GB2145913A - Agricultural ground rollers - Google Patents

Abstract

An agricultural ground roller in the form of a so-called "packer" roller comprises integral groups or crowns 15 of teeth 14 that project outwardly from an inner ring 16. The groups or crowns 15 alternate with plain cylindrical sleeves 17 which fit against the opposite sides of the inner rings 16 at the root ends of the teeth 14 so as to position the groups or crowns 15 relative to one another in regularly spaced apart relationship. Shorter sleeves 18 at the opposite ends of the roller are connected to circular clamping plates 20 by supports 19 and struts 22 secure stub shafts 21 to the clamping plates 20 so as to project perpendicularly therethrough to beyond the axial ends of the roller where, in use, the stub shafts 21 are rotatably supported. Three axially extending tie rods 23 project through holes in the clamping plates 20 and are spaced apart from one another at substantially 120 DEG intervals around the longitudinal axis of the roller, the opposite ends of the tie rods 23 being provided with tensioning nuts 24 and co-operating washers and being located between pairs of the supports 19. The roller can be made in a variety of different axial lengths from a plurality of mass-produced parts without any welding, at least so far as its teeth 14 are concerned. Any badly damaged part can be individually replaced merely by temporarily disassembling the roller and substituting an undamaged part. <IMAGE>

Description

SPECIFICATION Agricultural ground rollers This invention relates to agricultural ground rollers ofthe kind which comprise a plurality of relatively spaced groups or crowns of teeth that are intended to penetrate into the soil during operative rotation ofthe roller. Such rollers are commonly known as "packer rollers" and are particularly, but not exclusively, useful as parts of soil cultivating implements (or machines) which employ a plurality of power-driven soil working members.

Such agricultural ground rollers conventionally comprise a cylinder to the outer curved surface of which the teeth are welded individually,orinintercon- nected numbersoftheteeth,toform said groups or crowns thereof. The formation is thus involved and expensive and, should any serious damage occurto the roller, it usually has to be replaced in its entirety.

An object ofthe present invention is to overcome, or at least very significantly to reduce, the disadvantages mentioned above and, accordingly, provides an agricultural ground roller ofthe kind setforth, wherein the groups or crowns of teeth are separate from one another and means is provided to secure them together in a single entity in a manner which is such that ready initial assembly, subsequent disassembly and re-assembly are possible.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a plan view of a soil cultivating implement embodying a ground roller in accordance with the invention, the implement being shown connected to the rear of an agricultural tractor, Figure 2 is a side elevation corresponding to Figure 1, Figure 3 is a view, to an enlarged scale, ofthe roller ofthe implementof Figures 1 and 2 as seen in an axial direction, Figure4 is a section taken on the lined IV-IV in Figure 3, Figure 5 is again a section taken on the line IV-IV in Figure 3 but illustrates a second embodiment of the roller, Figure 6 is again a section taken on the line IV-IV in Figure 3 but illustrates a third roller embodiment, Figure 7 is again a section taken on the line IV-IV in Figure 3 but illustrates a fourth roller embodiment, and Figure 8 is again a section taken on the line IV-IV in Figure 3 but illustrates a fifth roller embodiment.

Referring to the accompanying drawings, and firstly to Figures 1 to 4 inclusive thereof, the implement that is illustrated is a soil cultivating implement designed primarily, but not exclusively, forthe cultivation of previouslyworked agricultural soil to produce a seedbed. The implement that is illustrated comprises a hollow box-section frame portion 1 of elongate configuration that extends substantially horizontally transverse and usually, as illustrated, substantially horizontally perpendicular, to the intended direction ofoperativetravel of the implementthat is indicated in Figures 1 and 2 ofthe drawings by an arrow A.A plurality, of which there are twelve in the example that is being described, of substantially vertical, or at least upwardly extending, shafts 2 are rotatably mounted in upper and lowerwalls ofthe hollowframe portion 1 in such positions thattheir longitudinal axes are regularly spaced apartfrom one another at intervals which advantageously, but not essentially, each have a magnitude of substantially 25 centimetres. Each rotary shaft 2 projects downwardlyfrom beneath the bottom ofthe hollowframe portion 1 and the downwardly projecting portion thereof has firmly but releasably secured to it a corresponding soil working memberthat is generally indicated by the reference 3 (Figure 2).Each soil working member3 comprises a substantially horizontally disposed support or carrier 4 exhibiting diametrically opposed arms which radiate from a central hub secured to the shaft 2 concerned.

