Abstract:
An electronically addressable object carrier for enabling the management of removably suspended objects, such as keys, distributed in an object location space, The object carrier includes a housing having an object retention element for securing an object to the object carrier and at least one through aperture for removably receiving an electrically conductive suspension member capable of manifesting object address signals and power signals supplied by a source; a microcontroller carried by the housing, the microcontroller having a unique object address serving to identify an object secured to the object carrier; an electrically conductive element located in the at least one aperture for electrically coupling the microcontroller to the electrically conductive suspension member when the aperture is removably received on the electrically conductive suspension member; and a visible indicator coupled to the microcontroller for activation whenever the microcontroller receives an address signal representative of the unique object address. Two electrically conductive elements can be used: one having first and second electrically conductive members slidably and oppositely disposed in a single aperture and bias means for urging the first and second electrically conductive members toward each other to make contact with an electrically conductive suspension member when the carrier is mounted. Another being a pair of washers mounted in spaced first and second apertures in the housing. In use, the devices are removably suspended by one or two electrically conductive suspension members secured to a support element, such as the back board of a cabinet.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    This invention relates to collective objects management systems in general, and in particular to an improved collective objects management system using object identification with digital addresses. More particularly, this invention relates to an improvement for a collective objects management system using object identification with digital addresses, the improvement pertaining to removably suspended objects. 
         [0002]    The term “collective objects management systems” is a term coined to denote systems for generally keeping track of items (“objects”) in a collection of items. For example, an automobile parts warehouse at any given time has a collection of vehicle parts (“objects”) in inventory. The kind and number of such parts varies every day, as parts are sold and new parts are received. In order to keep track of the number and kind of vehicle parts in inventory, some type of collective vehicle parts management system must be used. Similarly, in a semiconductor manufacturing operation, at any given time there is a collection of integrated circuits (“objects”) of one or more types located somewhere in the facility, which must be accounted for using a collective integrated circuits management system. In supermarkets, a collection of a large number of different types of items, such as meats, produce, canned goods and the like is usually in inventory, with the number and types of objects varying widely on a daily basis and thus requiring a complex objects management system. In business offices and some homes, file storage cabinets are typically used to store documents used for both business and personal activities. A typical file storage cabinet has several pull-out drawers each containing a relatively large number of file folders (“objects”), with each folder containing one or more documents. In order to enable the documents contained in the various files to be readily accessed and inventoried, some type of file management system is necessary. 
         [0003]    Commonly assigned U.S. Letters Pat. No. 8,471,717 issued Jun. 25, 2013 for “Collective Objects Management System With Object Identification Using Addressable Decoder Units” discloses a system for managing objects distributed in an object location space. The disclosure of the &#39;717 patent is hereby incorporated by reference. The &#39;717 system comprises a container, such as a file drawer, having a plurality of mutually electrically isolated electrically conductive paths, at least one of which can receive address signals supplied by a source and specifying a sought object; and a plurality of object receptacles positioned in the container, each of the plurality of object receptacles having
       (a) a plurality of electrically conductive members, each of which is electrically coupled to a different one of the plurality of mutually electrically isolated electrically conductive paths;   (b) an address decoder circuit associated to an object in the receptacle, the address decoder circuit having a unique system address, the address decoder circuit further having a plurality of electrically conductive terminals in electrical contact with the plurality of electrically conductive members; and   (c) an indicator, such as a visible indicator (e.g., an LED) coupled to the address decoder circuit for activation whenever the address decoder circuit detects an address signal present on at least one of the plurality of electrically conductive members and representative of the unique system address of the object in the receptacle.       
 
         [0007]    The &#39;717 system further includes a source comprising an encoder for generating the address signals, the encoder having at least one input terminal for receiving object identification signals from a supply device, at least one output terminal coupled to each address decoder circuit of the plurality of object receptacles, and circuitry for generating a signal representative of the unique system address of the object specified by the object identification signals. 
         [0008]    In a specific embodiment, the container comprises a file folder drawer; and each object receptacle comprises a file folder having a pair of support braces, with one of the support braces containing the plurality of electrically conductive members. In this embodiment, the address decoder circuit and the indicator of each of the object receptacles are carried by one of the two support braces of each file folder. 
         [0009]    The file folder drawer has a front panel with an additional indicator mounted thereon; and the system further includes circuitry for operating the additional indicator whenever an address decoder circuit located in the file folder drawer detects an address signal present on the at least one of the plurality of electrically conductive members and representative of the unique system address of that address decoder. 
