Protective device for doors

Claim 1

IN A CHAIN LOCK FOR SECUREMENT TO A DOOR AND A DOOR FRAME WHICH MAY BE OPENED FROM THE OUTSIDE OF THE DOOR INCLUDING A CHAIN, A GUIDE BRACKET, MEANS FOR MOUNTING SAID GUIDE BRACKET ON A DOOR, AN ELONGATED SLOT FORMED IN SAID GUIDE BRACKET, AND A SLIDE ON ONE END OF SAID CHAIN FOR ENGAGEMENT WITH SAID BRACKET; THE IMPROVEMENT COMPRISING A LOCK HOUSING, MEANS FOR MOUNTING SAID HOUSING ON A DOOR FRAME, SAID HOUSING FORMED AT ONE END THEREOF WITH A CAVITY SIZED TO RECEIVE A LOCK CYLINDER, A TRANSVERSE SLOT FORMED WITHIN SAID HOUSING ADJACENT SAID CAVITY, A PLUNGER-RECEIVING OPENING FORMED IN SAID HOUSING EXTENDING FROM SAID CAVITY INTO SAID SLOT, A LOCK CYLINDER MOUNTED WITHIN SAID CAVITY FOR AXIAL MOVEMENT BETWEEN A LOCKED AND AN UNLOCKED POSITION, SAID CYLINDER HAVING A RETRACTABLE LATCH AND SAID HOUSING HAVING A LATCH OPENING FORMED WITHIN SAID CAVITY, SAID LATCH AND SAID LATCH OPENING DEFINING SAID LOCKED POSITION, SPRING MEANS BIASING SAID LOCK CYLINDER INTO SAID UNLOCKED POSITION, A PLUNGER RIGIDLY SECURED TO SAID LOCK CYLINDER EXTENDING THROUGH SAID OPENING AND MOVABLE WITH SAID LOCK CYLINDER INTO AND OUT OF SAID SLOT, AND A SOLID CHAIN FITTING SECURED TO THE OTHER END OF SAID CHAIN AND SIZED TO BE INTIMATELY RECEIVED WITHIN SAID SLOT, SAID FITTING HAVING A PLUNGERRECEIVING OPENING FORMED THEREIN FOR RELEASABLY SECURING SAID CHAIN TO SAID HOUSING, SAID ONE END OF SAID CHAIN BEING REMOVABLE FROM SAID SLIDE FROM THE INSIDE OF THE DOOR AND SAID OTHER END BEING DETACHABLE FROM SAID HOUSING FROM THE INSIDE AND FROM THE OUTSIDE OF SAID DOOR BY UNLOCKING SAID LOCK CYLINDER TO WITHDRAW SAID PLUNGER FROM SAID SLOT AND FROM SAID FITTING.