Abstract:
An electronic locking mechanism comprises a first rod and a second rod. The second rod secures to the first rod by a cam wafer, which is attached to the second rod. A locking and unlocking mechanism secures the cam wafer to the first rod and releases the cam wafer from the first rod via an electrical solenoid.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to locking mechanisms and, more particularly, to an electronic locking mechanism adaptable to fit enclosures of varying dimensions, while maintaining minimal power consumption. 
     BACKGROUND OF THE INVENTION 
     There are currently many different ways to lock things. One of the most common ways is the key locking mechanism. This type of mechanism is relatively secure and tamper proof. However, it is difficult to re-key a key lock to work with a different key if the original key is lost or stolen. Key locks can also be picked. In addition, it is sometimes inconvenient to keep a key. 
     Manual and electronic combination locking mechanisms provide many advantages. People may forget the combination, but at least they do not have to keep a key. The problem with manual combination locks such as those found on safes, vaults, lockers, and other enclosures, however, is that parts of the actual locking mechanism are often exposed and thus subject to tampering. In addition, mechanical combination locks require machining to high tolerances to avoid manipulation attacks. 
     While electronic combination locks are generally not exposed, they have other disadvantages. Electronic locks must keep the strike retracted until the user opens the lock, thus using large amounts of power. Another problem associated with electronic locks is that the strike operation can time out, thus forcing re-entry of the key. If one-time keys are used, access can be denied if the user is slow. 
     Another disadvantage of both key and combination locking mechanisms is their inability to accommodate enclosures of varying dimensions without having to alter the basic operation of the locking mechanism or having to use multiple locks for long doors. 
     Therefore, there is a need for an electronic locking mechanism that draws little power and that is adaptable to accommodate a broad range of enclosures. 
     SUMMARY OF THE INVENTION 
     One embodiment of the present invention provides an improved electronic locking mechanism that requires little power during operation and that is readily adaptable to fit enclosures of varying sizes without having to change the operation of the locking mechanism. The locking mechanism may be adapted to use two rods, a first and a second. The first rod may be attached to one side (i.e., a fixed portion) of an enclosure. The second rod may be attached to the door or lid (i.e., a movable) side of the enclosure. The first and second rod can be cut to the length necessary to fit the enclosure. Attached to one of the rods, preferably the second rod, are one or more cam wafers which are configured to engage to the first rod to lock the mechanism. 
     The locking mechanism itself is solenoid driven and can be secured to any one of the cam wafers in order to hold the lock in place. The solenoid is spring actuated and is powered by a battery or some other source of electricity. In the preferred embodiment, the electricity source is located in a module external from the locking mechanism. When the correct combination code is entered through a keypad and electronic controller, the controller energizes the solenoid just long enough for the solenoid to lift the pawl arm. When the pawl arm is lifted, no other force acts on the cam wafer in the locking mechanism. Because of the action of a torsion spring, which is coiled around the second rod with potential energy, when the force of the pawl arm is released from the cam wafer the second rod rotates and the cam wafer rotates and disengages from the first rod. 
     To lock the mechanism, the user manually pushes on the door or lid of the enclosure. The first rod contacts the cam wafer and, as the user pushes the door or lid shut, the second rod rotates and the cam wafer rotates. An aperture in the cam wafer slips behind a portion of the pawl arm, which comes down like a clamp and locks it in place. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example, and not limitation, in the figures of the accompanying drawings in which like reference numerals refer to similar elements and in which: 
     FIG. 1 is a perspective view of the locking mechanism shown in the locked position in accordance with one embodiment of the present invention. 
     FIG. 2A is a top view of the locking mechanism showing a cam wafer engaged with the first rod as would be the case when the locking mechanism is in the locked state. 
     FIG. 2B is a top view of the locking mechanism showing the cam wafer disengaging from the first rod as the locking mechanism is unlocking in accordance with one embodiment of the present invention. 
     FIG. 3 is a side view of the locking mechanism in the locked position in accordance with an embodiment of the present invention. 
