Abstract:
A method of evaluating a master key system. The method comprises entering criteria for the master key system and determining the available master key cuts and change key cuts based on the criteria. The determined available master key cuts and change key cuts are arranged under a standard progression format including at least two page masters. Each page master is displayed as a graphical page master arranged graphically relative to the other graphical page masters based on the master key hierarchy. The information is displayed as a master key illustrator.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates generally to master key systems and more particularly to a method of assigning change keys and master keys for a master key system. 
         [0002]    One of the most common requests seen on orders for new master key systems is to “provide for maximum expansion”. The customer makes this request to extend the life of the newly purchased master key system. Unfortunately the term “maximum expansion” is completely meaningless. The expansion potential of a key system is defined by the mechanical characteristics of the cylinder. There is no way to configure a system to exceed those characteristics, and there are several ways to allocate the expansion inherent in them. No single expansion configuration is optimal for every facility and none of them will accommodate every possible future event. 
         [0003]    The most effective strategy to prevent the early replacement of a key system is to: plan it using prudent budgeting techniques; implement it using effective project management; and protect it with sound key control practices. 
         [0004]    A system that is not correctly planned and budgeted is doomed to failure from the start. While this first step is essential, it is often shortchanged because the people in the best position to contribute have the least understanding of cylinder mechanics and the mathematics of master keying. To facilitate good planning in the key system design phase, a tool is needed which would allow those people to participate in the process effectively. 
         [0005]    Planning tools are paradigms that allow users to understand keying issues without having to understand locks. One such tool is the popular “dividing the key” paradigm. An example of the use of this tool would be to say that in a six pin grand master key system you were using “two pins for masters and four pins for changes.” That would yield (in a traditional Schlage lock style system) 16 masters of 256 changes each. The same expansion could have been allocated differently using, for example, “three pins for masters and three pins for changes” or “one pin for masters and five pins for changes.” Dividing the key is a very useful tool that allows rapid analysis of user requirements. However, it paints in too broad a stroke to be used for complex systems. 
         [0006]    The foregoing illustrates limitations known to exist in present master keying systems. Thus, it is apparent that it would be advantageous to provide an alternative directed to overcoming one or more of the limitations set forth above. Accordingly, a suitable alternative is provided including features more fully disclosed hereinafter. 
       SUMMARY OF THE INVENTION 
       [0007]    In one aspect, the invention relates to a method of evaluating a master key system. The method comprises entering criteria for the master key system and determining the available master key cuts and change key cuts based on the criteria. The determined available master key cuts and change key cuts are arranged under a standard progression format including at least two page masters. Each page master is displayed as a graphical page master arranged graphically relative to the other graphical page masters based on the master key hierarchy. 
         [0008]    In another aspect, the invention relates to a master key illustrator for illustrating the available master key cuts and change key cuts under a master key system. The illustrator comprises at least first and second graphical page masters. Each graphical page master is representative of a respective group of master key cuts and change key cuts available under the master key system. The graphical page masters are arranged graphically relative to the other graphical page masters based on the master key hierarchy. 
         [0009]    The foregoing and other aspects will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawing figures. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIGS. 1A through 1C  show a typical pin tumbler cylinder; 
           [0011]      FIGS. 1D and 1E  show a typical master keyed pin tumbler cylinder; 
           [0012]      FIG. 2  shows a sample key system schematic; 
           [0013]      FIG. 3  illustrates an exemplary key bitting array; 
           [0014]      FIG. 4  is an illustrative page master listing of all key bitting combinations generated by the bitting list generator for a given page master key; 
           [0015]      FIG. 5  is an illustrative master key illustrator showing graphically the master key system for the given key bitting array; 
           [0016]      FIG. 6  is an expanded view of the upper left quadrant of the master key illustrator of  FIG. 5 ; and 
           [0017]      FIG. 7  is an expanded view of the lower left quadrant of the master key illustrator of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]    The following are definitions of a few common master keying terms: 
         [0019]    Master key system is any keying arrangement that has two or more levels of keying. 
