U.S. patent number 3,854,120 [Application Number 05/355,583] was granted by the patent office on 1974-12-10 for electromechanical programmable lock.
Invention is credited to Victor G. Matto, Sandor A. Veres.
United States Patent |
3,854,120 |
Matto , et al. |
December 10, 1974 |
ELECTROMECHANICAL PROGRAMMABLE LOCK
Abstract
The programmable lock includes a portion made up of a plurality
of programmable key sections and a lock portion made up of a
plurality of programmable lock sections. Each lock section mates
with and coacts with a corresponding key section. Each key section
carries a plurality of key contacts and a fixed power supply
contact, and the mating lock section includes a lock contact for
each key contact and power contact for the fixed power supply
contact of the key section. A rotatable cylinder surrounds the lock
and includes two ring electrodes, one for contacting a selected
lock contact, and the other shaped to contact all of the other
contacts. The key section includes means for selecting one of the
key contacts which corresponds to the one lock contact selected by
the one ring electrode, and this represents a match for the lock
and key sections. Each of the lock and key sections can be
differently coded, and they can be arranged electrically so that,
when the key(s) properly match the lock(s), a useful output is
obtained, and, if they do not match, an alarm signal may be
obtained. A programmable lock can include any number of sections
made up of the parts described above to provide a unitary lock
having a large number of possible combinations.
Inventors: |
Matto; Victor G. (Kinnelon,
NJ), Veres; Sandor A. (Rutherford, NJ) |
Family
ID: |
23397983 |
Appl.
No.: |
05/355,583 |
Filed: |
April 30, 1973 |
Current U.S.
Class: |
340/5.25;
200/43.05; 340/5.65; 340/5.3; 361/172; 70/278.3; 200/42.02;
340/543 |
Current CPC
Class: |
G07C
9/00666 (20130101); Y10T 70/7079 (20150401) |
Current International
Class: |
G07C
9/00 (20060101); E05b 049/00 (); H01h 027/00 () |
Field of
Search: |
;340/147MD,164R,164A,149R,274 ;200/42,44,45 ;317/134 ;70/278 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Yusko; Donald J.
Attorney, Agent or Firm: Green; Robert A.
Claims
What is claimed is:
1. An electromechanical programmable lock comprising
an annular lock section and an annular key section removably
disposed within said lock section,
said lock section having a plurality of first electrical lock
contacts,
means in said lock section for selectively connecting one of said
first electrical lock contacts in a first circuit, such selective
connection comprising pre-programming of said lock section,
said key section having a plurality of second electrical key
contacts, each of which contacts one of said lock contacts, and
means in said key section for selectively connecting one of said
second electrical key contacts in a second circuit, such selective
connection comprising pre-programming of said key section, whereby
a selected first lock contact and a selected second key contact can
be pre-programmed to match so that, when the pre-programmed key
section is inserted into and matches the pre-programmed lock
section, said first circuit and said second circuit are connected
and operate as a permitted state for the programmable lock.
2. An electromechanical programmable lock comprising
a plurality of annular lock sections coupled together as a lock
unit and a plurality of annular key sections coupled together as a
key unit, said key unit being removably disposed within said lock
section,
each said lock section of said lock unit having a plurality of
first electrical lock contacts,
separate means in each said lock section for selectively connecting
one of said first electrical lock contacts therein to a separate
first circuit, such connection of a lock contact to a first circuit
comprising pre-programming of such lock contact,
each said key section of said key unit having a plurality of second
electrical key contacts which contact corresponding ones of said
first electrical lock contacts, and
separate means in each said key section for selectively connecting
one of said second electrical key contacts therein to a separate
second circuit, such connection of a key contact to a second
circuit comprising pre-programming of such key contact,
each said key section mating mechanically and being in operative
relation with a lock section to form a key-lock pair when said lock
unit is inserted in said key unit, whereby in each key-lock pair, a
selected first lock contact and a selected second key contact can
be pre-programmed to match so that, when the key unit is inserted
into the lock unit and all of the pre-programmed key-lock pairs
match, each said first circuit and each said second circuit of each
key-lock pair are connected together and operate as a permitted
state for the programmable lock.
