EP0047486A1 - Electronically coded latching device for locks - Google Patents

Abstract

The circuit arrangement has a key (1) for serial input of the code signals and is equipped with electronic devices for storing the code and for processing the signals. A signal is generated at the beginning or end of each keying and the time intervals between these signals are identified as "long", "medium" or "short". The sequence of these signal distances, i.e. the signal pauses are compared with the stored code. Such a code is particularly easy to remember as the rhythm of a song or as a melody and is very individual. The code entry, especially the decoding, is carried out "blind", i.e. without feedback. To carry out the individual functions, separate construction stages or a microcomputer (23) is used.

Description

The invention relates to a circuit arrangement provided for the electronically coded locking of locks, which is equipped with a key for serial input of the code signals and with electronic devices for storing the code to be recognized for unlocking and for processing the signals, i.e. for comparing the decoding signals with the stored code, for making a decision and for triggering the unlocking if the decoding signals match the stored code (decoding).

The circuit arrangement according to the invention is intended in particular for bags, suitcases and other portable containers, but it can also be used for door locks, car locks and other types of locks.

A code-controlled one-button electric door opener system (DE-AS 27 21 139, DE-AS 29 52 212) is already known, in which the Code signals are entered with the bell button, either counting the keyed pulses or, after pressing the bell button, a pulse generator is started which triggers a certain number of pulses depending on the duration of the button actuation; after releasing, waiting and pressing the bell button again, the next number is put into the next memory. If all coded numbers are selected correctly, the last memory finally releases the power supply for the electric strike contact for a limited period of time.

In such systems, counting the key press or feedback is required, in which e.g. the triggered pulses can be counted by a lighting lamp. The decoding, i.e. The input of the code to be recognized therefore requires concentrated attention in any case, and the feedback must be hidden from unauthorized persons in order not to reveal the code.

Mechanically codable locks in the form of the so-called number locks are known for suitcases and briefcases. As a rule, they have 4 to 6 ten-digit dials, which must be set to a specific number in order to unlock them in a predetermined or arbitrary order. The direction of rotation can also be prescribed. A disadvantage of such number locks is that setting the correct number is relatively cumbersome and requires visual contact.

Numeric locks with electronic coding are also known, in which each key is assigned a key, for example a six-digit number. To unlock the lock the keys must be pressed in a predetermined sequence, whereby the code number assigned to each position is selected by pressing each key several times. With these locks, too, the input of the code to be recognized takes full attention and visual contact is required.

Programming or setting the code is usually quite complicated with the known electronically coded closures and is therefore already carried out in the factory.

The invention is based on the object of overcoming the aforementioned disadvantages and creating a circuit arrangement with which the unlocking can be triggered without concentrated counting, without looking and without feedback of the input signals. The code should be easy to memorize or learn, yet individual and have a high number of encryption options to prevent unauthorized opening by randomly or systematically trying out all combinations.

In order to be able to use such a circuit arrangement for locking bags and suitcases, the energy consumption should also be so low that the electronics can be supplied with a dry battery for at least 1 year.

It has now been shown that this object can be achieved in a surprisingly simple, technically progressive manner with a circuit arrangement of the type mentioned at the beginning if a signal is only generated at the beginning or at the end of each keying and the sequence of the time intervals between the Signals, ie signal pauses, are evaluated as code, a distinction being made between at least two pause lengths (long, short).

According to the invention, the code signal sequence is entered serially with a single key. A visual contact or some other kind of feedback is not necessary because the number and length of the signal pauses that are generated by pressing the key form the signal sequence and are evaluated as a code in the manner described. The invention is based on the surprising finding that such a code, in which the signal pauses or the signal signal intervals generated and identified in the intended manner are decisive, can be very easily remembered even with a complicated structure, because such individual sequences can be activated the keys in a certain rhythm, e.g. build up to the rhythm of a song or a melody and have it entered as a code.

It turned out, which was by no means to be expected, that the pauses between the signals generated in the rhythm or their sequences for a certain song are individually very different, but that the same sequence with high constancy, regardless of mood, is the same for every person and from external influences, is preserved over long periods of time. If the circuit arrangement according to the invention has an electronic memory into which the code to be recognized can be entered individually, the encryption can be decoded very easily, quickly and inconspicuously by the authorized person and thus unlock the lock, while other people would have great difficulties even if the song was known .

