| 摘要 |
According to the present invention, a drill rod ( 10 ) comprises an elongate hollow shaft ( 12 ) with a first shaft end and a second shaft end ( 22 ), the first shaft end having a first connector for connecting the drill rod ( 10 ) to a drive mechanism, the second shaft end ( 22 ) having a first female tread ( 24 ); and an adapter ( 30 ) with a first adapter end ( 32 ) and a second adapter end ( 34 ), the first adapter end ( 32 ) having a first male thread ( 42 ) cooperating with the first female tread ( 24 ) of the second shaft end ( 22 ), the second adapter end ( 34 ) having a second connector for connecting a drill bit ( 46 ) thereto. When a drill bit ( 46 ) is connected to the drill rod ( 10 ), the adapter ( 30 ) is sandwiched between the hollow shaft ( 12 ) and the drill bit ( 46 ). The above configuration of drill rod allows a great variety of drill bits to be used in conjunction with a single hollow shaft. There is hence no need to provide a different hollow shaft if a different drill bit is to be used. Manufacturing costs of drill rods do hence not have to be considerably-increased if a variety of drill bits are to be used.
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