GB2155295A - Soil cultivating implements - Google Patents

Abstract

In a soil cultivating implement of the kind comprising a row of power-drivable rotary soil working members 3 that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel A of the implement, an elongate longitudinal element 13 which is parallel to said row lies in front of carriers 4 of soil working tools 5 of those members 3 at substantially the same horizontal level as the carriers 4. The longitudinal element 13 is fixedly secured (11,12) to a frame portion 1 of the implement and the rear of the element 13, which faces the members 3, is of resilient formation 14. This allows the resilient material 14 to compress forwardly to release a momentarily jammed stone or other hard object without damaging the element 13 or any soil working member 3. <IMAGE>

Description

SPECIFICATION Soil cultivating implements This invention relates to soil cultivating implements or machines, such as rotary harrows, of the kind which comprise a row of soil working members that extends substantially horizontally perpendicular, or at least transverse, to the intended direction of operative travel of the implement or machine with each soil working member power-rotatable about a substantially vertical, or at least upwardly extending, axis and exhibiting a carrier supporting at least one downwardly projecting soil working tool, and there being an elongate longitudinal element arranged in advance of the soil working members with respect to said direction of travel and at substantially the same horizontal level as that of the soil working member carriers, the implement or machine also comprising means which will allow the longitudinal element to be temporarily displaced from its normal operative position at any time during the use of the imple ment or machine. The term "implement(s) or on ma- chine(s)" is shortened to "implement(s)" alone throughout the remainder of this document for the sake of brevity.

In the use of implements of this known kind, the longitudinal element co-operates with the immediately following rotary soil working members in crumbling the soil to produce, for example, a good seedbed in which the well crumbled soil is uniformly distributed throughout the working width of the implement. The longitudinal element engages stones and other hard objects brought to the ground surface by the implement, or already lying upon that surface, and urges them downwardly into the soil. Any stone or the like which nevertheless becomes momentarily jammed between the element and at least one rotating soil working member being prevented from causing damage the element and/or to the carrier(s) and its/their tool(s) by virtue of the displacability of the element which allows it to move forwardly for a moment and facilitate release of the stone or the like without any bending or breakage of implement parts.

Known constructions necessitate extra provisions being made on the implement frame, which extra provisions raise the cost of production of the implement. Accordingly, an object of the invention is to maintain the aforementioned functions of the longitudinal element without the need for extra provisions on the implement frame.

In accordance with the invention, there is provided a soil cultivating implement of the kind set forth, wherein the rear of the longitudinal element, which faces said soil working members, is of resilient formation.

By this construction of the longitudinal element, the rear thereof is able, due to its flexibility, to cooperate effectively with the rotating soil working members during operation, whilst, at the same time, there remains the facility of being able to release a momentarily trapped stone or the like.

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, and Figure 2 is a section, to an enlarged scale, taken on the line ll-ll in Figure 1.

The soil cultivating implement which will be described, and that is illustrated in the accompanying drawings, is intended primarily, but not exclusively, for use in preparing seedbeds from previously worked soil in which seedbeds seeds can germinate and, after appropriate thinning of the seedlings, if required, can grow on to maturity. Referring now to the accompanying drawings, the soil cultivating implement that is illustrated therein is in the form of a rotary harrow and comprises a hollow box-section frame portion 1 of elongate configuration whose longitudinal axis extends substantially horizontally transverse and usually, as illustrated, substantially horizontally perpendicular, to the intended direction of operative travel of the implement that is indicated by an arrow A. A plurality, of which there are twelve in the example that is being described, of substantially vertical, or at least upwardly extending, shafts 2 are rotatably journalled in bearings carried by upper and lower walls of the frame portion 1 so as to lie in a single row that is parallel to the transverse length of the hollow frame portion 1, the longitudinal axes/axes of rotation of the twelve shafts 2 being parallel to one another and being spaced apart at regular intervals which advantageously, but not essentially, each have a magnitude of substantially 25 cms.

