AU692754B2 - Size reduction machinery - Google Patents

Description

SIZE REDUCTION MACHINERY

The present invention relates to machinery for treating materials in general and to machinery for reducing the size of materials in particular. In particular the present invention relates to machinery for treating vegetation, such as for example, to griding and/or chipping vegetation, and particularly to a high volume vegetation grinder, wood chipping machinery, wood chippers and the like which are used to reduce the size of waste vegetation to a size that can be handled more easily. Even more particularly, the present invention finds application in reducing the size of logs, limbs, branches, leaves and the like from primings or otherwise trimming trees, bushes, shrubs or the like in order to produce a useable or saleable product such as wood chip mulch, compost or the like or to facilitate removal of the waste material. The machinery of the present invention can be used to recycle a wide variety of materials.

Although the present invention will be described with particular reference to a wood chipper it is to be noted that the scope of the present invention is not limited to wood chippers generally or even to the wood chipper as described but rather the scope is more extensive so as to include other arrangements for reducing the size of vegetation and other material and to other applications of the machinery than those specifically mentioned or described in the specification such as for example for treating other materials.

Existing machinery suitable for use as vegetation grinders or for grinding vegetation have not always been entirely satisfactory for one reason or another. One problem associated with such grinders involves the arrangement of the cutting blades within the grinder, such as for example, the method of attachment of the cutting blades to the rotating drum of the grinder. In many currently available wood chippers the blades used to cut the vegetation or to hammer the vegetation have been fixedly attached which means that the blades and the remainder of the machinery, such as the rotating wheel structure often sustain damage when the blades strike a foreign object such as a metal bar or the like since the blade is fixed.

Another problem relates to the relationship between the orientation of the cutting blades to the remainder of the hardware of the grinder when the blades are fixed which reduces the efficiency of the grinder or results in an uneven distribution of the size of the chips being produced by the grinder in use. In some circumstances, both of these problems result in the blades being damaged when foreign objects such as steel fence posts, wire and the like are inadvertently introduced into the grinder along with the vegetation being treated.

The present invention seeks to overcome the problem of damage suffered by the blades and other components of the grinder when in use by providing an arrangement which allows the blades to be retracted or otherwise moved out of the way when the blades strike a foreign object without the blades being unduly damaged or the remainder of the machinery being damaged, such as by continually striking the foreign object until the machinery stops rotating. Additionally, the present invention seeks to provide an arrangement whereby material, particularly vegetation, is processed more quickly and efficiently. Furthermore, the present invention seeks to provide an arrangement whereby the blades of the machinery of the present invention can be changed in situ in the field without the machinery having to be returned to the workshop for repairs.

According to one aspect of the present invention there is provided a device for treating material to reduce the size of the material or to produce fragments of the material, said device comprising an inlet means for introducing material into the device and directing the material to a material treatment means, said material treatment means comprising at least one movable material treatment element, and a delivery means for discharging material that has been treated wherein said material treatment element is movably mounted so as to adopt a normal in use position for treating the material and being capable of being moved away from the normal in use position by contact with a foreign object in the material being treated in use so as to prevent or reduce further damage to the material treatment element or the device when the material treatment element contacts the foreign objeςt or other material which cannot be readily treated by the material treatment element.

According to another aspect of the present invention there is provided a wood chipper for reducing vegetation waste to wood chips, said wood chipper comprising an inlet means for introducing vegetation into the device and directing the vegetation to a rotating chipping drum, said rotating chipping drum being provided with a plurality of pivotable work elements, such as for example cutting blades, for converting the vegetation into wood chip mulch said work elements being pivotable to adopt a normal in use position advising operation of the device, and a delivery means for discharging the wood chip mulch from the wood chipper wherein the pivotable work elements are mounted so as to be pivotally movable from the normal in use position into the chipping drum to avoid continual contact with a foreign object when said work element contacts the foreign object in use of the wood chipper.

Typically, the treatment device of the present invention is a wood chipper or a wood chipping mill, more typically, a high volume vegetation grinder. Even more typically, the device is a continuously operating high volume vegetation grinder for chipping waste vegetation such as prunings and other material from trees, shrubs, bushes and the like into small particle size material that can be sold or used i.e. recycled.

