Patents by Inventor Philip Arthur Gifford

Philip Arthur Gifford 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).

  • Adjustable grating pain rock sifter
    Patent number: 6041943
    Abstract: A sorting apparatus includes a first grating of spaced parallel bars and a second grating of spaced parallel bars positioned parallel to the first grating. Relative lateral movement of the first grating and the second grating alters the lateral spacing between the parallel bars of the first grating in relation to the parallel bars of the second grating. This enables rocks to be sorted into three piles; a first pile of rocks that will pass through when openings in the first grating and second grating are out of register, a second pile of rocks that will pass through only when openings in the first grating and second grating are in register, and a third pile of rocks that will not pass through.
    Type: Grant
    Filed: August 5, 1998
    Date of Patent: March 28, 2000
    Assignee: Samuel Lenko
    Inventor: Philip Arthur Gifford