GB1592859A

GB1592859A - Cultivators

Info

Publication number: GB1592859A
Application number: GB416277A
Authority: GB
Original assignee: Haylock Ltd P J; Haylock P J
Current assignee: Haylock Ltd P J; Haylock P J
Priority date: 1978-02-01
Filing date: 1978-02-01
Publication date: 1981-07-08

Description

(54) IMPROVEMENTS IN OR RELATING TO CULTIVATORS (71) We, PETER JAMES HAYLOCK, a British Subject of Belmont, The Street, Bunwell, Norwich, Norfolk, and P. J. HAY LOCK LIMITED, a British Company of Norwich Road, Bunwell, Norwich, Norfolk, do hereby declare the invention, for which we pray that a Patent may be granted to us, and the method by which it is to be per formed, to be particularly described in and by the following statement: This invention relates to cultivators and in particular to cultivators for drawing behind a tractor to effect working of the earth.

Such working may comprise tilling or harrowing, or one of the various other earth-working operations which are performed in agriculture.

There have been designed various agricultural cultivators having a plurality of tines projecting downwardly from a frame, the cultivators being dragged across ground so that the tines effect working of the earth. For example, there have been many designs of harrow for breaking-up the clods of earth remaining after ploughing and which utilise this principle. The frame supporting the tines is coupled to the draught links of a tractor and the position of the frame relative to the ground is suitably adjusted by the lifting action of the links so that the tines have the required breaking action. However, the width of such a cultivator is limited if the harrow is to have an effective breaking action. This is because ground is in general relatively uneven. and if a wide rigid frame is mounted behind a tractor, the tines on the frame will in some places be completely clear of the ground whereas in others they will tend to dig in too far; only some of the tines will have the correct degree of penetration into the ground to obtain the required action. Such harrows should have a levelling action as well as the breaking action, but with a wide frame levelling does not usefully occur. Another problem limiting the width of such cultivators is that manoeuvrability and transport of the machine becomes very difficult.

In an attempt to overcome the above diffi culties, agricultural cultivators have been de signed with three rigid frame sections hinged together in an end-to-end manner across the width of the cultivator. the centre section being mounted on the draught links of a tractor. In this way, the centre section can be adjusted relative to the ground immediately behind the tractor and the two outer sections will hinge about the centre section to take up to some extent unevenness in the ground.

Also, for transport of the cultivator, the two outer sections may be hinged relative to the centre section so as to project approximately perpendicularly thereto, and the width of the cultivator may effectively be reduced by as much as nearly two-thirds. Though such hinged cultivators are an improvement over a rigid frame cultivator of a comparable width, it is found that they still are not entirely satisfactory, especially if attempts are made to increase the overall width to as much as 30 feet. This is because the relative disposition or each outer section is tied rigidly to the centre section by the hinge arrangement and so only a certain amount of unevenness in the ground can be accommodated. Also, because the weight of each outer section tends to hinge that section downwardly about its connection to the centre section, the loading on the groundworking implements, such as tines, on each outer section varies along the section. The innermost tines are more highly loaded if the outermost tines come clear of the ground than are the outermost tines if the innermost tines come clear of the ground: there is thus a tendancy for the cutermost tines not to penetrate the ground to the same extent as the innermost tines.

According to this invention, there is provided a cultivator for drawing behind a tractor for effecting earth-working, which cultivator comprises three substantially rigid sections disposed end-to-end and each adapted to carry earth-working implements, the centre section having means for attachment to a tractor with the two outer sections disposed laterally thereof for movement normal to the common centre line of all three sections, there being connecting means separately connecting each outer section to the centre section, which connecting means each comprises at least one link pivotally connected to both the associated outer section and the centre section so as to allow said outer section independently to rise and fall and to pivot with respect to the centre section, said connecting means restraining relative movement between the associated outer and centre sections in a horizontal direction normal to the said common centre line.

Throughout this Specification, the cultivator of this invention is described with reference to its normal mode of use when attached to a tractor. Thus, when the centre section is connected to a tractor by the draught links thereof, the three sections are disposed end-to-end in a line at right-angles to the normal direction of movement of the tractor.

The connecting means joining each outer section to the centre section is arranged to restrain movement between the sections in a horizontal direction parallel to the normal direction of travel of the tractor, but movement may occur between the sections in a vertical plane extending transverse to the normal direction of travel of the tractor-and thus each outer section may perform pivoting movement in that vertical plane as well as rising and falling movement in that vertical plane.

