Abstract:
There is disclosed a dead-latching slam bolt lock that includes a rotating dead-latching slam bolt which prevents attempts at breaking in without actuating the lock mechanism. A tongue or toggle acted on by the door jamb engages the bolt and initiates rotation thereof in the door closing direction, but is passive in the opening direction. The locking mechanism may be manual or electronic, and controls the position of a blocking element which alternately prevents and permits unlocking (rotation) of the rotating bolt. In a forward or blocking position, the blocking element prevents rotation of the bolt from a locked position, while in a retracted position the blocking element permits rotation of the bolt to an unlocked position. A spring detent plunger holds the rotating bolt in either its locked or unlocked positions.

Description:
RELATED APPLICATION INFORMATION 
       [0001]    This patent claims priority under 35 U.S.C. §119 from Provisional Patent Application No. 62/248,045, filed Oct. 29, 2015, titled DEAD-LATCHING SLAM BOLT LOCK which is expressly incorporated by reference in its entirety. 
     
    
     NOTICE OF COPYRIGHTS AND TRADE DRESS 
       [0002]    A portion of the disclosure of this patent document contains material which is subject to copyright protection. This patent document may show and/or describe matter which is or may become trade dress of the owner. The copyright and trade dress owner has no objection to the facsimile reproduction by anyone of the patent disclosure as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright and trade dress rights whatsoever. 
       BACKGROUND 
       [0003]    Field 
         [0004]    This disclosure relates to a door lock and more particularly, to a more robust dead-latching slam bolt door lock especially useful for safes and/or lockers placed inside larger safes. 
         [0005]    Description of the Related Art 
         [0006]    Safes, or high security containers, come in an infinite array of designs. One primary markets is commercial safes, where safes are often designed and manufactured to the client&#39;s requirements. Many of these safes are equipped with a conventional outer safe door, but also have locker(s) inside to facilitate different cash handling methods and processes. Electronic safe locks have evolved rapidly to replace mechanical systems since their introduction in the early 1990s. 
         [0007]    There are two fundamental locking systems used in safes: 
         [0008]    a. Boltwork Blocking: where a safe door is held closed by robust locking bolts, carried by a common carriage bar. The locking bolts are engaged behind a stationary jamb in the safe body. The boltwork is held in the locked position by a safe lock that prevents the articulation of the common carriage bar. These locks are typically “dead-latching,” meaning they can only be disengaged by the actuating the manual or electronic switch to open the lock. The carriage bar is articulated manually by a rotating or sliding handle mechanism. 
         [0009]    b. Direct Locking: where a safe lock directly engages the stationary jamb in the safe body. The locks of this type typically include a spring-biased ramped locking bolt that is depressed as the bolt contacts and passes the stationary jamb, thus making it unnecessary to activate the lock to close the locker door. The bolt action of this type of lock would be similar to a conventional door knob-lock, except the retraction is effected by the electronic locking system controls. These locks are often referred to as “Slam Bolt Locks,” as the closing action causes the spring-biased bolt to push open, then spring back behind the jamb when the door is fully closed. The name signifies that you “Slam” the door to close and lock it without any need for lock articulation. 
         [0010]    One problem with existing direct locking slam bolt-type locks is that the contents of a safe may interfere with opening of the lock. That is, a weight applied from inside the safe on the door tends to apply an outward load. The spring-biased bolt is thus pressed outward against the door jamb, which might interfere with its smooth opening. The resulting wear imposed on surfaces that were not intended to be structurally loaded may eventually lead to failure. Further, since the bolt must be free to push in as it contacts the jamb during door closure, it likewise can be pressed in against the spring force when the door is closed, and cannot be dead-latched. This is true for solenoid or knob actuated slam bolt locks and presents a security risk, as opening can be accomplished by using a fishing probe from any opening where access may be made. This is also in contrast to a dead-latching lock which can only be disengaged by actuating the manual or electronic switch to open the lock. 
         [0011]    There is thus a need for a more robust dead-latching slam bolt lock. 