3. The apparatus defined in claim 2 wherein each said key section
includes a generally annular insulating member having a central
aperture and an array of apertures disposed about its annular body
with a metal key contact disposed in each such aperture,
a program member rotatably disposed in said central aperture of
each said key section and comprising an insulating member having a
generally curved outer surface having a step therein,
a metal ring threaded on said program member of each key section
and having a portion engaging said step and contact portions
adapted to engage one of said key contacts, and
an electrical contact mounted on each said annular member and
making contact with its associated conductive ring and accessible
outside said annular member for connection to an electrical
circuit.
4. The apparatus defined in claim 2 wherein each said lock section
includes an annular member having a central aperture and having a
generally planar base and a pedestal rising therefrom, a plurality
of lock contacts seated on said pedestal and disposed about the
annular body thereof, there being one lock contact for each of said
second electrical contacts which are key contacts,
a first contact ring seated on the top surface of said base of each
annular member,
a second contact ring seated on the bottom surface of said base of
each annular member,
a terminal member mounted on each said pedestal and having a
portion extending from said annular member, and
a rotatable program ring seated on each said pedestal and carrying
a first split ring adapted to contact all but one of the associated
lock contacts and the associated first contact ring,
each said program ring also carrying a second split ring having a
portion adapted to contact said one of said first lock contacts and
said second contact ring of the adjacent lock section.
5. The apparatus defined in claim 2 wherein each said lock section
includes an annular insulating lock member having a central
aperture and having a generally planar base and a pedestal rising
therefrom, a plurality of lock contacts seated on said pedestal and
disposed about the annular body thereof, there being one lock
contact for each of said second electrical contacts which are key
contacts,
a first contact ring seated on the top surface of said base of each
annular lock member,
a second contact ring seated on the bottom surface of said base of
each annular lock member,
an electrical terminal member mounted on each said pedestal and
having a portion extending from said annular lock member for making
electrical connection thereto,
a rotatable program ring seated on each said pedestal and carrying
a first conductive member adapted to contact all but one of the
associated lock contacts and the associated first contact ring,
each said program ring also carrying a second conductive member
having a portion adapted to contact said one of said first lock
contacts and said second contact ring of the adjacent lock
section,
each said key section includes a generally annular insulating key
member having a central aperture and an array of apertures disposed
about its annular body with a metal key contact disposed in each
such aperture, each key contact touching one of said lock
contacts,
a program member rotatably disposed in said central aperture of
each said key section and comprising an insulating disk having a
generally curved outer surface having a step therein,
a metal selector ring threaded on said program member and having a
portion engaging said step and contact portions adapted to engage a
selectable one of said key contacts by rotation of said program
member, and
an electrical contact mounted on said annular key member and making
contact with said metal selector ring and accessible outside said
annular key member for connection to an electrical circuit.
6. An electromechanical programmable lock comprising
a plurality of lock sections formed as a unit and a plurality of
key sections formed as a unit, with said unit of key sections
inserted in said unit of lock sections and with each key section
mating with an associated lock section, there being first, second,
third, fourth, . . . and n.sup.th lock and key sections,
each lock section including a plurality of lock contacts disposed
in a serial array,
lock program means in each lock section for selecting one of said
lock contacts and connecting it in an electrical circuit,
each said key section including a plurality of key contacts
disposed in a serial array with each key contact touching one of
said lock contacts,
key program means in each key section for selecting one of said key
contacts and connecting it in said electrical circuit whereby an
electrical circuit is completed between a selected key contact in
each key section and a selected lock contact in the associated lock
section.
7. The apparatus defined in claim 6 wherein, in each lock section,
the selected lock contact is connected to an external operating
circuit.
