Patent Publication Number: US-8966946-B2

Title: Combination key lock box with anti-pick mechanism

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 61/828,016, filed May 28, 2013, which is hereby incorporated by reference in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a combination key lock box. 
     BACKGROUND OF THE INVENTION 
     A key lock box is a useful device when one forgets his key for the house because a spare key, which is placed inside a key lock box, can be used to gain the access of entrance of the house. In addition, a real estate agent can place the house key in the key lock box on the door knob to gain access to the house without carrying many keys around with him. Often, these key lock boxes in the existing market are with combination locking mechanisms, however, many of these mechanisms have a drawback of being able to be picked very easily within seconds. 
     SUMMARY OF THE INVENTION 
     The present invention relates to a combination key lock box that requires the user to push down the shackle to turn the dials to the correct combination to open the lock. As a result of this feature, an intruder cannot pull the shackle of the lock upward to feel the correct combination because the dials do not rotate when the lock is in a locked position and the shackle is pulled away from the body of the lock. 
     The lock comprises a plurality of clutches, wherein each clutch includes nine faulty notches and one lock-opening notch. The clutch structure reduces the likelihood of the lock being picked by an intruder. The lock also comprises a tube with a spring biasing the tube upward towards the short leg of the shackle. 
     In the locked mode, as the shackle is being pushed upward away from the lock body, extended protrusions on the long leg of the shackle engage with the faulty notches of the clutches, thereby preventing the dials of the lock from rotating. In the locked mode, the user can push and hold the shackle downward toward the lock body such that the extended protrusions disengage from the faulty notches of the clutches, to allow the user to rotate the dials. The rotation of the dials causes the clutches to rotate such that the lock-opening notch of each clutch aligns with the extended protrusions of the shackle when the dials are set to the correct combination to allow the shackle to release out of the lock body. 
     In the locked mode, an end of the long leg of the shackle is engaged with a hole of the lock box cover and a tail of the tube is engaged with a separate hole of the lock box cover, thereby securely locking the lockbox cover in a closed position. When the lock is opened, the shackle is pulled in an upward position and the tube is pushed upward by the spring. The long leg end of the shackle and the tail of the tube thereby move upward and disengage with the holes in the lock box cover. As a result, the user can release the cover by pulling the cover open, and can store and/or remove keys or other items inside of the storage compartment of the lock body. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows the combination key lock box according to the present invention in the locked position. 
         FIG. 2  shows the combination key lock box according to the present invention in the open position. 
         FIG. 3  shows a cross-sectional view of the combination key lock box according to the present invention in the locked position. 
         FIG. 4  shows a cross-sectional view of the combination key lock box according to the present invention wherein the shackle is engaged with the lock body. 
         FIG. 5  shows a cross-sectional view of the combination key lock box according to the present invention wherein the shackle is extended out of the lock body. 
         FIG. 6  shows a cross-sectional view of the combination key lock box according to the present invention in the position to reset the lock combination. 
         FIG. 7  shows a first lock body section of the combination key lock box according to the present invention in the position. 
         FIG. 8  shows a second lock body section of the combination key lock box according to the present invention in the position. 
         FIG. 9  shows the cover of the combination key lock box according to the present invention. 
         FIG. 10A  shows a first view of a clutch of the combination key lock box according to the present invention. 
         FIG. 10B  shows a second view of a clutch of the combination key lock box according to the present invention. 
         FIG. 11  shows a dial of the combination key lock box according to the present invention. 
         FIG. 12  shows the shackle of the combination key lock box according to the present invention. 
         FIG. 13  shows the tube of the combination key lock box according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in the  FIGS. 1-6 , the present invention relates to a combination key lock box  10  that requires the user to push down the shackle  40  towards the first lock body  20  and second lock body  30  to turn the dials  50  in order to open the lock. 
     The combination key lock box  10  comprises a body housing  15  formed by a first lock body  20  and a second lock body  30 , shown in  FIGS. 7 and 8  respectively. The body housing  15  contains various elements of the lock box  10 , including the long leg  41  and short leg  42  of the shackle  40 , the dials  50 , clutches  80 , tube  90  and spring  100 . The top of the body housing  15  is configured with a first slot  21  and a second slot  31  formed in the first lock body  20  and second lock body  30 , each of which is dimensioned for a protrusion  43  on the long leg  41  of the shackle  40  to pass through. A hole  23  in the body housing  15  is dimensioned for receiving the short leg  42  of the shackle  40 . Either or both of the first lock body  20  or second lock body  30  are configured with openings to correspond to the placement of the dials  50  within the body housing  15 , so that a portion of the dials  50  are visible externally. 
