AU785224B2 - Truss jigging/pressing systems - Google Patents

Description

AUSTRALIA

Patents Act 1990 P/00/011 Regulation 3.2

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT r Invention Title: TRUSS JIGGING/PRESSING SYSTEMS TTAI/ /-iusratia P Ld PRYDA (AUCT.) Prim LTD Applicant: The following statement is a full description of this invention, including the best method of performing it known to me: WwSH.aRONAiamM«PCTCOMPFOBMSPCTmFOBWS1DC T r 1 TRUSS JIGGING/PRESSING SYSTEMS This invention relates to improvements in jigging and pressing systems for the production of timber trusses, such as roof trusses. The invention relates more particularly to locator stops (also known as pucks) for use in truss jigging and pressing systems, and to tables and jigs having such stops or pucks.

Truss jigging and pressing systems are known. One form of such a system includes a truss table having a longitudinal series of table sections in which successive sections are separated by a respective transverse slot. Each table section can include a longitudinal series of transversely disposed relatively narrow panels with successive panels also separated by a respective transverse slot. Some slots, typically those between table sections, have a S. respective conveyor device able to be raised from a lower, retracted position to a position in which it is operable to move a substantially completed truss 15 laterally off the table. Other slots house either fixed nuts or movable carriers to each of which a respective locator stop or puck is able to be secured on the top surface of the table, by means of a bolt. Alternatively, the table can include a plurality of bore openings rather than slots and the locator stops or pucks are secured to the table through those openings. The openings typically would be spaced at equal intervals in an array across the table, say at 150mm spacing.

The stops are able to be secured in an array over the table surface, as required to enable them to accurately position sections or lengths of timber which are to be secured in assembly to form a timber truss of a required configuration in which the timber sections comprise chords and webs. The timber sections are at least partially secured at junctions therebetween by toothed truss plates or nail plates which have been pressed to force teeth of each plate into each of the timber sections forming a respective joint.

Another form of truss jigging/pressing system employs a jig rather than a table, which has a plurality of channels for support of the truss sections and to which locator stops or pucks can be secured. Still another form of truss jigging/pressing system includes a supporting jig or table for supporting truss sections and employs one or more C-clamps for clamping about each joint of the truss and pressing into that joint the relevant toothed truss or nail plate. The present invention is applicable to each of the above forms of truss W:%SK&ROMArdru*%PCTCOK-%TnzspgoVawrlpLdoc jigging/pressing systems. It will be convenient however to describe the invention in relation to its use with truss tables, although it should be appreciated that the invention is not restricted to that use, but could be employed in other truss jigging/pressing systems.

The truss or nail plates usually are partially pressed by a relatively light, travelling pressure roller which is passed over the truss table or by a platen press. The resultant partially completed truss then is moved off the table and pressing is completed by heavier finishing rollers. This double pressing procedure is used because pressing on a table takes place from the upper side of the table only, and the load applied is so great as to be likely to deform the panels of the table. The heavier finishing rollers typically apply load to each side of the truss.

In addition to these constraints on pressing, the locator stops or pucks are such that considerable time is expended in securing them in required 15 positions. Usually, each is secured by an Allen bolt, tightened relative to a nut or carrier. This needs to be done carefully for each stop in turn to ensure that none of the stops is able to be inadvertently displaced during jigging and pressing. In applicant's co-pending Australian patent application 59591/99, locator stops or pucks are disclosed that facilitate simplified placement and securing of locator stops or pucks on the truss table.

A further difficulty associated with known locator stops or pucks is that sometimes the timber used in truss construction does to always sit hard or firmly against each locator stop or puck. This can be the case particularly in relation to the bottom chord of a truss, generally because of slight misalignment of the machinery of the jigging/pressing system. The position tolerance of the bottom chord is typically 5mm, so that the locator stops or pucks associated with the bottom chord have to be shifted forward or back relative to the timber a relatively small distance. Altematively, a length of timber several metres long may bow from one end to the other, rather than being completely straight.

When positioned on the truss table, the timber may therefore sit away from one or more pucks, so that the truss sections are not firmly held in place. In that situation, it is necessary for the truss fabricator to shift the locator stops or pucks into engagement with the timber, or to proceed without firm engagement.

Shifting the locator stops or pucks can be tedious and time consuming even W:%SHARONAndrewUNCTCOMPTnnspggtVcwnpLLioc 3 with applicant's more readily movable locator stops or pucks, while the absence of firm engagement can result in the truss being constructed inaccurately.

