US3764859A

US3764859A - Electronic lock apparatus

Info

Publication number: US3764859A
Authority: US
Inventors: C Wood; E Wydro
Original assignee: Individual
Current assignee: Individual
Priority date: 1972-05-30
Filing date: 1972-05-30
Publication date: 1973-10-09
Anticipated expiration: 1990-10-09
Also published as: GB1438673A; DE2327363C3; FR2187001A5; JPS4962300A; SE390831B; DE2327363A1; DE2327363B2; IT986379B

Abstract

An electronic lock apparatus includes a tumbler key mechanism having tumblers as part of a series of switches for setting a first coded electronic signal in response to the insertion of a key. A second code means connected to the switches generates a second coded electronic signal in response only to receipt of a proper first electronic coded signal, and an electronic means responsive to said second coded electronic signal decodes said second electronic signal and generates an initiating signal to initiate the operation of a lock. The entire electronic lock apparatus is disabled if said series of switches for setting the first coded electronic signal are not set within a predetermined time frame.

Description

D United States Patent 1 [111 3,764,859

Wood et al. Oct. 9, 1973 ELECTRONIC LOCK APPARATUS [75] Inventors: Charles W. Wood; Edwin S. Wydro, j f g f g g l J 0th of hi3, Pa 8816 an xammer arry 0086, I. b p Attorney-Arthur H. Seidel et a1. [73] Assignee: Wilmer Gross, Jack Seidman and Jules I. Whitman, all of Phila- [57] ABSTRACT delphla, An electronic lock apparatus includes a tumbler key [22] Filed: May 30 1972 mechanism having tumblers as part of a series of switches for setting a first coded electronic signal in PP response to the insertion of a key. A second code means connected to the switches generates a second [52] Us. Cl 317/134 70/278 70/370 coded electronic signal in response only to receipt ofa 51 260/44 367/10 proper first electronic coded signal, and an electronic [51] Int CL E05b 49/00 means responsive to said second coded electronic sig- [581 Field I 97 200/42 nal decodes said second electronic signal and gener- 307/10 ates an initiating signal to initiate the operation of a lock. The entire electronic lock apparatus is disabled [56] References Cited if said series of switches for setting the first coded electronic signal are not set within a predetermined UNITED STATES PATENTS time frame 3,639,906 2/1972 Tritsch 317/134 2,905,926 9/1959 Aid 317 134 x 12 Clams, 6 Drawlng Flgures 3,641,396 2/1972 Kossen 317/134 n 3,610,943 l0/l971 Jones 3l7/l34 r0 Lac/r Hyji- PATENTEU [1m 9 SHEET 1 BF 5 FIG.

PATENTEU GET 9 I975 SHEET 2 0F 5 PATENTEB 91973 SHEET 5 0F 5 ML QVS Qk ELECTRONIC LOCK APPARATUS This invention relates to an electronic lock apparatus. More particularly, this invention relates to an electronic lock apparatus that operates only upon the generation of proper electronic codes.

Heretofore various coded electronic locks have been proposed. Such locks employ a coded electronic signal generated upon the insertion of a key into a key mechanism. The coded signal thus generated is used to initiate a mechanism for driving the lock bolt. The coded signal may be an analog or even binary. Examples of such locks are shown in U.S. Pat. Nos. 3,392,558, 3,411,046, 3,408,838, 3,415,087 and 3,392,559. Further patent references reflecting such technology can be found in the U.S. Patent Office classified in Class 340, Communications, Electrical; subclass 63, Theft or Burglar; subclass 64, Ignition Circuit Controled; and subclass 147, Selective.

The present invention improves upon such technology by providing an electronic lock apparatus that cannot be picked either by mechanical or electrical means. In accordance with the present invention the lock mechanism incorporates the concept of coded electronic signals. However, the present invention uses at least two coded electronic signals. The first coded electronic signal is set by the insertion of a key into a tumbler mechanism. The second coded electronic signal is set only upon the generation of a proper first coded electronic signal. The lock bolt mechanism can be operated only upon the generation of a proper second coded electronic signal. The second electronic coded signal has sufficient permutations that it cannot be readily decoded except by extensive effort.

Since the present lock mechanism depends upon the setting of the first electronic code, the invention also provides means to prevent the setting of such code except by the insertion of the proper key. Mechanical picking of the lock is prevented by providing a timer that disables the entire lock mechanism if the first coded signal is not set within a predetermined time frame. Still further, means are provided for preventing persons from manufacturing a key by first feeling the proper key settings and then making the key on machinery available for that purpose. This is accomplished by splitting the tumblers into two or more sections such that the cylinder of the lock may rotate at any one of a large number of tumbler positions. However, only one of such positions will set the first coded electronic signal.

