Safety switch device

Abstract

A safety switching device for safety-related interruptions of a safety circuit has a housing and a circuit system arranged in the housing. The circuit system comprises two switching elements which can be arranged in the safety circuit via a first terminal, a second terminal, a third terminal and a fourth terminal located on the housing and which can close the safety circuit redundantly when an actuation signal is present at each switching element. And a fifth terminal and a sixth terminal provided on the housing, to which a first input signal and a second input signal corresponding to an actuation signal of the switching element can be applied, such that the safety circuit is closed when the first input signal and the second input signal are applied to the fifth terminal and the sixth terminal. The circuitry disposed in the housing includes a further electrical element configured to extract energy for its own operation from an electrical signal applied to at least one of the first terminal, the third terminal, the fifth terminal, and the sixth terminal.

Description

Technical Field

[0001] The invention relates to a safety switching device for the safety-related interruption of a safety circuit. Background Art

[0002] Safety switching devices are the origin and backbone of safety automation technology. As stand-alone devices, safety switching devices monitor safety functions such as emergency stops, safety doors, light barriers, light grids, safety mats, etc. Safety switching devices perform defined safety functions and ensure, for example, controlled and therefore safe stopping of moving parts, position monitoring of movable protective devices and stopping of approaching moving parts when someone enters the protected area. Safety switching devices reduce risks to a minimum and initiate safe and reliable reactions in the event of a fault or an intrusion into the protected area. Safety switching devices can be found in almost all areas of mechanical and plant engineering, mainly where the number of safety functions is manageable.

[0003] Basically, a safety switching device is a switch that switches a safety circuit on or off depending on an input signal. The input signal is provided by a safety sensor or a safety transmitter (emergency stop button, light barrier, etc.) and is fed to the safety switching device when the safety sensor indicates a safe state, so that the safety switching device closes the safety circuit. If one of the input signals is missing, the safety switching device interrupts the safety circuit, which usually switches off the technical device or prevents it from starting. Alternatively, the interruption of the safety circuit may also cause another reaction of the technical device, which brings about a safe state.

[0004] Compared to ordinary switching relays, for safety switching devices - if wired correctly - neither a fault in the device itself nor a fault caused externally by a sensor or actuator will lead to a loss of the safety function. For this purpose, compared to ordinary switching relays, safety switching devices can have additional special circuits or special relay technology to ensure a safe switching process even in the event of a fault. The typical design of a safety switching device is redundant. Two relays with forced guided contacts provide safety switching contacts, which are also called safety outputs (safeoutput) or safety outputs (safety output). The two input circuits each control one of the two internal switches.

[0005] Since a separate safety switching device is usually used for each safety function, the number of safety switching devices and therefore the space required in the associated control cabinet increases with the individual safety functions of the technical installation. The increase in the number of required safety switching devices creates a need to minimize the space required for the individual safety switching devices. In this respect, in addition to the actual switching elements, the number of external terminals is also crucial. The more external terminals are required on the safety switching device, the greater the installation space required for the device.

[0006] It is therefore an object of the present invention to provide an improved safety switching device which, while offering the greatest possible range of functions, requires the least possible installation space, reduces the wiring effort and prevents errors during wiring. Summary of the invention

[0007] The object is solved by a safety switch device having a housing and a circuit system arranged in the housing. The circuit system comprises two switch elements, which can be arranged in a safety circuit via a first terminal, a second terminal, a third terminal and a fourth terminal located on the housing, and can redundantly close the safety circuit when an actuation signal is applied to each switch element, wherein a fifth terminal and a sixth terminal are arranged on the housing, and a first input signal and a second input signal corresponding to the actuation signal of the switch element can be applied to the fifth terminal and the sixth terminal, so that when the first input signal and the second input signal are applied to the fifth terminal and the sixth terminal, the safety circuit is closed, wherein the circuit system arranged in the housing comprises a further electrical element, and the further electrical element is configured to extract energy for its own operation from the electrical signal applied to at least one of the first terminal, the third terminal, the fifth terminal and the sixth terminal.

