| 摘要 |
A rotary mine drilling bit (10) for making blast holes having a connection (20) at one end (16) of the body (12) for attachment to a drill string and t he second end (18) of the body (12) having a plurality of longitudinally extending slots (22). A thrust shoulder (24) is provided between the ends (1 6 and 18) of the body (12) and longitudinally extending supporting legs (26) a re positioned in each of the slots (22) and are releasably connected to the bod y (12). One end of the supporting legs (26) are positioned the adjacent the shoulders (28) for receiving longitudinal thrust and for avoiding thrust on the connecting means (28). A roller bit (34) is connected to the end of each supporting leg (26).
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