       SUMMARY OF THE INVENTION 
       [0012]    The present application discloses a more robust dead-latching slam bolt lock that is relatively unaffected by outwardly-directed loads imposed on the door from inside the container. The lock includes a rotating dead-latching slam bolt which prevents attempts at breaking in without actuating the lock mechanism. A tongue or toggle acted on by the door jamb engages the bolt and initiates rotation thereof in the door closing direction, but is passive in the opening direction. The locking mechanism may be manual or electronic, and controls the position of a blocking element which alternately prevents and permits unlocking (rotation) of the rotating bolt. In a forward or blocking position, the blocking element prevents rotation of the bolt from a locked position, while in a retracted position the blocking element permits rotation of the bolt to an unlocked position. A spring detent plunger holds the rotating bolt in either its locked or unlocked positions. 
         [0013]    The disclosed lock includes a tongue or toggle, and is specific to the direct-locking door application. The present lock works on the plane of intended action, and is engineered to provide greater holding strength. The present lock actuates in an axial direction following the direction of door travel. It is mechanically stronger in the direction of door motion. The present lock provides better actuation, as it uses a rotational actuation path for the bolt that follows the geometry of the closure mechanics. The present lock is held in the locked position by a strong spring detent plunger that prevents the unintended loads from hindering the lock actuation. The present lock bolt is a rotating component that is blocked by a solenoid or other manual or electro-mechanical actuator. When the actuator is energized, the door can be pulled with moderate force to cause the bolt to “toggle” to the unlocked position. The spring loaded detent plunger works in an “over-center” or “bi-stable” action to also hold the bolt in an unlocked condition one the door is pulled open. There is a spring loaded release bar in the bolt that contacts the jam during closure, which trips the rotating bolt back into the locking position. The present lock is dead-locking, and cannot be articulated without using the intended electronics to actuate the blocking device. Once the lock is actuated, the door is opened by simply pulling on a knob. Once the bolt is locked, it cannot be moved to an unlocked position unless the internal blocking actuator is activated to provide the freedom of motion to rotate open. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0014]      FIG. 1A  is a horizontal sectional view through a door being closed showing a prior art slam bolt lock thereon, and  FIG. 1B  shows the bolt of the slam bolt lock engaged with a door jamb in a locked position; 
           [0015]      FIG. 2A  is a horizontal sectional view through a door being closed showing a toggle lock of the present application thereon, and  FIG. 2B  shows the bolt of the toggle lock engaged with a door jamb in a locked position; 
           [0016]      FIGS. 3A-3D  are elevational views of different sides of the exemplary toggle lock of the present application; 
           [0017]      FIGS. 4A-4B  are cutaway perspective views of the exemplary toggle lock from different angles and showing the mechanism in a locked configuration; 
           [0018]      FIGS. 5A-5C  are horizontal sectional views through a door having the toggle lock and showing a door closing sequence; 
           [0019]      FIGS. 6A-6C  are horizontal sectional views through a door having the toggle lock and showing a door opening sequence; and 
           [0020]      FIGS. 7A-7B  are cutaway perspective views of the exemplary toggle lock showing engagement of a tongue or toggle with the rotating bolt. 
       
    
    
       [0021]    Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number where the element is introduced and the two least significant digits are specific to the element. An element that is not described in conjunction with a figure may be presumed to have the same characteristics and function as a previously-described element having the same reference designator. 
       DETAILED DESCRIPTION 
       [0022]    The present application discloses an improved direct-latching lock of the slam-bolt variety. The lock partly relies on a tongue or toggle, and thus will be termed a “toggle lock” herein. The toggle lock is especially beneficial for use on lockers placed within larger safes, but may also be used as a safe lock as well as a lock for any door closure. The bolt for the toggle lock preferably rotates, though a linearly-actuated bolt for a toggle lock otherwise having the same features is contemplated; thus the term “displacement” for the bolt encompasses any possible form of movement. 
