| 摘要 |
FIELD: drilling equipment. SUBSTANCE: improved drilling device is operated with the use of liquid for driving of reciprocating piston hammer with respective percussive surfaces of hammer and drill. Drill bit has groove in form of ring whose axis coincides with central axis of drill bit. Hammer surface has projection in form of ring whose axis coincides with central axis of drill bit. Width and location of projection ensures possibility of its full accommodation in drill bit groove with indicated surfaces being in position of impact. EFFECT: higher efficiency. 13 cl, 4 dwg |
