Abstract:
An electronic security system includes an electronic lock mechanism and an electronic key, each of which is provided with a microprocessor controller and a memory storing data including an ID code and encryption key codes. The electronic lock security system preferably includes an electronic lock including a hollow cylinder, an opening into the cylinder, a bolt movable through the opening between an extended position and a retracted position, a cam member within the cylinder, the cam member contacting the bolt to move the bolt to an unlocked position, a solenoid within the hollow cylinder, the solenoid being engageable with the cam member, an electronic lock circuit within the hollow cylinder, a plug connected to the solenoid for rotating the solenoid, the plug having a keyway for insertion of a key for rotating the plug. In addition, the system also includes an electronic key insertable within the keyway for communicating with the electronic lock circuit to operate the lock. A torque transmitting solenoid is used in the system.

Description:
This application claims priority from prior provisional application serial no. 60/064,547, filed Nov. 5, 1997. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates generally to electronic security systems, and more particularly to electronic security systems for money-containing devices such as vending machines, etc., which must be periodically accessed by a collector in order to retrieve the funds accumulated in the device or by technicians to perform service and maintenance. 
     2. Background and Prior Art 
     Typically, the collection of money from coin or currency operated devices such as pay telephones, transit system fare card machines or the like is a costly and burdensome operation. For instance, a company may own tens or even hundreds of thousands of pay telephones for which tens or hundreds of thousands of keys must be kept in order to prevent the loss of a key from requiring the changing of locks on thousands of devices which would operate with the lost key. 
     Another problem involved with the collection of funds from currency operated devices is the possibility of fraud or theft by a collector. In some cases, a collector should remove a locked coin box from the device and replace it with an empty lock box to which he does not have access. However, it is possible that a removed coin box will not be replaced with another lock box but rather will be replaced with an unlocked receptacle which can be later removed by that collector before turning in his key at the end of the collection shift. In other cases, the coin box and validator are readily accessible to the collector or technician. 
     Yet another cost involved in the collection process is the significant manpower required for the task of distributing, collecting, and keeping track of many thousands of keys on a daily basis. 
     Although electronic security systems are known and have been used for various purposes, see e.g. U.S. Pat. Nos. 4,789,859, 4,738,334, 4,697,171, 4,438,426, applicants are unaware of any which specifically address the problems, noted above. 
     Another problem pertaining to existing locks is that certain mechanical lock structures are not readily adapted and/or modified to include electronic capabilities. For example, existing devices are not available that can easily upgrade vending locks, etc., (such as, for example, standard N.A.M.A. vending locks) to have electronic capabilities. 
     BACKGROUND TECHNOLOGY OF ASSIGNEE 
     The present invention also improves upon existing technology of the present assignee. This technology is described herein as background to the present invention, rather than as prior art. 
     The disclosures of U.S. patent application Ser. No. 08/026,781, entitled ELECTRONIC SECURITY SYSTEM WITH NOVEL ELECTRONIC T-HANDLE LOCK, filed Mar. 5, 1993, now U.S. Pat. No. 6,005,487, which is a continuation-in-part of the following application, (2) Ser. No. 07/865,849, filed Apr. 9, 1992, now U.S. Pat. No. 5,745,044, which is a continuation-in-part of the following application, (3) Ser. No. 522,017 filed May 11, 1990, now U.S. Pat. No. 5,140,317, are all incorporated herein by reference herein and discussed in this section. 
     FIGS. 1A and 1B illustrate an electronic key  100  according to one embodiment. The key has a key body  101  which contains logic and power transfer circuitry, and a key blade  102  with appropriately cut key bits for operating pin tumblers as is known in the art. The key  100  also carries a spring loaded data and power electrical contact  103 , which is made of a suitable material and is preferably gold plated. 
     Portable battery and logic housing  104  contains a battery power supply and electronic circuitry, a battery charging port  105 , a wrist strap or belt clip  106 , and a plug-connected cable  107  for transferring power and data signals between the housing  104  and the key body  101 . 
     FIG. 1B is an end view of the key body showing the orientation of the spring loaded contact  103  with relation to the key blade  102 . The key  100  and connected housing  104  with their components are portable and are referred to as “key means”. 
     FIG. 2 illustrates a lock cylinder and bolt mechanism included in a housing  201  (with its cover removed). As shown in FIG. 2, within the housing is a bolt  202  operated by a lock cylinder  203  containing a key cylinder plug  204  having a keyway  205  for key blade  102 , and an electrical contact  206  which makes contact with the power and data contact  103  of the key body when the key blade  102  is inserted into the key blade opening  205 . 
     A bolt cam  207  is rotated by the lock cylinder  203  to move the bolt  202  between the locked position shown and an unlocked position in which the bolt is withdrawn downward to be substantially within the housing  201 . The lock housing  201  further includes electronic logic circuitry  208  and an electrically powered solenoid  209 . Solenoid  209  includes a spring biased bolt blocking plunger  210  which, when extended, prevents bolt  202  from being withdrawn by the bolt cam into the housing  201  to its unlocked position. Upon operation of the solenoid  209 , bolt blocking plunger  210  is retracted toward the solenoid to enable the key  100  to be turned in the clockwise direction which rotates bolt cam  207  against the bolt  202  and causes the movement of the bolt  202  downward into the housing  201 . 
     FIG. 3 illustrates a programmer for writing data into and reading data from the circuitry in key body  104  through cable  107 . The programmer includes a host computer  301  which may be a minicomputer, personal computer, or any other type of computer, but which preferably is an IBM® compatible microcomputer. A key programmer interface unit  302  is connected to the computer  301  by means of a cable  303  which plugs into a communication port of the computer  301 . The programmer interface unit  302  contains a key receptacle  304  having electrical contacts into which the plug end of the key cable  107  is inserted after being disconnected from key body  101  to allow the computer to write into the memory within key housing  104 . The computer  301  is loaded with a software program  305  for loading and retrieving files from the key logic housing  104 . 
     FIG. 4 illustrates a portable programmer interface unit  401  including a modem which enables the portable programmer interface unit  401  to communicate with the computer  301  through the public switched telephone network (PSTN) via a standard phone jack  402 . In this embodiment, an operator in the field needing to update the contents of files in the key housing  104  would dial up the host computer using a standard phone set  403  which is connectable via a jack to the programmer interface  401 . Once communication with the host computer  301  is established, the programmer interface unit  401  operates in the same manner as the office programmer interface unit  302 . 
