GB2123662A - Soil cultivating implements - Google Patents

Abstract

In a soil cultivating implement of the kind which comprises a row of rotary power-driven soil working members 2 that extends substantially horizontally perpendicular, in use, to the intended direction of operative travel A of the implement, the expenses involved in rotatably supporting shafts 3 that embody the axes of rotation of the soil working members 2 are significantly reduced by providing a substantially horizontal carrier plate 13 at a level well beneath that of the bottom of a hollow transmission-containing frame portion 1 and a co-operating gearbox 27A, opening in the carrier plate 13 cooperating supportingly with tubes 4 which latter surround the shafts 3 and rotatably support them by way of vertically spaced apart ball-bearings 8 and 9. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines of the kind comprising a plurality of soil working members carried by an elongate frame portion so as to be power-drivable to rotate about corresponding substantially vertical, or at least upwardly extending, axes, the soil working members being arranged in a row that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement or machine and said elongate frame portion containing parts of a drive transmission to the rotary soil working members. The term "implement(s) or machine(s)" will be shortened to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

In implements of this kind, a very high-torque has to be transmitted to the soil working members via the shafts which carry them and, consequently, those shafts have to be strongly, carefuliy and very accurately supported so that the costs of manufacture and assembly tend to be high. An object of the invention is significantly to reduce these costs and accordingly, the invention provides a soil cultivating implement of the kind set forth, wherein a horizontal or substantially horizontal carrier is provided for a shaft which embodies the axis of rotation of each soil working member, said carrier being disposed at a level beneath that of the bottom of said frame portion.

Referring to the accompanying drawings, the soil cultivating implement that is illustrated therein is in the form of a rotary harrow which harrow has a hollow frame portion 1 that extends substantially horizontally transverse, and usually (as illustrated) substantially horizontally perpendicular, to the intended direction of operative travel of the harrow that is indicated by an arrow A in Figures 1, 2 and 3 of the drawings.

The hollow frame portion 1 is made from sheet steel and comprises a lower portion of channel shaped cross section (see Figures 2 and 4 of the drawings) having limbs that diverge upwardly away from the substantially horizontally disposed bottom thereof. The upper edges of the upwardly divergent limbs are bent-over substantially horizontally in opposite directions and a flat cover plate is secured to those bent-over edges or rims by a plurality of substantially regularly spaced apart and substantially vertically disposed small bolts (see Figure 3), a gasket being interposed between the edges or rims of the lower part of the hollow frame portion 1 and the top cover plate thereof to prevent the leakage of oil or other lubricant and the ingress of abrasive dirt.

Approximately mid-way between its front and rear, considered in the direction A, the hollow elongate frame portion 1 supports a row of underlying rotary soil working members 2 of which, in the example that is being described, there are twelve. The axis of rotation of each soil working member 2 coincides with the longitudinal axis of a corresponding vertically or substantially vertically disposed shaft 3, these axes of rotation conveniently, but not essentially, being spaced apart from one another at intervals of 25 cms so that, with this spacing, the implement that is being described has a working width of substantially 3 m, the strips of soil that are worked by the individual members 2 overlapping one another to some extent since each member 2 has an effective working width which is a little greater than is the spacing between the longitudinal axes of neighbouring shafts 3.

Each shaft 3 is surrounded throughout a central and major part of its length by a corresponding tube 4 whose internal diameter is considerably greater than the diameter of the shaft 3 concerned. The upper end of each tube 4 is entered upwardly through a hole in the substantially flat bottom of the lower part of the hollow frame portion 1, said upper end having a corresponding flange 5 welded to it and said flange 5 being securely but releasably fastened against the inner surface of the frame portion bottom by a plurality, such as four, of bolts 6 and 7 (see Figure 3) that are spaced apart from one another at substantially regular intervals around the axis of the corresponding shaft 3.Each shaft 3 has a constant diameter throughout substantially the whole of its length and projects both upwardly beyond the upper end of the corresponding tube 4 and downwardly below the lower end of that tube.

