Patents Assigned to Sphinzwerke Muller AG
  • Spiral drill
    Patent number: 4913603
    Abstract: A two-flute drill bit includes two drill webs each provided with a cutting lip. The cutting lips are unequally angularly spaced from each other and the smaller one of two pitch angles included between two cutting lips is preferably 160.degree.. One of the webs has two peripheral margin lands spaced from each other whereby a three-point guidance of the drill bit is obtained.
    Type: Grant
    Filed: July 18, 1988
    Date of Patent: April 3, 1990
    Assignee: Sphinzwerke Muller AG
    Inventors: Paul Friedli, Georges Petignat, Jean-Marc Salomon