GB2153642A - Soil cultivating implements - Google Patents

Abstract

A soil cultivating implement comprises an elongate hollow frame portion 5 supporting therebeneath a plurality of rotatable soil working members 7, the frame portion 5 being upwardly and downwardly displaceably connected to a carrying frame provided with a coupling member or trestle 77 for connection to a tractor or other vehicle three point lifting device or hitch, said carrying frame comprising a single elongate frame beam 1 that is substantially parallel to the frame portion 5 and which has its opposite ends located between the opposite ends of the hollow frame portion 5. A front stabilizer 87 and a longer rear stabilizer 84 directly and indirectly, respectively, couple the hollow frame portion 5 to frame beam 1 so as to prevent uncontrolled upward and downward movements of the hollow frame portion 5 relative to that frame beam 1. The implement also comprises two substantially axially aligned ground rollers 54 or a single roller associated with a centrally located stop baffle (122, Fig.9), a rear coupling mechanism 104 for the temporary connection of some other implement, machine or tool and a manually, vertically displaceable screen 28. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines of the kind which comprise a plurality of soil working members that are supported by an elongate hollow frame portion, extending substantially horizontally perpendicular, or at leasttrans- verse, to the intended direction of operative travel of the implement or machine, so as to be rotatable about corresponding substantially vertical, or at least upwardly extending, axes, the hollow frame portion being linked to a carrying frame that is provided with a three-point coupling member constructed and arranged for connection to the threepoint lifting device or hitch of a tractor or other vehicle.The expression "implement(s) or machines(s)" is replaced by "implement(s)" alone throughout the remainder of this document for the sake of brevity.

Known implements of the kind set forth above are usually of relatively large working width and several different construction have been tried to give the carrying frame the required high degree of rigidity.

Such constructions have proved to be complicated, wasteful of material and consequently unduly expensive and it is therefore an object of the present invention to overcome, or very greatly to reduce, these disadvantages by providing a soil cultivating implement of the kind set forth, wherein said carrying frame comprises a single frame beam whose opposite ends are located, when the implement is viewed from the rear in its intended direction of operative travel, between the opposite ends of said hollow frame portion.

For a better understanding of the invention, and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings, in which: Figure 1 is a plan view of a soil cultivating implement in accordance with the invention in the form of a rotary harrow that is intended principally, but not exclusively, for the preparation of seed beds, Figure 2 is a side elevation, to an enlarged scale, as seen in the direction indicated by an arrow II in Figure 1, Figure 3 is a section, to an enlarged scale, taken on the line Ill-Ill in Figure 1, Figure 4 is a section, to an enlarged scale, taken on the line IV-IV in Figure 1, Figure 5 is a rear view, to an enlarged scale, of lower substantially central rear parts of the implement as seen in the direction indicated by an arrow V in Figure 2, Figure 6 is a further rear view, to an enlarged scale, as seen in the direction indicated by an arrow VI in Figure 2, Figure 7 is a side elevation, to an enlarged scale, illustrating an alternative construction and arrangement or parts that can be seen best in Figure 4 or the drawings, Figure 8 is a similar view to that of Figure 2 of the drawings but illustrates an alternative construction of the implement, Figure 9 is a plan view as seen in the direction indicated by an arrow IX in Figure 8, and Figure 10 is a similar view to that of Figure 9 but illustrates an alternative construction.

Referring to the accompanying drawings and firstly to Figures 1 to 6 thereof, the soil cultivating implement that is illustrated is in the form of a rotary harrow which is intended primarily, but not necessarily exclusively, for preparing seed beds in pre viouslyworked agricultural land. The implement has a carrying frame which is constructed and arranged for connection to the three-point lifting device or hitch of an agricultural tractor or other moving and operating vehicle in a manner that will be further described below, said carrying frame being afforded principally by a single frame beam 1 that extends substantially horizontally transverse and usually, as illustrated, substantially horizontally perpendicular, to the intended direction or operative travel of the implement that is indicated in several Figures of the drawings by an arrow A.It can be seen in Figure 3 of the drawings that the frame beam 1 is of hollow formation having an oblong, rectangular crosssection and being so disposed that the longer parallel sides of the rectangle are substantially vertical whilst the shorter parallel sides thereof are substantially horizontally parallel to one another and to the direction A (as seen in the cross-sectional view of Figure 3). Plates 2 whose compound shapes can be seen best in Figures 2 and 3 of the drawings are rigidly secured to the opposite ends of the frame beam 1 so as to be substantially vertically parallel to one another and to the direction A.It can be seen in Figures 2 and 3 of the drawings that the plates 2 are very approximately Z-shaped, each plate 2 including a substantially vertically disposed upward projection 3 that is located principally rearwards of the frame beam 1 with respect to the intended direction of operative travel A.

The two upward projections 3 form parts of corresponding substantially symmetrically identical parallelogram linkages 4 connecting an elongate hollow frame portion 5 to the frame beam 1 in such a way that said frame portion 5 can move upwardly and downwardly without significant tilting relative to said frame beam 1. The hollow frame portion 5 extends substantially horizontally parallel to the frame beam 1 at a location behind the latter with respect to the direction A and it will be seen from Figure 1 of the drawings that the two parallelogram linkages 4 by which said frame portion 5 is coupled to the frame beam 1 are located approximately, although not exactly, one quarter of the way along the length of the frame portion 5 from corresponding opposite ends thereto.When the implement is viewed from the rear in the direction A, the hollow frame portion 5 projects by substantially equal distances beyond the opposite ends of the frame beam 1 and is located at substantially the same horizontal level as the latter, the precise relationship between the levels of the beam 1 and frame portion 5 being dependent upon the angularity of the two linkages 4 at any time.

Figures 3 and 4 of the drawings show that the hollow frame portion 5 is of trapezoidal cross section comprising a lower channel-shaped part whose limbs are upwardly divergent and an upper closure plate that is parallel to the flat bottom of the lower part and that is firmly but releaseably secured to front and rear horizontal rims of the latter by a plurality of substantially vertically disposed bolts, a gasket being sandwiched between the edges of the closure plate and the upper surfaces of said rims.

The vertical heightofthe hollowframe portion Sis substantially, although not exactly, equal to the fore-and-aft width of its bottom and this gives said hollow frame portion 5 a high structural rigidity.

A plurality, of which there are sixteen in the example that is being described, of substantially vertical, or at least upwardly extending, shafts 6 are rotatablyjournalled in upper and lower ball bearings (see Figure 3) carried by the hollow frame portion 5 so as to lie in a single row with their longitudinal axes/axes of rotation parallel to one another and advantageously, but not essentially, spaced apart from one another at regular intervals of substantially 25 centimetres. The single row of rotary shafts 6 is, of course, parallel to the transverse length of the hollow frame portion 5 and each shaft 6 has a lower portion which projects downwardly from beneath the bottom of that frame portion 5 to carry a corresponding soil working member that is generally indicated by the reference 7.Each soil working member 7 has a central internally splined hub that co-operates with matching external splines on the lower portion of the corresponding shaft 6, said hub being firmly but releaseably secured to that lower shaft portion by known means which includes a washer and a nut furnished with a split pin or some other unit designed to prevent the nut from working loose. The nut co-operates with a short lowermost screw-threaded extremity of the corresponding shaft 6. The hub of each soil working member 7 forms the central part of a carrier 8 of that frame portion which carrier comprises two arms that project outwardly and downwardly from the hub at opposite sides of the latter.The outer end of each carrier arm is integrally or rigidly provided with a corresponding sleeve-like tine holder in which an upper fastening portion of a corresponding rigid metallic soil work ing tool in the form of a tine 9 is firmly but releaseably secured with the aid of a nut that co-operates with a screw-thread at the upper end of the fastening portion thereof which projects a short distance above a mouth at the top of the sleeve-like holder concerned. Each time 9 has a downwardly tapering soil working portion which penetrates into the ground to an adjustable extent when the imple ment is in use as shown in Figures 2 and 3 of the drawings.

