Apparatus and method for finishing edges of glass sheets - Patents.com

Abstract

A method for finishing an edge of a glass sheet can include engaging the edge of the glass sheet with a groove of an edge finishing wheel as the edge finishing wheel is rotated by a motor. An operating current of the motor can be monitored as the edge finishing wheel engages the edge of the glass sheet. The operating current can represent an operating torque of the motor. The method can further include determining whether the operating torque of the motor is greater than an upper threshold torque value corresponding to a maximum groove depth. If the operating torque of the motor is greater than the upper threshold torque value, engaging a blade of a cutting head with an outer diameter of the edge finishing wheel, thereby chipping material from the outer diameter of the edge finishing wheel and reducing the operating torque of the motor.

Description

[Technical field]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application No. 63 / 282,291, filed November 23, 2021, the entire disclosure of which is incorporated herein by reference.

[0002] (Technical field) SUMMARY OF THE DISCLOSURE This disclosure relates generally to methods and apparatus for finishing the edges of glass sheets. [Background technology]

[0003] During the manufacturing process of glass sheets, the edges of the glass sheets may be finished, such as by grinding, polishing, and / or cleaning, to improve the quality of the glass sheets. In the final step of the finishing process, a glass edge finishing wheel may be utilized to polish the edges of the glass sheets to remove particulates and / or debris from the edges of the glass sheets. During this step, the edges of the glass sheets are inserted into grooves in the rotating glass edge finishing wheel, thereby removing defects and / or particulates from the edges of the glass sheets. However, the glass edge finishing wheels utilized in this final step are often made of a soft material that causes the wheels to wear rapidly during use, resulting in a poor edge finish over time. Summary of the Invention [Problem to be solved by the invention]

[0004] Therefore, there is a need for an alternative method and apparatus for finishing the edges of glass sheets that extends the useful life of glass edge finishing wheels. [Means for solving the problem]

[0005] A first aspect A1 includes a method of finishing an edge of a glass sheet, the method including the steps of engaging the edge of the glass sheet with grooves of an edge finishing wheel as the edge finishing wheel is rotated by a motor; monitoring an operating current of the motor as the edge finishing wheel engages the edge of the glass sheet, the operating current representing an operating torque of the motor; determining whether the operating torque of the motor is greater than an upper threshold torque value corresponding to a maximum groove depth; and if the operating torque of the motor is greater than the upper threshold torque value, engaging a blade of a cutting head with an outer diameter of the edge finishing wheel, thereby cutting material from the outer diameter of the edge finishing wheel and reducing the operating torque of the motor.

[0006] A second aspect A2 includes the method of first aspect A1, wherein the upper threshold torque value is an upper threshold torque ratio corresponding to a maximum groove depth; and the step of determining whether the motor's operating torque is greater than the upper threshold torque ratio includes the steps of determining the motor's operating torque ratio, where operating torque ratio = (motor operating current / motor maximum current) x 100; determining the difference between the motor's operating torque ratio and a baseline torque ratio, where baseline torque ratio = (motor baseline current / motor maximum current) x 100; and comparing the difference between the operating torque ratio and the baseline torque ratio to the upper threshold torque ratio.

[0007] A third aspect A3 includes any of the methods of aspects A1-A2, wherein the upper threshold torque ratio is within the range of 48% to 52%.

[0008] A fourth aspect A4 includes the method of any of aspects A1-A3, further including directing a liquid onto the blade of the cutting head and the edge finishing wheel when the blade of the cutting head engages the outer diameter of the edge finishing wheel.

[0009] A fifth embodiment, A5, includes the method of any of embodiments A1 through A4, further including collecting debris and liquid from scraping material from the outer diameter of the edge finishing wheel in a collection trough.

[0010] A sixth embodiment A6 includes any of the methods of embodiments A1 through A5, wherein a debris shield is positioned adjacent to the edge finishing wheel and oriented to direct liquid and debris projected from the edge finishing wheel into the collection trough.

[0011] A seventh embodiment A7 includes the method of any of embodiments A1-A6, further including applying a vacuum to the collection trough to drain the liquid and debris from the collection trough.

[0012] An eighth embodiment A8 includes the method of any of embodiments A1 through A7, further including directing the liquid and debris from the collection trough to a waste collection bin.

[0013] A ninth embodiment A9 includes the method of any of embodiments A1-A8, wherein the edge finishing wheel comprises abrasive grains embedded in a resin matrix.

[0014] A tenth embodiment A10 includes the method of any of embodiments A1-A9, wherein the edge finishing wheel comprises a plurality of grooves.

[0015] An eleventh embodiment, A11, includes the method of any of embodiments A1 through A10, wherein the depth of the plurality of grooves is greater than or equal to 0.3 mm and less than or equal to 0.6 mm.

[0016] A twelfth embodiment A12 includes the method of any of embodiments A1 through A11, wherein the pitch of the plurality of grooves is 1.5 mm or less.

[0017] A thirteenth aspect A13 includes an edge finishing apparatus for finishing an edge of a glass sheet, the edge finishing apparatus comprising: a finishing wheel assembly comprising an edge finishing wheel rotatably coupled to a motor, the edge finishing wheel comprising a plurality of grooves for engaging an edge of the glass sheet; a wheel dressing assembly comprising a cutting head mechanically coupled to an actuator; and a controller communicatively connected to the motor of the finishing wheel assembly and the actuator of the wheel dressing assembly, the controller comprising a processor and a non-transitory memory storing computer readable and executable instructions that, when executed by the processor, cause the processor to: receive a signal from the motor representative of an operating torque of the motor; determine whether the operating torque of the motor is greater than an upper threshold torque value corresponding to a maximum groove depth; and initiate a wheel dressing operation if the operating torque of the motor is greater than the upper threshold torque value, and the controller initiates the wheel dressing operation by actuating the actuator of the wheel dressing assembly to engage a blade of the cutting head with the edge finishing wheel.

[0018] A fourteenth embodiment A14 includes the edge finishing device of embodiment A13, wherein the upper threshold torque value is an upper threshold torque ratio corresponding to a maximum groove depth, and the processor determines whether the motor operating torque is greater than the upper threshold torque ratio by determining a motor operating torque ratio based on a signal representing the motor operating torque, where the operating torque ratio = (motor operating current / motor maximum current) x 100, and determining a difference between the motor operating torque ratio and a baseline torque ratio, where the baseline torque ratio = (motor baseline current / motor maximum current) x 100.

