REUSABLE HUB ASSEMBLY FOR ABRASIVE ARTICLES

BACKGROUND

Bonded abrasive wheels are typically provided with an attachment mechanism for connecting to a grinding system. A disc shaped flange extends radially from a medial portion of the bushing and terminates at a peripheral lip. The bushing is adapted to extend through a central bore of the wheel so that the lip engages the backing face of the wheel proximate an outermost circumference of the depressed center. A grinding face end of the bushing is flangeable radially outward to engage the front grinding face of the wheel and mechanically capture the wheel between the grinding face end and the flange. The flange, lip and backing face form a cavity into which epoxy resin is placed to chemically bond the hub to the wheel.

SUMMARY

A method of reusing a hub in an abrasive assembly is presented that includes removably coupling the abrasive wheel to a reusable hub. The abrasive wheel has an outer circumference and an inner circumference. The abrasive article has an inner circumference and an outer circumference. The method also includes abrading a worksurface by contacting the abrasive wheel to the worksurface. The reusable hub includes a coupling feature configured to directly couple to the abrasive article. The coupling feature includes an adhesive-free connection between the reusable hub and the abrasive wheel. The direct connection is a removable interlocking between the abrasive wheel and the reusable hub.

Systems and methods herein provide significant waste reduction compared to contemporary hubs for abrasive systems. Systems herein allow for a savings of greater than 30% of the volume of an abrasive disc that is often not available for abrading and is discarded. Additionally, the system herein provides for a hub that is reusable for multiple abrasive articles reducing waste and improving the sustainability of a customer's production process.

Systems and methods herein also provide improved damping of vibration caused by an abrading operation. Further, a better consistency of material removal is provided using hubs illustrated herein during a grinding operation, in part due to improved damping of vibrations caused during a grinding operation. Additionally, production of depressed center grinding wheels in particular may be easier since a tapered portion for the bond resin is not needed. The bonded construction is a simple round washer-like shape.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

FIGS. 1A-1B illustrate a depressed center grinding wheel without, and with, a metal hub.

FIG. 2 illustrates an exploded view of a reusable hub assembly in accordance with embodiments herein.

FIGS. 3A-3C illustrate cutaway views of reusable hub assemblies in accordance with embodiments herein.

FIG. 4 illustrates a position locking feature for a reusable hub assembly in accordance with embodiments herein.

FIG. 5 illustrates a method of using a reusable hub in accordance with embodiments herein.

FIG. 6 illustrates a method of abrading a workpiece in accordance with embodiments herein.

FIG. 7A-7B illustrates a mating ring design for a reusable hub assembly in accordance with embodiments herein.

DETAILED DESCRIPTION

Depressed center grinding wheels are one example of an abrasive article that can be used in a grinding operation. Many grinding wheels are used with a hub for mounting to a grinding assembly. FIG. 1A illustrates an exemplary depressed center grinding wheel of the prior art, and FIG. 1B illustrates such a wheel with a metal hub attached thereto.

U.S. Pat. No. 5,895,317, issued on Apr. 20, 1999, describes prior art hub assemblies for abrasive articles, specifically depressed center grinding wheels such as that illustrated in FIGS. 1A and 1B. Typically, the hub is attached to the wheel using an adhesive. The hub overlaps a portion of the abrasive article's surface, at least on the side it is adhered to. Unfortunately, this means that a user can only grind up to the edge of the hub. The outer diameter becomes smaller until the wheel is too small to be used. As the wheel diameter becomes significantly smaller, the radial speed of the wheel decreases significantly, and the performance degrades. Particularly for depressed center grinding wheels, the “depressed center” portion of the wheel is often discarded by the user. The discarded portion can be a significant fraction of the total material. For example, more than 30% of a 4.5″ outer diameter DCGW is in the discarded depressed center portion. Additionally, because the hub is discarded, it is not reusable.

A particular problem with hub design for depressed center grinding wheels is illustrated in U.S. Pat. No. 6,454,639, issued on Sep. 24, 2002. DCGWs are often used for face-grinding applications designed with a taper in order to accommodate a hub, such that the hub can couple to the DCGW such that the hub is flush to one side, as illustrated in FIG. 1 of U.S. Pat. No. 6,454,639. Alternatively, many hubs that connect to a planar wheel, as illustrated in FIG. 2 of U.S. Pat. No. 6,454,639 extend on either side of the wheel, making it unsuitable for face grinding as the hub material would contaminate the substrate. A reusable hub is desired that can be used with a planar wheel for face grinding applications without contaminating a substrate of an abrasive operation. In some embodiments herein, reusable hubs can couple to a grinding wheel without extending completely through the wheel, or by only extending through a thickness of the wheel, such that the wheel can be used for face grinding applications.