The outer ends of the substantially symmetrical arms of each support or carrier 4 are provided with sleeve-like holders in which upper fastening portions of soil working tools in the form of metallic tines 5 are firmly but releasably secured. Each tine 5 also comprises a soil working portion which projects downwardly into the ground which is to be cultivated bythe implementto an extentwhose maximum value is adjustable.

The opposite ends of the hollow frame portion 1 are closed by corresponding substantially vertical side plates 6which are parallel to one another and parallel or substantially parallel to the direction A, it being noted from Figures 1 and 2 ofthe drawings that the two side plates 6 extend both vertically above, and rearwardly behind with respect to the direction A, the remainder of the hollowframe portion 1.Strong pivots 7 that are substantially horizontally aligned in a direction that is parallel to the length of the hollow frame portion 1 and thus perpendicular, or at least transverse, to the direction A, are mounted adjacent upper leading, with respect to the direction A, corners ofthetwo side plates 6 and each pivot7 has the leading end of a corresponding armturnably mounted thereon at that side of the adjacent plate 6 which faces the centre of the implement. The two arms 8 both extend rearwardly, with respect to the direction A, alongside the corresponding plates 6 to locations behind the curved rearmost edges ofthe two plates 6.

Two manually operable adjustment mechanisms 9 that are of a construction which is known perse inter-connectthe rearoftheframe portion 1 and corresponding ones ofthetwoarms 8, each mechanism 9 incorporating a screw-threaded spindle that can be rotated by a crank handle at its upper end to turn the arm 8 concerned either upwardly or downwardly about the respective pivot 7 relative to the frame portion 1 and soil working members 3.

Rearend regionsofthetwo arms8 havethe upper ends of corresponding plate-like supports 11 secured to them so as to extend downwardly and rearwardly therefrom with respect two the direction A. A ground roller that is generally indicated bythe reference 13 has axially extending stub shafts 21 at its opposite ends which stub shafts 21 are rotatably received in corresponding horizontal bearings arranged in housings 12 that are carried by lower rear regions of the two supports 11.Clamping plates 10 firmly but releasably interconnectthe rear edges ofthe frame portion side plates 6 and upper regions of the two supports 11 and, when the roller 13 is to be moved bodily upwards or downwards relative to the frame portion 1 and soil working members 3 by operation of the mechanisms 9,the clamping plates 10 are temporarily loosened and, when the adjustment in level has been completed, are re-tightened. The clamping plates 10 serve to relieve the adjusting mechanisms 9 ofthe forces to which they would be subjected during the operation ofthe implement if they alone were to be relied upon to maintain the arms 8, and thus the roller 13, in a chosen angular position aboutthe axis defined bythe pivots 7 relative to the frame portion 1 andsoilworking members 3.

The ground roller 13 is in the form of a so-called packer roller and its cylindrical outer surface carries a plurality of substantially regularly spaced apart groups or crowns 15 oftine-liketeeth 14. The teeth 14 of each group or crown 15 are all integrally carried by a corresponding inner ring 16 and it will be seen from Figure 3 ofthe drawings that, in the examplewhich is being described, each group or crown 15 comprises ten of the teeth 1 which are spaced apartfrom one another at regular36" intervals around the substantially horizontal longitudinal axis ofthe rollerwhich is embodied in the two stub shafts 21.Each group or crown 15 which comprises an integral assembly of the teeth 14 and the corresponding inner ring 16 is advantageously formed from cast iron or cast steel, each inner ring 16 having an angular cross-section (Figure 4) and being of less thickness in a direction parallel to the longitudinal axis ofthe roller 13 than are the root ends of the teeth 14 which are integrally formed therewith.

