Patents by Inventor Harold J. Robertson

Harold J. Robertson 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: 4916988
    Abstract: A ratchet screwdriver contains a magnetic clutch assembly which is accessible by external switching means. The switching means can alternately switch the clutch assembly from a first position to a second position and vice-versa. When the clutch assembly is in the first position the handle will be in a fixed relationship with the shaft and head when the handle is turned in a clockwise direction but will rotate relative to the shaft and head when the handle is turned in a counterclockwise direction. ALternatively, when the clutch assembly is in the second position, the handle will be in a fixed position relative to the shaft and head when the handle is turned in a counterclockwise direction but will rotate relative to the shaft and head when the handle is turned in a clockwise direction. Previous ratchet drivers do not operate smoothly or they are much too complex.
    Type: Grant
    Filed: December 20, 1988
    Date of Patent: April 17, 1990
    Assignee: The George Cluthe Manufacturing Company Limited
    Inventors: Harold J. Robertson, Richard D. Cluthe