U.S. patent number 3,686,659 [Application Number 05/000,634] was granted by the patent office on 1972-08-22 for electronic locking device.
This patent grant is currently assigned to Dasy Inter S.A.. Invention is credited to Sten L. Bostrom.
United States Patent |
3,686,659 |
Bostrom |
August 22, 1972 |
ELECTRONIC LOCKING DEVICE
Abstract
A locking device, comprising a mechanical locking means adapted
to be electrically controlled, a source of electric energy, a
receiver for receiving such energy, a key insertable into a mating
keyhole means and arranged to thereby connect said source to said
receiver for transmission of electric energy thereto, a number of
target terminals distributed and spaced according to a first
predetermined pattern within said keyhole means, an equal number of
output terminals on said key distributed and spaced according to
said first pattern, each output terminal being arranged, upon the
correct insertion of said key into said keyhole means, to cooperate
with a respective target terminal to supply electric energy
thereto, a plurality of electric energy conducting paths within
said key each leading from said source to at least one of said
output terminals, a plurality of electric circuit components
comprised within said paths and arranged to modify predetermined
characteristic properties of electric energy propagated along said
paths, to thereby generate output conditions on said output
terminals according to a second predetermined pattern specific for
the key, a plurality of circuit means each having an input
connected to at least one of said target terminals and each being
arranged to generate an output signal when receiving as an input
signal a predetermined value of some characteristic property of the
electric energy, a plurality of bistable devices each connected to
a respective of said circuit means and arranged to be actuated when
receiving an input signal therefrom, said bistable devices being
arranged to be actuated according to a third predetermined pattern
when said second predetermined pattern corresponds to the pattern
of predetermined input signal values to said circuit means, said
third output pattern from the bistable devices being effective to
open said mechanical locking means and manual means for modifying
the electric properties of at least one of said paths.
Inventors: |
Bostrom; Sten L. (Hagersten,
SW) |
Assignee: |
Dasy Inter S.A. (Geneva,
CH)
|
Family
ID: |
21692358 |
Appl.
No.: |
05/000,634 |
Filed: |
January 5, 1970 |
Current U.S.
Class: |
70/416; 70/277;
361/172 |
Current CPC
Class: |
G08B
13/06 (20130101); G07C 9/00714 (20130101); Y10T
70/7915 (20150401); Y10T 70/7062 (20150401) |
Current International
Class: |
G08B
13/02 (20060101); G07C 9/00 (20060101); G08B
13/06 (20060101); G08b 013/06 () |
Field of
Search: |
;340/274,276,164R,149R,149A ;317/134 ;70/277 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Trafton; David L.
Claims
What I claim is:
1. A locking device, comprising
a. mechanical locking means adapted to be electrically
controlled,
b. a source of electric energy,
c. a receiver for receiving such energy,
d. a key insertable into a mating keyhole means and arranged to
thereby connect said source to said receiver for transmission of
electric energy thereto,
e. a number of target terminals distributed and spaced according to
a first predetermined pattern within said keyhole means,
f. an equal number of output terminals on said key distributed and
spaced according to said first pattern, each output terminal being
arranged, upon the correct insertion of said key into said keyhole
means, to cooperate with a respective target terminal to supply
electric energy thereto,
g. a plurality of electric energy conducting paths within said key
each leading from said source to at least one of said output
terminals,
h. a plurality of electric circuit components comprised within said
paths and arranged to modify predetermined characteristic
properties of electric energy propagated along said paths, to
thereby generate output conditions on said output terminals
according to a second predetermined pattern specific for the
key,
i. a plurality of circuit means each having an input connected to
at least one of said target terminals and each being arranged to
generate an output signal when receiving as an input signal a
predetermined value of some characteristic property of the electric
energy,
j. a plurality of bistable devices each connected to a respective
of said circuit means and arranged to be actuated when receiving an
input signal therefrom, said bistable devices being arranged to be
actuated according to a third predetermined pattern when said
second predetermined pattern corresponds to the pattern of
predetermined input signal values to said circuit means, said third
output pattern from the bistable devices being effective to open
said mechanical locking means, and
k. manual means for modifying the electric properties of at least
one of said electric energy conducting paths.
