Abstract
An abrasive article, in particular a coated abrasive disc, includes a plurality of holes which are arranged in a hole pattern. The density of holes decreases from an inner region of the hole pattern to an outer region of the hole pattern. At least one hole in the hole pattern is designed as an elongated hole.
Claims
1. An abrasive article comprising: a plurality of holes arranged in a hole pattern in which a hole density decreases from an inner region of the hole pattern to an outer region (of the hole pattern wherein at least one hole in the hole pattern is formed as an elongated hole.
2. The abrasive article as claimed in claim 1, wherein a first hole density in the inner region of the hole pattern is between 7.5% and 16.0%.
3. The abrasive article as claimed in claim 1, wherein a second hole density in the outer region of the hole pattern is between 1.5% and 4.8%.
4. The abrasive article as claimed in claim 1, wherein a ratio of a first hole density in the inner region to a second hole density in the outer region is between 1.9% and 6.9%.
5. The abrasive article as claimed in claim 1, wherein an overall hole density of the entire hole pattern is between 2.6% and 6.8%.
6. The abrasive article as claimed in claim 1, wherein a first number of elongated holes in the inner region of the hole pattern is greater than a second number of elongated holes in the outer region of the hole pattern.
7. The abrasive article as claimed in claim 1, wherein at least one of a first elongation and a first radius of a first elongated hole of the at least one hole is different from at least one of a second elongation and a second radius of a second elongated hole.
8. The abrasive article as claimed in claim 1, wherein the hole pattern is at least one of rotationally symmetrical, rotary-symmetrical, axially symmetrical, point symmetrical, and translation symmetrical.
9. The abrasive article as claimed in claim 1, wherein the hole pattern is at least one of rotationally asymmetrical, rotary asymmetrical, axial asymmetrical, point-asymmetrical, and translation asymmetrical.
10. The abrasive article as claimed in claim 1, wherein the hole pattern defines at least one spiral line arranged along the holes of the hole pattern.
11. The abrasive article as claimed in claim 10, wherein at least one elongated hole is arranged along each spiral line of the at least one spiral line.
12. The abrasive article as claimed in claim 10, wherein a respective elongated hole is arranged aligned along each spiral line of the at least one spiral line in such a manner that an axis defined by an elongation of the elongated hole extends substantially tangentially to the spiral line.
13. The abrasive article as claimed in claim 10, wherein the hole pattern comprises a center hole, wherein and a tangent to the center hole forms a tangent to the at least one spiral line.
14. The abrasive article as claimed in claim 1, wherein the abrasive article is a coated abrasive disk.
15. The abrasive article as claimed in claim 2, wherein the first hole density is between 9.0% and 12.0%.
16. The abrasive article as claimed in claim 3, wherein the second hole density is between 2.9% and 3.4%.
17. The abrasive article as claimed in claim 4, wherein the ratio is between 3.1% and 5.7%.
18. The abrasive article as claimed in claim 5, wherein the overall hole density is between 3.5% and 5.5%.
19. The abrasive article as claimed in claim 7, wherein the first elongated hole is in the inner region and the second elongated hole is in the outer region.
Description
DRAWINGS
[0048] The invention is explained in more detail in the following description by way of the exemplary embodiments shown in the drawings. The drawings, the description and the claims include numerous features in combination. The expert will also look at the features individually in an expedient manner and combine them to form sensible further combinations. Identical reference symbols in the figures designate identical elements.
[0049] The drawings are as follows:
[0050] FIG. 1 shows a schematic representation of an embodiment of an abrasive article according to the prior art;
[0051] FIG. 2 shows a schematic representation of a system with an abrasive article according to the invention as well as an abrasive instrument and a machining surface;
[0052] FIG. 3 shows a seriously enlarged detail from a schematic sectional representation of an embodiment of an abrasive article according to the invention;
[0053] FIG. 4 shows a schematic representation of a first embodiment of an abrasive article according to the invention;
[0054] FIG. 5 shows a schematic representation of an embodiment of an elongated hole as an example;
[0055] FIG. 6 shows a schematic representation of a second embodiment of an abrasive article according to the invention;
[0056] FIG. 7 shows a schematic representation of a third embodiment of an abrasive article according to the invention;
[0057] FIG. 8 shows a schematic representation of a fourth embodiment of an abrasive article according to the invention.
