Removable core cylinder lock

Abstract

A removable core cylinder lock utilizing twisting tumblers and a latch bar provides maximum security. Both operating and control keys have at least one skew cut bit to operating the twisting tumblers. A centrally positioned cylinder retainer is rotatable with a control key to remove the lock from its shell.

We claim: 
     
       1. A removable core cylinder lock comprising: (a) a cylinder lock shell have a cavity therethrough for reception of a cylinder lock case;   (b) means defining a retaining recess in the wall of the cavity intermediate the ends of the shell;   (c) an interchangeable cylinder lock case with an outside configuration to slidably fit into the cavity into the shell, the case including a plurality of pin tumbler holes and an interrupted cylindrical shape passage extending lengthwise of the case;   (d) a cylinder locking retainer having parallel pin tumbler holes and a cylindrical shaped passage shaped to correspond with the interrupted cylindrical shaped passages in the lock case to form a completed cylindrical passage through the lock case and retainer, the retainer being rotatable in the shell to a limited extent;   (e) a projection on the outer surface of the cylinder retainer for cooperating with the retainer recess when the retainer is rotated in one direction and clearing the retainer recess when the retainer is rotated in an opposite direction;   (f) means defining a latch bar groove in the wall of the completed cylindrically shaped passage in the lock case and retainer;   (g) twisting pin tumblers each having a pointed inner end and a longitudinal groove, one pin tumbler positioned in each pin tumbler hole in the lock case and retainer;   (h) a driver pin in each of the pin tumbler holes above the pin tumbler and means for biasing the driver pins and pin tumblers toward the longitudinal center of the case;   (i) a latch bar having projections from one side thereof cooperating with the longitudinal grooves in the pin tumblers when the tumblers are correctly oriented by a twisting movement, the opposite side of the latch bar from the projection being shaped to cooperate with the latch bar groove such that when any one projection is not in a tumbler groove, the latch bar will be kept seated in the latch bar groove   (j) a cylinder having a key way, pin tumbler holes, a slot for lateral movement of the latch bar, and an outside cylindrical surface for rotary movement inside the completed cylindrical passageway in the case and the retainer;   (k) an operating key having at least some bits cut at skew angles to cause the tumblers to raise to a shear line defined by the outside surface of the cylinder and the completed cylindrical passage and to twist to present the longitudinal groove to the latch bar projections at each tumbler position thereby allow the operating key to rotate the cylinder and operate the locks;   (l) a control key having its bits cut at the same angles as the operating key, the bits causing the tumblers to raise to a core removal shear line defined by the surface of the retainer and a cooperating surface of the case for at least one tumbler and defined for the remaining tumblers by the outside surface of the cylinder and the completed cylinder passage, and to cause the tumblers to twist to present the longitudinal groove of each tumbler to the latch bar projections to allow the key to retract the retainer projection from the recess and allow the core to be removed.   
     
     
       2. A removable core cylinder lock as defined in claim 1 wherein the retainer is operated under the control of two bits of the control key. 
     
     
       3. A removable core cylinder lock as defined in claim 2 wherein the two bits of the control key have identical skew angles as the operating key but different depths of bitting. 
     
     
       4. A removable core cylinder lock as defined in claim 3 wherein both the operating key and control key has six bits and the two bits of the control key which operate the retainer are the middle two bits of the key. 
     
     
       5. A removable core cylinder lock removable from a cylinder lock shell having a cavity there through for a reception thereof and a recess in the wall of the cavity, the cylinder lock comprising: (a) an interchangeable cylinder lock lock case with an outside configuration to slidably fit into the cavity into the shell, the case including a plurality of pin tumbler holes and an interrupted cylindrical shape passage extending lengthwise of the case;   (b) a cylinder locking retainer having parallel pin tumbler holes and a cylindrical shaped passage shaped to correspond with the interrupted cylindrical shaped passages in the lock case to form a completed cylindrical passage through the lock case and retainer, the retainer being rotatable in the shell to a limited extend;   (c) a projection on the outer surface of the cylinder retainer for cooperating with the retainer recess when the retainer is rotated in one direction and clearing the retainer recess when the .[.retained.]. .Iadd.retainer .Iaddend.is rotated in an opposite direction;   (d) means defining a latch bar groove in the wall of the completed cylindrically shaped passage in the lock case and retainer;   (e) twisting pin tumblers each having a pointed inner end and a longitudinal groove, one pin tumbler positioned in each pin tumbler hole in the lock case and retainer;   (f) a driver pin in each of the pin tumbler holes above the pin tumbler and means for biasing the driver pins and pin tumblers toward the longitudinal center of the case;   (g) a latch bar having projections from one side thereof cooperating with the longitudinal grooves in the pin tumblers when the tumblers are correctly oriented by a twisting movement, the opposite side of the latch bar from the projection being shaped to cooperate with the latch bar groove such that when any one projection is not in a tumbler groove, the latch bar will be kept seated in the latch bar groove;   (h) a cylinder having a key way, pin tumbler holes, a slot for lateral movement of the latch bar, and an outside cylindrical surface for rotary movement inside the completed cylindrical passageway in the case and the retainer; the arrangement being such that an operating key having at least some bits cut at skew angles will cause the tumblers to raise to a shear line defined by the outside surface of the cylinder and the completed cylindrical passage and to twist to present the longitudinal groove to the latch bar projections at each tumbler position to thereby allow the operating key to rotate the cylinder and operate the locks; and a control key having bits cut at the same angles as the operating key, to cause the tumblers to raise to a core removal shear line defined by the surface of the retainer and a cooperating surface of the case for at least one tumbler and defined for the remaining tumblers by the outside surface of the cylinder and the completed cylinder passage, and to cause the tumblers to twist to present the longitudinal groove of each tumbler to the latch bar projections to allow the key to retract the retainer projection from the recess and allow the core to be removed. .Iadd.     
     