The present invention is directed to providing an improved form of locator stop (or puck), and a truss table having such stops or pucks. At least in preferred forms, the stop of the invention enables at least some disadvantages of the known stops to be overcome or alleviated.

According to the present invention there is provided a puck including a mounting device, which is configured for mounting said puck on a truss table or the like and which includes first locking means for locking said device to the truss table, a locating member which is eccentrically mounted on said mounting device for relative rotation about an eccentric axis, said locating member having an external peripheral surface against which a timber section of a truss bears during truss fabrication, eccentric rotation of said locating member permitting said peripheral surface thereof to be shifted from a position spaced from 15 engagement with the timber section, to a position of engagement with the timber section, second locking means being provided to lock said locating member relative to said mounting device in a position of rotation of said locating member in which said external peripheral surface bears against said timber section.

As discussed earlier, the invention has application to various types of "-'*truss jigging/pressing systems, although for convenience, further discussion will relate only to the use of the invention with systems which employ truss tables.

A puck according to the invention advantageously facilitates bearing engagement with the timber section of a truss despite the existence of misalignment in the system or deviations in the timber that causes the timber to be spaced from proper engagement with the external peripheral surface of the locating member when the timber sections of the truss are assembled on the truss table. When such a spacing exists, the locating member can be eccentrically rotated relative to the mounting device to shift the external peripheral surface into engagement with the timber section and to thereby provide firm support for the timber section. The second locking means can be arranged so that rotation can be effected simply and quickly and without the need to shift the mounting device relative to the truss table.

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4 The spacing that can be taken up by rotation of the locating member typically will be small, such as less than 20mm, although the locating member can be shaped for taking up larger spacings as required. The amount of maximum spacing take up will depend on the shape of the locating member and on the eccentricity of its mounting to the mounting device. The take up amount further can be influenced by the range of rotation of the locating member relative to the mounting device.

The locating member preferably defines a circular external periphery and is mounted to the mounting device eccentrically relative to its central axis.

Preferably the locating member will be formed as a circular disc having substantially planar upper and lower surfaces and the external peripheral surface extending perpendicularly between those surfaces.

eeoc Alternatively, the external peripheral surface of the locating member may be formed part circular, with only that circular part being arranged for bearing engagement with a timber truss section, or the peripheral surface may be formed with a plurality of flat sections, such as hexagonal or octagonal shaped, with the flat sections being arranged for flat bearing engagement with the bearing surface of a timber section. This latter arrangement can be employed to minimise deformation of the timber section at the point of bearing engagement with the timber section. Still alternatively, the peripheral surface may be formed elliptically, or part elliptically, to achieve greater space take up S"than a circular or part circular peripheral surface. Any other suitable configuration may be employed.

The locating member may be mounted on the mounting device in any suitable manner to facilitate relative rotation therebetween. In one arrangement, the locating member includes a bore extending through its eccentric axis, for accommodating a mounting pin or post or the like. The bore is shaped complimentary to snugly accommodate the pin or post and preferably each is circular shaped with the bore having a slightly greater diameter than the pin or post, so that there is negligible slack between the locating member and the pin or post. This arrangement permits rotation of the locating member relative to the pin or post when the pin or post is accommodated within the bore of the locating member and the second locking means is disengaged to permit rotation.

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Alternatively, the bore and the post or pin may be shaped other than circular and may for example, be hexagonal shaped. In that arrangement, the second locking means may be constituted by the resistance to rotation provided by the mating engagement between the hexagonally shaped bore and the complimentary shaped pin or post. In this arrangement, the locating member would be lifted from the pin or post to disengage the mating hexagonal sections (which may or may not require complete separation of the locating member from the pin or post) for the locating member to be rotated relative to the mounting device. The bore and the pin or post could equally have alternative configurations, say having a greater or lesser number of faces than hexagonal.

In a puck in which the locating member is not restrained against rotation relative to the pin or post by engageable mating faces as discussed above, then the second locking means will have a different form. In one form, the second locking means includes a pin fixed to either of the locating member or the mounting device which can engage in one of a plurality of openings formed in the other of locating member or the mounting device. In a preferred arrangement, the pin is fixed to the locating member, to project therefrom for engaging in an opening formed in the mounting device. The pin preferably extends downwardly from the locating member for engagement within an opening which opens upwardly, so that the second locking means can be *"disengaged by lifting the locating member relative to the mounting device, to withdraw the pin from the opening. Rotation of the locating member relative to the mounting device may thereafter take place.

