U.S. patent application number 11/583449 was filed with the patent office on 2007-05-03 for vending machines with field-programmable electronic locks.
Invention is credited to Lawrence C. Brownfield, William D. Denison, Bradley S. Silvers.
Application Number | 20070096866 11/583449 |
Document ID | / |
Family ID | 29739343 |
Filed Date | 2007-05-03 |
United States Patent
Application |
20070096866 |
Kind Code |
A1 |
Denison; William D. ; et
al. |
May 3, 2007 |
Vending machines with field-programmable electronic locks
Abstract
A vending machine uses a field-programmable electronic lock that
learns a key code from a corresponding electronic key. The
electronic lock has a learning process activation device that is
accessible when the door of the vending machine is in the open
position. Using the learning process activation device, a service
person activates the electronic lock to perform a key code learning
operation, in which the electronic lock receives a key code
transmitted from an electronic key and stores the key code in a
non-volatile memory for future access control of the vending
machine. Data encryption is employed in the communications between
the key and the lock to ensure the security of the communications.
A communication device installed in the vending machine for
communicating with a home base computer allows the operation of the
electronic lock to be remotely controlled for access control and
auditing purposes.
Inventors: |
Denison; William D.;
(Naperville, IL) ; Silvers; Bradley S.;
(Yorkville, IL) ; Brownfield; Lawrence C.;
(Downers Grove, IL) |
Correspondence
Address: |
FACTOR & LAKE, LTD.
Suite 5G/H
1327 W. Washington Blvd.
Chicago
IL
60607
US
|
Family ID: |
29739343 |
Appl. No.: |
11/583449 |
Filed: |
October 19, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10997500 |
Nov 24, 2004 |
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11583449 |
Oct 19, 2006 |
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10329626 |
Dec 26, 2002 |
6900720 |
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10997500 |
Nov 24, 2004 |
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60344221 |
Dec 27, 2001 |
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Current U.S.
Class: |
340/5.23 ;
340/5.7 |
Current CPC
Class: |
H04L 2209/56 20130101;
G07C 9/00309 20130101; G07F 5/26 20130101; G07C 9/00817 20130101;
G07F 9/002 20200501; G07C 9/00896 20130101; G07C 2209/04 20130101;
H04L 9/3226 20130101; G07F 9/026 20130101; G07C 2009/00388
20130101; G07F 17/12 20130101; G07C 9/00571 20130101; G07C
2009/00793 20130101; H04L 2209/80 20130101; G07F 11/62 20130101;
H04L 9/3271 20130101; G07C 2009/005 20130101; Y10T 70/7079
20150401; G07C 2009/00412 20130101; G07C 2009/00849 20130101 |
Class at
Publication: |
340/005.23 ;
340/005.7 |
International
Class: |
H04L 9/32 20060101
H04L009/32; B60R 25/00 20060101 B60R025/00 |
Claims
1. A method for distributing an access code into an electronic lock
and accessing the electronic lock of a vending machine, the vending
machine having a door openable for accessing contents of the
vending machine and an electronic lock containing an encryption
code, the method comprising the steps of: selecting an electronic
key; interfacing the electronic key to a computer having a software
program for key management functionality, a database containing key
management data; and communicating, via a key reader, with the
computer for interfacing the computer with the electronic key; the
software program having computer-executable instructions for
performing a key programming operation comprising the steps of:
receiving identification of the electronic key, retrieving from the
memory information of a user of the electronic key and at least one
operation limit parameter for said user based on the key
identification; and sending at least one operation limit parameter
through the key reader to the electronic key for writing into a
memory of the electronic key; placing the electronic lock in a
learning mode; transmitting a first access code in an encrypted
form to the electronic lock while the electronic lock is in the
learning mode; decrypting, by the electronic lock, the received
first access code using the encryption code; and storing, by the
electronic lock, the first access code in the lock memory.
2. The method of claim 1 further comprising the steps of the
electronic key transmitting to the electronic lock a second key
code, and unlocking the door to provide access to the vending
machine if the second key code matches the first access code stored
in the lock memory.
3. A method of creating an access control route for a plurality of
vending machines, each lock containing a unique identification
number in a memory of said lock, and containing a same encryption
code, and accessible by at least one electronic key with said
encryption code, and including the steps of selecting an electronic
key containing said encryption code, the method comprising the
steps of: selecting a plurality of vending machines; loading said
key memory with a plurality of electronic identification numbers of
vending machines making up said route; providing a route driver
with said electronic key and said route driver visiting more than
one vending machines; and, wirelessly accessing a plurality of said
vending machines on said route.
4. A method of access control of a vending machine comprising the
steps of: selecting an electronic key to access a vending machine
door; accessing the vending machine to provide access to the
internal equipment of the vending machine including disabling an
electronic lock from operation, performing a maintenance task with
the vending machine controller to satisfy at least one condition of
said controller, and said electronic lock re-enabling based on said
controller condition being satisfied to resume operation.
5. A method of creating an access control route for a plurality of
vending machines each containing electronic locks each utilizing a
same access code and encryption code, the method comprising the
steps of: placing a plurality of vending machines into a learn mode
of operation; transmitting a same access code in an encrypted form
to the electronic lock while the electronic lock is in learn mode;
decrypting, by the electronic lock, the received access code using
the encryption code; storing the access code in a memory of the
electronic lock; providing a plurality of employees each an
electronic key containing said keycode; and, accessing a plurality
of vending machines on said route by a plurality of employees using
a plurality of electronic keys containing said access code.
6. The method of claim 5 wherein the plurality of vending machines
are accessed wirelessly.
7. A method of programming and distributing electronic keys for
accessing vending machines containing electronic locks, the method
comprising the steps of: selecting a key assigned to an employee; a
supervisor having appropriate data entering privileges entering
work schedule information of said employee into a memory of the
computer to establish at least one limit parameter of said
employee's key; and, interfacing said key to a communication port
of the computer to establish a programming operation; and,
programming a memory of said key with said at least one key limit
parameter(s).
8. A method of manufacturing a plurality of vending machines
containing electronic locks, distributing said vending machines to
soft drink bottlers and initializing the security of said vending
machine locks, the method comprising the steps of: assembling the
plurality of vending machines in a factory with an electronic lock
containing a factory access code; accessing the electronic lock
with a first key containing said factory access code at the
factory; shipping the plurality of vending machines to a soft drink
bottling facility; accessing said vending machine locks with a
second key containing said factory access code; placing the
electronic locks into a learn mode of operation; and transferring a
non-factory access code into a memories of said electronic
locks.
9. The method of claim 8 wherein the vending machine locks are
accessed wirelessly.
10. The method of claim 8 further comprising the step of using the
key to wirelessly access the lock by an encrypted communication
method.
11. The method of claim 8 wherein the non-factory access code is
transferred to the lock by an encrypted communication method.
12. The method of claim 8 wherein both the lock and the key contain
the same encryption code.