It can be seen in Figure3ofthedrawingsthateach tooth 14 has a substantially radial rear edge, with respect to the intended direction of operative rotation ofthe roller 13, and a shallowS-shaped leading edge, the two edges meeting one anotheratthe outermost extremity ofthe tooth 14 concerned where they form a substantially 900 junction. Each shallow S-shaped leading edgetapers outwardly (see Figure 4) to give that edge a significant cutting effect which will cause it to penetrate into the soil without difficulty.The substantially radial (with respect to the intended axis of rotation ofthe roller 13) leading edge of each tooth 14 is, however, relatively blunt and itwill be realised from Figure 2 ofthe drawingsthat,when these relatively blunt leading edges of those teeth 14 which are lowermostat anytime during the operation ofthe implement are in the soil, theywill not readily move forwards through the ground in the direction Aso that the roller 13, asawhole, isstrongly urged to rotate about its own longitudinal axis at a speed that will be proportional to the speed of travel in the direction A.

Itwill be seen from Figure 4 of the drawings that the roller 13 is afforded principally bya number of the crowns 15 alternating with cylindrical sleeves 17 betweeen successive ones of which the inner rings 16 ofthe groups or crowns 15 are positioning ly located.

Two axially shorter sleeves 18 are located at the opposite ends of the roller 13 and all ofthe alternate inner rings 16 and sleeves 17 are clamped axially therebetween. Each sleeve 18 has the endsofthree pairs of radially inwardly directed supports 19 9 (Figures 3 and 4) secured to it, radial edges ofthe six supports 19 being welded or otherwise rigidly secured to one side of a substantially circular clamping plate 20 whose general plane is perpendiculartothe longitudinal axis ofthe roller 13.Three strut plates 22 (Figures 3 and 4) obliquely and rigidly interconnectthe opposite side of each clamping plate 20 from that to which the supports 19 are secu red and an inner end region ofthe corresponding stub shaft 21, each such stub shaft 21 extending perpendicularlythrough the centre ofthe corresponding clamping plate 20 as will be apparentfrom Figure ofthe drawings.Three tie rods 23 extend axially parallel to one another and to the longitudinal axis of the roller 13, opposite end regions thereof being screw-threaded and being entered through three holes in the corresponding clamping plate 20 which holes are at substantially 1 20" intervals around the longitudinal axis of the roller and are located between the two supports 19 of each ofthe three pairs of those supports (see Figure 3). The screw-threaded ends of the tie rods 23 receive corresponding nuts 24, provided with appropriate anti-loosening washers, and, when the three tie rods 23 are placed strongly in tension bytightening the corresponding nuts 24 at their opposite ends to the required extent, the complete roller 13will function entirely reliably as a single unit.It is notedthatthe two supports 19 of each pair,whichbothexhibitobliquely outwardly facing edges, serve to protect the corresponding nuts 24 and screw-threaded portions ofthe tie rods 23 from damaging impacts against stones and the like, the nuts 24 nevertheless remaining readily accessible to a box or socket spanner or wrench operated from beyond the adjacent open end of the roller 13.

Thetenteeth 14 of each grouporcrown 15 are contained in a substantially vertical plane that is substantially parallel to the direction A and, between each successive group or crown 15, a corresponding soil-shedding scraper 25 bears against the outer surface ofthe cylindrical sleeve 17 concerned ata location which is generally at the rear of the roller 13 with respect to the direction k Preferably, as illustrated, a plane containing the edge of each scraper 25 which actually contacts, or is located very closely adjacent to, the outer surface of the corresponding sleeve 17, and which alsocontains the axis of rotation ofthe roller 13, is inclined upwardly and forwardly, relative to the direction A, atan angle of substantially 400tithe horizontal. Each scraper 25 is adjustably secured to a foot plate at the lower end of a corresponding carrying arm 26 and the upperendsof the arms 26 are adjustablyclamped, in groups (see Figure 1 to a carrier 27 that extends substantially horizontally parallel to the axis of rotation of the roller 13 at a location above and to the rear ofthat roller 13 with respectto the direction A. The opposite ends of the elongate carrier 27 are connected by supportipg structures 28 to the rear ends of the two arms 8 where those rear ends are fastened to the downwardly and rearwardly inclined supports 11.Strengthening struts ofwhich one can be seen in Figure 2 of the drawings interconnectthestructures 28 and lower rear regions of the supports 11 adjacent the bearing housings 12.

