Note: Descriptions are shown in the official language in which they were submitted.
CA 02504487 1996-02-26
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Description
Intelligent Lock System
Technical P'ield
The present invention relates to locking systems
generally and, more particularly, to a novel intelligent
lock system which is particularly useful for locks oa coin
operated telephones and locks oa cargo containers.
Background Art
While the present invention is described with
reference to locks on coin operated telephones or cargo
containers, for illustrative purposes, it will be understood
that it may be applied as well in any application in Which
it is desirable to be able to unlock a number of locks with
a single unlocking mechanism.
The coin boxes in cozn operated telephones must be
removed periodically to remove the coins. Conventionally, '
this is done by giving a coin collector a large shackle of
keys which holds a unique key for each telephone which is to
be opened to remove the coin boxes therein on a particular
day. As prior steps, the telephone boxes to be accessed
must be identified, the appropriate keys pulled, and a route
form prepared. The coin collector goes to each telephone,
selects the proper key, uses the key to operate a lock
release mechanism, uses another key to open the coin box
access door on the telephone, removes the coin box, checks
the coin box number against the one printed oa the route
form, and inserts an empty coin box. The empty receptacle
number is recorded on the route sheet and the receptacle
stub along with the time, date, and collector number. This
system is cumbersome and time consuming, since the coin
' collector must take time to select the correct key for each
telephone and make proper notations to assure that a coin
CA 02504487 1996-02-26
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box is identified to a particular telephone. The latter
step introduces opportunity for error.
It has been proposed to employ an 'intelligent key"
for use in unlocking coin operated telephones. The key
would be programmed, by a main computer, to unlock, say, 100
telephones on a given day. The coin collector would use a
bar code reading wand attached to the intelligent key to
read a bar code attached to an outside surface of the
telephone to obtain the identification of the telephone.
The smart key would look up the identification in its
programmable memory to verify that the telephone is one that
can be unlocked on that day. The intelligent key is then
inserted in the lock and the lock mechanism released by
means of data transfer between the two. Bar codes on the
full and empty coin boxes are scanned and this data is
inputted to a memory in the intelligent key. While this
system is an improvement over the conventional method of
accessing coin boxes, it has the substantial disadvantage of
having to read external indicia for verification of the
telephone. Such external indicia are subject to damage or
removal which represents a substantial maintenance cost and
which requires manual input of the information to the key.
A further disadvantage of conventional locks is that
the slots in which keys are inserted can easily accumulate
dirt, gum, ete., which foreign matter is .difficult to
remove.
Another disadvantage of conventional electronic locks
is that, whey an unauthorized user tries to unlock the lock
by force, the mechanism preventing opening is frequently
broken which, of course, requires repair before the lock can
be used normally. If not properly constructed, the breaking.
of the mechanism can even open the lock.
A disadvantage of conventional locks used with cables,
such as on cargo containers, is that the cable may be
deliberately severed, the contents of the containers
accessed, and then the cable repaired without any evidence
CA 02504487 1996-02-26
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of the same when the container is delivered to its
destination.
An additional disadvantage of conventional electronic
locks is that the key is often charged With static
electricity which interferes with the communication between
the lock and the key.
Accordingly, it is a principal object of the present
invention to provide a system for unlocking a coin operated
telephone which does not rely on reading external indicia
to
lp identify the telephone.
It is a further object of the invention to provide
such a system is which the lock mechanism itself identifies
the telephone.
It is another object of the invention to provide such
a system which permits a single programmable unlocking
mechanism to selectively unlock a large number of locks.
It is an additional object of the invention to provide
such a system that is conveniently and easily employed.
If is yet s further object of the invention to provide
such a system in which openings in which key means are
inserted are relatively immune to accumulating foreign
matter and are easily cleaned thereof.
It is yet another object of the invention to provide
such a system in which nothing in the lock mechanism can be
broken by an unauthorized attempt to forcibly unlock the
lock.
It is yet an additional object of the invention to
provide such a system in which the key is automatically
grounded before electrical communication between the key and
3Q the lock is established.
Another object of the invention is to provide an
indication that a cable secured by an electronic lock has
been broken and repaired.
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Other objects of the present invention, as well as
particular features, elements, and advantages thereof, will
be elucidated in, or be apparent from, the following
description and the accompanying drawing figures.