The upper end of each tube 4 is internally stepped and the step receives the outer race of a corresponding ball bearing 8 whose inner race immediately surrounds the shaft 3 concerned. A similar arrangement exists at the lower end of each tube 4 except that, at this location, the internal step of the tube 4 extends further inwardly of that tube than does the step at the upper end thereof, the step at the lower end receiving the outer race of a ball bearing 9 whose inner race again immediately surrounds the shaft 3 concerned. A spacing sleeve 10 surrounds each shaft 3 between the inner race of the corresponding lower ball bearing 9 and the upper surface of a washer 11 whose lower surface bears against the upper end of the hub of a carrier 12 forming part of the corresponding soil working member 2.An oil sealing ring also surrounds each spacing sleeve 10 between the washer 11 and the lower ball bearing 9, the latter being recessed some distance upwardly into the tube 4 due to the vertical extent of the internal step of that tube at its lower end. The hub of each soil working member carrier 12 is firmly but releasably secured to the downwardly projecting end of the shaft 3 which it surrounds by way of a transverse clamping pin which may be of a construction that is known per se.

Each tube 4 is entered, at a location a short distance beneath its mid-point, through a hole in a horizontally or substantially horizontally disposed plate 1 3 which plate 13 is parallel or substantially parallel to the bottom of the hollow frame portion 1. Each tube 4 projects downwardly beyond the plate 13 by a distance which is equal or substantially equal to its own external diameter.

The rear edge of the plate 13, which lies just behind the tubes 4, with respect to the direction A, is bent-over so as to extend substantially perpendicularly downwards. Three relatively short bolts 6 and one much longer bolt 3 correspond to each tube 4 and flange 5 and it will be seen from Figures 2, 3 and 4 of the drawings that each long bolt 7 has its shank surrounded by a spacing sleeve 14, the bolts 7 serving to assist in clamping the flanges 5 in position and to connect said flanges 5 positively to the plate 1 3. The leading unbent edge of the plate 13, relative to the direction A, is secured by a number of small substantially vertically disposed bolts 1 5 to the lower and rearwardly bent-over edge of a leading substantially vertically disposed plate 1 6. As can be seen in Figure 2 of the drawings, the upper edge of the substantially vertically disposed plate 1 6 is bent-over rearwardly and is secured to the leading rim of the hollow frame portion 1 by the same small and substantially vertically disposed bolts as connect the upper and lower parts of that frame portion to one another. The plates 13 and 1 6 extend throughout substantially the whole of the transverse length of the hollow frame portion 1.

The opposite ends of the hollow frame portion 1 are closed by parallel and substantially vertically disposed side plates 1 7 that are of generally, but not exactly rectangular configuration (see Figure 2), each side plate 1 7 having its upper edge at substantially the same level as the cover plate of the frame portion 1, its leading edge at the same position of advance, with respect to the direction A, as the plate 16, its rearmost edge in register with the rear rim of the frame portion 1 and its lowermost edge well below the bottom of that frame portion at the level of the extremity of the downwardly bent-over rear edge of the substantially horizontal plate 13, each side plate 1 7 being fastened to the corresponding edges of the plates 1 3 and 1 6. Each side plate 1 7 carries, at a location close to its leading edge and substantially mid-way betweenits uppermost and lowermost edges, a corresponding strong and substantially horizontal stub shaft 18, the two stub shafts 1 8 being substantially horizontally aligned so as to project in opposite directions from the relatively remote surfaces of the two side plates 1 7. Each substantially horizontal stub shaft 1 8 has the leading end of a corresponding arm 1 9 mounted thereon in such a way that said arm 1 9 is turnable upwardly and downwardly.The arms 19 project generally rearwardly from the stub shafts 1 8 alongside the corresponding plates 1 7 and, as can be seen in Figure 1 of the drawings, both project rearwardly of the hollow frame portion 1 by a considerable distance. Each side plate 1 7 is formed, close to a bevelled edge interconnecting its rearmost and lowermost edges, with an arcuately curved row of holes 20 which holes are equidistant from the corresponding stub shaft 1 8. Each arm 1 9 is also formed with a hole at the same distance from its stub shaft 18 and, as can be seen in Figure 2 of the drawings, the arms 1 9 can be releasably secured in desired angular settings about the axis defined by the stub shafts 1 8 by turning them upwardly or downwardly, as may be required, to .bring the holes therein into register with appropriate holes 20. Bolts 21 or other fastenings are then entered through the holes in the arms 1 9 and the chosen holes 20 to maintain the chosen angular setting of the arms 19 as long as may be required.

