GB2147783A - Soil cultivating implements - Google Patents

Abstract

In order that the drive transmission to a row of rotary soil working members 3 may be suitable to be power-driven from the power take-off shaft of a tractor which revolves at a speed of substantially 540 revolutions per minute or a speed of substantially 1000 revolutions per minute, said drive transmission comprises a first or upper gear box 32 which functions as a change-speed gear and a second gear box 46 which may be inter-changed with a gearbox 55, the box 46 and an accompanying bearing housing 41 being employed when the slower speed of applied rotation is to be used and the gear box 55 and an accompanying bearing housing 59 being employed when the faster speed of applied rotation is to be used. Interchangeable and/or exchangeable pinions 36 and 37 in the first or upper gear box 32 enable the speeds of rotation of the soil working members 3 to be increased or decreased to match the nature and condition of the soil to be cultivated. An alternative construction is described and illustrated in which the second gear box has an exterior gear lever by which the transmission ratio established therein can be changed to suit either of the indicated slower and faster speeds of rotation that may be applied to the leading end of its rotary input shaft. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines of the kind which comprise a frame portion movable over the ground and a plurality of soil working members supported by that frame portion so as to be rotatable above upwardly extending axes.

The expression "implement(s) or machine(s)" is shortened to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

Known implements of the kind set forth usually have their soil working members rotated by drive derived from the power take-off shaft of a tractor or other vehicle which moves the implement over the ground when it is in use. The tractor or other vehicle may have a power take-off shaft which rotates at a speed of substantially 540 revolutions per minute or at substantially 1000 revolutions per minute and an object of the present invention is to provide a single implement which will co-operate with either speed of drive, the implement requiring only a minimum of modification or adjustment to change from one applied speed of rotation to the other.Accordingly, the present invention provides a soil cultivating implement of the kind set forth, wherein the drive transmission to said soil working members comprises a first gear box and a second gear box which latter establishes a transmission ratio appropriate to the speed of revolution applied to the drive transmission in the use of the implement.

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 somewhat diagrammatic plan view of a soil cultivating implement constructed in accordance with the invention shown connected to the rear of an agricultural tractor, Figure 2 is a front elevation, to an enlarged scale, of a central region of the implement as seen in the direction indicated by an arrow II in Figure 1, Figure 3 is a section taken on the line Ill-Ill in Figure 2, Figure 4 is a section taken on the line IV-IV in Figure 3, Figure 5 is a section taken on the line V-V in Figure 3, Figure 6 is a sectional view similar to that of an upper region of Figure 3 but illustrates said upper region after certain parts shown in Figure 3 have been replaced by other parts.

Figure 7 is a view similar to that of a lower region of Figure 4 of the drawings but illustrates an alternative construction of certain parts, and Figure 8 is a sectional view similar to that of Figure 3 but showing an alternative embodiment of some parts of the implement Referring firstly to Figures 1 to 6 of the accompanying drawings, and particularly to Figure 1 thereof, the soil cultivating implement that is shown in Figure 1 is in the form of a rotary harrow which has a hollow box-section frame portion 1 of elongate formation 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 several Figures of the drawings by an arrow A.

The hollow frame portion 1 effectively constitutes a gear box and 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 lower walls of the frame portion 1 so as to extend parallel to one another in a single row in which the longitudinal axis of each shaft 2 is spaced from that of the or each immediately neighbouring and parallel shaft in said row by the same distance which advantageously, but not essentially, has a magnitude of substantially 25 cms. Each of the shafts 2 that has just been mentioned embodies the axis of rotation of a corresponding soil working member 3 (Figures 2 and 3) that is firmly but releaseably secured to the lower end of said shaft 2 which projects downwardly from beneath the bottom of the hollow frame portion 1.