13. A method of a vending route employee electronically and
wirelessly accessing and auditing the access control attempts of a
plurality of remotely located vending machines, said vending
machines each containing an audit trail memory of key
identification codes, datestamps and timestamps of when at least
one access attempt occurred, the method comprising the steps of:
visiting the plurality of vending machines at remote locations;
accessing said vending machines with an electronic key using an
encryption code, said electronic key receives and stores in a
memory of the key the contents of said audit trail memory from said
vending machine lock; said vending route employee returning to a
central location and interfacing the key to a communication port of
the computer to establish a download operation; said key
transferring said audit trail data from said key into a memory of a
computer; and, a supervisor with data observation privilege
selecting a method of sorting said audit trail data, sorts said
data, and reads said data from a display of the computer.
14. The method of claim 13 wherein the vending machines are
accessed wirelessly.
15. The method of claim 13 wherein the key wirelessly accesses the
lock by an encrypted communication method.
16. The method of claim 13 wherein both the lock and the key
contain the same encryption code.
17. A method of programming and distributing electronic keys that
electronically and wirelessly access vending machines containing
electronic locks, the method comprising the steps of: receiving an
order for electronic keys from a vending machine bottler in a
designated geographical territory; selecting a city code
representing said territory; programming said key to said city code
by transferring an electronic code representing said city code to a
memory of the key; sending said key to the vending operator in said
territory; placing an electronic lock into a learn mode of
operation; transferring said identification code representing said
city code to the memory of said electronic lock; and, placing the
vending machine containing said electronic lock in the geographical
territory represented by said city code.
18. The method of claim 17 further comprising the step of marking
the electronic key with the city code.
19. The method of claim 17 wherein an electronic key containing
said city code wirelessly accesses said electronic lock.
20. The method of claim 17 wherein the electronic key wirelessly
accesses the lock by an encrypted communication method.
21. The method of claim 17 wherein both the lock and the key
contain the same encryption code.
22. The method of claim 17 wherein the electronic keys contain
operation limit parameters.
23. The method of claim 17 wherein the electronic key collects data
in the audit trail memory of the electronic lock.
24. The method of claim 22 further comprising the step of
maintaining the operation limits of the electronic key with a
computer.
25. A method for unlocking a lock in a vending machine, the method
comprising the steps of: providing a lock shielded from external
access for unlocking the outer door of the vending machine having
an encryption code and an key having an encryption code; encrypting
information with the lock using the encryption code to generate a
first value, said first value comprising a lock identification
number; encrypting information with the key using the encryption
code to generate a second value, said second value comprising a
lock identification number; communicating at least one of the first
and second values with wireless communication conveyed through the
door of the vending machine; and, comparing a received lock
identification number with a lock identification number stored in a
memory to determine if the lock should be accessed.
26. A method for unlocking a lock in a vending machine, the method
comprising the steps of: providing a lock shielded from external
access for unlocking the outer door of the vending machine having
an encryption code and an key having an encryption code; encrypting
information with the key using the encryption code to generate a
first value; encrypting information with the lock using the
encryption code to generate a second value, said second value
comprising a lock identification number; communicating at least one
of the first and second values with wireless communication conveyed
through the door of the vending machine; and, comparing a received
lock identification number with a lock identification number stored
in a memory to determine if the lock should be accessed.
27. A method for unlocking a lock in a vending machine, the method
comprising the steps of: providing a lock shielded from external
access for unlocking the outer door of the vending machine having
an encryption code and an key having an encryption code; encrypting
information with the lock using the encryption code to generate a
first value, said first value comprising a lock identification
number; communicating the first value with wireless communication
conveyed through the door of the vending machine; encrypting
information with the key using the encryption code to generate a
second value, said second value comprising a lock identification
number; communicating the second values with wireless communication
conveyed through the door of the vending machine; and, comparing a
received lock identification number with a lock identification
number stored in a memory to determine if the lock should be
accessed.
28. A method for unlocking a lock in a vending machine, the method
comprising the steps of: providing a lock shielded from external
access for unlocking the outer door of the vending machine having
an encryption code and an key having an encryption code; encrypting
information with the key using the encryption code to generate a
first value; communicating the first value with wireless
communication conveyed through the door of the vending machine;
encrypting information with the lock using the encryption code to
generate a second value, said second value comprising a lock
identification number; communicating the second value with wireless
communication conveyed through the door of the vending machine;
comparing a received lock identification number with a lock
identification number stored in a memory to determine if the lock
should be accessed.
29. The method of claim 25 wherein the memory of the key contains
at least one operation limit parameter.
30. The method of claim 26 wherein the memory of the key contains
at least one operation limit parameter.
31. The method of claim 27 wherein the memory of the key contains
at least one operation limit parameter.
32. The method of claim 28 wherein the memory of the key contains
at least one operation limit parameter.
33. The method of claim 29 wherein the at least one operation limit
parameter in the key includes: number of days, days of the week,
hours of the day, number of accesses, at least one vendor
identification number.
34. The method of claim 30 wherein the at least one operation limit
parameter in the key includes: number of days, days of the week,
hours of the day, number of accesses, at least one vendor
identification number.
35. The method of claim 31 wherein the at least one operation limit
parameter in the key includes: number of days, days of the week,
hours of the day, number of accesses, at least one vendor
identification number.
36. The method of claim 32 wherein the at least one operation limit
parameter in the key includes: number of days, days of the week,
hours of the day, number of accesses, at least one vendor
identification number.
37. The method of claim 29 further comprising the step of modifying
the operation limits at a docking station controlled by a
computer.
38. The method of claim 30 further comprising the step of modifying
the operation limits at a docking station controlled by a
computer.
39. The method of claim 31 further comprising the step of modifying
the operation limits at a docking station controlled by a
computer.
40. The method of claim 32 further comprising the step of modifying
the operation limits at a docking station controlled by a
computer.
41. The method of claim 26 further comprising the step of the key
restricting transmission of the first value if a limit parameter is
exceeded.
42. The method of claim 28 further comprising the step of the key
restricting transmission of the first value if a limit parameter is
exceeded.
43. The method of claim 25 further comprising the step of the key
restricting transmission of the second value if a limit parameter
is exceeded.
44. The method of claim 27 further comprising the step of the key
restricting transmission of the second value if a limit parameter
is exceeded.
45. The method of claim 25 further comprising the step of the
electronic lock memory containing at least one identification code
of an electronic key that attempted to access the lock.
46. The method of claim 26 further comprising the step of the
electronic lock memory containing at least one identification code
of an electronic key that attempted to access the lock.
47. The method of claim 27 further comprising the step of the
electronic lock memory containing at least one identification code
of an electronic key that attempted to access the lock.
48. The method of claim 28 further comprising the step of the
electronic lock memory containing at least one identification code
of an electronic key that attempted to access the lock.
49. The method of claim 29 further comprising the step of the
electronic lock memory containing at least one identification code
of an electronic key that attempted to access the lock.
50. The method of claim 25 further comprising the steps of
transmitting said memory of at least one key identification code in
the electronic lock to the key and storing the key identification
code in the memory of the key.
