GB1589050A

GB1589050A - Agricultural implement support structure

Info

Publication number: GB1589050A
Application number: GB22869/78A
Authority: GB
Original assignee: Maskinfabriken Taarup AS
Current assignee: Maskinfabriken Taarup AS
Priority date: 1977-06-17
Filing date: 1978-05-25
Publication date: 1981-05-07
Also published as: DK269577A; FR2394236A1; DE2825678A1; DK141741B; DK141741C; FR2394236B1; IT1096386B; ES470809A1; IT7824324A0; NL7806217A

Description

(54) AGRICULTURAL IMPLEMENT SUPPORT STRUCTURE (71) We, MASKINFABRIKEN TAARUP A/S, a Danish company, of DK-5300 Kerteminde, Denmark, 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 performed, to be partic ularly described in and by the following statement: This invention relates to a support struc ture for securing a mowing beam or other agriculture implement to the three-point linkage of a tractor.

The specification of British Patent Application No. 11246/78 (Serial No 1 586730) discloses such a support structure which permits the agricultural implement, when it hits a stone or other dangerous obstacle, to swing rearwards and upwards so as to pass the obstacle. When the implement has passed the obstacle undamaged a balance spring, which is a pull (tension) spring, automatically draws it into the correct operating position again. In this support structure the weight of the agricultural implement is substantially carried by the balance spring. Therefore, there are limits to the size and weight of the implements that can be used in connection with this support structure.

According to the present invention there is provided a support structure for securing a mowing beam or other agricultural implement to the three-point linkage of a tractor, which support structure comprises a swing beam disposed transversely of the intended direction of operative travel of the tractor, one end of the swing beam protruding beyond the tractor as viewed from the rear and being adapted for carrying the agricultural implement, the other end of the swing beam, located behind the tractor, being adapted to be directly and swingably connected to the upper arm of the three-point linkage and to that one of the lower arms of the three-point linkage which is located farthest away from the protruding end of the swing beam so that the beam can swing around a line through these two connecting points, the portion of the swing beam abreast of the second lower arm of the three-point linkage being provided with a bracket extending forwardly with respect to said intended direction of travel, which bracket has an abutment for the upper end of a compression spring whose lower end is connected to said second lower arm of the three-point linkage. Such a support structure, while retaining the provision for rearward swing and automatic backswing of the agricultural implement, may be used for even bigger and heavier implements than the support structure of Application No.

11246178 (Serial No. 1586 730).

The invention will be described in more detail below, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a support structure securing an agricultural implement to a tractor in its operating position, and Figure 2 shows the same support structure with the agricultural implement in a rearwards swung position.

The drawings show the three-point linkage of a tractor, comprising an upper arm 1 and two lower arms 2 and 3. A swing beam 4 which comprises a substantially horizontal portion 4a disposed transversely to the intended direction of operative travel of the tractor and a downwardly sloping portion 4b connected thereto, is swingably connected to the upper arm 1 and the lower arm 2 so that it can swing around a line through these connecting points. One side of the horizontal portion 4a of the swing beam 4 extends beyond the tractor as viewed from the rear and has a bearing 5 in which an agricultural implement 6 is journalled.

Abreast of the lower arm 3 of the threepoint linkage a bracket 7 is secured on the upper surface of the portion 4a of the swing beam which bracket extends forwardly with respect to the intended direction of travel and has an abutment 8 for the upper end of a compression spring 9 whose lower end is connected to the lower arm 3 by a U-shaped support 10. The compression spring 9 is fitted around a guide rod 11 that may slide freely through the abutment 8.

The bracket 7 has a depending portion 12 whose lower end is provided with a contact member 13 which in the operating position of the agricultural implement is adapted to engage a corresponding abutment member 14 at the rearmost end of the lower arm 3, that is at the lower end of the spring 9.

In use the two linkages (the arms 1 and 2) of the three-point linkage of the tractor to which the swing beam 4 is swingably connected contribute considerably towards carrying the weight of the agricultural implement 6 and the swing beam 4, while in all essentials the function of the compression spring 9 is merely to apply to the swing beam 4 a sufficient turning moment around the line through the two connecting points to the arms 1 and 2 for maintaining the beam 4 in the position which corresponds to the operating position of the agricultural implement 6. At the same time the compression spring 9 makes it possible to adjust the pressure of the implement 6 against the ground. When the implement 6 hits an obstacle it forces rearwards the end of the swing beam 4 protruding beyond the tractor whereby the swing beam 4 swings around the line through its two connecting points with the upper arm 1 of the tractor linkage and the arm 2 located farthest away from the protruding end of the swing beam 4, respectively. This swing causes the compression spring 9 to be compressed, which forces the swing beam 4 to swing back once the obstacle has been passed.

