Patents Assigned to Cookson Metaux Precieux SA
  • 18 carat grey gold alloy, without nickel and without palladium, for jewellery
    Patent number: 6576187
    Abstract: The invention relates to a novel grey gold alloy essentially without whitening element such as nickel, palladium and cobalt, characterized in that it contains in addition to the gold, copper, silver and manganese, according to the following proportions in percentages by weight, of: gold 75-78  silver 1-10 manganese  7-15; and remainder of copper to 100. This alloy is particularly advantageous for manufacturing jewels, notably by the disposable wax casting technique.
    Type: Grant
    Filed: October 2, 2001
    Date of Patent: June 10, 2003
    Assignee: Cookson Metaux Precieux SA
    Inventors: Laurent Ribault, Annie LeMarchand