Stacked glazing

Abstract

A laminated glazing for a vehicle windshield is described, comprising a first sheet of glazing material joined to a second sheet of glazing material by at least a first sheet of adhesive interlayer material. At least a first weakening device is positioned between the first and second sheets of glazing material within a first opening in the first sheet of adhesive interlayer material. The first weakening device is positioned to fracture at least one of the first and second sheets of glazing material upon an impact to a major surface of the first sheet of glazing material.

Description

Technical Field

[0001] The present invention relates to laminated glazing for use in vehicles, particularly for use as the front glass of vehicles such as automobiles.

Background Art

[0002] Conventional laminated glazing for automotive front glass comprises two plies of soda-lime silicate glass joined by a sheet of polyvinyl butyral (PVB). Usually, each glass sheet has a thickness of 2.1 mm and the PVB sheet usually has a thickness of 0.76 mm.

[0003] An example of a known vehicle front glass is described in British Patent Application Publication No. 1225941.

[0004] As is known in the art, automotive laminated front glass provides improved safety benefits to the vehicle driver. However, automobile manufacturers are also addressing the safety of the vehicle in the event of a frontal collision with a pedestrian.

[0005] In the event of a collision with a pedestrian, the pedestrian may collide with the vehicle's front glass, thereby causing further injury to the pedestrian.

Summary of the Invention

[0006] It is an object of the present invention to provide a vehicle front glass arranged to reduce the risk of serious injury to a pedestrian in the event of a collision between the vehicle and the pedestrian.

[0007] Accordingly, from a first aspect of the present invention, the present invention provides a laminated glazing for a vehicle front glass, comprising a first sheet of glazing material joined to a second sheet of glazing material by at least one sheet of an adhesive intermediate layer material, wherein each of the first and second sheets of glazing material and the first sheet of the first intermediate layer material has a first major surface and an opposite second major surface, the second major surface of the first sheet of glazing material faces the first major surface of the second sheet of glazing material, the first sheet of the adhesive intermediate layer material is between the first and second sheets of glazing material, and further, at least a first weakening device is located between the first and second sheets of glazing material, the first weakening device is arranged to damage at least one of the first and second sheets of glazing material in case of an impact on the first major surface of the first sheet of glazing material, and the first weakening device is located within a first opening of the first sheet of the adhesive intermediate layer material, thereby providing a laminated glazing for a vehicle front glass.

[0008] By providing the weakening device within the opening of the first sheet of the adhesive intermediate layer material, the weakening device becomes part of the laminated glazing, facilitating the implementation of the present invention in a vehicle.

[0009] Preferably, at least a second weakening device is located within the first opening of the first sheet of the adhesive intermediate layer material. In such an embodiment, there are at least two weakening devices within the first opening of the first sheet of the adhesive intermediate layer material.

[0010] Preferably, at least a second weakening device is located within a second opening of the first sheet of the adhesive intermediate layer material. In such an embodiment, the first sheet of the adhesive intermediate layer material has at least two openings therein.

[0011] Preferably, the laminated glazing further comprises at least one other weakening device between the first sheet and the second sheet of glazing material, and the at least one other weakening device is located within each opening of the first sheet of the adhesive intermediate layer material.

[0012] In some embodiments, a barrier surrounds the first weakening device within the first opening, and the barrier restricts the flow of the intermediate layer material reaching the first weakening means during lamination.

[0013] Preferably, the barrier is dimensionally stable during the lamination process used.

[0014] Preferably, the barrier is in an annular form.

[0015] Preferably, the barrier comprises a compressible material, preferably rubber.

[0016] Preferably, the barrier comprises PET or polycarbonate.

[0017] Preferably, the barrier is chemically inert with respect to the first sheet of the adhesive intermediate layer material.

[0018] In some embodiments, the first weakening device comprises at least one impact device having a bottom portion for contacting the second major surface of the first sheet of glazing material and at least a first contact portion for contacting the first major surface of the second sheet of glazing material.

