Note: Descriptions are shown in the official language in which they were submitted.
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Background of the Invention
This invention is related to anti-theft devices
for automotive vehicles, and more particularly to digital
means for preventing the energization of either the engine
starting motor or the ignition coil unless the digital means -
are manipulated to predetermined selected positions.
Automobiles are often stolen because the owner has
forgotten the ignition key in the ignition swi~ch, or because
the ignition key was left in a parking lot to provide an
opportunity for an attendant to either duplicate the key or
to observe the code of an anti-theft system.
A variety of systems have been disclosed in the
prior art for use in automobiles to prevent theft. Such
prior art systems usually fail to deter thieves who physically
remove the ignition key mechanism and then "hot wire" the
starting motor and the ignition coil.
Summary of the Invention
The broad purpose of the present invention is to
pro~ide à digital control means which the user must manipulate
to a coded sequence of numbers in order to energize the vehicle.
The digital means is prominently mounted adjacent the dash
board, readily accessible to the user A hidden switch,
also accessible to the user, allows him to select either of
two coded numbers to be entered on the digi~al means to
energize the starter. Although a person such as a parking
lot attendant may be aware of one of the coded numbers, he
would not be aware of the other.
The preferred system incorporates a normally open
switch between the ignition switch and the starting system
which prevents the starting motor from being energized ~`~
unless the digital means are in a coded sequence. Upon
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starting the vehicle, the user readjusts the digital control means to a
random number so that if a thief takes the vehicle while the engine is
running, he cannot restart it in the event the engine stalls or is
de-energized.
In the preferred embodiment of the inYentiOn, both the starting
motor and the ignition coil are provided with circuitry for grounding a
hot wire should a thief attempt to directly connect either of these
devices to the battery without first properly adjusting the digital
control means and turning the ignition key in the conventional manner.
The preferred embodiment of the inventlon requires a minimum
of mechanical and electrical components, all commercially and readily
available and which can be easily installed in a con~entional automotive
~ehicle.
The digital control means preferably has a multiple wire cable
connecting the control housing to the vehicle to make it difficult for
a thief to select the wires that actually connect the control means to
the ignition circuit. Should the thief cut all the wires leading from
the control deYice, the starting motor cannot be energized because of
its grounded condition.
In accordance with the present invention, there is provided
in combination with a motor vehicle having an engine, a source of
electrical energy, and electrical starter means operable to turn said
engine, a plurality of digital members, each digital member being mov-
able to a plurality of positions, including a first selected position
and a second selected position, said digital members being disposed in
a first coded arrangenent when each digital member is disposed in its
respective first selected position, and being disposed in a second
coded arrangement when each digital member is disposed in its respective
second selected positioni an ignition key; electrical circuit means
including an ignition key switch for connecting said source of electrical
energy to said starter means to energize same at such times as the
ignition key is in a predetermined position in said ignition switch; a
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control switch ~ovable between a first position and a second position,
said control switch being connected in said circuit means such that the
starter means is connected to the source of electrical energy to turn
said engine in response to manipulation of the key in said ignition key
switch either when the control switch is disposed in said first position
and the digital members are disposed in said first coded arrangement, or
the control switch is disposed in said secc>nd position and the digital
members are disposed in said second coded arrangement, but manipulation
of the key in said ignition switch is inoperable to energize the starter
means when the digital members are not in a coded arrangement correspond-
- ing to the position of the control switch.
In accordance with the present invention, there is also pro-
yided in combination with a motor vehicle having an engine, a vehicle
frame; a battery having a first pole and a second pole; electrical
starter means; an ignition coil in said ignition circuit; first con-
ductor means connecting the vehicle frame to the starter means to prevent
energization thereof, and a first switch for opening said first con- ~ :
ductor means; second conductor means connecting the vehicle frame to the
ignition coil to prevent energization thereof, and a second switch for
opening said second conductor means; means connecting the first pole of
the battery to the frame; an ignition key; electrical circuit means
including an ignition key switch; and a plurality of digital members,
each digital me~ber being movable to a plurality of positions, including
a first selected position and a second selected position, said digital
members being disposed in a first coded arrangement when each digital
member is disposed in its respective first selected position, and being
disposed in a second coded arrangement when each digital member is dis-
posed in its respective second selected position; a control switch mov-
able between a first position and a second position, said control switch
being connected to the c:ircuit means such.that it is adapted to form a
connection between the second pole of the battery and both the starter
means and the ignition coil when the control switch is disposed in
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either said first position and the digital members are disposed in said
first coded arrangement, or in said second position and the digital
members are disposed in said second coded arrangement; and the ignition
key switch is so connected to the first switch and the second switch to
open same in response to the key being moved in said ignition key switch
whereby the starter means and the ignition coil are energized by the
battery.
