Acoustical ceiling suspension fastening system

Claim 1

IN A SUSPENDED CEILING GRID STRUCTURE HAVING A PLURALITY OF SPACED PARALLEL MAIN RUNNERS AND A PLURALITYL OF CROSS-T''S CONNECTING THE MAIN RUNNERS, BOTH MAIN RUNNERS AND CROSS-T''S HAVING AN AXIALLY EXTENDING UPSTANDING WEB AND A PAIR OF AXIALLY EXTENDING FLANGES PROJECTING HORIZONTALLY FROM THE WEB, TO THE MAIN RUNNERS COMPRISFOR CONNECTING THE CROSS-T''S TO THE MAIN RUNNERS COMPRISING A LATCH PROJECTING FORWARDLY FROM A CROSS-T WEB AND ARRANGED TO ENTER AN ADJACENT MAIN RUNNER WEB FIRST APERTURE WHEN ALIGNED BY ROTATING THE CROSS-T TO AN INCLINED POSITION IN A PLANE AT RIGHT ANGLES TO THE MAIN RUNNER WEB, SAID APERTURE BEING ADAPTED SO THAT SAID LATCH MAY BE ROTATED FROM SAID INCLINED POSITION TO AN UPRIGHT POSITION; AND A NOSE PROJECTION FORWARDLY FROM SAID CROSS-T WEB AND ADAPTED TO ENTER A MAIN RUNNER SECOND APERTURE WHEN SAID CROSS-T IS IN SAID UPRIGH POSITION, WHEREBY SAID CROSS-T IS LOCKED IN SAID URPRIGHT POSITION.