Vacuum suction cup

Abstract

A vacuum chuck is described, the vacuum chuck including a body portion having an elongated cavity and a contact surface for contacting a glass sheet to form a chamber with the elongated cavity and the glass sheet. An opening in the body portion is in fluid communication with the elongated cavity for connection to a low pressure source so that the contact surface can form a seal with the glass sheet to attach the vacuum chuck to the glass sheet. The periphery of the elongated cavity has a major axis and a minor axis that are orthogonal to each other, the major axis being longer than the minor axis. The periphery of the elongated cavity has a first end portion and a second end portion at respective ends of the major axis, the first end portion being larger than the second end portion. A method of using such a vacuum chuck to support a glass sheet during processing is also described.

Description

Technical Field

[0001] The present invention relates to a vacuum chuck for supporting a glass sheet, and a method for processing a thin glass sheet, in particular to a grinding operation of an edge of a thin glass sheet. Background Art

[0002] The use of vacuum cups in glass lifting and supporting operations is well known in the art, see for example US2,351,666. Vacuum cups with a circular perimeter or circular vacuum cups are often used in such operations. Vacuum cups with an elliptical perimeter (commonly referred to as elliptical vacuum cups) are also well known. Vacuum cups with different configurations are described in US4,925,225, US4,931,341 and DE19854826A1.

[0003] It is known that the edge of a glass sheet plays an important role in determining the strength of the glass sheet. It is also known that the freshly cut edge of a glass sheet is sharp and may cause cuts to a person.

[0004] It is known to grind the edge of a glass sheet using mechanical methods (often referred to as "edge processing"), such as using a grinding wheel. The grinding wheel can be used to remove the sharp edge of the glass sheet and provide the edge of the glass sheet with a certain type of profile, such as a C-shaped profile.

[0005] For thin glass sheets, it may be difficult to support the thin glass sheet during edge grinding. This is the case, for example, for thicknesses less than 1 mm and surface areas greater than 0.5 m 2 This is especially difficult for thin glass sheets with larger areas.

[0006] The present invention aims to at least partially provide a solution to this problem. Summary of the invention

[0007] Therefore, the present invention provides a vacuum chuck from a first aspect, the vacuum chuck comprising: a main body portion, the main body portion comprising an elongated cavity and a contact surface extending around the elongated cavity, the contact surface being used to contact a glass sheet and form a chamber with the elongated cavity and the glass sheet, the elongated cavity having a perimeter, and the contact surface having an edge facing the elongated cavity to define the perimeter of the elongated cavity; an opening in the main body portion in fluid communication with the elongated cavity, so that when the chamber is formed through the glass sheet and a low pressure source is connected to the opening in the main body portion, the contact surface forms a seal with the glass sheet to attach the vacuum chuck to the glass sheet; wherein the perimeter of the elongated cavity has a major axis and a minor axis orthogonal to the major axis, the major axis being longer than the minor axis, further wherein the perimeter of the elongated cavity has a first end portion at one end of the major axis and a second end portion at an opposite end of the major axis, wherein the first end portion of the perimeter of the elongated cavity is larger than the second end portion of the perimeter of the elongated cavity.

[0008] By having a vacuum chuck constructed according to the first aspect of the present invention, enhanced support can be provided for the edge region of the glass sheet to be edge processed. In addition, compared with traditional circular or oval vacuum chucks, such a vacuum chuck can provide improved support for the corner region of the glass sheet.

[0009] By configuring the elongated cavity such that a first end portion of its perimeter is larger than a second end portion of its perimeter, it is preferred that the perimeter of the elongated cavity is asymmetric about a line bisecting the long axis of the perimeter of the elongated cavity and orthogonal to the long axis.

[0010] The major axis of the perimeter of the elongated lumen may also be referred to as the length of the perimeter of the elongated lumen.

[0011] The minor axis of the perimeter of the elongated cavity may also be referred to as the width of the perimeter of the elongated cavity.

[0012] Between the first and second portions of the periphery of the elongated cavity, the periphery of the elongated cavity has a central portion having a first side and a second side, preferably wherein the first side of the central portion of the periphery of the elongated cavity is not parallel to the second side of the central portion of the periphery of the elongated cavity.

[0013] Preferably, the first side of the central portion of the periphery of the elongate cavity is straight, or substantially straight.

[0014] Preferably, the second side of the central portion of the periphery of the elongate cavity is straight, or substantially straight.

[0015] Preferably, the periphery of the elongated cavity is symmetrical about the long axis of the elongated cavity.

[0016] Preferably, said first end portion of the periphery of said elongate cavity is curved.

[0017] Preferably, said first end portion of the periphery of said elongate cavity is semi-circular, or substantially semi-circular.

