WO2024099958A1

WO2024099958A1 - Access protection system with an electronically readable locking gripper

Info

Publication number: WO2024099958A1
Application number: PCT/EP2023/080826
Authority: WO
Inventors: Thomas Buchwald; Udo Kienapfel
Original assignee: K.A. Schmersal Holding Gmbh & Co. Kg
Priority date: 2022-11-11
Filing date: 2023-11-06
Publication date: 2024-05-16
Also published as: DE102022129951A1

Abstract

The invention relates to an access protection system (10), to a locking gripper (34, 134) therefor, and to a method for providing safeguarding during maintenance work in a hazardous area (16). The access protection system (10) comprises an actuator (20) for attaching to a safety door (14) and a safety interlock (18) for attaching to a frame part (12). The safety interlock (18) has a receiving region (28) for the actuator (20). The access protection system (10) comprises, furthermore, a locking gripper (34, 134) with an engagement portion (36) for forming a gripper engagement arrangement with the receiving region (28), with the result that an engagement of the actuator (20) is precluded. A locking gripper RFID tag (50) is arranged on the engagement portion (36) of the locking gripper (34, 134), and an interlock RFID reader (32) is arranged on the receiving region (28) of the safety interlock (16). The locking gripper RFID tag (50) can be read in the gripper engagement arrangement by way of the interlock RFID reader (32).

Description

ACCESS SECURITY SYSTEM WITH ELECTRONICALLY READABLE LOCKING PLIERS

The invention relates to an access security system, a locking device therefor and a method for securing maintenance work in a danger area.

It is known to secure hazardous areas such as the working area of a machine or industrial plant using separating protective devices, i.e. protective fences, for example. Access to the hazardous area can be closed off by movable separating protective devices, generally referred to here as a safety door. A safety door is usually secured using a safety interlock on a frame part that is fixed opposite the safety door and which, when the safety door is closed, accommodates an actuator attached to the movable safety door in a receiving area of the safety interlock. By testing and/or mechanically securing the actuator in the receiving area, the safety interlock can monitor and ensure that the safety door is properly closed, so that, for example, an enable signal for operating the machine or plant in the hazardous area is only generated when the safety door is properly closed and the safety interlock is locked.

To gain access to the danger zone, for example to carry out maintenance work, it is known to use a mechanical locking device, generally referred to here as a locking pliers, to prevent the safety door from closing and the actuator from being attached to the safety interlock. This ensures that an escape route always remains open and the safety interlock cannot issue a release signal, so that unexpected start-up of the machine or system during maintenance work is ruled out. One well-known locking pliers is the applicant's SZ200-1. This includes a locking body with several openings that can be pushed through the actuator. The shackle of the maintenance staff's padlocks can be hooked into the openings, thus preventing unauthorized removal of the locking pliers.

DE 10 2017 003 453 Ai of the applicant describes a locking device for an actuator of a safety locking device. The actuator has an insertion opening for a mechanical lock. The locking device comprises a rigid clamp end that can be releasably snapped onto the actuator from the outside and a movable clamp end that is formed by an end-side locking section in a guide of a clamp back extension that is axially displaceable. The locking section can be used as an engagement member in the insertion opening when supported by the snapped-on rigid end. The bolt has a number of spaced holes that are aligned with holes in the clamp back extension for hanging locks for releasably blocking the locking section in the insertion opening.

It can be considered an object to provide an access security system, a locking device therefor and a method for securing maintenance work in a danger area, in which the access security system is locked in a particularly simple and at the same time safe manner and the locking state can be determined easily and reliably.

The object is achieved by an access security system according to claim 1, a locking pliers therefor according to claim 14 and a method according to claim 15. Dependent claims relate to advantageous embodiments of the invention.

The access control system according to the invention comprises at least one safety interlock with a suitable actuator and a suitable locking tongs.

In a manner known per se, the actuator is designed to be attached to a protective door and the safety interlock to be attached to a frame part. The term “protective door” is to be understood as any access barrier that can be opened and closed, which includes, for example, swing doors and sliding doors as well as flaps, barriers or other types of locks. The frame part is preferably a fixed part, relative to which the protective door can move when opening or closing, whereby the protective door can preferably rest against the frame part in a closed position.

The safety lock has a receiving area in which the actuator can be at least partially received, so that the actuator can be locked to the safety lock, preferably by means of a positive locking mechanism, preferably by means of a controllable locking element such as a tumbler bolt. The actuator can have various shapes, for example as a bracket, protruding tongue, etc. The receiving area is designed to accommodate the respective shape of the actuator, preferably in an opening or recess, and to lock it there, preferably by means of a locking element.

