During drilling, the drill bit is with drawn inside the DTH and pressed against the drive chuck.The piston strikes directly against impact surface of the shank of the bit.是什么意思_During drilling, the drill bit is with drawn inside the DTH and pressed against the drive chuck.The piston strikes directly against impact surface of the shank of the bit.在線(xiàn)翻譯_英語(yǔ)_讀音_用法_例句