GB2072473A - Seed drill - Google Patents

Abstract

A seed drill has a support (1) on which coulters are arranged in at least two cross rows located one behind the other and mounted in staggered arrangement; each coulter being pivotal in a vertical plane. Adjacent sowing coulters (5) are arranged in pairs on a common holder (2) laterally displaceable on the coulter support (1). Spacers 11 provide for one coulter of each pair to be adjustable relative to the holder. <IMAGE>

Description

SPECIFICATION A seed drill The present invention relates to a seed drill having at least one coulter support, on which sowing coulters are located, via coulter holders, in at least two cross rows located one behind the other and in staggered formation laterally adjustable at right angles to the direction of travel and pivotal in a vertical plane.

A similar seed drill is already known from the DE-PS 1 2 79 408. An advantage in this machine is that the adjustment of the spaces between rows between the individual sowing coulters is possible in two ways. On the one hand, the holders are displaceable on the coulter holders and, on the other hand, the coulter holders are additionally adjustable relative to the holders via holders or the sowing coulters relative to the coulter holders.

In this seed drill the chief disadvantage is that plates provided on the coulter holders for the lateral adjustment so constrict the free passage between the coulter holders that on untidy grounds blockages of these passages are inevitable. A further disadvantage resides in that in the very narrow coulter holding joints it is impossible to adjust the narrow spacings between rows, unless two coulter holders at a time are mounted on a holder or two sowing coulters provided to one coulter holder. This eliminates from the start, however, particularly on an uneven ground surface, a uniform depth conduction of the sowing coulters, since they are no longer able to reciprocate in vertically pendulum fashion.

Furthermore, blockages in front of the sowing coulter readily occur, because clods or plant components located in the upper spil layer cannot be carried past between the sowing coulters.

As a further disadvantage, the arrangement of this machine necessitates that during the changing of spacings between rows each coulter has to be adjusted, and that no additional holders with sowing coulters can be mounted because the holders are made detachable.

An object of the invention is to improve the known adjustment in such a manner that adjustment in pairs of spacing between rows of a minimum 6 cm is obtained in simple manner between each two adjacent coulters.

According to the present invention a seed drill having at least one coulter support on which in at least two cross rows one behind the other, sowing coulters are mounted by coulter holders in staggered formation adjustable at right angles to the direction of travel and pivotal in an upwardly extending or upright plane, is characterised by the feature that for at least two adjacent sowing coulters located with one rearward of the other in the direction of travel a common holder is provided for the joints of the coulter holders and is laterally adjustable on the coulter support.

This measure makes it possible in simple manner to obtain alternately a narrow and wide spacing between rows. Owing to the fact that the joints for the front sowing coulters are mounted directly on the holders and the joints for the rear sowing coulters are mounted on the rearwardly projecting struts, a widening of the joints of the coulter holders is made possible, whereby the bending moments in the joints are reduced.

To enable coulter holders of the same length to be used, it is necessary for the length of the struts to correspond to the spacing between the cross rows.

To obtain both a uniformly narrow and uniformly wide spacing between rows, the invention provides for the sowing coulters with the coulter holders to be adjustably arranged within the joint hoider. This is obtained preferably in that spacers are arranged between the joint holders and the joints of the coulter holders.

To allow subsequent mounting and dismounting of holders, it is proposed in accordance with the invention for the coulter supports to be detachably mounted. This makes it possible at any time for the number of sowing coulters and hence the spacings between rows of the sowing coulters to be mutually adapted in accordance with the requirements in practice.

The invention will be described further by way of example, with reference to the accompanying drawings, in which: Figure 1 is a plan view of the arrangement of the holders in accordance with the invention; and Figure 2 is an identical plan view of holders but showing the narrowest spacing between the rows.

On a coulter support 1 of a known and therefore not shown seed drill, holders 2 are secured by means of a shackle, butt strap or strap 3 and clamping screws 4. By slackening the screws 4 the holders 2 may be laterally displaced on the support 1, and thus two sowing coulters 5 at a time located on each holder by means of coulter struts 6 and hinges or joints 7.

The joint holders 8 for the sowing coulter 5 in the front cross row of the seed drill are welded directly at one end to the rear surface of the strap 3. A strut 9 projecting to the rear is welded on the other part of the rear surface of the strap 3 and at the rear end of the strut 9 a joint holder 10 is located. The joint holder 10 has the same inside width as the joint 7.

On the other hand, the joint holder 8 is wider by the width of spacers 11.

Fig. 1 shows the arrangement of the sowing coulters 5 having a spacing of uniform width, whereby the spacers 11 are arranged in the joint holder 8 on the surface or side 1 2 facing or projecting adjacent the strut 9. Further more, there is a large spacing between the holders 4. Fig. 2 on the other hand shows the arrangement of the sowing coulters 5 with the narrowest possible spacing between rows. For this purpose it is necessary for the holders 4 to be located close together and the spacers 11 to be arranged on the surface 1 3 remote from the strut 9.

It is, moreover, also possible that either the holders 4 alone are laterally displaced or, however, that the front coulter struts 6 assume a different position by transferring the spacers 11 within the joint holders 8. This produces alternately closer or greater spacings between rows between the sowing coulters 5.

The spacers 11 may also be replaced by other components, such as, for example, clamping straps, spring split pins etc., which are suitabie to define the lateral displaceability of the coulter struts.

Claims (7)

1. A seed drill having at least one coulter support on which in at least two cross rows one behind the other, sowing coulters are mounted by coulter holders in staggered formation adjustable at right angles to the direction of travel and pivotal in an upwardly extending or upright plane, is characterised by the feature that for at least two adjacent sowing coulters located with one rearward of the other in the direction of travel, a common holder is provided for the joints of the coulter holders and is laterally adjustable on the coulter support.

2. A seed drill as claimed in claim 1, in which the joints for the front sowing coulters are mounted directly on the holders and the joints for the rear sowing coulters are mounted on rearwardly projecting struts.

3. A seed drill as claimed in claim 2, in which the length of the struts corresponds to the spacing between the cross rows.

4. A seed drill as claimed in claim 1 or 2, in which the sowing coulters together with the coulter holders are located laterally adjustable within the joint holders.

5. A seed drill as claimed in claim 4, in which spacer members are arranged between the joint holders and the joints of the coulter holders.

6. A seed drill as claimed in any of claims 1 to 5, in which the holder is detachably mounted on the coulter support.

7. A seed drill substantially as herein described with reference to and as illustrated in the accompanying drawing.