     
       6.  A removable core cylinder lock comprising: (a) a cylinder lock shell having a cavity therethrough for reception of a cylinder lock case;   (b) means defining a retaining recess in a wall of the cavity in the cylinder lock shell;   (c) an interchangeable cylinder lock case with a sectional configuration allowing it to slidably fit into the cavity in the cylinder lock shell, the case including a cylindrically-shaped passageway extending lengthwise therethrough;   (d) a cylinder locking retainer having a cylindrically-shaped passageway corresponding in diameter and shape to the cylindrically-shaped passageway in the cylinder lock case, the cylinder locking retainer being fitted into the cylinder lock case so that the cylindrically-shaped passage in the cylinder lock case and the cylindrically-shaped passage in the cylinder locking retainer form a completed cylindrical passage through the lock case and the retainer, the retainer being rotatable in the shell to a limited extent;   (e) a projection on the outer surface of the cylinder locking retainer for cooperating with the means defining a retaining recess when the retainer is rotated in one direction and clearing the retainer recess when the retainer is rotated in an opposite direction;   (f) means defining a latch bar groove in the wall of the cylindrically-shaped passage in both the lock case and retainer;   (g) a latch bar positioned in the means defining the latch bar groove in the wall of the lock case and retainer;   (h) pin tumblers positioned in pin tumbler holes in the lock case and retainer, and drive pins one in each pin tumbler hole above each pin tumbler, and means for biasing the drive pins and pin tumblers toward the longitudinal center of the case;   (i) a cylinder having a keyway for a key with means thereon to operate both the pin tumblers and the latch bar;   the arrangement being such that a proper operating key controls the pin tumblers and the latch bar to allow rotation of the cylinder and a proper control key operates the tumblers and latch bar to allow rotation of the cylinder locking retainer for removal of the cylinder lock case from the cylinder lock shell..Iaddend. .Iadd.   
     
     
       7.  A removable core cylinder lock, removable from a cylinder lock shell having a cavity therethrough for reception of a cylinder lock, the cavity including a recess in the wall thereof for retaining a cylinder lock, the removable core cylinder lock comprising: (a) an interchangeable cylinder lock case slidable into and out of the cavity in the cylinder lock shell under control of a proper control key, the cylinder lock case having a passage therethrough for reception of a lock cylinder;   (b) a cylinder locking retainer having a sectional configuration so as to present an outside profile the same as the profile of the passageway in the lock case, and having a passageway therethrough for the passage of a lock cylinder, the cylinder locking retainer being fitted with the interchangeable cylinder lock case so that the passageway through the cylinder lock case and the passageway through the cylinder lock retainer are aligned and the cylinder lock retainer may rotate relative to the cylinder lock case about the center of the passageway;   (c) the cylinder lock retainer including a projection which is movable upon rotation of the cylinder lock retainer in one direction to cooperate with the recess in the cavity of the cylinder lock shell and movable on rotation of the cylinder lock retainer in an opposite direction to clear the recess in the cavity in the cylinder lock shell;   (d) a lock cylinder slidable into the passageway in the cylinder lock case and cylinder locking retainer;   (e) a latch bar groove extending along both the cylinder lock case and the cylinder locking retainer;   (f) a latch bar in the latch bar groove, the latch bar being operable from a portion of a key to control rotation of the lock cylinder;   (g) locking means cooperating between the lock cylinder and the cylinder lock case for allowing a proper operating key to control rotation of the lock cylinder while not affecting rotation of the cylinder locking retainer and allowing a proper control key to control rotation of the lock cylinder retainer only; and   (h) a keyway in the lock cylinder for the reception of a proper operating key or a proper control key, the proper operating key controlling the latch bar and operation of the cylinder lock retainer to rotate the cylinder lock retainer for the purpose of clearing the retaining recess and allowing the cylinder lock case to be removed..Iaddend.