[0008] Therefore, the idea of ​​the present invention is to provide a safety switching device configured to draw electrical energy from a signal applied to one of its terminals. The extracted energy is used to operate an electrical component within the safety switching device. In other words, the electrical component draws the current required for its intended use from the energy extracted from the signal.

[0009] The safety switching device can, for example, be a safety switching device specially designed for an active sensor which actively provides an input signal from which additional energy can be drawn. In addition to controlling the internal switching element, the energy provided can also contribute to powering at least one other element of the safety switching device. In this way, external terminals for a separate power supply can be omitted.

[0010] The reduction in the number of terminals enables the safety switching device to be arranged in a housing of smaller dimensions compared to a comparable safety switching device with external power supply terminals. In particular, the width of the housing in relation to the required installation space can be reduced. It is also conceivable to use the released terminals for other functions. This makes it possible, for example, to increase the number of safety outputs of the safety switching device without having to use a separate device or a device that provides additional external terminals for additional safety outputs. Thus, the reduction in the number of external terminals contributes to the improvement by allowing the use of a smaller housing with the same functionality or by providing additional functionality with the same housing size. In addition, the reduction in the number of external terminals simplifies the wiring of the safety switching device and prevents wiring errors. The purpose is thus fully solved.

[0011] In further refinements, the electrical signal may be at least one of the first input signal and the second input signal.

[0012] According to the improvement, energy for additional electrical components can be extracted from one or both input signals. In this case, the safety switching device can be configured for special use with active sensors. An active sensor is a safety sensor that provides an input signal independently of the power supply of the safety switching device. The active sensor can have an output signal switching device (OSSD) to generate the input signal. As part of a safety sensor, in particular an electro-sensitive protective device (ESPE), the output signal switching device can provide a signal that is interrupted in a fail-safe manner if the sensor part of the safety sensor is triggered. By dedicating the safety switching device to active sensors, terminals for output signals intended for passive sensors and provided with potentials by the safety switching device can be omitted. Therefore, when the safety switching device is dedicated to active sensors, other external terminals except the power supply terminals can be omitted or allocated differently.

[0013] In a further development, the electrical signal can be a potential which is switched by a switching element of the safety switching device.

[0014] According to this development, energy for the additional electrical component is extracted from the potential applied to the first terminal or the third terminal. The applied potential is the potential that is switched by the switching element in the safety circuit in the safe state. The switched potential can control a contactor in the power supply of the technical device monitored by the safety switching device. In this case, the electrical signal can be a 24V DC voltage that is often used in industrial environments. The safety switching device can use this voltage to power other electrical components.

[0015] In a further refinement, the electrical signal may be electrically isolated from other electrical components.

[0016] According to the improvement, the safety switching device can be decoupled from the electrical signal, which protects the safety switching device from overvoltage from the electrical signal. The coupling can be inductive or capacitive coupling. This effectively helps to improve the fault tolerance of the safety switching device.

[0017] In a further development, the additional electrical element can be an operating indicator, in particular an LED.

[0018] The safety switching device can have a display (operation indicator) indicating the operating state of the device. For the correct operation of the safety switching device, an operation indicator may be required according to the standard. According to a further development, the energy for operating the operation indicator can be extracted from the electrical signal, so that the operation indicator does not require an additional power supply. This design is particularly advantageous in the case where the operation indicator is the only electrical component that requires active power supply in addition to the safety switching device, because a separate power supply can be completely omitted. With regard to the operation indicator, it can also be advantageously coupled directly to the corresponding input signal or potential to be switched.

[0019] In a further development, the further electrical component can have a first state indicator which indicates the state of one of the switch elements.

[0020] According to this refinement, the status display (status indicator) of the channel can be provided with an operating voltage in a simple manner, so that no separate power supply is required. Therefore, this refinement also contributes to simplifying the necessary device electronics.

[0021] In another embodiment, the additional electrical component can be an electronic component which performs safety-related tasks in the safety switching device, for example a microcontroller.

[0022] In this refinement, the energy absorbed by the signal can be used to power a microcontroller for controlling and monitoring the safety switching device. According to this refinement, a separate power supply for the safety switching device can be omitted if the safety switching device has an extended functional range that requires a microcontroller.

