A DUAL PATH CUTTING MACHINE

Field of the Invention

The present invention relates to a dual path cutting machine which facilitates cutting of material along two paths .

Background of the Invention

Cutting machines for cutting material using a continuous or endless cutting wire or blade that moves along a continuous path are well known. A very basic form of such a machine is a band saw. Such cutting machines can use flexible saw blades or alternately, abrasive wires.

US Patent No. 4,915,000 describes a machine for cutting foam materials having an endless cutting wire supported on a number of wheels to travel along a fixed length path. Two of the wheels are mounted to move along respective parallel paths in synchronism to displace a portion of the wire extending between the two wheels in a plane of rotation of those rollers. A motor drives the endless wire about the path so that the foam material presented to a portion of the wire can be cut.

The wheels supporting the cutting wire are in turn supported on a frame that can also be moved lineally in a direction perpendicular to a plane containing the cutting wire .

The disclosure of the above prior art does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims of this application and in the description of the invention, except where the context requires

otherwise due to express language or necessary implication, the words "comprise" or variations such as "comprises" or "comprising" are used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

Summary of the Invention

According to one aspect of the present invention there is provided a dual path cutting machine comprising: a support frame defining an aperture; a first endless cutting element driven about a plurality of first wheels rotatably supported on the frame, the first endless cutting element traversing a first cutting path in a first direction, the first cutting path being moveable to at least partially extend into the aperture; and, a second endless cutting element driven about a plurality of second wheels rotatably supported on the frame, the second endless cutting element traversing a second cutting path in a second direction, the second cutting path being moveable to at least partially extend into the aperture ; wherein the first direction is not parallel to the second direction.

In one embodiment, the first and second directions are perpendicular to each other. The plurality of first wheels may comprise two first traverse wheels which are located at opposite ends of the first cutting path, the two first traverse wheels supported on the frame to move in unison to translate the first cutting path in a direction perpendicular to the first direction.

The plurality of second wheels may comprise two second traverse wheels which are located at opposite ends of the

second cutting path, the two second traverse wheels supported on the frame to move in unison to translate the second cutting path in a direction perpendicular to the second direction.

The first and second wheels may be supported on opposite sides of the frame.

In one embodiment, the machine may further comprise a conveyer system having first and second conveyers, the first and second conveyers lying in a common plane and arranged end to end with a gap therebetween through which the second cutting element runs when traversing the second cutting path.

In this embodiment, the machine may further comprise a moveable guard that extends along and substantially covers the gap, the guard being provided with an opening through which the second cutting element runs when traversing the second cutting path. The guard may be coupled with the second cutting path wheels so that the opening moves when the second traverse wheels translate the second cutting path.

The guard may comprise flexible elements that are seated in the gap and are arranged to move lineally along the gap, the flexible elements having mutually adjacent ends that are spaced apart to form the opening . In one embodiment, the flexible elements are portions of a common belt formed in a loop. The guard may further comprise a carriage to which the belt is attached, and wherein the carriage is coupled to the second traverse wheels.

The cutting machine may further comprise a first translation system for translating the two first traverse wheels, the translation system comprising a first drive shaft with which two first timing belts are engaged, each

of the first traverse wheels being coupled to a respective first timing belt.

The first translation system may further comprise for each of the first traverse wheels at least one rail along which the first traverse wheel is translated. The rail may comprise a rectangular section rail attached to the frame. The first translation system further comprises a linear bearing coupled with the first traverse wheel that rides along the rail. More particularly, the first translation system may comprise, for each of the first traverse wheels, a pair of parallel and spaced apart substantially rectangular section rails and, a pair of linear bearings coupled to the first traverse wheel, respective bearings riding along respective rails. In this embodiment, the timing belt is coupled to its corresponding first traverse wheel at a location between the rails in the pair of rails for that first traverse wheel.

The cutting machine may further comprise a second translation system identical to the first translation system for translating the two second traverse wheels.

