context of steel framing within the building industry.

It is an object of the present invention to overcome or substantially ameliorate at least some of these disadvantages of the prior art.

Accordingly, the invention provides a framing system comprising a first thin walled framing element having a protruding tongue formation and a second thin walled framing element having a complementary slot, said tongue formation being adapted to pass through said slot and subsequently to be deformed sufficiently to prevent withdrawal, thereby joining the first and second framing elements; and wherein each tongue formation includes an aperture adapted, upon folding, to align with a complementary aperture formed in the second framing element behind said slot to receive a supplementary fastening element.

Unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', and the like are to be constructed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Preferably, the first and second framing elements comprise U-shaped elongate channel sections defined by parallel side flanges and an intermediate web. The channel sections are preferably roll formed from galvanised steel or another suitable metal. It will be appreciated, however, that any suitable material, even plastics, may alternatively be used.

The tongue formation is preferably an extension of the web and initially extends in a direction parallel to the general longitudinal extent of the first framing element. The slot is preferably formed adjacent one end of the second framing element and extends S.transversely across the web. The tongue of the first element is preferably deformed by oooo folding through 900, so as to lie substantially flat against the web of the second element.

:In the preferred embodiment like tongues are disposed on opposite ends of the 15 first framing element to form a framing stud. In this embodiment. Like slots are i similarly formed on opposite ends of the second framing element. In this configuration, •*go the second framing elements can be used for form top and bottom plates, adapted for connection to a pair of spaced apart studs in orthogonal relationship.

In the preferred embodiment, the supplementary fastening element includes a plastic plug or like connector. It will be appreciated, however, that rivets, tack screws or other fasteners may alternatively be used.

A preferred embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:- -6- Figure 1 is a perspective view showing a first framing element of a framing system according to the invention; Figure 2 is a perspective view showing a second framing element according to the invention; Figure 3 is an exploded perspective view showing a first mode of assembly for the first and second framing elements of Figures 1 and 2; Figure 4 is a perspective view showing the framing elements in a second mode of assembly; and Figure 5 is a plan view showing a third mode of assembly.

10 Referring firstly to Figure 1, the invention provides a first framing element 1 in the form of a generally U-shaped channel section. The channel is roll formed and punched from galvanised steel and is defined primarily by side flanges 2 and an intermediate web 3. The channel is approximately 75 mm wide, 32 mm deep and the steel around 1 mm thick. The web 3 has a central longitudinally extending depression 4 to enhance bending 15 strength and torsional rigidity. The first framing element further includes a tongue formation 5 extending from the web 3 in a direction generally parallel to the longitudinal •extent of the framing element.

Referring to Figure 2, the invention further provides a second framing element which, like the first element, is roll formed and punched from galvanised sheet steel as a channel defined primarily by side flanges 2 and an intermediate web 3. The second framing element further includes a slot 11 extending transversely across the web closely adjacent the end of the section.

-7- As best shown in Figure 3, like tongues 5 are disposed on opposite ends of the first framing element 1 to form a framing stud 15. Similarly, slots 11 are disposed on opposite ends of each second framing element 10 to form respective top and bottom plates 16 and 17. As will be appreciated from the drawing, each tongue is adapted to pass through the adjacent slot and thereafter to be deformed by folding flat against the web of the respective top or bottom plate, to prevent subsequent disengagement. It will be appreciated that the tongue formation, once folded flat, is accommodated entirely within the depression 4, so as not to protrude above the upper surface of the associated •gig o channel web. The tab 18 protruding beyond each slot 3 is similarly folded against the o• web of the adjoining stud, for additional strength. In this way, a pair of spaced apart *studs are easily and conveniently joined to top and bottom plates in orthogonal relationship to form a structural frame without any mechanical, electrical or other extraneous fastening means.

Each tongue 5 includes a circular aperture 20 adapted, upon folding, to align with a 15 complementary elongate aperture 21 formed in the adjacent section of the web of the adjoining second framing element, behind the slot 11. The apertures 20 and 21 thus .ooo aligned are adapted to receive a supplementary fastening element such as a plastic plug, rivet, tack screw and the like (not shown). This supplementary fastener adds a degree of additional rigidity and also prevents the tongue from folding out under load, which might otherwise allow inadvertent disengagement of the framing elements.

Cross braces in the form of channel members or steel straps (not shown) are positioned to extend diagonally between the top and bottom plates 16 and 17. A similar -8joining mechanism may be employed by engaging tongues formed on the cross braces with secondary slots 11 A.

