Patents by Inventor David D. MacKenzie

David D. MacKenzie 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).

  • Book support assembly
    Patent number: 4463854
    Abstract: A book support assembly comprises a system of adjustable bookends including two end members connected together by a relaxed cord which cord is adjustable in length by use of a manually operated mechanical windlass device. The book support assembly is convertable from bookends to a lectern.
    Type: Grant
    Filed: January 17, 1983
    Date of Patent: August 7, 1984
    Inventor: David D. MacKenzie