[0018] Preferably, the first end portion of the periphery of the elongated cavity is curved and has a radius of curvature greater than 40 mm, or between 41 mm and 400 mm, or between 41 mm and 300 mm, or between 41 mm and 200 mm, or between 41 mm and 100 mm, or between 41 mm and 80 mm.

[0019] Preferably, said second end portion of the periphery of said elongate cavity is curved.

[0020] Preferably, said second end portion of the periphery of said elongate cavity is semi-circular, or substantially semi-circular.

[0021] Preferably, the second end portion of the periphery of the elongate cavity is curved and has a radius of curvature of less than 40 mm, or between 5 mm and 40 mm, or between 10 mm and 40 mm, or between 20 mm and 40 mm.

[0022] Preferably, the second end portion of the periphery of the elongate cavity is part of a circle having a radius of curvature of less than 40 mm, or between 5 mm and 40 mm, or between 10 mm and 40 mm, or between 20 mm and 40 mm.

[0023] Preferably, the body portion is of unitary construction, however the body portion may be made from more than one component part.

[0024] Preferably, the main body portion is made of elastic material.

[0025] Preferably, the body portion is made from an elastomeric material.

[0026] Preferably, the body portion comprises one of the materials selected from the list consisting of natural rubber, synthetic rubber, silicone rubber and polyurethane.

[0027] Preferably, the body portion comprises a material having a Shore A DIN53505 hardness between 60 and 100 or between 60 and 95.

[0028] Preferably, the contact surface is an elastic surface.

[0029] Preferably, the contact surface is flat.

[0030] The contact surface has a width, and preferably the contact surface extends around the elongate cavity such that the width of the contact surface is substantially constant.

[0031] In some embodiments, the body portion is enclosed in a holder and the holder has an opening therein in fluid communication with the opening in the body portion.Preferably, the holder is made of a rigid material, in particular a metal, such as stainless steel or aluminium.

[0032] In some embodiments, the first end portion of the periphery of the elongated cavity is semicircular having a first end and a second end, and the second end portion of the periphery of the elongated cavity is curved or semicircular having a first end and a second end, and a central portion between the first and second end portions of the periphery of the elongated cavity has: a first edge between a first end of the semicircular first end portion and a first end of the curved or semicircular second end portion; and a second edge between a second end of the semicircular first end portion and a second end of the curved or semicircular second end portion.

[0033] Preferably, the first side of the central portion is straight, or substantially straight.

[0034] Preferably, the second side of the central portion is straight, or substantially straight.

[0035] In some embodiments, the perimeter of the elongated cavity is keyhole-shaped.

[0036] In some embodiments, the perimeter of the elongated cavity is egg-shaped, for example having an oval shape.

[0037] In some embodiments, the perimeter of the elongated cavity is teardrop-shaped, such as a lanceolate.

[0038] In some embodiments, the perimeter of the elongated cavity is triangular, fan-shaped, trullate, or trapezoidal.

[0039] In some embodiments, the elongated cavity has a plurality of channels therein.

[0040] Preferably, one of the channels is parallel to the major axis or the minor axis.

[0041] Preferably, the elongated cavity comprises at least one channel parallel to the minor axis and at least one channel parallel to the major axis.

[0042] In some embodiments, the elongated cavity has a bottom and at least one raised portion extending from the bottom toward the contact surface.

[0043] Preferably, at least one raised portion has a surface for contacting the glass sheet when the contact surface of the main portion contacts the glass sheet. The surface of the at least one raised portion for contacting the glass sheet when the contact surface of the main portion contacts the glass sheet can be referred to as a raised portion contact surface.

[0044] Preferably, the raised portion contact surface of the at least one raised portion is coplanar with the contact surface.

[0045] Preferably, one or more of said raised portions define at least one channel in said elongate cavity.

[0046] Preferably, at least one of the channels is parallel to the major axis or the minor axis.

[0047] Preferably, the elongated cavity comprises at least one channel formed by at least one raised portion parallel to the minor axis and at least one channel formed by at least one raised portion parallel to the major axis.

[0048] The present invention also provides a method for processing a thin glass sheet from a second aspect, the method comprising the following steps: (i) providing a glass sheet having a first main surface and an opposite second main surface; (ii) providing at least one (first) vacuum chuck having a configuration according to the first aspect of the present invention; (iii) positioning the first vacuum chuck on the first main surface of the glass sheet close to a first edge portion of the glass sheet to be processed so that the first end portion and the second end portion of the periphery of the elongated cavity are along the direction of the first edge portion and the contact surface contacts the first main surface of the glass sheet; (iv) connecting a low pressure source to the opening to reduce the pressure in a chamber formed by the elongated cavity and the glass sheet, thereby supporting the glass sheet close to the first edge portion; and (v) processing the first edge portion.