At locations which are between the third and fourth soil working members 7 counting from either end of the hollow frame portion 5, the top of said frame portion 5 has the base edge of an upright substantially isosceles triangular plate 10 firmly but releaseably secured to it with the aid of correspond ing pairs of front and rearfeet 11 and 12, which feet are welded to the plates 10 whose general planes are substantially vertically parallel to one another and to the direction A. It will be seen from Figure 3 of the drawings that the plates 10 afford rear portions, with respect to the direction A, of the two parallelogram linkages 4, the base edge of each plate 10 extending throughout substantially the whole ofthefore-and- aft width of the top of the hollow frame portion 5.

Some of the same bolts as are employed to secure the closure plate of the hollow frame portion 5 to the lower part thereof also serve to fasten the front and rear feet 11 and 12 of the plates 10 to the top of said frame portion 5 and it will be noted from the drawings that the front feet 11 are of greater extent in the direction A than are the rear feet 12.

Four substantially horizontally disposed pivot bolts 13 turnably connect the leading and rear ends of the upper pairs of links 14to the two upward projections 3 and to the two triangular plates 10 and, similarly, further pivot bolts 13 turnably connect the opposite ends of lower pairs of links 15 to the same parts at a level spaced beneath that of the upper links 14. The upper and lower pairs of links 14 and 15 are, of course, parts of the corresponding parallelogram linkages 4.

A stop plate 16 is welded or otherwise rigidly secured to the leading upwardly inclined edge of each plate 10 at a location which is a short distance above the mid-point of that edge, each stop plate 16 being so disposed that it will prevent the hollow frame portion 5 from moving downwardly, relative to the frame beam 1, beyond substantially the position that is shown in Figure 3 of the drawings in which the lower edge of the illustrated stop plate 16 bears against the upper edges of the corresponding pair of lower links 15. The lower pairs of links 15 are of stronger formation than are the upper pairs of links 14 and it will be noted that each pair of lower links 15 is formed with aligned holes 17 (Figure 3) which holes will registerwith a single hole formed through the corresponding intervening plate 10.

When a horizontal locking pin is entered through the hole 17 and the hole in the intervening plate 10, the parallelogram linkage 4 concerned is rendered ineffective and the hollow frame portion 5 will then occupy a fixed position with respect to the frame beam 1. The locking pins in question are not shown in Figure 3 of the drawings but a careful inspection of Figure 1 thereof will show the oblique handles of the two removable locking pins installed in their operative positions. It will be noted from Figure 3 of the drawings that the upper and lower pivot bolts 13 which are at the rear ends of the upper and lower links 14 and 15 of each parallelogram linkage 4 have their substantially horizontal longitudinal axes contained in, or located very close indeed to, a substantially vertical plane which also contains the longitudinal axeslaxes of rotation of all of the rotary shafts 6. This arrangement enables forces resisting continued progress in the direction A of the revolving soil working members 7 to be resisted in a particularly advantageous manner which is such that bending and breakage is very considerably reduced, if not entirely eliminated.

The opposite ends of the hollow frame portion 5 are closed by corresponding strengthening side plates 18 of oblong configuration (Figure 2) which side plates 18 extend substantially vertically parallel to one another and to the direction A. Shield plates 19 whose symmetrically identical shapes can be seen best in Figure 2 of the drawings are also provided adjacent the opposite ends of the frame portion 5 and actually just beyond the opposite ends of the single row of rotary soil working members 7.

Each shield plate 19 co-operates with the immediately neighbouring rotary soil working member 7 in working the soil to the same thorough extent as is produced by co-operation between neighbouring soil working members 7 at locations closer to the centre of the implement. However, in addition, the shield plates 19 prevent the rapidly moving tines 9 from flinging stones and other hard objects laterally of the path of travel of the implement so that damage and injury which might otherwise be caused in this way is substantially eliminated.The lower edges of the shield plates 19 are shaped to slide forwardly over the ground surface in the direction A and each shield plate 19 is carried by a corresponding arm 20 that includes a portion which is mounted on top of the hollow frame portion 5 so as to be turnable about a corresponding substantially horizontal axis that is parallel or substantially horizontal axis that is parallel or substantially parallel to the direction A. This allows the shield plates 19 to move upwardly and downwardly to match undulations in the surface of the ground that may be met with during operative progress in the direction A and also enables each shield plate 19 to be turned upwardly and inwardly about the axis concerned through substantially 180 to reach an inoperative transport position in which it is inverted on top of the hollow frame portion 1.

The front of the hollow frame portion 5, with respect to the direction A, is provided at two locations which are mid-way between the second and third soil working members 7, counting from the opposite ends of the single row of such members 7, with corresponding pairs of upright support strips 21 whose upper oblique edges are rigidly intercon nected by horizontally extending tie strips 22 (Fig ures 1 and 4). The tie strips 22 are at the leading ends of the downwardly and rearwardly inclined upper edges of the two parallel but horizontally spaced apart support strips 21 of each pair and each such pair carries, towards the upper ends thereof, a respective pivot bolt 23 that is substantially horizontally parallel to the frame beam 1 and hollow frame portion 5. A lever 24 is turnably mounted on each pivot bolt 23 between the corresponding pair of support strips 21.The leading end of each lever 24, with respect to the direction A, projects a short distance in front of the respective support strips 21 alongside a much shorter strip 25 that projects substantially only forwardly from the pivot bolt 23 concerned in horizontally spaced apart relationship with the leading end of the lever 24 under consideration, a spacing sleeve being provided on the pivot bolt 23 to produce this spaced relationship. The leading end of each lever 24 and the neighbouring shorter strip 25 project forwardly in fork-like relation ship and have the upper end of a corresponding horizontal pivot pin 26 defining an axis that is substantially parallel to that of the aligned pivot bolts 23 and the longitudinal axis of the hollow frame portion 5.