It is desired to reduce the amount of wasted material, both from a raw materials concern as well as an environmental waste concern. Additionally, it is desired to have a reusable hub that can be releasably connected to an abrasive article and reused from grinding operation to grinding operation. In some embodiments, the re-useable hub is made of a material that provides sufficient stability. Additionally, it is desired that hub could be mated to an appropriate spindle as needed. It is also further desired to manufacture the reusable hub form a sustainable material.

Sustainable materials may include recyclable materials, such as plastics, metals or other materials that can be recaptured and recycled. Additionally, some embodiments herein include reusable hubs with one or more substainable polymer components, such as bio-based or degradeable polymers or mixtures of polymers. Such materials may be preferred in some embodiments as the polymer mixtures may provide tuneable properties, as described in U.S. Provisional Patent Application with Ser. No. 63/074,617, filed on Sep. 4, 2020. FIGS. 1A-1B illustrate a depressed center grinding wheel (DCGW) without, and with, a metal hub. An abrasive layer 110 has a depression 120 that a hub 140 can attach to. A connection ring 130 facilitates insertion of a shaft through the abrasive article. Hub 140 is metal and adhered to the surface of wheel 110.

As illustrated in FIG. 1B, a portion of abrasive wheel 110 represented by radius portion 142 is covered by the surface area of hub 140. Portion 142 is discarded after use as it is unusably coupled to hub 140. It is desired that the entire area of wheel 110, represented by radius portion 112, is usable during a grinding operation.

It is noted that DCGWs may also have poorer performance as the product nears the end of its life, due to the linear speed as the outer diameter decreases and wheel 110 is ground down to the edge of hub 140. This is exhibited in both cut consistency and rate of degradation of the wheel. Embodiments herein provide improved cut consistency as well as reduced waste during manufacturing and use. Embodiments herein also provide benefit of limiting use of cutting and grinding wheels at small wheel diameter, as well as reducing waste during production and use.

FIG. 2 illustrates an exploded view of a reusable hub assembly in accordance with embodiments herein. An abrasive article 230 receives a reusable hub 210, in one embodiment, by using a mating ring 220. Mating ring 220 receives hub 210, in the illustrated embodiment, by corresponding threading. However, while threading to a mating ring 220 is illustrated as one fastening mechanism, other suitable fasteners may be used for removably coupling hub 210 to abrasive article 230. For example, the mating ring 220 could be coupled to a hub using clamping, threading, clipping, magnetic connection, removable screws or rivets, quick-release fasteners, interlocking grooves or another suitable removable mechanism, such as friction-based contact. In some embodiments, the coupling is a toolless coupling, such that a user can remove hub 210 from an abrasive article 230 without using a tool, e.g. by hand force alone. The removable fastening may be any mechanical fastening system that can be manually or semi-automatically during assembly or installation.

As illustrated in FIG. 2, hub 210 has a thickness 212 that is substantially the same as thickness 232 of the abrasive hub. Hub 210, therefore, provides stability throughout the entire thickness 232 of abrasive article 230.

FIGS. 3A-3C illustrate cutaway views of reusable hub assemblies in accordance with embodiments herein. FIG. 3A illustrates a single component hub 300, while FIG. 3B illustrates a two-component hub 350 coupled to a grinding wheel 370.

FIG. 3A illustrates a cutaway view of a hub 300 with a housing 310 and an interior 320. Interior 320, in one embodiment, is the same material as the housing, and is designed to reduce vibrations during use. In another embodiment, interior 320 is a different material than housing 310, but is a material designed to reduce vibrations. Hub 300 illustrates a threaded connection 340 for coupling to a shaft of a tool. Additionally, a threaded connection 330 is also illustrated for coupling to a mating ring, for example, or directly into corresponding threading in an abrasive article. However, other connection mechanisms are expressly contemplated, including driving a thread into the inner diameter of the wheel, creating a self-mating thread system.

FIG. 3B illustrates a cutaway view of a hub assembly 350. Hub assembly includes two different hub components, a top component 352, and a bottom component 356. Top component 352 may have an interior 354 with a damping material, and bottom component 356 may also contain damping material 358. For example, damping material 358 may include an O-ring, a rubber washer, light-weight hub material, semi-rigid hub or semi-flexible hub material, etc. A material may be considered as a “damping material” if it has a loss factor (tan(delta)) more than 10× the loss factor of aluminum, as measured by the ASTM standard D4065 for dynamic mechanical analysis.