2. A locking device according to claim 1, further comprising
starting means arranged to actuate said source of electric energy
to produce such energy upon correct insertion of said key into said
keyhole means.
3. A locking device according to claim 1, further comprising means
for blocking said mechanical locking means and for modifying the
output from said source upon sensing an input condition pattern to
said gate unit different from said third pattern.
Description
The present invention relates to a tamperproof locking device,
which permits a practically unlimited number of combination and
which is practically impossible to use are unauthorized manner and
practically impossible to imitate.
For this purpose a locking device according to the invention
comprises a locking device, comprising a mechanical locking means
adapted to be electrically controlled, a source of electric energy,
a receiver for receiving such energy, a key insertable into a
mating keyhole means and arranged to thereby connect said source to
said receiver for transmission of electric energy thereto, a number
of target terminals distributed and spaced according to a first
predetermined pattern within said keyhole means, an equal number of
output terminals on said key distributed and spaced according to
said first pattern, each output terminal being arranged, upon the
correct insertion of said key into said keyhole means, to cooperate
with a respective target terminal to supply electric energy
thereto, a plurality of electric energy conducting paths within
said key each leading from said source to at least one of said
output terminals, a plurality of electric circuit components
comprised within said paths and arranged to modify predetermined
characteristic properties of electric energy propagated along said
paths, to thereby generate output conditions on said output
terminals according to a second predetermined pattern specific for
the key, a plurality of circuit means each having an input
connected to at least one of said target terminals and each being
arranged to generate an output signal when receiving as an input
signal a predetermined value of some characteristic property of the
electric energy, a plurality of bistable devices each connected to
a respective of said circuit means and arranged to be actuated when
receiving an input signal therefrom, said bistable devices being
arranged to be actuated according to a third predetermined pattern
when said second predetermined pattern corresponds to the pattern
of predetermined input signal values to said circuit means, said
third output pattern from the bistable devices being effective to
open said mechanical locking means and manual means for modifying
the electric properties of at least one of said paths.
The energy receiver can electromagnetically operate one or several
mechanical locking means. The key is arranged in such a way that
when it is inserted into a keyhole, it will actuate a starting
means which causes the source to deliver electric energy to the
key, so that said energy is transmitted to the receiver. The key is
provided with means which can be manually actuated to control or
actuate one or several paths of electric energy or intensities of
electric energy through the key to the receiver. In an embodiment
of the invention some of the targets of receiver comprise
amplifiers connected thereto, which, when receiving a predetermined
input energy from their target, suitably actuate an associated
flip-flop or change-over switch. The flip-flops or the change-over
switches each control a logical gate unit, which is provided with a
series of inputs and, when a predetermined input condition pattern
is present on the series of inputs, controls a means for actuating
the lock, but for all other input condition patterns than the
pre-determined correct pattern makes actuation of the lock
impossible. The key is arranged to direct electric current along
different paths in the key to different output terminals of the key
located adjacent corresponding targets terminals of the receiver.
Thereby the key can damp or reduce, amplify or increase different
parameters of electricity respectively in different ways. In a key
operated by alternating current energy said key can be arranged to
modulate the phases of different components of the alternating
current in different ways. The key can also be arranged to direct
or diverge different parameters of electricity to different output
terminals of the key located right in front of and communicating
with different desired target terminals of the receiver. The
logical gate unit is suitably assembled of a number of serial
stages of parallel simple AND-gates or OR-gates or both. The key
intended to operate with direct current potentials comprises
resistance components that apply different potentials on different
output terminals of the key for delivery to respective target
terminals of the receiver. The starting or initiating means,
therefore, is suitably a ground connection contact and a contact,
which are inter-connected by the key. In the receiver there are
suitable means to feed blocking potential to the means operating
the lock or other coupling means. The source of electric energy can
also be arranged to selectively excite oscillators in the key,
which provide different target terminals with different frequencies
via filters associated therewith.
