초록 ▼

A stemming plug constructed from a durable, resilient material and comprising a circumferential wall defining an inner cavity, an end wall at the first end and an open second end. In the preferred embodiment, the circumferential wall is fluted so that it can easily compress and seat in a borehole wh

A stemming plug constructed from a durable, resilient material and comprising a circumferential wall defining an inner cavity, an end wall at the first end and an open second end. In the preferred embodiment, the circumferential wall is fluted so that it can easily compress and seat in a borehole while maintaining a snug friction fit. The plug is inserted in the borehole over the explosive charge. Stemming material, preferably rock, is placed on top of the plug. The stemming material covers the top and slides down around the circumferential wall and is lodged between the circumferential wall and the borehole. Upon explosion, the blast energy is forced into the inner cavity causing the circumferential wall to expand outwardly and thereby engaging the stemming material and the borehole wall to secure the plug in place. The stemming material can also be placed inside the plug, with blast energy inverting the plug end wall to wedge stemming material within the borehole.

대표청구항 ▼

[ We claim:] [1.] An integral one piece stemming plug for introduction into a blasting borehole comprising:a substantially cylindrical body having a first end and a second end, said cylindrical body including a circumferential wall defining an inner cavity;said cylindrical body having a diameter gre

[ We claim:] [1.] An integral one piece stemming plug for introduction into a blasting borehole comprising:a substantially cylindrical body having a first end and a second end, said cylindrical body including a circumferential wall defining an inner cavity;said cylindrical body having a diameter greater than the diameter of any borehole into which it locates;a wall across said first end;said cylindrical body and wall being impervious and forming a seal in the borehole when a charge is exploded;said circumferential wall being formed of a resilient, flexible material so that when an explosive charge is set below said plug, the explosive force entering said inner cavity causes the circumferential wall to expand against the borehole thereby securing the plug within the borehole.