Shield plates 29 are arranged immediately beyond the opposite ends ofthe single row of rotary soil working members 3, the two shield plates 29 normally being substantially vertically parallel to one another and to the direction A. The shield plates 29 have rims and are shaped so thattheir lower edges will slide forwardly overthe ground surface during operative progress in the direction A (see Figure 2). Each shield plate 29 is carried by a corresponding arm of which a portion is mounted on top of the hollowframe portion 1 so asto beturnable about a substantially horizontal axis that is substantially parallel to the direction A.

This allowsthe shield platesto move upwardly and downwardly, when the implement is in operation, to match undulations in the surface of the soil that may be met with during forward progress in the direction A. The shield plates 29 are also turnable upwardly and inwardly about the axes defined by the pivotally mounted portions of the corresponding arms to bring them to inverted positions in which they lie on top of the hollowframe portion 1 when, forexample, the implement is undergoing inoperative transport. The shield plates 29 co-operate with the rotary soil working members 3 at the opposite ends of the single rowthereof in cultivating thesoil to substantiallythe same thorough extent as is produced by co-operation between neighbouring members 3 at locations closer to the centre ofthe implement.In addition, the shield plates 29 prevent stones and other hard objects from being flung laterally of the path of travel of the implement bythe rapidly moving tines 5 of its soil working members 3 and thus very significantly reduce the danger of damage or injurythat might be caused thereby.

Each shaft2 is provided, inside the hollowframe portion 1, with a corresponding straight- or spurtoothed pinion 30, the sizes of the pinions 30 being such that each of them has its teeth in mesh with those ofthe or each immediately neighbouring pinion 30 in the single row of twelve (in this embodiment) such pinions. One of the centre pair of shafts 2 in the single row of twelve shafts has an upward extension through thetop ofthe hollowframe portion 1 into a gear box 31 that is fastened in position on top of the hollow frame portion 1. Shafts and bevel pinionswithin the gear box 31 place the upward extension ofthe shaft 2 that has just been mentioned in driven connection with a rotary input shaft 33 of the gear box 31 that projects substantially horizontallyforwards from the front of that gear box in substantially the direction A.The rear ofthe gear box3l,with respectto the direction A, is provided with a change-speed gear32.Thechange- speed gear32 is notthe subject of the present invention and if suffices to saythattwo splined shaft ends project into the change-speed gear 32 where they are drivingly interconnected buy a pair of straightor spur-toothed pinions of different sizes whose hubs are internally splined to match the external splines of the shaft ends. The transmission ratio between the two shafts can be altered by interchanging the two pinions on the shaft ends or, alternatively, by removing them and substituting an alternative pair of pinionsof different sizes.This is readily accomplished merely by temporarily removing a cover of the change-speed gear32.The change-speed gear 32 allows the rotary soil working members 3to be revolved at a faster or slower speed without having to change the substantially standard speed of rotation that is applied to the leading end ofthe rotary input shaft 33 of the gear box 31 by drive derived from the rear powertake-offshaftof an agricultural tractor or other operating vehicle through the intermediary of a telescopictransmission shaft 34 of known construction having universal joints at its opposite ends. The forwardly projecting rotary input shaft 33 of the gear box 31 is splined or otherwise keyed for co-operation with the universal joint atthe rear end of the transmission shaft 34.

A leading central region of the hollowframe portion 1 carries a coupling member ortrestle 35that is of substantially isosceles triangular configuration as seen infrontorrearelevations.The coupling member ortrestle 35 is constructed and arrangedforcooperation with the upper and lower lifting links of a three-point lifting device or hitch mounted at the rear ofthe tractor or other vehicle which both moves and operates the implement in the use ofthe latter. This basically known arrangement is illustrated somewhat diagramatically in Figures 1 and 2 ofthe drawings.

