Patents by Inventor William J. Smurthwaite, Jr.

William J. Smurthwaite, Jr. 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).

  • Patent number: 7520519
    Abstract: A wheelchair includes a standard foldable frame for supporting a seat with a first and second drive wheel driven by drive levers. Each wheel has a transmission providing for three forward speeds and a reverse speed, as well as a neutral position. The transmissions for the two wheels may be constructed of identical parts with the wheels being caused to rotate in opposite directions from the driving lever merely by reversing the direction of the pawls within the transmissions. The ratchet drive surfaces are provided with pawl engaging surfaces which may be driven in either of two directions. The wheelchair does not require any bulky equipment and the hub containing the transmission may be the size of a bicycle hub. The transmissions in both wheels are shifted by a single control. The wheelchair is provided with disk brakes.
    Type: Grant
    Filed: April 10, 2007
    Date of Patent: April 21, 2009
    Inventor: William J. Smurthwaite, Jr.