Typically, the inlet means comprises a feed roller, more typically a constant speed hydraulically operated in-feed roller and conveyor system. Even more typically, the in- feed roller is vertically adjustable with respect to the normal in use operating orientation of the device to accommodate differently sized vegetation, branches, limbs, logs and the like and to feed the differently sized vegetation to the work element.

Typically, the treatment means comprises a rotating drum or grinder, more typically a constant velocity rotating drum, grinder or roller. Even more typically the speed of rotation of the in-feed roller is directly proportional to the speed of rotation of the rotating drum. More typically, the speed of rotation of the in-feed roller is the same as that of the rotating drum so that material is introduced into the device at the same rate it is treated to ensure a constant supply of material to be treated.

Typically, the rotating drum is provided with a plurality of treatment or work elements, typically, in the form of cutting units, each having a cutting blade. Typically, there are 16, 32 or more separate cutting units provided on the rotating drum. More typically, the rotating drum is circumferentially subdivided into quadrants and the cutting units are arranged in groups of 4, 8 or more per quadrant.

Typically, each cutting unit, including the cutting blade, is of a specific shape and/or weight to ensure that when the drum is rotating at a predetermined speed which is the normal speed of operation of the device, the cutting tips of the blades of each cutting unit are centripetally thrown out to a specific distance and angle with respect to the rotating drum and to the centre line or central axis of the device so as to ensure efficient cutting of the vegetation into chips. Typically, the cutting blades are mounted so that their respective cutting tips are located about 10° in front of the centre line of the cutting unit when the device of the present invention is in the normal operating position.

Typically, the cutting units are mounted singly or in pairs within the quadrant.

Typically, the device of the present invention is provided with an adjustable steel plate anvil surface. More typically, the orientation of the cutting elements as they rotate past the edge of the anvil result in the production of wood chips or the like of a more or less substantially same size or having a more or less uniform size distribution of sizes. The orientation of the cutting tips of the blades with respect to the anvil is determined by the exact size and shape of the cutting unit to provide for efficient operation of the device.

More typically, the cutting units are arranged at spaced apart locations across the entire width of the device so as to contact more or less completely any vegetation to be treated being fed over the entire width of the device. Even more typically, the cutting units are arranged in turn in the quadrants in staggered relationship so as to present cutting blades to the vegetation in overlapping relationship in the transverse direction of the device so that the entire width of the in-feed roller and conveyor are covered.

Typically, the cutting units are provided with replaceable and/or adjustable cutting blades. More typically, the cutting blades may be easily and quickly replaced or adjusted in situ without having to dismantle the device or remove the device or part of the device such as for example the rotating drum, to a workshop or similar for repair.

The present invention will now be described by way of example with particular reference to the accompanying drawings in which

Figure 1 is a partial schematic side view of one form of the device of the present invention showing the arrangement of the various subasse blies.

Figure 2 is a transverse cross-sectional view of one form of the rotating drum used in the device of the present invention illustrated in Figure 1. Figure 3 is a partial longitudinal cross-sectional view of the form of the rotating drum of Figure 2.

Figure 4 is a perspective view of a cross-section of part of the rotating drum of Figure 2 showing one form of the cutting unit of the present invention in more detail.

In Figure 1, there is shown one form of the material treatment device, of the present invention being a wood chipper, generally denoted as 2. Wood chipper 2 generally comprises a number of sections or subassemblies which perform different but related functions and include a feed portion generally denoted as 4, a grinding portion generally denoted as 6 and a delivery portion 8 assembled together sequentially in line to allow material in the form of vegetation to be comminuted by passage through the device 2.

Feed portion 4 generally comprises a feed chute 12 in the form of a bin, hopper or the like having an open base or similar. A movable feed conveyor 14 is located along the base of the feed chute 12 and comprises a driven conveyor wheel or roller 13 and a support wheel or roller (not shown) located at either end of an endless belt 16. Driven conveyor wheel or roller 13 is driven by a suitable motor (not shown) or similar. Another motor or similar (not shown) drives in-feed roller 18 and the speed of roller 13 is controlled in accordance with the speed of in-feed roller 18 so that material to be treated is fed at a rate in accordance with the rate it can be treated in each particular circumstance.