[0023] In further refinements, further electrical components may be electrically connected to the first terminal, the third terminal, the fifth terminal and / or the sixth terminal.

[0024] According to this improvement, the further electrical components are connected to one or more terminals to which the electrical signal is applied. Depending on the type of electrical signal, the electrical components can be connected to the terminals directly or via additional components. In this way, power supply can be achieved simply and effectively using externally applied signals.

[0025] In a further development, the safety switching device can have an electrical component which is connected to the further electrical element and provides a voltage and / or power supply for operating the further electrical element.

[0026] According to this improvement, a further electrical component can be provided that converts the energy received from the electrical signal for the operation of a further electrical element. For example, the electrical component can be a resistor to which a voltage is applied and acts as a current source for the LED. A rectifier or a voltage regulator can also be used. This design enables a wider range of possible electrical signals that can be used as an energy source.

[0027] In a further development, the safety switching device can have an energy storage device which buffers energy for actuating further electrical components, wherein the electrical signal charges the energy storage device.

[0028] According to the improvement, an energy storage device can be provided upstream of the additional electrical component in order to provide the energy required by the electrical component. The energy storage device can be an inductive or capacitive component that buffers or smoothes the voltage or current required for the operation of other electrical components. This means that different electrical signals can be used as energy sources. Therefore, the design helps to make the device effectively adapt to a larger number of electrical signals.

[0029] In a further refinement, a seventh terminal may be provided on the housing, and a reference potential of the electronic component may be connected to the seventh terminal.

[0030] According to this improvement, at least one additional terminal can be provided so that a uniform reference potential is available. If it corresponds to a potential, the supply voltage can be easily generated from the electrical signal using this reference potential. It goes without saying that the potential connected to the second terminal or the fourth terminal can also be used as a reference potential without the seventh terminal.

[0031] In a further refinement, the additional electrical components may be powered solely by energy extracted from the electrical signal.

[0032] According to this improvement, therefore, no additional energy source is required to operate the additional electrical components. Therefore, this improvement is particularly advantageous for reducing external terminals and simplifying the circuit system.

[0033] In another embodiment, the housing may have two side surfaces and a plurality of functional surfaces connecting the side surfaces, the two side surfaces and the plurality of functional surfaces together defining a closed space in which the circuit system is arranged, wherein the distance between the side surfaces defines the maximum width of the housing, and the terminals are arranged on the functional surfaces. The maximum width may be equal to or less than 22.5 mm.

[0034] The safety switch device may have a housing suitable for installation in a switch cabinet. Such a housing generally has a width that is many times smaller than the depth and height of the housing. The housing may, for example, be box-shaped, having two side surfaces and four functional surfaces connecting the side surfaces. One of the functional surfaces (the front surface) faces the user and carries the external terminals when correctly installed in the switch cabinet. The two side surfaces define the width of the housing. Therefore, reducing the external terminals can reduce the width of the housing.

[0035] It is to be understood that the features mentioned above and those yet to be explained below can be used not only in the combination indicated in each case but also in other combinations or alone, without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Examples of implementations of the invention are shown in the drawings and are explained in more detail in the following description.

[0037] Figure 1 A schematic representation of a safety switching device according to a first embodiment of the present disclosure is shown.

[0038] Figure 2 A schematic representation of a safety switching device according to a second embodiment of the present disclosure is shown.

[0039] Figure 3 A simplified schematic representation of an application scenario of a safety switching device according to the present disclosure is shown.

[0040] Figure 4 A simplified perspective view of an embodiment of a housing of a safety switching device according to the present disclosure is shown.

[0041] Figure 5 A reference example of a safety switching device according to the prior art is shown. DETAILED DESCRIPTION

[0042] Figure 1 A safety switching device according to a first embodiment of the present disclosure is shown in a schematic representation. The safety switching device is designated here as a whole by the reference numeral 10 .