The rearmost ends of the arms 19 carry horizontal bearings between which an open-work cage-formation ground roller 22 is mounted in a freely rotatable manner. The longitudinal axis/axis of rotation of the roller 22 is parallel or substantially parallel to a plane containing the axes of rotation of the twelve soil working members 2.

The carrier 12 of each soil working member 2 extends in two opposite directions from its hub and the free ends of its two limbs integrally carry corresponding downwardly projecting sleeve-like holders 23. Each holder 23 is arranged to receive an upper fastening portion of a corresponding flat spring steel tine 24.The two tines 24 of each soil working member 2 are arranged so that they trail downwardly and rearwardly to some extent with respect to the intended direction of operative rotation of the soil working member 2 concerned (see the small arrows in Figures 1 and 3 of the drawings) and, preferably, each tine 24 is formed with a plurality of vertically spaced apart holes or notches to enable it to be secured in its holder 23 in different positions of projection from that holder, a clamping pin or other fastening being provided to secure each tine 24 in its chosen position of projection from the co-operating holder 23.This arrangement enables the tines 24 to be moved downwardly in their holders 23 to compensate for the inevitable wear of their lower ends to prevent such wear from making it otherwise impossible to adjust the implement to operate at its maximum working depth unless the tines were to be completely replaced.

The uppermost end of each shaft 3 has a corresponding spur-toothed or straight-toothed pinion 25 welded to it just above the corresponding upper ball bearing 8. The pinions are of such a size, and are so arranged in the hollow frame portion 1, that the teeth of each pinion 25 are in mesh with those of the or each immediately neighbouring pinion 25 and it will be realised that, with this arrangement, each pinion 25, shaft 3 and soil working member 2 will revolve, during the use of the implement, in the opposite direction to the or each immediately neighbouring similar assembly. One of the centre pair of pinions 25 is provided, immediately thereabove, with a bevel pinion or crown wheel 26 which lies in an appropriately positioned opening formed in the top or cover plate of the hollow frame portion 1. The bevel pinion or crown wheel 26 rotatably surrounds, by way of upper and lower ball bearings 28, the lower end of a non-rotatable shaft 27 that is nevertheless in axial alignment with the shaft 3 that corresponds to said one of the centre pair of pinions 25. A major portion of the length of the non-rotatable shaft 27 is received in a downwardly tapering embossed sleeve 31 of a cast gear box 27A, said gearbox 27A having an open bottom and being fastened to the hollow frame portion 1 by some of the small bolts that hold the two parts of that frame portion together, the fastening position of the gearbox 27A being such that its open bottom is in substantial register with the aforementioned opening in the top or cover plate of the hollow frame portion 1 in which the bevel pinion or crown wheel 26 is principally disposed.This arrangement facilitates inexpensive manufacture and easy assembly since a high degree of precision is not required. An internal double shoulder 29 of the hub of the bevel pinion or crown wheel-26 spaces apart the outer races of the upper and lower ball bearings 28, the inner race of the lower ball bearing 28 abutting against a flange 30 formed at the extreme lowermost end of the shaft 27, said flange 30 being spaced by only a very short distance above the top of the corresponding pinion 25 where it is welded to the shaft 3 that is aligned with the non-rotatable shaft 27. The inner race of the upper ball bearing 28 abuts against the flat lowermost end of the cast sleeve 31.The uppermost end of the fixed shaft 27 is of reduced diameter and projects from the mouth of the sleeve 31 in the gearbox 27A, this end of the shaft 27 being recessed to receive a locking ring 32 which prevents downward axial movement of the shaft 27. In the construction example which is being described, the bevel pinion or crown wheel 26 is secured to said one of the pinions 25 by four smooth pins 33 having flanges or heads at their lowermost ends, said pins 33 being entered upwardly through aligned holes in the underlying pinion 25 and overlying bevel pinion or crown wheel 26, the flanges or heads of the pins 33 being countersunk into matchingly shaped recesses formed in the lower surface of the pinion 25.The upper ends of the shanks of the pins 33 project short distances into downwardly tapering recesses formed in the upper surface of the bevel pinion or crown wheel 26 and said pins 33 may be retained in their appointed positions in any one of several different ways. A strong and quick-setting adhesive such as a cyanoacrylate ester or an epoxy resin may be employed or the upper ends of the shanks may be welded into said recesses or known claw couplings or fastenings (not illustrated) may be employed. None of these different possibilities necessitates assembly with a high degree of accuracy.