         [0023]      FIG. 1A  is a horizontal sectional view through a door  20  being closed showing a prior art slam bolt lock  22  mounted thereon. The door includes a front panel  24  mounted on one or more hinges  26  to a door frame  28 , which forms a part of a safe, locker or other container of items to be secured. The slam bolt lock  22  engages a door jamb  30  on one side of the door frame  28 . In the step of closing the door  20 , a bolt  32  of the slam bolt lock  22  is pushed in by contact with the door jamb  30 . In particular, a rear face of the bolt  32  is curved or ramped so that the jamb  30  cams the bolt  32  laterally inward into the body  34  of the slam bolt lock  22  and against the resistance of an internal spring (not shown). 
         [0024]      FIG. 1B  shows the bolt  32  of the slam bolt lock  22  engaged behind the door jamb  30  in a locked position. That is, once the front outer corner of the bolt  32  clears the door jamb  30 , the internal spring pushes it back outward to its locked position. A flat front face of the bolt  32  then contacts the door jamb  30 , which interference prevents the door  20  from opening. Although not shown, an internal solenoid or other actuator may be used to retract the bolt  32  laterally into an unlocked position to enable opening of the door  20 . The lateral actuation direction of the bolt  32  to unlock it is shown. 
         [0025]    As mentioned above, there are two main drawbacks to this simple design. First, the bolt  32  is not dead-latching, meaning it can be retracted laterally in the actuation direction into its unlocked position through the use of a thin tool or other such device (think of a credit card used to push back a conventional slam bolt lock in the door of a structure). Secondly, any loads imposed on the inside of the lock  22  or door panel  24  in the opening force direction tends to cause the bolt  32  to press against the door jamb  30 . This interferes with the operation of the opening solenoid and may even prevent the lock  22  from functioning properly or ultimately cause damage to the lock  22 . 
         [0026]      FIG. 2A  is a horizontal sectional view through a door  40  being closed showing a toggle lock  42  of the present application mounted thereon. As before, the door  40  includes a front panel  44  mounted on one or more hinges  46  to a door frame  48 , which forms a part of a safe, locker or other container of items to be secured. The slam bolt lock  42  engages a door jamb  50  on one side of the door frame  48 . In the step of closing the door  40 , a bolt  52  of the toggle lock  42  rotates from a retracted or unlocked position within a body  54  of the toggle lock  42  into an advanced or locked position as shown in  FIG. 2B . It should be understood that the generic door configuration shown represents numerous locking door assemblies, and the present toggle lock will be useful in any number of such assemblies. 
         [0027]      FIG. 2A  shows a tongue or toggle  56  of the toggle lock  42  extending laterally out from the lock body  54 . As the door panel  44  closes, the toggle  56  eventually contacts an outer face of the door jamb  50  causing it to rotate; a counter-clockwise (CCW) direction in the orientation shown. As will be explained below, the toggle  56  internally engages the bolt  52  and causes rotation thereof from its retracted (unlocked) position to its advanced (locked) position. The bolt  52  simply rotates into the position of  FIG. 2B  behind the door jamb  50 , without contact therewith, while toggle  56  ends up in a resting state between the door jamb  50  and the toggle lock body  54 , just inside of the door panel  44 . As with the prior art slam bolt lock  22  described above, when in the advanced position a flat front face of the bolt  52  of the toggle lock  42  is juxtaposed against an inner face of the door jamb  50  and contacts the door jamb when an opening force is applied to the door panel  44 , which interference prevents the door  40  from opening. 
         [0028]      FIGS. 3A-3D  are elevational views of different sides of the exemplary toggle lock  42  of the present application. As mentioned, the toggle lock  42  includes a body  54  formed of high strength steel or the like. Typically the body  54  includes two somewhat similar halves securely joined together to form a hollow interior within which the locking mechanism is mounted. The toggle lock  42  is shown in its locked state with the bolt  52  extended from within the body  54  and the toggle  56  rotated to the position as seen in  FIG. 2B . 