     FIG. 5 is a schematic block diagram illustrating the components within the electronic key housing  104 . The components include a microcontroller or microprocessor  501 , an electrically erasable programmable read only memory (EEPROM)  502  coupled to the controller  501 , an oscillator or clock  503  which provides clock signals for the operation of controller  501 , and a battery power source  504  which operates the controller  501  as well as the solenoid  209  and the circuitry  208  within the lock mechanism housing  201 . The electronic key components further include an electronic switch  505  operated by the controller  501  and a power sensing circuit  506 . 
     FIG. 6 is a schematic block diagram of the electronic circuitry  208  within the lock housing  201 . This circuitry includes a microprocessor  601 , an EEPROM  602  coupled to the microprocessor  601 , an oscillator or clock  603  for providing operational clock signals to the microprocessor  601 , a power filter  604 , electronic switch  605  and load  606  for transmission of signals to the key controller  501  via line  607 , and an electronic switch  608  for allowing power to flow from power source  504  within the key housing  104  through cable  107  and contacts  103 - 206  through the solenoid  209  to ground to activate the solenoid. 
     FIG. 7 is a schematic diagram of the electronic key programmer interface unit  302 . It is noted that the portable key programmer interface unit  401  contains substantially the same components as the programmer  302 , in addition to the modem and telephone jack not shown. The programmer interface unit  302  includes a microcontroller  701 , a clock oscillator  702 , an electronic switch  703  and load  704  combination which operate similarly to the switch  605  and load  606 , a power supply  705 , and a standard RS-232 receiver and driver  706  which couples the programmer interface unit  302  to the host computer  301 . 
     The operation of the system components will now be described with reference to FIGS. 5-7. 
     The electronic key  100  is inserted into the key programmer interface unit  302  or  401  to be programmed by the host computer running the customized software application  305  via cable  107  as described above. 
     Using the example of a lock for pay telephones for illustration, the EEPROM  502  is loaded with data corresponding to a specific collection route. The data can be entered manually through a keyboard provided with the host computer  301 , or the data can be transferred to the EEPROM  502  from files on a floppy disk inserted into a standard floppy disk drive of the computer  301 . 
     EEPROM  502  is loaded with specially encrypted data corresponding to specific ID codes stored in each of the electronic lock memories  602  of the locks on the specific collection route. Data encryption is performed by an encryption algorithm in a known manner. EEPROM  502  also is loaded with the date of key programming, the start date as of which the key is valid, and a time window during which the key can be used, for example, 24, 48 or 72 hours from the start date. EEPROM  502  also contains an address location storing the particular key category, for example, whether the key is a collection key or service key, and a serial number for key identification. The data is encrypted using a specific algorithm performed by the software  305 . 
     The computer  301  may also print out the particular collection route, lock key codes, time window, and start date for confirmation by the programmer. 
     Controller  501  keeps track of the current time and date by counting the clock inputs of oscillator  503  and using the key programming date as a reference. 
     The data is written into EEPROM  502  through switching of electronic switch  703  by microcontroller  701  which serves to increase and decrease the amount of power consumed by the load  704  which in turn provides the logic levels for binary “1” and “0” digital communication to the microcontroller  501 . This increase and decrease in power is sensed by the power sense circuit  506  and is converted into digital signals readable by the microcontroller  501 . 
     Referring now to FIG. 6, the lock mechanism microprocessor  601  is coupled to EEPROM memory  602  which stores a specific ID code for that specific lock. One important feature is that the lock mechanism of FIG. 2 contains no power supply itself but is completely powered by the power source  504  of the electronic key  100 . Power filter  604  is provided to supply power to the logic circuits from the key  100  over line  607 , the power filter smoothing the voltage waveform so that power interruptions caused by data transmission over line  607  will not affect the operation of the logic circuits. 
     As an additional security feature, a solenoid activation switch  609  can be mechanically coupled to the bolt blocking plunger  210  of FIG. 2 to detect the retraction of the bolt blocking plunger. In telephones equipped with a so-called “Smart Terminal” or circuit board  610 , which is provided with a modem to link the telephone to the host computer over a telephone line, activation switch  609  can be used to send an alarm to the host computer when switch  609  detects the retraction of the bolt blocking plunger in the absence of generation of an enable signal by the microprocessor  601 , which would be indicative of someone tampering with the lock by trying to manually pry the bolt blocking plunger away from bolt  202 . An additional line  611  may be provided to establish communication between the lock microprocessor and the smart terminal  610 . 
     The use of a smart telephone terminal  610  also allows the use of a host confirmation feature as an additional feature of the present invention. Part of the data stored in the key memory  502  is the key&#39;s particular serial number. Using the host confirmation feature, the host computer  301  would dial up the smart terminal  610  via a modem and transmit a host confirmation message to the microprocessor  601 . The message may instruct the microprocessor to allow the solenoid  209  to be powered by any mechanically operable key inserted into the key slot  205 , may instruct the microprocessor  601  to prevent any key at all from operating the lock by prohibiting powering of the solenoid  209 , or may instruct the microprocessor  601  to allow only a key having a particular serial number, transmitted by the host computer, to operate the lock by powering the solenoid. The host confirmation data may then be stored in the memory  602  coupled to the microprocessor  601 . 
     Referring now to FIG. 8, the overall operation of the electronic lock system will be described. 
     After the key blade  102  is inserted into the keyway  205  and the contact  103  is electrically coupled to the key cylinder contact  206 , the electronic lock logic circuitry is powered up or awakened at step  801 . At step  802 , microprocessor  601  communicates with the microcontroller  501  to read the data stored in the memory  502 . At step  803 , microprocessor  601  checks whether the current date stored in memory  502  is after the start date written into memory  502  during the programming mode of the key, determines whether the current time read from memory  502  is within the time window stored in memory  502  which has been programmed by the host computer in advance. If the start date read from the key memory is subsequent to the current date read from the key memory, or if the current time is outside of the time window stored in the key memory, the microprocessor advances to step  809  at which the key is determined to be invalid, the microprocessor  601  is reset, and no further action is taken. If the time and date data is valid, the microprocessor  601  proceeds to step  804  in which the list of ID codes stored in key memory  502 , corresponding to the locks that key  100  is to operate on this particular collection route, is compared with the current ID code stored in the memory  602 . If the ID code in memory  602  is contained in the list stored in memory  502 , the process proceeds to step  805  in which the presence of a host confirmation feature is checked. If not, the microprocessor proceeds to step  809 . If the telephone is not equipped with a smart terminal  610 , processing proceeds to step  806  in which microprocessor  601  calculates a new ID code according to a pre-stored algorithm in memory  602 , encrypts the new ID code and stores it in memory  602 , replacing the previous ID code stored therein. At step  807 , microprocessor  601  transmits a signal to electronic switch  608  which allows power to flow from power source  504  through solenoid  209 , and causes bolt blocking plunger  210  to retract in the direction toward the solenoid  209  for a predetermined period of time such as 5 seconds. At this time, the operator may turn the key body  101  and unlock the bolt. The microprocessor  601  then resets before the key body  101  is withdrawn from the insert slot  205 . After the bolt is re-locked, the bolt blocking plunger  210  moves back to its blocking position shown in FIG. 2 by spring bias action. 