[0043] The safety switching device 10 has a housing 12 and a circuit system (electronic device) 14 arranged in the housing 12. The circuit system 14 includes two switching elements 16, in particular forced-guided relays, whose contacts can be arranged in a safety circuit 18. The contacts of the two switching elements 16 are routed to the outside via terminals 20 on the housing 12. The safety switching device 10 has at least a first terminal 201, a second terminal 202, a third terminal 203 and a fourth terminal 204, so as to redundantly wire the safety circuit via the contacts of the switching elements 16.

[0044] Furthermore, the safety switching device 10 has a first input circuit 22 and a second input circuit 24, which can also be contacted from the outside via the terminal 20 on the housing 12. The first input circuit 22 can be externally connected via the fifth terminal 205, and the second input circuit 24 can be externally connected via the sixth terminal 206, wherein the input circuits 22, 24 are preferably externally connected only via the fifth terminal 205 and the sixth terminal 206. A first input signal from a safety sensor (not shown here) can be received via the fifth terminal 205, and a second input signal from a safety sensor (not shown here) can be received via the sixth terminal 206. When the safety sensor signals a safety state of the technical device to be monitored, the first input signal and the second input signal are then present at the fifth terminal 205 and the sixth terminal 206 of the safety switching device 10.

[0045] When the first input signal and the second input signal are appropriately applied to the fifth terminal 205 and the sixth terminal 206, the input circuits 22, 24 provide the actuation signal 26 to the two switching elements 16, which close the safety circuit 18 based on the actuation signal 26. If one of the input signals is not present, or if the safety switching device 10 detects a fault in an input signal or in another device of the safety switching device 10 in any other way, no actuation signal 26 is provided, so that the switching elements 16 interrupt the safety circuit 18 and thus force a safe state on the technical device to be monitored.

[0046] The safety switch device 10 further comprises an additional electrical element 28. The additional electrical element 28 may be part of the circuit system 14 and may be arranged, for example, on a common circuit board together with the switch element 16 and the input circuits 22, 24. The additional electrical element 28 may be an electrical or electronic component that performs the functions of the safety switch device 10 (except the switch element 16). In various embodiments, the additional electrical element 28 may be a display (indicator), which is implemented, for example, by one or more light-emitting diodes 30. Alternatively or additionally, the additional electrical element 28 may also be a control element, such as a microcontroller (μC) 31 or an FPGA, and assume the control function of the safety switch device. Such a control element may, for example, perform additional safety-related tasks of the safety switch device 10, such as continuous comparison of input signals, cross-circuit detection or diagnostic functions. Of course, the additional electrical element 28 is not limited to these functions.

[0047] The further electrical element 28 is configured to extract energy for its own operation from an electrical signal applied to at least one of the first terminal 201, the third terminal 203, the fifth terminal 205 and / or the sixth terminal 206. The electrical signal may correspond to one or two input signals or a signal routed via the safety circuit 18. The electrical signal may be, for example, a static potential applied to the aforementioned terminals, from which energy may be directly drawn. Alternatively, a dynamic signal (clock signal) may also be applied to the terminals, from which energy may be drawn from a static component or with an effective value according to these signals.

[0048] The further electrical element 28 may be a safety-related device which contributes to the fulfillment of regulatory requirements which may be imposed on the safety switching device. For example, it is conceivable that the safety switching device only meets regulatory requirements if it can visualize its state or the state of the switching element (channel) by means of an operating indicator or a status indicator. It is also conceivable that, in addition to the safety switching of the safety circuit, the safety switching device must also perform other functions provided by the electrical (integrated) circuit in order to achieve a certain safety level.

[0049] Regardless of the type of the further electrical element 28, the energy required for the further electrical element 28 is taken from the electrical signal present at the aforementioned terminals. The safety switching device preferably has no additional power source, such as a voltage source or a current source, for operating the further electrical element 28. By omitting an additional power source for the additional electrical element 28, it is advantageously possible to omit external terminals provided on the housing 12 for this purpose or to use these terminals for other purposes.

