US3863212A

US3863212A - Thief alarm for a vehicle or the like

Info

Publication number: US3863212A
Application number: US276073A
Authority: US
Inventors: Wladimir Nyc
Original assignee: Individual
Current assignee: Individual
Priority date: 1970-03-20
Filing date: 1972-07-28
Publication date: 1975-01-28
Anticipated expiration: 1992-01-28

Abstract

A thief alarm comprising a cylinder lock including means for establishing a ground circuit when the lock cylinder is partially rotated by a thief attempting to jimmy the lock. Means are provided for protecting the lock against unauthorized access, whether by removing the lock from its mounting, or by cutting through a shield for the lock, or by gaining access through other openings into the interior of a compartment guarded by the lock or containing, for example, electrical equipment controlled by the lock if the lock is intended as an electrical switch actuating lock. Such guards are arranged to complete the grounding circuit, and grounding of the circuit actuates an alarm. The lock is provided with selective means for disarming the alarm. The lock includes a piston engaged in an opening when the lock is in locked position, electrical contact means being provided in the opening which may be engaged by the piston when the lock cylinder is partially rotated when the piston has not been moved into the position conforming the insertion of a proper key into the lock.

Description

[ 1 Jan. 28, 1975 Nyc l l THIEF ALARM FOR A VEHTCLE OR THE LIKE [76] lnventor: Wladimir Nyc, 5254 San Jose Blvd.,

Jacksonville. Fla. 32207 [22] Filed: July 28, 1972 [21] Appl. No.: 276,073

Related US. Application Data [63] Continuation-impart of Ser. No.'2l,368, March 20,

1970, abandoned.

[52] US. Cl. 340/64, 307/10 AT, 200/44 [51] Int. Cl. B60r 25/10 [581 Field of Search 340/63, 64, 65; 200/42 R, 200/44; 180/114; 307/10 AT [56] References Cited UNITED STATES PATENTS 2,637,789 5/1953 Critchfield et al 200/44 2,782,396 2/1957 Marsh et al 340/63 2,839,736 6/1958 Tinsley et al. 340/63 3,219,767 ll/1965 Shrode et al 200/44 3,281,785 10/1966 Oursler 340/63 3,427,413 2/1969 Hawkins 200/44 3,485,969 12/1969 Millen 200/44 3,541,505 11/1970 Lee 340/64 3,648,491 3/1972 Kennard 200/44 Primary E.\'uminerAlvin H. Waring Attorney, Agent, or Firm-George H. Baldwin; Arthur G. Yeager [57] ABSTRACT A thief alarm comprising a cylinder lock including means for establishing a ground circuit when the lock cylinder is partially rotated by a thief attempting to jimmy the lock. Means are provided for protecting the lock against unauthorized access, whether by removing the lock from its mounting, or by cutting through a shield for the lock, or by gaining access through other openings into the interior of a compartment guarded by the lock or containing, for example, electrical equipment controlled by the lock if the lock is intended as an electrical switch actuating lock. Such guards are arranged to complete the grounding circuit. and grounding of the circuit actuates an alarm. The lock is provided 'with selective means for disarming the alarm. The lock includes a piston engaged in an opening when the lock is in locked position, electrical contact means being provided in the opening which may be engaged by the piston when the lock cylinder is partially rotated when the piston has not been moved into the position conforming the insertion of a proper key into the lock.

18 Claims, 12 Drawing Figures Patented Jan. 28, 1975 5 Sheets-Sheet 1 FIG.|

. FIGS FIG.4

Patented Jan. 28, 1975. 3,863,212

5 Sheets-Sheet 2 FIG..

. .1 TI-IIEF ALARM FOR A VEHICLE on THE LIKE This application is a continuation-in-part of my now abandoned application Ser. No. 2l ,368, filed Mar. '20, 1970, and nowabandoned.

An object of theinvention is to provide a lock system which will make it extremely difficult if not impossible for a thief or robber to pick the lock without sounding an alarm.

It is a further object of the invention to provide an ignition and doorlock alarm system for an automobile which is relatively simple and inexpensive, yet which will operate unfailingly to sound an alarm when an unauthorized person attempts to pick the lock of a door of the automobile, or having gained access to the interior, to pick the ignition lock, or to gain, by opening the hood of the automobile, access to the battery, starter switch and ignition circuits for the purpose of jumping the ignition.