Disclosure of Invention
The present invention achieves the above objects,
among others, by providing, in a preferred embodiment, a
lock system including a lock and a key, comprising: a lock
IO housing; a rotatable member disposed in said housing,
rotation of which rotatable member selectively effects
locking and unlocking of said lock; blocking means
operatively connected to said rotatable member to prevent
unlocking of said lock except-upon receipt of as electrical
unlocking signal; key means having an end insertable in said
housing and into an end of said,rotatable member for
rotation of said rotatable member; and means to permit a
portion of said rotatable member to rotate without damage to
any_elements of said lock if rotation of said rotatable '
meter is attempted without receipt of said electrical
unlocking signal.
Brief Decsription of Drawings
Understanding of the present invention and the various
aspects thereof will be facilitated by reference to the
accompanying drawing figures, submitted for purposes of
illustration only and not intended to define the scope of
the invention, in which:
Figure 1 is a perspective view of a conventional coin
operated telephone.
Figure 2 is an exploded perspective view of one
embodiment of the present invention.
Figure 3 is an exploded perspective view of another
embodiment of the present invention.
Figures 4A and 48 illustrate details of the embodiment
of Figure 3.
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Figure 5 is a block/schematic diagram of the
embodiment of Figure 2.
Figure 6 is a timing/logic diagram illustrating the
operation of the present invention.
Figure 7 is a perspective view of the hardware
components of the embodiment of Figure 2.
Figure 8 is a front elevational view, partially cut
away, of an alternative lock mechanism embodiment according
to the present inventioa.
Figure 9 is a cross-sectional view taken along lice "9-
9" of Figure 8. '
Figure 10 is a front elevational view of the
embodiment of Figure 8.
Figure 11 is a side elevational view of a wrench for
use With the lock mechanism of Figures 8-10.
Figure 12 is a top plan view, partially in cross-
section, of the wrench of Figure il.
Figure 13 is a schematic diagram illustrating the
electrical/electronie circuitry of the lock mechanism of
Figures 8-10.
Figure 14 is an exploded perspective view showing the
major elements of another intelligent lock/key system
according to another aspect of the invention.
Figure 15 is an exploded perspective view showing the
operation of the embodiment of Figure 14.
Figures 16 and 17 are exploded perspective views
showing construction details of the embodiment of Figure 14.
Figure 18 is as exploded perspective view of the
barrel assembly of Figure 14.
Figure 19 is a perspective view showing the barrel of
the lock of Figure 14 in normal position.
' Figure 20 is a perspective view showing the barrel of
the lock of Figure 15 when unauthorized, forced entry is
attempted.
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Figure 21 is a perspective view of an alternative
embodiment of the lock of Figure 14 useful for locking cargo
containers.
Best Mode for CarryinQ Out the Invention
Reference should now be made to the drawing figures,
on which similar or identical elements are given consistent
identifying numerals throughout the various figures thereof,
and on which reference numerals in parentheses direct the
reader to the figures) on which the elements) being
described are best seen, although the elements) may be sees
on other figures) also.
Figure 1 illustrates a conventional coin operated
telephone, gener~llly indicated by the reference numeral 10.
Since telephone 10 is conventional, only those elements
thereof with which the present invention is concerned will
be described. It will be understood that the base of
telephone 10 includes a coin box (not shows) into which fall
coins inserted into the telephone to permit operation
thereof. Telephone 10 includes a lock mechanism, generally
indicated by the reference numeral 12, which has a tumbler
slot 14 into which a wrench (not shown) can be inserted to
permit a elide bolt 16 to be withdrawn into the housing 18
of the mechanism. Once slide bolt 16 is so withdrawn, an
internal mechanism. (not_showa) permits access door 24 to be
...,. ._
opened by insertion of a key (not shown) into key slot 26.
This operation gives access to the coin box as is more fully
described above.
Figure 2 illustrates one embodiment of a lock
mechanism according to the present invention, generally
indicated by the reference numeral 30. Lock mechanism 30
includes a housing 32 in Which is disposed for sliding back
and forth movement a slide bolt 34. A support pin 36
having a threaded distal portion 38 and an intermediate
unthreaded portion 40 is inserted through an opening 42
defined in the rear wall of housing 32, with the unthreaded
portion engaging the wall of the opening. Disposed on
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unthreaded portion 40 are a cam 46 and a printed circuit
board 48. The threaded end of support pin 36 engages a
barrel 50 so that, unless otherwise impeded, the support pin
and the barrel will rotate together. A shear pin 54 fixed
to cam 46 extends through as opening 56 defined in printed
circuit board 48 and into barrel 50 so that those elements
will rotate with the barrel and support pin 36.
