Abstract:
The disclosed device is directed towards a key operated lock. The key operated lock comprises a barrel defining an interior, the barrel having an alignment block at the interior. A core is insertable into the interior. The core demountably coupling with the alignment block in both a clockwise and a counterclockwise direction.

Description:
BACKGROUND OF THE INVENTION 
     The present disclosure relates to the field of pin tumbler locks and more particularly to a pin tumbler lock having a removable internal core. 
     Conventional pin tumbler cam locks comprise a core including an annular cylinder and rotary plug. The core is located within a lock housing. The plug has a row of individual tumbler pins slidable toward or away from the plug rotational axis. The annular cylinder has a corresponding row of spring-biased drive pins in registration with the tumbler pins. The drive pins are normally urged partway into the mounting holes for the tumbler pins so that the plug cannot rotate. 
     In the locked position, a key may be inserted into a key slot in the plug to push the tumbler pins outwardly, thereby moving the drive pins out of the tumbler pin mounting holes. These tumbler pin movements align the outer ends of the tumbler pins to become coincident with the plug outer surface. The plug can be rotated to the open position by turning the key. The plug supports a lock plate that swings behind a keeper to lock or unlock the device. 
     In a more sophisticated arrangement, a pin tumbler cam lock can have a multiplicity of rows of pin tumblers. The pin tumblers can be arranged in a manner in that a relatively large number of tumbler pins can be accommodated in a relatively small size lock housing. The rotary plug can have a key slot with a narrow rectangular cross-section. The mating key can have two parallel flat side surfaces and two connecting edge surfaces. Rows of conical depressions are defined in the flat side surfaces and the edge surfaces of the key. The plug has three rows of tumbler pins located in the plug in order that the pins register with the conical depressions defined in the key. The pin inner ends are conically shaped in order to mate with the conical depressions on the key. 
     When the key is inserted into the key slot the depressions in the key locate the tumbler pins at the correct height in the mounting holes. Spring-biased drive pins are mounted in a stationary cylinder surrounding the rotary plug to normally extend partly into the mounting holes for the tumbler pins. The key upon insertion into the plug, moves the tumbler pins outwardly to drive the drive pins out of the plug. With the drive pins free of interference, the plug can rotate freely. There are three rows of tumbler pins extending radially from the pin rotational axis. In some lock arrangements, the pins are arranged in the plug in three rows with one row containing five sets of drive pins and tumbler pins and springs. The other two rows contain six sets of drive pins, tumbler pins and springs. The arrangement has a total of seventeen sets of pins and springs for securing the lock and resisting lock picking. 
     The plug motion is controlled by a feature known as a stop arm or tab extending from the rear of the stationary cylinder through an aperture in the rear of the lock housing shell. The stop arm cooperates with a stop plate carried on the rotary plug and in registration with the stop arm. The stop arm is designed to limit the rotation of the stop plate in two directions. The plug position is determined by the limitation of the rotation. The plug can be positioned in the locked condition of the lock and the plug can be positioned in the unlocked condition of the lock. The single stop arm determines both end positions of the rotary plug and therefore provides for more accurate control of the plug motion. Manufacturing tolerances and tolerance build-up becomes less of an adverse factor. 
     The plug control through the stop arm on the exterior of the structure provides for a shorter lock length. This shorter lock length is done without the elimination of pins or tumblers. 
     The plug in the lock is inserted into an annular cylinder that is covered by a housing sleeve to form the core. The housing sleeve is inserted into a housing shell. The housing shell is typically inserted into a cabinet door and permanently fastened to the cabinet door. The entire lock including the fixed housing shell in the door, the rotatable plug within the cylinder and sleeve combined provide for locking the cabinet door. The housing shell has threaded side surfaces that receive a nut in order to fasten the lock onto the cabinet door. The cabinet has a keeper that is fixed to the cabinet to block the cabinet from opening. The lock has a corresponding lock plate that rotates into locked and unlocked position depending upon the relationship to the keeper on the cabinet. The lock plate is attached to the plug on the end of the plug opposite the key slot. The plug has a threaded stem that receives the lock plate and a nut to threadably tighten and fix the lock plate to the plug. The plug rotates the lock plate into and out of engagement with the keeper on the cabinet. 
