Note: Descriptions are shown in the official language in which they were submitted.
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BACKGROUND OF INVENTION:
(a) Field of Invention
The present invention relates to an electronic
sequential combination locking device utili2ing a
plurality of manually actionable switches operable in a
predetermined sequence in order to activate an operable
device when the sequence of switches are activated
within a predetermined time limit.
(b) Description of Prior Art
Various electronic anti-theft circuits are
known to prevent automobile theft or to prevent entrance
within an enclosure through a closure device, such as a
door. However, some disadvantages of this known prior
art are that the circuits are expensive to construct
and utilize special components and in some cases the
circuitry is easily defeated by expertise. Other disadvan-
tages of known circuits are that the device will permit a
vehicle to be started and the alarm is sounded only after
a predetermined time lapse after the vehicle is in motion.
Therefore, this would permit theft by transporting the
vehicle in a transport vehicle. A further disadvantage
of some prior art circuits is that they handle only very
light loads and cannot trigger a multitude of alarm
devices. A further disadvantage is that the device can
2S be circumvented by jumping wire connections.
SUMMARY INVENTION:
It is a feature of the present invention to
provide an improved electronic sequential combination
locking device which substantially overcomes all of the
disadvantages.
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Another feature of the present invention is
to provide an electronic sequential combination locking
device which can handle various types of alarms, which
is economical to construct, easy to install, and which
may be used with automobiles, aviation and aerospace
devices, and for the protection of domestic enclosures.
According to the above features, from a broad
- aspect, the present invention provides an electronic
sequential combination locking device comprising a main
switch with a timer circuit connected thereto through a
first relay device. The timer circuit is activated by
the main switch to provide a timer output signal after
a predetermined time lapse. An electronic switching
element is connected to receive the timer output signal.
An alarm means is connected to the electronic switching
element and operable by the timer output signal. A
combination lock circuit having a plurality of manually
actionable switch circuits is operable in a predetermined
sequence to activate a second relay device and disable the
electronic switching element through a feedback connec-
tion between the first and second relay devices. The
electronic switching element when activated by the timer
output signal after the time lapse applies power to the
first relay device which activates the alarm means and
disables the combination lock circuit. The supply switch
provides a supply to an ignition circuit of an automobile.
The second relay device has two sets of contacts through
which power is supplied to the ignition circuit when the
second relay device is activated and the alarm means is
simultaneously disabled.
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BRIEF DESCRIPTION OF D:RAWINGS:
A preferred embodiment of the present invention
will now be described with reference to the accompanying
drawings in whic'n:
FIGURE 1 iS a block diagram showing the location
of the electronic sequential combination locking device
of the present invention as utilized with an automobile
ignition system, and
FIGURE 2 is a detailed schematic view showing
the construction of the electronic sequential combination
locking device of the present invention.
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DESCRIPTION OF PRFFERRED EMBODIMENTS:
Referring now to the drawings and more parti-
cularly to Figure 1, there is shown generally at 10
the electronic sequential combination locking device of
the present invention. I'he input voltage to the device
10 is connected at the input terminal 11 and taken across
the 12-volt line 8 leading from the automobile ignition
SWitC'.l 12 to the ignition coil 13. The output terminal
9 of the device 10 is also connected to the line 8 which
is open-circuited at 7. A battery 14 supplies power to
the ignition switch 12 and the line 8.
The electronic sequential combination locking
device 10 is rendered operative by a combination lock
circuit utilizing a plurality of manually actionable
switch lS mounted on a console 16, which is conveniently
secured to the dashboard of an automobile. To activate
the device 10 a predetermined sequence of these switches
is depressed within a predetermined time determined by a
timer circuit located within the device 10. With the
proper combination code depressed, continuity is achieved
between the input terminal 11 and output terminal 9
thereby providing power to the ignition coil 13 or +12V
of an electronic ignition unit (not shown) or electronic
fuel injection unit (not shown) etc., permitting an
automobile to start.
The device 10 is provided with a first output
connection 17 which activates an alarm device 18~which
can be of any suitable form such as the lights of an
automobile, a paging receiver, or a horn relay of a
vehicle. The horn 19 of the vehicle is activated by a
signal at the output 20 which provides a pulsating signal
to a horn relay 21, thus providing a pulsating 12-volt
signal to the horn.
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- Referring now to Figure 2, there is shown
the construction of the electronic sequential combination
locking device 10 and it consists of a timer circuit 22
which has an astable square wave generator 23 having an
output connection 24 connected to the base of transistor
25 through a biasing resistor 26'. The transistor 25 acts
as an inverting switch which supplies the positive pulse
required to fire the silicon control rectifier 26. The
rectifier 26 appiies the power to the winding 27 of a
relay device 28.