Barrel 50 extends through an opening 62 defined in a
anti-removal retainer 64 which is fixedly attached to the
face of side panel 60 of a telephone (not shown) and through
an opening 58 defined in the side panel. A cover plate 63
is fixedly attached over anti-removal retainer 64 so, with
the elements of lock mechanism assembled as described above,
those elements cannot be extracted from the telephone
without disassembly of the telephone. '
The rotatable elements, elements 50, 48, 46, and 35,
of lock mechanism 30 are prevented from rotatioa is the
direction indicated by the arrow shown on Figure 2 by means
of a latch pin 68 fixedly attached to cam 46 which latch pin
engages the bottom of a latch bar 70 rotatably attached to
side panel 60 by means of a shaft 72. Latch bar 70 is held
in the position shown by means of a return spring 74
attached to side panel 60. Also attached to side panel 60
is a solenoid 76 operatively connected to the upper end of
.,_. . . ..
latch bar 70 to withdraw the latch bar from engagement with
..
latch pin 68 and permit the above-noted rotatable elements
of lock mechanism 30 to rotate.
The means by which lock mechanism 30 is unlocked
includes a wrench, generally indicated by the reference
n~eral 80. Wrench 80 includes a housing 82 with a data
probe 84 and a pin 86 extending therefrom. Data probe 84
and pin 86 are insertable into lock mechanism 30 through
channels 88 and 90, respectively, defined in barrel 50.
Data probe 84 extends through barrel 50 and contacts printed
circuit board 48, while pin 86 terminates in the barrel.
Probe 84 is of the spring loaded type. Wrench 80 is
connected to a computer (described below) by means of a
cable 92.
CA 02504487 1996-02-26
In operation, wrench 80 is inserted in lock mechanism
30 so that prvba 84 contacts printed circuit board 48. When
appropriate signals have been exchanged over cable 92,
solenoid ?6 is activated causing the disengagement of latch
bar ?0 from latch pin 68 and the wrench can then be rotated
clockwise as indicated by the arrow. Such rotational
movement causes sliding engagement of a cam surface 94 with
a shoulder 96 formed on slide bolt 34 causing the slide bolt
to withdraw its distal end into housing 32, thus releasing
an internal mechanism (not shown) in the telephone as
described above with reference to a conventional telephone
lock mechanism. Data probe 84 includes an annular channel
98 which engages the edge of a cut-out 100 in opening 62 to
-, prevent removal of wrench 80 when lock mechanism 30 is in
its unlocked state.
Figure 3 illustrates another embodiment of a lock
mechanism, generally indicated by the reference numeral
30'. Elements of lock mechanism identical, or nearly so, to
those of lock mechanism 30 of Figure 2 are given primed
reference numerals. Lock mechanism 30' includes a support
pin journaled for rotating motion in opening 42' and having
a smooth shaft portion 110 on which is mounted cam 46'.
Lock mechanism 30' further includes a barrel 112 fixedly
attached to side panel 60' and having an axial channel 114
2S defined centrally therethrough. An anti-removal retainer
.. _
116 having a slotted opening 118 defined therethrough and
aligned with channel 114 is fixedly attached to side panel
60'. Cam 46' has holes 124 and 126 defined therethrough for
fasteners (not shown) which pass through holes 128 and 130
defined through printed circuit board 48' and into a
rotation ring 139 to fasten those three elements together so
that they are rotatable as a unit. Rotation ring 139 has a
channel 136 defined therethrough axially aligned with
channel 114 and opening 118. Extending radially into
channel 136 is a shear pin 138.
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Unlocking of lock mechanism 30' effects the same
result as the unlocking of lock mechanism 30 (Figure 2);
however, lock mechanism 30' employs a different wrench,
generally indicated by the reference numeral 444. Wrench
444 includes a housing 446 and a probe, generally indicated
by the reference numeral 448. With reference also now to
Figures 4A and 48, probe 448 includes a shaft portion 450
and a distal tip portion 452, between which is an annular
channe1.454. Distal tip portion 452 includes two flats 456
spaced apart by 180 degrees on opposite sides of the tip
portion and two channels 458 and 460 spaced apart by 180
degrees on opposite sides of the tip portion intermediate
., the flats. A spring loaded probe tip 464 extends from tip
portion 452.
The elements of lock mechanism 30' are configured so
that distal tip portion 452 may pass through channel 114.
Flats 456 permit passage of tip portion 452 through slotted
opening 118 in one orientation, but not if wrench 444 is
rotated from that orientation. Tip portion 452 may be
inserted in channel 136 and, when the orientation of the tip
portion to rotation ring 139 is as shown on Figure 3, shear
pin 138 will be captured in one of channels 458 and 460.
When wrench 444 is so inserted in lock mechanism 30', probe
tip 464 will contact printed circuit board 48'.