[0019] A fifteenth embodiment A15 includes the edge finishing device of any of embodiments A13-A14, wherein the upper threshold torque ratio is in the range of 48% to 52%.

[0020] A sixteenth aspect, A16, includes the edge finishing apparatus of any of aspects A13 to A15, wherein the edge finishing apparatus further includes a nozzle positioned to direct liquid onto the cutting head and the edge finishing wheel, and initiating the wheel dressing operation includes actuating at least one valve operatively associated with the nozzle to direct liquid onto the cutting head and the edge finishing wheel.

[0021] A seventeenth embodiment A17 includes the edge finishing apparatus of any of embodiments A13 to A16, further comprising a collection trough disposed below the edge finishing wheel and cutting head, the collection trough positioned to collect debris and liquid during the wheel dressing operation.

[0022] An eighteenth embodiment, A18, includes the edge finishing apparatus of any of embodiments A13 to A17, further including a vacuum system fluidly connected to the collection trough by a drain line, and a waste collection bin connected to the drain line, and initiating the wheel dressing operation includes activating the vacuum system fluidly connected to the collection trough to drain debris and liquid from the collection trough to the waste collection bin.

[0023] A nineteenth embodiment, A19, includes the edge finishing apparatus of any of embodiments A13 to A18, further comprising a debris shield positioned adjacent to the edge finishing wheel and oriented to direct liquid and debris projected from the edge finishing wheel during the wheel dressing operation into a collection trough.

[0024] A twentieth embodiment A20 includes the edge finishing device of any of embodiments A13 to A19, wherein a depth of the plurality of grooves is greater than or equal to 0.3 mm and less than or equal to 0.6 mm, and a pitch of the plurality of grooves is less than or equal to 1.5 mm.

[0025] Additional features and advantages of the methods and apparatus described herein will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description, or will be recognized by practicing the embodiments described herein, including the following detailed description, the claims, and the accompanying drawings.

[0026] It should be understood that the foregoing summary and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein and, together with the description, serve to explain the principles and operation of the claimed subject matter. [Brief description of the drawings]

[0027] [Figure 1A] 1 illustrates a schematic of an edge finishing wheel engaging an edge of a glass sheet and the forces acting on the edge of the glass sheet. [Figure 1B] 1A and 1B show schematic diagrams of the edge of a glass sheet engaged with new (unworn) grooves of an edge finishing wheel and the resulting forces acting on the edge of the glass sheet. [Figure 1C] 1 illustrates diagrammatically the edge of a glass sheet engaged with the used (worn) grooves of an edge finishing wheel and the resulting forces acting on the edge of the glass sheet. [Diagram 2] 1 illustrates a schematic diagram of an edge finishing apparatus for finishing an edge of a glass sheet according to one or more embodiments shown and described herein. [Diagram 3] 1 illustrates a schematic cross-section of an edge finishing wheel according to one or more embodiments shown and described herein. [Figure 4] 3 illustrates a schematic diagram of the edge finishing apparatus of FIG. 2 during a wheel dressing operation according to one or more embodiments shown and described herein. [Diagram 5]1 is a flowchart of a method of initiating a wheel dressing operation on an edge finishing wheel of an edge finishing apparatus according to one or more embodiments shown and described herein. [Figure 6] 13 is a partial flow chart of an alternative method of initiating a wheel dressing operation on an edge finishing wheel of an edge finishing apparatus according to one or more embodiments shown and described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0028] Reference will now be made in detail to embodiments of an apparatus and method for finishing the edges of a glass sheet, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar elements. One embodiment of an apparatus for finishing the edges of a glass sheet is illustrated in FIG. 2. A method for finishing the edges of a glass sheet using an apparatus may generally include engaging an edge of the glass sheet with a groove of an edge finishing wheel as the edge finishing wheel is rotated by a motor. As the edge finishing wheel engages the edge of the glass sheet, an operating current of the motor may be monitored. The operating current may represent an operating torque of the motor. The method may further include determining whether the operating torque of the motor is greater than an upper threshold torque value corresponding to a maximum groove depth. If the operating torque of the motor is greater than the upper threshold torque value, a blade of the cutting head engages an outer diameter of the edge finishing wheel, thereby chipping material from the outer diameter of the edge finishing wheel and reducing the operating torque of the motor. Various embodiments of an apparatus for finishing the edges of a glass sheet and methods of use thereof are described in further detail herein with particular reference to the accompanying drawings.

[0029] Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value to the other particular value. Similarly, when values ​​are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will further be understood that the endpoints of each of the ranges are significant in relation to the other endpoint, and independently of the other endpoint.

[0030] Directional terms used herein, e.g., upper, lower, right, left, front, rear, above, below, are given only with reference to the illustrated figures and are not intended to imply absolute directions.

[0031] Unless otherwise indicated, the methods described herein are not intended to be construed as requiring that its steps be performed in a particular order, or that it require a particular orientation of any apparatus. Thus, where a method claim does not actually recite an order in which its steps are to be followed, or where any apparatus claim does not actually recite an order or orientation for individual components, or where the steps are not specifically recited in the claim or specification otherwise to be limited to a particular order, or where no particular order or orientation for the components of the apparatus is recited, no order or orientation is intended to be inferred in any respect. This is true for all possible non-expressive bases for interpretation, including logical considerations regarding the arrangement of steps, operational flow, order of components, or orientation of components, general meaning derived from grammatical construction or punctuation, and the number or type of embodiments described in the specification.

[0032] As used herein, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Thus, for example, reference to an "a" component includes aspects having two or more such components unless the context clearly dictates otherwise.

