Access protection system with an electronically readable locking gripper

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

[0001] Description

[0002] ACCESS SECURITY SYSTEM WITH ELECTRONICALLY READABLE LOCKING CLAMP

[0003] The invention relates to an access control system, a locking device therefor and a method for securing maintenance work in a danger area.

[0004] It is known that hazardous areas, such as the working area of ​​a machine or industrial plant, can be secured by means of separating protective devices, i.e. protective fences. Access to the hazardous area can be closed off by movable separating protective devices, generally referred to here as safety doors. A safety door is usually secured by means of a safety interlock on a frame part that is fixed opposite the safety door. When the safety door is closed, this interlock 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 properly closed state of the safety door can be monitored and ensured by the safety interlock, so that, for example,An enable signal for operation of the machine or system in the danger zone is only generated when the protective door is properly closed and the safety interlock is locked.

[0005] To access the hazardous area, e.g., to perform maintenance work, it is known to use a mechanical locking device, generally referred to here as a locking pincer, to prevent the safety door from closing and the actuator from being attached to the solenoid interlock. This ensures that an escape route always remains open and the solenoid interlock cannot emit a release signal, thus ruling out unexpected start-up of the machine or system during maintenance work. One well-known locking pincer is the applicant's SZ200-1. This comprises a locking body with several openings that can be pushed through the actuator. The shackle of the maintenance personnel's padlocks can be hooked into the openings, thus preventing unauthorized removal of the locking pincer.

[0006] DE 10 2017 003 453 Ai, the applicant's patent application, describes a locking device for an actuator of a safety interlock. 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 formed by a locking portion at the end of the clamp that is axially displaceable in a guide of a clamp back extension. When supported by the snapped-on rigid end, the locking portion can be inserted into the insertion opening as an engagement member. The bolt has a number of spaced holes that are aligned with holes in the clamp back extension for attaching locks to releasably block the locking portion in the insertion opening.

[0007] It can be regarded as an object to specify an access control system, a locking tong therefor and a method for securing maintenance work in a danger zone, in which the access control system is locked in a particularly simple and at the same time safe manner and the locking state can be determined easily and reliably.

[0008] The object is achieved by an access control 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.

[0009] The access control system according to the invention comprises at least one safety interlock with a suitable actuator and a suitable locking pliers.

[0010] In a conventional manner, the actuator is designed for attachment to a safety door, and the safety interlock is designed for attachment to a frame member. The term "safety door" refers to any access barrier that can be opened and closed, including, for example, swing doors and sliding doors, as well as flaps, barriers, or other types of barriers. The frame member is preferably a stationary part, relative to which the safety door can move during opening and closing. Preferably, the safety door can rest against the frame member in a closed position.

[0011] The safety interlock has a receiving area in which the actuator can be at least partially received, enabling locking of the actuator to the safety interlock, preferably by positive engagement, preferably by a controllable locking element such as a tumbler pin. The actuator can have various shapes, e.g., a bracket, a 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 a locking element.

[0012] The actuator and solenoid interlock are preferably mounted on 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 solenoid interlock. A preferred, but not mandatory, design of the receiving area is such that the actuator is surrounded by at least two opposing sides. An arrangement formed by fitting the actuator in the receiving area can be referred to as an actuator engagement arrangement. The solenoid interlock is preferably designed to output a release signal only when the actuator engagement arrangement is formed.

[0013] According to the invention, a guard locking RFID reader is arranged in the receiving area of ​​the safety guard locking device. RFID technology is known to be a system for identifying and / or locating an RFID tag, i.e., a transponder that, when excited by 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 circuitry in the form of a signal unit, wherein the signal unit generates signals to be transmitted by the antenna and processes signals received at the antenna.

