AU5263199A - An apparatus for cutting vegetation - Google Patents

Description

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Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT Applicants: TANUSI PTY LTD Invention Title: AN APPARATUS FOR CUTTING VEGETATION The following statement is a full description of this invention, including the best method of performing it known to us: 2 AN APPARATUS FOR CUTTING VEGETATION The present invention relates to farming and has a particular application to crops grown in rows.

Using the example of the cotton industry, traditionally after a cotton harvest has been completed, the residue of spent cotton plants must be chopped and dispersed so that operations can commence to prepare the soil for the planting of the next crop.

Different machines have been used for chopping and dispersing crop residue and such machines include mowers, slashers and flail mulchers. These all cut and shred the stubble in various forms using high speed blades or flails.

However they are inefficient requiring high power inputs, high maintenance and have limited potential for increased sizes of machine and speed of operation.

It would be desirable to provide a device mainly for row crop applications that provides more efficient, lower °.".power input, long wear life, potential for high ground speed of operation and a more controlled finished product that 20 will not cause problems of blockages in subsequent field ;operations.

The present invention provides an alternative method of dealing with the above problem.

According to the present invention there is provided an t. 25 apparatus for cutting vegetation, having a cutting means including at least one pair of cutting wheels mounted on first and second shafts respectively and each wheel having a too**: cutting portion including at least one engagement face which overlaps the at least one engagement face of the other wheel in the pair, whereby the overlapping engagement faces are adapted to cut vegetation during rotation of the wheels.

It is preferred that the at least one cutting portion includes an annular portion.

H:\SueB\Keep\Speci\P35527.1.doc 1/10/99 3 The annular portion may be located on an upper and/or lower face of the wheel.

The at least one cutting portions engagement face of each wheel may have a planar face which is substantially perpendicular to the axial direction of the wheel.

The at least one cutting portion engagement face preferably includes two engagement faces including an upper engagement face and a lower engagement face.

The upper engagement face includes an upper surface of the wheel.

The lower engagement face may include a lower face of the wheel.

According to one embodiment the apparatus includes a plurality of cutting portions, each cutting portion including a circumferential rim.

According to another embodiment each rim has an upper and/or lower engagement face.

According to another embodiment the at least one cutting portion includes an upper cutting portion and a o 20 lower cutting portion, the upper cutting portion including an upper engagement face and the lower cutting portion comprising a lower engagement face.

.Each engagement face may comprise a substantially flat upper and/or lower peripheral surface.

S. 25 Each cutting portion may comprise an outer edge.

Each cutting portion preferably comprises an outer edge.

Each outer edge preferably meets the engagement portion to form a corner portion.

Each outer edge may extend at an angle of between 100 and 1350 with respect to the engagement face.

According to one embodiment each outer edge is at right angles to the engagement face.

H:\SueB\Keep\sp-ci\P355 27 .1.doc 1/10/99 4 According to another embodiment each outer edge is oriented at 450 with respect to the engagement face.

The outer edge may slope inwardly from the engagement face.

Each engagement face may be located on an outer face of the cutting portion.

The cutting portion preferably comprises an annular rim with the engagement face on an axial face thereof.

The corner portion of each cutting portion may extend radially past an innermost portion of the cutting portion of the other wheel in the pair of wheels.

It is preferred that both wheels in a pair are arranged symmetrically with their central axis in parallel.

The width of the cutting portion is preferably the same for all cutting wheels.

The engagement face may have a width of less then The distance between the centres of both wheels in the pair is preferably less than the diameter of one of the wheels and optionally is the diameter of one of the wheels 20 minus the radial thickness of one of the cutting portions.

Each wheel may have substantially the same diameter.

The shafts may be connected to a tool bar which is -:•connectable to a vehicle.

The shafts may be connected in a vertical orientation 25 to the tool bar.

According to another embodiment the shafts may be in angled orientation.

.oooo: S"The shafts may be connected in parallel.

It is preferred that the apparatus comprises a plurality of shafts.

Preferably the tool bar includes a plurality of shafts equispaced in parallel.

Each shaft may have a plurality of wheels.

H:\SueB\Keep\speci\P355 27 .1 .doc 1/10/99 5 Each wheel preferably is movable axially on the shaft on which it is located.

According to one embodiment each wheel is held on its shaft by a weight or the weight of the wheel.