Each soil working member 3 comprises a substantially horizontal support or carrier 4 having two arms which radiate from a central hub that is fastened to the lower end of the shaft 2 concerned. The outer end of each arm is provided with a corresponding sleeve-like holder in which an upper fastening portion of a corresponding soil working tool in the form of a metallic tine 5 is firmly but releaseably received. As can be seen in Figures 2 and 3 of the drawings, the tines 5 have soil working portions which project downwardly into the ground, when the implement is in use, to an extent whose maximum magnitude is adjustable in a manner which will be described below.The opposite ends of the hollow frame portion 1 are closed by corresponding side plates 6 which extend substantially vertically parallel to one another and to the direction A, the size and shape of each side plate 6 being such that it is larger than the cross-sectional area of the frame portion 1 itself so that, in particular, it projects vertically above thatframe portion 1 and rearwardly behind the rest of the frame portion 1 with respect to the direction A. Upper leading regions of the two side plates 6 carry substantially horizontally aligned stub shafts 7, the axis defined by the aligned stub shafts 7 being substantially parallel to the single row of rotary soil working members 3 and thus perpendicular or substantially perpendicularto the direction A.

The leading end of a corresponding arm 8 is turnable upwardly and downwardly about each of the two stub shafts 7, said arms 8 extending generally rearwardly from those stub shafts 7 alongside the relatively remote outer surfaces of the corresponding plates 6 to locations which are well behind the rear edges of those plates 6 with respect to the direction A. A rear region of each frame portion side plate 6 that lies behind the remiander of the frame portion 1 with respect to the direction A is formed with a curved row of holes that are equal in distance from the axis defined by the aligned stub shafts 7 and each arm 8 is formed with at least one hole that can be brought into register with any chosen hole in the corresponding plate 6 by turning the arm 8 concerned either upwardly or downwardly about its stub shaft 7.Bolts 9 or like secure fastening members are entered through the holes in the arms 8 and through chosen aligned holes in the frame portion side plates 6 to retain those arms 8 reliably in any desired angular setting about the axis defined by the stub shafts 7 for as long as may be required.

Lower end regions of the arms 8 are inclined downwardly and rearwardly, or have downwardly and rearwardly inclined support plates secured to them, a ground roller that is generally indicated by the reference 10 being mounted in a freely rotatable manner between substantially horizontally aligned bearings carried by said arms 8 themselves or by the support plates which have just been mentioned. The roller 10 which is diagrammatically illustrated in Figure 1 of the drawings is an open-work, cageformation ground rollerwhich may be of a construction that is known perse having its ground-engaging cylindrical surface defined by a plurality of relatively spaced elongate elements that are preferably, but not essentially, wound helically round the longitudinal axisxaxis of rotation of the roller that is embodied in a central axially extending shftthereof.The roller 10 is not the subject of the present invention and, since it may of known formation, it will not be described in detail.

A central region of the top and front, with respect to the direction A, of the hollow frame portion 1 is provided with a coupling member or trestle 11 whose shape can be seen best in Figures 2 and 3 of the drawings. The top of the coupling member or trestle 11 comprises a carrier beam 12 that extends substantially horizontally perpendicular to the direction A, said carrier beam 12 being of hollow formation and having an angular cross-section which is preferably, as illustrated, a substantially square one. The carier beam 12 is so disposed about its own longitudinal axis that diagonals of its substantially square cross-section are respectively substantially but not exactly vertically, and substantially but not exactly horizontally, disposed (see Figure 3).Opposite end regions of the carrier beam 12 are bolted to the top of substantially symetrically identical coupling member parts or frame parts 13 each of which is formed substantially wholly by folding a corresponding sheet steel or other sheet metal plate. The two frame parts 13 extend downwardly and have lower edge portions which are secured by bolts 15 between pairs of stop strips 17 and the juxtaposed upper edges of brackets 14. Each pair of brackets 14 defines, between those brackets, a longitudinally extending box in which a corresponding arm 16 of double-strip formation is mounted so as to be upwardly and downwardly pivotable to a limited extent about a substantially horizontal axis located close to its rear end. The limit ofthe upward movement of each arm 16 in the corresponding box which is possible is defined by the corresponding stop strips 17.The leading end of each arm 16, with respect to the direction A, is forked to enable it to be pivotally connected to the rear end of one of the lower lifting links of a three-point lifting device or hitch mounted at the rear of an agricultural tractor or other operating vehicle. This arrangement is shown somewhat diagrammatically in Figure 1 of the drawings. The juxtaposed brackets 14 which principally define the boxes in which the arms 16 are arranged are formed from sheet steel or other sheet metal and have horizontally bent-over foot plates which are firmly but releasably secured to the top of the hollow frame portion by bolts at locations adjacent to the front and rear edges of that frame portion top with respect to the direction A.As will be evident from the drawings, each arm 16, and the box in which it is upwardly and downwardly pivotable to a limited extent, extends substantially, although not necessarily exactly, horizontally parallel to the direction A.

