GB2124062A - Soil cultivating implements - Google Patents

Abstract

In a soil cultivating implement, such as a rotary harrow, of the kind which has a packer roller 12 located behind the soil working members thereof relative to the intended direction of operative travel of the implement, said roller 12 comprises a cylindrical carrier 13 rotatable about a central axis a and a plurality of groups or crowns of projections 14 that are spaced apart from one another at regular intervals along the length of the carrier 13. Scrapers 15 are arranged between neighbouring groups or crowns of projections 14 and, in order significantly to increase the effective life of each scraper 15 before replacement due to wear becomes necessary, that scraper 15 is formed from spring steel, is of oblong shape and has two effective scraping edges. Each scraper 15 is carried by a corresponding inclined foot 16A at the lower end of an arm 16 and, when the lower edge of the scraper 15 has become worn, the scraper 15 is inverted to substitute a fresh unworn edge for the worn edge, a bolt 18 and a locating pin 19 being employed to connect each scraper 15 to the corresponding foot 16A employing two spaced holes in the scraper 15. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines, such as rotary harrows, of the kind which comprise a plurality of soil working members and a packer roller arranged to the rear of those members with respect to the intended direction of operative travel of the implement or machine, said roller having a cylindrical soil-contacting carrier on which a number of projections, arranged in groups or crowns, are mounted in side-by-side relationship, soil scrapers being arranged between said groups or crowns of projections. The term "implement(s) or machine(s)" is shortened to "implement(s)" throughout the remainder of this document for the sake of brevity.

The rollers of known implements of the kind set forth comprise a large number of scrapers, particularly when the implement is of large working width, and the cost of their replacement is accordingly considerable when they become worn thus rendering the use of these very effective rollers less widespread than would otherwise be the case. An object of the invention is to lengthen the effective life of the scrapers to a considerable extent thus rendering the use of implements incorporating such scrapers a much more economic proposition.

According to one aspect of the invention, there is provided a soil cultivating implement of the kind set forth, wherein each of at least some of the scrapers comprises at least two effective scraping edges and is so constructed and arranged that, when one such effective edge is worn, the scraper can be repositioned to substitute a further effective edge.

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 lisa somewhat diagrammatic plan view of a soil cultivating implement in accordance with the invention shown connected to the rear of an agricultural tractor, Figure 2 is a side elevation corresponding to Figure 1, Figure 3 is a section, to an enlarged scale, taken on the line Ill-Ill in Figure 1, and Figure 4 is a rear elevation as seen in the direction of an arrow IV in Figure 3.

Referring to the accompanying drawings, the soil cultivating implement that is illustrated is in the form of a rotary harrow and comprises a hollow boxsection frame portion 1 that extends substantially horizontally transverse and usually, as illustrated, substantially horizontally perpendicular, to the intended direction of operative travel of the implement that is indicated in Figures 1 and 2 of the drawings by an arrow A.A plurality, of which there are twelve in the illustrated embodiment, of upwardly extending and usually, as illustrated, substantially vertically disposed, shafts 2 are rotatablyjournalled in bearings carried by the upper and lower walls of the hollow frame portion 1 and are arranged in a row that extends parallel to the transverse length of the frame portion 1 with the axis of rotation of each shaft 2 spaced from that of the or each of its immediate neighbours in the row by a uniform distance which advantageously, but not essentially, has a magnitude of substantially 25cm.The lower end of each shaft 2 projects downwardly from beneath the bottom ofthe hollow frame portion 1 and is there provided with a corresponding soil working member 3 (Figure 2) comprising a support or carrier 4 having a central hub that is firmly but releasably secured to the lowermost end of the shaft 2 concerned, two arms which extend in opposite directions from said hub, sleeve-like holders mounted at the outer ends of the arms and two rigid tines 5 whose fastening portions are firmly but releasably secured in the holders and whose soil working portions project downwardly into the ground, as diagrammatically illustrated in Figure 2, to an extent whose magnitude can be controlled.

The opposite ends of the hollow frame portion 1 are closed by substantially vertical side plates 6 that extend substantially parallel to one another and to the direction A. It will be seen from Figures 1 and 2 of the drawings that the side plates 6 extend vertically above the remainder of the frame portion 1 and project some distance rearwardly thereof with respect to the direction A. Each side plate 6 carries, adjacent to its leading uppermost corner, a corresponding strong pivot 7 that is substantially horizontally disposed and in alignment with the pivot 7 that corresponds to the other one of the two side plates 6.