8. The apparatus defined in claim 6 wherein each key section
includes a key input terminal to which an external circuit can be
connected.
9. The apparatus defined in claim 7 wherein said external circuit
includes a relay for performing an operating function as determined
by the mating of said key and lock units.
10. The apparatus defined in claim 7 and including an AND gate, to
the input of which each of said selected lock contacts is
connected, said AND gate having its output connected to a control
circuit which is operated when said key and lock sections match in
the programs and said AND gate receives signals representative of
such matching.
11. The apparatus defined in claim 6 wherein the selected lock
contact of the first lock section is connected to the selected key
contacts of all of the other key sections of said lock,
all of the other selected lock contacts of the other lock sections
being connected to a separate output lead on which an output signal
may appear.
12. The apparatus defined in claim 6 wherein an input potential is
coupled to the selected key contact of said first key section,
the selected lock contact of said first section being connected to
the selected key contact of said second key section,
the selected lock contact of said second section being connected to
the selected key contact of said third key section and so forth,
with the selected key and lock contacts of all of the sections
being connected in a series electrical circuit.
13. The apparatus defined in claim 6 and including an input circuit
connected in parallel to the selected key contact of all of said
key sections, and
a separate output lead from the selected lock contact of each of
said lock sections.
14. The apparatus defined in claim 6 wherein the selected lock
contact of each said lock section is connected through an
electronic switch, which is normally closed, to a utilization
device,
a plurality of non-selected lock contacts connected to an alarm
circuit whereby when said lock and key sections match in their
selected contacts, said electronic switch operates said utilization
device but when said lock and key sections do not match in their
selected contacts, said alarm circuit operates.
Description
BACKGROUND OF THE INVENTION
In the prior art, combination locks are known which require a
particular key or combination of movements of a dial to be
operated. However, either such locks cannot be easily set to a
different combination, or they are limited in the number of
combinations possible. In addition, the prior art does not include
locks which are easily programmed and reprogrammed and can provide
control electrical output signals.
SUMMARY OF THE INVENTION
Briefly, a programmable lock embodying the invention includes a
plurality of separately programmable key sections formed as a unit
and adapted to operate with a plurality of separately programmable
lock sections and formed as a unit with each lock unit having an
associated key unit. Means are provided for coupling electrical
power to the entire unit in various ways and extracting signals in
various ways to add to the programming flexibility of the
apparatus.
DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a perspective exploded view of the lock of the
invention;
FIG. 2 is a perspective exploded view of the key portion of the
lock of FIG. 1;
FIG. 3 is a side elevational view of the key portion of FIG. 2
shown assembled;
FIG. 4 is a side view of the key section of FIG. 2 showing some of
the parts assembled;
FIG. 5 is a perspective exploded view of the lock section of the
lock of FIG. 1;
FIG. 6 is a side elevational view showing portions of two lock
sections coupled together;
FIG. 7 is a side elevational view of a portion of a lock section
with some of its parts assembled;
FIG. 8 is a side elevational view of a lock section showing some of
its parts assembled;
FIG. 9 is a schematic representation of a lock section and a key
section as they appear assembled and in operative relation;
FIG. 10 is a schematic representation of a plurality of lock and
key sections when assembled and one circuit connection arrangement
in which they can be used;
FIGS. 11 to 14 are schematic representations of a complete lock
unit and various circuit connection arrangements that can be made
therewith;
FIG. 15 is a schematic circuit showing one mode of operation of the
lock unit of the invention; and
FIG. 16 is a schematic representation of another circuit for using
the lock unit of the invention;
FIG. 17 is a truth table for the FIG. 16 operation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A programmable lock 10 (FIG. 1) embodying the invention comprises a
lock portion 14 made up of a plurality of lock sections 300 and a
key portion 16 made up of a plurality of key sections 20 coupled
together and operable as a programmable lock unit having a large
number of possible combinations, depending on the number of lock
and key sections provided, as will be clear to those skilled in the
art.
