Abstract
A clearing strip for the clearing shield of a snow plow has a front steel plate and a rear steel plate between which an elastic rubber layer with at least one hard material body embedded in the rubber compound thereof is incorporated by vulcanization. The hard material body is movable relative to the steel plates with elastic deformation of the rubber compound. To better secure the hard material bodies embedded in the rubber compound against uncontrolled fall-out from the clearing strip upon overheating, each individual hard material body is anchored within the clearing strip by an additional anchoring device that does not limit the movability of the hard material bodies relative to the steel plates.
Claims
1. A clearing strip (1) for the clearing shield of a snow plow, which strip has a front steel plate (2) and a rear steel plate (4), between which an elastic rubber layer (5) having at least one hard-material body (6) embedded into the rubber compound is vulcanized in, wherein the hard-material body (6) is movable relative to the steel plates (2, 4), with elastic deformation of the rubber compound, wherein each individual hard-material body (6) is anchored in the interior of the clearing strip (1) by means of an additional anchoring apparatus, wherein this additional anchoring apparatus does not restrict the movability of the hard-material bodies (6) relative to the steel plates (2, 4), wherein the anchoring apparatus has at least one anchoring element that is passed through the hard-material body (6), and wherein the anchoring apparatus has at least one bolt (9e), which is attached with play through the hard-material body (6) and rigidly on the rear and/or front steel plate (2, 4).
2. The clearing strip (1) according to claim 1, wherein the anchoring apparatus comprises a heat-resistant material.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Other objects and features of the invention will become apparent from the following detailed description considered in connection with the accompanying drawings. It is to be understood, however, that the drawings are designed as an illustration only and not as a definition of the limits of the invention.
(2) In the drawings,
(3) FIG. 1a: shows schematically, the front view of a clearing strip according to the invention, using a first exemplary embodiment.
(4) FIG. 1b shows schematically, a cross-section through the clearing strip from FIG. 1a;
(5) FIG. 2a shows schematically, the front view of a clearing strip according to the invention, using a second exemplary embodiment;
(6) FIG. 2b shows schematically, a cross-section through the clearing strip from FIG. 2a;
(7) FIG. 3a shows schematically, the front view of a clearing strip according to the invention, using a third exemplary embodiment;
(8) FIG. 3b shows schematically, a cross-section through the clearing strip from FIG. 3a;
(9) FIG. 4a shows schematically, the front view of a clearing strip according to the invention, using a fourth exemplary embodiment;
(10) FIG. 4b shows schematically, a cross-section through the clearing strip from FIG. 4a;
(11) FIG. 5a shows schematically, the front view of a clearing strip according to the invention, using a fifth exemplary embodiment;
(12) FIG. 5b shows schematically, a cross-section through the clearing strip from FIG. 5a;
(13) FIG. 6a shows schematically, the front view of a clearing strip according to the invention, using a sixth exemplary embodiment;
(14) FIG. 6b shows schematically, a cross-section through the clearing strip from FIG. 6a;
(15) FIG. 7a shows schematically, the front view of a clearing strip according to the invention, using a seventh exemplary embodiment;
(16) FIG. 7b shows schematically, a cross-section through the clearing strip from FIG. 7a;
(17) FIG. 8a shows schematically, the front view of a clearing strip according to the invention, using an eighth exemplary embodiment;
(18) FIG. 8b shows schematically, a cross-section through the clearing strip from FIG. 7a.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
(19) In the drawings, a clearing strip is indicated with the reference symbol 1. The clearing strip 1 has a front steel plate 2 having multiple bores 3 in the upper region, and a rear steel plate 4, also having bores 3 in the upper region. The front and rear steel plate 2, 4 can be connected by means of a screw connection, not shown, through the bores 3, and attached to a clearing shield, also not shown, of a snow plow. An elastic rubber layer 5 is vulcanized on between the two steel plates 2 and 4. A hard-rubber body 6 is embedded into the elastic rubber layer 5. Here, this hard-material body 6 has a tungsten carbide core 8 surrounded by a steel mantle 7.
(20) In practice, it has been shown that a clearing strip 1 structured in this way is far superior to conventional clearing strips with regard to its useful lifetime and its robustness. Due to the rubber layer 5 that surrounds the hard-material bodies 6, these can move back into the rubber layer in the case of impacts caused by uneven areas on the surface to be cleared, and are therefore not damaged by these impacts. However, due to the demands with regard to clearing speed and uninterrupted use of the clearing strips 1, which demands are becoming ever greater, the strips become increasingly hot. At their wear surface at the lower end, in particular, very high temperatures occur due to friction heat. This can lead to the result that the hard-material bodies are heated to red heat. Since the rubber layer 5 can only conduct this heat away poorly, it is at risk of becoming brittle at the boundary layer to the hard-material body, in particular in the lower region, and/or the connection between rubber and hard-material body, which was achieved by means of adhesives, is at risk of dissolving. Consequently, secure hold of the hard-material bodies 6 due to their embedding in the rubber layer 5 is no longer guaranteed. The hard-material bodies can fall out of the clearing strip 1 in uncontrolled manner, and thereby cause damage to the snow plow, but also represent a hazard for the traffic following the snow plow.
