Abstract:
A method of duplicating a key includes receiving a master key in a key duplicating machine. The machine automatically detects a cross sectional profile of the master key. The machine automatically determines, based on the detected cross sectional profile, a type and model of the master key. The machine automatically selects a key blank that matches the type and model of the master key, and then automatically cuts the selected key blank to duplicate a key tooth pattern of the master key.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This is a continuation of U.S. application Ser. No. 13/622,036, filed Sep. 18, 2012, which is a division of U.S. application Ser. No. 11/998,101, filed Nov. 28, 2007, now U.S. Pat. No. 8,287,215, which claims priority from U.S. Provisional Application No. 60/867,403, filed Nov. 28, 2006, and from U.S. Provisional Application No. 60/867,796, filed Nov. 30, 2006. All of the above applications are hereby incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This is directed to the field of key duplication. More specifically, this is directed to the field of apparatuses and methods of automatic key duplication involving as little trained human operator input as possible. 
       BACKGROUND 
       [0003]    Duplicate keys are typically cut from pre-existing master keys using a hand-operated table-top tool having two clamps, a cutting wheel, a follower and a cleaning wheel. A schematic of such a conventional key cutting tool appears in  FIG. 1 . In operation, a locksmith or someone of at least some training on the machine examines the master key A, tries to determine what type of key it is by eye/tool, tries then to determine which model of key it is by eye, and selects a corresponding key blank B from an array of scores of different models. The master key A is then clamped at the following station C, and the key blank B is clamped at the cutting station D. The two stations C and D are attached to a common base E, which is opposite the follower F and cutter G (which are both together mounted on base H). 
         [0004]    Base H is then pressed down towards base E, or, conversely, base E is moved up towards base H, depending on the machine model, in the direction of arrow Y. This causes the cutter G to be brought into contact with the key blank B. The keys are moved longitudinally in the direction of arrow X with respect to the follower F and cutter G. Since the key blank B and the master key A are mechanically linked (i.e., they are clamped to the same base E), the follower F rides along the tooth pattern of the master key A, and the cutter G simultaneously cuts into the blank blade of the key blank B, removing blade material in the same configuration as the tooth pattern of the master key A. When the cutting is done, the operator removes both keys and places the newly cut key under a rotating cleaning wheel or brush (not shown) to remove burrs and any stray material left over from the cutting process. 
         [0005]    This process is fraught with potential problems and mistakes. First, the operator may select the wrong type of key blank. Since each type of key (e.g., Kwikset, Schlage, Segal, etc.) has a differently shaped cross-sectional profile, using the wrong type will result a key that will not be able to enter the lock properly. Second, the operator may select the right type of key but the wrong model. Keys of the same type come in different lengths, for example, and the operator may select a blank having the wrong length. Moreover, there are many models of keys currently on the market. Many of the models are very similar in shape and cross-section. Even to the trained professional, model identification can be quite difficult and erroneous. This problem is only made worse by the tens of aftermarket manufacturers that produce keys with models that are designed to have the same dimensional features, but are actually manufactured with differences. Key model identification is necessary before duplication of a key. Third, the operator may not properly align the master key in clamp C, thereby causing the two keys to be out of register and he may not align the blank properly. Fourth, the operator may apply too little pressure or inconsistent pressure on base E and cause key B to be cut too shallowly or incompletely. Other problems may arise. In addition, since the device must be operated by someone trained on the device, duplicate keys may not always be readily available. Conventional key cutting machines are usually located in locksmith shops and hardware stores, or similar avenues of commerce not typically known to be open late into the evening. For these and other reasons, there is a long felt need to automate the process of key duplication so that ordinary consumers can obtain accurate duplicate keys by themselves, without requiring a specialty shop to be open for business, and without requiring a skilled tradesperson on hand to operate the machine. 
         [0006]    Several attempts to automate the process of key duplication have been partly successful at best. There are several patents to so-called “automated” key identifying and/or duplicating devices, such as U.S. Pat. Nos. 4,899,391 and 5,127,532 to Cimino; U.S. Pat. No. 5,351,409 to Heredia; U.S. Pat. No. 3,956,968 to Crasnianski; and U.S. Pat. No. 5,538,374 to Cole et al. However, in each of these and others like them, one or more of the steps required to duplicate a key are still manual. For example, in some devices and methods, the operator must still determine what type of key the master key is and select a corresponding key blank. In other (and/or the same) devices, the master key is still aligned by hand and clamped by hand. Many of these prior devices still require a skilled tradesman to operate the machinery. In fact, even in the most automated key machine of today, the following steps are still performed by the operator: insertion of customer/master key, partial alignment of customer/master key, clamping of customer key, identification of customer key model, retrieval of key blank, insertion of key blank, partial alignment of key blank, clamping of key blank, starting machine, unclamping of customer key, removal of customer key, unclamping of key blank, removal of key blank, de-burring of key blank, returning customer key to customer, giving new key to customer and charging the customer a fee for the service. 
         [0007]    Thus, there is still a long-felt need for a fully automatic key identifying and/or duplicating machine that can be operated by an ordinary consumer in a manner as easy as purchasing an item from a vending machine or receiving money from an automated teller machine. 
       SUMMARY 
       [0008]    The invention fulfills the above and other long felt needs. In one embodiment, a master key clamping module receives and secures a master key having a tooth pattern to be duplicated and a master key alignment module is movably disposed into and out of proximity with the master key clamping module. The master key is aligned by the alignment module within the master key clamping module. A master key identification module is disposed in fixed relation to the master key clamping module and identifies a type of key secured in the master key clamping module. A key cutting module is provided including a key blank cutter. A central positioning base is automatically movable into and out of engagement with the master key alignment module and alternately automatically movable into and out of engagement with the key cutting module. The central positioning base is adapted to move the master key alignment module into proximity with the master key clamping module and adapted to secure a key blank to be cut at the key cutting module in accordance with the tooth pattern of a clamped master key. 