Afurther pair of upright support strips 21 have a further carrying arm 27 pivotally connected to them in the same way at a location which is spaced a short distance to one side of the centre of the transverse length of the hollow frame portion 5 but, at this location, there is no lever 24 nor shorter strip 25. The lower ends of the three carrying arms 27 are all secured to a screen 28 that extends substantially horizontally parallel to the hollow frame portion 5 at a location immediately in advance of the rotary soil working members 7, with respect to the direction A, and at substantially the horizontal level of the carriers 8 of those members 7. The screen 28 extends throughout substantially the whole of the combined working width of the sixteen soil working members 7 that are provided in the example which is being described.The screen 28 (Figure 4) takes the form of a beam that is channel-shaped in crosssection, said channel having a flat substantially vertically disposed bottom from the opposite edges of which two limbs diverge steeply upwardly and rearwardly and downwardly and rearwardly, respectively, the lower limb being longer (as seen in cross-section) than the upper limb. The two limbs are strengtheningly interconnected towards their rear edges by a plate 29 that is substantially vertically parallel to the bottom of the channel portion of the screen 28. This formation of the screen 28 gives it a high degree of rigidity. A bracket 30 (Figure 4) is provided on each carrying arm 27 and the screen 28 at a location which is principally behind the arm 27 concerned with respect to the direction A.Each bracket 30 includes an upright portion 30A and a portion which extends substantially horizontally forwards from the portion 30A to be secured to a corresponding one of the carrying arms 27. The upright portion 30A of each bracket 30 normally bears rearwardly against a forwardly directed upright limb 32 of a stop bracket 31 that is fastened to the front of the hollow frame portion 5 at an appropriate position therealong by means which includes the bolts that secure the upper closure plate of the hollow frame portion 5 to the lower part thereof. Beneath its upright limb 32, each stop bracket 31 is bent over rearwardly to form a portion in perpendicular relationship with the inwardly and forwardly inclined front wall of the lower part of said frame portion 5. The upright limb 32 of each stop bracket 31 has a considerably greater vertical extent than does the upright portion 30A of the bracket 30 which bears against it and this arrangement allows such bearing contact to be maintained whilst the carrying arms 27 are displaced upwardly and downwardly using the levers 24.

As can be seen best in Figure 4 of the drawings, each outer pair of upright support strips 21 (but not the substantially central pair thereof) is formed with upper and lower pairs of aligned holes 34 and the corresponding lever 24 and shorter strip 25 is formed with holes that can register with either set of holes 34 depending upon the angular position of said level 24 and shorter strip 25 about the axis defined by the pivot bolts 23. A horizontal locking pin 33 is provided for entry through the holes in each lever 24 and the corresponding strip 25 and either the upper pair of holes 34 or the lower pair of holes 34 in the corresponding pair of support strips 21.

Thus, the screen 28 can be retained in either the lowered position illustrated in Figure 4 of the drawings or an alternative raised position. In the illustrated lowered position, the lower edges of the levers 24 and strips 25 bear against stop strips 35 which interconnect the two support strips 21 of each outer pair whereas, in the alternative raised position, the upper edges of the levers 24 and shorter strips 25 bear against the lower surfaces of the tie strips 22 which tie strips thus also afford a "stop" function.

Further holes may be provided to define at least one other "intermediate" position of the screen 28.

Each carrying arm 27 is formed, at a location a short distance above its mid-point, with a hole into which the leading end of a corresponding helical tension spring 36 is hooked. Each tension spring 36 extends substantially horizontally rearwards from the corresponding carrying arm 27 to have its rear end hooked into an eye 37 which eye is coupled adjustably to a corresponding bracket 38 bolted to the top and rear of the hollow frame portionS. Each eye 37 has a screw-threaded shank which is entered through a hole in an upright portion ofthe corres ponding bracket 38, said shank being provided at the side of that bracket portion which is remote from the corresponding spring 36 with a pair of nuts 39 which are adjustable lengthwise of said shank to increase or decrease the initial tension of the spring 36 concerned whilst being arranged to act normally in the well known manner of lock nuts. The pressure by which the brackets 30 normally bear rearwardly against the stop brackets 31 can be increased or decreased by increasing or relaxing the initial ten sion in the springs 36.Either the raised or the lowered position of the screen 28 may be adopted by the user of the implement having regard to the nature and condition of the soil that is to be dealt with and with a view to said screen 28 engaging stones and other hard objects and deflecting them downwardly into the soil to avoid damage to the carriers 8 of the soil working members 7 and the upper fastening portions of the tines 9. In addition, the screen 28, and particularly its plate 29, will co-operate with the rotating members 7 in crumbling the soil and will thus augment the crumbling action that is produced by co-operation between immedi ately neighbouring soil working members 7 them selves.Should a large stone or other hard object become momentarily jammed between at least one of the soil working members 7 and the rear of the screen 28, that screen 28 can deflect forwardly to allow release of the stone or other hard object, without damage, by turning about the axis defined by the pivot pins 26 against the adjustable restoring action of at least one of the tension springs 36. The ready deflectability of the screen 28, against the restoring action of the springs 36, is important to the efficient functioning of the implement having regard to the factthat said screen 28 extends, as a single unit, throughout substantiallythe whole of the relatively great working width of the implement.

Figure 7 of the drawings illustrates an alternative construction to that which has been described with particular reference to Figure 4, those parts that are illustrated in Figure 7 but which are similar or identical to parts that have already been described with reference to Figure 4 being indicated in Figure 7 by the same reference as are used in Figure 4 so that a repeated description thereof is rendered unnecessary. In the embodiment of Figure 7, the brackets 30 and co-operating stop brackets 31 are no longer employed.The front of the lower part of the hollow frame portion 5 is, instead, provided with a match inglyshaped bracket 41 at each of the locations which registers, in the direction A, with one of the carrying arms 27, each bracket 41 being releaseably secured in its appointed position by some of the bolts that fasten the top closure plate of the frame portion 5 to its lower part. Each bracket 41 carries an obliquely forwardly directed fork between the limbs of which an axle pin 42 is mounted so as to extend substantially horizontally parallel to the transverse length of the frame portion 5.Each axle pin 42 has a corresponding roller mounted thereon in a freely rotatable manner between the limbs of the corresponding fork and the front of each roller 40, with respect to the direction A, bears against a track strip 43 which is welded or otherwise rigidly secured to the rear edge of the carrying arm 27 concerned in perpendicular relationship with the general plane of that carrying arm 27.The upper end of each track strip 43 is bent over perpendicularly rearwardly from the corresponding carrying arm 27 to lie between the two supporting strips 21 of the corresponding pair so that, when the levers 24 are used to move the screen 28 upwardly or downwardly, the bent over ends of the track strips 43 move between the supporting strips 21 in the manner of guides or stops that prevent the screen 28 from being displaced to any significant extent in a lateral direction parallel to its own transverse length. The springs 36 act normally to maintain the track strips 43 firmly in contact with the rollers 40 but, as described above, forward deflection of the screen 28 is possible, against the restoring action of the springs 36, to release a momentarily jammed large stone or other hard object.

Lugs 44 project forwardly and upwardly from the frame beam 1 at locations spaced by short distances from the opposite ends of the latter, the flat lugs being substantially vertically parallel to one another, to the direction A and to the plates 2, each lug 44 being spaced by only a relatively short distance from a corresponding one of those plates 2. The leading downwardly inclined end of an arm 47 is turnably mounted between each lug 44 and the neighbouring plate 2 with the aid of a respective strong horizontal pivot 45 and a sleeve 46 which surrounds that pivot 45 in such a way that the arm 47 concerned lies alongside the lug 44 rather than the neighbouring arm 2. The two arms 47 extend generally rearwardly from the lugs 44 and arms 2 and a further pair of similar lugs 44 are mounted on the frame beam 1 at a short distance to one side of the mid-point of that frame beam, these further two lugs 44 having the leading end of a third arm 47 turnably mounted between them by a strong pivot that is in aligned relationship with the strong pivots 45. When the implement is viewed from the rear in the direction A, the pair of lugs 44 that has just been mentioned is located a short distance to the right of the mid-point of the frame beam 1.

