发明授权
US3907367A Coal breaker combined with longwall drum 失效
断路器与长壁鼓组合

Coal breaker combined with longwall drum
摘要:
A coal cutting machine having a cutting roll and breaking roll installed on a swingable supporting arm. The cutting roll cuts into the face of the coal vein while the breaking roll acts like a mace to smash large unwielding chunks of coal.
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