The invention relates to a device for removing wood vegetation, wood vegetation hereinafter referred to as tree growth.

Especially in the countryside, the growth of perennial woody species in undesired places is a problem. These plants, mostly trees or shrubs, can reach several metres in height, are often densely packed and can seriously impair visibility for traffic. This could cause traffic accidents, or be part of the reason for traffic accidents, thereby compromising traffic safety.

It is therefore important that this tree growth is removed and that new shoots are prevented as far as possible.

In the past, this tree growth was primarily combated by killing the plants with herbicides; however, this method has since been prohibited by law. The tree growths are currently removed mechanically by cutting or sawing them off or completely uprooting them from the ground.

When cutting or sawing, there is the problem that the plant can grow very rapidly from the stub (=stump) up to several metres in height per year. Within a couple of months after removal of the tree growths, the stumps' new shoots can already cause serious hindrance for traffic. This is all the more problematic because without additional ecological measures, removal of these plants is only permitted in the winter months.

Complete uprooting from the ground has the

disadvantage that roots of the tree growth tear the turf and whole pieces of turf are taken out. This is particularly undesirable when the tree growth is located in the verge or in (the embankment of) a ditch.

Another solution could be to remove the tree growth with a mobile excavator with a standard bucket; the disadvantage of this is that with a bucket designed for the purpose of digging, a relatively large guantity of soil and turf material would also be taken out. Also, the tree growth excavated in this way could easily fall out of the bucket in an uncontrolled manner .

It is now an object of the invention to reduce or to prevent the abovementioned drawbacks.

This object is achieved with a device according to the preamble, which device comprises:

- a base frame for attaching the device to a mobile machine, such as a wheeled excavator;

- a subframe securely fixed to the base frame with a scissor part securely fixed to it;

- a movably on the subframe mounted part which, in conjunction with the fixed scissor part belonging to the subframe, over the bottom (horizontal) edge can perform a cutting function and over the other edges a pinching function.

In an open position, the movable part and the fixed part can be pushed a few centimetres into the ground, with the stubs of the to be removed tree growth being located between the movable part and the fixed part of the subframe. By moving the bottom edge of the movable part towards the fixed scissor part, the tree growth can underground be cut, torn off or even pushed up and finally cut off from its roots against the fixed scissor part. The stubs are disconnected from their roots that remain in the ground. The trunks of the, from the ground loosened, tree growth including the stubs can be clamped between the vertical edges of the fixed scissor part and the movable part. The movable part can be moved downwards from the subframe, as a result of which the tree growth, along with a small quantity of soil and turf material can be released from the device. The stubs of the tree growth removed in the manner described will die and can no longer grow new fast growing shoots. The roots that remain in the ground will also mostly die and will not produce fast growing new shoots.

The advantage of using the part which is movable relative to the subframe is that this, like the bucket of an excavator, can be pressed onto and partly into the ground and pressed through the turf when moving, assuring the stubs to be cut off deep enough under the ground surface in order to prevent woody plants growing again from the stubs as new shoots. The fixed part also ensures that the movable part does not go too deep into the ground, meaning that only a small quantity of soil and turf material is taken in the device.

In a preferred embodiment of the device according to the invention, the movable part is fixed to the subframe with hinges. The use of hinges has the advantage that controlled movement can be achieved in a constructively easy manner, which can be constructed in a simple and robust manner.

In another preferred embodiment of the device according to the invention, the device is constructed in such a way that the movable part can slide over the scissor part of the subframe. In this way a simple, firm and robust device can be obtained with which it is both possible to cut with certainty along the bottom edge and easily pinch the trunks of the tree growth along the other edges .

In another preferred embodiment of the device according to the invention, the bottom (horizontal) edge of the movable part consists of a bevelled cutting edge, which can easily cut through turf, ground and roots. Less force needs to be exerted in order to move the part that is movable in relation to the subframe.