The novel features which are believed to be characteristic of this invention are set forth with particularly in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, in which:

FIG. 1 is a partially sectional side view of lock assembly in accord with the invention;

FIG. 2 is a sectional end view taken along line 2 2 of FIG. 1;

FIG. 3 is a view similar to FIG. 2 but showing parts in positions assumed when the lock cylinder has been turned by a key;

FIGS. 4 and 5 are sectional views on an enlarged scale showing portions of a typical lock cylinder useful in the invention,

FIG. 6 is a detail view, partially in section, showing piston portions of the lock cylinder of FIGS. 4 and 5; FIG. 7 is a detail view partially broken away and in section showing the internal key-following pins or tumblers of the lock cylinder;

FIG. 8 is a fragmentary detail view, partially in section, showing portions of the hood and adjacent portions of an automobile with elements of the invention applied thereto;

FIG. 9 is a schematic diagram of an automobile ignition circuit protection system in accord with the invention;

FIG. 10 is a side elevational view of a lock in accord with the invention specifically adapted for door locking protection;

FIG. 11 is a sectional view taken along line 11 ll of FIG. 10; and

FIG. 12 is a schematic diagram of an automobile protection system including an alarm protecting against tampering with or picking of door or ignition locks.

According to one aspect of the invention, a novel lock mechanism of the rotatable cylinder type, such as that shown and described in US. Letters Pat. No. 3,630, and in subsequent modifications and developments thereof exemplified, for example, in U.S. Letters Pat. No. 2,294,495; No. 3,2l9,767; and No. 3,427,413, the locksbeing characterized by a piston or pin which is movable laterally with respect to a rotatable cylinder by means of an inserted key, the movement being inwardly and outwardly of the lock body, from a locked position in which the pin spans between the cylinder and the lock body to prevent the rotation of the cylinder with respect to the body, into an unlocked position in which the piston or pin is retracted into either the cylinder or lock body and is no longer engaged in an opening in the other of such members. According to the invention, such opening from which the pin'is retracted is provided with one or more internal electrical contact means for closing an electrical circuit when an attempt is made to rotate the cylinder without having theretofore moved, such as by means of a proper key in the lock, all of the pistons and pins into the proper position corresponding to the unlocked condition of the lock.

Further in accord with the invention, such lock may be used as an ignition lock in an automobile and provided with the novel alarm circuit shown schematically in FIG. 9. With an additional switching provision, such lock may be used on the doors of a vehicle and connected with an alarm system, which systemalso includes, preferably, an ignition lock-according to the invention, such as isshown schematically in FIG. 12.

The lock as used for ignition circuit control is shown in FIGS. 1 8, and, as adapted for use in locking doors, is shown in FIGS. 10 and 11.

As seen in FIG. I, the ignition lock 1 includes a face plate 2 having a rim 3 engaged against dash 4, it being understood that a key opening, (not shown) is exposed in the usual manner approximately centrally of the face plate. The lock, immediately behind the dash, is provided with a protective cover assembly or container 5 which includes an outer. electrically conductive shell 6, an inner conductive shell 7, and an insulating layer 8 interposed therebetween. The shell extends from substantially the dash to and through the tire wall 9 of the vehicle. The outer shell 6 is grounded by contact with the metal lock body 10 and therethrough to the dash, and by direct contact with the metal fire wall, or by other appropriate means. All of the operative elements of the lock are disposed within the protective housing, and should one attempt to improperly gain access to the lock, or to the protective elements associated therewith, by using a hack saw or the like to saw through the shield 5, the blade upon cutting through the outer wall 6 and the insulating layer 8 will establish contact between walls 6 and 7, thereby establishing a ground connection to wall 7, which, in turn is connected through conductor 11 to an alarm circuit.

The lock body 10 is retained in position by means of depressable spring clips or ears 12. A suitable switch mechanism (not shown) actuated by the lock cylinder is incorporated in an insulated plastic plug or housing 13 fixedly mounted in shield assembly 5.

A small rod 14 of conductive material is slidably mounted in

small metal bosses

15 and 16 extending from a side of the lock body 10. The forward end 17 of rod 14 bears against a shoulder 18 formed on the lock body, while the other end 19 of the rod is urged forwardly by a compression spring 20 footing on fixed plastic switch housing 13. Should any attempt be made to extract the lock body forwardly through the dash, rod 14 would move forwardly along with the lock body under the influence of spring 20. The rod carries a small laterally projecting electrical contact 21 which is grounded through the

bosses

15, 16 to the lock body, as well as by the contact'of end 17 of the rod with the shoulder 18. A cooperating stationary electrical contact 22 is mounted to the insulated stationary switch housing 13 so as to be in a position to be contacted by contact 21 upon any forward motion of the lock body. Contact 22 is electrically connected by a the lock body and includes a metal casing 25 grounded to the lock body and internally connected to a switch contact normally connecting conductor 26 to ground. Depressing switch buton 27 operates switch 24' to disconnect conductor 26from ground.