[0033] As described herein, the edges of a glass sheet can be finished using a series of grinding, polishing, and cleaning steps. These steps utilize a rotating glass edge finishing wheel that engages the edge of the glass sheet. An example edge finishing step is shown generally in FIG. 1A, where a rotating edge finishing wheel 201 contacts the edge 110 of the glass sheet 100 as the glass sheet 100 translates in the direction indicated by arrow 200 (i.e., in the +Y direction of the coordinate axes shown in FIG. 1A) and the edge finishing wheel 201 rotates in the XY plane of the coordinate axes shown in FIG. 1A in the direction indicated by arrow 202. The glass edge finishing wheel 201 utilized in the final steps of the edge finishing step is often made of a softer material than the finishing wheels used in the earlier grinding and polishing steps. As such, the glass edge finishing wheels utilized in the final finishing step often wear out quickly. As the grooves in the glass edge finishing wheels deepen due to wear, the force acting on the edge of the glass sheet is reduced, which over time results in a poor edge finish and requires replacement of the edge finishing wheels, which creates process downtime and reduces the manufacturing throughput of the glass sheets, increasing manufacturing costs in terms of lost production time and increased material costs.

[0034] It has now been discovered that the underlying cause of the decrease in the force of the edge finishing wheel 201 acting on the edge 110 of the glass sheet 100 is related to the manner in which the force from the edge finishing wheel 201 is distributed onto the glass sheet 100 as the grooves of the edge finishing wheel 201 deepen over time. In particular, the resultant force (F Total ) is the normal force component (F Normal , acting in the −X direction of the coordinate axes shown in FIG. 1A ), and a tangential force component (F Tangential, acting in the -Y direction of the coordinate axes shown in FIG. 1A ). Normai is primarily due to the polishing and / or cleaning performed on the edge 110 of the glass sheet 100.

[0035] 1A and 1B together, FIG. 1B illustrates the engagement of the edge finishing wheel 201 with the edge 110 of the glass sheet 100 when the edge finishing wheel 201 is new and the grooves 205 of the edge finishing wheel 201 are shallow (i.e., unworn). FIG. 1B also illustrates the normal force component F acting in the −X direction of the coordinate axes shown in FIG. Normal and the tangential force component F acting in the -Y direction of the coordinate axis shown in Figure 1B. Tangential The magnitude of the resultant force F acting in the −X direction on the edge 110 of the glass sheet 100 when the edge finishing wheel 201 is in a new condition is also shown. Total Normal force component F Normal is the tangential force component F acting in the -Y direction Tangential 2, the edge finishing wheel 201 efficiently cleans and / or polishes the edge 110 of the glass sheet 100.

[0036] 1A and 1C together, FIG. 1X illustrates the engagement of the edge finishing wheel 201 with the edge 110 of the glass sheet 100 when the edge finishing wheel 201 is in a worn condition such that the grooves 205 of the edge finishing wheel 201 are deeper than those shown in FIG. 1B. FIG. 1C also illustrates the normal force component F acting in the −X direction of the coordinate axes shown in FIG. 1C. Normal and the tangential force component F acting in the -Y direction of the coordinate axis shown in Figure 1C. Tangential 1C. As the edge finishing wheel 201 wears over time, the grooves 205 in the edge finishing wheel 201 deepen, as shown in FIG. 1C. The deepening grooves in the edge finishing wheel 201 result in increased contact between the edge finishing wheel 201 and the surface(s) 102 of the glass sheet 100, which in turn increases the magnitude of a resultant force F acting on the glass sheet 100 in the −Y direction of the coordinate axis shown in FIG. 1C. Total The tangential force component FTangential increases, while the normal force component F acting in the -X direction shown in Figure 1C increases. Normal decreases. The normal force component F Normal The reduced contact of the edge finishing wheel 201 with the edge 110 of the glass sheet 100 may reduce the effectiveness of the cleaning and / or polishing performed by the edge finishing wheel 201 on the edge 110 of the glass sheet 100, resulting in a reduced quality of the finished glass sheet and / or the need for additional steps to complete the finishing of the edge 110 of the glass sheet 100. Additionally, increased contact of the surface(s) 102 of the glass sheet 100 with the edge finishing wheel 201 may damage the surface(s) 102 of the glass sheet 100, such as by abrasion, further reducing the quality of the glass sheet 100 and potentially resulting in the disposal of the glass sheet 100 as waste glass. In either situation, wear on the edge finishing wheel 201 may reduce production efficiency and potentially increase production costs.

[0037] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments disclosed herein relate to methods and apparatus for mitigating the effects of edge finishing wheel wear during the manufacturing and finishing of glass sheets.

[0038] 2, there is shown a schematic diagram of an edge finishing apparatus 10 for finishing the edge(s) 110 of a glass sheet 100 in accordance with one or more embodiments shown and described herein. The edge finishing apparatus 10 generally comprises a finishing wheel assembly 250, a wheel dressing assembly 300, a debris collection system 400, and a controller 500. The various components of the edge finishing apparatus 10 will now be described in further detail, with particular reference to FIGS. 2 and 3.

[0039] In the embodiments described herein, the finishing wheel assembly 250 of the edge finishing apparatus comprises an edge finishing wheel 201 and a motor 252. In embodiments, the finishing wheel assembly 250 may optionally include a multi-axis positioning stage 254. The edge finishing wheel 201 is rotatably coupled to an armature 256 of the motor 252 to facilitate rotation of the edge finishing wheel 201 in a plane parallel to the XY plane of the coordinate axes shown in FIG.

[0040] In embodiments in which the finishing wheel assembly 250 includes a multi-axis positioning stage 254, the multi-axis positioning stage 254 can be coupled to the motor 252 via a linkage 262. The multi-axis positioning stage 254 can include two or more linear actuators, such as linear actuators 258 and 260, to facilitate adjustment of the position of the motor 252 and attached edge finishing wheel 201 along at least two axes. For example, in the embodiment shown in FIG. 2, the multi-axis positioning stage 254 includes a first linear actuator 258 to facilitate movement of the motor 252 and attached edge finishing wheel 201 relative to the edge 110 of the glass sheet 100 in the + / -X direction of the coordinate axes shown in FIG. 2, as represented by arrow 264. The multi-axis positioning stage 265 can also include a second linear actuator 260 orthogonal to the first linear actuator 258 to facilitate movement of the motor 252 and attached edge finishing wheel 201 relative to the glass sheet 100, as represented by arrow 266. Although not shown in FIG. 2, it is understood that the multi-axis positioning stage 265 may optionally include a third linear actuator orthogonal to the first and second linear actuators 258, 260 to facilitate movement of the motor 252 and attached edge finishing wheel 201 relative to the glass sheet 100 in the + / -Y direction of the coordinate axes shown in FIG. 2. If included, the multi-axis positioning stage 254 may be used, for example, to index the edge finishing wheel 201 relative to the edge 110 of the glass sheet 100 to accommodate dimensional changes in the edge finishing wheel after wear and subsequent (re)dressing of the edge finishing wheel 201 as a result of wear, as will be described in more detail herein. The multi-axis positioning stage 254 may be used, for example, to index the edge finishing wheel 201 relative to the edge 110 of the glass sheet 100 such that the glass sheet 100 may be positioned in a particular one of a series of grooves formed in the outer diameter of the edge finishing wheel 201.