In a highly preferred embodiment of the device according to the invention, the device is equipped with a power supply for moving the movable part towards the fixed scissor part. The use of a power supply has the advantage that the cut and pinch function can also be performed when considerable resistance, which will generally be the case, must be overcome.

A further embodiment of the device according to the invention involves powering the movement by means of one or more hydraulic cylinders. The use of hydraulic cylinders in this case has the advantage that large forces can be exerted with accuracy and fine control. Moreover, the mobile tools to which the device can be fitted are often equipped with a hydraulic system to which the hydraulic cylinders can be easily connected. The invention furthermore relates to a method for removing tree growth using a device according to the invention, which method comprises the following steps:

-A. positioning the device according to the invention with respect to the tree growth, in such a manner that the stubs of the tree growth are located between the movable part and the scissor part of the subframe.

-B. moving the movable part of the device according to the invention towards the scissor part of the subframe in such a way that the bottom edge of the movable part moves slightly under the ground, cuts through or tears off roots under the ground and finally cuts the stubs loose from the remaining roots against the scissor part of the subframe.

Roots, which have been cut through, torn loose or clipped, remain in the ground and will mostly die there. During the cutting, the movable part can be slid over the scissor part of the subframe if necessary. Due to this movement, the tree growth is clamped with the associated stubs between the movable part and the scissor part of the device's subframe.

-C. moving the movable part of the device according to the invention away from the scissor part of the subframe, allowing the tree growth and associated stubs to be released and deposited on site.

The steps are repeated until the tree growth has been sufficiently removed.

In a preferred embodiment of the method according to the invention, before releasing the tree growth from the device, the following process step is carried out:

- the device according to the invention, including the loosened tree growth, is moved to a desired site where the tree growth and stubs can be deposited by moving the mobile machine to which the device is attached. Such a desired site, from where the deposited tree growth can usually be easily further

collected and transported, is generally located within ten metres from the site where the tree growth is removed.

In strongly preferred embodiment of the method according to the invention, the device is attached to the boom of a wheeled excavator. A large part of the required movements and positionings of the whole device in accordance with the invention can only be performed by using the boom of the wheeled excavator.

These, and other, characteristics of the invention are explained in more detail by means of the enclosed drawings.

Figure 1 shows a perspective view of a first embodiment of the device according to the invention;

Figure 2 shows a side view of the device from Fig. 1;

Figure 3 shows a perspective view of the device from Fig. 1 fitted to a wheeled excavator and in use.

Figure 1 shows a device 1 for removing tree growth. Device 1 has a base frame (2) that can be connected, for example, to the boom of an excavator.

Subframe 3 is rigidly fixed to base frame 2. Subframe 3 is equipped with a scissor part 7. Movable part 6 is attached with hinges to subframe 3 by means of hinge shaft 4. The position of movable part 6 can be set up in relation to subframe 3 by means of hydraulic cylinders (5). Here, movable part 6 can rotate around shaft 4 until scissor part 7 is located within movable part 6. Movable part 6 has a bottom edge 8, which can cut through ground, turf and roots and cut off the stubs in conjunction with the lower edge of scissor part 14. The tree growth can be clamped between other, in this case two vertical, edges of scissor part 15 and the corresponding edges 16 of the movable part.

Figure 2 shows a side view of the device 1 from Figure 1 in the open position. In this position, the device can be positioned in such a way that the bottom parts of the trunks of the tree growth to be removed are located between scissor part 7 and movable part 6.

In Figure 3, the device is shown in operation, attached to the boom 10 of a mobile crane 11 located on the road 12. With movable part 6 with cutting edge 8, the roots of the tree growth beside the road 13 are cut through, torn off or cut off from the stubs by shifting movable part 6 with the bottom cutting/shearing edge 8, around scissor part 7 of subframe 3. The clipped tree growth 9 is clamped between the vertical edges of scissor part 7 and the corresponding vertical edges of movable part 6. The device is then brought, by moving the boom of the crane, to a position where the clipped tree growth 9 can be released.