The three arms 47 all extend generally rearwardly overthe hollow frame portion 5 from the pivotally mounted obliquely downwardly and forwardly inclined leading ends thereof. Each arm 47 comprises a straight and more or less horizontal portion that is of progressively increasing vertical width from front to rear, this portion integrallyterminating in a downwardly and rearwardly inclined portion. Thus, as seen in side elevation (Figure 2) each arm 47 is of shallow arched formation which leaves sufficient room beneath the central straight and more or less horizontally disposed portion thereof for the hollow frame portion 5 to move upwardly and downwardly relatived to the frame beam 1 without fouling said arms 47.

The rearmost extremity of each arm 47 is firmly but releaseably secured by four bolts 48 to a leading region of a corresponding plate 49. The central plate 49 is a little different in shape as compared with the outer plates 49 but the three plates 49 are substantially vertically parallel to one another and to the direction A, each of them being welded or otherwise rigidly secured to both an upper beam 50 and a lower beam 51. The upper beam 50 lies vertically above the lower beam 51, said beams 50 and 51 both extending throughout the length of the hollow frame portion 5 in substantially perpendicular, or at least transverse, relationship with the direction A.

The lower beam 51 is both substantially straight and substantially horizontal whereas the upper beam 50 is of inverted very shallow V-shaped configuration, said beam 50 thus comprising two straight limbs which diverge outwardly and downwardly from the mid-point of the beam (see Figure 5) in such a way that the distance between the two beams 50 and 51 at the ends thereof where they are interconnected by substantially vertical plates 52 (Figure 2) is significantly less than is the distance between them at their mid-points (Figure 5). Stay plates 53 strengtheningly interconnect the upper and lower beams 50 and 51 at intervals along the lengths thereof.The arms 47, beams 50 and 51 and associated parts afford a carrying assemblyfortwo axially aligned ground rollers 54 which, in the example that is being described, are both in the form of so-called "packer" rollers, the neighbouring ends of the two rollers 54 being closely adjacent to one another.

The mid-points of the upper and lower beams 50 and 51 are interconnected by a plate 55 which extends generally downwardly and forwardly from those beams with respect to the direction A in substantially vertically parallel relationship with that direction A. The lower leading end of the plate 55 has a support 56 of inverted U-shaped formation rigidly secured to it in such a way that the limbs of the support extend downwards in corresponding vertical planes from the curved base thereof whose convex surface is fastened to the plate 55. The two limbs of the support 56 are formed with aligned bearing holes in which corresponding stub shafts 57 at the neighbouring axial ends of the two rollers 54 are freely rotatably received with some clearance.

The holes in the limbs of the support 56 thus function as plain rotary bearings but could be provided with ball bearings or the like. The two stub shafts 57 are mounted on plates carried at the corresponding ends of hollow cylinders 58, of circular cross-section, whose outer surfaces are the curved surfaces of the rollers 54 that will bear against the ground when the implement is in use.

The opposite outer ends of the two rollers 54 are provided with bearing housings 59 (Figure 2) which housings 59 carry horizontal ball or other bearings which receive corresponding stub shafts 60 that are fastened to downwardly and forwardly inclined support plates 61 which are secured, in turn, to the plates 52 interconnecting the ends of the upper and lower beams 50 and 51 by groups of four bolts 62.

The outer surface of the cylinder 58 of each ground roller 54 is provided with a plurality of groups or crowns offlat-liketeeth 63, each group or crown being contained in a corresponding plane that is substantially vertically parallel to the other groups or crowns of the same roller 54 and to the direction A, the groups or crowns being spaced apart from one another at regular intervals along the axial length of each roller 54 (Figures 1 and 5). In the example which is being described, each group or crown of teeth 63 comprises ten of those teeth which are spaced apart from one another at regular 36 intervals around the longitudinal axis of the corresponding roller 54.

Scrapers 64 which are intended to prevent mud, clods of soil, root remnants and other crop debris from adhering to the rollers 54, and particularly from becoming jammed between their groups or crowns of teeth 63, are provided behind the rollers 54 with respect to the direction A at a level which is only a short distance above that of the ground surface (see Figure 2). The scrapers 64 are substantially oblong in shape and each of them has a leading edge which is located very closely adjacent to, but preferably not in actual contact with, the outer surface of the cylinder 58 of the corresponding roller 54 between two neighbouring groups or crowns of the teeth 63.The scrapers 64 are adjustably mounted on feet carried at the lower leading ends of downwardly and forwardly inclined carrier arms 65, the upper ends of these carrier arms 65 being secured by U-bolts 67 to plates 66 in groups of four, that is to say, each plate 66 has four arms 65 and thus four scrapers 64 fastened to it in such a way that the complete group can be angularly adjusted about the longitudinal axis of the lower beam 51 to bring the four scrapers 64 of that group either closer to, or further away from, the outer curved surface of the associated roller cylinder 58. Each plate 66 is of very shallow channel-shaped cross-section, the very short perpendicularly bent over limbs thereof being formed with concave recesses which match the convex curvature of the outer surface ofthe lower beam 51.To adjust each group of four scrapers 64, as a whole, relative to the corresponding roller cylinder 58, it is only necessary to loosen the nuts on the shanks of the corresponding four U-bolts 67 and to displace the group angularly in the required direction around the longitudinal axis of the lower beam 51. Re-tightening of the nuts will maintain the freshly adjusted position as long as may be required but, preferably, the nuts are not tightened to such an extent that a pointed stone or other object penetrating between one of the scrapers 64 and the surface of the corresponding cylinder 58 cannot deflect the corresponding group of four scrapers around the axis of the lower beam 51 against the frictional clamping action of the U-bolts 67 to prevent breakage or bending damage.

Horizontal bolts 46A (Figure 5) and surrounding spacing sleeve 68 secure the central one of the three arms 47 to a relatively parallel support plate 69 at a location towards the rearmost end of that arm 47, the support plate 69 being provided, at its front with respect to the direction A, with a horizontal pivot pin 70 (Figures 2 and 5) which connects the plate 69 to a forkatthe outer end of the piston rod of a hydraulic piston and cylinder assembly 71 which extends obliquely upwardly and forwardly from the pivot pin 70 to carry, at the upper leading end of its cylinder, a support 72 for a screw-threaded adjusting mechanism 73 comprising a manually operable crank handle at its upper leading end.The support 72 is turnably connected buy a horizontal pivot pin 74 to a bracket 75 which projects upwardly from the top of a horizontal beam 76 affording an upper part of a coupling member or trestle 77 by which the frame beam 1 of the implement can be connected to a three-point lifting device or hitch mounted at the rear of an agricultural tractor or other vehicle which both moves the implement in the direction A and oper ates the moving parts thereof. The hydraulic piston and cylinder assembly 71 is provided with hydraulic connections (not shown) for coupling it to the hydraulic system of the tractor or other vehicle which both moves and operates the implement.

