Patents Assigned to Pilkington Brothers Limited
  • Patent number: 4200448
    Abstract: In a glass melting tank, a plurality of stirrers are spaced apart across the tank and arranged to extract heat from the forward flowing glass so as to achieve a differential extraction of heat from the glass which flows along a return path towards the inlet end after stirring, and that glass which continues along a forward path to the outlet end of the tank.
    Type: Grant
    Filed: May 19, 1978
    Date of Patent: April 29, 1980
    Assignee: Pilkington Brothers Limited
    Inventor: George A. Dickinson
  • Patent number: 4198226
    Abstract: A gas-fluidized bed of particulate material is operated by extracting gas from a localized region of the bed to produce an unfluidized static condition of the material in that region. The region may be in the upper part of the fluidized bed, or may be a region adjacent a side opening into the bed where the unfluidized static material obturates the opening. There may be a plurality of unfluidized static regions in the bed.The invention is applicable to the thermal toughening of glass quenched in the fluidized bed.
    Type: Grant
    Filed: September 21, 1978
    Date of Patent: April 15, 1980
    Assignee: Pilkington Brothers Limited
    Inventors: Donald C. Wright, Brian Marsh
  • Patent number: 4194898
    Abstract: An article, for example a glass sheet, is treated in a gas-fluidized particulate material by advancing the article along a path leading into the gas-fluidized particulate material and extracting gas from a region of the path at a rate sufficient to pack the particulate material in that region and thereby obturate the path. An opening leading into a container for a gas-fluidized bed of particulate material may be obturated in this way. The packed state of the material obturating the opening is such that an article can pass through the opening.
    Type: Grant
    Filed: September 21, 1978
    Date of Patent: March 25, 1980
    Assignee: Pilkington Brothers Limited
    Inventors: Donald C. Wright, Brian Marsh, Willem Wiechers
  • Patent number: 4188444
    Abstract: Glass is coated with an alkali-resistant silicon coating by moving the glass past a coating station while the glass is at least at 400.degree. C. Silane-containing gas is released close to the glass surface, which gas includes a proportion of a gaseous electron-donating compound which imparts a predetermined alkali-resistance to the coating produced when silane in the gas pyrolyzes at the glass surface.
    Type: Grant
    Filed: February 23, 1978
    Date of Patent: February 12, 1980
    Assignee: Pilkington Brothers Limited
    Inventor: Manfred Landau
  • Patent number: 4173486
    Abstract: A method of coating glass fibres to protect them from deterioration in an alkaline environment such as a Portland cement matrix, in which the glass fibres are coated with a composition containing a water-soluble film-forming material having free aliphatic hydroxyl groups in the molecule, a water-soluble ester formed by reaction of a tri-hydroxy- or di-hydroxy-substituted aromatic carboxylic acid with an alcohol having at least two hydroxyl groups in the molecule, and a cross-linking agent, the composition is cured and dried at elevated temperature so as to cross-link hydroxyl groups of the film-forming material and thereby form a thermoset film coating on the glass fibres which also retains the ester. The ester acts as a protective material to protect the glass fibres from alkaline attack.
    Type: Grant
    Filed: November 8, 1977
    Date of Patent: November 6, 1979
    Assignee: Pilkington Brothers Limited
    Inventors: Colin J. Cheetham, Phillip Maguire
  • Patent number: 4144684
    Abstract: A glazing unit comprising a sheet of glass having a coating consisting essentially of silicon on a major face thereof, and a frame for that sheet.
    Type: Grant
    Filed: December 13, 1976
    Date of Patent: March 20, 1979
    Assignee: Pilkington Brothers Limited
    Inventors: Bernard J. Kirkbride, Robert A. Downey, Charles V. Thomasson, Joseph E. Lewis
  • Patent number: 4140258
    Abstract: For separating glass sheets, especially sheets of wired glass, into separate sheet portions and stacking the sheet portions in spaced stacks, the sheets are cut to define the sheet portions, which are gripped by respective relatively movable groups of suction gripping devices. The cutting may be effected by scoring the glass sheet before it is gripped by the suction devices, and then snapping it either before or after gripping it with the suction devices. The sheets may be lifted from a roller delivery conveyor into engagement with the suction gripping devices by a series of transverse lifting tines. The groups of suction gripping devices are then moved apart to separate the cut sheet portions, and in the case of wired glass this also severs the wires.
