Welding adapter with clearing knife

Abstract

Welding adapter with clearing knife for excavators with a fastening device for the excavator arm on the top of a welding plate (1), wherein the clearing knife is designed as a hook arranged on the underside of the welding plate, which consists of a part (2) projecting downwards from the underside of the welding plate (1) and a part (3) extending transversely thereto, and which tapers at least on one side over its entire length transversely to the plane of the hook to a sharp knife edge (4), characterized in that the hook is formed from two plates (2, 3), one of which, designated as a cutting plate (2), forming the downwardly projecting part, is attached with an edge to the underside of the welding plate (1), and one of which, designated as a cutting plate (3), forming the part extending transversely to the downwardly projecting part, is attached to the lower edge of the cutting plate (2) transversely thereto.wherein at least one edge of the stitch plate and scraper plate is tapered on the same side towards the knife edge (4), wherein the knife edge of the scraper plate projects beyond the knife edge of the stitch plate, and wherein the stitch plate and the scraper plate form legs of an ‘L’.

Description

[0001] The invention relates to a welding adapter with a rotary knife and a method for removing rootstocks.

[0002] When trees are felled, especially in parks and urban areas, the stumps and roots—hereafter, the rootstock—must be removed. This is done to allow for leveling and replanting of the surface, and in cases where a tree is to be planted again in the same location. Roots left in the planting area have a biologically adverse effect on the growth of new trees.

[0003] The current state of the art involves milling away root fragments. Stump grinders are used for this purpose, which have a number of disadvantages: The milling depth is limited by the radius of the milling drums. The excavated material is a mixture of soil and wood chips. Stump grinders are expensive.

[0004] Another state-of-the-art solution is proposed in DE 936 605 B. It is a "digging hook" or "digging tooth," which is usually referred to as a "ripper tooth" in the state of the art. This "ripper tooth" is attached to the end of an excavator arm. It is guided under the tree stump by the excavator arm and then moved upwards, resulting in the tree stump being torn out.

[0005] This solution has the disadvantage that very heavy excavators must be used because the forces required to tear out a tree stump are very high. To avoid this disadvantage, DE 19 40 446 A proposes that the ripper tooth be pushed under the tree stump in a rotating manner until the excavator arm rests on the ground, and the tree stump is then torn out of the earth by the continued rotation of the ripper tooth. This solution has not been adopted.

[0006] Another solution is disclosed in DD 242 161 A1: It is a device for splitting tree stumps with two cutting elements, similar to pliers or scissors. The two elements enclose the tree stump, close together, and thus cut—split—the stump. A disadvantage is that the forces required for the splitting process must be applied via a hydraulic mechanism, which must be very complex to implement because these forces are very high.

[0007] The object of the invention is to provide a cost-effective device and a method for removing even deep root stumps in such a way that the woody parts can be removed largely unmixed with soil. This object is achieved by a welding adapter according to claim 1 and a method according to claim 11.

[0008] Welding adapters are commercially available accessories for excavators. These are plates with a mounting device on the top for the excavator arm. The arm hooks and snaps into this mounting device from above. Any desired device can be welded to the underside of the plate, which then moves with the excavator.

[0009] In the Fig. 1 to Fig. Figure 3 of the drawing shows an embodiment of the invention.

[0010] According to the invention, a hook is provided on the underside of the welding plate (1), which is tapered at least on one side transversely to the hook plane so that a sharp edge - hereinafter: knife edge (4) - is formed. (Claim 1)

[0011] Such a hook can be made from plates. A plate is attached to the underside of the welding plate with one of its edges projecting downwards from the welding plate - hereinafter: throat plate (2). A further plate is attached to the edge (6) of the throat plate facing away from the welding plate in such a way that its surface is perpendicular to the surface of the throat plate - hereinafter: scraper plate (3). Of the two other edges of the throat plate and scraper plate, at least one each is tapered to the knife edge (4). The taper is expediently achieved by leaving one of the boundary planes of the plates unchanged and the other being beveled towards the knife edge.

[0012] This allows rootstocks to be removed with an excavator in such a way that the wood of the stump with the approximately vertically running fibers is split or scraped off with the throat plate (2) and at the same time the root parts close to the trunk are scraped or split off by the scraping plate (3), also approximately along their fibers.

[0013] The throat plate (2) is advantageously positioned on the welding plate (1) so that its surface lies in the plane in which the excavator arm moves. This results in the knife edge (4) pointing in this direction. This arrangement is also preferred if the hook does not consist of a throat plate and welding plate but is constructed in a different way.

[0014] An angle of attack of around 5° is also useful, as it facilitates the penetration of the throat plate into the trunk part of the rootstock. It is advisable to give the knife edge of the throat plate an angle of attack similar to the blade in a plane. This angle, by which the plane on which the excavator arm performs its movements is inclined relative to one of the two planes forming the knife edge, must not be greater than 5°. This angle of attack further facilitates the penetration of the throat plate into the trunk part of the rootstock. If the angle is greater, this is not made easier, but rather more difficult.

[0015] Advantageously, the throat plate (2) is positioned perpendicularly to the welding plate (1) and the scraping plate (3) is positioned perpendicularly to the throat plate. (Claim 3)

[0016] However, an exact right angle is not a prerequisite for the usability of the device. A right angle between the throat plate (2) and the welding plate (1) is particularly advantageous, and an angle (α) between the throat plate (2) and the scraping plate (3) which deviates from a right angle by no more than 10°, so that the throat plate and scraping plate are arranged in a manner similar to an open hook. This arrangement improves the functionality of the device in the following application: If a root stock has already been largely worked off and the roots have been cut off at the edge of the intended excavation pit, the excavator can be driven under the root stock, which has thus already been largely separated from the soil, and the entire root stock can be excavated using the "hook" formed by the throat plate and scraping plate. (Claim 4)

[0017] With this arrangement, it is advantageous that the center of gravity of the scraper plate, when its surface is flat, is positioned vertically below the center of gravity of the entire machine. This ensures that the entire machine rests securely on the scraper plate, which in turn allows for easy gripping and locking of the weld plate's fastening elements to the excavator arm.