The pin may be fixed to the locating member or the mounting device, or may be integrally formed therewith. In the earlier embodiment, the pin may be friction fitted to a bore formed in either of the locating member or the mounting device, or it may otherwise be fixed, such as by a key or by screw thread. The fixing may be permanent or releasable. In the latter arrangement, the pin may be releasable for rotation of the locating member and thereafter reinserted for locking. This arrangement may however suffer if the pin is easily misplaced or lost. Alternatively, the pin may be cast or machined as an integral part of the locating member or mounting device.

The second locking means provides for locking the locating member in place relative to the mounting device, in at least two, but preferably more W:%Srk1ROMAJXU!V.PCTCOMPTfJsskgb'oWI1lidoc 4 6 positions of relative rotation. Accordingly, in the above arrangement, two or more openings for pin receipt can be provided, so that the locating member can be rotated and fixed relative to the mounting device at any one of the rotationally spaced opening positions. The openings may be spaced apart at equal or unequal intervals as required. The spacing may for example, be arranged to provide for take-up in equal intervals, say of 2mm intervals, and the spacing of the openings will be arranged to achieve that according to the shape of the external periphery of the locating member.

The preferred arrangement as described above is such that the locating member is lifted to disable the second locking means for rotation of the locating member and in this arrangement, it is preferred that the puck include retaining means to prevent the locating member from complete separation from the mounting device. In one arrangement, the pin or post of the mounting device is formed with a lip or flange which forms a bearing surface for a coil spring. The 15 lip or flange may be formed for example, by a circlip, or by suitable machining or casting. The coil spring bears against the lip or flange and against an opposed bearing surface of the locating member and permits the locating member to be lifted against the biasing influence of the coil spring. The lifting travel of the locating member is restricted when the coil spring is fully compressed.

The opposed bearing surface of the locating member can be an upper surface thereof or more preferably, the bore for receiving the pin or post of the mounting device can be of enlarged diameter at the upper end thereof, so as to define an upwardly facing step which forms the bearing surface and which is opposed to the bearing surface of the lip or flange of the mounting device. This permits the retaining means to be retained within the locating member rather than projecting outwardly thereof.

Alternatively a third locking means could be employed, which includes a lock nut threadably connected to a threaded shaft associated with the mounting device and which bears against a surface of the locating member to retain that member against separation from the mounting device. The lock nut may be loosened upwardly on the threaded shaft to permit lifting of the locating member away from the mounting device for rotation and when the locating member has been rotatably repositioned relative to the mounting device, the lock nut can be tightened down the threaded shaft into bearing engagement with the locating W:%SHAROtAAndrvwPCTCOMPTrusspogWQcoff%'Idoc member. That bearing engagement may be with any suitable surface of the locating member, such as an upper surface thereof, or more preferably a recessed surface.

The mounting device can take any suitable form, but preferably includes a base section for mounting on the truss table, and a pin or post upstanding from the base section on which the locating member is mounted. The base section is preferably of plate form and provides a supporting surface on which the locating member is supported.

The first locking means can take any form suitable to lock the mounting device to a truss table and that may include a threaded member that extends below the base section, through a slot between adjacent panels of a truss table, for securing the mounting device to the truss table by a threaded opening or nut. The threaded member could extend integrally from the base section, or that section could include an opening or openings to receive a threaded member. In a preferred form, the pin or post which extends upwardly from the base section includes a bore for receipt of a threaded member and the bore includes a seat against which the head of the threaded member bears against.

Alternative to a threaded member can be an unthreaded pin, which is received within an opening, such as a bore, in the truss table. The pin can extend to beneath the table as with the threaded member. Like the threaded member, the pin can be formed as an integral or separate part of the mounting device and if separate, it can be fixed to the mounting device by any suitable means.

In one arrangement, a single threaded member or pin extends from the base of the mounting device and the base section straddles the slot or bore opening through which the threaded member or pin extends.

In an alternative arrangement, the mounting device includes a base section which straddles a pair of adjacent slots or bore openings of the truss table and which includes a pair of spaced apart members extending downwardly therefrom for receipt within or extension through each of the slots or bore openings. In this arrangement, the mounting device can include facility for mounting the locating member anywhere between the pair of members. In this arrangement the locating member may have a fixed position, or the position may be adjustable between the pair of members.