Each shaft 2 projects downwardly from beneath the bottom of the hollow frame portion 1 and is there provided with a corresponding soil working member that is generally indicated by the reference 3 (Figure 2). Each soil working member 3 comprises a substantially horizontally disposed support or carrier 4 defining arms that project in diametrically opposite directions from the shaft 2 concerned and whose outer ends have fastening portions of corresponding soil working tools in the form of rigid tines 5 firmly but releasably secured to them by means which includes corresponding pairs of bolts. The lines 5 have soil working portions which are of downwardly tapering formation and these portions project into the ground, when the implement is in use, to an extent that 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. Upper leading portions of the two side plates 6 are provided with horizontally aligned pivots 7 about which respective arms 8 are upwardly and downwardly turnable alongside said plates and against the surfaces of those plates 6 which face the centre of the implement. Each arm 8 extends generally rearwardly, with respect to the direction A, from the corresponding pivot and is of a downwardly and rearwardly offset construction (not visible in the drawings) towards the rear end thereof which projects well behind the frame portion 1 with respect to the direction A. Substantially the rearmost and lowermost ends of the two arms 8 carry substantially horizontally aligned bearings in which stub shafts at the opposites ends of a ground roller 9 are received in a freely rotatable manner. The construction of the ground roller 9 is not the subject of the present invention but said roller is advantageously of cylindrical shape and an open-work, cage-like construction exhibiting a plurality of elongate rods that extend helically around the longitudinal axis of the roller 9 so as principally to define its skeletal ground-engaging surface. Rear portions of the two side plates 6 that project behind the remainder of the frame portion 1 with respect to the direction A are formed with curved rows of holes with the centre of curvature of each row coinciding with the substantially horizontal axis that is defined by the aligned pivots 7. Each arm 8 is formed with at least one hole at the same distance from that axis and, upon bringing the holes, or chosen holes, in the arms 8 into register with chosen holes in the rear portions of the side plates 6 by turning the arms 8 upwardly or downwardly about the pivots 7, bolts 10 can be entered horizontally through the aligned holes and be tightened to retain the ground roller 9 at a corresponding bodily level relative to that of the frame portion 1 and rotary soil working members 3 as long as may be required. It will be realised that the implement bears upon the ground principally by way of the roller 9 so that it is this bodily level which is the major factor in determining the maximum depth of penetration of the tines 5 into the soil that is possible whilst the implement is in operation.

The front of the frame portion 1, with respect to the direction A, is provided at two locations with corresponding forwardly directed supports 11, said locations being mid-way between the second and third soil working members 3 counting from either end of the single row thereof when the implement is viewed in the direction A.

A carrier 12 projects substantially vertically downwards from the forwardly projecting portion of each support 11 and the lower ends of the carriers 12 are welded or otherwise rigidly secured to a longitudinal element 13 that is of L-shaped crosssection, being arranged with one limb of the L extending obliquely upwardly and rearwardly with respect to the direction A from the 90 junction between limbs whilst the other limb, which is of greater length as seen in cross-section, extends downwardly and rearwardly from the same junction with respect to the direction A. The integrally interconnected limbs of the preferably metallic beam or bar that principally affords the longitudinal element 13 have a filling 14 of resilient material arranged between them in such a way that said filling 14 presents a cylindrically curved convex surface that faces rearwardly towards the carrier 4 of the soil working members 3, the lowermost extremity of the filling 14 being at substantially the same horizontal level as are the bottoms of the carriers 4 whilst the uppermost extremity of the filling 14 is at a level well above that of the tops of the same carrier 4. The resilient filling 14 may be natural or synthetic rubber bonded or otherwise adhesively secured to the limbs of the angular beam or bar that principally affords the elenment 13 or said filling 14 may be a foamed or solid synthetic plastics material of sufficient resilience and durability either bonded or adhesively secured to the limbs of the beam or bar. Other angular shapes of said beam or bar may, if preferred, be employed.

The front of the hollow frame portion 1, with respect to the direction A, is provided with a coupling member or trestle 18 that is located mid-way between the general planes of the frame portion side plates 6 and that is of substantially isosceles triangular configuration as seen in front or rear elevation. The coupling member or trestle 18 defines two lower horizontally spaced apart coupling points for pivotal co-operation with the lower lifting links of a three-point lifting device or hitch carried by a tractor or other propelling and operating vehicle and also, at substantially its apex, a single upper coupling point for connection to the free end of the upper adjustable-length lifting link of the same lifting device or hitch. Downwardly and rearwardly divergent tie beams strengtheningly connected substantially the apex of the coupling member or trestle 18 to two widely spaced apart points at the top and rear of the hollow frame portion 1.

Each shaft 2 is provided, inside the hollow frame portion 1, with a corresponding straight- or spurtoothed pinion 19, the twelve (in this embodiment) pinions 19 being of such a size that the teeth of each such pinion 19 are in mesh with those of the or each immediately neighbouring pinion 19 in that row. One of the centre pair of shafts 2 in the row of twelve such shafts has an upward extension through the top of the hollow frame portion 1 into a gear box 20 that is fastened in position immediately above the frame portion 1. Bevel pinions and shafts within the gear box 20 place this upward extension of one of the shafts 2 in driven connection with a substantially horizontal shaft that is parallel to the direction A and which has a splined or otherwise keyed leading end that projects forwardly from the front of the gear box 20 in that direction to enable it to be placed in driven connection with the power take-off shaft of an operating tractor or other vehicle (not shown) by way of a telescopic transmission shaft (also not shown) that is of a construction which is known per se having universal joints at its opposite ends. The rear of the gear box 20, with respect to the direction A, is provided with a change-speed gear 21 whose construction is not the subject of the present invention. It suffices to say that pairs of intermeshing toothed pinions of different sizes can be interchanged in the change-speed gear 21 or can be exchanged for cooperating pairs of other sizes, to vary the transmission ratio between the forwardly projecting rotary input shaft of the gear box 20 and the upward extension of said one of the shafts 2 from which all of the soil working members 3 are driven. This al lows the soil working members 3 to be revolved at faster or slower speeds in response to a more or less standard speed of input rotation which is applied to the rotary input shaft of the gear box 20 when the implement is in use.