[0014] For the system according to the invention, a locking tong is provided, which is also considered an invention separately (claim 14). The locking tong has an engagement portion for receiving in the receiving area of ​​the safety interlock. The engagement portion can preferably have the same size and shape as the actuator belonging to the system. The arrangement formed when the engagement portion of the locking tong is received in the receiving area of ​​the safety interlock is referred to here as a tong engagement arrangement. In the tong engagement arrangement, the receiving area is blocked, thus ensuring that engagement by the actuator is excluded, in particular to form an actuator engagement arrangement. The locking tong thus blocks the safety interlock for the actuator and preferably prevents the protective door from closing, which would require reaching an actuator engagement arrangement.

[0015] According to the invention, a locking pliers RFID tag, i.e., an RFID transponder, is arranged on the engagement portion of the locking pliers. The locking pliers RFID reader is positioned on the receiving area such that, in the pliers engagement arrangement, the locking pliers RFID tag can be read by the locking pliers RFID reader.

[0016] The position of the locking tongs on the solenoid interlock can be determined electronically by evaluating the signals received by the solenoid interlock RFID reader. A control device, which can be located in the solenoid interlock and / or linked to it via a data connection, can identify the locking tongs RFID tag, and the solenoid interlock and / or the control device can then be put into locking tongs or maintenance mode, for example. The solenoid interlock is then not only locked mechanically, but preferably also in a special operating mode in which no release signal is issued. Furthermore, in an operating environment in which various locking tongs exist that differ in terms of the data on the locking tongs RFID tags, it is possible to recognize the specific identity of the locking tongs currently picked up in the pick-up area.

[0017] The design and arrangement of the locking tongs RFID tag and the guard locking RFID reader can be such that the reading of the locking tongs RFID tag is only possible when the tongs are engaged, i.e., only when the locking tongs are properly positioned and received in the receiving area. RFID technology has a relatively short range, so it is possible to select the positioning and transmission / reception properties of the antenna of the guard locking RFID reader in such a way that reading an RFID tag located only in the vicinity of the receiving area is not possible; instead, actual positioning within the receiving area is required.

[0018] It is possible for RFID tags arranged on the locking pliers and / or on the actuator to have an antenna with a transmission / reception characteristic aligned along a preferred direction, and for the tumbler RFID reader to be arranged on the receiving area such that, when the pliers engagement arrangement or actuator engagement arrangement is formed, it is positioned in the preferred direction. Conversely, it is also preferred for the tumbler RFID reader to have an antenna with a transmission / reception characteristic aligned along a preferred direction, and for the locking pliers RFID tag and / or the actuator engagement arrangement to be positioned in the preferred direction starting from the antenna of the tumbler RFID reader when the pliers engagement arrangement is formed. The transmission / reception characteristics of the RFID reader can, for example,be bundled as a beam so that only RFID tags within the beam are read, while RFID tags that are spatially close 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 at a predetermined position in the direction of the beam relative to the guard locking RFID reader and not in a position deviating from this. In alternative designs, however, it is also possible to select a non-directional or less directional 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.

[0019] The locking pliers RFID tag can be used to achieve increased security in use and reliable detection of the locked state.

[0020] According to a further development of the invention, the locking pliers have an adjusting element that can be adjusted between a release position and a blocking position. In the release position, the locking pliers can be inserted into and / or removed from the receiving area. In the blocking position of the adjusting element, the locking pliers received in the receiving area cannot be removed from the receiving area. The locking pliers thus 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 cannot be removed and the secured state is therefore not canceled. The adjusting element can be adjusted in various ways, e.g. by rotation or pivoting. It is preferably displaceable between the release and blocking positions, particularly preferably in a linear guide.In a preferred embodiment, the adjusting element can be designed as a flat strip which is preferably displaceable along its longitudinal axis.

[0021] Preferably, the adjusting 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 adjusting element by positive engagement and prevents displacement from the blocking position. Furthermore, the lock is preferably lockable, so that it cannot be released without a key. A padlock can particularly preferably be used; depending on the design, the key can be a mechanical key, an electronic key, and / or information such as a numeric code that can be set on a combination lock.

[0022] 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 open position, the lock openings are not aligned. When the lock is inserted, adjustment of the adjustment element is thus impossible. Several pairs of lock openings allow the insertion of several locks, whereby adjustment from the blocking position is only possible after all locks have been removed.

