# US 7,411,158 B2 · Heated laminated glazing > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,411,158 B2 - Document ID: US7411158B2 - Status: Granted - Kind: B2 - Application number: 10/578,326 - Filed: 2004-11-03 - Published: 2007-05-17 - Granted: 2008-08-12 - Earliest claimed: 2003-11-07 - Assignees: Saint-Gobain Glass France - Inventors: Jan Andrt - Web page: https://patentgrep.com/patent/US7411158B2 ## CPC - B64F 1/06: using catapults - B32B 17/10385: {for ohmic resistance heating} - B32B 17/10761: {containing vinyl acetal} - B32B 17/10788: {containing ethylene vinylacetate} - H05B 3/84: Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields - H05B 2203/002: Heaters using a particular layout for the resistive material or resistive elements - H05B 2203/016: Heaters using particular connecting means - B64F: GROUND OR AIRCRAFT-CARRIER-DECK INSTALLATIONS SPECIALLY ADAPTED FOR USE IN CONNECTION WITH AIRCRAFT; DESIGNING, MANUFACTURING, ASSEMBLING, CLEANING, MAINTAINING OR REPAIRING AIRCRAFT, NOT OTHERWISE PROVIDED FOR; HANDLING, TRANSPORTING, TESTING OR INSPECTING AIRCRAFT COMPONENTS, NOT OTHERWISE PROVIDED FOR - B32B: LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract A heatable composite pane having a trapezoidal outline, including a heating area having heating wires embedded in the composite and at least two main busbars. The two main busbars connect ends of a first group of parallel heating wires electrically in parallel. The outer triangular surface of the trapezoidal outline includes at least a second group and a third group of parallel heating wires that can be fed electrically via busbars. The second group and the third group of heating wires have different lengths and are combined to be connected in parallel with the first group. The second group and the third group are electrically connected to one another in series such that an effective wire length between the two main busbars is increased to homogenize heating power in the triangular surface with heating power in the heating area. ## Claims ### Claim 1 A heatable composite pane, comprising: a heating area including heating wires embedded in the composite pane, the composite pane having a trapezoidal outline; at least two main busbars that connect ends of a first group of heating wires to one another electrically in parallel and that are located opposite along side edges of the composite pane, which run parallel to one another, and at least one of the busbars extends along the side edge in an area of an outer triangular surface of the trapezoidal outline, wherein the outer triangular surface of the trapezoidal outline includes at least a second group and a third group of heating wires that can be fed electrically via the busbars and that run essentially parallel to one another, in the area of the outer triangular surface, heating wires in the second group and the third group have different lengths and are combined to be connected in parallel with the first group, and the second group and the third group are electrically connected to one another in series such that an effective wire length between the two main busbars is increased, to homogenize heating power in the triangular surface with heating power in the heating area. ### Claim 2 (depends on 1) The heatable composite pane as claimed in claim 1, further comprising: an additional busbar configured to connect the second group and the third group of heating wires. ### Claim 3 (depends on 2) The heatable composite pane as claimed in claim 2, wherein the additional busbar is arranged in parallel with the two main busbars. ### Claim 4 (depends on 1) The heatable composite pane as claimed in claim 1, wherein a number of wires in the first group, the second group, and the third group of heating wires is different. ### Claim 5 (depends on 1) The heatable composite pane as claimed in claim 1, wherein limbs of the two main busbars also extend along at least one side edge in the area of the outer triangular surfaces of the trapezoidal outline, and end on both sides of a separation point. ### Claim 6 (depends on 5) The heatable composite pane as claimed in claim 5, wherein external connections of the two main busbars are arranged in an area of free ends of the limbs on both sides of the separation point. ### Claim 7 (depends on 1) The heatable composite pane as claimed in claim 1, wherein external connections of the two main busbars are connected in a physically adjacent form close to a corner of the composite pane. ### Claim 8 (depends on 1) The heatable composite pane as claimed in claim 1, wherein at least one of the busbars is subdivided into two electrically separate sections, each of which includes an external connection. ### Claim 9 (depends on 1) The heatable composite pane as claimed in claim 1, wherein the heating wires in the outer triangular surface have an electrical resistance per unit length that differs from that of the heating wires in the central heating area. ### Claim 10 (depends on 9) The heatable composite pane as claimed in claim 9, wherein the heating wires in the outer triangular surface have a higher resistance than the heating wires in the central heating area. ### Claim 11 (depends on 9) The heatable composite pane as claimed in claim 9, wherein the heating wires in the outer triangular surface have a lower resistance than the heating wires in the central heating area. ### Claim 12 (depends on 1) The heatable composite pane as claimed in claim 1, including an edge area provided with an opaque colored strip that optically coats the busbars. ### Claim 13 (depends on 1) The heatable composite pane as claimed in claim 1, wherein the heatable composite pane is a windshield or a rear windshield in a vehicle. ### Claim 14 (depends on 1) The heatable composite pane as claimed in claim 1, wherein the busbars are located on a perimeter of the composite pane such that none of the heating wires extend outside of the busbars. ### Claim 15 (depends on 1) The heatable composite pane as claimed in claim 1, wherein the first group, the second group, and the third group of the heating wires are substantially perpendicular to parallel edges of the trapezoidal outline of the composite pane. ### Claim 16 (depends on 1) The heatable composite pane as claimed in claim 1, further comprising: a fourth group of heating wires located in the outer triangular surface; and an additional busbar configured to connect the fourth group of heating wires in series with the third group of heating wires. ### Claim 17 A heatable composite pane, comprising: a first group of substantially parallel heating wires embedded in the composite pane and traveling from a top region of the composite pane to a bottom region of the composite pane; a second group of substantially parallel heating wires embedded in the composite pane and traveling from a side region of the composite pane to the bottom region of the composite pane; a third group of substantially parallel heating wires embedded in the composite pane and traveling from the side region of the composite pane to the bottom region of the composite pane; a fourth group of substantially parallel heating wires embedded in the composite pane and traveling from the side region of the composite pane to the bottom region of the composite pane; a first busbar extending along the top region and a portion of the side region of the composite pane and receiving top ends of the first group and the second group of heating wires; a second busbar provided at the bottom region of the composite pane and receiving bottom ends of the first group and the fourth group of heating wires to connect the first group of heating wires in parallel with a combination of the second group, the third group, and the fourth group of heating wires; a third busbar provided at the bottom region of the composite pane and receiving bottom ends of the second group and third group of heating wires to connect the second group and third group of heating wires in series; and a fourth busbar provided at the side region of the composite pane and receiving top ends of the third group and the fourth group of heating wires to connect the third group and fourth group of heating wires in series, wherein the composite pane has a trapezoidal shape. ### Claim 18 A heatable composite pane, comprising: a first group of substantially parallel heating wires embedded in the composite pane and traveling from a top region of the composite pane to a bottom region of the composite pane; a second group of substantially parallel heating wires embedded in the composite pane and traveling from a side region of the composite pane to the bottom region of the composite pane; a third group of substantially parallel heating wires embedded in the composite pane and traveling from the side region of the composite pane to the bottom region of the composite pane; a first busbar extending along the top region and a first portion of the side region of the composite pane and receiving top ends of the first group and the second group of heating wires; a second busbar provided at the bottom region and a second portion of the side region of the composite pane and receiving bottom ends of the first group and top ends of the third group of heating wires to connect the first group of heating wires in parallel with a combination of the second group and the third group of heating wires; and a third busbar provided at the bottom region of the composite pane and receiving bottom ends of the second group and the third group of heating wires to connect the second group and the third group of heating wires in series, wherein the composite pane has a trapezoidal shape.