The screw-threaded adjusting mechanism 73 acts, upon rotation of its screw-threaded spindle by turning the crank handle in an appropriate direction, to move a stop (not visible) either upwardly or downwardly inside the cylinder of the assembly 71, the adjustment being carried out to control the location to which the piston of the assembly 71 can move in the cylinder with this position correspond ing to a chosen horizontal level of the ground rollers 54 relative to that of the frame portion 5 and soil working members 7.Thus, an advantageous relative level with has been set for a particular cultivating operation can quickly be re-established, after, purely for example, an over-night stoppage, merely by extending the assembly 71 hydraulically until the piston thereof meets the adjustable stop, no re adjustment being necessary until a fresh job is to be undertaken under different conditions. It should be noted that it is the level of the ground rollers 54 relative to that of the frame portion 5 and soil working members 7 which principally governs the maximum depth of penetration of the tines 9 of the soil working members 7 into the soil which is possible.The opposite ends of the beam 76 of the coupling member or trestle 77 are connected to the top ofthe frame beam 1 by corresponding upright plates 78 (Figure 2) which plates are substantially vertically parallel to one another and to the direction A. The relatively remote sides of the two plates 78 are provided with strengthening supports 79 (Figure 2) whose lower ends are secured to the top of the frame beam 1.Shaped lower leading portions of the plates 78 substantially match the shapes of parallel and closely neighbouring plates 80 (Figure 2) and each pair of plates 78/80 affords a lower coupling point of the three-point coupling member or trestle 77, the single central upper coupling point thereof being afforded by two parallel spaced apart plates 81 (Figures 1 and 2) which surround the upper horizontal beam 76 at a location substantially mid-way along the transverse length of that beam 76. Figures 1 and 2 of the drawings somewhat diagrammatically illustrate the way in which the free ends of the upper and lower lifting links ofthethree-point lifting device or hitch at the rear of an agricultural tractor or other operating and moving vehicle are turnably connected to the two lower coupling points and single upper coupling point which have just been discussed.

A fork 82 (Figure 5) is provided at that side of the support plate 69 which is remote from the neighbouring and parallel central arm 47 and one end of an elongate lateral stabilizer 84 is turnably mounted between the limbs of the fork 82 by a pivot pin 83.

The stabilizer 84, which is adjustable in length, is loosely and therefore universally movably connected to the fork 82 by the pivot pin 83 and extends from the fork 82 towards the right end of the implement when the latter is viewed from the rear in the direction A, the opposite end of the stabilizer 84 being loosely and therefore universally movably connected by a pivot pin 85 to a forked bracket 86 mounted atthe rear of the hollow frame portion 5 very close to the right end of that frame portion when the implement is again viewed in the direction which has just been mentioned.A second but much shorter stabilizer 87 which is again adjustable in length loosely interconnects a forked bracket 88 carried by the coupling member or trestle 77 adjacent the bottom thereof and a further forked bracket 89 at the rear of the frame beam 1, the second stabilizer 87 extending to the left from the coupling member or trestle 77 when the implement is viewed from the rear in the direction A and having a maximum length which is only approximately one third of that of the first-mentioned stabilizer 84.

Each shaft 6 is provided, inside the hollow frame portion 5, with a corresponding straight- or spurtoothed pinion 90, the size of each pinion 90 being such that its teeth are in mesh with those of the or each immediately neighbouring pinion 90 in the single row of sixteen, in this embodiment, such pinions. One of the centre pair of shafts 60 in the single row of sixteen shafts has an upward extension into a speed-reducing gearbox whose rotary input shaft, in turn, extends into a gearbox 91.Shafts and bevel pinions inside the gearbox 91 indirectly place the upward extension of the shaft 6 mentioned above in driven connection with a rotary input shaft 93 of the gearbox 91 which shaft 93 projects substantially horizontally forwardly from the front of the gearbox 91 and is splined or otherwise keyed to enable it to be placed in driven connection with the rear power take-off shaft of the tractor or other vehicle which is to move and operate the implement by way of an intermediate telescopic transmission shaft 94, which is of a construction that is known per se, having universal joints at its opposite ends. The rear of the gearbox 91, with respect to the direction A, is provided with a change-speed gear 92 whose construction is not illustrated in detail since it does not form the subject of the present invention.It suffices to say that two splined or otherwise keyed shafts project into the change-speed gear 92 and carry a pair of meshing straight- or spur-toothed pinions whose sizes establish a pre-determined transmission ratio between the two shafts concerned. The change-speed gear 92 has a readily removable cover and the pinions which have just been mentioned can be interchanged on the shafts, or be exchanged for another pair of co-operating pinions of different sizes, to change the transmission ratio between the two shafts. Thus, the speed at which the soil working members 7 will all be rotated can be increased or decreased without having to alter the speed of driving rotation that is applied to the rotary input shaft 93 of the gearbox 91 from the rear power take-off shaft of the operating tractor or other vehicle.It will be seen from Figure 1 of the drawings that the shaft 93 which protrudes from the front of the gearbox 91 also protrudes from the rear of the change-speed gear 92 to enable it to be used as a source of rotary power for the moving parts of some other implement, machine or tool that may be coupled to the rear of the soil cultivating implement, for use in combination therewith, in a manner which will be described below. Such implement, machine or tool might be, for example, a seed drill or a planting machine.

The tops of the two upright plates 78 of the coupling member or trestle 77 have the leading ends of corresponding upper arms 95 turnably connected to them by aligned strong pivots 96 which define a substantially horizontal axis that is parallel or substantially parallel to the frame beam 1, said arms 95 extending more or less horizontally rearwards from the pivots 96 to locations in rear regions of the implement. The same upright plates 78 also have the leading ends of corresponding lower arms 97 connected to them by horizontally aligned strong pivots 98 which define an axis that is parallel to the axis of turnability of the upper arms 95 which is defined by the aligned pivots 96. The pivots 98 are mounted in the upright plates 78 at locations spaced upwardly and rearwardly from the top of the frame beam 1 (see Figure 2).The arms 97 again extend more or less horizontally rearwardly from their pivots 98 for approximately the sme distance as do the upper arms 95, the pair of upper arms 95 being rigidly and transversely interconnected, towards their rear ends by a horizontal beam 99 of hollow formation and circular cross-section. Similarly, the pair of lower arms 97 is rigidly and transversely interconnected by a horizontal beam 100. However, in this case, the hollow beam 100 is of oblong (see Figure 2), or alternatively square, cross-section and interconnects the extreme rear ends of the two arms 97 rather than being spaced forwardly from those extreme rear ends as is the hollow beam 99 in relation to the upper pair of arms 95.

The rearmost ends of the two lower arms 97 are bevelled inwardly (Figure 1) and, at the locations of their junctions with the interconnecting hollow beam 100, have the upper leading ends of corresponding downwardly and rearwardly inclined brackets 101 fastened to them. A coupling mechanism 104 is turnably connected by horizontal aligned pivots 102 to the rear ends of the upper arms 95 and by aligned parallel pivot bolts 103 to the lower rear ends of the brackets 101. As can be seen best in Figure 6 of the drawings, the coupling mechanism 104 is of basically rectangular configuration including an upper horizontal beam 105 of angular, and preferably square, cross-section which extends substantially parallel to the frame beam 1.Two beams 106 of the same cross-sectional shape and size as the beam 105 extend downwardly and more or less rearwardly from the opposite ends of the beam 105 in parallel relationship with one another, the lower ends of the beams 106 being secured to bevelled plates and further relatively parallel portions of these plates being turnably connected to the respective brackets 101 by the pivot bolts 103.