The actuator and safety interlock are preferably attached to the frame part and the safety door in such a way that when the safety door is closed, the actuator is accommodated in the receiving area of the safety interlock. A design of the receiving area in which the actuator is surrounded by at least two opposite sides is preferred, but not mandatory. An arrangement formed by appropriately accommodating the actuator in the receiving area can be referred to as an actuator engagement arrangement. The safety interlock is preferably designed to output a release signal only when the actuator engagement arrangement is formed.

According to the invention, a locking RFID reader is arranged in the receiving area of the safety locking device. RFID technology is known to be a system for identifying and/or locating an RFID tag, i.e. a transponder which, when stimulated with signals in the form of electromagnetic waves or alternating electric or magnetic fields of a suitable frequency, emits an identification code, also as a signal in the form of an alternating field or an electromagnetic wave. The RFID reader comprises at least one antenna and a circuit in the form of a signal unit, whereby the signal unit generates signals to be emitted by the antenna and processes signals received at the antenna.

For the system according to the invention, a locking pliers is provided, which can also be ordered separately (Claim 14) is considered to be an invention. The locking pliers have an engagement section for receiving in the receiving area of the safety lock. The engagement section can preferably have the same size and shape as the actuator belonging to the system. The arrangement formed when the engagement section of the locking pliers is received in the receiving area of the safety lock is referred to here as a pliers engagement arrangement. In the pliers engagement arrangement, the receiving area is blocked and thus it is ensured that engagement by the actuator is excluded, in particular to form an actuator engagement arrangement. The locking pliers thus lock the safety lock for the actuator and preferably prevents the protective door from closing, which would require reaching an actuator engagement arrangement.

According to the invention, a locking pliers RFID tag, i.e. an RFID transponder, is arranged on the engagement section of the locking pliers. The locking pliers RFID reader is positioned on the receiving area in such a way that the locking pliers RFID tag can be read by the locking pliers RFID reader in the pliers engagement arrangement.

The positioning of the locking tongs on the safety interlock can be determined electronically by evaluating the signals received on the interlock RFID reader. A control device that can be located in the interlock and/or linked to it via a data connection can identify the locking tongs RFID tag and the safety interlock and/or the control device can then be put into a locking tongs or maintenance mode, for example. The safety interlock is then not only locked mechanically, but preferably also in a special operating mode in which no release signal is issued. In addition, in an operating environment in which various locking tongs exist that differ in terms of the locking tongs RFID tags, it is possible to recognize the specific identity of the locking tongs currently received in the receiving area.

The design and arrangement of the locking pliers RFID tag and the locking RFID reader can be such that the reading of the locking pliers RFID tag is only possible when the pliers engagement arrangement exists, i.e. only when the locking pliers are correctly positioned and received in the receiving area. The RFID Technology has a relatively short range, so that it is possible to select the positioning and transmission/reception properties of the antenna of the RFID reader in such a way that it is not possible to read an RFID tag that is only located in the vicinity of the recording area, but that the actual positioning within the recording area is necessary for this.

It is possible that RFID tags arranged on the locking pliers and/or on the actuator have an antenna that has a transmission/reception characteristic aligned along a preferred direction, and the tumbler RFID reader is arranged on the receiving area in such a way that it is positioned in the preferred direction when the pliers engagement arrangement or actuator engagement arrangement is formed. Conversely, it is also preferred that the tumbler RFID reader has an antenna that has a transmission/reception characteristic aligned along a preferred direction, and that when the pliers engagement arrangement is formed, the locking pliers RFID tag and/or when the actuator engagement arrangement is formed, the actuator RFID tag is positioned in the preferred direction starting from the antenna of the tumbler RFID reader. The transmission/reception characteristics of the guard locking RFID reader can, for example, be designed as a bundled beam, so that only RFID tags within the beam are read, while RFID tags that are in close proximity but geometrically outside the beam are not detected. This ensures that a detected locking tongs RFID tag and/or actuator RFID tag is actually arranged in a predetermined position in the direction of the beam relative to the guard locking RFID reader and not in a position that deviates from this. In alternative designs, however, it is also possible to select a non-directional or less strongly directed transmission/reception characteristic, e.g. as a broadened beam, so that a lower selectivity in the arrangement of the RFID tag to be read is achieved.

With the locking pliers RFID tag, increased safety in use and reliable detection of the locked state can be achieved.

According to a further development of the invention, the locking pliers have an adjustment element that can be adjusted between a release position and a blocking position. In the release position, the locking pliers can be introduced into the receiving area and/or removed from can be removed from it. In the blocking position of the adjustment element, the locking pliers accommodated in the receiving area cannot be removed from the receiving area. The locking pliers therefore comprise a mechanical adjustment between the release and blocking positions. In the blocking position, with an existing pliers engagement arrangement on the receiving area, it is ensured that the locking pliers are not removed and the secured state is therefore not canceled. The adjustment element can be adjusted in different ways, for example by turning or pivoting. It is preferably displaceable between the release and blocking positions, particularly preferably in a linear guide. In a preferred embodiment, the adjustment element can be designed as a flat strip, which is preferably displaceable along its longitudinal axis.