It is preferred that cutting in the context of the invention includes chopping, severing, breaking, tearing, ripping, etc.

According to another aspect of the present invention a tool is provided for cutting vegetation, the tool having a shaft and a plurality of wheels, each wheel having a cutting portion including at least one engagement face which is adapted to overlap the at least one engagement face of a wheel of another tool, whereby the overlapping engagement faces are adapted to cut vegetation.

The tool is preferably adapted to be connected to a tool bar which may be connected to a trailer or vehicle.

According to another aspect of the present invention there is provided a vehicle having a tool bar and a plurality of tools connected thereto.

The wheels of the tool are preferably able to move axially on the shaft.

*It is preferred that the wheels comprise an annular portion which is connected by radiating members to a central portion adapted to slide on the shaft.

25 The annular portion may include the cutting portion.

S According to another aspect of the present invention there is provided a wheel for cutting vegetation the wheel having a cutting portion including at least one engagement face which is adapted to overlap the engagement face of a cutting portion of another wheel whereby rotation of the wheel with another wheel enables vegetation to be cut by the overlapping engagement faces.

H:\SueB\Keep\speci\P35527.1.doc 1/10/99 6 It is preferred that the wheel comprises two cutting portions.

The two cutting portions may include upper and lower cutting portions.

The cutting portion may include a detachable blade.

Each cutting portion is preferably in the form of an annular rim with an upper and lower face corresponding to respective upper and lower cutting faces.

Each cutting face preferably has an edge.

According to another embodiment the wheel is dish shaped.

It is preferred that each edge slopes inwardly.

The upper and lower cutting faces preferably are in the form of annular ribs with the edge forming the outermost peripheral face thereof.

It is preferred that the edge is in the form of a cylindrical surface and forms a right angle corner with the respective upper and lower cutting faces.

It is preferred that the at least one engagement face e *20 includes the cutting face.

.According to another embodiment the edge of each cutting portion forms a raised lip above the level of the top face of the cutting portion.

The edge may have a curved outer face or conical outer 25 face to form a dish like shape for the cutting portion.

~According to another embodiment the edge is flush with the level of the upper/lower face.

According to another embodiment the cutting portion comprises a ring element located between two annular wheel segments and is adapted to extend beyond the peripheral extent of each wheel segment.

H:\Sue\Keep\speci\P35527-1.doc 1/10/99 7 According to another embodiment the cutting portion comprises an annular element connectable to a main section of the wheel on an upper and/or lower face thereof.

It is preferred that the engagement face is located on the upper and lower face of the cutting portion and corresponds to the majority of the radial width of the ring element.

It is preferred that the wheel is adapted to receive a shaft therethrough.

The upper and lower cutting portions are preferably separated by a middle section of the wheel.

It is preferred that the middle section of the wheel includes a feed means.

The feed means preferably includes peripheral protrusions for directing vegetation to the overlapping engagement faces.

The peripheral protrusions preferably are evenly spaced around the exterior of the mid section.

It is preferred that the protrusions extend proud of 20 the peripheral edge of the cutting portions.

It is preferred that the apparatus includes feed means for directing vegetation to the cutting means.

*The feed means preferably includes a plurality of protrusions rotatable with rotation of the shafts.

25 According to one embodiment the feed means includes a wheel with a plurality of peripheral protrusions located between cutting wheels.

The feed means may include a plurality of protrusions located around the periphery of the wheel.

The plurality of protrusions are preferably in the form of teeth.

H:\SueB\Keep\speci\P 355 2 7 l1 .doc 1/10/99 8 Each cutting wheel may be spaced apart from adjacent cutting wheels on the same shaft by the interposing cutting wheel of an adjacent shaft.

It is preferred that the upper and lower faces of the wheel forming the engagement faces are substantially planar.

It is preferred that the feed means is located between the upper and lower engagement faces.

The feed means may comprise a wheel separate from the cutting wheel. Alternatively the feed means is part of the cutting wheel.