An alarm circuit 29 is connected to a first
contact 30 of a first set of contacts of the relay device
28~ The other contact 31 of that same set connects to a
further alarm circuit which may be, for example, the
light circuit of a vehicle or a paging transmitter. Power
to this device is prov;ded fr~m the power source connec-
tion 32 which connects through switch 33 and fuse 34 to
the contact arms 35 and 35' of the relay device 28.
Thus, when the contact arms are in their upper position
the alarms are triggered. When the contact arms are in
their initial position as shown in Figure 2, the power
supply terminal 32 is connected to the astable square wave
generator 23 through connection 36 to supply power thereto.
The period of the timer circuit is controlled by a
resistor 37 and capacitor 38. The power source is also
applied to the relay coil 27 through the relay device 28
at all times to permit the relay device to be enabled.
The alarm circuit 29 is comprised of a beeper
circuit constituted by a square wave signal generator 39
connected at an output 40 thereof to a beeper relay device
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41. The square wave generator 39 produces a square wave
output signal to the relay device 41 to activate an
alarm device with a pulsating tone. In this particular
instance the alarm device would be connected across the
output connections 42 and 43 and would be constituted
by the horn of a vehicle, if the device 10 was connected
as an automobile anti-theft device. As can be seen from
the circuit, the output connection 40 provides the
necessary supply to the relay coil 44 which causes the
switch contacts 45 and 45' to switch on and off thereby
providing a pulsating output. The supply is taken through
a connection 46 via the relay device 28 which receives its
power from supply terminal 32.
The device also com~rises a combination lock
circuit 50 having a plurality of manually actionable
switch circuits 51 through 58 connected to the power
supply line 59 through the relay contact 35 of relay
device 28 and back to the supply terminal 32. Each
electronic switch circuit 51 to 58 is comprised of a
silicon control rectifier 60 which is fired by closing an
Ø switch contact 61 whereby the anode 62 of the rectifier
60 is grounded or brought to a very low potential. When
the switch contacts 61 associated with the switch circuits
51 through 58 are depressed in a predetermined sequence
the power supply will be connected to the relay coil 63 of
the supply relay device 64 causing its contact arms 65 and
65' to engage a respective one of contacts 66 and 66'
whereby connecting the-power supply terminal 32 to the
~utput connections 67 which are connected in the ignition
switching circuit, as described with reference to Figure 1.
7 2 9
It is pointed out that switch 33 is normally
contained on the console 16 with the N.O. switch contacts
61 and depressed in sequence whereby the supply can be
pro-~ided to the output terminal 67. Should the switch-
ing circuits 51 to 58 be depressed in the wrong order,
then the relay coil 63 will not energize the relay
device 64 and after the predetermined count of the timer
device 22 the relay coil 27 will be energized causing
the alarms to trigger. Should the relay coil 63 be
energized within the proper sequence, the timer device
is disabled as the power supply connection line 70
becomes disconnected as terminal 69 of relay 64 is no
longer engaged with the switch arm 65 to which the
power supply is connected. Thus, power is removed from
transistor 25 and therefore preventing the relay device
28 from latching. The power line 59 is connected to the
contact arm 35 and the contact 31' to the power supply
and to one of the output connections 67 through contact
arm 65' of relay 64.
Resistances 71 in each of the switch circuits
51 through 58 are chosen so that ample anode current is
available to ensure reliable (holding) current for each
silicon control rectifier 60. Resistances 22' and 73
connected across relay coil 27 and 63 of relay devices
28 and 64 respectively are also chosen so that sufficient
current is avilable to ensure reliable latching and
holding of the relays. This precaution is necessary
with inductive loads such as relay coils. For the same
reason, diode 74 is used on the beeper relay device 41
to reduce the possible reverse inductive spike voltage
or current.
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With further reference to Fig. 1 it is
pointed out that if the cable 6, between the console 16
and the device 10, was to be severed, then the entire
device and vehicle would be rendered inoperative as
switch 33 is normally open to cut the main supply.
It is within the ambit of the present
invention to cover any obvious modifications provided
such modifications fall within the scope of the
appended claims. For example, the output terminal 67
of relay 64 may be connected to an electromagnet (not
shown) which would activate a dead bolt (not shown)
which w~uld secure closure device, such as a door, to
prevent access to an enclosure, such as a home. Of
course, the electronic sequential combination locking
device of the present invention may be used in many
other applications and should not be restricted to its
use in an automotive vehicle, as is described herein with
reference to an example of a preferred embodiment.
Further, there can be any suitable member of sequential
switches.
