Patents by Inventor David Ian Kershaw

David Ian Kershaw 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).

  • Screws and threadforms
    Patent number: 6371709
    Abstract: A screw thread having a threadform including a ridge rising from root to crest with the crest having two peaks, separated by a trough the depth of which is less than the height of the ridge from root to crest. It has particular use as a screw for timber, and is especially suited to fixing railway rails to sleepers.
    Type: Grant
    Filed: October 27, 2000
    Date of Patent: April 16, 2002
    Assignees: Hanstock Fasteners Pty Limited, Reid Construction Systems Pty Limited
    Inventors: Fotios Papafotiou, David Ian Kershaw