         [0009]    Preferably, at least one magazine is provided for housing a plurality of key blanks; the central positioning base is movable into and out of proximity with the magazine and is adapted to cause removal one of the key blanks from the at least one magazine and move the removed key blank to the key cutting module. The central positioning base preferably includes a key blank securing groove and a key blank clamp on at least one side of the key blank securing groove adapted to secure a key blank inserted into the key blank securing groove. Preferably, a plurality of the magazines are provided, each of the magazines adapted to house a different model or color of the key blanks 
         [0010]    A key extraction module is provided engageable with the central positioning base substantially adjacent the key blank securing groove and slidingly disposed along the plurality of magazines and movable to a selectable one of the magazines by the central positioning base. The key extraction module preferably includes a reciprocatable push rod, disposable behind a lowermost key blank housed in one of the magazines, adapted to push the lowermost key blank out of the magazine. A guide roller is disposable adjacent the key blank being pushed out of the magazine by the push rod, substantially opposite the key blank securing groove of the central positioning base when the central positioning base engages the key extraction module. The guide roller preferably includes a circumferential guide groove receiving the key blank being pushed out of the magazine. 
         [0011]    The extraction module preferably further includes an extraction base supporting the push rod and the guide roller and a cam rider projecting from and mechanically linked to the push rod. A key support arm is hingedly attached to the extraction base and cammingly connected to the push rod via the cam rider, the key support arm having a blade support platform at a distal end, the key support arm being spring-biased upward towards the push rod. When a key blank is being removed from one of the magazines, the key support arm is biased upward to cause contact between the blade support platform and the blade of the emerging key blank. The key support arm preferably further includes a proximal raised camming surface, a distal raised camming surface, and a central lowered camming surface. When the cam rider rides over either of the proximal or distal camming surfaces, the cam rider pushes the key support arm down away from the emerging key blank to prevent contact between the emerging key blank head and the blade support platform. 
         [0012]    Each of the key blank magazines preferably further includes a pair of substantially parallel leaf springs disposed at one end of the magazine, the leaf springs being spaced apart to guide a lowermost key blank in the magazine out of the magazine during extraction, and generally to avoid the bottom keys from being knocked out/coming out by accident. 
         [0013]    The master key alignment module preferably includes an alignment head, spring mounted on a reciprocating shaft, preferably in a distal position, the head being engageable with the master key as the master key is being inserted into the master key clamping module when the master key alignment module is in proximity to the master key clamping module. A locking switch is preferably provided engageable with the reciprocating shaft; when the locking switch engages the reciprocating shaft, the shaft is pushed with greater force and locked in the distal position. The locking switch preferably includes a rotating locking lever engageable with the reciprocating shaft by movement of the central positioning base against the locking lever in a direction substantially perpendicular to a sliding direction of the master key alignment module. The master key alignment module preferably further includes a master key shoulder detecting switch. When the master key is fully inserted into the master key clamping module, a shoulder of the inserted master key abuts against the master key shoulder detecting switch. The alignment head preferably includes a sloped leading surface and more preferably a groove adapted to accommodate and lead a master key as the master key is being inserted into the master key clamping module. 
         [0014]    The master key clamping module preferably includes guideway projections that receive and guide a master key being inserted into the master key clamping module as well as an open section exposing teeth of the inserted master key. 
         [0015]    The master key identification module includes a blade length sensing element spring-biasedly disposed within the master key clamping module and abuttable against a distal end of a master key inserted into the clamping module. At least one blade cross-section detector is also provided laterally engageable with the blade of the inserted master key, the cross-section detector having a profile corresponding to a cross-sectional profile of a given type of key. When the blade cross-section detector engages a key of the type corresponding to the profile, the profile substantially engages the blade and the master key is determined to be of the given key type. When a key type match is determined and the blade length sensing element determines the length of the inserted master key, the master key is determined to be a specific key model. The blade cross-section detector includes at least one pair of sliding elements disposed within the clamping module on opposite sides of the inserted master key, each of the sliding elements having a profile. When the sliding elements engage a key of the type corresponding to its profile, the sliding elements substantially close around the master key blade, and when the sliding elements engage a key not of the type corresponding to the profile, the sliding elements do not close around the master key blade or close too far around the master key blade. 
         [0016]    A plurality of the pairs of the sliding elements are preferably provided. Each of the pairs of the sliding elements preferably have different respective profiles each corresponding to different types of keys. 
         [0017]    The key cutting module preferably further includes a cut key cleaner, such as, for example, a rotating cleaning wheel; the key blank cutter may be, for example, a rotating cutting wheel. A first enclosure is provided substantially but not entirely surrounding the key blank cutter, the first enclosure having a first window exposing a portion of the key blank cutter for cutting. A second enclosure is provided substantially but not entirely surrounding the cut key cleaner, the second enclosure having a second window exposing a portion of the cut key cleaner for cleaning A vacuum source is in communication with the first and second enclosures that creates negative pressure substantially around the key blank cutter and the cut key cleaner to substantially remove debris created during cutting and cleaning of a key blank. Flexible flaps are preferably disposed on proximal and distal sides of the first and second windows (and more preferably, also on the top and bottom of the windows), engageable with the central positioning base when the central positioning base is securing a key blank at the key cutting module. The flaps on the distal sides of the windows are preferably longer than the flaps on the proximal sides of the windows. The key blank cutter preferably includes a cutting wheel rotatable in a first direction, and the cut key cleaner includes a cleaning wheel rotatable in a second direction opposite the first direction. 
         [0018]    The central positioning base is preferably movable in an X direction by a first motor, preferably a gear box motor, and a Y direction by a second motor, preferably a direct drive motor. The central positioning base preferably includes a follower tracing the tooth pattern of the secured master key. When the central positioning base is securing the key blank at the key cutting module, the second motor is preferably provided with a variable amount of power depending on a substantially instantaneous height of the master key tooth pattern being traced. More preferably, when the follower rides along an uphill portion of the master key tooth pattern, the power provided to the second motor is reduced, and when the follower rides along a downhill portion of the master key tooth pattern, the power provided to the second motor is increased. 
         [0019]    The master key alignment module is preferably slidingly disposed on a first rail in the Y direction, and the extraction module is preferably slidingly disposed on a second rail in the Y direction. 
