Expansion shell with swaged connecting strap

Claim 1

AN EXPANSION SHELL FOR MINE ROOF SUPPORT AND THE LIKE COMPRISING TWO LIKE SHELL SEGMENTS OF MALLEABLE IRON, EACH OF SAID SHELL SEGMENTS HAVING EXTERNAL ARCUATE GRIPPING TEETH AND INTERNAL WEDGING SURFACES, AND BEING THICKER AT ONE END THAN THE OTHER, AND EACH OF SAID SHELL SEGMENTS HAVING A FLAT BOTTOM DOVETAIL SHAPED RECESS IN ITS OUTER SURFACE AT THE SAID OTHER END, AND A U SHAPED STRAP COMPRISING AN ELONGATE STRIP OF RESILIENT SHEET METAL OF UNIFORM SECTION IN ITS CENTRAL PORTION, AND HAVING A SWAGED DOVETAIL CONFIGURATION AT ITS OPPOSITE ENDS COMPLEMENTAL TO THE RECESSES OF SAID SEGMENTS, AND SEATED THEREIN, SAID DOVETAIL ENDS BEING OF WIDENING CHANNEL SECTION CONFIGURATION WITH A SUBSTANTIALLY TRIANGULAR WEB AND DIVERGING SIDE FLANGES, THE WEB PORTIONS BEING SEATED AGAINST THE FLAT BOTTOM OF THE RESPECTIVE SAID RECESSES, AND INTEGRAL FINGERS INTEGRAL WITH SAID SHELL SEGMENTS DISPOSED ON THE OPPOSITE SIDES OF EACH OF SAID RECESSES, SAID FINGERS BEING FORMED OVER THE RESPECTIVE SIDE FLANGES OF SAID CHANNEL SECTION DOVETAILED ENDS WHEREBY TO PROVIDE A SECURE CONNECTION BETWEEN THE STRAP ENDS AND THE SHELL SEGMENTS.