[0023] 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 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 secures the locking pliers to the receiving area.

[0024] The adjustment element can preferably interact with the blocking element. When the adjustment element is in the blocking position, the blocking element is preferably held in the extended position. This allows the locking pliers, with the adjustment element in the release position, to be inserted into the receiving area, and the blocking element can then be moved into the extended position, preventing the locking pliers from being removed from the receiving area. If the adjustment element is then moved into the blocking position, the locking pliers are secured to the receiving area. This arrangement can be secured by one or more locks.

[0025] According to a preferred embodiment, the adjusting element can be movable in a longitudinal direction of the locking pliers and the blocking element in a direction transverse thereto, i.e. perpendicular or also oblique. In this case, the adjusting 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 adjusting 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 adjusting element and arranged such that the ramp engages with the blocking element when adjusted in the direction of the blocking position and thereby causes the blocking element to move in the direction of the extended position.

[0026] The locking pliers RFID tag can, in principle, be located anywhere or on any element on the engagement section of the locking pliers. For example, it can be located on the adjustment element or on the locking pliers body. In a particularly preferred embodiment, however, the locking pliers RFID tag is located on the blocking element. This ensures, in particular, that the blocking element responsible for locking the locking pliers can be monitored in its position by reading the locking pliers RFID tag.

[0027] The safety interlock can have various types of movable elements for securing an actuator and / or a locking pin. In a preferred embodiment, the safety interlock can have a tumbler pin that can be extended into the receiving area in a pin longitudinal direction to lock the actuator. The tumbler pin can be actuated, for example, by a spring and / or by a controllable drive. It is particularly preferred that the tumbler RFID reader is arranged opposite the tumbler pin in the receiving area. The area opposite the tumbler pin is well suited for arranging the tumbler RFID reader, especially if no movable elements are arranged there. Preferably, no metal elements that would interfere with reception are arranged between the tumbler RFID reader (or its antenna) and the receiving area.

[0028] 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 tongs RFID tag, i.e. it can be read in the same way, e.g. with the same frequency, but distinguishable, i.e. it sends a different code when read. Preferably, the code already determines whether the read RFID tag belongs to an actuator or to a locking tong. Preferably, the actuator RFID tag is readable in the actuator engagement arrangement by the guard locking RFID reader, particularly preferably exclusively in the actuator engagement arrangement. In this way, operational reliability and security against manipulation can be increased with regard to the actuator engagement, and the guard locking orA controller can detect the current status by reading the actuator RFID tag.

[0029] The inventive method 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 an open and closed position. A safety interlock is attached to a frame part and an actuator is attached to the protective door. As previously described, the safety interlock has a receiving area for the actuator. In one operating mode, the protective door is in the closed position, and the actuator forms an actuator engagement arrangement with the receiving area of ​​the interlock.

[0030] 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.

[0031] 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.

[0032] Embodiments of the invention are described in more detail below with reference to the drawings. In the drawings:

[0033] Fig. 1a, 1b show in perspective view a first embodiment of a locking pliers in blocking position and release position;

[0034] Fig 2 is a perspective exploded view of the locking pliers from Figures 1a, 1b;

[0035] Fig 3a, 3b representation of longitudinal sections through the locking pliers from figure 1a, ib, 2 along the line A;

[0036] Fig. 4 shows a perspective view of an arrangement of a safety interlock and a locking tong as elements of an access control system;

[0037] Fig. 5 is a representation of a longitudinal section through the arrangement of Figure 4 along the line A;

[0038] Fig. 6 shows a perspective view of part of the arrangement of the safety interlock and locking tongs from Figure 4 with the housing partially removed; Fig. 7 shows a partially schematic view of elements of the access control system on a protective door

[0039] Fig 8a, 8b in perspective view a second embodiment of a locking pliers in blocking position and release position;

[0040] Fig 9a, 9b a perspective exploded view of the locking pliers from Figure 8a, 8b in views from above and below;

[0041] Fig 10a, lob Representation of longitudinal sections through the locking pliers from Figures 8a, 8b, 9 along the line B.