         [0020]    In another embodiment, the invention is an automatic key duplicating machine having a master key clamping module adapted to receive and secure a master key having a tooth pattern to be duplicated. A master key alignment module is movably disposed into and out of proximity with the master key clamping module, the master key being aligned by the alignment module within the master key clamping module. A key cutting module is provided including key blank cutter. A central positioning base is automatically movable into and out of engagement with the master key alignment module and alternately automatically movable into and out of engagement with the key cutting module. The central positioning base is adapted to move the master key alignment module into proximity with the master key clamping module and adapted to secure a blank key to be cut at the key cutting module in accordance with the tooth pattern of a clamped master key. 
         [0021]    In another embodiment, the invention is an apparatus for automatically determining a type of a master key for duplication having a key clamp into which the master key is inserted and secured, the key clamp having a key receiving guideway, and at least one blade cross-section detector movably disposed within the key clamp in a direction substantially perpendicular to the key receiving guideway and laterally engageable with the blade of the inserted master key. The cross-section detector has a profile corresponding to a cross-sectional profile of a given type of key. When the blade cross-section detector engages a key of the type corresponding to the profile, the profile substantially engages the blade and the master key is determined to be of the given key type. 
         [0022]    In another embodiment, the invention is an apparatus for automatically aligning a master key to be duplicated, having a key clamp into which the master key is inserted and secured, the key clamp having a key receiving guideway. An alignment base is provided movable into and out of proximity with the key receiving guideway. An alignment head is mounted on a reciprocating shaft substantially perpendicular to the key receiving guideway and spring-biased in a distal position away from the alignment base. The alignment head is engageable with the master key as the master key is being inserted into the master key clamping module when the master key alignment module is in proximity to the master key clamping module. A master key shoulder detecting switch is disposed on the alignment base. When the master key is fully inserted into the key clamp, a shoulder of the master key abuts against the master key shoulder detecting switch to indicate full insertion of the master key. 
         [0023]    In another embodiment, the invention is a system for extracting a key blank from a pre-selected plurality of key blanks for cutting into a duplicate of a master key. At least one magazine houses a plurality of key blanks. A base is movable into and out of proximity with the magazine, the base having a key blank securing groove and a key blank clamp on at least one side of the key blank securing groove adapted to secure a key blank inserted into the key blank securing groove from the magazine. A key extraction module is provided engageable with the movable base substantially adjacent the key blank securing groove and movable to the magazine by the movable base. The key extraction module includes a reciprocatable push rod, disposable behind a lowermost key blank housed in one of the magazines, adapted to push the lowermost key blank out of the magazine. 
         [0024]    The invention also includes a fully automated method of duplicating a master key. A master key inserted into a guideway in a clamping base is aligned by pressing down on outward-facing teeth side of the inserted master key. Complete insertion of the master key into the guideway is detected. A locking force is applied on the blade against the clamping base in a direction substantially perpendicular to the axis of the blade. The master key is clamped while the master key is subject to the locking force applying step. The type of master key that is clamped is identified by determining a plurality of physical parameters of the key. A key blank to be cut is secured in a movable base having a follower. The follower of the movable base is pressed against the master key tooth pattern while simultaneously pressing the secured blank against a key cutter such as a cutting wheel. 
         [0025]    Preferably, a plurality of key blanks are provided in at least one magazine, more preferably a plurality of magazines each housing a different type, model, or color of key blank. The physical parameters determined in said identifying step enable automatic selection and extraction of a key blank from a specific magazine. Preferably, one key blank is extracted from the magazine by pushing on the lowermost key blank in the magazine and guiding the lowermost key blank into a key blank receiving groove. Preferably, the complete key insertion detecting step further includes the step of detecting the abutment of a shoulder of the master key against an alignment base. 
         [0026]    Preferably, the master key identifying step further includes the steps of sensing a length of the inserted master key and detecting the cross-sectional profile of the blade of the inserted master key. The profile detecting step preferably further includes the step of attempting to close at least one pair of sliding elements around the blade of the inserted master key, the sliding elements being provided with the profile of a model/type of key. If the attempting step is successful and the sliding elements substantially close around the blade, the inserted master key is determined to be of the type having the profile of the sliding elements. A plurality of pairs of sliding elements are preferably provided, each pair being provided with a different profile corresponding to a different type of key. 
         [0027]    Preferably, a vacuum source is provided substantially around the key blank cutter that removes substantially all debris created during cutting of a secured key blank. Additionally, a cut key cleaner is provided such as a rotating cleaning wheel, and the vacuum source is provided substantially around the cut key cleaner, and substantially all debris created during the cleaning of a secured cut key blank is removed. The key blank cutter is preferably rotated in a first direction while cutting the secured key blank, and the cut key cleaner is preferably in a second direction opposite the first while applying the secured cut key blank to the cut key cleaner. 
         [0028]    The pressing step of the inventive method further includes the steps of varying the amount of power provided to a motor tasked with generating torque for the pressing step depending on a substantially instantaneous height of the master key tooth pattern in contact with the follower. More specifically, the power is reduced when the follower rides along an uphill portion of the master key tooth pattern, and the power is increased when the follower rides along a downhill portion of the master key tooth pattern. 
         [0029]    In another embodiment, the invention is an automated method of duplicating a master key, including the steps of: aligning a master key inserted into a groove by pressing down on outward-facing side teeth of the inserted master key; detecting complete insertion of the master key into the groove; applying a locking force on the blade of the master key; clamping the master key thus aligned; extracting a key blank from a plurality of key blanks housed in at least one magazine; securing a key blank to be cut in a movable base having a follower; and pressing the follower of the movable base against the master key tooth pattern while simultaneously pressing the secured blank against a key blank cutter such as a cutting wheel. 
         [0030]    In another embodiment, the invention is a method of duplicating a master key, including the steps of: aligning the master key within a clamp on a first base; clamping the master key thus aligned; securing a key blank to be cut in a second base having a follower, the key blank and the follower being fixed relative to each other; and engaging the follower of the second base with the master key tooth pattern while simultaneously engaging the secured blank with a key blank cutter. 