[0058] FIG. 1 shows an abrasive article 110 as is known in the prior art. The abrasive article 110 is realized as a coated abrasive disk which is provided for use with a commercially available abrasive instrument 200 (for example a disk-type sander or orbital sander))compare FIG. 2. The abrasive article 110 comprises a plurality of holes 112 which are arranged in a hole pattern 114. The holes 112 are realized as through holes which serve for the extraction of material abrasion, in particular abrasive dust or other material generated on a machining surface 202 (cf. FIG. 2), during the abrasive process by means of an extraction device of the abrasive instrument 200. The holes 112 are realized as circular, same-size holes. The holes 112 comprise a radius r.sub.L of approximately 1.2 mm. The holes 112 of the abrasive article 110 are made for example by punching or laser cutting into a previously produced abrasive article 110 which does not yet include holes 112. The abrasive article 110 shown comprises a total of one hundred and twenty holes 112, all holes 112 together forming the plurality of holes which are arranged in a hole pattern 114. The hole pattern 114, in this case, covers substantiallyi.e. up to a narrow, insignificant distance from the edge (the envelope of the hole pattern, i.e. a circle enclosing the hole pattern. here comprises a radius of more than 0.95R.sub.outeras a result, the hole pattern covers more than 90% of the abrasive disk and consequently substantially the entire abrasive disk) the entire abrasive article surface 116 of the abrasive article 110.
[0059] The hole pattern 114 and here also the abrasive article 110 divide into an inner region 118 and an outer region 120, the outer region 120 surrounding the inner region 118 completely. In the embodiment shown of the abrasive article 110 as a substantially circular abrasive disk, the inner region 118 and the outer region 120 are arranged concentrically to one another, the inner region 118 and the outer region 120 being arranged concentrically to the center 122 of the hole pattern 114 and of the abrasive article 110. The inner region 118, in this case, provides a circular disk 119 with radius R.sub.inner of 7.5 cm, whilst the outer region 120 provides a circular ring 121 which adjoins the inner region 118, the smaller radius R.sub.inner thereof corresponds to 7.5 cm and the greater radius R.sub.outer thereof corresponds to the diameter of the abrasive article 110 (i.e. the abrasive disk) of 15 cm. The inner region 118 comprises a surface area of A.sub.S.inner=44.2 cm.sup.2, whilst the outer region 120 comprises a surface area A.sub.S.outer=132.5 cm.sup.2. The overall surface of the abrasive article 110 is A.sub.S.overall=176.7 cm.sup.2. The inner region 118 comprises a total of forty-two holes 112 (with an overall hole surface of A.sub.L.inner=1.9 cm.sup.2), whilst the outer region 120 comprises a total of seventy-eight holes 112 (with an overall hole surface of A.sub.L.outer=3.5 cm.sup.2). The hole density of the outer region 120 is 2.7%, whilst the hole density of the inner region 118 is 4.3 %. The hole density of the entire hole pattern is 3.1%.
[0060] FIG. 2 shows an abrasive instrument 200 formed by a disk-type or orbital sander which serves for abrasively machining a machining surface 202. The abrasive instrument 200 comprises a housing 204 which surrounds a drive unit which is not shown in any more detail and is formed by an electric motor. The drive unit is supplied with electric power in an operating state by means of a power cable 20b which is arranged on an end of the housing 204. As an alternative to this, the abrasive instrument can also be battery driven. A switching element 208, which is mounted in the housing 204 so as to be displaceable, is provided for activation of the drive unit. The switching element 208 is formed by a switching slider. The housing 204 forms a first, cylindrical gripping region 210 which is arranged on the end facing the power cable 206. A further gripping region 212, which is arranged on an end of the housing 204 remote from the power cable 206, is additionally provided. The further gripping region 212 is realized in a dome-shaped manner. The first gripping region 210 and the further gripping region 212 are provided for the purpose of being grasped by a hand of the operator and of guiding the abrasive instrument 200 in an operating state relatively, in particular guiding it relative to a machining surface 202. A tool receiving means 214 is arranged on the end of the abrasive instrument 200 remote from the power cable 206. The tool receiving means 214 connects to the housing 204. The tool receiving means 214 includes an abrasive plate 216. The tool receiving means 214 is provided for the purpose of receiving an abrasive article 110, 10a-d, in particular an abrasive disk. The abrasive article 110, 10a-d, in particular the abrasive disk, and the abrasive instrument 200 together form a system.
