AU605636B2 - Manufacture of wooden beams - Google Patents

Description

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Form PATENTS ACT 1952 COMPLETE SPECIFICATION

(ORIGINAL)

FOR OFFICE USE Short Title: Int. Cl: h Application Number: Lodged:

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*.ji tDInplete Specification-Lodged: Accepted: Lapsed: Published: 4* 44 49 Related Art: 4S

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-10cinll, cofl Utils thec ~e~pJmc (S adeunider it 49 mxd is correct for 4* .4 9 Ii Nia t me of Applicant: Aft~.ss of Applicant'.

TO BE COMPLETED BY APPLICANT EZIJOIN PTY. LTD., a company incorporated under the Tawsof the state of Victoria, of 40 Beach Street, Port Melbourne, Victoria 3207, Australia.

Actual Inventor: -FRANCIS IAN EZARD Address for Service,. Care of: COWXI CARTER HENDY, Patent Attorneys, 71 queens Road, Melbourne, Vic., 3004, Complete Specification for the invention entItledt Asrla MANUFACTURE OF WOODEN BEAMS The followIng statement Is a full description of this invention, including the best method of performing It known to Notet The description is to be typed In double spacing, pica typo Jac*, in an area not exceeding 250 mm In depth and J100mm In width, on tough white paper Of good qualtY and It to to be Insewed Inside this form.

t4d99/78-L 141$917-t.Printed by CJ.TibomrsoN. Commonwealth Government Pintjr, Cantbetta

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i i BACKGROUND OF THE INVENTION This invention relates to improvements in the manufacture of wooden beams and relates particularly to improved apparatus for manufacturing wooden beams with butt-joined timber lengths.

In many applications in the building industry it is necessary to provide lengths of timber of substantial width and length in relation to thickness, such as for' use as structural beams, floor joists, lintel beams, roof beams, rafters and the like.

With present date timber shortages and environmental control regulations, it is becoming increasingly difficult to obtain desired solid timber in wide sections and long lengths, and in particular in defect-free quality.

In the past it has been known to provide spliced beams by edge gluing two or more separate lengths of timber.

It has also been known to butt-join timber lengths using known nail plates on either side of the lengths of timber to be joined and/or by machining interlocking formations, such as dovetail formations, in the ends of the timber lengths to be butt-jointed. Experience has shown that spliced beams and butt-joined beams formed by these known methods are unsatisfactory and uneconomic and such beams are generally usable only for substantially load-free applications.

BACKGROUND ART

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United States Patent Specification Nos. 2,877,520, 3,011,226 and 3,016,586 and Australian Patent Specification, No. 291,878 all disclose forms of structural wooden joints formed of timber members connected solely by metal plates having nail-like projections -1 -L i or teeth struck out from the plane of the plate and embedded in the timber members. Such plates very effective in the manufacture of trusses and similar timber structures having several timber members extending in different and being interconnected with each other by the disclosed nail plates, which are limited to flat c~onnectors.

United States Patent No. 3,305,252 discloses another form of nail. plate useful as a corner connector to be applied to two or three surfaces of a structure which intersect at an angle with respect to one another.

United States Patent No. 3,365,222 discloses a wall brace having a U-shaped joist receiving member and a gussetted projection which is secured to a wal.l or the *415 like. The joist receiving member has a number of inwardly extending teeth or fastening means which are driven or hammered into a joist to secure the joist relative to .~the wall or the like.

~'United States Patent No. 3,427,055 discloses another 2 a 0 form of plate connector for a corner joint having teeth of varying height to facilitate engagement of the teeth within the timber members forming the corner joint without distortion of the plate connector.

United States Patent No. 4,318,628 discloses a device for assembling and connecting two or more const Iruction 4 elements, the device being formed with seats to receive the elements in the desired relationship, and one or morelock 'ing projections intended to penetrate into the elements.

The projections extend from a bottom wall of each seat to engage and penetrate an and surface of the respective elements.

British Patent No. 1579794 relates to a modified forch of nail plate fastener particularly useful for Joining angula~ly related timber members. The fastener comprises a bent plate having teeth struck from each portion, at least come of the tooth having an angularly extending shank portion and a tip portion which projects from the shank towards the plate portion. This type of projection %2lr i 3 enables the fastener to be located in position before the tip portions of each tooth are driven into the timber members being connected, the shank portion then lying in the plane of the respective plate portion. Teeth of this type are commonly referred to as ",knuckle nails", While the prior art forms of fasteners may be used for joining timber members to form comers, trusses and the like, it has been found that such fasteners are ineffective for butt-joining timber lengths to produce structurally sound beams as the strength of such beams is restricted by the holding power of the projections or teeth embedded in the timber sections.