         [0010]    Each address decoder circuit includes circuitry for generating a VALID signal whenever that address decoder circuit detects an address signal present on the at least one of the plurality of electrically conductive members and representative of the unique system address of that address decoder circuit. 
         [0011]    A cabinet microcontroller supplies power signals to the plurality of object receptacles via some of the electrically conductive paths, and address signals via the at least one of the electrically conductive paths; and receives VALID signals generated by each address decoder circuit when an incoming address matches a given address decoder circuit system address. The microcontroller also includes circuitry for generating information signals identifying the location in the system of any address decoder circuit which generates a VALID signal. 
         [0012]    The &#39;717 technique provides objects management capability for objects distributed in an object location space which is superior to older, manual techniques implemented in the past. 
         [0013]    A unique class of collective objects is comprised of those objects designed to be removably suspended for storage, access and display purposes. One example of this class of collective objects is a collection of keys each provided with a key holder which can be removably attached to a suspension device, such as a hook or a peg. Several key holders and keys are usually removably stored in one or more key cabinets, depending on the number of keys in the collection. Each key or key holder is normally provided with a label containing information identifying the associated key and its application. Another example of this class of collective objects is a collection of mechantable items (such as dry cell batteries, hardware items, or the like) carried by a packaging unit designed to be removably attached to a suspension device and provided with identifying information for the item. The key holders and packaging units are typically provided with a through aperture for enabling removable mounting on the suspension device. While this class of collective objects could benefit from the advantages afforded by the electronically addressable collective objects management system described above with reference to the &#39;717 patent, to date there has been no commercially available implementation of the principles of the electronically addressable collective objects management system to the class of removably suspendable objects. 
       SUMMARY OF THE INVENTION 
       [0014]    The invention comprises an electronically addressable removably suspendable object carrier and a system for management of objects carried thereby. 
         [0015]    In a device aspect, the invention comprises an electronically addressable object carrier for enabling the management of objects distributed in an object location space, the object carrier comprising a housing having an object retention element for securing an object to the object carrier and at least one through aperture for removably receiving an electrically conductive suspension member capable of manifesting object address signals and power signals supplied by a source; a microcontroller carried by the housing, the microcontroller having a unique object address serving to identify an object secured to the object carrier; an electrically conductive element located in the at least one aperture for electrically coupling the microcontroller to the electrically conductive suspension member when the aperture is removably received on the electrically conductive suspension member; and an indicator coupled to the microcontroller for activation whenever the microcontroller receives an address signal representative of the unique object address. The indicator is a visible indicator, preferably an LED light source. 
         [0016]    In one embodiment the housing has a single through aperture, and the electrically conductive element comprises first and second electrically conductive members slidably and oppositely disposed in the at least one aperture and bias means for urging the first and second electrically conductive members toward each other so that the first and second electrically conductive members are urged into ohmic contact with an electrically conductive suspension member when the aperture is removably received on the electrically conductive suspension member. In this embodiment, the bias means preferably comprises a pair of springs each engaged with a different one of the first and second electrically conductive members. This embodiment is intended for use with a suspension member having two electrically conductive portions separated by an electrically non-conductive central portion. One such suspension member has substantially cylindrical geometry; another has substantially rectangular geometry. 
         [0017]    In another embodiment the housing has first and second mutually spaced through apertures for removably receiving first and second electrically conductive suspension members, at least one of the first and second electrically conductive suspension members being capable of manifesting object address signals and power signals supplied by a source. In this embodiment each of the first and second apertures is provided with an electrically conductive element located therein for electrically coupling the microcontroller to the first and second electrically conductive suspension members when the first and second mutually spaced apertures are removably received on the first and second electrically conductive suspension members. The electrically conductive element preferably comprises a serrated washer. 
         [0018]    The object retention element preferably includes an additional through aperture formed in the housing so that an object can be attached to the housing. 
         [0019]    The device according to the invention may also include an additional indicator coupled to the microcontroller for activation whenever the microcontroller receives power signals. 
         [0020]    In use, the devices according to the invention are removably suspended by a plurality of electrically conductive suspension members capable of manifesting object address signals and power signals supplied by a source, the suspension members being secured to a support element, such as the back board of a cabinet. 
