AU736695B2 - Timber sawing apparatus - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

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0 a.

Name of Applicant: Actual Inventor: Address for Service: Invention Title: GRAHAM ROSS RAYNER GRAHAM ROSS RAYNER CULLEN

CO.,

Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, QId. 4000, Australia.

TIMBER SAWING APPARATUS Details of Associated Provisional Application: No. PP3381 FILED 6 MAY 1998 The following statement is a full description of this invention, including the best method of performing it known to me: TIMBER SAWING APPARATUS This invention relates to a timber sawing apparatus. In particular, the invention relates to an apparatus for sawing timber for use in making hip, creeper and jack and other rafters or frames for roofs of structures.

The timber for use in making rafters not only needs to be cut to the desired length but an end of the timber must be cut so that it properly fits the particular rafter configuration being constructed. In recent times roofs with hip end structures with corners meeting at angles greater than 900 have become popular. Since the hip trusses of such structures do not extend at 450 to the corners of the building the coincidence of hip to jack and creeper trusses and rafters occur an angles less than 450 necessitating a compound angle cut to the side of the jack/creeper truss/rafter to allow it to fit snugly against the hip rafter/truss. Double compound cuts, single compound cuts or simple cuts on either end of the timber member need to be produced and the angle of the cut or 15 cuts may need to be varied for each piece of timber.

Single and double mitre saws have been proposed for cutting ends of timber pieces for rafters. One disadvantage of known sawing apparatus used for this purpose is the inability to cut the end of the pieces of timber to a small enough angle such as 150. Generally, all known double mitre saws cannot mitre to a hip to jack coincidence angle less than 45o In fact one such double mitre S"saw had cutting heads mounted on a common guide rail thus preventing them from being adjusted to angles independent of each other. Therefore the mitres produced were fixed to It is an object of the present invention to provide a timber sawing apparatus which at least minimises this disadvantage.

According to an aspect of the invention there is provided a timber sawing apparatus having a main frame, a sub-frame pivotally connected to the main frame for pivotal movement about a vertical axis, a first cutting head assembly coupled to a first guide assembly and mounted for movement along the guide assembly, a second cutting head assembly coupled to a second guide assembly and mounted for movement along the second guide assembly, the guide assemblies being connected to the sub-frame for independent pivotal I 1 3 movement about a common axis extending across the vertical axis, and a respective locking mechanism associated with each said guide assembly for locking the guide assembly at desired position relative to the sub-frame.

A particular preferred embodiment of the invention will now be described by way of example with reference to the drawings in which: Figure 1 is a plan view of sawing apparatus according to an embodiment of the invention; Figure 2 is a partial side elevational view of the apparatus of figure 2 taken in the direction of arrow A in figure 1; 10 Figure 3 is a partial side elevational view of the apparatus also in the direction of arrow A in figure 1; Figure 4 is a diagrammatic side elevational view of part of the apparatus showing the range of adjustment of cutting heads; Figure 5 is a partial plan view of a part of the apparatus of the 15 invention; Figure 6 is a front view of that part of the apparatus shown in figure Figure 7 is a rear elevational view of part of the apparatus of an embodiment of the invention; Figure 8 is an elevational view of the apparatus of figure 1; ¢oooo S"Figure 9 shows a plan view of a complex hip roof structure; Figure 10 shows a compound double cut end on a piece of timber; and Figure 11 shows a compound single cut end on a piece of timber.

Figure 1 shows a plan view of a sawing apparatus 10 according to an embodiment of the invention. The apparatus has a main housing 11 mounted to a main frame 13 for rotation about a vertically extending pivot axis 12 to allow the housing to be pivoted between a first position where it extends substantially at right angles as shown in full outline in the figure to a second position where it extends at 45o across the apparatus. This movement allows a compound cut to be achieved at an end of a piece of timber. The housing 11 is pivotally coupled to the main frame 13 in a manner described in greater details below. The housing is secured to a sub-frame 14 (see figure The sub-frame 14 supports a table 15 which has an arcuate leading edge 16. An infeed conveyor 17 extends from an upstream side of the apparatus 10 and has side rails 18, 19 between which a plurality of horizontally disposed conveyor rollers 20 are arranged to extend. Vertically arranged guide rollers 21 are arranged at spaced locations along side rail 18. A stop arm 22 forms a longitudinal extension to rail 18. Timber members may be placed on the rollers 20 and in contact with the arm 22 and against guides 21 during use of the apparatus.