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 shows a front view of an apparatus for cutting vegetation in accordance with a first embodiment of the present invention; Figure 2 shows a top view of the apparatus shown in Figure 1; Figure 3 shows the apparatus of Figure 1 in use; 20 Figure 4 shows a front view of an apparatus for cutting vegetation according to a second embodiment of the present invention; "Figure 5 shows a top view of the apparatus shown in Figure 4; 25 Figure 6 shows a front view of cutting edges of adjacent cutting wheels according to one embodiment of the invention; ~Figures 7a and 7b show a front view of cutting edges of adjacent cutting wheels according to different embodiments of the invention; Figure 8 shows a top view of overlapping cutting edges according to a further embodiment of the present invention; H:\SueB\Keep\spei\P 3 552 7 .l1doc 1/10/99 9 Figure 9 shows a front view of an apparatus for cutting vegetation according to a third embodiment of the present invention; Figure 10 shows a top view of a feed wheel for use in the apparatus shown in Figure 9; Figure 11 shows a front view of an apparatus for cutting vegetation according to a fourth embodiment of the present invention; Figure 12 shows a top view of the apparatus shown in Figure 11; Figure 13 shows a front view of an apparatus for cutting vegetation according to a fifth embodiment of the present invention; Figure 14 shows a top view of the apparatus shown in Figure 13; Figure 15 shows a schematical front view of an apparatus according to the present invention incorporating a drive chain; and Figure 16 shows a top view of the apparatus shown in 20 Figure According to one preferred form of the present invention a cutting apparatus consisting of at least two shafts 11, 12 is attached to a tool bar (not shown). The tool bar may form part of a trailer which may be connected 25 to a tractor or other vehicle or may be part of a purpose built vehicle.

Figure 1 shows shafts 11, 12 with seven cutting wheels fee*: 0 13, 14 located thereon.

Each cutting wheel 13, 14 consists of an upper annular rim 15, 16 and a lower annular rim 17, 18.

Between the upper and lower rims 15, 17 and 16, 18 radially extending protrusions or sprockets are provided equally spaced around the periphery of the wheels 13, 14.

H:\SueB\Keep\speci\P355 2 7 .1.doc 1/10/99 10 As shown in Figure 1 each wheel 13, 14 is spaced from an adjacent wheel 13, 14 on the same shaft 11, 12 by the interposing wheel from the adjacent shaft.

According to the first embodiment the upper and lower rims 15, 17 and 16, 18 have an outermost periphery 21, 22 and 23, 24 respectively. These outermost peripheries in this embodiment instead of being at right angles with the adjacent upper or lower face 15, 16 and 16, 18 slope inwardly approximately at an angle of 30° or As shown in Figure 2 the upper surfaces 15, 16 of the respective rims of each of the wheels 13, 14 have a relatively small radial thickness and these rims 15, 16 overlap in a central area located approximately midway between the adjacent shafts (11, 12) so that the distance between the adjacent shafts is less than the combined radius of each wheel 13, 14 on each shaft.

In the embodiment shown in Figures 1 and 2 the rims and 16 overlap to the extent that the outermost portions of each overlapping portion does not extend beyond the innermost wall of each rim 15, 16.

As shown in Figure 1 because the shape of the rims 16 are identical the outermost peripheries 22, 23 have parallel peripheral edges.

Each of the sprockets 19 of a wheel extends beyond the 0* 25 peripheral extent of each rim 15, 17 and 16, 18 and thus where the wheels overlap the sprockets 19, 20 extend almost a third of the radius of each wheel towards the opposing shaft.

According to one method of operating the apparatus shown in Figures 1 and 2 a stem 25 of a plant as shown in Figure 3 is captured by the sprockets 19, 20 of engaging/overlapping cutting wheels 13, 14. Each of these shafts 11, 12 rotate in opposite directions so that the H:\SueB\Keep\SpeCi\P355 2 7 .1.dOC 1/10/99 11 sprockets 19, 20 draw the stem 25 inwardly towards the overlapping rims 15, 16. As a result the stem 25 is cut at each location where the rims of the wheels overlap and thus at 13 places where the individual wheels of both shafts overlap, this being because the uppermost rim of the top wheel and shaft 11 and the lowermost rim of the lowermost wheel of the shaft 12 do not overlap with an adjacent wheel.

According to another variation of the embodiment shown in Figure 1 each of the wheels are spaced slightly further apart on their respective shafts so that there is a small gap between the overlapping portions 22 and 23 of overlapping wheels 13, 14.

In its preferred form the apparatus disclosed above is able to chop and disperse agricultural crop residue usually after harvest and is applicable as a single or multiple row unit. Furthermore, lowermost wheels on each of the shafts are able to operate close or below ground level to cut up the roots of plants as well.

