Patent Application
20110000045
1. Field of Invention
The invention relates to a scraper blade made of a flat metallic material for a scraper for scraping materials off a substrate, with a scraping section which has at least one scraping surface for scraping off materials on the front end and with a fastening section for fastening to a fastening part of the scraper on the back end. Moreover this invention also relates to a hand scraper, long-handled scraper or stripper, for scraping materials off a substrate with a fastening part for fastening a scraper blade.
2. Description of Related Art
In building rehabilitation or the like, floor coverings, wall coverings or roof coverings must often be removed from a substrate, the floor, the wall or the roof. Often, these coverings, especially building floor coverings, such as PVC floors, carpeted floors, parquet or laminate floors, generally a floor or floor planks, are fixed to the substrate with cement. In these cases the coverings and cement layers adhere especially strongly to the substrate. To detach these coverings and/or cement layers, scrapers, such as, for example, hand scrapers, long-handled scrapers, or strippers are used, the known scrapers having a fastening part for fastening a scraper blade. By forward movement of the front cutting edge of the scraper blade along the substrate the materials to be removed are scraped off the substrate. The scraper blades are made of a flat metallic material or a piece of sheet metal which on one end has a fastening section which can be clamped between an upper fastening piece and a lower fastening piece of the fastening part. The fastening pieces of the fastening part are made such that, when the fastening pieces are joined, a recess is formed for holding the scraper blade.
In the course of scraping, the material parts which have already separated from the substrate are transported in the direction to the fastening part by the following scraped-off material on the top of the scraper blade. The scraped-off materials push against the fastening part; this leads to damage of the fastening part and to increased wear in this region. In particular, for manually actuated scrapers, the scraped-off material components coming into contact with the fastening part leads, otherwise, to increased resistance when the substrate is being scraped, so that removing material from the substrate is tedious. If material components cannot be scraped off the substrate during scraping, they can push against the fastening part on the bottom of the scraper blade as the scraper blade continues to be advanced; this likewise can lead to increased wear of the fastening part and to increased expenditure of force during scraping.
The object of this invention is to make available a scraper blade and a scraper of the initially named type with which it is easily possible to detach materials from a substrate with low wear of the scraper and with low expenditure of force.
The aforementioned object is achieved by a scraper blade in which there is at least one guide section for diverting the scraped-off material over at least a front pushing edge of the fastening part, and the guide section can be obtained by forming of the flat metallic material. In this connection, the at least one guide section for diverting the scraped-off material over at least one front pushing edge of the fastening part has the highest point of a top-side guide surface located above the upper pushing edge and/or the low point of a bottom-side guide surface is located underneath the lower pushing edge of the fastening part or is aligned with the pushing edge, it being further provided in accordance with the invention that the guide section can be obtained by shaping of the flat metallic material.
The guide section ensures that, during scraping, the scraped-off material components cannot come into contact with the front, for example, the face-side pushing edge of the fastening part. The guide section automatically guides the following, scraped-off material past the upper or lower pushing edge of the fastening part so that wear on the fastening part does not occur when the material is being scraped off and the scraping process requires only little compressive force. The guide section has a guide surface on the top side which is angled and/or bent relative to the scraping surface in order to ensure diversion of the scraped-off material. In the direction to the front scraping or cutting edge the guide section of the scraper blade passes without interruption into the scraping section. Fundamentally, it is also possible for the scraper blade to run in an arc with a uniform direction of curvature, extending from the front scraper edge to the highest point of the top-side guide surface, the transition between the scraping surface and guide surface being fluid. However, preferably, the scraping surface is made as a straight or plane section of the scraper blade, the transition of the scraping surface to the guide surface taking place continuously and the surfaces bordering one another being aligned. In this way, the diversion of the scraped-off material is simplified.
If the low point of the bottom guide surface of the guide section is located underneath the lower pushing edge of the fastening part or is aligned with the pushing edge, the lower guide surface, during scraping, ensures that the fastening part with the face side does not hit against the material components which have not been scraped off in the scraping process and which are adhering strongly to the substrate. Then, in the forward motion of the scraper, in any case slight, lifting of the fastening part takes place as a result of the material components which have not been scraped off. Otherwise, the scraped-off material components on the bottom of the scraper blade are also routed past the fastening part.
The term “forming” for the purposes of the invention is defined as a generic term for all production processes in which metals are plastically transferred into another form (shaped) in a controlled manner. Plastic deformations of metallic materials take place by flow, deformations taking place as the load increases. The forming processes which can be used in conjunction with the invention include, for example, compressive forming, tension-pressure forming, tensile deformation, and bending.
