Framing system for a suspended ceiling

Claim 1

IN A CEILING CONSTRUCTION HAVING A PLURALITY OF SPACED PARALLEL LONGITUDINAL MEMBERS, AND A PLURALITY OF SPACED TRANSVERSE MEMBERS CONNECTED TO SAID LONGITUDINAL MEMBERS TO FORM OPENINGS IN WHICH CEILING TILES AND THE LIKE ARE SUPPORTED, SAID LONGITUDINAL AND TRANSVERSE MEMBERS HAVING SUBSTANTIALLY EQUAL HEIGHT, AN IMPROVED LOCKING SYSTEM FOR SAID LONGITUDINAL AND TRANSVERSE MEMBERS, COMPRISING: (A) HOOK PORTIONS FORMED AT THE END OF EACH TRANSVERSE MEMBER, (B) AN OPENING IN SAID LONGITUDINAL MEMBER ADAPTED TO RECEIVE SIMULTANEOUSLY THE HOOK PORTIONS OF TRANSVERSE MEMBERS INTERSECTING SAID LONGITUDINAL MEMBER ON OPPOSITE SIDES THEREOF, SAID LONGITUDINAL AND TRANSVERSE MEMBERS INTERSECTING IN THIS MANNER WITHOUT ROTATION OF EITHER OF THESE MEMBERS ABOUT ITS VERTICAL AXIS, SAID TRANSVERSE MEMBERS AND LONGITUDINAL MEMBER BEING THEN RELATIVELY MOVABLE VERTICALLY TO A POSITION WHEREIN SAID HOOK PORTIONS ENGAGE WITH LONGITUDINAL MEMBER AT THE PERIMETER OF SAID OPENING, IN SAID LAST POSITION SAID TRANSVERSE AND LONGITUDINAL MEMBER BEING LOCKED TOGETHER AGAINST RELATIVE MOVEMENT IN THE HORIZONTAL PLANE, (C ) AND A TAB PORTION ON SAID LONGITUDINAL MEMBER PIVOTABLE BETWEEN AN OPEN AND CLOSED POSITION, IN SAID OPEN POSITION SAID TAB PERMITTING SAID HOOK PORTIONS TO MOVE VERTICALLY WITH RESPECT TO SAID OPENING, IN SAID CLOSED POSITION SAID TAB PREVENTING SUCH RELATIVE VERTICAL MOVEMENT AND THEREBY LOCKING SAID FRAMING MEMBERS TOGETHER.