Deadlocking auxiliary latch construction

Claim 1

AN AUXILIARY DOOR LATCH MECHANISM INCLUDING A LATCH HOUSING, A LATCH BOLT RECIPROCABLY MOUNTED IN SAID HOUSING AND BIASED NORMALLY TO EXTEND FROM ONE END OF SAID HOUSING, AN ENDWISELY INSERTIBLE INDEPENDENT RETRACTOR ASSEMBLY RECIPROCABLY MOUNTED IN AND BIASED TO EXTEND FROM THE OTHER END OF SAID HOUSING, LEVER MEANS PIVOTALLY SUPPORTED ON SAID HOUSING OPERATIVELY CONNECTING SAID LATCH BOLT AND RETRACTOR ASSEMBLY, AND ARRANGED TO WITHDRAW SAID LATCH BOLT INTO SAID HOUSING AS SAID RETRACTOR ASSEMBLY IS SHIFTED INTO SAID HOUSING, A DOGGING LEVER HAVING AN ANNULAR BEARING PIVOTALLY MOUNTED ON A CYLINDRICAL TRUNNION CARRIED BY SAID RETRACTOR ASSEMBLY, SAID LEVER HAVING FORWARD AND REARWARD BRANCHES, COMPRESSION SPRING MEANS INTERPOSED BETWEEN SAID REARWARD BRANCH AND SAID RETRACTOR ASSEMBLY BIASING SAID FORWARD BRANCH IN BLOCKING POSITION IN THE PATH OF MOVEMENT OF SAID LATCH BOLT AS THE SAME IS SHIFTED INTO SAID HOUSING, AND STATIONARY MEANS ON SAID HOUSING POSITIONED TO ENGAGE SAID REARWARD BRANCH AS SAID RETRACTOR ASSEMBLY IS SHIFTED INTO SAID HOUSING EFFECTIVE TO PIVOT SAID LEVER TO SHIFT SAID FORWARD BRANCH OUT OF SAID PATH OF SAID LATCH BOLT.