It is preferred that the apparatus cuts plant material 20 into small pieces allowing it to be disposed of by spreading S* evenly on the ground and returning to the soil in a manageable form or so that it is able to be collected.

An advantage of the apparatus described above is that because of the shape of the outermost edges of each of the 25 rims 15, 17 and 16, 18 as the overlapping faces of each of these rims begin to wear vegetation is still able to be cut with the same quality of cut because the overlapping 5 surfaces 22, 23 maintain substantially the same edge facing.

Because each wheel is able to freely move on its shaft as a rim wears down the weight of the wheel ensures contact still is maintained between overlapping rims of the wheels.

If necessary a biasing spring may be incorporated on the shaft.

H:\SueB\Keep\speci\P355 27 dOC 1/10/99 12 Because each shaft is provided with its own gang of wheels it is possible to replace each shaft with its wheels as a single row unit.

Because the wheels overlap they provide a rolling scissor action as they rotate and are able to cut stalks into lengths as determined by the wheel width, that is the distance between the upper and lower faces of each rim.

According to another embodiment of the invention the cutting edges at the outermost periphery of each of the rims are dish shaped to improve the wearability of the each of the wheels. In such an instance the wear produced on these faces gives self sharpening effect to the cutting edges.

In the embodiment where the cutting edges do not contact the adjacent overlapping cutting edge cutting of vegetation can itself produce sharpening of the cutting edges as a result of wear caused by the vegetation rather than any grinding contact with the overlapping cutting edge.

e..e It is preferred that the cutting wheels 13, 14 are S. mounted to shafts which at their top ends are connected to o 20 hydraulically, pneumatically, mechanically, electrically or *other drive means. In this fashion the shaft with its gang of wheels can be removed by unbolting the top flange "component of the shaft from the driving shaft to which it is connected. Thus the driving shaft itself is fixed firmly to the tool bar of the trailer or vehicle and does not need to be continually detached and reattached.

Figure 8 shows a more detailed view of the overlapping cutting edges 30, 40 of two overlapping wheels. In the embodiment shown the cutting faces 30, 40 actually overlap to such an extent that they extend beyond the inner periphery of each cutting edge.

Figure 6 shows one embodiment of the cutting edges in which the outermost edge 41 of the top wheel 42 slopes at H:\SueB\Keep\speci\P 3 5 5 2 7 .1.doC 1/10/99 13 approximately 300 or 450 from the bottom face 43 of the rim 44. Similarly the lower wheel in this situation has its outermost cutting edge 31 sloping downwardly from the upper face 33 down to the bottom of the rim 32.

In contrast Figure 7a shows overlapping wheels 50, with outermost cutting edges 51, 61 respectively which are perpendicular to both the upper and lower faces of their respective rims 50, 60. The overlapping cutting edges 52, 62 are substantially in direct contact with each other as before. Thus it can be appreciated as the cutting faces 52, wear the thickness of both rims 50, 60 reduces. Once the rims are close to being worn down, it is clearly apparent to an observer that they need to be replaced. However, up until this occurs the quality of a cutting operation is relatively consistent.

It is clear from the above that the cutting edge ro. geometry will operate with a wide range of angles of the 0outermost edge with respect to the overlapping cutting edges. The smaller leading edge angles give a cleaner and o0eo S• 20 more efficient cutting while larger angles give more :crushing and tearing action.

o ~Figure 7b shows another embodiment of cutting geometry in which cutting edges 51, 61 slope slightly inwardly with respect to each other at their overlapping ends *see 25 The sprockets preferably serve to give a bruising crushing action to the stalks of vegetation prior to cutting. They also are able to put the stalks into tensi0on ooo by crushing it from either side into a zig zag shape. This tension improves the cutting efficiency provided by the cutting surfaces.

As previously described the sprockets also serve to gather and feed plants into the cutting faces.

H:\SueB\Keep\SpeCi\P3 5 52 1.1doC 1/10/99 14 Another embodiment of the invention is shown in Figure 4 in which cutting wheels 70 are distinct from feeding/crushing wheels 71. Thus in Figure 4 each shaft 72, 73 is provided with a layered construction of cutting wheels 70 and interposing feed wheels 71. In the embodiment shown there are seven cutting wheels and seven feed wheels.

The cutting action involved in the embodiment shown in Figures 4 and 5 is similar to that shown in Figures 1 to 3.

