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EP-4546386-B1 - SAFETY SWITCH DEVICE

EP4546386B1EP 4546386 B1EP4546386 B1EP 4546386B1EP-4546386-B1

Inventors

  • Preißer, Frank

Dates

Publication Date
20260513
Application Date
20241009

Claims (15)

  1. A safety switching device (10) for safety-related interruption of a safety circuit (18), comprising: a housing (12) and circuitry (14) arranged in the housing, wherein the circuitry (14) comprises two switching elements (16) which can be arranged in the safety circuit (18) via a first, second, third and fourth terminal (20; 201-204) located on the housing (12) and close the safety circuit (18) redundantly when an actuation signal is present at each switching element (16), wherein a fifth terminal (20; 205) and a sixth terminal (20; 206) are provided on the housing (12), to which a first input signal and a second input signal can be applied, which correspond to the actuation signals of the switching elements (16), so that the safety circuit (18) is closed when the first and second input signals are applied to the fifth and sixth terminals (205, 206), and characterized in that the circuitry (14) arranged in the housing (12) comprises a further electrical element (28) which is configured to extract energy for its own operation from an electrical signal applied to the first, the third, the fifth and/or the sixth terminal (201, 203, 205, 206).
  2. The safety switching device of claim 1, wherein the electrical signal is the first input signal and/or the second input signal.
  3. The safety switching device of claim 1 or 2, wherein the electrical signal is a potential that is switched by the switching elements (16).
  4. The safety switching device of any one of claims 1 to 3, wherein the electrical signal is electrically isolated from the further electrical element (28).
  5. The safety switching device of any one of claims 1 to 4, wherein the further electrical element (28) is an indicator, in particular an LED, indicating an operating state of the safety switching device and/or a status of one of the switching elements (16).
  6. The safety switching device of any one of claims 1 to 5, wherein the further electrical element (28) is an electronic element, in particular a microcontroller (31), and performs a safety-related task of the safety switching device (10).
  7. The safety switching device of any one of claims 1 to 6, wherein the further electrical element (28) is electrically connected to the first, the third, the fifth and/or the sixth terminal (201, 203, 205, 206).
  8. The safety switching device of any one of claims 1 to 7, further comprising: an electrical component connected to the further electrical element (28) and establishing a voltage and/or a current supply for operating the further electrical element (28).
  9. The safety switching device of any one of claims 1 to 8, further comprising: an energy storage device that buffers the energy for operating the further electrical element (28), wherein the electrical signal charges the energy storage device.
  10. The safety switching device of any one of claims 1 to 9, wherein a seventh terminal (207) is provided on the housing (12), to which a reference potential for the circuitry (14) can be connected.
  11. The safety switching device of any one of claims 1 to 10, wherein the further electrical element (28) is powered exclusively from the energy extracted from the electrical signal.
  12. The safety switching device of any one of claims 1 to 11, wherein the housing (12) has two side surfaces (68, 70) and a plurality of functional surfaces (72, 74, 76, 78) connecting the side surfaces, which together define an enclosed space in which the circuitry (14) is arranged, wherein a spacing of the side surfaces defines a maximum width (66) of the housing (12) and the terminals (20) are arranged on one of the functional surfaces (72, 74, 76, 78), in particular wherein the maximum width (66) is equal to or less than 22.5 mm.
  13. The safety switching device of any one of claims 1 to 12, wherein the first, second, third and fourth terminals (201-204) located on the housing represent two safe outputs, each of which can interrupt the safety circuit (18), wherein six further terminals (207, 208; 214-217) are provided on the housing (12), which together form three further safe outputs.
  14. The safety switching device of any one of claims 1 to 13, wherein the first input signal is a coded signal, in particular a signal of an output signal switching device, also known as an OSSD signal (50), and is provided by an output signal switching device (48) of a protective device, in particular a contactless protective device.
  15. The safety switching device of any one of claims 1 to 14, wherein the terminals (20) of the safety switching device are screw terminals or spring terminals.

Description

The present invention relates to a safety switching device for safety-related interruption of a safety circuit. Safety switching devices, such as those used in the DE 10 2014 116188 A1 Safety switching devices are the origin and backbone of safe automation technology. As standalone units, they monitor safety functions such as emergency stops, safety doors, light barriers, light curtains, safety mats, and many more. Safety switching devices thus perform defined safety functions, ensuring, for example, the controlled and therefore safe stopping of a movement, the position monitoring of movable separating protective devices, and the interruption of a closing movement in the event of an intervention. Safety switching devices primarily serve to reduce risk and initiate a safe and reliable response in the event of a fault or breach of protective zones. Safety switching devices are found in almost all areas of mechanical and plant engineering, primarily where the number of safety functions is manageable. A safety switching device is essentially a switch that turns a safety circuit on or off depending on an input signal. These input signals are supplied by safety sensors or safety devices (emergency stop buttons, light barriers, etc.) and fed to the safety switching device when the safety sensors indicate a safe state, whereupon 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 typically shuts down a technical system or prevents it from starting up. Alternatively, interrupting the safety circuit can also trigger a different response from the technical system that brings about a safe state. Unlike a standard switching relay, a safety switching device – when correctly wired – must not experience a loss of safety function due to a fault within the device itself or an external fault caused by a sensor or actuator. To this end, a safety switching device incorporates additional specialized circuitry or relay technology compared to a standard switching relay, ensuring reliable switching even in the event of a fault. The typical design of a safety switching device is redundant. Two relays with positively guided contacts provide the safe switching contacts, also known as safe outputs or safety outputs. Two input circuits each control one of the two internal relays. Since a separate safety switching device is typically used for each safety function, the number of safety switching devices and thus the space required in the associated control cabinet increases with each safety function in a technical system. This increasing number of required safety switching devices necessitates minimizing the space required for each individual device. In addition to the actual switching elements, the external connections are of crucial importance. The more external connections a safety switching device requires, the greater the installation space it occupies. It is therefore an object of the present invention to provide an improved safety switching device which, with the greatest possible range of functions, requires little installation space, reduces cabling effort and prevents cabling errors. The problem is solved by a safety switching device with a housing and electronics arranged in the housing, wherein the electronics have two switching elements which can be arranged in the safety circuit via a first, second, third and fourth connection on the housing and which close this circuit redundantly when a control signal is present at each switching element, wherein a fifth connection and a sixth connection are provided on the housing, to which a first input signal and a second input signal can be applied, corresponding to the control signals of the switching elements, so that when the first and the second input signal are present at the fifth and sixth connections, the safety circuit is closed, wherein the electronics arranged in the housing have a further electrical element which is configured to draw energy for its own operation from an electrical signal present at the first, the third, the fifth and/or the sixth connection. It is therefore an idea of the present invention to provide a safety switching device that is configured to extract electrical energy from a connected signal. The extracted energy is used to operate an electrical element within the safety switching device. In other words, an electrical element draws the current required for its intended use from the energy extracted from the signal. The safety switching device can, for example, be a safety switching device specifically designed for active sensors that actively provide an input signal from which additional energy can be drawn. This supplied energy can contribute to powering at least one other element of the safety switching device, in addition to controlling the internal switching elements. In this way, external connections for a separate power supply can be adva