# US 5,350,613 A · Safety windowpanes made of laminated glass; processes for their manufacture > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,350,613 A - Document ID: US5350613A - Status: Granted - Kind: A - Application number: 08/036,030 - Filed: 1993-03-23 - Granted: 1994-09-27 - Earliest claimed: 1992-03-26 - Assignees: Vertal Nord Est - Inventors: Jean-Pierre Deprez; Christian de la Rochefoucauld - Web page: https://patentgrep.com/patent/US5350613A ## CPC - B32B 17/10761: {containing vinyl acetal} - B32B 17/10036: {comprising two outer glass sheets} - B32B 17/10568: {varying in thickness} - B32B 17/10688: {Adjustment of the adherence to the glass layers} - B32B 17/10917: {between two pre-positioned glass layers} - B61D 25/00: Window arrangements peculiar to rail vehicles (vehicle window arrangements in general B60J; cleaning vehicle windows B60S; heating arrangements specially adapted for transparent or reflecting areas H05B3/84) - Y10T 428/15: Sheet, web, or layer weakened to permit separation through thickness - Y10T 428/23: Sheet including cover or casing - Y10T 428/24322: Composite web or sheet - Y10T 428/24331: including nonapertured component - Y10T 428/24851: Intermediate layer is discontinuous or differential - Y10T 428/24942: including components having same physical characteristic in differing degree - Y10T 428/24983: Hardness - Y10T 428/315: Surface modified glass [e.g., tempered, strengthened, etc.] - Y10T 428/31616: Next to polyester [e.g., alkyd] - Y10T 428/3163: Next to acetal of polymerized unsaturated alcohol [e.g., formal butyral, etc.] - Y10T 428/31649: Ester, halide or nitrile of addition polymer - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - B61D: BODY DETAILS OR KINDS OF RAILWAY VEHICLES (vehicles in general B60; adaptation of vehicles to special systems B61B; underframes B61F) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A safety windowpane and process of manufacture made of laminated glass. The windowpane includes two glasses made of annealed, hardened or quenched glass 1, 2 bonded to one another by an insert sheet of synthetic material 3 to the opposite faces of which the glasses are adhesively attached. The sheet includes in the material a line 4 of discontinuity in mechanical strength of relatively small width. The line defines an outline of preopening of a surface area such that after breaking of the glasses 1, 2 and rupture along the outline, it offers a sufficient passage for a human body. ## Claims ### Claim 1 A laminated glass safety windowpane comprising two glass layers selected from annealed, hardened or quenched glass bonded to each other by an insert sheet of synthetic material selected from the group consisting of polyvinylbutyral and ultraviolet-polymerizable transparent acrylic resin to the opposite faces of which said glasses are adhesively attached over a complete surface thereof, in which said sheet comprises in said material a line of discontinuity in mechanical strength of relatively small width, said line defining an outline of an opening in the surface area of said insert sheet which is capable of rupturing and providing an emergency exit upon breakage of said glass layers of said window pane. ### Claim 2 (depends on 1) The windowpane as claimed in claim 1, wherein said insert sheet additionally comprises at least one punctual region of discontinuity in mechanical strength in said material located separate from said line of discontinuity, designated as region of impact for a tool, capable of facilitating the breaking of one of said glass layer through the other glass. ### Claim 3 (depends on 2) The windowpane as claimed in claim 2, wherein said line and/or region of discontinuity in said insert sheet have a hardness which is appreciably lower than that of said synthetic material of which this sheet consists. ### Claim 4 (depends on 1) The windowpane as claimed in claim 1, wherein said line of discontinuity in said synthetic material extends along the three sides of a rectangle. ### Claim 5 (depends on 1) The windowpane as claimed in claim 1, wherein said line of discontinuity in the synthetic material is an interrupted line, namely a line consisting of consecutive regions in which said synthetic material of which said sheet consists is alternately present and absent. ### Claim 6 (depends on 5) The windowpane as claimed in claim 5, in which said insert sheet of synthetic material is produced by casting and polymerization in situ between said glass layer, wherein said line of discontinuity is formed by virtue of sections of polyethylene foam tape, adhesive having high adhesiveness on both its faces so as to be adhesively bonded between said glass layer and embedded in said material of said sheet, of a thickness which is appreciably equal to that of said sheet. ### Claim 7 (depends on 1) The windowpane as claimed in claim 1, wherein said synthetic material of which the sheet consists is a transparent synthetic resin of acrylic, capable of being polymerized by the ultraviolet. ### Claim 8 (depends on 1) The windowpane as claimed in claim 1, in which said insert sheet of said synthetic material consists of a double-faced adhesive laminated between said glass layer, wherein said line of discontinuity in said material consists of a line of cut made in said sheet, along said desired outline of opening. ### Claim 9 (depends on 8) The windowpane as claimed in claim 8, wherein said synthetic material consists of a polyvinylbutyral (PVB). ### Claim 10 (depends on 2) The windowpane as claimed in claim 2, wherein said punctual region of discontinuity is devoid of any material or is occupied by a tablet of material of a strength less than that of said glass layer.