GB2325607A

GB2325607A - Boom mounted cutting implement

Info

Publication number: GB2325607A
Application number: GB9809838A
Authority: GB
Inventors: Michel Delbaere
Original assignee: Noremat SAS
Current assignee: Noremat SAS
Priority date: 1997-05-07
Filing date: 1998-05-07
Publication date: 1998-12-02
Also published as: FR2762962B1; FR2762962A1; GB9809838D0

Abstract

A cutting implement A having a horizontal rotor, borne on the end of an arm B is borne laterally by a vehicle C, mounted on a horizontal shaft D facing towards the front. The implement is mounted on said horizontal shaft D by coupling means E, by means of which it is drawn and not pushed.

Description

IMPROVEMENTS TO CUTTING DEVICES HAVING HORIZONTAL-AXIS ROTORS.

The present invention relates to improvements to cutting devices having horizontal-axis rotors.

These cutting implements, usually referred to as "hedgers", are used either for clearance or for mowing.

They are generally borne at the end of an articulated ann, arranged on the side of a vehicle such as a tractor or a lorry, which makes it possible to clear the verges of roads, ditches and embankments.

Since these articulated arms are arranged on the side of the bearing vehicles, this forces the driver to watch both the side of the vehicle and in front of the vehicle, which requires great attention and results in a very slow speed of advance.

In order to reduce this disadvantage, the hedger is arranged in front of the end of the articulated bearing arm, which positions it sufficiently far forward for the driver to be able to watch both the road in front of him and monitor the working implement more easily.

However, it turns out that when an implement of this type is pushed, it operates unsatisfactorily, because it tends to sink into the ground, which slows it down considerably and subjects the arm bearing it to very great stresses, such that the driver is constantly forced to raise it and lower it again. As a result, at the same time, the cutting height is irregular, the speed of advance is reduced and the driver becomes very tired.

According to a first aspect of the present invention, the implement is coupled to the end of the bearing arm by means of a coupling device which enables it to be both placed in front of said end of the bearing arm while being drawn and not pushed by this arm.

According to a second aspect of the present invention, elastic means are interposed between the coupling device and the implement.

By way of example and in order to facilitate understanding of the invention, the following have been shown in the appended drawings: Figure 1 a general diagrammatic view showing a cutting implement borne on the side of a tractor.

Figure 2 a detailed view of Figure 1 showing the conventional mounting of the cutting implement at the end of the arm in the pushed position.

Figure 3 a view of the device according to the present invention.

Figure 1 shows a cutting implement with a horizontal rotor A, which is borne at the end of an articulated arm B, arranged on the side of a tractor C.

As can be seen in this figure, the lateral arm B is fastened to the rear of the tractor C such that if the implement A were fastened to the rear of the end of the arm B, the driver would be forced to look back to monitor the work being performed. As a result, the driver would be obliged to turn his head constantly in order to monitor the progress of the tractor C and the work of the implement A at the same time.

In order to avoid this, as is shown in Figure 2, the implement A is arranged in front of the end of the arm B (the direction of advance being indicated by the arrow F), the implement A being borne by a horizontal shaft D arranged in front of the arm B, such that said implement A is free to rotate relative to the articulated arm B about the axis of the horizontal shaft D.

The implement thus positioned can be more readily monitored by the driver.

However, it turns out that a "dropping" phenomenon frequently occurs, that is to say that the implement A, owing to the fact that it is pushed from its rear, tends to sink into the ground when it encounters a significant resistance to its advance, which only serves to increase further said resistance to advance and hence the stress applied at the end of the arm B.

The driver therefore has to react immediately to lift the implement as soon as he notices resistance to its advance, and then to lower it again. The result is that the cutting height constantly varies, and the driver is obliged to be extremely vigilant, which causes him to reduce the speed of advance of the tractor.

Referring to Figure 3, it will be seen that according to the invention the implement A is connected to the horizontal shaft D by a coupling part designated by the general reference E which is interposed between the shaft D and the implement A.

This coupling part E is formed by a small horizontal beam 1, and by two arms 2, arranged in an inverted V, each arm 2 being firstly connected to the beam 1 at its upper end and secondly connected to a clevis 3 placed in front of the implement A at its lower end, this latter connection being effected by means of a journal 4.

The beam 1 is fastened in a U-shaped bar 5 fastened to the front end of the shaft D.

The implement A comprises a small beam 6 integral with its framework, of the same dimensions as the beam 1.

