EP1378620A2 - Anti-tampering electromagnet arrangement, electronic cylinder lock and method of preventing tampering of an electromagnet arrangement - Google Patents

Abstract

The lock has an electromagnetic system (30) with a coil (42) surrounding an armature (44) with a connection (26) to a cylindrical locking core. The armature may be moved forward from the rest position (R) to a switching or locked position (S). When in the locked position, the head of the armature is adjacent to a magnetic security system. It resists movement of the armature by an extraneous magnetic field (58) produced by a magnet (56) used to try and manipulate the lock. A housing (40,50) surrounds the end of the armature.

Description

The present invention relates to a tamper-proof Electromagnet arrangement for actuating a switching device, in particular a clutch in an electronic locking cylinder, with an electromagnet that has at least one coil and has an armature, which by means of the coil from a rest position movable in an axial direction to a switch position is, the electromagnet assembly magnetic security means has, which to an external magnetic field, of a manipulation site outside the electromagnet arrangement goes out, address such that movement of the armature in the Switch position is inhibited.

Furthermore, the present invention relates to an electronic Lock cylinder with a coupling for coupling a locking lug or a lock bit with a shaft and with an electromagnet arrangement to actuate the clutch.

Finally, the present invention relates to a method to prevent tampering with an electromagnet arrangement, which includes an electromagnet, the at least one coil and has an armature which is moved from a rest position by means of the coil movable in an axial direction to a switch position is, the electromagnet assembly magnetic security means which has an external magnetic field, that from the manipulation site outside the electromagnet assembly goes out, respond so that movement of the armature is inhibited in the switch position.

Such a tamper-proof electromagnetic arrangement associated method for preventing tampering and such electronic locking cylinders are from EP 0 999 328 A1 known.

Lock cylinder for installation in locks, especially mortise locks, have been known for many years, especially as mechanical locking cylinders with pin tumblers.

Furthermore, so-called electronic locking cylinders have been in use for some years in use. In these, there is a coupling between the lock bit and an actuating device or handle (e.g. knob or pusher) after verification of an electronic one Access control codes. This can be done using a card reader assigned to the lock, a key switch, etc. or wireless, usually by radio or also inductive.

Wireless identification is often used as a "key" So-called transponders are used, which are both active and in a passive design. An evaluation electronics that the Lock is assigned, then receives the unique code of the Carrier of the electronic key and, if the access authorization is given, then couples the lock bit with the Actuating device (for example knob or pusher) rotatably so that the actual unlocking process by hand can be done by the knob / pusher and thus the lock bit is rotated. By means of suitable time control, the The clutch is then opened again. In the open state does not result in actuation of the actuating device an unlocking of the lock.

To couple Knauf (pusher) with the lock bit, in usually used electromagnet assemblies. These can be miniaturize sufficiently strongly, for example for installation in the housing of a standardized profile cylinder. The electromagnet arrangement can be mono- or bistable or as bidirectional magnet arrangement are formed.

The electromagnet arrangement has a conventional manner a coil and an anchor. The anchor is usually soft magnetic. By applying a voltage to the coil generates a magnetic field that magnetizes the soft magnetic armature. Magnetic forces then cause the armature to move axially Direction is moving. This can be against spring force, for example to achieve a stable resting position. Through the Axial movement of the armature can be a switching device, in particular operate a clutch in an electronic locking cylinder.

This type of electronic lock cylinder is conventional superior to mechanical locking cylinders in many ways, especially with regard to usability and variability (quick change of access authorizations, setup and change of time zones, telecontrol options, logging of locking processes and integration in locking systems).

However, unlocking security is sometimes problematic. There the anchor is soft magnetic, it is generally conceivable to use a apply a very strong magnetic field so that the anchor can be used without Bring activation of the coil to the switch position.

Electromagnets can be installed in such a way that a external magnetic field from the door outside the electromagnet cannot manipulate in the direction of the switch position. Of the An external magnetic force then has a successful effect on the inside for manipulative coupling. This is special disadvantageous for cylinders closing on both sides.

