Abstract:
The invention relates to a safe mechanism for resistance to drilling, by use of a door mounted crankshaft mechanism. The crankshaft includes a shoulder which transfers force to the safe door rather than transmitting it to other lock mechanism components. A crank plate attached to the crankshaft rotates from an open position to a locking position, and by rotation moves a link arm with attached locking pins laterally into engagement with the doorframe. A re-locker device locks both the crank plate and the link arm in place to make entry more difficult.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to safe mechanisms, and more particularly relates to safe mechanisms which are resistant to drilling, cutting, and pounding attacks from outside the safe. 
     2. Background Information 
     Locking mechanisms for securing safe doors have existed for many years, and there are large varieties of techniques utilized in such locking mechanisms. Many of such locking mechanisms strive to make it hard for a person to break into a safe by hammering or drilling. When a person tries to break into a safe, they may try to attack the lock mechanism in order to open the safe door. Since most locks have a locking mechanism such as a keyed tumbler, a combination lock, a keypad lock, a fingerprint or other biometric recognition lock, or other locking devices exposed on the surface of the lock, these are points of attack. Many locks also have a handle which is turned to release the safe door and open it. The handle and the handle shaft that goes through the safe door are other points of attack for drilling and hammering. The mechanisms behind the handle shaft and the lock mechanisms are also subject to attack by drilling and hammering. 
     Many safe designs are configured to deter such attacks on the lock, the handle, the handle shaft, and the mechanisms behind both of these attack points. One way to protect the lock mechanisms behind the handle shaft is to provide a secure support strap behind them. Typically, the shaft would extend through the safe door, and be supported and attached to a support strap which is sometimes placed at an angle across the other parts of the lock mechanism, such as extending from a seven o&#39;clock position to a two o&#39;clock position. A disadvantage of this type of support for the shaft is that if the handle or the handle shaft is struck with a heavy blow, the energy of the blow is transmitted through the safe door to the support strap. With sufficient blows, the support strap can give way and this can give rise to the lock mechanism being defeated. 
     Another way that safes can be attacked is by drilling out the shaft which is attached to the handle. The shaft can easily be cut off flush to the face of the safe door, and then drilled straight through the shaft, basically eliminating the shaft. If the safe mechanism is not designed to defeat this, drilling out the shaft can lead to the defeat of the locking mechanism. Another part of the safe that is subject to attack is the linkage between the shaft and the pins which extend into the doorframe of the safe. One way to sever these linkages is to use a drift drill to cut sideways through such linkages. A safe needs to be designed to make such cutting or drilling of the linkages difficult. 
     The safe can also be attacked by drilling out the lock mechanism, such as the keyed tumblers or the combination lock and also drilling or pounding on the tongue which extends from the lock mechanism, and which causes the mechanism to be locked. Pounding on the lock tongue to drive it out of engagement should not result in failure of the lock system. 
     To address the modes of attack on the lock mechanism, it is an object of the invention to provide a safe mechanism which jams in the locked position if the shaft is drilled out. It is the further object of the invention to provide a safe mechanism that jams in the locked position if the tongue of the lock mechanism is driven out of position, damaged, or deformed, or if any parts of the linkages between the crank or shaft and the locking pins are drilled out, or cut off. It is a further object of the invention to provide a shaft which transmits force to the safe door rather than to the mechanism behind the safe door, when pounded. It is a further object of the invention to provide an anti-drill protection for the lock mechanism itself and nearby components. It is a further objective to provide a safe mechanism which meets all the above requirements and is also simpler to manufacture and of a narrow profile, so that the safe door can be relatively thin. 
     SUMMARY OF THE INVENTION 
     These and other objects are accomplished by the safe mechanism disclosed herein. The safe mechanism is designed to be used with a safe which typically includes a separately manufactured lock mechanism, a safe door, and a slider with one or more attached locking pins. In many safe configurations, the slider is a linear piece with locking pins attached, which extend into a frame surrounding the safe door, and thus serves to secure the door in place. The safe mechanism includes a link arm which attaches to the slider of the safe door. The link arm has a first end and second end, and a link arm body in which a slot is defined. The link arm is attached at its second end to the slider. Thus movement of the link arm causes movement of the slider, and the locking pins into and out of engagement with the frame of the door. 
     The safe mechanism of the invention also includes a crank assembly. The crank assembly includes a crankshaft, a crank plate which is attached to the crankshaft, and a crank slider pin attached to the crank plate. The crank plate is mounted adjacent to the link arm, so that the slider pin engages the slot in the link arm. When the crank plate is rotated about the crankshaft, it thus causes lateral movement of the link arm by movement of the crank slider pin in the slot of the link arm. The crank plate is configured for engagement with the lock mechanism. Thus, when the lock is engaged, the crank plate is prevented from rotating. When the lock mechanism is disengaged, the crank plate may rotate around the crankshaft. 