The upwardly and forwardly facing surface of the substantially square cross-section carrier beam 12 has the outwardly bent-over rims of two vertically disposed but horizontally spaced apart plates 18 secured to it, substantially centrally along its length, by corresponding groups of four of the bolts 15, the patterns in which said bolts 15 are arranged being clearly visible in Figure 2 of the drawings. It is noted that all of the bolts 15 may be of substantially the same size and type. Horizontally aligned holes in leading regions of the two plates 18 effectively afford a single upper coupling point to which the free end of the upper adjustable-length lifting link of the three-point lifting device or hitch of a tractor or other vehicle can be pivotally connected in the manner which is shown diagrammatically in Figure 1 of the drawings.

Each shaft 2 is provided, inside the hollow frame portion 1, with a corresponding straight- or spurtoothed pinion 19, the size of each pinion 19 being such that its teeth are in mesh with those of the or each immediately neighbouring pinion 19 in the single row of twelve such pinions which are provided in the embodiment that is being described. One of the centre pair of shafts 2 in the single row of twelve such shafts is integral with, or rigidly secured to, an axially coincident connecting shaft 20 (Figure 4) that extends upwardly above the top of the hollow frame portion 1 inside a surround sleeve 21 which has a flange 22 near its lower end but above the top of the hollow frame portion 1.Bolts 24 are entered substantially vertically through holes in the flange 22 and in the rim of a hole in the top of the frame portion 1 which receives the sleeve 21 and into screw-threaded holes in a stiffening plate 23 which surrounds the lower end of the sleeve 21 immediately beneath the top of the hollow frame portion 1. The connecting shaft 20 extends upwardly into a substantially oblong first or upper gear box 32 immediately beneath which it is rotatably supported by a bearing 25 that is mounted in a bearing housing 26 fastened by bolts 27 and an upper flange 28 of the sleeve 21 to a supporting plate 29 that is substantially horizontally disposed and of substantially oblong shape. The front of the supporting plate 29, relative to the direction A, is secured by an angular fastening strip 30 and a plurality of bolts 31 to the upwardly and rearwardly facing surface of the carrier beam 12 (see Figures 3 and 5). The angular fastening strip 30 extends throughout all of of the transverse length of the leading edge of the supporting plate 29. Some of the already mentioned bolts 31 also secure the flat bottom of the gear box 32 to the upper surface of the supporting plate 29.

The first or upper gear box 32 is formed from sheet steel or other sheet metal and comprises a lid-like top or cover 33 which is fastened by a plurality of bolts 34 and a positioningly rimmed edgeto an underlying lower portion 35 which lower portion 35 includes the flat bottom that is secured to the underlying supporting plate 29.In addition to the uppermost end of the connecting shaft 20 that is disposed inside the first gear box 32, the uppermost axially splined end of a parallel but much shorter shaft 38 extends into said gear box 32 from beneath, the similarly sized and splined ends of the two shaft 20 and 38 that are disposed inside the gear box 32 carrying corresponding straight- or spur-toothed pinions 36 and 37 (see Figure 5) of different sizes, the internally splined hubs of the pinions 36 and 37 co-operating with the splines of the corresponding ends of the shafts 20 and 38 and the sizes of the two pinions 36 and 37 being such that, when mounted on the shaft ends, their teeth are in mesh with one another. The interior of the first or upper gear box 32 is readily accessible merely by temporarily removing the bolts 34 and lifting off the cover 33.The pinions 36 and 37 can then be interchanged on the ends of the shafts 20 and 38 or be exchanged for a cooperating pair of pin ions of different sizes to give chosen corresponding transmission ratios between the two shafts 20 and 38. The first or upper gear box 32 thus functions as a simple change-speed gear and its cover 33 is disposed in a particularly accessible position close to the top of the implement. The shaft 38, which is parallel to the shaft 20, extends downwardly from the gear box 32 and, as seen in plan (Figures 1 and 5), is located to one side of the shaft 20 and a little to the rear of that shaft 20 with respect to the direction A.The shaft 38 is rotatably supported in a bearing housing 41 by lower and upper bearings 39 and 40, respectively, said bearing housing 41 having a rim 42 that surrounds the upper bearing 40 and penetrates through the bottom of the lower gear box portion 35 and into the first gear box 32 by a short distance. As well as extending through an opening in the bottom of the lower portion 35 of the gear box 32, said upright rim 42 also extends through a registering opening in the supporting plate 29 that immediately underlies said gear box 32.

