Patent Application
20220203502
The following is directed to an abrasive article, and particularly, an abrasive article including bonded abrasive segments.
A variety of abrasive tools have been developed over the past century for various industries for the general function of removing material from a workpiece, including, for example, sawing, drilling, polishing, cleaning, carving, and grinding. Abrasive cup wheels are typically used for edge grinding AlTiC for HDDs. Cup wheels that provide the necessary precision can become less accurate quickly as the wheels wear down. Cup wheels made of longer lasting materials do not provide the finish necessary for certain applications. The industry continues to demand improved cup wheel materials, capable of achieving improved grinding performance.
The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.
The following description in combination with the FIGURES is provided to assist in understanding the teachings provided herein. The following disclosure will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application.
As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a method, article, or apparatus that comprises a list of features is not necessarily limited only to those features but may include other features not expressly listed or inherent to such method, article, or apparatus. Further, unless expressly stated to the contrary, “or” refers to an inclusive-or and not to an exclusive-or. For example, a condition A or B is satisfied by any one of the following: A is true (or present), and B is false (or not present), A is false (or not present), and B is true (or present), and both A and B are true (or present).
Also, the use of “a” or “an” is employed to describe elements and components described herein. This is done merely for convenience and to give a general sense of the scope of the invention. This description should be read to include one or at least one, and the singular also includes the plural, or vice versa, unless it is clear that it is meant otherwise. For example, when a single item is described herein, more than one item may be used in place of a single item. Similarly, where more than one item is described herein, a single item may be substituted for that more than one item.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The materials, methods, and examples are illustrative only and not intended to be limiting. To the extent that certain details regarding specific materials and processing acts are not described, such details may include conventional approaches, which may be found in reference books and other sources within the manufacturing arts.
The following is directed toward abrasive articles, and more particularly, an abrasive article that includes one or more abrasive bodies, particularly, abrasive bodies of different abrasive characteristics. The abrasive bodies can be in the form of bonded abrasive bodies, having abrasive particles contained within a three-dimensional volume of bond material. The abrasive article may be suitable for grinding a workpiece, and particularly suited for grinding of hard materials, and more particularly, AlTiC.
In an embodiment, an abrasive article 100 can include a body comprising abrasive segments 101 coupled to a major planar surface of a substrate 102. The abrasive segments include a first abrasive segment and a second abrasive segment; wherein the first set abrasive segment has a first bond composition, and the second abrasive segment has a second bond composition, and the first bond composition and the second bond composition are different; and further wherein the first abrasive segment comprises a first wear life index (w1) that is different than a second wear life index (w2). The wear life index of an abrasive segment may be measured by rubbing the wheel against a 320 mesh SiC sandpaper under a constant normal force of 30N for 10 s with water coolant and measuring the amount of material removed.
In an embodiment, the first abrasive segment can be prepared from a mixture.
In an embodiment, the wear life index of the first abrasive segment w1 may be a particular wear life index that provides improved manufacturing and/or performance of the abrasive article. In an embodiment, w1 can be at least 1, at least 2, at least 3, at least 4, at least 5, or at least 6. In an embodiment, w1 can be not greater than 8, not greater than 9, not greater than 10, not greater than 11, not greater than 12, not greater than 13, not greater than 14 or not greater than 15. It will be appreciated w1 may be between any of the maximum and minimum values noted above, including, for example, but not limited to, at least 1 and not greater than 8, at least 2 and not greater than 13, or at least 6 and not greater than 8.
In an embodiment, the wear life index of the second abrasive segment w2 may be a particular wear life index that provides improved manufacturing and/or performance of the abrasive article. In an embodiment, w2 can be at least 0.05, at least 0.1, at least 0.15, at least 0.2, or at least 0.25. In an embodiment, w2 can be not greater than 2, not greater than 1.5, not greater than 1.25, not greater than 1, not greater than 0.9, or not greater than 0.8. It will be appreciated w1 may be between any of the maximum and minimum values noted above, including, for example, but not limited to, at least 0.1 and not greater than 0.8, at least 0.2 and not greater than 1.25, or at least 0.15 and not greater than 1.