Below switch 24 the lock body is arcuately slotted as seen at 28, and an arm 29 connected-to the rotatable cylinder within the body extends outwardly through the slot, in a vertically downward direction when the switch is in locked position. Arm 29 terminates downwardly in a blade portion 30. Means for unlatching the vehicle hood include a handle 31 exposes through the dash and connected to core 32 ofcoaxial cable 33. The core 32 includes an enlarged portion 34 underlying the lock body, and in this area the portion 34 slides within a solid tube 35. Both the tube 35 and the core rod 34 are notched to receive blade 30 therethrough when the lock cylinder is in closed, locked, or ignition of position. With the blade in the downward position engaged in the notches the handle 31 can not be pulled out to release the hood latchfTo open the hood, then, one would have to resort to the use of a crowbar of the like.

An insulating plastic plug or socket 36 is preferably provided within housing cooperable with plug housing 13 for completing electrical ignition and accessory connections to the switch 13, as well as for completing the circuits of

conductors

11 and 26. Since such connections are well known in the art, details thereof are omitted for clarity of the drawing.

Further in connection with FIGS. 1 3, it will be seen that the lock body includes an opening 37 lined with a layer of insulating material 38 within which are disposed electrical

conductive walls

39 and 40. These walls may be electrically interconnected by means of conductiveend walls, such as end wall 41, and these inner conductive walls are electrically connected to conductor 11. Lock piston 42 extends upwardly into opening 37 and spacedly between

walls

39 and 40 when no key, or an improper key, is in the lock. In accord with the invention, when any attempt is made to rotate the cylinder without a proper key in the lock, the piston 42 will contact wall 39 or wall 40, thereby, since the piston is conductive, grounding conductor 11.

Further details of the construction may be seen in FIG. 2 which shows a key hole 43 in lock cylinder 44.

Arm 29 is connected to the rotatable cylinder 44 and extends outwardly therefrom through slot 28. Hood latch locking blade 30 will be seen to be positioned to prevent core 34 from sliding in tube 35. Lock piston 42 is disposed in opening 37 between the

conductive walls

39 and 40. It will be seen that any rotation of cylinder 44 will bring piston 42'into electrical contact with wall 39 or wall 40.

It will be understood that the size of opening 37 is shown somewhat enlarged from a desirable size in which, for example, from 2 to 4 or 5 degrees of rotation of cylinder 44 would bring the piston 42 into electrical contact with one or the other side of the opening. The thickness of the shield walls and insulating

layers

6, 7 and 8, respectively, are also shown magnified for the purposes of illustration, and these elements may be substantially thinner than-as represented.

FIG. 3 is similar to FIG. 2 but shows the arrangement with a proper key 45 in the key hole. The insertion of the key has caused-retraction of piston 42, and the cylinder 44 has thus been released for free rotation. As shown in FIG. 3, the cylinder has been rotated by approximately 45 toward the left. Such rotation has swung blade 30 from its locking position for locking the hood release cable into a position in which it has contacted and has depressed the button 27 of switch 24 to open the switch and remove the ground from conductor 26. 7

Further details of the lock mechanism are shown in FIGS. 4, 5, 6 and 7. The lock piston 42 is biased by springs 46 toward the sides of a plurality of tumblers 47, 48, each of which has a respective side notch, such as notch 49 in tumbler 47 and notch 50 in tumbler 48. The tumblers are raised by a proper key against respective biasing springs, such as springs 51 and 52, by the insertion of a key 45 into the key hole 43. A proper key will raise each of the tumblers by the correct amount to align all of the notches, such as

notches

49 and 50,

with the angular, wedge-shaped inner end portion 53 of the piston 42, and when this occurs, the piston 42 is retracted inwardly of opening 54 in the lock cylinder 44, that is, from the position shown in FIG. 4 to the position shown in FIG. 5. Should any one of the notches, such as

notch

49 or 50, not be accurately aligned with the end portion 53, the piston 42 remains unretracted to span between the lock body 10 and the cylinder 44 as shown in FIG. 2.

Referring to FIG. 8, the hood 55 of the automobile is held in closed position by a hand lever 56 which engages the shoulder 57 ofa latch member 58 attached to the hood. The hand lever may be moved away only when a pin 59, which engages in an opening in the lever, has been retracted by a pull on core 32 of flexible cable 33. Such pull may be prevented by lock blade 30 as described in connection with FIGS. 1 through 3.