A flange 43 surrounds the bearing housing 41 at the base of the rim 42 and, in turn, immediately underlies the supporting plate 29 to which latter it is releaseably secured by bolts 43A (Figure 4). The end of the bearing housing 41 has a rim 44 which surrounds the lower bearing 39 and, immediately above the rim 44, a flange 45 which bears against the top of a cast iron or other cast metal second gear box 46 whose top is releaseably connected to the bottom of the bearing housing 41 by more of the bolts 43A whose positions cannot be seen in the drawings.

The bottom of the cast iron or other cast metal second gear box 46 rests upon an underlying substantially horizontal plate 47 which is welded to a substantially vertically extending sleeve 48 so as to surround a location very close to the uppermost end of that sleeve 48 which uppermost projects a very short distance above the plate 47 into a registering opening in the bottom of the gear box 46. It is noted that the bottom of the second gear box 46 is not positively secured to either the plate 47 or the sleeve 48 but merely rests upon the plate 47 in a position which is accurately dictated by the upward projection of the sleeve 48 into the fitting opening in the bottom of the gear box 46. The interior of the second gear box 46 is in open connection with the interior of the sleeve 48.An oblique strengthening strut 49 interconnects the front of the sleeve 48, with respect to the direction A, and the lower surface of the plate 47 alongside the leading edge of that plate 47. A substantially horizontally disposed and substantially oblong plate 50 is welded or otherwise rigidly secured to the lower end of the sleeve 48 and the plate 50 is bolted to the top of the hollow frame portion 1 along the rear edge of that top with respect to the direction A. The second gear box 46 is thus firmly but readily releaseably sandwiched, together with the bearing housing 41, between the underlying plate 47 and the overlying supporting plate 29 that lies immediately beneath the first gear box 32 which functions as a change-speed gear.The gear box 46 can readily be removed, when required, merely by releasing the plate 50 and sleeve 48 from the frame portion 1 and releasing the bolts 43A which secure the bearing housing 41 between the supporting plate 29 and the top of said second gear box 46. Replacement of the gear box 46 is effected in an equally simple manner merely by correctly positioning the various parts and installing the required fastening bolts.

The lower end of the shaft 38 which projects into the second gear box 46 is there provided with a bevel pinion 51 whose teeth are in mesh with those of a further bevel pinion 52 carried by a shaft 53 which extends substantially horizontally parallel to the direction A through the interior of the gear box 46 so as to project both forwardly and rearwardly from the front and back of that gear box 46. As can be seen best in Figure 3 of the drawings, both projecting ends of the shaft 53 are externally splined, the leading end being 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 54 (Figure 1) of known construction having universal joints at its opposite ends.The rearwardly projecting splined end of the shaft 53 is available for use, when required, in powering the moving parts of some other implement, machine or tool that might be used in combination with the soil cultivating implement to lie immediately behind that implement with respect to the direction A, good examples of such additional implements, machines or tools being seed drills, planting machines and artificial fertilizer spreaders.