     If the coin telephone is one equipped with a smart terminal, processing proceeds from step  805  to step  808 . In this step, microprocessor  601  determines whether the key serial number matches the serial number transmitted from the host computer, or whether the host computer has sent a message to prevent all keys from operating. If the key data matches the data stored in the memory  602 , processing proceeds to step  806  as described above. If the key data does not match, or microprocessor  601  has received a prohibit message, processing proceeds to step  809 . 
     As an additional feature, each lock may write its serial number and current time into a specific location of the memory  502  of the key in the event that all key data is valid to indicate that the specific lock was operated at the particular time stored with the serial number. Upon return of the key to the central office, the key may be re-inserted into the programmer interface unit  302  and the files in memory  502  read by the host computer in order to maintain a list of the locks that were operated as well as those that were not operated. All of the algorithms utilized by each of the lock microprocessors  601  are stored in the host computer  301  such that after the key is returned at the end of a collection cycle, the key may be reprogrammed with the new ID codes currently being stored in each of the operated locks, while the ID codes for the locks that have not been operated are left unchanged within the key memory  502 . 
     Description will now be made of a second construction with reference to FIGS. 9-12. FIG. 9 illustrates a programmer  301   a , which may be similar to the microcomputer programmer  301  of FIG.  3 . The programmer  301   a  includes a CPU  901 , a pair of look-up tables  902  and  903 , and a daykey encrypter  904 . Look-up table  902  contains a listing of various IDNs (identification numbers) and IDKs (encryption key codes) for each lock of the system. Every lock is identified by a lock identification number or IDN, and has associated therewith a corresponding encryption key code IDK which is used by the lock to encrypt data. 
     Look-up table  903  contains a listing of various IDNs and IDKs for each key unit  104   a  of the system. Each key unit  104   a  is also identified by a key IDN and has associated therewith a corresponding encryption key code IDK which is used by the key unit to encrypt data. 
     Daykey encrypter  904  contains an arbitrary encryption key code which is changed daily in the programmer  301   a  (thus the designation “daykey”). 
     Key unit  104   a  includes a key module  906 , a handheld computer  908 , and optionally a modem  910 . The module  906  interfaces the handheld computer  908  to the key device  101 . Handheld computer  908  is a commercially available device such as a Panasonic Model JT-770, and may be implemented by any other equivalent apparatus. The computer  908  includes a key memory  502  which stores route stop information programmed from the programmer  301   a . The route stop information is organized into a route table containing specific routes labeled by date. The key interface module  906  includes the IDN and IDK for the key unit  104   a.    
     In operation, route stops for each collector are compiled by the programmer  301   a . These route stops may be selected by a management operator, or may be downloaded into the programmer  301   a  from a central host management system. For each key unit  104   a , which is identified by a particular key module IDN and corresponding encryption key code IDK, the programmer  301   a  compiles a set of locks which are to be serviced for collection (or other operations) by reading out a number of IDNs and associated IDKs of the locks to be accessed by the particular key unit  104   a , from the look-up table  902 , to thereby generate a route table for transmission to the key unit  104   a.    
     The IDNs and IDKs of the various locks are encrypted by the encrypter  904  using the particular daykey encryption key code in use on that day. The daykey encryption key code is then itself encrypted using the IDK encryption key code of the specific key unit  104   a  for which the route table is being compiled. The encrypted daykey, denoted as DAYKEY (IDK), is then also transmitted to the computer  908  of key unit  104   a.    
     In the key unit  104   a , the IDN identification number and IDK encryption key code are stored in the key interface module  906 , while the encrypted daykey DAYKEY (IDK) and the encrypted route tables are stored in the key memory  502  of handheld computer  908 . 
     Referring now to FIG. 11, the lock memory  602  according to the second construction contains the IDN or lock identification number of that particular lock, the IDK encryption code associated with that particular lock, and an arbitrary seed number. The seed number is simply a certain numerical value, the actual value of which is not relevant. 
     In order for the encrypted IDNs and IDKs of the route tables stored in memory  502  to be decrypted, the handheld computer  908  sends the encrypted daykey to the key interface module  906 , which decrypts the DAYKEY (IDK) using its encryption key code IDK to obtain the decrypted daykey. The encrypted IDNs and IDKs are then sent to the module  906  to be decrypted using the daykey, and used by the module  906  in the verification process with the lock. 
     This feature is intended as an additional security measure to achieve an even higher level of security, for the reason that the module  906  is an add-on feature to the computer  908  and is removable therefrom. Thus, in the event that the module is lost or stolen, neither the module nor the handheld computer can be used for access to any information with respect to lock ID codes or encryption key codes. Further, since the daykey encryption code is periodically changed in the programmer, the particular daykey stored in the module  906  is of limited use. 
     Operation of the second construction will now be described with reference to the flow chart diagrams of FIGS. 10,  10 A, and  12 . 
     Upon insertion of the key  101  into the keyway of the lock at step  1001 , power is applied to the lock at step  1201 . At step  1202 , the lock sends a handshake protocol to the key, which receives the handshake at step  1002  and sends an acknowledge to the lock at step  1003 . At step  1203 , the lock recognizes the acknowledge and sends its IDN to the key at step  1204 . The key receives the lock IDN and acknowledges at steps  1004  and  1005 , and checks to see whether the lock&#39;s IDN exists in memory for the presently valid route table at step  1006 . As previously mentioned, the route tables are labeled by date, and the computer  908  includes a clock for keeping track of the current date. 
     At step  1007 , if the IDN is found, the key checks to see if the lock&#39;s corresponding IDK is found in memory for the particular IDN sent by the lock and acknowledges the lock if both IDN and IDK have been found, at step  1008 . Upon receiving the acknowledge at step  1205 , the lock sends the seed number from memory  602  to the key at step  1206 . The key acknowledges receipt of the seed number at step  1010 , and the lock then encrypts the seed number with its IDK at step  1208  upon receiving the acknowledge at step  1207 . 