In-feed roller 18 is located at the inboard end of feed conveyor 14 and extends widthwise across the device. In- feed roller 18 is journalled or otherwise mounted on a pair of widthwise horizontally spaced apart vertically arranged supports 20 so that the central axis of the in-feed roller 18 is movable vertically with respect to the upper surface of feed conveyor 14 in the direction of arrow A to accommodate feeding of differently sized materials in between the in-feed roller 18 and the feed conveyor for delivering vegetation to the grinding portion 6. Three positions of in-feed roller 18 are shown in Figure 1, the two extreme positions are shown in phantom at the highest and lowest settings respectively, and an intermediate setting is shown in solid. In feed roller 18 may take any desirable, conventional or suitable form. One particularly suitable form of the in-feed rollers 18 is provided with surface projections in the form of teeth, barbs or similar for securely gathering and holding material to enable it to be delivered to the grinding portion 6.

Grinding portion 6 comprises generally a widthwise extending grinding drum 30 which is journalled at either end by suitable bearings located in supports provided at either side of the wood chipper for rotation about a widthwise extending fixedly located central axis. An anvil 32 is located immediately before grinding roller 30 in the forward direction of material as it passes through the wood chipper. Anvil 32 is located horizontally slightly below the horizontal plane of conveyor 14 so as to impart a slight downwardly inclined orientation to material being fed by the conveyor to and over anvil 32 and then to grinding drum 30. Anvil 32 is provided with a square edge 34 over its entire width. Grinding drum 30 is provided with a shroud or cover 22 having a tangentially arranged opening 24 to which is attached an elongate delivery chute 26 provided with a discharge opening 28 for discharging chips cut from the vegetation by rotating drum 30.

With particular reference to Figures 2 to 4 grinding drum 30 is provided with a solid centrally located shaft 36 extending the full width of the roller and extending beyond both sides of the roller. Each end of shaft 36 is stepped down in diameter to form an axle 37 for mounting the drum 30. The pair of axles 37 are journalled in bearings 38 located to support drum 30. Two generally annular end plates 40, 42 are attached to shaft 36 at either end of shaft 36 by suitable means such as welding or similar. Four flat generally rectangular longitudinal plates 44a,b,c,d extend longitudinally between the two end plates in the lengthwise direction of shaft 36. Longitudinal plates 44a,b,c,d are located regularly spaced apart around the diameter of shaft 36 at 90° to one another to subdivide grinding drum 30 into four quadrants generally denoted as 46a,b,c,d.

Each end plate 40,42 is provided with four apertures 48a,b,c,d and 50a,b,c,d, respectively. Each aperture 48 is provided in the centre of each quadrant of end plate 40 whereas each aperture 50 is provided in the centre of each quadrant of end plate 42 such that apertures 48a and 50a are aligned in lengthwise extending register with each other, apertures 48b and 50b are aligned lengthwise extending in register with each other, apertures 48c and 50c are aligned in lengthwise extending register with each other and apertures 48d and 50d are aligned in register with each other such that a hollow tube 54a may be passed through aligned apertures 48a,50a, hollow tube 54b passed through aligned apertures 48b,50b, hollow tube 54c passed through aligned apertures 48c,50c and hollow tube 54d passed through aligned apertures 48d,50d.

Even though there are four quadrants, since each quadrant is provided with the same cutting assembly arrangement, one only of the cutting assemblies will be described for the sake of clarity and brevity of description. Taking one cutting assembly which is denoted as 60, there is provided the hollow tube 54 extending lengthwise between the two end plates 40,42 by being received through one pair of the aligned apertures 48,50. Tube 54 is then cut into sections and removed from the areas where there are no cutting units so that the tube forms a bush for each cutting unit. A pin 62 is received through each of the sections of tube 54 remaining after tube 54 has been cut i.e. where each cutting unit is located. Pin 62 is securely fastened in place by suitable fastening means, at end plates 40,42 such as for example pin 62 terminating in a square over which is fitted a plate having a square hole or similar such arrangement.

A pair of quadrant plates 64,66 are located on one end of tube 54 in spaced apart relationship. Three further spaced apart pairs of quadrant plates are arranged at spaced apart locations on tube 54 in the lengthwise extending direction of drum 30. Each quadrant plate is provided with a centrally located aperture through which tube 54 is received prior to being cut into sections and pin 62 is received through the remaining sections of tube 54 when all of the apertures are aligned in register.

