Mortise-type, reverse-pivoted latch mechanism

Claim 1

IN A DEVICE OF THE CLASS DESCRIBED, A ROLL-BACK LATCH BOLT MOUNTED FOR PIVOTAL MOVEMENT BETWEEN PROJECTED AND RETRACTED POSITIONS, AN AUXILIARY BOLT MOUNTED ADJACENT SAID ROLL-BACK BOLT FOR MOVEMENT BETWEEN PROJECTED AND RETRACTED POSITIONS, MEANS RESILIENTLY URGING SAID AUXILIARY BOLT TOWARD PROJECTED POSITION, DEADLOCK MEANS MOUNTED FOR MOVEMENT INTO AND OUT OF A POSITION BLOCKING SAID ROLL-BACK BOLT AGAINST RETRACTION, A FURTHER ELEMENT MOUNTED FOR COOPERATION WITH SAID DEADLOCK MEANS AND MOVABLE IN ONE DIRECTION TO URGE SAID DEADLOCK MEANS TOWARD SUCH BLOCKING POSITION AND IN THE OPPOSITE DIRECTION TO WITHDRAW SAID DEADLOCK MEANS FROM SUCH BLOCKING POSITION, AND MEANS PROVIDING A POSITIVE, TWO-WAY OPERATIVE CONNECTION BETWEEN SAID AUXILIARY BOLT AND SAID FURTHER ELEMENT.