[0050] By assuming that the safety sensors connected to the input circuits 22, 24 are active safety sensors, additional terminals can also be saved in the present safety switching device compared to known safety switching devices. Active safety sensors are characterized by the fact that they can provide input signals independently of the safety switching device 10. In other words, these active safety sensors are devices that have their own power supply and are equipped with an output signal switching device (OSSD), which can provide a safe input signal depending on the sensor part of the safety sensor. In contrast to passive safety sensors such as emergency stop buttons, active safety sensors do not rely on a safety switching device to provide a switching potential for the safety sensor. Therefore, by focusing on active sensors, no additional terminals are required on the housing to provide the switching potential. Therefore, each input circuit only requires one connection on the housing to receive the input signal of the active safety sensor.

[0051] Limiting to active safety sensors also has the advantage that, depending on the function, an electrical signal is applied as an input signal to the safety switching device, from which energy not provided by the safety switching device can be drawn. With respect to output signal switching devices (OSSDs), the input signal provided is referred to as an OSSD signal, the electrical characteristics of which are usually specified in the standards of various applications. Therefore, it is easy to provide power to other electrical components based on the OSSD signal because the power supply can adapt to the electrical characteristics. The additional electrical component 28 can be selected, for example, so that the additional electrical component 28 can be directly coupled to the OSSD signal when the OSSD signal is present so as to be energized. However, it is also conceivable to provide additional components connected between the terminals of the electrical signal and the additional electrical component 28 or connected in parallel with the additional electrical component 28 in order to set a suitable voltage supply for the additional electrical component 28. The other components may be simple resistors or rectifying elements such as diodes. In addition, a voltage regulator may be connected between the terminals of the electrical signal and the additional electrical component 28 in order to set a defined and constant voltage at the additional electrical component 28. However, the present disclosure is not limited to any particular form of energy extraction.

[0052] In addition to the aforementioned first terminal 201 to the sixth terminal 206, the safety switching device can optionally have further terminals, as shown in the embodiment shown here. For example, the safety switching device can have a seventh terminal 207 and an eighth terminal 208. The seventh terminal 207 and the eighth terminal 208 form a further safety output, similar to the two safety outputs formed by the first terminal 201 and the second terminal 202 and the third terminal 203 and the fourth terminal 204. Therefore, in each case, the safety output is formed by two terminals 20, which are connected via the switch contacts of the switching element 16. As shown here, the safety switching device 10 can have three safety outputs.

[0053] A ninth terminal 209 can also be provided on the safety switching device 10, which is coupled to the circuit system 14 of the safety switching device 10. For example, a reference potential can be applied to the ninth terminal 209, with which the supply voltage of the other electrical components 28 is formed together. The reference potential can be, for example, a common ground potential of the circuit system 14. In principle, such a potential can also be applied to the second terminal or the fourth terminal, so that no additional terminal will be required, although measures must then be taken to galvanically decouple the reference potential from the other circuit systems 14.

[0054] In addition, the safety switching device 10 can have further devices, circuits and terminals, as shown by the dashed lines in the present embodiment. Another circuit can be a start circuit 32, which can be used to control the switching process, for example. The start circuit 32 can receive a start signal via the tenth terminal 210 and is designed in such a way that the switching element 26 closes the safety circuit 18 only when the start signal is present. It is also conceivable to have a diagnostic device 34, which provides a signal at the eleventh terminal 211 to signal the current switching state of the switching element.

[0055] Finally, the safety switch device 10 may also have a twelfth terminal 212 and a thirteenth terminal 213, which, like the safety outputs (terminals 201 to 204; 207 to 208), are connected via the contacts of the switching element 16, but not via a forward-driven normally open (NO) contact, but via a forward-driven normally closed (NC) contact. The normally open (NO) contact is a contact that closes the connection between the contacts when the switching element is actuated (i.e., when turned on), while the normally closed (NC) contact is a contact that opens the connection between the contacts when the switching element is actuated. The twelfth terminal 212 and the thirteenth terminal 213 can be used as a feedback circuit and can be connected to the start circuit 32, for example, in order to prevent an erroneous restart.

