Abstract: A sealed insulating unit includes two parallel opposed panes with a spacing and sealing system between the two panes. The panes and the spacing and sealing system together define a sealed gas space. The spacing and sealing system includes a spacer frame with a primary seal between each side of the spacer frame and the opposing pane face and a secondary seal extending between the panes outside the outer peripheral face of the spacer frame. Each primary seal is greater than 0.4 mm thick on construction of the unit and has at least 7 grams of sealant material on each side of the spacer frame per meter of the spacer frame length. A spacer for a sealed insulating unit has side walls in which are defined elongate recesses, the dimensions of the recesses being selected such that sufficient primary sealant can be accommodated to provide in the sealed insulating unit opposed primary seals each at least 0.4 mm thick.

Abstract: A method of making an electrically heated window from at least two plies of transparent glazing material, at least one ply of interlayer material and an electrically resistant heating area device extending over one of the plies includes laying at least one length of busbar strip on one of the plies to form part of a busbar, positioning a separate corner piece of busbar strip adjacent the length of busbar strip to form a corner of the busbar, and electrically connecting the corner piece and the length of busbar strip to one another. An electrical connection device is arranged to extend from the electrically resistant area heating device past the peripheral edge of the window to terminate outside the window. The plies of glazing material are then laminated together with the ply of interlayer material and the electrically resistant area heating device extending between them.

Abstract: A method of bending glass sheets, the method including the steps of gravity bending a glass sheet at elevated temperature on a gravity bending mould in a gravity bending zone of a furnace, press bending the gravity bent glass sheet to a desired shape with an upper mould while the glass sheet is supported by the gravity bending mould as a lower mould in a press bending zone of the furnace and controlling the ambient temperature in the press bending zone thereby to control the cooling rate of the glass sheet in the press bending zone. The invention also provides a method of press bending glass sheets, the method including providing an initially bent glass sheet carried on an articulated gravity bending mould and press bending the glass sheet to a final bent shape by an upper press bending mould which is lowered onto the upper surface of the glass sheet, the upper press bending mould having a net weight of from 50 to 150 kg.

Abstract: A busbar supplies current to an electrically resistant area heating device, such as an array of fine closely-spaced wires, which extends over a window, e.g. a laminated vehicle windscreen. The busbar is arranged to turn a corner, e.g. a corner of the window, by providing a separate corner piece of busbar strip which is electrically connected to adjacent lengths of straight busbar strip. This facilitates concealment of the busbar, as is desirable for vehicle windscreens, especially when the corner piece is shaped to suit the corner of the window. Electrical connection of the corner piece to the adjacent lengths of busbar strip is achieved by use of a solder of low melting point, which melts on autoclaving of the window.

Abstract: A method of operating a regenerative glass furnace for melting glass for the manufacture of shaped glass articles so as to minimize emission of NOx in waste gases leaving the furnace, the furnace having sealed regenerators which act as heat exchangers, the method including supplying fuel in excess of that required for stoichiometric combustion to ensure that glass of the required quality at the required production rate is obtained, and that the waste gases leaving the furnace through the regenerators contain combustible material, and reacting the combustible material with sufficient air to ensure that the waste gases exiting to atmosphere contain permissible levels of combustible material and contain permissible levels of NOx. Alternatively, the furnace may be operated at substantially stoichiometric conditions and fuel is supplied to waste gases as they leave the melting chamber. The invention also relates to a regenerator glass furnace for use in the method.

Abstract: A method of operating a cross-fired regenerative glass furnace for melting flat glass so as to minimize emission of NOx in waste gases leaving the furnace, the furnace having sealed regenerators which act as heat exchangers, the method including supplying fuel in excess of that required for stoichiometric combustion to ensure that glass of the required quality at the required production rate is obtained, and that the waste gases leaving the furnace through the regenerators contain combustible material, and reacting the combustible material with sufficient air to ensure that the waste gases exiting to atmosphere contain permissible levels of combustible material and permissible levels of NOx. Alternatively, the furnace may be operated at substantially stoichiometric conditions and fuel is supplied to the waste gases as they leave the melting chamber. The invention also relates to a cross-fired regenerator glass furnace for use in the method.