It is therefore desirable to provide an improved fastener which is effective to produce structurally sound timber beams by butt joining or splicing timber lengths.

It is also desirable to provide apparatus for producing butt-jointed beams which are able to be used in load carrying applications.

i It is also desirable to provide apparatus of forming a butt-joint between adjacent ends of lengths of timber which apparatus is economic to make and use and which results in a load carrying beam.

It is also desirable to provide apparatus for producing butt-joined beams which provide an alternative to solid timber beams of equivalent strength using more readily available component sections of better quality.

According to one aspect of the invention there is provided apparatus for forming a butt-joint between adjacent ends of abutting lengths of timber sections using a pair of joining plates each having a base part and integral side parts along opposite side edges of the base part and with timber engaging projections extending from the side parts, said apparatus comprising clamp means operable to hold said timber lengths 125 in end butting relationship, base press means mounted adjacent said clamp means and movable transversely irelative to the timber lengths after operation of the clamp means to engage one of the joining plates to press said base part of said engaged joining plate into operative engagement with coplanar surfaces of said held timber lengths at their abutting ends, side press means mounted adjacent to the clamp means and movable transversely relative to the timber lengths and relative to the base press means while the timber lengths are held by the clamp means and while the base part is held in pressed engagement with the timber lengths by the base press means so that the side press means engages said integral side parts of the respective joining plate and bends said integral side parts relative to the base part and into operative 4 engagement with opposed side surfaces of said held timber lengths at their abutting ends thereby embedding said projections into said timber lengths; the other of said pair of joining plates being similarly operatively engageable with the timber lengths at the joint opposite side by said base press means and said side press means.

The projections of both side sections may be of the "knuckle nail" type or may be of the tooth type commonly employed in other known forms of nail plate type fasteners.

The joining plate used in the apparatus of the invention is preferably formed with the base and side sections substantially coplanar although in a modified form, the side sections may extend at an angle to the base section, The base section is engaged with the timber lengths to be joined and the projections or driven fasteners are embedded into the timber lengths, which are maintained in end butted relationship.

The side sections are then folded around the sides of the timber lengths and the S4 projections struck from the side sections are embedded in the opposite sides of the timber lengths.

The butt-jointed timber lengths are thus firmly joined together with the joining plate engaging on three sides thereof, the projections or driven fasteners from the base section and the projections from the opposed side sections extending perpendicular to "",each other to interlock the joining plate to the timber sections, .The portions of the base and side sections immediately adjacent the corners of the U-shaped plate -4A- *are free of projections and holes and provide structural integrity and rigidity of the joint by providing areas along the corners which are not weakened by holes or struck projections. The strength of the joining plate is therefore enhanced by the rigid corner parts and resist tensile and shear forces transmitted to the joining plate through the projections and/or driven fasteners.

Freferably, the projections are struck from the side sections of the joining plate to extend at approximately 90 degrees to the plane of the respective side, although the projection angle may vary but preferably by not more than 5 degrees from the right angle. In a preferred form, the number of projections on each side section amount to no more than five projections per square inch of section area.

In one embodiment, said bending is performed by a rolling action using a forming roller which engages with the surface of one of the side sections opposite that surface from which the projections extend, the forming roller being moved in a direction perpendicular to the plane of the base section to roll the side section into engagement with the surface of the timber lengths. Preferably, a pair of forming rollers are used to simultaneously bend the side sections of the joining plate Into engagement with the opposed side surfaces of the timber lengths.

In another arrangement, for use particularly when the joining plate is formed with the side sections extending at an angle to the base section# the side sections are bent to engage the sides of the timber length by opposed presses acting on the side sections and compressing the sections and timber lengths therebetween to force the projections into the timber.

in the most preferted arrangements according to the invention, the butt-joined timber lengths are corinebted by a pair of joining plates the bases of which engage opposite sides of the timber lengths. The butt-joint~d timber lengths can then be used in any orientation and under any loading situation.

