SECURITY DEVICE

Description

[0001] The invention relates to a safety device.

[0002] Such safety devices are used in the field of safety engineering, particularly in the area of ​​machine safety.

[0003] A typical monitoring function of a safety device consists of monitoring a separating protective device, such as a safety door, through which access to a danger area on a machine or system is enabled.

[0004] Known safety devices feature safety switches.

[0005] The operation of a hazardous system within the danger zone is only authorized by a safety controller if the safety switch detects that the separating protective device is in its closed position. For this purpose, the safety switch can, for example, include an RFID unit that detects a transponder assigned to the separating protective device. The functionality of the safety switch can be extended by a locking mechanism that interlocks the separating protective device in its closed position. The locking mechanism engages by retracting a locking element of the locking device, in particular a locking bolt, into a locked position. An electric or electromagnetic actuator is provided for retracting the locking element into the locked position.

[0006] A mechanical overload acting on the locking device can cause the locking element to break, leading to a malfunction of the locking device. This can result in the danger zone becoming accessible to personnel despite the safety function generated by the safety switch, potentially creating hazardous situations, especially if the machine or system still exhibits dangerous, uncontrolled residual machine or system conditions.

[0007] DE 103 51 665 A1 relates to a locking system for a motor vehicle, comprising an opening mechanism, wherein the opening mechanism, in its closed position, holds a door, hood, or flap closed and, in its open position, releases it for opening, and a first locking element and a second locking element, each of which can assume a locking position and a releasing position. The opening mechanism is locked in its closed position as long as at least one of the two locking elements is in its locking position. The opening mechanism is only moved from its closed position to its open position when the first locking element and the second locking element are in their releasing positions.

[0008] DE 199 02 561 C5 relates to a locking device with a rotary latch that can be engaged in a closed position by a pawl and, after pivoting the pawl from this locked position to a release position by actuating a pawl actuating element, can be moved from this locked position to a release position. In its locked position, the pawl is prevented from moving by a blocking element that can be pre-released when the pawl actuating element is actuated. The actuating element is a lever that pivots about a clearance to the pawl against a stop on the pawl and has a control ramp for moving the blocking element. The blocking element is a lever whose lever arm, in the locked position, lies in front of a pawl section and can be pivoted in front of the opening of a deflection recess in the pawl.

[0009] US Patent 4,783,102 A relates to a locking pawl assembly with a pawl element and a fork element that interacts with it. The locking pawl assembly forms a two-stage locking system, which is used particularly for doors of motor vehicles.

[0010] The invention is based on the objective of providing a safety device with a high level of safety.

[0011] The features of the independent claims are provided to solve this problem. Advantageous embodiments and expedient further developments of the invention are described in the dependent claims.

[0012] The invention relates to a safety device comprising a safety module and an actuator movable relative to the module, wherein the actuator can be brought into a closed position in or on the safety module. Furthermore, a locking device is provided by means of which the actuator can be locked in its closed position. A safety system is provided by means of which the actuator can be additionally locked in its closed position. The safety system is designed to lock the actuator in its closed position if the locking function of the locking device is disabled due to a malfunction. The locking of the actuator by the locking device is effected by the insertion of an element of the locking device into a first receptacle of the actuator.The locking of the actuator by the safety system is achieved by inserting an element of the safety system into a second receptacle of the actuator.

[0013] The invention further relates to a corresponding method.

[0014] The safety device according to the invention is used in the field of safety technology, in particular in the field of machine safety, and advantageously has a fail-safe design that complies with the normative requirements.

[0015] The safety device comprises a safety module that interacts with an actuator. The safety module and actuator can be used to secure a separating protective device.

[0016] A particularly advantageous separating protective device is a safety door that can close off access to a hazardous area of ​​a machine within the system. Generally, the separating protective device can also be a flap, a door, or the like.

[0017] In principle, the safety device can include a sensor module, a locking module, an actuator, a control and evaluation module, or the like, as a safety module.

[0018] The safety module is particularly advantageous when designed as a safety switch.

[0019] The safety switch checks whether the actuator is in its closed position. For this purpose, the safety switch can have an RFID unit that reads data from a transponder in the actuator when the actuator is in its closed position at the safety switch.

[0020] If such a safety switch is used to secure a separating protective device as access to a danger zone on a system, the operation of the system is only permitted if the safety switch determines that the actuator, and thus the separating protective device to which the actuator is attached, is in its closed position and that this closed position is locked.