Preferably, the adjustment element can be secured at least in the blocking position by a lock. A lock is understood to mean any mechanically blocking part that is preferably coupled to the adjustment element by positive engagement and prevents movement from the blocking position. The lock can also preferably be locked so that it cannot be released without a key. A padlock can particularly preferably be used, whereby, depending on the design, the key can be a mechanical key, electronic key and/or information such as a numerical code that can be set on a combination lock.

In a preferred embodiment, the locking pliers have a locking pliers body, relative to which the adjustment element is adjustable. At least one lock opening is formed on the locking pliers body and on the adjustment element, preferably several lock openings each. In the blocking position, the lock openings on the locking pliers body are aligned with the lock openings on the adjustment element, so that one or more locks can reach through. In the opening position, the lock openings are not aligned. When the lock is inserted, adjustment of the adjustment element is therefore impossible. Several pairs of lock openings allow several locks to be inserted, whereby adjustment from the blocking position is only possible after all locks have been removed.

According to a further development of the invention, the locking pliers have a blocking element that can be moved into an extended position. The receiving area of the safety lock The locking device has a suitable receptacle for the blocking element. If the blocking element is moved into the extended position in the pliers engagement arrangement, it engages in the receptacle in the receiving area in such a way that the locking pliers cannot be removed from the receiving area. For this purpose, an undercut is preferably formed between the blocking element and the receptacle, which fixes the locking pliers in the receiving area.

The adjustment element can preferably work together with the blocking element. Preferably, when the adjustment element is in the blocking position, the blocking element is held in the extended position. The locking pliers with the adjustment element in the release position can be inserted into the receiving area and the blocking element can be brought into the extended position there so that the locking pliers cannot be removed from the receiving area. If the adjustment element is now brought into the blocking position, the locking pliers are secured to the receiving area. This arrangement can be secured using one or more locks.

According to a preferred embodiment, the adjustment element can be movable in a longitudinal direction of the locking pliers and the blocking element in a direction transverse to this, i.e. vertically or also diagonally. The adjustment element can preferably be coupled to the blocking element via a ramp. For example, the ramp can be formed on the blocking element and arranged such that the adjustment element engages with the ramp when adjusted in the direction of the blocking position and thereby causes the blocking element to move in the direction of the extended position, or the ramp can be formed on the adjustment element and arranged such that the ramp engages with the blocking element when the adjustment element is adjusted in the direction of the blocking position and thereby causes the blocking element to move in the direction of the extended position.

In principle, the locking pliers RFID tag can be arranged at any point or on any element on the engagement section of the locking pliers. For example, it can be arranged on the adjustment element or on the locking pliers body. In a particularly preferred embodiment, however, the locking pliers RFID tag is arranged on the blocking element. This ensures in particular that the The locking element used in the locking pliers can be monitored in its arrangement by reading the locking pliers RFID tag.

The safety lock can have various types of movable elements for securing an actuator and/or a locking pliers. In a preferred embodiment, the safety lock can have a tumbler bolt that can be extended into the receiving area in a bolt longitudinal direction to lock the actuator. The tumbler bolt can be acted upon by a spring and/or by a controllable drive, for example. It is particularly preferred that the tumbler RFID reader is arranged opposite the tumbler bolt in the receiving area. The area opposite the tumbler bolt is well suited for arranging the tumbler RFID reader, particularly if no movable elements are arranged there, with no metal elements that would interfere with reception preferably being arranged between the tumbler RFID reader (or its antenna) and the receiving area.

The actuator preferably has an actuator engagement section for forming an actuator engagement arrangement with the receiving area. According to a preferred embodiment, an actuator RFID tag is arranged on the actuator engagement section. The actuator RFID tag is preferably compatible with the locking pliers RFID tag, i.e. can be read in the same way, e.g. with the same frequency, but can be distinguished, i.e. it sends a different code when read. The code preferably already determines whether the RFID tag read belongs to an actuator or to a locking pliers. The actuator RFID tag can preferably be read in the actuator engagement arrangement by the locking RFID reader, particularly preferably exclusively in the actuator engagement arrangement. In this way, operational and manipulation security can also be increased with regard to the actuator's engagement, and the locking or a control system can recognize the current state by reading the actuator RFID tag.

The method according to the invention for securing maintenance work in a hazardous area provides for securing the hazardous area by means of a protective door that can be moved between the open and closed positions, with a safety interlock being attached to a frame part and an actuator being attached to the protective door. As previously described, the Safety interlock has a receiving area for the actuator. In one operating mode, the safety door is in the closed position and the actuator forms an actuator engagement arrangement with the receiving area of the interlock.

