Patents by Inventor Trevor W. Shaw

Trevor W. Shaw 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).

  • Arc monitor for electrical discharge machining
    Patent number: 4322595
    Abstract: Apparatus for monitoring EDM is described in which the voltage across the gap between an electrode and a workpiece is passed through a filter which selects those frequencies which are present only during sparking across the gap. The voltage across the gap is also applied to a comparator which detects discharge across the gap by determining whether the gap voltage is between two levels. The proportion of discharge time in which arcs occur is derived by a time-divider circuit which receives signals after processing from the filter and the comparator.
    Type: Grant
    Filed: July 29, 1980
    Date of Patent: March 30, 1982
    Assignee: National Research Development Corporation
    Inventors: Alan Fowell, Trevor W. Shaw, John R. Crookall