Patents Represented by Law Firm Feterstonhaugh & Co.
  • Apparatus for servicing gas lines
    Patent number: 4497332
    Abstract: An apparatus and method for working on a section of gas main while it is in service comprising a work chamber formable around a section of the gas main and having means for admitting a tool thereto in a manner that it can be manipulated from outside the work chamber; means for removing the tool from the work chamber while maintaining the work chamber under gas pressure and means for safely evacuating the work chamber of gas.
    Type: Grant
    Filed: February 24, 1984
    Date of Patent: February 5, 1985
    Assignee: Union Gas Limited
    Inventors: John S. Sewell, Frederick A. McColl, Peter M. Petkoff