Abstract:
A key system including a key for use with a barrel lock having a rotating locking mechanism. The key includes a grip portion and a shank portion operatively attached to the grip portion. The shank portion includes at least one cam surface for rotatably engaging the rotating locking mechanism to permit rotation of the mechanism in one of a clockwise or counter-clockwise direction, but not the other direction, to lock the barrel lock.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application claims priority to U.S. Provisional Application No. 60/864,257, filed on Nov. 3, 2006, titled “ROTATING BARREL LOCK WITH LOCKING KEY,” which is hereby incorporated by reference in its entirety. 

   FIELD OF THE INVENTION 
   The present invention relates generally to a key system for a rotating barrel lock and more particularly to a key system that allows the barrel lock to be delivered to installers in an unlocked state and also allows installers to lock but not unlock the barrel lock thereby reducing key costs and providing an increased level of security. 
   BACKGROUND OF THE INVENTION 
   Utility boxes, such as electric meter boxes, are typically secured to prevent unauthorized access to the meter. Many of such boxes are secured through the use of split ring that is placed directly around the meter and locked through the use of a barrel lock. Other utility boxes, referred to as “ringless” boxes, do not include a lockable meter ring. Ringless boxes are secured by securing a lock assembly containing a barrel lock on either a side wall or a bottom wall of the box. 
   A preferred type of barrel lock for use with the above-described utility boxes is known as a rotating disk barrel lock. These locks include multiple rotating combination disks that, when rotated into the proper position via a key, will open the lock. Known barrel locks include relatively complicated working surfaces on the rotating disks, and correspondingly complicated key surfaces, to obstruct attempts at picking the lock. An example of such a rotating disk barrel lock is described in U.S. Pat. No. 5,086,631, which is hereby incorporated by reference in its entirety. 
   To remove a key from known rotating disk barrel locks, the key must be rotated to a locked position. This rotates a cylinder of the lock to a locked position and scrambles the rotating disks in such a way that a lock keyway is formed allowing the key to be withdrawn. 
   In view of the above, known rotating disk barrel locks are delivered for installation in a locked state. As will be appreciated, in order to install these locks, they must be first unlocked with a key, installed in a split ring or a body of a ringless box lock, and then relocked. 
   As will be appreciated, this requires installers to carry a key capable of both locking and unlocking the barrel lock. These keys are relatively complex with intricate cam surfaces, expensive and, if lost or stolen, could potentially threaten the security of an entire utility system, which typically utilizes a single lock and key for a system. Moreover, the installation process is unnecessarily complicated by the fact that the barrel lock must first be unlocked prior to installation. 
   With the forgoing concerns in mind, it is the general object of the present invention to provide a key system for a rotating barrel lock that includes a master key, which allows the barrel lock to be delivered to installers in an unlocked state, and a simplified dummy key which allows the barrel lock to be locked but not unlocked thereby reducing costs and providing an increased level of security. It is also a general object of the present invention to provide a key system that will work with certain known barrel locks. 
   SUMMARY OF THE INVENTION 
   It is an object of the present invention to provide a key system for a rotating barrel lock. 
   It is an object of the present invention to provide a key system for a rotating disk barrel lock that provides an enhanced degree of security and simplifies the installation process. 
   It is an object of the present invention to provide a key system for a rotating disk barrel lock that reduces manufacturing costs and provides an ease of manufacture. 
   It is an object of the present invention to provide a key system for a rotating disk barrel lock that provides an enhanced degree of security through the use of a master key that can be removed when the lock is in an unlocked state. 
   It is an object of the present invention to provide a key system for a rotating disk barrel lock that provides an enhanced degree of security through the use of a master key that can be removed when the lock is in an unlocked state so that the barrel can be delivered for installation unlocked. 
   It is an object of the present invention to provide a key system for a rotating disk barrel lock that provides an enhanced degree of security, reduced manufacturing costs, and an ease of manufacture through the use of a simplified key that is capable of locking the barrel lock but not unlocking the lock. 
   It is another object of the present invention to provide a key system for a rotating disk barrel lock which may be utilized with certain known rotating disk barrel locks. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1A and 1B  are a perspective view and a cutaway side view of a known rotating disk barrel lock. 
       FIGS. 2A-2C  are plan views of a rotating disk, lifting disk and combination disk of the known lock of  FIG. 1 . 