     The combination key lock box  10  also includes a storage compartment  22  formed between a section of first lock body  20  and a cover  70 . In one embodiment shown in  FIG. 2 , the bottom-end  25  of the storage component  22  includes a rod  60  to secure the first lock body  20  and cover  70 . The rod  60  is riveted through rod-receiving hole  24  of the first lock body  20  and two holes  74  on the cover  70  which securely holds the storage compartment  22  and the cover  70  together and allows the cover  70  to pivot away from the storage component  22  in order to open the storage component  22 . As seen in  FIG. 9 , the cover  70  further comprises locking holes  71  and  72  configured to engage the tube  90  and long leg  41  of the shackle  40 , respectively. The cover  70  is configured to engage either or both of the shackle  40  and tube  90  in order to securely close the cover  70  and the storage compartment  22 . It is noted that the cover  70  and storage compartment  22  are not limited to the embodiments shown in the Figures, but may include modifications within ordinary skill in the art. 
     In the locked mode, long leg end  45  of the shackle  40  is engaged with the hole  72  of the cover  70 . Further, in the locked mode, the tail  92  of the tube  90  is engaged with the hole  71  of the cover  70 . Because both holes  71  and  72  are engaged with the tail  92  of tube  90  and long leg end  45  of the shackle  40 , respectively, the cover  70  is securely locked and cannot be pulled to open. In alternative embodiments, the cover  70  may be secured by only one of the tube  90  or shackle  40 , and may comprise alternative means to the holes  71  or  72  to secure the cover  70  closed. 
     As seen in  FIG. 12 , the shackle  40  is formed with a long leg  41  and a short leg  42 . The long leg  41  of the shackle  40  includes a first protrusion  43  and a series of extended protrusions  44 . The extended protrusions  44  are in alignment with each other. The short leg  42  of the shackle  40  is contacted by the top end  91  of the tube  90 . The spring  100  biases the tube  90  towards the short leg  42 , thereby applying a force towards releasing the shackle  40  from the body housing  15 . 
     The lock box  10  includes a plurality of dials  50  and a plurality of clutches  80 , which are shown individually in  FIG. 11  and  FIGS. 10A and 10B , respectively. Each of the dials  50  contains a series of external indicia or symbols, such as a series of numbers (0-9). The internal circumference of the dial  50  comprises a plurality of teeth  51 . The teeth  51  are configured such that the space between a pair of adjacent teeth  51  is dimensioned to engage an extended fin  83  of a clutch  80 . By engaging the extended fin  83  of the clutch  80  with the teeth  51 , rotation of the dial  50  further causes a rotation of a clutch  80 , and preventing the rotation of the clutch  80  further prevents rotation of the dial  50 . 
     The clutch  80  further comprises a single lock-opening notch  81  and plurality of faulty notches  82 , as can be seen in  FIG. 10A . In the embodiment shown in the Figures, there are nine faulty notches  82  in view of the ten symbols indicated on the dial  50 . As shown in  FIG. 10B , there is a flat surface  84  on the side opposite the faulty notches  82 . There is a segment of the flat surface  84  removed however in the position of the lock-opening notch  81 . The width of a faulty notch  82  is configured to receive and engage one of the extended protrusions  44  of the shackle  40 . As a result, when an extended protrusion  44  is engaged with a faulty notch  82 , the extended protrusion  44  and the shackle  40  are blocked by the sides of the faulty notch  82  from rotating laterally and are blocked from moving in an upward direction (relative to the configuration shown in  FIG. 2  for example), because the faulty notch  82  is not opened in that direction. Because the lock-opening notch  81  is open for vertical, upward movement, when each of the extended protrusions  44  are aligned with each of the lock-opening notches  81 , the extended protrusions  44  can pass through the notches  81  and the shackle  40  can move in an upward direction. 
     In the embodiment shown in the Figures and described herein, there are an equal number of dials  50 , clutches  80  and extended protrusions  44 , such that each clutch  80  corresponds to a single dial  50  and a single extended protrusion  44 . 