51. The method of claim 26 further comprising the steps of
transmitting said memory of at least one key identification code in
the electronic lock to the key and storing the key identification
code in the memory of the key.
52. The method of claim 27 further comprising the steps of
transmitting said memory of at least one key identification code in
the electronic lock to the key and storing the key identification
code in the memory of the key.
53. The method of claim 28 further comprising the steps of
transmitting said memory of at least one key identification code in
the electronic lock to the key and storing the key identification
code in the memory of the key.
54. The method of claim 25 further comprising the step of the
electronic key containing a memory consisting of a plurality of key
identification codes of electronic keys that attempted to access at
least one vending machine.
55. The method of claim 26 further comprising the step of the
electronic key containing a memory consisting of a plurality of key
identification codes of electronic keys that attempted to access at
least one vending machine.
56. The method of claim 27 further comprising the step of the
electronic key containing a memory consisting of a plurality of key
identification codes of electronic keys that attempted to access at
least one vending machine.
57. The method of claim 28 further comprising the step of the
electronic key containing a memory consisting of a plurality of key
identification codes of electronic keys that attempted to access at
least one vending machine.
58. The method of claim 25 wherein the second value contains a key
identification number.
59. The method of claim 27 wherein the second value contains a key
identification number.
60. The method of claim 26 wherein the first value contains a key
identification number.
61. The method of claim 28 wherein the first value contains a key
identification number.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 10/997,500, filed Nov. 24, 2004, which is a
continuation of U.S. patent application Ser. No. 10/329,626, now
U.S. Pat. No. 6,900,720, which claims priority of U.S. Provisional
Application Ser. No. 60/344,221, filed Dec. 27, 2001.
[0002] This application is also related to a co-filed U.S. patent
application Ser. No. ______, filed on Oct. 19, 2006, having
attorney docket number MET-061192, and entitled VENDING MACHINES
WITH FIELD-PROGRAMMABLE ELECTRONIC LOCKS.
FIELD OF THE INVENTION
[0003] This invention relates generally to vending machines, and
more particularly to vending machines equipped with electronic
locks.
BACKGROUND OF THE INVENTION
[0004] Vending machines are widely used in various locations as
automated means for selling items such as soft drinks, snacks, etc.
Traditional vending machines are equipped with mechanical locks,
which can be unlocked with a corresponding mechanical key to open
the door of the machine to allow reloading of goods and collection
of money.
[0005] One significant problem with conventional vending machines
is the difficulties in managing the distribution and usage of the
keys to ensure the security of the locks on the vending machines.
The process of collecting money from the vending machines scattered
at different places is a very manpower-intensive operation that
requires many employees to go into the field with numerous
mechanical keys for operating the locks on the vending machines. It
requires a considerable amount of attention and efforts to manage
and track the distribution of the keys to the field workers to keep
the keys secure.
[0006] Moreover, the mechanical keys and lock cores of vending
machines are a point of attack for vandals. The keys can be lost or
copied easily, and the stolen or copied keys may then be used by an
unauthorized person to access the machines, and it is difficult to
discover such misuses and security breaches. Also, a skilled vandal
can easily pick or drill-out the lock core tumblers and measure the
key cuts of the lock core tumblers to re-produce a like key and
compromise the security. In the event a security breach is
identified, the mechanical lock cores of the affected vending
machines typically have to be manually replaced, which is a
time-consuming and very costly process. Furthermore, mechanical
keys and locks are devices that cannot be partially limited in
operation they operate indefinitely if in use. Also, they do not
have the ability to record access operation attempts of their
operation.
SUMMARY OF THE INVENTION
[0007] In view of the foregoing, the present invention provides a
vending machine with a field-programmable electronic lock. The
electronic lock can learn a key code from a corresponding
electronic key. Alternatively, the electronic lock can learn that
it should be accessed by an electronic switch controlled by a
mechanical lock that can be opened with an associated mechanical
key. The electronic lock has a learning process activation device
that is accessible only when the door of the vending machine is in
the open position. Using the learning process activation device, a
service person sets the electronic lock in a learning mode, in
which the electronic lock receives a key code transmitted from an
electronic key, and stores the key code in a non-volatile memory
for future access control of the vending machine. In the case where
the lock access is to be controlled by the switch-lock combination,
during the learning process the electronic lock controller receives
an electronic closure signal from the switch. The lock thus learns
that it is to open the door of the vending machine in response of
the switch signal in lieu of reception of key codes from electronic
keys.
[0008] The key-learning process in accordance with the invention
allows electronic locks in vending machines to be easily and
inexpensively programmed in the field. Thus, the electronic locks
do not have to be manufactured with pre-defined permanent key codes
and are not tied to any specific electronic keys for field use.
There is no need to replace any physical part of the electronic
lock in this key-learning process to learn a new key code and/or
replacing an old key code. In contrast, mechanical locks
conventionally used on vending machines have lock cores that have
to be manufactured for specific keys, and once manufactured the
lock cores cannot be changed. If the mechanical key is lost, the
entire lock cores have to be replaced. More than one electronic key
can possess a given keycode. The electronic lock on a vending
machine can allow more than one keycode to be learned into the lock
and used to access the lock.
[0009] The use of the field-programmable electronic locks for
vending machines provides an effective way to reduce theft and
fraud in terms of unauthorized access to the machines. The
electronic keys provide a greater level of key security compared to
mechanical keys, as they cannot be copied as easily as conventional
mechanical keys. The use of non-contact wireless data communication
between the key and the lock prevents breeches of security
associated with vandals measuring key cuts, copying keys and
picking locks. The use of data encryption in the wireless
communications between the key and the lock prevents the key code
from being copied by electronic monitoring and eavesdropping. The
data transmission between the key and lock may be implemented in
the infrared range to provide close-proximity highly directional
communication of secure codes to further prevent eavesdropping of
the security codes and to prevent accidental unlocking of
locks.
[0010] The use of programmable electronic locks on vending machines
and the associated electronic keys also provides advantages in
terms of significant reduction in the costs associated with
managing the distribution of the keys for unlocking the machines
and the monitoring of the usage of the keys. Key IDs in addition to
the key codes used in accessing the lock may be used to distinguish
keys having the same key codes. Customized access limitations may
be programmed by a supervisor into the electronic keys to restrict
when and how they can be used to access the vending machines. Each
key may also be programmed with a specific list of lock IDs
identifying the electronic locks on vending machines that the key
is allowed to unlock.
[0011] In accordance with one aspect of the invention, a history of
access attempts may be stored in each of the electronic key and the
electronic lock for audit purposes. The key may store the access
history each time it is used to access an electronic lock on a
vending machine. Likewise, each electronic lock on a vending
machine may store audit data regarding the access attempts directed
to it. The audit data may be transferred from the electronic lock
to the electronic key during an unlocking operation, and the audit
data of different vending machines collected by an electronic key
can be later downloaded to a computer for analysis.