     In one configuration of the safe mechanism, the slot which is defined in the link arm, has a vertical section and a horizontal section, which join each other at ninety degrees (90°). In this configuration of the safe mechanism, the crankshaft extends through the horizontal section of the slot. The slot in the link arm can be recessed into the link arm, or it can penetrate completely through the body of the link arm. In the configuration in which the slot extends completely through the link arm, the crank slider pin can also extend completely through the slot and the link arm body. The crank slider pin can also extend partially into the slot, if the slot is recessed into the link arm but does not pass all the way through it. The crankshaft penetrates through the safe door and is attached to a handle which is on the exterior side of the safe door. This handle can take a variety of configurations, and can be a wheel with one or more spokes which attaches to the crankshaft, or it can be a lever which extends to one or both sides of the center of the crankshaft, or the handle can be configured as spokes of a wheel, without the wheel itself, or it can be a knob or other configuration which allow a person outside the safe to turn the handle, and the attached crankshaft. 
     One configuration of the safe mechanism is one in which the crank plate includes a first notch, which is configured for engagement with the tongue of the lock mechanism. When the tongue of the lock mechanism is extended in a locked position, it engages the first notch of the crank plate. When the tongue of the lock mechanism is retracted, in an open position, then the crank plate may rotate freely. The safe may also include a second notch which is positioned to be engageable with a re-locker. The re-locker is a device which is normally kept in a retracted position. When certain triggers are activated, the re-locker is activated and serves as a secondary locking mechanism, or as a back up to the lock mechanism. 
     One embodiment of the safe mechanism can also include a crankshaft which includes a shoulder which is configured for mounting on the exterior of the safe door. In this way, if pressure from the exterior is applied to the crankshaft, that pressure is transferred to the safe door by means of the shoulder built into the crankshaft. For instance, if a person breaking into the safe pounded on the exterior end of the crankshaft with a hammer, the force from the hammer blows would press the shoulder into the safe door, and would not press the interior end of the crankshaft against interior components. This can be accomplished by a recess around the crankshaft in the safe door, in which the shoulder is completely or partially recessed. This can also be accomplished by use of a backing piece which is mounted around the crankshaft hole and on the inside surface of the safe door. The shoulder would then press against the backing piece, which becomes an extension of the safe door. In this configuration, the crank passage in the backing piece would be sized smaller than the crankshaft shoulder in order to transfer pressure from the shoulder into the safe door. When used with a backing piece, the shoulder can be fully or partially recessed in the crank passage in the safe door. 
     Another configuration of the safe mechanism is for use with a safe as described above, which includes a re-locker mechanism which acts as secondary lock to the lock mechanism, and which, when activated, extends a re-locking tool for engagement with both the crank plate and the link arm. The purpose of this is to provide a higher level of security so that if the re-locking of the crank plate can be defeated, the link arm will still be locked in place. If the link arm were freed, then the crank arm would still be locked in place. In order to defeat this re-locker mechanism, engagement of the re-locker with both the crank plate and the link arm would have to be defeated. The re-locking tool can be a rectangular bar which is extendable for engagement with the crank plate and the link arm. The re-locker mechanism can operate by the generally rectangular bar engaging a re-locker notch in the crank plate and a re-locker notch in the link arm. 
     One of the triggers for activation of the re-locker mechanism is a deflection of the lock mechanism from its normal operating position. Another mechanism for triggering the re-locker mechanism is deflection of the lock tongue of the lock mechanism from its normal engaged position. Yet another trigger means for activation of the re-locker mechanism is deflection of the protective cage. Yet another trigger means for activation of the re-locker mechanism is deflection of the back of the lock mechanism. 
     Another embodiment of the safe mechanism of the invention is one having the features listed below. This embodiment of the safe mechanism includes a link arm whose body includes a first and a second end. The second end is attached to a slider, and when the link arm moves back and forth, the slider also moves back and forth, and pushes linking pins which are attached to the slider into engagement with the doorframe of the safe. This version also includes a crank assembly which includes a crankshaft with a shoulder section built into it, a crank plate with a first and a second notch, and crank slider pin which is attached to the crank plate and extends out from the crank plate. The link arm body includes a notch with a horizontal section and a vertical section which are joined to each other at approximately a ninety-degree (90°) angle. The crank plate is mounted adjacent to the link arm, so that the crank slider pin of the crank plate fits in the slot of the link arm, and the crankshaft also passes through the slot in the link arm. As the crank plate is rotated, the movement of the crank slider pin in the slot of the link arm causes the link arm to move laterally, thus engaging and disengaging the locking pins which are attached to the slider, which itself is attached to the link arm. This version of the safe mechanism also includes a re-locker mechanism, which, when released by an arming plate  78 , engages both the crank plate and the link arm, by a generally rectangular re-locker bar engaging a notch in the crank plate and the link arm. 
     Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an elevational view of the lock mechanism in an open position. 
     FIG. 2 is an elevational view of the lock mechanism in a closed position. 
     FIG. 3 is an elevational view of the lock mechanism with protective covers in place. 
     FIG. 4 is a perspective view of the crank plate. 
     FIG. 5 is an elevational view of the link arm. 
     FIG. 6 is a side, cross-sectional view of the safe door and the lock mechanism. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the invention is susceptible of various modifications and alternative constructions, certain illustrated embodiments thereof have been shown in the drawings and will be described below in detail. It should be understood, however, that there is no intention to limit the invention to the specific form disclosed, but, on the contrary, the invention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention as defined in the claims. 
     One of the preferred embodiments of the invention is shown in FIGS. 1 through 6. FIG. 1 is an elevational view with a partial cutaway. It shows the safe mechanism  10  and the components parts which include the crank plate  14 , the crankshaft  12 , the link arm  18 , the lock mechanism  22 , the re-locker  24 , the link arm slot  20 , the crank slider pin  16 , positioning bolts  28 , the open position lock  26 , the slider  30 , and locking pins  32 . In this device, a safe door (not shown in FIG. 1) is secured when a slider  30  is pushed laterally by the link arm  18  so that locking pins  32  engage the doorframe  52 , and secure the safe door to the doorframe  52 . The link arm  18  is made to slide laterally by rotation of the crankshaft  12  by a handle (shown in FIG.  6 ), which is attached to the crankshaft  12 , exterior to the safe door  54  (shown in FIG.  6 ). The crankshaft  12  is best shown in FIG.  6 . The crankshaft  12  includes a shoulder  40  and a flat-sided first end  56  and a threaded second end  58 . The handle  38  is affixed to the flat-sided first end  56  so that turning handle  38  causes crankshaft  12  to turn through the safe door  54 . The crankshaft  12  passes through a crankshaft passage  62  in the safe door  54 . Attached, preferably by welding to the interior of the safe door  54 , is a backer plate  60 , which also has a crankshaft passage  62  through which the crankshaft  12  extends. The shoulder  40  of the crankshaft  12  is pulled against the backer plate  60  by a nut  44  which is attached to the threaded second end  58  of the crankshaft  12 . The crankshaft  12  passes through a link arm slot  20  in the link arm  18  and through the crank plate  14 , to which the crankshaft is rigidly attached. By its attachment to the crank plate  14 , when the handle  38  is turned, the crankshaft  12  turns the crank plate  14 , unless the crank plate  14  is in a locked position. 
     Referring to FIG. 1, the safe mechanism  10  is shown in an open position. In this position, the crank plate  14  has been rotated counterclockwise (when looking at the view shown in FIG. 1, which is the back view of the safe door). Descriptions of the operation of the safe mechanism will be described by reference to the view of the safe mechanism shown in FIGS. 1 and 2, that being the looking at the back side of the safe door from inside the safe. By rotating the crank plate  14  counterclockwise, the crank slider pin  16 , sliding freely in the link arm slot  20 , causes the link arm  18  to move to the left, or away from the doorframe  52 . As the link arm  18  moves to the left of FIG. 1, the link arm slot  20  moves past the crankshaft  12 , until the crankshaft  12  is in the extreme right hand side of the horizontal portion of the link arm slot. The link arm slot has a vertical portion and a horizontal portion, and in this configuration of the device, the link arm slot  20  extends through the link arm  18 , and the crank slider pin  16  and the crankshaft  12  extend through the link arm slot as shown. 
     In order to permit the rotation of the crank plate  14 , as shown in FIG. 1, the lock mechanism first has to be moved to an unlocked position, in which the lock tongue  34  is withdrawn from contact with the first crank plate notch  48 . In this position, the open position lock  26  also engages with the second crank plate notch  50 , and would not allow the crank plate  14  to be rotated counterclockwise until the open position throw  64  is depressed, or moved to the right of the view in FIG.  1 . The open position throw  64  is depressed when the safe door  54  is closed, and the doorframe  52  of the safe door pushes against the release button  66  of the open position throw  64 . In this way, the open position lock  26  prevents the locking pins  32  from being extended unless the safe door  54  is closed. 
     FIG. 2 shows the safe mechanism  10  in a locked position. To reach this position from that which is shown in FIG. 1, the crankshaft  12  would be rotated clockwise (from the point of view as shown in FIGS.  1  and  2 ), which would cause clockwise rotation of the crank plate  14 . As the crank slider pin  16  of the crank plate  14  rotates clockwise, it would move in link arm slot  20 , causing link arm  18  to move laterally to the right, along with the attached slider  30  and locking pins  32 . In this position, first crank plate notch  48  is aligned with the tongue lock  34 . In this position, if the tongue lock  34  is extended, the safe is locked and the crank plate and the link arm  18  to which it is connected would not be able to move. 