According to an aspect of the invention described herinafter in connection with FIG. 12, additional protection for the hood may be provided by a push button 7 switch 60 of which the button 61 is normally depressed by an ear 62 mounted on the hood, the switch 60 being mounted to a stationary part 63 underlying the automobile hood and within the closedengine compartment. One of the electrical connections 64 of the switch is grounded, for example, by being connected to the grounded body of the switch 60, while the other connection 65 is led to other portions of the alarm system as-later described. The connection 65 is grounded by the switch when the hood israised. Accordingly, as will be seen, even if the hoodis pried up with a crowbar,

v switch 60 will activate the alarm.

Referring to FIG. 9, it will be seen that there are several' ways in which conductor 11 may be grounded. The lock piston 42, upon rotation of lock cylinder 44 to the right, will contact the conductive wall 39 or, upon rotation to the left, will contact the conductive wall 40, if such rotation occurs in the absence of a proper key in the lock and while the lock piston 42 is not retracted into the opening in the lock cylinder. Since the piston 42 is grounded, as symbolically represented at 66, contact of piston 42 with either

wall

39 or 40 grounds conductor 11.

A fragment of shield 5 is shown and it will be seen that any instrument which would make contact between outer wall 6 and inner wall 7 will similarly result in grounding of conductor 11. Conductor 11 is also connected through conductor 23 to switch contact 22, and, since rod 14 is grounded, forward movement of the lock body 1 will cause contact 21 to meet contact 22 thereby to ground conductor 11.

The alarm circuit is arranged to be energized by a battery 67, which may be the storage battery of the vehicle. The battery has a grounded terminal 68 and an ungrounded terminal 69. The ungrounded terminal is connected in the alarm circuit through a normally closed time delay switch 70 including a bi-metal strip 71 normally in contact with contactor 72 and arranged to be heated by a resistor 73. Typically, the contact 72 remains closed against the bi-metal strip for a period of approximately 5 minutes of heating by resistor 73 and then opens, initiating a cooling cycle until the contact is again closed.

Strip 71 is connected to the coil 74 of a relay 75 having normally

open contacts

76 and 77. The other terminal of the coil is connected by a conductor 78 to conductor 11. Should conductor 11 be grounded by any of the aforementioned means, that is by slight rotation of the ignition lock cylinder while the piston 42 is extended, or by forward movement of the lock body, or by sawing through the lock-protecting shell 5, relay 75 is activated to close

contacts

76 and 77, thereby estab lishing a holding circuit for the relay, with conductor 78 from the relay coil'being grounded through

contacts

77 and 76 and thence through conductor 26 to the grounding switch 24. Accordingly, any momentary grounding by any of the aforesaid means is effective to close the relay and to apply through the relay contacts a ground connection to hold the relay in and to ground the conductor 11 independently of the grounding signal which first closed the relay. The holding circuit may be broken by the insertion of a proper key in the ignition switch lock and by then rotating the lock cylinder to the left toward the accessory energizing direction until switch 24 is opened.

When conductor 11 is grounded, the ungrounded terminal of the battery is connected through the bi-metal switch 70 and conductor 79 to bi-metal element 80 of a flasher switch. When cold, element 80 is in contact with fixed contact 81 and battery voltage is applied to heating coil 82 connected between contact 81 and conductor 11. As the bi-metal element 80 is heated, it breaks the circuit at 81 and closes against contact 83 thereby supplying battery voltage through conductor 84 to a signal lamp 85 orto an audible alarm such as bell 86, or to such other alarm devices as may be desired. The bi-metal element 80 and heating coil 82 are selected to provide oscillation of the element 80 between

contacts

81 and 83 at approximately 1 second intervals, whereby a lamp 85 would blink on and off, or a bell 86 would sound, at approximately I second periods.

After approximately 5 minutes, the bi-metal switch 70 will open, thereby breaking the circuit to coil 74 and permitting the relay to drop out. If in the meantime the initial grounding of conductor 11 has been removed, the subsequent cooling of bi-metal element 71 and reestablishment of contact with 72 will not again initiate the alarm. For example, if a thief has attempted to pick the ignition lock and has initiated the alarm by causing contact between piston 42 and wall 40, but if now the thief has given up and this contact is broken, the alarm sounds for 5 minutes but will not be reinitiated upon such subsequent closure of switch 70.