[0012] In accordance with another aspect of the invention, the
electronic lock may accept more than one type of keys and
corresponding key codes. The different key types may be associated
with different levels of security of the unlocking operations and
the type of data transmitted between the key and lock during the
unlocking operations.
[0013] In accordance with another aspect of the invention, the
electronic lock in a vending machine can work in conjunction with
an electronic communication device in the vending machine that is
in wireless communication with a home base to accomplish many of
the same access control, auditing, and additionally some inventory
and money settlement processes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a schematic view of a vending machine and an
electronic key for opening an electronic lock inside the vending
machine;
[0015] FIG. 2 is a perspective view of an electronic lock assembly
mounted on a door of a vending machine;
[0016] FIG. 3 is a block diagram showing electronic circuit
components of an electronic lock used in a vending machine;
[0017] FIG. 4 is a block diagram showing electronic circuit
components of an electronic key;
[0018] FIGS. 5A and 5B are schematic diagrams showing key codes
stored in the memories of an electronic key and an electronic lock,
respectively;
[0019] FIG. 6 is a schematic diagram showing the transmission of
data between an electronic lock on a vending machine and an
electronic key during a simplified unlocking process;
[0020] FIG. 7 is a schematic diagram showing communications between
an electronic lock on a vending machine and an electronic key
during an unlocking process that has higher security than the
process in FIG. 6;
[0021] FIG. 8 is a schematic diagram showing communications between
an electronic lock on a vending machine and an electronic key
during an unlocking process similar to that FIG. 7 but with a step
of checking the lock ID for access control;
[0022] FIG. 9 is a schematic diagram showing a computer used to
program operational limitations into an electronic key;
[0023] FIG. 10 is a schematic diagram showing the downloading of
audit data from vending machines to an electronic key; and
[0024] FIG. 11 is a schematic diagram showing an example of audit
data uploaded from a vending machine to an electronic key.
[0025] FIG. 12 is a flowchart showing the key code learning process
of an embodiment of the electronic lock;
[0026] FIG. 13 is a flowchart showing an operation by an embodiment
of the electronic key to back up the time and date for restoring
the clock of the key in case of a faulty or removed battery;
[0027] FIG. 14 is a flow chart showing an operation by the
electronic key to record the number of power-up of the key to
prevent tampering by battery removal;
[0028] FIG. 15 is a schematic block diagram showing an embodiment
of a vending machine that has a communication device that is
interfaced to the electronic lock and in wireless communications
with a home base for access control and auditing purposes; and
[0029] FIG. 16 is a schematic diagram showing vending machines
accessible by an electronic key that has a narrow wireless signal
transmission pattern to avoid accidental opening of the vending
machines.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0030] Referring now to the drawings, the present invention is
directed to an electronic lock system for use in vending machines
that provides significantly improved security and ease of
management over conventional vending machines equipped with
mechanical locks. The term "vending machine" as used herein means a
device that performs a money transaction, which may involve the
insertion of cash or commercial paper, or the swiping of a credit
and/or debit card, and may (but not required to) dispense an item
or items or provide functions in response to the money transaction.
In this regard, this term is meant to cover broadly machines
commonly used for vending drinks and snacks, ATM stations, change
machines, toll machines, coin-operated laundry machines, video
arcades, etc. FIG. 1 shows, as an example, a vending machine 20
with an embodiment of an electronic lock of the invention mounted
therein. The vending machine 20 has a front panel 22 or door that
can be opened when the electronic lock is unlocked with a properly
programmed electronic key 26. It will be appreciated that the
vending machine and the electronic key are not shown to scale in
FIG. 1, and the view of the electronic key is significantly
enlarged with respect to the vending machine to show its
features.
[0031] The key 26 and the lock preferably communicate with each
other wirelessly, which may be via an infrared or radio frequency
(RF) channel. In a preferred embodiment, the wireless
communications between the key and the lock is via infrared
transmissions. The infrared medium is preferred because it is
directional and short range, and the infrared circuitry in the lock
is not sensitive to the metal cabinet enclosure of the vending
machine. Thus the vending machine will less likely be opened
accidentally if the key is accidentally operated of if the key is
operated to unlock another vending machine nearby. In addition, the
infrared light can travel through the selection buttons on the
vending machine. This allows the infrared transceiver of the
electronic lock to be positioned behind a selection button 30 of
the vending machine, as illustrated in FIG. 1. To that end, the
vending machine 20 has an infrared transceiver disposed to receive
infrared transmission through its front panel 22, and the
electronic key 26 has an infrared transceiver at one end 32. As
shown in FIG. 1, in one implementation, the electronic key 26 has a
very simple profile, having only a "START" button 36 that can be
activated by a user for lock opening and key code learning
operations. In a preferred embodiment, the "START" button 36 need
not be continuously pressed in order for the key to transmit the
encrypted code to the lock. Instead, the user only has to only
momentarily press the button 36, and the key will automatically
stop transmitting after a few seconds, thus the key will not
transmit indefinitely and deplete the battery if the button is
stuck down. The electronic key 26 also has a light-emitting diode
(LED) 38 exposed through a hole in the housing of the key for
indication the operation status of the key.
[0032] In accordance with an aspect of the invention, the
electronic lock assembly is mounted inside the vending machine 20
to prevent unauthorized access and tampering. It can be physically
accessed only when it is properly unlocked and the door 22 or front
panel of the vending machine is opened. In one embodiment, as shown
in FIG. 2, the electronic lock assembly 48 is mounted on the inside
of the door 22, and opening the door of the vending machine exposes
the lock assembly housing 40. The electronic lock 48 includes a
lock shaft 42 that engages into a corresponding receptacle in the
body of the vending machine to prevent the door from being opened
when it is in a locked position. The electronic circuit of the lock
resides in the housing 40 of the lock assembly. The housing 40 has
two holes. Behind one hole 44 is a "LEARN" switch connected to the
electronic lock circuit. This switch can be accessed and pressed
down with a thin object, such as a screwdriver or a car key. Behind
the other hole 46 is a light-emitting diode (LED), which servers as
a means for providing an indication of the operational state of the
electronic lock during a key code learning operation or a lock
opening operation, as will be described in greater detail
below.
[0033] Turning now to FIG. 3, in one embodiment, the circuit of the
electronic lock 48 comprises a microcomputer 50, a non-volatile
memory 52, a half-duplex IRDA infrared communication interface 54
for communicating with an electronic key, a power supply voltage
regulator 56, a lock motor or solenoid control circuit 58, position
feedback switches 60, a learn switch 62 as mentioned above, and the
LED 64 for state indication. The non-volatile memory is for storing
key codes 68, encryption codes 70, and audit data 72, as will be
described in greater detail below.
[0034] In an alternative embodiment, the vending machine with the
electronic lock is to be accessed using a mechanical key rather
than an electronic key. To that end, the electronic lock includes
an interface to a combination (the "switch-lock" combination) of an
electrical switch 74 and a mechanical lock 76 that has a cam for
moving the switch into a closed or open position. The electrical
switch 74 is normally in an open state and is closed when the
mechanical lock 76 is opened using an associated mechanical key 78.
