Patents by Inventor John M. Christopher

John M. 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).

  • Caliper system
    Patent number: 4731931
    Abstract: An improved caliper apparatus comprises a host caliper including a jaw assembly having two opposing, flat reference edges for measuring edge-to-edge and point-to-point distances; and further includes removable, reference off-setting assemblies which are removably attached to the jaw elements of the host caliper; and which reference off-setting assemblies reposition the reference points of the caliper to provide hole-to-hole and edge-to-hole measurements while maintaining the integrity of the direct reading off the caliper scale.
    Type: Grant
    Filed: March 16, 1987
    Date of Patent: March 22, 1988
    Assignee: Andromeda Technology, Inc.
    Inventors: John D. Goodman, John M. Christopher