In a maintenance mode, a locking pliers with an engagement portion is brought into engagement with the receiving area such that the engagement portion forms a pliers engagement arrangement with the receiving area in which an engagement of the actuator is excluded, preferably at least by mechanical blocking.

According to the invention, in maintenance mode, a locking pliers RFID tag on the engagement section of the locking pliers is read by a locking RFID reader on the receiving area.

Embodiments of the invention are described in more detail below with reference to drawings.

Fig. la, ib in perspective view a first embodiment of a locking pliers in blocking position and release position;

Fig 2 is a perspective exploded view of the locking pliers of Figures la, ib;

Fig. 3a, 3b representation of longitudinal sections through the locking pliers from figures la, ib, 2 along the line A;

Fig. 4 shows a perspective view of an arrangement of a safety locking device and a locking tongs as elements of an access control system;

Fig. 5 is a representation of a longitudinal section through the arrangement of Figure 4 along the line A;

Fig. 6 shows a perspective view of part of the arrangement of safety interlock and locking tongs from Figure 4 with the housing partially removed; Fig 7 in partially schematic representation elements of the access control system on a protective door

Fig. 8a, 8b in perspective view a second embodiment of a locking pliers in blocking position and release position;

Fig. 9a, 9b are perspective exploded views of the locking pliers of Figures 8a, 8b in views from above and below;

Fig 10a, lob Representation of longitudinal sections through the locking pliers from Figures 8a, 8b, 9 along the line B.

Figure 7 shows, partially schematically, parts of an access control system 10 with a protective door 14 that is movable relative to a frame part 12 (shown here in two positions, open and closed). The protective door 14 and the frame part 12 are part of a separating protective device with which a danger area 16 is separated.

A safety interlock 18 is attached to the frame part 12 and an actuator 20 is attached to the protective door 14. The actuator 20 has, as shown only schematically here, a recess 22 provided for engagement with the safety interlock 18 and an actuator RFID tag 24.

The safety interlock 18 is connected to a control device 26 via a data connection. The control device 26 controls the safety interlock 18 and receives information from it about the current state. In particular, the safety interlock 18 generates a release signal when the actuator 20 is properly received in a receiving area 28. This is only the case when the protective door 14 is closed; then the actuator 20 forms an actuator engagement arrangement with the receiving area 28 of the safety interlock 18.

In the actuator engagement arrangement, the safety interlock 18 can, as described in more detail below, fix the actuator 20 to the receiving area 28 by means of a tumbler bolt 30 (not shown in Figure 7) which engages in the recess 22. In the In addition, a guard locking RFID reader 32 (also not shown in Figure 7) on the safety guard locking 18 can read the actuator RFID tag 24 so that its correct positioning in the actuator engagement arrangement and its correct identity as the actuator 20 assigned to the safety guard locking 18 can be checked at the same time.

If the safety locking device 18 detects the correct formation of the actuator engagement arrangement, i.e. correct reception of the actuator 20 in the reception area 28, locking by the locking bolt 30 and correct recognition of the actuator RFID tag 24, it reports a release signal to the control device 26, which, for example, enables the operation of a machine in the danger zone 16.

To allow access to the danger zone 16, e.g. for maintenance work, the safety interlock 18 is unlocked, the actuator engagement arrangement is released and the protective door 14 is opened. To ensure that the protective door 14 cannot be closed and a release signal cannot be issued by the safety interlock 18 while people are present in the danger zone 16, a locking pliers 34, 134 (not shown in Figure 7) is inserted into the receiving area 28 of the safety interlock 18 and locked as explained below. By accommodating the locking pliers 34 in the receiving area 28, this is mechanically blocked and complete closing of the door 14 with the actuator 20 accommodated in the receiving area 28 is excluded.

A first embodiment of a locking pliers 34 is shown in Fig. 1-6. As can be seen from Fig. 1a, ib, the locking pliers 34 in the embodiment shown are elongated. At the front end they have an engagement section 36 which, as shown and described below, can be received in the receiving area 28 of the safety lock 18. Otherwise, the locking pliers 34 are formed by a locking pliers body 38 made of plastic and an adjusting element 40 in the form of an elongated metal tongue which is slidably guided on this. The adjusting element 40 is slidable in the guide of the locking pliers body 38 along a longitudinal axis A between a front stop shown in Figure 1a, which corresponds to a blocking position, and a rear stop shown in Figure ib, which corresponds to a release position of the adjusting element 40. As can be seen in particular from Fig. 2, 3a, 3b, first lock openings 42a are formed on the locking pliers body 38 and second lock openings 42b are formed on the adjusting element 40. As can be seen from Fig. la, ib and the associated longitudinal sections Fig. 3a, 3b, the respective first and second lock openings 42a, 42b are aligned in the blocking position (Fig. la, Fig. 3a), but not in the release position (Fig. ib, Fig. 3b). With a lock 44 pushed through (Fig. 3a), e.g. the shackle of a padlock, the locking pliers 34 can be locked in the blocking position so that a displacement of the adjusting element 40 into the release position is excluded.

