SALES UNIT WITH A DEVICE FOR TRIGGERING AN ELECTRIC SWITCH

Description

[0001] The invention relates to a sales unit with a device for triggering an electrical switch.

[0002] The main task of today's circuit breakers is to switch current and voltage on or off in a section of a system, as well as to automatically trip the circuit breaker in the event of an overload or a short circuit.

[0003] Additionally, there is a customer requirement to trip a circuit breaker by changing the voltage state in a customer-configured current loop. For this purpose, tripping assemblies are installed in internal circuit breaker accessory pockets, typically located to the right and left of the switch operating lever (handle). These tripping assemblies are connected to the customer-configured current loop. When the voltage in the current loop changes, these tripping assemblies activate a plunger (also called a tripping lever), which, via a tripping shaft inside the circuit breaker, trips the circuit breaker and thus opens its contacts.

[0004] Essentially, two types of trigger assemblies are distinguished: 1. Voltage release: The trip loop is de-energized in its normal (neutral) state. The voltage release only trips when the customer applies a voltage to the trip loop via a push button or switch. 2. Undervoltage release: A voltage is present across the trip loop in its normal (neutral) state. The undervoltage release only trips when the customer interrupts the voltage in the trip loop via a push button or switch. This system incorporates so-called emergency stop circuits.

[0005] Typical trip assemblies contain coils, each with a magnetic plunger that releases mechanical energy stored in a spring when tripped. In both cases of typical voltage and undervoltage releases, the width of the trip assembly's mechanical structure is essentially determined by the coil diameter. A trip assembly typically requires three slots in the respective accessory pockets. Depending on the circuit breaker's design, it may only have three slots each in the left and right accessory pockets, meaning that if a trip assembly is installed, there is no longer any room for additional accessories such as auxiliary switches.

[0006] Trigger assemblies, which serve as safety-relevant components because they are sometimes integrated into emergency stop loops, are highly complex designs with many, sometimes delicate, components that must withstand considerable mechanical stress and sometimes reach the limits of their load-bearing capacity. Even today, complying with the force and path specifications of the interface data sheet requires a certain amount of effort in production.

[0007] The actuator WO 2009 / 042306 A1 comprises a shape memory alloy element configured to change its shape, such that this shape change triggers the actuator. The actuator also comprises a circuit configured to provide a current signal that causes the shape memory alloy to change shape. Furthermore, the actuator comprises a circuit configured to control a current source to apply a second current signal that puts the shape memory alloy into a pre-activated state.

[0008] The electric cooler of FR 2 757 735 A1 has a power supply circuit controlled by a main switching system. The circuit is powered by a source that supplies current to a radiating element, which is electrically and thermally conductive. This element can be made of, for example, aluminum or an aluminum alloy. An auxiliary element, made of a shape-memory material capable of changing its state, is also included. This auxiliary element operates within the power supply circuit and either prevents or allows the radiating element to be powered when a first temperature threshold (S1) is exceeded. Depending on the temperature, the element switches between a solid, rigid state and a non-rigid state.

[0009] It is therefore an object of the invention to provide a device for triggering an electrical switch that reduces the complexity described above many times over and is compact and functional with a simple mechanical and electrical design.

[0010] This problem is solved according to the invention by the sales unit according to claim 1.

[0011] The device for triggering an electrical switch according to claim 1 comprises a release lever that is movable between a neutral position and a release position, wherein the device comprises an actuator with a first shape and a second shape and a control element moved by the actuator by means of its shape, which moves the release lever directly or indirectly, wherein the actuator in its first shape moves the release lever into the release position, wherein the actuator in its second shape moves the release lever into the neutral position, and wherein the actuator is a shape memory alloy actuator.

[0012] An advantage of this is that the device according to the invention, for example, does not include a tension spring in the energy storage device for rotating a trigger wheel, and therefore also no loads perpendicular to this tension spring. In typical trigger assemblies, this additional load on the tension spring can lead to breakage at very high switching cycles. By designing trigger assemblies with shape memory alloy actuators, tension springs can be replaced in such a way that they are only loaded in the tensile direction, for which they were originally designed, and spring breakage can be avoided.

[0013] Furthermore, the device according to the invention enables the realization of mechanically narrower assemblies with a small installation volume while fully utilizing all force and travel reserves. High forces are possible, which, with appropriate gear ratios, also allow for large travel distances. The smaller and more powerful shape memory alloy actuators will make it possible to design assemblies so narrow that they occupy only one accessory pocket. This allows for the accommodation of additional accessories in the remaining accessory pockets.