[0019] When a collision occurs between the laminated glazing and the first major surface of the first sheet of glazing material, the first contact portion of the impact device contacts the first major surface of the second sheet of glazing material, damaging the second sheet of glazing material.

[0020] Preferably, the first contact portion is pointed.

[0021] Preferably, the bottom part of the impact device tapers towards the first contact part.

[0022] Preferably, the impact device is conical or pyramidal in shape.

[0023] Preferably, the first contact part is harder than the second sheet of glazing material.

[0024] Preferably, the first contact part comprises at least one of boron nitride, boron carbide, tungsten carbide and diamond.

[0025] Preferably, at least the first raised part extends from the bottom part, the first raised part having a first end adjacent to the bottom part and a second end opposite the first end of the first raised part, the second end of the first raised part comprising the first contact part.

[0026] Preferably, the first raised part is integrally formed with the bottom part, although in some embodiments the first contact part is made of a material different from the bottom part.

[0027] Preferably, the first raised part is conical or pyramidal or spike-shaped.

[0028] In some embodiments, the laminated glazing further comprises another weakening device located within another opening of the first sheet of adhesive intermediate layer material, the first opening being spaced apart from the other opening by a first spacing.

[0029] Preferably, the first spacing is from 0.5 cm to 50 cm, more preferably from 0.5 cm to 40 cm, more preferably from 0.5 cm to 30 cm, more preferably from 0.5 cm to 20 cm, more preferably from 0.5 cm to 10 cm.

[0030] In some embodiments, the first opening is spaced apart from the periphery of the laminated glazing.

[0031] Preferably, the first opening is spaced from the periphery of the laminated glazing by 1 cm to 20 cm, more preferably 1 cm to 15 cm, more preferably 1 cm to 10 cm, more preferably 1 cm to 9 cm, or 1 cm to 8 cm, or 1 cm to 7 cm, or 1 cm to 6 cm, or 1 cm to 5 cm.

[0032] Preferably, the first opening is spaced from the periphery of the laminated glazing configured to be the lower edge of the laminated glazing when installed in the vehicle.

[0033] In some embodiments, the first opening is in a region of the laminated glazing having an obscuring band thereon.

[0034] In some embodiments, the first and / or second sheet of glazing material comprises one or more weak points or lines arranged to weaken the laminated glazing upon impact with the laminated glazing.

[0035] Preferably, the weak points or lines are on the major surfaces of the first and / or second sheet of glazing material.

[0036] In some embodiments, the laminated glazing is part of a vehicle windshield for installation in a vehicle.

[0037] In some embodiments, there are a plurality of openings in the first sheet of the adhesive interlayer material.

[0038] Preferably, the plurality of openings are spaced from the periphery of the laminated glazing configured to be the lower edge of the laminated glazing when installed in the vehicle.

[0039] Preferably, the plurality of openings are arranged in a row. Preferably, the line is parallel to the periphery of the laminated glazing, and more preferably, is the periphery configured to be the lower edge of the laminated glazing when installed in the vehicle.

[0040] In some embodiments, the first sheet of the glazing material has a thickness of 1 mm to 5 mm, preferably 1.3 mm to 3 mm.

[0041] In some embodiments, the second sheet of the glazing material has a thickness of 1 mm to 5 mm, preferably 1.3 mm to 3 mm.

[0042] In some embodiments, the second sheet of the glazing material is thinner than the first sheet of the glazing material.

[0043] In some embodiments, the first major surface of the first sheet of the glazing material is convex, and the second major surface of the second sheet of the glazing material is convex.

[0044] In some embodiments, there is only one sheet of the adhesive intermediate layer material between the first sheet and the second sheet of the glazing material.

[0045] In some embodiments, the first opening of the first sheet of the adhesive intermediate layer material is circular.

[0046] In some embodiments, the first opening of the first sheet of the adhesive intermediate layer material is oval or square or rectangular or trapezoidal or triangular.

[0047] In some embodiments, the first opening of the first sheet of the adhesive intermediate layer material has at least a first axis of symmetry, preferably a first and a second axis of symmetry.

