| 摘要 |
<p>Stemming apparatus which includes a member, a propellant charge and an initiator for igniting the propellant charge. Stemming (32) is placed into the hole (10) from the rock face (14) covering the cartridge to a desired extent. The stemming is consolidated by being tamped in position. A member (34), which is made from a plastics materials such as polypropylene, is then placed over the stemming (32). The member has a conical leading end (36) which faces downwardly into the stemming and, in this example, has a substantially planar trailing end (38) which faces upwardly. The maximum diameter of the member (34) is slightly less than the nominal diameter of the hole (10). A propellant charge (40) is placed on the member or, preferably, is incorporated in the member under factory conditions. An initiator or igniter (42) is engaged with the propellant charge. Control leads (44) lead from the initiator to the control unit which is used for firing the initiator (28).</p> |