[0014] Typical coils used today are highly dependent on manufacturing parameters in their magnetic and mechanical behavior. Coils from the same production batch can behave very differently. In some cases, these coils must be measured and combined with specific other mechanical components to produce triggers with identical behavior. These coils can be replaced by using shape memory alloy actuators.

[0015] A typical trigger mechanism needs to be reset after activation. This is usually done by the customer manually rewinding the trigger via a mechanical connection using the switch handle. The shape memory alloy actuator can reset the trigger by applying an electric current, eliminating the need for a reset lever.

[0016] Overall, the device according to the invention can achieve a simpler design with fewer parts, which has more force and travel reserves, is more stable and cost-effective, and can be manufactured with less manufacturing and development support effort.

[0017] In one embodiment of the device according to the invention, the actuator in its first embodiment is powered by connecting cables, and in its second embodiment the actuator is not powered by the connecting cables or vice versa.

[0018] In a further embodiment of the device according to the invention, the control element is designed as a control pin which is mounted in a guide between the trigger position and the neutral position.

[0019] In one embodiment, the control pin in the guide undergoes a linear movement between the trigger position (extended control pin) and the neutral position (retracted control pin), or between the trigger position (retracted control pin) and the neutral position (extended control pin). The actuator can move the control pin against the force of a control pin spring.

[0020] The problem according to the invention is also solved by the voltage release according to claim 6, which comprises a device according to the invention, a deflection lever and a spring, wherein the release lever is driven indirectly by the device by means of the deflection lever and the spring acts on the release lever in the direction of the neutral position.

[0021] The problem according to the invention is also solved by the undervoltage release according to claim 7, wherein the undervoltage release comprises a device according to the invention, a deflection lever and a spring, wherein the release lever is driven directly by the device and the spring acts on the release lever by means of the deflection lever in the direction of the release position.

[0022] The problem according to the invention is solved by the sales unit according to claim 1, wherein the sales unit consists of a device according to the invention, a spring, a deflection lever and a housing with two paired holding points, wherein in the first pair one holding point is fixedly arranged on the housing and the other holding point on the deflection lever and in the second pair one holding point is fixedly arranged on the housing and the other holding point on the release lever, wherein in the housing the spring is attached to the first pair of holding points and the device is attached to the second pair of holding points for an undervoltage release or spring and device are attached in reverse for a voltage release.

[0023] The properties, features and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer and more easily understood in connection with the following description of the embodiments, which are explained in more detail in relation to the figures.

[0024] This shows: Figs. 1A and 1B: typical voltage release and typical undervoltage release; Figs. 2A and 2B: voltage release according to the invention and undervoltage release according to the invention; Fig. 3: sales unit; Figs. 4A and 4B: actuator, control pin in guide and control pin spring for a standard extended control pin; and Figs. 5A and 5B: actuator, control pin in guide and control pin spring for a standard retracted control pin.

[0025] In Figure 1AA voltage release 2100 is shown. The voltage release 2100 comprises a coil 2102 and a magnetic plunger 2103. In the event of tripping, a voltage increase in a current loop magnetizes the coil 2102, which then attracts the magnetic plunger 2103. The magnetic plunger 2103 tears open the retaining element 2105 of the spring accumulator 2104. The spring accumulator 2104 releases its energy and pushes the trip plunger 2106 out of the assembly, enabling it to trip a circuit breaker. If, during the service life of the trip assembly 2100, the spring 2104 in the spring accumulator breaks, the trip assembly 2100 will fail.

[0026] Figure 1BFigure 2200 shows an undervoltage release in which, upon tripping, the voltage drop in a current loop demagnetizes the coil 2202. This releases the magnetic plunger 2203, which then releases the retaining element 2205 of the spring accumulator 2204. The energy stored in the spring accumulator can then be discharged. The trip plunger 2206 is pushed out of the assembly and can, in turn, trip a circuit breaker. If, during the service life of the trip assembly 2200, the spring 2204 in the spring accumulator breaks, the trip assembly 2200 will fail.

[0027] In both cases of the Figures 1A and 1B The mechanical width of the trip assemblies 2100; 2200 is essentially determined by the diameter of the coils 2102; 2202. Typical trip assemblies 2100; 2200 require three slots in an accessory pocket of a circuit breaker.

[0028] In Figure 2AFigure 1 shows a voltage release device according to the invention for an electrical switch 1000. The voltage release device comprises a device 100 for triggering an electrical switch 1000 and a release lever 190, which is movable between a neutral position and a trigger position.

[0029] In the Figures 4A and 4B This device 100 according to the invention is shown in more detail below. The device 100 comprises an actuator 110 with a first shape and a second shape, and a control element 120 moved by the actuator 110 by means of its shape, which directly or indirectly moves the release lever 190. As shown in the illustration in the Figure 4A This control element 120 protrudes from a guide 150 with a length D1. In Figure 4AThe device 100 is shown in the release position for triggering an electrical switch 1000 if the release lever 190 is directly driven by the device 100. The actuator 110 is in its first configuration, and thus the control element 120 is in the release position.