In one embodiment, the plurality of first wheels further comprise two first idler wheels each idler wheel having an idler axle about which that wheel rotates, each idler axle coupled via a respective pivot assembly to the frame wherein each pivot assembly is configured to allow adjustment of the inclination of the idler axle.

Each pivot assembly may comprise a base configured and coupled to the frame and a top to which the idler axle is coupled, the base and the top having complimentary mutually abutting arcuate surfaces, the base and the top being coupled together and moveable relative to each other along the arcuate surfaces to thereby change the inclination of the idler axle.

Each pivot assembly may comprise a locking plate that is attached to both the base and the top, the locking plate provided with at least one arcuate slot through which a fastener passes to engage one of the base and the top.

Brief Description of the Drawings

An embodiment of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is an isometric view of an embodiment of a dual path cutting machine in accordance with the present invention;

Figure 2 is an elevation view of a horizontal axis end of the machine shown in Figure 1; Figure 3 is an elevation view of a vertical axis end of the machine shown in Figures 1 and 2;

Figure 4 is a side view of the machine shown in Figure 1 ;

Figure 5 is a top view of the machine shown in Figure 1;

Figure 6a is a schematic representation of the first endless cutting element incorporated in the machine;

Figure 6b is a schematic representation of a second cutting element incorporated in the machine; Figure 7 is a representation of a portion of a frame incorporated in the machine and showing a drive wheel and tensioning arrangement for the first cutting elements;

Figure 8 is a view from the top of a right hand side of the machine shown in Figure 2 ; Figure 9 is an exploded view of an idler wheel and bracket incorporated in the machine;

Figure 10 is an exploded view of a second type of traverse idler wheel and bracket incorporated in the machine ;

Figure 11 is a schematic representation of a guard included in the machine;

Figure 12 is a schematic representation of a pivot assembly and idler wheel assembly incorporated in the machine ;

Figure 13 is a side view of the pivot assembly and idler assembly shown in Figure 12; and,

Figure 14 is an exploded view of the pivot assembly and idler wheel assembly.

Detailed Description of Preferred Embodiment

Referring to the accompanying drawings, and in particular Figures l-6b a dual path cutting machine 1- (hereinafter referred to as "machine 10") comprises a support frame 12 defining an aperture 13; first and second endless cutting elements in the form of wire loops or more simply "wires" 14 and 16 respectively (see Figures 6a and 6b) ; a plurality of (in this instance five) first wheels 18a-18e (hereinafter referred to in general as "wheels 18"); and a plurality of (again, in this case five) second wheels 20a- 20e (referred to hereinafter in general as "wheels 20") . The wire 14 is driven about the wheels 18 which are rotatably supported on the frame 12. The wire 14 traverses a cutting path 22 in a first direction Dl (see Figure 6a) and extends between wheels 18b and 18c. The cutting path 22 is moveable to at least partially span or extend into the aperture 13.

The wire 16 is driven about wheels 20 which are rotatably supported on the frame 12 and traverses a second cutting path 24 in a second direction D2. The cutting path 24 extends between the wheels 20b and 20c. The path 24 is moveable so as to at least partially span or extend into

the aperture 13. The directions Dl and D2 of the cutting paths 22 and 24 respectively are arranged so as to not be parallel to each other. In this way, the machine 10 is able to cut material, such as foam, in two different directions. In the illustrated embodiment, the directions Dl and D2 are mutually perpendicular with the direction Dl extending horizontally and the direction D2 extending vertically. However this need not necessarily be the case and either, the directions Dl and D2 can be mutually perpendicular but not run horizontally and vertically, or alternately directions Dl and D2 can be oblique relative to each other.

Conveniently, the wheels 18 and 20 are supported on opposite sides 26 and 28 respectively of the frame 12 as shown in Figures 1-3. The wheels 18a-18e are rotatably coupled to axles 30d-30e respectively (referred to in general as "axles 30") . The axles 30 in turn being supported on the frame 12.