     The key also encrypts the seed number from the lock at step  1011 , using the IDK found for the IDN received from the lock. At step  1012 , the key sends the encrypted seed number to the lock, which receives it at step  1209 . The lock then compares the encrypted seed number received from the key with the encrypted seed number which the lock itself generated, at step  1210 . If the numbers match, the key is determined to be authorized to access the lock. At step  1211 , the key writes the encrypted seed number into the memory  602  over the old seed number. The encrypted seed number will be used as the new seed number for the next access request from a key. At step  1212 , the lock sends an acknowledge to the key to inform it of a successful access request, and activates the solenoid at step  1213 . The lock then resets at step  1214 . If any of the acknowledges from the key are not received within a predetermined amount of time, the lock routine also advances immediately to step  1214  for reset. 
     Upon receiving the acknowledge from the lock at step  1013 , the key unit writes the date of access into the route table at step  1014 , over the IDK previously stored there. As such, the key unit will thereafter not be able to access the lock without being reprogrammed by the programmer  301   a . Such can be accomplished either by bringing the key unit  104   a  back to the management center, or by calling into the programmer via modem  910  for reprogramming in the field. 
     The key unit then proceeds to step  1015  where it is reset for the next lock access attempt. 
     In an alternative mode of operation, the key unit may be programmed to have a set number of accesses to each lock before requiring reprogramming. Such is shown in FIG. 10A, wherein a counter is incremented at step  1014   a , and the value stored in the counter is compared with a preset maximum number of accesses at step  1014   b . If this number has been reached, the lock IDK is replaced by the date of access and the key unit is reset at steps  1014   c  and  1015 ; otherwise the key unit is immediately reset at step  1014   d . In either event, additional access to the lock may be denied upon an attempted access to another lock. 
     FIG. 13 illustrates an electronic security system according to a construction relating to T-handle lock type vending machines such as snack and beverage machines, newspaper machines, gaming devices such as slot machines, stand alone lottery machines, money loaders for ATMs (automated teller machines), and transit system farecard machines. 
     In this construction, a portable, conventional handheld computer (HHC)  1301  is provided with an internal circuit board or option card  1310 , having a CPU, memory and associated firmware or software. The option card is installed either as a built-in daughter board or may be inserted into an existing option slot in the HHC  1301 , and communicates with the CPU  1325  of the HHC through an interface bus  1320 . The option card  1310  of FIG. 13 replaces the add-on module  906  of the embodiment of FIG.  9  and generally performs the same functions as the module  906 . As such, further description of the operation of the option card  1310  will be omitted to eliminate repetition. The HHC  1301  is connectable to a host management system  1304  through an interface  1305 . An electronic key device  1302  is connected to the HHC  1301  through an input/output (I/O) port  1330  of the HHC. The option card  1310  communicates with electronic T-lock device  1340  of vending machine  1303  through the I/O port  1330  of the HHC, to transfer decrypted ID code data therebetween and thus provide access to the vending machine. Key device  1302  is similar to key device  101  of FIG.  1 A. 
     The HHC  1301  is used to access vending machine  1303 . The vending machine includes a novel electronic T-lock device  1340  (to be described in detail below). The electronic T-lock device  1340  communicates with the HHC  1301  via the key device  1302 , which supplies power to the T-lock device as in the first and second embodiments. Electronic T-lock device  1340  also communicates with electronic coin vending circuitry  1350  through optocoupler interface  1360 . The electronic coin vending circuitry  1350  includes a memory for maintaining information regarding the amount of money deposited in the vending machine, inventory information relating to the different types and quantities of merchandise sold and still on hand, and other pertinent information relating to the operation of the vending machine. The electronic coin vending circuitry  1350  is conventionally known in the art and for this reason will not be further described. The optocoupler interface consists of LED and optotransistor circuitry and is also well known in the art. The optocoupler interface  1360  enables existing vending machines to be retrofitted with novel electronic T-lock devices  1340  by providing isolation coupling between the existing coin vending circuitry and the T-lock device, to avoid any possible damage due to voltage incompatibility between the components. The optocoupler interface  1360  allows inventory data to be transferred from the vending machine circuitry  1350  to the handheld computer  1301  where it is stored in memory. While optocoupling circuitry is used in the preferred embodiment, it is noted that other types of interfacing including hardwiring may be used in the invention with equivalent function. 
     One advantage lies in the ability of the HHC  1301  to download inventory data from the vending machine  1303  by simply inserting the key device  1302  into the T-lock device  1340 . Upon successful transfer of coded security information, the T-lock will retrieve inventory data from the vending circuity  1350  and transfer it to the HHC  1301 . Service personnel may then read the inventory information from the HHC display, allowing the servicer to determine the quantities and types of inventory that require restocking in the vending machine, without requiring the servicer to open the machine to either access the coin vending circuitry, or to visually inspect the inventory, thus saving considerable time and enhancing convenience. The inventory data may also be uploaded to the host management system  1304  along with the route collection data as described previously, for use by management. The access protocols between the HHC  1301  and the T-lock device  1340  are the same as shown in FIGS. 10 and 12. 
     FIG. 14 illustrates a mechanical T-lock assembly which is used in conjunction with the modified electronic T-lock device discussed below. The mechanical aspects of the T-lock assembly are disclosed in U.S. Pat. No. 5,038,588, assigned to the assignee of the present invention and incorporated herein by reference. 
     In general, a locking mechanism  30  having a bolt  18  is mounted within a cylinder/extension rod housing  22 . A threaded extension rod  20  is mounted in the housing at the other end thereof and is secured within the housing by means of a head  48  and teeth  58  which mate with corresponding cam means in the end of the housing  22 . The lock assembly of FIG. 14 is shown in its unlocked position in which bolt  18  is retracted from engagement with an opening  44  a hollow shank portion  46  in T-handle housing unit  16 . Bolt  18  is engageable with opening  44  through an aperture  42  in the cylinder/extension rod housing  22 . Upon retraction of the bolt  18  from the opening  44 , spring  60  forces the end of the housing  22  into engagement with the teeth  58 . Front handle  15  thus pops out of its nested position within housing  16  and allows the extension rod  20  to be unscrewed from its complementary threaded section within the vending machine. The T-lock device  1340  is mounted within a door or access panel of the machine or box with which it is associated, and thus unscrewing of the extension rod  20  allows the interior of the vending machine or other type of box to be accessed. Key device  1302  is inserted into a keyway of locking mechanism  30  and is turned in order to retract bolt  18  from engagement with opening  44 . 