     In order to remove the plug from the housing, the nut holding the lock plate must be removed from the threaded end of the plug. Removal of the nut can only be done when the cabinet door is open and the back of the lock is exposed for removal of the nut and lock plate. With the nut and lock plate removed, the plug, cylinder and housing sleeve, i.e., the core can be removed from within the fixed housing shell in the cabinet door. 
     In many lock applications, the contents of the cabinet are sensitive to exposure from the external environment, such as dust and moisture from the exterior of the cabinet. In other applications, the contents require security from unauthorized persons and tampering with the contents. 
     Also in many lock applications, the key for the specific lock becomes lost or must be rekeyed for security purposes. The corresponding pin and tumbler arrangement must be changed to match the new key. The lock plug and cylinder assembly (core) must be removed in order the change the pin and tumbler arrangement for the new key. The resultant problem arises with the need to remove the plug. The cabinet door must be opened creating the above mentioned environmental and security risks. 
     There have been lock core designs that allow for the removal of the core without the need to open the cabinet door to access the rear of the lock. These prior art locks require plug and cylinder arrangements that are bulky as well as limit the range of rotation of the plug. Additionally, after removal of the core, the replacement core would have realignment malfunctions with the lock plate or cam actuators at the back end of the lock. The weight of the lock plate may cause the lock plate to inadvertently rotate out of alignment with the replacement plug. The plug is also limited to only a left handed turn or limited to only a right handed turn, (clockwise, counterclockwise) so that the lock can only be installed in a cabinet door with the hinges on the left or only installed in a cabinet door with the hinges on the right. 
     What is needed in the art is a compact lock with a removable plug that can rotate in any direction with full range of rotation that does not require the locked cabinet door to be opened for the removal of the plug as well as a replacement core that will realign in the lock housing with ease. 
     SUMMARY 
     The disclosed device is directed towards a key operated lock. The key operated lock comprises a barrel defining an interior, the barrel having an alignment block at the interior. A core is insertable into the interior. The core demountably coupling with the alignment block in both a clockwise and a counterclockwise direction. 
     In another embodiment the disclosed device is directed towards a key operated lock comprising a barrel defining an interior and an exterior, the barrel having a front end and a rear end opposite thereof. The barrel defining an alignment block in the interior proximate to the rear end. A core is demountably insertable in the interior of the barrel. The core comprises an inner inserted rotatable into an outer. A retainer is disposed over the inner proximate to a rear of the inner and inserted rotatable into the outer at a rear of the outer. A sleeve is disposed over the outer and configured to retain a plurality of drive pin and spring sets disposed through the outer. The plurality of drive pin and spring sets being in operable communication with a corresponding tumbler pin disposed through the inner, wherein the retainer demountably couples with the alignment block in both a clockwise and counter-clockwise direction. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES 
     FIG. 1 is a side view schematic of an exemplary lock; 
     FIG. 2 is an exploded perspective view of an exemplary lock; 
     FIG. 3 is a front view of an exemplary inner; 
     FIG. 4 is a side view of an exemplary inner; 
     FIG. 5 is a top view of an exemplary inner; 
     FIG. 6 is a front view of an exemplary outer; 
     FIG. 7 is a top view of an exemplary outer; 
     FIG. 8 is a sectional view of an exemplary outer as shown in FIG. 6; 
     FIG. 9 is a front view of an exemplary retainer; 
     FIG. 10 is a side view of an exemplary retainer; 
     FIG. 11 is a top view of an exemplary retainer; 
     FIG. 12 is a top view of an exemplary barrel; 
     FIG. 13 is a side view of an exemplary barrel; 
     FIG. 14 is a front view of an exemplary barrel; 
     FIG. 15 is a sectional view of an exemplary barrel as shown in FIG. 14; 
     FIG. 16 is a front view of an exemplary tail piece; 
     FIG. 17 is a side view of an exemplary tail piece; and 
     FIG. 18 is a top view of an exemplary tail piece. 