The bevel pinion or crown wheel 26 has its teeth in driven mesh with those of a smaller bevel pinion 34 carried internally of the gearbox 27A at the inner end of a substantially horizontal rotary input shaft 35 of that gearbox. The input shaft 35 is rotatably mounted in a pair of horizontally spaced apart ball bearings 36 and has a splined or otherwise keyed end which projects forwardly from the front of the gearbox 27A in substantially the direction A. This end of the rotary input shaft 35 is intended to be placed in driven connection with the rear power take-off shaft of an agricultural tractor or other operating vehicle by way of a telescopic transmission shaft 37 (Figure 1) that is of a construction which is known per se having universal joints at its opposite ends.A blade 38 (Figures 3 and 4) is located at one side. of the bevel pinion or crown wheel 26 at such a position that it is immediately above the pinions 25 and intersects a vertical plane containing the axes of rotation of all twelve of the rotary soil working members 2. The blade 38 is welded to the leading end of a supporting bracket 39 which bracket is secured to the flat bottom of the hollow frame portion 1 by a pair of bolts 41 and a spacing block 40 or equivalent spacing sleeves.It can be seen in Figure 3 of the drawings that the blade 38 is inclined to the plane which contains the axes of rotation of all twelve of the soil working members 2 in such a way that the operative bevelled end thereof (see Figure 4) which is very closely adjacent to the bevel pinion or crown wheel 26 in rearmost relative to the direction A, the straight strip-shaped blade 38 being inclined to the plane which has just been mentioned at an angle which is preferably substantially 300. The rearmost, with respect to the direction A, bevelled end of the blade 38 is shaped to lie very close indeed to the inverted frusto-conical radially outermost surface of the bevel pinion or crown wheel 26.A second blade 42 is arranged in front of the blade 38 with respect to the direction A and is secured to the substantially flat bottom of the hollow frame portion 1 by a horizontally spaced apart pair of bolts 43. As seen in plan view (Figure 3), the second blade 42 is of substantially isosceles triangular configuration having one straight side and two concave curved sides, these two curved sides being shaped to match the curvature of the radially outermost cylindrical surface of each of an immediately neighbouring pair of two of the pinions 25. The straight base edge, as seen in Figure 3, of the blade 42 is foremost with respect to the direction A and lies at the front of the inner surface of the substantially flat bottom of the hollow frame portion 1.Approximately the rear half of the blade 42 is inclined upwardly and rearwardly from the part thereof that is secured to the bottom of the frame portion 1 at an angle of substantially 300 to that bottom (see Figure 4).