[0061] The abrasive article 110 in FIG. 1and analogously thereto also the abrasive article 10a-d according to the invention shown below in FIGS. 4, 6 to 8are provided for the purpose of being reversibly detachably connected to such an abrasive plate 216 of such an abrasive instrument 200. With the abrasive instrument 200 in the activated state, in this case, the abrasive plate 216 plus the abrasive article 110, 10a-d fastened thereon is driven by the abrasive instrument 200, in particular in a rotational movement and/or eccentric movement and/or orbital movement.
[0062] As shown in FIG. 3 in a schematic, seriously enlarged sectional representation, each of the coated abrasive articles 110, 10a-d descried here includes a carrier element 124. In the exemplary embodiment, the carrier element 124 is formed from paper or from cardboard, as an alternative to this, for example, also from vulcanized fiber, and serves as a flexible support for the abrasive layer 126 applied thereon. The abrasive layer 126 includes abrasive grains 128 and a binding agent 130 (base binder) which connects the abrasive grains 128 and the paper or the cardboard together. The binding agent 130 can consist, for example, of a phenol resin. The abrasive layer 126 forms an abrasive surface 132 (abrasive article surface). The carrier element 124 comprises a round main extension surface (cf. FIGS. 1, and 6 to 8), the abrasive surface 132 extending parallel to the main extension surface of the carrier element 124. The carrier element 124 of the abrasive article 110, 10a-d, in this case, is realized in a disk-shaped manner and comprises here a diameter of 15 cm. On a side of the carrier element 124 located on the back opposite the abrasive surface 132, a receiving region is arranged which is not shown here. The receiving region includes a Velcro element which is provided. for the purpose of corresponding with a Velcro element of the abrasive plate 216 of the abrasive instrument 200 and interacting with it in an adhering manner. The Velcro element is connected fixedly to the carrier element 124 of the abrasive article 110, 10a-d and extends parallel to the main extension surface of the carrier element 124. The holes 112, 12a-d made in the abrasive article 110, 10a-d completely penetrate the carrier element 124 and the abrasive layer 126. The holes 112, 12a-d penetrate the abrasive article 110, 10a-d substantially parallel to one another (not shown in any more detail here). The holes 112, 12a-d form an extraction surface parallel to the main extension surface of the carrier element 124.
[0063] The extraction surface includes the overall surface of the spaces 134 surrounded by holes 112, 12a-d. The holes 112, 12a-d, when viewed parallel to the main extension surface of the carrier element 124, form a hole pattern (cf. FIGS. 1, 4 and 6 to 8 (reference symbols 114, 14a, 14b, 14c, 14d. there)), the hole pattern extending in the exemplary embodiments shown here over the entire main extension surface of the carrier element 124 of the abrasive article 110, 10a-d. In addition, the layer of binding agent 130 and abrasive grains 128 can also be coated with a top binder 136, for example produced from phenol resin.
[0064] The abrasive article 110 shown in FIGS. 1 and 3 and the application on the abrasive instrument 200 shown in FIG. 2 form the starting base for the following representation of exemplary embodiments of the proposed abrasive article 10a-d according to the invention which differs from the known abrasive articles 110 of the prior art by the hole pattern 14a-d according to the invention. The proposed abrasive article 10a-d comprises a structural design comparable in principle and serves for the same purpose or the same application as an abrasive article 110 of the prior art. The nomenclature and background information introduced within the framework of FIGS. 1 to 3 can consequently be transferred directly to the embodiments of the abrasive article 10a-d according to the invention shown as an example in each case in the following figures.