Two tie beams diverge steeply downwardly and rearwardly from a location close to the apex of the coupling memberortrestle 35 so as to strengthen the assembly, their lower rear ends being secured to the top and rear of the hollowframe portion 1 at widely spaced apart locations.

In the use of the soil cultivating implement that has been described, its coupling member or trestle 35 is connected to the three-point lifting device or hitch of the agricultural tractor or other vehicle which is both to operate it and move itforwardly in the direction A and the known telescopic transmission shaft 34 is arranged drivingly between the rear power take-off shaft of the tractor or other vehicle and the forwardly projecting end of the rotary input shaft 33 of the gear box 31. Adjustments which may, if necessary, be made beforeworkcommences include moving the ground roller 13 bodily upwards ordownwards, using the adjusting mechanisms 9 and the clamping plates 10, to govern the maximum depth of penetration of the tines 5 into the soil which is possible.The speed of rotation ofthe members 3 may be increased, or decreased, by an appropriate adjustment of the change-speed gear 32 and a check should be made to ensure that the scrapers 25 are co-operating properly with the roller sleeves 17. These adjustments, and particularly the first thereof, are made primarily with regard to the nature and condition ofthe soil that isto be cultivated by the implement and the particular purposeforwhichthatsoil is required after its cultivation. As the implement moves forwardly in the direction A, the inter-meshing relationship ofthe pinions 33 causes each assembly of one pinion 33, one shaft 2 and one soil working member 3 to revolve in the opposite direction to the or each immediately neighbouring assembly. Each soil working member3 cultivates an individual strip of ground that extends in the direction A but, since the effective distance between the soil working portions of the tines 5 of each member3 is the same as, or a little greaterthan, the distance between the longitudinal axes of im mediately neighbouring shafts 2, the strips worked by the individual members 3 overlap, or at least adjoin, one another so that a single broad strip of worked soil is produced. When the preferred dimensions that are referred to above are used, this broad strip of worked soil will have a width of substantially, but not necessarily exactly, three metres. It will be realised that a broader or narrower strip could be produced by increasing or decreasing the number of rotary soil working members3 in the single rowthereof.

The packer roller 13 is readily produced from a plurality of substantially identical toothed crowns 15, a plurality of sleeves 17, two similar but axially shorter sleeves 18,two clamping plates 20 which carry the corresponding supports 19,stub shafts 21 and strut plates 22 andthree tie rods 23 provided with appropriate nuts 24 and co-operating washers. Once the tie rods 23 are placed in tension by tightening the nuts 24, the whole assemblyfunctions reliably as a single coherent unit.

Figure 5 ofthe drawings illustrates an alternative constructionoftheground roller 13 in which each group or crown 15 of teeth 14 includes an inner ring in the form of a doublefoot36which hasa significant axial extent lengthwise ofthe roller 13 and whose external diameter is substantially the same as the internal diameter of each sleeve 17 and 18. Thus, as shown in Figure 5, the double feet 36 lie inwardly of the sleeves 17 and 18with the teeth 14 projecting outwardly between successive sleeves 17 or 17 and 18.If desired, although not illustrated, the edges ofthe sleeves 17 and 18 may be notched or otherwise shaped forco-operation with the teeth 14 and the arrangement maybe such that each group or crown 15 isturned angularly by a few degrees around the longitudinal axis of the roller 13 relativeto the or each of its immediate neighbours. With this arrangement, the teeth 14 may extend in helical rows around the longitudinal axis of the roller 13.

Figure 6 ofthe drawings illustrates a packer ground rollerthat is generally indicated by the reference 37, this third form of roller 37 comprising a plurality of identical groups or crowns 38 of teeth 14, each group orcrown 38 integrally including a sleeve 39 which, at the right end as seen in Figure 6, is plain butwhich, at the left end as seen in Figure 6, has an inwardly off-set rim ofangularshapewhich, as clearly illustrated in Figure 6, will co-operate with the plain rim ofthe next sleeve 39 to the left as illustrated in that Figure.