Top component 352 and bottom component 356 both are received by a mating ring 360, illustrated in the embodiment of FIG. 3B. However, it is expressly contemplated that, in some embodiments, a mating ring 360 is not required. For example, the mating feature may be integrated into the grinding layer itself. Alternatively, a mating ring could be applied during or after the curing of the bonded wheel.

Described herein are multiple embodiments of damping structures that may be useful in either a single-component hub construction, like that of FIG. 3A, or a multi-component hub construction, like that of FIG. 3B. Additionally, while a multi-component construction may be the result of an additive manufacturing process, a customer may interact with an assembled hub that behaves like a single-component construction. Both embodiments have been designed with mating such that the grinding layer and reusable hub are intimately attached and function like a typical cutting or grinding wheel.

The present system is an improvement over previous designs, such as that of U.S. Pat. No. 6,454,639 issued on Sep. 24, 2002. The design illustrated herein includes two components outside of the grinding wheel that connect together by threading. Mating ring 230 and hub 220 have a depth that extends throughout the entire grinding layer 210, which offers a simpler design for manufacturing and use, and provides the stability desired by the inventors of U.S. Pat. No. 6,454,639 without the need for the included damping layers and use of glue to adhere clamping components together. The design also provides a simpler connection between the hub 220 and a haft of a tool, as the hub 220 is the only portion of the assembly 200 that couples to the shaft.

It is also noted that, compared to contemporary designs, the assembled wheel 250 provides sustainability benefits. While there is a slight overlap between hub components 254, 256 and grinding layer 270, the design presents a significant improvement in waste reduction of abrasive material. And many designs herein, as discussed in the Examples, provide improved damping.

FIG. 3C illustrates another cutaway view of a reusable hub 370, with a connection mechanism 380. Like the constructions of FIGS. 3A and 3B, hub 370 may couple to an abrasive article such that a majority of an attached abrasive article is fully available for a grinding operation, reducing waste. Additionally, FIG. 3C provides a damping system 374 within a hub housing 372. Damping system 374 includes damping structures 376 and 382 coupled by connectors 378. Damping structures 376, 382 are illustrated as rod-like structures that can be curved (376) or straight (382). In some embodiments, the structures 376, 382 may have the ability to flex. FIG. 3C illustrates a damping system 374 suspended within housing 372. However, it is also expressly contemplated that damping system 374 may be encased in a filler material within housing 372 to provide additional vibrational damping.

FIG. 3C illustrates one possible structured damping system 374. However, it is expressly contemplated that others are possible. For example, U.S. Provisional Application with Ser. No. 63/198,574, filed Oct. 28, 2020, illustrates several possible damping structures.

FIG. 4 illustrates a position locking feature for a reusable hub assembly in accordance with embodiments herein. FIG. 4 illustrates a reusable hub assembly 400 with a first hub component 402 and a second hub component 404. A position lock feature 420 is present on a mating feature 450 coupled to the abrasive wheel 460. While a mating ring 450 is illustrated in FIG. 4, it is expressly contemplated that, in some embodiments, the position locking feature 420, as well as any additional coupling features, if any, may be molded or machined directly into abrasive wheel 460. For example, portion 450 may represent a portion of wheel 460 free of abrasive particles. It may have grooves, threading, protrusions or recesses machined or molded during manufacturing.

A reusable hub 400 is illustrated with a tool-receiving bore 410 on an interior diameter and position locking features 422 on an outer diameter. As reusable hub 410 moves into place with respect to an abrasive article 460, with component 402 moving in direction of arrow 440, it couples to portion 404, either directly or through a mating feature 450. For example, portions 402, 404 may couple together directly, and protrusions 422 may couple into apertures 420 . . . . However, while a separate mating feature 450 is illustrated, it is expressly contemplated that, in some embodiments, wheel 460 may be formed such that a corresponding portion 450 does not include abrasive particles and consists of bonding and filler material instead, reducing abrasive particle waste. In such embodiments, a locking mechanism, such as protrusions 420, may be machined or molded into article 460.

While protrusions 422 and corresponding apertures 420 are illustrated as one example of a suitable position lock, it is expressly contemplated that other locking mechanisms may be suitable, such as expandable or spring-loaded features that actuate when a hub is in position with respect to abrasive article 460. Additionally, lever-based or other suitable position lock mechanisms are also expressly contemplated.

Reusable hub 400 may include a damping feature 406, in some embodiments, which may be a flexible material different from a material forming hub portions 402, 404. As illustrated in FIG. 4, an O-ring is used as a damping feature.