[0049] During step (iv), the contact surface of the body portion forms a seal with the first major surface of the glass sheet.

[0050] Preferably, during step (v), the first edge portion is processed by a grinding step. The grinding step may be performed using a conventional abrasive grinding wheel.

[0051] Preferably, during step (v), the first edge portion is treated by applying a localized heat source, such as a laser or a gas cutting torch, to the first edge portion.

[0052] In some embodiments, during step (iii) and / or step (iv), a first side of a central portion of the perimeter of the elongated cavity is adjacent to a first edge portion of the glass sheet to be processed.

[0053] Preferably, the first side of the central portion has a curvature that matches the curvature of the adjacent first edge portion.

[0054] Preferably, during step (iii) and / or step (iv), the first side of the central portion is parallel to the first edge portion of the glass sheet to be treated.

[0055] In some embodiments, before step (v), a second vacuum chuck constructed according to the first aspect of the present invention is provided, and the second vacuum chuck is positioned on the first major surface of the glass sheet near a second edge portion of the glass sheet to be processed. The second edge portion and the first edge portion may be portions of the same edge of the glass sheet, or the first edge portion may be at an angle to the second edge portion so that a corner portion of the glass sheet is supported by the first vacuum chuck and the second vacuum chuck.

[0056] Preferably, the first vacuum suction cup and the second vacuum suction cup have the same structure.

[0057] Preferably, the first and second vacuum cups are fed by a single low pressure source.

[0058] Other embodiments of the second aspect of the invention have other preferred features.

[0059] Preferably, the glass sheet to be treated has a thickness of less than 1 mm.

[0060] Preferably, the glass sheet to be treated has a thickness greater than 0.2 mm.

[0061] Preferably, the glass sheet to be treated has a thickness in the range of 0.4 mm to 0.8 mm.

[0062] Preferably, after step (v), the treated glass sheet is chemically strengthened using a suitable chemical strengthening process.

[0063] Preferably, the glass sheet to be treated is of alkali-aluminosilicate glass composition.

[0064] Preferably, the glass sheet to be treated comprises at least about 6 wt % aluminum oxide.

[0065] Preferably, the glass sheet to be treated has a composition comprising 66-72 mol% SiO2, 1-4 mol% Al2O3, 8-15 mol% MgO, 1-8 mol% CaO, 12-16 mol% Na2O, preferably wherein MgO+CaO is between 12 and 17 mol% and CaO / (MgO+CaO) is in the range of 0.1 to 0.4.

[0066] Preferably, the glass sheet to be treated has a composition including (by weight) 58% to 70% SiO2, 5% to 15% Al2O3, 12% to 18% Na2O, 0.1% to 5% K2O, 4% to 10% MgO and 0% to 1% CaO, wherein the sum of Al2O3 and MgO is required to exceed 13%, the sum of the amount of Al2O3 plus the amount of MgO divided by the amount of K2O exceeds 3, and the sum of Na2O plus K2O plus MgO exceeds 22%.

[0067] Preferably, the glass sheet to be treated is of borosilicate glass composition.

[0068] After step (v), the treated glass sheet can be used as a layer in a laminated glazing, wherein the treated glass sheet is joined to another glass sheet using a sandwich structure, the sandwich structure comprising at least one sheet of an adhesive interlayer material, such as polyvinyl butyral (PVB), acoustically modified PVB, ethylene copolymers such as ethylene vinyl acetate (EVA), polyurethane (PU), polycarbonate, polyvinyl chloride (PVC), or a copolymer of ethylene and methacrylic acid.

[0069] In such laminated glazings, the treated glass sheet may be the inner or outer ply. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The invention will now be described with reference to the following drawings (not drawn to scale), in which:

[0071] Figure 1 A plan view showing a main body portion of a vacuum chuck having an elongated cavity therein according to the present invention;

[0072] Figure 2 Shown as Figure 1 An isometric schematic diagram of a vacuum chuck of the main body portion shown in , the vacuum chuck being positioned below a glass sheet for subsequent processing of the edge of the glass sheet;

[0073] Figure 3 a schematic cross-sectional view showing a vacuum chuck attached to a glass sheet;

[0074] Figure 4 Show Figure 2A schematic plan view of three vacuum cups of the type shown in , the three vacuum cups being shown supporting edge and corner regions of a glass sheet;

[0075] Figure 5 A schematic plan view showing two vacuum cups approaching an edge region of a glass sheet;

[0076] Figure 6 A schematic plan view showing three vacuum cups shown supporting edge and corner regions of a glass sheet; and

[0077] Figure 7 A schematic plan view of three vacuum chucks is shown, which are shown supporting edge areas and corner areas of a glass sheet. DETAILED DESCRIPTION

[0078] As background, it is well known that vacuum cups (or suction cups) are often used as "grippers" in manual or automated handling applications. Vacuum cups can hold and help move a variety of products, such as bottles, bricks, planks, metal sheets, pipes, and sheets of glass or windows. The vacuum cups essentially act as an interface between the vacuum system and the workpiece.

[0079] As is known in the prior art, a vacuum suction cup does not attach and grip the surface of a product by itself. Rather, when the suction cup contacts the surface of a workpiece, the wash cup typically activates a vacuum generator (such as a vacuum ejector, blower or pump) and extracts air from the inside of the suction cup and creates a vacuum. Assuming that the air pressure inside the suction cup is therefore lower than the air pressure outside the suction cup, the atmospheric pressure holds the workpiece against the suction cup (i.e., the suction cup is attached to the workpiece). The greater the difference between the ambient pressure and the vacuum pressure inside the suction cup, or the greater the effective area of ​​the suction cup acting on the workpiece, the greater the holding force pressing the suction cup onto the workpiece.

[0080] Ideally, the vacuum cup should fit against a smooth, non-porous surface. Then, when the vacuum is created, the cup edge is completely sealed to the atmospheric air and the air inside can be evacuated quickly, thereby firmly gripping the workpiece.

[0081] Flat suction cups are suitable for handling workpieces with flat or slightly curved surfaces, such as metal and glass sheets, plastic sheets and wooden boards. Flat suction cups usually have a small internal volume and can therefore be emptied quickly and can be gripped in a very short time.

[0082] refer to Figure 1 , showing a plan view of the bottom side of the main body portion of the vacuum chuck according to the present invention. The bottom side of the main body portion is the side facing the main surface of the glass sheet when the vacuum chuck is attached to the glass sheet.

[0083] The main body 1 is preferably made of an elastomeric material such as silicone rubber and is preferably of unitary construction. The main body may be made of a castable polyurethane material such as Or Vibrathane, and may have a Shore A DIN 53505 hardness between 60 and 100. The body portion 1 has a contact surface 3 for contacting a flat glass sheet to be treated. The contact surface is configured to contact a major surface of the glass sheet to form a chamber with the elongated cavity and the glass sheet.

[0084] refer to Figure 1 and Figure 2 , the contact surface 3 has an outer edge 5 and an inner edge 7. The inner edge 7 surrounds an elongated cavity in the body portion. The spacing between the outer edge 5 and the inner edge 7 defines the width of the contact surface 3. Preferably, the outer edge 5 is spaced apart from the inner edge 7 by a fixed amount so that the width of the contact surface 3 is constant. The elongated cavity has an inner wall 9 and a bottom 11. The intersection of the inner wall 9 and the contact surface 3 defines the inner edge 7. The outer wall (not numbered) intersects the contact surface 3 to define the outer edge 5.

[0085] An opening 15 is located in the bottom 11, which extends through the body portion for connection to a low pressure source such as a vacuum pump. In this example, the body portion 1 is secured to a metal holder 17 using a suitable adhesive. A suitable metal for the metal holder 17 is aluminum. The body portion 1 in the metal holder 17 may be referred to as a vacuum chuck (labeled 1'). The metal holder 17 surrounds the body portion 1, but is sized to allow the contact surface 3 to contact the glass sheet rather than the metal holder. A duct 19 extends from the holder 17 and communicates with the opening 15 so that air can be drawn through the duct 19 in the direction of arrow 21. When the body portion 1 is positioned over the glass sheet (a portion of which is in the Figure 2 When the main body 1 is placed on the glass sheet 23 and shown in the figure and marked as 23, the contact surface 3 contacts the glass surface to form a chamber with a portion of the glass sheet and the elongated cavity. When the conduit 19 is connected to a vacuum pump, the contact surface 3 forms a seal with the glass surface and the main body 1 adheres to the glass sheet due to the pressure reduction in the chamber. The glass sheet 23 can then be supported by the vacuum suction cup. Once the low pressure source is removed from the connection with the conduit 19, the main body 1 can be removed from the glass sheet. The main body 1 in the metal holder 17 can be referred to as a vacuum suction cup (in Figure 2 is marked as 1').

[0086] The elongated cavity formed by the bottom 11 and the inner wall 9 has a major axis shown as line A-A' in a plan view, which extends along the length of the main body portion 1 between the opposite parts of the inner wall 9. The elongated cavity also has a minor axis shown as line BB', which extends along the width of the main body portion between the opposite parts of the inner wall 9. The major axis is orthogonal to the minor axis. The length 25 of the elongated cavity is equal to the length of the line A-A', and the width 27 of the elongated cavity is equal to the length of the line BB'.

[0087] In this example, the bottom 11 has a plurality of raised portions 13. Figure 1 and Figure 2 Only three of them are marked in FIG. 1 . The raised portion 13 is arranged relative to the base 11 to form an array of channels 29 , 31 . The channels 29 extend parallel to the line AA′ and the channels 31 extend parallel to the line BB′. Figure 2 In FIG. 2 , only one channel 29 is marked and only one channel 31 is marked.

[0088] The channels 29, 31 help provide a uniform low pressure area in the chamber when the vacuum chuck is attached to the glass sheet. The raised portion 13 preferably has a height that is consistent with the height of the inner wall 9 (i.e., the end 13' of the respective raised portion 13 at the end opposite to the bottom 11 is coplanar with the contact surface 3) so that when the body portion 1 is positioned on the glass sheet, the raised portion 13 also contacts the glass sheet (in addition to the contact surface 3 contacting the glass sheet). This is Figure 3 The additional contact from the end 13' of the raised portion 13 helps to increase the adhesion of the vacuum chuck to the glass sheet when the conduit 19 is connected to a suitable low pressure source and helps to prevent the glass sheet from deforming inside the inner edge 7.

[0089] The perimeter of the elongated cavity has a first end portion 33 at one end of the line A-A' and a second end portion 35 at the opposite end of the line A-A'. The first end portion 33 is larger than the second end portion 35. For example, by dividing the perimeter of the elongated cavity into two parts using a line that bisects the major axis (line A-A') and is orthogonal to the major axis, the perimeter of the elongated cavity is asymmetric about the bisector.

[0090] Between the first and second end portions 33, 35, the perimeter of the elongated cavity has a central portion. On one side, the central portion starts at point B and extends downward to point C. On the opposite side, the central portion starts at point B' and extends downward to point C'. Points B, B' are on the perimeter of the elongated cavity (and are used to define the minor axis). Points C, C' are also on the perimeter of the elongated cavity and the line C-C' connecting points C, C' is orthogonal to line A-A' and parallel to line B-B'.

[0091] References Figure 1 In the orientation of the perimeter of the elongated cavity shown in , the first end portion 33 is on the left hand side of the line BB' and the second end portion 35 is on the right hand side of the line CC'.

[0092] In this example, the first end portion 33 is curved, being a semicircle with a radius of curvature of about 60 mm. Therefore, the length of the perimeter of the elongated cavity between point B and point B' is about (π×60) mm=188 mm. The second end portion 35 is also curved and is part of a semicircle with a radius of curvature of about 30 mm. If the end portion 35 is a semicircle with a radius of curvature of about 30 mm, the length of the perimeter of the elongated cavity between point C and point C' will therefore be about (π×30) mm=94 mm (less than 188 mm). Assuming that the end portion 35 is not completely semicircular, the length of the perimeter of the elongated cavity between point C and point C' is less than 94 mm, being about 70 mm (also less than 188 mm).

[0093] Similarly, the area of ​​the semicircular first end portion is approximately 1 / 2 (π×60×60) mm 2 =5,655mm 2 For a semicircular second end portion having a radius of curvature of 30 mm, the area of ​​such a second end portion is approximately 1 / 2 (π×30×30) mm 2 =1,414mm 2 (less than 5,655mm 2 ).

[0094] The perimeter of the elongated cavity has a first side 37 (between points B' and C') connecting the first end portion 33 to the second end portion 33 and a second side 39 (between points B and C). Both the first and second sides 37, 39 are straight and non-parallel. The central portion of the perimeter of the elongated cavity includes the first and second sides 37, 39.

[0095] In use, it is preferred that the first edge 37 or the second edge 39 is adjacent to the edge of the glass sheet to be edge processed, for example, Figure 2 When the vacuum chuck 1 ′ is attached to the glass sheet 23 , the second edge 39 will be adjacent to the edge 43 of the glass sheet 23 .

[0096] Figure 3 A schematic cross-sectional view (along the long axis, i.e., line A-A') of a portion of a vacuum chuck 1' attached to a glass sheet is shown. Figure 3 ) is already connected to a suitable low voltage source.

[0097] exist Figure 3 (and also refer to Figure 1 and Figure 2), the body portion 1 is shown in a metal holder 17. The body portion 1 is shown attached to a lower major surface 24 of a glass sheet 23. The contact surface 3 of the body portion 1 is in contact with the lower major surface 24 of the glass sheet 23 and forms a seal therewith due to the low pressure source being provided to the conduit 19.