In an embodiment, the w1 and w2 can have a particular difference that provides improved manufacturing and/or performance of the abrasive article. In an embodiment, w1 and w2 can be different by at least 5%, at least 10%, or at least 15%, or at least 20%, or at least 25%. In an embodiment, w1 and w2 can be different by at least 1, or at least 2, or at least 3, or at least 4, or at least 5. In an embodiment, the difference between w1 and w2 can be not greater than 12, not greater than 11, not greater than 10, not greater than 9, not greater than 8, or not greater than 7. In an embodiment, the difference between w1 and w2 can be not greater than 99%, or not greater than 98%, or not greater than 97%, or not greater than 96%, or not greater than 95%. It will be appreciated that the difference between w1 and w2 can be between any of the minimum and maximum values noted above, including, for example, at least 1 and not greater than 10, or at least 5% and not greater than 99%.
In an embodiment, the abrasive article can include a first set of abrasive segments having the first bond composition and a second set of abrasive segments having the second bond composition. The first set of abrasive segments can provide a first surface area SA1, and the second set of abrasive segments provides a second abrasive surface area SA2.
In an embodiment, the abrasive article can include a particular ratio of SA1/SA2 that provides improved performance and/or manufacturing of the abrasive article. In an embodiment, SA1/SA2 can be at least 0.1, or at least 0.2, or at least 0.3, or at least 0.4, or at least 0.5. In an embodiment, SA1/SA2 can be not greater than 10, or not greater than 9, or not greater than 8, or not greater than 7, or not greater than 6, or not greater than 5. It will be appreciated that SA1/SA2 can be between any of the minimum and maximum values noted above, including, for example, but not limited to at least 0.1 and not greater than 10, at least 0.3 and not greater than 7, or at least 0.5 and not greater than 8.
In an embodiment, the abrasive segments can be arranged in an alternating fashion. In an embodiment, the abrasive segments can be arranged such that the first set of abrasive segments is grouped together, and the second set of abrasive segments is grouped together. In an embodiment, the abrasive segments can be arranged in a series of n1 abrasive segments from the first set of abrasive segments, followed by n2 abrasive segments from the second set of abrasive segments, followed again by n1 segments from the first set of abrasive segments, and so on and so forth. In an embodiment, n1 can be any integer from 1-10. In an embodiment, n2 can be any integer from 1-10.
In an embodiment, the first abrasive segment can include a first set of abrasive particles in a first bond composition.
The first set of abrasive particles can be a particular material that size provides improved performance and/or manufacturing of the abrasive article. In an embodiment, the first set of abrasive particles can include an oxide, carbide, nitride, boride, diamond, or any combination thereof.
The first bond composition can be a particular material that size provides improved performance and/or manufacturing of the abrasive article. In an embodiment, the first bond composition can comprise vitreous bond material, a resinous bond material, or a metal bond material. In an embodiment, the first bond composition can comprise vitreous bond material.
In an embodiment, the second abrasive segment can include a second set of abrasive particles in a second bond composition. The second set of abrasive particles can be a particular material that size provides improved performance and/or manufacturing of the abrasive article. In an embodiment, the second set of abrasive particles can include an oxide, carbide, nitride, boride, diamond, or any combination thereof.
The second bond composition can be a particular material that size provides improved performance and/or manufacturing of the abrasive article. In an embodiment, the second bond composition can comprise vitreous bond material, a resinous bond material, or a metal bond material. In an embodiment, the second bond composition can comprise resinous bond material.
In an embodiment, the abrasive article can be a cup wheel. In an embodiment, the abrasive segments can be arranged in a radial alternating manner relative to each other.
In an embodiment, the first set of abrasive particles may be a particular median particle size D50ap1 provides improved performance and/or manufacturing of the abrasive article. In an embodiment, D50ap1 can be at least 1 micron, at least 1.1 microns, or at least 1.2 microns, or at least 1.3 microns, or at least 1.4 microns, or at least 1.5 microns, or at least 1.6 microns, or at least 1.7 microns, or at least 1.8 microns, or at least 1.9 microns, or at least 2 microns, or at least 2.1 microns, or at least 2.2 microns, or at least 2.3 microns, or at least 2.4 microns, or at least 2.5 microns. In an embodiment, D50ap1 can be not greater than 7 microns, or not greater than 7.5 microns, or not greater than 8 microns, or not greater than 8.5 microns, or not greater than 9 microns, or not greater than 9.5 microns, or not greater than 10 microns. It will be appreciated that D50ap1 can be between any of the minimum and maximum values noted above, including, for example, but not limited to at least 1 micron and not greater than 10 microns, or at least 1.5 microns and not greater than 8 microns.
