Safety roller door latch mechanisms

Claim 1

IN A DOOR LATCH MECHANISM COMPRISING A KEEPER FIXED ON A DOOR POST AND HAVING A LATCH RECEIVING OPENING PROVIDED THEREIN THAT IS NOTCHED ON ONE SIDE TO DEFINE A RACK, A ROTARY TOOTHED LATCH CARRIED ON THE ADJACENT EDGE FACE OF A DOOR ARRANGED TO ENTER THE OPENING IN THE KEEPER AND HAVE INTERMESHING ENGAGEMENT WITH THE RACK IN THE CLOSING OF THE DOOR AS THE LATCH ROLLS INTO PLACE IN THE KEEPER, MEANS FOR RELEASABLY LOCKING SAID LATCH AGAINST TURNING TO LOCK THE DOOR IN CLOSED POSITION, AND MANUALLY OPERABLE MEANS FOR RELEASING SAID LAST MENTIONED MEANS TO PERMIT OPENING OF THE DOOR, THE IMPROVEMENT WHICH CONSISTS IN THE PROVISION, IN FIXED SPACED RELATION TO THE EDGE OF THE DOOR, OF AN ANTI-FRICTION ROLLER FOR ROLLING ENGAGEMENT ON A TRACK PROVIDED BEHIND THE KEEPER IN SUBSTANTIALLY PARALLEL RELATION TO SAID RACK, SAID ROLLER BEING DISPOSED IN CONCENTRIC RELATION WITH SAID LATCH AND BEING LARGE IN DIAMETER IN RELATION TO THE LATCH AND THE OPENING IN THE KEEPER AND ARRANGED IN THE CLOSING OF THE DOOR TO RUN ON SAID TRACK INTO OPERATIVE POSITION BEHIND SAID KEEPER WHEREBY POSITIVELY TO LIMIT THE SPREADING APART OF THE DOOR AND DOOR POST.