With wrench 444 so inserted in lock mechanism 30' and
the appropriate signals having been exchanged over cable
92', solenoid 76' will be activated, withdrawing latch bar
from engagement with latch pin 68' and cam 46' may be
rotated clockwise as indicated by the arrow, by virtue of
the engagement of shear pin 138 with one of channels 458 and
460 (Figures 4A and 4B).
Lock mechanisms 30 and 30' cannot be unlocked by brute
force with a tool fabricated for that purpose, since shear
pins 54 and 138, respectively, will be severed by rotation
of the tool, absent activation of solenoids 76 and 76' Which
breaks mechanical communication between a tool inserted in
the lock mechanisms and cams 46 and 46'. Shear pins 54 and
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138 are selected of such diameter and material that they can
be forcibly severed much more easily than latch pins 68 and
68', respectively. Were the situation reversed, the latch
pins would be severed, the cams would be rotatable, and the
respective lock mechanisms 30 and 30' could be unlocked by
brute force.
Reference now to Figures 5 and 6 together will aid in
understanding the operation of the present invention.
While the reference numerals on Figure 5 are given for
the embodiment shown oa Figure 2, it will be understood that
the schematic applies as well to the embodiment on Figure
3. On Figure 5, a computes 150 includes a microprocessor
152 which receives operating power from a voltage regulator
144 which is connected to internal battery 148 when computer
150 is configured as a portable unit. The power source,
here, battery 148, is also connected to a communication line
154 in cable 92 through a resistor 156. Microprocessor 152
provides outputs to a maximum power switching transistor 160
and~to s data transmitting switching transistor 162.
Microprocessor 152 has SENSE and RECEIVE DATA inputs.
Communication line 154 is connected through probe 84
to a microcontroller 170 in lock mechanism 30, the
microcontroller receiving operating power from a voltage
regulator 172 which is connected to the communication line
154 through an isolation diode 174. A capacitor 1?6
connected between voltage regulator 172 and diode 174 is
connected to ground. Microcontroller 170 provides outputs
to a data transmitting switching transistor 180 and to a
power switching transistor 184 connected between solenoid 76
and ground. Microcontroller 170 has a RECEIVE DATA input
connection to communication line 154.
Figure 6 is a timing/logic diagram for the circuitry
shaven on Figure 5. A complete unlock/lock sequence is
divided into seven segments, A-G. Segment A is wrench
insertion, going from an out position to an in position.
During that time, communication line 154 (Figure 5) and
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resistor 156 are at full battery voltage V1. At the point
that probe tip 464 (Figure 4B) makes contact with printed
circuit board 48', the voltage on communication line 154
drops to a value determined by a voltage divider network
comprising resistors 156 and 178, here, voltage V3. A
comparator (not shown) at SENSS input to microprocessor 152
receives voltage V3 and, since V3 is between voltage limits
V2 and V4, the output of the comparatar goes positive
providing a presence sense signal in the microprocessor.
The presence sense signal stays at that condition until
removal of the wrench. The comparator window is provided so
that, if there is a short circuit oa insertion of the
wrench, the sequence will be not be started.
Once the presence sense signal is established,
microprocessor 152 starts charging, segment C, by turning on
transistor 160 which shorts resistor 156 and charges
capacitor 176 through diode 1?4. Voltage regulator 172
starts to provide operating power for microcontroller 170.
Capacitor 176 maintains a charge on voltage regulator 172
during the communication cycle and diode 174 isolates the
voltage on capacitor 176 from being discharged. At the end
of segment C, transistor 160 is turned off.
Segment D is the communication segment in which
transistors 162 and 180 are alternately turned on depending
on whether microprocessor 152 or microcontroller 170,
respectively is transmitting during bidirectional
communications. Turning on either transistor 162 or 180
pulls down resistor 156 which becomes a pull up resistor.
Microprocessor 152 first sends microcontroller 1?0 as
interrogation signal. Microcontroller 170 answers with the
serial number of lock mechanism 30. If the serial number
corresponds with one stored in microprocessor 152, that is,
it identifies a lock that is to be unlocked at this time,
microprocessor 152 transmits a password to microcontroller
170 and then turns on transistor 160 to provide power for
solenoid 76. When microcontroller 170 verifies the
password, it turns on transistor 184, activating solenoid 76
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and releasing latch bar 70 from cam 46. Cam 46 can then be
rotated, forcing slide bolt 34 (Figure 2) into housing 32. w
Rotation of wrench 80 during segment E leads to unlock
segment F during which transistor 184 is turned off. During
g this segment, the presence sense signal is still positive
and microcontroller 170 continues to output as unlocked
signal to microprocessor 152. Wrench 80 cannot be removed
from lock mechanism 30 unless the wrench is rotated back to
the zero.positioa.