[0098] It can be seen that the inner wall 9 extends vertically upwards from the bottom 11 to intersect the contact surface 3, thereby forming an inner edge 7. The position of the outer edge 5 defines the width of the contact surface 3. Preferably, the width of the contact surface 3 is substantially constant around the perimeter of the elongate cavity.

[0099] Raised portions 13a and 13b (two raised portions among the plurality of raised portions 13) also extend vertically from the bottom 11. Raised portion 13a has a contact surface 13a' (i.e., raised portion contact surface 13a') that contacts the lower main surface 24 of the glass sheet 23. Raised portion 13b has a contact surface 13b' (i.e., raised portion contact surface 13b') that contacts the lower main surface of the glass sheet 23. The respective contact surfaces of each raised portion prevent deformation of the glass sheet and allow vacuum to be provided over the entire surface of the suction cup.

[0100] exist Figure 3 Only one channel 31 is marked in FIG. 1 , and it can be seen that the one channel is formed between the inner wall 9 , a part of the bottom 11 , and the surface of the raised portion 13 a facing the inner wall 9 .

[0101] Figure 4 Three vacuum cups 51, 53, 55 (e.g., in the same manner as in FIG. 1 ) are shown attached to a major surface 57 of a glass sheet 59. Figure 3 in the same manner as the vacuum chuck 1' shown in FIG.

[0102] The glass sheet 59 has a first peripheral edge 61 that intersects with a second peripheral edge 63 to form a corner portion 65 of the glass sheet.

[0103] The vacuum chucks 51, 53 are close to and in the direction of the first peripheral edge 61. The straight sides of the elongated cavity of the vacuum chuck 51 and the straight sides of the elongated cavity of the vacuum chuck 53 are adjacent to the first peripheral edge 61. Due to the elongated cavities in the vacuum chucks 51, 53, the glass sheet 59 is better supported so that the glass edge grinding operation on the first peripheral edge 61 is more simply performed.

[0104] The vacuum cup 55 is close to the second peripheral edge 63 and is located in the direction of the second peripheral edge. That is, the major axis of the elongated cavity of the vacuum cup 55 is substantially aligned with the second peripheral edge. The straight side of the elongated cavity of the vacuum cup 55 is adjacent to the second peripheral edge 63. The vacuum cups 53, 55 provide improved support for the corner portion 65, thereby allowing easier processing (i.e. edge grinding) of the first and second peripheral edges 61, 63 in the area of ​​the corner portion 65.

[0105] Although only three vacuum cups are shown attached to the glass sheet, there may be additional vacuum cups attached to the glass sheet to support other edge regions of the glass sheet, or to support more central regions of the glass sheet. For example, additional vacuum cups may be attached to a central region of the major surface 57 of the glass sheet 59, inside the vacuum cups 51, 53.

[0106] Figure 5 Two vacuum chucks constructed in accordance with the present invention are shown attached to a glass sheet 69 proximate a first peripheral edge 71. A first vacuum chuck 73 has a body portion having an elongated cavity 77 therein. The elongated cavity 77 has a first end portion 79 and a second end portion 81. The first end portion 79 is larger than the second end portion 81. The vacuum chuck 75 is constructed in a similar manner. The central region between the first and second end portions 79, 81 has curved, non-parallel sides.

[0107] Figure 6 Three vacuum cups constructed in accordance with the present invention are shown attached to a glass sheet 83. The vacuum cups 85, 87, 89 each have a respective elongated cavity 91, 93, 95 having a perimeter arranged in a trapezoid with four straight sides. The vacuum cups 85, 87 are proximate to a first peripheral edge 97 of the glass sheet 83, and the vacuum cup 89 is proximate to a second peripheral edge 99 of the glass sheet 83.

[0108] Figure 7 Three vacuum chucks constructed in accordance with the present invention are shown attached to a glass sheet 101. Each of the vacuum chucks 103, 105, 107 has a respective elongated cavity 109, 111, 113 having a keyhole-shaped perimeter, i.e., there is a portion of a circle at one end connected to a portion of a trapezoid at the other end. The vacuum chucks 103, 105 are proximate to a first peripheral edge 115 of the glass sheet 101, and the vacuum chuck 107 is proximate to a second peripheral edge 117 of the glass sheet 101.

[0109] Once processed (ie, such that at least one edge has been ground), the glass sheet 23, 59, 69, 83, 101 may be further processed, such as cleaned, heat treated, chemically strengthened, coated, and the like.

[0110] The glass sheet after edge processing (and any other subsequent treatment) can be used as a layer in a laminated glazing, which layer can be flat or curved in at least one direction. Preferably, the radius of curvature in at least one direction is between 500 mm and 20000 mm, more preferably between 1000 mm and 8000 mm.