The invention will now be described more in detail in connection
with an example of an embodiment illustrated in the accompanying
drawings in which:
FIG. 1 shows a key inserted in a keyhole,
FIG. 2 shows an example of a gate unit of the locking device,
FIG. 3 schematically illustrates a cross section through the key
and
FIG. 4 shows a table of examples of different types of gates which
can be used.
As is evident from FIG. 1 the key N on its handle is provided with
a dial IS having an indication mark IM and a scale cooperating
therewith on the side of the key handle. The exemplary figure
graduation on the scale shown is divided in eight positions 1-8.
Another dial can be arranged on the opposite side of the handle. In
addition to, or instead of dials, one or several rings having or
cooperating with figure markings for setting a code number of
several digits may be provided in a manner well known in the
combination locks art. In order to simplify the description, it is
here assumed that only the dial IS shown is present and that said
dial, via a belt RM, actuates a setting means in the form of for
example a resistor R5 located in the interior of the key, which
will be described in detail below. The position of the dial shown
with the digit 2 opposite the indication mark IM is assumed to be
the correct code position for the key in question.
When the key N is inserted into a mating keyhole, the physical
shape of which may be "female" if the key is "male," the end of the
key, for example when being turned in the direction of the arrow
appearing in FIG. 3 actuates a contact K (FIGS. 1 and 3) in the
bottom of the hole, which contact via a resistance RO connects the
key to ground. During this turning operating of the key a row of
contact elements 100-110 in the key will also come in contact with
a corresponding row of contact elements 200-210 in the keyhole
(FIG. 1).
The left hand terminals of a series of resistors R1, R2, R3 and the
left hand terminals of the two diodes D1 and D2 are connected to a
ground return line 10 in the key, which at one side is connected
with the contact K and at the other side with the contact or input
terminal 110 of the key. The other terminals of the resistors R1,
R2, R3 and of the diodes D1 and D2 are connected to the respective
contact elements or output terminals 100, 101, 103 and 102. The
diode D2 is connected via a second counterdirected diode D3 to the
contact element or output terminal 104. From the connection point
between the diodes D2 and D3 a circuit containing a resistor R6
leads to the contact element or output terminal 109. A resistor R4
and a diode D4 are at one of their terminals connected to said
connection point and at their other terminals are connected to the
contact elements or output terminals 105 and 106, respectively. A
variable resistor R5 has its sliding contact driven by the belt RM
connected to the contact element or output terminal 107 and its
other terminal connected to the contact element or output terminal
108.
The contact elements or target terminals 200, 203 and 206 of the
keyhole are interconnected. They have a common connection with a
threshold amplifier NV1. The contact elements or target terminals
202 and 207 are interconnected as are the contact elements or
target terminals 204 and 205. The contact element or target
terminal 201 is connected to a threshold amplifier NV3. The contact
element or target terminal 208 is connected contact element a
threshold amplifier NV2, and the contact element or target terminal
209 is connected to an amplifier NV4. The contact or output
terminal 210 is connected to a driving circuit or source of
electric energy DR, which supplies, for example, -12 volts to the
return line 10 via the contact elements 110, 210 when a correctly
set mating key is inserted in the keyhole, but +12 volts when an
incorrect or incorrectly set key is inserted. The output from the
amplifier NV2 is connected with the interconnected contact elements
204 and 205. Each amplifier NV1-NV4 is connected with an associated
bi-stable flip-flop FFA, FFB, FFC and FFD, respectively. The
driving circuit DR is biased by a flip-flop FFN. Each flip-flop
FFA, FFB, FFC, FFD has two outputs indicated respectively by
reference letters A and A, B and B, C and C, D and D. These outputs
are each individually connected to an associated input in a gate
circuit GK, which has an end portion SS, which in turn is connected
to a locking gate LG operating a magnetic lock, for example. A
combination circuit KK has inputs connected to the respective
outputs from the flip-flops FFA-FFD, as is evident from the
corresponding letter indications at said inputs. The circuit KK has
two outputs E and E connected to the flip-flop FFN and the gate LG.