[0048] In embodiments where the first opening is one of a plurality of openings, it is preferred that each of the plurality of openings has the same shape and / or the same area.

[0049] The laminated glazing has other preferred features as well.

[0050] Preferably, the laminated glazing is curved in at least one direction. Preferably, the radius of curvature in at least one direction is from 500 mm to 20,000 mm, more preferably from 1,000 mm to 8,000 mm.

[0051] Preferably, the first sheet of the adhesive interlayer material comprises a copolymer of ethylene such as polyvinyl butyral (PVB), sound-absorbing modified PVB, ethylene vinyl acetate (EVA), polyurethane (PU), polyvinyl chloride (PVC), a copolymer of ethylene and methacrylic acid (EMA), or Uvekol (liquid curable resin).

[0052] Preferably, at least one sheet of the adhesive interlayer material has a thickness of from 0.3 mm to 2.3 mm, more preferably from 0.3 mm to 1.6 mm, and most preferably from 0.3 mm to 0.8 mm.

[0053] Preferably, the first and / or second sheet of the glazing material has a thickness between 1 mm and 3 mm.

[0054] Preferably, the first and / or second sheet of the glazing material has a thickness of from 1.4 mm to 2.8 mm, more preferably from 1.6 mm to 2.3 mm.

[0055] Preferably, the thickness of the laminated glazing is from 3 mm to 10 mm.

[0056] Preferably, the first and / or second sheet of the glazing material is a sheet of soda-lime silicate glass, in particular a sheet of float glass.

[0057] Preferably, the first and / or second sheet of the glazing material is a sheet of alkali aluminosilicate glass.

[0058] Preferably, the first and / or second sheet of the glazing material comprises at least about 6 wt% (weight percent) of aluminum oxide (Al2O3).

[0059] Preferably, the first and / or second sheet of the glazing material is chemically strengthened, i.e., chemically strengthened glass. When the first and / or second sheet of the glazing material is chemically strengthened, preferably, the chemically strengthened sheet of the glazing material has a thickness of less than 1.2 mm, more preferably 0.3 mm to 1 mm, and even more preferably 0.4 mm to 0.9 mm.

[0060] The present invention also provides, from a second aspect, the use of the laminated glazing according to the first aspect of the present invention as a front glass of a vehicle, reducing the possibility of injury to a person involved in a collision with the vehicle.

[0061] Here, the present invention will be described with reference to the following drawings (not to scale).

Brief Description of the Drawings

[0062]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Embodiments for Carrying Out the Invention

[0063] FIG. 1 shows a plan view of a laminated glazing according to the present invention. In this example, the laminated glazing 1 is a vehicle windshield.

[0064] In the plan view, the windshield 1 is substantially trapezoidal and has lower corners a and b and upper corners c and d. The lower edge a - b is in the position closest to the vehicle hood when the windshield 1 is installed in the vehicle.

[0065] The laminated glazing 1 has an obscuring band 6 extending around its periphery.

[0066] Referring to FIGS. 1, 2, 3 and 4, the laminated glazing 1 comprises a first glass sheet 3 joined to a second glass sheet 5 by a sheet 7 of polyvinyl butyral (PVB).

[0067] The first glass sheet 3 has a first major surface 3a and an opposite second major surface 3b. The second glass sheet 5 has a first major surface 5a and an opposite second major surface 5b. The PVB sheet 7 has a first major surface 7a and an opposite second major surface 7b.

[0068] The second major surface 3b faces the first major surface 5a and the PVB sheet 7 is between the first glass sheet 3 and the second sheet 5.

[0069] In this example, the first glass sheet 3 is the outer glass sheet and the second glass sheet is the inner glass sheet.

[0070] Using the conventional nomenclature, the first major surface 3a of the first glass sheet 3 is the "surface 1" (or S1) of the laminated glazing 1. The second major surface 3b of the first glass sheet 3 is the "surface 2" (or S2) of the laminated glazing 1. The first major surface 5a is the "surface 1" (or S1) of the laminated glazing 1. The second major surface 5b of the second glass sheet 5 is the "surface 4" (or S4) of the laminated glazing 1.