[0056] According to the first embodiment, the safety switch device 10 can have thirteen terminals, as shown here. However, as shown above, six terminals are sufficient for the main function of the safety switch device 10, namely, safely interrupting the safety circuit according to redundant input signals. Therefore, in the safety switch device 10 according to the first embodiment, the size of the housing 12 can be reduced compared to safety switch devices that usually have ten or more external terminals to provide the main functions. Alternatively or additionally, the free terminals can be used for other tasks. Figure 2 An example of this is shown in .

[0057] Figure 2 A safety switching device according to a second embodiment of the present disclosure is shown in a schematic representation. The safety switching device is designated here as a whole by the reference numeral 10 .

[0058] exist Figure 2 In the example, components with the same function are used Figure 1 The same reference numerals as those in the drawings are used to represent the elements, and detailed description of these elements is omitted.

[0059] The safety switch device 10 according to the second embodiment has a housing 12, an electrical circuit system 14, two switch elements 16, a plurality of terminals 20, and a first input circuit 22 and a second input circuit 24. The plurality of terminals 20 include a first terminal 201 to a sixth terminal 206. In addition, the safety switch device 10 has a further electrical element 28, which, as previously described with respect to the first embodiment, extracts energy for its own operation from an electrical signal present at the first terminal, the third terminal, the fifth terminal, or the sixth terminal.

[0060] As in the first embodiment, in the second embodiment, the seventh terminal 207 to the thirteenth terminal 213 may be optionally provided in the same manner.

[0061] The second embodiment differs from the first embodiment in the design of the switching element 16. The switching element 16 here also has a positively driven NO contact which is led to the outside of the housing 12 via the fourteenth terminal 214, the fifteenth terminal 215, the sixteenth terminal 216 and the seventeenth terminal 217. The fourteenth terminal 214 and the fifteenth terminal 215 form the fourth safety output of the safety switching device 10, and the sixteenth terminal 216 and the seventeenth terminal 217 form the fifth safety output of the safety switching device 10.

[0062] Therefore, compared with the safety switch device of the prior art, in the safety switch device 10 according to the second embodiment, five safety outputs can be advantageously provided without significantly increasing the number of external terminals 20. This can be achieved by eliminating or releasing the external terminals in the input circuit or power supply of the safety switch device due to the energy extraction.

[0063] Figure 3 A simplified schematic representation of a possible application scenario of the safety switching device 10 according to the present disclosure is shown.

[0064] Figure 3 An automated robot 38 is shown as a technical device 36 to be monitored. The robot 38 has a defined working area in which a robot arm 40 can move. Access to the working area is secured by a safety sensor. The safety sensor here is a non-contact protective device (ESPE) in the form of a light barrier 42. The light barrier 42 has a first part 44 and a second part 46, between which light beams can be exchanged. The light barrier 42 signals a safe state only if the light beams are exchanged in a defined manner and no further errors have occurred in the light barrier 42. The signaling takes place via an output signal switching device (OSSD) 48, which provides a redundant output signal (OSSD signal 50) when the light barrier 42 is operating correctly and has not yet registered an access to the technical device 36.

[0065] The safety switching device 10 according to an embodiment of the present disclosure is connected to the output signal switching device 48 of the light barrier 42, for example, via a cable 52. Therefore, the safety switching device 10 redundantly receives the OSSD signal 50 as the first input signal and the second input signal, and switches the switching element 16 according to the signal. The switching element 16 is arranged in the safety circuit 18 in the above-described manner, so that when the light barrier 42 provides the OSSD signal 50, the redundant contactor 54 is energized. The normally open contact 56 of the contactor 54 can in turn be arranged in the power supply of the technical device 36, so that power is only supplied to the technical device 36 when and as long as the output signal switching device 48 provides the OSSD signal 50. In this way, the safety switching device 10 provides a safety function of monitoring access to the technical device 36 in combination with the light barrier 42.