     Shown in FIGS. 1 and 2 is the re-locker  24 . The re-locker  24  includes a re-locker tool  68 , a re-locker spring  70  which is within the re-locker  24 , and an arming plate  78 . The re-locker tool  68  is normally held in a closed position, but when triggered, the re-locker tool  68  extends from the re-locker  24  and engages the second crank plate notch  50 , thus preventing counterclockwise rotation of the crank plate  14 . Shown in FIG. 2 is the partially cut away cage  42 . As shown in FIG. 6, protective cage  42  confines link arm  18  to a plane parallel to the door of the safe, This prevents crank slider pin  16  from separating from the L shaped slot in link arm  18 . A portion of the arming plate  78  holds the re-locker tool  68  within the re-locker  24 , and partially overlaps the protective cage  42 . In this way, if the cage  42  is pounded on and becomes deformed, then the re-locker tool  68  is released, and engages the second crank plate notch  50  and also the notch  76  in the link arm  18 . The protective cage holds the link arm  18  and the crank plate  14  in proximity, as shown in FIG.  6 . Holding these two pieces in proximity with the crank slider pin  16 , which is engaged with the L-shaped slot of the link arm, the cage  42  Prevents the movement of the link arm past the crank plate without rotation of the crank plate. The lock mechanism  22  is purchased as a complete unit, and may be operated by a key, touch pad, magnetic swipe, fingerprint or other biometric identification, or as a simple combination lock as shown in FIG.  6 . 
     Shown in FIG. 6 is an anti-drill plate  72 , which is mounted so that it must be drilled through if the lock mechanism is to be drilled from outside the safe door  54 . 
     FIG. 4 is a view which shows the crank plate  14 , with the crankshaft passage  62 , the first crank plate notch  48 , and the second crank plate notch  50 . Crank slider pin  16  protrudes from the surface of the crank plate  14 , and would extend through the link arm slot  20 . Although the safe mechanism could be designed in a number of sizes and configurations, and with different materials and thickness of materials, the preferred embodiment of the safe utilizes a crank plate made of three-eighth inch (⅜″) steel. 
     FIG. 5 shows the link arm  18 , with positioning bolt holes  74 , and positioning bolts  28 . Positioning bolts  28  would extend through these holes, and attach the link arm to the slider  30 , which is then welded to prevent access by drilling out the bolts  28 . The link arm of FIG. 5 also includes a link arm slot  20  and a re-locker notch  76 . The re-locker notch  76  engages the re-locker tool  68 , when it is extended from the re-locker  24 . In this way, if the locking mechanism were defeated, and the crank plate  14  could be caused to rotate, the link arm  18  would still be locked in place if the re-locker had been activated while defeating the locking mechanism. The link arm could be of various dimensions, and made of various materials, but twelve (12) gauge steel is the preferred material for this embodiment of the claimed device. The slider  30  is also twelve (12) gauge steel, but could also be made in various sizes, materials and thickness. The locking pins  32  are made of steel, and could be a variety of sizes, such as one-half (½″) inch diameter through hardened steel cylindrical posts. 
     FIG. 3 shows an elevational view of the safe mechanism as seen from inside the safe looking at the back of the safe door  54 , with the safe mechanism in an open position, and the protective cage  42  in place. This also shows the re-locker arming plate  78  in place, covering the re-locker  24  and part of the lock mechanism  22 . If either the re-locker arming plate  78 , or the protective cage  42  were deformed or dislodged, the re-locker  24  would extend the re-locker tool  68  and engage the link arm  18  and the crank plate  14 . Shown is a stiffening bar  80 , which is attached to link arm  18 . If the link arm  18  is cut, the protective cage  42  holds the piece of link arm  18  with the slot in place. If the crank slider pin  16  is drilled out, and part of the link arm  18  removed, the stiffening bar  80  prevents the remnant of the link arm  18  from passing past the crank arm  14 , thus preventing unauthorized retraction of the slider  30  and the locking pins  32 . 
     The anti-drill plate  72 , shown in FIG. 6, is a material which faces the front of the safe door, and makes it difficult or impossible to drill through the anti-drill plate  72  into the lock mechanism  22 , without breaking drill bits. Any type of commercially available anti-drill plating can be utilized, but one which is particularly preferred is an anti-drill plating in which hard particles such as sintered tungsten carbide granules are brazed onto a steel plate with a brazing material such as nickel silver, or similar brazing material. 
     While there is shown and described the present preferred embodiment of the invention, it is to be distinctly understood that this invention is not limited thereto but may be variously embodied to practice within the scope of the following claims. 
     From the foregoing description, it will be apparent that various changes may be made without departing from the spirit and scope of the invention as defined by the following claims.