GB2082883A - Sowing machine - Google Patents

Abstract

Sowing machine for use on unworked ground with one or more cutting shares 1,9 being moved around in circles so that when the sowing machine is moved in the driving direction a width corresponding to the rotational diameter of the shares is sown. The shares are pivot suspended so that they always cut in the intended way irrespective of the ratio of the rotary speed to the towing speed of the sowing machine. By the pivot suspension it will also be easier for the shares to avoid stones and other obstacles in the ground. The weight of the machine is taken on supporting discs 6a. <IMAGE>

Description

SPECIFICATION Sowing machine When sowing tilled ground so-called seed drills are used today, where a plurality of shares are suspended side by side and trailed in the driving direction. A pre-requisite for these sowing machines is that the earth has been carefully -worked so that a loosened surface layer has been obtained as the shares cannot penetrate a hard surface layer. In the first place this is due to the fact that many shares placed on one level are used and that each share requires a great force if you try to draw it through unworked ground. In addition to the need of a loosened surface layer any obstacle in the form of stones and the like must be eliminated in order not to damage the machine.

However, the last discoveries in agricultural research have shown that the best earth structure is obtained if the ground is subjected to as little mechanical working as possible and that it is best for the earth to be worked instead by microorganisms and earthworms normally present in the ground. This is not possible with the known constructions of the sowing machines. Certainly attempts have been made to make the shares of the sowing machine so strong that they can also cut down into unworked ground, but as a result of this a very strong tractive force of the towing tractor is required, which will then exert a very great pressure on the ground and cause a detrimental mechanical working thereof, and in spite of this sowing machines of this kind will be sensitive to disturbance in the form of stones and other obstacles in the ground.Thus, one problem is that there are so far no suitable machines to manage sowing without working even if agricultural research has established that such a sowing is suitable.

It is the object of the invention to eliminate this deficiency, the sowing machine of the invention being provided with a few cutting shares which are not only towed by a tractor or the like but are brought to cover via a separate drive a considerably longer distance than merely the distance driven, the necessary cover of the surface being achieved. By adapting the towing speed and the motion speed of the shares the desired sowing density can be obtained. As the shares move a longer way than the towing distance during the same time the motion of the shares in the ground will not merely result in forces directed straight backwards, but component forces in other directions will also arise.In this way it will be possible to transfer the force otherwise necessary to move a great number of shares through the ground to the drive of the sowing machine instead of the towing force thereof. As a consequence of this the towing tractor need not be big and heavy, either, to carry out the required work.

In a suitable design of the invention the sowing machine consists of shares placed on arms, which arms are rotated so that the shares substantially perform circular movements in the earth. It may then be possible to have the shares pivot suspended to make it possible that they always adjust themselves to the driving direction. In order to obtain a good equilibrium of the forces of the shares these can e.g. be mounted on diametrically opposite arms rotating around a common centre.

In this case a dispersing pattern of the seed is obtained which provides a tighter placing of the seeds at the edge of the sown line. However, this can be counteracted by controlling the feeding of the seeds so that it will be more sparse in the corresponding positions of the shares. Especially at variations of the towing and driving speed of the shares the pivot suspension of the shares is important in order that the shares might cut straight into the ground. Moreover, by the pivot motion it will be possible for the share to avoid stones and the like. However, for safety's sake some kind of sliding clutch should be arranged in the rotation drive of the arms supporting the shares or the like.

In a further development of the invention the shares are moreover adjustable at various angles to the ground to achieve different degrees of earth seeking and depths which desired values are decided by the ground and the seeds, respectively, to be set.

Seed feeding preferably takes place through the centre of rotation of the shares and, moreover, out through the arms supporting the shares, through the pivot suspension and out on the back side of the shares.

Additional advantages of the invention are apparent from the following description in connection with the enclosed drawings, which show illustrative examples.

Fig. 1 shows schematically a perspective view of the principle of a sowing machine according to the invention, Fig. 2 is a lateral view of a sowing machine according to the invention and Figs. 3 and 4 are a suitable embodiment of a share.

