Mine roadway support stilt

A mine roadway support stilt for use with an I-beam joist support, said roadway experiencing lateral strata movement, which comprises:

• a hollow steel tube of generally rectangular section dimensioned to permit the longitudinal insertion therein of said joist support;
• a plurality of longitudinally inwardly extending indentations on two opposing faces of said tube, said indentations being deformed by said joist as said joist is forced downwardly into said tube by external force, said longitudinally extending indentations extending from the bottom of said tube to within a predetermined distance from the top of said tube thereby to provide overlap between said tube and said inserted joist support so as to provide sufficient rigidity therebetween to prevent lateral displacement of said stilt or said joist support before deformation of said longitudinally extending indentations commences, and the upper end of each longitudinally extending indentation sloping inwardly at a gradual angle of from 31/4 to 5 degrees from the vertical to cause the initial deformation of said indentations to be smooth and positive;
• means for inhibiting the improper insertion of said joist support within said tube including at least one medial, inwardly extending, indentation formed at the upper end of each of the two remaining opposing faces of said tube;
• and
• a rectangular base plate mounted to the bottom of said tube, the leading edge of said plate for projecting into the mine roadway being bent upwardly through an acute angle to form a lip thereby to prevent lateral displacement of said stilt and the opposite edge of said plate being extended backwards and under the body of said plate to form a raised heel thereby to cause said plate to slope at a predetermined angle relative to the horizontal mine roadway floor on which it stands thereby resisting said lateral strata movement.