By jaws, buckets, or scoops that scoop-out the mineral (E21C27/30)

E   Fixed constructions(159344)
E21C     ining or quarrying(17294)
E21C27/30                     By jaws, buckets, or scoops that scoop-out the mineral(31)

Tunnel shield // 2166088
The invention relates to underground construction
 
2551089.
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