       FIG. 3  is an enlarged view of a combination disk of the known lock of  FIG. 1 . 
       FIG. 4  is an enlarged view of a second combination disk of the known lock of  FIG. 1 . 
       FIG. 5  is an enlarged, perspective view of a stack of disks of the known lock of  FIG. 1  showing the disks in an unlocked position. 
       FIG. 6  is an enlarged, perspective view of a cylinder end of the known lock of  FIG. 1  depicting the lock in an unlocked position. 
       FIG. 7  is an enlarged, perspective view of the stack of disks of  FIG. 5  showing the disks in a locked position. 
       FIG. 8  is an enlarged, perspective view of a cylinder end of the known lock of  FIG. 1  depicting the lock in an unlocked position. 
       FIG. 9  is an enlarged, perspective view of a master key of a key system for a rotating disk barrel lock in accordance with an embodiment of the present invention. 
       FIG. 10  is an enlarged, perspective view of cam surface sections of the master key of  FIG. 9 . 
       FIG. 11  is a front, cross-sectioned view of the master key of  FIG. 9  showing the key engaging combination disks of the known lock of  FIG. 1 . 
       FIGS. 12A-12D  are front, cross-sectioned views of the cam surface sections of a shank of the master key of  FIG. 9 . 
       FIG. 12E  is a composite view of the cam surface sections of  FIGS. 12A-12D . 
       FIG. 13  is a view of a profile of the shank of the master key of  FIGS. 12A-12D  superimposed on a shank profile of a known key. 
       FIG. 14  is a front, cross-sectioned view of the shank engaging spiral cam surfaces of the known lock of  FIG. 1 . 
       FIG. 14A-14D  are front, cross-sectioned views of a cam surface section engaging a combination disk of the known lock of  FIG. 1  and rotating the disk to an unlocked position. 
       FIG. 15  is a perspective view of a simplified contractor key in accordance with an embodiment of the present invention. 
       FIG. 16  is a front, cross-sectioned view of the simplified contractor key of  FIG. 15  inserted in the known lock of  FIG. 1  in an unlocked state. 
       FIG. 17  is a front, cross-sectioned view of the simplified contractor key and lock of  FIG. 16  in which the key has been rotated counter-clockwise to place the lock in a locked state. 
       FIG. 18  is a perspective, cross-sectioned view of the simplified contractor key and lock of  FIG. 16  showing the interaction of a cam surface of the key with a flat contact portion of an aperture of a combination disk. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIGS. 1A and 1B  depict a known rotating disk barrel lock  10  and known operating key  20 . The barrel lock  10  includes a cylinder portion  30 , which contains a series of rotatable elements  40  that are arranged in a stacked relationship. 
   Referring now to  FIGS. 2A-2C , the rotatable elements  40  include a lifting disk  45  which is located at the inner end of the cylinder, a rotating disk  50  at the outer end of the cylinder and a plurality of combination disks  55  between the rotating and lifting disks. The combination disks  55  are separated from each other, and from the rotating and lifting disks, by washers (not shown). As depicted, all of the disks include a central aperture  60  with curved or spiral cam surfaces  65  on opposite sides of the aperture and flat contact portions  68  directly adjacent to each spiral cam surface  65  on both sides of the aperture  60 . The central apertures  60  of the disks align axially to define a keyway  62 , which is configured to accept the shank of a key. 
   Referring now to  FIGS. 3-5 , the combination disks  55  differ from one another in the orientation of their spiral cam surfaces  65  relative to a notch  75  on each disk which, when aligned, form a channel  80  which receives a locking bar  78  ( FIGS. 5 and 6 ). As will be appreciated, given the varying placement of the notches  75  on the disks, when they are aligned, the spiral cam surfaces  65  are not in alignment and the key way  62  is partially obstructed thwarting removal of existing operating keys  20  which are shaped to closely fit within a completely aligned keyway. 
     FIGS. 5 and 6  illustrate a stack of disks in an unlocked position in which the locking bar  78  resides in the channel  80 . As shown, the spiral cam surfaces  65  are not aligned in this position. As such, existing operating keys capable of both locking and unlocking the above-described locks cannot be removed as the misaligned spiral cam surfaces  65  that form the keyway  60  contact cam surfaces on the operating key  20  preventing it from being withdrawn from the lock. 