The open/close state of the switch 76 is detected by the
microcomputer 50 and is used to determine whether the mechanical
lock 76 is opened or closed. T The microcomputer 50 is programmed
to unlock the door 22 of the vending machine 20 in response to the
closing of the switch contact caused by unlocking of the mechanical
lock 76 using the mechanical key 78. Thus, the unlocking process
does not involve the passing of a key code between the electronic
lock and an electronic key. Accordingly, as described in greater
detail below, during a learning process, the electronic lock learns
that it is to be accessed using a mechanical key instead of an
electronic key with a key code.
[0035] As shown in FIG. 4, in one embodiment, the electronic key 26
includes a microcomputer 80, a non-volatile memory 82, a
half-duplex IRDA infrared communication interface 84 for
communicating with the electronic lock of a vending machine or with
a computer for programming the key, a power source (e.g., a
battery) 86, a real-time clock integrated circuit (IC) 94 for
generating data indicating the date and time, and the "START"
switch 36 and the LED light 38 as mentioned above. The non-volatile
memory 82 is for storing a key code 88, encryption codes 90, and
audit data 92 generated by the key and/or downloaded from vending
machines operated using the key, as will be described below.
[0036] The key codes in the keys and the locks of the vending
machines are used to define the security and access control
strategy of the electronic lock system. Each electronic key 26 has
a key code 88 stored therein, and the same key code is stored in
the memory 52 of the electronic lock in each vending machine to be
operated with the electronic key. During each access attempt, the
key code in the electronic key is transferred from the key to the
electronic lock using a secured communication method. The
electronic lock can be unlocked if the key code it receives from
the electronic key matches the key code stored in the memory of the
lock.
[0037] In one implementation as shown in FIG. 5A, a key code 68
stored in an electronic key includes seven (7) digits. The first
digit of the key code is used to indicate the type of the key. As
the value of the key-type digit may go from 0 to 9, there may be up
to 10 total key types. As will be described below, in one
embodiment of the electronic lock system, there are three different
key-types: low-security key, standard key, and auto-tracking key,
which correspond to different levels of security in lock-opening
operation and audit data collection. The next 6 digits in the key
code are the access code (000,000 to 999,999). In addition to the 7
digits representing the key type and access code, a key code stored
in the electronic key additionally includes two lower digits, which
may be used as the identification (ID) code of that key. In this
example, the key ID may vary from 0 to 99. Thus, there may be up to
100 keys that have the same key type and access code but different
key ID numbers.
[0038] Similarly, as shown in FIG. 5B, a key code 68 stored in the
electronic lock has seven (7) digits. The first digit indicates the
key type, and the remaining 6 digits are the access code. As
mentioned above, there may be up to 10 different key types, and the
electronic lock may be programmed to accept a number of key codes
of different key types.
[0039] In accordance with a feature of the invention, the
electronic lock 48 of the vending machine 20 is field-programmable.
In other words, the key code or key codes of the electronic lock 48
can be programmed (or "learned") into the non-volatile memory 52 of
the lock after the vending machine has been installed in a given
location. In a preferred embodiment, the electronic keys to be used
to operate the vending machines are programmed with a permanent key
code at the factory and ordered by the users of the electronic
locks. In the example given above, the users may order up to 100
keys with the same access code. In contrast, the electronic locks
to be used in the vending machines are not programmed with any
customer-specific key code. Instead, the electronic locks are
programmed with a universal code at the factory. The "universal
code" is the code put in the lock by the manufacturer of the lock
or the vending machine, and is used by the customers to unpack and
open the machines after they receive the machines. Thereafter, the
electronic locks are installed in the vending machines, which are
then shipped to and set up at their respective operating places. In
accordance with the invention, the access control strategy is
established by "learning" or transferring the access code of the
electronic key to be used to operate the machine into the
electronic lock via a secured transfer process.
[0040] Referring back to FIGS. 1-3 and 12, in one embodiment, to
make the electronic lock 48 learn the access code from an
associated electronic key 22 or that it is to be controlled by a
switch-lock, the service person has to gain access to the LEARN
switch 62 of the lock. In addition, it is preferred that the lock
microcomputer senses, using the position switches 60, that the lock
is in the unlocked position to allow entering into the "learn" mode
(step 260 in FIG. 12). To that end, if the door 22 of the vending
machine is originally closed and the lock contains the universal
key code programmed at the factory, the service person uses a key
containing the universal key code to unlock the vending machine and
open the door to gain access to the LEARN button of the lock. As
mentioned above, the LEARN switch 62 should be at a secured
location such that it can be accessed only when the lock is
properly unlocked (as opposed to a forced entry) and when the door
is open. An assumption in the access control strategy is that an
authorized person is servicing and/or reprogramming the lock if the
door is properly unlocked and opened. If the microcomputer 50
detects (step 262) that the LEARN switch 62 is pressed (e.g., held
for longer than three seconds), it waits (step 266) for the switch
to be held in that position for a pre-selected time period (e.g., 3
seconds) and then enters a LEARN process (step 268). In response to
the pressing of the learn button, the LED 64 is turn on (step 270).
In alternative embodiments, the LEARN switch 62 can be substituted
by another activation means that provides a greater level of
security, such as a keypad for entering a service authorization
code or an electromechanical switch lock that requires a mechanical
or another electronic key.
[0041] Once the lock 48 is put in the LEARN mode, the service
person operates the electronic key 22 containing the desired key
code by pressing the button 36 on the key. This causes the key 22
to transmit the key code stored in its memory to the electronic
lock. If the electronic key and the lock employ encryption
techniques in their communications, the electronic key 22 first
encrypts the key code 88 with the encryption codes 90 in its
non-volatile memory and then transmits the encrypted code.
[0042] The service person is given a pre-selected timeout period
(e.g., 15 seconds) to press the key to transmit the key code. To
that end, the lock 48 determines whether it has received the
transmitted key code (step 272). If it determines (step 274) that a
key code transmission is not received within the timeout period,
the learning process is terminated. If a key code has been
transmitted within the timeout period, the electronic lock 48
receives the transmitted key code via its receiver port 30. If the
transmitted code is encrypted, the electronic lock decrypts the
received data with the encryption codes 72 in its memory 52. In a
preferred embodiment, the encryption codes in the electronic key
and the electronic lock are inserted during manufacturing at the
factory, and different encryption codes may be used for different
vending machine owners (e.g., different soft drink bottlers) so the
keys given to one owner may not be learned into and used to access
the vending machines of another owner.
[0043] If the encryption codes of the key and the lock do not
match, the electronic lock will not be able to successfully decrypt
the received key code. In that case, the process will end arid the
lock will not learn the new key code. If, however, the decryption
was successful, the lock stores the key code at a proper location
in its non-volatile memory 52 according to its key type (step 276).
