| 摘要 |
<p>Apparatus for plugging a hole, such as a bore hole used in blasting, comprises a platform shaped to fit within the hole and to support material such as explosives or stemming at a desired depth in the hole. The platform takes the form of a plate or tray which is generally ellipsoidal in shape so that it fits snugly within the hole when inclined transversely relative to a longitudinal axis of the hole. The plate has a central load support region and a peripheral region for engaging the wall of the hole. The apparatus includes a locking member, typically a length of rigid pipe, attached movably to the platform. The locking member is moveable between a first position in which it is supported clear of the wall of the hole below the platform, and a second position in which it spans the hole to lock the platform in position in the hole. An elongated actuating member in the form of a cord or line is connected to the locking member and platform for lowering the apparatus into the hole and for moving the locking member between its first and second positions.</p> |