         [0021]    For a fuller understanding of the nature and advantages of the invention, reference should be made to the ensuing detailed description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0022]      FIG. 1  is a perspective view of a first embodiment of a removably suspended object in the form of a key and a key holder object carrier removably suspended on two suspension members; 
           [0023]      FIG. 2  is a schematic front plan view of the key holder object carrier of  FIG. 1  illustrating the principal components of the key holder; 
           [0024]      FIG. 3  is a perspective view of a cabinet for removably storing several removably suspended objects of the type shown in  FIG. 1 ; 
           [0025]      FIG. 4  is a schematic block diagram showing the principal system components in a collective objects management system using the removably suspended objects according to the invention; 
           [0026]      FIG. 5  is a perspective view of an alternate storage board having several leaves for removably storing several removably suspended objects of the type shown in  FIG. 1 ; 
           [0027]      FIG. 6  is a perspective view of a second embodiment of a removably suspended object in the form of a key and a key holder object carrier removably suspended on a single round suspension member; 
           [0028]      FIG. 7  is a composite schematic view of the single suspension member of the embodiment of  FIG. 6 ; 
           [0029]      FIG. 8  is a perspective view of a third embodiment of a removably suspended object in the form of a key and a key holder object carrier removably suspended on a single square suspension member; and 
           [0030]      FIG. 9  is a side view illustrating the square suspension member mounted to the back wall of a cabinet. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0031]    The invention has wide application to a large variety of electronically addressable removably suspendable objects. The following is a detailed description of one application of the invention to removably suspended objects which are keys attached to object carriers which are key holders. 
         [0032]    Turning now to the drawings,  FIG. 1  is a perspective view of a first embodiment of a removably suspended object in the form of a key and an object carrier in the form of a key holder removably suspended on two suspension members. As seen in this Fig., a key  10  is secured by a key ring  12  to a key holder generally designated with reference numeral  15 . Key ring  12  is received in a through-aperture  13  formed in the lower region of key holder  15 . Key holder  15  is provided with two through-apertures  16 ,  17  in the upper region thereof so that key holder  15  can be removably suspended by two electrically conductive suspension members  21 ,  22  secured to a backboard  25 . 
         [0033]    Once installed, key  10  should permanently remain attached to key holder  15 . To reduce or eliminate entirely the removal of a key  10  from its associated key holder  15 , key ring  12  should preferably be sealed in such a manner that (a) the key  10  cannot be removed from the key ring  12 ; and (b) the key ring  12  cannot be removed from the key holder  15 . This can be done in several different ways, depending on the material from which the key ring  12  is fabricated. If key ring  12  is fabricated from spring steel, adjacent windings of key ring  12  can be welded together, or bonded together with an epoxy material. If key ring  12  is fabricated from a tough plastic material, adjacent windings of key ring  12  can be fused together by ultrasonic welding, or bonded together using a suitable epoxy or other adhesive material that cures to a durable state. Other such techniques will occur to those of ordinary skill in the art. 
         [0034]    Suspension members  21 ,  22  may be straight rods as illustrated, or may comprise hooks with upturned outer ends to promote retention of key holder  15  on the suspension members. Suspension members  21 ,  22  are formed to a diameter dimension which is conformable with the inner diameters of key holder through-apertures  16 ,  17 . Suspension members  21 ,  22  are fabricated from an electrically conductive material for a purpose described below. 
         [0035]    The facing surface of key holder  15  is further provided with two apertures  18 ,  19  which are dimensioned to accommodate a pair of visible indicators, such as LED light sources, described below. 
         [0036]    With reference to  FIG. 2 , a pair of electrically conductive contact elements  26 ,  27  are secured, respectively, in through-apertures  16 ,  17  of key holder  15 . Contact elements  26 ,  27  preferably comprise conventional serrated electrically conductive steel washers, each of which is ohmically connected by means of ohmically conductive paths  28 ,  29  to a different input port of an object carrier microcontroller unit (MCU)  30 . MCU  30  is preferably a type PIC 10F202 device available from Microchip Technology, Inc. of Chandler, Ariz. and incorporates a memory unit which stores a unique identification character serving to identify the key holder  15  in which it is located. Object carrier microcontroller  30  is ohmically connected to suspension members  21 ,  22  via conductive paths  28 ,  29  and contact elements  26 ,  27  whenever key holder  15  is removably suspended on suspension members  21 ,  22 . MCU  30  also has two output ports which are individually connected to a power on visible indicator  33  and an address match visible indicator LED  34 . Power on visible indicator  33  is activated whenever current flows from MCU  30 , which occurs whenever MCU  30  is ohmically connected to suspension members  21 ,  22  via conductive paths  28 ,  29  and contact elements  26 ,  27 , and electrical power is present on suspension members  21 ,  22 . Address match visible indicator  34  is activated by object carrier microcontroller  30  whenever an address signal matching the identification of key holder  15  is presented to object carrier microcontroller  30  from suspension members  21 ,  22 . Visible indicators  33 ,  34  may comprise any one of a number of known elements capable of providing a visible signal when activated in the manner described below. Examples of suitable indicators are a conventional LED indicator, and a type 276-036 flashing LED indicator available from Radio Shack Corporation. To avoid confusion, visible indicators  33 ,  34  preferably emit light of different colors, such as red for power on visible indicator  33  and green for address match visible indicator  34 . 