     FIG. 16 illustrates the constituent parts of the modified electronic T-lock device and the locking mechanism  30 . Bolt  18  is mounted in bolt housing  1640 . The bolt  18  may be a spring-loaded bolt or a deadbolt. Bolt  18  includes a channel  181  and a cam slot  182  as shown in FIGS. 17E and 17F. Bolt cam  1630  is mounted within bolt housing  1640 , and includes a cam pin  1631  which engages within the channel  181  and rests within slot  182  as the bolt  18  is being retracted through rotation of the key. FIGS. 17C and 17D respectively show a front and rear view of the bolt cam  1630 . As shown, bolt cam  1630  includes a teardrop slot  1632 , and a 180° slot  1633 . 
     The bolt cam  1630  is engaged by shaft  1622  of armature  1623 . Shaft  1622  has a projection  1625  at the end thereof adjacent the bolt cam  1630 . The shaft  1622  and projection  1625  fit into the teardrop slot of the bolt cam  1630 . The armature  1623  is mounted within solenoid  1620 , and is normally biased toward the bolt cam by a spring  1624 . Spring  1624  forces the shaft  1622  fully within the bolt cam so that the projection  1625  is located within 180° slot  1633 . The other end of the shaft  1622  is slotted along the edge thereof; this slot engages with chamfer  1615  of plug assembly  1610 , as shown in FIG.  17 B. Plug assembly  1610  has a keyway  1613  and a data contact terminal  1614  at the front end thereof, as shown in FIG. 17A. A 180° channel  1612  is provided on the back end of plug assembly  1610 . This channel interacts with a roll pin  59  which projects into the interior of housing  22  when the plug assembly is mounted therein. An alignment slot  1501  is provided in opening  1510  of front handle  15 , as shown in FIG. 15, to ensure that the plug assembly, and thus projection  1625 , is properly aligned with the teardrop slot  1632 , by requiring the keyway  1613  to be aligned with the alignment slot  1501  in order for the key device  1302  to be inserted into the keyway. Tabs on the end of housing  22  engage with a vertical slot in front handle  15 , and the housing  22  is rigidly secured to the front handle by means of a set screw  1503  which is threaded through thread hole  1504  in handle  15 . The electronic lock circuit as shown in FIG. 16 is formed on an IC chip  1502  which is mounted within a hollowed out section of front handle  15 . Wire contacts  1611  connect the data/power contact terminal  1614  to the IC chip  1502  and power terminals  1621  connect the solenoid  1620  to the IC chip  1502 . Additional wiring (not shown) connects the IC chip to the optocoupler interface  1360 . 
     In operation, when the solenoid  1620  is unenergized, the spring  1623  forces the projection  1625  into the 180° slot  1633  of the bolt cam. Thus, insertion of a key or other instrument in keyway  1613  will allow the plug assembly  1610  and armature  1623  to be freely rotated 180° without engaging the bolt cam to retract the bolt  18 . Upon the proper transfer of decrypted ID code data from the HHC to the lock circuit  1502 , the lock circuit allows power to be transmitted to the solenoid  1620 , drawing the armature  1623  in toward the solenoid. In this position, the projection  1625  engages with the teardrop slot  1632 , and rotation of the key  1302  will thus rotate the bolt cam  1630  causing the bolt  18  to retract and providing access to the vending machine. 
     While the disclosed T-lock assembly uses a threaded extension rod, this is not critical to the operation thereof, and other equivalent attachment mechanisms for securing the T-lock to the housing enclosure such as ratchets, latches, pins, etc. may be used equivalently. 
     SUMMARY OF THE INVENTION 
     The present invention provides an electronic security system which overcomes the above and other problems in the background art. 
     The present invention also provides an electronic security system that can sigificantly reduce collection costs and which can eliminate the requirement of costly re-keying in the event of a key loss. The present invention can also provide a very space efficient electronic lock. Among other things, this enables existing systems to be readily adapted to include electronic capabilities. 
     The present invention further provides an electronic security system which substantially eliminates the possibility of internal fraud and theft. 
     According to a first aspect of the invention, an electronic security system is provided which includes i) an electronic lock, including: a hollow cylinder; an opening into the cylinder; a bolt movable through the opening between an extended position and a retracted position; a drive member within the cylinder, the drive member contacting the bolt to move the bolt to an unlocked position; a solenoid within the hollow cylinder, the solenoid being engageable with the drive member; an electronic lock circuit within the hollow cylinder; a plug connected to the solenoid for rotating the solenoid, the plug having a keyway for insertion of key means for rotating the plug; and ii) key means insertable within the keyway and having electronic means for communicating with the electronic lock circuit to operate the lock. The terminology “key” and “keyway” refer to both the traditional meaning thereof in the art as well as to a general reference to a key “tool”. 
     According to another aspect of the invention, the plug is fixedly connected to the solenoid such that the solenoid moves with the plug. 
     According to another aspect of the invention, the drive member is a cam member that includes a rotatable plate portion and a drive portion mounted thereto, the drive portion being engageable with a surface of the locking bolt upon rotation of the rotatable plate to move the locking bolt. 
     According to another aspect of the invention, a blocker member mounted to the rotatable plate portion, the blocker member being moved to a position beneath the locking bolt when the locking bolt is extended to operate as a dead bolt. 
     According to another aspect of the invention, a solenoid is provided that is adapted to transmit a torque when energized. Torque transmission is preferably accomplished through a magnetic clutch or through a mechanical interlock. In one exemplary embodiment, the torque transmitting solenoid includes a shaft that is either retracted (pulled) or extended (pushed) when the solenoid is energized, the rotatable plate portion having a bore configured to receive the shaft, such that when the key means is inserted into the keyway and the solenoid is energized, rotation of the key means results in simultaneous rotation of the rotatable plate portion and the drive member. 
     According to another aspect of the invention, an electronic lock device is provided which includes: i) a lock including a mechanical drive train for opening an access door; ii) an electronic device for electronically controlling access through the access door; iii) the electronic device including a solenoid situated within the mechanical drive train; iv) the solenoid having a housing that is rotated as a part of the drive train, the solenoid engaging a drive member upon energization of the solenoid, such that rotation of the solenoid when energized causes the drive member to simultaneously rotate to connect the drive train and to allow access through the access door. Preferably, the solenoid has a movable shaft member that has an engaging member which engages a corresponding engaging member of the drive member upon engergization of the solenoid. The electronic lock device can be used for an access door of, for example, a building through which an individual walks or a device having an enclosed housing into which manual access is desired. 
     The above and other advantages, features and aspects of the present invention will be more readily perceived from the following description of the preferred embodiments thereof taken together with the accompanying drawings and claims. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and are not limitative of the present invention. 
     I. 
     FIGS. 1-17 illustrate background technology of the present assignee. 