According to one embodiment of the invention, the time intervals between the signals triggered during the keying are identified as short, medium or long pauses, "short" between 0.05 and 0.1 s, "medium" between 0.1 and 0.2 s as well as "long" between 0.2 and 0.4 s, encryption is obtained which is extremely secure against unauthorized decoding.

In order to keep the power consumption to a minimum, unlocking is advantageously triggered by a short pulse when the code is recognized and is automatically terminated again by a further pulse or a pulse sequence after a predetermined time. The unlocking and also the locking can be triggered automatically after recognizing the code or can only be prepared and made dependent on a renewed actuation of the key or an additional key. According to a further advantageous embodiment of the invention, voltage monitoring is provided, which triggers, prepares and / or signals the unlocking when a predetermined threshold value is undershot. It could also suffice to merely prevent a new locking if the threshold value is undershot. It is also advantageous to check the supply voltage automatically after each closure actuation under load and / or regularly at defined time intervals without load or with a low load. In a special embodiment of the invention, when the supply voltage drops to a threshold value which is 70 to 90% of the nominal voltage, all functions are switched off, the return to the normal operating state being effected by pressing a button again or by applying an external voltage source; the memory content is retained until the voltage drops to 30 to 50% of the nominal value.

As a further safety measure, a mechanically secured emergency program can also be pre-programmed, with which the release can be triggered even after a total failure of the supply voltage - after connecting an external source.

The circuit arrangement according to the invention can be equipped with a time counter which is reset with each keying and which clears the total input after a predetermined period of time, the reset of the time counter after detection of the code being prevented. In an alternative embodiment, the circuit arrangement according to the invention contains a microcomputer for storing and processing the signals.

If an electronic memory is provided, a new code can be entered into it only by actuating an associated function switch. On the other hand, a mechanically adjustable memory can also be provided, in which the code can be changed using switches, wire jumpers or the like; This has the advantage that the code is retained even in the event of a power failure or battery change.

In order to make it possible to learn the functions or the top of the electronic coding and decoding, a switch is provided according to a further embodiment of the invention, after its actuation a lock is prevented and a display signal is triggered to identify the correct entry of the code. Finally, a further embodiment provides for the circuit arrangement to be constructed in such a way that the locking can only be triggered after the decoding signals have been entered after the programming.

Further features, advantages and possible uses of the invention will become apparent from the following description of further details with reference to the accompanying figures.

• Figur 1 im Blockschaltbild eine Schaltungsanordnung gemäß einer Ausführungsart der Erfindung,
• Figur 2 im Blockschaltbild eine Ausführungsart, bei der ein Mikrocomputer als Speicher und zur Steuerung der verschiedenen Funktionen verwendet wird, und
• Figur 3 eine als Codierung geeignete, von einer Melodie abgeleitete Signalfolge.

Show it

• 1 is a block diagram of a circuit arrangement according to one embodiment of the invention,
• Figure 2 is a block diagram of an embodiment in which a microcomputer is used as a memory and to control the various functions, and
• FIG. 3 shows a signal sequence suitable as coding and derived from a melody.

In the exemplary embodiment shown in FIG. 1, the circuit arrangement according to the invention essentially consists of a key 1 for serial input of the code signals, a control unit 2, evaluation logic 3, a plurality of shift registers 4-6 and 10-12, the memories 7-9 and a comparator. and decision circuit 13 and a signal generator 14. Furthermore, an operating mode or function switch 15, a clock generator 16, a time counter 17, a voltage monitor 18 and an unlocking and locking unit 19 or 20 are provided. The power supply is symbolized with 21, the locking mechanism controlled by the circuit according to the invention with 22.

In the embodiment of the invention shown here, electronic memories 7-9 are provided for encryption. For coding, the operating mode switch 15 is brought into the "programming" position and the desired signal sequence is then keyed in. In the control unit 2, the input signal is recognized as a "long", "medium" or "short" signal and a corresponding pulse is sent to the evaluation logic 3 with the aid of a clock generator 16. The following key presses the time identifier, ie "long", "medium" or "short", adopted in the associated shift register 4, 5 or 6. After entering the last key, the information stored in the shift registers 4-6 is read into the program memory 7, 8 or 9 and stored.

When programming begins, that is to say when key 1 is pressed for the first time, signal generator 14 is also activated in the embodiment shown. After completion of the input, the signal generator 14 is reset in connection with the time counter 17 and the control unit 2 after approximately 3 s and thus releases the system for the functions “test” or “operation” which will be described later. The coding is now finished and the switch 15 is switched from the "programming" position to the "test" or "operation" position.