The rearmost tip of the inclined part of the blade 42 is disposed at a horizontal level which is substantially mid-way through the vertical thickness of the pinions 25 and is located, considered in the direction A, rearwardly of the leading extremities of the pinions 25 by a distance which is substantially half the radius of one of those pinions 25. The two blades 42 and 38 act to guide oil or other lubricant upwardly from the interior of the hollow frame portion 1 through the opening in the cover plate of that frame portion in which the bevel pinion or crown wheel 26 is primarily located and into the open bottom of the gearbox 27A.This guidance or feed of lubricant into the gearbox 27A is caused because of the disposition of the blades 38 and 42 relative to the directions of rotation (see Figure 3) of the two pinions 25 (and the bevel pinion or crown wheel 26 which is secured to one of them) that are their immediate neighbours.

A coupling member or trestle 44 which is of approximately arched configuration as seen in front or rear elevation is mounted substantially centrally at the front of the implement where it is secured to the leading upright plate 1 6. The top of the arched coupling member or trestle 44 is substantially horizontally disposed and in paralle' relationship with the transverse length of the hollow frame portion 1, the opposite ends of this top being strengtheningly connected to wide spaced apart locations at the top and rear of the hollow frame portion 1 by downwardly and rearwardly divergent tie beams 45. The centre of the top of the coupling member or trestle 44 carries a pair of horizontally spaced apart upright lugs 46 in which at least one pair of horizontally aligned holes is formed.In the use of the implement, which is somewhat diagrammatically illustrated in Figure 1 of the drawings, a pivot pin mounted in the holes in the lugs 46 turnably connects one end of the upper, adjustable length, lifting links of a three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle to the coupling member of trestle 44 of the implement. The coupling member or trestle 44 also comprises substantially horizontally aligned strong pivot pins 47 (figures 1 and 2) near its bottom and these pivot pins 47 are, in the use of the implement (Figure 1), turnably connected to the free ends of the lower lifting links of the same three-lifting device or hitch.

In the use of the soil cultivating implement that has been described, the coupling member or trestle 44 is employed to connect the implement to the three-point lifting device or hitch at the rear of an agricultural tractor or other propelling and operating vehicle and the known telescopic transmission shaft 37 is employed to place the rear power take-off shaft of the same tractor of other operating vehicle in driving connection with the forwardly projecting end of the rotary input shaft 35 of the gearbox 27A.The maximum depth of penetration of the spring steel or other tines 24 into the ground which is possible during a harrowing operation can, if required, be adjusted, before work commences, by temporarily removing the bolts 21 and turning the ground roller 22 and its arms 1 9 bodily upwards or downwards, as may be required, about the aligned stub shafts 18 until appropriate fresh holes 20 in the side plates 1 7 are in register with the holes in the arms 19. The bolts 21 are then replaced and re-tightened.

As the implement moves operatively in the direction A, the tines 24 of the soil working members 2 penetrate into the soil to a controlled depth and each member 2 rapidly revolves about the axis of its shaft 3 in a direction which is opposite to the direction of rotation of the or each immediately neighbouring member 2. It is preferred that each soil working member 2 should have a working width of substantially 25 cms and that the spacing between the axes of the shaft 3 should be such that the strip of soil worked by each individual member 2 overlaps that worked by the or each of its immediate neighbours. However, depending upon legal requirements as to the maximum width of implements which can be transported along roads in various countries, the sizes of the members 2 and the spacing between the shafts 3 can be changed.Also, an implement having twelve soil working members 2 is by no means mandatory and that number can be either increased or decreased which will, of course, again change the effective width of the implement.

The rotary shafts 3 have the same diameter through their lengths and therefore do not need expensive machining operations. Moreover, the rotary support of the shafts 3 from the tubes 4 avoids the need for cast bearing housings, each tube 4 preferably having a length, as illustrated, which is substantially the same as the diameter of one of the pinions 25, this diameter again preferably being substantially 25 cms. In addition to very significantly stiffening and thus strengthening the hollow frame portion 1, the plates 13 and 1 6 give a good protection against damage by stones and other hard objects that may be met with in the soil when the implement is.in use. The tubes 4 are quickly and easily installed in their appointed positions using the flanges 5 in which the screw-threaded holes 6 and 7 are already formed.The pinions 25 are easily welded to the upper ends of the corresponding shafts 3 and, since the bottom of the gearbox 27A is open, it can be formed and assembled in an inexpensive manner. In particular, the non-rotatable shaft 27 having the flange 30 at its lower end can quickly and easily be placed in its appointed position in the sleeve 31 without complicated precautions as to a high degree of precision being necessary.