However, one integral group or crown 38 (the one furthestto the right as seen in Figure 6) includes a ring 39Awhich, at both its axial ends, has inwardly off-set rims of angular shape. The previously described clamping plates20 are replaced bycircularclamping plates 40 each of which has a large cylindrical rim 41 whose outer edge is formed with an outwardly directed retrorse collar. The retrorse collars receive the inwardly off-set rims of the rings 39 at the opposite ends ofthe roller 37 and the assembly is once again completed by the appropriate tensioning of three tie rods 23 using co-operating nuts 24 and washers. It will, however, be noted that, in the embodiment of Figure 6, the supports 19 are omitted since the continuous rims 41 alone provide sufficient strength.

Figure 7 illustrates a fourth form of packer ground rollerwhich is generally indicated by the reference 41A. Inthisembodiment,apluralityofintegralgroups orcrowns42 of projecting teeth each include a cylindrical sleeve 43 which extends axially to the left, as seen in Figure 7, from the teeth concerned and a right-angled recess at its right-hand end which recess axially undercuts the group or crown of teeth concerned.

The roller 41A has a central axially extending shaft 45 throughout its length which shaft45, of course, projects beyond the opposite axial ends ofthe roller 41Afor co-operation with the horizontal bearings in the bearing housings 12. The clamping means at each end ofthe roller41Acomprises a circular clamping plate44formedwith acentral plain hubthroughwhich the shaft45 extends, the outer edge of the plate 44 having a rim which carries a sleeve 46 ofthe same diameter but a shorter axial length than each of the sleeves 43, there being a group or crown of teeth at the integral junction between the rim ofthe plate 44 and the sleeve 46 which teeth are identical to those ofthe groups or crowns 42.In addition, a circular groove is formed atthe root ends oftheteeth ofthe clamping plate 44 at the side of those teeth which is remote from the sleeve 46, the groove being shaped and dimensioned positioninglyto receive the free edge of one of the sleeves 43 or, in the case ofthe clamping plate 44 which is atthe right hand end of the roller41A as seen in Figure 7 of the drawings, one of two plain edges of a simple non-toothed sleeve 47 that is required to complete the roller assembly.The axial length of the plain sleeve 47 is, of course, such thatthe groups or crowns of teeth are all uniformly spaced apartfrom one another lengthwise along the roller41A. Each clamping plate 44 is formed with three holes and the previously described three tie rods 23 and the co-operating washers and nuts 24 are tensioned to form the assembly into a reliably constructed single coherent unit.Atransverse retaining pin 46A is entered perpendicularlythrough the shaft45 and through matching bores in the hub of one ofthe two clamping plates 44to fix the central shaft 45 reliably against axial and rotational displacement relative to the remainderofthe roller41A. Itwill be notedthatthe plain non-toothed sleeve 47 is located adjacent that end ofthe roller 41A where the shaft 45 is not secured to the hub ofthe corresponding clamping plate 44.

Figure 8 ofthe drawings illustrates a fifth form of packer ground roller in accordance with the invention which roller is generally indicated by the reference 48.

The roller48 has a central axially extending shaft 49 of circular cross-section which continues throughoutthe length of the rollerto project byshortdistances beyond its opposite endsforco-operation with the bearings in the bearing housings 12. In this embodiment, there are a plurality of identical groups or crowns 50 of projecting teeth 14, the teeth 14 being integrally secured to the external surfaces of corresponding sleeves 52 and each sleeve 52 being integral with an internal disc 51 that is co-planarwith the group or crown 50 concerned. Each circular disc 51 is thickened in a central region and that central region is formed with a circular hole through which extendsthe shaft 49.The edges of successive sleeves abut against one another in a simple mannersincetheco-operation of the central shaft 49 with the holes in the discs 51 provides the required positioning ofthe sleeves 52 with respect two one another. Two circular clamping plates 53 are arranged at opposite ends ofthe assembly of integral groups or crowns 50, each annular plate 53 having a central strengtheningly ribbed hub through which the shaft 49 is entered. As can clearly be seen in Figure 8,the outer edge of each circular plate 53 is formed with a right-angled recess orgroovewhich is shaped and dimensioned to receive one edge ofthe immediately neighbouring sleeve 52.