    
    
     DETAILED DESCRIPTION 
     Persons of ordinary skill in the art will realize that the following description of the present invention is illustrative only and not in any way limiting. Other embodiments of the invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. 
     FIG. 1 illustrates a side view schematic of an exemplary lock  10 . The lock  10  is operated with a key  12 . The lock  10  comprises a housing shell or barrel  14  having an exterior  16  with a threaded side surface  18  adapted to receive a nut  20 , whereby the barrel  14  can be mounted on a structure  22 , for example, the structure can be the outer door of a vending or gaming machine. The dimension indicated at L is known in the art as a locking dimension. In exemplary embodiments the locking dimension can be substantially shortened. The lock  10  includes a tailpiece  24  that carries a lock plate  26 . 
     As shown in FIG. 1, the lock plate  26  extends downwardly to engage a fixed keeper  28 , whereby the lock  10  is in a locked condition to prevent rightward motion of structure (door)  22 . The key  12  is insertable into a key slot  30  (shown at FIG. 2) in a plug or inner  32  to rotate the inner  32  to lock or unlock the lock  10 . The key  12  is removable from the key slot  30  only when the lock is in a locked condition. 
     FIG. 2 illustrates an exploded perspective view of an exemplary lock  10 . The lock  10  comprises a housing sleeve or simply sleeve  34  telescoped into barrel  14 . In an exemplary embodiment, the housing sleeve  34  is steel. The purpose of the sleeve  34  is to provide a sleeve inner surface that is precisely centered relative to a lock rotational axis  36 , whereby the positions of the internal components are precisely controlled in relation to the rotational axis  36 . Barrel  14  can be a zinc die casting without precision surfaces. 
     Mounted within sleeve  34  is an annular cylinder or simply an outer  38 . In a preferred exemplary embodiment the outer  38  is formed of brass. The outer  38  is disposed over the inner  32 . The outer  38  has an inner cylindrical surface  40  that acts as a bearing for the inner  32 . The inner  32  is inserted into the outer  38  allowing rotary motion relative to the outer  38 . Inner  32  may also be formed of brass. The inner  32  is adapted to rotate about the rotational axis  36 . The key slot  30  extends longitudinally within inner  32  in generally parallel relation to the rotational axis  36 , whereby when key  12  is inserted into the slot  30  the key is able to rotate the inner  32  about the rotational axis  36 . 
     The inner  32  has three rows of holes  42  extending from an outer surface  44  to the key slot  30 . FIG. 2 shows two rows of holes  42  in the inner  32 . A third row of holes extends from the non-visible surface of the inner  32 . As shown in FIGS. 2-5, each row contains five or six holes  46  for a total of seventeen holes in the inner  32 . Each hole  46  is designed to slidably receive a tumbler pin  48 . 
     A representative hole  46  has a counter bore  50  designed to accommodate the enlarged head of the associated tumbler pin  48 . The shank portion of each tumbler pin has a conical inner end. When the key  12  is inserted into the key slot  30 , conical depressions in the key surfaces mate with the conical ends of the tumbler pins to move the pins outwardly in their mounting holes  46 . When the key  12  is withdrawn from slot  30  the tumbler pins  48  are driven toward the rotational axis  36  into the slot  30 . Shoulder surfaces of counterbores  50  limit movements of pins  48  toward the slot  30 . 
