AU693165B2

AU693165B2 - Connectors for dog-bone beams

Info

Publication number: AU693165B2
Application number: AU17801/95A
Authority: AU
Inventors: Samuel Murray Ford Johns; Robin William Minogue; Ian Malcolm Ronald Worthington
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-04-28
Filing date: 1995-04-28
Publication date: 1998-06-25
Anticipated expiration: 2015-04-28
Also published as: AU1780195A

Description

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MIZIR

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT APPLICANTS and Inventors: JOHNS, Samuel Murray Ford MINOGUE, Robin William WORTHINGTON, Ian Malcolm Ronald 800084 4 8 ADDRESS FOR SERVICE: Paul A Grant and Associates P0 Box Fisher, ACT 2611 INVENTION TITLE: CONNECTORS FOR 'DOG-BONE' BEAMS

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ASSOCIATED PROVISIONAL APPLICATION: Nil The following statement is a full description of this invention, including the best method of performing it known to me:i Lii 2 TECHNICAL FIELD This invention relates to means for connecting steel (or other metal) I-beams of socalled 'dog-bor.d' section. Such 'dog-bone beams' are typically roll-formed from steel strip to form a hollow, triangular-section chord along each edge of the strip, the edge itself being returned and automatically welded to the central portion of the strip which forms the web of the beam that separates the chords.

The invention is particularly concerned with connector means which will allow such Sbeams to be easily connected in angle and T-joints on a construction site.

BACKGROUND TO THE INVENTION Dog-bone beams are supplied commercially in two or three basic sizes and are lightweight and economical in comparison with hot-rolled steel bpams, otherwise known as RSJs (rolled steel joists). They are becoming popular in Australia for the framing of sheds and light industrial buildings because they are cheaper and lighter than RSJs (hot-rolled steel joists). They are of great potential value to farmers, for example, for the framing of farm sheds.

*q4#4 However, joining dog-bone beams at the angles and in the manner needed to fabricate a building with a gabled roof beams, or with rafter-to-wall joints for example, presents awkward problems for farmers and other would-be users. The large nonrectangular hollow chords make the beams extremely difficult to cut on-site at an angle with the precision needed for effective welding of the relatively light-gauge sheet metal. Accordingly, the normal procedure for joining or connecting dog-bone beams is to weld or bolt patch-plates to the webs of the beams. Because the web of a dogbone beam is much less deep than that of an RSJ of the same general overall dimensions, the patch plates need to be of heavy section and relatively long in n comparison with similar plates used for RSJs. This makes them difficult to cul and drill on-site, but when they are drawn-up, manufactured and drilled (together with matching holes in the beam webs) by the steel supplier, their cost can often exceed the cost of the beams themselves. Thus, much of the cost and convenience advantage of dog-bone beams is lost.

3 Of course, the alternative to obtaining properly designed and manufactured plates is to fabricate them on-site using flame cutters and drill-presses. This is time consuming V and often results in joints which are structurally inferior, if not actually dangerous.

OBJECTIVES OF THE INVENTION J Accordingly, it is an objective of the present invention to provide a connector system and connectors for use with metal I-beams in general and dog-bone beams in particular, which will permit ready on-site fabrication of metal frame structures without the need for heavy tools or work-shop fabrication of custom joining plates.

OUTLINE OF INVENTION The present invention is based upon the realisation that the ends of the beam to be joined can be encased within a pre-formed multi-part or split sock or sleeve of sheet metal which fully encircles and closely fits the profile of the dog-bone beam ends to be connected. Preferably, each part of the sock or sleeve is press-formed from a single piece of metal. By fully encircling the portions of the beams to be joined (which is effected by overlapping opposing parts of the sleeve), two important o~ advantages are obtained: a standardised joint is produced with designed-in strength, and, sufficiently light-gauge material can be used to permit the use of many small- 20 diameter bolts, the holes for which can be readily drilled with light portable power drills. Indeed, and preferably, self-drilling and self-tapping bolts are used for this purpose.

To help ensure that the correct number and gauge of bolts are used in each part of 25 the joint, the sleeves may be pre-printed or pre-punched to indicate wh'aro-very bolt is required. Moreover, it is envisaged that they will be marked to ensure that, where self-tapping bolts are used, they are inserted from both sides of each part of the sleeve.

From one aspect, the invention comprises a connector sleeve for joining the juxtaposed ends of two dog-bone section beams of the same size together in a structural manner, said connector sleeve comprising: rz~h -1~ j '-i -f 4 a first elongate element formed from sheet metal to closely conform with the profile of the side of the beam section, said element including upper and lower flanges conforming to at least portion of the upper and lower chord faces (respectively) of the beam section, and 5 a second elongate element formed from sheet metal to also closely conform with the profile of the side of the beam section, said second element also including upper and lower flanges conforming to at least portion of the upper and lower chord faces (respectively) of the beam section, such that said elements of the connector sleeve can be brought together from opposing sides of the juxtaposed ends of the beams to be joined so as to completely encircle them, the said upper and lower flanges of the elements overlapping one another on the upper and lower chord faces of the beam, and such that the elements maybe readily secured to one another and to the beam by bolts or screws driven through the elements and into the beam.