[0021] According to the invention, the locking of the actuation in its closed position is achieved not only with a holding device but also with a safety system.

[0022] This provides a two-channel locking structure, which increases the fault tolerance of the safety device according to the invention.

[0023] Crucially, the safety system is adapted to the locking device in terms of its design and function in such a way that, in the event of a malfunction of the locking device, particularly a breakage of an element of the locking device that disables its locking function, the safety system remains functional and locks the actuator. Thus, in the safety device according to the invention, the locking of the actuator is ensured by the safety system even in the event of a malfunction of the locking device and a resulting loss of its locking function.

[0024] Thus, the locking device and the safety system form a diverse, redundant mechanical locking structure.

[0025] The diversity of the dual-channel locking structure is due to the different functions of the locking device and the safety system.

[0026] In particular, when external forces act on the actuator which is locked in its closed position by means of the locking device and the safety system, the locking device is subjected to greater forces than the safety system.

[0027] This is achieved by different connections between the locking device and the safety system and the actuator in its closed position. When the actuator is locked by means of the locking device and the safety system, their attachment to the actuator is such that forces acting on the actuator are transferred directly to the locking device, and not to the safety system.

[0028] In the event of an overload situation acting on the actuator, preferably via the separating protective device, only a malfunction of the locking device will occur, in particular in the form of a breakage of an element of the locking device, thereby disabling the locking function of the locking device. Since the safety system was not subjected to the overload at this point, or only to a minor degree, it remains functional and maintains the locking of the actuator.

[0029] The fault tolerance of the safety device according to the invention is advantageously increased further by the fact that detection means are provided for detecting a malfunction of the locking device.

[0030] The locking device is generally operated by an actuator to cause it to move into a locking position at the actuator or to cause it to move out of the locking position.

[0031] The detection devices are used to monitor this actuator to determine whether it has moved the locking device into the locked position or not.

[0032] Furthermore, the detection means include sensor elements that determine whether the locking device actually locks the actuator. Specifically, the sensor elements determine whether an element of the locking device engages in a receptacle of the actuator and thereby locks it. The sensor elements can, for example, be a light barrier.

[0033] If the detection means for monitoring the actuator determine that the actuator has moved the locking device into the locking position, and if the sensor means simultaneously determine that the locking device does not cause the actuator to lock, then there is a malfunction of the locking device, in particular a breakage of the locking device due to a mechanical overload.

[0034] If such a malfunction of the locking device is detected, the release signal for the operation of the system is canceled, in particular by output signals from the safety module, especially the safety switch, and the system is put into a safe state.

[0035] Furthermore, the actuator's locking mechanism remains active, preventing the separating protective device on which the actuator is located from opening, thus preventing persons from entering the danger zone.

[0036] This will prevent dangerous situations for people with a high degree of certainty.

[0037] According to the invention, the locking of the actuator by the holding device is effected by the fact that an element of the holding device is inserted into a first receptacle of the actuator, and the locking of the actuator by the safety system is effected by the fact that an element of the safety system is inserted into a second receptacle of the actuator.

[0038] In this case, the locking device element is in direct contact with the first receptacle. The safety system element is inserted into the second receptacle with some play.

[0039] This means that forces acting on the actuator are transferred directly to the locking device, but not to the safety system.

[0040] According to a first embodiment of the invention, the locking device and the safety system perform independent positioning movements.

[0041] It is advantageous to assign an actuator to both the locking device and the safety system, which effects the respective positioning movements.

[0042] According to a second variant of the invention, the locking device and the safety system perform coupled positioning movements.

[0043] In this case, only one actuator is needed, which performs the positioning movements of both the locking device and the safety system.

[0044] In this case, it is advantageous if the locking device malfunctions, as the safety system is decoupled from the locking device.

[0045] This prevents a malfunction of the locking device from impairing the locking function of the safety system.

[0046] Decoupling can be achieved by a break in the element of the locking device inserted into the first receptacle, in that the safety system does not detach from the actuator in the event of such a break.

[0047] Decoupling is particularly advantageous when achieved by a safety coupling that responds to an overload acting on the holding device.

[0048] The safety system has a particularly advantageous safety element that performs positioning movements and can be inserted into the second receptacle.

[0049] The positioning movements are advantageously effected by means of an actuator.