     FIGS. 1A and 1B are side and end elevational views, respectively, of an electronic key with its own power supply according to one preferred embodiment; 
     FIG. 2 is a front elevation view of a lock cylinder and associated mechanisms (shown with the housing cover removed) for operation with the key of FIGS. 1A and 1B; 
     FIG. 3 is a schematic view of a first embodiment of an electronic key programmer; 
     FIG. 4 is a schematic view of another embodiment of a portable key programmer; 
     FIG. 5 is a schematic block diagram of the circuit elements of the electronic key of FIG. 1A; 
     FIG. 6 is a schematic block diagram of the electronic components of the lock mechanism of FIG. 2; 
     FIG. 7 is a schematic block diagram of the electronic key programmer of FIGS. 3 and 4; 
     FIG. 8 is an operational flow chart diagram of the electronic lock mechanism operation; 
     FIG. 9 is a schematic block diagram of an electronic key programmer and an electronic key unit according to a second embodiment; 
     FIG. 10 is a flow chart diagram of the operation of the key unit  104   a  of FIG. 9; 
     FIG. 10 a  is a flow chart diagram of an alternative routine for step  1014  of FIG. 10; 
     FIG. 11 is block diagram of the contents of lock memory  602  according to the second embodiment; 
     FIG. 12 is a flow chart diagram of the operation of the lock unit  201  according to the second embodiment; 
     FIG. 13 is a block diagram of an electronic security system relating to T-handle type vending machines; 
     FIG. 14 is a partly cross sectional side view of a T-handle lock assembly; 
     FIG. 15 is a front view of the cylinder front handle  15  of FIG. 14; 
     FIG. 16 is an exploded partly cross sectional side view of a cylinder front handle, cylinder/extension rod housing subassembly, and modified bolt release assembly; 
     FIG. 17A is a front view of plug assembly  1610  of FIG. 16; 
     FIG. 17B is a rear view of plug assembly  1610 ; 
     FIG. 17C is a front view of bolt cam  1630  of FIG. 16; 
     FIG. 17D is a rear view of bolt cam  1630 ; 
     FIG. 17E is a front view of bolt  18  of FIG. 16; and 
     FIG. 17F is a side view of bolt  18 . 
     II. 
     FIGS. 18-21 illustrate the preferred embodiments of the present invention. 
     FIG. 18 is a cross-sectional side view of a preferred embodiment of the invention related to fitting of an electronic lock assembly within a lock cylinder; 
     FIG. 19A is a cross-sectional side of an embodiment similar to that shown in FIG. 18; 
     FIG. 19B is a cross-sectional view in the direction of arrows  19 -B shown in FIG. 19A; 
     FIG. 19C is a schematic end view in the direction of arrow  190 C shown in FIG.  19 (A); 
     FIG. 20A is a conceptual view showing the bolt in a retracted state; 
     FIG. 20B is a conceptual view showing the bolt in an extended state; and 
     FIGS. 21A-21D show cross-sectional views of some alternative variations of the solenoid according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The lock shown in FIGS. 18-21 preferably utilizes an electronic control like that described with reference to the background technology shown in FIGS. 1-17. In particular, a key or key means can be used similar to that described herein-above, and the circuitry can employ means like that detailed herein-above. As should be understood by those in the art based on this disclosure, the electronic control can include features described herein-above as applicable to the present invention discussed below. It is noted that the features pertaining to the “smart” capabilities—as, for example, encircled and labeled SC in FIGS.  6  and  8 —are not to be included in the most preferred embodiments. In alternate embodiments, the lock illustrated in FIGS. 18-20 can utilize other known electronic controls used in other electronic security systems. 
     FIG. 18 illustrates an electronic security system according to a preferred embodiment of the present invention relating to locks having cylinders, such as, for example, vending machines such as, e.g., snack and beverage machines, postal machines, dollar/coin exchange machines, and transit system farecard machines. The present invention can be used, for example, to retrofit cylinders of locks and to provide electronic ability to (a) improve key control, key management, and route management, (b) control access, (c) increase accountability, (d) reduce problems associated with lost keys, and (e) reduce internal theft and fraud. As one example, the present invention can be located within the cylinder portion of a standard T-lock, such as, e.g., within a cylinder housing portion  22  shown in FIG.  14 . As another example, the present invention can be used within the space dimensions of a N.A.M.A. standard vending lock. For example, a circuit assembly, a splendid device, a blocking mechanism, a bolt and an inner plug are all locatable within a standard cylinder according to the present invention. Thus, one of the benefits of the present invention is that—if desired—it can easily be minimized. The present invention can easily be located within a cylinder that is substantially less than an inch wide and substantially less than a few inches long, or even within substantially smaller cylinders, or within other small volumes. 
     In the preferred embodiment shown in FIG. 18, a cylinder  2000  has essential components mounted therein—e.g., a circuit  2100 , a solenoid  2200 , a drive member  2300  (e.g., a cam member in this embodiment), a locking bolt  2400 , and a plug  2500 . In the preferred embodiments, the cylinder  2000  is a standard pop-out cylinder having dimensional characteristics in accordance with N.A.M.A. 
     The circuit  2100 , e.g., a printed circuit board, is electrically connected to an inserted key via the connector  2150 . The circuit  2100  can include circuitry like that discussed above in the preceding section regarding FIGS. 1-17. Although not illustrated in FIGS. 18-20, the key means used can be the same as that of any of the above-noted embodiments. For example, a key means like that shown in FIG. 1A can be utilized. 
     The solenoid  2200  can be driven by way of the key means and the circuit  2100  in the same ways as discussed in the preceding section pertaining to FIGS. 1-17. In one preferred embodiment of FIG. 18, the solenoid linearly extends a shaft  2250 . The shaft  2250  can be received in a corresponding bore  2350  in the cam member  2300 . The cam member  2300  is preferably a rotatable plate member. The shaft  2250  and bore  2350  preferably have like shapes, such that the shaft fits within the bore and is not freely rotated therein. For example, the shaft  2250  and the bore  2350  can both be hexagonal, octagonal, square, gear toothed, etc., or any irregular shape. Preferably, the shaft and bore both have a symmetrical shape that creates a plurality of aligning keys at a number of angular positions, such as with gear teeth, etc. 