In Fig. 1 it is shown how seeds 4 are fed down along the centre of rotation 5 of arms 7 supporting the shares. The seeds are thrown by centrifugal force out through the arms 7 to pivot suspensions 2 of the shares 1, which are moved at the desired depth of the ground 6, and the seeds 4 then fall down into the groove after the share before this has closed. The angle between the cutting edge of the share and the ground surface has been designated by 3 and this angle can preferably be adjustable for adaptation to the hardness of the ground surface as it is necessary that the shares 1 and the seeds 4 reach the intended depth under the ground surface 6.

The sowing machine shown in Fig. 2 has a disc 11 at its bottom, in which four shares 8, of which only three are shown, are suspended via pivotal rings 10. The shares 8 have each a cutting edge 9 which extends into the ground and a pressure plate 6 carrying the weight of the sowing machine and securing that the edge always cuts with the same depth. The seeds are laid out behind the cutting edge 9 after being conveyed in a way not shown in detail, radially in the disc 11 by centrifugal force and then by gravity down through the share 6. At the centre of the disc 11 suitable means are arranged in a space 12 in a way not shown in detail in order that the right amounts of seeds should be portioned to the shares 8 via interior channels.Within the scope of the invention it is possible that these portioning means are non-linear to provide a completely even surface distribution of the seeds. The disc 11 with the shares 8 are driven via a shaft 13 from a gearbox 14 which on its input side is provided with a sliding clutch driven by a belt transmission 16, which is driven, in its turn, by a shaft 1 7 connected to a power outlet of a tractor not shown. Moreover, the sowing machine is attached to the tractor at the point of attachment 1 9 and the stand 20 of the sowing machine supports a container 1 8 for the seeds to be sown. The container 1 8 has an aperture down through the gearbox 13 and the drive shaft 13 of the disc 11.

For the drive of the portioning means disposed in the space 12 a shaft is arranged centrally in the aperture from the container 18 down into the space 12, which shaft is attached nonrotatably to the container 1 8 at the top. The required pressure to the ground is achieved by the weight of the sowing machine, but within the scope of the invention it is also possible to have cushioned shares, separately or in common.

Figs. 3 and 4 show another illustrative example of a suitable share with an adjustable edge 22 which, moreover, is spring-loaded by a spring 23 against its working position in order to reduce the risK of damage as a result of stones etc. Moreover, the share is provided with a pressure plate 24 which in a rearward direction from the projecting cutting edge has a slit 25 to secure that the seeds falling down into the slit in the ground 6 are not disturbed by material trailed along.

It goes without saying that the abovementioned sowing machine is not only useful in agriculture for sowing on unworked ground, but it is also possible to use it for sowing on lawns in parks and golf-links, and to improve existing grass slopes very simply and comfortably. Moreover, it should be mentioned that the sowing machine according to the invention is extremely well suited for the new technique with pelletized seeds.

Claims (11)

1. Sowing machine with one or more cutting shares intended for use on unworked ground, characterized in that the shares (1: 8) are moved on the ground, and substantially parallelly to the ground surface (6), a distance longer than that which the sowing machine is moved for a certain time.

2. Sowing machine according to claim 1, characterized in that a rotary motion is imparted to the shares (1; 8).

3. Sowing machine according to claim 1 or 2, characterized in that the shares (1) are each pivot suspended (2; 10).

4. Sowing machine according to any of the foregoing claims, characterized in that the number of the shares (2; 10) is at least 2.

5. Sowing machine according to claims 3 and 4, characterized in that at least two shares (2) are arranged to rotate around a common rotary shaft (5) and that they are distributed around the periphery.

6. Sowing machine according to any of the foregoing claims, characterized in that the angle of each share to the ground surface (6) is adjustable.

7. Sowing machine according to any of the foregoing claims, characterized that each share is provided with a pressure plate (11; 24) by which the share (8; 22) is unloaded against the ground.

8. Sowing machine according to claim 7, characterized in that the pressure plate (24) has a slit (25) extending from the share and rearwards.

9. Sowing machine according to any of claims 2-8, characterized in that the distances of the shares from the centre of rotation are different.

10. Sowing machine according to any of the foregoing claims, characterized in that the shares are resilient to be able to spring away from stones etc.

11. Sowing machine according to any of the foregoing claims, characterized in that the number of the shares is 3.