     As a result of this unique configuration, an intruder cannot pull the shackle  40  upward away from body housing  15  to feel the correct combination because the dials  50  cannot rotate when in the locked position. In the locked mode, as the shackle  40  is being pushed upward by the spring  100 , the extended-protrusions  44  of the shackle  40  will engage with the faulty notches  82  of the clutches  80 , which prevents the dials  50  from rotating. In the locked mode, the user can push and hold the shackle  40  downward such that the extended-protrusions  44  will disengage from the faulty notches  82  of the clutches  80  and allow the user to rotate the dials  50 . The rotation of the dials  50  rotate the clutches  80  such that the opening notch  81  of each clutch  80  will align with the extended protrusions  44  of the shackle  40  to allow the shackle  40  to release out of the locking hole  23  of the body housing  15 . In the opened mode, when the dials  50  are in the correct combination, the lock-opening notches  81  are aligned with the extended-protrusions  44  of the shackle  40 , which allows the shackle  40  to be pulled open in an upward position. As the shackle  40  is released in an upward direction, the tube  90  is pushed by the spring  100  in the same direction. In such an arrangement, the long leg end  45  of the shackle  40  will move upward and disengage with the locking hole  72  of the cover  70 . The tail  92  of the tube  90  is also disengaged with the locking hole  71  of the cover  70 . As a result, the user can release the cover  70  by pulling the cover  70  open, and can store and/or remove the keys or other items inside of the storage compartment  22 . 
     The modes of operation of the invention, locked, opened and combination reset, are described in greater detail below. 
     Locked Mode 
     In the locked mode, shown for example in  FIGS. 1 and 3 , the combination is not aligned in the predetermined combination for opening the lock. Therefore, at least one of the plurality of lock-opening notches  81  of the clutches  80  is not aligned with the corresponding extended protrusion  44  of the shackle  40 . 
     In the locked mode, the tube  90  is configured to push the shackle  40  upward such that at least one of the extended protrusions  44  will engage with the corresponding faulty notches  82  of the corresponding clutch  80  to prevent the dials  50  from rotating. The upward biasing of spring  100  causes the top end  91  of the tube  90  to push the short leg  42  of the shackle  40  upward, which also pushes long leg  41  and its extended protrusions  44  of the shackle  40  upward until the at least one of the extended protrusions  44  engages the corresponding faulty notches  82  of the clutches  80 . 
     With such an arrangement, the dials  50  cannot be moved because at least one extended protrusion  44  of the shackle  40  engages at least one of the faulty notches  82  of the clutches  80  that will prevent the rotational movement of the clutches  80 , which also prevents the rotational movement of the dials  50 . As previously described, the dials  50  do not move because the teeth  51  of the dials  50  and the extended fin  83  of the clutch  80  are engaged together. Because the dials  50  are not free to rotate, the lock cannot be picked by feeling the correct combination by rotating the dials  50 . 
     If one or more of dials  50  are set to the correct symbol in the combination, the configuration of the lock box  10  still prevents the particular dials  50  from being rotated. In such a circumstance, the extended protrusion  44  would be aligned with and contained in the corresponding lock-opening notch  81  of the clutch  80 . The side walls of the lock opening notch  81  come into contact with the extended protrusion  44 , thereby preventing the clutch  80  and the dial  50  from being rotatable in that position. The engagement of at least one of the plurality of extended protrusions  44  with at least one corresponding faulty notch  82  prevents the upward movement of the entire long leg  41  of the shackle  40 , regardless of whether any of the other extended protrusions  44  are aligned with a corresponding lock-opening notch  81 . 
     In the locked mode, the cover  70  is held in place by rod  60  which is riveted between the rod-receiving hole  24  at the bottom-end  25  of the storage compartment  22  of the first lock body  20 . The cover  70  is closed, and the locking holes  71  and  72  of the cover  70  are engaged with the tail  92  of the tube  90  and the long leg end  45  of the shackle  40 , which restrict any movement of the cover  70 . With such an arrangement, the cover  70  cannot be pulled open, and the content which is placed inside of the storage compartment  22  is securely stored. 
     Opened Mode 
     The opened mode of the lock can be seen for example in FIGS.  2  and  4 - 5 . In order to open the lock box  10 , while in the locked mode, the user pushes and holds the shackle  40  downward into the body housing  15 . The downward movement of shackle  40  and long leg  41  causes each of the extended protrusions  44  of the shackle  40  to disengage from the faulty-notch slots  82  and/or the lock-opening notches  81  of the clutches  80 . By holding down the shackle  40 , the factors that prevented the dials  50  and clutches  80  from rotating are removed. 