As can be seen from Fig. 2, the locking pliers body 38 forms a cavity 46 on the inside of the engagement portion 36, in which a blocking element 48 with a locking pliers RFID tag 50 is positioned.

The locking pliers RFID tag 50 contains a special locking pliers code as information that can be read out contactlessly when appropriately stimulated, which on the one hand uniquely identifies the individual locking pliers 38 and on the other hand already indicates its nature as a locking pliers RFID tag through its type (number range) and is thus distinguishable from the actuator RFID tag 24.

The locking pliers RFID tag 50 has an antenna which is essentially oriented in a plane perpendicular to the axis B and can thus preferably be read in the axial direction.

The recess 22 is formed on the blocking element 48, directed downwards along the axis B, into which the locking bolt 30 can engage (Fig. 5).

The blocking element 48 is displaceable within the cavity 46 in the direction of the axis B shown in Fig. 1a to Fig. 4, i.e. transversely to the longitudinal axis A of the locking pliers 38.

The blocking element 48 has an annular projection 54 at the lower end, which projects in the direction of the axis B and surrounds the recess 22. The annular projection 54 has a slope 66 directed towards the front of the engagement from the section 36. By moving the blocking element 48 into the lower position shown in Fig. 3a, the projection 54 protrudes from the underside of the locking pliers 38, which is referred to here as the extended position, while the blocking element 48 in the upper position shown in Fig. 3b is completely received in the cavity 46 and does not protrude.

The adjustment element 40 and the blocking element 48 work together. In the extended position shown in Fig. 3a, the adjustment element 40 located above it in the blocking position blocks the movement of the blocking element 48 in the direction of the axis B and thus holds it in the extended position.

In the position shown in Fig. 3b with the adjusting element 40 in the release position, the adjusting element 40 releases the blocking element 48 so that the latter can move upwards from the extended position along the axis B.

In this case, a ramp 52 is formed on the blocking element 48, on which the adjusting element 40 acts during the movement from the release position to the blocking position and thus brings it into the extended position when the adjusting element reaches the blocking position (Fig. 3a).

The adjustment element 40 has a cutout 58 in the form of a round opening on the engagement section 36. In the blocking position (Fig. 3a), the opening 58 is aligned along the axis B with the locking pliers RFID tag 50 so that it can be read from above through the opening 58. Because the adjustment element 40 is designed as a metal tongue, this shields the locking pliers RFID tag 50 without an aligned arrangement of the opening 58 so that it cannot be read. However, if in an alternative embodiment the adjustment element 40 is not made of metal but, for example, of plastic, the opening 58 can also be dispensed with and the locking pliers RFID tag 50 can be read through the adjustment element 40.

Fig. 4 shows a perspective view of the safety interlock 18 with the receiving area 28 formed thereon in the form of a recess, which is enclosed by the safety interlock 18 on three sides, including the opposite top and bottom, but is otherwise open. The locking pliers 38 or the actuator 20 can thus be introduced into the receiving area 28 when the protective door 14 is closed.

Fig. 4 shows the locking pliers 38 in the blocking position when forming a pliers engagement arrangement with the safety lock 18, i.e. when the engagement section 36 is centrally received in the receiving area 28. Due to the pliers engagement arrangement of the locking pliers 38 on the receiving area 28 of the safety lock 18, the latter is mechanically locked and thus blocked for the reception of an actuator 20.

The pliers engagement arrangement thus formed is shown in section in Fig. 5.

At the receiving area 28, an opening running in the direction of the axis B is formed as a receptacle 56, which has an annular peripheral edge.

The tumbler bolt 30 is linearly movable along the axis B, acted upon by a spring 62 and can be locked by a plunger 64 that is linearly adjustable by a motor or, for example, by a lifting magnet. The tip of the tumbler bolt 30 engages in the recess 22 on the blocking element 48, so that the engagement section 36 is locked to the safety lock.

As shown in Fig. 5, the adjustment element of the locking pliers 38 is in the blocking position so that the blocking element 48 is fixed in the extended position.

As a result, the projection 54 on the blocking element 48 of the locking pliers 38 engages in the receptacle 56 on the receiving area 28 of the safety lock 18, so that an undercut is formed between the outer edge of the projection 54 and the inner edge of the receptacle 56. As a result, the engagement section 36 of the locking pliers 38 is fixed in the receiving area 28 of the safety lock 18 independently of the locking by the tumbler bolt 30.

