Abstract:
A pin tumbler lock releasing system includes keyway insertible and universally configured lift, key and shim devices that cooperatively work to raise the pin stacks within a pin tumbler lock to just above the pin tumbler lock&#39;s shear line so that its plug element may be rotated within its outer casing in order to disengage its locking mechanism.

Description:
This nonprovisional application claims the benefit of provisional application 61/113,550. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention generally relates to devices used for non-destructive lock picking, and it is specifically directed to a system of tools used for releasing a lock of the “pin tumbler” type in a novel fashion that neither damages the lock nor requires use of a typical lock key. 
     Pin tumbler locks generally feature four primary components: an outer casing, a plug, a locking mechanism and a series of parallel pin stacks. Formed through the casing is a cylindrical bore within which the cylindrical plug is rotatably housed. Opening at the front end of the plug is a slot, or “keyway,” that extends axially into it and is configured to receive a key having a specific cut. At the rear end of the keyway typically is a lever or cam arrangement that actuates the locking mechanism to engage or release the lock upon relative rotation of the plug and casing. Formed within both the casing and plug is a parallel series of aligned holes (typically, four to six, but can be more or less) that open to the keyway and extend radially upward (when the keyway&#39;s front opening is vertically oriented) into the casing where their respective upper ends are closed. The plug and casing portions of these aligned holes meet along an imaginary plane line commonly referred to as the “shear line.” 
     Within each aligned hole is a tumbler pin stack defined by a spring-loaded “driver pin” pressing downward against a sliding “key pin.” When the keyway is empty (i.e., no key is within it) the bottom of each key pin rests along a short flange that juts into the keyway and runs transverse to the pin axis to prevent key pins sliding completely down into the keyway slot. The upper ends of the driver pins abut coil springs that force the driver pins, and therefore the key pins, down toward the keyway. 
     When no key is filling the keyway, either the driver pin or the key pin of one to all of the pin stacks straddles the shear line and thereby prevents the plug from rotating within the casing. Moreover, because the key pins are not all uniform in length (the driver pins are), when a key that is not cut to operate with the specific lock at hand is inserted into the keyway, one or more of the key pins and/or driver pins will be positioned straddling the shear line. However, when the proper key is inserted, the flat top of each key pin will abut the bottom of its driver pin counterpart precisely at the shear line boundary between the plug and casing. This precise alignment of the pin contact surfaces with the shear line renders the pin stacks ineffective in inhibiting plug rotation so that the locking mechanism can be released by delivering torque to the plug via the key. 
     In situations in which a pin tumbler lock must be opened, but a properly cut key is not available to the lock owner, the owner or a locksmith will likely be forced to either destroy the lock or employ a lock “picking” or “bumping” technique in order to open a lock. Generally speaking, lock picking involves manipulation of all the existent pin stacks, in one-by-one sequence, until they are all aligned with the shear line so as to permit plug rotation. A variety of devices, ranging from crude tools to more sophisticated instruments have been recognized as effective in picking pin tumbler and other types of locks. In contrast, lock bumping is a technique practiced exclusively on pin tumbler locks. Bumping basically involves utilization of a specially cut key to impart to the key pins and, in turn, to the driver pins an impact force that causes each driver pin and key pin pairing to momentarily separate such that all of the driver pins are elevated entirely above the shear line, while all key pins remain entirely below it. Bumping further requires that a rotational force be applied to the plug during that extremely brief moment of pin stack displacement. 