Similarly, the mounting of the bevel pinion or crown wheel 26 on top of one of the pinions 25 is a simple and inexpensive proceeding which does not require a high degree of accuracy, the assembly being particularly quick and easy when the flanged or headed pins 33 are retained in their appointed positions by the use of known claw couplings or fastenings (not shown). Heat generated during the use of the implement is readily conducted from the bevel pinion or crown wheel 26 to the underlying pinion 25 which it contacts throughout a considerable area, the latter pinion being continuously cooled by the oil or other lubricant in which it is at least partly immersed. Lubrication in the gearbox 27A itself is, as previously mentioned, ensured during the use of the implement by the upward deflection of oil or other lubricant from the hollow frame portion 1 by way of the guide blades 42 and 38 which very closely neighbour two of the pinions 5 and the bevel pinion or crown wheel 26, respectively, said guide blades 42 and 38 being shaped and positioned to co-operate with the rotating pinions, during the use of the implement, in feeding oil or other lubricant upwardly through the opening in the top or cover plate of the hollow frame portion 1 and into the open bottom of the gearbox 27A.

The various features which have been described enable this implement to be manufactured and assembled with a considerable saving in cost as compared with comparable known implements due, principally, to the employment of less expensive materials, the reduction of machining to a minimum and to rapid assembly techniques that do not require excessive accuracy.

The soil cultivating implement that has been described also forms the subject of our co-pending Patent Application No. 83 (Serial No.

2 A) to which reference is directed.

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 that has been described and/or that is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (10)

1. A soil cultivating implement of the kind set forth, wherein a horizontal or substantially horizontal carrier is provided for a shaft which embodies the axis of rotation of each soil working member, said carrier being disposed at a level beneath that of the bottom of said frame portion.

2. An implement as claimed in claim 1, wherein each shaft is arranged principally in a tube and is rotatably supported at locations adjacent to both the top and the bottom ends of that tube.

3. An implement as claimed in claim 1 or 2, wherein said carrier is fastened to the frame portion by means which includes at least one spacing sleeve located adjacent to a corresponding one of the shafts that embody the axes of rotation of the rotary soil working members.

4. An implement as claimed in any preceding claim, wherein said carrier is connected to the frame portion by means which includes an upright plate.

5. An implement as claimed in claim 4, wherein said upright plate is connected to the front, with respect to the intended direction of operative travel of the implement, of said frame portion and extends throughout substantially the whole of the working width of the implement.

6. An implement as claimed in claim 4 or 5, wherein the horizontal or substantially horizontal carrier and said upright plate are interconnected at locations adjacent to the opposite ends of the elongate frame portion by means which includes upwardly extending side plates.

7. An implement as claimed in claim 2 or in any pne of claims 3 to 6 when read as appendant to claim 2, wherein each tube has a flange by which it is secured to the bottom of the frame portion so as to project downwardly from that bottom.

8. An implement as claimed in claim 7, wherein each flange is located against the upper surface of said frame bottom portion and is formed with a plurality of screw-threaded holes.

9. An implement as claimed in claim 2 or in any one of claims 3 to 8 when read as appendant to claim 2, wherein each tube has an axial length which is equal or substantially equal to the diameter of a straight-toothed or spur-toothed pinion that is mounted internally of the frame portion on the shaft which is received in said tube.

10. An implement as claimed in claim 2 or in any one of claims 3 to 9 when read as appendant to claim 2, wherein each tube projects downwardly from beneath said carrier by a distance which is equal or substantially equal to its own diameter.