[0071] In this example, each of the first and second glass sheets 3, 5 has a thickness of less than 4 mm. In this example, the first glass sheet 3 has a thickness of 2.1 mm and the second glass sheet 5 has a thickness of 1.8 mm. The PVB sheet 7 has a thickness of 0.76 mm, but can be from 0.3 mm to 1.6 mm thick.

[0072] A defrosting band 6 is present on a part of the second major surface 5b of the second glass sheet 5. The defrosting band has an optically opaque region 6a and a fade - out region 6b with a plurality of optically opaque dots.

[0073] The defrosting band can be on any of the major surfaces 3a, 3b, 5a, 5b, either individually or in any combination thereof.

[0074] The first and / or second glass sheets can have a soda - lime - silicate composition. The composition (by weight) of normal soda - lime - silicate glass is SiO2 69 - 74%, Al2O3 0 - 3%, Na2O 10 - 16%, K2O 0 - 5%, MgO 0 - 6%, CaO 5 - 14%, SO3 0 - 2%, Fe2O3 0.005 - 2%. The glass composition can also contain other additives, for example, refining aids which can be present in an amount of usually up to 2%. The soda - lime - silicate glass composition can contain other colorants such as Co3O4, NiO and Se to give the glass a desired color when viewed through transmitted light. The transmitted color of the glass can be measured based on recognized standards such as BS EN410.

[0075] Other glass compositions, such as alkali aluminosilicate glass, may also be used, and the first and / or second glass sheets may be chemically strengthened. When using chemically strengthened glass sheets, the thickness of such glass sheets is less than 1 mm, preferably in the range of 0.4 mm to 0.9 mm.

[0076] The PVB sheet 7 has a plurality of circular openings 9 therein (only one of which is labeled in FIG. 1). In the illustrated example, there are nine circular openings 9 (labeled 9a) arranged in a row, substantially parallel to the lower edge a - b of the laminated glazing 1. That is, the center of each opening 9 is on a line substantially parallel to the lower edge a - b of the laminated glazing 1. Each opening 9 has the same diameter. In other embodiments, the openings 9 may have different shapes and / or areas.

[0077] Each opening 9 communicates with the first major surface 7a at one end and with the second major surface 7b at the other end.

[0078] A ring 11 of rubber or other similar compressible material (i.e., other elastic polymers or elastomers) is disposed in the circular opening 9. The ring 11 can be an O - ring.

[0079] Within the ring 11 is located an impact device 13 in the form of integrally molded particles. Examples of such particles include precision - molded particles of the type provided under the Cubitron (trademark) from 3M (trademark).

[0080] The impact device 13 has a bottom portion 15 for contacting the second major surface 3b of the first glass sheet 3 and a pointed portion 17 for contacting the first major surface 5a of the second glass sheet 5.

[0081] Each opening 9 of the row of openings 9a has its respective ring 11a and an impact device 13a located therein.

[0082] The bottom part 15 is circular and fits inside the ring 11. The diameter of the bottom part 15 may be slightly smaller than the inner diameter of the ring 11.

[0083] In the embodiment shown in FIG. 2, the bottom part 15 contacts the second main surface 3b of the first glass sheet 3, and the pointed part 17 contacts the first main surface 5a of the second glass sheet 5. In other embodiments, the impact device 13 may be sized to be movable within the space between the glass sheets 3, 5 such that the bottom part 15 and / or the pointed part 17 do not permanently contact the respective glass surfaces within the laminated glazing 1.

[0084] When an impact occurs in the direction of arrow 19 (on the first main surface 3a of the laminated glazing 1), the impact device 13 breaks the second glass sheet 5 as the pointed part 17 is pressed against the first main surface 5a of the second glass sheet 5. The impact device 13 has a higher hardness than the second glass sheet 5 and propagates cracks into the second glass sheet 5.

[0085] When broken, the fragments of the broken second glass sheet 5 may remain bonded to the sheet 7 of the adhesive interlayer material (PVB in this example).