         [0029]    The toggle lock body  54  preferably mounts to the door panel  44  via a mounting plate  58  extending out from the body and having holes through which a plurality of Allen bolts  60  extend. More preferably, the body  54  has a plurality of outwardly-extending flanges (not shown) with elongated holes that align with the mounting plate  58  holes so that the body  54  may be adjusted laterally with respect to the door panel  44  before the bolts  60  are tightened. A small pointer  64  on the mounting plate  58  registers with a series of position markings on the body  54  for this purpose. 
         [0030]      FIG. 3D  shows a pair of vertically stacked communication ports  62  opening rearwardly from the body  54 . Although not shown in  FIGS. 2A and 2B , an electronic lock control such as a numeric touch pad will also be mounted to the door panel  44  or frame  48  and connected to the communication ports  62  to actuate the toggle lock  42 . There are numerous types of such electronic lock controls available, and the present application is not limited thereby. Furthermore, although the lock actuation described herein is electro-mechanical, purely manual lock controls may also be incorporated as will be appreciated by those of skill in the art. In this sense the term “lock control” refers to both manual and electro-mechanical versions. 
         [0031]      FIGS. 4A-4B  are cutaway perspective views of a front portion of the exemplary toggle lock  42  of the present application. The bolt  52  is shown extending out of an aperture in the body  54  in its advanced or locked position. The bolt  52  rotates about an axis  64  fixed with respect to the body  54  via a journal bearing or simple shaft and tube arrangement. The direction of rotation is shown by a double-headed arrow. Likewise, the toggle  56  rotates about the same axis  64 . 
         [0032]    A spring-loaded detent plunger  66  has a lower end  68  rotatably mounted to a shaft stub (not numbered) carried by the bolt  52  and an upper end  70  rotatably mounted to another shaft stub (also not numbered) on a solenoid body  72  fixed within the toggle lock body  54 . The shaft stub axes are parallel to the axis  64 . The lower end  68  of the detent plunger  66  is thus carried by the bolt  52  when it rotates. The detent plunger  66  includes a piston  74  connected to its lower end  68  that slides within a cylinder  76  connected to its upper end  70 , with a relatively strong spring  78  interposed therebetween to bias the piston out of the cylinder. The shaft stub on the bolt  52  to which the lower end  68  mounts traces an arc of rotation  80  that comes closest to the shaft stub on the solenoid body  72  at about a mid-point of travel of the bolt  52 . In this way, the spring-loaded detent plunger  66  applies opposite rotational forces to the bolt  52  depending on whether the bolt is in its locked or unlocked positions. That is, the spring  78  causes the piston  74  to extend from the cylinder  76  and hold the bolt  52  in its locked and unlocked positions. The bi-stable nature of the detent plunger  66  keeps the bolts  52  advanced with the door is closed and retracted with the door is open. 
         [0033]      FIGS. 5A-5C  are horizontal sectional views showing snapshots of closure of the door having the toggle lock  42 . Initially, as in  FIG. 5A , the bolt  52  is retracted into the lock body  54  with the detent plunger  66  rotated CCW past the mid-point of its travel so that is biases the bolt in that direction. As will be described, the toggle  56  is spring-biased as well in a CCW direction about the axis  64  so that it remains extending generally laterally from the lock body  54  in an extended position and in the path of the door stop  50  as the door panel  44  rotates closed. 
         [0034]      FIG. 5B  shows further closure of the door panel  44  at a point where the door stop  50  makes contact with the toggle  56  and rotates it CCW. Engagement between the toggle  56  and the bolt  52  causes likewise CCW rotation of the bolt, as shown by the movement arrow. The shape and rotational path of the bolt  52  allows it to rotate around to the back side of the door stop  50  with ease. In this moment the detent plunger  66  rotates CCW as well toward its mid-point of travel, at which time it will apply an opposite rotational bias to the bolt  52 . Closure of the door panel  44  in this regard thus must overcome the force of the spring  78  on the detent plunger  66 , but the weight of the door and its relatively large leverage overcomes the spring fairly easily. It should be noted that the rear face of the bolt  52  is curved as with conventional slam bolt locks, although the purpose is not for engagement with the door jamb  50 , rather the curved surface facilitates rotation in and out of the body  54 , and reduces the overall size of the lock  42 . 