W:%SAROk~rWV2CCOMT~ss~oracmPIdoc 8 The pair of members can be in the form of pins, or threaded shanks, or other form suitable to locate the mounting device on the truss table. Pins are suitable for truss tables that include bore openings to receive the pins rather than elongate slots. If threaded members are employed, a threaded nut can tighten the mounting device to the truss table. While the members described above provide a general example of how the mounting device is fixed to a truss table, any suitable arrangement may be employed for that purpose, such as the arrangements disclosed in the applicant's co-pending Australian patent application 59591/99, the disclosure of which is herein incorporated by crossreference.

The attached drawings show example embodiments of the invention of the foregoing kind. The particularity of those drawings and the associated description does not supersede the generality of the preceding broad description of the invention.

,i S" 15 Figure 1 is a cross-sectional view of a locator stop or puck according to one embodiment of the invention.

Figure 2 is a plan view of the mounting device of the puck of Figure 1.

Figure 3 is a cross-sectional view of the mounting device of Figure 2.

SFigure 4 is a plan view of the locating member of the puck of Figure 1.

Figure 5 is a cross-sectional view of the locating member of Figure 4.

Figure 6 is an underneath view of the puck of Figure 1.

Figure 7 is a cross-sectional view of a further puck arrangement according to the invention.

Figure 8 is a plan view of the locating member of the puck of Figure 7.

Figure 9 is a cross-sectional view of the locating member of Figure 8.

Figure 10 is a cross-sectional view of mounting device of the puck of Figure 7.

Figure 11 is a plan view of the mounting device of Figure Figure 12 is a plan view of the plate 118 of Figure 7.

Figure 13 is a cross-sectional view of the pin 114 of Figure 7.

Figure 14 is a cross-sectional view of the plate 118 of Figure 12.

Figure 15 is an underneath view of the puck arrangement of Figure 7.

Figure 1 is a cross sectional view of a locator stop or puck (hereinafter "puck"), according to one embodiment of the invention. The puck 10 shown in WsH*AROW~rewInr PCrrrrMr'nnlggI 9= doc

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9 Figure 1 includes a locating member 11 and a mounting device 12. The mounting device 12 includes a base section 13 and a post 14 which might otherwise be described as a spigot or hub. The base section 13 has an upper surface 15 and a lower surface 16. The upper surface 15 is a support surface for the locating member 11, while the lower surface 16 is arranged in use of the puck 10 to rest on the upper surface of a truss fabricating table. As shown in Figure 1, the upper and lower surfaces 15 and 16 are parallel and the base section 16 is therefore formed in a plate-like manner.

The base section 13 is formed in plan view as a cylindrical disc, while the post 14 is also formed cylindrically. A plan view of the mounting device 12 is shown in Figure 2 and the cylindrical nature of each of the base section 13 and the post 14 are evident from that figure. A bore 17 extends fully between the upper surface 18 of the post 14 and the lower surface 16 and this is clearly shown in Figure 3. Referring to that figure, the bore 17 is divided into a larger diameter opening 19 and a smaller diameter section 20. A step surface 21 extends between the bore opening 19 and the bore section The post 14 further includes a circlip groove 22 for receipt of a circlip 23 as shown in Figure 1. The circlip 23 provides a bearing surface for a coil spring 24 shown in Figure 1.

The base section 13 further includes a plurality of openings 25 to 29, spaced apart at unequal intervals about the same radius.

.4 The locating member 11 of Figure 1 is shown in more detail in each of Figures 4 and 5. Figure 4 is a plan view of the locating member 11, while Figure 5 is a cross-sectional view, but rotated through 180 0 C compared to Figure 1. Referring to Figure 4, the locating member 11 includes an external peripheral surface 30 which is generally circular and which is preferably formed as a tapered surface. The locating member 11 further includes an upper surface 31 and a lower surface 32 (see Figure A bore 33 extends fully through the locating member 11 between the upper and lower surfaces 31 and 32 and the bore 33 includes an enlarged diameter opening 34 and a reduced diameter section 35. The bore 33 therefore includes a step surface 36. As is clearly evident from Figure 4, the bore 33 is formed eccentrically with respect to the circular outer peripheral surface WASMROM~rdrewVICTC4OWNanao I 9=1 dOc The locating member 11 further includes a bore 37 which also extends fully between the upper and lower surfaces 31 and 32 and as shown in Figure 1, the bore 27 accommodates a locating pin 38. The locating pin 38 is fixed within the bore 27 by a friction fit or permanent fixing and preferably the pin 38 is formed as spring pin, which can be comprised for easy insertion into the bore 37 and thereafter expanded under its own resistance to frictionally engage the wall of bore 37. Alternatively, the pin could be made oversize and forcibly inserted within the bore 37.

