Automobile burglar alarm

An automobile burglar alarm and theft prevention device for use in an automotive vehicle is adapted to prevent operation of the vehicle when the device is placed in an operative mode. The device comprises an alarm circuit which includes the battery of the vehicle, the alarm and vibration detectors which are adapted to close said alarm circuit upon sensing vibrations caused by automobile tampering. The device also includes an automobile operating circuit comprising the battery, the electrically powered automotive starting elements, a switch for selectively connecting either the alarm circuit or the automobile operating circuit to the battery, and a relay for (1) switching the switch to connect the alarm circuit to the battery while disconnecting the automobile operating circuit and the battery, and (2) switching the switch to connect the automobile operating circuit to the battery while disconnecting the alarm circuit and the battery, thereby disabling the electrically powered automotive starting elements at all times that the alarm circuit is connected to the battery and preventing activation of the car. In alternate embodiments, the automotive accessories are (1) operative, and (2) inoperative, regardless of whether the alarm circuit or the automobile operating circuit is connected to the battery.

FIELD OF THE INVENTION 
This invention relates generally to the field of automotive burglar alarms 
and more particularly to an automobile burglar alarm and theft prevention 
device which, when activated, disables the engine of the automobile. 
BACKGROUND OF THE INVENTION 
Since automobiles are often parked in secluded, unattended areas for 
lengthy periods of time, they have become prime targets for thiefs and 
vandals. Some thiefs are so skilled that they are able to steal a locked, 
parked car in a matter of seconds. A percentage of the car-driving public, 
in an effort to deter, if not halt such burglary, have installed alarm 
systems in their automobiles. Such alarm systems as heretofore known are 
adapted to sense vibrations of the automobile which occur when the doors, 
trunk or hood of the vehicle are opened. 
Burglars, in response to known alarm systems, have developed techniques for 
cutting alarm wires without triggering the alarm circuitry. After so 
disabling the alarm, the burglar "hot wires" or otherwise starts the 
automobile and drives away to sell the vehicle en masse or to sell it for 
parts. So, while alarm systems heretofore developed might hinder amateur 
vandals, the professional burglar is not deterred. 
It is one object of the present invention to provide an automobile burglar 
alarm and theft prevention device which prevents operation of the 
automobile starting elements when the alarm is in its operative condition 
so that the automobile cannot be started, even after disabling the alarm. 
It is a further object of the present invention to provide an automobile 
burglar alarm and theft prevention device which is activated by a 
high-frequency transmitter. 
It is still another object of the present invention to provide an 
automobile burglar alarm and theft prevention device which prevents 
operation of the automotive accessories as well as the automotive starting 
elements when the alarm is in its operative condition. 
These and other objects and advantages of the present invention will become 
apparent from the review of the drawings and the detailed description of 
the invention which follows. 
SUMMARY OF THE INVENTION 
There is disclosed herein an automobile burglar alarm and theft prevention 
device for use in an automotive vehicle. The automotive vehicle is 
conventional in operation and includes a twelve volt D.C. battery, 
electrically powered automotive starting elements, electrically powered 
automotive accessories, and a selectively positionable ignition switch. 
The ignition switch is adapted to draw power from the battery to start the 
automobile and operate the automotive accessories when in a first position 
and the ignition switch is adapted to draw power from the battery to 
operate the automotive accessories without starting the automobile when in 
a second position. 
The automobile burglar alarm and theft prevention device includes an alarm 
circuit, an automobile operating circuit, and a switch for selectively 
connecting either the alarm circuit or the automobile operating circuit to 
the battery of the automobile. The alarm circuit includes the battery, an 
alarm signal, and vibration detectors for sensing automobile tampering and 
operative upon sensing vibrations to close the alarm circuit when the 
alarm circuit is connected to the battery. The automobile operating 
circuit includes the battery and the electrically powered automotive 
starting elements. 
The burglar alarm and theft prevention device also comprises an element for 
(a) switching the switch to connect the alarm circuit to the battery while 
disconnecting the automobile operating circuit and the battery, and (b) 
for switching the switch to connect the automobile operating circuit to 
the battery while disconnecting the alarm circuit and the battery, thereby 
disabling the electrically powered automotive starting elements at all 
times that the alarm circuit is connected to the battery. 
In one embodiment the switch includes an alarm switch which connects and 
disconnects the alarm circuit to the battery and a start switch which 
connects and disconnects the automobile operating circuit to the battery. 