In this embodiment, tensioning ofthe rollerto provide its coherent unity is provided by the central shaft 49 which isformedjust beyond each clamping plate 53 with a short externally screwthreaded portion upon which a matchingly screw-threaded nut 54 is mounted with the provision ofan appropriate anti-loosening washer 55. It will be noted that the tensioning force exerted bythetightened nuts 54 acts upon the enlarged and strengtheningly ribbed hubs ofthe clamping plates 53.

In the embodiments of Figures 7 and 8 of the drawings in which central shafts 45 and 49, respectively, are employed that extend throughout the axial lengths ofthe rollers 41Aand 48, it is not essential that those shafts should be of circular cross section. They may, as alternatives, have polygonal cross-sections or have cross-sections which exhibit ribs or other projections that are wound helically around the longitudinal axes ofthe shafts. Naturally, in such cases, the hubs of the clamping plates 44, the holes through the central regions ofthe discs 51 and the hubs of the clamping plates 53 will have matching shapes.An agricultural ground roller in accordance with the invention is constructed from a plurality of separate parts each of which individual parts is of a formation that enables itto be easily manufactured by mass production methods. Welding together of parts to produce such a roller is, in some embodiments, entirely eliminated and, in others, is very greatly reduced as compared with the conventional produc tionofagricultural packer rollers intended for similar purposes. If one part of one ofthe rollers that has been described should become seriously damaged, it is only necessary to disassemble the rollerto enablethat partaloneto be replaced so that, after re-assembly, the roller is restored to full efficiency at relatively low expense.Itwill readily be apparentthat rollers of different axial lengths can easily be assembled by the employment of an appropriate number of parts, only the lengths ofthe tie rods 23 in the embodiments of Figures 1 to 6 and the lengths ofthe central shafts 45 and 49 in the embodiments of Figures 7 and 8 needing to be changed when rollers of different lengths are to be made. The various ground rollers which have been discussed above have all been described as being parts of soil cultivating implements but it is empha sisedthatasoilcultivating implement has been mentioned only as a good example of an implement incorporating a ground roller in accordance with the invention.A ground roller in accordance with the invention may be employed as part of some other agricultural implement such, purely for example, as a cultivator or a vibratory harrow, and may, of course, be used alone, orwith atleastoneotherrollerthat may, or may not, also be a roller in accordance with the invention, when rotatably mounted in a suitable frameforgroundtreatment Although certain features of the several embodiments of ground roller and of a soil cultivating implement which employs such a ground rollerthat have been described andlorthatare illustrated in the accompanying drawings will be set forth in the following claims as inventive features, it is emphasised that the invention is not necessarily limited to those features and that it includes within its scope each ofthe parts of each ground roller embodiment and ofthe soil cultivating implementthat has been described, and/orthat is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (22)

1. An agricultural ground roller of the kind set forth, wherein the groups or crowns of teeth are separated from one another and means is provided to secure them together in a single entity in a manner which is such that ready initial assembly, subsequent disassembly and re-assembly are possible.

2. Arollerasclaimed in claim 1,wherein clamping means which is common to all ofthe groups or crowns of teeth secures those groups or crowns together in a single entity.

3. A roller as claimed in claim 1 or 2, wherein each grouporcrown of teeth includes means arranged to fixthe position ofthat group or crown relative to the other groups orcrownswhen secu red together in a single entity.

4. A roller as claimed in claim 3, wherein each group or crown includes an inner ring arranged to co-operate positioninglywith the edges of sleeves arranged in relatively spaced relationship between the successive groups or crowns.

5. A roller as claimed in claim 4, wherein each inner ring is in the form of a foot having a significant extent in a direction axially parallel to the longitudinal axis of the complete roller, each such foot projecting in two opposite directions from the general plane of the corresponding teeth and having such a diameter that it co-operates positioningly with the corresponding sleeves.