All the flip-flops are connected to a reset terminal RE.
The gate unit GK can be designed in a great number of different
ways. By way of example, a number of elementary types of gates of
the AND- and OR-type of which said gate unit can be composed are
shown in FIG. 4.
In the table of FIG. 4, four types of AND-gates are shown in the
left column, four types of OR-gates in the middle column, and in
the right column the input and output conditions for said gates are
shown. In the table, a and b indicate inputs and z outputs. Only
gates having two inputs a,b and one output z are shown, but it is
obvious that a great number of other types of more complicated
gates known per se can be used for designing the unit GK.
In the right column, where the input conditions and output
conditions for the gates shown are exhibited in table form, the two
possible conditions are indicated by letters L and H, respectively,
which for example can signify low voltage and high voltage,
respectively. It is evident from the top of said column that an
input condition L on both inputs a and b gives an output condition
L on output 2, that input conditions H and L on a and b,
respectively, and the reverse combination of L and H on inputs a
and b gives output condition L on output z, but that input
condition H on both inputs a and b gives condition H on output
z.
In FIG. 2 an example of possible design of the circuit GK is shown,
using only the types of OR-gates O and P and AND-gates Q and S
shown in FIG. 4. In FIG. 2 it is assumed that the correct key has
been inserted in the lock and the flip-flops FFA, FFB, FFC, FFD are
then all in the setting conditions with the condition L on the left
hand terminals and the condition H on the right hand terminals.
Thus on the input terminal series in FIG. 2 the conditions L and H,
counted from left to right, are present. Said conditions are fed to
the gate circuit GK and to the combination circuit KK. The gate
circuit GK is assumed according to FIG. 2 to comprise three gates
O,S,Q connected to said input terminals, but the terminals B and B
are shown without connection. The first gate O receives L on both
inputs and then delivers L. The second gate S receives H on both
its inputs and then delivers L. The third gate Q receives H on one
input and L on the other, and then delivers H, which all is in
accordance with the table of input- and output conditions for the
respective type of gate according to FIG. 4. The three output
conditions L, L, H, respectively, are delivered to other gates, and
more particularly the conditions L and H from the gates S and Q,
respectively, are delivered to a second gate S, which for said
input conditions gives the output condition L. This condition and
the condition L from gate O is delivered to a further gate P, which
then gives the output condition L which is transmitted to the
locking gate LG, so that this gate can operate, i.e., unlocking the
magnetic lock.
As mentioned, the indicated series of output conditions from the
terminals A,A, B,B, C,C, D,D, were transmitted also to the
combination circuit KK, which is also composed of gates, i.e., of
the kind shown in FIG. 4. Said circuit is arranged in such a way
that on its output E, when the input combination of condition L and
H is the one shown in FIG. 2, i.e., the one which corresponds to
insertion of the correct key, it gives such information to the
flip-flop FFN that said flip-flop does not bias DR, which then
gives out -12 volts to the contact element 210 and thence to the
key. Any other incorrect input combination of L and H to the
circuit KK results in change-over of the flip-flop FFN, which then
changes over the driving circuit DR, so that instead said circuit
DR, for example, gives a +12 volts to the key, as will be described
below in greater detail. The other output E from the circuit KK is
connected to the locking gate LG, which, when the correct key is
used, receives for example the condition L on its right hand input,
but when the wrong key is used receives the condition H. The left
hand input of LG is fed, as is evident from FIG. 2, with the
condition L, when the key is the correct one, but otherwise with
the condition H. The conditions L on both inputs of the gate LG,
which for example can be of the type shown in the second row in
FIG. 4, gives an operating current to the magnetic lock on the
output from LG. The magnetic locking means is shown in FIG. 1.