(21) For this reason, additional anchoring of the hard-material bodies 6 in the clearing strip 1 is necessary. In this regard, however, the additional anchoring must guarantee the movability of the hard-material body 6 in the elastic rubber layer 5, and is not allowed to significantly restrict it. This means that the hard-material body 6 must continue to be able to move back in the case of impacts caused by uneven areas on the surface to be cleared.
(22) Such additional anchoring can be implemented in different ways. Possible embodiments are shown in the drawing.
(23) In FIG. 1a/b, the additional anchoring is implemented by means of a woven aramid tape 9a. The woven aramid tape 9a is passed through a bore 10 through the hard-material body 5. The ends of the woven aramid tape 9a are clamped in place in the upper region of the clearing strip 1, between the front and rear steel plate 2, 4, and are thereby connected with the two steel plates with force fit. Furthermore, the woven aramid tape 9a is vulcanized into the rubber layer. The woven aramid tape 9a is not laid tightly through the rubber layer 5 and the hard-material body 6, so that the hard-material body 6 remains movable in the rubber layer 5. Furthermore, the bore 10 has play with regard to the cross-section of the woven aramid tape 9a, so as to additionally guarantee the movability of the hard-material body 6 in this way, too. Furthermore, the woven aramid tape 9a is also not additionally damaged due to friction on the hard-material body 6.
(24) In FIG. 2a/b, a steel tape 9b is provided in place of the woven aramid tape 9a for anchoring of the hard-material body 6. The ends of the steel tape 9b are also clamped in place in the upper region, between the front and rear steel plate 2, 4, and vulcanized into the rubber layer 5, so that the steel tape 9b, as described above, also holds the hard-material body 6 in the clearing strip 1 in secure and movable manner.
(25) In FIG. 3a/b, the anchoring apparatus of the hard-material body 6 is provided by means of a wire cable 9c. Anchoring of the hard-material body 6 takes place here in the same way as in the case of the two embodiments mentioned above. In this embodiment, the cross-section at the ends of the wire cable 9c is deformed due to being clamped in place between the two steel plates 2, 4. As a result, the surface of the wire cable 9c adapts to the surface of the two steel plates 2, 4 in this region, and the force fit is reinforced in this way.
(26) In FIG. 4a/b, two bent hooks 9d are passed through the bores 10 of the hard-material body 6. The bent hooks 9d hold the hard-material body 6 in the clearing strip 1 with shape fit, in the region above the hard-material body 6, due to the bent shape. In this regard, the hard-material body 6 retains its movability relative to the remainder of the clearing strip. It would also be possible that the bent hooks 9d are brought together to form a loop above the hard-material body 6. The bent hooks 9d can be made of aramid or steel, but other materials are also possible.
(27) In FIG. 5a/b, an embodiment is shown in which anchoring of the hard-material body 6 in the clearing strip 1 is implemented by means of a bolt 9e. The bolt is passed through the hard-material body 6 with play and through the rear steel plate 4 with precise fit. Due to the geometry of the bolt 9e and of the elements of the clearing strip 1, a shape-fit connection is produced, by means of which the hard-material body 6 is held in the clearing strip in secure and simultaneously movable manner.
(28) In FIG. 6a/b, the anchoring apparatus is represented by two bolts (9e), which are welded onto the hard-material body at their one end, and passed through bores 11 in the front and/or rear plate (2, 4) with play at their other end. In the case of this anchoring apparatus, as well, the hard-material body is remains movable in the rubber compound. It would also be conceivable if the bolts (9e) were welded onto the respective steel plate (2, 4) and passed through the hard-material body with play.
(29) In FIG. 7a/b and FIG. 8a/b, embodiments are shown in which it is possible to do without a bore through the hard-material body 6, and the hard-material body 6 is nevertheless attached in the clearing strip in secure and movable manner. For this purpose, an anchoring element is welded on at the upper end of the hard-material body 6. It is important, in this regard, that the anchoring element is anchored well in the rubber layer 5. The shape of the anchoring element is decisive for this, so as to produce the best possible shape-fit and material-fit connection with the surrounding rubber layer 5. The hard-material body 6 is held in the clearing strip 1 in secure and movable manner by means of this anchoring element.
(30) As an example, the anchoring element is shown in FIG. 6a/b in the form of a bracket 9f. In FIG. 7a/b, the anchoring element has a horizontal helical spring 9g. However, other forms of the anchoring element, not shown, are also possible, for example a vertical helical spring.
(31) Although only a few embodiments of the present invention have been shown and described, it is to be understood that many changes and modifications may be made thereunto without departing from the spirit and scope of the invention.
REFERENCE SYMBOL LIST
(32) 1 clearing strip 2 front steel plate 3 bore 4 rear steel plate 5 rubber layer 6 hard-material body 7 steel mantle 8 tungsten carbide core 9a woven aramid tape 9b steel strip 9c wire cable 9d bent hook 9e bolt 9f bracket 9g helical spring 10 bore