While the lock physically shown and described in connection with FIGS. 1 through 7 comprises a single piston or locking bar 42 operative in response to alignment of a plurality of tumblers 47, 48, the contacting arrangement is equally applicable to cylinder locks having a plurality of pins or tumblers which, in the absence of a proper key, may project from the cylinder. Thus, if the lock comprises a plurality of pistons or pins which may project from the cylinder into an opening in the lock body, and if the lock body is slightly wider than sufficient to receive such pistons or pins and has electrical contacts along each side of the opening, rotation of the cylinder with any one of the plurality of such pistons extending outwardly therefrom will cause grounding of the contact when such one or more, pistons en gages the contact. Such an arrangement is specifically shown and described in my aforesaid application, Ser. No. 21,368.

The arrangement heretofore described in connection with FIGS. 1 9 is typically associated with a lock in an ignition system for an automobile. The alarm arrangements may be similarly associated with locks for other purposes, and FIGS. 10 and 11 show a lock embodying the same arrangement. for closing an electrical circuit upon slight rotation of the cylinder in the absence of a proper key but modified with the addition of further contact closing means, and as so modified the lock is particularly adapted to use inthe doors of automotive vehicles.

The lock as shown in FIG. 10 includes components heretofore described in connection with FIGS. 1 through 7 which are identified by the same numerals to which primes are added. The foregoing description is equally applicable to such respective components. The lock is also seen to include a door latching element 87 operated by the cylinder in place of the ignition switch of the earlier described lock. As further seen in FIGS. 10 and 11, the cylinder 44' is provided with a post 88 fixedly attached thereto and extending upwardly through ,an arcuate slot 89 in the lock body 10'. Mounted on the upper end 90 of post 88 are two

spring contact fingers

91 and 92, respectively, which are grounded through the post to the cylinder and lock body. A shallow groove 93 is formed at least partially around the lock body extending from each end of the slot 89. This groove is lined with insulating material 94 g and the insulating material mounts respective

insulated contact fingers

95 and 96 adjacent the ends of the groove 89 and aligned for contact with the spring contact fingers. Specifically, if the cylinder 44' is rotated to the right, contact finger 92 will be brought in contact with and will ground insulated contact 96, and when the cylinder is rotated to the left, contact finger 91 will contact and establish a ground connection to insulated contact element 95.

Conductors

97 and 98 are connected respectively to

contacts

95 and 96 and serve to connect these contacts to the alarm circuit.

FIG. 12 shows a circuit diagram embodying generally the same elements as those included in FIG. 9 and additional elements associated with door locks as shown in FIGS. 10 and 11. Those elements of FIG. 12 which correspond to the elements of FIG. 9 are identified by the same numerals to which primes have been added and it will be understood that the descriptions heretofore given in connection with the corresponding elements so identified apply equally to FIG. 12. In FIG. 12 ignition lock cylinder 44 is shown including, as explained in connection with FIGS. 1 through 7, lock bolt 42 arranged to apply a grounding connection to conductor 11', a lock protective shield 5, contact points 21 and 22 arranged for closing upon any displacement of the i'gnition lock forwardly, and a hood switch 60, all arranged as heretofore described to apply ground signals to conductor 11'.

FIG. 12 further includes two door locks, such as shown in FIGS. and 11 and described above, with contacts 39' and 40 of the one arranged to ground conductor 11 when, piston 42' engages either such contact upon an attempt to pick the door lock, and contacts 39" and 40" of the other similarly arranged for grounding upon engagement by piston 42".

When conductor 11 is grounded by any of the aforesaid means, current is supplied through time delay switch 70 from battery 67 to coil 74 of relay 75 thereby tov complete a holding circuit to ground through conductor 26'. Flasher switch 80 is thus energized to periodically actuate alarm bell 86 The doors of the vehicle may be protected by pushbutton switches of the type presently employed in automobiles to close a circuit to turn on the dome light. One such switch is shown in FIG. 12 at 99. It is intended that each door of thevehicle would be protected by a switch of this type. The switches would all be connected in parallel so that the opening of any door would close a circuit through conductor 100 to ground. Conductor 100 may be connected through relay armature 101 to conductor 11' by selective actuation of the relay resulting from appropriate manipulation of the door lock, thereby to arm the open door alarm. The door alarm is so armed by rotating a door lock cylinder 44' to the left with a proper key in key hole 43 until contact 91 is engaged with 95, thereby to excite relay coil 102.

The armature 101 will remain closed against contact 103 thereafter until the opposing coil 104 is excited. Coil 104 may be excited to disarm the door alarm by rotating a door lock cylinder 44' to the right to bring contact 92 into grounding engagement with contact 96 thereby exciting coil l04,and opening contacts 101 to 103. Hood switch 60 is connected in parallel with the oneor more door switches 99, and this switch is armed when switch 99 is armed.

