GB2033719A

GB2033719A - Tractor linkage system

Info

Publication number: GB2033719A
Application number: GB7935158A
Authority: GB
Original assignee: Lemken GmbH and Co KG
Current assignee: Lemken GmbH and Co KG
Priority date: 1978-10-17
Filing date: 1979-10-10
Publication date: 1980-05-29
Also published as: FR2438959B1; ATA594179A; GB2033719B; NL188675C; DE2845111A1; BE879417A; DE2845111C2; NL7907430A; AT362951B; FR2438959A1

Abstract

A device is provided for the adjustment of the width of the first plough body and of the ideal tractor towing point 20 in mounted ploughs with three-point linkage. The plough frame is connected through two links 11, 14, which form a quadrilateral linkage, with the swivel pin 8 of the three-point linkage which constitutes the connection with the tractor. The one link 11 is formed as a link transmitting traction, flexure and torsion forces and the other 14 as a link of variable length. Between the two an adjustable length diagonal link 17 is so placed that the angles of the quadrilateral linkage are variable. The width is regulated by means of the link of variable length and the position of the ideal tractor towing point is regulated by means of the adjustable diagonal link. <IMAGE>

Description

SPECIFICATION Tractor linkage system The invention relates to a transmission for the adjustment of the width and of the ideal tractor towing point of a mounted plough connected by means of a three-point linkage with the tractor.

With the known devices for adjustment of the width of the foremost plough body, in the adjustment the rear coupling rod of the threepoint linkage is offset laterally and is set at an acute angle to the direction of travel. The point of intersection of the imaginary forward prolongatuons of the lower links, namely the ideal guide point of the lower links, then wanders out laterally on an ideal pole path.

This however signifies that the line of connection of the ideal towing point of the plough with the ideal guide point of the lower links no longer passes through the middle of the rear axle of the tractor, so that by reason of the resistance forces of the soil a lateral traction is exerted upon the tractor, to the detriment of the steerability of the tractor.

It is known from German Publ. Sp. No.

11 68 148 to bring about the shifting of the ideal guide point of the lower links without simultaneously influencing the width setting of the plough inter alia in that the plough frame forms with the rear coupling rod of the three-point linkage, or with its swivel pin, by means of two links, a quadrilateral linkage which is adjustable in angle by means of a diagonal link.

For the adjustment of width either the plough is shifted laterally on the rear coupling rod, or a multi-member transmission with laterally displaceable transmission members is provided. Both proposed embodiments are constructionally expensive and feasible only with considerable means, if at all.

The invention is intended to solve the problem, in a statically satisfactory manner, of transmitting the occurring forces from the rear coupling rod, possibly from the swivel pin, to the plough frame and in doing so of bringing about the shifting of the ideal guide point of the lower links of the three-point linkage without simultaneously influencing the width setting of the plough.

On the basis of the transmission known from German Publ. Spec. No. 11 68 148, the invention consists in that the one link is formed as a main link which transmits the traction, flexure and torsion forces and the other link is made variable in length, and it is advantageous if the main link and the link of variable length are directed approximately to the ideal guide point of the lower links of the three-point linkage.

The invention is represented in an example of embodiment in the drawing, wherein:~ Figure 1 shows the plan view of a tractormounted plough in diagrammatic representation, Figure 2 shows the main link in lateral elevation.

The chassis of the tractor is designated by 1 and the two rear wheels by 2. The lower links 3 and 4 of the three-point linkage are articulatedly connected with the chassis 1 at 5 and 6. The rear ends of the lower links 3 and 4 are connected by the stoutly formed rear coupling rod 7, while the centrally arranged upper link is omitted for the sake of simplicity.

The swivel pin 8, which is provided with a laterally protruding arm 8', is mounted in the usual way in the rear coupling rod 7. The plough frame 10 equipped with several plough bodies 9 has a laterally protruding arm 10'. The arms 8' and 10' are connected with one another by a main link 11 by means of hinge pins 12 and 13, the main link 11, as shown especially by Fig. 2, being of such stout formation that it is adapted to transmit the traction, flexure and torsion forces occurring during ploughing work. The free ends of the arms 8' and 10' are articulatedly connected with one another by a link 14 of variable length, by means of hinge pins 15 and 16. A diagonal link 17 of variable length connects the hinge pin 15 with a hinge pin 18 of the main link 1 1.

The width of the foremost plough body 9 is set so that the outer edge of its share 9' reaches to the furrow edge 19. The prolongations of the centre lines of the two lower links 3 and 4 intersect at the point 20, the ideal guide point of the lower links. If the ideal plough traction point, which is assumed to be at 21, is connected with the ideal guide point 20 of the lower links by the so-called resistance line 22 of the plough, then it can be determined that the point of intersection of the resistance line 22 with the central axis 23 of the rear wheels 2 of the tractor 1 lies laterally of the centre line 24 of the tractor.

Thus a lateral traction is exerted upon the tractor, which is detrimental to the steerability of the tractor, so that a correction of the position of the resistance line 22 is necessary.

This is effected by a shortening of the diagonal link 17, whereby the rear coupling rod 7, its swivel pin 8 and the protruding arm 8' come into the position as illustrated in chain lines, whereby the ideal guide point 20 of the lower links is shifted laterally on a pole path, so that the point of intersection of the resistance line 22 goes through the middle of the rear axle 23 of the tractor. The cutting width of the front plough body is not thereby altered. The width of the front plough body can be varied by variation of length of the link 14.

Within the scope of the invention it is possible to connect the arm 10' articulatedly with the plough frame 10, to make the link 14 of variable length and to connect the articulation point 16 with the plough frame 10 by an additional link of variable length.

Claims

1. Transmission for the adjustment of the width and the ideal tractor towing point of a mounted plough connected with the tractor by means of a three-point linkage, the frame of which plough forms a quadrilateral linkage with the rear coupling rod of the three-point linkage or with its swivel pin by means of two links, which quadrilateral linkage is adjustable in angle by means of a setting device, for example a diagonal link of variable length, characterised in that the one link is formed as a main link transmitting the traction, flexure and torsion forces and the other link is made of variable length.

2. Transmission according to Claim 1, characterised in that the main link and the link of variable length are directed approximately to the ideal guide point of the lower links of the three-point linkage.

3. Transmission for the adjustment of the width and the ideal tractor towing point of a mounted plough connected with the tractor by means of a three-point linkage substantially as described with reference to the accompanying drawings.