[0065] FIG. 4 shows an abrasive article 10a according to the invention in the form of a circular abrasive disk. The abrasive article 10a comprises a diameter of 15 cm. The abrasive article comprises a plurality of holes 12a for the extraction of abrasive dust from a machining surface 202 during an abrasive process on the machining surface 202. The plurality of holes 12a are arranged in a hole pattern 14a, the hole pattern 14a covering the entire abrasive article 10ai.e. up to a narrow, insignificant distance from the edge (the envelope of the hole pattern, i.e. a circle enclosing the hole pattern, comprises here a radius of more than 0.92R.sub.outerconsequently, the hole patters covers more than 85% of the abrasive disk and consequently substantially the entire abrasive disk). As already introduced in conjunction with FIG. 1, the hole patterns 14a-d of the abrasive article 10a-d described below are also divided into a respective inner region 18a-d and a respective outer region 20a-d, the outer region 20a-d enclosing the inner region 18a-d completely. The respective inner regions 18a-d and the respective outer regions 20a-d are arranged concentrically to one another and in addition concentrically to the center 22a-d of the hole pattern 14a-d. The respective inner region 18a-d provides, in this case, a circular disk 19a-d with radius R.sub.inner of 7.5 cm, whilst the respective outer region 20a-d provides a circular ring 21a-d adjoining the respective inner region 18a-d, the smaller radius R.sub.inner corresponds to 7.5 cm and the greater radius R.sub.outer corresponds to the diameter of the abrasive article 10a-d (i.e. of the respective abrasive disk) of 15 cm (as explained, the edge is insignificant here).
[0066] The hole pattern comprises twenty holes 12a which are formed as elongated hole 38a and are arranged in part in a star-shaped and symmetrical manner in the inner region 18a of the hole pattern 14a. In this case, every six elongated holes 38a form two axes 40, 42 which are aligned perpendicularly to one another and additionally also form an axis of symmetry each of a mirror symmetry underlying the hole pattern 14a. In the center 22a, the hole pattern 14a comprises a center hole 44a which comprises a diameter of 10 mm (surface 78.5 mm.sup.2). In addition, eight further elongated holes 38a are arranged about said center hole 44a. As shown in FIG. 5, a corresponding elongated hole 38a (as the elongated holes 38b, 38c, 38d also described in following FIGS. 6, 7 and 8) is describable by a radius r.sub.LL and a length l.sub.LL and defines an axis which is given by the direction of the elongation (i.e. in the direction of the length l.sub.LL) (cf. here the axes 40, 42). The elongated holes 38a shown (just as 38b, 38c, 38d in FIG. 6 or 7 or 8) each comprise a length l.sub.LL of 5.25 mm and a radius r.sub.LL of 1.05 mm. The elongated holes 38a comprise a surface area of a total of 200 mm.sup.2.
[0067] In addition, the hole pattern 14a comprises twenty-six circular, same-size holes 13a in the inner region 18a. The circular holes 13a comprise a radius r.sub.L of approximately 1.5 mm (with a total hole surface of A.sub.L.inner=1.8 cm.sup.2), whilst the outer region 20a comprises a total of seventy-two circular holes 13a (with a total hole surface of A.sub.L.outer=5.1 cm.sup.2). The hole density of the outer region 20a is 3.8%, whilst the hole density of the inner region 18a is 10.5%. The hole density of the entire hole pattern is 5.5%. The hole density of the hole pattern 14a decreases significantly from the inner region 18a of the hole pattern 14a to the outer region 20a of the hole pattern 14a. The ratio of hole density in the inner region to the hole density in the outer region is 2.8.
[0068] FIG. 6 shows an abrasive article 10b in the form of a circular abrasive disk. The abrasive article 10b comprises a diameter of 15 cm. The abrasive article 10b comprises a plurality of holes 12b for the extraction of abrasive dust from a machining surface 202 during an abrasive process on the machining surface 202. The plurality of holes 12b are arranged in a hole pattern 14b, the hole pattern 14b covering the entire abrasive article 10bi.e. up to a narrow, insignificant distance from the edge (the envelope of the hole pattern, i.e. a circle enclosing the hole pattern, comprises here a radius of more than 0.98R.sub.outerconsequently, the hole pattern covers more than 96% of the abrasive disk and consequently substantially the entire abrasive disk). The hole pattern 14b provides a rotationally symmetrical hole pattern 14b (eightfold). The hole pattern 14b describes eight spiral lines 46, arranged along the holes 12b of the hole pattern 14b. The hole pattern 14b comprises in the inner region 18b twenty-four holes 12b formed as elongated hole 38b which are arranged along the spiral lines 46. In this case, the spiral lines 46 extend in a common circumferential direction (here anticlockwise). Three elongated holes 38b are arranged along the respective spiral line 46 per spiral line 46. The respective elongated holes 38b are arranged along a respective spiral line 46 aligned in such a manner that an axis 50 defined by the elongation of the elongated hole 38b extends substantially to the spiral line 46. In the center 22b, the hole pattern 14b comprises a center hole 44b which comprises a diameter of 10 mm (surface 78.5 mm.sup.2). The spiral lines 46 are formed in such a manner that a tangent to the spiral line provides, as it were, a tangent to the center hole 44b. The elongated holes 38b comprise a radius r.sub.LL of 1.05 mm and a length of 5.25 mm. The elongated holes comprise a surface area of a total of 240 mm.sup.2.