[0041] 3, a cross-section of one embodiment of an edge finishing wheel 201 is shown diagrammatically. The edge finishing wheel 201 generally comprises abrasive grains, such as silicon carbide particles, embedded in a resin matrix. By way of example, the edge finishing wheel 201 may comprise a Scotch-Brite™ Molded Wheel XR-WM (DLO Wheel) from 3M Abrasive Systems. However, it should be understood that other types of wheels and other materials are also contemplated and possible for the edge finishing wheel.

[0042] As shown in FIG. 3, the edge finishing wheel 201 has an initial outer diameter D w (i.e., diameter D w is the diameter of the edge finishing wheel before it is used for edge finishing. In an embodiment, the initial outer diameter D wmay be, for example, 150 mm. However, it should be understood that edge finishing wheels 201 having larger or smaller initial outer diameters are also envisioned and possible. The edge finishing wheel 201 may further include a series of grooves 205, such as grooves 205a, 205b, 205c, 205d, and 205d, formed in the edge 204 of the edge finishing wheel 201. During a glass edge finishing operation, as the edge finishing wheel 201 rotates, the edge of the glass sheet is received in one of the grooves 205a, 205b, 205c, 205d, for example, to facilitate polishing and cleaning of the edge of the glass sheet by the edge finishing wheel 201. In the embodiment of the edge finishing wheel 201 shown in FIG. 3, a total of five grooves 205a, 205b, 205c, 205d are shown for illustrative purposes. However, it should be understood that the edge finishing wheel 201 may include more or less than five grooves. For example, in embodiments, the edge finishing wheel 201 can include 10 grooves, 15 grooves, or even 20 or more grooves. As shown in FIG. 3, the grooves 205 have a pitch P. In embodiments of the edge finishing wheel 201 described herein, the groove pitch P can be less than 2 mm, such as less than 1.9 mm, 1.8 mm or less, 1.7 mm or less, 1.6 mm or less, 1.5 mm or less, 1.4 mm or less, 1.3 mm or less, 1.2 mm or less, 1.1 mm or less, or even 1 mm or less. The grooves 205a, 205b, 205c, 205d have a depth d from the outer diameter of the edge finishing wheel 201. In embodiments, the groove depth d of a new (unworn) edge finishing wheel 201 can be, for example, without limitation, 0.3 mm or more and 0.6 mm or less.

[0043] Referring again to FIG. 2, the wheel dressing assembly 300 generally comprises a housing 302 supporting a cutting head 304 including a blade 306. As described in more detail herein, the cutting head 304 and blade 306 are utilized to dress (e.g., scrape) the outer diameter of the worn edge finishing wheel 201 and restore (i.e., reduce) the groove depth of the worn edge finishing wheel 201, thereby improving the finishing performance of the edge finishing wheel 201. The housing 302 of the wheel dressing assembly 300 may be supported by posts 312 such that the cutting head 304 and blade 306 are positioned proximate to the outer diameter of the edge finishing wheel 201. The wheel dressing assembly 300 also includes an actuator 308 disposed within the housing 302. The actuator 308 may be, for example, a linear actuator. The actuator 308 is mechanically coupled to the cutting head 304 to facilitate extension and retraction of the cutting head 304 relative to the housing 302, as indicated by arrow 310, which results in the blade 306 of the cutting head 304 engaging the edge finishing wheel 201 to facilitate periodic dressing of the edge finishing wheel 201. For example, the actuator 308 can extend the cutting head 304 such that the blade 306 of the cutting head 304 engages the outer periphery of the edge finishing wheel 201 to shave off a portion of the outer periphery from the edge finishing wheel 201, which results in the diameter of the edge finishing wheel 201 decreasing from an initial outer diameter D w 2, the wheel dressing assembly 300 is generally located at the end of the diameter of the edge finishing wheel 201 opposite the glass sheet 100, thereby reducing the risk of the glass sheet 100 interacting with the wheel dressing assembly 300 or causing any spalling by the wheel dressing assembly 300.

[0044] With further reference to FIG. 2, the edge finishing apparatus may also include a debris collection system 400. The debris collection system 400 may include a nozzle 402 positioned to supply a liquid, such as water, to the blade 306 of the cutting head 304 and the edge finishing wheel 201 when the blade 306 engages the edge finishing wheel 201. In the embodiment shown in FIG. 2, the nozzle 402 is positioned above both the cutting head 304 and the edge finishing wheel 201 such that liquid from the nozzle is directed from above onto the cutting head 304 and the edge finishing wheel 201 to wash any debris generated during the wheel dressing operation downward and away from the edge finishing wheel 201. In an embodiment, the nozzle 402 and an associated control valve (not shown) operatively associated with the nozzle 402 may be configured to automatically supply liquid to the blade 306 of the cutting head 304 and the edge finishing wheel 201 when the cutting head 304 extends toward the edge finishing wheel 201. In effect, the liquid supplied to the blade 306 from the nozzle 402 serves to cool the blade 306 of the cutting head 304 and also washes away debris (such as shavings) from the edge finishing wheel 201 as it is dressed by the blade 306 of the cutting head 304.