Still further objects and advantages of the invention will
become readily apparent to those skilled in the art to which the invention
pertains upon reference to the following detailed description.
Description of the Drawings
The description refers to the accompanying drawings in which
like reference characters refer to like parts throughout the several
views, and in which:
FIGURE 1 is a diagrammatic view of the preferred
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embodiment of the invention; and
FIGURE 2 is a schematic view showing the manner
in which the digital control means is wired.
Description of the Preferred Embodiment
: Referring to the drawings, Figure 1 illustrates
a conventional automotive vehicle engine 10 having a starter
12 operatively connected to a solenoid 14.
An ignition switch 16 is operated by a key 18
which is movable between several conventional positions
including a "start" position illustrated in ~igure 1, and
an "ignition contact circuit" position illustrated in
phantom at "A".
A battery 20 has a pole 22 connected by conductor
24 to ignition switch 16, and a second pole 26 connected
by conductor 28 to vehicle frame 30 to which the battery
is grounded. When key 18 is in its start position, it is
operable to provide a full 12 volts to starting motor 12
as well as voltage to an ignition coil 32. When engine 10
is turning over, the user releases key 18 which then moves
toward position "A" to de-energize the starter but continue
providing current to the ignition coil.
A circuit 34 provides means for conducting
energy from battery 20 to starter 12, and a circuit 36
provides means for electrically connecting the battery to
the ignition coil. Each of the circuits depend upon key 18
~eing in a predetermined position with respect to ignition
switch 16.
Circuit 34 includes conductor means 38
connecting ignition switch 16 to solenoid 14. A normally
open relay contact is inserted in conductor means 38
between switch 16 and solenoid 14. A normally closed relay
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contact 50 has one side connected between contact 40 and
solenoid 14, and its oppositc side grounded at 30. Thus
the starter solenoid is electrically grounded at such times
as relay contact 40 is open an~ relay contact 50 is closed.
Digital means 42 is connected by conductor 44
to conductor 38 between relay contact 40 and ignition
switch 16. A relay 48 has one side of its coil connected
between digital means 42 and its opposite side connected
to ground 30 by conductor 52.
Digital means 42 includes a three station thùmb
wheel switch 56 mounted in housing 54, and includes three
digital members 58, 60, and 62 which may be individually
manipulated by the user to a selected position chosen from
a possible ten positions. Relay 48 cannot be energized
to open contact 50 and close contact 40 unless digital
means 42 has been set to a selected position of digital
members 58, 60, and 62. A three pole double-throw switch
64 illustrated in Figure 2 is either mounted in housing 54
or is remotely mounted.
Preerably a 30 wire cable 66 is connected to
housing 54 and has a plurality of wires 68 connected between
th~ digital switch and the automotive vehicle body (not
shown? as well as conductors 44 and 46.
Referring to Figure 2, a thumb wheel switch 56
has three stations 68, 7~, and 72, each station having
ten output terminals and a pair of common terminals. ~ -
Each terminal of each station is connected to the
com~lon terminal. Each station also has two seIected
terminals connected to provide alternative paths for connecting
the ignition switch to relay coil 48. Thus two selected
sequences of numbers are wired to slide switch S4, illustrated
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in Figure 2, so that the user can form a connection between
the ignition switch and relay coil 48 depending upon the
position of switch 64 which is mo~able between either an
upper position or a lower position. Switch 64 has button 74
mounted on housing 54 so as ~o have two operative positions
depending upon whether button 74 is in its upper position or
its lower position. Switch 64 has three upper terminals 76,
78, and 80 normally closed to terminals 88, 90, and 92,
respectively, when button 74 is pushed upwardly.
Three lower terminals 82, 84, and 86 are open
when the button is in its upward position. In the downward
position, a common terminal 88 is connected ~o terminal 82, ~`~
a common terminal 90 is connected to terminal 84, and a
common terminal 92 is connected to terminal 86.
The user wires switches 56 and 64 for two sepera~s
discrete numbers each composed of three digits. Assuming the
first discrete nunber is 2 3 4, a conductor 94 is connected
between terminal No. 4 of station 68 and terminal ~o. 3 of
station 70. A conductor 96 connects the common terr,linal
o1~ station 70 to the common terminal 88 of switch 64~ and
to termina1 76 to terminal No. 2 of sta~ion 72. The common
terminal of station 72 is connected to relay coil 48.