A single key section 20 is shown exploded in FIG. 2 and includes
matching and mating right and left insulator rings 30 and 30', each
having a flat outer surface 40, 40' and an inner surface 50, 50' in
which are formed ten generally cylindrical spaced slots 60, 60'
having conical bases 70, 70' (FIGS. 2 and 3). Each slot 60, 60' is
separated by a wall portion or web 80, 80'. Each insulating ring
also includes an enlarged projecting tab 90, 90' which includes a
channel 100, 100' in which is formed a contact receiving form or
pedestal 110, 110'. A metal key contact 120 is seated in each of
the slots 60, and each contact is preferably cylindrical to match
the cylindrical slots 60, 60', and each contact 120 has a generally
conical end 122 which rests in a mating conical depression 70, 70'
at the base of each slot 60, 60' (FIG. 3). Thus, when the two
insulator sections 30, 30' are put together to form a key section
(FIG. 3), the contacts 120 are held securely in place in the
cylindrical slots 60, 60', with their ends in the conical
depressions 70, 70' at the bases of the slots. A power input
contact 130, which is formed of a metallic strip suitably bent and
shaped into a generally U-shaped section, is seated on the forms
110, 110' in the tab portions 90, 90'. The contact 130 has curved
end surfaces which project out of the front and rear ends of the
slots 100, 100' so that contact can be made thereto in a manner to
be described.
The insulator rings 30, 30' have generally circular central
openings 140, 140' (FIG. 2) in which is seated an insulating disc
150, called a program cam, having a bore 160 of hexagon shape or
the like and having an outer surface 170 which is generally
smoothly curved except for a step portion 180 formed therein. A
metallic program ring 190 is threaded on the program cam 150, and
includes an arm 200 which engages the step 180 in cam 150 and a
pair of tabs 210, 220 which protrude from its outer surface and can
engage one of the key contacts 120 or power input contact 130 (FIG.
4). When tabs or arms 210, 220 contact one of the key contacts 120,
then the body of ring 190 contacts terminal 130 (FIGS. 4 and 8).
The tabs 210, 220 are of different lengths to prevent their jamming
during programming of each key section which is accomplished by
rotating cam 150 and ring 190 to place tabs 210, 220 in contact
with a selected contact 120 or contact 130. The parts of the key
section are held together by means of rivets 230 or the like which
extend through the insulating rings 30, 30' (FIG. 3).
The key portion 16 is made up of a plurality of sections 20 of the
type described above, all mounted on a rod 240 (FIG. 1) which
includes a shaft 250 of hexagonal cross-section shape to receive
the program cams 150, having hexagonal bores. The mounting rod also
has, at one end, a numbered ring portion 260 and a finger-gripping
portion 270 to permit rotation of the shaft. The opposite end 280
of the shaft 250 is threaded to receive a lock nut 290 to lock the
key sections 20 in place thereon.
Each lock section 300 (FIG. 5) includes an insulating ring member
310 having a base portion 314 which includes oppositely disposed
apertured mounting tabs 340. An annular pedestal 360 rises from the
front surface 350 of base member 310. The rear surface 320 of base
310 is provided with an annular depression 330 (FIG. 6) for
receiving a metal contact ring 333 having a terminal 335, and the
front surface of base 310 is provided with an annular depression
363 for receiving a metal contact ring 376 having a terminal 378.
The annular pedestal 360 has ten spaced portions of reduced
thickness 370, each of which is adapted to receive and hold a
generally U-shaped metal lock contact 380. A similar U-shaped metal
contact 390 having a projecting terminal portion 400 is mounted on
its portion 370' in the pedestal 360, with terminal 400 seated in a
depression 403 in base 314 so that it is beneath, spaced from and
insulated from metal ring 376. An insulating pad 410 is disposed on
terminal 400, and it rests between terminal 400 and ring 376 (FIG.