In an embodiment, the second set of abrasive particles may be a particular median particle size D50ap2 that provides improved performance and/or manufacturing of the abrasive article. In an embodiment, D50ap2 can be at is at least 5 microns, or at least 5.2 microns, or at least 5.4 microns, or at least 5.6 microns, or at least 5.8 microns, or at least 6 microns, or at least 6.2 microns, or at least 6.4 microns, or at least 6.6 microns, or at least 6.8 microns, or at least 7 microns, or at least 7.2 microns, or at least 7.4 microns, or at least 7.6 microns, or at least 7.8 microns, or at least 8 microns. In an embodiment, D50ap2 can be not greater than 30 microns, or not greater than 29.5 microns, or not greater than 29 microns, or not greater than 28.5 microns, or not greater than 28 microns, or not greater than 27.5 microns, or not greater than 27 microns, or not greater than 26.5 microns, or not greater than 26 microns, or not greater than 25.5 microns, or not greater than 25 microns. It will be appreciated that D50ap2 can be between any of the minimum and maximum values noted above, including, for example, but not limited to at least 5 microns and not greater than 25 microns, or at least 8 microns and not greater than 25 microns.
In an embodiment, the abrasive article can include a particular ratio of D50ap1/D50ap2 that provides improved performance and/or manufacturing of the abrasive article. In an embodiment, D50ap1/D50ap2 can be at least 1.1, or at least 1.15, or at least 1.2, or at least 1.25, or at least 1.3, or at least 1.35, or at least 1.4, or at least 1.45, or at least 1.5. In an embodiment, D50ap1/D50ap2 can be no greater than 10, or no greater than 9.5, or no greater than 9, or no greater than 8.5, or no greater than 8, or no greater than 7.5, or no greater than 7. It will be appreciated that D50ap1/D50ap2 can be between any of the minimum and maximum values noted above, including, for example, but not limited to at least 1.1 and not greater than 8, or at least 1.2 and not greater than 7.
In an embodiment, the first abrasive segment can include a particular wt. % of abrasive particles that provides improved performance and/or manufacturing of the abrasive article. In an embodiment, the first segment can include at least 30% abrasive particles for a total weight of the abrasive segment or at least 31%, or at least 32%, or at least 33%, or at least 34%, or at least 35%, or at least 36%, or at least 37%, or at least 38%, or at least 39%, or at least 40%, or at least 41%, or at least 42%, or at least 43%, or at least 44%, or at least 45% abrasive particles for a total weight of the abrasive segment. In an embodiment, the first segment can include not greater than 70% abrasive particles for a total weight of the abrasive segment, or not greater than 69%, or not greater than 68%, or not greater than 67%, or not greater than 66%, or not greater than 65%, or not greater than 64%, or not greater than 63%, or not greater than 62%, or not greater than 61%, or not greater than 60%, abrasive particles for a total weight of the abrasive segment. It will be appreciated that the wt. % of abrasive particles can be between any of the minimum and maximum values noted above, including, for example, but not limited to at least 31% and not greater than 67%, or at least 40% and not greater than 60%.
In an embodiment, the second abrasive segment can include a particular wt. % of abrasive particles that provides improved performance and/or manufacturing of the abrasive article. In an embodiment, the second segment can include at least 30% abrasive particles for a total weight of the abrasive segment or at least 31%, or at least 32%, or at least 33%, or at least 34%, or at least 35%, or at least 36%, or at least 37%, or at least 38%, or at least 39%, or at least 40%, or at least 41%, or at least 42%, or at least 43%, or at least 44%, or at least 45% abrasive particles for a total weight of the abrasive segment. In an embodiment, the second segment can include not greater than 70% abrasive particles for a total weight of the abrasive segment, or not greater than 69%, or not greater than 68%, or not greater than 67%, or not greater than 66%, or not greater than 65%, or not greater than 64%, or not greater than 63%, or not greater than 62%, or not greater than 61%, or not greater than 60% abrasive particles for a total weight of the abrasive segment. It will be appreciated that the wt. % of abrasive particles can be between any of the minimum and maximum values noted above, including, for example, but not limited to at least 31% and not greater than 67%, or at least 40% and not greater than 60%.