Two of wheels 18, namely wheels 18b and 18c comprise traverse wheels which are located at opposite ends of the first path 22 and their respective axles 30b and 30c are able to move in unison to translate the first cutting path 22 along a line Tl (see Figure 6a) that is transverse to the direction Dl. It will be appreciated that the motion along line Tl can be in either direction, i.e. either an up or down direction along the line Tl. Thus, the cutting path 22 is able to move up and down in a vertical plane across the aperture 13.

The wheels 20a-20e rotate on axles 32a-32e respectively (hereinafter referred to in general as "axles 32") which are supported on the frame 12. The axles 32b and 32c are able to move in unison to translate the second cutting path 24 along a line T2 that is transverse to the direction D2. This coincides with a side to side

direction relative to the frame 12. Thus, in summary, the cutting path 22 (which may be termed "the horizontal cutting path") is able to move up and down across the aperture 13 while the cutting path 24 (which may be termed "the vertical cutting path") is able to move from side to side across the aperture 13.

Referring to Figures 1,2 and 8, a first translation system 34 translates the wheels 18b and 18c up and down along the frame 12. The translation system 34 comprises a drive shaft 36 (see Figures 1 and 8) and timing belts 38 that engage the shaft 36 and are coupled to the wheels 18b and 18c respectively. The shaft 36 is rotatably supported within an upper horizontal portion of the frame 12 and is provided with toothed wheels or gears 40 at opposite ends that mesh with the timing belts 38. The timing belts 38 are in the form of elongated straps that extend along the opposite upright sides of the frame 12 and loop about respective idler gears 41. The translation system 34 also includes rails 42 for guiding the up and down motion of the wheels 18b and 18c. Two parallel spaced apart rails 42 are provided for each of the wheels 18b and 18c. The axles 30b and 30c for the wheels 18b and 18c are mounted on respective brackets 44 and 46. A stop is fitted to bracket 46 to stop scrap foam entering the machine.

Linear bearings 48 are attached to the underside of the brackets 44 and 46 at locations so as to engage and run along the rails 42. The rails 42 have a cross-sectional shape of a square with U-shaped channels 43 cut on opposite sides of the square. This is most evident from viewing the rails 42 in Figure 8.

From Figures 8 and 9 it will be seen that the bracket 44 comprises a mounting flange 47 in the form of a strip of metal with pointed ends, while from Figure 10 it can be seen that the bracket 46 comprises a mounting flange 49 in the form of a square plate with a diagonal cut-out made

between two adjacent sides. Apart from this difference in the shape of the respective mounting flanges, both brackets 44 and 46 have essentially identical features. Both are provided with the bearings 48 bolted to an underside of their flanges 47,49. A belt tensioner 50 is bolted to an underside of each bracket 44 at a location between the bearings 48 and thus between the rails 42. The tensioner 50 includes two spaced apart clamps 52 for clamping opposite ends of the timing belt 38. Each timing belt 38 is formed as an elongate strip that loops about a driven gear 40 and corresponding idler gear 42 with opposite ends of the belt clamped into respective clamps 52. The clamps 52 on the tensioner 50 are able to slide relative to each other to enable adjustment of tension in the belt 38. The shaft 36 is driven by a stepper motor

(not shown) that engages the shaft 36 via a further timing belt 53 and gear wheel 54 coupled to the shaft 36 near the gear wheel 40.

Figure 9 further depicts in phantom an alternate location of the belt tensioner 50. The location of the tensioner depends on the orientation of the timing belt 38 on the main frame. For example, Figure 2 depicts two carraiges with respective timing belts on the left or right hand side.

As the timing belts 38 are coupled to a common draft shaft 36 the traverse wheels 18b and 18c are able to move up and down along the line Tl in unison thereby translating the cutting path 22 up and down the aperture 13.

A second translational system 56 of essentially the same construction and configuration as the translation system 34 is provided to translate the wheels 20b and 20c in unison from side to side across the aperture 13. In brief, the secondary translation system 56 comprises a drive shaft 58 (Figure 5) and extends along an upright

side of the frame 13 and is provided at opposite ends with gear wheels 59 which are identical in construction to the gears 40 and mesh with corresponding timing belts 60 (seen in Figure 3) . The timing belts 60 loop around idler gears 62 supported on the opposite upright of the frame 12.