[0050] Advantageously, the locking device further comprises an intermediate element which has a segment that engages in the first receptacle when the intermediate element is in a locking position. The intermediate element can be locked in its locking position by means of a locking element.

[0051] In the first case, the locking element is inserted into this first receptacle, particularly by means of an actuator, to lock the actuator.

[0052] In the second case, the locking device has an intermediate element, wherein, to lock the actuator, a segment of the intermediate element engages in the second receptacle of the actuator when the intermediate element is in a locked position. For example, the intermediate element can be a rotatably mounted switching disc whose outer contour forms a positive guide such that, when the actuator is retracted, the switching disc is automatically moved into the closed position. In any case, the intermediate element is locked to the locking element in its locked position, thereby locking the actuator to the locking device.

[0053] The invention will be explained below with reference to the drawings. The drawings show: Figure 1: Exemplary embodiment of the safety device according to the invention for a separating protective device. Figure 2: First embodiment of a locking mechanism for an actuator attached to a protective door when the protective door is open. Figure 3: Arrangement according to Figure 2 with the safety door ajar. Figure 4: Arrangement according to Figure 2 with the safety door engaged. Figure 5: Arrangement according to Figure 2 Figure 6: Second embodiment of a locking mechanism for an actuator mounted on a safety door when the safety door is open. Figure 7: Arrangement according to Figure 6 with the safety door locked. Figure 8: Arrangement according to Figure 6 in case of overload. Figure 9: Partial view of a safety coupling of the arrangements according to Figures 6 to 8 .

[0054] Figure 1Figure 1 schematically shows a safety device 1 for a separating protective device 2, in the form of a safety door, which can be used to close or open access to a hazardous area 3 at a system 4. The safety device 1 monitors the separating protective device 2 and, depending on this, generates output signals that control the operation of a safety controller 5 of the system 4.

[0055] The separating protective device 2 is integrated into a fence 6 that surrounds the danger zone 3.

[0056] The safety device 1 comprises a stationary safety switch 7 mounted on the enclosure 6 and an actuator 8 mounted on the separating protective device 2. The safety switch 7 has a locking device. An RFID reading unit is also integrated into the safety switch 7. A transponder is located in the actuator 8.

[0057] If the separating protective device 2, and thus also the actuator 8, is in a closed position, the transponder is within the reading range of the RFID reader, allowing the reader to access and read the data from the transponder. Only when the closed position is detected by the safety switch 7 by reading the data from the transponder, and when the actuator 8 is locked in the closed position, does the safety switch 7 generate an output signal that enables the operation of the system 4.

[0058] The Figures 2 to 5 Figure 1 shows a first embodiment of a locking mechanism for the safety device 1 according to the invention. In the present case, the locking mechanism is part of the safety module, i.e., the safety switch 7.

[0059] The locking mechanism is associated with the actuator 8, which is attached to the safety door. The actuator 8 has a first receptacle 9 in the form of an elongated hole. Furthermore, the actuator 8 has two identical second receptacles 10, which are also designed in the form of elongated holes.

[0060] The locking mechanism has a rotatably mounted switching disc 11, which has a notch 12 opening out on its outer surface.

[0061] A gear 13 is attached to both end faces of the switching disc 11.

[0062] Below the switching disc 11 is an actuator 14 with a locking element 15. The actuator 14, which can be, for example, an electric motor or electromagnet, enables the locking element 15 to perform linear positioning movements.

[0063] The locking element 15 with the switching disc 11 and the locking element 15 forms a locking device.

[0064] According to the invention, a safety system is also provided as part of the locking mechanism, which in the present case has two identical rod-shaped safety elements 16.

[0065] The locking device and the safety system form a two-channel locking structure for locking the actuator 8 in its closed position. Advantageously, the locking device and the safety system can be locked using separate units.

[0066] Figure 2 The actuator 8 indicates when the safety door is open. Figure 3 The diagram shows actuator 8 when the safety door is ajar. In both positions, actuator 8 has not yet reached its closed position.

[0067] Figure 4Figure 1 shows the position of the actuator 8 when it is retracted into the closed position. The actuator 8 is then engaged, having rotated the switching disc 11 into its locked position by means of its specific outer contour. In this locked position, a segment 11a of the switching disc 11 projects into the first receptacle 9. The segment 11a rests against an edge of the first receptacle 9, thereby transmitting forces acting on the actuator 8 directly to the switching disc 11.