Many different aspects and embodiments are possible. Some of those aspects and embodiments are described herein. After reading this specification, skilled artisans will appreciate that those aspects and embodiments are only illustrative and do not limit the scope of the present invention. Embodiments may be in accordance with any one or more of the embodiments as listed below.
An abrasive article comprising: a body comprising abrasive segments coupled to a major planar surface of a substrate; wherein the abrasive segments include a first abrasive segment and a second abrasive segment; wherein the first set abrasive segment has a first bond composition and the second abrasive segment has a second bond composition, and the first bond composition and the second bond composition are different; and further wherein the first abrasive segment comprises a first wear life index (w1) that is different than a second wear life index (w2) of the second abrasive segment by at least 5%.
The abrasive article of embodiment 1, wherein the first wear life index is at least 1, at least 2, at least 3, at least 4, at least 5, or at least 6.
The abrasive article of embodiment 1, wherein the first wear life index is not greater than 8, not greater than 9, not greater than 10, not greater than 11, not greater than 12, not greater than 3, not greater than 14 or not greater than 15.
The abrasive article of embodiment 1, wherein the second wear life index is not greater than 2, not greater than 1.5, not greater than 1.25, not greater than 1, not greater than 0.9, or not greater than 0.8.
The abrasive article of embodiment 1, wherein the second wear life index is at least 0.05, at least 0.1, at least 0.15, at least 0.2, or at least 0.25.
The abrasive article of embodiment 1, wherein the first wear life index (w1) is different than the second wear life index (w2) of the second abrasive segment by at least 5% or at least 10% 10% or at least 15%, or at least 20%, or at least 25%.
The abrasive article of embodiment 1, wherein the first wear life index (w1) is different than the second wear life index (w2) of the second abrasive segment by not greater than 99%, or not greater than 98%, or not greater than 97%, or not greater than 96%, or not greater than 95%.
The abrasive article of embodiment 1, wherein the difference between the first wear life index and the second wear life is at least 1, or at least 2, or at least 3, or at least 4, or at least 5.
The abrasive article of embodiment 1, wherein the difference between the first wear life and the second wear life is not greater than 12, not greater than 11, not greater than 10, not greater than 9, not greater than 8, or not greater than 7.
The abrasive article of embodiment 1, wherein the ratio of the first wear life index to the second wear life, w1/w2, is at least 1, or at least 2, or at least 3, or at least 4, or at least 5, or at least 6, or at least 7, or at least 8, or at least 9, or at least 10.
The abrasive article of embodiment 1, wherein w1/w2 is not greater than 20, or not greater than 21, or not greater than 22, or not greater than 23, or not greater than 24, or not greater than 25.
The abrasive article of embodiment 1, wherein the body comprises a first set of abrasive segments having the first bond composition and a second set of abrasive segments having the second bond composition, wherein the first set of abrasive segments provides a first abrasive surface area SA1 and the second set of abrasive segments provides a second abrasive surface area SA2, and wherein the first abrasive surface area to the second abrasive surface area, SA1/SA2, is at least 0.1, or at least 0.2, or at least 0.3, or at least 0.4, or at least 0.5.
The abrasive article of embodiment 1, wherein the first set of abrasive segments provides a first abrasive surface area SA1, and the second set of abrasive segments provides a second abrasive surface area SA2, and wherein the first abrasive surface area to the second abrasive surface area, SA1/SA2 not greater than 10, or not greater than 9, or not greater than 8, or not greater than 7, or not greater than 6, or not greater than 5.
The abrasive article of embodiment 1, wherein the first abrasive segment comprises a first set of abrasive particles having a median particle size D50ap1, wherein D50 ap1 is at least 1 micron, at least 1.1 microns, or at least 1.2 microns, or at least 1.3 microns, or at least 1.4 microns, or at least 1.5 microns, or at least 1.6 microns, or at least 1.7 microns, or at least 1.8 microns, or at least 1.9 microns, or at least 2 microns, or at least 2.1 microns, or at least 2.2 microns, or at least 2.3 microns, or at least 2.4 microns, or at least 2.5 microns.