In a second embodiment the switch includes an alarm-start switch for 
either connecting the alarm circuit to the battery while disconnecting the 
automobile operating circuit and the battery, or connecting the automobile 
operating circuit to the battery while disconnecting the alarm circuit and 
the battery.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring now to the drawings and particularly to FIG. 1, one preferred 
embodiment of the automobile burglar alarm and theft prevention device of 
the present invention is illustrated generally by the reference numeral 
10. The automobile burglar alarm and theft prevention device 10 is adapted 
for use with a conventional, electrically started automotive vehicle, such 
as 12, shown diagrammatically in FIG. 6. 
Conventional automotive vehicles such as 12 include a plurality of internal 
compartments susceptible to forceable entry techniques by experienced 
burglars and car thieves, as well as by novice vandals and joy-riders. 
These compartments comprise an engine cavity 14 in which the engine, the 
drive train and the electrical system of the vehicle are housed; a trunk 
cavity 16 in which the spare tire, luggage and other valuables may be 
housed; and the passenger cavity 18 in which the vehicle controls are 
positioned and personal belongings are often left unattended. In order to 
gain access to these compartments, hood locks, trunk locks and door locks 
must be opened. 
Still referring to FIG. 6, vibration detecting devices 20, 22, 24, and 26 
are attached to the doors 21, 23, 25, and 27 of the automobive vehicle 12. 
Similar vibration detecting devices 28 and 30 are attached, respectively, 
to the hood 29 and trunk 31 of the automotive vehicle 12. These devices 
are adapted to be sensitive to and detect vibrations incident to opening 
the doors, hood or trunk of the vehicle 12. The vibration sensing devices 
20, 22, 24, 26, 28, and 30 are shown schematically as 34 in FIGS. 1 and 5, 
but are actually connected in parallel so that the activation of any one 
of the individual devices 20, 22, 24, 26, 28, or 30 will operate to close 
an alarm circuit and produce an alarm signal when that alarm circuit is 
operatively connected to the battery of the vehicle 12. 
Within the engine compartment 14 of the conventional automotive vehicle 12, 
a 12-volt DC battery 32 provides the electrical power for (1) starting the 
engine by energizing the automobile starting elements, shown generally as 
36, and (2) operating various automobile accessories, shown generally as 
38. The accessories 38 normally include a radio, heater, windshield 
wipers, etc. The starting elements 36 normally include such devices as a 
coil, a bendix, and a starter. The battery 32 is part of an automobile 
operating circuit which circuit, in the preferred embodiment of FIG. 1, 
also includes the automobile starting elements 36 and a switch means. The 
battery 32 may be selectively connected or disconnected to the automotive 
starting elements 36 by, respectively, closing or opening the switch means 
and then turning on or off an ignition switch 42. The switch means 
includes alarm switch relay means 50, an alarm switch 46, start switch 
relay means 48 and a start switch 40. The start switch 40 is movable 
between a first position, shown in phantom lines in FIG. 1 (position X), 
in which said automobile operating circuit is operable, i.e., is able to 
draw power from the battery, and a second position, shown in solid lines 
in FIG. 1 (position Y), in which said automobile operating circuit is 
inoperable, i.e, cannot draw power from the battery 32. When the starting 
switch 40 is in operable position X, movement of the ignition switch 42 to 
position C will activate the electrically powered starting elements 36. 
It should be clear that with the start switch 40 in its operable, closed 
circuit position (position X) and the ignition switch turned to its "on" 
position (position C), the automobile operating circuit is closed and 
power from the battery 32 is delivered to the automotive starting elements 
36 and the automotive accessories 38. It should be further noted that the 
automotive ignition switch 42 commonly includes a position (position B) 
for energizing the accessories thereof without starting the automotive 
vehicle 12. In this position, as in the "on" position, the automobile 
operating circuit is closed, but now power is supplied only to the 
accessories 38 and not to the automobile starting elements 36. The 
ignition switch 42 also has an off position (position A) in which the 
starting elements and the accessories are inoperative, i.e., can receive 
no power from the battery 32. As the aforementioned 
tri-position(off-accessory-on) ignition switch 42 is conventional and 
forms no part of the instant invention, further description thereof is 
believed to be unnecessary. 
The automotive vehicle 12 is also provided with an alarm circuit which 
includes the battery 32, an audible and/or visual alarm means 44, a 
selectively operable alarm switch 46 for selectively connecting or 
disconnecting the alarm means 44 to the battery 32, and the vibration 
detection means 34. The vibration means 34 senses automobile tampering and 
is operative, upon sensing vibrations, to close the alarm circuit when the 
alarm switch 46 connects the battery 32 to the alarm means 44. 