DESCRIPTION OF EXAMPLES Having broadly portrayed the nature of the present invention, particular embodiments will now be described by way of example and illustration only. In the following description, reference will be made to the accompanying drawings in which: Figure 1A is a perspective of a three-part T-joint sleeve for use in effecting a T-joint between two dog-bone beams, the beams not being shown in this view. This joint comprises the first example of the application of the invention.

25 Figure 1B is a perspective of the joint of the first example (shown in Figure 1A), prior to fixing, showing one of the two dog-bone beams in place.

Figure 1C is a perspective of the joint of the first example after being fixed to two dog-bone beams so as to complete the T-joint.

Figure 2A is a perspective of an angle-joint sleeve which comprises the second example of the invention, the joint being shown ready for assembly about two beams arranged at right angles.

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I *0* 4 I I Figure 28 is a perspective of a completed angle-joint sleeve of the second example shown in Figure 2A.

Figure 3A is an exploded perspective of a ridge-joint sleeve ready for assembly about a pair of dog-bone beams which are arranged to form a ridged roof beam. This joint comprises the third example of this invention.

Figure 3B is a perspective of the joint of the third example after completion.

Figures 4A and 4B are respectively a side elevation and a sectional end elevation of a modified gable joint like that of Figures 3A and 38.

Turning more particularly to Figures 1A-1C, the first example of the use of a connector formed in accordance with this invention concerns a T-joint to be effected between tw, horizontal and coplanar dog-bone beams arranged with their webs vertical. Such joints are required, for example, between the ends of floor joists and the side of the bottom plate of a wall, or between ceiling joists and the top plate of a o wall. The connector sleeve 10 comprises three parts or elements each formed by o 444 cold-pressing a single strip of sheet steel. There is a straight back element 12, a left- 20 side right-angled element 14 and right-side right-angled element 16, each having a profile which conforms closely to that of the beams to be joined.

@4 41 Figure 2B shows a joist beam 18 slipped in place between left and right sleeve elements 14 and 16. It will be seen that the dog-bone beam has upper and lower 25 triangular-section hollow chords 20 and 22 joined by an integral web 24. Each connector element is formed with upper and lower flanges which conform closely to the profile of the chords of the beam. Thus straight element 12 has upper and lower p C-shape flanges 26 and 28 (Figure 1A), left element 14 has similar upper and lower flanges 30 and 32 while right element has similar upper and lower flanges 34 and 36.

As will be most clearly seen from Figure 1 A, the corresponding flanges or the left and right joint elements 14 and 16 are arranged so that they overlap one another when they are fitted around beam 18 so that the beam is tightly closed thereby. Though more clearly shown in the completed joint of Figure 1C, the flanges of the left and .nnn i I 0- 6 right elements which oppose those of the straight element are also arranged to overlap one another when the connector 10 is assembled.

In Figure 1 C, the completed connector 10 is shown affixing joist beam 18 to wall-plate beam 40, the joint being secured by the use of many small-diameter sc.;-drilling and self-tapping screws or bolts, some (42) being driven vertically through the tops and bottoms of the connector flanges into the chords of the beams while others (44) are driven horizontally through the webs of the connector elements and the webs of the beams. Screws or bolts 44 are preferably driven alternately from opposite sides of the connector and are not fitted with nuts.

Turning now to Figures 2A and 2B which illustrate a right-angle connector 50 that comprises the second example of the application of this invention, Figure 2A shows an inner connector element 52 and an outer connector element 54 as they are being assembled about two dog-bone beams 56 and 58, and Figure 2B showing the completed joint. Beams 56 and 58 may be the bottom plates, or the top plates, of two adjacent side walls of a building. In this example, each element is again coldpr -ed from a single strip of steel. As in the first example also, the flanges of two elements overlap as they are placed around the beams and the connection is secured by a series of vertically-oriented screws 60 driven through the flanges of the elements into the chords of the beams, and, a series of horizontal screws 62 driven through the webs of the elements into the webs of the beams.

b S 0I The final example, shown in Figures 3A and 3B, is concerned with a connector 70 for effecting a ridge-joint between two dog-bone roof-beams 72 and 74 at an angle of, say, 12 degrees. Here, the beams will be arranged in a common vertical plane with their webs vertical. The connector 70 of this example also comprises two elements 76 and 78 cold-pressed from single strips of sheet steel to conform to the profile of the beams. In this case, however, the webs of the elements and the beams are essentially coplanar rather than angled. The joint is shown in exploded form in Figure 3A and as completed in Figure 3B. As before, the flanges of the elements of the connector are overlapped so as to form a sleeve which closely encircles the beams and, also as described above, the connector is completed by the use of vertical bolts n J 7 or screws 80 which enter the chords of the beams and horizontal bolts or screw 82 which are driven into the webs of the elements and the beams.

Finally, Figures 4A and 4B show a similar gable joint 90 to that of Figures 3A and 3B fixed to roof beams 92 and 94. The difference here is that integral triangular bracing plates 96 and 97 are formed on each half of the joint 90 and are bolted together with bolts. Thus, the bottom edges of joint-halves 90 do not overlap one another as in the case of the joint of Figures 3A and 3B.

While it will be appreciated that the examples of the invention described above meet the objects and advantages set out at the beginning of this specification, those skilled in the art will understand that many variations and modifications can be made to the invention as disclosed without departing from its scope as defined by the following claims.

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