Patents by Inventor David A. Cockeram

David A. Cockeram 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: 4720974
    Abstract: A servo-mechanism includes a piston and cylinder unit controlled by a valve coupled in known manner by a linkage means to a movable control element to provide closed loop servo operation to position the piston and cylinder unit piston rod according to the position of the movable element. The movable element is fast with an annular gear segment of an epicyclic gear mechanism of which the sun gear forms a main control input and the planet pinion carrier forms an override input. The mechanism is of utility in an hydraulic transmission of the variable stroke pump/fixed stroke motor type, the overrride input being actuable by a pump port pressure limit sensor.
    Type: Grant
    Filed: May 26, 1987
    Date of Patent: January 26, 1988
    Assignee: Commercial Hydraulics Gloucester Ltd.
    Inventor: David A. Cockeram