It is known from EP 0 999 328 A1 mentioned at the outset to provide a counter magnet in a central section of the armature. This is preferably due to an external magnetic field magnetizable, but must have a magnetic decoupling direction be isolated from the rest of the magnetic circuit. Further is a disc made of ferromagnetic on the same anchor section Material provided. When trying to manipulate then by means of a strong external magnetic field the counter magnet has a stronger force on the ferromagnetic Exercise disc on the anchor as a drive device so that the anchor is pushed into the rest position. It is also mentioned that the counter magnet can be designed so that it is a Locking device activated when an external magnetic field too Manipulation purposes is created. The locking device is then designed so that they engage or close the Coupling prevented.

Against this background, there is the object of the present invention in being a structurally simpler and more tamper-proof Electromagnet arrangement, and one equipped with it electronic lock cylinder and an associated method specify.

This task is tamper-proof in the aforementioned Solenoid arrangement solved in that the magnetic Security means in an area between that of the Switch position facing end of the armature in the rest position and the manipulation site are arranged.

In the electronic locking cylinder mentioned at the beginning solved this problem in that such an electromagnet arrangement is included.

In the method according to the invention, this object solved that the magnetic security means in one area between the end of the armature facing the switching position in the rest position and a manipulation location on a magnetic Foreign field from the manipulation site outside the Magnet arrangement goes out, respond so that movement of the armature is inhibited in the switching position.

Due to the installation position of the magnetic security devices ensures that the magnetic security means earlier respond to the external magnetic field or more sensitive are for this, so that a higher security compared to the state the technology can be guaranteed. Furthermore, can by the installation position a simpler and therefore less expensive construction of magnetic security means.

It is understood that the end of the armature is on the soft magnetic Part of the anchor relates. Therefore, if the Switch position facing end of the armature in the rest position a non-magnetizable section protrude, so can the magnetic security means also in the area of the above non-magnetizable sections of the armature are provided his.

The term "inhibition" should be used in this context be understood that a movement of the armature in the switching position usually completely prevented in everyone Case, however, is made considerably more difficult.

The above task is thus solved completely.

According to a first preferred embodiment, the magnetic Safety means a reed switch on between the end of the armature facing the switching position and arranged the manipulation site and connected to control means that prevent the armature from moving into the switch position, when the reed switch is exposed to the external magnetic field is.

This embodiment of magnetic security means is comparatively inexpensive, since reed relays or switches in diverse forms are available cheaply. Furthermore, the wiring of a reed switch.

It is particularly preferred if the control means the movement of the armature in the presence of an external magnetic field prevent by controlling the coil so that the Electromagnet actively holds the armature in the rest position.

This can be done, for example, by using the coil Control means is reversed and actively controlled so that the force exerted by the coil on the armature the magnetic Counteracts foreign field.

Such a polarity reversal is also comparative in the control means easy to implement. Since the anchor is in the Rest position usually at least partially within the Coil is a comparatively small enough Coil current out to a very strong external magnetic field counteract so that the armature is not in the switching position device.

Additionally or alternatively, it is also possible that the Control means the movement of the armature in the presence of a Prevent external magnetic field by the control means Activate locking mechanism acting transversely to the axial direction, that holds the anchor in a positive position in the rest position.

In this embodiment, movement of the armature can the rest position can be prevented by positive locking. The electromagnet arrangement can also be caused by extremely strong external fields therefore do not manipulate.

In an alternative preferred embodiment, the magnetic security means a passive movable soft magnetic Blocking element on that of the external magnetic field from one that does not influence the mobility of the anchor Nominal position is pulled in the way of the anchor, so that the Anchor is held positively in the rest position.

The basic idea in this embodiment is just as simple how convincing. Due to the arrangement of the movable soft magnetic Locking element in the area between the end of the Anchor and the manipulation site can be safely guaranteed that the soft magnetic locking element on the magnetic Foreign field reacts more sensitively than the anchor and consequently initially is pulled into the locked position before the anchor could move from the rest position by means of the external field.

As soon as the locking element is in the locking position, it blocks the anchor so that it is positively in the rest position is held.

It is understood both in the embodiment with reed switches as well as in the embodiment with soft magnetic Blocking element that it is essential that this Safety equipment against the external magnetic field react more sensitively than the anchor. In both embodiments it is therefore conceivable that they also in other areas the electromagnet assembly as the area between that of the Switch position facing end of the armature in the rest position and the manipulation site, provided that the higher sensitivity is guaranteed.