         [0020]    Change key is a key that operates only one cylinder or one group of keyed alike cylinders in a keying system. 
         [0021]    Bitting is the number(s) which represent the dimensions of the key cut(s) on a key. 
         [0022]    Key bitting array is a matrix (graphic) display of all possible bittings for change keys and master keys as related to the top master key. 
         [0023]    Levels of keying are the divisions of a master key system into hierarchies of access. Level 1 is the lowest level and consists only of change keys. The highest level is the top master key that operates all locks in the master key system. 
         [0024]    MACS is maximum adjacent cut specification, or the maximum allowable difference between adjacent cut depths. 
         [0025]    Cross keying is the deliberate process of combinating a cylinder (usually in a master key system) to two or more different keys which would not normally be expected to operate it together. 
         [0026]    Master key is a key which operates all the master keyed locks or cylinders in a group, each lock or cylinder usually being operated by its own change key. 
         [0027]    Page master key is the master key for all combinations listed on a page in the standard progression format. 
         [0028]    Block master key is the master key for all combinations listed as a block in the standard progression format. 
         [0029]    Horizontal group master key is the master key for all combinations listed in all blocks in a line across the page in the standard progression format. 
         [0030]    Vertical group master key is the master key for all combinations listed in all blocks in a line down a page in the standard progression format. 
         [0031]    Row master key is the master key for all combinations listed on the same line across a page in the standard progression format. 
         [0032]    Grand master key is a key which operates two or more separate groups of locks, which are each operated by a different master key. 
         [0033]    Sequence of progression is the order in which bitting positions are progressed to obtain change key combinations, typically either a 1 step, using a one increment difference between bittings of a given position, or 2 step progression, using a two increment difference between bittings of a given position. 
         [0034]    Standard progression format is a systematic method of listing and relating all change key combinations to all master key combinations in a master key system. The listing is divided into segments known as blocks, horizontal groups, vertical groups, rows, and pages, for levels of control. 
         [0035]      FIGS. 1A through 1C  show a typical pin tumbler cylinder  10 . The cylinder  10  consists of a shell  12  having a rotatable plug  13  within. The plug  13  has an axially extending keyway  14 , which accepts key  15 . A series of cuts  16  are placed on the upper edge of key  15 . Within the shell  12  and plug  13  are a plurality of pins  20  and springs  21 . Pins  20  are comprised of at least two segments, a bottom pin  20   a  and a top pin or driver  20   b.  When a cylinder has been pinned for master keying, one or more master pins  20   c  (see  FIGS. 1D and 1E ) are used in each pin stack. The depths of the cuts  16  on the key  15  are called bittings and typically are numbered from  0  to  9 . With no key  15  inserted in the cylinder  10 , the top pins  20   b  and bottom pins  20   a  are forced by the springs  21  down into the plug  13 . The top pins  20   b  are then partially in the shell  12  and partially in the plug  13 , forming an obstacle that keep the plug  13  from turning, as shown in  FIG. 1A . When a proper key  15  is inserted into the cylinder  10 , the bitting depth of the cuts  16  brings the top of each of the bottom pins  20   a  exactly to the surface of the plug  13 , forming a shear line  24 , as shown in  FIG. 1B . With the tops of the bottom pins  20   a  aligned with the shear line  24 , the key  15  and the plug  13  can be turned. When an incorrect key  15  is inserted, one or more of the top and bottom pins  20   b,    20   a  will not align with the shell  12  surface to form the shear line  24 , thereby preventing rotation of the key  15  and plug  13 , as shown in  FIG. 1C . 
