No. 75-1670. Argued March 9, 1976. Decided April 7, 1976. Matthew J. Broderick and Gregory D. Keeney, Dechert Price Rhoads, Philadelphia, Pa., for petitioner. John S. Irving, Gen. Counsel, Elliott Moore, Deputy Associate Gen. Counsel, John Ferguson and Alfred Norek, Attys., N.L.R.B., Washington, D.C., for respondent. Robert Z. Lewis, Frank J. Donner, and James G. Mauro, Jr., New York City, for intervenor. Before KALODNER, VAN DUSEN and WEIS, Circuit Judges. OPINION OF THE COURT VAN DUSEN, Circuit