[0066] The safety switching device 10 can be arranged in a control cabinet 58 together with other control devices. In particular, additional safety switching devices can be arranged in the control cabinet 58, via which additional safety functions can be realized. Other safety switching devices are shown here with dotted lines. Individual safety switching devices can be arranged close to each other on a top hat rail 60. The terminals 20 for wiring and the additional indicators 62 are each arranged on a front surface 64 of the safety switching device, which faces the user after being installed in the switch cabinet 58. The width of the front surface 64 substantially defines the required installation width 66 of the safety switching device and substantially depends on the number of required terminals 20 on the corresponding front surface 64. The standard size of the installation width 66 of a single safety switching device is, for example, 22.5 mm.

[0067] Therefore, by reducing the number of external terminals 20 on the safety switch device according to the present disclosure, the actual installation space required for the safety switch device in the control cabinet 58 can be reduced. At the same time, if no external power supply is required for the safety switch device, the wiring is simplified. In principle, the reduction in the number of terminals 20 can effectively reduce wiring errors.

[0068] Figure 4 A simplified perspective view of an embodiment of a housing of a safety switching device according to the present disclosure is shown.

[0069] according to Figure 4 , the safety switching device 10 is arranged in a substantially rectangular housing 12. The box-shaped housing 12 has two opposite side surfaces 68, 70, and in this example has four functional surfaces 72, 74, 76, 78 connecting the side surfaces 68, 70. When the safety switching device 10 is installed in the control cabinet as intended, the functional surface 72 corresponds to the front surface 64 of the safety switching device 10. For installation, the housing 12 can have, for example, a holder for mounting on the top hat rail 60 on the functional surface 78 opposite to the front surface 64.

[0070] The main operating elements and indicator elements of the safety switch device and the external terminals 20 are arranged on the functional surface 72, which is used as the front surface and faces the user after being installed in the control cabinet. In the present embodiment, six external terminals 20 and the display element 62 are arranged on the front surface 72 of the safety switch device 10. The six external terminals 20 can correspond to the above-mentioned first terminal 201 to the sixth terminal 206, and can be realized, for example, by screws or spring-loaded terminals commonly used in automation technology. The indicator 62 can, for example, have three indicators showing the operating state of the safety switch device as a whole and the separate states of the two switch elements. The indicator 62 can be regarded as another electrical element 28 within the meaning of the present disclosure, and the power supply of the indicator can be provided via an electrical signal applied to the terminals 201 to 206 in the above-mentioned manner.

[0071] If the terminals 20 are arranged on the front surface 72 of the housing 12 in the manner customary in automation technology, the installation width 66 corresponding to the maximum distance between the side surfaces 68, 70 can be advantageously reduced by reducing the number of external terminals 20 in the above-described manner. In this way, it is possible to provide a suitable safety function (for example in combination with ESPE, such as Figure 3 The safety switch device 10 shown in FIG. 1 ) has a smaller width 66 than a similar standard device. In addition, wiring costs and wiring errors can be advantageously reduced by such a safety switch device.

[0072] at last, Figure 5 A reference example of a safety switch device 80 according to the prior art is shown. The safety switch device 80 differs from the safety switch device 10 according to the first embodiment of the present disclosure in that the power supply 82 of the internal circuit system can be coupled to an external power supply via two terminals 84, 86 on a housing 88.

[0073] In addition, the reference example is different in that there is no corresponding device for extracting energy from the electrical signal applied to the other terminal and using the extracted energy to power the electrical element of the safety switch device that does not correspond to the switching element as described previously. Specifically, in the safety switch device 80 of the prior art, the electrical element within the meaning of the present disclosure is powered by the additional power supply 82.

[0074] The prior art safety switch device 80 further comprises two input circuits 90, 92, each having two external terminals on the housing 88. The additional terminals 94, 96 of the input circuits 22, 24 are used to provide output signals which can be switched via passive safety sensors and fed back to input terminals 98, 100. Therefore, the safety relay 80 is not designed for special use with active safety sensors, but is designed for general use with passive or active safety sensors.

[0075] The safety switch device 10 according to the first and second embodiments is characterized by a reduced number of external terminals or a different allocation of available terminals. However, it goes without saying that the embodiments represent the subject matter of the invention only by way of example and the invention is limited only by the claims.