The arrangement is such that when button 74 is
in its upper position. a circuit is completed from the common
terminal to terminal No. 4 of station 68, to terminal No. 3
of station 70, and then from the common terminal of station 70
to the common terminal 88 throu~h to terminal 76 of switch 64,
through conductor lO0 to terminal No. 2 of station 72, then
to the common terminal of station 72 to relay 48.
Assuming the other discrete numbsr is 5 6 7,
conductor lOZ is connected from terminal No. 7 of station 68
to terminal 92 of switch 64. A conduc~or 104 con~ects
terminal 9~ to terminal No. 6 of station 70~ and a conductor
106 connects terminal 8~ to terminal No. 5 of station 72.
Continuity through the first set of discrete numbers 2 3 4
is bro~en and continuity established between terminals
5 6 7 when the button is in its lower position.
The arrangement is such that each of the Ihumb
wheels of stations 68, 70, and 72 can be moved to any of
ten positions. However, when button 74 of switch 64 is in
its upper position, the thumb wheels must be moved to positions
in which they establish continuity through terminals 2, 3,
and 4 of the three stations to establish continuity between
the ignition switch and relay coil 48. When button 74 is in
its lower position, the thumb wheels must be manipulated to
the stations establishing contact through terminals 5, 6, and
7 to energize coil 48. It is apparent that the use~ can wire
the three stations to any desired three digit code. Although
the button of slide switch 64 is illustrated as being mounted ~ -
on the side housing 54, it can be mounted in any convenient
place within the passenger compartment of the vehicle.
When relay 48 is energized, normally open relay
contact 40 closes to energize starter 12, and normally closed
contact 50 opens the ground connection between the starter
and ground conductor 52. Preferably, after starting the
engine the user rotates the thumb wheels to a random
sequence so that the vehicle cannot be started again unless
the digital control means is manipulated to the exact coded
sequence. Similarly, when button 74 is in its lower position,
starter 12 can be started only when the app~opriate discrete
number 5, 6, and 7 is arranged by manipulating digital
members 58, 60, and 62.
Referring to Figure 1, conductor 110 connects the
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ignition contact terminal Or ignition switch 16 to ignition
coil 32. The output of ignition coil 32 is through a
conductor 112 to the distributor to energize the spark
plugs (not shown), and through a conductor 114 to an appropriate
pulse generating system (not shown) in the manner well ~nown
to those skilled in the art. A normally open relay contact 118
is connected in conductor 110. One side of coil 120 of
contact 118 is connected in conductor 124 to a normally
closed relay contact 128 and to ground 30. When relay 120
is energized, its normally closed contact 128 opens and
its normally open contact 118 closes.
Conductor 110 is connected to an ignition coil
terminal 130 which is normally the terminal connected by a
hot wire (not shown) employed by a thief for connecting the
battery to the ignition.
Assuming the engine has not been started and key 18
is not in the engine start position, switch 128 is closed
to ground the ignition coil. When a hot wire is connected
to terminal 130, the thief experiences an electrical shock
because the positire side of the battery is also connected
to ground. In many cases, his jumper wire will burn up in
his hand.
When the engine has been properly started by
appropriately manipulating the digit control means with
key 18 in the start position, relay 120 automatically
closes contact 118 to energize the ignition coil and opens
contact 128 ~o break the connection between terminal 130
and ground.
Thus the user can leaYe his key 118 in the
ignition switch and safely leave his vehicle as long as the
digit oontrol means is not in the properly coded position.
The thief then has to take the time to manipulate the three
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thumb wheels to a properly coded position. If he believes
he knows the properly coded position he may be attempting
an impossible task if the button 74 is in the wrong
position.
Assuming the thief attempts to hot wire the
vehicle, he will make only a connection between the battcry --
and ground to form a shower of sparks for his efforts.
A by-pass switch (not shown) can be connected in conductors
52 and 12~ to enable a mechanic to pe~form repairs. A
light 130 is mounted above members 58, 60, and 62 for
illuminating the digit means by appropriate connections
to ~he dome light circuit (not shown) of the vehicle so
that the user can start the vehicle in the evening. The ~
digital switch may be of the type internally luminated by - - -
light emitting diodes (LED).
Having desc~ibed my invention, I claim:
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