In FIG. 12 the two door locks are seen to comprise

cylinders

44 and 44" respectively, with selectively

groundable arming contacts

95 and 95 connected in parallel and disarming contacts 96 and 96' similarly connected in parallel.

When any door lock is turned to the left, a contact 95 or 95' is grounded, energizing coil 102 and arming the alarm circuit which is associated with the dooractuated switches 99. Armature 101 then remains in contact with contact 103 until one of the

contacts

96, 96 of one of the door locks is grounded, thereby to excite coil 104 and disarm the system. The door alarm system may thus be armed by operating any one of two or more door locks and thereafter disarmed by operating the same or any other one, of the door locks.

When the door alarm is armed, with armature 101 in contact with contact 103, opening of a door will close switch 99 thereby grounding conductor 11' to cause relay 75 to pick up and operate the alarm bell 86.

The door locks are preferably of the spring loaded, lost motion type in which, when the key is turned from center to the left, the latch 87 is moved to locked position, and contact or 95' is grounded, andwhen the key is released, it springs back to center and contact 96 is disengaged but with latch 87 remaining in locked position. Momentary energization of coil 102 is effective to arm the alarm circuit. When the key is turned to the right, the latch 87 is moved to unlocked position and contact 96 or 96' is momentarily grounded to disarm the door alarm circuit.

, It will thus be understood that the door lock is preferrablyof the type provided, as is well known in the art, with a lost motion connection between its cylinder and the latch element 87, and with biasing meansfor returning the cylinder to its centeredposition following an operation thereof, whereby, when the cylinder is turned from centered position by manually rotating the key in one direction the latch is moved into door locking position and the cylinder then springs back to centered position when the key is released, and the door is subsequently unlocked by rotation of the cylinder by means of the key in the opposite direction, thereafter to be returned by the bias when the key is released into its centered position.

A time delay switch 105 is shown including a heating element 106. Heating element 106 is excited during the period while switch 70 is closed and conductor 11 is grounded, and after, for example, approximately 2 or 3 minutes of operation of the heater, the switch .105 closes to connect relay coil 104, through, its conductor 98, to conductor 11, thereby to'excite coil 104, open the relay armature circuit, and disarm the door switches.

It will be apparent that there may be provided as many parallel connected door switches 99 as desired, including one for each door of a vehicle and one for the trunk, for example. Or one to protect each door and window of a building.

It will also be apparent that more or less than two door locks may be provided, the electrical elements of each lock being connected in parallel with the corresponding elements of the other lock or locks. As explained, operation of any one of such'. door locks by means of a proper key would then arm the door alarm circuit when the lock was turned to the left and would disarm the circuit when the lock was turned to the right, and any improper operation of any such lock, which would result in the .grounding any one of the contacts 39 or 40' of any of the locks, would provide the grounding of conductor 11' to initiate a 5 minute period of alarm signal operation.

The bimetal switches, solenoids and alarm bell, together with the interconnecting wiring, may be located in any convenientprotected space in the vehicle, such as within the engine compartment, or, as to-devices small enough, within the shield container 5. The battery 67 or 67' will normally be within the engine compartment.

While this invention has been particularly shown and described in connection with a system for protection of an automobile vehicle, it will be understood that locks as shown in FIGS. 1 through 7, or in FIGS. 10 and 11, and alarm circuits as shown in FIGS. 9 and 12 may be used or readily adapted for use in other environments, such as for door locks in homesor other buildings, in power boats and elsewhere.

While the invention has been described with respect to certain specific embodiments, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention.

What is claimed as new and what it is desired to secure by Letters Patent of the United States is:

1. In a door alarm system for a vehicle comprising two doors each provided with a respective lock and a respective normally open switch which closes in response to opening of the door, said switches being connected in parallel, a double throw relay including switch means connected in series with said switches, each said door lock comprising a double throw switch connected to the coils of said relay and selectively operable in response to operation of the respective lock to open and close said switch means.

2. The combination according to claim 1, in which each said double throw switch has an open circuit intermediate position and is momentarily closeable in one and the other of its throw positions in accord with locking and unlocking operation of the respective door lock.

3. In an alarm for a vehicle having a fire wall, an engine compartment closed by a hood, and a passenger compartment, a hood latch including a remote control release cable extending through said fire wall into said passenger compartment, an ignition switch lock, locking means operated by said switch lock for locking the portion of said cable in said passenger compartment against hood release movement, a protective shielding container extending from said fire wall into said passenger compartment outwardly around and enclosing said locking means and said cable portion and said switch lock, said container comprising conductive inner and outer walls and an interposed insulating layer, and an alarm circuit associated with said walls actuated upon establishment of an electrical connection between said walls.