In the final, unlock, segment G, wrench 80 is rotated
and removed, while communication line 154 is again pulled up
to battery voltage, V1, and the presence sense signal drops
to zero.
A number of methods may be used to provide th~
password to microcontroller 170 from microprocessor 152.
For further security, microcontroller 170 may be provided
with a~real time clock so that a time encryption method may
be used advantageously. Such a method is described in
copending US Patent Application Serial Number 0?/520,763,
2p filed May 9, 1990, by James 8. Hianco et al, titled "Method
and MeanB to Limit Access to Computer Systems,' now US_,
Patent Number 5,067,155, issued November 19, 199 1.
In the method described therein, an accessing device
encrypts identification information with. real time so that
5 the resulting password can be used only for a limited,
predetermined period of time.
Figure 7 illustrates a hardware embodiment of the
present invention, including wrench 80 attached to computer
150 by cable 92 to form a compact, easily carried-unit.
30 Computer 150 has attached thereto a bar code reading wand
190 which may be used to scan bar codes oa coin boxes and
for other ingut functions. Computer 150 further includes a
data display 192 and a keyboard 194 for manual input of
data. Also included in computer 150 is an LED 198 which
35 provides. a visual indication when solenoid 76 (Figure 5) has
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been energized and wrench 80 can be rotated to unlock lock
mechanism 30.
Prior to the beginning of collection rounds, data ae
to route, serial numbers of telephones to be accessed, and
other information can be downloaded by a main computer to
computer 150. At the same time, battery 148 in computer 150
can be replaced or recharged as necessary.
Figures 8-10 illustrate an alternative preferred
embodiment of a lock mechanism, generally indicated by the
reference numeral 300.
Referring primarily to Figures 8 and'9, lock mechanism
300 is characterized in that it is very simple, having only
three moving parts: a slide bolt 302, a cam 304 fixedly
mounted on a drive shaft 306 by means of a shear pin 308,
and a solenoid plunger 310 on the distal end of which is
fixedly mounted a stop 312. Solenoid plunger 310 moves up
and down within a solenoid body 314 (Figure 8).
The foregoing moving parts are disposed in a housing
320 having extending therefrom mounting flanges 322 and
324. An internal cavity 326 is defined internally of
housing 320, which internal cavity is closed by means of a
cover plate 328 attached to housing 320 by means of screws
330 and 332 (Figure 10). A printed circuit board 340 is
disposed against the inner surface of cover plate 328. A
cylindrical wrench retainer 350 (Figures 9 and 10) is
_ . _
fixedly attached to and extends orthogonally outwardly from
cover plate 328 and drive shaft 306 is journaled in, and
extends between, the wrench retainer and the rear wall 352
(Figure 9) of housing 320. A spacer 354 is disposed
parallelly between slide bolt 302 and rear wall 352. Slide
bolt 302 is_disposed for back-and- forth horizontal motioa
within housing 320.
In use, lock mechanism 300 operates in a very similar
manner to the way lock mechanisms 30 and 30' (preceding
figures) operate, except for two very important features.
The first feature is that slide bolt 302 has mounted thereon
a wiper contact 360 which contacts printed circuit board 340
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to permit sensing of the position of the elide bolt. This
is important for it allows sensing that bolt 302 is in the
locked position notifying external electronics of that
fact. The information can be duly noted in the transaction
data that lock mechanism 300 was physically unlocked and
then locked. This is required for audit purposes.
The second feature is that stop 312 engages a contact
on printed circuit board 340 when lock mechanism 300 is is
the locked position (Figures 8 and 9). Thus, it can easily
be sensed that solenoid plunger 310 has returned to the
locked position and is not stuck inside solenoid body 314,
leaving slide bolt 302 in the locked position but without
stop 312 in the locked position such that lock mechanism 300
could be unlocked without the necessary electronic
clearance. If some one should tamper with stop 312 or
plunger 310, that fact would be duly noted when the next
time lock mechanism 300 were used and the data collected.
Another of the important features of lock mechanism
300 is that it is sealed at the point of exposure to the
outside and, therefore, extremely protected against
tampering. As is shown on Figure 9, drive shaft 306 seals
against the inner wall of wrench retainer 350 and an
electrical contact 362 is disposed concentrically within the
wrench retainer external to housing 320.