The abrasive article of embodiment 1, wherein the first abrasive segment comprises a first set of abrasive particles having a median particle size D50ap1, wherein D50 ap1 is not greater than 7 microns, or not greater than 7.5 microns, or not greater than 8 microns, or not greater than 8.5 microns, or not greater than 9 microns, or not greater than 9.5 microns, or not greater than 10 microns.
The abrasive article of embodiment 1, wherein the second abrasive segment comprises a second set of abrasive particles having a median particle size D50ap2, wherein D50 ap2 is at least 5 microns, or at least 5.2 microns, or at least 5.4 microns, or at least 5.6 microns, or at least 5.8 microns, or at least 6 microns, or at least 6.2 microns, or at least 6.4 microns, or at least 6.6 microns, or at least 6.8 microns, or at least 7 microns, or at least 7.2 microns, or at least 7.4 microns, or at least 7.6 microns, or at least 7.8 microns, or at least 8 microns.
The abrasive article of embodiment 1, wherein the second abrasive segment comprises a second set of abrasive particles having a median particle size D50ap2, wherein D50 ap2 is not greater than 30 microns, or not greater than 29.5 microns, or not greater than 29 microns, or not greater than 28.5 microns, or not greater than 28 microns, or not greater than 27.5 microns, or not greater than 27 microns, or not greater than 26.5 microns, or not greater than 26 microns, or not greater than 25.5 microns, or not greater than 25 microns.
The abrasive article of embodiment 1, wherein the first abrasive segment comprises a first set of abrasive particles having a median particle size D50ap1 and a second set of abrasive particles having a median particle size D50ap2, wherein D50ap2/D50ap1 is at least 1.1, or at least 1.15, or at least 1.2, or at least 1.25, or at least 1.3, or at least 1.35, or at least 1.4, or at least 1.45, or at least 1.5.
The abrasive article of embodiment 1, wherein the first abrasive segment comprises a first set of abrasive particles having a median particle size D50ap1 and a second set of abrasive particles having a median particle size D50ap2, wherein D50ap2/D50ap1 is no greater than 10, or no greater than 9.5, or no greater than 9, or no greater than 8.5, or no greater than 8, or no greater than 7.5, or no greater than 7.
The abrasive article of embodiment 1, wherein the first set of abrasive particles comprise a wt. % of the first abrasive segment of at least 30%, or at least 31%, or at least 32%, or at least 33%, or at least 34%, or at least 35%, or at least 36%, or at least 37%, or at least 38%, or at least 39%, or at least 40%, or at least 41%, or at least 42%, or at least 43%, or at least 44% or at least 45%.
The abrasive article of embodiment 1, wherein the first set of abrasive particles comprise a wt. % of the first abrasive segment of not greater than 70%, or not greater than 69%, or not greater than 68%, or not greater than 67%, or not greater than 66%, or not greater than 65%, or not greater than 64%, or not greater than 63%, or not greater than 62%, or not greater than 61%, or not greater than 60%.
The abrasive article of embodiment 1, wherein the second set of abrasive particles comprise a wt. % of the second abrasive segment of at least 30%, or at least 31%, or at least 32%, or at least 33%, or at least 34%, or at least 35%, or at least 36%, or at least 37%, or at least 38%, or at least 39%, or at least 40%, or at least 41%, or at least 42%, or at least 43%, or at least 44%, or at least 45%.
The abrasive article of embodiment 1, wherein the second set of abrasive particles comprise a wt. % of the second abrasive segment of not greater than 70%, or not greater than 69%, or not greater than 68%, or not greater than 67%, or not greater than 66%, or not greater than 65%, or not greater than 64%, or not greater than 63%, or not greater than 62%, or not greater than 61%, or not greater than 60%.
The abrasive article of embodiment 1, wherein the first bond composition comprises a vitreous bond material, a resinous bond material, or a metal bond material.
The abrasive article of embodiment 1, wherein the first bond composition comprises a vitreous bond material.