     The outer  38  includes drive pins  52  that are slidably mounted in socket holes  54  in the outer  38  (See FIGS.  2  and  6 - 8 ). A spring or generally a biasing member  56  is associated with each drive pin  52 . The biasing members  56  bias the drive pins  52  to provide the necessary forces to move the tumbler pins  48  toward the key slot  30 . When key  12  is removed from slot  30  each drive pin  52  extends part way into the associated counterbore  50  of inner  32 , preventing the inner  32  from rotating within the outer  38 . 
     The shank portions of the tumbler pins  48  have the same length. However, the head portions of the tumbler pins  48  may have varying lengths. In a representative structure four different head lengths are used—i.e., 1.79 mm., 1.44 mm., 1.09 mm., and 1.34 mm. Each pin  48  has one of such head dimension. The conical depressions in the key surfaces vary in depth, whereby when key  12  is inserted into the key slot  30  all of the tumbler pins  48  are forced outwardly in their respective mounting holes  46  to positions wherein all of the drive pins  52  are out of counter bores  50 . The key then can be turned to rotate the inner  32  to the unlocked condition or back to the locked condition. 
     Referring to FIGS. 2-11, retainer  58  is disposed over the inner  32  proximate to a rear  60  of said inner  32 . The retainer  58  is also insertable into the outer  38  proximate to a rear  62  of the outer  38 . The retainer  58  is movable about the inner  32  as well as movable within the outer  38  in a rotary motion. The rotary motion can be both clockwise and counterclockwise. A retaining clip  64  holds the retainer to the inner  32  while allowing for rotation of the retainer  58 . The retainer  58  includes sockets or pin holes  66  for receiving tumbler pins  48  biased and driven by biasing members  56  and drive pins  52  respectively. The retainer  58  is restricted or released to rotate about the inner by the drive pin and tumbler pin sets. In a preferred exemplary embodiment, there is any number of and at least one drive pin and tumbler pin associated with the retainer  58 . The retainer  58  includes a retaining ear  68  defined in the retainer  58 . The retaining ear  68  can be formed at an end of the retainer  58 . In a preferred exemplary embodiment, the retaining ear  68  is machined to form an extension portion of an end flange  70 . The end flange  70  includes a diameter d and the retaining ear includes a diameter D that is larger than the diameter d through the centerline C of the retainer  58 . The retainer  58  includes an inner diameter ID and an outer diameter OD. The outside diameter OD can vary from the diameter of the flange d and the retaining ear diameter D. The difference between the inner diameter ID and the outside diameter OD, called the difference  71 , allows for the retainer  58  to be operated without a wafer (not shown). The retainer  58  requires no special wafer in order to operate with a core key. No wafers are required since the difference  71  can be changed in thickness in order to accommodate various key tumbler combinations. The dimensions of the difference  71  is maintained in whole number dimensions not to exceed the numerical difference between the longest and shortest tumbler pins used in the lock for the retainer  58 . 
     The combination of inner  32 , the outer  38  including all the drive pin/spring sets and tumbler pins covered by the sleeve  34  and including the retainer  58  are collectively called the core  72 . The core  72  is demountably inserted/removed from the barrel  14 . The core  72  is removable in order that the combinations of tumblers to key sets can be varied to prevent compromising the lock  10 . As described above, the removable core  72  allows for a rapid and simple change of the lock/key set. The core  72  facilitates the change without the need to open the structure  22  that is held shut by the lock. The core  72  is inserted and removed with the core key. The retainer  58  maintains the core  72  inside the barrel  14  as well as releases the core  72  from the barrel  14 . The retainer  58  rotates into a position to couple to the barrel  14 . 