An arm 8 is turnably mounted on each pivot 7 so as to be movable upwardly and downwardly about that pivot 7 immediately alongside the corresponding plate 6. It can be seen from the drawings that each arm 8 extends generally rearwardlyfrom the corresponding pivot 7 alongside the inner surface of the corresponding side plate 6, that is to say, alongside that surface thereof which faces the centre of the implement.It can also be seen clearly in Figure 2 of the drawings that each arm 8 comprises a leading upwardly and rearwardly inclined portion, a downwardy and rearwardly inclined portion that is integrally connected to the first-mentioned portion by an obtuse angular bend and a final rearmost portion that is integrally connected to the second portion by a further obtuse angular bend in such a way that the first and last portions are parallel or substantially parallel to one another. The final rearmost portion of each arm 8 has a corresponding downwardly and rearwardly inclined support 10 firmly but releasably secured to it by a group of three bolts 9 whose relative positions can be seen best in Figure 3 of the drawings.The lower ends of the two supports 10 are slotted and carry the housings 11 of corresponding substantially horizontal bearings in which a soil compacting ground roller or packet roller 12 is mounted in a freely rotatable manner.

The packer roller 12 has stub shafts at its opposite ends which stub shafts are received in the corresponding substantially horizontal bearings to define the intended substantially horizontal axis of rotation a of the roller. The roller 12 also comprises a cylindrical carrier 13 having an external diameter which is conveniently, but not essentially, substan tially 30cm. The external surface of the carrier 13 has welded to it a plurality of outwardly directed tine-like projections 14 which projections 14 are arranged around the carrier 13 in groups or crowns with each group or crown spaced by an equal distance along the axial length of the roller 12 from the or each immediately neighbouring group or crown.It can be seen in Figures 3 and 4 of the drawings that the projections 14 are formed in integral pairs from pieces of flat sheet metal that are welded to the convexly curved surface of the carrier 13 in such a way that the general plane of each pair of projections 14 is perpendicular or substantially perpendicular to the axis a. The shape of each integral pair of projections 14 is clearly illustrated in Figure 3 of the drawings and it is noted that, if desired, the tine-like projections 14 may be formed in integral numbers of more than two. Purely for example, since there are ten projections 14 in each group or crown thereof, five projections 14 may be formed integrally so that two such integral assemblies, rather than five, may be juxtaposed to form a single group or crown of the projections 14.It will be appreciated that the amount of welding which has to be undertaken to mount the projections 14 in their appointed positions on the carrier 13 is significantly reduced by forming the projections 14 in integral assemblies of as many of them as possible. A reduction in the amount of the sheet metal used to form the projections 14 can also be accomplished in this way.

When one of the projections 14 is located at the bottom of the roller 12, the front edge thereof, with respect to the direction a, is substantially radially disposed whilst the shallow S-shaped rear edge extends upwardly and rearwardly away from the outermost end of the straight edge and generaly towards the outer curved surface of the carrier 13.

Scrapers 15 are arranged between the successive groups or crowns of projections 14 considered lengthwise along the roller 12, the scrapers 15 being supported (see Figures 1 and 4) in groups of four.

Each scraper 15 take the form of an oblong plate that is advantageously, but not absolutely essentially, made of spring steel. It is releasably secured by a bolt 18 to a foot 1 6A that is welded to the lower end of a corresponding arm 16 of channnel-shaped cross-section, the arm being so disposed that the limbs or flanges thereof project rearwardly with respect to the direction A from the web or base thereof. Each arm 16 is approximately vertically disposed but, as can be seen in Figures 2 and 3 of the drawings, actually projects downwardly and forwardly with respect to the direction A at a few degrees to the strictly vertical.The upper ends of the four arms 16 that correspond to each group of four scrapers 15 are welded or otherwise rigidly secured to a corresponding support plate 17 and it will be apparent that it is necessary for the number of groups or crowns of projections 14 to be four times the number of groups of scrapers 15 plus a single "extra" group or crown of projections 14 at one axial end of the roller 12.Each oblong scraper 15 is formed with two holes, the lower one of which co-operates with the corresponding bolt 18 whereas the upper one co-operates with a pin 19 bent over from the material of the corresponding foot 16A in such a way that, when the leading lower edge of the scraper 15 becomes worn to an unacceptable extent, the bolt 18 can be temporarily removed and the scraper 15 be inverted through 1800 so that what was its unworn upper edge becomes its lower edge and vice versa, the bolt 18 then being replaced. Although not shown, it is well within the scope of the invention to employ, for example, square, hexagonal or octagonal scrapers having edges that can be used in turn.It is preferred that the inclination of each foot 16A to the rear of the corresponding arm 16 should have a magnitude of not less than 30 and not more than 45". The shorter upper and lower edges of each oblong scraper 15 extend throughout the greater part of the distance between each neighbouring pair of groups or crowns of projections 14 and are, of course, the effective portions of the scraper 15, an unworn edge being substituted for a worn edge in the manner described above before, eventually, inevitable wear makes the provision of a new scraper 15 necessary.

