Patents by Inventor John R. Cartwright

John R. Cartwright 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).

  • Methods for manufacturing magnetic transducing heads
    Patent number: 4249301
    Abstract: A method of forming a magnetic ferrite element for the core of a magnetic transducing head is disclosed in which spacers for determining the length of a non-magnetic gap are formed by providing a masking layer at locations on a surface of the element at which the spacers are required and eroding away the masking layer and the unmasked portions of the surface by an ion beam to produce a new surface having a spacer projecting at each of the locations by a distance determined by the relative rates of erosion of the ferrite and the masking material and by the predetermined thickness of the masking layer.
    Type: Grant
    Filed: August 10, 1979
    Date of Patent: February 10, 1981
    Assignee: Data Recording Instrument Company Limited
    Inventor: John R. Cartwright