7).
Depressions 330 and 363 in the base 314 for metal rings 333 and 376
are not required, and other arrangements may be provided for
seating these rings and relating them to contact 390.
Referring to FIG. 5, an insulating program ring 420, provided
surrounding the pedestal 360, includes ten selector numerals on its
outer surface and annular depressions 430 and 440 in its inner
surface adjacent to its outer opposite surfaces. One depression 430
receives a split metal contact ring 450, and the other depression
440 receives a split metal contact ring 460 having an inwardly
projecting arm 470. The split contact ring 450 and contact ring 370
are of such dimension and shape that, when the program ring 420 is
in place on the pedestal 310, as illustrated in FIG. 6, the split
contact ring 450 makes electrical contact with the ring 370.
Similarly, the second contact ring 460 and ring 333 are of such
size and dimension that, when two insulator lock rings 310 are
placed side by side in a lock assembly, ring 460 makes contact with
the ring 333 on the rear surface 320 of the adjacent insulator ring
member 310. In addition, arm 470 of split ring 460 makes contact
with one lock contact 380 (FIG. 8), and split ring 450 makes
contact with all of the other lock contacts 380.
The lock portion 14 of programmable lock 10 includes a plurality of
lock sections 300 equal in number to the number of key sections 20
in the key portion 16. The lock sections are held together by means
of suitable fasteners 343 inserted in the aligned apertured tabs
340 in each lock section.
A lock 10 includes a plurality of key sections and a plurality of
lock sections. As noted, for convenience, the lock 10 has a decimal
numberal base, and there are ten key contacts 120 and ten lock
contacts 380 in each key and lock section. Accordingly, each
program ring 420 carries numerals 1 to 10 on its outer surface, and
in each section, rings 430 and 440 are so positioned that the
numerals 1 to 10 are properly aligned with the similarly designated
lock and key contacts. This permits the lock and key sections to be
programmed as desired.
The lock 10 is used as follows. First, each lock section is set by
rotating each program ring 420 to bring it into a desired setting
in which tab 470 of ring 460 is brought into contact with a
selected lock contact 380 and to place ring 450 in contact with all
of the other lock contacts 380. This provides a desired lock
setting for each lock section. Now, each key portion 20 is set so
that it will operate with the corresponding lock portion when the
key is inserted in the lock. This is done by rotating each core 150
so that tabs 210 and 220 of each ring 190 contact a selected key
contact 120 which corresponds to the selected lock contact 380 of
the associated lock section. Thus, if lock section "1" has ring 470
in contact with the first lock contact 320, then the key section
"1" has tabs 210 and 220 of ring 190 in contact with the first key
contact 120. Similarly, if lock section "2" has ring 470 in contact
with the third lock contact 320, then the key section "2" has tabs
210 and 220 of ring 190 in contact with the third key contact 120.
The other related lock and key sections are similarly properly
programmed.
As noted, each ring 190 in each key section (FIG. 2) contacts power
input contact 130 to which a power source V is connected.
The principles of the mode of operation of the invention are
illustrated schematically in FIG. 9 for a simple lock including one
key and one lock section. If the lock section and key section
match, when the key is inserted in the lock, power is connected
from voltage source V through input contact 130, ring 190, tabs 210
and 220, key contact 120, lock contact 380 which key contact 120
contacts, ring 460 and ring 333 to an external circuit which may
include a relay 500 for operating a door or the like.
It is clear that, if the lock and key sections were not programmed
properly so that the selected lock contact 380 did not contact the
corresponding key contact 120, then the required output signals
would not be provided and the door relay would not be operated.
Another more complex mode of operation of the invention is
illustrated in FIG. 10 for a three-section lock 10, only portions
of which are shown. In this case, two output rings 333 are
operative, and they are connected through an AND gate 510 to
apparatus such as the door relay 500. Again, if the lock and key
sections match properly, the two outputs from rings 333 operate the
AND gate and provide an output signal to operate the door relay. On
the other hand, if the key does not match the lock, the AND gate is
not operated, and the door relay is not operated.