     That the present inventor is aware, all prior art devices known to be effective in opening pin tumbler type locks, be they picking devices or bumping devices, are designed to manipulate the pin stacks such that each driver pin ends up being disposed entirely within a lock&#39;s outer casing while each key pin is disposed entirely within its plug. Depending on the sophistication of the particular tools used, lock picking can be a tedious proposition simply due to the incremental manner in which each pin stack must be properly aligned with the shear line before the locking mechanism can be released. Lock bumping can also be difficult due to the delicateness and precise timing that may be needed in applying to the key pins an impact force of appropriate magnitude and direction to cause the desired separations of the key pins and driver pins about the shear line while also initiating plug rotation during the fleeting moment in which the pins are so displaced. Consequently, it can be appreciated that there exists a need for a new technique for opening pin tumbler locks that represents an alternative to known picking and bumping techniques, and there is a concomitant need for tools that would enable a user to practice such a technique without having acquired any particular expertise or exhibiting any particular skill. The present inventor submits that the present system of tools and his conceived method of using them on a pin tumbler lock substantially fulfill these outstanding needs. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a method for actuating release of any lock that employs a pin tumbler mechanism, and for doing so without the intended key. It is a further object that such a method be able to be practiced in an identical manner with equal effectiveness on a variety of pin tumbler locks, despite differences in their total numbers of tumbler pin stacks (e.g., 3-pin, 4-pin, 5-pin, etc.) and irrespective of their outer casing configurations (cylinders, padlocks, etc.). 
     It is an associated object of the present invention to provide at least one combination instruments that a person possessing no adeptness whatsoever at lock picking can easily use to practice the instant lock releasing method. 
     In one aspect of the invention, pin tumbler locks are opened in a manner that is quite unconventional in the respect that the instant method does not involve an aligning of driver and key pin contact surfaces with the imaginary shear line between the plug and outer casing elements of a pin tumbler lock, but rather involves using a system of instruments to press key pins beyond the plug&#39;s periphery and entirely into the outer casing, along with their abutting driver pins, so that the bottoms, not the tops, of the key pins become coplanar with the shear line. In distinguishing it from well-known picking and bumping techniques, the present inventor has coined the term “jamming” (as entire pin stacks are essentially “jammed” above the shear line) in reference to the pin tumbler lock releasing technique of the present invention. 
     In another aspect of the invention, the aforedescribed jamming technique can be manually implemented using three distinct instruments: a pin stack lifting tool, a key having a uniformly toothed blade and a shim for providing underlying support for the key. A fourth device, a common torque wrench, can be utilized as well to aid in turning a lock plug. 
     Preferably, the lift device comprises a handle as well as a blade that can be inserted into an upper portion of most pin tumbler lock keyways. The key device similarly comprises a handle and a blade that has the same vertical profile as that of the lift blade. However, along the key blade is a series of uniformly spaced teeth that are adapted to fit into the vertical holes formed within the lock plug (those in which pin stacks reside). The respective thicknesses of the blade portions of the lift and key devices are such that both blades snugly fit side-by-side into the keyway. The shim device also comprises a handle and blade, and it is configured so that its blade can be wedged underneath the key blade in order that the key teeth push the key pin bottoms up into alignment with the shear line. Finally, in some embodiments of the present invention, a torque wrench can be inserted into the keyway next to the shim device to provide the user a moment arm for transmitting torque that rotates the plug and disengages the lock. 
     It should be noted that the term “blade,” as it is used throughout this disclosure, generally denotes a portion of the pertinent instrument that is relatively elongate and is adapted to be inserted into a typical keyway, but does not necessarily imply anything regarding the contour or sharpness of the edge(s) of that portion nor any other of its structural aspects. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side perspective view of a key, lift device and shim of the preferred embodiment of the pin tumbler lock releasing system of the present invention, the view showing all three instruments distanced from a pin tumbler lock that is in a lock released state; 
         FIG. 2  is a side elevational view of the key and lift device of the preferred system, the view showing both instruments fully inserted into the lock, shown in cross-section, while it is in a locked state; 