[0042] Figure 7 shows, partially schematically, parts of an access control system 10 with a protective door 14 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 used to separate a danger zone 16.

[0043] A safety interlock 18 is mounted on the frame part 12, and an actuator 20 is mounted on 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.

[0044] 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 regarding its current status. In particular, the safety interlock 18 generates an enable 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.

[0045] In the actuator engagement arrangement, the safety interlock 18 can, as described in more detail below, secure the actuator 20 to the receiving area 28 by means of a tumbler pin 30 (not shown in Figure 7) that engages the recess 22. In the actuator engagement arrangement, a tumbler RFID reader 32 (also not shown in Figure 7) on the safety interlock 18 can also 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 interlock 18 can be checked at the same time.

[0046] If the safety interlock 18 detects the proper formation of the actuator engagement arrangement, i.e. proper reception of the actuator 20 at the reception area 28, locking by the tumbler bolt 30 and correct recognition of the actuator RFID tag 24, it sends an enable signal to the control device 26, which, for example, enables the operation of a machine in the danger zone 16.

[0047] To allow access to the danger zone 16, e.g., for maintenance work, the solenoid interlock 18 is unlocked, the actuator engagement arrangement is released, and the protective door 14 is opened. To reliably prevent the protective door 14 from closing and the output of an enable signal by the solenoid interlock 18 while persons are present in the danger zone 16, a locking tong 34, 134 (not shown in Figure 7) is inserted into the receiving area 28 of the solenoid interlock 18 and locked as explained below. By accommodating the locking tong 34 in the receiving area 28, this area is mechanically blocked, and complete closing of the door 14 with the actuator 20 accommodated in the receiving area 28 is prevented.

[0048] 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 portion 36, which, as shown and described below, can be received in the receiving area 28 of the safety locking device 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 thereon. 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. On the locking pliers body 38, as can be seen in particular from Fig.2, 3a, 3b, first lock openings 42a are formed on the adjusting element 40, and second lock openings 42b are formed on the adjusting element 40. As can be seen from Fig. 1a, 1b and the associated longitudinal sections Fig. 3a, 3b, the respective first and second lock openings 42a, 42b are aligned in the blocking position (Fig. 1a, Fig. 3a), but not in the release position (Fig. 1b, Fig. 3b). With a lock 44 (Fig. 3a) pushed through, e.g., the shackle of a padlock, the locking pliers 34 can thus be locked in the blocking position, thus preventing any displacement of the adjusting element 40 into the release position.

[0049] As can be seen from Fig. 2, the locking pliers body 38 forms a cavity 46 on the inside of the engagement section 36, in which a blocking element 48 with a locking pliers RFID tag 50 is positioned.

[0050] The locking pliers RFID tag 50 contains a special locking pliers code as information that can be read out contactlessly upon appropriate excitation, 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 by its type (number range) and is thus distinguishable from the actuator RFID tag 24.

[0051] The RFID tag 50 has an antenna that is essentially oriented in a plane perpendicular to the axis B and is thus preferably readable in the axial direction.

[0052] The recess 22 is formed on the blocking element 48, directed downwards along the axis B, into which the tumbler bolt 30 can engage (Fig. 5).

[0053] The blocking element 48 is displaceable within the cavity 46 in the direction of the axis B shown in Fig. 1a to Fig. 4, ie transversely to the longitudinal axis A of the locking pliers 38.

[0054] The blocking element 48 has an annular projection 54 at its lower end, which projects in the direction of the axis B and surrounds the recess 22. The annular projection 54 has a bevel 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 is completely received in the cavity 46 and does not protrude in the upper position shown in Fig. 3b.

[0055] The adjustment element 40 and the blocking element 48 cooperate. 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 axis B and thus holds it in the extended position.

[0056] 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 it can move upwards along the axis B from the extended position.