         [0037]      FIG. 3  is a perspective view of a cabinet for removably storing several removably suspended objects of the type shown in  FIG. 1 . As seen in this Fig., a cabinet generally designated with reference numeral  40  has a back wall  25 , a top wall  41 , a bottom wall  42 , a left side wall  43 , a right side wall  44  and a hinged door  45 . Door  45  may be fabricated from a transparent material, such a transparent plastic or tempered glass so that the interior contents are visible from outside the cabinet  40  when door  45  is closed. A conventional electrically operable lock mechanism  46  is attached to the interior of cabinet  45  and a catch  47  operable with lock mechanism  46  is secured to door  45 . A plurality of pairs of suspension members  21 - 1 ,  22 - 1 , . . . ,  21 - n,    22 - n  is secured to back wall  25  for removably suspending a plurality of key holders  15 - 1 , . . . ,  15 - n  in the interior of cabinet  40 . Cabinet  40  has a cabinet visible indicator  48  mounted in a prominent location, such as on top wall  41 . Cabinet visible indicator  48  is activated whenever a sought key holder  15 - i  is located within that cabinet  40 . A pair of address signal and power connectors  49 ,  50  is mounted to cabinet  40  in a convenient location, such as the bottom portion of right side wall  44 . Connectors  49 ,  50  are preferably conventional USB connectors. One of the connectors, such as connector  49 , provides communication capability between cabinet  40  and a cabinet controller described below; the other connector, such as connector  50 , provides communication capability between cabinet  40  and another cabinet (when  2  or more cabinets are deployed in a system). 
         [0038]    As already noted, cabinet  40  is connected to a cabinet controller generally designated with reference numeral  51  and shown in  FIG. 4  within the dotted rectangular outline. As seen in this Fig., cabinet controller  51  includes a microcontroller unit (MCU)  52 , and a memory unit  53 . MCU  52  is preferably a type LPC1766 device available from NXP Semiconductor Corporation of Eindhoven, The Netherlands. Memory unit  53  may be any memory device which is compatible with MCU  52  and has sufficient capacity to store key holder information for the maximum number of key holders  15 - i  which can be accommodated by a maximum number o of cabinets  40 - i.  Cabinet controller microcontroller unit  52  is configured to communicate with a host computer  60  either via hard wired conductors  61 ,  62  or via a wireless communication link. Cabinet controller microcontroller unit  52  communicates with individual key holders  15 - i  in individual cabinets  40  via channel communication links  55 - 1 , . . . ,  55   m,  where m is the maximum number of channels MCU  52  is capable of independently controlling. Each channel  55 - i  is connected between MCU  52  and the first cabinet  40 - i - 1  in a cascaded collection of cabinets via the input connector  49  of the first cabinet  40 - i - 1  in the series. The first cabinet  40 - i - 1  in the series is connected to the next cabinet  40 - i - 2  via the output connector  50  of the first cabinet to the input connector  49  of the second cabinet, etc. 