         [0031]    In another embodiment, the invention is a fully automatic key duplicating machine, having a master key clamping module adapted to receive and secure a master key having a tooth pattern to be duplicated. A master key alignment module is provided movably disposed into and out of proximity with the master key clamping module, the master key being aligned by the alignment module within the master key clamping module. A master key identification module is disposed in fixed relation to the master key clamping module, and identifies a type of key secured in the master key clamping module. A key cutting module is provided and includes a key blank cutter such as a rotating cutting wheel. A central positioning base is automatically movable into and out of engagement with the key cutting module and secures a key blank to be cut at the key cutting module in accordance with the tooth pattern of a clamped master key. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    The invention will be better understood from the following description of preferred embodiments together with reference to the accompanying drawings, in which: 
           [0033]      FIG. 1  is a schematic of a conventional manual key duplicating machine. 
           [0034]      FIGS. 2A-B  are schematics of a key duplicating machine in accordance with the invention. 
           [0035]      FIGS. 3A-B  are schematic overviews of a fully automatic key duplicating machine in accordance with the invention. 
           [0036]      FIGS. 4A-G  are schematics of an automatic master key alignment system in accordance with the invention. 
           [0037]      FIGS. 4H-I  are schematics of the key alignment system of  FIGS. 4A-G  including a master key clamping module in accordance with the invention. 
           [0038]      FIG. 5  is a top elevation view of a master key alignment module in accordance with the invention. 
           [0039]      FIG. 6A  is a side elevation view of a typical key. 
           [0040]      FIGS. 6B-D  are exemplary cross sectional views of different types of keys taken at the sectional line in  FIG. 6A . 
           [0041]      FIGS. 7A-D  are front, side, and top elevation schematic views, respectively, of an automatic key identification system in accordance with the invention. 
           [0042]      FIGS. 8A-B  are front sectional schematic views of one pair of sliding elements opening and substantially closing around a key blade of the same corresponding type as that of the sliding elements in accordance with the invention. 
           [0043]      FIG. 9  is a front sectional schematic view of the sliding elements of  FIG. 8  failing to close around a key blade of a different type not corresponding to that of the sliding elements in accordance with the invention. 
           [0044]      FIG. 10  is an exploded perspective view of a key identification module in accordance with the invention. 
           [0045]      FIGS. 11A  and B are perspective views of a key identification module in relation to a key clamping module in accordance with the invention. 
           [0046]      FIGS. 12A-C  are right, left, and top elevation views of a key extractor module in accordance with the invention. 
           [0047]      FIG. 13A  is a top perspective view of the key extractor module of  FIG. 12  removing a key blank from a magazine and guiding it into a key blank securing groove in accordance with the invention. 
           [0048]      FIG. 13B  is a top perspective view of a key blank secured in the securing groove of the central position base on its way to be cut in accordance with the invention. 
           [0049]      FIG. 14  is an exploded perspective view of the key cutting module with the cutting wheel and brush removed for clarity. 
           [0050]      FIG. 15  is an enlarged perspective view of a mechanism for removing a finished duplicate key in accordance with the invention. 
           [0051]      FIGS. 16A  and B are top perspective and top elevation views, respectively, of a central positioning base in accordance with the invention.  FIG. 16C  is a corresponding side elevation view. 
           [0052]      FIG. 17A  is an exploded perspective view of a fully automatic key duplicating machine in accordance with the invention. 
           [0053]      FIG. 17B  is an enlarged view of the detail identified in circle  17 B shown in  FIG. 17A . 
           [0054]      FIG. 18  is a lower perspective view of a key blank magazine in accordance with the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0055]    Although the invention will be described in connection with certain preferred embodiments, it will be understood that the invention is not limited to those particular embodiments. On the contrary, the invention is intended to cover all alternatives, modifications, and equivalent arrangements as may be included within the spirit and scope of the invention as defined by the appended claims. 
         [0056]    Description of the invention will now be given with reference to  FIGS. 2-18 . It should be understood that these figures are exemplary in nature and in no way serve to limit the scope of the invention, which is defined by the claims appearing hereinbelow. 
         [0057]    Key duplication requires the analysis of the master key to determine model and tooth pattern, and then the forming of corresponding teeth on a key blank. It is generally necessary to firmly hold the master key and key blank. As shown in  FIG. 1  and described above, existing key duplication machines accomplish this task by fixing the master key and the key blank with respect to each other, such that they are oriented and aligned in a fixed and specific manner. Once secured, the existing machine performs one of the following duplicating procedures: (1) the keys remain fixed relative to each other and are moved in unison across a fixed tracer and a fixed cutter, or (2) the keys remain fixed relative to each other and fixed relative to the machine, and the tracer and cutter are moved in unison across the keys. In both cases, the keys remain fixed relative to each other, and the tracer and cutter remain fixed to each other. 
         [0058]    It is generally found that the keys loading locations are relatively close to each other and are in the same general alignment. This is likely due to the fact that a human operator is required to load both keys into the machine, and it is more user-friendly and intuitive for the operator if the loading locations are close to one another and have the same alignment configurations. 
         [0059]    Such a configuration proves difficult for automated processes. For a fully automatic process, the inventors have discovered that it is desirable to enable the consumer to insert a master key into a slot and have the key duplicated from the insertion point with the head of the key always projecting from the machine, in the same fashion as when the consumer opens a door. Consumers become nervous when their personal property such as a key is fully withdrawn into a machine, not to be seen for even a minute. Additionally, if a person inserts either a non-recognizable key or a foreign object into the insertion slot of the automatic device and it is fully withdrawn inside, a significant problem may arise in trying to eject the key/object, potentially causing damage to both the inserted key/object and the machine in itself. 