Lugs 107 surround the opposite ends of the beam 105 and portions thereof project forwardly, with respect to the direction A, and actually establish the pivotal connections, by way of the aligned pivots 102, to the rear ends of the upper arms 95 (see Figure 2). The plates at the lower ends of the beams 106, and the brackets 101, are turnably connected to the upper ends of rearwardly directed hooks 108 by the respective aligned pivot bolts 103 and these hooks 108 afford the two horizontally spaced apart lower coupling points of a three-point lifting device or hitch of the implement itself which is afforded by the coupling mechanism 104.The single upper coupling point of this lifting device or hitch is afforded by a pair of substantially vertically parallel, but horizontally spaced apart, plates 109 which surround a central region of the beam 105 and project downwardly and forwardly therefrom (Figure 2), the downwardly and forwardly projecting portions being formed with horizontally aligned holes through which an upper coupling pin can be entered.

The construction and arrangement of the three-point lifting device or hitch of the implement itself is such that a further implement, machine or tool which may be mounted behind the soil cultivating implement is located as close as possible to the latter thus facilitating a compact disposition of the complete combination.

The hollow beam 99 which transversely interconnects the upper pair of arms 95 towards their rearmost ends carries two forwardly projecting lugs 110 at locations spaced by equal short distance from its opposite ends. Each lug 110, and the corresponding upper arm 95, is formed with a relatively short axially extending slot 112 (Figure 2) and each such pair of slots has a horizontally pivot pin 111 entered horizontally therethrough in perpendicular relationship with the lengths of the arms 95 and lugs 110 and in such a way as to be movable lengthwise along the slots 112 concerned.Each pivot pin 111 is surrounded by a sleeve (see Figure 1) at the free end of the piston rod of a corresponding fluid pressureoperated piston and cylinder assembly 113, the leading lower end of the cylinder at each assembly 113 being turnably connected to a shoulder of the corresponding upright plate 78 by a strong horizontally disposed pivot 114. It will be noted that the axis defined by the two horizontally aligned strong pivots 114 is located at substantially the same horizontal level as is the bottom of the beam 76.

The pivots 96 by which the upper arms 95 are turnably connected to the upright plates 78 of the coupling member or trestle 77 also have corresponding latches 115 turnably mounted on them, the latches 115 being located at the relatively remote or outer sides of the upright plates 78 and upper arms 95. The rear end of each latch 115, with respect to the direction A, is formed with a jaw whose shape can be seen in Figure 2 of the drawings and each such jaw is arranged to co-operate retainingly with a corresponding pin 116 that projects horizontally from the outer side of the corresponding lower arm 97. As can be seen in Figure 2 of the drawings, the pins 116 are mounted on the lower arms 97 at locations which are short distances to the rear of the mid-points of those arms.The latches 115 project short distances forwardly of the pivots 96 and these forwardly projecting portions are formed with holes 117 into which extend, with sufficient clearance to allow limited turning movements of the latches 115 about the pivots 96, corresponding stop pins 118. Each latch 115 has the end of a cable or other flexible but inextensible operating member 119 connected to it at a point spaced from the corresponding pivot 96, the members 119 extending to locations on the agricultural tractor or other vehicle that moves and operates the implement and these locations being readily accessible to the driver of that tractor or other vehicle so that, upon pulling them forwardly, the latches 115 will be raised to the extent that is allowed by the co-operation between the holes 117 and stop pins 118 which is sufficent to disengage the latch jaws from the pins 116 on the lower arms 97.

In the use of the soil cultivating implement that has been described in preparing a seed bed, its coupling member or trestle 77 is connected to the three-point lifting device or hitch at the rear of a tractor or other operating vehicle using the lower plates 88 and the upper plates 81 for that purpose.

The rotary input shaft 93 of the gearbox 91 is placed in driven connection with the rear power take-off shaft of the same tractor or other vehicle using the known telescopic transmission shaft 94 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 two ground rollers 54 relative to that of the frame portion 5 and soil working member 7 using the hydraulic piston and cylinder assembly 71, powered from the hydraulic system of the tractor or other operating vehicle, for that purpose, remembering that the adjusting mechanism 73 can be set, as described above, to enable any chosen bodily level of the rollers 54 to be quickly and easily regained after work has been discontinued for a time.The speed at which the soil working members 7 will all revolve in response to a more or less standard speed of rotation applied to the rotary input shaft 93 of the gearbox 91 can be changed, if required, by altering the transmission ratio established in the changespeed gear 92. These adjustments will usually be made having regard to the nature and condition of the soil that is to be dealt with and the particular purpose for which that soil is required after its cultivation. Periodic checking of the position of the scrapers 64 is also required to ensure correct operation of the implement. As the implement moves operatively in the direction A, the maximum depth of penetration of the tines 9 of its soil working members 7 into the soil which is possible is governed by the bodily level of the "packer" ground rollers 54 relative to that of said soil working members 7.Each pinion 90, shaft 6 and soil working members 7 will revolve, due to the inter-meshing arrangement of the pinions 90, in the opposite direction to the or each immediately neighbouring similar assembly as shown by small arrows for most of these assemblies in Figure 1 of the drawings and the distance between the two tines 9 of each member 7 is such that the strips of ground, extending in the direction A, that are worked by the individual members 7 overlap, or at least adjoin, one another to produce a single broad strip of worked soil extending in the direction A.With the preferred distance of substantially 25 centimetres that has been discussed above between the axes of rotation of immediately neighbouring members 7, this single broad strip of worked soil will have a width of substantially, although not necessarily exactly, four metres in the case of the implement that is being described. Greater or smaller working widths could be produced by increasing or decreasing the number of soil working members 7 in the single row thereof and a construction in accordance with the invention is particularly advantageous for an implement having a relatively large working width of substantially three metres or more.

Upon temporary removal of the locking pins 33, the screen 28 can be moved either upwardly or downwardly in accordance with either the construction described with reference to Figure 4 or that described with reference to Figure 7 of the drawings to enable, depending upon the chosen working depth, the screen 28 to occupy substantially an optimum protective position for the upper parts of the soil working members 7. The levers 24 by which, after removal of the locking pins 33, the screen 28 is moved upwardly or downwardly may, as an alterna tiveto what has been described and illustrated, be arranged to project forwardly with respect to the direction A rather than rearwardly thereof.