The alarm switch 46 is positionable in two positions, M and N. By 
selectively positioning the alarm switch 46 into an alarm connect 
(position M) or an alarm disconnect (position N) position, either the 
automobile operating circuit or the alarm circuit is rendered operative, 
i.e., connected to the battery 32. More specifically, with the alarm 
switch means 46 connecting the alarm means 44 and the battery 32 (position 
M), a vibration sensed by any of the vibration detection means 34 will 
close the alarm circuit, thereby activating the alarm means 44. Likewise, 
with the alarm switch means 46 in position N, a start switch relay 48 is 
activated to move start switch 40 from its normally open, spring biased 
position Y into its closed position, position X. When the alarm switch 
means 46 is in position N and the start switch 40 is in position X, the 
ignition switch receives power from the battery 32 to energize the 
automotive starting elements 36 or the automobile accessories (depending 
upon the ignition switch position). 
It should be noted that the accessories 38 are operable only at such time 
as the alarm switch 46 is in position N, thereby closing the automobile 
operating circuit. The accessories cannot be operated when the alarm 
circuit is operable. (position M). 
The alarm switch means 46 is moved between its two positions by an alarm 
switch relay 50 which reacts to signals generated by a pulse generator 52 
which may be part of a radio receiving unit 54. The radio receiving unit 
54 responds to high frequency waves from a push button transmitter 56. The 
receiver 54 and transmitter 56 are similar to the receiver and transmitter 
commonly employed with automatic garage door openers and further 
explanation thereof is believed unnecessary. 
It is to be understood that Applicant is not limiting his invention for use 
with a high frequency transmitter and relay switches, but any conventional 
switches and switch activating means may be employed without departing 
from the spirit and the scope of the invention. 
An alternative preferred embodiment of the automobile burglar alarm is 
illustrated in FIG. 5 wherein like numbers have been used to refer to 
elements substantially identical with those of FIG. 1. In FIG. 5, the 
alarm switch 46 and the start switch 40 have been replaced by a single 
alarm-start switch 41, and the alarm switch relay 50 and the start switch 
relay 48 have been replaced by a single alarm-start switch relay 49. In 
this simplified embodiment, as in the FIG. 1 embodiment, it is of primary 
importance that the automobile operating circuit be disabled, i.e., not 
connected to the battery 32, when the alarm circuit is connected to the 
battery 32, and that the alarm circuit be disabled, i.e., not connected to 
the battery 32, when the automobile operating circuit is connected to the 
battery 32. 
The connection of the battery 32 to either the alarm circuit or the 
automobile operating circuit is accomplished by moving the alarm-start 
switch 41 either to position M or to position N. In order to render the 
alarm circuit operative, it is also necessary to place the ignition switch 
42 in its off position, position A, wherein power is delivered via the 
ignition switch 42 to the alarm means 44. With the alarm-start switch 41 
in position M and the ignition switch 42 in position A, vibrations 
detected by the vibration detecting means 34 will close the alarm circuit 
and activate the alarm means 44. In order to render the automobile 
operating circuit operative, it is also necessary to place the ignition 
switch 42 in its "start" position, position C, wherein power is delivered 
via the ignition switch 42 to the starting elements 36. 
It should be apparent from a review of FIG. 5, that, in this embodiment, 
the accessories 38 are adapted to always be operable, i.e., to always draw 
power from the battery so as to be energizable whether (1) the alarm-start 
switch 41 is in position M or N, or (2) the ignition switch 42 is in 
position A, B, or C. More specifically, when the ignition switch 42 is in 
position B, and the alarm-start switch 41 is in position N, power is 
provided directly to the accessories 38. When the ignition switch 42 is in 
position C and the alarm-start switch is in position N, since the 
accessories 38 are disposed in parallel relation to the starting elements 
36, power is provided directly to the accessories 38 as well as to the 
starting elements 36. And when the ignition switch 42 is in position A and 
the alarm-start switch 41 is in position M, power is provided to the 
accessories 38 from the battery 32 via the ignition switch 42 and the line 
43. 
If the alarm-start switch 41 is in position M and the ignition switch 42 is 
moved into position C in an effort to start the vehicle 12, the automobile 
operating circuit is open and the vehicle 12 cannot be started. Likewise, 
if the alarm start switch 41 is in position N and if any of the vibration 
sensing detectors 34 are closed, the alarm means 44 will not be activated 
because the alarm circuit is open. 