The mode of operation of the locking device will be described in
connection with the embodiment shown in the drawing. Certain values
of the voltages used will be assumed, and consequently certain
special values of the components will also be assumed.
Thus the amplifiers NV1-NV4 are assumed to be set for the lower
threshold voltages -3 volts, -7.5 volts, -5 volts, -2 volts,
respectively, and the resistance values used are assumed to be
selected in such a way that said values of the voltages are
obtained when the source of the driving voltage DR gives -12 volts
to the contact 110 of the key. The upper threshold voltages of the
amplifiers, i.e., the voltages above which they do not function,
are assumed to be somewhat above said lower threshold voltages.
The operation of the system will be described, assuming that the
correct key has been inserted in the lock.
The driving circuit then, as mentioned, gives -12 volts to the
contact 110 and the circuit 10. The resistances R1 and R3 are then
assumed together to give -3 volts to the amplifier NV1 via the
contacts 200 and 203. Said potential is also present on the diode
D4 via contact 106. This voltage, -3 volts, is the correct voltage
for the amplifier NV1, and therefore the change-over of the
flip-flop FFA takes place, so that said flip-flop gives the
condition L on the terminal A and the condition H on the terminal
A.
The potential -12 volts applied to the resistor R2 is assumed to
give -5 volts to the amplifier NV3, which is the correct voltage to
said amplifier, and therefore the flip-flop FFC is charged over to
the conditions L and H on the outputs C and C, respectively.
The driving circuit DR further gives -12 volts to the top terminal
of the diode D1 and of the diode D2. From diode D1 said potential
is received at the sliding contact of the resistor R5, which is set
in the way described above by means of the dial IS. The resistance
value of resistor R5 is assumed to be set so that -7.5 volts from
R5 is delivered to the amplifier NV2 via the contacts 108, 208,
which is the correct voltage for said amplifier, so that the
corresponding flip-flop is changed over to the conditions L and H
on the outputs B and B, respectively.
From resistors R1 and R3 the potential -3 volts is present on the
lower terminal of the diode D4. With -12 volts on the top terminal
and, for example, -7.5 volts from the output of NV2 the diode D2 is
blocked. On the top terminal of the diode D4 the potential -7.5
volts is thus present from the connection point between D2 and D3.
The diode D4 thereby will be blocked. From said connection point
also the potential -7.5 volts is delivered to the top terminal of
the resistor R6. The last mentioned resistor then is assumed to
give -2 volts via the contacts 109, 209 to the amplifier NV4, which
is the correct voltage for said amplifier, so that the flip-flop
FFD is changed over and gives the conditions L and H on the outputs
D and D, respectively.
All the outputs A, B, C, D then have the condition L according to
FIG. 2 and all the outputs A, B, C, D then have the condition H,
also according to FIG. 2.
According to FIG. 2 it is then understood that the condition L is
obtained to the gate LG. Then likewise the condition L is obtained
on output E to the aforementioned gate LG. Thereby the lock is
automatically opened.
If, on the contrary, an incorrect key is inserted in the lock at
least one of the amplifiers NV1-NV4 from the beginning receives the
wrong voltage.
If it is assumed that, for example, the incorrect key has only a
single discrepancy from the correct key, e.g., the resistor R1
having an incorrect value, then the amplifier NV1 receives the
wrong input voltage. Thus its output voltage will be 0 volt, and
the flip-flop FFA will not change over, because its output A
receives the condition H and its output A receives the condition L
(which according to FIG. 2 is the opposite condition compared to
the correct one, namely L,H). The combination circuit KK further
receives the wrong input condition and gives out the condition H on
the output E to the gate LG, which then cannot operate. Further, it
is evident from FIG. 2 and 4 that the condition H on A and L on A
gives the output condition H on gate 0 instead of L, and L instead
of H on gate Q. The other gate S thereby receives the wrong output
condition H and both the inputs of the gate receive the condition H
instead of L. Thereby the wrong input condition H at the locking
gate is obtained, because of which said gate remains blocked.