The abrasive article of embodiment 1, wherein the second bond composition comprises a vitreous bond material, a resinous bond material, or a metal bond material.
The abrasive article of embodiment 1, wherein the second bond composition comprises a resinous bond material.
The abrasive article of any of the preceding embodiments further comprising a plurality of abrasive bodies attached to a major planar surface of a substrate, wherein the plurality of abrasive bodies includes a plurality of first abrasive bodies and a plurality of second abrasive bodies, wherein the first and second abrasive bodies are arranged in a radial alternating manner relative to each other.
The abrasive article of embodiment 1, wherein the abrasive article is a cup wheel.
A method of using the abrasive article of embodiment 1, comprising edge grinding.
A method of using the abrasive article of embodiment 1, comprising grinding a material that comprises AlTiC.
Vitreous Segments
Vitreous bond abrasive segments were prepared according to the following procedure. A mixture of abrasive diamond particles and glass frit was prepared according to the composition detailed below in table 1. The mixture was mixed in a Resodyn LabRam acoustic mixer for 1 min at 100% intensity. A round divot was then created in the center of the mixture, and a PEG binder was added. The mixture was again mixed in a Resodyn LabRam acoustic mixer for 1 min at 100% intensity. The mixed powder is then screened through a 20ss screen and left out to dry overnight. The following day the mixture is screened again.
The mix was molded in a steel mold with a diameter of 5.02″ and a target molded thickness of 0.325″. The mold was pressed with 25 tons of force for 15 seconds to form an abrasive body precursor.
The abrasive body precursor was placed on a 6″ square batt and then placed in a furnace for firing. The timing and temperature of the filing process are detailed below in Table 2.
The fired abrasive body was allowed to cool and was then removed from the furnace.
Resin Segments
Vitreous bond abrasive segments were prepared according to the following procedure. A mixture of abrasive diamond particles and phenolic resin particles was prepared according to the composition detailed below in Table 3. The mixture was mixed in a Resodyn LabRam acoustic mixer. Glass spheres were added according to Table 1, and then the mixture was mixed again.
The mixture was then pressed in a hot press at 180° C. for 20 minutes in order to form an abrasive body.
Finishing
The vitreous and resin abrasive bodies were then cut into abrasive segments and cemented to a substrate in an alternating fashion. The cement is then cured 4 hours at 60° C., forming an abrasive cup wheel.
Benefits, other advantages, and solutions to problems have been described above with regard to specific embodiments. However, the benefits, advantages, solutions to problems, and any feature(s) that may cause any benefit, advantage, or solution to occur or become more pronounced are not to be construed as a critical, required, or essential feature of any or all the claims. Reference herein to a material including one or more components may be interpreted to include at least one embodiment wherein the material consists essentially of the one or more components identified. The term “consisting essentially” will be interpreted to include a composition including those materials identified and excluding all other materials except in minority contents (e.g., impurity contents), which do not significantly alter the properties of the material. Additionally, or in the alternative, in certain non-limiting embodiments, any of the compositions identified herein may be essentially free of materials that are not expressly disclosed. The embodiments herein include a range of contents for certain components within a material, and it will be appreciated that the contents of the components within a given material total 100%.
The specification and illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The specification and illustrations are not intended to serve as an exhaustive and comprehensive description of all of the elements and features of apparatus and systems that use the structures or methods described herein. Separate embodiments may also be provided in combination in a single embodiment, and conversely, various features that are, for brevity, described in the context of a single embodiment, may also be provided separately or in any subcombination. Further, reference to values stated in ranges includes each and every value within that range. Many other embodiments may be apparent to skilled artisans only after reading this specification. Other embodiments may be used and derived from the disclosure, such that a structural substitution, logical substitution, or another change may be made without departing from the scope of the disclosure. Accordingly, the disclosure is to be regarded as illustrative rather than restrictive.
This application claims priority under 35 U.S.C. § 119(e) to U.S. Provisional Patent Application No. 63/131,524, filed Dec. 29, 2020, by Cecile O. MEJEAN, et al., entitled “ABRASIVE ARTICLE AND METHOD OF USE,” which is assigned to the current assignee hereof and incorporated herein by reference in its entirety for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 63131524 | Dec 2020 | US |
