• 

  Berger Lahr (Schneider Electric)

• 

  Bohle

• 

  Hellermann Tyton

• 

  Kübler

• 

  Leybold

• 

  Moeller (Eaton)

• 

  Penny & Giles (now Curtiss-Wright)

• 

  Viledon

• 

  Allen Bradley

• 

  Blickle