FIG. 5 illustrates a method of using a reusable hub in accordance with embodiments herein. Method 500 may be useful for a reusable hub engaging with any number of suitable abrasive wheel designs, including depressed center grinding wheels (DCGW), Cut off wheels (COW), Cut-and-Grind wheel (C&G wheel), Flex-wheel, Cylindrical grinding wheels (ID/OD/Centerless grinding wheels), Cam/Crank grinding wheels, surface grinding wheels, or gear grinding wheels (single rib, threaded, bevel gear grinding wheels), plunge grinding, edge grinding, finishing grinding wheels, super-finishing grinding wheels, polishing grinding wheels.

In block 510, a first disc is used with the reusable hub. The reusable hub may provide vibrational damping, as indicated in block 512. The reusable hub may also allow substantially all of the abrasive wheel volume to be used, as indicated in block 514. Additionally, in embodiment where the wheel includes a nonabrasive portion that interacts with a lip of the hub, at least 90% of the abrasive volume may be used. In some embodiments, a lip overhanging from a hub onto an abrasive article is covers about 5% of the abrasive article. The reusable hub may also have other features, as indicated in block 516, such as a locking feature to maintain a relative position with the abrasive wheel.

In block 520, the first disc is changed out for a second disc. The first disc may be changed out when insufficient abrasive article volume is left for an abrading operation to continue. Insufficient abrasive article volume may be indicated, for example by reaching a lip or overhang of the hub, or an end-of-life indicator. For example, a mating ring may couple to an abrasive article using spikes or other protrusions that reach into the wheel volume. An end-of-life indication may be exposure of the mating ring protrusions. In general, the abrasive article reaches an end-of-life when insufficient volume is left to maintain structural integrity during a grinding operation as broken grinding wheel portions can be dangerous.

The hub is removed from the first disc and re-used with the second disc, as indicated in block 524. This may involve unlocking a locking feature, unscrewing a threaded connection between the hub and the abrasive article, or otherwise removing the hub. It may also include discarding a mounting ring or flange used in the first abrading operation and retrieving a new mounting ring for use with the second disc. The second disc is then attached to the reusable hub, for example using threading, a locking feature, or other suitable temporary or semi-permanent attachment mechanism.

In some embodiments, such as that illustrated in FIG. 3B, changing out the first disc for a second disc involves decoupling a first hub component from a second hub component. The first and second hub components may be made of the same, or of different, materials. For example, one component may be more compliant, to provide damping, while the second component is made of a material selected for structural integrity.

In block 530, the second disc is used with the reusable hub. The reusable hub may provide vibrational damping, as indicated in block 532, and may allow for substantially all of the abrasive wheel volume to be used, as indicated in block 534. The hub may also provide other features, as indicated in block 536. FIG. 6 illustrates a method of abrading a workpiece in accordance with embodiments herein. Method 600 may be useful with any suitable abrasive wheel, including but not limited to: depressed center grinding wheels (DCGW), Cut off wheels (COW), Cut-and-Grind wheel (C&G wheel), Flex-wheel, Cylindrical grinding wheels (ID/OD/Centerless grinding wheels), Cam/Crank grinding wheels, surface grinding wheels, or gear grinding wheels (single rib, threaded, bevel gear grinding wheels), plunge grinding, edge grinding, finishing grinding wheels, super-finishing grinding wheels, polishing grinding wheels.

In block 610, a reusable hub is removably coupled to an abrasive wheel. The coupling may include a mounting ring 612, threading 614 between the hub and the abrasive wheel, or between the hub and the mounting ring, a locking feature 616 that maintains a relative position between the hub and the abrasive wheel, or another suitable non-permanent connection feature. The connection between a reusable hub and an abrasive wheel is a mechanical connection, and not a chemical connection, in some embodiments. Additionally, in some embodiments the connection is an adhesive-free connection.

In block 620, the reusable hub is removably coupled to a tool that causes rotation of the hub and associated abrasive wheel. The hub may have an internal bore with threading 632, for example, which may facilitate the removeable connection. The hub may also have a locking feature 634, to maintain a relative position of the hub and the tool. Other connection features may also be present, as indicated in block 636.

In block 630, an abrasive operation is conducted by contacting the abrasive wheel to a work surface and actuating rotation. The reusable hub may provide vibrational damping, as indicated in block 632. The reusable hub may also be sized such that a at least 90% of the abrasive article is available for abrading, as indicated in block 634. As discussed in the Examples below, this is in contrast to previous versions, where up to 30% of the abrasive article was discarded.