A cutting unit or block 80 (which will be described in more detail later) is located between both of the quadrant plates forming the one pair and is provided with an internally arranged bore and plastic bush through which pin 62 is received. A generally arcuate cover plate 70 is provided to span the space between adjacent pairs of quadrant plates by extending from one plate of the pair of quadrant plates to the contiguous plate of an adjacent pair of quadrant plates in order to provide a cover for the area between adjacent pairs of quadrant plates so as to prevent unwanted material from lodging between the pairs of quadrant plates and causing damage to the wood chipper generally. Cover plate 70 may take any suitable, desirable or convenient form. The particular form as described is welded between adjacent quadrant plates.

Cutting unit or block 80 located between the two quadrant plates of a single pair of quadrant plates is free to pivot on pin 62 and is capable of transcribing circle 82 as shown in Figure 2. Cutting block 80 generally comprises a generally hooked shaped body 84 of solid metal having bore 86 located towards one end for receiving the plastic bush and pin 62 therethrough. Body 84 is provided with a generally V-shaped cut out portion 87 having two side surfaces 88,90 oppositely inclined at 90° to each other defining a head portion 91 which is provided with a pair of spaced apart parallel bores 93a,b. A blade 92 is securely fastened to side surface 90 by means of a locking plate 94 provided with two spaced apart apertures and two socket head cap screws 96 passing through aligned apertures and bores respectively. Nuts 97 and lock nuts 98 are provided on the end of bolts 96a,b. Locking plate 94 is provided with milled grooves on one side in the form of serrations.

Blade 92 is provided with cutting edge 99 and is positioned such that cutting edge 99 extends outwardly beyond head portion so that as block 80 rotates cutting edge 99 transcribes circle 82. Blade 92 is provided on one side with milled grooves in the form of serrations in a similar manner to locking plate 94. The two sets of grooves are placed face to face permitting adjustment of the blade 96 with respect to block 80 to allow blade 92 to cut the vegetation to the particle size required.

Although one form of the blade having parallel sides is described and illustrated, blade 96 may be of a wedge shape having a tapering body.

It is to be noted that although only part of one quadrant has been described in detail the remainder of that quadrant and the other quadrants are either identical or similar to that portion of the quadrant which has been described, except that it is further to be noted that the pairs of quadrant plates are located on respective tubes 54 and pins 62 such that the entire width of feed conveyor is covered by the exact location of the pairs of quadrant plates being staggered along the lengths of tube 54 and pins 62 to ensure complete coverage of the width and complete overlap. Further it is to be noted that while each assembly has been described as having four pairs of quadrant plates, each shaft may have any number of pairs of quadrant plates with the proviso that the position of the pairs is staggered so as to ensure complete coverage of the entire width of the wood chipper.

in operation of the wood chipper of the present invention material, such as for example in the form of prunings or other waste vegetation, is introduced into delivery chute 12 and conveyed by conveyor 14 towards in-feed roller 18. As in-feed roller is mounted so as to be capable of vertical movement the material is fed between conveyor 14 and in-feed roller 18 but is maintained in contact with in- feed roller 18. In-feed roller 18 further feeds the material to anvil 32 which is located below the plane of conveyor 14 and spaced apart from conveyor 14 to such an extent that the material adopts a slightly downwardly directed inclination as it is fed to anvil 32. The end of material on anvil 32 is further directed towards rotating cutting blades 92 of drum 30 by in-feed roller 18. As the end of the material approaches close to rotating drum 30 the cutting blades 92 shave or otherwise remove slices, slivers, chips or similar from the end of the material. The angle of inclination of cutting blade 92 is arranged with respect to the angle of inclination adapted by the material being cut to ensure the material is being cut cleanly and the chips are of a size that allows delivery of the chips through the remainder of the wood chipper. The angle of the cutting blade to the drum and the angle that the cutting blade contacts the vegetation all assist in the efficient operation of the device of the present invention.

Additionally, since the cutting blade 92 and the cutting unit 80 is free to pivot about shaft 54 when the cutting blade 92 strikes a foreign object which is too hard to cut such as for example a piece of steel, iron, wire or the like blade 92 and block 80 can merely pivot backwards so that blade 92 is swung away to adopt a position within the outside diameter of the quadrant cover plates, 64,66 i.e. within the outside circumference of grinding drum 30 thus preventing damage to the drum or remainder of the device. Should the cutting unit 80 and blade 92 not be free to pivot backwards to be swung out of the way but rather should the cutting blade or block be held rigid the cutting blade 92 and perhaps also block 80 would be considerably damaged by repeatedly hitting the foreign object until the drum stops rotating and perhaps, the entire structure also which may in turn prevent the wood chipper from being used until major repairs are effected.