         [0036]      FIGS. 1D and 1E  illustrate a typical cylinder  10  which has been pinned for master keying. The term “master keyed” usually denotes that each individual cylinder is operated by two or more different keys. The key that normally opens only one cylinder or keyed alike group of cylinders is called a change key. The key that opens all the cylinders in a group or series is called a master key. An example of a simple master key system would be in a small office building. There would be an individual change key for each office door, and there would be a master key to operate all office doors. The essential difference between an ordinary pin tumbler cylinder and a master keyed cylinder is the use of master pins  20   c.  A master pin is an additional top pin, usually shorter, which is inserted between the bottom pin  20   a  and the top pin  20   b.  In each pin chamber where a master pin  20   c  is located, a second shear position is created. The cylinder can be operated at either shear position. Thus, different key bittings can be used for each position where there is a master pin.  FIG. 1D  shows a master keyed cylinder  10  with a change key  15  inserted and  FIG. 1E  shows the same master keyed cylinder  10  with a master key  15  inserted. In both figures, the pins  20  have aligned to form a shear line  24 , thereby permitting the key  15  and plug  13  to rotate. 
         [0037]      FIG. 2  shows a key system schematic for a five level system of change keys and master keys. The levels are numbered from 1 (L 1 ), the lowest level and which is assigned to the change keys, to the highest level n (L 5  in  FIG. 2 ) which consists of the master key which will operate all the locks in the system. The first level below level L n  is assigned a key symbol of A, B, . . . , Z. (However, if the master key below level L n  has no master keys below it, key symbols of AA, BB, . . . , ZZ are used.) The next level below is AA, AB, . . . , AZ for master keys below A and AAA, AAB, . . . , AAZ for master keys below AA. Change keys are always level L 1  and have a key symbol the same as the master key with which they are grouped followed by a number. In  FIG. 2 , there are 16 change keys grouped under master key AAA having key symbols, AAA 1 , AAA 2 , . . . , AAA 16 . The first level above the change keys are named Master Keys (MK). The highest level master key is named based upon the number of levels in key system schematic, even if it is also a first level master key above a group of change keys. In the example shown in  FIG. 2 , a five level system, the top level (L 5 ) master key is named Great Great Grand Master Key (GGGMK). Intermediate level master keys are named according to the number of levels below them. Master Keys AAA and AAB are Level L 2 . Master key AA, level L 3 , is named Grand Master Key (GMK). Master keys AB and AC, BB, CC are named Master Keys and are level L 2  since they are the first master keys above change keys. Master key A is a Great Grand Master Key (GGMK) and is level L 4 . 
         [0038]    To determine the available master keys and change keys for a given master key system, the present invention utilizes a bitting list generator to calculate all of the available key cuts for the system. The bitting list generator is preferably a computer operated system which starts with a key bitting array (KBA)  30  and calculates all of the available key cuts based on the intended sequence of progression (SOP). An acceptable bitting list generator is a spreadsheet which is configured to calculate each key cut based on the KBA  30  and SOP and to eliminate any cuts which violate the MACS. Any other system capable of performing the necessary calculations and coordination of data may alternatively be utilized. 
         [0039]    An illustrative KBA  30  is shown in  FIG. 3 . A user enters a desired KBA  30  into the bitting list generator following general master keying rules and the intended SOP. In the illustrated KBA  30 , the user begins by entering the top master key (TMK) cut sequence  32 . The user will then check the KBA  30  to be sure the necessary sequencing rules have been adhered to, for example, there are no digits from the TMK  32  in the Progression Possibilities  34 , that the Progression Possibilities  34  increment by two digits and are all odd or even digits depending on system parity, and that the SOP  36  uses digits 1-6 and they do not reoccur. These are the requirements for this given master key system, but each master key system can have its own requirements in accordance with known master keying principals. 