The positioning of the gear box 46 between the underlying frame portion 1, which itself functions as a further gear box, and the overlying first gear box 32 enables the cast iron or other cast metal gear box 46, in conjunction with the plates 29, 47 and 50, the sleeve 48 and the strut 49, entirely satisfactorily to resist the forces which tend bodily to displace the shaft 53 when it is being operatively rotated from the transmission shaft 54, these forces being still greater in magnitude when the rear end of the shaft 53 is also employed to transmit drive to an implement, machine or tool used in combination with the soil cultivating implement. The plate 50 at the lower end of the sleeve 48 seals closed that lower end and enables the interior of the sleeve 48 to contain a supply of lubricating oil additional to that contained in the overlying and communicating second gear box 46.The lubricating oil, in addition to performing its primary lubricating function, serves to conduct away from the interior of the gear box 46 any excess heat that may be produced during the operation of the implement, such heat being dissipated through the walls of the gear box 46 and also through the cylindrical wall of the sleeve 48.

In the use of the soil cultivating implement that has been described with reference to Figures 1 to 5 of the accompanying drawings, its coupling member or trestle 11 is connected to the free ends of the upper and lower lifting links of the three-point lifting device or hitch at the rear of an agricultural tractor or other operating vehicle and the leading end of the shaft 53 is placed in driven connection with the rear power take-off shaft of the same tractor or other vehicle through the intermediary of the known telescopic transmission shaft 54 which has universal joints at its opposite ends.Adjustments which may, if required, be made before work commences include raising or lowering the bodily level of the ground roller 10 relative to that of the frame portion 1 and soil working members 3 to increase or decrease the maximum depth of penetration of the tines of those members 3 into the ground which will be possible during operative progress in the direction A. In addition, the speed at which the members 3 will revolve in response to a predetermined speed of rotation supplied from the rear power take-off shaft of an operating tractor or other vehicle to the shaft 53 can be either increased or decreased by removing the lid or cover 33 of the upper or first gear box 32 and either interchanging the pinions 36 and 37 on the splined ends of the shafts 20 and 38 or by exchanging those pinions 36 and 37 for a different pair of co-operating pinions of other sizes.These adjustments will usually be made in the light of the nature and condition of the soil that is to be dealt with by the implement and the particular purpose for which that soil is required after its cultivation. As the implement moves operatively in the direction A, each rotary soil working member 3 will work a corresponding strip of land extending in that direction but, since the effective distance between the soil working portions of the tines 5 of each member 3 is the same as, or a litte greater than, the spacing between the axes of rotation of immediately neighbouring shafts 2, the twelve strips of land (in this embodiment) will overlap, or at least adjoin, one another to produce a single broad strip of worked soil extending in the direction A.

When the implement has twelve of the soil working members 3 and the preferred spacing between the axies of rotation of the shafts 2 that is mentioned above is employed, the implement will have a working width of substantially, but not necessarily exactly, three meters. It will readily be apparent that this working width could be increased or decreased by employing a greater or lesser number of the soil working members 3 in the single row of those members. The inter-meshing relationship between the pinions 19 means that each pinion 19, together with the corresponding shaft 2 and soil working member 3, will revolve in the opposite direction to the or each immediately neighbouring similar assembly as indicated by small arrows in Figure 1 of the drawings.The upper gear box 32, which affords a change-speed gear, is supported by the plate 29 in a very effective manner and, during the assembly of the implement, the supporting 29 enables both the first gear box 32 and the second gear box 46 to be quickly and easily installed in their correct positions. The implement that has so far been described is suitable for use with agricultural tractors and other vehicles whose rear powertakeoff shafts will transmit to the shaft 53 of the second gear box 46 a driving speed of rotation of substantially 540 revolutions per minute.

