AU749650B2 - Chopper adjustment apparatus - Google Patents

Description

P/00/011 Regulation 3.2

AUSTRALIA

Patents-Act 1990 te e °a *o 4 I° o a a a

I

P

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: CHOPPER ADJUSTMENT APPARATUS" The following statement is a full description of this invention, including the best method of performing it known to us:-

TITLE

"CHOPPER ADJUSTMENT APPARATUS" FIELD OF THE INVENTION THIS INVENTION relates to an apparatus for adjusting blade clearance of a chopper, such as applicable to harvesters, although without being limited thereto. Also provided is a kit and method for chopper adjustment.

BACKGROUND OF THE INVENTION Harvesters typically employ choppers which cut harvested material into smaller pieces. In the case of sugarcane harvesters, the harvested sugarcane is cut into billets to convert the relatively long sugarcane plants into a more compact and hence more manageable form.

A common chopper assembly includes a pair of chopper shafts each with an attached blade. Each chopper shaft may be fixed at one end thereof to a mounting bracket which is itself coupled to a gear bracket such as by splining. The gear bracket is usually bolted to a gear, ::the gears forming a meshed pair. The other end of one chopper shaft is coupled to a drive shaft. The chopper shafts, gears and other components are suitably housed in a gearbox, usually with a covered inspection port to allow inspection and maintenance of the chopper assembly.

Rotation of the drive shaft, such as by a motor, drives rotation of the chopper shaft, blade, and the gear coupled thereto.

Rotation of this gear causes rotation of the paired gear to which it is meshed, thereby causing rotation of the chopper to which the meshed KJ.V~ifrV.- X rw%'r7\# V~.ThV t~-.J*,,flVf~Nr ~M V~t~Th*~"W 3 gear is attached. Usually, the paired chopper shafts, blades and gears are arranged so that the blades counter-rotate with one blade slightly leading the other, thereby cutting in a scissor-type fashion.

Crucial to chopper performance is correct clearance between counter-rotating blades. If the clearance becomes too great, then cutting efficiency diminishes significantly. This can occur through ageing and wearing of blades, or by inadvertent ingress of solid material such as rocks, metal objects and the like which may contact the blades.

Therefore, provision of means for adjusting chopper blade clearance has become a desirable feature. Generally, these have :eoeooinvolved opening the gearbox to thereby obtain access to the internal 00;:--components of the gearbox. In such cases, chopper blade adjustment is usually a laborious and time-consuming process requiring disassembly ::o.*and reassembly of several components of the chopper assembly. Also, 0. 15 there is the possibility that by opening the gearbox to the external 00000 environment, dust, debris and the like may enter the gearbox and cause damage to the components thereof.

In this regard, reference is made to Australian Patent No.

679897 which discloses an adjustable chopper shaft whereby adjustment does not require access to the gearbox. In this case, the chopper shaft extends outside the gearbox and terminates in a flanged outer adjustment plate which is formed integrally with the shaft. The outer adjustment plate is bolted against an inner adjustment plate which is concentric to the chopper shaft, and which is itself bolted to a bush fixed to the gear. In order to adjust the chopper shaft, and hence the attached blade, the bolts fixing the inner and outer attachment plates are loosened and the outer adjustment plate rotated relative to the inner adjustment plate, bush and gear, thereby causing relative rotation of the chopper shaft and gear.

Because this adjustment apparatus is located externally to the gearbox, a seal must be provided between the bush and gearbox wall to prevent ingress of debris into the gearbox.

A particular disadvantage of this apparatus is that it requires at least substantial modification, if not replacement of the chopper shaft, in order to provide the flanged outer adjustment plate. Should the special ly-modified chopper shaft break or otherwise become inoperable, replacement or repair of the shaft is expensive and time-consuming. This problem is exacerbated by the adjustment apparatus being external to the gearbox, thereby being susceptible to accidental contact which may lead *.15 to damage.

OBJECT OF THE INVENTION It is an object of the invention to provide a chopper adjustment apparatus which is releasably connectable to an existing chopper assembly.

SUMMARY OF THE INVENTION In one aspect, the present invention resides in an adjustment apparatus for a chopper assembly having a gear and a chopper shaft, said adjustment apparatus comprising:a first member releasably connectable to the gear; and (ii) a second member releasably connectable to the chopper shaft; whereby in use, adjustment is performed by rotation of said first member and/or said second member which causes corresponding rotation of said gear and/or said chopper shaft respectively.