The flat metallic material, preferably, has an essentially uniform thickness in the scraping direction over the entire extension of the scraper blade. In this connection, the concept “essentially” takes into account the circumstance that unwanted minor alterations of the sheet metal thickness can occur during forming. By using forming methods, large numbers of scraper blades in accordance with the invention can be easily and economically produced. Otherwise, it is easily possible to form the flat metallic material at certain locations in a controlled manner, and the shape and size of the forming regions can be fixed if necessary. By using forming methods, flat metallic materials with very small thickness can be used as scraper blades and accordingly guide sections can be made in the flat material.
Moreover, a covering can be easily scraped off the substrate due to the low thickness of the material. Otherwise, grinding of the scraper blade is easily possible, the ground scraper blades having greater sharpness than, for example, scraper blades which can be machined out of a flat metallic material by cutting. Compared to these flat materials with a greater thickness, the scraper blades of thin sheet metal in accordance with the invention also have higher flexibility which makes it easier to penetrate into the area between a covering and a substrate during scraping. In this connection, the scraper blade in accordance with the invention can have a thickness from 0.25 to 2.0 mm, preferably between 0.5 to 1.5 mm, especially between 0.75 to 1.0 mm.
The width of the scraper blades which are used for manually actuated scrapers can be between 15 to 30 mm, preferably roughly 20 mm. The length of the aforementioned scraper blades, in this case, is between 100 to 300 mm, preferably up to 200 mm. Scraper blades for so-called strippers can extend transversely to the scraping direction over a length from 200 to 400 mm, and the extension of the scraper blades in the scraping direction can be between 40 to 80 mm, preferably roughly 60 mm. Otherwise, the scraper blades of the type under consideration are, for the most part, rectangular with partially rounded corners. In order to ensure that the blade is securely held on the scraper, the scraper blade is preferably clamped over the entire extension of the blade transversely to the scraping direction in the fastening part.
The scraper blade can also be hardened differently, and in the region of the scraping edge the scraper blade should have the greatest hardness. This contributes to low wear of the scraper blade during the scraping process.
Preferably, the guide section passes without interruption into the fastening section. The guide section in this case can be obtained by impressing the metallic flat material without tearing or pushing through the material. In this case, the scraper blade has a continuous surface over its entire length and width so that the scraped-off material components can be diverted essentially completely over the guide section. In another embodiment of the invention, the guide section can be obtained by bending the punched sheet metal region up or down so that in the scraping process the scraper blade has an interruption in the transition region between the guide section and the fastening section.
The fastening section can be made as a straight or plane clamping region; this enables secure clamping in the fastening part of the scraper. Moreover, there can be a holding region which is angled and/or bent relative to the clamping region and which passes into the guide section, and furthermore, preferably the holding region can be bent or angled up and/or down by roughly 30° to 90° relative to the clamping region. In the corresponding execution of the fastening part, the holding region can contribute to secure fixing of the scraper blade in the fastening part. In this connection, for a scraper of the initially named type it can be provided that the recess formed between the fastening pieces of the fastening part have a first, preferably plane recess region for the clamping region of the fastening section and a second recess region connected to the first recess region for the holding region of the fastening section, the second recess region being bent and/or angled relative to the first recess region and the second recess region having the exit opening.
In this connection, the exit opening of the recess is preferably on the top or the bottom of the fastening part, and the planar fastening section of the blade can be clamped essentially horizontally between the fastening pieces. In this embodiment, the exit opening is not in the region of the center longitudinal axis of the fastening part. The shape of the recess between the fastening pieces in the scraping direction is matched here to the shape of the fastening section of the scraper blade.
Fundamentally however, it is also possible for the holding region of the scraper blade after clamping into the fastening part to be located outside the fastening part, for example, on a face side of the fastening part adjoining the holding region so that the scraper blade in the scraping process is securely held on the fastening part and some of the compressive force necessary in scraping is delivered into the scraper blade via the holding region.
In order to simplify the scraping-off of covering residues, the scraping section can be a planar, flat region. The scraping section and the clamping region of the fastening section can, moreover, be located in a common plane, the guide section being bent and/or angled up and/or down relative to the plane. If the scraping section and the clamping region of the fastening section are located in a clamping plane, high compressive forces can be easily transferred to the substrate by way of the scraper blade during scraping.
The guide section preferably has an ascending slope and/or a descending slope of less than 30°, preferably less than 20°. In this way, reliable and complete diversion of the scraped-off materials is ensured with low expenditure of force and the forming effort in production of the guide section is reduced. The holding region of the fastening section and the guide section can have the same ascending slope or the same descending slope so that the scraper blade, in accordance with the invention, has a corrugated profile in a longitudinal section whose flanks are formed by the holding region, on the one hand, and the guide section, on the other. This embodiment can be easily produced and enables scraping with a low expenditure of force.
