John A. Campbell

Person

  • Minneapolis, MN, US

Patents Grantslast 30 patents

  • Information Patent Grant

    Muffler assembly and method of manufacture

    • Patent number 4,969,537
    • Issue date Nov 13, 1990
    • Donaldson Company, Inc.
    • Wayne M. Wagner
    • F01 - MACHINES OR ENGINES IN GENERAL ENGINE PLANTS IN GENERAL STEAM ENGINES
  • Information Patent Grant

    Exhaust system and muffler lap joint

    • Patent number 4,113,289
    • Issue date Sep 12, 1978
    • Donaldson Company, Inc.
    • Wayne M. Wagner
    • F01 - MACHINES OR ENGINES IN GENERAL ENGINE PLANTS IN GENERAL STEAM ENGINES