     Referring to FIGS. 12-15 the multiple views of an exemplary embodiment of the barrel  14  are illustrated. The barrel  14 , as described above at FIG. 1, is adapted to be fixed in place by nut  20  and secured to the structure  22 . The barrel  14  does not rotate relative to the structure  22 . The core  72 , as well as the retainer  58 , is rotatable within the barrel  14 . The barrel  14  defines an alignment block  74  located proximate to a rear  74  of the barrel  14 . In other embodiments, the alignment block  74  can be located at any distance from the rear  74 . The alignment block  74  forms a tab or indent into an interior  78  of the barrel  14 . In a preferred exemplary embodiment, the alignment block  74  is formed from the same material as the barrel  14 . The alignment block  74  cooperates with the retainer  58  to secure the core  72  in the interior  78  of the barrel  14 . A slot  79  is formed on the outer  38  to allow for the outer to insert into the barrel  14  without interfering with the alignment block  74 . An alignment marker  80  is defined in the barrel  14 . The alignment marker  80  is configured to indicate the position of the alignment block  74  within the barrel  14  to facilitate the ease of insertion of the core  72 . In a preferred exemplary embodiment, the alignment marker  80  is a notch formed in the barrel  14  at a conspicuous location distal from the rear of the barrel  76 . The barrel  14  includes a stop tab  82  formed from the barrel  14  at the rear of the barrel  76 . The stop tab  82  cooperates with a force plate  84  (See FIG.  2 ). The force plate  86  abuts the stop tab  82  and inhibits the rotation of the tailpiece  24 . 
     Referring to FIGS.  2  and  16 - 18  an exemplary embodiment of the tailpiece is illustrated. The tailpiece  24  includes an exterior  86  having a threaded side surface  88  for securing the force plate  84  along with the lock plate and associated tailpiece nut  90  securing the assembly together. A tailpiece washer  92  can be included between the tailpiece nut and the lock plate  26 . The tailpiece  24  is normally in operable communication with the core  72  and is separate and distinct from the core  72 . The tailpiece  24  is insertable into the barrel  14  at the interior of the barrel  78  proximate to the rear of the barrel  76 . A flange or head  94  on the tailpiece  24  cooperates with a tailpiece flange  96  defined at the rear of the barrel  76 . The tailpiece  24  is mounted in the barrel  14  and rotates within the barrel  14 . The tailpiece  24  includes a groove formed proximate to the head  94 . The groove  98  is configured to couple with a drive element  100  formed at the rear of the inner  60 . The drive element  100  and groove  98  cooperate to transfer the rotational motion from the key  12  through the inner  32  to the tail piece  24  to rotate the lock plate  26 . The lock plate  26  when rotated clockwise and/or counterclockwise locks or unlocks the lock  10 . The groove  98  on the tailpiece can be formed with adaptive features such as bevels, notches and cross notches, and the like. The drive element  100  can have similar features that maintain coupling between the tailpiece  24  and the inner  32 . The alignment marker  80  can enhance the coupling between the tailpiece  24  and the inner  32 . In an exemplary embodiment, the groove  98  is a rectilinear slot and the drive element  100  is a rectilinear tab. The mating of the slot and tab be enhanced by registering the alignment marker  80  with the orientation of the key  12  that results in mating orientation of the groove  98  and the drive element  100 . Since the tailpiece  24  and the core  72  are independently constructed, the core  72  can be removed and inserted without the need to open or expose the lock plate  26  or tailpiece nut  90  from outside the structure  22 . The assembled tailpiece nut  90 , lock plate  26 , and force plate  84  disposed over the tail piece  24  does not have to be disassembled in order to remove the core  72 . A core change out can be accomplished with the tailpiece  24  and attached components in place at the rear of the barrel  14 . The lock plate  26  can remain secured to the fixed keeper  28 , securing the contents of the structure  22  and eliminating the risks of exposure to the outside environment. 
     In another exemplary embodiment, the lock  10  can merely include the core  72  insertable into the barrel  14 . The inner  32  includes an extended drive element  100  configured to actuate a control arm  102  (see FIG. 1) or control actuator  102  adapted to actuate a control element  104  such as a switch or actuator and the like. The lock  10  can be employed to actuate an electronic control circuit (not shown) or actuate some other device separate from or in addition to providing a barrier to lock the structure  22 . 
     While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims.