Abstract
The invention relates to an abrasive article 1 for abrading at least one workpiece, the abrasive article with: a carrier body 2, at least one abrasive layer 3 with a main surface and a predefined thickness, the at least one abrasive layer being arranged on the carrier body, at least two visual indicators 6 with a cross-section in the main surface of the abrasive layer, wherein the size, shape and/or location of the cross-section of the visual indicators in the main surface of the abrasive layer depends on the thickness of the abrasive layer at more than one location of the visual indicators.
Claims
1. An abrasive article for abrading at least one workpiece, the abrasive article comprising: a carrier body; and at least one abrasive layer with a main surface that faces away from the carrier body and a predefined thickness, the main surface of the at least one abrasive layer being arranged in segments on the carrier body, wherein the abrasive article is a disk, and the main surface extends in a radial direction of the abrasive article, and wherein at least two of the segments comprise visual indicators with a cross-section in the main surface of the abrasive layer, wherein the size, shape and/or location of the cross-section of each visual indicator in the main surface of the abrasive layer depends on the thickness of the abrasive layer where that visual indicator is located, wherein each of the visual indicator has a different height in the thickness direction of the abrasive layer, wherein each of the visual indicators comprises a discrete element, wherein the discrete elements are arranged in a circle in a clock like system in a corresponding segment such that going along the circle, the height of a subsequent indicator increases, and wherein the discrete elements appear or disappear in a defined order during the use of the abrasive article while the thickness of the abrasive layer is reduced.
2. The abrasive article according to claim 1, wherein the visual indicators comprise a predefined shape with a cross-section that is visible on the main surface of the abrasive layer.
3. The abrasive article according to claim 1, wherein the cross-section of the visual indicators is visible through a whole tool lifetime of the abrasive article.
4. The abrasive article according to claim 1, wherein the visual indicators comprise a cross-section in a plane parallel to the main surface of the abrasive layer that varies through the thickness of the abrasive layer.
5. The abrasive article according to claim 1, wherein the abrasive article comprises more than two visual indicators, wherein the visual indicators are equally shaped, sized and/or arranged at the same height.
6. The abrasive article according to claim 4, wherein the visual indicators are arranged in a pattern in the abrasive layer.
7. The abrasive article according to claim 1, wherein the visual indicators comprise a different color than the abrasive layer.
8. The abrasive article according to claim 1, wherein the visual indicators comprise a different material than the abrasive layer.
9. The abrasive article according to claim 1, wherein the abrasive article is a grinding wheel or a dressing ring.
10. A kit of parts comprising a pair of abrasive articles for use in a double disk grinding process, wherein at least one of the abrasive articles is an abrasive article according to claim 1.
Description
(1) The invention will now be described in more detail with reference to the following Figures exemplifying particular embodiments of the invention:
(2) FIG. 1 three-dimensional view of a grinding wheel with a carrier body and an abrasive layer;
(3) FIG. 2a cross-sectional view of a segment of an abrasive layer of an abrasive article with one embodiment of a visual indicator;
(4) FIG. 2b transparent three-dimensional view of the segment of FIG. 2a;
(5) FIG. 3a cross-sectional view of a segment of an abrasive layer of an abrasive article with another embodiment of a visual indicator;
(6) FIG. 3b transparent three-dimensional view of the segment of FIG. 3a;
(7) FIG. 4a cross-sectional view of a segment of an abrasive layer of an abrasive article with another embodiment of a visual indicator;
(8) FIG. 4b transparent three-dimensional view of the segment of FIG. 4a;
(9) FIG. 5a top view of a grinding wheel according to one embodiment of the invention with several visual indicators;
(10) FIG. 5b cross-sectional view of the grinding wheel of FIG. 5a; and
(11) FIG. 6a top view of a grinding wheel according to another embodiment of the invention with several visual indicators;
(12) FIG. 6b top view of the grinding wheel onto the main surface of the abrasive layer; and
(13) FIG. 7 three-dimensional view of a kit of parts comprising a pair of grinding wheels illustrated in FIG. 1.
(14) Herein below various embodiments of the present invention are described and shown in the drawings wherein like elements are provided with the same reference numbers.
(15) FIG. 1 shows a grinding wheel 1 with a carrier body 2 and an abrasive layer 3. The carrier body 2 has the shape of a disk and the abrasive layer 3 is arranged on one of its two parallel surfaces. The abrasive layer 3 provides a main surface which is built by a plurality of hexagonally shaped segments 4. The segments 4 are spaced apart from each other such that according channels 5 are created between the segments 4. The segments 4 are adhered to the carrier body 2.