As already mentioned, a construction in accordance with the invention is particularly advantageous for implements having a relatively large working width of substantially three metres or more. The carrying frame which is afforded principally by the frame beam 1 is considerably shorter in axial length than is the hollow frame portionS, preferably having a length which is approximately half that of said frame portion 5. The beam 1 provides supportforthe hollow frame portion 5 in a manner which adds very considerably to the rigidity of the latter in a particularly simple manner that is economic as regards both material and weight.As the implement is moving operatively in the direction A, the hollow frame portion 5 can move or "float" upwardly and downwardly relative to the frame beam 1 through the intermediary of the dual parallelogram linkage 4 and is sustained from the ground surface by the immediately following closely adjacent ground rollers 54. The carrying assemblyforthe rollers 54 which compriss the arms 47 and the upper and lower beams 50 and 51 sustains the carrying frame in a most effective manner which tends to distribute reaction forces exerted upon the implement during its operation in a way which makes breakge or bending damage a very rare occurrence indeed.The simple bearing arrangement at the neighbouring ends of the two ground rollers 54 allows sufficient bodily movement of those rollers to take place to accommodate local ground irregularities and the like without significant disturbance to the cultivating operation. The power-operated bodily displacement of the rollers 54 by the hydraulic piston and cylinder assemby 71 mades any adjustment both quick and easy to perform and the use of the adjusting mechanism 73 makes it possible rapidly to regain any advantageous setting after an interruption to work whilst also furnishing means by which the assembly 71 is prevented from having to resist all of the jolting and other forces to which it would otherwise be subject during the use of the implement.

Figures 8 and 9 of the drawings illustrate an alternative soil cultivating implement in accordance with the invention which is similar in many respects to the implement that has already been described but that, instead of comprising two separate and substantially coaxial ground rollers 54, is sustained from the ground surface by a single ground roller 54A which extends throughout the combined working width of all of the soil working members 7. Those parts of the implement of Figures 8 and 9 of the drawings which are similar, or identical, to parts that have already been described are indicated by the same references as are used in Figures 1 to 7 of the drawings and will not be described in detail again.

The ground roller 54A of this embodiment is an open-work, cage-formation roller comprising a plurality of regularly spaced apart support plates that are substantially vertically parallel to one another and to the direction A, the shape of one such support plate being visible in Figure 8. A plurality, of which there are seven in the embodiment that is being described, of tubular, or alternatively rod-formation, elongate elements 54B interconnected the peripheries of the support plates at regularly spaced apart angular intervals around the central longitudinal axis/axis of rotation of the roller 54A and preferably, as can be seen in Figure 9, the elements 54B are wound helically around that central axis of the roller to some extent.When a single roller, suh as the roller 54A, is used in an implement of relatively large working width and is also temporarily combined with a rear-mounted further implement, machine or tool, such as a heavy potato planting machine, the forces acting on the single roller 54A during operative progress in the direction A reach such magni tudesthatacentral un-supported region of the roller tends to be deflected upwardly either flexibly or by bending and this is, of course, most undesirable.

Accordingly, in order to prevent such upward deflection occurring to any significant extent, a stop baffle 122 is provided substantially centrally along the axial length of the roller 54A.

A curved plate 124 is connected to both the upper beam 50 and the lower beam 51 by a shaped plate 123 whose lower concave edge is spot-welded or otherwise secured to the matchingly shaped convex side of the curved plate 124, by a substantially vertical clamping plate 120 whose leading surface is centrally secured to the rear upright edge of the shaped plate 123, and by upper and lower pairs of U-bolts 121 that clampingly embrace the upper and lower beams 50 and 51 in such a way that their screw-threaded shanks are provided with nuts which bear against the leading surface of the clamping plate 120 with the nuts corresponding to one U-bolt of each pair located at one side of the shaped plate 123 whilst those corresponding to the other U-bolt of the same pair are located at the opposite side of the plate 123.The substantially vertically disposed shaped plate 123 is parallel or substantially parallel to the direction A and the curved plate 124 that is fastened in its arcuately recessed lower edge has its centre of curvature co-incident with the axis of rotation of the roller 54A and subtends an angle of 180", or marginally less than 180 , at that axis of rotation. As can be seen in Figure 8 of the drawings, the lower concave surface of the curved plate 124 is normally just clear of contact with the elongate elements 54B of the roller 54A during rotation of the latter.

If, during operation, the roller 54A should be heavily loaded as briefly discussed above, its central region may be flexed upwardly but, when this occurs, the curved plate 124 of the stop baffle 122 will bear against the upwardly deflected central region of the roller 54A and will prevent any further upward deflection, to such an extent that permanent bending might result, whilst still allowing rotation of the roller in an anti-clockwise direction as seen in Figure 8 of the drawings with the successive elongate elements 54B sliding around the concave surface of the plate 124. Thus, the roller 54A will continue correctly to control the working depth of the implement whilst maintaining its normal rotation.

Figure 10 of the drawings again shows the provision of the stop baffle 122 but, in this case, the roller 54A with which it co-operates is of similar construction to each of the previously described rollers 54 except that the roller 54A of Figure 10 is a single roller extending throughout the combined working width of the soil working members 7 of the implement. With this construction, the relatively narrow curved plate 124 of the stop baffle 122 normally closely partially surrounds the cylinder 58 of the roller 54A and is disposed between two groups or crowns of teeth 63 carried by that cylinder 58. The corresponding scraper 64 may, if desired, be omitted since, at this single location, the stop baffle 122 itself will act to shed mud and lumps of soil from between the groups or crowns of teeth 63 under consideration.

The longer and shorter stabilizers 84 and 87 which have been described above act substantially to prevent, during operation of the implement, uncontrolled upward and downward movements of the hollow frame portion 5 and the soil working members 7 and also any tendency to lateral displacements and/or tilting thereof, this ensuring that the members 7 will perform their cultivating function in a uniform manner without disturbance. Since both stabilizers 84 and 87 are adjustable in length, their stabilizing effect upon upward and downward movements of the frame portion 5 and soil working members 7 can be increased or decreased as may be considered necessary having regard to the work that is to be carried out.It will be remembered that horizontal locking pins can be entered in the holes 17 (Figure 3), when required, to fix the hollow frame portion 5 and soil working member 7 bodily in position relative to the frame portion 1 when required, for example, for inoperative transport purposes. The three-point coupling mechanism 104 at the rear of the implement itself is most effective in enabling an additional implement, machine or tool, such as a seed drill or planting machine, to be temporarily coupled to the soil cultivating imple mentfor use in combination therewith, such additional implement, machine or tool having a sufficient freedom of movement relative to the soil cultivating implement because the dual rollers 54 are, or the single roller 54A is, located in advance of the carrying assembly thereof that is afforded by the upper and lower beams 50 and 51 and since the rear ends of the straight arms 97 are effectively prolonged downwardly and rearwardly by the brackets 101.

The piston and cylinder assemblies 113 have their rear ends coupled to the upper arms 95 by the hollow beam 99, the lugs 110 and the pivot pins 111 which are movable lengthwise of the short slots 112.

Extension or retraction of the piston rods of said assemblies 113 enables the coupling mechanism 104 to be smoothly raised or lowered using the hydraulic system of the tractor or other operating vehicle and controls accessible to the driver of that tractor or other vehicle. When raising the coupling mechanism 104, the pins 116 eventually enter the jaws of the latches 115 and, after hydraulic pressure is withdrawn, the latches 115 remain engaged and the coupling mechanism 104 is disposed principally over and above the remainder of the implement where its loading effect upon the three-point lifting device or hitch of the operating tractor or other vehicle is minimised as far as possible during operations such as raising the implement from the ground and subsequently performing inoperative transport thereof.When the coupling mechanism 104 is again required for use, the cables or the like affording the operating members 119 are pulled forwardly from the driving cabin or driving seat of the tractor or other vehicle which action lifts the latches 115 to disengage the pins 116 therefrom. If ,the hydraulic controls are then set to allow drainage of the hydraulic pressure medium in advance of the pistons of the two assemblies 113, the mechanism 104 will gently return to substantially the position illustrated in Figure 2 of the drawings under the action of gravity alone. The co-operation between the holes 117 and the stop pins 118 maintains the latches 115 in the positions in which they will engage the pins 116 when so required.