[0068] The safety elements 16 of the safety system are inserted into the second receptacles 10 of the actuator 8 by means of the gears 13. The safety elements 16 are positioned with clearance in the second receptacles 10, i.e., the safety elements 16 are not in contact with the actuator 8, so that forces acting on the actuator 8 are not transmitted to the safety elements 16.

[0069] Figure 5Figure 1 shows the actuator 8 locked to the locking device and the safety system. Locking is achieved by the switching disc 11, in the locked position, directing the actuator 14 upwards as a locking element 15, so that it is inserted into the notch 12 of the switching disc 11. This locks the switching disc 11 and thus also the segment 11a of the switching disc 11, which is inserted into the first receptacle 9. As a result, the locking device locks the actuator 8 in its closed position. Furthermore, the actuator 8 is also locked to the safety elements 16 of the safety system, since the locking element 15 in the notch 12 also blocks the movement of the safety elements 16.

[0070] In the event of an overload acting on the actuator 8, segment 11a of the switching disc 11 may break off, so that the locking device no longer locks the actuator 8. In this case, however, the safety system with the safety elements 16 takes over the locking of the actuator 8 alone and thus prevents uncontrolled opening of the safety door.

[0071] The breaking off of segment 11a of the switching disc 11 can be monitored using sensor means such as an optical sensor. In addition, the position of the locking element 15 is monitored.

[0072] If it is detected that the locking element 15 is extended to lock the switching disc 11, but segment 11a of the switching disc 11 is not detected in the first receptacle 9, a malfunction of the locking device has occurred. Accordingly, the safety switch 7 generates an output signal with which the system 4 is brought into a safe state, in particular shut down.

[0073] The Figures 6 to 8 show a second embodiment of a locking mechanism for the safety device according to the invention 1.

[0074] The embodiment of the Figures 6 to 8 differs from the embodiment of Figures 2 to 5 by providing a safety coupling 17 as overload protection for connecting the gears 13 to the switching disc 11 ( Figure 9The safety coupling 17 is an overload coupling, in this case designed as a slip coupling with a friction element 17a. Generally, the safety coupling 17 can also be designed as a torsion bar or spring coupling. The spring of the spring coupling causes a self-resetting action.

[0075] Actuator 8 of the Figures 6 to 8 corresponds to actuator 8 of the embodiment of the Figures 2 to 5 .

[0076] Figure 6 shows the locking mechanism with the safety door open, i.e., the actuator 8 is not in its closed position. Figure 7 shows the actuator 8, locked with the locking device and the safety system, in its closed position.

[0077] Analogous to the embodiment of the Figures 2 to 5The locking is achieved by segment 11a projecting into the first receptacle 9 of the actuator 8, and by the safety elements 16 being inserted with clearance into the second receptacles 10. Segment 11a is inserted into the first receptacle 9 by rotating the switching disc 11. The safety elements 16 are inserted into the second receptacles 10 by means of the gears 13.

[0078] In the present case, the locking of the switching disc 11 and the safety elements 16 is achieved by extending the locking element 15 by means of the actuator 14 and inserting it between two teeth of a gear 13.

[0079] A light barrier 18 is provided as a sensor means for detecting the rotational position of the switching disc 11. Furthermore, a projection 19 extends from the outer surface of the switching disc 11, reaching around the circumference of the switching disc 11 over its predetermined angular range.

[0080] If the actuator 8 is not yet in its closed position ( Figure 6 ) the projection 19 of the switching disc 11 lies in the beam path of the light barrier 18, i.e., the beam path of the light beams of the light barrier 18 is interrupted, i.e., the light barrier 18 generates a corresponding switching signal. If the actuator 8 is in its closed position and is locked with the holding device and the safety system, the projection 19 of the switching disc 11 is not in the beam path of the light barrier 18 and this generates a corresponding switching signal ( Figure 7 ).

[0081] In the event of an overload acting on the actuator 8, this is only transferred to the switching disc 11 and not to the safety elements 16 ( Figure 8This is achieved by the safety clutch 17 engaging when an overload occurs. The overload causes the switching disc 11 to rotate out of its locked position, so that the segment 11a is no longer inserted into the first receptacle 9, i.e., the locking mechanism with the holding device is released. The engagement of the safety clutch 17 decouples the safety elements 16 from the movement of the switching disc 11 and locks the actuator 8.