The outermost two arms 16 of the four arms that correspond to each group of scrapers 15 are formed with upper and lower slots 20 and the opposite screw-threaded ends 22 of corresponding brackets 21 (Figure 3), in the form of U-bolts, are entered through the upper and lower slots 20, the brackets themselves being engaged around a hollow beam 23 of square cross-section.The screw-threaded ends 22 of the brackets 21 co-operate with matchingly screwthreaded nuts which can be tightened to clamp the support plates 17, and thus the groups of scrapers 15, firmly in position relative to the hollow beam 23 which latter ridigly interconnects the rear ends of two supports 24 that project rearwardly from the final portions of the two arms 8 to which they are firmly and displaceably connected by the same bolts 9 as connect the arms 8 to the supports 10, the supports 24 being formed with horizontal slots 24A to enable them to be adjustable in position relative to the arms 8 and support 10 to a limited extent. It is noted that the hollow beam 23 affords a carrier of the scrapers 15 which extends substantially parallel to the axis a and that said hollow beam 23 and the two supports 24 together constitute a carrying frame 25 for all of the groups of four scrapers 15. Each support 24 has the upper end of a corresponding guide arm 27 connected to it, adjacent the beam 23, by a bolt 26, said guide arm extending downwardly and forwardly with respect to the direction A, from the bolt 26 to have its lower leading end connected to the neighbouring support 10 by one of the bolts whch secures the corresponding bearing housing 11 to the lower end of the support 10.

When mounting the packer roller 12 in its appointed position, the scrapers 15 are set in the following manner. The bolts 9 are not initially tightened nor are the bolts 26 and the bolts at the lower ends of the guide arms 27 which couple those guide arms 27 to the supports 10 and bearing housings 11. All of the groups of scrapers 15 are initially arranged in the lowermost possible positions in which the screw-threaded ends 22 of the brackets 21 bear against the uppermost ends of the corresponding slots 20.The nuts which co-operate with those screw-threaded ends 22 for the brackets 21 of the end groups of scrapers 15 that are closest to the two supports 10 are then tightened and the whole carrying frame 25 is displaced forwardly using the setting means that is constituted by the bolts 9, the slots 24A and the guide arms 27 that are turnable about the bolts located at their opposite upper and lower ends. This displacement is effected until the lower leading edges of the scrapers 15 are spaced by substantially 1 mm from the cylindrically curved surface of the carrier 13, the roller 12 then being rotated about the axis a to check that the correct clearance of said edges of the scrapers 15 of the two outermost groups of those scrapers from the curved surface of the carrier 13 is constant.A minimum clearance of Omm is permissable in which said edges just barely touch the surface of the carrier 13.

When this adjustment and subsequent clearance check have been made, the bolts 9, the bolts 26 and the bolts by which the lowermost ends of the guide arms 27 are secured to the supports 10 and bearing housings 11 are all tightened. It is subsequently desirable to check the clearance of the lower edges of the other groups of scrapers 15 from the surface of the carrier 13, using the slots 20 and the nuts which co-operate with the screw-threaded ends 22 of the brackets 21 to increase or decrease the clearance if so required.Wen the scrapers 15 have become worn, the outermost arms 16 of the corresponding groups can be moved vertically, as may be required, to compensate for that wear and it will be remembered that each oblong scraper 15 can itself be inverted, after temporarily removing the corresponding bolt 18, to substitute a fresh unworn edge for an edge which has reached the end of its useful life. The arms 8 and thus the roller 12 and the scrapers 15 which they carry can be turned upwardly or downwardly about the substantially horizontal axis defined by the aligned pivots 7 employing two manually operable screw assemblies 28, having crank handles at their upper ends, which assemblies 28 will not be described in detail, and are not illustrated in detail in the drawings, since they are of a construction which is well known per se.It is this adjustment which principally determines the maximum depth of penetration of the tines 5 of the soil working members 3 into the ground which is possible since it changes the level of the packer roller 12 relative to that of the hollow frame portion 1 and the soil working members 3.