If the pause between successive keyings is longer than approx. 3 s, this is considered an incorrect entry. In this case, the entire system is reset to the starting position under the influence of the time counter 17 and the previous entry is thus deleted. The coding can start again.

After flipping switch 15 to the "Test" or "Operation" positions, the code to be decrypted must be entered using key 1 to unlock or trigger an unlocking signal. Again, as described in connection with the coding, the keyed pulse pauses are identified as "short", "medium" or "long" and with the help of the clock generator 16, the control unit 2 and the evaluation logic 3 in the associated shift register 4, 5 or 6 initiated. In contrast to the coding process, however, the information from the shift registers 4-6 is not read into the program memories 7-9 and instead the comparison between the coding signals and the encryption contained in the memories 7-9, ie the code to be recognized, initiated. For this purpose, the information stored in the program memories 7-9 is read into the program shift registers 10-12 and compared with the information in the shift registers 4-6 using the comparator 13.

If the switch 15 is in the "operation" position, if the read and stored signals match, the unlocking device 19 is activated via the control unit 2 and an unlocking pulse or pulse sequence is generated. The detection of the stored code is signaled to the user at the same time via the signal transmitter 14 and the request to open the locking mechanism is thus given. After the time period of approx. 3 s predetermined by the time counter 17 has expired, the signal in the signal generator 14 goes out and in the construction stage 20 a locking pulse is triggered or prepared; in an embodiment not shown here, the locking pulse is only triggered after pressing button 1 again. If the keyed pulse sequence does not match the stored code, the entire system is reset to the starting position via the time counter 17 after a few seconds, without an unlocking pulse being issued or a signal being triggered.

In the third position, referred to as "test", of the operating mode or function switch 15, if the read-in and stored code matches, i.e. when the code is recognized, only the signal generator 14 is activated. Unlocking and locking pulses are not triggered; the unlocked state is maintained.

In the "Test" position, the user should familiarize himself with the electronic coding and decoding without that the container is permanently closed, at least for the life of the battery, by a signal sequence that is no longer reproducible and entered as encryption.

In order to ensure the opening of the container when the voltage falls below a certain level of the power supply 21, which here contains a battery, as soon as the voltage falls below a limit value, the unlocking is triggered and a new locking is prevented. At the same time, the signal generator can be activated, which then e.g. generates a flickering signal or triggers an optical signal that remains recognizable even when the battery is completely discharged.

Instead of the electronic memories 7-9, a mechanical coding switch or a coding field that can be set and changed with the aid of solder bridges could also be used. Changing the coding would be more cumbersome, but the coding would remain even if the power supply fails, e.g. Battery change, received. In this case, automatic unlocking when the supply voltage drops could be dispensed with if the power supply could be established via external contacts even when the lock was locked. It is conceivable that such an embodiment would be preferred by some users or would have advantages for certain applications.

It has now proven to be advisable to initially block the "operation" position of the function switch 15 when the lock is delivered to the user with the circuit arrangement according to the invention. The "Operation" function should only be released after precise knowledge of the operating instructions and several successful decoding processes, which are indicated optically or acoustically by the signal generator 14 in the "Test" position.

In the embodiment of the invention shown in FIG. 2, all essential functions are controlled by a microcomputer 23. The coding and decoding signals are entered serially using key 1. Auxiliary functions or additional devices can be controlled with the key indicated by dashed lines in block 1.

In this embodiment too, an operating mode switch 15 is provided, which has the positions "coding", "test" and "operation".

In order to achieve a particularly high frequency stability, an oscillator 24 can be connected externally to the microcomputer 23, from which the frequency divider 25 expediently derives a lower operating frequency of the microcomputer, which is more favorable for the intended use; the power consumption is reduced at a lower frequency.

The locking and unlocking signals are fed via line 26 to the construction stage 29 framed in FIG. 2. The locking mechanism in this case contains, as an essential element, an electric servomotor 30, which moves a locking bolt (not shown) axially - depending on the direction of rotation - from one end position to the other, with limit switches 31, e.g. Hall effect position switch, the respective end position is reported back to the microcomputer via line 28. The control, here motor control "right / left", is symbolized with 32 in FIG. 33 is an additional motor current monitoring, which e.g. when "locking" the locking mechanism comes into operation and either via the microcomputer 23 (connecting line 27) and the motor control 32 causes a reversal of the direction of rotation or a shutdown to prevent overloading the motor and premature consumption of the batteries.