Figure 2 is a side elevational view of part of the apparatus looking in the direction of arrow A infigure 1. An end wall of the housing 11 has been removed for the sake of clarity and the components to which the motors 30, 31 of the cutting head assemblies 32, 33 are mounted have also been omitted. Sub frame 14 which carries the housing 11 is pivotally coupled to the main frame 13 by pivot connections 34, 35 at an upper and a lower part of the frame 13. Subframe 14 has an arm 36 which is upwardly inclined and has the table 15 mounted to its upper end. The table 15 has a beveled downstream end 37. A clamping bar 40 extends across the apparatus and is mounted for rotation about its longitudinal axis. The clamping bar carries a clamping finger assembly 41 which, when the bar rotates causes a piece of timber to be clamped between the assembly 41 and the table SAs shown in figure 2, two cutting head assemblies 32, 33 are located within the housing 11. Assembly 32 has a motor 30 which drives a circular saw blade 42. Assembly 33 drives a saw blade 43. In this view both of the blades are shown in full outlined in a 150 limit position. The blades cannot be moved closer than this position because of the presence of the arm 22, the table the bar 40 and assembly 41. The assemblies 31, 32 may be pivoted from the full outline positions to a position at which the blades 42, 43 are at 900 to the table 15, that is, the blades are in a vertical position. However, the 900 position cannot be achieved simultaneously for both assemblies. Assembly 33 has its other extreme position shown in ghost outline. The assembly 33 has a mounting which carries an infeed stop member 51.

Figure 3 is a view of a side of the apparatus also taken in the direction of arrow A in figure 1. Upright 52 forms part of the sub-frame 14 and has rollers 53, 54 secured to a lower end. When the sub-frame 14 pivots relative to the frame 13 these roller track along the frame 13 and provide a measure of support for the sub-frame during its movement.

A guide assembly 60 is present for guiding the cutting head assembly 32 it is movement across the apparatus. The guide assembly includes two transversely spaced arms 61, 62 pivotally connected to upright 52 and 52A (see figure 7) by pivot connection 63 and 64. A connecting frame member 65 extends between the arms 61, 62. Arm 61 has a quadrant 66 10 secured to it and this quadrant has teeth 67. An arcuate slotted guide member .o 68 extends from the arm 61. Two guide rails 69, 70 extend between the arms 61, 62 and the cutting head assembly 32 has a mounting like mounting 50 shown in figure 2 coupled to rails 69, 70 for movement along the rails. A gear 71 is mounted to upright 52 and meshes with the teeth 67 on the quadrant 66. A 15 locking mechanism 75 mounted to the upright 52 cooperates with the slotted guide 68 to lock the arms 61 and 62 at a desired angular position relative to the uprights 52 and 52A as the arms pivot about the pivot connections 63, 64. The locking mechanism 75 is shown in greater detail in the inset view. The mechanism 75 has a handle 130 coupled to a clamping bolt 131. The handle 130 when rotated moves the clamping shoe 132 towards and away from upright 52 and captures the slotted guide member 68 between two rubber blocks 133, 134. In this way the cutting head assembly 32 may be moved between the 150 and 900 positions illustrated in figure 4 and locked into a desired position. Gear 71 may be rotated by the handle mechanism 80 shown in figure 7 to pivot the arms 61, 62.

A guide assembly 60a is present for guiding the cutting head assembly 33 in its movement across the apparatus. The guide assembly includes two transversely spaced arms 82, 83 pivotally connected to uprights 52, 52A (see figure 7) by the pivot connections 63, 64 in common with the guide assembly 60. A connecting frame member 84 extends between the arms 82, 83.