[0111] In the previous example, the glass sheet can be a soda-lime-silica glass composition. Typical soda-lime-silica glass compositions are (by weight) 69%-74% SiO2; 0-3% Al2O3; 10%-16% Na2O; 0-5% K2O; 0-6% MgO; 5%-14% CaO; 0-2% SO3; 0.005%-2% Fe2O3. Such glass can be manufactured using a float process.

[0112] Alternatively, the glass sheet to be treated may be of alkali-aluminosilicate glass composition and may contain at least about 6 wt % aluminum oxide.

[0113] Other glass compositions may be used, such as borosilicate glass compositions.

[0114] Therefore, the present invention provides a vacuum chuck from a first aspect, the vacuum chuck comprising a main body portion having an elongated cavity therein and a contact surface for contacting a glass sheet to form a chamber with the elongated cavity and the glass sheet. The elongated cavity has a periphery, and the contact surface has an edge facing the elongated cavity, thereby defining the periphery of the elongated cavity. An opening in the main body portion is in fluid communication with the elongated cavity for connection to a low pressure source so that the contact surface can form a seal with the glass sheet to attach the vacuum chuck to the glass sheet. The periphery of the elongated cavity has a major axis and a minor axis orthogonal to each other, the major axis being longer than the minor axis. The periphery of the elongated cavity has a first end portion and a second end portion at respective ends of the major axis. The first end portion of the periphery of the elongated cavity is larger than the second end portion of the periphery of the elongated cavity.

[0115] The present invention is particularly applied in the field of vehicle glazing, where edge regions of thin glass sheets in the glazing pane require suitable edge processing. Thin glass sheets, for example with a thickness between 0.4 mm and 0.9 mm, are typically laminated to another thicker glass sheet (with a thickness in the range of 1.5 mm to 10 mm) using a sandwich structure comprising a sheet of an adhesive material, such as polyvinyl butyral. The edge processed edges of the thin glass sheets of the laminated glazing may be exposed in use, for example in the upper edge region of a movable vehicle side window. By using the vacuum suction cup according to the invention, better support can be provided for the outer peripheral edge of the glass sheet and / or the corner region of the glass sheet during edge processing.

Claims

1. A vacuum suction cup, comprising: a main body portion made of an elastomeric material, the main body portion comprising an elongated cavity and a contact surface extending around the elongated cavity, the contact surface being used to contact the glass sheet and forming a chamber with the elongated cavity and the glass sheet; The elongated cavity has a perimeter, and the contact surface has an edge facing the elongated cavity to define the perimeter of the elongated cavity; an opening in the body portion in fluid communication with the elongated cavity such that when the chamber is formed by the glass sheet and a low pressure source is connected to the opening in the body portion, the contact surface forms a seal with the glass sheet to attach the vacuum chuck to the glass sheet; The periphery of the elongated cavity has a major axis and a minor axis orthogonal to the major axis, wherein the major axis is longer than the minor axis, Furthermore, wherein the perimeter of the elongated cavity has a first end portion at one end of the elongated axis and a second end portion at an opposite end of the elongated axis, wherein the first end portion of the perimeter of the elongated cavity is larger than the second end portion of the perimeter of the elongated cavity, Wherein between the first end portion and the second end portion of the periphery of the slender cavity, the periphery of the slender cavity has a central portion, the central portion has a first side and a second side, and wherein the first side of the central portion of the periphery of the slender cavity is not parallel to the second side of the central portion of the periphery of the slender cavity.

2. The vacuum suction cup according to claim 1, characterized in that: The first side of the central portion of the perimeter of the elongated cavity is straight, or substantially straight.

3. The vacuum suction cup according to claim 2, characterized in that: The second side of the central portion of the perimeter of the elongated cavity is straight, or substantially straight.

4. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The perimeter of the elongated cavity is symmetrical about the long axis of the elongated cavity.

5. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The first end portion of the perimeter of the elongated cavity is curved.

6. The vacuum suction cup according to claim 5, characterized in that: The first end portion of the perimeter of the elongated cavity is curved and has a radius of curvature greater than 40 mm, or between 41 mm and 400 mm, or between 41 mm and 300 mm, or between 41 mm and 200 mm, or between 41 mm and 100 mm, or between 41 mm and 80 mm.

7. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The second end portion of the perimeter of the elongated cavity is curved.

8. The vacuum suction cup according to claim 7, characterized in that: The second end portion of the perimeter of the elongated cavity is curved and has a radius of curvature of less than 40 mm, or between 5 mm and 40 mm, or between 10 mm and 40 mm, or between 20 mm and 40 mm.

9. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The main body part is of integral structure.

10. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The contact surface is an elastic surface.

11. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The first end portion of the periphery of the elongated cavity is semicircular having a first end and a second end, and the second end portion of the periphery of the elongated cavity is curved having a first end and a second end, and a central portion of the periphery of the elongated cavity between the first end portion and the second end portion has: a first side between a first end of the semicircular first end portion and a first end of the curved second end portion; and a second side between a second end of the semicircular first end portion and a second end of the curved second end portion.

12. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The perimeter of the elongated cavity is egg-shaped, spear-pointed teardrop-shaped, triangular, trapezoidal, fan-shaped or ovate-shaped.

13. The vacuum suction cup according to claim 1, characterized in that: The elongated cavity has a bottom and at least one raised portion extending from the bottom toward the contact surface.

14. The vacuum suction cup according to claim 13, characterized in that: One or more raised portions define at least one channel in the elongated cavity.

15. The vacuum suction cup according to claim 14, characterized in that: At least one of the channels is parallel to the major axis or the minor axis.

16. The vacuum suction cup according to any one of claims 13 to 15, characterized in that The at least one raised portion has a surface for contacting the glass sheet when the contact surface of the body portion contacts the glass sheet.

17. The vacuum suction cup according to claim 5, characterized in that: The first end portion of the perimeter of the elongated cavity is semi-circular, or substantially semi-circular.

18. The vacuum suction cup according to claim 7, characterized in that: The second end portion of the perimeter of the elongated cavity is semi-circular, or substantially semi-circular.

19. The vacuum suction cup according to claim 15, characterized in that: The elongated cavity includes at least one channel parallel to the minor axis and at least one channel parallel to the major axis.

20. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The elastic material is natural rubber, synthetic rubber or polyurethane.

21. The vacuum suction cup according to any one of claims 1 to 3, characterized in that: The elastic material is silicone rubber.

22. A method for processing a thin glass sheet, the method comprising the steps of: (i) providing a glass sheet having a first major surface and an opposite second major surface; (ii) providing at least one first vacuum chuck, the first vacuum chuck being a vacuum chuck according to any one of the preceding claims; (iii) positioning the first vacuum chuck on the first major surface of the glass sheet proximate a first edge portion of the glass sheet to be processed so that the first and second end portions of the perimeter of the elongated cavity are along the direction of the first edge portion and the contact surface contacts the first major surface of the glass sheet; (iv) communicating a low pressure source with the opening to reduce pressure in a chamber formed by the elongated cavity and the glass sheet, thereby supporting the glass sheet proximate the first edge portion; as well as (v) processing the first edge portion.

23. The method according to claim 22, characterized in that During step (v), the first edge portion is processed by a grinding step.

24. The method according to claim 22, characterized in that During step (v), the first edge portion is treated by applying a localized heat source to the first edge portion.

25. The method according to claim 22, characterized in that The glass sheet has a thickness of less than 1 mm.

26. The method according to claim 24, characterized in that The local heat source is a laser or a gas cutting torch.

27. The method according to any one of claims 22 to 26, characterized in that During step (iii) and / or step (iv), a first side of a central portion of the periphery of the elongated cavity is adjacent to the first edge portion of the glass sheet to be treated.

28. The method according to claim 27, characterized in that The first side of the central portion has a curvature that matches the curvature of an adjacent first edge portion.

29. The method according to claim 27, characterized in that During step (iii) and / or step (iv), the first side of the central portion is parallel to the first edge portion of the glass sheet to be treated.

30. The method according to any one of claims 22 to 26, characterized in that Prior to step (v), a second vacuum chuck is provided, the second vacuum chuck being the vacuum chuck according to any one of claims 1 to 23, and the second vacuum chuck is positioned on the first major surface of the glass sheet near a second edge portion of the glass sheet to be processed.

31. The method according to any one of claims 22 to 26, characterized in that After step (v), the treated glass sheet is chemically strengthened using a chemical strengthening process.

32. The method according to any one of claims 22 to 26, characterized in that After step (v), the treated glass sheet is used as a layer in a laminated glazing, wherein the treated glass sheet is joined to another glass sheet using a sandwich structure comprising at least one sheet of an adhesive interlayer material.

33. The method according to claim 23, characterized in that During step (v), the first edge portion is processed by a grinding step using an abrasive grinding wheel.

34. The method according to claim 32, characterized in that The adhesive interlayer material is polyvinyl butyral (PVB), acoustically modified polyvinyl butyral, ethylene copolymer, polyurethane (PU), polycarbonate, polyvinyl chloride (PVC), or a copolymer of ethylene and methacrylic acid.

35. The method according to claim 34, characterized in that The ethylene copolymer is ethylene vinyl acetate (EVA).

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