         [0040]    Once the KBA  30  has been entered, the bitting list generator calculates and outputs all of the available key cuts and master key combinations using a standard progression format. For example, the standard progression format may list the available key cuts divided into segments known as blocks, horizontal groups, vertical groups, rows, and pages, for levels of control. Referring to  FIG. 4 , an illustrative page master  50  for the KBA  30  of  FIG. 3  is shown. The page master  50  includes each change key cut  51  that is available under the page master key cut  53 . Additional master key cuts may also be available for the given page master  50 . For example, there may be a master key cut  54  for each vertical group  52 . In the illustrated embodiment, each of the first three vertical groups  52  has a respective master key cut  54 , but the fourth vertical group  52  does not have an available master key cut. In each vertical group  52  of this illustrated page master  50 , twelve change key cuts  51  are available. This means that four cuts in each of these rows violates the MACS, and therefore, is not listed as an available change key cut. 
         [0041]    The page master  50  also shows higher level master key cuts, for example, a master key cut  55  that will operate all of the key cuts on page master  50  for page one as well as page masters  50  for pages two through four. Another master key cut  57  operates all of the key cuts on page master  50  for page one as well as page masters  50  for pages two through sixteen. A third master key cut  59 , for the TMK, operates all of the key cuts on page master  50  for page one as well as page masters  50  for pages two through sixty-four. With this single page master  50 , a user would be able to create a six level master key system with the change key cuts  51  as L 1 , the vertical group master key cuts as L 2 , the page master key cut  53  as L 3 , the page one through four master key cut as L 4 , the page one through sixteen master key cut as L 5 , and the TMK master key cut as L 6 . 
         [0042]    The current KBA and the SOP are utilized with a cylinder having 6 pins which are all used for master keying. Under such a system, the bitting list generator will generate sixty-four page masters  50 . The number of page masters  50  will vary depending upon the set up of the cylinder and the configuration of the standard progression format. More or fewer page masters  50  may be generated as well as the particular number and arrangement of segments on each page master  50 . 
         [0043]    To allow an operator to visually see and understand how many master key cuts and change key cuts are available under a given master key system, the present invention further generates a master key illustrator  40  as shown in  FIGS. 5-7 . The master key illustrator  40  shows all page masters  50  of the given master key system graphically and interrelated to one another. Turning to  FIG. 7 , graphical page masters  50 ′ for page forty-nine and page fifty-two of the given master key system are shown shaded in different colors. As can be seen therein, each graphical page master  50 ′ is divided from adjacent graphical page masters  50 ′ by a heavy dashed lined. 
         [0044]    Turning to  FIG. 6 , graphical page master  50 ′, corresponding to page master  50  for page one as shown in  FIG. 4 , is shown. The graphical page master  50 ′ preferably includes an identifier  60  of the page, a listing of the page master key cut  53  and a total number of change key cuts  62  available under that page master key cut  53 . In the preferred embodiment, each graphical page master  50 ′ is further divided by small dashes to illustrate each graphical vertical group  52 ′. Within each graphical vertical group  52 ′, the vertical group master key cut  54  is listed as well as the total number of change key cuts  63  available under that vertical group master key cut  54 . 
         [0045]    The master key illustrator  40  is further configured to show higher level master key availability. In this regard, graphical page masters  50 ′ for larger groups are arranged within master key illustrator  40  adjacent to one another. Referring to  FIG. 6 , the graphical page masters  50 ′ for pages one through four are all arranged within a larger rectangle, which is illustrated contained within double solid lines, to define a graphical four page group master  70 . The graphical four page group master  70  preferably includes an identifier  72  of the pages, a listing of the four page group master key cut  55  and a total number of change key cuts  74  available under that four page group master key cut  55 . 
         [0046]    Similarly, the graphical page masters  50 ′ for pages one through sixteen are all arranged within a larger rectangle, which is illustrated contained within a single solid line, to define a graphical sixteen page group master  80 . As illustrated in  FIG. 5 , the master key illustrator  40  includes four of the graphical sixteen page group masters  80 . Referring again to  FIG. 6 , each graphical sixteen page group master  80  preferably includes an identifier  82  of the pages, a listing of the sixteen page group master key cut  57  and a total number of change key cuts  84  available under that sixteen page group master key cut  57 . 