Referring now to Figures 11 and 12, there ie
illustrated a wrench, generally indicated by the reference
numeral 370, for use with lock mechanism 300 (Figures 8-
10). Wrench 370 includes a generally cylindrical housing
372 having a two-conductor wire extending frora the proximal
end thereof and a drive pin holder 374 extending from the
distal end thereof. Mounted in and extending axially from
drive pin holder 374 are two drive pine 376 and 378 which
are insertable in drive sockets 380 and 382 (Figures 9 and
10) defined in the end of drive shaft 306.
Drive pin holder 374 has two, opposed tabs 386 and 388
in which drive pins 376 and 378 are mounted, respectively,
extending outwardly from the central portion of the drive
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pin holder so as to form a bar shape interrupted by the _
central portion of drive pin holder. A spring-loaded
contact pin 392 is disposed axially centrally of wrench 370
and is connected to the positive of the two conductors of
wire 374. The ground conductor of wire 374 is connected to
at least one of drive pins 37b and 378.
So configured, drive pin holder 374 is insertable into
wrench retainer 350 so that tabs 386 and 388 engage a wrench
slot 390 (Figure 10) defined in the wrench retainer, drive
pins 376 and 378 are inserted in drive sockets 380 and 382,
and spring-loaded contact 392 engages contact 362.
Wrench slot 390 (Figure 10) serves as a clean-out slot
and allows chewing gum and the like to be easily removed by
., a simple tool or pick. Spring-loaded contact 392 in wrench
370 is protected against static and damage and forming
housing 372 of plastic further reduces the possibility of
static.
Lock mechanism 300 works in a simple fashion se
follows: When wrench 370 is inserted into wrench retainer
350, drive pins 376 and 378 engage drive sockets 380 and 382
and, among other points of contact, this establishes a
ground for the electronic circuit. Spring-loaded contact
pin 392 in wrench 370 contacts the center contact in lock
mechanism 300 and establishes a path for power and
communications.
As before, with lock mechanisms 30 and 30', when power
and communications are established between wrench 370 and
lock mechanism 300, the decision is made whether access is
permitted or denied. If access is denied, it will be
impossible to rotate wrench 370 in either direction. (See
Figure 8). Rotation counterclockwise is stopped by cam 304
striking slide bolt 302 at surface 400. Rotation clockwise
causes cam 304 to strike slide bolt 302 at surface 402. Cam
304 then causes slide bolt 302 to slide to the right until
the bolt hits stop 312. Further travel of slide bolt 302 is
prevented by the stop, for it is forced against the wall of
CA 02504487 1996-02-26
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housing 320. Continued pressure clockwise of drive shaft
306 by the wrench will cause shear pin 308 to sever, thus
rendering the drive shaft useless and preventing forced
entry.
If access is permitted, solenoid 314 will cause
solenoid plunger 310 to retract and compress a return spring
318. Stop 312 will thereby be moved out of the way of slide
bolt and clockwise rotation of drive shaft 306 will cause
cam 304 to move slide bolt 302 to the right on Figure 8 into
the retracted or open position. As soon as wiper contact
360 on slide bolt disconnects from a sense point on printed
circuit board 340, the power to solenoid 314 is removed at
that point, greatly reducing the power drain on the
,_ batteries energizing the solenoid. When drive shaft 306 is
turned approximately 45 degrees clockwise, a flange 344
extending from the right side of slide bolt 302 will strike
the right side of housing 320 (Figure 8). At this point,
slide bolt 302 is completely retracted and lock mechanism
300 is open. It should be noted that when the power is
zemoved from solenoid 314, spring 318 cannot return stop
312
to the locked position for it is held in the compressed
positioa by bolt flange 344. Whea wrench 370 is turned
counterclockwise approximately 35 degrees, atop 312 will
slide off elide bolt flange 344 into the locked position,
thus striking the contact sense point on the printed circuit
...
board 340.
Wrench 370 may only be removed from wrench retainer
350 when wrench tabs 386 and 388 are aligned with wrench
slot 390 in the retainer ring. This prevents the accidental
removal of wrench 370 when lock mechanism 300 is in the open
position. Note that slide bolt 302 allows stop 312 to
return to the locked position when drive shaft 306 is only
returned 35 degrees counterclockwise. The remaining 10
degrees is to insure that the lock is closed before the
wrench is removed.
CA 02504487 1996-02-26
_17_
Referring now to Figure 13 there is illustrated the
electrical/electronic circuitry of lock mechanism 300.