If desired, the flexible but inextensible cables or the like which afford the operating members 119 may be replaced by cables or the like having some degree of elasticity to ensure that the pins 116 will be released from the jaws of the latches 115 very easily.

As a further alternative which is shown in Figure 8 of the drawings, the cables or the like which afford the members 119 may remain flexible but inextensible but may include in their lengths helical tension springs 11 9A or alternative short lengths of a strong but elastic material such as natural or artificial rubber. With one of these arrangements, the latches 115 can be disengaged from the pins 116 by applying hydraulic pressure to the assemblies 113 for a very short period of time, this effectively "shaking" the pins 116 free of the jaws of the latches 115.

Although certain features of the soil cultivating implement embodiments that have been described and/or that are shown in the accompanying drawing will be set forth in the following description as inventive features, it is emphasized that the invention is not necessarily limited to those features and that it includes within its scope each of the parts of each soil cultivating implementembodimentthat has been described, and/orthat is illustrated in the accompanying drawings, both individually and in various combinations.

Claims (24)

1. A soil cultivating implement of the kind set forth, wherein said carrying frame comprises a single frame beam whose opposite ends are located, when the implement is viewed from the rear in its intended direction of operative travel, between the opposite ends of said hollow frame portion.

2. An implement as claimed in claim 1, wherein the length of said frame beam of the carrying frame is substantially half that of the hollow frame portion.

3. An implement as claimed in claim 1 or 2, wherein at least one ground roller is arranged to the rear of said soil working members, with respect to the intended direction of operative travel of the implement, and is pivotally connected to said single frame beam by arms which extend over the hollow frame portion.

4. An implement as claimed in claim 3, wherein two ground rollers are provided in side-by-side approximately coaxial relationship with one another, the neighbouring axial ends of said two ground rollers being freely rotatably carried by a support formed with openings in which shafts projecting from said axial ends of the rollers arejournalled so as to be bodily movable, as well as rotatable, in the openings.

5. An implement as claimed in claim 4, wherein said roller support is of substantially inverted Ushaped configuration, the limbs of the U being directed downwardly and each of them being formed with one of said openings.

6. An implement as claimed in claim 3, wherein a single ground roller is provided that extends substantially throughout the combined working width of said soil working members, the single ground roller being rotatably supported at substantially its opposite ends and a stop baffle being provided in register with substantially the axial mid-point of the roller to co-operate with the roller, when required, to prevent significant deformation of the latter due to heavy loading.

7. An implement as claimed in claim 6, wherein said stop baffle is secured to a carrying assembly of the single roller.

8. An implement as claimed in claim 6 or 7, wherein said stop baffle comprises an arcuately shaped member whose centre of curvature substantially coincides with the longitudinal axis of the single roller and which subtends an angle of substantially 180 at the axis.

9. An implement as claimed in claim 8, wherein the arcuately shaped member is in the form of an elongate curved plate whose width is parallel or substantially parallel to the longitudinal axis of the single roller.

10. An implement as claimed in claim 3 or in any one of claims 4 to 9 when read as appendant to claim 3, wherein a fluid pressure-operated piston and cylinder assembly is provided to set the bodily level of the or each ground roller relative to that of said hollow frame portion, said assembly also being provided with a stop whose position is adjustable to govern the length of the stroke of the piston of that assembly.

11. An implement as claimed in any preceding claim, wherein the hollow frame portion is upwardly and downwardly displaceable relative to the single frame beam, and wherein stabilizers interconnect said hollow frame portion and the single frame beam, the stabilizers extending generally lengthwise of the latter.

12. An implement as claimed in claim 11, wherein two stabilizers are provided which are located at opposite sides of the mid-point of said hollow frame portion, one stabilizer interconnecting the front of that hollow frame portion, with respect to the intended direction of operation travel of the implement, and said single frame beam whilst the other stabilizer interconnects a carrying assembly, or said carrying assembly, for at least one ground roller, or said at least one ground roller, and the rear of the hollow frame portion with respect to the same direction.

13. An implement as claimed in claim 11 or 12, wherein the ends of the stabilizers are universally movable relative to the parts to which they are connected, and wherein the length of each stabilizer is adjustable.

14. An implement as claimed in claim 12 or in claim 12 and claim 13, wherein the stabilizer which is connected to the front of the hollow frame portion is pf shorter axial length than is the stabilizer connected to the rear thereof.

15. An implement as claimed in any preceding claim, wherein each soil working member comprises a carrier for at least one soil working tool of that member and, in front of said carriers with respect to the intended direction of operative travel of the implement and at substantially the same horizontal level as those carriers, a screen is provided which extends substantially horizontally perpendicular, or at least transverse, to said intended direction of operation travel, the screen being upwardly and downwardly adjustable in position relative to the carriers by at least one lever.

16. An implement as claimed in claim 15, wherein the or each lever is pivotable about an axis which is located above the hollow frame portion, the or each lever being movable about said axis between at least two different positions and means being provided to retain it in any chosen one of those positions.

17. An implement as claimed in claim 16, wherein said screen is mounted on upright carrying arms which arms are pivotally connected to said lever or levers in front of the fulcrum or fulcrums thereof with respect to the intended direction of operative travel of the implement.

18. An implement as claimed in any one of claims 15to 17, wherein said screen comprises brackets arranged to co-operate movably with corresponding stop brackets mounted on the front of said hollow frame portion with respect to the intended direction of operative travel of the implement.

19. An implement as claimed in claim 18, wherein resilient means is provided to urge said stops resiliently into engagement with said stop brackets.

20. An implement as claimed in claim 18 or 19, wherein each stop bracket includes a roller arranged to bear rotatably against the corresponding bracket.

21. An implement as claimed in any preceding claim, wherein said single frame beam has connected to it a coupling mechanism for temporarily connecting to the soil cultivating implement an additional implement, machine or tool that is to be used in combination therewith, said coupling mechanism including arms which extend rearwardly from said single frame beam to locations which are behind a ground roller or ground rollers, or behind said ground roller or ground rollers, with respect to the intended direction of operative travel of the implement, and wherein said coupling mechanism defines a three-point lifting device or hitch of the implement itself and includes upper and lower pairs of arms and members transversely interconnecting the upper pairs of arms and the lower pairs of arms.

22. An implement as claimed in claim 21, wherein each upper pair of arms is connected to a corresponding fluid pressure-operated piston and cylinder assembly employable to turn said arms upwardly.

23. An implement as claimed in claim 21 or 22, wherein as seen in side elevation, the upper and lower pairs of arms and a generally upright portion of the coupling mechanism are pivotally interconnected and form sides of a pivotable quadrilateral linkage.

24. A soil cultivating implement of the kind set forth, substantially as hereinbefore described with reference to any of the embodiments that are illustrated in the accompanying drawings.