Thus the implement A may either be fastened directly to the end of the shaft D, the beam 6 being placed in the U-shaped part 5, or connected to the shaft D by means of the coupling part E, the beam 1 being placed in the part 5.

It is then possible to use the implement A either by pushing it or by drawing it, as desired.

Preferably, as shown in Figure 3, an elastic means is interposed between the coupling part E and the framework of the implement A.

In the example illustrated, the elastic means is formed by two springs 7 which bear firstly on the top of the framework of the implement A and secondly on the bottom of the beam 1.

Preferably, the two springs 7 are placed obliquely, their lower ends being further apart from one another than are their upper ends, which increases the lateral stability of the implement A.

According to the invention, the object of the elastic means is not to press the implement A elastically against the ground in order to increase its pressure on the ground, rather the object of this elastic means is that the implement A is elastically suspended at the end of the arm B in order to reduce its apparent weight acting on the ground. This is why the springs 7 are extension springs and not compression springs.

Thus, owing to the fact that the implement A is not only drawn but capable of pivoting about the transverse axis XX formed by the two journals 4 (this axis XX being located in front of the working parts), it can very easily follow the irregularities in the ground.

But most of all, owing to the fact that it is furthermore elastically suspended by the extension springs 7, the implement A very readily follows the irregularities in the ground.

It follows that not only the phenomena of dropping are prevented, but also the cutting quality is considerably improved, the vigilance required of the driver is reduced, which results in a considerable increase, of the order of 30%, in the speed of advance and hence of the efficiency of the implement.

Moreover, owing to the prevention of the dropping phenomena and the reduction in weight of the implement acting on the ground, it is possible, using the same tractor C and the same arm B, to use a heavier implement A, that is to say, one having a greater cutting width, which improves the efficiency still further.

On the other hand, when the implement A is used for clearance work comprising the removal of coppices or bushes, it must remain stable: in this case, the coupling device E is removed and the implement A is linked directly to the shaft D by the beam 6, as shown in Figure 2.

The present invention therefore makes it possible not only to adapt the implement A to the work to be carried out, mowing or clearance, but also in the case of mowing to obtain a considerable improvement in the efficiency of the work.

Obviously, the invention is not limited to the case in which the elastic means is formed of extension springs 7, and any other elastic device which performs the same function can be used.

Claims

1. A cutting implement (A) having a horizontal rotor, such as a hedger intended for use for clearance or mowing, borne, so that it can be raised or lowered, on the end of an articulated arm (B) arranged laterally on a vehicle (C), said implement (A) being positioned in front of the end of the articulated bearing arm, being mounted on a horizontal shaft (D) arranged in front of said articulated arm (B), characterised by the fact that said implement (A) is connected to the horizontal shaft (D) by coupling means (E), interposed between said shaft (D) and the implement (A), by means of which it is drawn and not pushed.

2. A cutting implement according to Claim 1, characterised by the fact that the implement (A), as desired, is either mounted on the horizontal shaft (D) by coupling means (E) by means of which it is drawn, or mounted directly on said horizontal shaft (D), in which case it is pushed.

3. A coupling device (E) for the cutting implement according to Claims 1 and 2, characterised by the fact that it is formed of: a small horizontal beam (1) to which are connected two arms (2) which in turn, at their other ends, are each connected to a clevis (3) by a journal (4), the two journals defining an axis (XX) about which the implement (A) can pivot.

4. A device according to Claim 3, characterised in that the horizontal shaft (D) located at the end of the articulated arm (B) is provided at its end with a fastening piece (5) into which can be fastened either the beam (1) of the coupling device (E) or a beam (6) of the same dimensions as the beam (1) fastened directly to the framework of the implement (A).

5. A coupling device according to Claim 3, in which an elastic means, operating in traction, is interposed between the coupling device and the framework of the implement (A), such that the latter can elastically pivot about the axis (XX).

6. A coupling device (E) according to Claim 5, in which the elastic means is formed by extension springs (7).

7. A coupling device (E) according to Claim 6, in which the two extension springs are arranged in an inverted V.

8. A cutting implement according to Claims 1 and 2, provided with a coupling device (E) according to Claim 5, characterised by the fact that it is elastically suspended from the end of the articulated arm (B) so as to be in contact with the ground with only part of its weight.

9. A cutting implement substantially as herein described with reference to the accompanying drawings.

10. A coupling device substantially as herein described with reference to the accompanying drawings.