[0045] In embodiments, the debris collection system 400 may further include a collection trough 404 and a waste collection bin 406 for collecting and removing debris generated from the edge finishing wheel 201 during dressing of the edge finishing wheel 201 by the blade 306 of the cutting head 304. In the embodiments described herein, the collection trough 404 is positioned below the edge finishing wheel 201 and the cutting head 304 and is fluidly connected to the waste collection bin 406 by a drain line 408. Optionally, a vacuum system 410 may be connected to the drain line 408 to draw a vacuum through the drain line 408, thereby facilitating the movement of debris from the collection trough 404, through the drain line 408 and into the waste collection bin 406.

[0046] In operation, liquid expelled from the nozzles 402 onto the blade 306 of the cutting head 304 and the edge finishing wheel 201 as the edge finishing wheel 201 is dressed by the blade 306, along with any debris that is washed off the edge finishing wheel 201, is collected in the collection trough 404. The liquid and debris collected in the collection trough 404 is directed by gravity or a vacuum system 410 into the waste collection bin 406 where it is collected for further processing and / or disposal.

[0047] In an embodiment, the debris collection system 400 may optionally include a debris shield 364. The debris shield 364 may be coupled to the housing 302 of the wheel dressing assembly 300 and positioned relative to the edge finishing wheel 201, for example and without limitation, such that debris generated during dressing of the edge finishing wheel 201 with the blade 306 of the cutting head 304 is intercepted by the debris shield 364, thereby preventing the debris from contaminating other areas of the edge finishing apparatus 10 and / or damaging the glass sheet 100 being finished by the edge finishing apparatus 10. For example, engagement of the blade 306 of the cutting head 304 with the rotating edge of the finishing wheel 201 during dressing of the edge finishing wheel 201 creates particulate debris that mixes with the liquid emitted from the nozzle 402. The debris and liquid may be projected by the edge finishing wheel 201 in the direction of rotation of the edge finishing wheel 201. The debris shield 364 is positioned such that the emitted debris and liquids impinge upon and are thereby intercepted by the debris shield 364. The debris shield 364 is also positioned such that the debris and liquids impinging thereon flow down the debris shield 364 into the collection trough 404 where they are directed to a waste collection bin 406 for further processing and / or disposal.

[0048] 2, the edge finishing apparatus 10 further includes a controller 500. In the embodiment of the edge finishing apparatus 10 shown in FIG. 2, the controller 500 is positioned within the housing 302 of the wheel dressing assembly 300. However, it should be understood that other locations are contemplated and possible for the controller 500. For example, the controller 500 may be a stand-alone unit that is separate and apart from each of the finishing wheel assembly 250, the wheel dressing assembly 300, and the debris collection system 400.

[0049] In the embodiments described herein, the controller 500 includes a processor 502 communicatively coupled to a non-transitory memory 504 storing computer readable and executable instructions that, when executed by the processor 502, facilitate operation of the edge finishing apparatus 10. In particular, the computer readable and executable instructions may facilitate wheel dressing operations by the edge finishing apparatus 10 to improve or restore the effectiveness of the edge finishing performed by the edge finishing apparatus 10. In an embodiment, the controller 500 is communicatively coupled to the motor 252 of the finishing wheel assembly 250, the actuator 308 of the wheel dressing assembly 300, and one or more valves (not shown) operatively associated with the nozzles 402 of the debris collection system 400. The controller may also be communicatively connected to the vacuum system 410 of the debris collection system 400 and to the linear actuators 258, 260 of the multi-axis positioning stage 254 of the finishing wheel assembly 250 (if the finishing wheel assembly 250 includes a multi-axis positioning stage 254).

[0050] In an embodiment, the controller 500 and associated processor 502 are operable to receive a signal from the motor 252 of the finishing wheel assembly 250 indicative of the operating current of the motor 252. In the embodiments described herein, the operating current of the motor 252 is itself indicative of the torque of the motor 252. The controller 500 and associated processor 502 may also be operable to send control signals to the actuator 308 of the wheel dressing assembly 300 and one or more valves (not shown) operatively associated with the nozzle 402 of the debris collection system 400 based on and in response to the signal received from the motor 252 indicative of the operating current of the motor 252. The controller 500 and associated processor 502 may also be operable to send control signals to the vacuum system 410 of the debris collection system 400 and to the linear actuators 258, 260 of the multi-axis positioning stage 254 of the finishing wheel assembly 250 (if the finishing wheel assembly 250 includes a multi-axis positioning stage 254) based on and in response to a signal received from the motor 252 representing the operating current of the motor 252.

[0051] For example, when the edge finishing wheel 201 of the finishing wheel assembly 250 is rotated by the motor 252 but is not under load (i.e., when the edge finishing wheel 201 is not engaged with the edge 110 of the glass sheet 100), the operating current of the motor 252 may have a baseline value (i.e., a "baseline current" value) that generally corresponds to the baseline torque (i.e., a "baseline torque" value) of the motor 252. However, when the edge finishing wheel 201 of the finishing wheel assembly 250 is rotated by the motor 252 and is under load, for example when the edge finishing wheel is engaged with the edge 110 of the glass sheet 100, the operating current of the motor 252 under load may be greater than the baseline current value, and the operating current value (i.e., an "operating current" value) of this loaded condition will generally correspond to the torque (i.e., an "operating torque" value) of the motor 252 under load. In an embodiment, a computer readable and executable set of instructions stored in the memory 504 of the controller 500 utilizes the operating current value alone or in conjunction with the baseline current value to initiate a wheel dressing operation whereby the cutting head 304 of the wheel dressing assembly 300 engages the edge finishing wheel 201 to dress or scrape the edge finishing wheel 201 and control (i.e., reduce) the groove depth of the edge finishing wheel 201, thereby improving and / or restoring the effectiveness of the edge finishing operation.

