Door lock

Claim 1

IN A LATCH MECHANISM FOR A SWINGING DOOR, A SUPPORT HAVING A PLATE PORTION FOR DISPOSITION AT A FREE EDGE WALL OF THE DOOR, A PAIR OF JAW ELEMENTS PIVOTALLY MOUNTED ON ONE SIDE OF SAID PLATE PORTION FOR COUNTER-SWINGING MOVEMENT FROM AN UNLATCHED POSITION TOWARD EACH OTHER TO A LATCHED POSITION IN WHICH SAID JAW ELEMENTS ARE ADAPTED TO ENGAGE A STRIKER PIN THEREBETWEEN, A PAIR OF CONTROL PLATES MOUNTED ON THE OPPOSITE SIDE OF SAID PLATE PORTION EACH OF WHICH IS FIXEDLY COUPLED TO ONE OF SAID JAW ELEMENTS FOR PIVOTAL MOVEMENT THEREWITH, A PAIR OF DETENT MEANS EACH PIVOTALLY MOUNTED ON SAID PLATE PORTION AND ENGAGEABLE WITH DETENT ENGAGEABLE PORTIONS ON THE RESPECTIVE CONTROL PLATES TO RESTRAIN SAID JAW ELEMENTS IN DOOR LATCHED POSITION, SPRING MEANS BIASING SAID JAW ELEMENTS TOWARD UNLATCHED POSITION, SAID SPRING MEANS COMPRISING A PAIR OF COUNTERWOUND SPIRAL SPRINGS, EACH OF SAID SPRINGS BEING COUPLED TO ONE OF SAID CONTROL PLATES, RESPECTIVELY, TO URGE THE SAME IN COUNTERCLOCKWISE DIRECTION OF ROTATION, SAID SPRING MEANS BEING COUPLED TO EACH OTHER THROUGH A COMMON LINK PORTION, SAID LINK PORTION PROVIDING A REACTION MEANS AGAINST WHICH SAID SPRINGS REACT TO URGE SAID CONTROL PLATES AND THEREBY SAID JAW ELEMENTS IN UNLATCHED DIRECTION, AND MANUALLY OPERABLE MEANS ENGAGEABLE WITH SAID PAIR OF DETENT MEANS TO SIMULTANEOUSLY DISENGAGE THE LATTER FROM THE RESPECTIVE CONTROL PLATES TO PERMIT MOVEMENT OF SAID DETENT MEANS RESTRAINED JAW ELEMENTS TO UNLATCHED POSITION.