DE10252025A1 - Lock has interrogation head fixed to housing so as to only receive identification signals from transponders fixed to locking bar and holder if locking bar is in closed position and locked by holder - Google Patents

Abstract

The lock has a housing, a locking bar, a holder for locking the bar in its closed position, a sensor for monitoring the bar locking position with first and second transponders attached to the bar and holder that emit first and second identification signals and an interrogation head fixed to the housing so as to only receive the identification signal from a transponder if the bar is in its closed position and locked by the holder. The lock has a housing (26), a locking bar (22), a holder (34) for locking the bar in its closed position and a sensor (44) for monitoring the bar locking position. The sensor has a first transponder (46) attached to the bar that emits a first identification signal, a second transponder (48) attached to the holder that emits a second identification signal and an interrogation head (50) fixed to the housing so as to only receive the identification signal from a transponder if the bar is in its closed position and locked by the holder.

Description

The invention relates to a lock with a housing, a Bolt, a tumbler for locking the bolt in its closed position and with a sensor device for monitoring the closed position of the bolt.

Such locks are used in particular Locking doors, Flaps etc. used with which access to a danger zone is released can be. The danger zone can e.g. to the walkable Interior of a machine center for workpiece machining or around a Act barrier that surrounds a metal press. If the danger in the danger zone of machines, they are often like this connected to the sensor device of the lock that they only then start operating if the latch is reliable in its closed position located. This is the case with the sensor devices used to date Reaching the closed position of the bolt mostly recognized by the fact that in this position an electrical Contact is closed. Such sensor devices are, however quite prone to errors, because the necessary Contacts are exposed to moisture and contaminants, which Impair function can.

By the present invention hence a lock according to the preamble of claim 1 are specified, the sensor device particularly simple and reliable is constructed.

According to the invention, this task is performed by one such a lock solved, that the Sensor device includes:

• a) a first transponder attached to the latch and through which a first identification signal can be emitted,
• b) a second transponder that attaches to the tumbler and can be used to transmit a second identification signal is and
• c) a query head, which is so fixed to the housing Bolt and tumbler is arranged that he is the first and the second Identification signal only then from both the first and from can receive the second transponder when the bolt is in its closed position located and is locked by the tumbler.

Since the two transponders and the Non-contact query head interact with each other, the sensor device according to the invention works even under adverse external conditions reliable and maintenance free. About that the new castle is also out highest Security requirements, since not only the closed position of the bolt itself, but also monitors the position of the tumbler becomes. The risk of that The sensor device incorrectly due to malfunctions or manipulations assumes that the bolt in its closed position is, can significantly reduce in this way.

This high level of security is also guaranteed with little constructive effort. This depends on one together that it the common transponders and the query head relatively inexpensive Components. Moreover is for the two transponders only provided a common query head, which is cheap affects space requirements, design effort and costs. As a transponder is here by the way denotes each transceiver, that works according to the query-response system.

Preferably the transmission is respective identification signals for each transponder separately can be triggered by a query signal emitted by the query head. Both Transponders can therefore independent be queried from each other. Difficulties arising from one simultaneous reception of identification signals could result avoided this way from the start.

With the identification signals can be bit sequences, for example. Such bit strings enable It is easy to distinguish the transponders from one another. The reliability depends on this especially the length the bit sequences; already with 16, 32 or 64 bit sequences is the probability that it due to transmission errors there is little confusion between the transponders.

The identification signals can then z. B. can be emitted as the pulse sequences corresponding to the bit sequences. Such pulse sequences can be particularly special from the query head receive and process in a simple manner, without being expensive Demodulationsmaßnahmen should be taken.

In another advantageous embodiment the inven tion is at least one transponder at least partially in an electrically non-conductive material e.g. B. plastic, embedded. The at least one transponder can thus be inserted into a sleeve be made essentially of the electrically non-conductive material consists. This ensures that the transponder does too modulating electromagnetic field is not shielded in such a way that it the transponder may not even achieved when the bolt in its closed position located and is locked by the tumbler.

The first transponder can be in a side surface of the deadbolt inserted by the query head through one Gap is separated, the thickness of which is preferably 1 mm to 5 mm. On this way well-defined interaction conditions between the first Transponder and the query head are created.

The first transponder is preferably in the immediate vicinity of a recess or hole tion arranged in which the tumbler engages to lock the bolt. If the tumbler is then designed as a bolt displaceably arranged along its longitudinal axis, with the second transponder arranged on its end facing the interrogation head, it is ensured that both transponders are arranged in close proximity to one another in the locked locking position of the bolt, so that they can be queried together by the query head.