In a particularly preferred embodiment, the soft magnetic Blocking element by gravity in the nominal position held.

As a result, no further means are necessary for the soft magnetic To keep the blocking element inoperative as long as none magnetic external field is applied.

According to a further preferred embodiment, the soft magnetic Locking element is a soft magnetic antenna element assigned that in a range between the magnetic External field and the soft magnetic blocking element fixed to the housing is arranged.

The soft magnetic antenna element can the magnetic "Focus" the foreign field in such a way that it is guaranteed that the soft magnetic locking element pulled into the locking position becomes. In other words, through targeted arrangement of the Soft magnetic antenna element ensures that the magnetic Foreign field regardless of the relative position of the Third-party magnets used transversely to the axial direction for this purpose can be, the soft magnetic locking element in the locking position to draw.

It is particularly preferred if the antenna element is a Cover portion of a housing of the electromagnet assembly.

Since such a lid section is regularly present anyway can be to form the soft magnetic antenna element consequently, no additional element is required. Alternatively, the cover section can also be used as a separate one Be formed element that is associated with the housing.

According to a particularly preferred embodiment, this soft magnetic locking element in the form of a ball.

This can ensure that the soft magnetic Locking element itself with the least possible friction from the nominal position can be pulled into the locked position. It is general also conceivable that the locking element has a polyhedral shape, in this case, however, is often more of a flat Go out frictional contact, so that higher friction can be expected is.

It is also preferred if the space in which the locking element is movably supported by a housing section made of paraoder diamagnetic material is formed.

This ensures that the soft magnetic locking element freely influenced by gravity within the room and from weak magnetic fields (e.g. the stray field of the electromagnet) remains unaffected.

Furthermore, it is generally preferred if the soft magnetic Locking element stored in the nominal position in an annulus is.

The annular space is preferably concentric to the axis aligned the electromagnet assembly. The ball can move in the annulus depending on the respective rotary installation position move freely by gravity. Indeed the annulus offers a variety of possible nominal positions, in which the locking element the mobility of the anchor not affected, regardless of the relative installation position the electromagnet arrangement with respect to the gravitational field the earth.

It is particularly preferred if the soft magnetic antenna element with an inner wall of the para- or diamagnetic Housing section is aligned. The antenna element focuses consequently despite the para or diamagnetic housing section magnetic field lines of the external field in the annulus into it so that the soft magnetic locking element through the External field drawn towards the soft magnetic antenna element and so gets into the locked position. Through the aligned Alignment ensures that the locking element is on the way no steps or the like in the locked position must overcome. alternative the antenna element can also easily face the inner wall stand back.

It is understood that instead of an annulus with a smaller one Variability of installation positions also only a ring sector space or only one radial channel can be provided. It is crucial that the soft magnetic locking element itself within this space from a nominal position in which the mobility the anchor is not affected, in the locked position can move in which the soft magnetic locking element Anchor "blocked".

It is understood that the above and those below Features to be explained not only in each case specified combination, but also in other combinations or can be used alone without the scope of the to leave the present invention.

Fig. 1

eine schematische perspektivische Ansicht eines elektronischen Schließzylinders;

Fig. 2

eine schematische Längsschnittansicht durch eine Elektromagnetanordnung des Schließzylinders der Fig. 1;

Fig. 3

eine schematische Schnittansicht ähnlich der Fig. 2 mit einer ersten Ausführungsform von magnetischen Sicherheitsmitteln;

Fig. 4

eine Schnittansicht entlang der Linie IV-IV von Fig. 3; und

Fig. 5

eine schematische Schnittansicht ähnlich der Fig. 2 mit einer zweiten Ausführungsform von magnetischen Sicherheitsmitteln.

Embodiments of the invention are shown in the drawing and are explained in more detail in the following description. Show it:

Fig. 1

a schematic perspective view of an electronic lock cylinder;

Fig. 2

is a schematic longitudinal sectional view through an electromagnet arrangement of the lock cylinder of FIG. 1;

Fig. 3

a schematic sectional view similar to Figure 2 with a first embodiment of magnetic security means.