         [0039]    Cabinet controller microcontroller unit  52  can respond to information requests from host computer  60  in several ways. For example, host computer  60  may send a request to microcontroller unit  52  to locate a specific key holder  15 . Upon receipt of such a request, microcontroller unit  52  generates the address signals for that specific key holder  15  and places these signals on all channels  55 - i  of the system. These address signals are coupled to all of the suspension members  21 ,  22  in all of the cabinets  40 - i  configured in the system. If the key holder  15  specified by the address signals is present in a cabinet  40 - i,  microcontroller unit  52  will receive a key holder found signal from the key holder MCU  30  having the matching address. Also, the key holder MCU  30  having the matching address will activate its address match visible indicator LED  34 . Upon receipt of the key holder found signal, microcontroller unit  52  activates the visible indicator device  48  of that cabinet via the channel to which the cabinet containing the found key holder  15  is connected, activates the cabinet door lock  46  to unlock the cabinet door  45 , and sends an information signal to host computer  60  indicating that the specified key holder  15  has been located and indicating the identity of the cabinet  40  in which the found key holder  15  is located. Activation of the cabinet visible indicator device  48  by microcontroller unit  52  enables a human operator to quickly locate the cabinet containing the sought key, while activation of the address match visible indicator LED  34  by the key holder MCU  30  pinpoints the location of the sought key in the cabinet. 
         [0040]    If microcontroller unit  52  does not receive a key holder found signal, an information signal is sent to host computer  60  indicating that the specified key holder was not located. In response, host computer  60  can update the master system data base to reflect this information. 
         [0041]    Host computer  60  may send a request for an update of the object identification contents of the cabinet(s) to which microcontroller  52  is connected. In response to such a request, microcontroller unit  52  reads this information from memory device  53  and send this information to host computer  60 . In this way, the master system data base can be quickly updated on a periodic or random basis. 
         [0042]    Microcontroller unit  52  is also configured to perform periodic polling of the object carrier microcontroller units  30  located in the individual cabinets  40   i.  In particular, microcontroller unit  52  is configured to place a polling request on communication links  55   i  in a periodic manner, preferably every second in the preferred implementation of the invention. In response to the polling request, each object carrier microcontroller unit  30  operationally located in each cabinet  40   i  responds with its identification and this information is stored in memory device  53  by microcontroller unit  52 . Microcontroller unit  52  also compares the received identification information with the identification information previously stored in memory device  53 . If any identification is missing from the received responses, microcontroller unit  52  erases this identification from memory device  53  and sends this result to host computer  60  to update the master system data base. If new identification information is included in the received responses (indicating, e.g., that a new key holder  15  has been added to the cabinet or a key holder  15  has been transferred to a different cabinet), microcontroller unit  52  enters this information into memory device  53  and sends this result to host computer  60  to update the master system data base. 
         [0043]    Instead of removably storing the keys  10  and associated key holders  15  in one or more cabinets  40  as described above and illustrated in  FIGS. 3 and 4 , the storage board arrangement illustrated in  FIG. 5  can be used. As seen in this Fig., a storage board having a plurality of storage leaves (three illustrated) are pivotally mounted together in book-like fashion. The rear-most leaf is attached to a mounting member (such as a wall) by means of fasteners  63 , such as screws or bolts. Each leaf has a plurality of pairs of suspension members  21 ,  22  arranged in the same manner as in the embodiment of  FIG. 3  for removably retaining key holders  15   i  to which individual keys  10  are permanently attached. A control, address and power signal cable is connected at one end to microcontroller unit  52  (not illustrated in  FIG. 5 ) and at the other end to a plurality of conductive paths  67   i,    68   i  formed on the reverse surface of each page. Each conductive path  67   i  is ohmically connected to a different suspension member  21   i,  while each conductive path  68   i  is ohmically connected to a different suspension member  22   i.  As with the  FIG. 3  arrangement, the suspension members  21   i,    22   i  extend outwardly from the front surface of each leaf to facilitate removable suspension of the key holders  15   i.  Each leaf is also furnished with a leaf visible indicator  48   i,  which functions in the same manner as the visible indicators  48   i  for cabinets  40   i  of  FIG. 3 . 