     As shown in FIG. 18, a plug  2500  is configured to received a key means in a manner to align an electrical contact  2155  of an electrical connector means  2150  with an electrical contact on the key or key means. The electrical contact on the key or key means can be like that discussed in the preceding section regarding FIGS. 1-17, such as the electrical contact  103  shown in FIG.  1 . In this regard, the plug  2500  preferably includes a slot  2520  for receiving a key blade or the like. The key blade can, if desired, overlap the circuit  2100  to extend further into the cylinder  2000 . The plug  2500  can include a portion  2500 B (shown with dotted lines) that extends around the circuit  2100  and connects to the solenoid. Preferably, there is no relative movement between the solenoid, circuit and plug so that the solenoid, circuit and plug move together as an integral unit. As long as the solenoid, circuit, and plug move together, they can be connected together in a variety of ways. The solenoid, circuit and plug can also be accommodated within a unitary shell sized to fit and rotate within the cylinder  2000 . In an alternative construction, the plug  2500  and solenoid  2200  could be mounted to rotate as a unit while the circuit  2100  is fixed within the cylinder  2000 . For example, a circuit board  2100  could surround a portion of the plug extending to the solenoid and could include sliding contacts to provide electrical connections. Nevertheless, the illustrated embodiments are preferred. 
     In operation, the key means is inserted into the plug  2500  so that the contact on the key means communicates with the printed circuit board. The electrical communication between the key means and the circuit board can be like that discussed above in the preceding section regarding FIGS. 1-17. Then, the key means is rotated. Rotation of the key means results in a corresponding rotation of both the circuit board  2100  and the solenoid  2200 . In the event that the electrical system approves the use of the inserted key, the solenoid  2200  (which, as noted, is preferably powered by a battery in the key means) biases the shaft  2250  from a normally unkeyed position inside the solenoid towards a keyed bore  2350  in the cam member  2300 . When the solenoid  2200  is rotated to a position where the shaft  2250  and the bore  2350  align, the shaft  2250  moves by the force of the solenoid to a position that engages the bore, thereby transmitting the torque from the plug to the cam. Further rotation of the key or key means rotates the cam  2300 . As a result, the locking bolt  2400  can be extended and/or retracted by appropriately rotating the key. In this embodiment, the solenoid  2200  can—if desired—be made very small. For example, in one preferred construction, the shaft  2250  moves only about 0.1 inch. 
     In an alternative embodiment, as shown in FIGS. 19A and 19B, the solenoid  2200  operates as a magnetic drive clutch. That is, the solenoid can operate in a manner to impart an engaging force due to the magnetic field of the solenoid, the solenoid magnetically grasping the cam (or other like drive member) upon energization. In addition to the pure magnetic force, the cam (or other like drive member) can also be caused to frictional engage the solenoid upon energization. That is, rather than extending a shaft within a bore  2350 , the solenoid can energize a wide element  2351  to frictionally engage a side surface  2352  of the cam  2300 . This frictional engagement can even be enhanced by roughening up the contacting surfaces or the like, if desired. In order to ensure full disengagement upon de-energization of the solenoid, one or more springs can be provided to force the cam (or like drive member) and the solenoid apart from one another upon de-energization. That is, the force of the spring would be overcome upon energization, but would facilitate separation upon denergization. With respect to the embodiments employing a movable shaft instead of a magnetic drive clutch, it is noted that these shafts are preferably normally biased to a disengaged state and moved into an engaged state upon energization. This normal bias can, for example, be effected with springs or the like. It is noted that the most preferred embodiments of the present invention include a movable shaft  2350 , especially when the solenoid size is minimized. 
     A number of variations, showing some alternative embodiments, of the solenoid  2200  are illustrated in FIGS.  21 (A)- 21 (D). The alternative shown in FIG.  21 (A) shows that the shaft  2350  can be made to retract upon energization such that an engaging member  2355  mounted to the shaft engages an engaging member  2305  of the cam  2300 . The engaging member  2305  is shaped and sized to receive the engaging member  2355  so as to cause the cam  2300  to be rotated along with rotation of the shaft  2350 . FIG.  21 (B) illustrates that the cam  2300  can be located within the housing of the solenoid  2200 . FIG.  21 (B) also illustrates that the solenoid can include a keyway  2205  that is configured to receive keys  2356  attached to the shaft  2350  upon energization. The use of such keys  2356  and keyway  2205  enable the shaft to be fully disengaged from the solenoid  2200  and the cam  2300  until energization. The keys and keyway can also be used within the solenoid in the embodiment illustrated in FIG. 18 or in any other embodiment, such as in the embodiment shown in FIG.  21 (C) discussed below. Alternatively, in any of the disclosed embodiments, the keys and keyway can be configured to remain in engagement at all times (as one example, the keys can be constructed to extend along the entire length of the shaft  2350 ), rather than engaging only upon energization. The keys can also be integral in the shape of the shaft  2350 &#39;s cross-sectional shape, i.e., as long as the solenoid can impart rotation to the shaft. In the preferred construction, the engaging member  2355  includes peripheral gear teeth  2358  and are received within corresponding gear teeth  2308  in the engaging member  2305 . The resulting mechanical couple allows a high degree of torque carrying capacity from the solenoid housing to the rotatable plate for purposes of rotating or translating objects with the drive pin, during energization of the solenoid. 
     FIG.  21 (C) shows an alternative embodiment, wherein the shaft  2350  includes an end bore  2357  and the cam  2300  includes a corresponding projection  2307 , wherein the bore  2357  is extended to receive the projection  2307  upon energization of the solenoid  2200 . FIG.  21 (D) shows an alternative embodiment similar to that shown in FIG.  21 (B), wherein the engaging element  2355  engages the engaging element  2305  upon energization by extending outward into engaging, rather than retracting into engagement. 
     The solenoid  2200  of the present invention is, thus, constructed to transmit torque upon energization for the purposes of, for example, rotating or translating objects. In particular, upon energization, rotation of the solenoid mechanically imparts a rotational force to the cam  2300  and applies a rotational force therethrough. The solenoid, thus, acts as a torque transmitting member. Although the shaft is preferably an elongated member as shown, the terminology “shaft” herein is intended to encompass any mechanical element(s) that is/are movable by a solenoid. 
     As noted, in the preferred embodiments, in an unenergized condition, the solenoid housing can be rotated, but the applied torque is not transmitted to the rotatable cam  2300 , while in an energized condition, the shaft moves to an engaging position and, thus, torque can be applied through rotation of the solenoid. In addition, when a magnetic clutch solenoid is used, the magnetic force can cause the cam  2300  and solenoid to engage and, thus, torque can be applied through rotation of the solenoid. 
     The use of a torque transmitting solenoid has applicability in a variety of applications other than as shown with respect to the preferred embodiments herein. In brief, the torque transmitting solenoid can be used in any application to impart a torque or rotational force via a solenoid element. Although the illustrated embodiment pertains to transmission of a torque applied by hand via a hand-held key, the torque transmitting solenoid can be applied in a variety of devices, such as other devices having means for manually rotating the solenoid or having means for automatically rotating the solenoid. The solenoid of the present invention can be useful in any type of drive train or transmission. 