[0082] Detection devices determine that the actuator 14 has extended the locking element 15 into its locking position. Additionally, the light barrier 18 detects that the projection 19 of the switching rail 11 lies within the path of the light beams. The combination of signals from the detection devices and the light barrier 18 thus detects the malfunction of the locking device due to the overload, causing the safety switch 7 to generate an output signal that puts the system 4 into a safe state. Reference symbol list

[0083] (1) Safety device (2) Protective device (3) Danger zone (4) System (5) Safety control (6) Enclosure (7) Safety switch (8) Actuator (9) First receptacle (10) Second receptacle (11) Switching disc (11a) Segment (12) Notch (13) Gear (14) Actuator (15) Holding element (16) Safety element (16a) Segment (17) Safety coupling (17a) Friction element (18) Light barrier (19) Projection

Claims

1. Safety device (1) comprising a safety module and an actuator (8) movable relative thereto, wherein the actuator (8) can be moved into a closed position in or on the safety module, and wherein a locking device is provided by means of which the actuator (8) can be locked in its closed position, wherein a safety system is provided by means of which the actuator (8) can be additionally locked in its closed position, wherein the safety system is designed to lock the actuator (8) in its closed position if its locking function is disabled due to a malfunction of the locking device, characterised in that the locking of the actuator (8) by the locking device is effected by an element of the locking device being inserted into a first receptacle (9) of the actuator (8), and that the locking of the actuator (8) by the safety system is effected by an element of the safety system being inserted into a second receptacle (10) of the actuator (8).

2. Safety device (1) according to claim 1, characterised in that the locking device and the safety system form a diverse redundant mechanical locking structure.

3. Safety device (1) according to one of claims 1 or 2, characterised in that, in the event of a mechanical failure of the locking device, the locking of the actuator (8) by the locking device is released and the actuator (8) is locked in its closed position solely by the safety system.

4. Safety device (1) according to any one of claims 1 to 3, characterised in that, when external forces act on the actuator (8) locked in its closed position by means of the locking device and the safety system, the locking device is subjected to greater forces than the safety system.

5. Safety device (1) according to claim 4, characterised in that forces acting on the actuator (8), which is locked in its closed position by means of the locking device and the safety system, are transmitted directly only to the locking device.

6. Safety device (1) according to claim 5, characterised in that the element of the locking device is in direct contact with the first receptacle (9), and that the element of the safety system is inserted with play into the second receptacle (10).

7. Safety device (1) according to any one of claims 1 to 6, characterised in that the locking device and the safety system perform independent actuating movements.

8. Safety device (1) according to any one of claims 1 to 6, characterised in that the locking device and the safety system perform coupled actuating movements.

9. Safety device (1) according to claim 8, characterised in that, in the event of a malfunction of the locking device, the safety system is decoupled from the locking device.

10. Safety device (1) according to claim 9, characterised in that the decoupling is effected by a break in the element of the locking device inserted into the first receptacle (9), or that the decoupling is effected by a safety clutch (17) which responds to an overload acting on the locking device.

11. Safety device (1) according to any one of claims 1 to 10, characterised in that the safety system comprises a safety element (16) capable of performing actuating movements, which can be inserted into the second receptacle (10).

12. Safety device (1) according to any one of claims 1 to 11, characterised in that the locking device comprises an intermediate element which has a segment (Ila) that engages with the first receptacle (9) when the intermediate element is in a locking position, and in that the intermediate element can be locked in its locking position by means of a locking element (15).

13. Safety device (1) according to claim 12, characterised in that the intermediate element is a switching disc (11).

14. Safety device (1) according to any one of claims 1 to 13, characterised in that detection means are provided for detecting a malfunction of the locking device.

15. Safety device (1) according to any one of claims 1 to 14, characterised in that the safety module is a safety switch (7).

16. Method for operating a safety device (1) comprising a safety module and an actuator (8) movable relative thereto, wherein the actuator (8) can be moved into a closed position within or on the safety module, and wherein a locking device is provided by means of which the actuator (8) can be locked in its closed position, wherein a safety system is provided by means of which the actuator (8) can be additionally locked in its closed position, wherein the safety system is designed to lock the actuator (8) in its closed position if its locking function is disabled due to a malfunction of the locking device, characterised in that the locking of the actuator (8) by the locking device is effected by an element of the locking device being inserted into a first receptacle (9) of the actuator (8), and that the locking of the actuator (8) by the safety system is effected by an element of the safety system being inserted into a second receptacle (10) of the actuator (8).