[0052] Reference is now made to Figure 4, which diagrammatically illustrates the edge finishing apparatus 10 during a wheel dressing operation initiated by the controller 500. The processor 502 of the controller 500 executes a set of computer readable and executable instructions stored in the memory 504 of the controller 500 based on a signal received from the motor 252 representing the motor 252 current to initiate a wheel dressing operation in which the blade 306 of the cutting head 304 engages the edge finishing wheel 201 and liquid 450 is directed using the nozzle 402 toward the blade 306 of the cutting head 304 and the edge finishing wheel 201. For example, the processor 502 of the controller 500 can send a control signal to an actuator 308 coupled to the cutting head 304, causing the actuator 308 to advance the cutting head 304 toward the edge finishing wheel 201, thereby causing the blade 306 of the cutting head 304 to engage and dress the edge finishing wheel 201, thereby reducing the depth of the grooves 205a, 205b, 205c, 205d, 205e in the edge finishing wheel 201. Simultaneously, the processor 502 of the controller 500 can send a control signal to one or more valves (not shown) operatively associated with the nozzle 402 to open the valve, thereby allowing a flow of liquid 450 to be emitted from the nozzle 402 onto the blade 306 and the edge finishing wheel 201. In an embodiment, the processor 502 of the controller 500 can also send control signals to the vacuum system 410, thereby activating the vacuum system 410, so that liquid and debris collected in the collection trough 404 is discharged into the waste collection bin 406 during the wheel dressing operation, as indicated by arrow 460.

[0053] In an embodiment, the wheel dressing operation can be designed to remove a predetermined amount of material from the outer diameter of the edge finishing wheel 201. For example, the controller 500 of the edge finishing apparatus 10 can be programmed to incrementally advance the cutting head 304 of the wheel dressing assembly 300 by a predetermined amount for each wheel dressing operation that the controller 500 initiates, so that the same amount of material is removed from the outer diameter of the edge finishing wheel 201 each time a successive wheel dressing operation is initiated. In an embodiment, for example, the controller 500 of the edge finishing apparatus can be programmed to remove 40 micrometers of material from the outer diameter of the edge finishing wheel 201 for each wheel dressing operation that is initiated. Thus, the controller 500 can be programmed to advance the cutting head 304 an additional 40 micrometers for each successive wheel dressing operation that is initiated by the controller 500 to account for the reduction in the outer diameter of the edge finishing wheel 201.

[0054] Once the wheel dressing operation is completed (e.g., after a predetermined number of revolutions of the edge finishing wheel 201 following engagement of the blade 306 with the edge finishing wheel 201, or after a period of time has elapsed following engagement of the blade 306 with the edge finishing wheel 201), the processor of the controller 500 sends a control signal to the actuator 308 coupled to the cutting head 304, causing the actuator 308 to retract the cutting head 304 and blade 306 from the edge finishing wheel 201, thereby clearing the blade 306 of the cutting head 304 from the edge finishing wheel 201. The processor 502 of the controller 500 then sends a control signal to one or more valves (not shown) operatively associated with the nozzle 402 to close the valves, thereby ceasing the flow of liquid 450 from the nozzle 402. The processor 502 of the controller 500 may also send a control signal to the vacuum system 410 to deactivate the vacuum system 410.

[0055] In some embodiments, after the wheel dressing operation is completed, the processor of the controller 500 can send a signal to the linear actuators 258, 260 of the multi-axis positioning stage 254 of the finishing wheel assembly 250 (if the finishing wheel assembly 250 includes a multi-axis positioning stage 254) to adjust the position of the motor 252 and the attached edge finishing wheel 201 relative to the edge 110 of the glass sheet 100 based on the new diameter of the edge finishing wheel 201 after the wheel dressing operation.

[0056] 1A-1C, as the grooves 405 in the edge finishing wheel 201 wear and deepen, the force distribution on the edge 110 of the glass sheet 100 changes. In particular, the resultant force F acting on the glass sheet 100 due to contact with the edge finishing wheel 201 changes. Total The tangential force component F Tangential increases as the grooves become deeper and thus more area of ​​the surface(s) 102 of the glass sheet 100 comes into contact with the grooves of the edge finishing wheel 201. At the same time, the resultant force F acting on the glass sheet 100 Total Normal force component F Normal and the effectiveness of the glass edge finishing operation decreases. Indeed, as contact with the surface(s) 102 of the glass sheet 100 increases, the operating torque of the motor increases. That is, as the groove depth increases, the operating torque of the motor may increase. Thus, in an embodiment, the edge finishing apparatus controller 500 may utilize the value of the operating torque of the motor 252 as an indication to initiate a wheel dressing operation, which will decrease the groove depth of the edge finishing wheel 201 and restore the effectiveness of the glass edge finishing operation performed by the edge finishing wheel 201.

[0057] In particular, upon determining that the operating torque of the motor 252 has increased beyond a threshold determined from the operating current of the motor 252, the controller 500 may initiate a wheel dressing operation, causing the diameter of the edge finishing wheel 201 to decrease, thereby decreasing the depth of the grooves of the edge finishing wheel 201. As a result, the contact area between the surface(s) 102 of the glass sheet 100 and the grooves of the edge finishing wheel 201 decreases, thereby decreasing the resultant force F acting on the glass sheet 100 due to contact with the edge finishing wheel 201. Total The tangential force component F Tangential is reduced, and the resultant force F acting on the glass sheet 100 is Total Normal force component F Normal This increases the effectiveness of glass edge finishing work.

[0058] 2-5, Figure 5 is a flow chart 600 of one embodiment of a method for operating the edge finishing apparatus 10. In block 602, the processor 502 of the controller 500 monitors the operating torque of the motor 252 by receiving a signal representative of the operating torque of the motor 252 during the edge finishing operation (i.e., when the edge finishing wheel 201 is engaged with the edge 110 of the glass sheet 100). In an embodiment, the signal received from the motor 252 may be an operating current of the motor during the edge finishing operation, which corresponds to the torque of the motor 252 as described herein.

[0059] Thereafter, in block 604, the processor 502 of the controller 500 determines whether the operating torque of the motor 252 is greater than an upper threshold torque value corresponding to the maximum groove depth of the edge finishing wheel 201. In one embodiment, the processor 502 determines whether the operating torque of the motor 252 is greater than an upper threshold torque value corresponding to the maximum groove depth of the edge finishing wheel 201 by directly comparing the operating torque of the motor 252 to the upper threshold torque value. In this embodiment, the upper threshold torque value is an empirically determined constant stored in the memory 504 of the controller 500. The upper threshold torque value corresponds to the operating torque of the motor 252 of the edge finishing apparatus 10 when the edge finishing wheel 210 engages the edge 110 of the glass sheet 100 and the groove 205 of the edge finishing wheel 201 reaches a depth at which the effectiveness of the edge finishing operation decreases with increasing depth d of the groove 205. In an embodiment, the value of the upper threshold torque value is determined by the desired edge finish achieved by the edge finishing wheel as a function of the groove depth of the edge finishing wheel. For example, the upper threshold torque value may be determined empirically by correlating groove depth with the desired edge finish quality. If the operating torque value of the motor 252 is not greater than the upper threshold torque value, the processor 502 of the controller 500 repeats the method beginning with block 602. However, if the operating torque value of the motor 252 is greater than the upper threshold torque value, the processor 502 of the controller proceeds to block 606 and initiates a wheel dressing operation as described herein with respect to FIG.