When the cultivator of this invention is attached to a tractor, the height of the centre section above the ground may be adjusted by means of the draught links of a tractor, the links providing any required downward force to obtain the required penetration. Since, however, the outer sections may rise and fall with respect to the centre section, it is preferred for there to be means to bias the outer sections downwardly with respect to the centre section, such that the downward force on all three sections is substantially equal. Such bias may be provided in several ways, as will be described hereinafter.

To control the action of the outer sections, it is also preferred for there to be means to limit the maximum displacement of each outer section downwardly with respect to the centre section. Optionally, means may also be provided to limit the extent of the upward movement of each outer section with respect to the centre section. So that the operation of each outer section may be fully controlled, further means may be provided to restrict the maximum pivoting movement of each outer section with respect to the centre section.

Each outer section may pivot about its connection with the associated link connecting it to the centre section-although the extent of this pivoting movement may be restricted as mentioned above-and in order to ensure that the pressure of any earthworking implements mounted on the outer section is uniform across the section, it is preferred for the pivotal connection of the link to the outer section to be substantially at the mid-point of the outer section, considered in said transverse direction. Thus, the section should laterally be "balanced" about its pivotal connection to the link.

In order to give sufficient rigidity to the complete cultivator, it is preferred for the means connecting each outer section to the centre section to comprise a pair of links spaced apart along the normal direction of travel of the cultivator, and hinged to the centre section and the outer section respectively about common, horizontal axes extending along the normal direction of travel. To prevent the sect ions twisting relatively, about the common centre-line, such a pair of links are preferably rigidly inter-connected by appropriate cross-braces. In order to assist the restriction of movement between adjacent sections in a direction perpendicular to the common centre line of the three sections (i.e.

to restrict movement in the direction of travel) it is preferred for the adjacent edges of the centre and outer sections to have pairs of brackets between the limbs of which the links fit for all normal relative dispositions of the sections when in use as a cultivator. If restraint of the permissible movement of the outer section is to be provided, this can then conveniently be arranged by the insertion of pins through holes provided in the limbs of the brackets, to each side of the links. For the case in which the connecting means comprises a pair of inter-connected links, separate pairs of brackets are preferably provided for each link of the pair, four such pairs of brackets thus being provided for each connection means, two on each section along the adjacent edges thereof.

To assist the control of the movement of the outer sections, it is preferred for there to be provided a member of adjustable length disposed to restrain downward pivoting movement of the link connecting two sections about its pivotal connection to the centre section.

Though this member could be in the form of a screw-threaded adjuster, it is preferred to use a double-acting hydraulic ram for this purpose. Conveniently, the ram is pivoted to a pillar provided on the centre section, the piston rod of the ram passing through an aperture in a suitable bracket provided on the link. To prevent the bracket of the link coming off the piston rod, an end stop should be provided thereon, the bracket otherwise being slidable along the rod.

If a bias on the outer sections is to be provided, this preferably is arranged by fitting a compression spring on the rod, which spring is compressed by upward pivoting movement of the link. An alternative would be to connect the piston rod to the link to restrain relative sliding movement therebetween, and to provide an accumulator in the hydraulic system of the ram so that upward pivoting movement of the link may take place only against the bias provided by the accumulator.

An advantage of the arrangement using a double-acting hydraulic ram is that contraction thereof may hinge the link-and hence the outer section-upwardly about the pivot point of the link to the centre section, and by a suitable choice of dimensions, each of the two outer sections may in this way be hinged to lie generally at 900 to the centre section, to allow greater manoeuvrability and transport of the cultivator as a whole.

Each section is preferably in the form of a frame to which various forms of agricultural implements may be attached. For instance, rigid or spring tines may be mounted on the frames, in one or more rows, and if more than one row is chosen, the tines of each row may be staggered to give a more uniform breaking effect on the ground being cultivated. By appropriate adaptation of the sections, various other agricultural tillage implements may be mounted on the sections in manners known in the art.

By way of example, one specific embodiment of this invention will now be described, reference being made to the accompanying drawings, in which: Figure 1 is a plan view of a cultivator arranged in accordance with this invention, only the centre section and one outer-section thereof being shown; Figure 2 is a front view of the cultivator of Figure 1, again with one of the outer sections omitted, but showing levelling harrow tines mounted on the sections; Figure 3 is an enlarged sectional view ob the means connecting the centre and outer sections of the cultivator of Figures 1 and 2; and Figure 4 is an end view on the cultivator shown in the other Figures.