         [0060]    One solution to this issue is depicted generally in  FIGS. 2A-B . Here, master key A and key blank B are not fixed relative to each other, as in conventional systems. Rather, two basic units  10  and  20  are provided. Unit  10  includes a tracer or follower  12  and key blank clamp  14 . Opposite unit  10  is provided unit  20 , which includes master key clamp  22  opposite follower  12  and cutter  24  opposite key blank clamp  14 . Master key A and key cutter  24  of unit  20  are in a fixed position, while unit  10  is movable in the X-Y direction. This configuration, compared with conventional key duplication, requires a re-orientation of key blank B and of cutter  24 . In this embodiment, key blank B faces master key A and is loaded from the opposite direction than master key A. Cutter  24  is oriented with the angled edge facing master key A. Unit  10  has means for moving in the X direction indicated by the lateral arrow. During duplication, force is applied in the negative Y direction as indicated by the downward vertical arrows. The tracer or follower  12  and key blank B translate across the original key A and cutter  24  to reproduce the master key&#39;s tooth pattern on key blank B  FIG. 2B  shows the system in mid-operation with a portion of the profile already formed into key blank B. 
         [0061]    The invention is well suited for a fully automated key duplication machine, for at least the following reasons. First, it allows the master key to remain in a fixed position, thus preventing any intentional and unintentional movement by the human user which might cause misalignment either before the process starts or in mid-duplication. Second, it allows for a mechanically favorable situation in which the cutter and its components remain fixed. Also, it allows the key blank to be easily loaded from the ‘back’ side. This may be inconvenient for a human operator in a conventional setting, but it is well-suited for an automatic loading system which requires space to move and operate. Finally (but by no means exclusively), the orientation of the key blank is also well-suited for an automatic system loading from the back side. From the perspective of a rear-placed loading system, it allows for ‘blade first’ loading. 
         [0062]    One such rear-placed blade-first blank loading system is described hereinbelow, first conceptually with respect to  FIGS. 3A and 3B , then with more specific detail in the remaining  FIGS. 4-18 .  FIG. 3  shows an overall schematic of a fully automatic key duplicating machine  40 . The chief components are: master key alignment module  50 ; master key clamping module  100 ; master key identification module  130 ; key blank extractor module  150 ; key cutting module  200 ; and central positioning base  250 . Central positioning base  250  is movable amongst several of the other modules and is capable of engaging two of the other modules for interaction with fixed components of the system. Base  250  is powered by any conventional mechanism of moving an object in one or two dimensions, such as a pair of encoded motors (one for the X direction, one for the Y direction) run by a computer, PLC, or a similar controlling device. The powered movement of base  250  is depicted by solid line arrows; when other movable but not self-locomotive components move as a result of engagement with base  250  (or via other means), such movement is depicted by dotted line arrows. 
         [0063]    The initial step i of the inventive method is the moving of alignment module  50  into position near clamping module  100  so that a master key A inserted therein (at step  0 ) will be properly aligned. Alignment module  50  properly aligns the inserted master key (in a manner such as the exemplary alignment method to be described below), and when alignment is complete, clamping module  100  secures master key A by clamping it. Once the master key is aligned and secured, master key identification module  130  determines which type and model of key the master key is so that an appropriate key blank can be selected. 
         [0064]    Next, central positioning base  250  disengages from alignment module  50  and moves to engage key blank extraction module  150  at step ii. Before base  250  disengages from alignment module  50 , base  250  moves alignment module  50  out of the way of the secured master key inside clamping module  100  in step iii as shown in dotted lines. Alignment module is preferably spring-biased to remain out of the way after central positioning base  250  disengages therefrom. Extraction module is movable along one or more magazines  190  that house a plurality of key blanks Central positioning base  250  moves extraction module  150  to the appropriate magazine  190  in step iv, and extraction module  150  removes a key blank therefrom and guides it into key blank clamp  270  of base  250  for securement. 
         [0065]    In step v, central positioning base  250  moves over to both key cutting module  200  and master key clamping module  100 , which is possible because the alignment module  50  was moved out of the way (either by spring force or some other mechanism) in advance. The key blank disposed in blank clamp  270  is moved into engagement with the key cutting module  200  and is cut in accordance with the tooth pattern of master key A in clamping module  100 . In the preferred embodiment, base  250  includes a follower  290  which traces or follows along the tooth pattern of the master key as base  250  is moved across key cutting module  200  and key clamping module  100  in step vi (see  FIG. 3B ). 
         [0066]    Alignment module  50  is described in more detail in  FIGS. 4-5 . Module  50  includes a main base  52  on which reciprocating rod  54  is mounted. On the distal end of rod  54  is mounted alignment head  56 ; rod  54  (and thus head  56 ) are kept extended in a distal position (see  FIGS. 4A-B , for example) by spring  58 . Alignment head  56  preferably includes an angled or sloped leading surface  57  to accommodate insertion of a master key A into master key clamping module  100 ; as key A is inserted, the blade easily rides along sloped leading surface  57  and preferably in a groove in the underside of head  56  to move alongside alignment head  56  and to push head  56  upward slightly in the +Y direction. A master key shoulder detecting switch  60  is provided on alignment head  52  closest to the outer wall or housing  400  of the device  40  (see  FIGS. 4A-B , for example). When a master key A is fully inserted (see  FIG. 4D ), the key shoulder abuts shoulder detecting switch  60  to indicate to the system that the key is fully inserted and the alignment process can begin. 
         [0067]    As best shown in  FIG. 5 , alignment module  50  is preferably movable along rail  51  by operation of central positioning base  250 . In the preferred embodiment, alignment module  50  includes an engagement hub receiver  55  which is adapted to receive an engagement hub  260  disposed on central positioning base  250 . Base  250  is preferably used to move alignment module  50  out of the way of clamping module  100 , and spring  53  is preferably provided to keep alignment module  50  out of the way of clamping module  100  when central positioning base  250  disengages its engagement hub  260  from engagement hub receiver  55  (e.g., if the machine  40  is jostled or bumped, it is possible for the alignment module to roll down its rail  51  if it were riot restrained by spring  53 ). 
