论文部分内容阅读
我队以前曾发生过几次提引钩掉下伤人事故,为克服这一弊病,我们用双切口废钻杆锁接头(65或57大接手),将一端打扁,再在打扁处开一个40毫米的
In order to overcome this problem, we used a double-cut, spent drill stem lock joint (65 or 57 large receivers) to flatten one end and hit the flat end. Open a 40 mm