Arms 82 has a quadrant 85 secured to it and this quadrant has teeth 86. An arcuate slotted guide member 87 extends from arm 82. Two guide rails 88, 89 extend between the arms 82, 83 and the cutting head assembly 33 has a mounting 50 coupled to the rails 88, 89 for movement along the rails. A gear is mounted to the upright 52 and meshes with the teeth 86 on the quadrant 85. A locking mechanism 91 identical to the mechanism 75 cooperates with the slotted guide 87 to lock the arms 82, 83 at a desired angular position relative to the uprights 52 and 52A as the arms pivot about the common pivots connection 63, 64. In this way the cutting head assembly 33 may be moved between the and 900 positions illustrated in figure 4 and locked into a desired position. Gear may be rotated by the handle mechanism 92 shown in figure 7 to pivot the S• 10 arms 82 and 83.

:Figure 4 is a diagrammatic side elevational view of part of part of the apparatus and shows the degree to which the cutting head assemblies 32, 33 may be pivoted about a common axis A extending through pivot connections 63, 64 in figure 7. Each of the assemblies is coupled to a mounting 50 and these 15 mountings are adapted to travel along the guide rails 69, 70 and 88, 89 of the guide assemblies 60 and Figure 5 is a partial plan view of a part of the apparatus 10 of the invention. An end portion of the infeed conveyor 17 with side rails 18 and 19 is shown. A brake unit 100 is shown. Unit 100 has opposed brake pads which may be moved into engagement with opposite faces of the table 15 to retain the table S"in a particular desired position relative to the conveyor 17. The clamping assembly 41 has a plurality of fingers 101 and is secured to the clamping bar A cylinder assembly 102 extends between the bar 40 and frame member 103 of the sub-frame 14. The assembly 102 functions to rotate the bar 40 and bring the fingers 101 into and out of engagement with a piece of timber positioned on the conveyor 17 and against the arm 22.

Figure 6 is an elevational view of that part of the apparatus shown in plan in figure Figure 7 is an elevation view of part of the apparatus of the invention. In this view the cutting head assemblies 32, 33 are shown in a position which has the blades 42, 43 oriented in a horizontal plane. The blades would never both assume such as orientation in actual use and are shown in this position to simplify the figure. The blades 42, 43 are circular and the assemblies 32, 33 in use are arranged spaced part so that the centers of the blades are less than one blade radius apart. In this figure the blades are shown further apart than this.

The cutting head 32, 33 assemblies are connected to each other by a link rod 120 connected between the mountings 50 as shown with end B of the rod connected to location B and end C connected to location C. A cylinder assembly 121 extends between arm 82 and the mounting 50 of assembly 33. In this way, extension and retraction of the cylinder assembly causes both S 10 assemblies 32, 33 to be transported across the apparatus.

Figure8 is an elevational view of the apparatus 10. The housing 11 has an end wall 140 with a semicircular slot 141. Graduations may be present along the length of the slot and a portion of the guide mechanisms for the cutting head assemblies within the housing may be visible through the slot to .0 15 indicate the angular position at which the blades 42, 43 are positioned. The main frame 13 has legs 150 and the upstream end of the conveyor 17 is supported by transversely spaced legs 151.

If the apparatus is to be used to produce a cut at the end of a piece of timber other than a compound cut, the housing 11 is retained it is 900 position as shown in figure 1. The clamping assemblies 75 and 91 are operated to allow winding of the mechanisms 80 and 92 to adjust the relative positions of the cutting head assemblies. Once the desired position is achieved the clamping assemblies are used to hold the cutting head assemblies in that position. The cutting head assemblies are then driven across the apparatus to achieve the desired cuts. More than one piece of timber may be cut at any one time by arranging them side by side on the infeed conveyor. A compound cut may be achieved in a similar way except that the housing is first pivoted from the 900 position of figure 1.