   Indeed, the locked position shown in  FIGS. 7 and 8  is the only position in which spiral cam surfaces  65  of the disks are completely aligned. In this locked position, the keyway  62  is fully formed and the close fitting operating key  20  can be removed. 
   As will be appreciated, known locks are delivered for deployment in the field locked, as they cannot be set to an unlocked position and shipped with current operating keys. In view of the above, installers must carry a key capable of both locking and unlocking the locks which presents security concerns if a key is lost or stolen. Moreover, known operating keys are relatively complicated and expensive to manufacture as they include intricate cam surfaces. As described in greater detail below, the present invention provides a key system that allows a rotating disk barrel lock to be delivered unlocked for installation and provides installers with a simplified contractor key only capable of locking the above-described lock. 
   The inventive key system is comprised of two keys, the first of which, referred to as the master key  100 , is depicted in  FIGS. 9-14D . The master key  100  has a shank portion  105 , which includes longitudinally spaced cam surface sections  110 . The number of cam surface sections  110  corresponds to the number of disks in the barrel lock. Each cam surface section  110  engages a separate disk. As will be apparent, this number may vary depending on the configuration of the barrel lock. The shank  105  is shown with a number of cam surfaces sections  110 , which corresponds to the known barrel lock described above. 
   As shown in  FIG. 11 , the shank cam surfaces  110  are sized and shaped to engage certain portions of the spiral cam surfaces  65  of the disks. Each cam surface  110  is shaped to engage the spiral cam surfaces  65  of a specific disk and allow each disk to be rotated. The shapes of the cam surface sections  110 , as viewed from the front of a key shank  105 , are shown in  FIGS. 12A-12D . As shown there are four basic shapes several of which may be repeated along the shank of the master key. The composite frontal profile of the cam surfaces sections  110  of the shank  105  is shown in  FIG. 12E . 
   Referring now to  FIG. 13 , the shank  105  of the master key  100  has a much smaller profile than that of the known key  20 , which is shown superimposed on the inventive shank  105 . The reduced profile allows the key  100  to be withdrawn from a lock while it is in an unlocked state and the keyway is partially obstructed. 
   As will be readily appreciated, the reduced profile of the master key  100  is an important aspect of the present invention as it allows the key to be withdrawn from an unlocked lock. This allows locks to be shipped to installers unlocked which, as discussed below, facilitates the use of a complementary contractors key which can only be used to lock an already unlocked lock. 
   The interaction between the master key  100  and the disks of a lock is shown in  FIG. 14 . Specifically, an unlocked disk configuration is depicted with the locking bar  78  deployed in the channel  80 . In this state, the keyway  60  is partially obstructed by the spiral cam surfaces  65  of the disks. The shank  105  is shaped, however, such that it may be removed from the lock even though the keyway is partially blocked. This is due to the fact that the cam surfaces  110  of the shank  105  do not extend beyond the peripheral boundaries of the spiral cam surfaces  65  of the disks. 
   For reference, the smaller profile of the shank  105  as compared to the profile of the known operating key  120  is as shown in  FIG. 13 . The known key  120  has a much larger profile and has cam surfaces on its shank, which are shaped to closely mate with the spiral cam surfaces  65  of the known lock. This larger profile prevents the key  120  from being removed when the lock is unlocked and the keyway is partially obstructed. 
   While the shank of the master key has a reduced overall profile to facilitate removal, each of its cam surface sections  110  is designed to engage with enough of the spiral cam surfaces  65  of a combination disk so that all of the disks may be rotated clockwise to place the lock in an unlocked position. This is graphically illustrated in  FIGS. 14A-14D  which shows the interaction between a single cam surface section  110  and a combination disk  55 . 
   In particular, the cam surface section  110  engages a relatively small portion of the spiral cam surface  65  of the disk  55 . As the cam surface section  110  rotates, the disk  55  correspondingly rotates clockwise until the lock is unlocked. The key  100  is incapable of rotating the disks counter-clockwise, however, as the shaft  110  lacks sufficient cam surfaces or cuts for effective counter-clockwise disk rotation. 
