为确保松散粉状矿层取心和有效的捞取裂隙、溶洞中泥砂状充填物,我们加工了一种双活瓣钻头(见附图)
朱朝森,钟光辉.双活瓣钻头[J].钻探工程,1983,(3):59.. [J]. Drilling Engineering, 1983,(3):59.