Some tractors and other operating vehicles have rear power take-off shafts which rotate at a speed of substantially 1000 revolutions per minute and, if the implement that has been described is to be operated by such a tractor or other vehicle, all that is neessary is to substitute for the second gear box 46 the cast iron or other cast metal second gear box 55 which is shown in Figure 6 of the drawings together with an alternative bearing housing 59, an alternative shaft 56 (which is shorter in length than the shaft 38) and associated parts.When the second gear box 55 that is shown in Figure 6 of the drawings is employed, the axially shorter but thicker shaft 56 is rotatably supported by a lower bearing 57 and an upper bearing 58, the bearing housing 59 being arranged in substantially the same way as the bearing housing 41 that has already been described but having different dimensions to that housing 41 to suit the requirements of the gear box 55 and the shaft 56. As in the case of the gear box 46, the bottom of the gear box 55 is in open communication with the interior of the tubular sleeve 48 which sleeve 48 again serves as a lubricating oil reservoir and to assist in conducting excess heat produced in the gear box 55 to the surrounding atmosphere. In this embodiment, the lower end of the shaft 56 carries, inside the second ger box 55, a relatively large bevel pinion 60 whose teeth are in driven mesh with those of a relatively small bevel pinion 61, the latter being mounted, inside the gear box 55, on a shaft 62 that extends substantially horizontally parallel to the direction A right through the second gear box 55 to have splined ends which project both forwardly in front of and rearwardly behind said gear box 55.The transmission ratio between the relatively small and relatively large pinions 61 and 60 in the second gear box 55 matches the faster speed of rotation applied to the shaft 62 so that the shaft 56 shown in Figure 6 of the drawings will rotate at substantially the same speed, when the shaft 62 is rotated at substantially 1000 revolutions per minute, as the previously described shaft 38 when the shaft 53 of the gear box 46 is rotated at substantially 540 revolutions per minute.

Instead of using the integral shaft 2 and connecting shaft 20 (Figure 4), a much shorter shaft 2 that extends for only a relatively small distance above the top of the hollow frame portion 1 may be employed as shown in Figure 7 of the drawings. The lower end of a separate connecting shaft 63 and the upper end of the corresponding shaft 2 are both axially splined and these facing ends are surrounded by a strong matchingly internally splined sleeve 62A which simply and reliably transmits drive from the shaft 63 to the shaft 2 and, by way of the pinions 19, to all of the other eleven shafts 2. The upper end of the connecting shaft 63 is identical to the upper end of the already described connecting shaft 20 and carries the pinion 36 inside the first gear box 32 which affords a change-speed gear.Construction and assembly costs can, in many cases, be simplified by substituting the arrangement which can be seen in Figure 7 of the drawings for that which is illustrated in a lower region of Figure 4 thereof.

Figure 8 of the drawings illustrates an alternative gear box arrangement to the use of one, or the other, of the two second gear boxes 46 and 55 which have been described above. In the construction of Figure 8 of the drawings, the implement is provided with a second gear box 64 whose top is again connected by the bearing housing 41 to the supporting plate 29 and the bottom of the first or upper gear box 32 which affords ds a change-speed gear. The bottom of the S1- '.J gear box 64 is provided with a projection whic. r co-operates with a postioning cup fastened to the top of a sleeve 65 which is similar to the previously described sleeve 48 except that it is of greatly reduced vertical extent and that its hollow interior is sealed from the interior of the gear box 64.

The lower end of the sleeve 65 is again secured to the plate 50 which, in turn, is secured to the top of the hollow frame portion 1. The supporting plate 29, which is releaseably connected to the carrier beam 12 by the strip 30 and the bolts 31, again reliably secures the second gear box 64, the bearing housing 41 and the upper gear box 32 in their appointed positions and allows them readily to be installed in the implement and to be removed therefrom if tht should prove to be necessary. A shaft 66 extends substantially horizontally right through the second gear box 64 in a direction that is parallel or substantially parallel to the direction A and has splined ends projecting both forwardly in front of and rearwardly behind the gear box 64 for the same purpose as has already been described with reference to the shafts 53 and 62.The shaft 66 has a relatively long axially splined portion located inside the gear box 64 along which portion an integral pair of larger and smaller straight- or spur-toothed pinions 67 and 68 are together slideable, the pinions 67 and 68 being axially spaced apart from one another by a portion around which a ring is rotatably mounted.The ring carries opposed trunnion pins which are entered in slots formed in the limbs of a yoke which yoke is turnable about substantially horizontally aligned pivots by a gear lever 69 that projects to one side of the gear box 64 and which lever 69, when turned about the axis defined by said pivots, will "change" gear from the illustrated position in which the larger pinion 67 is in driving mesh with a pinion 70 of substantially the same size mounted on a rotary shaft 72 in the gear box 64 in parallel relationship with the shaft 66 but at a higher horizontal level than that shaft 66.It will be readily apparent from Figure 8 of the drawings, that upon moving the gear lever 69 to an alternative position, the integral pair of pinions 67 and 68 will be moved rearwardly lengthwise along the shaft 66 until the smaller pinion 68 comes into driving mesh with the teeth of a second and larger pinion 71 that is mounted on the shaft 72. The two pinions 70 and 71 are located towards the leading and rear, respectively, ends of the shaft 72 and it will be immediately apparent from Figure 8 of the drawings that, at any one time, only the pinion 67 can be in driving mesh with the pinion 70 or the pinion 68 be in driving mesh with the pinion 71.However, the dimensions are such that an intermediate neutral position in which no drive is transmitted is possible and known means which is not illustrated in the drawings may be provided to retain the lever 69 in either drive position or in the intervening neutral position.