After verifying that the key code is stored correctly in the proper
key type location, the lock 48 provides a signal to the service
person by flashing the LED 64 to indicate that the LEARN process is
successfully completed (step 278). From this point forward, the
electronic lock will use the newly learned key code for access
control. In other words, it will compare this key code with the key
code transmitted from an electronic key to determine whether the
door should be unlocked. If there was a key code of the same key
type previously stored in the memory 52 prior to the LEARN
operation, that old key code will be erased and can no longer be
used to access the vending machine.
[0044] As mentioned above, in an alternative embodiment, the
vending machine equipped with the electronic lock may be accessed
with a mechanical key rather than an electronic key. The electronic
lock learns that it is to be controlled by the combination of the
electrical switch 74 and the mechanical lock in a learning process
similar to the one for learning a key code as described above.
Specifically, to enable the lock access via the switch-lock, the
service person puts the electronic lock into the learn mode by
pressing the LEARN switch 62 as described above. Once the
electronic lock 48 is in the learn mode, the service person uses
the mechanical key 76 to unlock the mechanical lock 76. When the
mechanical lock 76 is moved to its unlocked position, its cam
closes the contact of the electrical switch 74. The microcomputer
50 of the electronic lock receives the contact-closure signal
(i.e., detecting that the electrical switch is closed) and treats
the signal as indication that the vending machine is to be accessed
using a mechanical key. In response, the microcomputer set its
operation mode such that in the future it will unlock the door of
the vending machine in response to detecting the closure of the
contact of the electrical switch 74. Thus, from this point forward,
the vending machine is accessed using the mechanical key 78, which
replaces one or more types of electronic keys.
[0045] It will be appreciated that the key learning process
described above does not require changing or replacing any physical
components of the lock. If the electronic key for operating the
lock on the vending machine is stolen or lost, the service person
will first use a back-up key that has the key code of the key that
is lost, or a key that has a different key code that has been
previously learned into the lock, to open the door. The service
person then uses the key learning process described above to change
the key code in the memory of the lock to a new value. This
field-programmability of the electronic lock makes key management
significantly easier and cost-effective, and provides a greater
level of key security compared to mechanical keys. In contrast,
with conventional vending machines using mechanical locks, the
mechanical keys may be copied or stolen easily, and the entire lock
core of each of the vending machines affected has to be replaced in
order to change to a different key.
[0046] In the illustrated embodiment, one digit in each key code
stored in the lock indicates the type of the key, and there may be
up to ten different key types. A lock is able to learn one key code
for each allowed key type. A key code of a first type may be that
learned from a "primary" electronic key for the vending machine,
while a key code of a second type may correspond to a different
electronic key, such as a "master" key that can be used as a
back-up in case the primary key is lost, stolen, broken, or
otherwise unavailable.
[0047] In a preferred embodiment, as briefly mentioned above,
different types of electronic keys (indicated by the different
values of the key type digit) are provided that correspond to
different levels of security (and the associated complexity of
communication) and audit data collection function. The three types
of electronic keys are economy key, standard key, switch-lock, and
auto-tracking key. The operation of each of these three types of
keys is described below.
[0048] Referring to FIG. 6, the economy key employs a simple
one-way communication process for interacting with a corresponding
electronic lock on a vending machine. Since the communication
process is simpler and the one-way communication does not require a
receiver in the key, the key can be build at a lower cost. As shown
in FIG. 6, the memory 102 of the economy key contains a key code
104, an encryption code 106, and a random number 108. In a
preferred embodiment, the key starts with a given value of the
random number, and the random number changes every time the key
cycles through a key code transmission. When a user activates the
key by pressing the button on the key, the key uses the encryption
code to encrypt (step 110) the key code 104 together with the
random number 108, and transmits the encrypted number 112 to the
electronic lock. When the electronic lock receives the transmitted
encrypted data, it decrypts (step 116) the data with the encryption
code 118 in its memory 52. The lock then retrieves the key code 122
from the decrypted data and compares it with the key code 120 of
the same type in its memory. If the two key codes do not match, the
process ends. If they match, the electronic lock proceeds to unlock
the door of the vending machine.
[0049] In comparison with the economy key, the standard key
provides a more secure unlocking process that requires 2-way
encrypted communications between the key and the electronic lock.
The 2-way communications is in the form of a bi-directional
challenge-response process. Referring to FIG. 7, the memory 130 of
the key contains the key code 132, the encryption code 134, a
real-time clock timestamp 136, and a random number 138. Similarly,
the memory 52 of the electronic lock of the vending machine
contains a learned key code 140, the encryption code 142, and an ID
146 of the electronic lock. When the service person presses the
transmission button on the electronic key, the electronic key
encrypts (step 150) the key code 132 in its memory together with
the time stamp 136 and the random number 138, and transmits the
encrypted key code and timestamp to the electronic lock of the
vending machine. The electronic lock receives the transmitted data
152 through its infrared communication interface and decrypts (step
156) the received data with the encryption code 142 in its memory.
Next, the electronic lock compares (step 162) the decrypted key
code 160 with the key code 140 of the same type in its memory. If
the two key codes don't match, the process ends, and the door will
not be unlocked. In that case, the electronic lock sends a code to
the key to indicate that the key has tried an incorrect key
code.
[0050] If the two key codes match, the process continues and enters
a second phase in which the electronic lock transmits data to the
electronic key. Specifically, the lock encrypts (step 164) the key
code, the lock ID 146, and the random number. It then transmits the
encrypted key code, lock ID, and the random number (originally sent
by the key) to the electronic key. The electronic key receives the
encrypted data 166 and decrypts (step 168) the data to retrieve the
key code and the lock ID. If the key determines (step 172) that the
key code 170 returned by the lock matches the key code 132 in the
memory of the key, it stores data regarding the access event,
including the lock ID, in an audit trail data portion of the key's
memory for audit purposes.
[0051] The key then proceeds to the third phase of the unlocking
process, in which the key communicates to the lock to allow access.
To that end, the key encrypts (step 176) the received lock ID and
transmits the encrypted lock ID and random number to the lock. The
lock receives the transmitted data 180 and decrypts (step 182) the
data to retrieve the lock ID. If the received lock ID 186 matches
the lock ID 146 stored in the memory of the lock, the microcomputer
of the lock proceeds to unlock the door of the vending machine.
[0052] The unlocking operation described above has several
advantages. It allows the transfer of the lock ID and the key codes
between the electronic key and the lock on the vending machine
without repeating numbers or a distinguishable pattern of numbers
in case of eavesdropping of repeated access attempts. It also
prevents a transfer of data between the key and the lock with
different encryption codes. Further, it provides a consistent and
secure means of data transfer between the key and the lock for a
condition where many keys with the same key code will be expected
to communicate with many locks on different vending machines
containing that key code. This bi-directional challenge-response
encryption scheme provides no risk of the keys and the locks going
out of sequence, which is a common problem with unidirectional
rolling-code encryption systems.