In order that the Invention and its manner of performance may be more fully understood, reference will now be made to embodiments of the invention with reference to the accompanying drawings, DESCRIPTION OF' T14E DRAWINGS Figur'e 1 is a side elevational view of butt-jointed timber lengths using a pair of joining plates of the present invention;f Figure 2 is a vitaw token along the line# 2-2 of V <2 Figure 1; Figure 3 is an end elevational view of a pair of Joining plates connected to abutted timber lengths, the plates being of a modified form; Figure 4 is a perspective view of the modified form of joining plate before being engaged and secured IL to the abutted timber lengths; Figure 5 is a view illustrating one method and apparatus for applying a joining plate to abutted end portions of timber lengthi; Figure 6 is a view illustrating a second form of apparatus; and t Figure 7 is a view illustrating a third form of apparatus.

DESCRIPTION OF THlE PREFERRCD EME1ODTME.NTS Referring to Figures 1 and 2 of the~ drawtngs# the joining plate 12 of this embodiment comprises, in its operative form, a base section 14 and side sections 16. Each of the base and side sections 14 and 16 have a plurality of projections'17 extending from the respective planes of the sections 14 and 16 and which are preferably formed from the plate material by a stamping operation.

The formation of the projections 17 thus produces the' plurality of slots 18 shown in Figure 1. As will be seen, the projections '17 extend substantially at right angles to the plane of tha rebpective base and side sections 14 and 16, altht.igh deviations of up to 50 can occur.

the joining plate 12 In operative engaged position on abutted and portions of two timber lengths 19, the projections 17 extending from the side sections 16*'interlock with the projections 17 extending from the base section 14 to thereby securely fasten the joining plate 12 to the timber lengths 19. Any load applied to a timber beam formed of butt-joined sections in accordance with the invention gives rise to tensil.e and shear forces which are distributed evenly through the joining plate 12, the jointed timber sections acting very much as though the timber beam was of a single length. Naturally, the dimensions of the joining plate 12, the projections 17 and the timber lengths 19 should be selected to ensure proper engagement between the joining plate 12 and the timbeir lengths 19 to provide the necessary strength.

The joining plate 12 is shown in Figures 1 and 2 in operative engagement with the abutted timber lengths 19. The plate 12, however, will normally be constructed as a flat plate having the desired projections struck from the plate material. In one form, the flat plate is continuously formed from a roll of steel in coil form which is passed through a stamping machine to form the projections. The plate material may then either be re- 5 coiled or cut to desired lengths. The projections 17 may be o#2 any suitable form known in the art. Thus, the projections 17 may be formed with barbs or teeth to more firmly engage in the timber lengths 19. The projections 17 each preferably lie in planes transverse to the longitudinal axis of the timber lengths 19. Other orientations of the projections, and the corresponding apertures 18 got formed thereby, may be adooted if desired. The projections ~17 may all be of one length or may be of varying lengths a aa for particular purposes.

Referring to Figures 3 and 4, a modified constiruction of joining plate i2a is shown which is identical to that of the previous embodiment except that the base section 14a is pr~ovided with holes 25 instead of projections.

The holes 25 enable fasteners, such as nails 20, to be to secure the base section 14a to one side of the I abutted timber lengths.

Further, the plate 12a is partially pre-bent# as~shown In Figure 4, to facilitate its engagement with the timber lengths 19 prior to the side sections 16 being bent to the aperture engaged position as illustrated in Figure 3.

As will be seen in the drawings, the joining plate 12 and 12a of both embodiments have areas of metal on the base and side sections adjacent the corners which are free of holes 18 and 25, thus providing structural integrity of the plate along each corner which enhances plate rigidity and strength in use.

Further, the provision of such areas free of holes ensures that edges of the timber lengths joined are not split, and therefore weakened, by projections or nails positioned too close to the respective edges.

Referring to Figures 5 to 7, three different forms of apparatus for applying a joining plate of the invention to abutted timber lengths are illustrated.

Figure 5 illustrates apparatus for applying the joining plate 12 to the timber lengths 19 using a press plate 21 and rollers 22. The joining plate 12 is Initially Ii 5 formed as a planar plate with the plurality of projections 17 extending from one surface thereof. With the abutted end portions of the timber lengths 19 held together, the base section 14 of the plate 12 is engaged with side surfaces of the timber lengths 19. The press plate 21 which is hydraulically or pneumatically operated forces the base section 14 against the surfaces of the timber lengths V 19 so that the projections'17 extending therefrom become I embedded in the timber.

I Form rollers 22 are then moved to engage the side sections 16 of the plate 12 and further movement of the h form rollers 22 in the direction of the arrows shown in Figure 5 causes the side sections 16 to bond about the edges 23 of the timber lengths 19. The side sections 16 are, finally rolled into engagement with the opposed side surfaces 24 of the timber lengths 19 with the projections 17 extending from both side sections 16 embedded A in the timber.

