Patents by Inventor Walter S. Christopher

Walter S. Christopher 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: 4617813
    Abstract: A picking tool adapted to open a cylinder lock of the axial pin tumbler type having its tumblers arranged in a coplanar configuration, includes a planar torquing core insertable into the lock keyway in a longitudinal direction, a plurality of longitudinal guideway channels formed on opposing faces of the core, and respective tumbler probes longitudinally reciprocable in the channels. A holder, which acts as a handle for manipulating the picking tool, also serves as a housing surrounding the core and the probes. The holder is formed with a pair of radial openings in opposite sides thereof which receive respective brake segments for exerting a frictional drag on the probes. An adjustable hoop clamp surrounds the brake segments for manually adjusting the frictional drag, so that the proper tumbler displacement action can be achieved. Setscrews are threaded into the body of the holder for clamping the probes in their final tumbler-displacing positions.
    Type: Grant
    Filed: July 29, 1982
    Date of Patent: October 21, 1986
    Assignee: Chicago Lock Co.
    Inventors: Walter S. Christopher, Robert T. Kriskovich, Robert L. Steinbach
  • Patent number: 4075879
    Abstract: A plate tumbler-type cylinder lock mechanism includes a plurality of longitudinal internal splines therearound adapted for receiving tumbler ends, means providing at least three internal circumferentially extending tumbler movement paths on the barrel and extending between one spline and another spline which is different for each path, a key plug assembly rotatable in the barrel and including a key plug and a plurality of spring-pressed plate tumblers mounted in the plug, the tumblers being mounted for reciprocal transverse movement upon insertion and withdrawal of a bitted key with opposite tumbler ends projecting alternately from opposite sides of the plug, certain tumblers being adapted to be projected outwardly with their ends in respective registering movement paths when a key is inserted, whereby such ends may travel in the movement paths when the plug is rotated, and means adjacent to at least one end of each movement path adapted for engagement with the tumbler end traveling in the path to prevent tra
    Type: Grant
    Filed: June 22, 1977
    Date of Patent: February 28, 1978
    Assignee: Chicago Lock Co.
    Inventor: Walter S. Christopher
  • Patent number: 4019353
    Abstract: A key-operated keeper lock for a slide fastener includes an outer tubular barrel, an anvil projecting radially from the barrel and adapted for supporting a fastener lacing element thereon, a tubular handle rotatable in the barrel, means securing the handle against substantial axial movement relative to the barrel, a keeper arm fixed to and projecting radially from the handle for rotation therewith and adapted to overlie the anvil and a fastener lacing element thereon for retaining the lacing element between the keeper arm and the anvil to prevent operation of the fastener, a lock cylinder rotatable in the handle, tumbler means movable between the lock cylinder and the handle for alternately preventing and enabling rotation of the lock cylinder relative to the handle, a lock bolt mounted in the handle and movable when the keeper arm overlies the anvil between a position locking the handle to the barrel and an unlocking position freeing the barrel for rotation, and means coupling the lock cylinder and the lock
    Type: Grant
    Filed: May 15, 1975
    Date of Patent: April 26, 1977
    Assignee: Chicago Lock Co.
    Inventor: Walter S. Christopher