Once chips or the like are cut from the material being treated by the device of the present invention they are propelled through the remainder of the device between the grinding drum 30 and the shroud 22 into delivery opening 24 and delivery chute 26 for discharge through discharge opening 28 for collection in a hopper or similar or for ultimate disposal in a heap or similar.

One modification of the device of the present invention is that block 80 may take any form, shape or arrangement as desired so that it is balanced when rotating to permit blade 92 to extend outwardly from drum 30 to allow for replacement of blades 92 rather than of the entire block.

The described arrangement has been advanced by explanation and many modifications may be made without departing from the spirit and scope of the invention which includes every novel feature and novel combination of features hereindisclosed.

Those skilled in the art will appreciate that the invention described herein is susceptible to variations and modifications other than those specifically described. It is understood that the invention includes all such variations and modifications which fall within the spirit and scope.

Claims (20)

1. A device for treating material to reduce the size of the material or to produce fragments of the material, said device comprising an inlet means for introducing material into the device and directing the material to a material treatment means, said material treatment means comprising at least one movable material treatment element, and a delivery means for discharging material that has been treated wherein said material treatment element is movably mounted so as to adopt a normal in use position for treating the material in use of the device and being capable of being moved away from the normal in use position by contact with a foreign, object in use so as to prevent or reduce further damage to the material treatment element or the device when the material treatment element contacts the foreign object or other material which cannot be readily treated by the material treatment element.

2. A device according to claim 1 in which the material treatment device is a wood chipper or a wood chipping mill or a high volume vegetation grinder.

3. A device according to any preceding claim in which the inlet means comprises a feed roller which is a constant speed hydraulically operated in feed roller and a conveyor system.

4. A device according to in which the feed roller is vertically adjustable in use with respect to the normal operating orientation of the device so as to accommodate differently sized material being introduced into the device.

5. A device according to any preceding claim in which the treatment means comprises a constant velocity rotating drum or grinder.

6. A device according to claim 5 in which the speed of rotation of the in-feed roller is directly proportional to the speed of rotation of the rotating drum.

7. A device according to claim 5 or 6 in which the rotating drum is provided with a plurality of treatment or work elements.

8. A device according to claim 7 in which the treatment or work elements are cutting units having cutting blades.

9. A device according to any preceding claim in which there are 16, 32 or more separate material treatment elements provided on the rotating material treatment means.

10. A device according to any preceding claim in which the rotating drum is subdivided into quadrants and the cutting units are arranged in 4, 8 or more per quadrant.

11. A device according to any preceding claim in which each cutting unit including each cutting blade, is of a specific shape and/or weight to ensure that when the drum is rotating at a predetermined speed, the cutting tips of the blades of each cutting unit are centripetally thrown out to a specific distance and angle with respect to the rotating drum and the centre line or central axis of the device so as to ensure sufficient cutting of the material, said orientation being the normal in use position of the work element.

12. A device according to claim 11 in which the cutting blades are mounted so that the respective cutting tips are located about 10° in front of the centre line of the cutting line of the cutting unit when the device of the present invention is in the normal operating position.

13. A device according to any preceding claim further comprising an adjustable steel plate anvil surface such that the cutting units are arranged with respect to the steel plate anvil surface so that the cutting blades remove material of a predetermined size and shape distribution.

14. A device according to any preceding claim further comprising four longitudinal plates attached to a central axis to extend therefrom to divide the rotating drum into quadrants.

15. A device according to any preceding claim further comprising two endplates, one plate located at either end of the four longitudinal plates, said end plates each having four apertures, said apertures being arranged in pairs located in register for receiving a pin therethrough.

16. A device according to claim 15 in which the cutting units are free to pivot about the pins.

17. A device according to any preceding claim further comprising a cover plate extending from adjacent quadrant plates.

18. A method of reducing the size of material using the device according to any preceding claim.

19. A device for treating material to reduce the size of material or to produce fragments'of the material substantially as hereinbefore described with reference to any one of the accompanying drawings.

20. A method of reducing the size of material substantially as hereinbefore described with reference to any one of the accompanying drawings.