4. In combination,'in an automobile, a lock having a switch closeable upon an attempted picking of the lock, a source of power having a terminal grounded to metal parts of the automobile and an ungrounded power terminal, alarm means connected to said ungrounded terminal actuated by completion of a connection therefrom to ground, said switch being connectedto complete said connection, and a holding relay responsive to such completion of said connection to complete a parallel ground connection for said alarm means.

5. The combination according to claim 4, and a normally closed releasing switch electrically connected in series in said parallel ground connection, said lock being provided with means responsive to predetermined normal key-actuation of the lock for opening said releasing switch.

6. in a vehicle protective alarm system, a door lock including a cylinder having a centered position and operative to lock the door upon movement in one direction from said position and to unlock the door upon subsequent movement from said position in the opposite direction, a double throw relay, means operably connected to said cylinder responsive to such opposite movements thereof to throw said relay between its throw positions, alarm means, electrical means responsive to predetermined improper tampering with the vehicle in circuit with said alarm means for actuating said alarm means, said relay comprising when in one of its said throw positions disabling means for disabling said electrical means.

7. The combination according to claim 6 wherein said door lock comprises electrical contact means connected to said alarm means actuated by attempted picking of said lock to actuate said alarm means.

8. The combination according to claim 6 wherein said alarm means comprises a holding relay operated upon momentary response of said electrical means to such tampering to maintain said alarm means active thereafter independently of the condition of said electrical means.

9. The combination according to claim 7 wherein said alarm means comprises a holding relay operated upon momentary actuation of said alarm means by either said electrical means or said electrical contact means to maintain said alarm means active independently of the conditions of said electrical means and of said electrical contact means.

10. The combination according to claim 6 and an ignition switch lock comprising electrical contact means connected to said alarm means actuated by attempted picking of said ignition switch lock to actuate said alarm means.

11. The combination according to claim 7 and an ignition switch lock comprising second electrical contact means connected to said alarm means actuated by attempted picking of said ignition switch lock to actuate said alarm means.

12. The combination according to claim 8 wherein said alarm means further comprises normally closed time delay circuit means actuated upon said operation of said holding relay interposed in the holding circuit of said relay.

13. A vehicle protective alarm system comprising an ignition switch lock including means for completing an electrical connection upon attempted picking of the lock, said lock having a body, means mounting said lock in the passenger compartment of said vehicle, switch means in said compartment for closing an electrical connection upon removal of said body from said mounting means, said lock being controllingly connected to an ignition wire, respective wires connected to said switch means and to said connection completing means, said respective wires and said ignition wire extending from said passenger compartment through the fire wall into the engine compartment of the vehicle, a protective shield comprising inner and outer walls insulated from each other by an interposed insulating space surrounding said lock, said switch means and the por-" tions of all of said wires which are in said passenger compartment, connecting means from an insulated one of said shield walls extending inwardly of said shield into said engine compartment, and alarm means in said engine compartment operatively connected to said connecting means and to said wires from said switch means and from said connection completing means.

14. In a vehicle, a protective alarm'system comprising in the passenger compartment an ignition switch lock including a cylinder and a mechanical hood latch release mechanism comprising latch means at the forward end of the vehicle hood and mechanical remote control means extending under said hood from said latch means and into said compartment and including a portion within said compartment disposed adjacent to said lock, said cylinder being rotatable by a key from a centered locked, switch off position to a noncentered, switch on position, and mechanical locking means carried by said cylinder for lockingly engaging said portion of said control means when said cylinder is in said centered position to prevent operation thereof and disengaging said portion to release said control for operation upon rotation of said cylinder into said noncentered position.

15. The combination according to claim 14 wherein said lock is provided with alarm circuit means energized in response to attempted picking thereof, and alarm means in the engine compartment of the vehicle operatively connected to said circuit means.

16. The combination according to claim 15 wherein means are provided for protecting said circuit means, said lock, said portion of said control means and said mechanical locking means within said passenger compartment, said protecting means comprising a hollow, double wall container of which the walls are not in electrical contact and are adaptedfor short circuit by an externally applied wall-penetrating conductive tool, and means for operatively connecting said walls in said alarm circuit.

17. The combination according to claim 6, wherein a second door of the vehicle is provided with a respective second such lock provided with a second respective such means operably connected to the cylinder thereof, and wherein said cylinder-connected means of each said lock comprises a respective momentary double throw switch each operably connected to said relay,

whereby, after the relay is thrown into its other said throw position by movement of one said cylinder in one direction from its said centered position, the relay is thrown to its said one throw position by subsequent movement in said opposite direction from its centered position of the cylinder of either said lock.

