In Murphy Diesel Co. v. NLRB, 454 F.2d 303 (7th Cir. 1971), the court emphasized that the "right to impose work rules and discipline" was not a part of the contract or the negotiations leading to it.
In National Labor Relations Board v. John S. Swift Co., 277 F.2d 641; National Labor Relations Board v. Knight Morley Corp., 251 F.2d 753; National Labor Relations Board v. Southern Silk Mills, 209 F.2d 155; National Labor Relations Board v. J.I. Case Co., 198 F.2d 919.