During the rearward swing of the swing beam 4 and the consequent swing around the line just mentioned the agricultural implement 6 is lifted upwardly and over the obstacle.

In a preferred embodiment of the support structure, the compression spring 4 is provided with means for adjusting the force it exerts in the position of the swing beam 4 which corresponds to the operating position of the agricultural implement 6. The contact member 13, in co-operating with the abutment member 14, serves to define the position of the swing beam 4 which corresponds to the operating position of the agricultural implement 6.

WHAT I CLAIM IS:- 1. A support structure for securing a mowing beam or other agricultural implement to the three-point linkage of a tractor, which support structure comprises a swing beam disposed transversely of the intended direction of operative travel of the tractor, one end of the swing beam protruding beyond the tractor as viewed from the rear and being adapted for carrying the agricultural implement, the other end of the swing beam located behind the tractor, being adapted to be directly and swingably connected to the upper arm of the threepoint linkage and to that one of the lower arms of the three-point linkage which is located farthest away from the protruding end of the swing beam so that the beam can swing around a line through these two connecting points, the portion of the swing beam abreast of the second lower arm of the three-point linkage being provided with a bracket extending forwardly with respect to said intended direction of travel, which bracket has an abutment for the upper end of a compression spring whose lower end is connected to said second lower arm of the three-point linkage.

2. A support structure according to claim 1, wherein the compression spring is provided with means for adjusting the force it exerts in the position which corresponds to the operating position of the agricultural implement.

3. A support structure according to claim 1 or 2, wherein the bracket has a downwardly extending portion provided with a contact member for co-operating with a corresponding abutment member at the lower end of the compression spring for defining the position of the swing beam which corresponds to the operating position of the agricultural implement.

4. A support structure substantially as described herein with reference to the accompanying drawings.

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. rod 11 that may slide freely through the abutment 8. The bracket 7 has a depending portion 12 whose lower end is provided with a contact member 13 which in the operating position of the agricultural implement is adapted to engage a corresponding abutment member 14 at the rearmost end of the lower arm 3, that is at the lower end of the spring 9. In use the two linkages (the arms 1 and 2) of the three-point linkage of the tractor to which the swing beam 4 is swingably connected contribute considerably towards carrying the weight of the agricultural implement 6 and the swing beam 4, while in all essentials the function of the compression spring 9 is merely to apply to the swing beam 4 a sufficient turning moment around the line through the two connecting points to the arms 1 and 2 for maintaining the beam 4 in the position which corresponds to the operating position of the agricultural implement 6. At the same time the compression spring 9 makes it possible to adjust the pressure of the implement 6 against the ground. When the implement 6 hits an obstacle it forces rearwards the end of the swing beam 4 protruding beyond the tractor whereby the swing beam 4 swings around the line through its two connecting points with the upper arm 1 of the tractor linkage and the arm 2 located farthest away from the protruding end of the swing beam 4, respectively. This swing causes the compression spring 9 to be compressed, which forces the swing beam 4 to swing back once the obstacle has been passed. During the rearward swing of the swing beam 4 and the consequent swing around the line just mentioned the agricultural implement 6 is lifted upwardly and over the obstacle. In a preferred embodiment of the support structure, the compression spring 4 is provided with means for adjusting the force it exerts in the position of the swing beam 4 which corresponds to the operating position of the agricultural implement 6. The contact member 13, in co-operating with the abutment member 14, serves to define the position of the swing beam 4 which corresponds to the operating position of the agricultural implement 6. WHAT I CLAIM IS:-

1. A support structure for securing a mowing beam or other agricultural implement to the three-point linkage of a tractor, which support structure comprises a swing beam disposed transversely of the intended direction of operative travel of the tractor, one end of the swing beam protruding beyond the tractor as viewed from the rear and being adapted for carrying the agricultural implement, the other end of the swing beam located behind the tractor, being adapted to be directly and swingably connected to the upper arm of the threepoint linkage and to that one of the lower arms of the three-point linkage which is located farthest away from the protruding end of the swing beam so that the beam can swing around a line through these two connecting points, the portion of the swing beam abreast of the second lower arm of the three-point linkage being provided with a bracket extending forwardly with respect to said intended direction of travel, which bracket has an abutment for the upper end of a compression spring whose lower end is connected to said second lower arm of the three-point linkage.