US830586A Coalcutting machine. Google Patents
By this construction the rotational mechanism is simplified, and I am enabled, as will be seen in Fig. 4, to bring the axis of the drilllcylinder as as close as practicable to the column or offset stud. ... Coalcutting machine. Country Status (1) Country Link; US (1) US830586A (en) Cited By (2) * Cited by examiner, † Cited by third party ...