The locking mechanism formed cannot be released without the adjustment element 40 being moved from the blocking position to the release position. Thus, the mechanical locking can be achieved by one or more locks 44 in the aligned lock openings 42a, 42b. see blocking of the receiving area 28 and the inclusion of an actuator 20 there as well as the closing of the protective door 14 can be safely excluded.

The tumbler RFID reader 32 is arranged on the receiving area 28 with its antenna 60, which is coupled to an electrical circuit in the form of a signal unit 68 (see Fig. 6) and is controlled by the latter. The antenna 60 is arranged opposite the tumbler bolt 30 above the receiving area 28 in alignment with the axis B with the preferred direction in the axial direction. The antenna 60 is designed as a coil with a transmission/reception characteristic in the form of a bundled beam along the axis B.

In addition to the mechanical reception of the locking pliers 38 in the reception area, the arrangement and correct positioning of the engagement section 36 in the reception area 28 is also recognized by the tumbler RFID reader 32 by reading the locking pliers RFID tag 50. In the pliers engagement arrangement, as shown in Fig. 5, the antenna 60 of the tumbler RFID reader 32 and the locking pliers RFID tag 50 are arranged parallel to one another and thus with the same preferred direction directly in front of one another, so that the locking pliers RFID tag 50 can be read through the opening 58 on the adjustment element 40. The plastic housing wall in between does not interfere with reception.

Fig. 8a, 8b, 9 show an alternative second embodiment of a locking pliers 134. The locking pliers 134 according to the second embodiment correspond in many details to the locking pliers 34 according to the first embodiment. The same elements in both embodiments are designated by the same reference numerals. The following description of the second embodiment focuses on the differences between the embodiments.

The locking pliers 134 according to the second embodiment are also of elongated shape, as can be seen from Fig. 8a, 8b, with a front engagement section 36 for receiving in the receiving area 28 of the safety lock 18. The locking pliers 134 are formed by a locking pliers body 38 made of plastic and a Adjustment element 140, which is also made of plastic and can be moved in the guide of the locking pliers body 38 along the longitudinal axis A between the front stop (Fig. 8a, 10b blocking position) and the rear stop (Fig. 8b, 10a, release position). As in the first embodiment, first lock openings 42a are provided on the locking pliers body 38 and second lock openings 42b are provided on the adjustment element 140, which are aligned in the blocking position (Fig. 8a, 10b), so that with a lock 44 pushed through (Fig. 10b), a displacement of the adjustment element 140 can be prevented and the locking pliers 134 can thus be locked in the blocking position.

In the second embodiment (see e.g. Fig. 9a), a cavity 46 with a blocking element 48 movable therein in the direction of the axis B and with a blocking pliers RFID tag 50 with a unique blocking pliers code is also arranged on the engagement section 36 of the locking pliers body 38. As in the first embodiment, the blocking element 48 has the downwardly directed recess or trough 22 for the engagement of the tumbler bolt 30 and an annular projection 54 protruding in the direction of the axis B.

While in the first embodiment a ramp 52 is arranged on the blocking element 48, which interacts with the adjustment element 40, in the second embodiment a ramp 152 is attached to the underside of the adjustment element 140 (see bottom view in Fig. 8b). If the adjustment element 40 is moved into the blocking position (Fig. 8a, 10b), the ramp 152 presses the blocking element 48 downwards so that it is blocked in the extended position so that the projection 54 protrudes from the underside. If the adjustment element is in the release position (Fig. 8b, 10a), the ramp 152 is also retracted so far that it does not interact with the blocking element 48, so that the latter is movable within the cavity 46 so that the blocking element 48 can be retracted.

In the locking pliers 134 according to the second embodiment, the adjustment element 40 is not made of metal, so that there is no shielding of the locking pliers RFID tag 50. When the locking pliers 134 are arranged in the receiving area 28 of the safety lock 18, the latter can thus read the locking pliers RFID tag 50 regardless of the position of the adjustment element 140. The use of the locking pliers 34 according to the first embodiment (and also the locking pliers 134 according to the second embodiment) to lock the safety lock 18 is carried out in the following manner:

First, the protective door 14 is opened so that the actuator 20 is disengaged from the receiving area 28 of the safety interlock 18.

The adjustment element 40, 140 of the locking pliers 34, 134 is brought into the release position and the engagement section 36 is pushed into the receiving area 28. Since the blocking element 48 in the cavity 46 is axially movable in the direction of the axis B in the release position, it slides into the cavity 46 when its leading bevel 66 comes into contact with the receiving area, so that the engagement section 36 can be pushed into the receiving area 28 until the locking pliers RFID tag 50 is positioned on the axis B.

Then, the adjusting element 40, 140 is pushed into the blocking position, whereby the blocking element 48 is brought into the extended position via the ramp 52, 152, in which the projection 54 engages in the receptacle 56 and the locking pliers 34, 134 are thus mechanically blocked.