     FIG. 4 illustrates various components of the locking mechanism including the cam wafer, the solenoid, the cam spring, the pawl arm, the microswitch and the pawl spring in accordance with an embodiment of the present invention. 
     FIG. 5 is a perspective view of the lock box, the cam wafer, and the pawl arm components of the locking mechanism in accordance with an embodiment of the present invention. 
     FIG. 6 is a side view of the locking mechanism showing how multiple cam wafers may be added to the second rod as might be needed when locking a large enclosure. 
    
    
     DETAILED DESCRIPTION 
     Throughout the following description specific details are set forth in order to provide a more thorough understanding of the invention. However, the invention may be practiced without these particulars. In other instances, well known elements have not been shown or described in detail to avoid unnecessarily obscuring the present invention. Accordingly, the specification and drawings are to be regarded in an illustrative, rather than a restrictive, sense. 
     Referring now to FIG. 1, there is shown a perspective view of an adaptable electronic locking mechanism configured in accordance with one embodiment of the present invention. The locking mechanism  100  includes a first rod  20  and a second rod  22 . The first rod  20  is a round rod and is attached to one side of an enclosure. The second rod  22  is a hexagonal rod and is attached to the door or lid side of the enclosure. The first rod  20  and second rod  22  are cut to the length necessary to fit the enclosure. Note, in this example the rods have the cross-sectional shapes recited above, but this is not critical to the present invention. Rods of any convenient cross-sectional shape may be used so long as the overall functionality of the locking mechanism remains substantially similar to that described below. 
     Attached to the second rod  22  is a cam wafer  30  which is configured to engage to the first rod  20  to lock the mechanism. The cam wafer  30  includes a thru-hole  32  through which the second rod  22  may pass. In this way the cam wafer  30  may be secured to the second rod  22 . A u-shaped hole  34  in the cam wafer  30  engages the first rod  20  and is fitted to the diameter of the first rod  20 . A clip on the cam wafer (not shown in this view) extends below the horizontal plane of the body of the cam wafer  30  and engages the torsion spring  40  which is coiled around the second rod  22  below the cam wafer  30 . A portion of the cam wafer  30  may bend downward in a right angle to the main horizontal plane of the cam wafer  30 . The bent portion of the cam wafer  30  may have a u-shaped hole  36  to engage the end of the torsion spring  40  at the base of the locking mechanism  100  and thus provide a self-opening tension for the door. 
     Circumferential or semi-circumferential grooves (not shown in this view) may be cut into the second rod  22  directly above and below the cam wafer  30 . These grooves can accommodate an upper e-clip  42  and a lower e-clip  44 , which in this example are dome-shaped wafers made of spring steel. The domed portion of the upper e-clip  42  and the lower e-clip  44  is inserted laterally into the respective grooves on the second rod  22  thereby securing the upper e-clip  42  and the lower e-clip  44  to the second rod  22 . The cam wafer  30  is held firmly in place between the upper e-clip  42  and the lower e-clip  44  and is thus prevented from moving up or down the second rod  22 . Similarly, other shapes for the e-clips  42  and  44  may be used. However, regardless of the configuration of the e-clips  42  and  44 , it is desirable to include some method such as press-fittings or set screws to prevent displacement of the cam wafer  30  along the second rod  22 . 
     The locking mechanism includes a lock box  60  that may be fabricated from stainless steel or other suitable material and shaped to form a three sided housing which may be attached to the inside of an enclosure (not shown in this view). The lock box  60  may be mounted on the rear or inside surface of the enclosure by conventional fastening means, such as screws and bosses. The present invention is useful in a variety of applications. Therefore, the lock box  60  may be mounted to the inside of a safe, a locker, a storage container, a vault, or other types of enclosures. 
     The lock box  60  encloses a solenoid  10  that can be mounted vertically between an upper flange  70  and a lower flange  72  or other fastening means which are secured to the distal wall of the lock box  60 . A pawl arm  80  is pivotably mounted on a fixed axis (not shown in this view) which is secured to the base of the lock box  60 . The solenoid  10  is positioned in the housing so that the pin  12  of the solenoid  10  may be attached to the frontal portion of the pawl arm  80 . A pawl spring  90  is suspended from a third flange  74  which is secured to the distal wall of the lock box  60 . One end of the pawl spring  90  is secured to the flange  74 . The other end of the pawl spring  90  is secured to the distal portion of the pawl arm  80 . 