The leading end of the shaft 72, with respect to the direction A, carries a bevel pinion 73 whose teeth are in driving mesh with those of the previously mentioned bevel pinion 51 which pinion 51, as previously described and illustrated, is mounted at the lowermost end of the shaft 38 to whose upper end is releaseably connected the pinion 37 in the upper gear box 32 which functions as a change-speed gear.

As shown in Figure 8 of the drawings the pinion 51 is, of course, located inside the second gear box 64 rather than inside the gear box 46.

The use of the second gear box 64 enables the same implement, without any structural atleration, to co-operate correctly with either a tractor or other vehicle whose power take-off shaft revolves at substantially 540 revolutions per minute or a tractor or other vehicle whose rear power take-off shaft revolves at substantially 1000 revolutions per minute. This is particularly convenient for farmers and other operators who might have agricultural tractors of both kinds and who might wish to use the same soil cultivating implement with either tractor.The position illustrated in Figure 6 in which the pinion 67 is drivingly in mesh the pinion 70 is suitable for co-operation with a tractor or other vehicle whose rear power take-off shaft revolves at substantially 540 revolutions per minute whilst the other possible operative position in which the pinion 68 has its teeth in driving mesh with those of the pinion 71 is the correct position for co-operation with a tractor or other vehicle whose rear power take-off shaft rotates at a speed of substantially 1000 revolutions per minute. The two different transmission ratios are such that the shaft 72 will be revolved at substantially the same speed whichever co-operating pair of pinions 67 and 70 or 68 and 71 is chosen depending upon the corresponding position of the lever 69. It will be appreciated that, whilst the primary intention of the second gear box 64 is to enable the implement to co-operate correctly with a tractor or other vehicle whose rear power take-off shaft has one or the other of the two substantially standard speeds of rotation that have just been mentioned, itwould be possible to use the pinion combination 67,70 with the faster speed of rotation of the shaft 66, or conversely, to use the pinion combination 68, 71 with the slower speed of rotation of the shaft 66. Bearing in mind that different transmission ratios can also be established in the upper gear box 32, it will be appreciated that the provision of the second gear box 64,63 effectively increases the range of speeds at which the soil working members 3 can be rotated to a considerable extent.

The first gear box 32 which affords a changespeed gear is particularly readily accessible in each of the embodiments that have been described and only a relatively small range of second gear boxes 46, 55 and 64 and associated parts, such as the different bearing housings 41 and 59 and the alternative supporting sleeves 48 and 65, is required to enable the same basic implement to be furnished ready for use with a tractor or other vehicle whose rear power take-off shaft revolves at substantially 540 revolutions per minute or at substantially 1000 revolutions per minute or so as to be able to co-operate correctly with either speed of power take-off shaft rotation merely by moving a lever (the lever 69 of Figure 8 of the drawings) from one position to another.The supporting plate 29 and the alternative supporting sleeves 48 and 65 facilitate ready assembly of the implement in any of the described and illustrated versions, the assembly and dismantling procedure being so simple that a user of the implement who might, purely for example, change the co-operating tractorto one having a different speed of rotation of its rear power take-off shaft, can readily replace the initial second gear box 46 or 55 by the required fresh gear box 55 or 46 or can substitute the second gear box 64 which will co-operate correctly with either standard speed of powertake-offshaft rotation.