[0053] The lock ID code is used in the unlocking operation
described above for generating audit data for audit trail
identification purposes and also for data transfer encryption
purposes. In an alternative embodiment, however, it is also be used
to provide a method for controlling which vending machines a key is
allowed to access. In this method, there may be many keys
containing the same key code, and there may be many vending
machines that have "learned" the same key code. It is possible,
however, to specify which vending machines a given key is allowed
to access so that a single key cannot, open all the vending
machines. Referring to FIG. 8, this is accomplished by loading a
list of lock ID codes 192 into the memory 130 of that key prior to
operation. During an unlocking operation, the key receives a lock
ID 174 from the electronic lock on the vending machine and compares
the received lock ID with the list of lock IDs 192 in its memory.
Only if it is determined (step 198) that the received lock ID 174
matches one of the lock IDs in the list will the key proceed to
send the unlock command signal (e.g., the transmission 180 in the
third phase) to the electronic lock. As shown in FIG. 8, the
unlocking process is otherwise similar to that shown in FIG. 7.
This method of access control provides supervisors of the operation
the flexibility of allowing or disallowing a given key to access
selected vending machines.
[0054] In an alternative embodiment, an electronic key may also be
programmed with other types of limits of operation of the key. For
instance, the key may be programmed with limit registers that
contain values chosen by a supervisor to limit the operation of
that particular key. In a preferred embodiment, the limit registers
200 (FIG. 4) are part of the non-volatile memory 52. The operation
limits include, for example, time of data, date, number of days,
number of accesses, number of accesses per day, etc. When the user
of the key presses the button on the key to initiate a key code
transmission, the microcomputer of the key first compares the
limits set in the registers with a real-time clock in the key and
an access counter in the key memory. If any of the limits is
exceeded, the key will not transmit the key code to the electronic
lock and will terminate the operation.
[0055] Referring to FIG. 9, the key operation limits may be set by
the supervisor 208 of the employee that uses the electronic key 212
to access vending machines in the field. The limits can be selected
by using a personal computer (PC) 210 with the appropriate software
program. The limits for each key may be customized depending on,
for instance, the work schedule or habits of the employee to whom
the key is given. For illustration purposes, FIG. 9 shows an
exemplary user interface screen 216 for prompting the user 208 to
enter the limits. After the limits are selected on the PC 210, they
are loaded from the PC into the operation limit registers in the
electronic key 212 in a communication process between a key
read/write device 218 and the key. During this communication
process, other types of data, such as data for updating the
real-time clock in the key, may also be loaded into the key. Also,
the communication process may be used to transfer data, such as the
audit trail data collected from vending machines by the key during
previous field operations, from the electronic key 212 to the PC
210.
[0056] In accordance with an aspect and alternative embodiment of
the invention, an advantage of electronic keys is that they can be
used to record and collect and track the attempted accesses of
locks on vending machines in the field. Keys that provide this
function are of the "auto-tracking" type mentioned above. Referring
to FIG. 10, with an auto-tracking key 212, each access attempt
triggers an audit data event in both the electronic key and the
electronic lock in the vending machine 20. To that end, a space for
audit data is reserved in each of the non-volatile memories of the
key 212 and the lock 48. During an access attempt, the key 212
transfers the key code 220 and a timestamp 222 to the lock.
Regardless of whether the access attempt succeeds or fails, the
lock stores the key code and timestamp in its audit data memory. In
one implementation, the lock will filter the number of accesses
from a given key in a given period (e.g., one attempt per key for
every 20 minutes) so that it does not create a separate record for
each access attempt. It may, however, include data in the record
counting the number of access attempts from the key in the time
period. This minimizes the chances that when a key is used to make
many access attempts in a row it will fill the audit trail memory
and erase existing records of previous access attempts. One way to
set this time period in the lock is to transfer the value of the
period from a key (which is in turn set by a supervisor using a PC)
to the lock.
[0057] If the access attempt results in a key code mismatch or if
the key is disallowed for access because an operation limit in its
limit registers is reached, the access process is terminates. In
either case, the lock transfers its lock ID 228 to the key 212. The
key is expected to store the lock ID and the timestamp in its audit
data memory as an invalid access attempt.
[0058] If, on the other hand, the access attempt results in a valid
match of key code and the key has not exceeded its operation
limits, the lock still transfers its lock ID to the key 212. The
key 212 then stores the lock ID and timestamp in the audit data
memory as a record of a proper access. In addition, as the
electronic key is an auto-tracking key, the lock transfers all the
audit data 228 entries in its audit data memory to the key. The
data in the audit data memory includes the lock ID, a record for
each access attempt that includes the entire key code (including
the key ID digits) received from the key that made the access
attempt, and the timestamp for that access attempt. The
auto-tracking key 212 then stores the audit data 228 of the lock in
its own non-volatile memory. In this regard, each key preferably is
capable of uploading the audit data memories of 200-300 vending
machines. This eliminates the need for a separate process or
equipment in the field for performing the same data retrieving
function.
[0059] When the electronic keys 212 are returned to the home base,
the audit data they generated themselves and the audit data they
collected from the vending machines 20 can be transferred to a
central control computer 210. The audit data can be downloaded to
the PC 210 by the supervisor using the key read/write device 218
that is also used for programming the electronic key.
[0060] By way of example, FIG. 11 shows exemplary audit data
collected by an auto-tracking key from a vending machine. In this
example, the key code stored in the lock on the vending machine is
"A100". The vending machine was accessed using the auto-tracking
key on Dec. 8, 2001. Since the key contains the correct key code,
the access operation is successful. Thereafter, there were two
unauthorized access attempts. The first unauthorized access attempt
on Dec. 19, 2001 failed, because the key code ("A500") in the
electronic key did not match the key code in the lock. The second
unauthorized attempt on December 20 used a stolen key with the
right key code and was successful. When the auto-tracking key is
used on Dec. 22, 2001 to unlock the vending machine, the audit data
232 stored in the memory of the electronic lock on that vending
machine are transferred to the auto-tracking key, which stores the
transferred audit data in its own memory. As stored in the key, the
audit data 236 identifies the vending machine from which the audit
data are uploaded. The audit data 236 stored in the key are later
downloading to the home base PC.
[0061] Due to the various complexities of this system concerning
multiple key users, key codes, and the multiple keys sharing the
same key codes, as well as the flexibility provided by the ease of
changing access codes of the vending machines in the field, it is
often desirable to provide simple diagnostic capabilities to the
keys, electronic locks. It may also be desirable to provide special
reader tools for use in the field.
[0062] In one implementation, the electronic key uses its LED light
to provides several diagnostic signals to the user when its START
button is pressed and when it is communicating with the electronic
lock. If the key correctly communicates with the lock and the key
codes match, the LED light is on continuously for about five
seconds. If the key correctly communicates with the lock but the
key codes do not match, the LED light flashes around five times a
second for about five seconds. If the key cannot establish correct
communication with the lock, the LED light is set to flash faster,
such as 25 times a second, for about five seconds. If the key
correctly communicates with the lock and the key codes match, but
the operation limits set in the limit registers are exceeded, the
LED flashes at a lower frequency, such as three times per second
for about 3 seconds. If the START switch of the key is pressed and
the key does not communicate with the lock and its operation limits
are exceeded, the LED first flash quickly, such as 25 times per
second, for up to 5 seconds, and then flash three time per second
for up to three seconds.