         [0068]    A locking switch or lever  62  is provided on alignment base  52  engageable with the proximal end of reciprocating rod  54  (see  FIG. 5 ). Preferably, locking lever  62  is rotatably mounted on base  52 . When engagement hub  260  of central positioning base  250  fully and firmly engages hub receiver  55 , the edge of central positioning base  250  abuts against locking lever  62  to press it into locking engagement with shaft  54  to generate a “locking force” against rod  54  which keeps alignment head  56  fixed in its distal position. A strong spring  64  is preferably provided to transfer force and to prevent full surface-to-surface contact between central positioning base  250  and alignment module  50 , which over time might result in damage to either component, owing to the central positioning base effectively bumping into alignment module  50  every time a key is made. Spring  64  provides a large compressive force to stiffen the position of alignment head  56  yet allows for some flexibility or play to accommodate variations in tooth height on master key A. 
         [0069]    Operation of alignment module  50  is as follows. In  FIG. 4A , alignment module  50  begins distant from clamping module  100 , preferably by passive operation of spring  53 . When the customer begins the ordering process, central positioning base  250  and its engagement hub  260  are already in engagement with hub receiver  55 . Before the customer inserts a key, base  250  moves alignment module into position just opposite master key clamping module  100  as shown in  FIG. 4B . The customer is then instructed to insert her key into slot S, and does so in  FIG. 4C . Key insertion begins in the +X direction. Key length sensor  132  (part of master key identification module  130 , to be described below) is pushed in the +X direction as key A is inserted against the biasing force of spring  134 . Length sensor  132  measures the key length. Owing to the biasing force of spring  58 , alignment head  56  guides the blade of the key, confines key movement, and loosely aligns the key blade by pushing it down in the −Y direction into the clamp (to be described below). 
         [0070]    Master key A is shown fully inserted in  FIG. 4D , and key shoulder A 1  engages shoulder switch  60 . When switch  60  is engaged, and if length sensor  132  determines master key A to be of an acceptable length, central positioning base  250  moves alignment module  50  down in the −Y direction as shown in  FIG. 4E . This causes force to be applied just in front of the shoulder A 1  and under alignment head  56 . The alignment head  56  still has some play, owing to the resilience of spring  58 . Next, central positioning base  250  moves slightly in the −X direction to cause base  250  to engage spring  64  and produce force on locking lever  62 , thereby transferring force to rod  54  (and thus alignment head  56 ) causing extra force to be applied to key A (see  FIG. 4F ). This locking force provides final alignment to the master key. 
         [0071]    At this point, after a complete alignment sequence, the key is clamped into position, and central positioning base  250  returns module  50  to its “out” location and disengages from alignment module  50 . Spring  53  maintains module  50  away from clamping module  100  in the +Y direction, as shown in  FIG. 4G . 
         [0072]    Master key clamping module  100  is best shown in  FIGS. 4H  and I. Module  100  includes a clamping base  102  having proximal and distal clamping jaws  104 A, B. To ensure that the master key A does not become misaligned as it is being inserted while the tip of its blade passes between proximal clamping jaws  104 A and distal clamping jaws  104 B, guideway piece  110  is mounted therebetween. Guideway piece  110  preferably includes projections  112  and a central guideway  114  that receives the inserted key A. In between adjacent projections are provided identification slot  116 , for reasons which will become clear below. Guideway piece  110  is preferably mounted to only one of the two portions of clamping base  102 . 
         [0073]    Once the alignment module is finished aligning the key as described above, the two portions of clamping base  102  move together to lock the key in place. It is not necessary for both portions of base  102  to move to clamp key A; one portion may be fixed, and the other portion may move to meet it. 
         [0074]    Master key identification module  130  is depicted best in  FIGS. 6-11 . One portion of identification module  130  has already been described: key length sensor  132  shown in  FIG. 4 . When master key A is fully inserted (as detected by shoulder switch  60 ), the length of the key is determined by spring-biased length sensor  132 . That is one piece of information, but it does not determine what type of key has been inserted. As shown in  FIG. 6  the blade of master key A ( FIG. 6A ) can have one of several different cross-sectional profiles, as shown in  FIGS. 6B-D ;  FIG. 6B  depicts a first cross sectional profile A′,  FIG. 6C  depicts a second cross-sectional profile A″, and  FIG. 6D  depicts a third cross-sectional profile A″′. Determining which profile a key has effectively determines what type of key it is. 
         [0075]      FIG. 7  shows the other portion of master key identification module  130 : sliding elements  140  that can slide to and away from the key ( FIG. 7 ) through identification slots  116  provided in guideway piece  110  (see  FIGS. 4H-I ). As depicted in  FIG. 7 , four pairs of slides  140 -A-D are provided. Each slide  140  has a profile  142  that corresponds or is similar to the cross-sectional profile A′-A″′ of one side of a specific model of a key. Each identifiable model of key would have a pair of slides  140  each with a corresponding profile for that side of the key, so that when the slides are closed completely together, they form a hole in the shape of a keyhole for that particular type. Several pairs of slides  140  may be provided in each system as to be able to identify several types of key. Means are provided for identifying when each slide is in an open position, fully closed position, or past closed position; such means may include an optical switch or electronic contact switch. The slides are provided with means for moving back and forth, such as a spring, motor or solenoid. The preferable default position of the system leaves the slides in the open position. 
         [0076]      FIG. 10  shows a more detailed embodiment of the alignment system of the invention. For clarity and simplicity, only the left-side elements are shown. Sliding elements  140 A-C are respectively provided with profiles  142 A-C, which correspond to different types of keys. For example, profile  142 A may correspond to a Schlage key, profile  142 B may correspond to a Kwikset key, and profile  142 C may correspond to a Weiser key. Other key types may be identified with other corresponding profiles. Sliding elements are provided with spring bias by springs  144 A-C, and are slidable into and out of housing  146 . Proximal ends of sliding elements are provided with optical sensor flags  148 A-C. Positions of sensor flags are read by optical recognition printed circuit board  147  through the window in isolation foil  145 . 
