US3174698A US324333A US32433363A US3174698A US 3174698 A US3174698 A US 3174698A US 324333 A US324333 A US 324333A US 32433363 A US32433363 A US 32433363A US 3174698 A US3174698 A US 3174698A Authority US United States Prior art keywords breaker shaft housing cylindrical mounting Prior art date 1963-11-18 Legal status (The legal status is an assumption and is