GB2059734A

GB2059734A - Skim coulter

Info

Publication number: GB2059734A
Application number: GB8027397A
Authority: GB
Original assignee: FARM MILJOE HB
Current assignee: FARM MILJOE HB
Priority date: 1979-09-07
Filing date: 1980-08-22
Publication date: 1981-04-29
Also published as: DK378380A; DE3033569A1; FI802709A; FR2464620A1; SE430202B; SE7907444L

Abstract

This invention relates to a skim coulter for cutting off and laying down a strand of the furrow slice which is formed in the ploughing of soil by a plough provided with a conventional ploughshare (14) see Figure 2 (not shown), which skim coulter is provided with a blade (6) which is attached above the ploughshare and can swing back in relation to the ploughshare when overloaded. An adjustable biasing force (8) resists the break-back movement and the position of the coulter blade relative to the ploughshare is adjustable. The skim coulter according to the invention can prevent adherence of soil on its blade and effect more constant contact of the blade with the soil. <IMAGE>

Description

SPECIFICATION Skim coulter This invention relates to a so-called skim coulter as an attachment to ploughs intended for soil working, i.e. ploughing.

When ploughing with conventional ploughs the ploughshare cuts open a soil layer in the form of a furrow slice, which thereafter is turned over by the mould-board through 180 . The thickness and width of the furrow slice are determined by the working depth of the plough and by the size and shape of the ploughshare. The plough result depends on how well the plough turns over the slice and how tightly adjacent one another are the resultant ridges laid by the plough. When ploughing with conventional ploughs, however, the result suffers from the fact that plants at one edge of the ridge often are not covered with soil but continue to grow after ploughing. A further undesirable result is a tendency for cavities to form between or beneath the ridges when they are of a relatively rigid nature.

It is known that, in order to improve the ploughing result, ploughs are provided with skim coulters, which cut off a strand along that edge of the furrow slice which it is difficult to cover with soil and thereby prevent continued plant growth. After said strand has been cut off it is positioned by the coulter beneath the ridge so that no cavities are formed in the ploughing operation. Conventional skim coulters, however, are mounted rigidly relative to the ploughshare and have the disadvantage that soil lumps and straw readily adhere to the coulters and gradually accumulate to form large heaps which, upon their release from the plough, renderthe ploughing non-uniform. Skim coulters occasionally become overloaded and thereby bring about a ploughing result which is worse than itwould have been had the plough only been used.Another disadvantage of the known skim coulters is that they cut off from the furrow slice too thick a strand when, due to varying soil hardness, the ridge increases in thickness, with consequent increase in the ploughing resistance beyond the tractor capacity. Similarly the skim coulters lose their contact with the furrow slice when the slice decreases in depth, whereby plant growth remains at the ridge edge. When the coulter disengages from the ridge, straw usually adheres to the coulter and facilitates the accumulation of adhering soil lumps.

The present invention aims to produce a skim coulterwhich avoids or ameliorates the shortcomings of known constructions. This object is achieved in that the coulter is attached so that during the ploughing operation it is movable relative to the ploughshare according to the load exerted by the soil on the coulter. It has been found that no soil lumps adhere to the coulter and, consequently, no heaps accumulate on the plough. Furthermore, the coulter upon being overloaded swings back and thereby opens a passage for the ridge over the ploughshare. By changing the tension of the spring, the coulter can be so adjusted that it swings back at a predetermined load. A further aim of the invention is to maintain the skim coulter by its resilience always in contact with the ridge, so that a strand always is cut off and thereby prevents straw from adhering to the coulter blade.

An embodiment of the invention is described in the following description by way of example and with reference to the accompanying drawing, in which: Fig. lisa iateral view of the invention attached to a conventional plough; and Fig. 2 is a view from above of the invention at the secion A-A in and enlarged relative to Fig. 1.