It is a feature of this embodiment of the invention that the movement of the form rollers 22 initially bonds both side sections 16 in such 4i way that the eqds of the projections closest to the edges 23 engage with the side surfaces 24 a distance from the edges 23 which substantially corresponds with the distance between the projection ends and the edges 23 before engagement of the ba ,a section 14 on the timber sections 19. In other words, when the projections 17 closest to the edges 23 are rolled into the timber those projections remain substantially perpendicular to the side sections 16 and the rolling action causes a neat penetration resulting in the projections being firmly embedded.

Two stages of the rolling of the side sections 16 iato engagement with the end portions 19 are illustrated in dotted lines In Figure S.

Figure 6 illustrates a second form of apparatus designed for use with a joining plate 12, having pre-bent side sections 16 and projections 17 extending from the base section 14 and the side sections 16, The end-abutted ;15 timber lengths 19 to be joined are supported by means inot shown) to enable the press plate 32 to press the base section 16 against a side surface of the timber length 19 so that the depending projections 17 penetrate the timber.

20 The opposed press plates 33 and 34 are then moved together to press the side sections 16 against the timber surfaces with the depending! projections 17 penetratzng dad the timber to be secured thereto. It has been found that, subject to timber density, the side sections 16 tend to bond about the points of engagement of those projectidns 17 nearest the corners 23 before those projections are driven into the timber. This tends to ensure that the projections are driven in a substantially perpendicular direction.

Figure 7 shows apparatus similar to that of Figure except that, instead of form rollers to bend and secure the sloie sections 16# press plates 36 and 37 are pivoted to Z~ppoolte side edges of the central press plate 38.

The pivot connections 39 ensure that the press plates 36 and 37 move in the necessary arc to bond and secure the side sections 14 of the joining plate 12 in position*.

A hydraulic or pneumatic cylinder 41-t piston rods 42 and lovers 43 transmit the required motion and securing forces to the press plates 36 and 37.

Claims (7)

1. Apparatus for forming a butt-joint between adjacent ends of abutting lengths of timber sections using a pair of joining plates each having a base part and integral side parts along opposite side edges of the base part and with timber engaging projections extending from the side parts, said apparatus comprising clamp means operable to hold said timber lengths 'n end butting relationship, base press means mounted adjacent said clamp means and movable transversely relative to the timber lengths after operation of the clamp means to engage one of the joining plates to press said base part of said engaged joining plate into operative engagement with coplanar surfaces of said held timber lengths at their abutting ends, side press means mounted adjacent to the clamp means and movable transversely relative to the timber lengths and relative to the base press means while the timber lengths are held by the clamp means and while the base part is neld in pressed engagement with the timber lengths by the base press means so that the side press means engages said integral side parts of the respective joining plate and bonds said integral side parts relative to the base part and into operative engagement with opposed side surfaces of said held timber lengths at their abutting end,, thWreby embedding said projections Into said timber lengths; the other of said pair of joining plates being similarly operatively engageable with the timber lengths at the joint opposite side by said base press means and said side press means,

2. An apparatus according to claim I wherein the joining plates each have timber engaging projections extending from their base parts and said base press means engages and moves each respective joining plate with a force such that the projections extending from each said base part embed into said timber lengths.

3. Apparatus according to claim 1 wherein said side press means to engage said side parts Includes a pair of form rollers movable substantially perpendicular to the plane of said base part.

4. Apparatus according to claim I wherein said side press means to engage said side parts includes a pair of press members movable towards each other, Apparatus according to claIm 4 w herein said press members are each pivoted relative to said base press means and are movable about said pivots to bend said side parts nbout edges of said coplanar surfaces into engagement with the opposed sides of sald tliber lengths.

6. Apparatus neearding to claim I wherein said base press means comprises a A S__ i 11 plate having a width not exceeding the width of the timber lengths, said plate being mounted on a hydraulic or pneumatic cylinder and movable towards and away from the timber lengths.

7. Apparatus according to claim 6 wherein said engaging means comprises a pair of rollers spaced apart about the width of the timber lengths, the rollers moving parallel to the plate when the base part is engaged with the timber lengths.

8. Apparatus for joining timber lengths substantially as hereinbefore described with reference to the accompanying drawings. DATED this 18th day of October, 1990. EZIJOIN PTY. LTD. 4 4,rr 4 P1 4 4 *I 4 #4 4*r 4491 9 9<1 i i 64~ p~ rJiiltl J i byi~e. jb