Claims

1. A safety switching device (10) for safety-related interruption of a safety circuit (18), comprising: a housing (12) and a circuit system (14) arranged in the housing, The circuit system (14) comprises two switch elements (16), which can be arranged in the safety circuit (18) via a first terminal, a second terminal, a third terminal and a fourth terminal (20; 201-204) located on the housing (12) and can redundantly close the safety circuit (18) when an actuation signal is present at each switch element (16), A fifth terminal (20; 205) and a sixth terminal (20; 206) are provided on the housing (12), a first input signal and a second input signal corresponding to the actuation signal of the switch element (16) can be applied to the fifth terminal (20; 205) and the sixth terminal (20; 206), so that when the first input signal and the second input signal are applied to the fifth terminal and the sixth terminal (205, 206), the safety circuit (18) is closed, and Wherein, the circuit system (14) arranged in the housing (12) includes: another electrical component (28), which is configured to extract energy for its own operation from the electrical signal applied to at least one of the first terminal, the third terminal, the fifth terminal and the sixth terminal (201, 203, 205, 206).

2. The safety switch device according to claim 1, wherein: The electrical signal is any one of the first input signal and the second input signal.

3. The safety switch device according to claim 1 or 2, wherein: The electrical signal is a potential switched by the switching element (16).

4. The safety switch device according to any one of claims 1 to 3, wherein: The electrical signal is electrically isolated from the further electrical component (28).

5. The safety switch device according to any one of claims 1 to 4, wherein: The further electrical component (28) comprises an operating indicator, in particular a light emitting diode LED.

6. The safety switch device according to any one of claims 1 to 5, wherein: The further electrical component (28) comprises a first state indicator indicating a state of one of the switch elements (16).

7. The safety switch device according to any one of claims 1 to 6, wherein: The further electrical component (28) is an electronic component, in particular a microcontroller (31), and performs safety-related tasks of the safety switching device (10).

8. The safety switch device according to any one of claims 1 to 7, wherein: The additional electrical component (28) is electrically connected to any one of the first terminal, the third terminal, the fifth terminal and the sixth terminal (201, 203, 205, 206).

9. The safety switch device according to any one of claims 1 to 8, further comprising: An electrical component is connected to the further electrical element (28) and establishes at least one of a voltage and a power supply for operating the further electrical element (28).

10. The safety switch device according to any one of claims 1 to 9, further comprising: An energy storage device is provided for storing energy for operating the further electrical component (28), wherein the electrical signal charges the energy storage device.

11. The safety switch device according to any one of claims 1 to 10, wherein: A seventh terminal (207) is provided on the housing (12), and a reference potential of the circuit system (14) can be connected to the seventh terminal (207).

12. The safety switch device according to any one of claims 1 to 11, wherein: The further electrical component (28) is powered solely by energy extracted from the electrical signal.

13. The safety switch device according to any one of claims 1 to 12, wherein: The housing (12) has two side surfaces (68, 70) and a plurality of functional surfaces (72, 74, 76, 78) connected to the side surfaces, the two side surfaces (68, 70) and the plurality of functional surfaces (72, 74, 76, 78) together defining a closed space in which the circuit system (14) is arranged, wherein the spacing between the side surfaces defines a maximum width (66) of the housing (12), and the terminal (20) is arranged on one of the functional surfaces (72, 74, 76, 78).

14. The safety switch device according to claim 13, wherein: The maximum width (66) is equal to or less than 22.5 mm.

15. The safety switch device according to any one of claims 1 to 14, wherein: The first terminal, the second terminal, the third terminal and the fourth terminal (201-204) located on the housing represent two safety outputs, each of which is capable of interrupting the safety circuit (18), wherein six additional terminals (207, 208; 214 to 217) are arranged on the housing (12), and the six additional terminals (207, 208; 214 to 217) together form three additional safety outputs.

16. The safety switch device according to any one of claims 1 to 15, wherein: The first input signal is a coded signal, in particular an OSSD signal (50), and is provided by an output signal switching device (48) of a protection device, in particular a contactless protection device.

17. The safety switch device according to any one of claims 1 to 16, wherein: The terminal (20) of the safety switch device is a screw terminal or a spring terminal.

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