Thread coupling structure

Claim 1

A THREAD COUPLING STRUCTURE FORMED TO RECEIVE A BOLT HAVING A PREDETERMINED DIAMETER AND A HELICAL THREAD OF PREDETERMINED PITCH THEREON, SAID STRUCTURE BEING IN THE FORM OF AN ELONGATED MEMBER OF UNIFORM CROSS-SECTION THROUGHOUT THE LENGTH THEREOF AND EMBODYING TWO SPACED RIGID WALLS WITH PARALLEL EDGES, SAID WALLS HAVING AN OPEN SIDED SLOT THEREBETWEEN PRESENTING OPPOSED FACES SPACED APART A SUFFICIENT DISTANCE TO RECEIVE A BOLT OF SAID PREDETERMINED DIAMETER THEREBETWEEN, EACH OF SAID FACES BEING PROVIDED WITH A PLURALITY OF BOLTENGAGING RIBS EXTENDING LONGITUDINALLY OF THE SLOT PARALLEL TO SAID EDGES, THE BOLT-ENGAGING RIBS ADJACENT THE OPEN SIDE OF SAID SLOT AND ON SAID OPPOSED FACES OF THE SLOT BEING EQUALLY SPACED BOLT-GUIDING RIBS PRESENTING CRESTS LOCATED IN SUBSTANTIALLY PARALLEL PLANES AND ARRANGED IN INTERMEDIATE, STAGGERED AND COMPLEMENTARY OPPOSED RELATION WITH RESPECT TO EACH OTHER AND SPACED APART A DISTANCE EQUAL TO SAID PREDETERMINED PITCH TO CAUSE A PLURALITY OF SAID BOLT-GUIDING RIBS TO ENGAGE A PLURALITY OF TURNS OF THE THREAD ON OPPOSITE SIDES OF SUCH A PREDETERMINED BOLT UPON SCREWING THEREOF INTO SAID SLOT, THERE BEING AT LEAST ONE OTHER BOLT-ENGAGING RIB ON ONE OF THE FACES OF SAID SLOT, SAID OTHER BOLT-ENGAGING RIB BEING A BOLT-GRIPPING RIB POSITIONED BELOW BOLT-GUIDING RIBS IN THE SLOT AND PRESENTING A SUBSTANTIALLY FLAT SURFACE LYING IN A PLANE INCLUDING THE CRESTS OF THE BOLT-GUIDING RIBS, SAID SURFACE OF THE BOLT-GRIPPING RIB BEING OF A WIDTH AT LEAST EQUAL TO SAID PREDETERMINED PITCH SO THAT WHEN SUCH A PREDETERMINED BOLT IS SCREWED INTO SAID SLOT THE THREAD THEREON WILL FIRST ENGAGE THE THREAD GUIDING RIBS AND THEREAFTER WILL CUT A FEMALE THREAD IN SAID SURFACE OF THE BOLT-GRIPPING RIB.