6. A roller as claimed in any one of claims 1 to 3, wherein each group or crown ofteeth comprises a sleeve from which said teeth project outwardly, the sleeve having one plain edge and one edge which is shaped to co-operate positioningly with the plain edge ofthesleeve of an immediately neighbouring group or crown.

7. A roller as claimed in any one of claims 1 to 3, wherein each group or crown of teeth comprises a sleeve from which said teeth project outwardly, said sleeve projecting in one direction from the general plane of the teeth and being formed with a groove in, oradjacentto,thatplane,which groove is shaped and dimensioned to receive the free edge ofthe sleeve of an immediately adjacent group or crown in the completed roller.

8. A roller as claimed in claim 2 or in any one of claims 3to 7 when read as appendantto claim 2, wherein said clamping means comprises at least one tie rod extending lengthwise of the roller, the or each tie rod co-operating with clamping plates located adjacentthe opposite axial ends of the roller.

9. A rolleras claimed in claim 8, wherein each clamping plate hasa substantially cylindrical rim whose free edge is shaped to co-operate positioningly with the free edge of a sleeve, or of said sleeve, forming part of an immediately neighbouring group or crown ofteeth.

10. A roller as claimed in claim 8, wherein said clamping plate includes a group or crown of outwardly projecting teeth, which, at their root ends, are connected with a sleeve which projects axially in one direction from the general plane of said piece and, at the other side, is formed with a groove that is shaped and dimensioned to co-operate with the free edge of a sleeve, or of said sleeve, of one ofthe groups or crowns ofteeth that is separate from said clamping plate.

11. A roller as claimed in any one of claims 8to 10, wherein each clamping plate surrounds a corresponding stub shaft by which, in use, the corresponding end ofthe roller is rotatably supported.

12. A roller as claimed in any one of claims 8 to 10, wherein the roller has a central shaft extending throughoutthe axial length thereof, said clamping plate being arranged in surrounding relationship with opposite end regions of that central shaft.

13. A roller as claimed in any one of claims 8to 12, wherein three tie rods are provided, said tie rods being spaced apart from one another at substantially 1 20 intervals around the longitudinal axis ofthe roller.

14. A roller as claimed in claim 12, wherein each group or crown ofteeth includes an annular disc arranged in surrounding relationship with said central shaft, the periphery of each disc comprising a sleeve whose outer surface carries the outwardly projecting teeth at a location substantially mid-way between the opposite edges ofthe sleeve.

15. A roller as claimed in claim 14,wherein each roller clamping plate is formed at its periphery with a recess or groove shaped and dimensionedto receive the free edge ofthe sleeve of an immediately neighbouring group or crown ofteeth.

16. A roller as claimed in claim 14, wherein the clamping plates are fastened to the central shaft.

17. A roller as claimed in anyone of claims 14to 16, wherein said central shaft is of circular crosssection.

18. A roller as claimed in anyone of claims 14to 16, wherein said central shaft is of polygonal crosssection.

19. A roller as claimed in anyone of claims 14to 16, wherein said central shaft comprises at least one rib orother outward projection which iswound helically around the longitudinal axis ofthe shaft.

20. A roller as claimed in any preceding claim, and forming part of a soil cultivating implementwhich comprises a plurality of soil working members that are rotatable about corresponding upwardly extending axes, said soil working members being arranged in a row that lies in advance ofthe roller,with respect to the intended direction of operativetravel ofthe soil cultivating implement, said row being substantially horizontally perpendicular, or at least transverse, to that direction.

21. An agricultural ground roller substantially as hereinbefore described with reference to Figures 1 to 4, FigureS, Figure 6, Figure 7 or Figure 8 ofthe accompanying drawings.

22. A soil cultivating implement substantially as hereinbefore described with reference to Figures 1 to 4 ofthe accompanying drawings or with reference to Figures 1 to 4 as modified by Figure 5, or Figure 6, or Figure 7, or Figure 8 of those drawings.