FIGS. 7A and 7B illustrates a mating ring design for a reusable hub assembly in accordance with embodiments herein. As described, one advantage of reusable hubs herein is the ability to use them, with an attached grinding wheel, for face grinding applications. FIGS. 7A and 7B illustrate partial views of one such embodiment of a mating ring 700 coupled to an abrasive wheel 720. As illustrated, an abrasive wheel 720 has both a planar first side 722 and second side 724. This is different from traditional depressed center grinding wheels, which usually have an abrasive layer 720 with a taper that allows for a mating feature (such as a reusable hub) to couple to both first surface 722 and second surface 724 while maintaining a planar grinding surface on side 722. In contrast, reusable hubs herein may couple to abrasive article 720 substantially only along an interior area, for example covered by mating ring 710.

As illustrated in FIG. 7A and more clearly in FIG. 7B, mating ring 710 does not extend completely from side 722 to side 724. Instead, a spacing 728 is present, which ensures that a reusable hub does not engage a worksurface during a face grinding operation.

While a mating ring 710 illustrated in FIGS. 7A and 7B, it is expressly contemplated that a mating feature 710 could instead be integral to wheel 720. For example, a bonded wheel could be molded or machined to have threading, allowing wheel 720 to directly receive the reusable hub using corresponding threading. Other mechanical coupling mechanisms besides threading are also contemplated, such as corresponding protrusions and apertures, grooves and ridges or a close enough fit for friction alone to be sufficient.

Accordingly, although exemplary embodiments have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions, and substitutions are possible. Therefore, the disclosure is not limited to the above-described embodiments but may be modified within the scope of appended claims, along with their full scope of equivalents.

The method may be implemented such that the direct connection is a toolless connection.

The method may be implemented such that the direct connection includes the reusable hub interacting with a receiving feature on the inner circumference of the abrasive wheel.

The method may be implemented such that the receiving feature is threading, grooves, or receiving apertures.

The method may be implemented such that the direct connection includes the reusable hub coupling to a mating feature which directly couples to the abrasive article.

The method may be implemented such that the mating feature includes a mating ring coupled to the abrasive article.

The method may be implemented such that the reusable hub couples to the mating ring using threading, clamping, clipping, grooves, magnetic forces or friction forces.

The method may be implemented such that the reusable hub, when coupled to the abrasive wheel, extends from a coupling side partway through a thickness of the abrasive article.

The method may be implemented such that the reusable hub extends through a thickness of the abrasive article and is flush with an opposing side.

The method may be implemented such that the reusable hub extends over halfway through the thickness of the abrasive article.

The method may be implemented such that the reusable hub includes a damping feature.

The method may be implemented such that the damping feature includes a material composition of the hub. The material composition includes metal, plastic, or reinforced composite.

The method may be implemented such that the damping feature is an interior structure of the reusable hub.

The method may be implemented such that the interior structure is a series of repeating units within the reusable hub.

The method may be implemented such that the interior structure is a second material. The hub includes a housing made of a first material. The second material differs from the first material.

The method may be implemented such that the first material has a first storage modulus and the second material has a second storage modulus. The second storage modulus is less than the first storage modulus.

The method may be implemented such that the second e-modulus is at least 10× less than the first storage modulus.

The method may be implemented such that the damping feature is an infiltrated material, a co-extruded material, a layer within the reusable hub, or a 3D-printed structure within the reusable hub.

The method may be implemented such that the reusable hub has a radial width extending from an interior edge to an exterior edge. A system width, extending from the interior edge to the outer circumference is less than 10% greater than a sum of the radial width of the reusable hub and a radial distance from the inner to outer circumference.

The method may be implemented such that the reusable hub further includes a position locking mechanism.

The method may be implemented such that coupling includes coupling the reusable hub to a mating ring that couples directly to the abrasive wheel.

The method may be implemented such that the reusable hub includes a first portion and a second portion. Coupling includes coupling the first portion to the second portion such that the abrasive wheel is in between the first and second portions.

The method may be implemented such that the first portion includes a metal.

The method may be implemented such that the first portion is a plastic.

The method may be implemented such that the first portion has an elastic modulus greater than 1 GPa.

The method may be implemented such that the damping feature includes a flexible feature.

The method may be implemented such that the flexible feature is an o-ring.

The method may be implemented such that the abrasive wheel is a depressed center grinding wheel, a cut off wheel, a cut-and-grind wheel, a flex-wheel, an inner-diameter grinding wheel, an outer-diameter grinding wheel, a centerless grinding wheel, a Cam/Crank grinding wheel, a surface grinding wheel, a gear grinding wheel, a plunge grinding wheel, an edge grinding wheel, a finishing grinding wheel, a super-finishing grinding wheel, or a polishing grinding wheel.

