1963年发生了全世界予以密切关注的莱恩特(Lengede)矿山大事故。该事故发生后为救援遇难者,钻了救护孔。自此以后,为改进救护钻机及设备进行了大量的工作。如今世界上一些主要采矿国家已使用有效设备从地面或在井下钻救护孔。在钻救护孔时,使人感到棘手的是冒落物中夹有木头或钢支护部件。至今,还没有一种具有足够能力的可钻通冒落物中木质或 In 1963 there was a major mine accident in Lengede that the world paid close attention to. After the accident to rescue the victims, drilled a rescue hole. Since then, a great deal of work has been done to improve ambulance rigs and equipment. Today some of the world’s major mining nations have used effective equipment to drill holes in the ground or downhole. When drilling holes, it is tricky to have clogged wood or steel retaining members in them. To date, there is no such kind of wood that has the ability to drill through