     The dials  50  can then rotate, which in turn rotates the clutch  80  in the same manner as explained above. As the user turns each dial  50  to achieve the correct combination, the lock opening notches  81  comes into alignment with the respective extended protrusions  44 . When this alignment occurs for each extended protrusion  44  of the shackle  40 , the shackle  40  is allowed to be pulled upward for opening. Adjacent to the openings for displaying the dials  50 , the second lock body  30  comprises a series of indicators  32  to indicate where the alignment of the symbols on the dials  50  is made for entering the combination. 
     The combination is formed by a series of symbols, wherein each symbol in the combination indicates the position that each dial  50  must be in for the corresponding extended protrusion  44  to be aligned with the corresponding lock opening notch  81 . When the correct combination, or sequence of symbols, are aligned on each of the dials  50 , each corresponding extended protrusion  44  is aligned with each corresponding lock opening notch  81 . Because of this alignment, the biasing effect of spring  100  on tube  90  and short leg  42  is no longer blocked as described above, but is able to force the short leg  42  of the shackle  40  out of the hole  23  of the body housing  15  into an open configuration. The protrusion  43  on the long leg  41  is further forced through the first slot  21 . 
     As the shackle  40  moves upward, the long leg  41  of the shackle  40  disengages from the locking hole  72  of the cover  70  and the tube  90  is pushed upward by the spring  100  and the tail  92  disengages from the locking hole  71  of the cover  70 . Because the tail  92  of the tube  90  and the long leg  41  of the shackle  40  disengage from the locking holes  71  and  72  of the cover  70 , the cover  70  can be freely pulled open. 
     As shown in  FIGS. 3-6 , a ball bearing  130  is placed in the first and second lock bodies  20  and  30 . The ball bearing  130  is received by a groove-cut  73  of the cover  70  in the lock mode. Ball bearing  130  is biased by a spring  140 . When the cover  70  is closed, the ball bearing  130  will engage from the groove-cut  73  of the cover  70 . In the open mode, as the shackle  40  is opened, the user will need to exert some force to overcome the ball bearing  130  to pull the cover  70 . This force to the cover  70  is such that when the shackle  40  and tube  90  are in upward position, the cover  70  does drop suddenly and hit the user or drop the contents of the storage compartment  22 . The user must pull the cover  70  to open because of the force applied by the ball bearing  130 . The cover  70  may comprise a tab or other mechanism to aid the user in opening. 
     Resetting the Combination 
       FIG. 6  shows the lock box  10  of the invention in the mode where the combination can be reset. When the shackle  40  is pulled upward in the open mode, the shackle  40  can rotate freely. The user can turn the shackle  40  at a pre-designated angle (e.g., counterclockwise 90 degrees) and push the shackle  40  downward into the body heading  15 . As the shackle  40  is pushed downward, the protrusion  43  of the shackle  40  passes through the second slot  31  of the second lock body  30  and the extended protrusions  44  of the shackle  40  will contact the flat surface  84  of the clutches  80  and can push the set of clutches  80  downward. The downward movement of the clutches  80  disengages the respective extended fins  83  from each corresponding dial  50 . As the extended fins  83  of the clutches  80  are no longer engaging the teeth  51  of the dials  50 , the user can turn the dial  50  without also turning the clutch  80 . This allows the user to turn the dials  50  to a new combination while each of the clutches  80  remains in a position where each extended protrusion  44  is aligned with each lock-opening notch  81 . After the user sets the combination, the user can then release the shackle  40 . A spring  120  is positioned underneath a spacer ring  110  beneath the arrangement of dials  50  and clutches  80 . Upon release of the shackle  40 , the spring  120  causes the spacer ring  110  and the clutches  80  to move upward. As the clutches  80  move back to the original position, the extending fins  83  of the clutches  80  will engage back to the teeth  51  of the dials  50 . 
     Although the present invention has been described above with reference to the exemplary embodiment shown in the Figures, it should be noted that several alternative embodiments of the present invention exist without departing from the scope or spirit of the invention. For example, in alternative embodiments, the tube may be positioned beneath the long leg of the shackle. Additionally, the present invention is not limited to the particular number of dials/clutches or the number or type of symbols presented on the dials. 
     While there have been shown and described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the devices and methods described may be made by those skilled in the art without departing from the spirit of the invention. For example, it is expressly intended that all combinations of those elements and/or method steps which perform substantially the same function in substantially the same way to achieve the same results are within the scope of the invention. Moreover, it should be recognized that structures and/or elements and/or method steps shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice. It is the intention, therefore, to be limited only as indicated by the scope of the claims appended hereto. Furthermore, in the claims means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Thus although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts, a nail and a screw may be equivalent structures.