Fig. 4

a sectional view taken along line IV-IV of Fig. 3; and

Fig. 5

a schematic sectional view similar to FIG. 2 with a second embodiment of magnetic security means.

In Fig. 1, an electronic locking cylinder is a total of Designated 10.

The locking cylinder 10 has a housing 12, in the illustrated Embodiment a profile housing. In the housing 12 a cylinder core 14 is rotatably supported, in itself conventionally approximately from the center of an opening in the housing 12 projects a locking bit 16 which rotatably with the cylinder core 14 is connected. The cylinder core 14 can be both massive component as well as a hollow component.

At 18 is a conventional threaded hole for one Forend screw shown.

A knob 20 on the inside of the door is rotationally fixed to the cylinder core 14 connected so that unlocking movements of the lock bit 16 directly by means of the knob 20 on the inside of the door can be done.

Instead of the knob 20, a pusher or the like can also be used Actuator may be provided.

A knob 22 (or handle) on the outside of the door is non-rotatable with connected to a shaft 24 which is rotatably supported in the housing 12 is. The shaft 24 is designed as a hollow shaft and is aligned coaxially to the cylinder core 14.

The shaft 24 is by means of a schematically indicated clutch 26 connectable to the cylinder core 14.

If the clutch 26 is open, the outside of the door can be Turn knob 22 freely, without affecting the lock bit 16. With clutch 26 closed, twisting of the knob 22 on the outside of the door for rotating the locking bit 16th

To actuate the clutch 26 is also in Fig. 1 schematically indicated electromagnet arrangement 30 is provided. The electromagnet arrangement 30 is connected to control means 32. The control means 32 are in the illustrated embodiment integrated in the profile housing 12, but can also be arranged outside the profile housing 12.

The control means 32 serve to grant access authorization to a to check the person standing outside the door. If the outside of the door standing person is authorized to control the Control means 32, the electromagnet assembly 30 so that the Clutch 26 is closed. Otherwise there is no activation the electromagnet assembly 30.

The access authorization takes place in the illustrated embodiment wirelessly by means of a transponder card 34 in which a transponder 36 is integrated.

The transponder 36 can be an active transponder that operates on Activation by the control means 32 an access authorization code sends to the control means 32, as schematically at 38 is shown.

Alternatively, the transponder 36 can also be act a passive transponder that has a coil arrangement which activates the control means 32 from a reading field is used to induce a voltage from a chip of the Transponders 36 is used to identify the code read out and over the same or a different coil arrangement to send to the control means 32.

2 shows the electromagnet arrangement in a schematic sectional illustration 30 shown in greater accuracy.

The electromagnet arrangement 30 has a housing 40, which at least in sections through the housing 12 of the locking cylinder can be formed. However, it can also be a separate one Act housing.

In the housing 40, a coil 42 is mounted fixed to the housing. Within the coil 42 is an armature 44 made of a soft iron material Slidably mounted in the axial direction.

One end of the electromagnet assembly 30 emerging from the Armature 44 is connected to the clutch 26. In the illustration 2, the anchor 44 is shown in a rest position R, in the clutch 26 is open. Although not shown the anchor 44 can be in the rest position by means of a spring R be biased.

By applying an electrical voltage to the coil 42 can the anchor 44 from the rest position R shown in a dashed Switch position S shown are moved, as is schematic is shown at 46. If the anchor 44 in the Switch position S is located, the clutch 26 is closed.

The housing 40 has one in the illustrated embodiment Cylinder section 48 and a cover section 50. The lid section 50 closes in the direction of the switching position S lying open end of the cylinder section 48.

On the inside of the cover section 50 there is a projection formed of a stop 52 for the armature 44 in the Switch position S forms.

The solenoid assembly 30 can be monostable, as above mentioned, so that the anchor 44 generally in a stable position is biased, for example by means of a mechanical spring. The arrangement 30 can, however, also be designed to be bistable be so that the armature 44 after reaching the switching position S remains in this position, even without adding electrical Energy to the coil 42. The return to the rest position R can then, for example, by reversing the polarity of the coil 42 respectively. Alternatively, it is also possible for the electromagnet arrangement 30 works bidirectionally, so that, for example by energizing a second coil, not shown the armature 44 from the switch position S back to the rest position R can be moved.