In the use of the soil cultivating implement that has been described with reference to the drawings, its coupling member or trestle 18 is connected to the three-point lifting device or hitch at the rear of an agricultural tractor or other propelling and operating vehicle and, before work commences, the adjustments that may, if required, be made include raising or lowering the bodily level of the ground roller 9 relative to that of the soil working members 3 and altering the transmission ratio inside the change-speed gear 21 to increase or decrease the rate of revolution of the soil working members 3. These adjustments will normally be made in the light of the nature and condition of the soil that is to be cultivated by the implement and the particular purpose for which that soil is required after the work has been completed. As the implement moves operatively in the direction A, the intermeshing relationship between the neighbouring pinions 19 ensures that each shaft 2, soil working member 3 and pinion 19 will rotate in the opposite direction to the or each immediately neighbouring similar assembly. The distance between the two tines 5 of each soil working member 3 is either the same as, or a little greater than, the distance between the axes of rotation of immediately neighbouring shafts 2 so that, as a consequence, the twelve soil working members 3 will work overlapping, or at least adjoining, strips of ground that extend in the direction A thus producing a single broad strip of worked soil which, in the case of the embodiment that is being described, will have a width of substantially, although not necessarily exactly, 3 metres. It will be apparent that the working width of the implement could be increased or decreased by increasing or decreasing the number of rotary soil working members 3 in the single row thereof.

As the tines 5 move rapidly through the soil during advance of the implement in the direction A, streams of displaced soil are move forwardly by the tines 5, particularly where the tines 5 of two neighbouring soil working members are both moving forwardly relative to the direction A. Similarly, rearwardly moving streams of soil are produced, particularly where the tines 5 of two immediately neighbouring members 3 are both moving rearwardly with respect to the direction A. The soil tends to start breaking up immediately in advance of the soil working members 3 throughout all or most of the working width of the implement and, particularly when the tines 5 project deeply into the ground, a transverse accumulation of broken soil tends to build up just in front of those members 3 and as far forwardly therefrom as the bottom of the longitudinal element 14. This accumulation may also extend in front of the element 14 and is, of course, constantly being augmented by fresh soil and depleted by the removal of soil as the implement continues its advance, the tendency being for the volume of the accumulation to remain more or less constant. The longitudinal element 14 and the soil working members 3 thus effectively co-operate with one another in a way which improves the degree of soil crumbling that is produced and that tends to improve the uniform spreading of the crumbled soil throughout the working width of the implement.

Any stones or other hard objects that may be brought to the soil surface by the tines 5 tend to encounter the leading surface of the element 14 that extends obliquely downwardly and rearwardly with respect to the direction A. This surface will, due to the continuing progress in the direction A, tend to push such stones or other hard objects downwardly beneath the surface of the worked soil. Stones and other hard objects thus rarely encounter the connections of the tines 5 to their carriers 4 so that damage from this cause is very signifcantly reduced, if not entirely elimated, and it is very uncommon for a stone or other hard object to become jammed between the contra-rotating carriers 4 of neighbouring soil working members 3, such jamming, if the stone or other hard object is not substantially immediately broken or otherwise released, being a potential cause of serious damage to the implement, and particularly the drive transmission to its soil working members 3.

Should a stone or other hard object become momentarily jammed between at least one of the rotating carriers 4 and the cushion-like resilient filling 14, serious damage will almost always be avoided because the convex surface of the filling 14 will deform resiliently forwards til continued rotation of the or each affected carrier increases the distance between it and said filling 14 allowing that filling to regain its natural uncompressed shape and the momentarily jammed stone or other hard object to be released and fall downwardly into the soil being worked by the members 3. The convex surface of the filling 14 tends, it has been found, to facilitate the quick release of a momentarily jammed stone or other hard object. It is not essential that the rear surface of the element 13 that faces the soil working member carriers 4 should be in the form of the resilient filling 14 and some other resilient, or at least elastic, structure may, if preferred, be used as an alternative.

Claims (5)

1. A soil cultivating implement of the kind set forth, wherein the rear of the longitudinal element, which faces said soil working members, is of resilient formation.

2. An implement as claimed in claim 1, wherein the resilient formation of the rear of said longitudinal element is produced by providing resilient material at the rear of that element.

3. An implement as claimed in claim 2, wherein the resilient material exhibits a convex surface that faces the carriers of said soil working members.

4. An implement as claimed in any preceding claim, wherein the longitudinal element comprises a beam or bar of L-shaped, or at least angular, cross-section, and wherein a filling of resilient material is arranged between the limbs of said beam or bar to face rearwardly towards said soil working members.

5. A soil cultivating implement of the kind set forth, substantially as hereinbefore described with reference to the accompanying drawings.