The wheels 20b and 20c can travel along parallel spaced apart rails 64 of identical configuration to the rails 42. To this end the wheels 20b and 20c are mounted on brackets 66 and 68 via their respective axles 32b and 32c. The brackets 66 and 68 are of substantially identical configuration to the brackets 44 and 46 respectively.

By applying torque to the drive shaft 58, the wheels 20b and 20c will move in unison from side to side along their respective rails 64.

Referring to Figures 2 and 7, the wheel 18a constitutes a drive wheel for the wire 14, being driven by a motor 70 (a rear view of which is shown in Figure 3) . The remaining wheels in the wheel set 18 namely wheels 18b, 18c, 18d and 18e constitute donkey wheels in the sense that they are not directly driven by corresponding motors, but rather rotate about their respective axles 30 by virtue of seating and contacting the wire 14.

The axle 30a of the drive wheel 18a is mounted on a plate 72 which is coupled via four linear bearings 74 (two of which are shown in Figure 7) on the rails 42. A pneumatic ram 76 is also coupled between the frame 12 and the plate 72. The ram 76 is pressurized to bias the drive wheel 18a in a downward direction along the rails 42 to maintain a predetermined tension in the wire 14.

The drive wheel 20a is likewise mounted on the rails 64 via a plate or bracket 78 and linear bearings (not shown) . A ram 80 is coupled between the frame 12 and the plate 78

to apply bias to the drive wheel 20a to tension the wire 16.

It will be evident from Figures 6a and 6b that each of the wires 14 and 16 cross themselves at respective cross over points 82 and 84 as they run about their respective wheels 18 and 20. In order to ensure that the wires do not contact themselves at the cross over points 82 and 84 some of the wheels are offset so as to be inclined to a vertical plane. This corresponds with the respective axles being inclined from the horizontal. The precise angle of offset or inclination of the wheels and their respective axles in order to obtain a desired spacing of a wire from itself at the cross over point may vary depending on the size and nature of the machine 10. However as an example, in a prototype, inclining the wheels and axles by approximately three degrees provides a gap or spacing of approximately 15mm at their cross over points 82 and 84. The manner in which the offset is obtained is described as follows.

With reference to the wheels 18, the drive wheel 18a is mounted on the plate 72 to lie in the plane which is offset by three degrees from the vertical. This is achieved by fixing its corresponding axle 30a at an angle of three degrees from the horizontal. The wire 14 runs in a vertical plane as it traverses the cutting path 22 between the wheels 18b and 18c. The wheel 18e is inclined from the vertical so as to align the wire 14 as it turns around the wheel 18e with the inclined drive wheel 18a. The wheel 18d may also be inclined to the vertical. The inclination of wheel 18e and where appropriate 18d is achieved by mounting the respective axles 3Oe and 3Od on respective pivot assemblies 86 shown in Figures 12-14.

The pivot assembly 86 comprises two main components a base 88 that is configured to be coupled to the frame 12 and a

pivot block 90 that is coupled to the base 88 and to which the idler wheel 18e, and more particularly its axle 3Oe, is coupled. The base 88 and pivot block 90 have complimentary mutually abutting arcuate surfaces. The arcuate surface 92 on the base 88 is provided as the respective surface of two concavely curved recesses 94. The arcuate surface 96 on the pivot block 90 is provided as respective surfaces of two convexly curved shoulders 98. By sliding the surfaces 92 and 96 relative to each other the relative inclination or attitude of the base 88 and pivot block 90 can be changed thereby changing the inclination or pivot angle of the axle 3Oe and thus the idler wheel 18e.

The base 88 and pivot block 90 are coupled together by two locking plates 100 on either side of the pivot assembly 86. Each locking plate 100 comprises two upper holes for receiving bolts 102 that screw into corresponding threaded holes 104 in the pivot block 90. Each plate 100 also is formed with two arcuate slots 106 that receive bolts 108 that screw into holes 110 in the base 88. The slots 106 have the same radius of curvature as the arcuate surfaces 92 and 96.