     When tumblers are correctly aligned through the proper combination, key, or other unlocking means such as an electronic controller (not shown in this view) a battery, capacitor, or some other electricity source (not shown in this view) energizes the solenoid  10  momentarily. In the embodiment represented by FIG. 1, the battery is external to the locking mechanism and is part of a module that might also include a key pad, a display screen, a smart-card slot, a barcode reader, a light emitting diode, or a scanner linked to a computer database of authorized individuals and their associated unique personal characteristics such as fingerprints or iris patterns. 
     When the solenoid  10  is energized the pin  12  retracts and lifts the pawl arm  80 . The frontal portion of the pawl arm  80  has been fabricated to bend downward so that it engages an aperture  36  in the cam wafer  30  to secure the device. When the pawl arm  80  is lifted it disengages from the aperture  36  in the cam wafer  30 . Because of the action of the torsion spring  40  which is coiled with potential energy, when the force of the pawl arm  80  is released from the cam wafer  30 , the energy in the torsion spring  40  starts to release which causes the second rod  22  to rotate and the cam wafer  30  to rotate and disengage from the first rod  20 . The pawl arm  80  rests upon the upper plane of the cam wafer  30  when the mechanism  100  is unlocked and the door is open to indicate an unlocked state. 
     Preferably, a microswitch  82  may also be fitted to the lock box. The distal portion of the pawl arm  80  depresses the microswitch  82  when the frontal portion of the pawl arm  80  is lifted. This information may be passed through electronic circuitry (not shown in this view) in a manner well known in the art and may be shown in an optional display panel in a module external to the locking mechanism (not shown in this view) to indicate to the user whether the mechanism is in an unlocked or locked state. 
     To re-lock the enclosure, the user pushes on the door or lid of the enclosure. The first rod  20  engages the cam wafer  30  and, as the user pushes the door shut, the second rod  22  rotates and the cam wafer  30  rotates. The aperture  36  of the cam wafer  30  rotates to reengage the frontal portion of the pawl arm  80 , thereby securing the mechanism. 
     In the embodiment of FIG. 1, the locking mechanism  100  is made of stainless steel and may be used to lock enclosures of varying materials including but not limited to metal, wood, and plastic. In other embodiments, the locking mechanism may be made of rolled steel, various other metals, composites such as fiberglass, carbon fiber, or plastics. The locking mechanism may also be mounted horizontally in the enclosure, such that the first rod  20  is attached to the door or lid of the enclosure and the second rod  22  is attached to a side of the enclosure. 
     In still other embodiments, the cam wafer engages  30  directly with a door or lid frame within the enclosure. The locking mechanism in this embodiment thus requires only one rod. 
     FIG. 2A is a top view of the locking mechanism  200  showing the cam wafer  210  engaged with the first rod  220  as would be the case when the locking mechanism  200  is in the locked state. The second rod  222  passes through the thru-hole  224  in the cam wafer  210 . In this view, the top plane of the solenoid  230  is shown as it is mounted to the upper flange  232  which is secured to the distal wall of the lock box (not shown in this view). The pawl arm  240  is pivotably mounted on a fixed axis  242  to the base of the lock box (not shown in this view). In the locked state, the pawl arm  240  engages an aperture (not shown in this view) in the cam wafer  210  to secure the locking mechanism. 
     FIG. 2B is a top view of the locking mechanism  250  showing the cam wafer  260  disengaging from the first rod  270  as the locking mechanism  250  is unlocking in accordance with one embodiment of the present invention. The second rod  272  passes through a thru-hole  274  in the cam wafer  260 . In this view, the top plane of the solenoid  280  is shown as it is mounted to the upper flange  282  which is secured to the distal wall of the lock box (not shown in this view). The pawl arm  290  is pivotably mounted on a fixed axis  292  to the base of the lock box (not shown in this view) and is in the lifted state and thus disengaged from the aperture (not shown) in the cam wafer  260 . 
