No. 82-2160. Submitted June 14, 1983. Decided July 11, 1983. William A. Lubbers, Gen. Counsel, John E. Higgins, Jr., Deputy Gen. Counsel, Robert E. Allen, Associate Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel, John P. Coyle, Atty., N.L.R.B., Washington, D.C., for respondent. Felhaber, Larson, Fenlon Vogt, P.A., James M. Dawson, Minneapolis, Minn., for petitioner. Petition for review from the National Labor Relations Board. Before HEANEY, Circuit Judge, and FLOYD R. GIBSON, and HENLEY