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This application is a continuation-in-part of application Ser. No. 11/809,172, filed May 30, 2007, which was a regular filing from provisional application No. 60/810,195, filed May 31, 2006. The disclosure of that copending application is incorporated here in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     This invention concerns locks for cabinets, lockers, drawers, access panels and similar situations. Specifically the invention embraces an electronic cam lock that fits standard cam lock openings. 
     Metal and wood file cabinets, desk and cabinet drawers, locker doors, access panels and doors, mail boxes, dispensers and other secure situations often utilize relatively simple lock mechanisms known as cam locks. Such cam locks may or may not involve a camming action. In some cases they move other mechanisms that are engaged with the door or drawer of the cabinet or engaged with other mechanisms that are linked to the door and drawer of the cabinet or multiple doors or drawers of the cabinet. In one of the simplest forms, a cam lock on a cabinet door typically fits in a ¾ inch diameter D-shaped or double D-shaped hole and, at the back side of the cam lock cylinder unit, has a metal blade or arm called a cam that rotates when the key is turned, from a position disengaged from surrounding cabinet hardware to a position of engagement in a slot or behind a ledge of the surrounding cabinet hardware. Other locks, such as those for desk drawers, commonly referred as cabinet locks, involve a camming type action as the key and plug are rotated. The rotation causes a cam or nipple to move a deadbolt linearly to a locking or unlocking position or in the case of a spring loaded latch or deadlatch the rotation causes the cam or nipple to move a latch or deadlatch to unlocking position and removing the key keeps the latch or deadlatch in the extended locked position. 
     Metal filing cabinets often utilize cam locks, or a variation known as a plunger type lock in which a spring loaded plunger/lock cylinder located in the top horizontal margin of the cabinet, when pushed in, will lock all drawers. The use of a key releases the spring plunger to return to the outward position and unlock the drawers. 
     Locker and cabinet locks have included electronic locking devices, some of which utilized keypads and some of which utilized IButtons or other ID or non-volatile memory devices which work on contact to release the lock. See, for example, U.S. Pat. Nos. 5,894,277, 5,886,644, 6,655,180 and 6,791,450. The disclosures of all of these patents are incorporated herein by reference. 
     There is a need for a relatively simple, easily used, reliable and compact electronic lock, with a keypad but optionally operable by an electronic key, or both, for situations in which typically cam, plunger and cabinet locks were employed, and capable of fitting in a standard opening or bore of a standard cam, plunger or cabinet lock cylinder in a cabinet, door, access panel, mail box, dispenser, etc. and alternatively capable of fitting in a standard shell of a standard cam, plunger or cabinet lock cylinder in a cabinet, door, access panel, mail box, dispenser, etc. This is an objective of the current invention described below. 
     SUMMARY OF THE INVENTION 
     The invention addresses these needs with a low profile and very compact electronic lock that, in one application, fits in the top one inch horizontal margin of a steel file cabinet. The compact electronic locking device in one embodiment has a knob or handle that can rotate the cam lock cylinder plug when such manual rotation is permitted by the lock electronics. A keypad for entry of a code may be included, and if so, the code can be either permanently set to a reprogrammable code, or set in each case by a temporary user, who can then input the same code to lock and unlock the lock, this feature depending on circumstances and function desired. 
     In one preferred embodiment particularly adapted for a file cabinet, the locking device in one embodiment is less than one inch in height (about ⅞ inch), about two inches in length and roughly about ½ inch in depth or thickness (or about ½ to ⅝ inch), as to the housing of the device. A cam locking device of this size will fit unobtrusively on the surface of the horizontal top margin area of a steel file cabinet. The housing may contain several small battery cells, such as two AAA batteries, but preferably smaller batteries such as coin cell or button-type batteries for further reduction of housing size. From the back of the housing in one embodiment extends the cam lock cylinder unit of conventional cam lock size, and with a length to fit the application, i.e. the depth of material and configuration where mounted. The rear-extending cylinder unit preferably has an external thread, and a nut or threaded ring is tightened down to firmly retain the cylinder and housing in place. In other embodiments a dummy plug can extend back from the housing unit, or simply a driver or spindle. Since the cam lock opening in the cabinet or door or panel will typically be the conventional D-shaped opening or double D-shaped opening, the housing is fixed in place against rotation by this configuration. However, another fastening location(s) may be included, such as a machine screw assembled from the back and through a hole in the drawer or panel, engaging in a threaded hole provided in the housing, or screw posts extending from the back of the housing. This threaded hole or screw post is preferably is at an opposite end of the housing from the location of the cylinder and turning knob or handle. There may be more than one threaded hole or screw post depending on the mounting preferences. In an alternative configuration, the housing back can simply have a nipple that extends in a hole formed in the cabinet, drawer or door, or a hook-shaped element that extends from the back of the housing and engages firmly in the hole, particularly for relatively thin metal cabinets. 