         FIG. 3  is a side elevational view of the key and shim of the preferred system, the view showing the key fully inserted into the lock and the shim approaching the lock&#39;s keyway (with the key handle being motioned upward in order to accommodate shim insertion) while the lock, shown in cross-section, is in a locked state; 
         FIG. 4  is a side elevational view of the key and shim of the preferred system, the view showing both instruments fully inserted into the lock, shown in cross-section, while it is in a locked state; 
         FIG. 5  is a side elevational view of the key and shim of the preferred system, the view showing both instruments fully inserted into the lock and being rotated clockwise, causing the lock, shown in cross-section, to release; 
         FIG. 6  is a side elevational view of the key, lift device and shim of the preferred system; 
         FIG. 7  is a side perspective view of a key, lift device, shim and torque wrench of an alternative embodiment of the pin tumbler lock releasing system of the present invention, the view showing all four instruments distanced from a pin tumbler lock that is in a lock released state; 
         FIG. 8  is a side elevational view of the key and shim of the alternative system, the view showing both instruments fully inserted into the lock, shown in cross-section, while it is in a locked state; and 
         FIG. 9  is a side elevational view of the key and shim of the alternative system, the view showing both instruments fully inserted into the lock and being rotated clockwise, causing the lock, shown in cross-section, to release. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     This disclosure, as defined by the claims that follow and as illustrated, by way of example, in the accompanying drawings, relates to an apparatus system and method for releasing pin tumbler-type locks. Most of the accompanying drawings depict the system being used on a pin tumbler padlock  60 . This particular lock  60  comprises a cylindrical plug  80  disposed within an outer casing  70 . The lock  60  has a keyway  82  and four pin stacks that each comprise a driver pin  68  and a key pin  64  disposed within aligned vertical apertures, or “tumbler pin holes,” formed within both its plug  80  and casing  70 . Coil springs  68  are mounted to both the closed top ends of the pin holes and the driver pins  68  to bias both pins  68 ,  64  downward. The lock  60  also features a locking mechanism comprising a pair of oppositely oriented cams  96 ,  98  that pivot, upon rotation of the plug  80 , to lock and release a spring-loaded shackle  90 . Nevertheless, pin tumbler locks adapted for use with dwelling doors (interior and exterior), vehicles, etc. may be operated upon using the present system in the present manner. It should be understood that the presently disclosed lock releasing system has utility in the opening of pin tumbler locks generally, and its relevance is not limited to pin tumbler-type locks of the particular configuration depicted in the accompanying drawings and described above and throughout this disclosure. In fact, the present system is compatible with a plethora of locks of varying features, such as differences in total numbers of tumbler pin stacks, in number of pins within individual stacks (e.g., some pin tumbler locks may include an additional “spacer” pin(s) situated between each driver pin and key pin) and in the configurations of their locking mechanisms. Of course, certain specifications of the instruments employed in the present invention may need to be varied accordingly. 
       FIG. 1  illustrates a preferred embodiment of the lock releasing system of the present invention. That preferred embodiment is a three-piece system  2  comprising a key  20 , a lift device  30  and a shim  10  that operate with the pin tumbler lock  60 . The key  20  comprises a handle portion  22  and an insert portion  24 , or blade. The key blade  24 , itself, comprises a rectangularly elongated base  28  that has multiple teeth  26  projecting upward from it. The number of teeth included on the key blade  24  can differ, as any given system key  20  will properly operate with only locks that feature the same number of tumbler pin stacks as the number of teeth  26  along that key  20 . So, for example, since the lock  60  shown in cross-section in  FIGS. 2-4  has four pin stacks, a suitable system key  20  will feature four teeth  26   a - d . Furthermore, the height of the uniformly profiled key teeth  26   a - d , as measured from troughs between teeth  26  (i.e., top borders of the key blade&#39;s base  28 ), must be exactly equal to the length of the plug segment of a tumbler pinhole. 
     The lift device  30  also comprises a handle  32  and a blade  34 . As shown in  FIG. 6 , the lift blade  34  features an arcuately beveled leading edge  36 , and it has the same vertical height H 2  as does the key blade  24 . This enables the lift blade  34  to slide under and raise key pins  64  that are protruding down into the keyway  82 , as it escorts the key blade  24  into the keyway. The key blade  24 , if unaccompanied by the lift blade  32 , might not smoothly insert into the uppermost portion of the keyway  82  because of tooth jaggedness issues. Finally, the shim  10  also comprises a handle  12  and blade  14 . The shim blade  14  may be grooved to conform to a lower portion of a typical keyway. 