The locking tongs RFID tag 50 is read by the guard locking RFID reader 32 and the locking tongs 34, 134 are thus identified. The safety guard locking 18 is put into a maintenance mode or locking tongs mode and this and the identification of the locking tongs 34, 134 read from the locking tongs RFID tag 50 are reported to the control device 26.

By means of a lock 44, the adjustment element 40, 140 is locked in the blocking position so that the locking pliers 34 cannot be removed.

The danger zone 16 can now be safely entered, e.g. for maintenance work. Closing the protective door 14 is impossible due to the mechanical blocking of the receiving area 28. Since the safety interlock 18 is in maintenance mode or If the locking tongs mode is activated, the signaling of a release signal is excluded, so that it is ensured that the control device 26 cannot, for example, start a machine or system in the danger zone 16.

After completion of the work, the lock 44 is removed. The adjustment element 40, 140 can now be pushed into the release position. By releasing the movement of the blocking element 48 upwards along the axis B, the engagement between the projection 54 and the receptacle 56 is released, so that the locking pliers 34, 134 can be removed from the receptacle area 28.

The safety interlock 18 and/or control device 26 must now preferably be switched from the maintenance mode or locking tongs mode to a regular operating mode, for example by a control command. The control command may require authorization, such as the entry of a security code, a password and/or recognition of a token or a biometric property.

The protective door 14 can then be closed and the actuator 20 can be picked up again in the receiving area 28. The actuator RFID tag 24 is recognized there. After the actuator 20 has been locked by extending the locking bolt 30, the safety locking device 18 sends a release signal to the control device 26.

Now, for example, a machine or system in the danger zone 16 can be operated by the control device 26.

Alternatively, the safety locking device 18 and the control device 26 can also be operated in a different way, for example in such a way that after removing the locking tongs 34, 134, a change to the operating mode and continued operation of the safety locking device 18 and the control device 26 can take place without a control command, for example to change the mode.

For example, the following alternatives and variants for operation are possible:

- As described above, the locking pliers 34, 134 lock the safety interlock 18 mechanically, in addition, the safety interlock 18 is electronically locked, namely by means of the Locking pliers RFID tags 50 are put into locking pliers mode. To continue operation, the mechanical removal of the locking pliers 34, 134 is required, as is a control command to change the mode.

To change the mode after removing the locking tongs 34, 134, it may be necessary to use an additional release RFID tag, i.e. even after removing the locking tongs 34, 134, the safety interlock 18 does not issue a release signal (or the control device 26 does not accept it) until the locking tongs mode has been canceled using the release RFID tag.

- In an alternative, purely electronic locking tongs operation, the mechanical locking of the locking tongs 34, 134 on the safety interlock 18 is eliminated or is no longer absolutely necessary. By arranging the locking tongs 18 with the locking tongs RFID tag 50 on or in the safety interlock 18 so that the locking tongs RFID tag 50 is read by the interlock RFID reader 32, an electronic lock is triggered, i.e. the safety interlock 18 and/or the control device 26 is switched from the operating mode to the locking tongs or maintenance mode, in which no release signal is issued and/or accepted.

In a variant of the purely electronic locking tongs operation, it is possible for one or more users to register with several RFID tags on the locking device, for example one after the other. Comparable to mechanical locking using several locks, these RFID tags would replace the mechanical locks, so that the operating mode can only be reached again after all previously registered RFID tags have been logged out. Logging out can be done using the RFID tag used for locking and/or using control commands, preferably in combination with suitable authorization. A corresponding release RFID tag can also be used for each RFID tag used for locking. (19229.0) List of reference symbols

10 Access security system

12 Frame part

14 Protective door

16 Danger zone

18 Safety interlock

20 actuators

22 Deepening

24 Actuator RFID tag

26 Control device

28 Receiving area of the safety interlock

30 locking bolts

32 RFID reader

34, 134 Locking pliers

36 Locking pliers engagement section

38 Locking pliers body

40, 140 Adjustment element of the locking pliers

42a Lock openings on the locking pliers body

42b Lock openings on the adjustment element

44 Castle

46 Cavity at the engagement section

48 Locking element of the locking pliers

50 Locking Pliers RFID Tag

52, 152 Ramp

54 Lead

56 Holder for the blocking element

58 Opening on the adjustment element 6o Antenna of the locking RFID reader

62 Spring

64 Tappets

66 slope

68 Signal unit

A Longitudinal direction of the locking pliers

B Bolt longitudinal direction

Claims

Expectations

1. Access control system (io), with

- an actuator (20) for attachment to a protective door (14),

- a safety locking device (18) for attachment to a frame part (12), wherein the safety locking device (18) has a receiving area (28) for the actuator (20).