18. In a vehicle protective alarm system, circuit means operable between two-conditions, alarm means connected to said circuit means and armed thereby when said circuit means is in one of said conditions and disarmed when said circuit means is in the other of said conditions, a plurality of door locks each comprising momentary switch means actuated in response to operation of the respective lock and controllingly connected to operate said circuit means between its said conditions, each said door lock comprising a cylinder having a centered neutral position and being rotatable in one and the opposite direction therefrom to lock and unlock the respective door, each said switch means being a momentary double throw switch having a neutral centered position and being actuated therefrom to momentarily close a connection to one and the other of its fixed contacts by, and in accord with the respective direction of, such rotation of the respective said cylinder, said fixed contacts of each said switch being respectively connected to operate said circuit means into said one condition upon rotation of any said cylinder from neutral position in its door locking direction and into said other condition upon subsequent rotation of any said cylinder from neutral in its door unlocking direction.

Claims

4. In combination, in an automobile, a lock having a switch closeable upon an attempted picking of the lock, a source of power having a terminal groundeD to metal parts of the automobile and an ungrounded power terminal, alarm means connected to said ungrounded terminal actuated by completion of a connection therefrom to ground, said switch being connected to complete said connection, and a holding relay responsive to such completion of said connection to complete a parallel ground connection for said alarm means.

13. A vehicle protective alarm system comprising an ignition switch lock including means for completing an electrical connection upon attempted picking of the lock, said lock having a body, means mounting said lock in the passenger compartment of said vehicle, switch means in said compartment for closing an electrical connection upon removal of said body from said mounting means, said lock being controllingly connected to an ignition wire, respective wires connected to said switch means and to said connection completing means, said respective wires and said ignition wire extending from said passenger compartment through the fire wall into the engine compartment of the vehicle, a protective shield comprising inner and outer walls insulated from each other by an interposed insulating space surrounding said lock, said switch means and the portions of all of said wires which are in said passenger compartment, connecting means from an insulated one of said shield walls extending inwardly of said shield into said engine compartment, and alarm means in said engine compartment operatively connected to said connecting means and to said wires from said switch means And from said connection completing means.

14. In a vehicle, a protective alarm system comprising in the passenger compartment an ignition switch lock including a cylinder and a mechanical hood latch release mechanism comprising latch means at the forward end of the vehicle hood and mechanical remote control means extending under said hood from said latch means and into said compartment and including a portion within said compartment disposed adjacent to said lock, said cylinder being rotatable by a key from a centered locked, switch off position to a non-centered, switch on position, and mechanical locking means carried by said cylinder for lockingly engaging said portion of said control means when said cylinder is in said centered position to prevent operation thereof and disengaging said portion to release said control for operation upon rotation of said cylinder into said non-centered position.

16. The combination according to claim 15 wherein means are provided for protecting said circuit means, said lock, said portion of said control means and said mechanical locking means within said passenger compartment, said protecting means comprising a hollow, double wall container of which the walls are not in electrical contact and are adapted for short circuit by an externally applied wall-penetrating conductive tool, and means for operatively connecting said walls in said alarm circuit.

17. The combination according to claim 6, wherein a second door of the vehicle is provided with a respective second such lock provided with a second respective such means operably connected to the cylinder thereof, and wherein said cylinder-connected means of each said lock comprises a respective momentary double throw switch each operably connected to said relay, whereby, after the relay is thrown into its other said throw position by movement of one said cylinder in one direction from its said centered position, the relay is thrown to its said one throw position by subsequent movement in said opposite direction from its centered position of the cylinder of either said lock.

18. In a vehicle protective alarm system, circuit means operable between two conditions, alarm means connected to said circuit means and armed thereby when said circuit means is in one of said conditions and disarmed when said circuit means is in the other of said conditions, a plurality of door locks each comprising momentary switch means actuated in response to operation of the respective lock and controllingly connected to operate said circuit means between its said conditions, each said door lock comprising a cylinder having a centered neutral position and being rotatable in one and the opposite direction therefrom to lock and unlock the respective door, each said switch means being a momentary double throw switch having a neutral centered position and being actuated therefrom to momentarily close a connection to one and the other of its fixed contacts by, and in accord with the respective direction of, such rotation of the respective said cylinder, said fixed contacts of each said switch being respectively connected to operate said circuit means into said one condition upon rotation of any said cylinder from neutral position in its door locking direction and into said other condition upon subsequent rotation of any said cylinder from neutral in its door unlocking direction.