     The first step of the preferred “jamming” method of the present invention involves simultaneously inserting the key  20  and lift device  30  into an upper portion of the keyway  82 , as shown in  FIG. 2 . Again, the lift blade  34  slightly raises the all four key pins  64   a - d  upward against their spring biases and provides clearance for the key blade  24 . Once fully inserted, each of the four key blade teeth  26   a - d  are aligned and in contact with one of the four key pins  64   a - d , and the key pins  64   a - d  will generally be positioned partly within the plug  80  and partly within the outer casing  70  such that they straddle the lock&#39;s shear line  78 . Thus, the plug  80  and casing  70  remain held in fixed relation. As a next step, the lift device  30  can be withdrawn from the keyway  82  while the key  20  is steadily held in place. 
     Theoretically, the key  20  can then be carefully raised, without its handle  22  being rocked upward or downward, in order to press the key pins  64   a - d  in alignment with the shear line  78 . However, because that would require a user to manually exert precisely constant and identical upward pressure on every key pin  64   a - d  while simultaneously attempting to revolve the key handle  22  about an axis that is offset from the key handle&#39;s rotation axis, it is preferred that a shim device  10  be used as an underlying support for the key  20 . Therefore, as a third step shown in  FIG. 3 , the blade  14  of the shim device  10  is slid into a lower portion of the keyway  82 . Depending upon the configurations of the key handle  20  and shim handle  12 , the key handle  20  may need to be momentarily rocked slightly upward to accommodate initial insertion of the shim blade  14 . 
     Because the sum of the height H 1  of the key blade base  20  and the height H 3  of the shim blade  14  (see  FIG. 6 ) is only very slightly less than the vertical width of the keyway  82  (giving them a slide clearance fit into the keyway  82 ), the shim blade&#39;s insertion presses the key teeth  26   a - d  into their corresponding pin tumbler holes as illustrated in  FIG. 4 . The shim&#39;s presence within the keyway  82  also stabilizes the key  20  and allows the user to manipulate only the shim handle  12  at this point. Moreover, because the key teeth  26   a - d  have height profiles equivalent to the lengths of the plug segments of the pin tumbler holes, as previously mentioned, the respective contact surfaces  76  between the key teeth  26   a - d  and the key pins  64   a - d  are elevated into alignment with the shear line  78 , and the cylindrical plug  80  ceases to be inhibited from rotating about its axis. Therefore, as a fourth step, the shim  10  is turned clockwise to transmit torque to the plug  80 . As the plug  80  is then rotated, the cams  96 ,  98  also rotate and dislodge from conforming notches  94 ,  92  along the shackle  90 . Consequently, one end of the spring-loaded shackle  90  releases from the casing  70  as shown in  FIG. 5 . 
     As an alternative embodiment illustrated in  FIG. 7 , the present system  4  may include a fourth piece, in the form a typical torque wrench  50  having a handle portion  52  and insert portion  54 , that accompanies a key  20 , lift device  30  and shim  40 . The use method for this alternative system  4  is executed exactly as that recited above for the preferred three-piece system  2 , except that the insert portion  54  of the wrench  50  is inserted into the keyway horizontally adjacent and flush against the shim blade  44  (see  FIG. 8 ) so that the user can simply turn the torque wrench  50  to release the lock  60  as shown in  FIG. 9 . Typically, the blade portion  44  of a shim device  40  used in this alternative four-piece system  4  will have a shorter vertical profile and a lesser thickness profile than does its counterpart used in the preferred system  2 . This dimensioning enables the shim blade  44  to insert below any inward flange that might exist along the keyway  82  and be completely flush against and symmetric with the adjacently inserted portion  54  of the torque wrench  50 . Of course, in order to stably cooperate with such a vertically shorter shim blade  44 , the height H 1  of the key blade base  28  that it supports should be proportionately increased. 
     It is understood that substitutions and equivalents for and combinations of various elements set forth above may be obvious to those skilled in the art and may not represent a departure from the spirit of the invention. Therefore, the full scope and definition of the present invention is to be set forth by the claims that follow.