Patents by Inventor William N. Schoeffler

William N. Schoeffler 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: 4030745
    Abstract: An outer tubular body member has a plurality of circumferentially spaced outwardly bowed spring fingers on its inner surface projecting downwardly to near the lower end of the body member and normally spaced apart. An inner tubular member is longitudinally movable in the body member and has a ring portion at its lower end surrounding the upper portions of the spring fingers and movable downwardly to cam the fingers inwardly to grasp a loose article in the well. Latching tongues on the spring fingers engage the ring when the fingers are cammed inwardly. In one form the body member is attachable to a drill string and the upper end of the inner member functions as a piston to be pushed downwardly by drilling mud from the drill string. In another form the inner member can be attached to the drill string and held in an upper position relative to the body member by shear pins which are severable by the weight of the drill string.
    Type: Grant
    Filed: June 16, 1976
    Date of Patent: June 21, 1977
    Inventors: William N. Schoeffler, Romona B. Schoeffler