The distance between the highest point of the top-side guide surface or the low point of the bottom-side guide surface and the center longitudinal axis of the scraping section and/or the center longitudinal axis of the fastening section of the blade can be less than 10 mm, preferably less than 5 mm, especially less than 3 mm. In this way, the forming cost is reduced and the routing of force through the scraper blade is disrupted only a little relative to the routing of force through a straight or plane, unformed scraper blade.
As has already been pointed out above, the scraping surface and the guide surface should be aligned in order to ensure simple diversion of the scraped-off material. In this connection, the guide section in the transition region to the fastening section can have a rounded diversion edge which leads to the scraped-off material being automatically detached from the scraper blade by the material which follows in the scraping process and being transported away beyond the pushing edge of the fastening part.
Fundamentally, it is possible for the guide section to extend transversely to the scraping direction over the entire scraper blade. In order to enable removal of the material adhering to the scraper blade, on the one hand, and on the other, the diversion of material past the pushing edge of the fastening part, there can also be a plurality of guide sections, the guide sections extending transversely to the scraping direction in regions over the scraper blade. The guide sections can be obtained by forming of the metallic flat material in sections. In this connection, the guide sections in one preferred embodiment of the invention are located next to one another transversely to the scraping direction and spaced apart from one another. Therefore, there is a continuous row of formed regions of the scraper blade which are surrounded by regions which have not been formed.
In a hand scraper, the scraper blade is preferably ground on both sides. The front end of the scraping section are beveled on the bottom and top so that the two sides of the scraper blade can be used for scraping. Unilateral grinding of one scraper blade in the scraping process can, however, be advantageous since the blade sharpens itself in the scraping process. In this connection, scraper blades ground on one side are usable preferably in stripping.
The invention is explained in further detail below with reference to the embodiments described by way of example in conjunction with the accompanying drawings.
In the scraping process in the scraping direction X, the scraped-off material components are transported opposite the scraping direction X on the scraping surface 7 and possibly also along the bottom of the scraper blade 3 in the direction to the front face side 9 of the fastening part 2. This is shown schematically by the arrows Y. The material components push against the end face surfaces 9, the end face surfaces 9 constituting the pushing edges for the purposes of the invention. When the scraped-off material comes into contact with the pushing edges of the fastening part 2, abrasion occurs on the outer surface of the fastening part 2; this can lead to destruction of the hand scraper 1 and endangers secure attachment of the scraper blade 3 between the fastening pieces 4, 5. Otherwise, the expenditure of force which is necessary in the scraping process for scraping off the material component increases.
Each scraper blade 10 has at least one middle guide section 18 for diverting the scraped-off material over at least one front pushing edge 19 of the fastening part 15, and the guide section 18 can be obtained by forming of the scraper blade 10. As follows from
Diverting the scraped off material over the guide section 18, 20 ensures that wear of the fastening part 15 in the region of the front pushing edge 19, 21 by the scraped-off material cannot take place. Thus, a floor covering can be scraped off with less expenditure of force by diverting the scraped-off material.
The guide section 18 is bent and/or angled up and/or down relative to the scraping section 13 which is planar or which runs straight, and the guide section 18, 20 preferably can have an ascending slope and/or a descending slope of less than 30°, preferably less than 20°. In the scraper blades 10 shown in
The scraper blades 10 in the scraping direction X have an essentially constant thickness d over the entire extension, and the thickness can be between 0.25 to 2 mm, preferably between 0.5 to 1.5 mm. In the embodiments shown in
The fastening section 14 can have a holding region 26 which is bent and/or angled relative to the clamping region 25, as is shown in
As follows especially from
Otherwise, due to the low thickness d of the scraper blades 10 for diverting the scraped-off material it is simply necessary to form the scraper blade 10 to a minor degree. The distance a1, a2, a3 between the highest point 23 and/or the low point 28 of the guide surface 22, 29 and the center longitudinal axis X1 of the scraping section 13 and/or the center longitudinal axis X2 of the clamping region 25 of the fastening section 14 can therefore be less than 10 mm, preferably less than 5 mm, especially less than 3 mm. This is shown schematically in
Otherwise the scraper blade 10 in the transition region of the guide section 18 to the fastening section 14 is rounded in order to prevent the scraped-off material from striking the scraper blade 10 in this region and to promote release of the scraped-off material from the scraper blade 10.
Otherwise, the scraper section 13 can be beveled on the bottom and/or on the top in the region of the scraping edge 24. The embodiments shown in
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP08/01597 | 2/29/2008 | WO | 00 | 8/24/2010 |