     It is an important feature of the invention that the electronic lock device be compact and relatively simple, at least as to mechanical elements, and without any further electronics or housing required at the back side of the door or panel. Essentially the only element at the back side of the door, drawer or panel is the rear-extending cam or cabinet lock cylinder unit or actuator, an actuator, latch or cam positioned to engage with a ledge or slot or other hardware to retain the door(s) or panel locked. In some embodiments the rear-extending element is a dummy plug or a driver. An alternative form of the lock still comprises a single housing but is positioned at the back side of the panel, drawer, etc., in a through-the-panel mounting with only the knob or handle and the access terminal or keypad extending through the panel. 
     In one preferred form, the invention is embodied in a compact housing containing electronics and having an electronic key receptacle for entry of codes by a user, a cam cylinder unit or driver extending from a back side of the housing, in a standard cam lock size adapted to fit through a standard cam lock opening in a cabinet or door for extending therethrough, and with a knob or handle on the housing for operating the cam lock manually when permitted by the electronics. A battery compartment in the housing, accessible from the front of the cabinet, contains one or more battery cells for operating the electronics. 
     In another preferred form, the invention is embodied in a cam lock for a door, cabinet or drawer and includes a compact housing containing electronics and having an electronic key receptacle for entry of codes by a user, a plug of the cam, plunger or cabinet lock cylinder unit extending from a back side of the housing that matches the size and shape of the cam lock shell already mounted on the door, cabinet or drawer, and with a knob or handle on the housing for operating the cam lock manually when permitted by the electronics. Again, a battery compartment in the housing, accessible from the front of the cabinet, contains one or more battery cells for operating the electronics. 
     In another preferred form, the invention is embodied in a cam lock for a door, cabinet or drawer and includes a compact housing containing electronics and having an electronic key receptacle for entry of codes by a user, a specially shaped driver unit extending from a back side of the housing that matches an opening on the plug of the cam cabinet or drawer, a lock shell already mounted on the door, and with a knob or handle on the housing for operating the cam lock manually when permitted by the electronics. Again, a battery compartment in the housing, accessible from the front of the cabinet, contains one or more battery cells for operating the electronics. 
     In another preferred form, the invention is embodied in a cam lock for a door, cabinet or drawer mountable from back of the door, cabinet or drawer such that only the user interface extends through the face of the door, cabinet or drawer and includes a compact housing containing electronics and having an electronic key receptacle and in some cases, a keypad for entry of codes by a user, a specially shaped driver unit extending from a back side of the housing that matches the end of a cam lock or cam lock plug of the typical mechanical lock for engaging with a strike or other locking bars, cams or apparatus, and with a knob or handle on the housing for operating the cam lock manually when permitted by the electronics. A battery compartment in the housing, accessible from the back of the lock, contains one or more battery cells for operating the electronics. 
     In another preferred form, the invention is embodied in a cam lock for a door, cabinet or drawer mountable from back of the door, cabinet or drawer such that only the user interface extends through the face of the door, cabinet or drawer and includes a compact housing containing electronics and having an electronic key receptacle and an RF reader or wireless reader or IButton reader for entry of a code by a user, a specially shaped driver unit extending from a back side of the housing that matches the end of a cam lock or cam lock plug of the typical mechanical lock for engaging with a strike or other locking bars, cams or apparatus, and with a knob or handle on the housing for operating the cam lock manually when permitted by the electronics. 
     In another preferred form the lock devices are fitted with an RJ45 jack or wireless antenna for network connectivity and external power. 
     It is therefore among the objects of the invention to improve over prior cam and cabinet locks, with an electronic cam lock that can be retrofitted to existing cam lock, cabinet lock, switch lock or plunger lock openings in doors, drawers, access panels, mail boxes, dispensers, etc. as well as provide an improved locking solution for new applications wherein the internal locking systems for locking multiple points are configured to receive a cam, plunger or cabinet lock. The device is relatively simple, compact and unobtrusive. These and other objects, advantages and features of the invention will be apparent from the following description of preferred embodiments, considered along with the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing an electronic cam type lock of the invention, for a cam lock and similar functions, with a receptacle for electronic input and without a keypad. 