It will be appreciated that by virtue of the first member and the second member being releasably connectable to the gear and the chopper shaft respectively, the apparatus of the invention has the advantage of being removably mountable to an existing chopper assembly, and does not require substantial modification or replacement of the chopper shaft. Furthermore, when connected, the adjustment apparatus of the invention is located within a gearbox which houses the S. 15 gear and chopper shaft, and therefore is less likely to be damaged during chopper operation than is an externally-located apparatus.

It will also be appreciated that the apparatus of the invention S- provides a means whereby fine adjustment of chopper blade clearance may be achieved by rotation of the chopper shaft in the absence of gear rotation, by rotation of the gear in the absence of chopper shaft rotation, or by rotation of both the gear and the chopper shaft.

Suitably, the second member is releasably connectable to the chopper shaft by way of a mounting means.

In typical chopper assemblies, such as applicable to 6 harvesters, chopper blades are coupled to said chopper shaft via a mounting bracket and said gear is mounted to a gear bracket. This may be achieved by the gear bracket being fixed, such as by splining, to the mounting bracket.

Therefore, in an embodiment, the mounting means in use connects the second member to the gear bracket fixed to the chopper shaft mounting bracket.

Preferably, the mounting means is in the form of bolts, which in use, extend through spaced apertures in the second member and thereby connect the second member to the gear bracket.

According to one embodiment, the second member is annular, ring- or disc-like, and the first member has a base and a hub projecting therefrom. The base is preferably in the form of a flange.

Furthermore, the hub is locatable in the interior of the annular second member by being of reduced diameter relative to the internal diameter of the annular member. The annular first member is therefore seatable on the flanged base of the second member with the hub of the second member located inside said first member and concentric therewith.

According to this embodiment, the second member has spaced apertures extending longitudinally therethrough which are alignable with respective spaced slots located in the base of the first member. The slots in the base are themselves alignable with respective gear slots. Mounting means in the form of bolts extend through the spaced apertures, aligned slots in the flanged base and gear slots, a threaded end of each bolt being screw- 7 threadedly engaged by a respective tapped aperture located in the gear bracket.

Once connected, there is suitably no rotation of the gear relative to the first member.

Suitably, rotational movement of the gear relative to the first member is prevented by a coupling means. The coupling means may be in the form of a one or more plain pins or dowels, threaded pins, plugs, bosses or the like.

As hereinbefore described, typically, the gear slots are ooooo 10 alignable with spaced slots located in the base of said first member.

Therefore, in an embodiment of the coupling means, one or more dowels or plugs may be used which fit tightly into respectively aligned gear slots and spaced slots.

In another embodiment of the coupling means, one or more bosses projecting from the base may fit tightly into one or more respectively aligned gear slots.

In yet another embodiment, the coupling means is in the form of a pair of threaded pins, each having a threaded end and a plain end. Preferably, the threaded ends each screw-threadedly engage a respective tapped aperture or bore in the base of the first member. The tapped apertures are spaced so that when the threaded pins are located therein, the plain end of each threaded pin can be inserted into a gear slot thereby preventing lateral movement of the gear slot relative thereto, and hence preventing rotation of the gear relative to the first member.

4~k~ 8 In still yet another embodiment of the coupling means, one or more alignable drill holes may be made in the gear and in the base of the first member into each of which is insertable a plain pin or dowel.

From the foregoing, it will be understood that in use, the mounting means and coupling means co-operate to releasably connect the first member to the gear.

Suitably, in order to adjust chopper blade clearance, the mounting means is loosened so that rotation of the first member and/or the second member may be achieved. Preferably, an actuating tool is provided which assists manual adjustment of blade clearance.

Preferably, the actuating tool co-operates with teeth or splines in the second member to form a ring .gear and pinion assembly which facilitates relative rotation of the second member and the first member and hence gear and chopper shaft respectively. This affords relatively simple fine adjustment of chopper blade clearance, as will be described in detail hereinafter.

Preferably, tightening of the mounting means is performed so as to achieve a desired tension which will prevent relative rotation of the first and second members under conditions of normal operation of a harvester, for example, but also allow relative rotation of chopper shaft and gear should the chopper blades inadvertently encounter a solid obstacle such as rock, wood, metal objects or the like. Limited "slippage" between gear and chopper shaft reduces the likelihood of chopper shaft breakage or damage should such an encounter occur.

