Locks, especially for pivoting leaf doors

Claim 1

IN A LOCK FOR LOCKING A LEAF DOOR ADAPTED TO SWEEP INSIDE A ROOM WHEN OPENED AND HINGED TO A DOOR JAMB PROVIDED WITH A RECESS FACING THE ROOM AND ENGAGEABLE BY THE FREE EDGE OF THE CLOSED LEAF DOOR, THE COMBINATION OF A PIVOT PARALLEL WITH THE DOOR HINGE AND CARRIED IN THE PART OF THE DOOR RECESS FURTHEST FROM THE ROOM AND OUT OF THE PATH OF THE FREE EDGE OF THE LEAF DOOR, A HOOKSHAPED MEMBER REVOLVABLY CARRIED BY THE PIVOT AND INCLUDING A STRAIGHT SECTION STARTING FROM THE LOCATION OF THE PIVOT AND A FIRST AND A SECOND PROJECTION SUBSTANTIALLY FACING THE LOCATION OF THE CLOSED LEAF DOOR AND RIGID WITH THE STRAIGHT SECTION, SAID FIRST PROJECTION BEING NEAR THE PIVOT END AND SAID SECOND PROJECTION BEING NEAR THE OUTER END OF THE STRAIGHT SECTION, WITH A GAP FORMED BETWEEN THE PROJECTIONS, THE MINIUMUM WIDTH OF THE GAP BEING EQUAL TO THE THICKNESS OF THE LEAF DOOR, THE FIRST PROJECTION LYING PERMANENTLY IN THE PATH OF THE FREE EDGE OF THE LEAF DOOR TO BE SHIFTED THEREBY OUT OF AN INOPERATIVE POSITION IN WHICH THE SECOND PROJECTION LIES OUTSIDE THE PATH OF THE FREE EDGE OF THE LEAF DOOR INTO AN OPERATIVE POSITION IN WHICH THE LEAF DOOR IS HELD IN ITS CLOSED POSITION THROUGH APPLICATION OF BOTH PROJECTIONS AGAINST THE OPPOSITE SIDES OF THE CLOSED LEAF DOOR, A SPRING URGING THE HOOK-SHAPED MEMBER INTO ITS OPERATIVE POSITION TO RELEASE THE LEAF DOOR, A BOLT ADAPTED TO POSITIVELY HOLD THE HOOKSHAPED MEMBER IN ITS OPERATIVE POSITION AGAINST THE ACTION OF THE SPRING, MEANS URGING THE BOLT INTO ENGAGEMENT WITH THE HOOK-SHAPED MEMBER WHEN SHIFTED TO ITS OPERATIVE POSITION, AND MEANS FOR RELEASING THE BOLT TO ALLOW THE SPRING TO ACT ON THE HOOK-SHAPED MEMBER.