         FIGS. 2 and 3  are sectional plan and elevation views showing the lock device of  FIG. 1 . 
         FIGS. 4A and 4B  are partially sectioned side elevation views showing a modified lock device as fitted into an existing cam lock or similar situation. 
         FIGS. 5A ,  5 B and  5 C are perspective views showing a drawer or door panel having provision (a hole) for a cam lock or cabinet lock; an embodiment of a cam lock of the invention, and the cam lock as installed in the panel. 
         FIG. 6  is a perspective view, exploded, showing a lock device of the invention and indicating its installation into a modified cylinder device of a cam lock or cabinet lock. 
         FIG. 7  is a view somewhat similar to  FIG. 6 , but showing the device being fitted with a pin/tumbler cylinder of a cabinet lock and with a spring latch. 
         FIG. 8  is a perspective view showing a modified lock device of the invention with provision for recessed mounting. 
         FIGS. 9A to 9C  are perspective and cross section views showing a through-panel mounting for an electronic lock of the invention. 
         FIGS. 10A to 10C  are perspective and cross section views similar to  FIG. 9A-9C , showing a modified lock with a keypad.  FIG. 10D  shows an alternative battery arrangement. 
         FIG. 11  is a perspective view showing a lock device of the invention with a key reader and an IButton reader. 
         FIG. 12  is a perspective view showing a lock device of the invention with a key reader and a wireless reader. 
         FIG. 13  is the same lock device shown in  FIG. 11  but configured for mounting through the panel of a door, cabinet or drawer. 
         FIG. 14  is the same lock device shown in  FIG. 12  but configured for mounting through the panel of a door, cabinet or drawer. 
         FIG. 15  is the same lock device shown in  FIG. 10A  but with the addition of a network antenna, network jack receptacle and external power port. 
         FIG. 16  is the same lock device shown in  FIG. 9A  but with the addition of a network antenna, network jack receptacle and external power port. 
         FIG. 17  is the same lock device shown in  FIG. 13  but with the addition of a network antenna, network jack receptacle and external power port. 
         FIG. 18  is the same lock device shown in  FIG. 14  but with the addition of a network antenna, network jack receptacle and external power port. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIGS. 1-3  show a lock  40  according to the invention. The lock  40 , which has a housing  42 , preferably has batteries within a battery compartment  44  shown on a side of the unit, and a terminal  45  is also included. The lock unit  40  is the sole electronic housing for a lock, and may be part of a cam lock or cabinet lock, as well as a locker lock or a driver for any kind of lock or key switch mechanism which is mounted on a panel behind the lock  40 . All of the drawings show different forms of this compact electronic lock unit. 
     The lock  40  has a rotatable knob or handle  46  extending from the housing  42  (the handle could be a lever if required or desired). The lock  40  is preferably without a keypad but in other respects is preferably very similar to the lock shown in copending application Ser. No. 11/809,172. The lock unit  40  is very compact and if it has onboard batteries they can be small standard cells or coin cell type batteries. A status indicator light is shown at  48 . 
     The lock is operated using a key device such as that shown in copending application Ser. No. 12/072,557, as well as U.S. Pat. No. 7,336,150, and the disclosure of both are fully incorporated herein by reference. The key device preferably has batteries and makes contact with the electrical contacts  50  shown in the terminal  45  at the front side of the housing. The lock unit  40  can be without batteries; if it does have onboard batteries within the housing  42  (within the compartment  44  shown in  FIG. 1 ), then a set of key devices for the lock, or for a series of similar locks, can include small key contact devices having no battery and having two contacts for engagement with two of three contacts  50  shown in the terminal  45  on the lock. A master or manager&#39;s key device can be somewhat larger, with onboard batteries carried in the key device, with three contacts for engaging with all three of the contacts  50  in the terminal  45 . This enables a manager to use the special key to provide jump power to the lock  40  in a case where the lock&#39;s battery is low or when a user of the lock has forgotten his key or the key is somehow nonfunctional, or for both situations simultaneously. The terminal  45 , and the contacts on the key, can be structured in accordance with the drawings and description of copending application Ser. No. 12/072,557, as well as U.S. Pat. No. 7,336,150, for protection of the contacts of both the lock and the key and to ensure proper engagement. 