Since the basic operation thereof is the same as described
with reference to lock mechanism 30 on Figure 5, the
description of the basic operation will not be repeated
here. The differences are that lock mechanism 300 provides
an input from wiper contact 360 to microcontroller 170' and
stop 312 also provides an input thereto. Wiper contact 360
moves between a position in contact with a sense point 420
an printed circuit board 340 (Figure 9) when lock mechanism
300 is in its closed position and a position out of contact
with the sense point when the lock mechanism is in its open
,_ , position. Stop 312 moves between a position in contact with
a sense point 422 on printed circuit board (Figures 8 and
9), providing an input to microcontroller 170' whey lock
mechanism 300 is locked and a position not in contact with
the sense point when the lock mechanism is unlocked.
Figure 14 illustrates the major elements of another
lock/key system, according to the present invention,
generally indicated by the reference numeral 500. Lock/key
system 500 includes a lock assembly 502 and a key assembly
504, which may communicate electrically as described above
with reference to Figures 5, 6, and 13; although, other
unlocking protocols may be employed as well.
Lock assembly 502 includes a generally cup-shaped
housing 510 in which is disposed for back-and-forth movement
therein a slide plate 512 having a locking tongue 514 formed
at one edge thereof and extending through a wall of the
housing when the device (not shown) of which the lock
assembly is part is in its locked condition. Movement of
slide plate 512 to an unlocked position is prevented by the
engagement of a tab 516, formed at the other end of the
slide plate, with a stop plate 518 disposed at the end of a
plunger 520 of a solenoid 522. Such movement of slide plate
512 is also prevented by the engagement of an inner wall 530
CA 02504487 1996-02-26
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of the slide plate with an end 532 of a cam plate 534
forming part of a barrel assembly, the latter generally
indicated by the reference numeral 540. Housing 510 is
closed by a cover plate 550 having a printed circuit board
552, with electrical components mounted thereon, attached to
the inner surface thereof. Solenoid 522 is mounted to
printed circuit board 552.
Key assembly 504 includes a body portion 560 attached
to a power/communications cable 562 attached to power and
communications circuitry (not shown) and having a shaft 564
fixedly attached to and extending from an edge thereof.
Fixedly disposed at the distal end of shaft 564 is an oblong
. lobe 566 having a communications contact 568 centrally
_ disposed in the distal face thereof. Oblong lobe 566 is
insertable in a complementarily,shaped openinq 580 formed is
a housing member 582, fixedly attached to the outer surface
of cover plate 550, for insertion is a complementarily
shaped opening 584 formed in the end of barrel assembly 540,
with communications contact 568 in engagement with a
co~unications contact 586 disposed centrally at the base of
opening 584.
To unlock lock 502, first, oblong lobe 566 is inserted
into opening 580 of housing member 582 through an opening
590 defined through circuit board 552 and into opening 584
in barrel assembly 540. As lobe 566 is inserted into
,,~ . _ . .. _ .
opening 580, the sides of the lobe closely engage or pass by
the walls of the opening, thus grounding any static
electricity present on the lobe and key 504. With.lobe 566
inserted into opening 584, communications contacts 568 and
586 are engaged and appropriate identification and unlocking
signals are exchanged therebetweea. When ualocking power is
provided, solenoid 522 withdraws its plunger 520 (Figure
14), thus drawing stop plate 518 from engagement with tab
516. Then key 504 can be rotated clockwise, with a shoulder
536 on cam plate 534 engaging a sloped surface 538 on slide
plate 512, forcing the slide plate to the right on Figure 15
CA 02504487 1996-02-26
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and drawing locking tongue 514 into housing 510 to place
lock 502 in the unlocked condition. Locking of lock 502 is
accomplished by completing the above steps in reverse order.
Figure l6 further illustrates the arrangement of slide
plate 512 and housing 510. Slide plate 512 includes a guide
tab 600 which is dimensioned for back and forth movement is
a guide slot 602 defined in a wall of housing 510 as the
slide plate moves between unlocked and locked (Figures 14
and 15) positions. .A slot 604 is defined in another wall of
housing 510 for the movement outward and inward therein of
locking tongue 514. Slide plate 512 further includes a pia
610 extending orthogonally from the inner surface of the
slide plate, the purpose of which pin will ba described
below with reference to Figure 17. A coil spring 612 is
disposed between the outer surface of slide plate 512 aad
the inner surface of the rear wall of housing 510 to help
support and position the slide plate in the housing.
Figure 17 further illustrates the arrangement of
housing 510 and cover plate 550 and shows solenoid 522 and
barrel assembly 540 in place on printed circuit board 552.
The distal end of barrel assembly 540 termint~tes in an inner
shaft 620 which, when lock 502 is assembled, fits into an.
opening 622 defined in the rear wall of housing 510. A wave
washer 624 disposed on inner shaft 620 and against the inner
surface of the rear wall of housing 510 provides positive
force to seat barrel assembly 540.