The skim coulter is attached to the plough beam 1 through a holding plate 2, which is provided with two shackles 3 and a bracket 4, to which the movable parts of the coulter are attached. The movable parts consist of a swing arm 5 provided with a blade 6, a prestressing arm 7 for adjusting the desired initial stress of a spring 8 mounted between the swing arm 5 and prestressing arm 7, a cylinder 9 mounted eccentrically on the prestressing arm 7 and upon rotation increasing or reducing the distance between the holding plate 2 and the prestressing arm 7 and thereby increasing and, respectively, decreasing the initial stress in the spring 8, a control arm 10 attached to the cylinder 9 and a toothed disc segment 11 rigidly attached to the prestressing arm 7, to which disc the control arm 10 can be fixed in different positions corresponding to the degrees of initial stress in the spring 8.The swing arm 5 is pressed by the spring 8 against an adjustable stop member 12 on the bracket 4.

The blade 6 is attached to the swing arm 5 through a ball joint 13, whereby the blade 6 can be swung in all directions about said joint. The position of the blade 6 in the vertical direction can be adjusted in that the swing arm 5 is designed as a two-piece arm, the two pieces of which are telescopically movable relative to one another. When the skim coulter according to the invention is being attached to a plough comprising a share 14, the position of the blade 6 relative to the share 14 is adjusted by adjusting the position of the holding plate 2 on the plough beam 1, by adjusting the inclination of the swing arm 5 by means of the stop member 12, by adjusting the length of the swing arm 5 and by adjustment at the ball joint 13.

1. A skim coulter for cutting off and laying down a strand of a furrow slice formed in the ploughing of soil by a plough provided with a ploughshare, which skim coulter is provided with a blade, for attachment to the plough above the ploughshare by a swing arm, which allows the bladeto swing rearwardly, substantially against the ploughing direction, from an initial position againstthe bias of a spring means tending to return the swing arm to its initial position, characterized in that the skim coulter is provided with an adjusting means for adjusting the position of the blade in relation to the swing arm and ploughshare, and with means to prestress the spring means.

2. A skim coulter as claimed in claim 1, characterized in that the prestressing means comprises a prestressing arm, an eccentrically mounted cylinder