[0030] The actuator 110 can assume a second form, as shown in the Figure 4B The control element 120 is actuated by the actuator 110 as shown in the illustration. Figure 4B The actuator has pulled the control element 120 to the right against the force of a control pin spring 160. The control element 120 is in a neutral position in which it does not interfere with the electrical switch and does not trigger it. The neutral position does not affect the state of the electrical switch 1000. The actuator has pulled the control element 120 to the right, so that the control element 120 protrudes from the guide 150 only by a length D2, which is less than the length D1.

[0031] The Actuator 110 is a shape memory alloy actuator capable of assuming both a first and a second shape. Shape memory alloys have the property of returning to their original shape at certain elevated temperatures. This makes it possible to construct shape memory alloy actuators that can be forced into a different position or length at a low temperature. When the actuators are brought to this specific, higher temperature, which is determined by the alloy composition, they instantly assume their learned shape. The shape memory alloys can be heated indirectly via a heating element, or directly by passing an electric current through them.

[0032] Shape memory alloy actuators can be designed as a wire that contracts at a higher temperature, as a metal strip that bends at a higher temperature, as a cuboid that changes its volume at a higher temperature, or as an arbitrarily shaped geometry that fits optimally into the available installation space and changes its volume in a specific, desired direction at a higher temperature.

[0033] According to the Figures 4A and 4B The actuator 110 is designed as a wire. In its initial form, as in Figure 4A is the wire longer than in its second shaping according to the Figure 4B .

[0034] Connecting cables 115 and 116 are provided for heating the actuator 110 and for supplying it with current. For example, in its first configuration, the actuator 110 can be unpowered via the connecting cables 115 and 116, while in its second configuration, it can be powered via the connecting cables 115 and 116, as shown in the Figures 4A and 4B as shown. Likewise, the reverse procedure is possible, whereby the actuator 110 is energized in its first configuration and not in its second configuration.

[0035] By applying current, the actuator 110 is heated directly; it is also possible for the actuator 110 to be heated indirectly by a heating element which is supplied with current via power cable 115; 116.

[0036] Control element 120 can be designed as a control pin which is mounted in a guide 150 and can be moved between the trigger position and the neutral position, as shown in the Figures 4A and 4BThe control pin undergoes a linear movement in the guide 150 between the release position as an extended control pin, as shown in Figure 4A, and the release position as a retracted locking pin, as shown in the Figure 4B . Likewise, with the control pin extended, the device 100 can be in the neutral position and with the control pin retracted, in the release position, depending on whether the release lever 190 is driven indirectly or directly by the device 100 according to the invention.

[0037] The control element 120 is actuated by the control pin spring 160 as shown in the illustration. Figure 4A pressed to the left in the direction of the trigger position.

[0038] In the Figures 5A and 5B An alternative embodiment of the device 100 according to the invention is shown. In the first embodiment of the actuator 110, according to the Figure 5AThe control element 120 protrudes from the guide 150 through the control pin spring 160 with a length D2. If the actuator 110 now switches from the first shape to the second shape according to the Figure 5B , so the actuator 110 shortens and the control element 120 is adjusted according to the representation in the Figures 5A and 5B The control element 120 moves to the right against the force of the control pin spring 160. The control element 120 now has a projecting length D1 and can, for example, trigger an electrical switch 1000. The length D1 is greater than the length D2.

[0039] In Figure 2AIn addition to the device and the release lever 190, an intermediate deflection lever 191; 192 with a first leg 191 and a second leg 192 is shown. At the first end of the release lever 190 is a retaining point P4 to which a spring 180 is attached. The spring 180 is a tension spring. The other end of the spring 180 is fixed to the housing 199 at a retaining point P2. The spring 180 acts on the release lever 190 in the direction of the neutral position, meaning that the release lever 190 moves as far as possible, as shown in the illustration. Figure 2A has retracted to the left into housing 199.

[0040] A retaining point P3 is provided on the deflection lever 191; 192, which interacts with the device 100. The first leg 191 of the deflection lever 191; 192 is mounted on a rotational axis R. The control element 120 is attached to the retaining point P3 of the second leg 192 of the deflection lever 191; 192. The other end of the device 100 is fixedly attached to the housing 199 at a retaining point P1.