In contrast to the apparatus described in the first embodiment however the zig zag pattern with which a stalk is held is changed depending on the outer peripheral radius of the cutting surfaces of the cutting wheel 70 and the radial length of the teeth of the feed wheel 71.

Because each cutting wheel no longer includes sprocket teeth a hollowed out region is provided between the upper and lower rims 74, 75 in a similar fashion to a pulley wheel. This hollowed out region 76 is concave and lies adjacent the opposing sprockets of the feed wheel 71.

Another version of the invention is shown in Figures 9 20 and 10 in which the cutting wheels are replaced by cutting discs 80, 81. Each cutting disc 80, 81 is frustoconical in shape and abuts a similarly shaped disc 82, 83. The minor radial surfaces 84, 85 and 86, 87 face each other resulting in the major radial surfaces being the outermost surfaces.

25 The outermost edges of each of the discs overlap in a similar fashion to those previously described and indicated by item 90 in Figure Thin flat discs 100 include peripheral protrusions such as teeth which act as feeding mechanisms in a similar 30 fashion to previously described and shown more clearly in Figure According to a fourth embodiment of the present invention shown in Figures 11 and 12, one shaft 110 is H:\SueB\Keep\speci\P3 5 5 2 7.1.doc 1/10/99 15 provided with frusto conical cutting discs 111 which are fixed in position by spacers 112 which fit over the shaft 110.

Each of the discs 111 have a peripheral edge which tapers outwardly from the bottom to the top surface.

A pair of cutting discs 111 are grouped together and spaced apart by spacer 112. Above an upper cutting disc 113 a smaller spacer 114 is provided which separates the upper disc 113 from an upper feeder disc 115.

A spacer 116 separates lower disc 117 from lower feeder disc 118.

A series of paired cutting discs 111 are provided on shaft 110 and are all fixed in position.

An adjacent shaft 119 is provided with a similar configuration of cutting discs 120, spacers 121 and feeder discs 122. In contrast however the cutting discs 120 are inverted compared to those on shaft 110. This allows adjacent cutting discs 111 and 120 to have their cutting edges overlap in a manner previously described with 20 reference to Figures 6 to 8.

The resultant configuration of cutting discs 111, 120 and feeder discs 115, 122 results in a clear space being provided between adjacent components on each shaft 110, 119.

This allows cleaning bars to enter from the rear of the S 25 apparatus into the spaces between these components to keep them free from build up of rubbish.

According to a fifth embodiment of the present invention the embodiment shown in Figure 9 is varied so that thin cutting discs 130, 131 are paired together as shown in Figures 13 and 14 in a similar fashion to cutting discs 82 and 81, 83. In contrast however cutting discs 130 and 131 are spaced apart by spacer 132. Thus each feed disc 133 H:\SueB\Kee\speci\P3552 7 .1.doc 1/10/99 16 is vertically spaced between adjacent cutting discs of another shaft.

As with the previously described embodiment cleaning bars are able to fit between the spacers of each of the components located over shafts 134 and 135 of the apparatus.

According to another variation of the present invention feed chains 140 may be provided to feed in vegetation towards cutting discs. Thus as shown in Figure 16 two small sprocket wheels 141 would be provided at the front of the apparatus and the feeder chains 140 would extend around these small sprocket wheels 141 and larger feed wheels 142.

Feed chains of adjacent shafts 143, 144 would rotate in a direction which draws vegetation towards cutting edges of the cutting discs.

It is preferred that the feed chain and cutting discs have a peripheral speed which is higher than the ground speed of the vehicle to which they are ultimately connected.

Desirably the peripheral speed of the feed chains is sufficient to tilt a plant from the top first towards the 20 cutting discs. This provides a better method of controlling cutting and makes it easier to provide a serpentine cutting path.

It is preferred that the peripheral speed of the feed chains and cutting discs is approximately 20 percent greater 25 than the ground speed of the vehicle.

In addition to the embodiments described above it should be noted that if it is desired to have components on each shaft fixed in position separate spacers could be S" replaced by having discslwheels provided with flanges which 30 serve the same purpose, or alternatively fixing devices may be used to locate each of the components at a particular position on each shaft.

H:\SUeB\Keep\peci\P 35 52 7 .1 .doc 1/10/99 17 According to another embodiment of the present invention each of the shafts may be movable up or down relative to an adjacent shaft.