-Ms 9 It will be appreciated that the chopper adjustment apparatus of the invention is releasably connectable to an existing chopper assembly, and is housed within the gearbox. Therefore, it is preferable that the apparatus includes a cover which is affixable to an existing inspection port of a gearbox. The cover is suitably closed during harvester operation so as to prevent ingress of dirt and debris into the gearbox.

According to another aspect, the present invention provides a kit for adjusting a chopper assembly, said kit comprising:a first member releasably connectable to a gear; a firstecond member releasably connectable to a gear; (ii) a second member releasably connectable to a chopper shaft; (iii) coupling means for preventing rotation of said first member relative to said gear; (iv) bolts for releasably connecting said second member to said chopper shaft; an actuating tool for rotating said first member relative to said second member; and (vi) a cover affixable to a gearbox which houses said chopper assembly.

In yet another aspect, there is provided a method of adjusting a chopper assembly having a gear and a chopper shaft, said method comprising the step of rotating a first member releasably connected to the gear and/or a second member releasably connected to the chopper shaft, to thereby cause corresponding rotation of said gear and/or said chopper shaft respectively.

According to this aspect, is is preferable that an actuating tool facilitates relative rotation of the first member and/or the second member.

It will be appreciated that "comprise", "comprises" and "comprising" is used herein inclusively rather than exclusively, in that it is contemplated that one or more other integers may be included in addition to a stated integer or integer group.

*0000: 10 So that the invention may be understood in more detail, the ~skilled addressee is referred to the accompanying drawings and nono. limiting preferred embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS e•Oae FIG. 1: Exploded view of one embodiment of a chopper adjustment apparatus connectable to a chopper shaft and gear; FIG. 2: Exploded view of adjustment apparatus in relation to gear and chopper shaft located in gearbox; 0 FIG. 3: Sectional elevation of another embodiment of a chopper adjustment apparatus and hinged cover; FIG. 4: Perspective view of assembled chopper adjustment apparatus connected to chopper shaft and gear; FIG. 5: Schematic elevation showing lateral movement of long bolt shafts in gear slots during rotational adjustment of blade clearance; and ~-MIN VAY~.-i- FIG. 6: Exploded view of alternative arrangements for preventing rotational movement of gear.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIG. 1, chopper adjustment apparatus includes second member 11 and first member 12. Second member 11 is annular with step 14 therein, a portion of inner peripheral edge 13 having radially inwardly-facing teeth or splines 15. Spaced apertures 16 extend longitudinally through annular member 11 and are capable of receiving mounting means 17 in the form of long bolts. First member 12 has hub with flanged base 21 and slots 22 spaced around base 21. Hub 20 of first member 12 is of reduced diameter relative to internal diameter of annular member 11. Paired tapped apertures 23 are also located in flanged base 21, each of which are capable of receiving threaded pin 24. Hub includes recess 25 adjacent tapped apertures 23, there also being stub 26 located in recess In order to assemble chopper adjustment apparatus 10, hub of first member 12 is placed concentrically into annular member 11 so that apertures 16 are aligned with respective slots 22 so that recess 25 is juxtaposed adjacent teeth or splines 15. Long bolts 17 are inserted into aligned apertures 16 and slots 22 so that shaft 27 extends therethrough, with washer 18 and 0-ring 19 forming a seal between bolt head 28 and annular member 11. Screw-thireaded ends 29 of threaded pins 24 are fitted to tapped apertures 23 so that plain ends 30 extend therefrom.

With reference to FIG. 1 and FIG. 2, apparatus 10 is 12 releasably connectable to an existing chopper assembly as described herein. Chopper assembly 31 includes chopper shafts 32 to each of which is attached blade 33, each chopper shaft being attached at an end thereof to mounting bracket 34 (not visible in FIG. 2) via bolt holes 35 with mounting bracket 34 engaging gear bracket 36 by splining (not shown).

Gear bracket 36 is mounted to gear 37 by threaded bolts (not shown) which extend through gear slots 38 and screw-threadedly engage tapped gear bracket apertures 39. The location of chopper assembly 31 inside gearbox 40, and flywheel 41 external to gearbox 40 is shown in FIG. 2.