The method may be implemented such that the first material has a first damping factor, the second material has a second damping factor. The second damping factor is higher than the first damping factor.

The method may be implemented such that the hub includes a depressed center and is configured to couple to a planar abrasive wheel such that the a bottom surface of the planar abrasive wheel is offset from the reusable hub such that, when the bottom surface contacts a worksurface, the hub is spaced from the worksurface.

The method may be implemented such that the removable interlocking is magnetic.

The method may be implemented such that it also includes an o-ring. between the first and second portions.

The method may be implemented such that the reusable hub includes a housing composed of a structural material including: aluminum, a high carbon steel, stainless steel, a high nickel alloy, titanium, epoxy, polyamide, polycarbonate, acrylonitrile butadiene styrene, polyethylene terephthalate, polystyrene, polytetrafluorethylene, polyvinylidene fluoride, polymethyl methacrylate, phenolic resins, vinyl ester resins, and polyetherketones; a combination thereof, or a combination thereof reinforced with a glass fiber, a carbon fiber, a ceramic fiber, or a polyamide fiber.

The method may be implemented such that the damping feature includes a damping material including: an elastic and/or rubber material with elastic modulus at least 10×below that of the structural material.

The method may be implemented such that the damping material is polyisoprene, polychloroprene, silicone rubbers, nitrile rubber, polyisoprene, polyethylene, fluoroelastomers, styrene-butadiene rubber, polyolefins, a polyolefin copolymer, or a polyurethanes.

An abrading system is presented that includes an abrasive wheel including abrasive particles within a binder matrix. The abrasive wheel includes an outer circumference, an inner circumference, and a wheel width that extends from the outer circumference to the inner circumference. The system also includes a reusable hub including a mating feature that removably couples the reusable hub to the abrasive wheel.

The system may be implemented such that the mating feature is integral to the abrasive wheel.

The system may be implemented such that the mating feature is molded or machined into the abrasive wheel.

The system may be implemented such that the mating feature is integral to the reusable hub.

The system may be implemented such that the mating feature includes a mating ring that mechanically couples to the reusable hub, on a first side, and couples to the abrasive wheel, on a second side.

The system may be implemented such that the mating feature couples to the reusable hub using threading, clamping, clipping, a magnet, grooves or friction.

The system may be implemented such that the reusable hub includes an upper portion and a lower portion. The mating feature couples the upper portion to the lower portion on either side of the abrasive wheel.

The system may be implemented such that the reusable hub has a hub circumference, on an exterior edge, a bore circumference, on an interior edge, and a hub height extending between the hub circumference and the bore circumference. The abrading system has a system height including a distance from the bore circumference to the outer circumference. The system height is less than 10% more than the sum of the hub height and the wheel height.

The system may be implemented such that the reusable hub includes metal, plastic, or fiber-reinforced composite.

The system may be implemented such that the reusable hub includes a housing and an interior. The interior includes a damping feature.

The system may be implemented such that the damping feature is a material that fills the interior.

The system may be implemented such that the damping feature is a plurality of repeating units within the interior.

The system may be implemented such that it also includes a locking mechanism that fixes a relative position of the reusable hub to the abrasive wheel.

The system may be implemented such that the locking mechanism includes protrusions extending from the reusable hub.

The system may be implemented such that the protrusions are received by corresponding recesses in the mating feature.

The system may be implemented such that the mating feature is a mating ring.

The system may be implemented such that the abrasive wheel is a depressed center grinding wheel, a cut off wheel, a cut-and-grind wheel, a flex-wheel, an inner-diameter grinding wheel, an outer-diameter grinding wheel, a centerless grinding wheel, a Cam/Crank grinding wheel, a surface grinding wheel, a gear grinding wheel, a plunge grinding wheel, an edge grinding wheel, a finishing grinding wheel, a super-finishing grinding wheel, or a polishing grinding wheel.

The system may be implemented such that a portion of the wheel width includes an abrasive particle-free region.

The system may be implemented such that the abrasive particle-free region includes threading, grooves or apertures that receive a corresponding threading or protrusion of the mating feature.

The system may be implemented such that the reusable hub, when coupled to the abrasive wheel, provides a substantially flat grinding surface.

The system may be implemented such that, when the substantially flat grinding surface is in contact with a substrate, the reusable hub is spaced apart from the substrate.

The system may be implemented such that the abrasive wheel is substantially planar along the wheel width.