It will be clear to those skilled in the art that a lock embodying
the invention has many possible programs, and it may be used in
many different types of circuits. In addition, a circuit may be
devised to provide an alarm signal if a non-matching key is
inserted in a programmed lock. This is described below.
Some of the possible program modes of operation of the invention
are illustrated in FIGS. 11 to 15. The lock illustrated in FIG. 11
includes n sections, with each section including ten lock and key
sections, only some of which are shown. Section 1 has its lock
program ring 420 programmed so that the first lock contact
designated 380A is contacted by ring 460 which contacts ring 333
(not shown). A lead 520A is connected through tab 335 on ring 333
to ring 460 and to the lock contact 380A. All of the other lock
contacts 380 are connected together by ring 450 (not shown), which
contacts ring contact 376 (not shown) and has a lead 530A connected
to its tab 378.
In lock section 2, the program ring 420 is set to contact the
second lock contact 380B, and this portion of the lock has its
output lead 520B. The other lock contacts 380 are connected
together and have their output lead 530B. The other lock sections
are programmed as desired, and the n.sup.th section is programmed
as shown.
Now, referring to the key sections in FIG. 11, they are all
programmed to mate properly with the lock, and, accordingly,
section 1 has the tabs 210 and 220 of ring 190 in contact with the
first key contact 120A. In addition, in section 1, ring 190 is
connected through its contact 130 (not shown) and power input
terminal 390 to a source of operating potential V by a lead 540.
Section 2 has the tabs 210 and 220 of ring 190 in contact with the
second key contact 120B, and the other key sections are similarly
programmed to match the lock sections.
In the circuit arrangement illustrated in FIG. 11, the sections are
interconnected by having lead 520A of the selected program position
in section 1, the first position, connected to the power input
terminals 390 of each of the other sections by lead 550 whereby
power is coupled from source V to all of the sections of the lock.
In adddition, each of the leads 520 B to N and 530 has an output
terminal at which a signal or voltage can be detected if one is
present. Thus, in operation of the arrangement of FIG. 11, when the
key is inserted in the lock, the indicated circuits are completed
and all of the output leads 520 B to N show potential V at their
output terminals and the leads 530 show no potential. If leads 520
are connected to a circuit such as that shown in FIG. 10, a door
can be opened or some other operation can be performed.
FIG. 12 illustrates another arrangement for electrically connecting
the sections of a lock. In FIG. 12, the selected lock and key
positions are connected in series so that the circuit includes
power source V connected by lead 540 to power input contact 390 to
the selected second key contact 120B and to the second lock contact
380B and the various contact rings to lead 520A. Lead 520A is
connected to turn to power input terminal 390 of the second section
and through the selected first key and lock contacts to output lead
520B. Then output lead 520B is connected in series with the
programmed key and lock contacts of the third section, etc., with
lead 520.sup.n.sup.-1 of the n-1 section being connected to power
input contact 390 to the selected third key contact 120C and to the
corresponding lock contact 300C and output lead 520A of the nth key
and lock section.
In operation of the arrangement of FIG. 12, when the key is
inserted in the lock, the series circuit shown is completed and
potential appearing on output lead 520N can be used to operate a
door relay or the like.
In another circuit arrangement illustrated in FIG. 13, the voltage
input source V is coupled in parallel to the power input terminals
390 of all of the sections, and, when lock and key sections match
as shown, an output potential appears on all leads 520. As
described above, all leads 520 can be coupled to an AND gate and to
a door relay or the like.
