Abstract:
The magnetic anti-tampering system of the present invention provides a mechanical and magnetic security system. It utilizes a modified paracentric key and a locking assembly affixed to a component inside of a paracentric lock. The present invention increases the security of a pair centric lock by defeating the unauthorized operation of pair centric locks by unauthorized users, such as inmates, who have fabricated copies of the authentic, paracentric keys. Paracentric locks and keys are the most common type of locks used in jails, state prisons, and detention facilities. The locking system requires that both the teeth of the key and the magnetic pairs of the key and locking dog combine to open the lock.

Description:
[0001]    This application is based upon and claims priority from U.S. Provisional application Ser. No. 62/008879, which is incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    Applicants&#39; invention relates to a device for magnetic anti-tampering system. More particularly, it relates to magnetically paired keys and locks that use lever tumblers. 
         [0004]    2. Background Information 
         [0005]    There are many keys for many different types of locks. One type of lock and key commonly used in prisons and correctional facilities is the paracentric. Paracentric literally means to deviate from circularity, or changing the distance from a center. A paracentric key is distinguishable by the heavily contoured shape of its blade, which protrudes past the center vertical line of the keyway in the cylinder. Locks with paracentric keyways offer a higher level of protection against picking since they prevent direct access to the pins by traditional picking tools. A paracentric lock has a keyway with one or more wards on each side projecting beyond the vertical center line of the keyway. Instead of the wards on the outer face of the lock simply protruding into the shape of the key along the spine, the wards protrude into the shape of the key along the entire width of the key, including along the length of the teeth. The shape and wards of the paracentric lock and key are designed to hinder picking. This is the reason that person could locks and keys are often used in jails. However, even the paracentric lock and keys are not completely immune to picking by motivated individuals such as inmates. 
         [0006]    A pin tumbler lock is a lock mechanism that uses pins of varying lengths to prevent the lock from opening without the correct key. Pin tumblers are most commonly employed in cylinder locks, but may also be found in other types of locks as well. 
         [0007]    Pin tumbler locks are made up of a Bible which sits around a cylindrical plug. Unimpeded, the plug will rotate inside the Bible. The Bible of the lock contains the springs and the driver pins. The driver pins sit between the Bible and the plug of the lock. The plug is the portion of the lock that contains the keyway and will turn when the correct key is inserted. Below the driver pins are the key pins. The key pins will actually touch the key when it is inserted. The driver pins and the key pins are in contact and a thought one another but are not connected. All of the pins slide within a cylinder with the springs urging the pins down. The driver pins and springs are all the same length. In contrast, each of the key pins has a unique length that corresponds to the unique cuts (teeth) in the key. When no key is in the keyway, the springs urge the driver pins past the junction of the Bible and plug, thus the driver pins block rotation of the plug. If an incorrect key is inserted into the lock, then the lock teeth will either be too short or too tall. If a key tooth is too big, then the driver pin/lock pin combination is moved against the spring such that the lock pin extends beyond the junction of the Bible and plug and the lock pin blocks rotation of the plug. If a key tooth is too small, then like when there is no key at all, the spring urges the lock pin past the junction of the Bible and plug again blocking rotation of the plug. Of the Bible and plug is called the sheer line. When the correct key is inserted into the lock, the key pins are raised by the teeth such that the top of the key pins and the bottom of the driver pins sit at the sheer line. This allows the plug to rotate and disengage the lock. 
         [0008]    In contrast to the pin tumblers, a lever tumbler lock is a type of lock that uses a set of levers (instead of pins) to prevent the bolt from moving in the lock. In the simplest of these, lifting the tumbler above a certain height will allow the bolt to slide past. In a double acting lever lock a slot is cut in the lever so that the lever must be lifted to a certain height but not too far in order for the bolt to be allowed to move within the lock. The number of levers may vary, and may be increased in order to provide correspondingly increased levels of security. 
         [0009]    In the past, magnetic keys have been used with pin tumbler type locks. A magnetic-coded lock uses pins in combination with magnets to prevent unlocking with non-matching keys by teething and magnetic polarity. Magnetic locks/keys use paired magnets with opposing poles inside the key and plug. When a correctly matched key is inserted into the lock, not only are all the mechanical pins pushed into the correct positions, the magnetic pins are also driven to the appropriate level by the magnetic force inside the key. Magnetic-coded locks offer heightened security because in order to unlock a lock not only must the key teething fit with the pins, the magnetic pin locations and poles of the lock and key must correspond. The correct fitting position can be found by feeling the effect of the magnetic force, or by aligning with the markings. When the magnetic key is placed on a magnetic lock, the lock magnets online the magnetic catches arranged in a freely rotatable manner in relation to the key magnets such that the opposite poles oppose each other. Further, the lock magnets are pulled by the key magnets into locked positions. This occurs because the attractive force acting between the lock magnets and the key magnets is slightly greater in the online edition and the attractive force acting between the lock. If there is no magnetic key or respectively corresponding external magnetic force, the magnetic attraction of the key magnets combined so that the magnetic catches independently pull themselves into the locked position. This is in addition to the spring mechanisms of the pin tumbler locks. 