At 56, an outside of the electromagnet assembly 30 is arranged Foreign magnet shown, from which an external magnetic field 58 emanates.

The external magnet can be a strong permanent magnet or act as a strong electromagnet. The External magnet 56 is attached to the outside of the door, for example, to manipulate the solenoid assembly 30 by the armature 44 on even without applying an electrical voltage the coil 42 is pulled into the switch position S to the clutch 26 close.

To avoid the armature 44 in the presence of the magnetic Foreign field 58 is pulled into the switching position S magnetic security means 60 are provided. The magnetic Security means 60 are in a range between soft magnetic part of the armature 44 and the location arranged which the external magnet 56 are used for manipulation purposes can.

Due to this installation position, the magnetic security devices can 60 more sensitive to the external magnetic field 58 and take appropriate security measures to ensure that the armature 44 despite the presence of the external magnetic field 58 is not pulled into switch position S.

The key thing is that it is magnetic security acts that respond to a magnetic field 58. It is also crucial that the magnetic security means more sensitive respond to the foreign field 58 as the anchor 44. If this The magnetic security devices can be used 60 also at another location within the electromagnet arrangement 30 or inside or next to the lock cylinder 10 are arranged. In the illustrated embodiment there is a risk of tampering only with the Door outside. Because from the inside of the door is the middle of the knob 20 rigidly connected to the lock bit 16 anyway easy to open.

By suitable alignment of the electromagnet arrangement 30 basically be ensured that a magnetic Foreign field 58 does not move the armature 44 from the rest position R into the Switch position S can move, but rather the armature 44th pulls even more into the rest position R.

In theory, however, it is conceivable that the external magnetic field 58 the housing or a yoke of the electromagnet arrangement 30 magnetized, which then exerts a force on the armature 44 is exercised, which moves it into the switch position S. For in this case the magnetic security means 60 can be a Prevent movement of the armature 44 as the magnetic security means because of their arrangement and / or because of their magnetic properties and / or their easy mobility used to cause movement of the armature 44 lock.

Furthermore, the magnetic security means in such electronic Lock cylinders of importance where both the knob on the inside of the door and the knob on the outside of the door are generally decoupled from the lock bit 16. this concerns Lock cylinder, which can be opened both from the inside of the door as well as from the outside of the door only after an inspection the access authorization can take place.

In this case, at least in the axial installation position of the electromagnet arrangement 30 given the problem that a magnetic Foreign field 58 from one side (e.g. outside of the door) the anchor 44 pulls into the rest position from the other side (e.g. inside of the door) however in the switch position. In this case the magnetic security means 60 in any case on the more vulnerable to manipulation Page can be arranged, however theoretically can also be arranged on both sides.

3 and 4 is a first embodiment of magnetic Security means 60 'shown.

The magnetic security means 60 'become a soft magnetic one Locking element 70 used in the presence of a magnetic external field 58 the path of the armature 44 from the To block the rest position R in the switch position S.

Usually the soft magnetic locking element 70 is in one aligned concentrically to the axis of the electromagnet arrangement Annulus 72 stored. In the sectional view of the 3 is one of theoretically an infinite number of nominal positions 73, in which the soft magnetic blocking element 70 if there is no external magnetic field 58. In the Nominal position 73 hinders the soft magnetic blocking element 70 the mobility of the armature 44 is not.

As shown in Fig. 4, there is the soft magnetic Locking element 70 due to gravitational forces G in a lower area of the annular space 72. Through the annular space 72 it is ensured that the soft magnetic locking element 70th regardless of the rotational installation position of the electromagnet arrangement 30 is not in the path of the anchor 44.

The annular space 72 is formed by one or more parts Ring element 75, which has two radial projections 74 and 76, that of the inner circumference 78 of a cylinder section 77 of the Ring element 75 go out. The radial projections 74, 76 are in Spaced axially so that the soft magnetic Locking element 70 is mounted in the axial direction with play in between is.