[0060] 5 and 6, FIG. 6 illustrates generally an alternative embodiment of block 604 of flowchart 600. In this embodiment, the processor 502 of the controller 500 may utilize a torque ratio to determine whether the operating torque of the motor 252 is greater than an upper threshold torque value corresponding to a maximum groove depth. In this embodiment, determining whether the operating torque of the motor 252 is greater than an upper threshold torque value corresponding to a maximum groove depth (i.e., block 604 of flowchart 600) includes, at block 604a, determining an operating torque ratio of the motor 252 based on a signal representative of the operating torque of the motor 252. In particular, the signal representative of the operating torque of the motor 252 may be an operating current of the motor 252 during an edge finishing operation (i.e., the current of the motor when the edge finishing wheel 201 is engaged with the edge 110 of the glass sheet 100). The operating torque ratio of the motor 252 is determined by the processor 502 of the controller 500 by dividing the operating current of the motor 252 received by the processor 502 by the maximum current of the motor 252 and multiplying the quotient by 100 to obtain a percentage (i.e., operating torque ratio=(operating current / maximum current)×100). In an embodiment, the maximum current of the motor 252 is the rated current of the motor, which is a measurable characteristic of the motor 252 and may be stored in the memory 504 of the controller 500 for a particular edge finishing apparatus 10.

[0061] In block 604b, the processor 502 of the controller 500 determines the difference between the operating torque ratio of the motor 252 (determined in block 604a) and the baseline torque ratio of the motor 252 (i.e., operating torque ratio-baseline torque ratio). The baseline torque ratio may be stored in the memory 504 of the controller 500 or may be calculated by the processor 502 of the controller 500 based on values ​​stored in the memory 504 of the controller 500 or received by the processor 502 of the controller 500. The baseline torque ratio is the baseline current of the motor 252 divided by the maximum current of the motor 252 and multiplied by 100 to obtain a percentage (i.e., baseline torque ratio=(baseline current / maximum current)×100). In this embodiment, the baseline current of the motor 252 is the current of the motor during operation with no load on the edge finishing wheel 201 (i.e., the current flowing through the motor 252 when the edge finishing wheel is not engaged with the edge 110 of the glass sheet 100 during an edge finishing operation). In an embodiment, the baseline current of the motor 252 is a measurable characteristic of the motor 252 of the edge finishing apparatus 10 and may be stored in the memory 504 of the controller 500 for a particular edge finishing apparatus 10. Alternatively, the baseline current of the motor 252 may be measured during operation of the edge finishing apparatus 10 when the edge finishing apparatus 10 is not engaged with the edge 110 of the glass sheet 100. As described herein, the maximum current of the motor 252 is a measurable characteristic of the motor 252 and may be stored in the memory 504 of the controller 500 for a particular edge finishing apparatus 10.

[0062] Next, in block 604c, the difference between the actuation torque ratio and the baseline torque ratio is compared to an upper threshold torque value to determine whether the controller 500 should initiate a wheel dressing operation. In this embodiment, the upper threshold torque value is an upper threshold torque ratio corresponding to a maximum groove depth. In particular, the upper threshold torque value is an empirically determined constant stored in the memory 504 of the controller 500. For example, the upper threshold torque ratio may correspond to the difference between the actuation torque ratio and the baseline torque ratio of the motor 252 of the edge finishing apparatus 10. The actuation torque ratio value used to calculate this difference is determined when the edge finishing wheel 210 engages the edge 110 of the glass sheet 100 and the groove 205 of the edge finishing wheel 201 reaches a depth at which the effectiveness of the edge finishing operation decreases with increasing depth d of the groove 205. In an embodiment, the upper threshold torque ratio may be within a range of about 48% to about 52%.

[0063] If the difference between the operating torque ratio of the motor 252 and the baseline torque ratio of the motor 252 is not greater than the upper threshold torque value, the processor 502 of the controller 500 repeats the method beginning with block 602 (FIG. 5). However, if the difference between the operating torque ratio of the motor 252 and the baseline torque ratio of the motor 252 is greater than the upper threshold torque value, the processor 502 of the controller proceeds to block 606 (FIG. 5) and initiates a wheel dressing operation as described herein.

[0064] 2 and 3, in operation, the edge 110 of the glass sheet 100 engages with a groove, e.g., groove 205a, of the edge finishing wheel 201 as the edge finishing wheel 201 rotates, thereby polishing and / or cleaning the edge 110 of the glass sheet 100. During the finishing operation, the glass sheet 100 is translated or transported in the + / -Y direction along a plane parallel to the XY plane of the coordinate axes shown in FIG. 2 to facilitate polishing and / or cleaning the entire edge 110 of the glass sheet 100. As the edge 110 of the glass sheet 100 is finished by the edge finishing wheel 201, it leaves the groove 205a and the edge finishing wheel 201 indexes to accommodate the next successive glass sheet into the next successive groove of the edge finishing wheel 201, in this example groove 205b. In an embodiment, the indexing movement of the edge finishing wheel 201 is achieved by a multi-axis positioning stage 254. Alternatively, rather than indexing the edge finishing wheel 201, the position of the next successive glass sheet 100 can be indexed relative to the edge finishing wheel 201 so that the edge of the next successive glass sheet engages the next successive groove of the edge finishing wheel 201. This finishing / indexing cycle is repeated for each glass sheet 100 finished by the edge finishing apparatus 10, reducing edge finish variation across a population of glass sheets finished by the edge finishing apparatus 10.

