| 摘要 |
942,659. Percussive tools. SALZGITTER MASCHINEN A.G. Feb. 29, 1960 [March 11, 1959], No. 6965/60. Heading B4C. A boring device comprises a frame having a carriage on which a boring tool is mounted for vertical movement and having a fixed point for the attachment of a supporting cable, guide means for the supporting cable disposed between the fixed point and the lower end of the frame and about which the cable is reversed in direction, and actuating means on the frame to move the cable guide closer to and away from the fixed point whereby the boring device is moved upwardly or downwardly on the cable. As shown, a frame 1 has a boring tool 3 mounted on a carriage 2 and is supported by a cable 6 fixed to a point 9 and passing over a pulley 10 mounted on an hydraulic jack 11. In the retracted position of the jack the frame is clear of the shaft bottom and in the extended position a serrated point rests on the shaft bottom. A pair of radially extending arms may be provided to form a tripod support, Fig. 2 (not shown), and the frame may be adjustably supported from a central point to allow drilling at different radii, Fig. 5 (not shown). |