More specifically, the annular space 72 is defined by the inside 80 of the radial projection 74, through the opposite Inside 82 of the radial projection 76 and through the inside 78 of the cylinder section 48 '.

The radial projection 74 thus extends in the radial direction far that the armature 44 can pass in the axial direction. In the rest position R of the armature 44 is the end face 84 of the armature 44 aligned with the inside 80.

The radial leg 76 extends a similar distance in the radial direction, so that in the axial top view an opening remains in the annular space 72.

This opening is closed by the cover section 50, whose protrusion extends into the opening. The Front side of the projection, the stop 52 'for the Anchor 44 can form, is then flush or easily inserted aligned with the inside 82 of the radial leg 76.

When the armature 44 is in the rest position R, can the soft magnetic locking element 70 consequently in the whole Move space that includes the annular space 72 and that Space occupied by the armature 44 in the switch position S. becomes.

The cylinder section 77 including the radial protrusions 74, 76 is made of a para or diamagnetic material. This ensures that the locking element 70 to one is isolated from the stray field of the coil 42, the other, that the walls of the annulus under the influence of an external field 58 cannot magnetize themselves. By gravitation G the soft magnetic locking element 70 is always in one of nominal positions 73.

The cover section 50 ', however, is made of a soft magnetic Material made.

In the presence of an external magnetic field 58 the cover section 50 is magnetized and the field lines are concentrated on the protrusion of the lid portion 50, which extends to the annular space 72. Usually could the external magnetic field then also attract the armature 44 and spend in the locked position. The soft magnetic locking element However, 70 becomes 58 due to the external magnetic field pulled the projection of the lid portion 50 so that it blocked the path of the armature 44. This blocking position is in Fig. 3 shown in dashed lines at 86.

Due to the shape of the ball, the soft magnetic Locking element 70 with low friction within the annulus 72 move. Due to the aligned alignment of the inside 82 with the stop 52 'moves the soft magnetic locking element 70 easily into the locked position 86 without obstacles.

As an alternative to the spherical shape, it is also conceivable that the soft magnetic Locking element has the shape of a polyhedron, in particular a cuboid or cube. It is also conceivable instead of an annular space 72, only one annular sector space should be provided. This increases the variability with regard to the installation position somewhat restricted. With suitable assembly instructions however, this problem can be alleviated. In an extreme case it could instead of an annulus only a radial channel for the soft magnetic locking element 70 can be provided, as in Fig. 4 is indicated schematically at 88.

The soft magnetic locking element 70 does not necessarily have to in one piece or consistently from the same soft magnetic material consist. For example, it is also possible to use one soft magnetic jacket around a light plastic element, especially hollow plastic element to arrange around. Is too conceivable, the soft magnetic locking element 70 on the outside with a thin layer of another material to reduce friction to coat.

5 shows a further embodiment of magnetic security means 60 '' shown.

In this embodiment, a reed switch 90 is in the area between anchor 44 and the location of the attack by the Foreign magnets 56 arranged. The reed switch 90 is arranged that it occurs when a magnetic external field 58 switches immediately. The reed switch 90 is with the control means 32 "electrically connected so that the switching of the reed switch 90 can be recorded in it.

To prevent the armature 44 from the rest position R in the locking position S is pulled, it is provided that the control means 32 '' when switching the reed switch 90, the coil 42 Control reversed polarity (or with bidirectional magnets the corresponding one Is energized coil), so that of the coil 42 a Force exerted on the armature 44 in the direction of the rest position R. 5, as shown schematically at 92 in FIG. hereby the coil 42 is thus actively driven to the magnetic Counteracting foreign field 58 and to prevent that the armature 44 is pulled into the switch position S.

At 97, a shielding element 97 is shown schematically is made of a para or diamagnetic material and with the reed switch 90 opposite a stray field of the coil 42 isolated.

Alternatively or in addition, it is also possible that the Control means 32 '' upon detection of switching of the reed switch 90 control a locking mechanism 94, the Armature 44 is positively locked in the rest position R.

5 schematically shows a latch 96 of the latch mechanism 94 shown, which is designed in a corresponding to engage radial locking recess 98 of armature 44. alternative a latch mechanism could also be in the space between Grab anchor 44 and stop 50.