S•10 To mount apparatus 10 to components of chopper assembly ~31, bolts (not shown) are removed from gear slots 38 and gear bracket apertures 39. Apparatus 10 is then connected to gear 37 so that plain end 30 of both pins 24 fits into the same gear slot 38, long bolts 17 extending a. a• through respective gear slots 38 with threaded end 42 screw-threadedly 15 engaging gear bracket apertures 39. According to this embodiment, once connected to the chopper assembly, outer surfaces 43 and 44 of first member 12 and second member 11 respectively are substantially coplanar.

Preferably, the tension of long bolts 17 is adjusted, such as with a torsion wrench, so that during operation of the harvester, should the chopper blades encounter a solid object, the first member 12 and second member 11 can "slip" relative to each other and thereby reduce the possibility of breakage of chopper blades or shaft. At this point cover is closed to prevent ingress of material such as dust and debris during 13 operation of the harvester.

With reference to FIG. 2, cover 45 includes door 46 connected by hinge 47 to base 48 affixed to an existing inspection port in gearbox wall 49, such as via bolts 50. Quick release latch 51 is also provided together with handle 52.

With reference to FIG. 3, there is shown an embodiment where cover 45 has door 46 and base 48 with latch members 51A and 51 B respectively mounted thereto. Door seal 53 provides a seal between door 46 and base 48 when closed. Base seal 54 is located to prevent ingress of debris and egress of lubricant between second member 11 and base 48 of cover 45. According to this embodiment, hub 20 of first member 12 is substantially hollow with steps 55A, 55B and 55C formed therein. In contrast to the embodiment shown in FIG. 2, annular second member 11 extends beyond hub 20 of first member 12 and hence beyond stub 26 and recess 25. An advantage provided by the embodiment of FIG.

3 is that apparatus 10 is of relatively light weight construction and hence may be easier to install.

"With reference to FIG. 4, in order to adjust blade clearance of chopper assembly 31, cover 45 is opened so that long bolts 17 can be loosened. Actuating tool 56 includes pinion 57 with teeth 58 and tool handle 59 in use, pinion 57 co-operating with recess 25 and stub 26 of first member 12 and teeth 15 of annular second member 11 to form a ring gear and pinion assembly for rotating first member 12 and/or second member 11. Referring to FIG. 4 and FIG. 5, pinion 57 is placed in recess '3 14 pinion 57 also includes a recess (not shown) which engages stub 26 so that pinion teeth 58 firmly engage teeth 15 in annular second member 11. Rotation of handle 59 thereby causes rotation of second member 11 and/or first member 12. Accordingly, this rotation provides rotation of chopper shaft 32 and/or gear, 37. Generally, it is considered that fine adjustment of blade clearance is advantageously achieved by counterrotation of gear 37 and chopper shaft 32. This is achieved by first member 12 being non-rotatable relative to gear 37 by virtue of plain end of pins 24 engaging gear slot 38; (ii) second member 11 being bolted to gear bracket 36, whereby rotation of second member 11 rotates gear bracket 36 fixed to chopper shaft 32 via mounting bracket 34; and (iii) lateral movement of bolt shafts 27 within gear slots 38 and spaced slots 22 aligned therewith. However, it will also be appreciated that during adjustment, flywheel 41 may be manipulated so as to affect rotation of gear 37 via meshed gear 63. In fact, adjustment can be achieved via flywheel 41 alone, without using actuating tool 56.

The limit of rotation, as shown in FIG. 5, is indicated by two headed arrow 60 between hatched lines which represent centre line of shaft 27. Hatched circle 61 schematically represents rotation of chopper shaft 32. Ghost lines in FIG. 5 show chopper blade 62A coupled to gear 37 and chopper blade 62B coupled to meshed gear 63. It can be readily seen that clearance between blades 62A and 62B can be adjusted by movement of gear 37 and/or chopper shaft 32.

Note that although FIG. 5 shows adjustable chopper shaft I I I .111, I r I~ "I Z.MA "k having leading blade 62A, it is also possible that blade 62A trails blade 62B.

As described hereinbefore, central to adjustment of blade clearance by apparatus 10 is coupling of gear 37 to first member 12 so that there is no relative movement therebetween. There are a number of ways in which this can be achieved. With reference to FIG. 1, paired threaded pins 24 and apertures may be replaced by plug 67 which is accommodated by a slot 22 in flanged base 21 and respective gear slot 38 to thereby couple first member 12 and gear 37. Now with reference to 'ese..i 10 FIG. 6, there are provided other alternative arrangements. Flanged base of first member 12 includes bosses 64 which are located at opposed S...i edges of slots 22 and which fit snugly into gear slots 38 so that rotation of gear 37 relative to first member 12 is prevented. Again with reference to ~FIG. 6, aligned drill holes 65A and 65B may be made in flanged base 21 and gear 37 respectively, through which is placed plain pin or dowel 66.