       SUMMARY OF THE INVENTION 
       [0010]    The present invention incorporates magnets into lever tumbler and paracentric locks. 
         [0011]    The present invention provides a novel apparatus that will increase the difficulty in picking a lever tumbler, paracentric lock. 
         [0012]    The magnetic anti-tampering system of the present invention provides a mechanical and magnetic security system. It utilizes a modified paracentric key and a locking assembly affixed to a component inside of a paracentric lock. The present invention increases the security of a pair centric lock by defeating the unauthorized operation of pair centric locks by unauthorized users, such as inmates, who have fabricated copies of the authentic, paracentric keys. Paracentric locks and keys are the most common type of locks used in jails, state prisons, and detention facilities. Thus, the present invention is particularly adapted for prison and correctional facility door locks. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a perspective, exploded view of lever tumbler lock. 
           [0014]      FIG. 2  is a perspective, exploded view of the locking assembly. 
           [0015]      FIG. 3   a  is a perspective view of the locking assembly attached to the lock bolt. 
           [0016]      FIG. 3   b  is a perspective, cutaway view of the carriage assembly illustrating the locked position. 
           [0017]      FIG. 4  is a perspective, cutaway view of the carriage assembly illustrating the unlocked position. 
           [0018]      FIG. 5  is a perspective view of a paracentric key with embedded magnets. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    Referring to the figures,  FIG. 1  illustrates the parts of a lever tumbler, magnetic paracentric lock  10 . The magnetic paracentric lock  10  has a lock case  20  that has a generally hollow interior. The lock case  20  has a back  22  and sides  24  that enclose most of the sides of the lever tumbler lock  10 . The lock case  20  has attachment apertures  34  in the back  22  that allow the lever tumbler lock  10  to be attached to a wall or door using fasteners  36 , such as screws, bolts, welds, or other attachment means as are well-known in the industry. 
         [0020]    The lock case  20  has a bolt aperture  26  that is sized to allow a lock bolt  28  to slide through. The lock bolt  28  has an engagement end  30  and a locking end  32 . The engagement end  30  is generally thicker than the locking end  32 . The engagement end  30  is sized to slide through the bolt aperture  26 . Ideally, the tolerance between the engagement end  30  and the bolt aperture  26  is kept to a minimum. The locking end  32  has a horizontal rail  38  attached that extends generally perpendicularly to the lock bolt  28 . 
         [0021]    A tumbler set  40  is also rotatably attached in the interior of the lock case  20 . The tumbler set  40  is comprised of a multiplicity of levers  42 . Each lever  42  is generally rectangularly shaped with a first end  42   a  that is rotatably attached to the interior of the lock case  20 . The first end  42  a is also attached to a spring mechanism  44  that when engaged with the interior of a lock case  20  side  24 , tends to urge the second end  42   b  of the lever  42  toward a locked position. The second end  42   b  has and activation cutout  46  that has a channel  50  through the front of the second end  42   b  that is sized to allow the horizontal rail  38  to move horizontally through the activation cutout  46  and channel  50 , consequently allowing the lock bolt  28  to slide through the bolt aperture  26  so as to lock or unlock the subject door. Interior to the activation cutout  46  is a stop cutout  48  that is sized to allow the horizontal rail  38  to move vertically to a position away from the channel  50 . 
         [0022]    Thus, if a lever  42  is raised too high, or lowered too low, then the channel  50  will not line up with the horizontal rail  38  and the stop cutout  48  holds the lock bolt  28  from sliding through the bolt aperture  26 . If all of these levers  42  are set to the correct position (presumably by the teeth of a key  100 ) then the horizontal rail  38  will line up with the channel  50  allowing the lock bolt  28  to slide through the bolt aperture  26 . 
         [0023]    Mechanically engaged with the tumbler set  40  is a key cylinder  60 . The key cylinder  60  works similarly to the pin tumbler lock with the Bible and plug as described above except that instead of moving the pins, a key  100  turns and its teeth act to position the levers  42 . 
         [0024]    The lock bolt  28 , tumbler set  40 , and key cylinder  60  are enclosed in the interior of the lock case  20  by a lock cover  70  which is attached by fasteners  36  to the lock case  20 . The lock cover  70  has a key aperture  72  that allows access with a key  100  to the key cylinder  60 . The key aperture  72  may be shaped and sized in order to admit a paracentric key  100 . 