Referring back to Figure 1, the puck 10 is shown with the locating member 11 mounted about the post 14 and resting on top of the upper surface of the mounting device 12. The locating member 11 is a close fit on the post 14 and for example, the bore section 35 of the locating member 11 can be in the order 0.4mm larger than the outside diameter of the post 14. This permits the locating member 11 to be rotated relative to the post 14 easily.

.o Figure 1 shows the locating pin 38 extending into the bore 27 of Figure 2 and as will be readily appreciated, by that arrangement, the locating member 11 thereby is prevented from rotating relative to the mounting device 12.

The bore opening 34 of the locating member 11 accommodates the circlip 23 attached to the mounting device post 14, as well as the coil spring 24 and the step surface 36 of the locating member 11 provides an oppositely facing bearing surface to the circlip 23 against which the coil spring 24 can bear. The arrangement is such, that the locating member 11 can be lifted away from the upper surface 15 of the base section 13 against the biasing influence of the coil spring 24 in order to withdraw the locating pin 34 from the opening 27. The locating member 11 can be lifted until such time as the coil spring 24 is fully compressed, whereafter further lifting movement will be terminated.

Advantageously, this prevents complete separation of the locating member 11 from the mounting device 12.

The mounting device 12 can be secured to the upper surface of a truss table (not shown) by a socket head cap screw 41 shown in Figure 1. The screw 41 includes a head 42 and the head 42 is arranged for seating engagement on the step surface 21 of the mounting device 12 (see Figure The shank 43 of the screw 41 is threaded and extends in use, through a slot in the truss table between adjacent panels, to below the truss table and a nut, such as a flat nut W:.SMAROfnrrm CCO MP rusgg .d 11 can be threaded on to the shank 43 to tighten it against the undersurface of the truss table.

The puck 10 is operable as follows. The puck is first placed on the truss table, straddling a slot between adjacent panels of the table, with the shank 43 of the screw 41 extending into and through the slot to beneath the truss table.

The puck 10 is positioned according to the set-up required for a particular truss being fabricated and when the puck 10 is properly positioned, it is fixed in place by tightening of a nut on the threaded shank 43 and the action of the nut against the underneath surface of the truss table, and of the screw head 42 against the step surface 21 of the mounting device 12 firmly secures the puck 10 in the set position. The puck 10 is thereafter operable to provide edge support to a timber section of a truss being fabricated, by engagement of the peripheral surface of the locating member 11 with the truss section.

Generally a plurality of pucks 10 are spaced about a truss table in set 15 positions, so that the entire truss being fabricated can be set in place and properly supported, prior to joints, such as nail plates, being applied at junctions between separate timber sections and pressed into the timber sections to connect them in place. Any number of pucks 10 may be used depending on the size of the truss being fabricated and the necessary amount of edge support required. For example, a truss of say 5 meter span may require in the order of *"10 to 15 pucks, although that depends on the number of timber webs and chords from which the truss will be fabricated.

In theory, the timber sections will engage the external peripheral surface of each puck when positioned on the truss table. However, in practice, it is the case that timber sections used in truss manufacture are subject to tolerance considerations so that each timber section may not properly engage each puck and therefore the pucks fail to provide firm support to the timber sections.

Accordingly, it is often necessary to make slight variations in the position of the puck on the truss table. This however results in several disadvantages. Firstly, to move the puck requires it to be loosened from the truss table and retightened when the puck has engaged the truss section in an appropriate manner. This can be time consuming, particularly if the puck or pucks to be moved require the operator actually move across the table him or herself. The second disadvantage, is that by shifting one or more pucks, the risk is that the truss setw %KRNrrw7TOM Tafgqm~~ 12 up will be altered and the truss incorrectly fabricated. For example, if one puck is shifted to accommodate a deviation in one of the timber sections, if it is not returned to the puck set-up position after the truss has been fabricated, then the next truss that is laid on the table may not fit firmly against one or more of the other pucks and if the operator chooses to move further pucks, then the truss may start to take a different form, albeit only slightly different.

