Supporting framework for a mine gallery or shaft

Claim 1

MEANS FOR SUPPORTING OR LINING THE ROOF AND WALLS OF MINE GALLERIES, OR THE WALLS OF PITS, MINE SHAFTS OR LIKE EXCAVATIONS, COMPRISING A PLURALITY OF ELONGATED ELEMENTS WHICH ARE ARCHED LENGTHWISE AND OVERLAP PARTIALLY ONE ANOTHER LATERALLY ALONG THE LENGTH OF THE EXCAVATION, THE ELEMENTS BEING OF TWO KINDS OF WHICH A FIRST KIND ALTERNATES WITH A SECOND KIND ALONG THE LENGTH OF THE EXCAVATION, EACH OF SAID ELEMENTS EXTENDING OVER ONLY A PART OF THE CROSS-SECTION OF THE EXCAVATION, THE FIRST KIND OF ELEMENT PRESENTING A SUBSTANTIALLY FLAT OMEGA CHANNEL SECTION AS VIEWED FROM THE INTERIOR OF THE EXCAVATION AND THE SECOND KIND OF ELEMENT PRESENTING A SUBSTANTIALLY FLAT U CHANNEL SECTION FROM THE SAME POINT OF VIEW, THE TWO KINDS OF CHANNEL SECTION EACH HAVING OUTWARDLY INCLINED SIDE WALLS, A BASE ALONG THE MIDDLE OF WHICH IS FORMED A FLAT SHALLOW INWARDLY EXTENDING SALIENT BOUNDED BY TWO FLAT BOTTOMED GROOVES, AND A FLANGE WING FORMED ALONG THE FREE EDGE OF EACH SIDE WALL IN A PLANE SUBSTANTIALLY PARALLEL TO THE PLANES OF THE FLAT INWARD SALIENT AND OF THE FLAT BOTTOM F THE GROOVES, THE TWO KINDS OF ELEMENTS OVERLAPPING EACH OTHER AT ADJACENT SIDE WALLS BUT ONLY ALONG ONE END PORTION OF EACH ELEMENT, AND CONNECTING STIRRUPS COMPRISING AT LEAST A CLAMPING PIECE, A T-HEADED BOLT AND A TIGHTENING NUT, ONE SUCH STIRRUP BEING POSITIONED AT THE FREE END OF AN ELEMENT AND ENGAGED BOTH WITH SAID FREE END AND WITH THE LATERAL WINGS OF TWO ADJACENT ELEMENTS, AND THE STEM OF THE BOLT BEING POSITIONED AGAINST THE FREE EDGES OF THE SALIENT AT THE END OF AN ELEMENT.