[0065] While the edge 110 of the glass sheet 100 is being finished by the glass finishing apparatus 10, the controller 500 of the glass finishing apparatus 10 monitors the operating torque of the motor 252 of the edge finishing apparatus 10 to determine when to initiate a wheel dressing operation to mitigate the impact of wear of the edge finishing wheels on the edge finishing process, as described herein. The performance of periodic wheel dressing operations based on the operating torque of the motor further reduces the edge finish variability across the population of glass sheets finished by the edge finishing apparatus, thereby improving the quality and uniformity of the glass sheets, reducing the amount of waste glass, and improving production yields.

[0066] Additionally, performing periodic wheel dressing operations based on the motor's operating torque can further extend the useful life of the edge finishing wheel by providing a consistent groove depth over the useful life of the edge finishing wheel. In particular, performing periodic wheel dressing operations based on the motor's operating torque can allow the edge finishing wheel to utilize shallower grooves, which better maintain their structural integrity and can result in more grooves being formed on the edge finishing wheel. More grooves per edge finishing wheel can allow more linear meters of glass to be processed with a single wheel, resulting in reduced production costs.

[0067] It should therefore be appreciated that the edge finishing apparatus and methods described herein can be used to improve the quality of glass sheets processed in the edge finishing apparatus as well as reduce the manufacturing costs of the glass sheets.

[0068] It will be apparent to those skilled in the art that various modifications and variations can be made to the embodiments of the present disclosure without departing from the spirit and scope of the present disclosure. Therefore, the present disclosure is intended to cover such modifications and variations provided they come within the scope of the appended claims and their equivalents. [Explanation of symbols]

[0069] 10 Edge finishing device 100 Glass Sheets 110 Edge of glass sheet 201 Edge Finishing Wheel 205a,b Edge finishing wheel groove 250 Finishing Wheel Assembly 252 Motor 254 Multi-axis positioning stage 256 Armature 258 First Linear Actuator 260 Second Linear Actuator 262 Link Mechanism 264 + / -X Movement 266 + / -Z Movement 300 Wheel Dressing Assembly 302 Housing 304 Cutting head 306 Blade 308 Actuator 310 Cutting head extension and retraction 312 Post 364 Debris Shield 400 Debris Collection System 402 Nozzle 404 Collection Trough 406 Waste Collection Bin 408 Drainage Line 410 Vacuum System 500 Controller 502 processor 504 Memory

Claims

1. 1. A method for finishing an edge of a glass sheet, comprising: engaging an edge of the glass sheet with a groove in an edge finishing wheel as the edge finishing wheel is rotated by a motor; monitoring an operating current of the motor as the edge finishing wheel engages the edge of the glass sheet, the operating current representing an operating torque of the motor; determining whether the operating torque of the motor is greater than an upper threshold torque value corresponding to a maximum groove depth; if the operating torque of the motor is greater than the upper threshold torque value, engaging a blade of a cutting head with an outer diameter of the edge finishing wheel, thereby removing material from the outer diameter of the edge finishing wheel and reducing the operating torque of the motor; A method comprising:

2. the upper threshold torque value is an upper threshold torque ratio corresponding to the maximum groove depth, The step of determining whether the operating torque of the motor is greater than the upper threshold torque ratio comprises: determining an operating torque ratio of the motor, the operating torque ratio=(the operating current of the motor / maximum current of the motor)×100; determining a difference between the operating torque ratio and a baseline torque ratio of the motor, the baseline torque ratio = (baseline current of the motor / maximum current of the motor) x 100; comparing the difference between the operating torque ratio and the baseline torque ratio to the upper threshold torque ratio; The method of claim 1 , comprising:

3. The method of claim 2 , wherein the upper threshold torque ratio is within the range of 48% to 52%.

4. The method of claim 1 , wherein the edge finishing wheel comprises a plurality of grooves.

5. The method of claim 4 , wherein the depth of the plurality of grooves is equal to or greater than 0.3 mm and equal to or less than 0.6 mm.

6. The method of claim 4 , wherein the pitch of the plurality of grooves is 1.5 mm or less.

7. 1. An edge finishing device for finishing an edge of a glass sheet, comprising: a finishing wheel assembly comprising an edge finishing wheel rotatably coupled to a motor, the edge finishing wheel comprising a plurality of grooves for engaging the edge of the glass sheet; a wheel dressing assembly including a cutting head mechanically coupled to an actuator; a controller communicatively connected to the motor of the finishing wheel assembly and the actuator of the wheel dressing assembly; Equipped with The controller comprises a processor and a non-transitory memory storing computer readable and executable instructions that, when executed by the processor, cause the processor to: receiving a signal from the motor indicative of the operating torque of the motor; determining whether the operating torque of the motor is greater than an upper threshold torque value corresponding to a maximum groove depth; Initiating a wheel dressing operation when the operating torque of the motor is greater than the upper threshold torque value. Let them do so, The controller initiates the wheel dressing operation by actuating the actuator of the wheel dressing assembly to engage a blade of the cutting head with the edge finishing wheel.

8. the upper threshold torque value is an upper threshold torque ratio corresponding to the maximum groove depth, The processor: determining an operating torque ratio of the motor based on the signal representing the operating torque of the motor, wherein the operating torque ratio = (operating current of the motor / maximum current of the motor) x 100; and determining a difference between the operating torque ratio and a baseline torque ratio of the motor, wherein the baseline torque ratio = (baseline current of the motor / maximum current of the motor) x 100; 8. The edge finishing device of claim 7, wherein the motor operating torque is determined to be greater than the upper threshold torque ratio by:

9. The edge finishing apparatus of claim 8 , wherein the upper threshold torque ratio is within the range of 48% to 52%.

10. the edge finishing apparatus further comprising a nozzle positioned to direct a liquid onto the cutting head and the edge finishing wheel; 8. The edge finishing apparatus of claim 7, wherein initiating the wheel dressing operation includes actuating at least one valve operatively associated with the nozzle to direct the liquid onto the cutting head and the edge finishing wheel.

11. The depth of the plurality of grooves is 0.3 mm or more and 0.6 mm or less, The edge finishing device according to claim 7 , wherein the pitch of the plurality of grooves is 1.5 mm or less.

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