The above complications are attended to by the puck 10 of the invention, because that puck can accommodate small deviations in timber sections, without movement of the puck on the truss table from the set-up position. This advantageous result is achieved because of the allowable rotation of the eccentrically mounted locating member 11. Referring to Figure 6, this shows a view taken from the underneath--f the puck 10 shown in Figure 1 so that the mounting device 12 is shown from the lower surface 16. Accordingly, only the projecting part 44 of the locating member 11 can be seen in Figure 6. As shown in Figure 6, the peripheral surface 30 of the locating member 11 projects ahead of the front edge 45 (see Figures 1 and 6) of the base section 13 of the mounting device 12. The amount of that forward projection is representing in Figure 6 by the amount P. The amount P shown in Figure 6 is the maximum forward projection of the peripheral surface 30 relative to the front edge 45. To reduce the projection P, the locating member 11 is lifted against the biasing influence of the coil spring 24 to withdraw the locating pin 38 from the opening 27 and the locating member 11 is thereafter rotated either clockwise or anticlockwise, to locate the locating pin 38 in one of the other openings 25, 26, 28 or 29, depending on the amount of projection P required. Thus, the value P will reduce by rotation of the locating member 11 in either direction, but the amount of reduction will be dependent on which of the openings the locating pin 38 is subsequently inserted into.

In the arrangement illustrated in Figure 6, if the puck 10 was made to the scale illustrated then it could accommodate' timber section variations up to a maximum of 5mm. However, larger deviations could be accommodated by mounting the locating member 11 in a more eccentric manner, or by altering the profile of the peripheral surface of the locating member 11.

The operation of the puck 10 is extremely simple and advantageously the puck 10 does not need to be shifted on the truss table. All that is required is W.%S MOn~ioewl.-rTCOMPuTnas~ggpVC-lado 13 that the operator lift the locating member 11 to withdraw the locating pin 38 from the opening 25 to 29 in which it is disposed and to rotate the locating member 11 to reposition the locating pin 38 in a different one of those openings. The operator may still be required to move across the truss table to access all of the necessary pucks but he or she is not required to loosen each puck from underneath and to shift it on the truss table.

Figure 7 shows an alternative puck arrangement in cross section. The puck 100 of Figure 7 includes a locating member 101 and a mounting device 102. The locating member 101 has similarities to the locating member 11 of the earlier figures. Referring to Figures 8 and 9, the locating member 101 includes a circular external peripheral surface 103 and an eccentric bore 104. The bore includes a large diameter opening 105 and a reduced diameter section 106.

S"The bore 104 extends fully through the locating member 101 between the upper S:surface 107 and the lower surface 108 thereof. The difference in diameter 15 between the opening 105 and the section 106 forms a step surface 109.

The locating member 101 further includes a second bore 110 which also extends fully between the upper and lower surfaces 107 and 108.

The mounting device 102 is shown in part in Figures 10 and 11. The part of the mounting device 102 shown in Figures 10 and 11 is a base plate 111.

The base plate 111 has a lower surface 112 which rests upon a truss table when the puck 100 is in use. The base plate 111 further has an upper surface S"113 which supports the locating member 101. The base plate 111 is arranged to be fixed to a truss table at each of two spaced apart points, such as at each of two adjacent slots or openings of a truss table. Figure 7 shows a pair of fixing pins 114 and 115 and each of these pins extends through respective openings 116 and 117 to a position below the lower surface 112 and into or beneath the truss table on which the base plate 111 is supported. The fixing pins 114 and 115 are each secured in place with a plate that is fixed to the base plate 111 by threaded fasteners or by welding. Figure 12 shows the plate 118 associated with the fixing pin 114 and that figure shows the plate 118 to be of rectangular configuration and includes a pair of threaded openings 119 and an elongate stepped opening 120. The opening 120 is a stepped opening, comprising a first upper opening 121 and a second lower opening 122. This is more clearly shown in Figures 7 and 14. The opening 122 is arranged to accept w:%SHARONArdre*Y'CTCRkO'%Tnns I gm. A= 14 the fixing pin 114 which is shown in more detail in Figure 13. The fixing pin 114 includes a shank 123, a stepped shoulder 124 which defines a stepped surface 125, and a head 126. By the arrangement of the fixing pin 114 and the opening 120, the stepped surface 125 of the shoulder 124 engages the further stepped surface 127 (Figure 14) formed between the opening sections 121 and 122, to secure the pin to the base plate 111. The pin is restrained against movement laterally to the lengthwise extent of the opening 120, but the pin 114 can shift lengthwise of the opening 120 in the direction of the arrow A in Figures 7 and 12.

The plate 118 is fixed as shown in Figure 7, to the base plate 111 by the threaded fasteners 128 or by welding. This arrangement provides some flexibility for mounting of the puck 100 given that the fixing pin 14 can undergo some movement for location within a truss table slot or opening.