Figure 4 shows an alternative mode of connection wherein a pair of the first framing elements 1, in the form of noggins 22, are joined to an intermediate stud 15. In this case, it will be appreciated that the mutually opposing tongue formations 5 on the adjacent ends of the noggins extend through the same slot 11 in the stud. In this configuration, the tongue of the first noggin rests below the web of the second noggin whereas the tongue of the second noggin rests above the web of the first noggin. Any oooo resultant vertical misalignment is minimal and in any event, may be corrected by a slight I0 deflection of the tongues. In this mode of operation, it will be appreciated that the tongues are not folded or otherwise substantially deformed. Rather, the apertures 20 and 21 are aligned, permitting the noggins to be joined by supplementary fastening elements 25, again in the form of plastic plug connectors, rivets including pop rivets, tack screws or the like.

•15 Figure 5 shows a further mode of connection wherein four studs are connected at a junction, for example at the intersection of three walls, by means of a central connector 30. The central connector has a plurality of outwardly depending tongue formations 31 having apertures 32. The tongues extend through slots such as 11 and 11 A in the framing elements and thereby function in an analogous manner to the tongues 5 and apertures 20, as previously described.

It will be appreciated that the invention thus provides a simple, relatively inexpensive and efficient framing system which can be entirely prefabricated, and assembled on site with minimal skilled labour and with no specialised tools. Moreover, -9the joining technique does not damage the galvanised coating on the steel. The framing assembly can also be readily disassembled and the elements reused, if desired. The system further provides adequate structural integrity for housing construction. In all these respects, the invention thus provides a practical and commercially significant improvement over the prior art.

Although the invention has been described with reference to specific examples, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.

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Claims (17)

1. A framing system comprising a first thin walled framing element having a protruding tongue formation and a second thin walled framing element having a complementary slot, said tongue formation being adapted to pass through said slot and subsequently to be deformed sufficiently to prevent withdrawal, thereby joining the first and second framing elements; and wherein each tongue formation includes an aperture adapted, upon folding, to align with a complementary aperture formed in the second framing element behind said slot to receive a supplementary fastening element.

2. A framing system according to claim 1, wherein said first and second framing elements comprise generally U-shaped elongate channel sections defined by generally parallel side flanges and an intermediate web. S 15

3. A framing system according to claim 2 wherein said web has a generally 0 o central, longitudinally extending depression to enhance bending strength and torsional 0: rigidity. .040

4. A framing system according to either claim 2 or claim 3, wherein said channel sections are roll formed from galvanised steel. 20

5. A framing system according to any one of claims 2 to 4, wherein said tongue formation is an extension of said web and initially extends in a direction generally parallel to the longitudinal extent of said first framing element.

6. A framing system according to any one of claims 2 to 5, wherein said slot is formed adjacent one end of said second framing element and extends generally transversely across said web.

7. A framing system according to any one of claims 2 to 6, wherein like tongues aredisposed on opposite ends of said first framing element to form a framing stud. 11

8. A framing system according to claim 7, wherein like slots are formed on opposite ends of said framing element thereby facilitating the use of said second framing element as a top or bottom plate adapted for connection to a pair of spaced apart first framing elements in generally orthogonal relationship.

9. A framing system according to any one of the preceding claims wherein a tab protrudes beyond at least one of said slots.

A framing system according to claim 1 wherein said supplementary fastening element is a releasable plastic plug.

11. A framing system according to claim 1 wherein said supplementary fastening element is a tack screw. :0:00,

12. A framing system according to claim 1 wherein said supplementary fastening @oll 0• element is a pop rivet. S:

13. A framing system according to any one of the preceding claims, wherein said S* first framing element includes a number of said tongue formations for joining with a plurality of adjacent second framing elements. o•

14. A framing system according to any one of the preceding claims, wherein following insertion of said tongue into said slot, said tongue is deformed by folding through approximately 900 so as to lie substantially flat against said web of said second element.

15. A framing system according to claim 14, wherein said tab is adapted subsequently to be folded against web of the adjoining first frame element for additional joint strength.

16. A framing system according to any one of claims 3 to 15 wherein following said deformation, said tongue is substantially accommodated within the depression in the web. 12

17. A framing system substantially as herein described with reference to any one of the embodiments of the invention as illustrated in the accompanying drawings. Dated this 8~ Day of March 2002 Sekwah Pty Ltd trading as Austveyors (SA) By their Patent Attorneys Lesicar Perrin 0 00 0 0 0000 *0 00 0 0* 0* 00 0 0 0 00 0 00 0* 0 0000 0 *000 00 00 **00 0 0 0000 00 00 0 000000