Abstract: A method of operating a cross-fired regenerative glass furnace for melting flat glass so as to minimize emission of NOx in waste gases leaving the furnace, the furnace having sealed regenerators which act as heat exchangers, the method including supplying fuel in excess of that required for stoichiometric combustion to ensure that glass of the required quality at the required production rate is obtained, and that the waste gases leaving the furnace through the regenerators contain combustible material, and reacting the combustible material with sufficient air to ensure that the waste gases exiting to atmosphere contain permissible levels of combustible material and permissible levels of NOx. Alternatively, the furnace may be operated at substantially stoichiometric conditions and fuel is supplied to the waste gases as they leave the melting chamber. The invention also relates to a cross-fired regenerator glass furnace for use in the method.

Abstract: A method of operating a regenerative glass furnace for melting glass for the manufacture of shaped glass articles so as to minimize emission of NOx in waste gases leaving the furnace, the furnace having sealed regenerators which act as heat exchangers, the method including supplying fuel in excess of that required for stoichiometric combustion to ensure that glass of the required quality at the required production rate is obtained, and that the waste gases leaving the furnace through the regenerators contain combustible material, and reacting the combustible material with sufficient air to ensure that the waste gases exiting to atmosphere contain permissible levels of combustible material and contain permissible levels of NOx. Alternatively, the furnace may be operated at substantially stoichiometric conditions and fuel is supplied to waste gases as they leave the melting chamber. The invention also relates to a regenerative glass furnace for use in the method.

Abstract: A method of operating a regenerative glass furnace for melting glass for the manufacture of shaped glass articles so as to minimize emission of NOx in waste gases leaving the furnace, the furnace having sealed regenerators which act as heat exchangers, the method includes supplying fuel in excess of that required for stoichiometric combustion to ensure that glass of the required quality at the required production rate is obtained, and that the waste gases leaving the furnace through the regenerators contain combustible material, and reacting the combustible material with sufficient air to ensure that the waste gases exiting to atmosphere contain permissible levels of combustible material and contain permissible levels of NOx. Alternatively, the furnace may be operated at substantially stoichiometric conditions and fuel is supplied to waste gases as they leave the melting chamber. The invention also relates to a regenerator glass furnace for use in the method.

Abstract: A method of operating a cross-fired regenerative glass furnace for melting flat glass so as to minimize emission of NOx in waste gases leaving the furnace, the furnace having sealed regenerators which act as heat exchangers, the method includes supplying fuel in excess of that required for stoichiometric combustion to ensure that glass of the required quality at the required production rate is obtained, and that the waste gases leaving the furnace through the regenerators contain combustible material, and reacting the combustible material with sufficient air to ensure that the waste gases exiting to atmosphere contain permissible levels of combustible material and permissible levels of NOx. Alternatively, the furnace may be operated at substantially stoichiometric conditions and fuel is supplied to the waste gases as they leave the melting chamber. The invention also relates to a cross-fired regenerator glass furnace for use in the method.

Abstract: A method of producing front surface mirrors comprising depositing onto a hot ribbon of low transmissivity glass during the production process a low transmissivity reflecting coating whereby the mirrors have a transmissivity through the coated glass of up to about 10% in visible light. There is also provided a front surface mirror comprising a glass substrate of low transmissivity glass carrying a low transmissivity reflecting coating whereby the mirror has a transmissivity through the coated glass of up to about 10% in visible light.

Abstract: A mirror assembly comprising a glass substrate, a low transmissivity reflecting coating on the substrate and an opacifying member which is assembled adjacent to the glass substrate for a front surface mirror or the reflecting coating for a back surface mirror. The present invention also provides a method of producing a mirror assembly comprising depositing onto a hot ribbon of glass during the production process a low transmissivity reflecting coating and assembling an opacifying member adjacent to the glass substrate or the reflecting coating of the mirror so formed.

Abstract: The invention relates to the press bending and tempering of glass sheets, especially for use as glazings in vehicles. When the press bending system is not located in a heated environment such as a furnace, it is important to maintain the glass sheets at a sufficiently high temperature for an adequate degree of temper to be achieved on quenching the sheet. The present invention provides a method of bending and tempering a thin glass sheet comprising pressing the substantially horizontal sheet between moulds having opposed complementary shaping surfaces, at least one of the surfaces being heated, and subsequently quenching the surfaces of the sheet characterised in that the heated shaping surface is maintained at a temperature in the range from 200.degree. C. to 350.degree. C.