The other fixing pin 115 extends from a plate 129 as shown in Figure 7, and is fixed to the base plate 111 by a pair of threaded fasteners 130 (see Figure 15). A pot magnet 141 is secured to the base plate 111 by a countersunk head cap screw 142 which threads into a threaded opening in the plate 129. The pot magnet is employed when the base plate 111 is to be supported on a ferrous table and assists to locate the mounting device 102 in position.

The pins 114 and 115 may be threaded for threadably engaging a nut for securing the puck 100 to a truss table, in the same manner as described for the .t puck 10 of Figure 1. Alternatively, the pins may be unthreaded for receipt within an opening, such as a circular or square bore opening, as distinct from an elongate slot. Unthreaded pins advantageously simplify the procedure for mounting the puck on the truss table as the puck is simply placed on the table, with the pins received in appropriate openings, without needing to secure the puck from beneath the truss table.

The locating member 101 is fixed to the base plate 111 by a lock nut 134 defining a bearing surface 135. The bearing surface 135 is brought into bearing engagement with the step surface 109 of the locating member 101 (see Figure 9) and bearing pressure is exerted by a screw threaded fastener 136 which threadably engages the lock nut 134. Tightening of the lock nut 134 securely fastens the locating member 101 to the base plate 111. Alternatively the circlip WiSMARCmrdjrPcrCTCOMPITnru iggko ~doc and spring arrangement of the puck 10 could be employed for the same purpose.

The locating member 101 further includes a locating pin 137 fixed within the bore 110 of the locating member 101 in the same way as the locating pin 38 of Figure 1 is fixed. Likewise, the locating pin 137 is receivable within any one of the openings 138 shown in Figure The peripheral surface 103 of the locating member 101 is shown in Figure 15 extending from either side 139 and 140 of the base plate 111 and by rotation of the locating member 101 about its eccentric axis, the projection Pr of the peripheral surface 103 can be reduced or enlarged. That projection Pr is easily altered, by loosening the lock nut 134 so that the locating member 101 can be lifted to withdraw the locating pin 137 from the opening 138. Thereafter, :the locating member can be rotated to engage the locating pin 137 in any of the other openings 138 to increase or decrease the projection Pr and to bring the S 15 peripheral surface 103 into engagement with the timber section.

The arrangement shown in Figure 7 for releasing the locating member 101 is different to that shown in Figure 1 in relation to the locating member 11, however the arrangement shown in Figure 1 could equally be employed in the Figure 7 arrangement. Either arrangement has the advantage that the locating member 11 or 101 is restrained from complete separation from the mounting device. This prevents the locating member from being lost and in particular e S°from being dislodged when the assembled truss is lifted from the truss table.

The invention described herein is susceptible to variations, modifications and/or additions other than those specifically described and it is to be understood that the invention includes all such variations, modifications and/or additions which fall within the spirit and scope of the above description.

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Claims (30)

1. A puck including a mounting device, which is configured for mounting said puck on a truss table or the like and which includes first locking means for locking said device to the truss table, a locating member which is eccentrically mounted on said mounting device for relative rotation about an eccentric axis, said locating member having an external peripheral surface against which a timber section of a truss bears during truss fabrication, eccentric rotation of said locating member permitting said peripheral surface thereof to be shifted from a position spaced from engagement with the timber section, to a position of engagement with the timber section, second locking means being provided to lock said locating member relative to said mounting device in a position of :rotation of said locating member in which said external peripheral surface bears against said timber section.

2. A puck according to claim 1, wherein said external peripheral surface is circular.

3. A puck according to claim 2, said locating member being formed as a circular disc having substantially planar upper and lower surfaces and the external peripheral surface extending perpendicularly between those surfaces. i

4. A puck according to claim 1, wherein said external peripheral surface is part circular, with the part circular section being arranged to bear against the timber section.

A puck according to claim 1, wherein said peripheral surface is formed with a plurality of flat sections, for flat bearing engagement with the timber section.

6. A puck according to claim 1, wherein said peripheral surface is formed elliptically or part elliptically. W SXARONAnjmrwPCTCOMPVTnisggbpgw doc 17

7. A puck according to any preceding claim, said mounting device including an upstanding post and said locating member including a bore extending through said eccentric axis and snugly accommodating said post, and said locating member being rotatable about said post when said second locking means is disengaged.