Other advantages and features of Invention result from the following description of a embodiment based on the drawing. In it show:

1 : A perspective simplified representation of a sheet metal press and a barrier surrounding it, which has a door with the lock according to the invention;

2 : a vertical section through the lock according to the invention 1 in a simplified, not to scale representation in the closed position;

3 : the lock out 2 in the open position;

4 : a block diagram of one of two transponders of the lock shown in the figure and a query head working with the transponders; and

5 : a representation similar to 2 , in which a modified position control for deadbolt and guard locking are shown.

1 shows a sheet metal press designated overall by 10 in perspective, in which a form 12 in the vertical direction on a sheet 14 can be lowered. Because the stay near the metal press 10 the sheet metal press is dangerous during operation 10 from a barrier 16 surrounded, the dimensions of which correspond to the danger zone which must not be entered by people during operation. Access to the danger zone is only through a door 18 possible, which has a total designated 20 lock. The castle 20 has a latch 22 on the one with the door closed 18 in a recess 24 can intervene in that of the door 18 opposite part of the barrier 16 is provided. The castle 20 is with a control of the sheet metal press 10 connected such that the latter can only be put into operation if the bolt 22 secured by a tumbler in its closed position, ie in the recess 24 intervenes.

The 2 shows further details of the castle 20 in a vertical section. The castle 20 has a housing 26 on in which a guide channel 28 for the latch 22 is trained. The bar 22 and the guide channel 28 have coordinated rectangular cross-sections so that the latch 22 sliding in the guide channel 28 can be moved in the closing direction designated 30. To move the bolt 22 can e.g. B. one at the door 18 attached jack, a key or an electromagnet can be used. Since these components of the lock are known and are not important for the invention, they are not shown in the drawing.

The bar 22 protrudes in its in 2 shown closed position in the in the barrier 16 provided recess 24 inside, causing the door 18 is locked in its closed position.

Around the bar 22 To be additionally secured in its closed position, this is to be done with a cylindrical through hole 32 provided in the closed position of the bolt 22 a bolt-shaped tumbler 34 intervenes. That is the bar 22 in the guide channel 28 locked so that it is not in the closing direction 30 out of the recess 24 can be pulled out by actuating a pawl, a key, an electromagnet or the like. The tumbler 34 is from a compression spring 36 acted on such that they automatically into the through hole under their pressure 32 of the bolt 22 occurs when the latch 22 in the guide channel 28 in the closing direction 30 under the front 36 the tumbler 34 moved away.

This locking of the bolt can only be released with the help of an electromagnetic actuation device 38 that have an annular coil 40 and in the tumbler 34 embedded permanent magnets 42 includes. The coil encloses the guard locking 34 with the permanent magnet 42 so that when an electrical current is applied to the coil 40 the magnetic field that forms in it the permanent magnets 42 along with the tumbler 34 against the pressure of the compression springs 36 upwards from the through hole 32 pulls out and in this way the locking of the bolt 22 solves.

The one for applying a current to the coil 40 required circuitry can be in the housing 26 of the castle 20 or can also be arranged in a central control device, which releases the bolt 22 coordinated with other processes. In the exemplary embodiment shown here, this circuit can be designed, for example, in such a way that the locking of the bolt is released 22 takes place automatically as soon as the sheet metal press 10 has entered a safe operating state.

Conversely, to prevent the sheet metal press 10 is put into operation as long as the bolt is open 22 the lock is not yet reliably in its closed position 20 a sensor device designated overall by 44. The sensor device 44 has the task of determining whether the latch 22 in his in 2 shown closed position and additionally by the tumbler 34 is locked in this position. For this purpose, the sensor device 44 a first transponder 46 , a second trans ponder 48 and a query head 50 on.

The first transponder 46 is in a plastic sleeve 52 let in, which in turn in an out saving on the lower side surface 54 of the bolt 22 z. B. is fixed by gluing. The second transponder 48 is also in a plastic sleeve 56 used in a recess on the front 36 the tumbler 34 z. B. is fixed by gluing.

The query head 50 is in the housing 26 embedded and consists of a modulation / comparison base station 58 with a transmitting / receiving coil 60 and from a microcontroller 62 , The query head 50 works with the first and the second transponder 46 respectively. 48 together such that an output signal corresponding to a logic one only then from the interrogator 50 is generated when corresponding identification signals have been received by both the first transponder and the second transponder.

This requires, among other things, that the two transponders 46 and 48 in the immediate vicinity of the query head 50 are like this in 2 is shown for the closed position. The transponders 46 and 48 as well as the query head 50 can be designed so that a signal transmission between the transponders 46 and 48 on the one hand and the query head 50 on the other hand only takes place if the distance between them is only a few mm, e.g. B. 5 mm. As soon as a transponder from the query head 50 is further spaced, the signal transmission is interrupted due to insufficient electromagnetic coupling, so that the interrogator 50 generates a signal level that corresponds to a logic zero.