The present invention has particular use as an antitheft mechanism for automotive vehicles. However, it should be understood that the electronic lock apparatus is in no way intended to be limited to use only with such vehicles.

At the present time the typical automobile and other vehicles incorporate a combined lock and starting switch mounted on the steering column. In its off position and with the key removed, the lock mechanism disables the electrical system for the automobiles engine and also immobilizes the steering mechanism. Unfortunately, such locking mechanisms can be readily removed by force and the electrical system switched on by a technique known as jumping.

In accordance with the present invention a vehicle is disabled not only by the means described above, but also by mechanically disabling or locking a part of the vehicle that is not readily accessible to the thief attempting to steal an automobile in a street, parking lot or other place accessible to the public. By way of example, an automobile can be disabled by cutting off the flow of oil through the transmission. The apparatus for enabling the flow of oil through the transmission can be located therein and hence would be accessible only by entry into the transmission using a great amount of effort. Of course, there are many other ways to disable an automobile as pointed out hereinafter.

In accordance with the present invention, the lock apparatus described above is used to operate this inaccessible enabling-disabling mechanism. Since such mechanism is not readily accessible and since the lock mechanism cannot be picked, the stealing or unauthorized removal of automobiles by any means except physically towing the vehicle is prevented. Since most vehicles are stolen by forceably removing the lock mechanism and jumping the ignition system as described above, all within a period of five minutes, the present invention should greatly reduce the number of vehicles stolen each year.

For the purpose of illustrating the invention, there are shown in the drawings forms which are presently preferred; it being understood, however, that this invention is not limited to the precise arrangements and instrumentalities shown.

FIG. 1 is a partial sectional view of the electronic lock apparatus in accordance with the present invention.

FIG. 2 is a partial transverse sectional view taken along the line 22 in FIG. 1.

FIG. 3 is a partial sectional view taken along the line 3-3 in FIG. 1.

FIG. 4A is a portion of the electronic circuitry used in the present invention, shown schematically.

FIG. 4B is the remaining portion of the electronic circuitry.

FIG. 5 is a partial transverse sectional view of another embodiment of the present invention.

Referring now to the drawings in detail, wherein like numerals indicate like elements, there is shown in FIGS. 1 and 2 a partial view of a modified cylinder lock designated generally as 10.

As shown, the cylinder lock 10 includes a rotatably mounted plug or cylinder 12 in which is formed the keyway 14. A key 16 is shown positioned in the keyway 14.

In the locked position, a number of pin tumbler sets 18, 20, 22, 24 and 26 of different overall length are pressed down by

springs

28, 30, 32, 34 and 36 to engage with holes in the cylinder 12, thereby preventing the latter from rotating. When the key is inserted into the lock as illustrated in FIG. 1, the lower segments of the pin tumbler sets are raised by exactly the correct amount to bring their tops flush with the outer surface of the cylinder. As the segments of each tumbler are separate, i.e., not connected, the cylinder is then free to rotate when the key is turned. The cylinder actuates a bolt or the like to unlock the mechanism.

The cylinder lock 10 described herein may be associated with the steering column of an automobile. As such, it unlocks the steering column and permits the wheels to be turned from inside the automobile. In addition, the continued rotation of the cylinder 12 engages switches which permit the vehicle to be started by energizing th ignition. All of the foregoing is conventional and therefore need not be described in detail.

Rather, only modifications to such a cylinder lock for an automotive vehicle are described herein.

Although an automotive vehicle lock is described, it should be understood that the invention is no wise in tended to be so limited. The lock could, for example, be used in a door. The door referred to herein could be a closure for any building, apartment, safe, cabinet, box or any other place where locks are used to prevent the opening of a structure. Still further, the lock could be used in any mechanical mechanism in accordance with the principles described herein with respect to disabling an automotive vehicle.

Referring now to FIG. I, it should be noted that each of the pin tumbler sets 18-26 is divided into four segments so as to provide three interfaces. Reading from bottom to top, the first three segments are delineated by the letters a, b, and c. By way of example, pin tumbler set 20 includes

segments

20a, 20b, and 20c. The fourth segment of each set 18-20 is elongated and designated 48, 50, 52, 54 and 56. The purpose for dividing each of the sets of pin tumblers 18-26 into segments is to prevent determination of the initial (first) code by measuring the position of each tumbler that would permit the cylinder 12 to turn and then using such measured positions to manufacture a key on machines available for that purpose. This would be possible if conventional two-piece tumblers having only one interface were used.

The illustrated embodiment shows five sets of pin tumblers. It should be apparent to those skilled in the art that locks with more or less sets of pin tumblers can be used. A six pin tumbler lock is conventionally available as is a four pin tumbler lock. An even larger or smaller number of pin tumblers can be used as desired.

It is immediately apparent that by dividing each of the pin tumblers into three or more segments the lock is much easier to mechanically pick. Stated otherwise, the increased number of interfaces raise the combination of pin tumbler positions where the cylinder 12 will turn for a specific key. In particular, three interfaces for five sets of pin tumblers raise the combination where the lock will turn for a specific key or tumbler arrangement from 5 to 243. For a conventional 5 tumbler lock, there are 12,000 tumbler or key arrangements as is known.

Such an increase in the ease by which the lock may be mechanically picked is used as a trade off to substantially, completely prevent the determination of the electrical code. As stated above, it prevents picking the lock to get an initial code which is determined by the pin tumbler position using only the correct key.

In accordance with the present invention, an unauthorized attempt to mechanically pick the lock will result in the cylinder 12 being more readily rotated. In the case of an automobile, this will permit the steering column to be unlatched and also, presumably but not necessarily, permit the automobile engine to be started. This is allowed to occur because the unauthorized starting (jumping) of an automotive engine remains reasonably easy to accomplish regardless of the protective devices that have been incorporated heretofore. However, starting the automotive engine does not necessarily mean that the vehicle can be operated. In accordance with the present invention, the only way that the automobile can be operated is to have the proper initial code which in turn unlatches a vehicle disabling mechanism located at a part of the vehicle that is not readily accessible to a person making unauthorized use of the vehicle.

There are several methods for disabling an automobile. One could disable the oil flow to the hydraulic lifters which would prevent the valves from opening. Another approach is to pin the flywheel. This can prevent engine rotation, but is disadvantageous because it could cause serious damage to both the engine and transmission should the vehicle be pushed, towed, or hit. Another method for disabling the vehicle is to lock or disconnect the gear box at the lower end of the steering column. The disadvantage here is that a failure in this device will cause a serious safety hazard. A positively secured wheel lock also presents serious safety hazards in case of a lock-up at highway speeds. Also, police or other emergency vehicles could not remove the vehicle.

Still another method of disabling the vehicle is to shut off the fuel flow to the carburetor. Thus, the vehicle could be moved only as far as the fuel in the carburetor reservoir permits. Unfortunately, this approach is readily beaten by an unauthorized user who could tap a supplemental fuel supply into the fuel line at the carburetor. Still another approach would be to prevent fuel flow from the carburetor jets. This could be accomplished but would require complete redesign of the carburetors in use on vehicles today.

Other approaches are to provide control of a vent port in the intake manifold system or control of a butterfly valve mounted between the carburetor and the engine. All of these require redesign and retooling although less so with respect to the butterfly valve approach.

One approach which appears to accomplish the purposes of the invention is to bypass the automatic transmission oil using a solenoid controlled valve. Thus, unless the solenoid valve is properly actuated by the receipt and decoding of a proper code, oil does not flow in the correct manner through the transmission to permit the vehicle to be moved under its own power. The advantage of this is that it requires little or no retooling, except perhaps for the outer housings of the transmission. Also, the environment inside of a transmission is relatively cool (no more than about 200F) and therefore is not particularly hostile to a solenoid valve and electrical decoding circuits used with the present invention. Still further, the interior of a transmission is not accessible except by extensive effort and a properly equipped shop.

The foregoing points up the principles of the present invention. Thus, no attempt is made to inhibit the mechanical picking of a lock. Rather, the ability to pick it is enhanced. The tumblers themselves are part of electronic switches which define a particular code. The first code is difficult to ascertain because of the several hundred positions at which the lock can be mechanically picked while only one of those positions defines the proper code position. This first code is used to initiate a second electronic code which in turn is transmitted to a decoder located in an inaccessible part of the mechanism or device being protected; e.g. the transmission of a vehicle. The second electronic code is decoded and the remote portion operated only when the proper or second code is received. To prevent someone from ultimately picking the lock by trying all of the possible enhanced combinations, the electronic lock is provided with a device to completely disable it unless it is picked within a very short time frame.

As previously indicated, the pin tumbler sets 18-26 are used to generate an initial code. This initial code is represented by whether a series of switches complete an electrical circuit or not when a proper key is inserted into the cylinder. These switches designated 118, I20, 122, 124 and 126 are shown schematically in FIG. 4A. They correspond directly to the pin tumbler sets 18, 20, 22, 24 and 26. Thus, by way of example, pin tumbler set 18 is illustrated as switch 118 in FIG. 4A, and so forth.

Still further, each switch is designated in FIG. 4A by the letters N.O. or NC. The designation N.O. is used to indicate that a switch does not complete a circuit when the proper key is inserted into the cylinder 12 while the designation NC. is used to indicate that a switch does complete a circuit. In the circuit illustrated in FIG. 4A, the circuit is completed to ground.

The choice of whether a particular switch (pin tumbler set) completes or does not complete a circuit for a particular key is predetermined by the lock manufacturer, but such determination is wholly arbitrary. Moreover, it is varied from key to key. As such, the combination of switches 118-l26 (pin tumbler sets 18-26) represents the initiating means for generating a first coded electronic signal.

Referring once more to FIGS. 1 and 2, there is shown a lock construction whereby the segments of the pin tumblers can be used to complete or not complete an electrical circuit.

As best shown in FIG. 1, eact set of pin tumbler slide in aligned openings formed in the cylinder 12 and lock housing 38 when the cylinder lock is in its locked position. As best illustrated in FIG. 2, the opening in which the sets of pin tumblers slide within the lock housing 38 is formed by an insulator 40. The pin tumbler opening 39 is lined with a conductive sleeve 42 that extends to a point adjacent to but spaced away from the interface between lock housing 38 and cylinder 12. The spacing is provided by a collar 44 made of an insulating material.

Conductor 46 connects the sleeve 42 to the electronic circuit, and the cylinder 12 is electrically connected to ground. Therefore, a circuit can be completed to ground through the pin tumblers depending upon whether a particular segment or segments of pin tumblers bridging the space between sleeve 42 and cylinder 12 as defined by collar 44 are conductive or not conductive. Since the switch 118 is not connected to ground when the key 16 is inserted into the lock, the

segment

18c and 18b are made of non-conductive material. However, the switch 122 is to be connected to ground when the proper key 16 is positioned in the lock. This is accomplished by providing the segment 22c and 22b with at least an outer conductive coating to complete the circuit across the collar 44 associated with the pin tumbler set 22.

It should be apparent from the foregoing, that the segments of the pin tumblers may be made of an insulating material, such as plastic. Those pin tumbler segments that are to complete the circuit and thus define an N.C. switch, may be made of copper or brass or may be plastic coated with a thin layer of conductive material. Moreover, other combinations of conductive and non-conductive materials may be used to accomplish the same purpose.

It should also be understood that the present invention is not limited to the use of conductive sleeves as illustrated in FIGS. 1 and 2. Other means may be used to provide electronic switches operatively associated with the sliding pin tumbler sets 1826.

As shown in FIG. 5, the housing 38' supports by way of example, a pin tumbler set 18' made of plastic or brass, as desired. The pin tumbler set 18 is topped by an elongated segment 48' whose function in relation to the embodiment illustrated in FIGS. 1 and 2 is described in more detail hereinafter. An opening 58' is formed near the top of the elongated sgement 48' and defines a means for passing electromagnetic radiation from an emitter 60' to a photodetector 62'. The emitter 60 is, by way of example, a light emitting diode which emits infrared radiation. The photodetector 62' is a transistor device sensitive to infrared radiation.

The operation of the embodiment illustrated in FIG. 5 to provide the electronic switch should be apparent from what has been described. Thus, the photodetector 62 will receive or not receive radiation depending upon the presence or absence of an opening 58' in the elongated segment 48'. By repeating the elements illustrated in FIG. 5 for each tumbler set, an electronic switch, based upon the detection of electromagnetic radiation, has been provided.

The advantage of the optical approach used in the embodiment of FIG. 5 is that all of the segments of the pin tumbler sets can be made of the same material and hence slide with the same amount of friction. Hence, there will be no feel to the lock that could tell an expert which of the segments is insulative and which is conductive.

The pins can take other forms for providing switches. Mechanical switch contacts can be used. Another example would be to use magnetic detectors such as magnetic diodes, Hall devices, or small reed switches.

Referring now to FIG. 4A, the manner of processing the code initiated by the switches 1 18-126 is described. As shown, each of the switches 118-126 is connected to one of six inputs to a NAND gate 64. The well known function of a NAND gate is that it will provide a logical O at its output when all of its inputs have a logical I applied thereto. By completing a circuit to ground, each of the

switches

120, 122 and 126 provides the requisite logical I at the input of NAND gate 64. Switch 118 is connected to inverter 66 which inverts the logical 0 generated by that switch and converts it to a logical I Inverter 68 performs the same function for N.O. switch 124.

Inverters

66 and 68 are remotely located away from the switches 118-126 and preferably encapsulated together with NAND gate 64 so that physical inspection of the switches would not reveal which defines an N.C. or N.O. switch. Indeed, it is proposed that the

inverters

66 and 68 together with the NAND gate 64 be made in a single integrated circuit chip so that even if access to the chip could be had, it would be impossible to tell which were the N.O. switches and which were the NC. switches.

As previously indicated, the switches 118-126 provide five of the siz inputs to the NAND gate 64. The sixth input is provided by a timer described hereinafter. The timers function is to provide a logical I at the NAND gate 64 only for a limited period (hereinafter sometimes described as a time frame). If the NAND gate 64 does not have all logical Is within a predetermined time frame, then the timer maintains a logical at its input and only a logical l appears at the output of the NAND gate 64. This disables the lock apparatus as hereinafter described.

The output of NAND gate 64 is connected to the input of NAND gate 70 which functions as an inverter to invert the output of NAND gate 64 from a logical O to a logical l or vice versa.

It should be understood that it is not intended to limit this invention to the use of NAND gates as herein described. NAND gates are readily available and therefore have been chosen to illustrate the invention. However, AND gates could be used with equal facility. This applies throughout the entire description of the invention.

The output of the NAND gate 70 is connected to a bus as 72 which in turn is connected to all of the encode gates designated generally as 74. The presence of a logical l at one of the terminals of the encode gates 74 enables all of the gates and results in the generation of a second coded electronic signal.

The encode gates 74 are also NAND gates in the illustrated embodiment. However, they could be diode gates or any other gate that provides the requisite logic output.

Each of the other terminals of the encode gates is provided with either a ground or an open circuit selected completely at random and in a non-repeating fashion. Whether a particular gate is connected to ground or to an open circuit is determined by the lock manufacturer and this in turn determines the second coded electronic signal. The number of permutations of the code for any set of encode gates is mathematically determined by the number of gates. The number of permutations for particular codes is equal to 2 where n represents the number of gates. Thus, for either gates there are 256 permutations. For sixteen gates there would be 65,536 permutations.

The number of encode gates illustrated is eight. However, the number of such gates may be made larger or smaller. increasing the number of gates increases the amount of security.

The encode gates 74 are preferably encapsulated with the

NAND gates

64 and 70 as well as the

inverters

66 and 68. Indeed, they may be manufactured as part of one integrated circuit chip with such NAND gates and inverters. The chip is preferably encapsulated in a plastic material, such as epoxy. It may be physically located adjacent to cylinder lock 10.

The purpose of the encode gates is to prevent someone from tapping wires to look back into the electronic system to determine the first code. Anyone who taps into the wires leading from the output of the encode gates 74 get no electronic information that would permit the lock to be picked. Everything looks electronically alike.

The conductors connected to the outputs of the encode gates 74 are connected to a decoder located at some remote, inaccessible position in a vehicle or other device or structure being protected by the lock apparatus. If desired, dummy wires could be incorporated in random amounts to prevent even knowing the number of code permutations by counting the wires.

The timer, already mentioned, is also illustrated in FIG. 4A. The timer consists of five series connected

switches

180, 182, 184, 186 and 188. Each of these switches is operatively associated with the pin tumbler sets 18, 20, 22, 24 and 26 as hereinafter described. The switches 180-188 connect the input of NAND gate to ground. Should any one of these switches be opened, the input of NAND gate 90 goes from a logical 0 to a logical 1. Therefore, the output goes from a logical l to a logical 0. Stated otherwise, the output of NAND gate 90 is normally a logical l, but it reverses and goes to a logical 0 should any one of the switches 180-188 be opened.

The switches 180-188 are associated with pin tumbler sets 18-26. Accordingly, should any one of the pin tumblers 26 be disturbed, such as is necessary to mechanically pick the lock, then one of the switches 180-188 will be opened.

The output of NAND gate 90 is connected to an inverter 92 in the form of another NAND gate. NAND gate 92 therefore functions to invert a logical 0 to a logical l when any one of the switches 180-188 is opened. As such, NAND gate 92 acts as a switch in that it allows the capacitor 94 to commence charging up to the applied voltage which, in this case is 5 volts applied through resistor 96. Resistor 98 couples the output of NAND gate 92 to capacitor 94. Resistor 100 couples capacitor 94 to the input of OR gate 102. Therefore, the presence of'a logical 0 at the output of NAND gate 92 when all of the switches -188 are closed, clamps the capacitor 94 to ground.

Resistor 104 feeds back the output of OR gate 102 to its input. As thus connected, OR gate 102 functions as a level sensor. In particular, it is a Schmitt trigger circuit. The level at which it is set is substantially below the illustrative 5 volts applied to capacitor 94. it could, for example, be set to generate a pulsed output signal at 2 volts. Therefore, when the voltage on capacitor 94 goes above the preset voltage, both the input and output of OR gate 102 goes from a logical O to a logical l. The amount of time for this to occur depends upon the RC time constant as determined by the values of resistor 96 and capacitor 94. Preferably, it is set at between 1 to 5 seconds.

Recalling the description of the timer aforesaid, it should be apparent that the switches 118-126 must present the correct first code to the input of NAND gate 64 within the preselected time frame. The output of NAND gate 106 is connected to the sixth input of NAND gate 64. It is a precondition to the operation of the lock apparatus that all logical ls appear at the input of NAND gate 64. Hence, the appearance of a logical 0 at the termination of the time frame disables the entire electronic circuit. If this does not occur, then -a logical I will appear at the output of NAND gate 90 and hence also at the input of NAND gate 106. This means the NAND gate 106 will have a logical 0 at its output.

The advantage of the foregoing is that even if an intruder should stumble upon the correct first code, it would take more time by mechanical picking than is allowed by the time frame. Once the time frame is exceeded, the timer maintains a logical 0 at one of the inputs of NAND gate 64 and hence disables the lock apparatus.

The timer is reset at any time by withdrawing the key or any other mechanism that is disturbing the pins. This allows the pins to again connect the input of NAND gate 90 to ground and hence reset the timer by clamping capacitor 94 to ground. This procedure permits an authorized user to the lock who happens to fumble with the key to withdraw the key and re-insert it within the time frame. When the proper key is inserted within the time frame, then all logical ls will apear at the input of NAND gate 64 and a logical 1 will be applied to the bus 72. The time frame is chosen to be long enough to permit the proper key to be inserted into the cylinder 12, but to prevent mechanical picking of the lock. As previously indicated, a preferred time frame would be between 1 and 5 seconds.

If the proper key is inserted into cylinder 12 within the time frame, a logical 0 is connected by conductor 108 from the output of NAND gate 64 to the other input of NAND gate 106. This logic 0 provides a logical l at the output of NAND gate 106 and hence locks out the timer regardless of the logical condition of the output of OR gate 102.

As previously indicated, the operation of the timer depends upon the physical disturbance of the position of the pin tumbler sets 18-26. FIGS. 1, 2 and 3 illustrate how this is accomplished.

As illustrated in FIG. 1, the upper portion of each pin timbler set 18, 20, 22, 24 and 26 includes an

elongated segment

48, 50, 52, 54 and 56, respectively. Each elongated segment includes a bar designated respectively as 128, 130, 132, 134 and 136 which projects upwardly through an opening in a printed circuit 138 as illustrated in FIG. 3.

The top of each bar 128-136 is provided with a projecting

flange

140, 142, 144, 146 and 148 respectively. At least the bottom of each flange is made of an electrically conductive material such as copper. When the key 16 is withdrawn from the keyway 14, each of the flanges 140-148 rests on the top surface of the printed circuit 138. The printed circuit 138 is divided into

conductive segments

150, 152, 154, 156, 158 and 160. Accordingly, the conductive flanges complete a circuit to ground through the segments 150-160 when the key 16 is withdrawn. However, should any one of the pin tumbler sets 18-26 be raised either by the insertion ofa key or by a mechanical pick, so will one of the flanges 140-148. Accordingly, the circuit through the printed circuit board 138 will be broken and the timer will commence functioning as described above.

The foregoing describes one means for providing the requisite switches for operating the timer. It should be understood, however, that other means for accomplishing the same purpose may be provided. The described embodiment illustrates but one method by which the disturbance of any one of the pin tumbler sets initiates the operation of the timer. Other means for accomplishing the same purposes will be apparent to those skilled in the art.

As previously stated, the insertion of a proper key into the lock results in the presentation by NAND gate 70 of a logical l on bus 72. This in turn results in the generation of a second coded electronic signal on the output lines of the NAND gates of encode gates 74. This signal coded electronic signal is conducted to the decoder schown schematically in FIG. 4B. The decoder is located within an inaccessible part of the device being protected, such as the transmission of an automobile. It too is preferably an encapsulated integrated circuit chip incorporating the electronic elements schematically illustrated in FIG. 4B.

As shown, all of the conductors from encode gates 74 which define a logical l are connected to the bus 200 which is connected to the inputs of NAND gate 202.

All of the conductors which carry a logical 0 are connected to

inverters

204, 206 and 208, for example which invert the logical 0 to a logical 1. Thus, all logical ls appear on the buss 200. The presence of all logical ls on the bus 200 result in a logical 0 at the output of NAND gate 202. This is inverted to a logical l by the NAND gate 210. NAND gate 212 inverts the signal back to a logical 0 thereby causing NAND gate 214 to have a logical l at its output. This logical l is conducted to the base of transistor 216 which functions as a switch. Transistor 216 controls solenoid 218. Thus, the presence of a logical 1 at the base of transistor 216 permits solenoid 218 to be energized. The operation of solenoid 218 controls a mechanism which enables the device being protected. For example, it could control a valve that permits oil to properly flow through the transmission and permit the vehicle to be operated. It could also operate the bolt of a lock in other devices. Thus, the lock apparatus has completed its basic function. Of course, the solenoid 218 is but one form of device that can be used to lock or unlock the device being protected.

NAND gate 212 functions as an enable detector. It may be omitted from the circuit if an enabling function is not required. The conductor 220 connects one of the inputs of NAND gate 212 back to the lock. It is run as an extra line together with the conductors carrying the second encoded signal. At the lock electronic means are provided to place a logical 1 on conductor 220 and hence at the input of NAND gate 212 only when the vehicle ignition system is on. This provides added security by requiring yet another act before the solenoid 218 can be energized. Stated otherwise, solenoid 218 cannot be operated unless a logical 1 appears on line 220. In the case of an automotive vehicle, this could be the switching on of the ignition system. This is just one more act which must be accomplished if the lock system is to be picked.

There are several advantages to the foregoing invention which should be pointed out with more particularity, particularly as applied to preventing automotive theft. The foregoing invention effectively prevents the unauthorized use or theft of an automobile from a street, parking lot, driveway or other open area where a vehicle has been parked. In accomplishing this, operator (driver) requirements remain unchanged. Thus, the starting and driving procedures for the vehicle are unmodified.

Yet another advantage of the present invention is that its cost of implementation is comparatively low, not more than a few dollars. Moreover, it has the advantage of simplicity and reliability, nor does it jeopardize the safety of the occupant. Still further, it does not affect the performance of the engine or any antipollution devices associated therewith.

The use of the coded electronic signal in the manner described prevents the effective use of standard jumping techniques. Mechanically picking the lock is circumvented by the timing circuit that requires all coded signals to be present within the present time frame. Forceable extraction of the lock from the steering column results in an improper code and hence prevents current techniques for stealing an automobile. Without a key, entry into the driving compartment of the vehicle is of no value to the unauthorized user. Hence, a truly effective anti-theft device is provided.

It should also be pointed out that the electronic lock apparatus described herein does not require the use of a rotatable key cylinder. That much of the lock is conventional and is incorporated to preserve known habits. It should be apparent that the insertion ofa key and dis placement of the tumblers is sufficient to operate the lock. Thus, the lock could be incorporated into a system which does not use a rotatable key cylinder. For example, the insertion of the key could be used to switch on a hidden motor to slide a bolt into or out of engagement with a jamb. Such a device may have utility in the home to better secure doors or windows.

The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof and, accordingly, reference should be made to the appended claims, rather than to the foregoing specification as indicating the scope of the invention.

We claim:

1. An electronic lock apparatus comprising:

a. key means;

b. first code means for generating a first coded electronic signal in response to operation of the key means;

c. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and

d. electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of aa lock means.

2. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism;

b. said tumbler mechanism including tumblers and electronic switches which are opened or closed in response to the position of the tumblers;

c. said electronic switches defining a first code means for generating a first coded electronic signal in response to operation of the key means;

d. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and

e. an electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

3. An electronic lock apparatus in accordance with claim 2 wherein said tumblers are divided into three or more segments.

4. An electronic lock apparatus, comprising:

a. key means;

0. timer means for disabling the lock apparatus if a first proper coded electronic signal is not generated within a predetermined time frame;

(1. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of a proper first electronic coded signal; and

e. electronic means responsive to said second coded electronic signal to decode said second coded signal and generate an initiating signal for intitiating the operation of a lock means.

5. An electronic lock apparatus, comprising:

a. key means including a tumbler mechanism having a plurality of tumblers therein;

each of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers;

c. first code means for generating a first coded electronic signal in response to operation of the key means;

d. said first code means including electronic switches for setting the first coded electronic signal;

e. said electronic switches comprising said tumblers and conductive or non-conductive segments thereof for completing or not completing an electronic circuit depending on the position of said tumblers;

f. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and

g. electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

6. An electronic lock apparatus, comprising:

b. at least one of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers;

e. said electronic switches including said tumblers for completing or not completing an electronic circuit depending on the position of said tumblers;

g. electronic means responsive to said second coded signal to decode said second signal and generate an initiating signal for initiating the operation of a lock means.

7. An electronic lock apparatus, comprising:

d. timer means for disabling the lock apparatus if a proper first coded electronic signal is not generated within a predetermined time frame;

c. said first code means including electronic switches for setting the first coded electronic signal;

f. said electronic switches including tumblers for completing or not completing an electronic circuit depending on the position of said tumblers;

g. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and

h. electronic means responsive to said second coded signal to decode said second signal and generate an initiating signal for initiating the operation of a lock means.