Although certain features of the different versions of the 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, the invention is not necessarily limited to those features and includes within its scope each of the parts of each soil cultivating implement version that has been described, an door that is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (19)

1. A soil cultivating implement of the kind set forth, wherein the drive transmission to said soil working members comprises a first gear box and a second gear box which latter establishes a transmission ratio appropriate to the speed of revolution applied to the drive transmission in the use of the implement.

2. An implement as claimed in claim 1, wherein the first gear box is connected to said frame portion by means which includes a supporting plate.

3. An implement as claimed in claim 2, wherein the first gear box is located at the opposite side of said supporting plate from said second gear box.

4. An implement as claimed in claim 3, wherein the first gear box is located above the supporting plate and the second gear box is located below that plate.

5. An implement as claimed in claim 4, wherein the second gear box comprises a rotary take-off or output shaft capable of transmitting rotation to the moving parts of another implement. machine or tool.

6. An implement as claimed in any preceding claim, wherein said second gear box comprises means by which the transmission ratio established therein can be changed from the exterior of that gear box.

7. An implement as claimed in any preceding claim, wherein said second gear box is provided with an underlying hollow support whose interior serves as a lubricating oil reservoir.

8. An implement as claimed in claim 7, wherein said underlying support extends between the second gear box and said frame portion, and wherein said frame portion itself serves as a further gear box accommodating parts of the drive transmission to said soil working members.

9. An implement as claimed in claim 8, wherein the drive transmission comprises a connecting shaft extending between said frame portion which serves as a further gear box and said first gear box, the longitudinal axis of said connecting shaft being substantially coincident with that of one of the soil working members.

10. An implement as claimed in claim 9, wherein said connecting shaft comprises two initially separate portions.

11. An implement as claimed in claim 2 or in any one of claims 3 to 10 when read as appendant to claim 2, wherein said supporting plate is arranged in an upper region of a coupling member or trestle of the implement which coupling member or trestle is constructed and arranged for connecting the implement to the three-point lifting device or hitch of a tractor or other vehicle and is mounted on the top of said frame portion.

12. An implement as claimed in claim 11, wherein said supporting plate is arranged behind, with respect to the intended direction of operative travel of the implement, a substantially horizontally extending transverse carrier beam of said coupling member or trestle in such a position that it lies between the opposite ends of that carrier beam, and wherein said second gear box is disposed between frame parts of the coupling member or trestle which extend downwardly from said carrier beam thereof.

13. An implement as claimed in claim 9 or claim 10 or either claim 11 or claim 12 when read as appendantto claim 9 or claim 10, wherein said first gear box comprises two interchangeable andlor exchangeable pinions of which is one coupled to said connecting shaft and the other is coupled to a shaft which drivingly interconnects the first gear box and the second gear box.

14. An implement as claimed in any preceding claim, wherein said second gear box comprises a rotary input shaft which is constructed and arranged to be connectable to the power take-off shaft of a tractor or other vehicle.

15. An implement as claimed in any one of claims 1 to 5 or in any one of claims 7 to 14 when read as appendant to any one of claims 1 to 5, wherein said second gear box comprises one of at least two different second gear boxes each of which establishes a different transmission ration and either or any chosen one of which can be installed in the implement to provide the correct transmission ration for co-operation with a predetermined speed of revolution applied to the drive transmission in the use of the implement.

16. An implement as claimed in claim 6 or in any one of claims 7 to 14 when read as appendant to claim 6, wherein said means for changing the transmission ratio established by the second gear box from the exterior of that gear box comprises a lever.

17. An implement as claimed in any preceding claim, wherein said frame portion is of elongate, hollow formation and accommodates a row of inter-meshing pinions with each pinion mounted on a shaft that embodies the upwardly extending axis of rotation of a corresponding one of the soil working members.

18. An implement as claimed in any preceding claim, wherein said second gear box is disposed substantially mid-way between said first gear box and said frame portion.

19. A soil cultivating implement of the kind set forth substantially as hereinbefore described with reference to Figures 1 to 6 of the accompanying drawings or with reference to Figures 1 to 6 as modified by Figure 7 and/or Figure 8 of the accompanying drawings.