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

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Skim coulter This invention relates to a so-called skim coulter as an attachment to ploughs intended for soil working, i.e. ploughing. When ploughing with conventional ploughs the ploughshare cuts open a soil layer in the form of a furrow slice, which thereafter is turned over by the mould-board through 180 . The thickness and width of the furrow slice are determined by the working depth of the plough and by the size and shape of the ploughshare. The plough result depends on how well the plough turns over the slice and how tightly adjacent one another are the resultant ridges laid by the plough. When ploughing with conventional ploughs, however, the result suffers from the fact that plants at one edge of the ridge often are not covered with soil but continue to grow after ploughing. A further undesirable result is a tendency for cavities to form between or beneath the ridges when they are of a relatively rigid nature. It is known that, in order to improve the ploughing result, ploughs are provided with skim coulters, which cut off a strand along that edge of the furrow slice which it is difficult to cover with soil and thereby prevent continued plant growth. After said strand has been cut off it is positioned by the coulter beneath the ridge so that no cavities are formed in the ploughing operation. Conventional skim coulters, however, are mounted rigidly relative to the ploughshare and have the disadvantage that soil lumps and straw readily adhere to the coulters and gradually accumulate to form large heaps which, upon their release from the plough, renderthe ploughing non-uniform. Skim coulters occasionally become overloaded and thereby bring about a ploughing result which is worse than itwould have been had the plough only been used.Another disadvantage of the known skim coulters is that they cut off from the furrow slice too thick a strand when, due to varying soil hardness, the ridge increases in thickness, with consequent increase in the ploughing resistance beyond the tractor capacity. Similarly the skim coulters lose their contact with the furrow slice when the slice decreases in depth, whereby plant growth remains at the ridge edge. When the coulter disengages from the ridge, straw usually adheres to the coulter and facilitates the accumulation of adhering soil lumps. The present invention aims to produce a skim coulterwhich avoids or ameliorates the shortcomings of known constructions. This object is achieved in that the coulter is attached so that during the ploughing operation it is movable relative to the ploughshare according to the load exerted by the soil on the coulter. It has been found that no soil lumps adhere to the coulter and, consequently, no heaps accumulate on the plough. Furthermore, the coulter upon being overloaded swings back and thereby opens a passage for the ridge over the ploughshare. By changing the tension of the spring, the coulter can be so adjusted that it swings back at a predetermined load. A further aim of the invention is to maintain the skim coulter by its resilience always in contact with the ridge, so that a strand always is cut off and thereby prevents straw from adhering to the coulter blade. An embodiment of the invention is described in the following description by way of example and with reference to the accompanying drawing, in which: Fig. lisa iateral view of the invention attached to a conventional plough; and Fig. 2 is a view from above of the invention at the secion A-A in and enlarged relative to Fig. 1. The skim coulter is attached to the plough beam 1 through a holding plate 2, which is provided with two shackles 3 and a bracket 4, to which the movable parts of the coulter are attached. The movable parts consist of a swing arm 5 provided with a blade 6, a prestressing arm 7 for adjusting the desired initial stress of a spring 8 mounted between the swing arm 5 and prestressing arm 7, a cylinder 9 mounted eccentrically on the prestressing arm 7 and upon rotation increasing or reducing the distance between the holding plate 2 and the prestressing arm 7 and thereby increasing and, respectively, decreasing the initial stress in the spring 8, a control arm 10 attached to the cylinder 9 and a toothed disc segment 11 rigidly attached to the prestressing arm 7, to which disc the control arm 10 can be fixed in different positions corresponding to the degrees of initial stress in the spring 8.The swing arm 5 is pressed by the spring 8 against an adjustable stop member 12 on the bracket 4. The blade 6 is attached to the swing arm 5 through a ball joint 13, whereby the blade 6 can be swung in all directions about said joint. The position of the blade 6 in the vertical direction can be adjusted in that the swing arm 5 is designed as a two-piece arm, the two pieces of which are telescopically movable relative to one another. When the skim coulter according to the invention is being attached to a plough comprising a share 14, the position of the blade 6 relative to the share 14 is adjusted by adjusting the position of the holding plate 2 on the plough beam 1, by adjusting the inclination of the swing arm 5 by means of the stop member 12, by adjusting the length of the swing arm 5 and by adjustment at the ball joint 13. CLAIMS

2. A skim coulter as claimed in claim 1, characterized in that the prestressing means comprises a prestressing arm, an eccentrically mounted cylinder mounted to the prestressing arm for reaction against the plough, a contJi arm for rotating the cylinder relative to the prestressing arm to vary the distance between said arm and that part of the plough against which the cylinder reacts, and a toothed disc attached on the prestressing arm, to which disc the control arm can be fixed in any one of a plurality of different positions.

3. A skim coulter as claimed in claim 1 or 2, characterized in that the adjusting means comprises a ball joint

4. A skim coulter as claimed in claim 1,2 or3, characterized in that it comprises a holding plate attachable to a beam of the plough with two shackles and a bracket provided with an adjustable stop member, in which bracket the swing arm is supported.

5. A skim coulter having a mounting for attachmentto a mould-board plough and a blade connected to the mounting by a swing arm which allows the blade to swing rearwardly relative to the ploughing direction from an initial position of the blade taken up by the blade during ploughing when the blade is subject to normal soil pressure, a spring means being provided to resist said rearward swinging and return the blade to the initial position when the soil pressure on the blade returns to normal.

6. A skim counter substantially as hereinbefore described by reference to, and as shown in, the accompanying drawings.

7. A plough fitted with one or more skim coulters as claimed in any one of the preceding claims.