Building stage 34 is provided for energy supply. In a preferred embodiment of the invention, it contains four 1.5 V batteries connected in series. In order to be able to recognize the consumption of the batteries in good time, according to a further embodiment, the voltage is regularly measured using the device 35, which is also controlled by the microcomputer 23, and the battery is tested. For this purpose, each time the motor 30 is started after a delay of approx. 100 ms, i.e. after the start-up phase of the servomotor, the voltage is measured. If a threshold value is undershot, which is 4.8 V when the nominal voltage is 6 V, an acoustic or optical signal is triggered via the signal generator 14 and, at the same time, the locking, but not the unlocking, is prevented. Since in the exemplary embodiment described here the programmed code is retained until the voltage drops below 2.7 V, the normal function can be restored via the connections 36 after connecting an external battery, a power supply unit or the like. After the voltage drops below 2.7 V, this path is blocked; the coding is deleted, which should lead to the opening of the lock (after applying an energy source).

In order to enable only the authorized person to unlock the lock even after a total failure of the batteries 34, a hardware emergency program, namely a memory 37 with a mechanically secured, permanently programmed code, is provided according to FIG. After deleting the code electronically stored in the microcomputer due to a total failure of the power supply or after the voltage has dropped below 2.7 V, the lock remains locked and can only be unlocked with the help of the emergency code after connecting an external voltage source. This is particularly advantageous when using the circuit arrangement according to the invention for briefcases, suitcases or the like, are not used for a long time, which is why it can happen that the drop in battery voltage below 2.7 V is not recognized in time.

In yet another embodiment of the invention, the battery voltage is additionally checked every 24 hours, regardless of the actuation of the closure or the motor 30, and all functions are switched off when the threshold value falls below 4.8 V. As a result, the very low current required for the “internal routine” by the microcomputer 23 in the rest position is reduced again by at least a power of ten to the current required to obtain the stored code. In one embodiment, the quiescent current was reduced from 30 _/ uA to 1 _/ uA. With this measure, the electronically stored code can be retained for many months or even years, even if the battery is old and weak. When the lock is used again, all functions are switched on again and, if the supply voltage is still between 2.7 and 4.8 V, unlocking and, if necessary, a new locking is possible up to a certain limit.

The circuit arrangement according to FIG. 2 additionally contains a solar cell 37, with which the entire energy for all functions of the circuit arrangement according to the invention, also for the actuation of the servomotor 30, can be generated in connection with rechargeable cells instead of the batteries 34. In this case, the voltage source 34 only serves as a buffer. A button cell is sufficient, which despite its small dimensions has a lifespan of several years.

In order to take advantage of the many possibilities of a microcomputer, additional electronic devices, for example one Integrate electronic clock into the circuit arrangement with little additional effort. With the button 1, after switching over the operating switch 15 arranged in the inside of the case (operating mode "clock"), this clock could be set. A frequency-stable signal for controlling the clock can be derived from the already existing oscillator 24 with the frequency divider 25. With this clock, the actuation of the mechanics could also be limited to preselected times; this is important when using the circuit arrangement according to the invention for safes.

Furthermore, in the circuit arrangement according to FIG. 2, it is provided that the microcomputer 23 is only switched from the waiting position (stand by) to the operating state in which the internal routine runs completely and at the required speed after the input key 1 has been pressed via the construction stage 38. This measure also serves the goal of reducing energy consumption.

Although the invention provides for the signals to be entered serially using only one key 1, it can be advantageous in special cases to signal or control certain functions with the aid of the additional key shown in dashed lines in FIG. 1; e.g. completion of code entry, code acceptance, unlocking the lock regardless of the time of decoding, etc.

A signal sequence that is very difficult to reproduce by an unauthorized person can be derived, for example, from a song, as shown in FIG. 3. When key 1 is pressed in rhythm with such a song, a characteristic sequence of short, medium and long impulse pauses arises, which in FIG. 3 are symbolized by K, M, L, their duration by T _K , τ _M and τ _L and the sequence of which represents an individual code. It has been shown that the time intervals or the pauses between the pulses formed in the manner described, but not the keying times or keying pauses (ie the times during which the key is depressed or released) differ, and can therefore be evaluated Coding are suitable for a circuit arrangement of the type according to the invention. It can be seen from FIG. 3 that the keying times and keying pauses are individually very different for several people, without this having any effect on the code determined according to the invention. In the example explained with reference to FIG. 3, the pulse is triggered at the start of each keying. It is therefore irrelevant for the signal sequence, i.e. for the time intervals between the impulses, whether the user only presses the key briefly (2nd person in Figure 3) or with different durations according to the note value (1st person in Figure 3) actuated.