[0069] In addition, four further circular holes 13b are arranged along the respective spiral line 46 per spiral line 46, the respectively three outer circular holes 13b being situated in the outer region 20b of the abrasive article 10b and a circular hole 13b still being situated in each case in the inner region. 18b. The circular holes 13b comprise a radius r.sub.L of approximately 1.5 mm.
[0070] The hole pattern 14b consequently comprises in the inner region. 18b a hole surface of A.sub.L.inner=3.5 cm.sup.2, whilst the outer region 20b comprises a hole surface of A.sub.L.outer=2.0 cm.sup.2. The hole density of the outer region 20b is consequently 1.5%, whilst the hole density of the inner region 18b is 7.9%. The hole density of the entire hole pattern is 3.1%. The hole density of the hole pattern 14b decreases significantly from the inner region 18b of the hole pattern 14b to the outer region 20b of the hole pattern 14b. The ratio of the hole density in the inner region 18b to the hole density in the outer region 20b is 5.3.
[0071] FIG. 7 shows an abrasive article 10c according to the invention in the form of a circular abrasive disk. The abrasive article 10c comprises a diameter of 15 cm. The abrasive article 10c comprises a plurality of holes 12c for the extraction of abrasive dust from a machining surface 202 during an abrasive process on the machining surface 202. The plurality or holes 12c are arranged in a hole pattern 14c, the hole pattern 14c covering the entire abrasive article 10c i.e. up to a narrow, insignificant distance from the edge (the envelope of the hole pattern, i.e. a circle enclosing the hole pattern, comprises here a radius of more than 0.95R.sub.outer consequently, the hole pattern covers more than 90% of the abrasive disk and consequently substantially the entire abrasive disk). The hole pattern 14c also provides a symmetrical hole pattern 14c, in particular a rotationally symmetrical (eight-fold symmetry) hole pattern 14c. The hole pattern 14c describes sixteen spiral lines 46, along, which are arranged a plurality of holes 12c of the hole pattern 14c. Four circular holes 13c are arranged in each case along eight spiral lines 46, whilst four elongated holes 38c are arranged in each case along four other spiral lines 46. In this case, the spiral lines 46 extend in a circumferential direction (here anticlockwise), a spiral line 46, along which in each case four elongated holes 38c are arranged, being followed alternately by a spiral line 46 along which in each case four circular holes 13c are arranged. The respective elongated holes 38c are arranged along a respective spiral line 46 aligned in such a manner that an axis 50 defined by the elongation of the elongated hole 38c extends substantially tangentially to the spiral line 46. In the center 22c, the hole pattern 14c comprises a center hole 44c which comprises a diameter of 10 mm (surface 78.5 mm.sup.2). The spiral lines 46 are formed in such a manner that a tangent to the spiral line provides, as it were, a tangent to the center hole 44c. In addition, the spiral lines 4h are surrounded by a circle 48 of holes 12c, the circle 48 consisting of eight times repeat of the combination circular hole 13c elongated hole 38celongated hole 38c.