Figure 17 also shows a slot 630 defined is printed
circuit board 552 having an electrical contact wire 632,
attached to the circuit board, disposed at one end of the
slot. As slide plate 512 moves between locked and unlocked
positions, the distal end of pin 610 (Figure 16) moves back
and forth in slot 630. When slide plate 512 is in the
locked position, pin 610 touches contact wire 632, thus
completing a circuit and giving positive electrical
indication that the lock 502 is in locked positioa. Figure
17 also shows a communication contact wire 640 attached to
CA 02504487 1996-02-26
-20- '
printed circuit board 522 which wire contacts barrel
assembly 540.
Figure 18 illustrates the elements of barrel assembly
540 which include, in order, an outer shaft 650 in the face
of which (Figure 15) is defined opening 584, an insulator
652, a contact plate 654 which is contacted by communication
contact wire 640 (Figure 17) and which is electrically
connected to communications contact 586 (Figure 15), as
insulator 656, inner shaft 620, cam plate 534, and cupped
washers 658 and 660. All of the foregoing elements of
barrel assembly 540, except cam plate 534, and cupped
washers are aligned and are secured against relative
rotational movement by means of pins 670, 672, 674, 676,
678, and 680 disposed as shows. Inner shaft 620 and cam
plate 534 are yieldingly secured against relative axial
movement by means of the compression of cupped washers 658
and 660 between the upper surface of cam plate 534 and a
dowell pin 688 inserted into as opening 690 defined through
inner shaft 620. A detent is formed between inner shaft 620
and cam plate 534 by means of a raised portion 700 on the
cam plate which engages a complementarily shaped channel
702
defined in a horizontal shoulder on the inner shaft.
Figure 19 illustrates barrel assembly 540 is its
normal configuration. The strength of cupped springs 658
and 660 (Figure 18) is sufficient to keep elements 700 and
..,..
702 fully engaged while barrel assembly 540 is rotated to
lock and unlock lock 502. If, however, there ie as attempt
to forcibly unlock lock 502 by rotating barrel assembly 540,
cupped springs 658 and 660 will compress and elements 700
30._ and 702 will disengage and permit the elements of the barrel
assembly to rotate without damage. This is illustrated on
Figure 20. Since the communications contact wire 640 is in
sliding contact with communications contact plate 654, no
electrical connection is broken. When authorized entry is
again attempted, barrel assembly 540 is rotated to its
detented position (Figure 19) and the normal unlocking
CA 02504487 1996-02-26
-21-
procedure followed, without the necessity to repair any
elements.
Figure 21 illustrates an alternative embodiment of
lock/key system 500 shown on Figures 14-20, this embodiment
generally indicated by the reference numeral 500'. Elements
of lock/key system 500' similar in function to those of
lock/key system 500 are given primed reference numerals.
Rather than employing a slide plate for locking purposes,
lock 502' employs a cable 800 which may be used to secure
the door of a cargo container (not shown), for example.
Cable 800 has a fixed end 802 attached to housing 510' and a
free end 804 which may be inserted and releasably secured in
the housing.
Cam plate 534' includes a locking extension 810 at one
end thereof which is insertable in a complementarily
dimensioned slot 812 defined in free end 804 of cable 800.
Cam plate 534' further includes a slot 814 defined in the
opposite end thereof in which slot complementarily
dimensioned stop plate 518' is insertable. Cam plate 534'
is rotatable between an open position, as shown on Figure
21, and a closed position in which locking extension 810 is
inserted in slot 812 and stop plate 518' is inserted in slot
814. The unlocking procedure is similar to that described
with reference to the unlocking of lock/key 500 on Figure
15.
An important feature of lock/key 500' is the provision
of a conductive wire 820 disposed in cable 800 to form a
continuous loop therethrough, with ends of the wire
connected at pads 822 to printed circuit board 552'. Should
cable 800 be severed and then repaired, information as to
the same can be stored on printed circuit board 552' and
noted when the cargo container reaches its destination.
It will thus be seen that the objects set forth above,
among those elucidated in, or made apparent from, the
preceding description, are efficiently attained and, since
certain changes may be made in the above construction
without departing from the scope of the invention, it is
CA 02504487 1996-02-26
-22-
intended that all matter contained in the above description
or showa on the accompanying drawing figures shall be
interpreted as illustrative only and not in a limiting
sense.
It is also to be understood that the following claims
are intended to cover all of the generic and specific
features of the invention herein described and all
statements of the scope of the invention which, as a matter
of language, might be said to fall therebetween.
15
25
35
