No. 78-2392. Argued September 4, 1979. Decided October 11, 1979. John S. Irving, Gen. Counsel, John E. Higgins, Jr., Deputy Gen. Counsel, Robert E. Allen, Acting Associate Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel, Marjorie S. Gofreed, Sandra K. Williams (argued), Attys., N.L.R.B., Washington, D.C., for petitioner. George F. Lynch (argued), Stephen D. Bolerjack, Squire, Sanders Dempsey, Cleveland, Ohio, for respondent, Copes-Vulcan, Inc.; Terrence F. Srsen, Corporate Industrial Relations