Patents by Inventor Richard F. Porterfield

Richard F. Porterfield 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: 5051555
    Abstract: Compensation is made for inherent lateral shifting of portions of a pivoted working surface along a work surface, when the pivot point of the working surface is maintained on a line of feed into contact with said work surface, during relative pivoting of said working surface into conformity with said work surface. The working surface is supported by a quadrilateral linkage system having a remote instantaneous center point which, during pivoting of the working surface, is maintained substantially on a quiescent centerline of the linkage system. By spacing the pivot point of the working surface from this center point along the centerline, the pivot point is caused to move laterally of the centerline during exercising of the linkage system. The distance and direction of spacing the pivot point from the center point is selectable so as to cancel the inherent lateral shifting referred above.
    Type: Grant
    Filed: February 26, 1990
    Date of Patent: September 24, 1991
    Assignee: Universal Instruments Corporation
    Inventors: Richard F. Porterfield, Thomas M. Alunni, Frank Ksionzyk, Michael D. Snyder
  • Patent number: 4887351
    Abstract: The present device is directed to a nozzle tip for the head of a pick and place device for arranging electronic components as desired on a substrate. The tip permits both first and second vacuum areas to be selectively generated, thus facilitating the pick-up of components of widely varying sizes and shapes with a single tip.
    Type: Grant
    Filed: September 9, 1988
    Date of Patent: December 19, 1989
    Assignee: Universal Instruments Corporation
    Inventors: Richard F. Porterfield, Douglas A. Biesecker
  • Patent number: 4140407
    Abstract: A ribbon feed mechanism for a typewriter has a linkage for incrementally feeding a ribbon, a power roll rotated by a motor and a control member actuated by a printing mechanism for connecting the power roll to the linkage to incrementally feed the ribbon. The control member is also actuated by a carriage shift mechanism when shifting a carriage from an upper case position to a lower case position for connecting the power roll to the linkage to incrementally feed the ribbon.
    Type: Grant
    Filed: August 18, 1977
    Date of Patent: February 20, 1979
    Assignee: SCM Corporation
    Inventors: Richard F. Porterfield, Richard E. Shattuck
  • Patent number: 4131374
    Abstract: A ribbon feed mechanism for typewriters operable to incrementally feed a ribbon with a dual segment continuous motion ribbon feed. The ribbon is advanced an initial segment by a power actuated linkage and advanced a final segment by a spring urged arm acting on a multi-toothed cam. The initial segment feed occurs when a bellcrank is pivoted, and through a linkage, urges a ribbon metering shaft to rotate which, in turn, feeds the ribbon. Simultaneously, a spring biased cam follower is gradually displaced by the multi-toothed cam which is supported on the metering shaft. The final segment feed occurs as the spring biased cam follower is rapidly displaced down a cam surface of a tooth on the multi-toothed cam.
    Type: Grant
    Filed: August 18, 1977
    Date of Patent: December 26, 1978
    Assignee: SCM Corporation
    Inventor: Richard F. Porterfield