8. A puck according to claim 7, said post being of circular cross-section.

9. A puck according to claim 7 or 8 said second locking means being disengagable by lifting said locating member relative to said post, whereafter said locating member can be rotated relative to said post, and whereafter said *o:*•locating member may be returned from said lifted condition to re-engage said second locking means. 15

10. A puck according to claim 9, further including retaining means to retain said locating member against complete separation from said mounting device. C•

11. A puck according to claim 10, said retaining means being disposed between said post and said locating member and permitting limited lifting movement of said locating member to disengage said second locking means for relative rotation of said locating member, without complete separation of said locating member from said post.

12. A puck according to claim 11, said post and said locating member including facing abutments and biasing means being disposed between and in engagement with said facing abutments and said facing abutments being movable toward each other against the biasing influence of said biasing means to disengage said second locking means.

13. A puck according to claim 12, said abutment of said post being formed as a lip or flange, extending radially of said post.

14. A puck according to claim 12 or 13, said bore of said locating member including a first section for snugly accommodating said post and an enlarged w:%SKskRON~rdreV CTCOMPTnasggWVCmmli-Oc 18 bore section and said abutment of said locating member being formed by an upwardly facing step between said first bore section and said enlarged bore section.

15. A puck according to any one of claims 1 to 6, said mounting device including an upstanding post and said locating member including a bore extending through said eccentric axis and snugly accommodating said post, said post being of non-circular cross-section and said bore being of complementary shape, said second locking means being provided by cooperation between said post and said bore when said post is accommodated therewithin, and said locating member being removable from said post for rotation relative to said mounting device whereafter said locating member is :returned to accommodate said post of said mounting device within said bore at the relatively rotated position.

16. A puck according to claim 15, said post having a hexagonal-like cross- section.

.17. A puck according to any one of claims 1 to 14, said second locking means including a pin fixed to one of said mounting device and said locating member and arranged for receipt within one of a plurality of openings formed in S°the other of said mounting device and said locating member.

18. A puck according to claim 17, said pin being fixed to said locating member.

19. A puck according to claim 18, said pin extending downwardly from said locating member when said puck is in use, for extending into one of a plurality of openings formed in said mounting device and opening upwardly, said second locking means being disengaged by lifting said locating member relative to said mounting device to withdraw said pin from said one of said plurality of openings, to permit rotation of said locating member relative to said mounting device.

W.XSHAROM~ndreWVNCTCOMPTns$PggbVWMPI~do 19 A puck according to any one of claims 17 to 19, said pin being releasably fixed so that said locating member may be rotated relative to said mounting device when said pin is released.

21. A puck according to claim 10, said retaining means comprising third locking means having a lock nut threadably connected to a threaded shaft associated with said mounting device, said nut bearing against a bearing surface of said locating member in a locked condition to retain said locating member against separation from said mounting device. :090022. A puck according to claim 21, wherein said lock nut is disengaged from 0:0 said bearing surface of said locating member by threading said-nut along said shaft away from said post, whereby said locating member can be lifted away S: °from said mounting device to disengage said second locking means.

S" S.

23. A puck according to any preceding claim, said mounting device defining a base section for mounting on a truss table or the like and providing an upwardly facing supporting surface on which said locating member is C.oS. l supported.

24. A puck according to any preceding claim, said first locking means g including a threaded member that in use extends downwardly for securing said puck to a truss table or the like with a nut that engages with an oppositely facing surface of the truss table or the like to the surface on which the puck is supported.

A puck according to claim 24, said post including a bore for receipt of said threaded member.

26. A puck according to any one of claims 1 to 23, said first locking means including a pin that in use extends downwardly for receipt within an opening formed in the truss table or the like. W:'&ARtAn*mdWJTCOMPI-%Tnn3rkUwUgkadcc

27. A puck according to claim 26, said pin cooperating with said opening by threaded engagement.

28. A puck according to any preceding claim, said mounting device including an elongate base section which in use, straddles a pair of adjacent slots or bore openings of a truss table or the like and said first locking means including a pair of spaced apart members extending downwardly from said base section for receipt respectively within said adjacent slots or bore openings.

29. A puck according to claim 28, said locating member being lockably movable lengthwise along said base section between said spaced apart members. oi i

30. A puck substantially as herein described with reference to the 15 accompanying drawings. °0 oDATED: 28 March 2002 PHILLIPS ORMONDE FITZPATRICK Attorneys for: PRVYA (AUST.) ri LTD 1-Tw AL.S+r-ll P-y L4d SEC C113 4L 4$ o W:\YScoRONArre rPCCo&WTnaspggbpmomp doc