This situation is in 3 shown. The tumbler 34 is here in the manner already described above with the help of the actuator 38 against the force of the compression spring 36 upwards from the through hole 32 of the bolt 22 has been pulled out, causing the locking by the tumbler 34 was solved. In the open position of the castle 20 is the bar 22 so far in its leadership channel 28 inserted that he was no longer in the recess 24 of the door 18 opposite part engages, causing the door 18 can be opened. In 3 can be clearly seen that in this open position of the castle 20 the first and the second transponder 46 respectively. 48 far from the query head 50 are removed. In this position there is no signal transmission between the transponders due to insufficient electromagnetic coupling 46 and 48 on the one hand and the query head 50 on the other hand possible.

The following is the function of the transponder 46 and 48 as well as the query head 50 based on the in 4 block diagram shown explained.

The left in 4 first transponder shown 46 has an LC resonant circuit 70 which includes a coil L _t and a capacitor C _t . The coil L _t is on an end face of the first transponder 46 arranged.

The query head 50 also has an LC resonant circuit denoted by 72, the coil L _{a of which is} also on an end face of the interrogation head 50 is arranged as in the 2 and 3 is shown.

The resonant circuit 70 of the first transponder 47 has at least approximately the same natural frequency as the resonant circuit 72 of the query head 50 , so that both resonant circuits can be coupled to one another electromagnetically. This has the consequence that one with the help of an operating circuit 73 in the resonant circuit 72 excited vibration is contactless on the resonant circuit 70 of the first transponder 46 transfers.

In the resonant circuit 72 of the query head 50 is a loss resistor R _a connected via a switch 74 can be bridged. The desk 74 is from a control unit 76 controllable, which is part of the microcontroller 62 is. The control unit 76 is with a first modulation register 78 and a second modulation register 80 connected, both of which are designed as shift registers. The microcontroller 62 also has a comparator 82 on that with a first comparison register 84 and a second comparison register 86 is connected, the two comparison registers 84 and 86 are also designed as shift registers. In addition, the comparator 82 connected to a current measurement circuit indicated by 88, which is in the resonant circuit 72 is arranged.

The first transponder 46 also has a microcontroller, which in 4 is designated with a total of 90. The microcontroller 90 is basically constructed exactly like the microcontroller 62 of the query head 50 and includes a control unit 92 , a comparator 94 , a comparison register designed as a shift register 96 and a modulation register, also designed as a shift register 98 , The comparator 94 is also with one in the resonant circuit 70 connected in series connected current measuring circuit, which is designated 100.

The second transponder 48 Except for the bit sequences stored in the comparison and modulation register, it is constructed in exactly the same way as the first transponder 46.

The signal transmission between the query head 50 and the first transponder 46 runs as follows:

Via a control line connected to a higher-level control 102 becomes the control unit 76 of the query head 50 initiated to send out interrogation signals by means of which the first transponder is to be caused to in turn send out an identification signal. In particular, this works in such a way that a modulation register in the first, designed as a shift register 78 stored bit sequence, the length of z. B. 64 bits, is continuously circulated. This circulation is carried out in the control unit 76 existing clock clocked with a predetermined frequency. The control unit 76 carries this recirculated bit pattern the switch 74 to, so that the sequence of bits corresponds to the loss resistance R _a in the resonant circuit 72 switched or bridged. Due to this changing damping, the high-frequency vibration in the resonant circuit 72 modulated a bit string by the resonant circuit 70 of the first transponder 46 can be registered.

The current measurement circuit 100 of the first transponder 46 detected modulation is sent to the comparator 94 passed on this sequence with the content of one in the comparison register 96 stored bit sequence compares. This bit sequence is also in the comparison register using a clock 96 circulated, the clock frequency being the same as in the interrogator 50 , If there is a match between the received and that in the comparison register 96 stored bit sequence from the comparator 94 is determined by the control unit 92 causes the first transponder 46 now in turn an identification signal to the query head 50 sends.

This is done in the resonant circuit 70 arranged switch 104 corresponding to that in the modulation register 98 stored bit sequence clocked, whereby the loss resistance R _t in the resonant circuit of the first transponder 46 switched or bridged. The query head 50 registers the damping that changes as a result of this switching on of the loss resistance via the current measuring circuit 88 and compares the received bit pattern in the comparator 82 with those in the comparison registers 84 and 86 stored bit strings. Each of those in these comparison registers 84 and 86 stored bit sequences is one of the two transponders 46 respectively. 48 assigned. In this way, by comparing the received bit sequence with that in the comparison registers 84 and 86 stored bit sequences are determined from which transponder identification signals are received. In this way, the transponder is clearly identified by the query head 50 possible. The reliability of the identification increases with the length of the bit pattern used for identification.

