Patents Represented by Attorney John C. Black
  • Patent number: 3987883
    Abstract: An improved mechanism is provided for preventing long-term oil contamination of the print ribbon in a wire matrix printer. In the event that the print ribbon has an excess of oil thereon, it will cause the printed characters to be alternatively too light or too dark thereby reducing the print quality on the document. The print head of the wire matrix printer is operated to an idle or at rest position when printing is not being effected, a camming mechanism retracts the print head away from the platen and document. When this occurs, a stationary member on the printer carriage engages the ribbon and moves it away from contact with the print head in the vicinity of the apertures through which the print wires are guided for printing. With the ribbon moved away from the apertures, the lubricant oils on the print wires do not flow on to the ribbon. The retracting of the print head away from the platen and document by the camming mechanism also permits the easy insertion of new forms into the printer.
    Type: Grant
    Filed: April 17, 1975
    Date of Patent: October 26, 1976
    Assignee: International Business Machines Corporation
    Inventors: Daniel P. Darwin, Donald K. Rex
  • Patent number: D244464
    Type: Grant
    Filed: April 19, 1976
    Date of Patent: May 24, 1977
    Assignee: International Business Machines Corporation
    Inventor: Myron Fulenwider Davis, Jr.