[0072] The elongated holes 38c comprise a radius r.sub.LL of 1.05 mm and a length l.sub.LL of 5.25 mm. The elongated holes comprise a surface area of a total of 480 mm.sup.2. The circular holes 13c have a radius r.sub.L of approximately 1.5 mm and form a surface area of a total of 226 m.sup.2. The hole pattern 14c comprises in the inner region 18c a hole surface of A.sub.L.inner=4.0 cm.sup.2, whilst the outer region 20c comprises a hole surface of A.sub.L.outer=3.8 cm.sup.2. The hole density of the outer region 20c is consequently 2.9%, whilst the hole density of the inner region 18c is 9.1%. The hole density of the overall hole pattern is 4.4%. The hole density of the hole pattern 14c decreases significantly from the inner region 18c of the hole pattern 14c to the outer region 20c of the hole pattern 14c. The ratio of the hole density in the inner region 18c to the hole density in the outer region 20c is 3.1.
[0073] FIG. 8 shows a slightly modified exemplary embodiment of the abrasive article 10b shown in FIG. 6. The abrasive article 10d. is also realized in the form of a circular abrasive disk and comprises a diameter of 15 cm. The abrasive article 10d comprises a plurality of holes 12d for the extraction of abrasive dust from a machining surface 202 during an abrasive process on the machining surface 202. The plurality of holes 12d are arranged in a hole pattern 14d, the hole pattern 14d covering the entire abrasive article 10di.e. up to a narrow, insignificant distance from the edge (the envelope of the hole pattern, i.e. a circle enclosing the hole pattern, comprises here a radius of more than 0.98R.sub.outerconsequently, the hole patters covers more than 96% of the abrasive disk and consequently substantially the entire abrasive disk). The hole pattern 14d also describes eight spiral lines 46, along which holes 12d of the hole pattern 14d are arranged. The hole pattern 14d also comprises in the inner region. 18d twenty-four holes 12d formed as elongate hole 38d which are arranged along the spiral lines 46. In this case, the spiral lines 46 extend in a common circumferential direction (here anticlockwise). Three elongated holes are arranged per spiral line 46 along the corresponding spiral line 46. The respective elongated holes 38d are arranged along a respective spiral line 46 aligned in such a manner that an axis 50 defined by the elongation of the elongated hole 38d extends substantially tangentially to the spiral line 46. In the center 22d, the hole pattern 14d comprises a center hole 44d. which comprises a diameter of 10 mm (surface 78.5 mm.sup.2). The spiral lines 46 are formed. in such a manner that a tangent to the spiral line provides, as it were, a tangent to the center hole 44d.
[0074] The elongated holes 38d comprise a radius r.sub.LL of 1.05 mm and a length l.sub.LL of 5.25 mm. The elongated holes comprise a surface area of a total of 240 mm.sup.2.
[0075] In addition, four further circular holes 13d are arranged along the respective spiral line 46 per spiral line 46, the respectively three outer circular holes 13d being situated in the outer region 20d of the abrasive article 10d and a circular hole 13d still being located in each case in the inner region 18d. The circular holes 13d comprise a radius r.sub.L of approximately 1.5 mm.
[0076] The hole pattern 14d consequently comprises in the inner region 18d a hole surface of A.sub.L.inner=3.5 cm.sup.2, whilst the outer region 20d comprises a hole surface of A.sub.L.outer=2.0 cm.sup.2. The hole density of the outer region 20d is consequently 1.5%, whilst the hole density of the inner region 18d is 7.9 %. The hole density of the overall hole pattern is 3.1%. The hole density of the hole pattern 14d decreases significantly from the inner region 18d of the hole pattern 14d to the outer region 20d of the hole pattern 14d. The ratio of the hole density in the inner region 18a to the hole density in the outer region 20d is 5.3.
[0077] In contrast to the hole pattern 14d shown in FIG. 6, the holes 12d in this exemplary embodiment are at various distances along a respective spiral line 46, compared to the distances between the holes 12d along an adjacent spiral line 46. The hole pattern 14d consequently provides here an asymmetrical, in particular rotationally asymmetrical, rotary asymmetrical, axially asymmetrical, point asymmetrical and translation asymmetrical hole pattern 14d. The advantageous effects of a particularly good extraction are further strengthened on account of the asymmetrical distribution of the hole pattern 14d.
[0078] It must be noted once again that the abrasive article can also be realized in the form of an abrasive belt, an abrasive arch, an abrasive strip or another manufacturing form which appears sensible to an expert. In addition, the exemplary embodiments do not imply any restriction to an abrasive disk with a diameter of 15 cm.
