【摘要】 从三个阶段介绍了１９４９年以来中国煤矿井下用安全钻机的研究发展情况，总结了每一阶段研究的特点，论述了今后的发展方向更多还原

【Abstract】 Abstract The history of research and development of safe drills used in underground coal mines in China from 1949 to now was divided into three stages.The features in each stage were concluded and the developing orientation in the future was pointed out in this paper.更多还原