- and with a locking pliers (34, 134) with an engagement portion (36) for forming a pliers engagement arrangement with the receiving area (28) so that engagement of the actuator (20) is excluded,

- wherein a locking pliers RFID tag (50) is arranged on the engagement section (36) of the locking pliers (34, 134) and a locking pliers RFID reader (32) is arranged on the receiving area (28) of the safety locking device (18) such that the locking pliers RFID tag (50) in the pliers engagement arrangement can be read by the locking pliers RFID reader (32).

2. Access security system according to claim 1, in which

- the locking pliers (34, 134) have an adjusting element (40, 140) which can be adjusted between a release position and a blocking position, wherein in the release position of the adjusting element (40, 140) the locking pliers (34, 134) can be introduced into the receiving area (28) or removed therefrom,

- and in the blocking position the material received in the receiving area (28)

Locking pliers (34, 134) cannot be removed from the receiving area (28).

3. Access security system according to claim 2, in which

- the adjusting element (40, 140) can be secured at least in the blocking position by a lock (44).

4. Access security system according to claim 2 or 3, in which

- the adjusting element (40, 140) between the release position and the blocking position tion can be moved.

5. Access security system according to one of claims 2 to 4, in which

- the adjusting element (40, 140) is adjustable relative to a locking pliers body (38),

- and at least one lock opening (42a, 42b) is formed on the locking pliers body (38) and on the adjusting element (40, 140), wherein the lock openings (42a, 42b) are aligned in the blocking position so that a lock (44) can reach through, and the lock openings (42a, 42b) are not aligned in the opening position.

6. Access security system according to one of the preceding claims, in which

- a blocking element (48) is provided on the locking pliers (34, 134) which can be moved into an extended position,

- and a receptacle (56) for the blocking element (48) is arranged on the receptacle area (28),

- wherein in the pliers engagement arrangement the blocking element (48) in the extended position engages in the receptacle (56) such that the locking pliers (34) cannot be removed from the receptacle area (28).

7. Access security system according to claim 6 and one of claims 2-5, in which

- the blocking element (48) is held in the blocking position of the adjusting element (40) in the extended position.

8. Access security system according to claim 7, in which

- the adjusting element (40, 140) is movable in a longitudinal direction (A) of the locking pliers (34) and the blocking element (48) is movable in a direction (B) transverse thereto,

- wherein the adjusting element (40, 140) is coupled to the blocking element (48) via a ramp (52, 152).

9. Access security system according to one of claims 6 to 8, in which the locking tongs RFID tag (50) is arranged on the blocking element (48). Access security system according to one of claims 2 to 9, in which

- the adjusting element (40) has an opening (58),

- wherein in the blocking position of the adjusting element (40) the locking pliers RFID tag (50) is arranged in alignment with the opening (58). Access security system according to one of the preceding claims, in which

- on the safety locking device (18), a locking bolt (30) for locking the actuator (20) can be extended in a bolt longitudinal direction (B) into the receiving area (28),

- wherein at least one antenna (60) of the tumbler RFID reader (32) is arranged on the receiving area (28) opposite the tumbler bolt (30). Access security system according to one of the preceding claims, with

- with a controller (26) which is connected to the tumbler (18) via a signal connection, wherein the tumbler RFID reader (32) is designed to transmit data read from an RFID tag (24, 50) to the controller (26) via the signal connection. Access security system according to one of the preceding claims, in which

- the actuator (20) has an actuator engagement portion for forming an actuator engagement arrangement with the receiving area (28),

- wherein an actuator RFID tag (24) is arranged on the actuator engagement portion such that it can be read in the actuator engagement arrangement by the tumbler RFID reader (32). Locking pliers (18) for an access security system (10) according to one of the preceding claims, comprising

- an engagement portion (36) suitable for forming a pincer engagement arrangement with the receiving area (28) of the tumbler (18), and a locking tongs RFID tag (5) arranged on the engagement section (36). Method for securing maintenance work in a danger area (16), in which

- access to the danger zone (16) is secured by a protective door (14) which is movable relative to a frame part (12) between an open position and a closed position, wherein a safety interlock (18) is attached to the frame part (12) and an actuator (20) is attached to the protective door (14),

- wherein the safety locking device (18) has a receiving area (28) for the actuator (20), wherein in an operating mode the protective door (14) is in the closed position and the actuator (20) forms an actuator engagement arrangement with the receiving area (28) of the locking device (18),

- and wherein in a maintenance mode a locking pliers (34, 134) with an engagement portion (36) is brought into engagement with the receiving area (28) such that the engagement portion (36) forms a pliers engagement arrangement with the receiving area (28) in which an engagement of the actuator (20) is excluded,

- wherein in maintenance mode a locking pliers RFID tag (50) on the engagement section (36) of the locking pliers (34, 134) is read by a locking RFID reader (32) on the receiving area (28).