       FIGS. 2 and 3  show one form of the lock  40  in a side or top elevation view, installed in  FIG. 2  in a panel  52  such as on a door, file cabinet, drawer, locker door, or other type of application. In  FIGS. 2 and 3  the lock is essentially in the configuration of a cam lock, wherein the handle or knob  46  connects directly with a cam lock cylinder unit (without tumbler pins or wafers)  54 ; specifically, the handle  46  turns a moveable member, e.g. a rotatable bolt or core  56  which rotates within the fixed cylinder unit  54  when permitted by the electronics.  FIG. 2  shows one example of latching with the cam lock device, with a metal arm or cam  58  rotatable with the bolt  56 , to be rotated using the handle  46  when permitted. A nut or threaded ring  60  retains the lock unit to the panel  52 , in a position such that the arm or cam or latch  58  engages behind a ledge or in a slot or other appropriate element when the door, drawer, locker door, etc. is to be in a locked condition. 
     The lock unit  40  is extremely compact and can have dimensions of, for example, about two inches in width (the horizontal direction as seen in  FIG. 3 ); about ⅞ inch in height (the vertical direction in  FIG. 3 ); and about ½ inch in thickness. More broadly the size is in the range of about 1½ to 3 inches wide, about ⅞ to 1⅛ inch in height and about ⅜ to 1 inch thick. 
       FIGS. 4A and 4B  show a typical cam lock shell  70  mounted on a door or drawer  71 , with the typical cam lock plug removed, and replaced with an electronic lock  74  with a cylinder plug  75 , retrofitted into the shell  70  in accordance with the invention. The plug  75  is a “blank” plug that will operate the lock when installed via a retainer clip or pin  76 , with the electronics as discussed above to control access. In  FIG. 4A  the electronics housing  74  has a recess  78  shown in dashed lines, surrounding the extending plug  75 , for the purpose of accommodating the slightly protruding face  80  of the cylinder shell  70  as installed in the drawer or door  71 . Many cam locks used in furniture have this type of front loaded plug which can also be removed for service and re-keying purposes. This is similar to what is shown in copending Ser. No. 11/809,172, but with the more compact electronic lock unit of the type shown in  FIGS. 1-3 . This continuation is advantageous in applications where an existing mechanical lock is fitted to the cabinet that has a brand-specific cam device or other linkages that are attached to the cam device for operating multiple drawers or doors. 
       FIG. 5A  shows the door or drawer front  82  with a lock mounting hole  80   a . This hole may be round as shown or a single or double “D” shape commonly used in the industry. The mounting can be similar to  FIGS. 2 and 3 .  FIGS. 5A-5C  show a panel, drawer or door  82  with a conventional cam lock removed.  FIG. 5B  shows the compact self-contained electronic lock  74  of the invention as a replacement installed through the hole  80   a  in the same manner as the mechanical lock it replaces. 
     Reference is made to copending application Ser. No. 11/809,172 regarding other applications of the electronic lock generally as shown in  FIGS. 1-3  and  FIGS. 4A and 4B  herein. The compact lock of the invention can be formed with a cylinder plug type rear extension that fits into an existing cabinet lock with bolt or latch of the types as shown, for example, in  FIGS. 9-12  of that copending application. 
       FIG. 6  shows another application of the compact lock of the invention, similar to that of  FIGS. 13-14  of copending application Ser. No. 11/809,172. Here, a compact electronic lock  40   a  operates similarly to the lock  40  of  FIGS. 1-3  but has a simple spindle or driver  83  extending back from the rear of the unit, essentially straight and perpendicular to the back of the unit and having, for example, a square cross sectional shape. The driver  83  fits in driving contact with a similarly shaped driver hole or receiving socket  84  in a cam lock or lock unit  86 . The receiving socket  84  is in a rotatable plug  88  of the lock unit  86 . As discussed above, it should be understood that any slide-in keyed cross-sectional shape can be employed for the driver  83 , square being one example but also including flat, star-shaped, splined, hex, D-shaped, etc. The lock shown in  FIG. 6  is an alternative to other lock arrangements such as  FIGS. 4A-4B  wherein a dummy cylinder plug is the element that extends to the rear of the electronic lock unit. 