         [0077]    The operation of the slide elements is shown best in  FIGS. 8 ,  9 , and  11 . Each slide element  140  is initially positioned away from key A and is moved to close around the master key A. As shown in  FIG. 9 , if the profile of the key does not correspond to the profile of sliding elements  140 , and thus if contact is made between a sliding element  140  and the key before the slide reaches its fully closed position, then the optical switch will not be triggered for that slide. When a pair of slides has at least one un-triggered switch then it may be concluded that the sample key is not of the same type as the slider pair&#39;s profile. If premature contact is not made with the master key and the slide elements  140  closes substantially around the blade of the key, then the optical switch will be triggered for that slide. If both switches of a slider pair are triggered, then it can be concluded that the sample key cross-section is capable of fitting within that slide-pairs outlined hole (see  FIG. 8B ). 
         [0078]      FIG. 11A  depicts a master key A clamped in clamping module  100  with sliding elements  140 A-C in an open position.  FIG. 11B  depicts the same clamped master key A with sliding elements  140 A-C closing around the key. 
         [0079]    The slides are preferably made of a thin and strong material such as hardened steel. Such a thin material will allow several rows of sliders to be placed in one system. 
         [0080]    There are cases in which a certain number of slide-pairs may be capable of identifying more key models than there are slide-pairs. For example, after studying the combinations of models in a particular system, it may be concluded that a particular slide profile may substitute for multiple other slides. Further, in some cases, it may be possible to use different combinations of ON-OFF switches of different slides to determine models. Such configurations would reduce the amount of slides in a system. 
         [0081]    It is also important to note that a slide-pair may be designed in a way where they do not contact each other when in a closed position. The switches may be placed to determine position rather than determining a closed or not-closed situation. 
         [0082]    In an alternate embodiment, pins may be placed in strategic locations instead of slides to determine key types. 
         [0083]      FIGS. 12 and 13  illustrate details of the key blank extraction module  150 . Module  150  includes an extraction base  152  on which is mounted motor  154  ( FIG. 12A ). Motor  154  includes gear  155  which meshingly engages rack gear  156  ( FIG. 12B ). Slider  158  is mechanically linked or attached to gear rack  156 , and push rod  159  is attached or mechanically linked to slider  158 . Operation of motor  154  therefore causes push rod  159  to move. Extraction module  150  is disposed below and behind the lowermost key blank housed in a magazine  190  so that when motor  154  causes push rod  159  to move, push rod  159  pushes the key blank B out of magazine  190  and into key blank clamp  270  of central positioning base  250  (see  FIGS. 13-A-B ). A guide roller  170  is attached to base  152  via bracket  172 ; when a key blank is extracted from a magazine, the blade of the blank rides along guide roller  170 . Guide roller  170  is preferably provided with a circumferential channel or groove  174  for ensuring proper guidance and alignment of the blank. 
         [0084]    Proper alignment of the key blank is critical while the key blank is being extracted from the magazine and placed into blank clamp  270 . However, because keys have relatively narrow blades which terminate in a wider head, guiding and supporting the key while it is being extracted is made more complicated. In one embodiment, a key support arm  160  having a blade support platform  162  is provided attached to the extractor base  152 . In the preferred embodiment, blade support platform  162  includes vertical guide walls  162 A designed to keep the blade of the key from experiencing roll, pitch, or yaw. However, the blade support platform  162  must be moved out of the way when the key head is ready to pass therethrough, since the key head is wider than the space between guide walls  162 A. 
         [0085]      FIG. 12B  best shows one embodiment of the mechanism for moving the key support arm  160  and blade support platform  162  out of the way of the oncoming key head. Key support arm  160  is pivotably attached to base  152  at pin  161 ; arm  160  is biased upward by a spring (not shown). Slider  158  is provided with a cam rider  157  which rides along the upper surface of key support arm  160 . The upper surface of key support arm  160  includes a proximal raised camming surface  163 , a central lowered camming surface  165 , and a distal raised camming surface  167 . Ramped portions  164  and  166  are provided on either side of the lowered central camming surface  165  to smooth the transition between sections. When cam rider  157  rides over either of the proximal or distal raised camming surfaces  163  and  167 , the cam rider  157  pushes the key support arm  160  down away from the emerging key blank to prevent contact between the emerging key blank B and the blade support platform  162 . Only one motor  154  is required to extract the key blank and move the key support arm  160  into and out of engagement with the key blank. 
         [0086]    Extraction module  150  includes an engagement hub receiver  180  ( FIG. 12C ,  FIG. 13B ) for receiving engagement hub  262  on central positioning base  250 . Engagement module  150  is slidable along rail  175  (see  FIG. 13A ) as it is moved by central positioning base  250 . Rail  175  preferably runs underneath magazines  190  disposed in magazine rack  192 . Once the central positioning base  250  has received and clamped a key blank, it disengages from extraction module  150  as shown in  FIG. 13B  and moves over to key cutting module  200 . 
         [0087]    As shown in  FIG. 18 , the bottom of magazine  190  preferably includes a pair of leaf springs  194 , which serve several functions. First, leaf springs  194  help prevent the lowermost key blank from sliding out of slot  196  without the aid of extraction module  150 . Second, the pair of leaf springs  194  are spaced apart so as to serve as a guideway for the blade of the key. As the key blank is pushed out, leaf springs  194  keep the blade straight, until the head of the blank key passes over the springs at which point the leaf springs are simply pushed downward by the head of the key. Once the key is fully removed from the magazine, leaf springs  194  snap back into place to secure the next key. 
         [0088]    Key cutting module  200  is best depicted in  FIGS. 14 and 17B . A cutting wheel housing  202  and a cleaning wheel housing  204  are provided, respectively mostly enclosing a cutting wheel  222  ( FIG. 17B ) and a cleaning brush/wheel  224  ( FIG. 17B ). Housings  202  and  204  are connected by a main vacuum housing  206  to a vacuum source  208 . It is very important to provide a way to remove the debris caused by the cutting and cleaning processes, since there are a significant number of moving parts that can be compromised if metal shavings permeate the device. 