In the drawings, there is shown one embodiment of a cultivator constructed in accordance with this invention, the cultivator taking the form of a levelling harrow fitted with four rows of staggered tines. This embodiment comprises three sections arranged laterally end-to-end about a common centre line 9, normal to the intended direction of travel of the harrow (shown iin Figure 1 by the arrow A) though for clarity in the drawings only the centre section 10 and one outer section 11 is shown. In use, a second outer section would be mounted to the centre section, adjacent the edge thereof opposed to the outer section 11.

The centre section 10 comprises a plurality of box members 12 welded together to form a generally rectangular, substantially rigid frame having four longitudinal members 13, end members 14 and intermediate braces 15.

A sub-frame 16 is mounted centrally on the centre section 10, which sub-frame 16 is provided with plates 17 for attachment to the draught links of a tractor. The relative disposition of the plates 17, their spacing and the apertures provided therein are such that the centre section may be atached to a wide variety of tractors without the need to employ any special other attachment arrangement.

The outer section 11 shown in the drawings is mounted on the centre section 10 such that it is aligned with the centre section when viewed in plan (that is, as in Figure 1), though the mounting arrangement for the outer section 11 allows that section to "float" up and down with respect to the centre-section (having regard to the ordinary intended attitude of the levelling harrow) and also to pivot with respect to the centre section.

The outer section 11 also comprises a plurality of box members 18 welded together, there being four longitudnal members 19, an end member 20 and braces 21 inter-connecting the longitudinal members 19. The spacing between the longitudinal members 19 is the same as that between the longitudinal members 13 of the centre section 10.

The outer section is connected to the centre section 10 by means of a pair of links 22, provided with cross-braces 23, such that the links 22 and braces 23 form a rigid, generally rectangular frame. Outer ends 24 cf the links 22 are pivoted to two pairs of lugs 25 provided on the outer section 11 mid-way between the ends thereof, whereas the inner ends 26 of the links 22 are pivoted respectively to similar pairs of lugs provided on the centre section 10. Each link fits between a pair of upstanding brackets 28 provided on the braces 21 of the outer section adjacent the centre section, and between a pair of brackets 29 provided on the end member 14 of the centre section adjacent the outer section. Each pair of brackets 28 and 29 is provided with a plurality of horizontally extending apertures through which stop-pins (not shown) may be inserted to limit the pivoting movement of the links 22 with respect to the outer section 11 (so far as brackets 28 are concerned) and with respect to the centre section (so far as brackets 29 are concerned).

A fabricated pillar 30 upstands from the centre section adjacent the lugs 27 thereon, one pillar to each side of the sub-frame 16 for association with the outer section on that side. Pivotally mounted on the pillar 30 is the cylinder 31 of a double-acting hydraulic ram, the piston rod 32 of the ram 31 being connected to the mid-cross brace 23 interconnecting the links 22 by means of a bush 33 slidably mounted on the piston rod and pivoted to a pair of trunnion plates 34 welded to the cross brace. A nut 36, threaded on to the end of the piston rod 32, prevents the bush 33 from coming off the end of the piston rod, whereas movement of the bush along the piston rod 32, away from the nut 36, can take place only against the action of a resilient bias provided by a compression spring 37 fitted over the piston rod 32 and bearing against the bush 33 and a flange 38, welded to the piston rod partway therealong.

A second outer section, essentially the same as the above-described outer section, is mounted adjacent side 39 of the centre section 10, in a similar manner to that justdescribed above for outer section 11. The longitudinal members 13 and 19 of all the sections are provided with suitable apertures for the fitting of agricultural implements, such as levelling harrow tines 40 as are shown in the drawings. Four rows of such tines may be provided, as shown in Figure 4, the tines of each row being staggered with respect to the other rows whereby optimum coverage of the ground may be obtained. Of course, other tools besides the straight tines shown in the drawings may be fitted-for instance, spring tines.

In use, the cultivator described above is attached to the lifting and draught links of a tractor, by connecting the links to the plates 17 of the sub-frame 16. Prior to lowering the centre section to engage the ground to the required depth, the double-acting hydraulic rams 32 are energised so as to lower the outer sections with respect to the centresection, until the tips of the tines of the outer sections are nearer the ground than the tips of the tines of the centre section, typically by a few inches. The valves for the hydraulic system are then closed and the centre section lowered by means of the lifting and draught links of the tractor so that the tines of the centre section engage the ground to the required depth. As the tips of the centre section tines contact the ground, the two outer sections are lifted with respect to the centre section, and this can only occur by compression of the spring 37 as the links 22 pivot about their connection to lugs 27 of the centre section. Thus, this applies a verticallydownward load on the outer sections and by adjustments of the bias provided by the spring 37 as well as the amount by which the outer sections are lowered with respect to the centre section before lowering the centre section, the force on all the tines may be balanced across the entire cultivator.

By inserting pins through the apertures in brackets 28 and 29, it is possible to limit the amount of pivoting movement of the links 22, both about their pivotal connection to the centre section and about their pivotal connection to the outer section. Furthermore, should it be required for a particular piece of ground, the actions of the links 22 may completely be inhibited by inserting pins through the brackets 28 and 29 at appropriate positions to lock the pivoting movement of the links.

It will be appreciated that by pivoting each outer section to the links 22 at apover the whole width of the section, unlike the previous known arrangements in which the pressure on the ground decreased outwardly from the pivotal connection to the centre section. Furthermore, by the pivoting action of the links to the lugs 27 on the centre section, each outer section may rise and fall, within the limits imposed either by pins inserted in the brackets 29 on the centre section or by the action of the hydraulic ram and its spring bias.

When the apparatus is to be transported before or after use on the earth, the pins (if any) in brackets 29 on the centre section are removed and pins are inserted through appropriate apertures in brackets 28 on the outer section to lock the pivoting action ot the outer section with respect to the links 22. The hydraulic ram 31 is then actuated so as to contract, and this action hinges the entire outer section 11 and links 22 about the pivotal connection thereof to lugs 27. Each outer section may be pivoted in this way through a considerable angle, such that the outer sections lie largely within the confines of the centre section, by upstanding therefrom. By appropriate positioning of the pillars 30 and lugs 27 as well as the stroke of the ram 31, it is possible to ensure that the maximum width of the cultivator when the outer sections have been raised in the manner described is not substantially greater than the overall width of the centre section.

WHAT WE CLAIM IS:- 1. A cultivator for drawing behind a tractor for effecting earth-working, which cultivator comprises three substantially rigid sections disposed end-to-end and each adapted to carry earth-working implements, the centre section having means for attachment to a tractor with two outer sections disposed laterally thereof for movement normal to the common centre line of all three sections, there being connecting means separately connecting each outer section to the centre section, which connecting means each comprises at least one link pivotally connected to both the associated outer sections and the centre section so as to allow said outer section independently to rise and fall and to pivot with respect to the centre section, said connecting means restraining relative movement between the associated outer and centre sections in a horizontal direction normal to the said common centre line.

2. A cultivator as claimed in claim 1, wherein there are means to bias the outer sections downwardly with respect to the centre section.

3. A cultivator as claimed in any of the preceding claims, wherein means are provided to limit the maximum displacement of each outer section downwardly with respect to the centre section.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. 36, can take place only against the action of a resilient bias provided by a compression spring 37 fitted over the piston rod 32 and bearing against the bush 33 and a flange 38, welded to the piston rod partway therealong. A second outer section, essentially the same as the above-described outer section, is mounted adjacent side 39 of the centre section 10, in a similar manner to that justdescribed above for outer section 11. The longitudinal members 13 and 19 of all the sections are provided with suitable apertures for the fitting of agricultural implements, such as levelling harrow tines 40 as are shown in the drawings. Four rows of such tines may be provided, as shown in Figure 4, the tines of each row being staggered with respect to the other rows whereby optimum coverage of the ground may be obtained. Of course, other tools besides the straight tines shown in the drawings may be fitted-for instance, spring tines. In use, the cultivator described above is attached to the lifting and draught links of a tractor, by connecting the links to the plates 17 of the sub-frame 16. Prior to lowering the centre section to engage the ground to the required depth, the double-acting hydraulic rams 32 are energised so as to lower the outer sections with respect to the centresection, until the tips of the tines of the outer sections are nearer the ground than the tips of the tines of the centre section, typically by a few inches. The valves for the hydraulic system are then closed and the centre section lowered by means of the lifting and draught links of the tractor so that the tines of the centre section engage the ground to the required depth. As the tips of the centre section tines contact the ground, the two outer sections are lifted with respect to the centre section, and this can only occur by compression of the spring 37 as the links 22 pivot about their connection to lugs 27 of the centre section. Thus, this applies a verticallydownward load on the outer sections and by adjustments of the bias provided by the spring 37 as well as the amount by which the outer sections are lowered with respect to the centre section before lowering the centre section, the force on all the tines may be balanced across the entire cultivator. By inserting pins through the apertures in brackets 28 and 29, it is possible to limit the amount of pivoting movement of the links 22, both about their pivotal connection to the centre section and about their pivotal connection to the outer section. Furthermore, should it be required for a particular piece of ground, the actions of the links 22 may completely be inhibited by inserting pins through the brackets 28 and 29 at appropriate positions to lock the pivoting movement of the links. It will be appreciated that by pivoting each outer section to the links 22 at apover the whole width of the section, unlike the previous known arrangements in which the pressure on the ground decreased outwardly from the pivotal connection to the centre section. Furthermore, by the pivoting action of the links to the lugs 27 on the centre section, each outer section may rise and fall, within the limits imposed either by pins inserted in the brackets 29 on the centre section or by the action of the hydraulic ram and its spring bias. When the apparatus is to be transported before or after use on the earth, the pins (if any) in brackets 29 on the centre section are removed and pins are inserted through appropriate apertures in brackets 28 on the outer section to lock the pivoting action ot the outer section with respect to the links 22. The hydraulic ram 31 is then actuated so as to contract, and this action hinges the entire outer section 11 and links 22 about the pivotal connection thereof to lugs 27. Each outer section may be pivoted in this way through a considerable angle, such that the outer sections lie largely within the confines of the centre section, by upstanding therefrom. By appropriate positioning of the pillars 30 and lugs 27 as well as the stroke of the ram 31, it is possible to ensure that the maximum width of the cultivator when the outer sections have been raised in the manner described is not substantially greater than the overall width of the centre section. WHAT WE CLAIM IS:-

1. A cultivator for drawing behind a tractor for effecting earth-working, which cultivator comprises three substantially rigid sections disposed end-to-end and each adapted to carry earth-working implements, the centre section having means for attachment to a tractor with two outer sections disposed laterally thereof for movement normal to the common centre line of all three sections, there being connecting means separately connecting each outer section to the centre section, which connecting means each comprises at least one link pivotally connected to both the associated outer sections and the centre section so as to allow said outer section independently to rise and fall and to pivot with respect to the centre section, said connecting means restraining relative movement between the associated outer and centre sections in a horizontal direction normal to the said common centre line.

4. A cultivator as claimed in any of the

proximately the mid plane of the outer section, the section is balanced about its pivotal connection to the links 22. This ensures a uniform pressure on the ground by the tines preceding claims, wherein means are provided to limit the extent of the upward movement of each outer section with respect to the centre section.

5. A cultivator as claimed in any of the preceding claims, wherein means are provided to restrict the maximum pivoting movement of each outer section with respect to the centre section.

6. A cultivator as claimed in any of the preceding claims, wherein the pivotal connection of each link to the associated outer section is substantially at the mid-point of the length of the outer section, considered along said common centre line.

7. A cultivator as claimed in any of the preceding claims, wherein the means connecting each outer section to the centre section comprises a pair of links spaced apart along the normal direction of travel of the cultivator, and hinged to the centre section and the outer section respectively about common, horizontal axes extending along the normal direction of travel.

8. A cultivator as claimed in claim 7, wherein the links are rigidly inter-connected by cross-braces.

9. A cultivator as claimed in any of the preceding claims, wherein the adjacent edges of the centre and outer sections have pairs of brackets between the limbs of which the links fit for all normal relative dispositions of the sections when in use as a cultivator.

10. A cultivator as claimed in claim 9 and in claim 3 or claim 4, wherein holes are provided in the limbs of the brackets through which pins can be inserted to limit the movement of the links.

11. A cultivator as claimed in any of the preceding claims, wherein there is provided a member of adjustable length disposed to restrain downward pivoting movement of the link connecting two sections, about the pivotal connection of the link to the centre section.

12. A cultivator as claimed in claim 11, wherein said member of adjustable length comprises a double-acting hydraulic ram.

13. A cultivator as claimed in claim 12, wherein the ram is pivoted to a pillar provided on the centre section, the piston rod of the ram passing through an aperture in a suitable bracket provided on the link.

14. A cultivator as claimed in claim 13, wherein an end stop is provided on the free end of the piston rod to prevent the bracket on the link leaving the piston rod, the bracket otherwise being slidable along the rod.

15. A cultivator as claimed in claim 13 or claim 14, wherein a compression spring is fitted on the rod, which spring is compressed by upward pivoting movement of the link to provide bias on the outer section associated therewith.

16. A cultivator substantially as herein before described with reference to and as illustrated in the accompanying drawings.