         [0035]    Finally,  FIG. 5C  shows the door panel  44  closed against the door jamb  50  and the toggle lock  42  locked. The bolt  52  is fully advanced to its locked position behind the door jamb  50  and is biased into this position by the detent plunger  66 . An inside face  81  of the bolt  52  travels past a point at which a solenoid shaft  82  may extend from the solenoid body  72 . See also  FIG. 4B  where the solenoid shaft  82  is shown engaged with a chamfer  84  having a ledge that limits travel of the shaft. The chamfer  84  is shown on the front of the bolt  52  in  FIG. 3C  but extends around to the back side. 
         [0036]    Imposition of the solenoid shaft  82  behind the direction of travel of the bolt  52  prevents the bolt from rotating in a clockwise (CW) direction. The solenoid body  72  preferably has a direct drive solenoid coil and magnet within that has a relaxed state when the solenoid shaft  82  extends, and when energized pulls the solenoid shaft  82  back into its housing. The solenoid is actuated via signals received by the communication ports  62 . This linear movement of the solenoid shaft  82  may also be accomplished by a purely mechanical lock control, as mentioned, and the solenoid shaft  82  may rotate into its locked position rather than translate. Variations on these mechanisms are well known in the art, and the general term “blocking member” will be used to encompass the solenoid shaft  82  as well as other equivalent structures. 
         [0037]      FIGS. 6A-6C  are horizontal sectional views showing opening of the door panel  44  having the toggle lock  42 . Initially, the lock control is actuated so that the solenoid shaft  82  (or blocking member) retracts from within the rotational path of the bolt  52 . That is, the solenoid shaft  82  no longer abuts the inside face  81  of the bolt  52 . At this stage the bolt  52  remains in its locked position, but there is no longer anything preventing its movement other than the bias of the spring detent plunger  66 . 
         [0038]      FIG. 6B  shows the door panel  44  being opened such that the door jamb  50  contacts and rotates the bolt  52  in a CW direction about the axis  64 . Eventually the bolt  52  rotates far enough so that the detent plunger  66  passes the bi-stable point and consequently biases the bolt in the CW direction. 
         [0039]    Finally,  FIG. 6C  shows the bolt  52  fully retracted within the lock body  54  and held in this position by the detent plunger  66 . The lock  42  is fully open. It should be noted that actuation of the solenoid will not cause extension of the solenoid shaft  82  because of the presence of the bolt  52 . In this manner the door panel  44  is not prevented from closing. Desirably, with an electronic lock control, an attempt to actuate the solenoid when the door is open returns an error message. 
         [0040]      FIGS. 7A-7B  are cutaway perspective views of the exemplary toggle lock  42  showing engagement of the toggle  56  with the rotating bolt  56 . As mentioned, both the bolt  52  and toggle  56  rotate about the axis  64  fixed on the body  54 . The toggle  56  is free to rotate with respect to the bolt  52  within limits, and is spring biased in the CCW direction relative to the bolt  52 . More specifically, a coil spring  90  secures at one end to a pin  92  on the inside of the bolt  52  and at the opposite end to a finger  94  extending rearwardly from the toggle  56 . Further, a small rearwardly-extending wedge-shaped projection  96  on the toggle  56  comes into contact with the inside face  81  of the bolt  52 , as best seen in  FIG. 4B . When the toggle  56  rotates in a CCW direction from contact with the door jamb  50 , as seen in  FIG. 5B , the wedge-shaped projection  96  rotates the bolt  52  as well. In this way, the toggle  56  and bolt  52  move together when the door is closed. Likewise, when the door opens the door jamb  50  forces the bolt  52  and toggle  56  to rotate CW in tandem. The spring  90  maintains the wedge-shaped projection  96  in contact with the inside face  81  of the bolt  52  so that the toggle does not swivel loosely and interfere with the subsequent door closing operation. 