A further large slot 112 is formed centrally in each locking plate 100 through which a locking cam 114 extends. Respective locking cams 114 are rotatably mounted on each side of the base 88 adjacent the mid-point of the recesses 94. A bolt 116 passes through the slot 112 and through the cam 114 to respectively lock and release the cam 114 for rotation. A pair of grub screws 118 extend into one of the recesses 94 from opposite ends of a cord of the recess 94. Cutouts 120 are provided in the recess 94 to accommodate the grub screws 118. Corresponding cutouts 122 are formed in the adjacent shoulder 98. The cutouts 122 are each provided with planar surfaces 124 against which respective ends of the grub screws 118 can abut.

Locking nuts 126 are provided at ends of the grub screws 118 exterior of the base 98 to lock the grub screws from rotation.

The base 98 is supported on four elongate bolts 128.

Providing the elongate bolts 128 enables adjustment of the spacing of the pivot assembly 86 from a surface of the frame 12.

In order to vary the pivot angle or inclination of the axle 3Oe and thus the wheel 18e, the bolts 108 are loosened as are the lock nuts 126. The grub screws 118 are provided with recesses to receive an Allen key to enable them to be screwed in or out . By appropriately screwing the selected grub screw 118, its end will abut adjacent surface 124 of the cutout 122 causing the pivot block 94 to slide about the arcuate surface 92 thereby changing the inclination of the pivot block 90. When the inclination has been appropriately adjusted, the other grub screw is screwed in to abut the surface 124 of its corresponding cutout 112, and then the lock nuts 126 and bolts 108 and 118 are tightened.

Material to be cut by the machine 10 is supported on a conveyer system 130 (see Figures 1, 4 and 5) . The conveyer system 130 is controlled by a processor to move the article to be cut lineally in a plane perpendicular to the plane containing the aperture 13. The conveyer system 130 comprises two conveyers 132 and 134 arranged end to end and separated by a gap 136 that lies in a plane containing the vertical cutting path 24. More particularly the wire 16 runs vertically through the gap 136.

A guard 138 (shown in Figure 11) is provided to reduce the likelihood of debris being jammed in the gap 136 and to prevent loss of final product which may be small enough to

fall through the gap 136. The guard 138 also stops debris from falling onto the traverse wheels and the traverse travel path. Such debris could adversely affect the accuracy of cuts made by the wires 14, 16. For example debris protruding upwardly from the gap may cause the material supported on the conveyer system 30 to ride up as it traverses the gap 136. The guard 138 is provided with an opening 140 through which the wire 16 extends. Further, the guard 138 is able to move with the vertical cutting path 24 so that the wire 16 always travels through the opening 140. The guard 138 comprises flexible elements in the form of opposite end portions 142 of a belt 144 that is arranged in a loop about rollers 146. An upper run of the belt 144 which contains the portions 142 rides between the pair of parallel spaced apart angle irons 148 which are supported at their opposite ends on the frame 12. The portions 142 are attached to a carriage 150 that is supported on the angle irons 148 to slide lineally along the gap 136. A bracket arm or other link (not shown) couples the carriage 150 to the bracket 68 supporting the wheel 20c so that the carriage and thus the opening 140 moves in unison with the cutting path 24.

When in use, the machine 10 is able to cut an article such as a block of foam to any desired shape and configuration by cutting with either the wire 14 or the wire 16. The article is placed on the conveyer 130 and a desired cut pattern is fed into a processor which controls the first and second translation systems 34 and 56 to move the cutting paths 22 and 24, as well as the conveyers 130 to move the article lineally through the aperture 13. However cutting is performed by only one of the wires 14 and 16 at any one time. The other at that time is placed in a park position where its corresponding cutting path is to the side of the aperture 13 and overlying an adjacent part of the frame 12.

Modifications and variations of the machine 10 that would be obvious to a person of ordinary skill in the art are deemed to be within the scope of the present invention the nature of which is to be determined from the above description.