[0041] By moving the control element 120 according to the illustration in the Figure 2A To the left, the second arm 192 of the deflection lever 191; 192 is also moved to the left, and the first arm 191 of the deflection lever 191; 192 is rotated counterclockwise. This causes the release lever 190 to move as shown in the illustration. Figure 2A moved to the right into the trigger position to trigger an electrical switch 1000.

[0042] Figure 2BFigure 1 shows an undervoltage release for an electrical switch, also comprising a device 100 according to the invention and a deflection lever 191; 192 with a first leg 191 and a second leg 192 and a spring 180. Here, the spring 180 is fixedly attached to the housing 199 at a holding point P1 and to the second leg 192 of the deflection lever 191; 192 at a holding point P3, and the device 100 is fixedly attached to the housing 199 at a holding point P2 and to the release lever 190 at a holding point P4. The spring 180 acts on the release lever 190 in the direction of the release position. The release lever 190 is held in the neutral position by the control element 120 of the device 100. If the shape memory alloy actuator is not connected by the connecting cables 115; When 116 is energized, the control element 120 is activated according to the illustration in Figure 2Bmoved to the right, and thus the spring 180 can move the release lever 190 into the release position to trigger an electrical switch 1000.

[0043] Figure 3A shows a sales unit consisting of a device 100 according to the invention, a spring 180, a deflection lever 191; 192 and a housing 199 with two paired holding points P1, P3; P2, P4.

[0044] In the first pair P1, P3, the holding point P1 is fixed to the housing 199 and the other holding point P3 is arranged on the first leg 191 of the deflection lever 191; 192, and in the second pair P2, P4, one holding point P2 is fixed to the housing 199 and the other holding point P4 is arranged on the release lever 190.

[0045] Depending on how the housing 199 is equipped with the device 100 according to the invention and the spring 180, the customer can manufacture either an undervoltage release or a voltage release. If the spring 180 is attached to the first pair of mounting points P1, P3 and the device 100 to the second pair of mounting points P2, P4, an undervoltage release is created. If the device 100 is attached to the first pair of mounting points P1, P3 and the spring to the second pair of mounting points P2, P4, a voltage release is provided.

Claims

1. Sales unit - comprising a device (100), - comprising a spring (180), - comprising a deflection lever (191; 192), and - comprising a housing (199) with two pairs of retaining points (P1, P3; P2, P4), wherein one retaining point (P1) is arranged fixed to the housing (199) and the other retaining point (P3) is arranged on the deflection lever (191; 192) in the case of the first pair (P1, P3) and one retaining point (P2) is arranged fixed to the housing (199) and the other retaining point (P4) is fixed to the tripping lever (190) in the case of the second pair (P2, P4), wherein, in the housing (199), the spring (180) is suspended from the first pair of retaining points (P1, P3) and the device (100) is suspended from the second pair of retaining points (P2, P4) for an undervoltage release or the spring (180) and the device (100) are suspended the other way around for a voltage release, wherein the device (100) for tripping an electrical switch (1000) comprises a tripping lever (190), which can be moved between a neutral position and a tripping position, wherein the device (100) comprises an actuator (110) with a first shape and a second shape and a control element (120) which is moved by the actuator (110) owing to its shape and indirectly or directly moves the tripping lever (190), wherein the actuator (110), when it is in its first shape, moves the tripping lever (190) to the tripping position, wherein the actuator (110), when it is in its second shape, moves the tripping lever (190) to the neutral position, and wherein the actuator (110) is a shape-memory alloy actuator.

2. Sales unit according to Claim 1, in which the actuator (110) is energized by connection cables (115; 116) when it is in its first shape, and in which the actuator (110) is not energized by the connection cables (115; 116) when it is in its second shape, or vice versa.

3. Sales unit according to either of the preceding claims, wherein the control element (120) is designed as a control pin which, in a manner mounted in a guide (150), can be moved between the tripping position and the neutral position.

4. Sales unit according to Claim 3, wherein the control pin performs a linear movement in the guide (150) between the tripping position as the extended control pin and the neutral position as the retracted control pin or between the tripping position as the retracted control pin and the neutral position as the extended control pin.

5. Sales unit according to Claim 3 or 4, wherein the control pin is moved against the force of a control pin spring (160) by the actuator (110).

6. Sales unit having a device (100) according to any of the preceding claims and a deflection lever (191; 192) and a spring (180), wherein the tripping lever (190) is driven indirectly by the device (100) by means of the deflection lever (190; 191) and the spring (180) acts on the tripping lever (190) in the direction of the neutral position.

7. Sales unit having a device (100) according to any of the preceding Claims 1 to 5 and a deflection lever (191; 192) and a spring (180), wherein the tripping lever (190) is driven directly by the device (100) and the spring (180) acts on the tripping lever (190) by means of the deflection lever (191; 192) in the direction of the tripping position.