         [0089]    Housings  202  and  204  do not completely surround the cutting and cleaning wheels  222  and  224  or they would be incapable of cutting and cleaning; windows  203  and  205  are provided respectively in housings  202  and  204 . To maximize the focus of the negative pressure of the vacuum around the key blank being operated upon without interfering with the cutting and cleaning processes (and thus to maximize the removal of debris), flexible flaps  210 ,  212 , and  214  are provided surrounding windows  203  and  205 . Flaps  210 , the distal flaps, are longer than the proximal flaps  212 . This allows central positioning base  250  to move into engagement with the cutting and cleaning wheels and not inadvertently folding the flaps over the cleaning/cutting wheels. That is, the central positioning base  250  first moves against the distal flaps  210  to push them out of the way while clearing proximal flaps  212 . Then the central positioning base  250  can get closer to the cutting/cleaning wheels and pushes the proximal flaps  212  out of the way. 
         [0090]    In the preferred embodiment, cutting wheel  222  and cleaning wheel  224  are disposed on the same rotating shaft  226 , which is driven by drive belt  230  attached to motor  232 . Motor  232  is reversible and is reversed before the key blank is cleaned at the cleaning wheel; the rotatable shaft  226  is rotated first in one direction during cutting and then the other direction during cleaning, so as to cause the cleaning wheel  224  to remove flashes and burrs from the trailing edge of the newly cut duplicate key. Burrs and debris generally hang from the trailing edge of a newly cut key. By reversing the direction of motor  232  (and thus drive belt  230  and cleaning wheel  224 ), the duplicate key need not be rotated upside down or in any way removed from blank clamp  270  for extraneous material to be removed from the trailing edge. 
         [0091]    When the duplicate key is finished and ready to be removed from the machine  40 , central positioning base  250  moves the key under removal base  300  as shown in  FIG. 15 . Removal base  300  has a pin  302  which projects into the hole of finished duplicate key B′ when the key B′ is so positioned. Pin  302  engages the hole of key B′, blank clamp  270  releases the securing force on key B′, and central positioning base  250  moves away from base  300 . Because pin  302  is projecting within the hole of key B′, the key slides out of blank clamp  270  and falls down a dispensing chute or into a tray (not shown). 
         [0092]    The prime mover of many of the aforementioned modules and functions of the invention is central positioning base  250 , itself depicted in  FIGS. 16A-C . As indicated above, base  250  has two engagement hubs  260  and  262  (see  FIG. 16C ) for engaging master key alignment module  50  and key blank extraction module  150 , respectively, at their hub receivers  55  and  180 . Base  250  also includes key blank clamp  270 , having motor  272 , key sensors  274  for detecting the presence of a key, and jaw  276  for securing a key blank B inserted therein. Follower tip  290  traces along the tooth pattern of the master key A secured in master key clamping module  100  while key blank B is being cut at key cutting wheel  222 . 
         [0093]    As best illustrated in  FIG. 17A , central positioning base  250  is preferably movable along two rails, an X-axis rail  264  and a Y-axis rail  266 . Preferably, two separate motors are provided for respective movement in the X direction and the Y direction. The X-direction motor (“X-motor”) is preferably a gear box motor, and the Y-direction motor (“Y-motor”) is preferably a direct drive motor. The Y-motor can be used not only to move central positioning base  250  back and forth in the Y direction but also at lower power to maintain a fixed position of central positioning base  250  or to provide pressure to the key blank during the cutting and cleaning steps of the operation. Indeed, during the cutting step, the Y-motor is provided with a variable amount of power depending on a substantially instantaneous height of the master key tooth pattern being traced so that internal play or flexion or friction of the central positioning base  250  under significant pressure does not cause distortion of base  250  and thus misalign the key blank being machined and the follower  290  tracing the master key tooth pattern. Preferably, when follower  290  rides along an uphill portion of the master key tooth pattern, the power provided to the Y-motor is reduced, and when the follower rides along a downhill portion of the master key tooth pattern, the power provided to the Y-motor is increased. In a preferred embodiment, Y-motor power while tracing uphills in the master key tooth profile is approximately 70% of Y-motor power while tracing downhills in the master key tooth profile. 
         [0094]    The invention is not limited to the above description. For example, the alignment and identification modules are preferably used to align and identify the master key to be duplicated, however these modules could also be used to align and identify the key blank to be cut. Also, the exemplary embodiments shown above depict a central positioning base movable amongst several modules in an X-Y plane, i.e., in two dimensions. However, it is also contemplated to ‘stack’ the various modules vertically and have the central positioning base move in a vertical plane (a Y-Z plane, for example), or in three dimensions instead of two dimensions. 
         [0095]    Additionally, several modules are described as fixed and others as movable. However, in most cases, the reverse may be true, as long as there is substantially similar relative movement among the modules. For example, the key blank extraction module is described and shown in the preferred embodiment as being movable along a row of fixed magazines. However, it would also be within the scope of the invention to provide a fixed extraction module and a movable bank of magazines, for example on a carousel, where the proper magazine is selectively movable into engagement with the fixed extraction module. As another alternative, any module that is shown as being passively movable by the action of the central positioning base (e.g., the master key alignment module, the key blank extraction module) may be provided with its own motor for its own independent locomotion. 
         [0096]    Similarly, although in the preferred embodiment the key cutting wheel and key cleaning wheel are shown as being coaxial on a single shaft that can be rotated in both directions, it would also be within the scope of the invention to provide two separate rotating elements, one for the key cutter and one for the cut key cleaner. The invention is also not limited to the use of either a key cutting wheel or a key cleaning wheel per abut may instead employ other devices for cutting the key blank and for cleaning the cut key, either known now or to be developed in the future. 
         [0097]    As another variation, the key identification module may include an optical or electronic scanning device for detecting any of the parameters of the master key, including key length, blade cross-sectional profile, and/or tooth pattern. 
         [0098]    Having described certain embodiments of the invention, it should be understood that the invention is not limited to the above description or the attached exemplary drawings. Rather, the scope of the invention is defined by the claims appearing hereinbelow and any equivalents thereof as would be appreciated by one of ordinary skill in the art. 
         [0099]    While particular embodiments and applications of the present invention have been illustrated and described, it is to be understood that the invention is not limited to the precise construction and compositions disclosed herein and that various modifications, changes, and variations may be apparent from the foregoing descriptions without departing from the spirit and scope of the invention as defined in the appended claims.