         [0044]    In some applications of the invention it may be preferable to employ a single suspension member for each key holder  15 .  FIGS. 6 and 7  illustrate a first embodiment using a single essentially cylindrical suspension member generally designated with reference numeral  75 . As seen in these Figs., a key holder  70  having a similar key ring aperture  13 , and visible indicator apertures  18 ,  19  as the key holder  15  of  FIGS. 1 and 2  is provided with a pair of oppositely disposed electrically conductive pins  71 ,  72  in a single aperture formed centrally of the upper housing region of key holder  70 . Pins  71 ,  72  are biased inwardly by a pair of bias springs  73 ,  74 . Suspension member  75  has two electrically conductive elements  76 ,  77  separated by an electrically insulative central spacer element  78 . Elements  76 ,  77  provide electrical communication between microcontroller unit  52  and microcontroller unit  30  in the interior of key holder  70  in the same way as that described above for the embodiment of  FIGS. 1-4 . Spacer element  78  provides electrical insulation between electrically conductive elements  76 ,  77  which is necessary for the proper functioning of the system. To promote ohmic electrical connection between elements  76 ,  77  and microcontroller unit  30 , pins  71 ,  72  are biased by springs  73 ,  74  against the outer surface of elements  76 ,  77 . As shown in  FIG. 7 , the remote end  79  of suspension member  75  has an external thread to facilitate installation of suspension member  75  in an aperture formed in the mounting member, such as backboard  25  of  FIG. 1 . This is done by first threading a mounting nut onto the external thread, inserting end  79  into a mounting aperture, and threading a second mounting nut onto the external thread so that both nuts firmly engage opposite surfaces of the mounting member. Electrical connection to elements  76 ,  77  can be done in any suitable manner known to those of ordinary skill in the art, such as by soldering. The protruding end of suspension member  75  may be formed with an upward turn to promote retention of a key holder  70  thereon. 
         [0045]      FIGS. 8 and 9  illustrate a second embodiment of a single suspension member using a suspension bar generally designated with reference numeral  80 . As seen in these Figs., suspension bar  80  has two electrically conductive elements  81 ,  82  separated by an electrically insulative central spacer  83 . Elements  81 ,  82  provide electrical communication between microcontroller unit  52  and microcontroller unit  30  in the interior of key holder  70  in the same way as that described above for the embodiment of  FIGS. 1-4 . Spacer element  83  provides electrical insulation between electrically conductive elements  81 ,  82  which is necessary for the proper functioning of the system. Since suspension bar  80  has a rectangular cross section, the single aperture formed centrally of the upper housing region of key holder  70  must have a complementary shape in order to accommodate suspension bar  80  when key holder  70  is removably supported thereby. As with the  FIG. 7  embodiment, pins  71 ,  72  and bias springs  73 ,  74  provide effective electrical connection between suspension bar elements  81 ,  82  and microcontroller unit  30  in key holder  70 . Electrical connection to suspension member elements  81 ,  82  may be effected in the same manner as that described above with reference to the first embodiment shown in  FIG. 7 . Alternatively elements  81 ,  82  may be equipped with electrically conductive contact studs  84 ,  85  mounted in apertures formed at the rear, to which electrical conductors may be secured by soldering or the like. To promote retention of suspension member  80  in the corresponding aperture in mounting back board  25 , the rear portion of suspension bar  80  has an enlarged vertical dimension to provide an abutment notch  86  when suspension bar  80  is inserted into the mounting aperture in back board  25  from the rear. Lastly, the protruding end of suspension member  80  may be formed with an upward turn  87  to promote retention of a key holder  70  thereon. 
         [0046]    Although the above description is devoted to an implementation of the invention in the field of key management systems, the invention has much wider application. In general, the invention can be used in any collective object management system in which the need exists for a technique for rapidly identifying a given class or type of object from a collection of objects which are designed to be removably suspended on one or more suspension members of the type shown and described above. For example, in a retail store operation, the objects may be individual mechantable items (such as dry cell batteries, hardware items, or the like) carried by a packaging unit designed to be removably attached to a suspension device and provided with identifying information for the item. In any application, the object carrier microcontroller  30  and LED indicator  34  associated to a specific object are closely coupled to the object itself and electrically coupled to the local microcontroller  52  so that the circuits can respond to the reception of a desired object address and activate the indicator  34  in such a way that a human operator can locate the object specified by the address. 
         [0047]    Although the above provides a full and complete disclosure of the preferred embodiments of the invention, various modifications, alternate constructions and equivalents will occur to those skilled in the art. For example, while the invention has been described with reference to specific microcontroller devices, other comparable devices may be employed, depending on the preferences of the system designer. Moreover, while the indicator  48  has been described as a visible indicator, other types of indicators, such as audible indicators, may be used, if desired. Further, the invention may be used to manage a key system of many key cabinets positioned at different physical locations using an internal or an external computer network, if desired. In addition, while the embodiments described and illustrated in  FIGS. 1 and 2  show only one key  10  attached to one key holder  15 , in some implementations two or more keys  10  may be attached to a single holder  15  (as shown in  FIGS. 3 -5 ). Therefore, the above should not be construed as limiting the invention, which is defined by the appended claims.