A reusable hub for an abrasive article is presented that includes an abrasive connection mechanism for removably coupling to an abrasive article. The coupling between the reusable hub and the abrasive article is a mechanical connection. The reusable hub also includes a connection mechanism for removably coupling the reusable hub to a tool driveshaft. The reusable hub has a thickness along the connection mechanism sized to receive the abrasive article such that the reusable hub is coupled along an interior edge of the abrasive article.

The reusable hub may be implemented such that the reusable hub has a lip configured to extend over a surface of one side of the abrasive article such that it covers no more than 10% of an area of the abrasive article.

The reusable hub may be implemented such that the reusable hub includes metal, plastic or reinforced composite.

The reusable hub may be implemented such that the reusable hub, through the abrasive connection mechanism, couples to a mounting ring which couples to the abrasive article.

The reusable hub may be implemented such that the coupling between the reusable hub and the mounting ring includes threading, grooves clamping, clipping or friction.

The reusable hub may be implemented such that the coupling between the reusable hub and the abrasive article is a toolless coupling.

The reusable hub may be implemented such that the abrasive connection mechanism is integral to the abrasive article.

The reusable hub may be implemented such that the abrasive connection mechanism includes threading, groves or apertures.

The reusable hub may be implemented such that it includes a first portion and a second portion. The first and second portions are configured to removably couple together about an abrasive article.

The reusable hub may be implemented such that the vibrational damping mechanism is a material construction of the reusable hub. The material is metal, plastic or reinforced composite.

The reusable hub may be implemented such that the vibrational damping mechanism is a material internal to the reusable hub. The material is different from a hub housing material.

A method for exchanging abrasive articles for a reusable hub is presented that includes decoupling a first abrasive article from the reusable hub and coupling a second abrasive article to the reusable hub. The reusable hub couples and decouples using a mechanical feature of the hub. The method also includes contacting the second abrasive article to a worksurface.

The method may be implemented such that the mechanical feature includes threading, grooves, clipping, clamping, or protrusions.

The method may be implemented such that the mechanical feature couples directly to a corresponding feature integral to the second abrasive article.

The method may be implemented such that the mechanical feature couples directly to a mating ring which couples to the abrasive article.

The method may be implemented such that contacting the second abrasive article to the worksurface further includes providing vibrational damping.

The method may be implemented such that vibrational damping is provided by a material of the reusable hub, and wherein the reusable hub comprises metal, plastic or reinforced composite.

The method may be implemented such that vibrational damping is provided by a flexible feature.

The method may be implemented such that it also includes decoupling the second abrasive article from the reusable hub, and coupling a third abrasive article to the reusable hub. The reusable hub couples and decouples using the mechanical feature. The method may also include contacting the third abrasive article to a worksurface and providing vibrational damping.

The method may be implemented such that vibrational damping is provided by a material inside a hub housing.

The method may be implemented such that the material differs from the hub housing.

The method may be implemented such that it further includes positionally locking the reusable hub in place with respect to the second abrasive article.

The method may be implemented such that it also includes releasing a positional lock between the reusable hub and the first abrasive article.

EXAMPLES
Example 1

Depressed center grinding wheels (DCGW) were assembled with components demonstrated in FIG. 2. A reusable hub was machined from tool steel with inner diameter of inches and outer diameter of approximately 2.5 inches with a depression angle of approximately 25 degrees. The hub was threaded in accordance with ANSI standard 2.5″-20-UN threading. A separate mating ring was machined from aluminum with inner threading of 2.5″-20-UN. The mating ring, typical resin-bonded abrasive mix (phenolic resin, abrasive grain, and grinding aid), and 3 layers of glass fiber scrims were loaded into a mold and pressed at a pressure of 50 tons for 5 seconds into a flat grinding component. The glass fiber scrims were typical scrims for depressed center grinding wheels except that the inner diameter and outer diameter were cut to 2.5 inches and 4.5 inches respectively. The pressed construction was cured at a maximum temperature of 190° C. After curing, the grinding component could be threaded onto the reusable hub to assemble a depressed center grinding wheel.

The thickness of the grinding layer, as well as the reusable hub, were approximately 0.25 inches. The outer diameter of the grinding wheel was 4.5 inches. The relative volume of the grinding layer and reusable hub were calculated using Autodesk Inventor software and are tabulated in Table I, below. The reusable hub corresponds to a portion of the wheel which is often discarded. Thus approximately 30% of the raw materials and waste were avoided as a result of this design.

TABLE I

Calculated Volume Saving for DCGW with Reusable Hubs

Reusable
Grinding

Volume

Hub
Layer
Total
Percent

Volume
Volume
Volume
of Reusable

Sample
Description
(in³)
(in³)
(in³)
Component

Ex 1
Aluminum
1.13
2.63
3.76
30%

Hub,

Aluminum

Mating

Ring

Example 2

DCGWs were created with the same design as described in Example 1, except the materials used were epoxy resins. The reusable hub and mating ring were 3D-printed using stereolithography (SLA), where the resin was a UV-cured epoxy.