[0057] 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 into the blocking position and thus brings it into the extended position when the adjusting element reaches the blocking position (Fig. 3a).

[0058] 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 axis B with the locking tongs RFID tag 50, so that the latter can be read from above through the opening 58. Due to the design of the adjustment element 40 as a metal tongue, without an aligned arrangement of the opening 58, this shields the locking tongs RFID tag 50, so that it cannot be read. If, however, in an alternative embodiment, the adjustment element 40 is not metallic but, for example, plastic, the opening 58 can be omitted and the locking tongs RFID tag 50 can be read through the adjustment element 40.

[0059] Fig. 4 shows a perspective view of the safety interlock 18 with the receiving area 28 formed therein in the form of a recess. This area is enclosed by the safety interlock 18 on three sides, including the opposite top and bottom sides, but is otherwise open. Thus, the locking pincer 38 or the actuator 20 can be inserted into the receiving area 28 when the protective door 14 is closed.

[0060] Fig. 4 shows the locking tongs 38 in the blocking position when forming a tong engagement arrangement with the safety interlock 18, ie when the engagement section 36 is centrally received in the receiving area 28. Due to the tong engagement arrangement of the locking tongs 38 on the receiving area 28 of the safety interlock 18, this is mechanically locked and thus blocked for receiving an actuator 20.

[0061] The pliers engagement arrangement thus formed is shown in section in Fig. 5.

[0062] At the receiving area 28, an opening extending in the direction of the axis B is formed as a receptacle 56, which has an annular peripheral edge.

[0063] The tumbler bolt 30 is linearly movable along the axis B, acted upon by a spring 62 and lockable by a plunger 64 that is linearly adjustable by a motor or, for example, by a solenoid. 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.

[0064] As shown in Fig. 5, the adjusting element of the locking pliers 38 is in the blocking position, so that the blocking element 48 is fixed in the extended position.

[0065] As a result, the projection 54 on the blocking element 48 of the locking tongs 38 engages in the receptacle 56 on the receptacle area 28 of the safety locking device 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 tongs 38 is fixed in the receptacle area 28 of the safety locking device 18, independently of the locking by the tumbler bolt 30.

[0066] The resulting locking mechanism cannot be released without moving the adjustment element 40 from the blocking position to the release position. Thus, one or more locks 44 in the aligned lock openings 42a, 42b can ensure the mechanical blocking of the receiving area 28, reliably preventing the insertion of an actuator 20 there and the closing of the protective door 14.

[0067] The tumbler RFID reader 32 is arranged on the receiving area 28 with its antenna 60, which is coupled to and controlled by an electrical circuit in the form of a signal unit 68 (see Fig. 6). The antenna 60 is arranged opposite the tumbler bolt 30 above the receiving area 28, aligned with axis B, with a preferred direction in the axial direction. The antenna 60 is designed as a coil with a transmit / receive characteristic in the form of a focused beam along axis B.

[0068] In addition to mechanically receiving the locking pliers 38 in the receiving area, the locking RFID reader 32 also detects the arrangement and correct positioning of the engagement section 36 in the receiving area 28 by reading the locking pliers RFID tag 50. In the pliers engagement arrangement, as shown in Fig. 5, the antenna 60 of the locking RFID reader 32 and the locking pliers RFID tag 50 are arranged parallel to each other and thus directly in front of each other with a matching preferred direction, so that the locking pliers RFID tag 50 can be read through the opening 58 in the adjustment element 40. The plastic housing wall in between does not interfere with reception.

[0069] Fig. 8a, 8b, and 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. Identical elements in both embodiments are designated by identical reference numerals. The following description of the second embodiment focuses on the differences between the embodiments.

[0070] The locking pliers 134 according to the second embodiment is also elongated in 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 locking device 18. The locking pliers 134 are formed by a locking pliers body 38 made of plastic and an adjusting element 140 which is displaceably guided thereon and which is also made of plastic and is displaceable in the guide of the locking pliers body 38 along the longitudinal axis A between the front stop (Fig. 8a, 10b blocking position) and 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 adjusting 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 adjusting element 140 is prevented and the locking pliers 134 can thus be locked in the blocking position.