         [0047]    Referring to  FIG. 5 , the master key illustrator  40  includes all of the graphical page masters  50 ′ arranged within an outer rectangle, which is illustrated contained within a single, thick solid line, to define a graphical top master  90 . The illustrated graphical top master  90  includes four graphical sixteen page group masters  80  (single solid line), each of which is further divided into four graphical four page group masters  70  (double solid line), each of which is further divided into four graphical page masters  50 ′ (heavy dashed line), and each of which is further divided into four graphical vertical group masters  52 ′ (small dashed line). The graphical top master  90  preferably includes an identifier  92  of the pages, a listing of the top master key cut  59  and a total number of change key cuts  94  available under the top master key cut  59 . 
         [0048]    While the present master key illustrator  40  utilizes different line types to distinguish between the different levels, other indicators, for example, different line colors, can also be utilized. Additionally, as illustrated in  FIGS. 5-7 , a user may utilized different cell colors or shading to differentiate master keying levels or groupings for a desired project. 
         [0049]    The mater key illustrator  40  allows a user to quickly see and determine if a selected master key system, as defined by the KBA, will provide a desired number of change keys and master keys and also the expandability of a given system. Utilizing shading or coloring of the cells can further help in the planning and specific implementation of the system. 
         [0050]    For example, a university may want to determine if a master key system will be appropriate. In this example, the university includes a main dorm building with 500 rooms, two smaller dorms each with 150 rooms, a library with three areas of differing accessibility and two classroom buildings each with 35 classrooms. Turning to  FIG. 5 , the master key illustrator  40  may be utilized to determine if the master key system is the correct size, whether expansion is available and to plan the implementation of the system. Looking at the graphical top master  90 , the system includes a total of 3,216 change key cuts. Within that, there are four graphical sixteen page group masters  80  with two of those having 960 change key cuts each, one having 720 change key cuts, and the other having 576 change key cuts. From this, the designer can quickly designate the graphical sixteen page group master  80  of pages one to sixteen as appropriate for the main dorm building. 
         [0051]    Turning to the smaller buildings, the graphical sixteen page group master  80  of pages forty-nine to sixty-four has four graphical four page group masters  70 . Within these, the graphical four page group master  70  for pages sixty-one to sixty-four has only 144 change key cuts, and therefore, will not work for either of the smaller dorms. However, since this graphical four page group master  70  does include three page masters  50 ′, each with an available master key cut, this graphical four page group masters  70  can be designated for the library. The user can quickly see that a fourth page master key is not available and can determine if such is or is not necessary for possible expansion. 
         [0052]    As for the small dorms, the three remaining graphical four page group masters  70  each have 192 change key cuts available, and therefore, any two can be chosen for use with the respective dorms. The final graphical four page group master  70  includes four graphical page masters  50 ′, each with 48 change key cuts. Two of these graphical page masters  50 ′ can be chosen for the respective classroom buildings, leaving available expansion for two additional classroom buildings that could be keyed under the same four page group master key cut  55 . 
         [0053]    The user after shading the master key illustrator  40  as shown in  FIG. 5 , would also be able to see that after implementing the current design, there would still be plenty of room for expansion. The expansion could either be in fairly large blocks, for example, another large dorm of over 900 rooms (one of the sixteen page group masters) or smaller buildings have a need for sixty-four or less change keys (one of the page masters), down to smaller buildings yet needed sixteen or less change keys (one of the vertical group masters). 
         [0054]    If upon review of the master key illustrator  40  the user determines that a given master key system is too larger or too small for its needs, a new KBA can be entered and a new master key illustrator  40  generated for the new master key system. 
         [0055]    Additionally, a user with a current master key system may use the present system by entering information on the current master key system therein and generating a master key illustrator  40  for the current master key system to identify what master keys and change keys remain available in the current master key system. 
         [0056]    Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.