Two shield plates 30 that both extend substantially vertically parallel to the direction A are provided immediately beyond the opposite ends of the single row of twelve (in this embodiment) rotary soil working members 3. The shield plates 30 are upwardly and downwardlyturnable about axes that extend substantially horizontally parallel to the direction A, these axes being formed by portions of carrying arms that are turnably mounted in brackets located on top of the hollow frame portion 1 at short distances from its opposite ends. The principal function of the shield plates 30 is to co-operate with the immediately neighbouring soil working members 3 in cultivating the soil to substantially the same thorough extent as is effected by the co-operation of neighbouring pairs of members 3 at locations closer to the centre of the implement.The shield plates 30 can move upwardly and downwardly to match undulations in the surface of the soil over which the implement moves and also prevent stones and other potentially injurious objects from being flung laterally of the implement by the rapidly moving tines 5 of its soil working members 3. Each shaft 2 is provided, inside the hollow frame portion 1, with a corresponding straight- or spur-toothed pinion 29, these pinions 29 being of such a size that each of them has its teeth in mesh with those of the or each neighbouring pinion 29 in the single row thereof. It will readily be apparent that, with this arrangement, each pinion 29, shaft 2 and soil working member 3 will revolve in the opposite direction to that of the or each immediately neighbouring similar assembly.

The shaft 2 that corresponds to one of the centre pair of rotary soil working members 3 is upwardly extended through the top of the hollow frame portion 1 into a gear box 31 mounted on top of said frame portion 1. Bevel pinions and shafts (not shown) within the gear box 31 place the upward extension of said shaft 2 in driven connection with a rotary input shaft 33 of the gear box 31 whose leading end projects substantially horizontally forwards from the front of the gear box in substantially the direction A. The transmission between the rotary input shaft 33 and the upward extension of said shaft 2 includes a change-speed gear 32 that is mounted at the rear of the gear box 31. The change-speed gear 32 does not form the subject of the present invention and will not be described in detail.It suffices to say that it can be employed to change the transmission ration between the input shaft 33 and the upward extension of said one of the shafts 2 so that the twelve (in this embodiment) rotary soil working members 3 can be caused to revolve at a faster or slower rate without having to change the driving speed that is applied to the leading end of the rotary input shaft 33. The speed of rotation of the members 3 and the working depth thereof will, of course, be chosen in accordance with the nature and condition of the soil that is to be cultivated and the particular purpose for which that soil is required after cultivation.

A telescopic transmission shaft which is of a construction that is known per se, having universal joints at its opposite ends, is employed to place the leading splined or otherwise keyed end of the rotary input shaft 33 in driven connection with the rear power take-off shaft of a n an agricultural tractor or other moving and operating vehicle. A coupling member or trestle 35 that is of substantially triangular configuration as seen in front or rear elevation is mounted at the front of the hollow frame portion 1, with respect to the direction A, at a location midway across the working width of the implement, the apex of this coupling member or trestle 35 being strengtheningly connected to widely spaced apart locations at the rear of the hollow frame portion 1 by a pair of tie beams.

In the use of the soil cultivating implement that has been described, the coupling member or trestle 35 thereof is employed, in a manner that is basically known per se, to connect the implement to the three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle and the rotary input shaft 33 of the vehicle's gearbox 31 is placed in driven connection with the power take-off shaft of the same tractor or other vehicle using the known telescopic transmission shaft 34 that has universal joints at its opposite ends.Each of the twelve rotary soil working members 3 works an individual strip of iand extending in the direction A but, since the effective spacing between the two tines 5 of each member 3 is a little greater than is the distance between the longitudinal axes/axes of rotation of the neighbouring shafts 2, those strips of land overlap one other to produce a single broad strip of worked soil that will, in the case of the example that is being described, have a width of substantially 3m.

The maximum depth to which the tines 5 of the members 3 can penetrate into the soil is, if required, adjusted before work commences by using the screw assemblies 28 to move the roller 12 either bodily upwards or downward relative to the frame portion 1 and members 3.

As the implement moves operatively over the ground in the direction A, the projections 14 penetrate into the soil and cause the packet roller 12 to rotate about the axis a, the surface of the carrier 13 having a consolidating effect upon the immediately previously worked soil which effect is generally such that a lightly consolidated seed bed is formed in which optimum conditions for the germination and onward growth of seeds prevail. Adhesion of sticky soil to the surface if the carrier 13 for any length of time is prevented by the scrapers 15, these scrapers positively shedding any such sticky soil that may temporarily adhere to the carrier 13.The lower edge of each scraper 15 bears on the outer surface of the carrier 13 at a location which is such that an imaginary straight line joining the axis a and said location is inclined to a horizontal plane containing the axis a at an angle of not less than substantially 10 . This arrangement ensures that the scrapers 15 shed from the carrier 13 of the roller 12 relatively small lumps or pieces of adhering earth which pieces usually remain within the sphere of influence of the projections 14 of the revolving roller 12 so that such lumps or pieces of earth can be crumbled up by the projections 14.When some or all of the spring steel scrapers 15 in one of the groups thereof becomes worn to some extent, the corresponding brackets 21 can be temporarily loosened and said group be moved upwardly, using the slots 20, before re-tightening the nuts which co-operate with the screw-threaded ends 22 of the brackets 21. This, as will be evident from Figure 3 of the drawings, will bring the lower effective edges of the scrapers 15 of the group concerned into closer proximity to the surface of the carrier 13. Once the wear of the lower edge of one of the scrapers 15 has become so advanced that the adjustment which has just been mentioned will not compensate for that wear, the bolt 18 which secures that scraper 15 to the corresponding foot 1 6A is released and the scraper 15 is inverted before finally replacing the bolt 18. This substitutes the fresh unworn upper edge of the scraper 15 for the worn out lower edge thereof thus effectively doubling the life of each scraper 15 before final repiacement becomes necessary.