    Type: Grant
    Filed: March 4, 1976
    Date of Patent: February 20, 1979
    Assignee: Pilkington Brothers Limited
    Inventor: Martin E. Gray
  • Patent number: 4137086
    Abstract: A novel calcium fluoroaluminosilicate glass consisting essentially of from 25 to 35% by weight of silicon calculated as silica, from 30 to 40% by weight of aluminum calculated as alumina, from 20 to 35% by weight calcium, calculated as calcium oxide, and up to 9% by weight fluorine (preferably 4-7%) can be associated with a poly(carboxylic acid e.g. as an intimate mixture of glass and acid to constitute a composition curable on contact with water and useful, for example, as a loading on a splinting bandage. Such a bandage preferably has a ratio of set time to gel time from 4:1 to 8:1 with a minimum gel time.
    Type: Grant
    Filed: November 17, 1977
    Date of Patent: January 30, 1979
    Assignee: Pilkington Brothers Limited
    Inventors: William D. Potter, Andrew C. Barclay, Reginald Dunning, Richard J. Parry
  • Patent number: 4131222
    Abstract: Glass snapping apparatus comprises a plurality of conveyors diverging away from each other in the direction of advance, lifting means for raising the trailing edge of the sheet above the leading edge and for imposing on the trailing edge a bending moment sufficient to snap the sheet along any score line parallel to the direction of advance of the sheet.
    Type: Grant
    Filed: September 20, 1977
    Date of Patent: December 26, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: Joseph B. Hodgkinson
  • Patent number: 4131446
    Abstract: In flat glass manufacture on a molten metal bath, there is forward flow of molten metal entrained by accelerating glass over an upstream return flow of cooler molten metal which is received in a deepened region of the bath. Upstream molten metal flows are drawn from that deepened region to replenish the molten metal entrained by the accelerating ribbon.
    Type: Grant
    Filed: November 21, 1977
    Date of Patent: December 26, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: George A. Dickinson
  • Patent number: 4124733
    Abstract: A laminated glass windscreen comprises two sheets of glass laminated together with a layer of transparent plastics material. The inner sheet of the windscreen is of thickness in the range 0.5 mm to 3 mm and is toughened to a degree such that the central tensile stress in the glass is from 380 kg/cm.sup.2 to 1120 kg/cm.sup.2. The outer sheet may be an untoughened sheet of thickness 0.5 mm to 3.5 mm or a toughened sheet of thickness 0.5 mm to 3 mm and whose central tensile stress does not exceed 560 kg/cm.sup.2.
    Type: Grant
    Filed: May 3, 1977
    Date of Patent: November 7, 1978
    Assignee: Pilkington Brothers Limited
    Inventors: Richard Melling, Arthur J. Nobbs, Andrew Leff
  • Patent number: 4123287
    Abstract: Glass fibres for use as reinforcement in cement products are coated with a composition containing a material to protect them against the alkaline environment, which comprises at least one dihydroxybenzoic acid, preferably 2,5 dihydroxybenzoic acid, and which may also comprise a partially-cured A-stage phenol-formaldehyde resin of the water-dilutable resole type. A further coating of an epoxy resin may be applied over this composition to protect it from abrasion during handling of the fibres and preparation of the cement products. The coating composition may be applied as a size to the individual filaments immediately after they have been drawn from a bushing, or it may be applied later after the filaments have been combined into a strand.
    Type: Grant
    Filed: July 26, 1976
    Date of Patent: October 31, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: David R. Cockram
  • Patent number: 4120681
    Abstract: Glass is thermally treated by contacting the glass with a gas-fluidized particulate material of non-compacted particle structure which is such that the apparent density of the particles is less than the actual density of the material forming the particles. The buoyant particles constitute a gas-fluidized bed in a quiescent uniformly expanded state of particular fluidization, and the material of the particles and the temperature of the bed are selected so that the heat transfer coefficient of the bed is sufficient to produce a desired thermal treatment, for example thermal toughening of hot glass.
    Type: Grant
    Filed: November 8, 1977
    Date of Patent: October 17, 1978
    Assignee: Pilkington Brothers Limited
    Inventors: Raymond Peter Cross, Derek Edward Thomas
  • Patent number: 4120680
    Abstract: A fluidized bed for the thermal treatment of glass articles is maintained in a quiescent uniformly expanded state of particulate fluidization by establishing a high pressure drop across a porous membrane through which fluidizing gas is supplied to the bed, of at least 60% of the pressure at which the fluidizing gas is supplied to a plenum chamber beneath the membrane.
    Type: Grant
    Filed: June 10, 1977
    Date of Patent: October 17, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: Raymond Peter Cross
  • Patent number: 4113458
    Abstract: The thermal treatment of glass is effected by heat transfer between the glass and a gas-fluidized particulate material which is in a quiescent uniformly expanded state of particulate fluidization. Glass sheets are thermally toughened by immersing each glass sheet, which is at a temperature above its strain point, in the gas-fluidized bed prior to the immersion of the glass in the bed.