8. An electronic lock apparatus, comprising:

b. at least one of said tumblers being divided into three or more segments for permitting said tumber mechanism to be operated in more than one position of said tumblers;

c. first code means for generating a first coded electronic signal in response to operation of the key means,

d. timer means for disabling the lock apparatus if the proper coded electronic signal is not generated within a predetermined time frame;

e. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and

. electronic means responsive to said second coded electronic signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

9. An electronic lock apparatus comprising:

a. key means including a non-rotatable key cylinder and at least one tumbler in said cylinder;

b. said tumbler being unitary and displaceable in response to the insertion of a key into said cylinder;

c. first code means for generating a first coded electronic signal in response to displacement of said tumbler;

(1. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of a first electronic coded signal; and

e. electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

10. An electronic lock apparatus in accordance with claim 9 wherein said first code means includes at least one electronic switch for setting the first coded electronic signal, said electronic switch being responsive to the displacement of said tumbler by a key means.

11. An electronic lock apparatus in accordance with claim 9 including timer means for disabling the lock apparatus if a proper first coded electronic signal is not generated within a predetermined time frame.

12. A electronic lock apparatus, comprising:

a. key means including a tumbular mechanism having a plurality of tumblers therein;

at least one of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers;

e. electronic means responsive to said second coded electronic signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

Claims

1. An electronic lock apparatus comprising: a. key means; b. first code means for generating a first coded electronic signal in response to operation of the key means; c. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and d. electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

2. An electronic lock apparatus, comprising: a. key means including a tumbler mechanism; b. said tumbler mechanism including tumblers and electronic switches which are opened or closed in response to the position of the tumblers; c. said electronic switches defining a first code means for generating a first coded electronic signal in response to operation of the key means; d. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and e. an electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

4. An electronic lock apparatus, comprising: a. key means; b. first code means for generating a first coded electronic signal in response to operation of the key means; c. timer means for disabling the lock apparatus if a first proper coded electronic signal is not generated within a predetermined time frame; d. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of a proper first electronic coded signal; and e. electronic means responsive to said second coded electronic signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

5. An electronic lock apparatus, comprising: a. key means including a tumbler mechanism having a plurality of tumblers therein; b. each of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers; c. first code means for generating a fIrst coded electronic signal in response to operation of the key means; d. said first code means including electronic switches for setting the first coded electronic signal; e. said electronic switches comprising said tumblers and conductive or non-conductive segments thereof for completing or not completing an electronic circuit depending on the position of said tumblers; f. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and g. electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

6. An electronic lock apparatus, comprising: a. key means including a tumbler mechanism having a plurality of tumblers therein; b. at least one of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers; c. first code means for generating a first coded electronic signal in response to operation of the key means; d. said first code means including electronic switches for setting the first coded electronic signal; e. said electronic switches including said tumblers for completing or not completing an electronic circuit depending on the position of said tumblers; f. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and g. electronic means responsive to said second coded signal to decode said second signal and generate an initiating signal for initiating the operation of a lock means.

7. An electronic lock apparatus, comprising: a. key means including a tumbler mechanism having a plurality of tumblers therein; b. at least one of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers; d. timer means for disabling the lock apparatus if a proper first coded electronic signal is not generated within a predetermined time frame; e. said first code means including electronic switches for setting the first coded electronic signal; f. said electronic switches including tumblers for completing or not completing an electronic circuit depending on the position of said tumblers; g. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and h. electronic means responsive to said second coded signal to decode said second signal and generate an initiating signal for initiating the operation of a lock means.

8. An electronic lock apparatus, comprising: a. key means including a tumbler mechanism having a plurality of tumblers therein; b. at least one of said tumblers being divided into three or more segments for permitting said tumber mechanism to be operated in more than one position of said tumblers; c. first code means for generating a first coded electronic signal in response to operation of the key means; d. timer means for disabling the lock apparatus if the proper coded electronic signal is not generated within a predetermined time frame; e. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and f. electronic means responsive to said second coded electronic signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

9. An electronic lock apparatus comprising: a. key means including a non-rotatable key cylinder and at least one Tumbler in said cylinder; b. said tumbler being unitary and displaceable in response to the insertion of a key into said cylinder; c. first code means for generating a first coded electronic signal in response to displacement of said tumbler; d. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of a first electronic coded signal; and e. electronic means responsive to said second coded signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.

12. An electronic lock apparatus, comprising: a. key means including a tumbler mechanism having a plurality of tumblers therein; b. at least one of said tumblers being divided into three or more segments for permitting said tumbler mechanism to be operated in more than one position of said tumblers; c. first code means for generating a first coded electronic signal in response to operation of the key means; d. second code means connected to the first code means for generating a second independently determinable coded electronic signal in response only to the generation of the first electronic coded signal; and e. electronic means responsive to said second coded electronic signal to decode said second coded signal and generate an initiating signal for initiating the operation of a lock means.