Abstract: A method of producing mirrors comprising depositing onto a ribbon of hot glass during the production process a coating comprising a reflecting layer and at least two reflection enhancing layers whereby the mirrors have a visible light reflection of at least 70%. There is also provided a mirror having such a coating. In a preferred embodiment the coating comprises: an inner layer having a refractive index of at least 1.6; an intermediate layer of relatively low refractive index and; an outer layer having a refractive index of at least 1.6; the intermediate layer having a refractive index less than the refractive index of either said inner layer or said outer layer and less than 3, provided that at least one of said inner and outer layers is of silicon, the aggregate refractive index of the inner and outer layers is at least 5.5, and the thicknesses of the layers are such that the mirror has a visible light reflection of at least 70%.

Abstract: Glass sheets are press bent and tempered, especially for use as glazings in vehicles. Such glazings are required to be accurately bent to a complex shape while meeting high standards of optical quality and fracture safety at an acceptable cost. A method of bending and tempering a glass sheet is provided comprising heating the sheet in a furnace, including heating at least one portion of the sheet to a higher temperature than another portion, conveying the sheet out of the furnace and into a press bending station, shaping the sheet by pressing it between opposed complementary upper and lower press members, at least one of the members being internally heated, transferring the bent glass sheet onto a shuttle carrier ring conforming to the periphery of the sheet, and tempering the sheet while supported on the carrier ring. A corresponding apparatus is also described.

Abstract: A method of producing heatable mirrors comprising depositing onto a ribbon of hot glass during the production process a reflecting coating whereby the mirrors so formed have a visible light reflection of at least 70% and depositing an electroconductive heating layer onto the mirrors. There is also provided a heatable mirror comprising a glass substrate carrying a non-metallic reflecting coating whereby the mirror has a visible light reflection of at least 70% and an electroconductive heating layer deposited on the coated substrate.

Abstract: An apparatus for press bending glass sheets carried on a mold, the apparatus including a die having a lower surface shape to mold a glass sheet positioned thereunder to a desired curved shape, a first counterbalance assembly connected to the die for providing the die with a selected net weight, a frame mounted above the die, a plurality of flexible members connecting the die to the frame for suspending the die below the frame whereby the die is capable of unconstrained lateral and tilting movement relative to the frame and die moving device connected to the frame for vertically moving the die.

Abstract: A furnace is provided for the heating of glass sheets to be bent, whereby precise control of the temperature profile across a sheet may be achieved, resulting in improved control over the shape to which the sheet is bent. The furnace has at least one differential heating zone provided with a plurality of main heating elements, and at least one shield for directing heat radiated by said heating elements whereby a controlled differential heating of the glass sheet may be achieved. Transport means, e.g. wheeled boxes, are provided to advance the sheet through the furnace and bending means, e.g. gravity bending ring moulds, may bend the sheet either during, or subsequent to, the heating step.

Abstract: An apparatus for bending a glass sheet in a gravity bending step and in a subsequent press bending step includes a gravity bending mould having a fixed mould portion and an articulated wing portion adjacent to the fixed mould portion, a base on which the fixed mould portion is mounted and a hinged locking arm mounted between the wing portion and the base. The locking arm is movable from an unlocked position in which the wing portion is capable of moving vertically relative to the base to a locked position in which the wing portion is fixed in position relative to the base. A method of bending a glass sheet involves placing a glass sheet on a gravity bending mould having an articulated wing portion and a fixed mould portion, and conveying the mould carrying the glass sheet through a furnace in which the glass is heated to the glass softening point and is bent by gravity until the periphery of the glass sheet is in contact with and conforms to the shape of the upper surface of the gravity bending mould.

Abstract: An apparatus for press bending glass sheets, the apparatus comprising an upper die, a suspension system for the upper die for suspending and vertically moving the upper die, a lower gravity bending mould and a plurality of spacer devices for spacing the upper die and the lower mould a selected distance from each other when the upper die presses a glass sheet on the lower mould, the suspension system being adapted and the spacer devices being configured to permit lateral movement of the die relative to the mould. There is also provided a method of press bending glass sheets.