    Type: Grant
    Filed: November 8, 1977
    Date of Patent: September 12, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: Raymond Peter Cross
  • Patent number: 4111675
    Abstract: Glass articles are thermally treated in a gas-fluidized bed of particulate material which is maintained in a quiescent uniformly expanded state of particulate fluidization. Heat exchange within the bed with the material of the bed regulates the bed temperature, and the heat exchange is enhanced by engendering agitation within the bed.
    Type: Grant
    Filed: June 1, 1977
    Date of Patent: September 5, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: Geoffrey Martin Ballard
  • Patent number: 4109051
    Abstract: A composition for coating glass fibers intended for use as reinforcement in cementitious products, containing, as a protective material, at least one monocyclic or polycyclic aromatic compound which has at least three hydroxyl groups on the aromatic ring or (in a polycyclic compound) on at least one of the aromatic rings, said composition, when applied to a strand of glass fibres which is subsequently encased in a block of ordinary Portland cement paste which is allowed to cure and kept for 28 days at 50.degree. C, producing an improvement of at least 10% in the tensile strength of the strand as compared with that of a strand similarly treated and tested but without application of said composition. Preferably, the aromatic compound is soluble in a calcium hydroxide solution. A preferred compound is pyrogallol.
    Type: Grant
    Filed: January 6, 1976
    Date of Patent: August 22, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: David Ralph Cockram
  • Patent number: 4102693
    Abstract: Fast-response photochromic boro-silicate glasses which have silver halide crystals dispersed throughout the glass and are free from barium, comprise, in weight percentages:______________________________________ SiO.sub.2 31 to 59% B.sub.2 O.sub.3 18 to 28% Al.sub.2 O.sub.3 8 to 20% R.sub.2 O 6 to 16% ______________________________________Where R.sub.2 O represents one or more of Li.sub.2 O, Na.sub.2 O and K.sub.2 O in amounts within the ranges 0 to 3% Li.sub.2 O, 0 to 8% Na.sub.2 O and 0 to 16% K.sub.2 O, and where the content of silver, expressed as Ag.sub.2 O, lies within the range 0.05 to 0.4% by weight, while the content of halide lies within the range 0.13 to 1% by weight of the glass.Further optional constituents are MgO (up to 2.6%) and P.sub.2 O.sub.5 (up to 12%). Refractive index n.sub.D can be corrected to the standard ophthalmic value of 1.523 by additions of ZrO.sub.2, TiO.sub.2 and/or PbO.
    Type: Grant
    Filed: January 31, 1977
    Date of Patent: July 25, 1978
    Assignee: Pilkington Brothers Limited
    Inventors: Harry Owen, Thomas Barrow
  • Patent number: 4093471
    Abstract: Glass fiber reinforced cement composite materials are made by first preparing a cement slurry from a cement/water mix by a high shear mixing process which breaks up cement agglomerates into their primary particles, and then mixing chopped strands of glass fiber into the cement slurry by a low shear mixing process which restricts damage to the glass filaments to a minimum. Both the high shear and low shear processes may be carried out in the same impeller-type mixer using different power inputs and impeller speeds.
    Type: Grant
    Filed: July 2, 1976
    Date of Patent: June 6, 1978
    Assignee: Pilkington Brothers Limited
    Inventor: Ian Robert Kennedy Greig
  • Patent number: 4092174
    Abstract: Fast-response alumino-phosphate photochromic glasses having silver halide crystals dispersed throughout the glass consisting essentially of, in weight percentages:SiO.sub.2 : 8.5 to 25%, Al.sub.2 O.sub.3 : 13 to 36.5%, P.sub.2 O.sub.5 : 7.5 to 33.5%, B.sub.2 O.sub.3 : 7 to 28%; R.sub.2 O: 7 to 20.5%, R'O:0 to 21%, TiO.sub.2 : 0 to 6%, ZrO.sub.2 : 0 to 10%, PbO:0 to 8%,Where R.sub.2 O represents at least one of Na.sub.2 O, K.sub.2 O and Li.sub.2 O, the maximum content of Li.sub.O being 5%; and R'O represents at least one of MgO,CaO,SrO and BaO, within the following individual limits: MgO: 0 to 4%, CaO: 0 to 6.5%, SrO: 0 to 10%, BaO: 0 to 21%; the amount of SiO.sub.2 is not less than 16% when the B.sub.2 O.sub.3 content is less than 8%; and the silver content of the glass, expressed as Ag.sub.2 O, is not less than 0.05% by weight.Such glasses in which Al.sub.2 O.sub.3 is the largest constituent are preferred for ophthalmic purposes, but it is also possible for either B.sub.2 O.sub.3 or P.sub.2 O.sub.
    Type: Grant
    Filed: September 21, 1977
    Date of Patent: May 30, 1978
    Assignee: Pilkington Brothers Limited
    Inventors: Edric Ellis, Richard Gelder, Allan Hale