If alternatively, for example, the gate NV2 receives -3 volts
instead of the correct voltage of -7.5 volts, the output voltage
from NV2 will be incorrect and the flip-flop FFB will not change
over, its output condition being reversed compared to what is shown
in FIG. 2. However, the terminals B and B are not connected to the
gate unit GK. Said gate is thereby unaffected and, assuming that
all other input conditions in the beginning are the correct ones,
as in FIG. 2, said unit gives out the correct condition L to
locking gate LG. But the combination circuit KK receives the wrong
input voltage series and thereby gives the condition H to the gate
LG, which thereby would be blocked and remain inactive. Thus even
if one has not connected the terminals B,B to the unit GK, the gate
LG thereby not function, and this non-functioning condition is
further reinforced by the other conditions, which simultaneously
would take place in the key N. Because NV2 receives only -3 volts
and thereby gives out the potential -3 volts, the diode D3 will be
conducting with 0 volt from NV2 and short circuit the resistor R4.
The diode D4 also receives 0 volt and thus blocks the amplifier NV1
from the contact 206. The resistor R6 receives the wrong voltage,
whereby the amplifier NV4 cannot function. Because the input
conditions to the gate unit GK thereby will differ from the correct
conditions, the wrong condition is now received at locking gate LG.
The combination circuit KK also gives a changeover signal to the
flip-flop FFN, which changes over the driving circuit to give out
+12 volts to the circuit 10 via the contacts 210, 110.
The final result will be that, in addition to the amplifiers NV1,
NV2, NV4 dealt with above, the amplifier NV3, which from the
beginning has had the correct voltage, also receives the wrong
voltage thereby giving out an output voltage of 0 volt to its
flip-flop FFC, which returns to rest position. The zero position of
all the threshold amplifiers means that one cannot obtain any
knowledge of the correct key setting from electrical measurements
made at the lock.
The electric circuit components within the key are advantageously
not made as distinct components, but are for example integrated
circuits. Circuits of thin film, mini- or microcircuits can also be
used, which are cast in the very key itself in order to make it
impossible to arrive at any conclusions as to its design by
dismantling the key. Then it will be impossible to dismantle the
key without destroying its circuit components beyond recognition.
One can suitably use such integrated components, in which certain
connections have been cut or broken. It is evident that a very
great number of different couplings of the components in the key
can be made. Further, the key can comprise elementary components
other than resistors and diodes, as for example condensers,
inductors, filters, etc., and be fed with one or more alternating
currents of the same or different frequencies instead of with
direct current. Different magnetic components can also enter in the
design. The same possibilities of variation are also present in the
case of the stationary part of the locking device, and its
components are of course adapted to the components in the key
design. The energy transmission to the receiver can also be made
inductively.
In FIG. 1 only terminals 100-110 from the key and corresponding
terminals 200-210 in the keyhole have been shown. However, it is
obvious that a very great number of such series of terminals or
contacts can be arranged on the periphery of the key, with the
remainder being dummies, of which a certain small number will be
used in reality, i.e., be connected to the actual current circuit
components of the key. The keyhole then of course shall have the
corresponding number of input contacts. The key can also be
provided with only a small number of output contacts, while the
keyhole itself can have a great number of input contacts. It is
obvious that innumerable different combinations of keys and the
locks belonging thereto can be obtained by means of the
invention.
Further, a great number of combination possibilities are created by
the gate device GK permitting selection between a very great number
of different gate types, it being possible, by taking into account
the present state of the electrical circuit design art, to obtain a
practically innumerable number of different locking devices.
The invention has been described above in connection with a very
simple embodiment, and a number of modifications have been dealt
with in summary, but it is understood that the invention is not
limited thereto but that its scope is limited only by the
accompanying claims.
* * * * *