Installation of the packer roller 12 and the setting of the groups of scrapers 15 is a simple operation which can be carried out quickly and effectively.

Although certain features of the soil cultivating implement that have been described and/or that are 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 of the parts of the implement that has been described and/or that is illustrated in the accompanying drawings both individually and in various combinations.

Claims (17)

1. A soil cultivating implement of the kind set forth, wherein each of at least some of the scrapers comprises at least two effective scraping edges and is so constructed and arranged that, when one such effective edge is worn, the scraper can be repositioned to substitute a further effective edge.

2. An implement as claimed in claim 1, wherein at least some of the scrapers are each of rectangular shape, two opposite edges of each rectangular scraper affording said at least two effective scraping edges.

3. An implement as claimed in claim 1 or 2, wherein the construction and arrangement of each of at least some of the scrapers is such that a worn edge can be replaced by a further effective edge by turning said scraper through substantially 1800.

4. An implement as claimed in any preceding claim, wherein means is provided to adjust the positions of the scrapers relative to the cylindrical carrier of said roller.

5. An implement as claimed in any preceding claim, wherein each of at least some of said scrapers is carried by a foot located at the lower end of an upwardly extending arm.

6. An implement as claimed in claim 5, wherein the general plane of each foot is inclined to the length of the corresponding arm at an angle of not less than substantially 30 and not more than substantially 45".

7. An implement as claimed in any preceding claim, wherein the scrapers are supported by a carring frame and setting means is provided to enable that frame to be adjustably displaced relative to the cylindrical carrier of the roller.

8. An implement as claimed in claim 7, wherein guide means is provided for controlling displacement of the carrying frame relative to said cylindrical carrier.

9. A soil cultivating implement of the kind set forth, wherein the scrapers are supported by a carrying frame and setting means is provided to enable that frame to be adjustably displaced relative to the cylindrical carrier of the roller with the aid of guide means.

10. An implement as claimed in claim 8 or 9, wherein the setting means comprises slots formed in a front region, with respect to the intended direction of operative travel of the implement, of the carrying frame, and wherein the guide means comprises at least one guide arm interconnecting the carrying frame and a support of the roller.

11. An implement as claimed in claim 10, wherein the carrying frame and the or each guide arm can be retained in relatively fixed positions by bolts or like fastening means.

12. An implement as claimed in claim 5 or in any one of claims 6 to 8 when read as appendentto claim 5 wherein the scrapers are arranged in groups of four, the corresponding arms being of channelshaped cross-section and being arranged so that the limbs or flanges thereof project rearwardly from the webs or bases thereof with respect to the intended direction of operative travel of the implement.

13. An implement as claimed in claim 12, wherein the four arms that correspond to the four scrapers of each group are interconnected by a plate and are releasably disposable as a single unit on a carrying frame or on said carrying frame.

14. An implement as claimed in claim 12 or 13, wherein each of at least some of said groups of scrapers is upwardly and downwardly adjustable relative to the carrying frame or to said carrying frame.

15. An implement as claimed in any one of claims 12 to 14, wherein each of at least some of said groups of scrapers is retained in its appointed position by bracket whose ends are entered through slots formed in the arms at the opposite end of said group.

16. An implement as claimed in any preceding claim, wherein said plurality of soil working members is arranged in a row that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement with each soil working member mounted so as to be rotatable about a substantially vertical, or at least upwardly extending, axis, the maximum depth to which the soil working members can penetrate into the ground when the implement is in use being controllable by bodily upward or downward adjustment of the packer roller which lies behind them with respect to the intended direction of operative travel of the implement.

17. Asoil cultivating implementofthe kind set forth, substantially as hereinbefore described with reference to the accompanying drawings.