         [0041]      FIG. 7B  illustrates a hard stop  98  for the bolt  52 . Specifically, the stop  98  comprises a cylindrical post fixed within the body  54  that is received in a similarly shaped recess  99  formed in the rear face  81  of the bolt  52 . CW rotation of the bolt  52  when opening the door eventually causes the plunger  66  to bias the recess  99  into contact with the post  98 , thus limiting further travel. 
         [0042]    Some of the lock features and differences are: 
         [0043]    a. The present lock works on the plane of intended action, and is engineered to provide greater holding strength. Conventional “Slam Bolt” locks are adaptations of Boltwork Blocking Lock designs, where the intended locking direction is lateral in the direction of the Boltwork travel. These locks were never intended to be used where the forces are imposed in the axial direction, only lateral. Consequently, they are weak and easily broken or defeated in locker door use. In contrast, the present lock actuates in an axial direction following the direction of door travel. It is mechanically stronger in the direction of door motion. 
         [0044]    b. The present lock provides better actuation, as it uses a rotational actuation path that follows the geometry of the closure mechanics. Slam bolt locks are loaded in an unnatural direction when the locker doors are pulled. Many times, the doors retain contents like cash bags that impose a load on the inside of the door, pushing the slam bolt into the jamb, impeding the free motion of the bolt to retract, thus causing failed openings. Many slam bolt locks are actuated by a solenoid pulling the bolt into the unlocked position. The present lock is held in the locked position by a strong spring detent plunger that prevents the unintended loads from hindering the lock actuation. Further, in a Slam Bolt lock the bolt is retracted my one of two types of designs, 1) Manual Knob on the face of the door, and 2) by a direct-drive Solenoid that pulls the bolt to the unlocked position. The direction of loads and resulting wear are imposed on surfaces that were not intended to be structurally loaded. The present lock bolt is a rotating component that is blocked by a blocking element controlled by a manual or electro-mechanical actuator such as a direct-drive solenoid. When the actuator is energized, the door can be pulled with moderate force to cause the bolt to “toggle” to the unlocked position. The spring loaded detent plunger works in an “over-center” action to also hold the bolt in an unlocked condition one the door is pulled open. There is a spring loaded release bar in the Bolt that contacts the jam during closure, which trips the rotating bolt back into the locking position. 
         [0045]    c. The present lock is dead-locking, and cannot be articulated without using the intended electronics to actuate the blocking device. With a Slam bolt lock, the bolt can be pressed in against spring force, and cannot be dead-latched because it must be free to push in as it contacts the jamb during door closure. This is true for solenoid or knob actuated slam bolt locks. This presents a security risk, as opening can be accomplished by using a fishing probe from any opening where access may be made. The present lock is actuated by the pulling on the door (a pull knob is present, not shown). Once the bolt is locked, it cannot be moved to an unlocked position unless the internal blocking actuator is activated to provide the freedom of motion to rotate open. 
       CLOSING COMMENTS 
       [0046]    Throughout this description, the embodiments and examples shown should be considered as exemplars, rather than limitations on the apparatus and procedures disclosed or claimed. Although many of the examples presented herein involve specific combinations of method acts or system elements, it should be understood that those acts and those elements may be combined in other ways to accomplish the same objectives. Acts, elements and features discussed only in connection with one embodiment are not intended to be excluded from a similar role in other embodiments. 
         [0047]    As used herein, “plurality” means two or more. As used herein, a “set” of items may include one or more of such items. As used herein, whether in the written description or the claims, the terms “comprising”, “including”, “carrying”, “having”, “containing”, “involving”, and the like are to be understood to be open-ended, i.e., to mean including but not limited to. Only the transitional phrases “consisting of” and “consisting essentially of” respectively, are closed or semi-closed transitional phrases with respect to claims. Use of ordinal terms such as “first”, “second”, “third”, etc., in the claims to modify a claim element does not by itself connote any priority, precedence, or order of one claim element over another or the temporal order in which acts of a method are performed, but are used merely as labels to distinguish one claim element having a certain name from another element having a same name (but for use of the ordinal term) to distinguish the claim elements. As used herein, “and/or” means that the listed items are alternatives, but the alternatives also include any combination of the listed items.