[0086] The second glass sheet 5 may be formed as described, for example, in U.S. Patent Application Publication No. 2005 / 0175844 and / or U.S. Patent Application Publication No. 2006 / 0138798 and may have pre-generated microcracks in the vicinity of contact with the pointed part to enable the second glass sheet 5 to break more easily.

[0087] FIG. 5 shows the impact device 13 and the ring 11 in more detail. The ring 11 is circular and annular and has an outer diameter 11a and an inner diameter 11b.

[0088] The impact device 13 has a circular bottom part 15 that tapers towards the pointed part 17. The impact device 13 is a conical particle and may be solid or hollow.

[0089] The bottom part 15 has a diameter 15a and, in some embodiments, is sized to fit snugly within the ring 11. In other embodiments, the diameter 15a is smaller than the inner diameter 11b.

[0090] The impact device 13 has a height 16, which is the distance between the bottom part 15 and the end of the pointed part 17. The height 16 is preferably the same as the thickness of the PVB sheet 7, although it may be slightly smaller than the thickness of the PVB sheet 7 (and thus smaller than the spacing between the first glass sheet 3 and the second glass sheet 5).

[0091] FIG. 6 shows another impact device 23 for use in the present invention. In this example, the impact device can be a regular square pyramid, a single particle in the form of a square pyramid.

[0092] The impact device has a square bottom part 25 and a pointed part 27.

[0093] The impact device 23 can be incorporated into an opening of any shape in the PVB sheet 7, such as a circular opening 9. Preferably, a ring of material that fits the bottom of the particle 23 is used. The ring of material can be a square ring and the material can be compressible, i.e., rubber.

[0094] The impact devices 13, 23 are suitably hard compared to the first and / or second glass sheets 3, 5. Suitable materials for the impact devices 13, 23 (especially the pointed parts 17, 27) include boron nitride, boron carbide, tungsten carbide, and diamond.

[0095] Instead of being integrally formed, the impact devices 13, 23 can have a multi-component structure, especially at the pointed parts. For example, the pointed part can be a diamond tip.

[0096] FIG. 7 shows an exploded schematic perspective view of another laminated glazing 31 according to the present invention. In this example, the laminated glazing 31 is a vehicle front glass having the same configuration as the front glass 1 shown in FIG. 1 in plan view.

[0097] The laminated glazing 31 has a first glass sheet 33 joined to a second glass sheet 35 by a PVB sheet 37.

[0098] Each of the first and second glass sheets 33, 35 has a soda-lime silicate composition. Either or both of the first and second glass sheets 33, 35 may be chemically strengthened.

[0099] The PVB sheet 37 has four elongated openings inside arranged towards the lower edge a-b of the laminated glazing 31. The elongated openings are arranged in two rows, a first lower row including the elongated opening 39 and a second row (above the first row) including the openings 39’, 39’’, and 39’’’. Each row is arranged parallel to the lower edge a-b of the laminated glazing 31.

[0100] Inside the elongated opening 39, a ring of an elastomeric material 41 of appropriate size is located.

[0101] Inside each of the elongated openings 39’, 39’’, and 39’’’, rings 41’, 41’’, 41’’’ of elastomeric material of respective appropriate sizes are located.

[0102] Inside the ring 41, a shock device 43 is located. Inside the ring 41’, a shock device 43’ is located. Inside the ring 41’’, a shock device 43’’ is located. Inside the ring 41’’’, a shock device 43’’’ is located.

[0103] The shock devices 43, 43’, 43’’ and 43’’’ are each similarly configured and have the same width, but the shock device 43 is longer than the shock devices 43’, 43’’ and 43’’’.

[0104] The impact devices 43, 43', 43'' and 43''' each comprise a bottom portion and a plurality of raised portions extending from the bottom portion. The raised portions face towards the second glass sheet 35.

[0105] The impact devices 43, 43', 43'' and 43''' function substantially in the same manner as the impact device 13 shown in FIGS. 2 to 4. In the case of an impact in the direction of arrow 19, at least one of the raised portions of at least one of the impact devices 43, 43', 43'' and 43''' comes into contact and presses against the main surface of the second glass sheet 35 facing the first glass sheet 33, damaging the second glass sheet 35.