FIGS. 2-4 illustrate one type of electro-mechanical "micro-switch" which 
can be used as (1) a combination alarm switch 46, alarm relay 50, pulse 
generator 52 and receiver 54 in the FIG. 1 embodiment of the burglar 
alarm; or (2) a combination alarm-start switch 41, alarm-start switch 
relay 49 and receiver/generator 54 in the FIG. 5 embodiment of the burglar 
alarm. 
The micro-switch 50 includes a lower casing 51 in which the radio receiver 
elements are housed. These elements, being well known and conventional, 
and not being claimed as part of the instant invention need not be further 
described. 
Attached to the lower casing 51 is an upper switching unit 53 which 
includes a set of windings 54 having terminals T.sub.4 and T.sub.5, 
surrounding a lontitudinally reciprocable plunger 59. A coil spring 58 is 
compressed between a wall 60 of said unit 53 and an upwardly extending 
finger 62 so as to normally bias said plunger 59 outwardly of the interior 
of a housing 64 of the unit 53. A flanged frame 66 which surrounds the 
unit 53 secures said unit 53 to the upper surface 68 of the lower casing 
51. 
A flat plate 70, having a slot 74 through which the upper end of the finger 
62 extends, forms a base for an upper casing 72. Interiorly of the upper 
casing 72 is housed a latching relay 76 which comprises (1) a pair of 
terminals T.sub.1 and T.sub.2 contact surfaces 82 and 84, respectively, 
formed at the distal ends thereof; (2) a reciprocating switch having a 
spring biased pin 86 formed from a non-conductive material attached to 
sleeve member 90 formed from a conductive material, the sleeve member 90 
is reciprocable within bearings 88, and further includes a pair of 
elongated conductive elements 92 and 94 having contact surfaces 96 and 98, 
respectively, formed at the distal ends thereof; and (3) a terminal 
T.sub.3 which is always adapted for connection to the battery 32. 
A thin elongated rod 102 is secured at one of its distal ends 104 to the 
housing 64. The other distal end 106 of the rod 102 is pivotably secured 
within an opening 108 in a cam plate 110. The cam plate 110 is pivotably 
connected at 112 to the plate 70 and further includes a generally V-shaped 
opening 114 which receives the upper end of finger 62. Due to the action 
of a coil spring in sleeve 90, the end of pin 86 is biased against the rod 
102 approximate the mid-point of its length. 
In operation, the terminal T.sub.1 is connected to position M (shown in 
FIGS. 1 and 5) such that, when closed, it will connect the alarm means 44 
to the battery 32; the terminal T.sub.2 is connected to position N (shown 
in FIGS. 1 and 5) such that, when closed, it will connect the starting 
elements 36 to the battery 32; the terminal T.sub.4 is connected to ground 
or to the negative terminal of the battery 32; the terminal T.sub.5 is 
connected to the input of the windings 54 so that the receiver/generator 
is always operative to receive a signal from a transmitter such as 56; and 
the terminal T.sub.3 is always connected to the battery 32 and to the 
bearing sleeve 86 so that either the terminal T.sub.1 or the terminal 
T.sub.2 will always be "hot" and power either the alarm circuit or the 
automobile operating circuit. 
When the receiver 54 receives a signal from transmitter 56, the windings 54 
operate as an inductor coil and reciprocate the plunger 59. The finger 62 
moves within the V-shaped opening 114 in the cam plate 110 to move said 
cam plate 110 about pivot 112. The rod 102, being pivotably secured to cam 
plate 110 at 108, moves as said cam plate 110 moves and pushes against the 
spring bias of pin 86 so as to bring contact surfaces 84 and 98 into 
electrical contact, thereby connecting the battery 32 and the alarm means 
44 while opening the automobile operating circuit (since the contact 
surfaces 82 and 96 are simultaneously moved out of electrical engagement). 
When the receiver 54 receives a second signal from the transmitter 56, the 
process is reversed and the rod 102 pivots away from the upper housing 64 
so that the pin 86 is biased outwardly to abut the surface of rod 102. As 
the pin 86 moves outwardly, contact surfaces 84 and 98 move out of 
electrical engagement while contact surfaces 82 and 96 move into 
electrical engagement. In this manner, the signal from the transmitter 56 
operates to move alarm-start switch 41 into a closed alarm circuit 
position (position M) or a closed automobile starting circuit position 
(position N). 
While one form of the invention has been described, it will be understood 
that the invention may be utilized in other forms and environments, so 
that the purpose of the appended claims is to cover all such forms of 
devices not disclosed but which embody the invention disclosed herein.