Patents by Inventor John David Marsha

John David Marsha 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).

  • Infinitely variable gear transmission with parallel hydraulic ratio control
    Patent number: 7588509
    Abstract: Two parallel planetary gear sets with a common sun gear output are geared to a hydraulic pump and motor system. Input is applied to both planetary gear sets in parallel. Output is from both planetary gear sets in parallel. Two planetary gear set members, one in each set, are geared to the pump and motor and are used to control the ratio of the infinitely variable gear transmission (IVGT). The displacement ratio of the pump and motor, connected to these two members, controls the ratio of the IVGT.
    Type: Grant
    Filed: March 12, 2007
    Date of Patent: September 15, 2009
    Inventor: John David Marsha