Patents by Inventor Robert F. Johnston

Robert F. Johnston 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: 4668272
    Abstract: A rotary heating apparatus, for example, for liquefying glass batch or the like, is provided with dynamic stability by isolating structural support elements from vessel elements that are subject to thermal distortion and by supporting the vessel so as to be self-centering. The preferred embodiment entails a support ring separate from the vessel, rotatably supported at an elevation above the center of gravity of the vessel, and attached to a lower portion of the vessel by way of a plurality of link rods. Horizontal force is applied to the support ring to damp oscillations of the vessel. Rotation of the ring may be on a conical track to aid self-centering.
    Type: Grant
    Filed: January 2, 1986
    Date of Patent: May 26, 1987
    Assignee: PPG Industries, Inc.
    Inventors: George C. Newcamp, Robert F. Johnston, Jr., John F. McConnell, Paul R. Ross, Jr., Richard A. Caripolti, John W. Peter
  • Patent number: 4459475
    Abstract: A method and system for automatically calibrating a D.C. transducer are described in the environment of an illustrative film retrieval system. In this system, the output of a transducer such as a light sensor is amplified and the amplified output is compared to upper and lower limits within which it is desired to hold the transducer's amplified output. When either of the limits is exceeded, the amplification of the transducer's output is varied so as to shift its average value to a value which is between the upper and lower limits.
    Type: Grant
    Filed: March 29, 1982
    Date of Patent: July 10, 1984
    Assignee: Bell & Howell Company
    Inventors: John R. Flint, Robert F. Johnston
  • Patent number: 4448364
    Abstract: A web drive system for automatically reversing the direction of travel of the web when the end of the web is reached. A reversible electric motor provides power to either the supply or take up spindles. An end of the web is affixed to each of the spindles so that either spindle can be provided with power to draw the web from the other spindle. A planetary gear system provides power to whichever spindle acts as the take up spindle until the end of the web is sensed. The motor is then reversed and the planetary gear then provides power to the other spindle, which was previously the supply spindle.
    Type: Grant
    Filed: April 9, 1982
    Date of Patent: May 15, 1984
    Assignee: Bell & Howell Company
    Inventors: Richard Frystak, Robert F. Johnston, John R. Flint
  • Patent number: 4120573
    Abstract: A microfiche reader stores a library file of microfiche in a cartridge which may be inserted into the reader, so that it is not necessary to manually manipulate the individual microfiche. The reader automatically extracts and feeds a selected microfiche from a cartridge and then returns it to the vacated cartridge location. A right angle rack and pinion causes the extractor mechanism to provide an automatic feed mechanism which moves over a horizontal advance, raise, drop and back path so that hooks may be removed from and then returned into notches in a microfiche carrier, without damaging them. An automatic elevator mechanism positions the cartridge so that any selected microfiche may be placed on display.
    Type: Grant
    Filed: June 28, 1976
    Date of Patent: October 17, 1978
    Assignee: Bell & Howell Company
    Inventors: Robert F. Johnston, Thomas R. Wells
  • Patent number: 4032934
    Abstract: This invention relates to photographic apparatus having means for automatically moving a lens along an axis for properly focusing on an object. The apparatus includes a light emitter for transmitting a train of light signals toward the object at a constant angle relative to the axis, and a pair of movable photoreceptors disposed in spaced relationship with the emitter in the apparatus. The photoreceptors are adapted to receive the light signals upon reflection thereof from the object, and are further adapted to produce electrical signals corresponding to the amount of light received. An operational amplifier is adapted to receive the electrical signals produced by the photoreceptors, and produce a difference signal corresponding to the difference in strength of the electrical signals.
    Type: Grant
    Filed: December 26, 1974
    Date of Patent: June 28, 1977
    Inventors: Kenneth L. Hendrickson, Robert F. Johnston
  • Patent number: 3984846
    Abstract: A photographic apparatus having a lens movable along an axis for automatically focusing an object to be photographed is disclosed. The apparatus includes a rotatable sleeve controlled by electrical signals produced by photoreceptor means adapted to receive light emitted by the apparatus and reflected from the object. The sleeve effectuates the movement of the lens along an axis to bring the object into focus. The apparatus further includes assembly means, carrying the photoreceptor means, pivotably secured to the sleeve for adjusting the light received by the photoreceptor means by an amount corresponding to the rotation of the sleeve, thereby changing the electrical signals to maintain the object in focus.
    Type: Grant
    Filed: January 2, 1975
    Date of Patent: October 5, 1976
    Inventors: John A. Gallagher, Kenneth L. Hendrickson, Robert F. Johnston, John A. Thiel