[0106] FIG. 8 further shows details of the impact device 43' located in the ring 41'. FIG. 9 is a cross-sectional view taken along line N-N' of FIG. 8.

[0107] Referring to FIGS. 8 and 9, the impact device 43' has a bottom portion 45' and 16 raised portions 53 (only one of which is labeled) extending upward therefrom.

[0108] Each raised portion 53 has a square pyramid shape with respective bottom portions 55 and pointed portions 57. Each raised portion has the same height, and the pointed portions of the raised portions 53 are in a plane parallel to the inner surface of the second glass sheet 35.

[0109] The raised portions 53 can be integrally formed with the bottom portion 45'. Suitable materials for the raised portions 53 include hard materials suitable for the second glass sheet 35, including boron nitride, boron carbide, and tungsten carbide.

[0110] The other two impact devices 43'' and 43''' are configured in the same manner as the impact device 43'. The impact device 43 is similar to the impact device 43' except that its bottom portion is longer and there are more raised portions extending upward therefrom.

[0111] In another embodiment, one or more of the elongated openings 39, 39', 39'' and 39''' of the PVB sheet 37 include two weakening devices, for example, two impact devices of the type shown in FIG. 8, or one type of impact device shown in FIG. 8 and one type of impact device shown in FIG. 5 or 6.

[0112] FIG. 10 is a schematic view from the inside of a vehicle having a windshield 101 according to the present invention installed therein.

[0113] The vehicle windshield 101 is similar to the vehicle windshield 1 shown in FIGS. 1 to 4 and includes an outer glass plate joined to the inner glass by a sheet of an adhesive intermediate layer, which is PVB in this example.

[0114] The PVB sheet includes nine openings in its lower region. Three of the openings on the left side of the lower region are circular (group 103) and are similar to the openings 9 in the PVB sheet 7 of FIGS. 1 to 4. Three of the openings in the lower central region are elongated (group 105) and are similar to the elongated openings 39', 39'' and 39''' in the PVB sheet 37 of FIG. 7. Also, three of the openings on the right side of the lower region are also circular (group 107) and are similar to the openings 9 in the PVB sheet 7 of FIGS. 1 to 4.

[0115] In each opening of group 103 and group 107, there are located a ring of material and an impact device such as the impact device 13 shown in FIGS. 2 to 4. The ring of material prevents the PVB from flowing into the impact device within the opening during lamination (otherwise the effectiveness of the impact device would be reduced).

[0116] In each opening of group 105, there are located an elongated ring of material and an impact device such as the impact device 43' shown in FIGS. 7 and 8. The elongated ring of material (such as the rubber ring 41' in FIGS. 7 and 8) prevents the PVB from flowing into the impact device within the opening during lamination (otherwise the effectiveness of the impact device would be reduced).

[0117] The windshield 101 also has an obscuring band thereon (below line 106). The obscuring band prevents the openings 103, 105, 107 and the associated ring / impact devices of the material from being visible from the inside of the vehicle.

[0118] The arrangement of the openings may vary depending on the vehicle. Also, there may be rings and impact devices associated with openings extending on the left and / or right side of the windshield 101, or other areas.

[0119] In the previous example, one or more of the glass sheets may be provided with weaknesses of the type described in U.S. Patent Application Publication No. 2005 / 0175844 and U.S. Patent Application Publication No. 2006 / 0138798.

[0120] Furthermore, in the previous example, the rings of material were used to prevent the interlayer material from flowing into the openings of the sheet of adhesive interlayer material during a suitable lamination process for joining the first and second glass sheets by the sheet of adhesive interlayer material. In such a lamination process, suitable high temperature and high pressure are used. If the interlayer material flows into the opening and contacts the impact device, the performance when breaking the glass sheet may be reduced.

[0121] It may be possible to control the lamination process so that the adhesive interlayer material does not flow to the impact device, but this is not preferred because it is difficult to control how the adhesive interlayer flows during lamination. Therefore, it is preferred to use a barrier in the opening to prevent such flow of the adhesive interlayer material.