Figure 9 shows a roof structure having trusses 170 which meet a hip trusses 171 and 172. Trusses 170 require single compound cut ends while truss 173 requires a compound double cut end.

Figure 10 shows a typical compound double cut roof truss 174 8 while Figure 11 shows compound single cut roof truss 175.

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Claims (22)

1. A timber sawing apparatus having a mainframe, a sub-frame pivotally connected to the mainframe for pivotal movement about a vertical axis, a first cutting head assembly coupled to a first guide assembly and mounted for movement along the guide assembly, a second cutting head assembly coupled to a second guide assembly and mounted for movement along the second guide assembly, the guide assemblies being connected to the sub-frame for independent pivotal movement about a common axis extending across the vertical axis, and a respective locking mechanism associated with each said guide assembly for locking the guide assembly at a desired position relative to the sub-frame.

2. The apparatus of claim 1 wherein a table is supported by the sub-frame.

3. The apparatus of claim 2 wherein the table has an arcuate leading edge.

4. The apparatus of any one of claims 2 or 3 including an infeed conveyor 15 upstream of the sub-frame.

The apparatus of claim 4 wherein the infeed conveyor includes side rails :o.".and a stop member which forms an extension to one of the rails.

6. The apparatus of any one of claims 2 to 5 wherein the sub-frame is pivotally connected to the main frame by an upper and a lower pivot 20 connection.

7. The apparatus of claim 6 wherein the sub-frame includes an upwardly inclined arm with the table being mounted to an upper end thereof.

8. The apparatus of any one of claims 2 to 7 wherein the table has a beveled downstream end.

9. The apparatus of any one of claims 2 of 8 including a clamping bar is carried by the sub-frame and mounted above the table for clamping a work piece between the bar and the table.

The apparatus of claim 9 wherein the clamping bar includes fingers for engagement with the work piece.

11. The apparatus of claims 9 or 10 wherein the clamping bar is mounted to the sub-frame for pivotal movement relative to the sub-frame.

12. The apparatus of any one of claims 2 to 11 including a housing carried by the sub-frame with the cutting head assemblies and the guide assemblies being located within the housing.

13. The apparatus of any one of claims 2 to 12 wherein each said cutting head assembly includes a motor and a blade driven by the motor and a mounting for attaching the assembly to a respective said guide assembly.

14. The apparatus of claim 13 wherein each said guide assembly includes two transversely spaced arms with guide rails extending between them with a respective said cutting head assembly being mounted to the rails for movement along the rails.

15. The apparatus of claim 14 wherein one of the transversely spaced arms of each said guide assembly is pivotally coupled to a frame member of the .**sub-frame and said one arm carries an arcuate slotted guide member which may be clamped to the frame member to retain the guide assembly in a desired position relative to the sub-frame. •go 15

16. The apparatus of claim 15 including a clamping assembly secured to the frame member for clamping the arcuate slotted member to the frame member.

17. The apparatus of claims 14, 15 or 16 including a toothed quadrant mounted to one of the transversely spaced arms of each of the guide assemblies and a respective drive gear coupled to the sub-frame for engagement with the quadrants for pivotally moving the guide assemblies relative to the sub-frame.

18. The apparatus of any one of claims 14 to 17 wherein the cutting head assemblies are linked to each other so that they move across the apparatus and along the guide assemblies in unison.

19. The apparatus of claim 18 including a cylinder assembly extending between one of the cutting head assemblies and the sub-frame for moving the cutting head assemblies across the apparatus and along the guide assemblies.

20. The apparatus of claims 2 to 19 including a brake assembly for holding the table relative to the infeed conveyor to inhibit pivotal movement of the sub-frame relative to the main frame. 11

21. The apparatus of claim 20 wherein the brake assembly is mounted to the infeed conveyor and has brake pads for engagement with the table.

22. A cutting apparatus substantially as herein described with reference to Figures 1 to 8 of the drawings. DATED THIS 10 DAY OF MAY 1999 GRAHAM ROSS RAYNER BY HIS PATENT ATTORNEYS CULLEN CO e*