[0071] In the second embodiment (see, for example, Fig. 9a), a cavity 46 is also arranged on the engagement section 36 of the locking pliers body 38, with a blocking element 48 movable therein in the direction of axis B and containing a locking pliers RFID tag 50 with a unique locking pliers code. 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, as well as an annular projection 54 projecting in the direction of axis B.

[0072] While in the first embodiment a ramp 52 is arranged on the blocking element 48, which interacts with the adjusting element 40, in the second embodiment a ramp 152 is attached to the underside of the adjusting element 140 (see bottom view in Fig. 8b). If the adjusting element 40 is moved into the blocking position (Figs. 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 adjusting element is in the release position (Figs. 8b, 10a), the ramp 152 is also retracted far enough that it no longer interacts with the blocking element 48, so that the latter is movable within the cavity 46, so that the blocking element 48 can be retracted.

[0073] In the locking pliers 134 according to the second embodiment, the adjustment element 40 is not made of metal, so that the locking pliers RFID tag 50 is not shielded. When the locking pliers 134 are arranged in the receiving area 28 of the safety interlock 18, they 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 interlock 18 is as follows:

[0074] First, the protective door 14 is opened so that the actuator 20 is disengaged from the receiving area 28 of the safety interlock 18.

[0075] The adjustment element 40, 140 of the locking pliers 34, 134 is moved into the release position, and the engagement section 36 is inserted into the receiving area 28. Since the blocking element 48 is axially movable in the direction of axis B in the release position within the cavity 46, it slides into the cavity 46 upon contact of its guiding bevel 66 with the receiving area, so that the engagement section 36 can be inserted into the receiving area 28 until the locking pliers RFID tag 50 is positioned on axis B.

[0076] 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.

[0077] The guard locking RFID reader 32 reads the locking tongs RFID tag 50 and thus identifies the locking tongs 34, 134. The safety guard locking device 18 is placed into a maintenance mode or locking tongs mode, and this, as well as the identification of the locking tongs 34, 134 read from the locking tongs RFID tag 50, is reported to the control device 26.

[0078] By means of a lock 44, the adjusting element 40, 140 is locked in the blocking position so that the locking pliers 34 cannot be removed.

[0079] The danger zone 16 can now be safely entered, for example, for maintenance work. The mechanical blocking of the receiving area 28 prevents the protective door 14 from closing. Since the safety interlock 18 is in maintenance mode or locking tongs mode, the signaling of a release signal is prevented, thus ensuring that the control device 26 cannot, for example, start a machine or system in the danger zone 16.

[0080] After completing the work, the lock 44 is removed. The adjustment element 40, 140 can now be pushed into the release position. By releasing the upward movement of the blocking element 48 along axis B, the engagement between the projection 54 and the receptacle 56 is released, allowing the locking pliers 34, 134 to be removed from the receptacle area 28.

[0081] The safety interlock 18 and / or control device 26 must now preferably be switched from maintenance mode or locking tongs mode to a regular operating mode, e.g., 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 characteristic.

[0082] 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 is locked by extending the guard bolt 30, the safety interlock 18 sends a release signal to the control device 26.

[0083] Now, for example, a machine or system in the danger zone 16 can be operated by the control device 26.

[0084] 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.

[0085] For example, the following alternatives and variants for operation are possible:

[0086] - As described above, the locking pincer 34, 134 mechanically locks the safety interlock 18. In addition, the safety interlock 18 is electronically switched to locking pincer mode, namely by means of the locking pincer RFID tag 50. Continued operation requires the mechanical removal of the locking pincer 34, 134 and a control command to change the mode.

[0087] For the mode change after removing the locking tongs 34, 134, the use of an additional release RFID tag may be necessary, ie even after removing the locking tongs 34, 134, the safety interlock 18 does not output a release signal (or the control device 26 does not accept it) until the locking tongs mode has been canceled by means of the release RFID tag.