[0122] The laminated glazing 1 shown in FIGS. 1 - 4 can be manufactured as follows.

[0123] The first glass sheet 3 is placed on a suitable support such as a table having a horizontal surface. Next, a PVB sheet is prepared, and an opening 9 is made in the PVB sheet, for example, by punching or cutting, to obtain a PVB sheet 7 having an opening therein. Next, the PVB sheet 7 having the opening 9 is positioned on the first glass sheet 3.

[0124] Next, a rubber O-ring 11 is positioned within each opening 9. Next, an impact device 13 is positioned inside each rubber O-ring within each opening 9, and each rubber O-ring surrounds each impact device 13.

[0125] Next, the second glass sheet 5 is positioned on the PVB sheet 7.

[0126] Then, the unstacked stack of components is laminated at an appropriate high temperature and pressure to bond the first glass sheet 3 to the second glass sheet 5 by the PVB sheet 7. Each O-ring 11 forms a seal with the inner surfaces of the first and second glass sheets 3, 5 (the surface 3b of the first glass sheet 3 and the surface 5a of the second glass sheet 5), so that during lamination, the PVB could not pass through the O-ring 11. As a result, each impact device 13 remains within the opening of the PVB and does not come into direct contact with the PVB sheet 7.

[0127] If a liquid resin is used instead of a sheet of adhesive intermediate layer material before bonding the first glass sheet to the second glass sheet, the above method is modified.

[0128] A barrier is provided around the first glass sheet 3. Next, the O-ring 11 is positioned at a desired location on the first glass sheet 3, and the impact device 13 is positioned inside each O-ring 11. Next, the liquid resin is poured onto the first glass sheet 3, and since the O-ring 11 surrounds each impact device, contact with the impact device 13 is prevented. The O-ring 11 functions as a barrier to the liquid resin in the same manner as above when using a PVB sheet and applying appropriate high temperature and high pressure to the lamination process.

[0129] Next, the second glass sheet 5 is positioned on the uncured resin, and the uncured resin can be partially cured. The resin can be fully cured, whereby the first glass sheet 3 is joined to the second glass sheet 5.

[0130] The present invention finds a particular use as a windshield for vehicles such as automobiles, trucks, lorries or buses.

Claims

1. A laminated glazing for a vehicle front glass, comprising a first sheet of glazing material joined to a second sheet of glazing material by at least one sheet of an adhesive intermediate layer material, wherein the first and second sheets of each said glazing material and the first sheet of the first intermediate layer material each have a first major surface and an opposite second major surface, the second major surface of the first sheet of the glazing material faces the first major surface of the second sheet of the glazing material, and the first sheet of the adhesive intermediate layer material is between the first and second sheets of the glazing material, furthermore, at least a first weakening device is located between the first and second sheets of the glazing material, and the first weakening device is arranged to damage at least one of the first and second sheets of the glazing material in the event of an impact on the first major surface of the first sheet of the glazing material, the first weakening device is located within a first opening of the first sheet of the adhesive intermediate layer material, a laminated glazing for a vehicle front glass.

2. At least a second weakening device is located within the first opening in the first sheet of the adhesive intermediate layer material, the laminated glazing according to claim 1.

3. The laminated glazing according to claim 1 or 2, further comprising at least one other weakening device between the first and second sheets of the glazing material, and at least one of the at least one other weakening device is located within each opening of the first sheet of the adhesive intermediate layer material.

4. A barrier surrounds the first weakening device within the first opening and restricts the flow of the intermediate layer material reaching the first weakening means during lamination, and preferably, the barrier is in an annular form, the laminated glazing according to any one of claims 1 to 3.

5. The laminated glazing according to claim 4, wherein the barrier comprises a compressible material, preferably rubber, or the barrier comprises PET or polycarbonate.

6. The first weakening device includes at least one impact device having a bottom portion for contacting the second major surface of the first sheet of the glazing material and at least a first contact portion for contacting the first sheet. When the laminated glazing collides with the first major surface of the first sheet of the glazing material, the first contact portion of the impact device contacts the first major surface of the second sheet of the glazing material, causing damage to the second sheet of the glazing material. The laminated glazing according to any one of claims 1 to 5.

7. The bottom portion of the impact device tapers towards the first contact portion, and preferably, the impact device is in a conical shape or a pyramidal shape. The laminated glazing according to claim 6.

8. The first raised portion extends from the bottom portion, and the first raised portion has a first end adjacent to the bottom portion and a second end opposite to the first end of the first raised portion. The second end of the first raised portion includes a first contact portion, and preferably, the first raised portion is in a conical shape or a pyramidal shape or a spike shape. The laminated glazing according to claim 6.

9. The first contact portion is pointed. The laminated glazing according to any one of claims 6 to 8.

10. The first contact portion is harder than the second sheet of the glazing material. The laminated glazing according to any one of claims 6 to 9.

11. The first contact portion includes at least one of boron nitride, boron carbide, tungsten carbide, and diamond. The laminated glazing according to any one of claims 6 to 10.

12. The first opening of the first sheet of the adhesive intermediate layer material is circular or elliptical or rectangular or trapezoidal or triangular. The laminated glazing according to any one of claims 1 to 11.

13. The first opening is one of a plurality of openings, and each opening of the plurality of openings has the same shape and / or the same area. The laminated glazing according to any one of claims 1 to 12.

14. Further comprising another weakening device located within another opening of the first sheet of the adhesive intermediate layer material, wherein the first opening is separated from the another opening by a first interval, and the first interval is 0.5 cm to 50 cm, more preferably 0.5 cm to 40 cm, more preferably 0.5 cm to 30 cm, more preferably 0.5 cm to 20 cm, more preferably 0.5 cm to 10 cm. The laminated glazing according to any one of claims 1 to 13.

15. The laminated glazing according to any one of claims 1 to 14, wherein the first opening is separated from the periphery of the laminated glazing.

16. The first opening is separated from the periphery of the laminated glazing by 1 cm to 20 cm, more preferably 1 cm to 15 cm, more preferably 1 cm to 10 cm, more preferably 1 cm to 9 cm, or 1 cm to 8 cm, or 1 cm to 7 cm, or 1 cm to 6 cm, or 1 cm to 5 cm. The laminated glazing according to claim 15.

17. The laminated glazing according to claim 15 or 16, wherein the first opening is separated from the periphery of the laminated glazing configured to be the lower edge of the laminated glazing when installed in a vehicle.

18. The first sheet of the glazing material has a thickness of 1 mm to 5 mm, preferably has a thickness of 1.3 mm to 3 mm, or the first sheet of the glazing material is chemically strengthened, preferably has a thickness of less than 1.2 mm. The laminated glazing according to any one of claims 1 to 17.

19. The second sheet of the glazing material has a thickness of 1 mm to 5 mm, preferably has a thickness between 1.3 mm and 3 mm, or the second sheet of the glazing material is chemically strengthened, preferably has a thickness of less than 1.2 mm. The laminated glazing according to any one of claims 1 to 18.

20. The second sheet of the glazing material is thinner than the first sheet of the glazing material, and / or the thickness of the laminated glazing is 3 mm to 10 mm. The laminated glazing according to any one of claims 1 to 19.

21. The laminated glazing according to any one of claims 1 to 20, wherein the first opening is within a region of the laminated glazing having an obscuring band in at least a part of the first or second sheet of the glazing material.

22. The first and / or second sheet of the glazing material comprises one or more weak points or lines arranged to weaken the laminated glazing upon impact with the laminated glazing, preferably the weak points or lines are on the main surface of the first and / or second sheet of the glazing material. The laminated glazing according to any one of claims 1 to 21.

23. A vehicle windshield comprising the laminated glazing according to any one of claims 1 to 22.

24. A vehicle comprising the vehicle windshield according to claim 23.

25. Use of the laminated glazing according to any one of claims 1 to 22 as a vehicle windshield for reducing the likelihood of injury to a person involved in a collision with a vehicle.

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