| 摘要 |
<p>A prop, for example for supporting the roof of an underground mine, is provided in the form of a vessel. The vessel includes a base having a bottom and one or more sides. A cover, including a top and one or more sides is provided. The top includes a space for accommodating a roof bolt when installed in a mine. Sides of the cover and of the base overlap each other to a maximal extent in a collapsed configuration. A port is formed in the one or more sides for filling the vessel with material when the sides of the cover and of the base overlap each other to a minimal extent in an extended configuration. Consequently the prop is able to go from a collapsed configuration for transportation or storage, to an extended configuration for supporting the roof of the mine. The top of the vessel may comprise a flexible envelope fast with the one or more sides of the cover for receiving the filling, in order to present a deformable upper surface for bearing an uneven load.</p> |