       FIG. 7  shows another application of the compact electronic lock unit  40   a , with the specially shaped driver  83  positioned for assembly into a different type of lock, in this case a cabinet lock  90  of the type that has an off-center rotatable plug  92 , a replacement for a conventional cabinet lock device having internal pins and tumblers that act between the plug  92  and the cylinder shell  94 . Here, the driver  83  extends into a complementary hole  96  in the rotatable plug  92 . Note that the drawing shows a retractable spring latch or dead latch  98  in this embodiment, but instead there could be deadbolt. This is similar to an embodiment described in copending Ser. No. 11/809,172, but with the abbreviated and compact electronic lock  40   a  of the invention. As explained in the copending application, this application of the lock provides for more universal connections and standard provision of lock components as compared to some of the earlier-described embodiments. A manufactured line of cabinets, drawers, doors, etc. can have prescribed types of lock units, with a cam lock, cabinet lock, plunger or other types, and all can be arranged to be engaged with the electronic lock unit  40   a  of the invention. Depths to the different thicknesses of drawers, doors, etc. can be accommodated without providing a series of different shell depths for the shell  94  extending forward from the mechanical cam lock or cabinet lock or other lock unit. The electronic lock unit  40   a  can be universal for many different situations and applications. Note that a single threaded stud  99  is shown in this and other drawings for securing the compact lock to a door, drawer, etc., but any suitable form of attachment can be used. In the case of  FIG. 7  the stud  99  or studs (or threaded holes) must be wide enough out from the driver  83  that they will clear the cabinet lock unit  90 . 
       FIG. 8  shows a modified electronic lock unit  40   c  of the invention, in this case with a flange  110  designed to allow recess mounting of the base part  112  of the housing. The flange  110  may be integrally formed with the base part  112 . Thus, the flange  110  is configured to engage against the outside surface of a door or drawer. It should be understood, as pointed out in copending Ser. No. 11/809,172, that the rotatable knob or handle  46  shown in  FIG. 8  can be replaced with a lever, which may be needed for handicap access or for other purposes as desired. 
       FIGS. 9A through 9C  show a self-contained electronic lock unit  40   d  similar to the locks shown above and including a cylinder  115  with an appropriate actuator such as a cam or other latching device, or simply with a driver such as shown at  83  in  FIGS. 6 and 7 . In this case the electronic lock device  40   d  is mounted behind the panel  116  of a door, drawer, etc. in a through-the-panel mounting, with the knob or handle  46  and the terminal  45  having an adequate mounting depth protruding from a base plate  118  to extend through the thickness of the panel  116 , as shown in  FIGS. 9B and 9C . The base plate  118  installs flatly against the back side of the panel  116  and is secured by appropriate fasteners  119  through holes  120 . The depth to which the knob or handle  46  and the terminal  45  are floated out from the base  118  is matched to the type of panel  116  to which the lock is to be secured (e.g. wood panel, steel panel, etc.). It should be understood that although a cylinder structure is shown in  FIG. 9C , this could simply be a cam such as shown at  58  in  FIG. 2 , or a latch such as shown at  90  in  FIG. 7  or another type of engaging device for locking the panel to other structure. Depth concerns may dictate that a cam or latch be provided immediately behind the housing  122  shown in  FIG. 9C , without the cylinder structure  115  extending back to increase the depth. A battery compartment (not shown) can be located similarly to what is shown in the locks described above, with a battery door located for maximum convenience. In a low-battery condition a power jump can be made via the terminal  45  as described earlier. 
       FIGS. 10A through 10C  are similar to  FIGS. 9A through 9C , but show a keypad  125  on an electronic lock device  40   e . This lock device  40   e  is similar to embodiments shown in copending application Ser. No. 11/809,172, but with the lock unit mounted behind the panel  116   a  in a through-the-panel mounting, as described with respect to  FIGS. 9A-9C . Holes  126 ,  128  and  130  are provided in the panel for this purpose. Note that the holes  128  and  130  could be replaced by a singular rectangular opening. Again, a different latching or securing mechanism can be included instead of the cylinder structure  115  shown in  FIG. 10C , for the reason explained above for  FIGS. 9A-9C .  FIG. 10D  shows that, as an alternative to a battery compartment located accessibly in the housing of the lock  40   e , the battery can be in a separate battery pack or casing  138  as shown. The battery  138   a  connects to the lock housing by a wire  138   b ; a magnet  138   c  can be provided to mount the battery on a steel panel, or adhesives or Velcro (hook and loop fasteners) can be used. 