         [0025]      FIG. 2  shows an exploded view of the magnetic locking assembly  80 . The magnetic locking assembly  80  also fits in the interior of the lock case  20 . The magnetic locking assembly  80  is comprised of magnets  82 . These magnets  82  are anticipated to be neodymium type magnets, but are not required to be. “Neodymium” refers to magnets that are a type of rare-earth magnet. They are considered a permanent magnet made for the alloy of neodymium, iron, and boron. Permanent magnets are those made from materials that are magnetized and create their own persistent magnetic fields. The neodymium magnets  82  are embedded in a locking dog  84 . The locking dog  84  is attached to a locking carriage  86  by means of a pin or second fastener  90 . A connecting bracket  88  is connected to the locking carriage  86  opposite from the locking dog  84 . A third fastener  92  connects the connecting bracket  88  and locking carriage  86  to the lock bolt  28  in the interior of the lock case  20 . The locking assembly  80  holds the neodymium magnets  82  in magnetic communication with a magnetic key  100  inserted into the key cylinder  60 . The pin or second fastener  90  may be a hardened steel pin. The pin or second fastener  90  allows the locking dog  84  to rotate or rock while connected to the locking carriage  86 . A compression spring  90  is secured to the locking carriage  86  by the third fastener  92 . 
         [0026]      FIG. 3   a  shows the positioning of the locking assembly  80  attached to the lock bolt  28 . 
         [0027]      FIG. 3   b  illustrates how the connecting bracket  88  allows the locking assembly  80  to move in a linear motion with the lock bolt  28  as the key cylinder  60  rotates. The compression spring  90  is positioned such that it maintains constant positive pressure on the locking dog  84  and keeping the key cylinder  60  in the locked position until unlocked with the correct magnified key  100 . 
         [0028]      FIG. 4  illustrates how when the locking dog  84  is moved to the unlocked position by use of a magnetized paracentric key  100 , the key cylinder  60  is allowed to rotate and unlock the lock. 
         [0029]      FIG. 5  illustrates a portion of a magnetic paracentric key  100 . The basic parts of a key include a head or bow which provide a portion of the key for the user to hold, a shank or blade across which are the millings, grooves, bits, teeth and the like that are specific for a lock, a at the junction of the bow and blade controls how much of the blade will enter a lock, and the tip at the opposite end of the shank from the bow. In  FIG. 5 , a portion of the shank  102  is illustrated with bits  104  and groove  108  that can be made specific for an individual paracentric key cylinder  60 . In order to make the magnetic paracentric key  100  specific to a magnetic paracentric lock  10 , key magnets  110  are embedded in the shank  102  of the magnetic paracentric key  100 . As with the magnets  82  embedded in the locking dog  84 , the key magnets  110  are anticipated, but not required, to be neodymium type, permanent magnets. The key magnets  110  are embedded in predetermined locations along the shank  102  in the area between the key stop (not shown) to the tip  106 . The key magnets  110  are inserted in order that one of their two ( 2 ) magnetic poles is exposed at the surface of the shank  102 . The number of magnets  82  and key magnets  110  may vary, but generally is anticipated that there will be at least three (3) magnet  82 /key magnet  110  pairs. The magnet  82 /key magnet  110  pairs are generally paired and positioned such that the adjoining poles of the pairs are the same polarity—repelling each other. While fewer pairs could be used if the magnets were of sufficient strength, it is desirable to use a multiplicity of pairs to increase the interaction between the magnet pairs as well as making a legitimate copy of the magnetic paracentric key  100  more difficult. It is anticipated that there may be more key magnets  110  embedded in the magnetic paracentric key  100  and there are magnets  82  embedded in the locking dog  84 . The paired magnets—those that are involved in repelling the locking dog  84  to the unlocked position—are referred to as “active magnets” and those that are not are referred to as “passive magnets.” Once the active magnets of a magnetic paracentric key  100  are fully inserted into a paired magnetic paracentric lock  10 , the active key magnets  110  align with the magnets  82  embedded in the locking dog  84 , thus paired the locking dog  84  will be repelled against the urging of the spring  94  and moved to the unlocked position. When the locking dog  84  is in the unlocked position the key  100  and key cylinder  60  are allowed to rotate and unlock the lock  10 . When the correct, active key magnets  110  are not inserted with the key  100  in the key cylinder  60 , the spring  94  urges the locking dog  84  against the key cylinder  60  keeping it from rotating and unlocking the lock  10 . Thus, even if a key with its teeth, bits and grooves is otherwise shaped correctly, it will not turn the key cylinder  60  if the magnets  82  and active key magnets  110  are not positioned and paired correctly. The order of the magnetic poles expose along the shank  102  of the key  100  is referred to as the magnetic sequence combination. This design feature allows for multiple magnetic sequence combinations for keys with the same keyway (lateral grooves) and combination (key cuts). In a prison setting where the present invention is anticipated to be employed the magnetic pairs and sequence can frustrate an inmate who otherwise might be able to illegally duplicate the physical shape of the key  100 . 
         [0030]    Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.