Does the comparator 82 found that, at his request, both transponder responses successively 46 . 48 have been correctly preserved, so the comparator 82 on the line 62 a good signal in the form of a logical one ready. With this good signal z. B. the press 10 be activated again for work.

Since the in the first and the second modulation register 78 respectively. 80 stored bit sequences each with that in the comparison register 96 one of the two transponders 46 or 48 match, both transponders can be specifically queried independently of each other. In this way, it is impossible for both transponders to be queried at the same time and for the interrogation head to no longer be able to assign the received pulse sequences to one of the two transponders.

Alternatively to that in 4 The circuit shown can also be used with transponders whose resonant circuits have different natural frequencies. In this case, the natural frequency of the resonant circuit in the interrogator must be tunable to the natural frequencies of the resonant circuits of the transponders, which can be achieved, for example, by connecting a capacitor. The targeted interrogation of the transponders is then not carried out via bit sequences stored in the modulation registers, but rather via the different carrier frequencies with which identification signals are exchanged between the interrogation head and the transponders.

In a modification of the embodiment described above, the query head can 50 also train as in 5 shown:

The sink 60 and the comparator 62 are arranged and designed (reference values of the comparators) so that cooperation only with the transponder 46 he follows. For the transponder 48 is in the query header 50 a coil 60 ' and a comparator 62 ' intended. The output signals of the comparators 62 and 62 ' are through an AND circuit 110 together combined. This gives you on the line 102 again only a high level signal when latch 22 and tumbler 34 both are in the correct closed position.

In a further modification you can see the castle 20 also on the fixed door frame of the barrier 16 provide and the bolt latch (recess 24 ) on the door 18 Arrange.

Claims (14)

Lock with a housing ( 26 ), a latch ( 22 ), a tumbler ( 34 ) to lock the bolt ( 22 ) in its closed position and with a sensor device ( 44 ) to monitor the locking position of the bolt ( 22 ), characterized in that the sensor device ( 44 ) comprises: a) a first transponder ( 46 ) on the bolt ( 22 ) is attached and through which a first identification signal can be transmitted, b) a second transponder ( 48 ), the guard locking ( 34 ) is attached and through which a second identification signal can be emitted, and c) a query head ( 50 ), which is arranged in such a way that it only receives the first and the second identification signal from both the first and the second transponder ( 46 . 48 ) can receive if the bolt ( 22 ) is in its closed position and by the guard locking ( 34 ) is locked. Lock according to claim 1, characterized in that the transmission of the respective identification signals for each transponder ( 46 . 48 ) separated by a from the query head ( 50 ) transmitted query signal can be triggered. Closed after Claim 1 or 2, characterized in that the identification signals Play bit strings. Closed after Claim 3, characterized in that the identification signals can be emitted as pulse sequences corresponding to the bit sequences. Lock according to one of the preceding claims, characterized in that at least one transponder ( 46 . 48 ) at least partially in an electrically non-conductive material ( 52 . 56 ) is embedded. Lock according to claim 5, characterized in that the at least one transponder ( 46 . 48 ) in a sleeve ( 52 . 56 ) is used, which consists essentially of the electrically non-conductive material. Lock according to one of the preceding claims, characterized in that the first transponder ( 46 ) in a side surface ( 54 ) of the bolt ( 22 ) is inserted by the query head ( 50 ) is separated by a gap, the thickness of which is preferably 1 mm to 5 mm. Lock according to one of the preceding claims, characterized in that the first transponder ( 46 ) in the immediate vicinity of a recess or bore ( 32 ) is arranged, in which the tumbler ( 34 ) to lock the bolt ( 22 ) intervenes. Lock according to one of the preceding claims, characterized in that the guard locking device is arranged as a bolt which is displaceable along its longitudinal axis ( 34 ) is executed, at the end of which the query head ( 50 ) facing end face ( 36 ) the second transponder ( 48 ) is attached. Lock according to one of the preceding claims, characterized in that the guard locking by a servo motor ( 40 ) can be actuated. Lock according to one of the preceding claims, characterized in that the tracks of bolts ( 22 ) and guard locking ( 34 ) cut at an angle other than zero or cross over at a distance and that the query head ( 50 ) is arranged in the vicinity of the intersection or the crossing point of the webs. Lock according to one of the preceding claims, characterized in that the query head ( 50 ) two coils ( 60 . 60 ' ) and two comparators working with them ( 62 . 62 ' ) which each respond to one of the transponder identification signals. Lock according to claim 12, characterized by a with the output signals of the two comparators ( 62 . 62 ' ) applied AND gate ( 110 ). Lock according to claims 1 to 11, characterized in that the interrogation head has a coil ( 60 ) and a comparator working with it ( 62 ), which is based on the identification signals of both transponders ( 46 . 48 ) appeals.