[0018] If only one edge of the throat plate and scraper plate is designed as a knife edge, it is advisable for this edge to face the excavator. This allows the excavator's arm to be moved like a shovel excavator: It begins the work cycle extended, moves downward in a circular motion, and continues this movement back toward the excavator, with the knife edges splitting or cutting the rootstock material.

[0019] Particularly advantageous is the arrangement of the scraper plate (3) to the throat plate (2) such that the blade edge (4) of the scraper plate protrudes beyond the blade edge of the throat plate. (7) This arrangement ensures that both edges do not strike the rootstock as a single edge, which would immediately require the excavator to overcome considerable resistance. Instead, the blade edge of the scraper plate digs into the rootstock first, followed by the blade edge of the throat plate. (Claim 5)

[0020] It is also particularly advantageous if the angle (β) between the cutting edge of the scraper plate and the plane of the throat plate deviates from a right angle. This results in the blade edge of the scraper plate, when it hits the rootstock, not immediately across its entire length but at an angle, resulting in a pulling cut that utilizes the excavator's power particularly effectively. (Claim 6)

[0021] To optimize the knife edge, two requirements must be observed, which lead to opposing effects. The more acute the angle (γ) between the two planes forming the knife edge, the better it cuts and the more susceptible it is to damage. The more obtuse this angle (γ), the worse it cuts and the more robust it is in terms of damage. According to the invention, it is proposed that the angle (γ) be set no more acute than 25° and no more obtuse than 35°.

[0022] This simultaneously achieves a good dimensioning of the "nose" (7), which forms the cutting edge of the scraping plate where it meets the cutting edge of the throat plate, provided the design proposed in claims 5 and 6 is selected. Since the forces of the excavator act on the rootstock material in a point-like manner, very high pressures are generated there, which effectively initiate the subsequent splitting, peeling, or scraping. (Claim 7)

[0023] If the hook is formed with a throat plate and a welding plate, it should be large enough to allow efficient operation. For the same reason, it should not be too large. The following dimensions are suggested: A length between 20 cm and 40 cm is suggested for the knife edge (4) of the throat plate (2). For the knife edge (4) of the scraper plate (3), a length of between 5 cm and 15 cm is preferred. The edge formed by the throat plate and scraper plate preferably has a length of between 20 cm and 30 cm. (Claim 8)

[0024] If the hook according to the invention is designed with a throat plate and a welding plate, then the plates are usually welded together. The high forces that occur place such significant stress on the weld seams that they can tear. According to the invention, it is proposed that these points (5), (6) be reinforced. Either by reinforcing the weld seams themselves or by welding in metal rods, such as angle bars. This always results in the welding plate (1) and the scraper plate (3) being thicker there than in the rest of the plate area. (Claim 9)

[0025] As material for the throat plate (2) and the scraper plate (3) it is advisable to use steel with the properties that Hardox ® 500. (Claim 10)

Claims

[1] Welding adapter with a clearing knife for excavators with a fastening device for the arm of the excavator on the upper side of a welding plate (1), wherein the clearing knife is designed as a hook arranged on the underside of the welding plate, which hook consists of a part (2) projecting downwards from the underside of the welding plate (1) and a part (3) running transversely to this part and which is tapered at least on one side over its entire length transversely to the hook plane to a sharp knife edge (4), characterized bythat the hook is formed from two plates (2, 3), of which one plate (2), referred to as the throat plate, which forms the downwardly projecting part, is fastened by one edge to the underside of the welding plate (1), and one plate (3), referred to as the scraping plate, which forms the part running transversely to the downwardly projecting part, is fastened transversely to the lower edge of the throat plate (2), wherein at least one edge of the throat plate and the scraping plate are tapered on the same side to the knife edge (4), wherein the knife edge of the scraping plate projects beyond the knife edge of the throat plate, and wherein the throat plate and the scraping plate form legs of an "L". [2] Welding adapter according to the preceding claim, characterized by that the throat plate (2) is arranged vertically on the welding plate (1), and the scraping plate (3) is arranged vertically on the throat plate (2). [3] Welding adapter according to one of the preceding claims, characterized by that the angle (α) between the throat plate (2) and the cutting plate (3) is less than 90° and greater than 80°, [4] Welding adapter according to one of the preceding claims, characterized by that the knife edge (4) of the scraper plate (3) protrudes beyond the knife edge (4) of the throat plate (2). [5] Welding adapter according to one of the preceding claims, characterized by that the knife edge (4) of the scraper plate (3) and the line on which the scraper plate (3) and throat plate (2) abut each other are sides of an angle (β) which is less than 90°. [6] Welding adapter according to one of the preceding claims, characterized by that the angle (γ) between the two surfaces defining the knife edge (4) is greater than 25° and less than 35°. [7] Welding adapter according to one of the preceding claims, characterized bythat the knife edge (4) of the throat plate (2) has a length between 20 cm and 40 cm and / or the knife edge (4) of the scraper plate (3) has a length between 5 cm and 15 cm. [8] Welding adapter according to one of the preceding claims, characterized by that at least one inner edge (6) between the throat plate (2) and the scraping plate (3) or one inner edge (5) between the throat plate (2) and the welding plate (1) is reinforced in such a way that the respective material thickness is greater there than in the remaining area of the plates.

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