In all cases, shafts 27 of long bolts 17 pass through respective aligned slots 22 and 38 as hereinbefore described.

S°It will be appreciated that the chopper adjustment apparatus of the invention is not limited, to the particular combination of features described in detail herein, and that various modifications may be made which nevertheless fall within the broad scope of the invention as set forth herein.

Claims (19)

1. An adjustment apparatus for a chopper assembly having a gear and a chopper shaft, said adjustment apparatus comprising:- a first member releasably connectable to the gear; and (ii) a second member releasably connectable to the chopper shaft; 0.e.ee 0 whereby in use, adjustment is performed by rotation of said first member and/or said second member which causes eeee 0 10 corresponding rotation of said gear and/or said chopper shaft respectively.

2. The adjustment apparatus of Claim 1, which further comprises a mounting means for connecting the second member to the chopper shaft. 15

3. The adjustment apparatus of Claim 2, which further comprises a coupling means for preventing rotation of the first member relative to the gear.

4. The adjustment apparatus of Claim 3, wherein the mounting means and coupling means in use co-operate to releasably connect the first member to the gear.

The adjustment apparatus of any one of Claims 1-4, wherein the first member includes a hub with a flanged base.

6. The adjustment apparatus of Claim 5, wherein the first member includes spaced slots in the flanged base. ,~4rA% P~ A'A A a' AWItflWAWrAA~VV~ WAW, PAVJdA~~ VW'At~4tWAZ(A ~nr. .rA'A.:VACWXtAJ~lACrAVAW~',tVW(A A~J~J(A 17

7. The adjustment apparatus of any one of Claims 1-6, wherein the second member is annular.

8. The adjustment apparatus of Claim 7, wherein the annular second member includes spaced apertures extending longitudinally therethrough.

9. The adjustment apparatus of any one of Claims 6-8, wherein the second member is seatable on the flanged base of the first member, ~the hub of the second member being locatable inside said first member and concentric therewith, said spaced apertures in the first member being alignable with respective said spaced slots in the flanged base of the second member.

10. The adjustment apparatus of Claim 9, whereby, in use, 0.'"mounting means in the form of bolts extend through said spaced apertures in the second member and through aligned said respective oe .i 0 15 slots in the flanged base of the first member.

11. The adjustment apparatus of any preceding claim which further comprises an actuating tool to facilitate rotation of the first member and/or second member.

12. The adjustment apparatus of Claim 11, wherein the actuating tool co-operates with teeth or splines in the second member to form a ring gear and pinion assembly which facilitates rotation of the first member and/or the second member.

13. The adjustment apparatus of any one of Claims 1-10, which when connected to said gear and said chopper shaft, is located inside a 18 gearbox which houses said gear and chopper shaft.

14. An adjustment apparatus substantially as herein described with reference to the accompanying drawings.

A kit for adjusting a chopper assembly, said kit comprising:- a first member releasably connectable to a gear; (ii) a second member releasably connectable to a ooooo chopper shaft; ••go S(iii) coupling means for preventing rotation of said first member relative to said gear; (iv) bolts for releasably connecting said second member to said chopper shaft; an actuating tool for rotating said first member relative to said second member; and (vi) a cover affixable to a gearbox which houses said chopper assembly.

16. A method of adjusting a chopper assembly having a gear and a chopper shaft, said method comprising the step of rotating a first member releasably connected to the gear and/or a second member releasably connected to the chopper shaft, to thereby cause corresponding rotation of said gear and/or said chopper shaft respectively.

17. The method of Claim 16, wherein an actuating tool facilitates relative rotation of the first member and/or second member.

18. A chopper assembly to which is connected the adjustment 1 19 apparatus of any one of Claims 1-15.

19. A cane harvester which includes the chopper assembly of Claim 18. DATED this twenty-sixth day of August 1999. TRAIL BROS. STEEL AND PLASTICS PTY. LTD., by their Patent Attorneys, FISHER ADAMS KELLY. 9000 *9* 0 09 9 3 ~,iiu i i;l n~.r rx.~ ~i*l*iallw; j~ U ,lur,,rrmrtri~*~i i~