It is preferred that the cutting edge angle between cutting discs/wheels is between 10 to 200 so as to provide a self cleaning aspect to the invention.

According to different embodiments of the present invention it is possible for all of the shafts to be driven or one or more of the shafts to be driven. It is also possible for one shaft to drive another through interaction between driving sprockets of wheels located on the shafts.

According to another embodiment the cutting wheels may be provided with replaceable cutting edges so that if the edges become damaged or worn only the cutting edge needs to be replaced rather than the whole wheel.

It is possible to treat leading faces of cutting wheels to give them a longer life and enhance the self sharpening effect. Such treatments would include hard facings and different coatings and heat treatments that would give surface hardness and heat resistance but leave the remainder of the contacting faces softer.

The cutting edges of the cutting wheels are preferably circular but other shapes can be applied to the edges such as serrations, lobed tooth or waved profiles.

25 According to other variations of the present invention •the cutting wheels and/or feed wheels may be used in conjunction with other devices, for example on a tool bar.

Furthermore, other devices may be provided on the same o:oeo shafts or separate shafts as the cutting wheels such as root 30 cutter discs or stalk pullers.

In the embodiments described previously wheels or discs of certain shapes and configurations have been disclosed.

The present invention also contemplates different shaped H:\SueB\Keep\speci\P355 2 7 .1.dOC 1/10/99 18 wheels/discs being used on the same shaft or different shafts and that these wheels/discs are conical, flat, domed, curved or of other shapes which would enable effective cutting and feeding of vegetation.

H:\SeB\KeeP\spei\P35527.lddoc 1/10/99

Claims (16)

1. 2. The apparatus as claimed in claim 1 wherein the feed means is located between two adajacent cutting members.
2. 3. The apparatus as claimed in claim 2 wherein the feed means comprises feed devices having a plurality of protrusions which are adapted to direct vegetation towards cutting members.
3. 4. The apparatus as claimed in claim 3 wherein the feed means comprises a plurality of rotatable members 20 located on each of the shafts.
4. 5. The apparatus as claimed in claim 4 wherein each of the rotatable members have diameters greater than the diameters of the cutting members. fe
5. 6. The apparatus as claimed in claim 5 wherein each S' 25 rotatable member has peripheral feed protrusions.
6. 7. The apparatus as claimed in claim 6 wherein the cutting members comprise discs with peripheral protrusions.
7. 8. The apparatus as claimed in claim 6 or 7 wherein each rotatable member is removably attachable to one of the 30 shafts.
8. 9. The apparatus as claimed in any one of the preceding claims wherein the feed means of adjacent shafts H:\SueB\Keep\speci\P 3 5527 .1 .doc 1110/99 20 are adapted to tension a piece of vegetation in a serpentine shape for cutting by the cutting means. The apparatus as claimed in claim 8 wherein the protrusions comprise teeth located around the periphery of each feed member.
9. 11. The apparatus as claimed in claim 1 wherein the feed means comprises a plurality of elongate elements having peripheral protrusions.
10. 12. The apparatus as claimed in claim 11 wherein the elongate elements comprise chains which are connected to drive wheel sprockets located on the shafts.
11. 13. The apparatus as claimed in any one of the preceding claims wherein the cutting members are fixed on the shafts.
12. 14. The apparatus as claimed in any one of claims 1 to 12 wherein the cutting members are movable axially on the shaft on which they are located. The apparatus as claimed in any one of the preceding claims wherein at least one cutting portion 20 includes an annular portion.
13. 16. The apparatus as claimed in claim 15 wherein each cutting portion extends around the whole periphery of the cutting member and includes an outer edge which is adapted to at least partially overlap the outer edge of the cutting 25 member of another shaft.
14. 17. The apparatus as claimed in claim 16 wherein outer edges of overlapping cutting members are urged together. •Q
15. 18. The apparatus as claimed in claim 17 wherein shafts are movable axially to urge together outer edges of 30 overlapping cutting portions.
16. 19. An apparatus as claimed in claim 17 wherein each outer edge has a predetermined radial thickness. H:\SueB\Keep\speci\P355 27 dc 1/10/99 18 wheels/discs being used on the same shaft or different shafts and that these wheels/discs are conical, flat, domed, curved or of other shapes which would enable effective cutting and feeding of vegetation. *e. o* *g H:\SueB\Keep\peci\P355 27 .1.d.c 1/10/99