     The present invention has notable advantages in environments wherein a miniaturized torque transmitting component is desired. The most preferred environment pertains to electronic lock systems. The present solenoid can be useful in virtually all electronic lock systems, including, as some examples only, vending locks, ATM machine locks, pay telephone locks, parking meter locks, and door entrance locks. As other examples, it can be used in any cam locks, it can be used in any plug locks, it can be used in locks having tumbler pin systems, etc. The solenoid can, for example, be located within a drive train to allow the lock to be opened only upon energization of the solenoid. The energization of the solenoid can be effected through any known electronic accessing means. The present solenoid has notable advantages in electronic lock sets having doors that are openable via an torque-applying opening mechanism only upon electronic approval, such, as one example only, where a user slides an access card through a reader and then opens the door via a handle, knob, or lever. As some further examples, the solenoid can be used in the drive trains of lock devices like that shown in U.S. Pat. Nos. 4,163,215 to Iida and 4,148,092, the disclosures of which are incorporated herein by reference. 
     As generally shown at  2600  in FIGS. 19A and 19B, the device can include means, such as bearings or the like, to facilitate rotation of the plug, circuit, and solenoid within the cylindrical housing  2000 . In addition, the plug  2500  can include means to allow the key means to be rotated therein. For example, a portion of the plug, e.g., a core portion, could be rotated within the plug  2500 . 
     The rotated cam  2300  preferably also serves as a means to drive the bolt  2400  to the retracted position and to block the bolt when in the extended position. In this regard, the rotated cam  2300  can include a driver  2310  and a blocker  2320 . 
     As shown in FIG. 18, the locking bolt  2400  preferably includes a cut-out portion  2410  across the width w, FIG. 20A, thereof. The cut-out portion  2410  is configured to receive the driver  2310  of the rotated cam  2300 . Although the cut-out portion extends across the width w in the illustrated embodiments, the cut-out portion can extend across a portion thereof and/or can be curved or have an irregular shape, as long as the operation thereof remains similar A spring  2430  is preferably used to normally bias the locking bolt  2400  in an extended position. A variety of springs known in the art can be used, such as leaf springs, coil springs, etc. 
     The locking bolt  2400  can be moved from the extended position shown in FIG. 20B to the retracted position shown in FIG. 20A by rotating the cam  2300  clockwise in FIG.  20 B. During this rotation, the driver  2310  contacts the surface  2411  to drive the locking bolt  2400  to the retracted position—e.g., against the force of the spring  2430 . On the other hand, the locking bolt  2400  can be moved from a retracted position to an extended position, by rotating the cam  2300  counter-clockwise so that the driver  2310  moves generally in the direction A, FIG.  20 A. Thus, allowing the spring  2430  to bias the locking bolt  2400  to the extended position. 
     The preferred embodiments of the invention include a blocker, or locking pin,  2320  which moves to a position below the surface  2412  of the locking bolt  2400  when the locking bolt  2400  is in the extended position. In this manner, the blocker  2320  provides the added security of a dead bolt. The blocker  2320  is preferably arranged to move to the side of the locking bolt  2400  when retracted as shown in FIG.  20 A—such as in the environment where the cylinder  2000  is small, e.g., as with a standard N.A.M.A. lock. To facilitate movement of the blocker  2320  around the locking bolt  2400 , the locking bolt  2400  can include a chamfered corner  2440 , FIG.  20 A. In this manner, when the locking bolt  2400  is in the extended position, the blocker  2320  can easily be rotated to a position behind the locking bolt as shown in FIG.  19 C. In an alternative construction, the corner portion  2440  of the locking bolt can be squared off, and the blocker  2320  can be located closer to the locking bolt as shown at  2440 -X and  2320 -X in dotted lines in FIG.  20 B. In alternative embodiments, the driver  2310  and the blocker  2320  can have other configurations, and the locking bolt  2400  can be appropriately configured to be compatible therewith. As one example, the blocker  2320  can be made to have a square, or other, cross-section. The configurations can be altered as long as the operation and relative positioning of the parts remains similar. For example, the driver  2310  preferably includes at least a portion located at a radius, e.g., r 1 , of the cam  2300  that remains within a cut-out section  2410  of the locking bolt  2400  while the blocker  2320  is preferably at a radius, e.g., r 2 , that allows the blocker  2320  to move around the locking bolt  2400 . 
     The illustrated embodiments can operate with a single key that is inserted at each machine stop. On the other hand, traditional deadbolt designs require two key insertions, a first to open and a second to close the machine door. In addition, the illustrated embodiment enables spring latch convenience as well as the security of a dead bolt. 
     The preferred embodiments of the present invention enable a standard mechanical lock to easily be upgraded to having electronic control. For example, the embodiments shown in FIGS. 18-20 can be utilized within any lock having a T-handle regardless of the style thereof. Thus, the embodiments shown in FIGS.  18 ˜ 20  have substantial benefits over the construction shown in FIGS. 15-17, which are not as easily adapted to a variety of devices. An existing mechanical pop-out cylinder can easily be replaced with a modified pop-out cylinder having electronic components as shown in FIGS. 18-20. The present invention contemplates a novel, easy and efficient method of upgrading mechanical locks by simply removing existing mechanical pop-out cylinders and replacing the same with an improved electronic pop-out cylinder according to the present invention. Thus, the embodiments illustrated in FIGS. 18-20 have substantial benefits and can be used in a variety of applications, such as with a variety of vending machines, bottle machines, ATM machines, etc. 
     In another alternative construction, the driver  2310  can be used to move the locking bolt to the extended position, rather than or in addition to using a spring  2430 . In this regard, the cut-out section  2410  can be a narrower channel such that the driver  2310  moves the locking bolt in the directions A and B, FIG.  20 A. 
     Although the preferred embodiments do not use common tumbler pins and keys having bitting surfaces, the key slot  2520  into the plug  2500  can be made to have a specific configuration that allows the insertion of only a particularly shaped key. The plug  2500  could also be modified to include multiple parts, where a certain part thereof is connected to the solenoid, such that a key means must rotate that certain part of the plug. Further, the plug  2500  could be modified to contain common tumbler pins operated by keys having bitting surfaces. In the environment where the cylinder  2000  is small, e.g., such as with a standard N.A.M.A. lock cylinder, the plug is very small and is preferably made without locking pins and/or separately moved parts. 
     The invention being thus described, it will be apparent to those skilled in the art that the same may be varied in many ways without departing from the spirit and scope of the invention. Any and all such modifications are intended to be included within the scope of the following claims.