Example 3

DCGW with the structure diagrammed in FIG. 4 were formed by a process similar to that described in Example 3. Example 3 consists of a 2-part reusable hub, in which a top component could be threaded onto a spindle. A second hub component contained structures to thread onto spindle, as well as attaching without threading to a mating ring such that the mated components would couple relative motion in the axial and radial motion of the hub, mating ring and grinding layer. Additionally, a rubbery damping element was incorporated into the top hub component in the form of an AS568-038 silicone rubber o-ring with nominal diameter of 2.625 inches.

Comparative Example 1

Commercially available DCGWs were purchased from Grainger with manufacturer's model number 87453 (3M Co.). The nominal thickness (0.25 inches), inner diameter (0.875 inches) and outer diameter (4.5 inches) were the same as Example 1.

Comparative Example 2

DCGWs with nominal geometry identical to Comparative Example 1 were formed in a lab. The abrasive mix (abrasive grain, phenolic resin and grinding aids) were the same as described in Example 1. A flat wheel was fabricated by loading abrasive mix and 3 glass fiber scrims into a mold with outer diameter of 4.5 inches and pressing with a pressure of 50 tons. The wheel was then further shaped to add the depressed center by pressing between two plates having the “T27” shape at a pressure of 5 tons. The pressed wheel was then cured at a maximum temperature of 190° C.

Testing

Safety Testing: Burst speed and side load testing were conducted on select sample (see Table II) using equipment from Davide Maternini S.p.a. (Italy). Burst tests were performed using model MDM PVM 030/040 equipment. Rotational speed, in terms of RPMs and linear tangential velocity (m/s) were measured at burst using a photodetector to record the speed at which a sample failed and no longer blocked a light source from a detector.

Side load testing was conducted in a pass/fail manner using model MDM PVM UNI EN 12413-2011 side load tester from Davide Maternini, S.p.a, Italy. The side load was tested with a single-point load at a force of 290 N. Pass/fail values were indicated by whether the sample failed/broke after the load was applied. Results are illustrated in Table II, below.

TABLE II

RFS Testing for 4.5″ Outer Diameter DCGW

Burst
Burst
Side-Load

Speed
Speed
Testing @ 290

Example
Description
(rpms)
(m/s)
N (Pass/Fail)

CE1
Standard Lab
22004
131.6
Pass

DCGW

CE1
Standard
21971
131.4
Pass

Lab DCGW

Ex 1
Aluminum Hub,
23364
139.8
Pass

Aluminum Mating

Ring

Ex 1
Aluminum Hub,
22738
136.0
Pass

Aluminum Mating

Ring

Ex 2
Epoxy Hub, Epoxy
20110
120.3
Fail

Mating Ring

Ex 2
Epoxy Hub, Epoxy
20057
120.0
Fail

Mating Ring

Vibration Analysis: Tool vibration was measured for selected examples using a Larson Davis Model SEN041F accelerometer and Larson Davis Model HVM200 vibration meter. Average acceleration was used as a proxy for tool vibration. The accelerometer was adhered to an angle grinder (Bosch model 1375A) near the mount of the grinding wheel. Acceleration was averaged over 30 seconds for a free-spinning DCGW. Average acceleration values for select examples are listed in Table III. Wheel imbalance measurements are also listed in Table III. Wheel imbalance was measured by placing a wheel on a freely rotating spindle and allowing the heaviest portion to rotate downward due to gravity. Weight was then added to the top end of the wheel until the sample no longer had a preferred orientation on the freely rotating spindle due to gravity.

TABLE III

Wheel Vibration for 4.5″ Outer Diameter

DCGW Measured by Tool-Mounted Accelerometer

Average

Mass,
Imbalance
Acceleration

Example
Description
(g)
(g)
(m/s{circumflex over ( )}2)

N/A
Angle-Grinder Only
0
0
1.70

CE 2
3M Cubitron II
163.7
1.0
6.37

Ex 2
Epoxy Hub,
145.8
1.5
3.00

Epoxy Mating

Ring

Ex 1
Aluminum Hub,
210.4
2.0
6.09

Aluminum

Mating Ring

CE 1
Standard Lab DCGW
164.8
2
7.38

	Number	Date	Country
	63201644	May 2021	US
	63198575	Oct 2020	US

REUSABLE HUB ASSEMBLY FOR ABRASIVE ARTICLES

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