Patents by Inventor Roy C. Johnston

Roy C. 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: 4246979
    Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having internal sleeve and shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle engages an internal sleeve having ports that momentarily align with exhaust ports and then moves past, sealing off the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. By preventing further discharge of air with little or no loss in acoustic output, pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.
    Type: Grant
    Filed: April 5, 1979
    Date of Patent: January 27, 1981
    Assignee: Texas Instruments Incorporated
    Inventors: John T. Thomson, Roy C. Johnston
  • Patent number: 4225009
    Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is controlled by valve means for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. By preventing further discharge of air, with little or no loss in acoustic output, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.
    Type: Grant
    Filed: April 4, 1979
    Date of Patent: September 30, 1980
    Assignee: Texas Instruments Incorporated
    Inventors: Earnest R. Harrison, Roy C. Johnston
  • Patent number: 4219097
    Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle and external sliding valve control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is controlled by air pressure to move it upward, thereby permitting compressed air in the firing chamber to exhaust through exhaust ports. The external sliding valve had been held in a downward position by air pressure supplied from the firing chamber, compressing a spring. As the firing chamber pressure drops, the compressed spring expands, forcing the sliding valve to move upward, closing the exhaust ports. By preventing further discharge of air, secondary pulses are greatly reduced, with little or no loss in acoustic output, thereby enhancing the operation of the entire system. Further, by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.
    Type: Grant
    Filed: April 4, 1979
    Date of Patent: August 26, 1980
    Assignee: Texas Instruments Incorporated
    Inventors: Earnest R. Harrison, Roy C. Johnston
  • Patent number: 4219098
    Abstract: Disclosed is a seismic source device, known in the industry as an air gun, having shuttle control for allowing a predetermined discharge of compressed air into water for purposes of seismic exploration. The shuttle is indirectly controlled by a moveable plate for closing the exhaust ports before all of the compressed air in the firing chamber of the air gun is exhausted. In one embodiment, the plate is freely moveable; in a second embodiment, the plate is attached to the shuttle. By preventing further discharge of air, with little or no loss in acoustic output, secondary pulses are greatly reduced, thereby enhancing the operation of the entire system. Further by preventing all the air in the firing chamber from being discharged, the system becomes more efficient and more cost effective.
    Type: Grant
    Filed: April 5, 1979
    Date of Patent: August 26, 1980
    Assignee: Texas Instruments Incorporated
    Inventors: John T Thomson, Roy C. Johnston