Patents by Inventor John Michael Bradshaw

John Michael Bradshaw has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Chemically toughened glasses
    Patent number: 6518211
    Abstract: A glass composition capable of being chemically strengthened by ion-exchange within 100 hours to provide a glass with a surface compressive stress of greater then 400 MPa and an ion-exchange depth greater then 200 microns comprising: SiO2 58% to 70% (by weight), Al2O3 5% to 15%, Na2O 12% to 18%, K2O 0.1% to 5%, MgO 4% to 10%, CaO 0% to 1% with the provisos that the total of the Al2O3 and MgO is in excess of 13%, the total of the amounts of Al2O3 plus MgO divided by the amount of K2O is at least 3 and that the sum of the amounts of Na2O, K2O and MgO is at least 22%.
    Type: Grant
    Filed: September 14, 2000
    Date of Patent: February 11, 2003
    Assignee: Pilkington, PLC
    Inventors: John Michael Bradshaw, Ian Heaton Smith, Ashley Carl Torr, Stanley Lythgoe