     The term cam lock as used in the claims is intended to refer to a cam lock or cabinet lock, or a plunger lock or switch lock or T handle lock or locks of similar application. Also, references to a knob or handle are to be taken as referring to any type of turning device provided to operate the cam lock manually. Further, reference to a panel of a door, cabinet or drawer is intended to refer to any access panel or a fixed panel from which an openable component is controlled. 
     The term driver, although used above to refer to the cross-section specific driver  83  in  FIGS. 6 through 8 , more generally refers to an element that transfers the rotational motion of the knob or handle to the rear of the lock device, which can be through a cylinder, or via a dummy plug or other element, including a cross-section specific driver. 
     It should also be understood that the manually-operated locks described above could instead be automatic, with electromagnetic operation to retract a latch or rotated cam, such as a solenoid or miniature motor. 
       FIG. 11  shows a panel with another application of a compact lock  140  of the invention, similar to that of  FIG. 5C  but with the additional input device  141  designed to receive an IButton input, which can be the primary means of accessing the lock. 
       FIG. 12  shows another application of a compact lock  150  of the invention, similar to that of  FIG. 5C  but with an additional input device  142  designed to receive wireless input from wireless access credentials such as RFID tags, proximity access cards and other wireless access technologies. The wireless technologies are commonly used for accessing the lock devices of the invention, reducing the number of credentials the user has to carry. Additionally the lock devices may be fitted with Bluetooth or similar interfaces to communicate with handheld small computers, PDAs or mobile telephones for access as well as uploading and downloading data to and from the lock devices. This data may be access programming data or data containing audit trail or usage information as well as application specific data for the usage of the cabinet such as insertion or removal of files or other items to and from the cabinet.  FIGS. 15 and 16  also show the lock device of the invention with an antenna  133  for wireless network connection. This connection may be an Ethernet connection or Bluetooth or similar connection or both. The lock units  160  and  170  shown in  FIGS. 15 and 16  (similar to those of  FIGS. 10A and 9A ) are also equipped with a receptacle  134  for direct network connection (as an alternative to wireless) as well as a power receptacle  135  for external (line) power if required or desired. A network can be used to control what codes have access to a series of cabinets, drawers, etc. Such a network will include a terminal or central control system which can simply be a microprocessor with a database listing all locks. A laptop or hand held computer device is all that is required. With the central control a manager connects to any one lock or all locks when desired, to update which “keys” or codes will have access, and even the times of permitted access if desired. Each lock can include a processor to receive the control signal and to set the lock&#39;s electronics to allow access by employees A, B, C and D but not employee E, for example. This is changeable at any time, instantly. The programming and electronics for this networking and control function are well within the ability of a person of ordinary skill in the art. A panel hole  131  is provided for the antenna  133 . A single panel opening could be provided for all projecting elements, or one for the antenna, one for all keys and the terminal  45 , and one for the knob, or other similar arrangements. Note that the antenna and/or direct network receptacle, as well as the line power connection  135 , can be included on any of the embodiments described above. 
       FIGS. 13 and 14  show panels  132   a  and  132   b  with lock devices  140   a  and  150   a  similar to those shown in  FIGS. 11 and 12  but configured for installation through the panel of the door, cabinet or drawer. In this case the battery access will be from behind the lock device. The lock is mounted to studs on the panel through the mounting holes at each end or the unit may be mounted with screws or other fasteners directly to the panel from behind. Note again that common openings rather than individual holes can be provided in the panel for the knob, terminal, and input device. 
       FIGS. 17 and 18  show through-the-panel lock devices  180  and  190  as shown in  FIGS. 13 and 14  fitted with the same apparatus for network and power connections  134  and  135  (and antenna  135  if needed) discussed above for  FIGS. 15 and 16 . 
     The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit its scope. Other embodiments and variations to these preferred embodiments will be apparent to those skilled in the art and may be made without departing from the spirit and scope of the invention as defined in the following claims.

Summary:
An electronic lock replaces mechanical locks in cam lock, cabinet lock and switch lock applications, as well as other locks for file cabinets, desk and cabinet drawers, access panels and other secure situations that often utilize relatively simple lock mechanisms. In a preferred embodiment the lock is without a keypad, accessed by an electronic key making contact with a terminal.