(16) FIGS. 2a to 4b show single segments 4 of the grinding wheel 1 shown in FIG. 1 from different perspectives. The segments show differently shaped visual indicators. FIG. 2a is a cross-sectional view of a segment 4 with a conically shaped visual indicator 6. FIG. 2b is a 3-dimensional view of the segment 4 of FIG. 2a. The visual indicator 6 reaches from the upper surface of the segment 4, which is part of the main surface of the grinding wheel 1, to the lower surface of the segment 4, which faces the carrier body 2 of the grinding wheel 1. The cross-section of the visual indicator 6 that extends parallel to the main surface of the abrasive article 1 according to the line 2a-2a in FIG. 2b changes through the thickness of the segment 4. In the embodiment shown in FIGS. 2a and 2b its size increases when the thickness of the abrasive layer gets reduced. It is of course also possible to arrange the visual indicator the other way around in the segment 4, such that the size of its cross-section in the main surface decreases when the thickness of the abrasive layer/segment also decreases. The size of the cross-section that is parallel to the main surface correlates to the thickness of the segment 4. FIGS. 2a and 2b the larger the cross-section of the visual indicator 6, the thinner is the segment 4.
(17) FIG. 3a is a cross-sectional view of a segment 4 with a helically shaped visual indicator 6, that is built by a continuous ramp that is spirally formed. FIG. 3b is a 3-dimensional view of the segment 4 of FIG. 3a. The visual indicator 6 reaches from the upper surface of the segment 4, which is part of the main surface of the grinding wheel, to the lower surface of the segment 4, which faces the carrier body 2 of the grinding wheel 1. The cross-section of the visual indicator 6 that extends parallel to the main surface of the abrasive article 1 according to the line 3a-3a in FIG. 3b changes through the thickness of the segment 4. In the embodiment shown in FIGS. 3a and 3b it increases its size and it changes its shape. From a little dot it extends to a circular line. Thus, the size and the shape of the cross-section of the visual indicator 6 that is parallel to the main surface correlates to the thickness of the segment 4. The larger the cross-section of the visual indicator 6 and the more the line closes to a circle, the thinner is the segment 4.
(18) FIG. 4a is a cross-sectional view of a segment 4 with a clock-like visual indicator 6. FIG. 4b is a 3-dimensional view of the segment 4 of FIG. 4a. The visual indicator 6 reaches from the upper surface of the segment 4, which is part of the main surface of the grinding wheel, to the lower surface of the segment 4, which faces the carrier body 2 of the grinding wheel 1. The cross-section of the visual indicator 6 that extends parallel to the main surface of the abrasive article 1 according to the line 4a-4a in FIG. 4b changes through the thickness of the segment 4. In the embodiment shown in FIGS. 4a and 4b it comprises several indicator marks that are arranged in a circle like the numbers of a clock. Each of the indicator marks has a different height in the thickness direction of the abrasive layer. Going along the circle, they increase in their height. Depending on the thickness of the segment 4 the number of indicator marks visible on the main surface of the segment 4 increase. If all indicator marks are visible the circle is complete. This is an indication that the abrasive layer is almost worn off and the tool needs to be exchanged soon. If several segments 4 with clock like visual indicators 6 are used in one tool, it is possible to compare the number of visible indicator marks of each visual indicator 6 in the tool to determine if the main surface of the abrasive article 1 still as plane as required for achieving good grinding results.
(19) FIGS. 5a to 6b show abrasive articles 1 with several visual indicators 6 that have been used already and that provide a worn off non-planar main surface. The grinding wheel 1 of FIG. 5a comprises a carrier body 2 and an abrasive layer 3. Within the abrasive layer 3 several visual indicators 6 are arranged in an inner and an outer ring. They have a conical shape. The abrasive article 1 is more worn off at the outer edge as in the middle. This can clearly be seen in FIG. 5b which is a top view of the grinding wheel 1 onto the main surface of the abrasive layer 3. The visual indicators 6 of the outer circle have a larger diameter as the visual indicators 6 of the inner circle. This means that more material has been worn off on the outside of the grinding wheel 1 as on the inside.
(20) FIG. 6a shows the opposite scenario. The grinding wheel 1 of FIG. 6a comprises a carrier body 2 and an abrasive layer 3. Within the abrasive layer several visual indicators are arranged in an inner and an outer ring. They have a conical shape. The abrasive article 1 is more worn off in the middle as on the outer side. This can clearly be seen in FIG. 6b which is a top view of the grinding wheel 1 onto the main surface of the abrasive layer 3. The visual indicators 6 of the inner circle are larger as the visual indicators 6 of the outer circle. This means that more material has been worn off on the inside of the grinding wheel 1 as on the outside.
(21) FIG. 7 illustrates a kit of parts 20 comprising a pair of abrasive articles 1a, 1b of the present invention, illustrated as grinding wheels, that may be used in a double disk grinding process. Abrasive articles 1a, 1b are the same as abrasive article 1 in FIG. 1.