The magnetic security means 60 ″ consequently also securely prevents the armature 44 from being manipulated Foreign field 58 from the rest position R to the switch position S is pulled.

Although the illustrated embodiment is a double cylinder shows, it goes without saying that the invention also in half cylinders can be implemented.

Claims (14)

Tamper-proof electromagnet arrangement (30) for actuating a switching device (26), in particular a clutch (26) in an electronic locking cylinder (10), with an electromagnet which has at least one coil (42) and an armature (44) which is operated by means of the coil (42) is movable from a rest position (R) in an axial direction into a switching position (S), the electromagnet arrangement (30) having magnetic security means (60) that are directed to an external magnetic field (58) that originates from a manipulation location outside the Electromagnet arrangement goes out, respond in such a way that movement of the armature (44) in the switching position (S) is inhibited,
characterized in that the magnetic safety means (60) are arranged in a region between the end (84) of the armature (44) facing the switching position in the rest position (R) and the manipulation location. Electromagnetic arrangement according to Claim 1, characterized in that the magnetic safety means (60 ") have a reed switch (90) which is arranged between the end (84) of the armature (44) facing the switching position and the manipulation location and with control means (32 ''), which prevent the armature (44) from moving into the switch position (S) when the reed switch (90) is exposed to the external magnetic field (58). Electromagnet arrangement according to claim 2, characterized in that the control means (32 '') prevent the movement of the armature (44) in the presence of an external magnetic field (58) by driving the coil (42) in such a way that the electromagnet drives the armature (44 ) actively in the rest position (R). Electromagnetic arrangement according to claim 2 or 3, characterized in that the control means (32 '') prevent the movement of the armature (44) in the presence of a magnetic external field (58) by the control means (32 '') acting a locking mechanism transversely to the axial direction ( 94) control, which holds the armature (44) in a form-fitting manner in the rest position (R). Electromagnetic arrangement according to Claim 1, characterized in that the magnetic safety means (60 ') have a passive, movable, soft-magnetic blocking element (70) which, from the external magnetic field (58), moves from a nominal position (73) which does not influence the mobility of the armature Anchor (44) is pulled so that the armature (44) is held in a form-fitting manner in the rest position (R). Electromagnetic arrangement according to claim 5, characterized in that the soft magnetic blocking element (70) is held in the nominal position by gravity. Electromagnet arrangement according to claim 5 or 6, characterized in that the soft magnetic blocking element (70) is assigned a soft magnetic antenna element (50 ') which is arranged in a region fixed between the external magnetic field (58) and the soft magnetic blocking element (70). Electromagnet arrangement according to claim 7, wherein the antenna element (50 ') a cover section (50) of a housing (40 ') of the electromagnet assembly. Electromagnet arrangement according to one of claims 5-8, characterized in that the soft magnetic blocking element (70) has the shape of a ball. Electromagnet arrangement according to one of claims 5-9, characterized in that the soft magnetic locking element (70) is movably mounted in a space (72) which is formed by a housing section (48 ', 74, 76) made of para- or diamagnetic material. Electromagnet arrangement according to one of Claims 5 - 10, characterized in that the soft magnetic blocking element (70) is mounted in an annular space (72) in the nominal position (73). Electromagnet arrangement according to claims 7 and 10, characterized in that the soft magnetic antenna element (50 ') is aligned with an inner wall (82) of the para- or diamagnetic housing section (48', 74, 76). Electronic lock cylinder (10) with a clutch (26) for coupling a lock bit (16) with a shaft (24) and with an electromagnet arrangement (30) for actuating the clutch (26), characterized in that the electromagnet arrangement (30) is an electromagnet arrangement according to any one of claims 1-12. Method for preventing manipulation of an electromagnet arrangement (30), which includes an electromagnet, the at least one coil (42) and an armature (44) which by means of the coil (42) from a rest position (R) in an axial direction to a switch position (S) is movable, the electromagnet arrangement (30) between the end (84) facing the switching position (S) the anchor (44) in the rest position (R) and a manipulation site has magnetic security means (60), to a magnetic (58) external field from the manipulation site outside the electromagnet arrangement, respond so that movement of the armature (44) in the switching position (S) is inhibited.

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