[0063] In a preferred embodiment, a diagnostic tool 240 is used in
the field to communicate with electronic locks on vending machines,
which provide diagnostic information in the event of problems with
the operation of the lock or the door. As shown in FIG. 10, the
diagnostic tool 240 includes a display 242 that displays
information read from the electronic lock. For instance, the
display may show each of the access control key codes stored in the
non-volatile memory of the lock, the lock ID of that lock, and any
other information pertaining to the state of the electronic lock,
such as an indication of whether the lock expects the door to be in
a locked or unlocked state based on a position-control feedback
measured by the lock circuit.
[0064] In a preferred embodiment, security measures are implemented
in the electronic key concerning key tampering by replacing the
battery in the key. It is possible that the employees or thieves
that gain access to the electronic keys will attempt to trick the
security of the system by tampering with the key. Since the key
contains the clock that provides the time and date of access
limiting, it is likely the users will attempt to disable or trick
the clock to override the access limits. For example, if the key
operation limits are set to only allow accesses between 7 AM and 6
PM, the user may attempt to disconnect the battery of the key
in-between lock accesses to stop the clock in the key from counting
down the time and disabling the key.
[0065] Referring to FIG. 13, to reduce of risk of clock tampering
by removing the battery, the key is programmed such that it will
reset its clock back to approximately the correct time and date
after the battery is reconnected. This feature is provided for both
cases of the battery going low naturally or if it is tampered with
by the user. To that end, each time the START button 36 of the key
is pressed (step 290), the microcomputer 80 of the key reads the
time and date from the clock 94 (step 292), and stores the time and
date data 298 in the non-volatile memory 82 of the key (step 296).
Alternatively, the key may store the time and date periodically,
such as every 1-2 minutes. Referring now to FIG. 14, if the key
battery is disconnected and later a battery is inserted into the
key, the key starts a power-up process (step 300). The
microprocessor is programmed to read the back-up time and date 298
stored in the non-volatile memory 82 (step 302) and writes that
time and date into the clock 94 (step 306). The clock will then run
based on the restored time and date as a substitute until the
electronic key is re-docked into the cradle and the home base
computer 210 stores a new accurate time and date in the clock of
the key. When the restored time and date is in use, the key can
still be used to access locks on the vending machines as long as
the operation limits of the key are not exceeded.
[0066] In addition to the time-restoration feature, the
microcomputer 80 in the key employs logic that counts the number of
times the battery is removed and will immediately disable the key
indefinitely if the battery is disconnected and re-connected more
than a pre-selected number of times, such as three times.
Specifically, the microprocessor maintains in the non-volatile
memory 82 a counter 312 that counts the number of times the key has
been powered up since the last docking of the key. This counter 312
is cleared each time the key is docked. Each time a battery is
inserted in the key and the microcomputer 80 goes through the
power-up process (step 306), the microcomputer 80 reads the counter
302 (step 316). If the microcomputer determines (step 318) that the
counter reading has reached the allowed number of power-up, such as
3 times, it disables the key from any access operation. If the
allowed number of power-up is not reached, the microcomputer
increments the counter (step 320). Thereafter, the key continues
with regular key operation, but with each access attempt the key
will store a "battery removed" bit with the audit data for that
access event in the memories of the lock and the key. This "battery
removed" bit indicates that the time and date stamp of the access
event is recorded after the key battery was disconnected, and that
the accuracy of the time and date is questionable.
[0067] Referring to FIG. 15, in accordance with a feature of an
alternative embodiment, the vending machine 20 is equipped with an
electronic device for communicating with the home base. The
communication device 360 preferably communicates wirelessly, such
as over a RF channel, to the computer 210 at the home base of the
owner of the vending machine. The vending machine also includes a
vendor controller electronic circuit 362 for controlling the
operation of the lock 48. The vendor controller 362 is connected to
the lock 48 and the communication device 360. The electronic lock
48 working together with the vendor controller 362 and the
communication electronic device 360 in communication with the home
base can accomplish many of the same access control and auditing
functions described above and additionally some inventory and money
settlement processes. For example, the communication device 360 can
receive a command from the home base to disable operation of the
lock 360 regardless if an electronic key with the correct key code
attempts to access the vending machine. Also for example, the lock
48 can indicate to home base computer 210 through the communication
device 360 which keys have attempted to access of the vending
machine. This arrangement eliminates the need to use an electronic
key to collect, store, and transfer the audit events to the home
base via the memory and communication medium of the key.
[0068] Moreover, the communication device 360 may be used with the
vendor control 362 to keep track of the inventory and the cash
transactions of the machine. In many cases, when the service person
(route driver) visits the machine, his job is to fill the machine
and collect money. During this task, the vendor control 362 is
involved in interfacing with the service person to ensure the
proper resetting and settlement processes take place, and that the
service person closes the door of the vending machine. The vendor
controller 362 can inform the home base computer of the open/close
state of the vending machine door. In the case the Route Driver
does not satisfy the conditions of the vendor controller 362 by way
of inventory or monetary or debit card processing, the vendor
controller can send a disable signal to the electronic lock 48 so
the door of the vending machine cannot be closed and locked. Thus,
since the service person cannot leave a vendor unlocked, this
process would force him to complete the required resetting and
settlement processes so the vendor controller can allow the vendor
door to be locked before the service person leaves the vending
machine.
[0069] Referring now to FIG. 16, in accordance with a feature of a
preferred embodiment, the wireless transceiver of the electronic
key 26 is designed to have limited transmission range and angle to
prevent a vending machine 380 from being accidentally opened due to
receiving stray transmission from the key when the key is used to
open another vending machine 20 in its vicinity. Specifically, the
transmitter 382 of the key 20 has a pre-defined transmission angle
386. Also, due to the limited transmission power of the transmitter
382, the transmission from the key 26 has a limited transmission
power range 388, beyond which the signal strength is generally too
weak for the transceiver 390 of the electronic lock of the vending
machine 20 to reliably detect. In a preferred implementation, the
transmission power and the transmission angle 386 of the key 26 is
selected such that the width 392 of the transmission pattern at the
effective transmission range 388 is about the same or smaller than
the width of the vending machine 20. As mentioned above, in a
preferred implementation, the transceivers in the keys and the
electronic locks on vending machines are infrared transmitters for
transmitting and receiving infrared signals.
[0070] In view of the many possible embodiments to which the
principles of this invention may be applied, it should be
recognized that the embodiments described herein with respect to
the drawing figures are meant to be illustrative only and should
not be taken as limiting the scope of the invention. Therefore, the
invention as described herein contemplates all such embodiments as
may come within the scope of the following claims and equivalents
thereof.
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