Since in the first case the key pauses (J. Person) in the second case the duration of each key actuation (2nd person) are almost constant, the same pulse sequence would occur at the end of each keying - apart from the first and last signal - and could be as Code can be evaluated.

The number of required keyings or the length of the signal sequence consisting of pauses of different lengths depends on the storage capacity of the electronic components used. In many applications, 8-bit memories are sufficient to enable a sufficient number of combinations for effective encryption.

If the number of signals that can be stored is exceeded during the keying, this is irrelevant because, in the embodiment according to FIG. after detection of the code, the time counter 17 is stopped and the signal generator 14 is activated. The microcomputer in the embodiment according to FIG. 2 also triggers the unlocking after the code has been recognized, regardless of the input of further signals.

Claims (16)

1.Circuit arrangement for electronically coded locking of locks, with a key for serial input of the code signals and with electronic devices for storing the code to be recognized for unlocking and for processing the signals, i.e. to compare the decoding signals with the stored code, to make a decision and to trigger the release. Correspondence of the decoding signals with the stored code, characterized in that a signal is generated at the beginning or at the end of each keying and that the sequence of the time intervals (r) between the signals, i.e. the signal pauses, is evaluated as a code, a distinction being made between at least two pause lengths (long, short). 2. Circuit arrangement according to claim 1, characterized in that the time intervals between the signals triggered during the keying are identified as short (τ _K ), medium (τ _M ) or long (τ _L ) pauses, "short" between 0, 05 and 0.1 s, "medium" between 0.1 and 0.2 s and 'long' between 0.2 and 0.4 s. 3. Circuit arrangement according to claim 1 or 2, characterized in that the unlocking is triggered and terminated by short pulses when the code is recognized. 4. Circuit arrangement according to one of claims 1 to 3, characterized in that the unlocking is triggered automatically immediately after detection of the code and is ended again after a predetermined time. 5. Circuit arrangement according to one of claims 1 to 3, characterized in that the unlocking is triggered automatically after detection of the code and can be ended after a predetermined time by pressing the button (1) again. 6. Circuit arrangement according to one of claims 1 to 3, characterized in that the unlocking can be triggered after the code has been recognized by pressing the key (1) and can be ended again after a predetermined time by pressing the key again. 7. Circuit arrangement according to one of claims 1 to 6, characterized in that it is equipped with a voltage monitor (18, 35) which triggers or prepares and / or signals the unlocking when a predetermined threshold is undershot or which occurs after unlocking the lock prevented from being locked again. 8. Circuit arrangement according to one of claims 1 to 7, characterized in that the supply voltage (U _B ) is automatically checked after each shutter actuation and / or regularly at predetermined intervals. 9. Circuit arrangement according to one of claims 1 to 8, characterized in that when the supply voltage drops to a threshold value which is 70 to 90% of the nominal voltage, all functions are switched off, but the memory content until the voltage drops to 30 to 50 of the nominal value is retained, and that by pressing the button again or by applying an external voltage source (U _ext .) The return to the normal operating state takes place. 10. Circuit arrangement according to one of claims 1 to 9, characterized in that in addition a mechanically secured emergency program (37) is preprogrammed, with which the release can be triggered even after a total failure of the supply voltage. 11. Circuit arrangement according to one of claims 1 to 10, characterized in that it has a time counter (17) which is reset with each key and after a predetermined period of time deletes the total input, and that the reset of the time counter after detection of the code (decoding ) is prevented. 12. Circuit arrangement according to one of claims 1 to 10, characterized in that it contains a microcomputer (23) for storing and processing the signals. 13. Circuit arrangement according to one of claims 1 to 12, characterized in that it contains an electronic memory (7-9) in which a new code can be entered with the help of the enter key (1) after actuation of a function switch (15). 14. Circuit arrangement according to one of claims 1 to 12, characterized in that a mechanically adjustable memory is provided as a memory for the code to be recognized (encryption), and that the code can be changed with the aid of switches, wire jumpers or the like. 15. Circuit arrangement according to one of claims 1 to 14, characterized in that it has a switch (15), after its actuation prevents a lock and a display signal is triggered when the code to be recognized is entered. 16. Circuit arrangement according to one of claims 1 to 15, characterized in that it is equipped with an electronic code memory and that the locking can only be triggered after input of the decoding signals following the programming.

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