[0088] - In an alternative, purely electronic locking tong operation, the mechanical locking of the locking tong 34, 134 on the solenoid interlock 18 is eliminated or is no longer absolutely necessary. By arranging the locking tong 18 with the locking tong RFID tag 50 on or in the solenoid interlock 18 such that the locking tong RFID tag 50 is read by the solenoid interlock RFID reader 32, an electronic locking is triggered, i.e., the solenoid interlock 18 and / or the control device 26 is switched from operating mode to the locking tong or maintenance mode, in which no release signal is output and / or accepted.

[0089] In a variant of the purely electronic locking tongs operation, it is possible for one or more users to register with multiple RFID tags on the guard, for example, one after the other. Similar to mechanical locking using multiple locks, these RFID tags would replace the mechanical locks, so that operating mode can only be accessed again after deactivating all previously registered RFID tags. Deactivation can be performed using the RFID tag used for locking and / or 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

[0090] 10 Access control system

[0091] 12 frame part

[0092] 14 Protective door

[0093] 16 Danger zone

[0094] 18 Safety interlock

[0095] 20 actuators

[0096] 22 Deepening

[0097] 24 actuator RFID tag

[0098] 26 Control device

[0099] 28 Recording area of ​​the safety interlock

[0100] 30 tumbler bolts

[0101] 32 RFID reader

[0102] 34, 134 locking pliers

[0103] 36 engagement section of the locking pliers

[0104] 38 locking pliers body

[0105] 40, 140 Adjustment element of the locking pliers

[0106] 42a Lock openings on the locking pliers body

[0107] 42b Lock openings on the adjustment element

[0108] 44 Castle

[0109] 46 Cavity at the engagement section

[0110] 48 Blocking element of the locking pliers

[0111] 50 RFID tag locks

[0112] 52, 152 Ramp

[0113] 54 lead

[0114] 56 Holder for the blocking element

[0115] 58 Opening on the adjustment element 6o Antenna of the RFID reader

[0116] 62 spring

[0117] 64 tappets

[0118] 66 slopes

[0119] 68 signal unit

[0120] A Longitudinal direction of the locking pliers

[0121] B Bolt longitudinal direction

Claims

Claims 1. Access control system (io), with - an actuator (20) for attachment to a protective door (14), - a safety interlock (18) for attachment to a frame part (12), wherein the safety interlock (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 tongs RFID tag (50) is arranged on the engagement section (36) of the locking tongs (34, 134) and a locking tongs RFID reader (32) is arranged on the receiving area (28) of the safety locking device (18) such that the locking tongs RFID tag (50) in the tongs engagement arrangement can be read by the locking tongs RFID reader (32).

2. Access control system according to claim 1, in which - the locking pliers (34, 134) have an adjusting element (40, 140) which is adjustable 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 inserted 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 control system according to claim 2, wherein - the adjusting element (40, 140) can be secured at least in the blocking position by a lock (44).

4. Access control system according to claim 2 or 3, in which - the adjusting element (40, 140) between the release position and the blocking position tion is movable.

5. Access control 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 control 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) engages in the receptacle (56) in the extended position such that the locking pliers (34) cannot be removed from the receptacle area (28).

7. Access control system according to claim 6 and any one of claims 2-5, wherein - the blocking element (48) is held in the blocking position of the adjusting element (40) in the extended position.

8. Access control 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 control system according to one of claims 6 to 8, in which the locking tong 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 tong 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 interlock (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) 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 by the tumbler RFID reader (32) in the actuator engagement arrangement. Locking pliers (18) for an access control system (10) according to one of the preceding claims, comprising - an engagement portion (36) suitable for forming a pincer engagement arrangement with the receiving portion (28) of the tumbler (18), and a locking tong 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 interlock (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 interlock (18), - and wherein, in a maintenance mode, a locking pliers (34, 134) having 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 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 tumbler RFID reader (32) on the receiving area (28).

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