   In view of the above, the master key cannot lock known locks. This is not a concern, however, as the master key is intended for use as a tool to prepare locks for distribution to installers in the field. That is, the master key is most likely to be employed in a lock manufacturing or distribution facility and not in the field. 
   As mentioned above, the ability to remove the master key from an unlocked lock is an important aspect of the present invention as it allows locks to be delivered unlocked. This in turn makes it possible to develop simplified contractor keys capable of only locking known locks. 
   Furthermore, while the master key is an important aspect of the present invention, it may be possible to assemble a rotating disk lock in an unlocked position without the use of a master key. That is, during the manufacturing and assembly process, the disks may be placed into the cylinder in an unlocked state eliminating the need for a key. 
   Turning now to  FIG. 15 , the present key system also includes a dummy or contractor key  200  has a simplified, reduced profile shank  210 . More specifically, the shank  210  has the profile of a parallelogram and includes longitudinal grooves  215 . The shank  210  includes two opposite cam surfaces  220  which engage the flat contact surfaces  68  located on opposite sides of the apertures  62  of the disks. 
   The relatively simple profile of the shank is an important aspect of the present invention. The simple profile reduces manufacturing costs and provides an ease of manufacture not present with known operating keys. This is important as the contractor keys are likely to be widely deployed and if a key is lost or damaged, the utility is not burdened by the cost of purchasing an expensive replacement. 
   Referring now to  FIG. 18 , the cam surfaces  220  of the shank  210  abutingly engage the flat contact surfaces  68  of the aperture  62  and allow the shank  210  and disks  50 ,  55  to be rotated counterclockwise in direction D. In this figure the disks are shown in a locked configuration. 
   Turning back to  FIG. 16 , the shank  210  is shaped to fit into an unlocked lock where the aperture is partially obstructed by the cam surfaces of the disks. As shown, the shank  210  can be placed in an unlocked lock and rotated counter-clockwise causing the cam surfaces  220  to engage the flat contact surfaces  68 . Typically, one of the disks will first contact the cam surfaces  220  and rotate until the cam surfaces  220  pick up a second disk and third disk, until all disks rotate counterclockwise together. 
     FIG. 17  illustrates a locked position after the insertion and rotating of the contractor key  200  in an unlocked lock as shown in  FIG. 16 . As depicted, the apertures of the disks  55  are aligned and the keyway  62  is completely formed. In this state, the lock is locked and the disks are considered scrambled, i.e., the notches that form the channel for the locking bar are misaligned. 
   Importantly, the parallelogramatic profile of the contractor key  210  does not allow the key  210  to rotate the disks clockwise to unlock the lock. The portions of the shank  210  opposite the cam surfaces  220  are devoid of any camming structures or cuts, and, if rotated clockwise, will not engage a portion of the apertures of the disks to permit clockwise rotation sufficient to attain a disk combination that unlocks the lock. As such, the key cannot unlock known rotating disk barrel locks as described herein. 
   As will be readily apparent, the restricted ability to only lock known rotating barrel locks is a critical feature of the present invention. The present contractor key may be deployed in the field without the threat of a major security breach should the key be stolen or lost. As stated, utilities typically have a single combination, and corresponding single key, for all locks deployed by the utility. If a key capable of unlocking a lock is lost or stolen, it may be used to gain unauthorized access to all of the utility&#39;s meter boxes. With the inventive contractor key, this is not possible as it cannot be used to unlock previously installed and locked barrel locks. 
   Moreover, the ability to use the present key system with known types of barrel locks is a significant feature of the present invention. In particular, the inventive key system can be used for new orders of known locks without any compatibility issues. That is, if a utility uses the aforementioned known lock and places an additional order for the locks, which are delivered in an unlocked state and then installed/locked with the inventive contractor key, existing operating keys may be used to unlock the installed new locks. 
   In sum, the present invention provides a key system that includes a master key capable of removal from an unlocked known rotatable disk barrel lock. This master key allows such locks to be delivered to installers in an unlocked state. The inventive key system further includes a simplified contractor key which only allows the locks to be locked from an unlocked state. As such, the inventive key system reduces key costs and provides an enhanced level of security presently unknown in the art. 
   While the invention has been described with reference to the preferred embodiments, it will be understood by those skilled in the art that various obvious changes may be made, and equivalents may be substituted for elements thereof, without departing from the essential scope of the present invention. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims.