GB2175484A - Agricultural cultivator - Google Patents

Abstract

A cultivator 1 is located on the front of a tractor via a frontal three-point linkage which is connected to the tractor 2, via an attachment which is of short overall length and which is disposed between the tractor and the actinal cultivator. Solely tractive forces take effect thereby, because the attachment part is constructed as a linkage transmission 12, 13, 14, 19. This attachment part can be used unaltered for all manner of frontal implements because it is so positioned between tractor and frontal implement that the ideal guidance point or instantaneous centre of rotation 9 is located in front of the central point of force application of the frontal implement. <IMAGE>

Description

SPECIFICATION Agricultural cultivator Theinverr;fors relatesto anagricu It an agricultural cultivator, particularly an implementforfrontal mounting, constructed for rolling movement and adapted to be coupled to the front three-point linkage ofthe tractor via an attachment.

in the cultivation ofsoil,thetrailing implements directly associated with the plough or the tractor are as a rule attached to thethree-point linkag e of the tractor. For even loading ofthetractor, however, certain trailing implements which can also be used on the front of the tractor are also attached to the front of thetractor.

As a rule, this has a considerable effect on the steering of the tractor. Attempts have been made to resolve this problem by various means. To this end, it is known to mount atthefronton the three-point linkage or directly onthe front part ofthetractor a beam which extends quite some distance forwards and on the front of which the frontal implement is pivotally disposed. This construction makes it neees saryforvirtually everyfrontal implementto have a beam of its own or to use an attachment of its own because all these frontal implements are, of course, of different sizes.The attachment part must, however, be so constructed thatthe frontal implement is being pulled, as otherwise the steering of the tractorwould be too greatly affected and the implement would turn over. Consequently, the maintenance of corresponding attachments requires considerable outlay, quite apart from thefactthatthe beam which projects a long way in front does in itself constitute an obstacle to guiding the tractor and an obstruction to the driver's visibility. It is also unfavourable that accurate guidance ofthe frontal implement can only be varied at all with considerable effort.

The invention is based on the problem of providing an attachmentwhich is suitable forfrontal implements of different dimensions and constructions.

According to the invention, the problem is resolved in that the attachment is so positioned between tractor and frontal implementthatthe ideal guide point or instantaneous centre of rotation is located infront of the central point offorce application of the frontal implement, preferablyinfrontoftheentirefrontal implement.

With a cultivator which isso constructed, it is advantageously possible to use the most widely diverse frontal implements with one and the same attachmentwithoutthe need foranychanges to be made to the attachment. At the same time, the instantaneous centre of rotation is so favourably located that smooth running and steering ability of the tractor and of the frontal implement are guaranteed.

Furthermore"thefield of view is now kept clearforthe tractor driver since the forwardly projecting beam has been dispensed with, the preferably short attachment part preferably being used between tractor and frontal implement.

According to an expedient development ofthe invention, it is envisaged that the attachment com- prise a linkage transmission. Via this linkage transmission it is advantageously possible to provide an attachment which is lightweight in construction and which advantageously directs the movements of the frontal implement.

In addition to this, the invention provides for the attachment to comprise a rugged frame with arms pointing in the direction ofthe tractor, there being on the arms links which connect to fixing points for the frontal implements and tractor bottom links.

This attachment orthe frame is so located or should be so located between frontal implement and tractor thatthe overall length ofthefrontal part ofthetractor is not or is only insubstantially increased by it The frame comprises virtually the front three-point linkage of the tractor so that according to the construction onlytheframewidth or any connections to the frontal implementwhich may be infrontoftheframe result in the length of the front part ofthe tractor being lengthened. It is also conceivable to dispose these fixing points above one another. Inthis way, it is possible to maintain or even to reducethe length of the fronttractor overhang which is usuallyfound when a beam is fitted.

The ideal guidance point or instantaneous centre of rotation can advantageously and even with the most widely diverse frontal implements be located exactly in front ofthe axle or even in front of the entire implement in that a plurality of fixing points are associated with and are distributedoverthe length of the arms. As a result, the links can aiways be attached to different points ofthe frame of the attachment so that the links are of different inclination and move the ideal guidance pointforwards or backwards.

All in all, the links should according to the invention be advantageoulsy located to converge in the direc tionofthefrontal implement in order in this way to permit of adjustment of the instantaneous centre of rotation accordingto circumstances.

The links are expediently articulated, preferably via ball joints, to the arms and the tractor bottom links so that they can in each case adjust the steering ofthe tractor accordingly. The links are expediently constructed as traction links and with a corresponding configuration of suspension they are required only to absorb or pass on traction forces.

Also with regard to the upper link by which it is possible to liftoutthefrontal implement, versatility of the attachment is guaranteed because a development ofthe invention provides for the attachment to comprise atowerto one side ofwhich thetractortop link is connected while the trailing implement link is attached to the other. The tower is made tiltable so that movements of the frontal implement on the one hand or of the tractor on the other can easily be accommodated by whichever is the other part of the outfit concerned.

Expediently, lateral movement of the links is restricted in order not to overstress the suspension ofthe links of their connection to the U-shaped frame on the one hand and the tractor bottom links on the other.

According to the invention, the attachment part is constructed as a componentwh ich has to be associated with the tractor or which is integrated into the frontthree-point linkage so that regardless ofthe frontal implement provided, coupling to the tractor is possible. In this way, implements can even be changed in the field, i.e. during working without this requiring any substantial effort. It goes without saying that it is, however, also possible to associate the attachmentwith the relevantfrontal implement or, which is even more expedient, to construct it as its own component part so that upon completion ofthe work it can be set aside without difficulty and the tractoristhen available again forotherjobs.

According to another development ofthe invention, the attachment part is a sliding transmission and comprises a sliding guide which isforexample, arcuate or located at an angle being constructed with an instantaneous centre of rotation located in front of the axle. The sliding guide orthe entire sliding transmission therefore, just like the attachment part described above, constitutes an advantageouslyflexi bleapparatuswhich can besodisposed between tractor and frontal implement that the steering of the tractor is not or is only insubstantially influenced. The instantaneous centre of rotation lies thereby in front of the axle and in the region of symmetry ofthefrontal implement so that advantages stability is assured.It is expedienttherebyto constructthesliding guideto comprise a curved path in orderthus positively to influence displacement ofthe instantaneous centre of rotation and to be ableto move it more quickly out of its central position when required.

In anotherembodimentoftheobjectoftheinven- tion, two forwardly converging mountings are provided with spindles on which downwardly and forwardly directed arms are mounted which are con structedattheirbottomendswith points of articulation, ideally with balljoints,forconnection offrontal implements. The mountings are connected to the frame on which there are likewise connecting points forthetractorthree-point linkage. The frame likewise carries a towerforconnection ofthe tractortop link to the trailing implement link.It is advantageous to provide the point of articulation for the trailing implementlinkto be laterally displaceable to avoid an oblique attitude ofthetop linkwhich would thus influence guidance of the frontal implements.

Afurther embodiment is that in which the attachment is associated with the frontal implement or is integrated into the frontal implement or is integrated into thefrontal implement orthe implement frame thereof. This embodiment is advantageous if the tractor is only exceptionally used for such components, being as a rule used for example for levelling work and the like.

Furtherdetailsand advantages oftheobjectofthe invention will arise from the following description of the associated drawings which show preferred examples of embodiment with the details and component parts necessary. In the drawings: Fig. 1 shows acultivatorwith a linkage transmission as the connecting element; Fig.2 shows a cultivatorwith a sliding transmission as the connecting element; Fig. 3 shows a sliding guide with rotatable freely supporting links; Fig. 4 is a side view ofthe alternative embodiment in Fig. 3 indicating the tractor and packer roller, and Fig. 5 shows a cultivator with a compression loaded linkagetramsmission.

The frontal implement 1 shows in Fig. 1 is for example a packer or culti-pack roller connected to the frontthree-point linkage3 ofthetractor 2through an attachment part which isto be explained in greater detail hereinafter. As usual, thefrontthree-point iinkage 3 comprises tractor bottom links 4,5 and tractortop links6,the latteronly being indicatedinthe drawing.

Shown in front of the axle 8 ofthefrontal implement 1 is the instantaneous centre of rotation 9 which is maintained in this region in front ofthe axle 8 bythe special construction of the attachment partl0.To this end,theattachment part 10 comprises a linkage transmission 11 consisting essentially ofthe links 12 and 13.

These links 12 and 13 are in each case connected via ball joints 14 on the one hand to thetractor bottom links4and 5 and on the otherto the frame 15. The frame 15 is so located between the frontal implement 1 and thetractor2 that its arms 16,17 point in the direction ofthetractor. Disposed on the inside faces of these arms 16,17 aretheattachment points 18, 19 for the links 12,13. As shown, various attachment points 18,19 can be provided overthe length ofthe arms 16, 17. AsFig. 1 shows, it is thus possible to vary the converging attitude ofthe links 12, 1 and so alter the location ofthe instantaneous centre of rotation 9.

Pivotally disposed in the centre ofthe frame 15 is a tower 20 which is connected on the one hand to the tractortop link 6 and on the othertothetrailing implement link 22. All these parts are only shown here by way of indication because Fig. is a plan view and offers only limited facilityforshowing these parts.

Fig. 2 shows another development ofthe invention but here, instead ofthe linkage transmission 11 and the frame 15, a sliding transmission 24with a sliding guide 25 is provided. The sliding guide 25 is of arcuate construction, the arc being so chosen that the central point is in each case in front of the axle 8. Thus also the instantaneous centre of rotation 9 is located in this area so that the steering properties ofthetractor 2 are only slightly or remain completely unaffected bythe frontal implement 1.

Guided on the sliding guide 25 are rollers 26,27 which are so connected to the beam 30 through webs thatthefrontal implement 1 automaticallyfollowsthe tractor 2 as it swings in, by virtue of the shifted instantaneous centre of rotation 9. The beam 30 is connected via a corresponding memberto a cross beam which connects both tractor bottom links 4,5 so that here, too, the frontal structure of the tractor is not substantially altered.

Athird alternativeembodiment is shown in Fig. 3 where there are on theframe 15forwardly converging articulations 32,33, each of which carries on an associated and downwardly directed arm 34 a ball joint 35. This ball joint serves for connection to the bottom attachment points ofthetractor bottom links 4,5 ofthe frontal implement 1. In addition, aguide is provided in the region of the trailing implement link 22 and consists of a bar on which the end ofthe trailing implement link 22 is guided. To this end, the trailing implement link 22 has at the end a roller 36 adapted to roil along the bar38fixed on the frame 15. On the other side is a bolt37to preventthe guide slipping out.

Fig. 4 shows a side view ofthe attachment of the frontal implement 1 which is illustrated in Fig. 3. Here the same reference numerals are used so that there is no need forfurther explanation. This drawing shows the disposition and construction ofthe connection in the region of the tractor bottom links 4,5 and the special construction in the region ofthetractortop link 6 with the guide shown there by roller 36, bolt 37 and bar 38. The bar 38 which serves as a guide rod is mounted on the tower 20 ofthe frontal implement and so permits of accurate transmission of forces to the frontal implement 1 ortothe links of the front three-point linkage 3.

Finally, Fig. 5 shows a linkage arrangement for a pushed frontal implement 1 and here, in contrast to the previously described embodiments, the links 12', 13' have to accommodate compressive forces. In principle, the kinematics are otherwise unchanged and in particular the instantaneous centre of rotation 9 is located in front ofthe actual frontal implement 1so that a smoothly moving combined working implement is provided.

Claims (15)

1. Agricultural cultivator, particularly an implementforfrontal mounting, constructed for roiling movement and adapted to be coupled to the front three-point linkage ofthe tractor via an attachment, characterized in that the attachment (10) is so positioned between tractor (2) and frontal implement (1) that the ideal guide point or instantaneous centre of rotation (9) is located in front of the central point of force application ofthefrontal implement, preferably in front ofthe entire frontal implement,

2. Cultivator according to Claim 1, characterized in thatthe attachment (10) comprises a linkage transmission (11).

3. Cultivator according to Claim 1 and Claim 2, characterized in that the attachment (10) comprises a U-shaped frame (15) of which the arms (16,17) point in the direction ofthetractor (2), the arms being provided with attachment points (18,19) for links (12,13) which connect the frontal implement (1) and tractor bottom links(4,5).

4. Cultivator according to Claim 3, characterized in that a pluralityoffixing points (18,19) distributed over the length are associated with the arms (16, 17).

5. Cultivatoraccording to Claim 2 and Claim 3, characterized in that the links (12,13) are disposed to converge in the direction of the frontal implement (1).

6. Cultivator according to Claim 2 and Claim 3, characterized inthatthe links (12,13) are articulatingly connected to the arms (16, 17) and the tractor bottom links (5,6) preferablythrough a ball joint (14).

7. Culitvatoraccording to Claim 2 and Claim 3, characterized in thatthe attachment (10) has a tower (20), thetractortop links6} being attached to one side ofthe latter, the trailing implement link (22) being attached to the other.

8. Cultivator according to Claim 2 and Claim 3, characterized in that the links (12,13) are laterally restricted.

9. Cultivator according to Claim 1, characterized in thattheattachment (10) is constructed as a compo- nentto be associated with the tractor (2) orto be integrated intothe frontal three-point linkage (3).

10. Cultivator according to Claim 2 and Claim 3, characterized in that the links (12, 13) are constructed as traction links.

11. Cultivator accordingto Claim 1, characterized in thatthe attachment (10) comprises a sliding transmission (24) and a sliding guide (25) which is constructed in a curved shape or at an angle having an ideal guide point located in front ofthe axle (8).

12. Cultivator according to Claim 11, characterized in that the sliding transmission (24) consists of two forwardly converging articulations (32,33) with arms (34) mounted thereon and directed downwardly and which have at their ends ball joints (35) for connecting to the lower attachment points of the frontal implement(1).

13. Cultivator according to Claim 7, characterized in thatthetrailing implement link (22) ofthefrontal implement (1) is connected to a device which is constructed to permit of lateral displacement, preferably a sliding guide (25) guided by rollers (36) which are displaceable on a rod (38).

14. Cultivator according to Claim 1, characterized in that the attachment (10) is to be associated with the frontal implement(1) or integrated into the frontal implement orthe implementframethereof.

15. Agricultural cultivator as claimed in claim 1, substantially as described herein with reference to and as illustrated by any one ofthe examples shown in the accompanying drawings.