FIG. 14 illustrates the circuit situation when a key does not match
the lock in which it is inserted. For purposes of illustration, all
of the key and lock sections match; however, the nth sections do
not match. In this case, all of the output leads 520 except the
last provide the required output signal; however, the last does
not. Accordingly, an AND gate to which the outputs 520 are
connected will not receive a potential on lead 520N and will not
provide the required output signal to operate a door relay.
Referring to section n, the output lead 530N connected to the lock
contacts to which the key contact 120A is connected carries a
potential which can be used to energize an alarm or the like.
In the arrangement shown in FIG. 15, all of the lock sections have
their program rings 420 set so that rings 460 and their contact
rings 333 all contact power input terminals 390. The matching key
similarly has all of its contact rings 190 in contact with the
power input terminal 130 and none of the key contacts. In the
circuit arrangement of FIG. 15, input voltage source V is connected
by lead 540 to terminal 400 of input terminal 390 and thus to ring
460 and ring 333 and by lead 520A to all of the terminals 390.
As noted above, a lock 10 can be connected in a circuit for
properly opening a door or the like when the key matches the lock
or providing an alarm if there is a mismatch of any kind. One such
alarm circuit, shown in FIG. 15, includes a connection from each
programmed lock contact 380 (not shown) and its ring contact 333
through a resistive path 570 to a bus 580 which runs to ground. The
bus 580 is coupled to the base of an NPN transistor 590 which has
its emitter connected to one end of a load 600 such as a door
relay. The ground side of the bus 580 is also connected (1) to the
collector of PNP transistor 610, (2) through a resistive path 620
to the base of the transistor 610, and (3) through a resistive path
630 to the lead 640 between the emitter of transistor 590 and the
door relay 600. The emitter of transistor 610 is also connected to
the other end of the door relay. The rings 376 which are connected
to unselected contacts in the lock are coupled by lead 650 to the
base of transistor 610 and to an alarm 660.
In operation of the circuit of FIG. 15, transistor 590 is held OFF
by the biases applied thereto and transistor 610 is biased to be ON
and conducting. When a key is inserted into the lock and all
sections match, the potential applied to the base of transistor 590
through the paths 570 causes transistor 590 to turn on and conduct
and complete a current flow path through door relay 600 and ON
transistor 610. If one or more of the key sections does not match
the lock, positive potential is applied through a ring 376 to the
base of transistor 610 which is turned off, opens the load circuit,
prevents the door relay from operating, and operates the alarm
660.
Another alarm circuit shown in FIG. 16 has all of the selected
outputs from a multi-section lock represented by lines A, B, C, D,
connected as inputs to an exclusive OR gate 670 and to an AND gate
672. The non-selected outputs of the lock are connected together to
two inputs of an OR gate 674, the output of which is coupled to one
input of an exclusive OR gate 676 and to the alarm device 660. The
output of the exclusive OR gate 670 is coupled to one input of a
NAND gate 678 and to both inputs of an AND gate 680. The output of
the NAND gate 678 is coupled to two inputs of a NAND gate 682, the
output of which is coupled to one input of an exclusive OR gate
684, the output of which is coupled to the alarm device 660. The
output of the AND gate 680 is coupled to the second input of the
exclusive OR gate 684. The output of the AND gate 672 is coupled to
the second input of the NAND gate 678 and to the second input of
the exclusive OR gate 676, the output of which is coupled to the
lock opening mechanism or relay represented by block 600.
The operation of the circuit of FIG. 16 is represented by the truth
table of FIG. 17 in which numerals 1 to 9 represent the outputs of
the various gates of FIG. 16. The truth table shows that, when A,
B, C, D, etc., have the same polarity signal and E has the opposite
polarity, then the various gates have the polarities shown, and the
lock is operated in normal fashion. Another other combination of
signals operates the alarm.
It is to be noted that the illustrations of the invention in the
various figures of the drawings may not be dimensionally exact and
some parts may be omitted in various figures. However, these
drafting expedients are taken to simplify the illustration of the
invention and to facilitate the understanding of the invention by
one reading the specification.
* * * * *