     FIG. 3 is a side view of the locking mechanism  300  in the locked position in accordance with one embodiment of the present invention. The cam wafer  310  is configured to engage to the first rod  320 . The second rod  322  passes through a hole (not shown in this view) in the cam wafer  310 . The torsion spring  324  is coiled around the second rod  322  below the cam wafer  310 . An alternative embodiment of the pawl arm  330  is disclosed in this view. The solenoid  340  is vertically mounted between two flanges (not shown in this view) secured to the lock box (not shown in this view). A pawl arm  330  is pivotably mounted on a fixed axis  332  at the base of the lock box  350 . The solenoid  340  is positioned so that the solenoid pin  342  may be attached to the frontal portion of the pawl arm  330 . In the locked position, the solenoid coil  344  remains unenergized and the frontal portion of the pawl arm  330  bends downward and engages an aperture  312  in the cam wafer  310  to secure the device. A pawl spring  360  is suspended from a flange (not shown in this view) which is secured to the distal wall of the lock box (not shown in this view). In this embodiment, a microswitch  370  is fitted to the base of the lock box  350 . The microswitch  370  is in the open state and is not depressed by the distal end of the pawl arm  330 . 
     FIG. 4 illustrates various components of the locking mechanism including the cam wafer  410 , the solenoid  420 , the cam spring (or torsion spring)  430 , an alternative embodiment of the pawl arm  440 , the microswitch  450 , and the pawl spring  460 . 
     FIG. 5 is a perspective view of the lock box  500 , the cam wafer  510 , and the pawl arm  520  components of the locking mechanism in accordance with an embodiment of the present invention. 
     In a further embodiment of the present invention as illustrated by FIG. 6, multiple cam wafers  610 ,  620 , and  630  may be added to the second rod  640  to increase the security of the locking mechanism, such as might be needed to lock a large enclosure. FIG. 6 is a side view of the locking mechanism  600  in the locked state where an upper cam wafer  610  middle cam wafer  620  and bottom cam wafer  630  are secured to the second rod  640 . The cam wafers  610 ,  620  and  630  are configured to engage the first rod  650 . The second rod  640  passes through hole (not shown in this view) in the cam wafers  610 ,  620 , and  630 . A torsion spring  612  is coiled around the second rod  640  below the upper cam wafer  610  and a torsion spring  614  is coiled around the second rod  640  below the lower cam wafer  630 . In this embodiment, an e-clip  616  is secured to the second rod  640  below the middle cam wafer  620 . Of course, in another embodiment it would be possible to have a third torsion spring coiled around the second rod  640  at the base of the middle cam wafer  620 . An alternative embodiment of the pawl arm  650  is disclosed in this view. The solenoid  660  is vertically mounted between two flanges (not shown in this view) secured to the lock box (not shown in this view). The pawl arm  650  is pivotably mounted to a fixed axis  670  on the lock box base  680 . The solenoid  660  is positioned so that the solenoid pin  664  may be attached to the frontal portion of the pawl arm  650 . In the locked position, the solenoid coil  662  remains unenergized and the frontal portion of the pawl arm  650  bends downward and engages an aperture  622  in the cam wafer  620  to secure the device. A pawl spring  690  is suspended from a flange (not shown in this view) which is secured to the distal wall of the lock box (not shown in this view). Although in the embodiment of FIG. 6 three cam wafers  610 ,  620 , and  630  are secured to the second rod  640 , a plurality of cam wafers may be added to the second rod  640  for additional security. Only one solenoid  660  is necessary to power the locking mechanism, regardless of how many cam wafers  610 ,  620  and  630  are added to the second rod  640  to increase the strength of the locking mechanism. 
     An adaptable electronic locking mechanism has thus been described. Although the foregoing description and accompanying figures discuss and illustrate specific embodiments, it should be appreciated that the present invention is to be measured only in terms of the claims that follow.