Tripping mechanism for circuit breakers

Abstract

The invention relates to a tripping mechanism for circuit breakers comprising • a pawl which is attached to the operating element by means of a rotatably mounted pawl lever, wherein the pawl is rotatably mounted relative to the operating element, wherein a pawl lever is guided in a forced path when the rotatable operating element is moved from the first switching position to the second switching position, • wherein in a first state the latch can be supported on the release lever in the unactuated state of the release lever, and wherein the plunger is in a first position, whereby a first switch position is provided, • wherein in a second state, by actuating the rotatable operating element into the second switching position, the plunger is pushed into a second position, wherein a spring element is tensioned, wherein a second switching position is provided, • wherein in a third state, by actuating the release lever, the pawl moves back from the second position to the first position under the effect of the tension of the plunger.

Description

background

[0001] Overcurrent circuit breakers are used to protect electrical equipment. A circuit breaker is a mechanical switching device that can switch on, conduct, and break currents in a circuit under normal operating conditions. It should also be able to switch under specified exceptional conditions, such as a short circuit, at least for a specified duration.

[0002] Circuit breakers have two specific positions: an open position, which provides an air gap between the open contacts of the main circuit, thus interrupting the circuit, and a closed position, which provides an electrically conductive connection to allow electrical current to flow.

[0003] Typically, circuit breakers also include an operating part, which is part of the operating system and to which an external operating force can be applied so that the circuit breaker can be manually switched on or off.

[0004] Such circuit breakers have been developed and marketed for many years not only by the applicant but also by competitors of the applicant.

[0005] For example, German patent DE 10 2019 209 747 B3 is known from the prior art. Furthermore, an overcurrent protection switch is known from German patent DE 32 11 246 C1. Task

[0006] It would therefore be desirable to provide a tripping mechanism for circuit breakers that allows it to be used cost-effectively for a variety of different tripping elements. Brief description of the invention

[0007] The object is achieved by an arrangement according to claim 1. Further advantageous embodiments are the subject of the respective dependent claims, the figures and the description. Brief description of the characters

[0008] The invention is explained in more detail below with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way.

[0009] They show: Fig. 1a and Fig. 1b views of a circuit breaker with tripping mechanisms according to embodiments of the invention in a switched-off state, Fig. 2a and Fig. 2b views of a circuit breaker with tripping mechanisms according to embodiments of the invention in a switched-on state, Fig. 3 a perspective view of a trigger mechanism according to embodiments of the invention, and Fig. 4-6 a schematic view of a trigger mechanism according to embodiments of the invention in different states. Detailed description of the invention

[0010] The invention will be described in more detail below with reference to the figures. It should be noted that various aspects are described, each of which can be used individually or in combination. This means that any aspect can be used with different embodiments of the invention, unless explicitly presented as a mere alternative.

[0011] Furthermore, for the sake of simplicity, reference will generally be made to only one entity below. Unless explicitly stated, the invention may also comprise several of the entities in question. Therefore, the use of the words "a," "an," and "an" is to be understood merely as an indication that at least one entity is used in a simple embodiment.

[0012] Numerical values ​​are generally not to be understood as exact values, but also include a tolerance of + / - 1% to + / - 10%.

[0013] To the extent that standards, specifications, or the like are mentioned in this application, reference is always made to the standards, specifications, or the like applicable on the filing date. This means that if a standard / specification, etc., is updated or replaced by a successor, the invention is also applicable to it.

[0014] Unless otherwise stated, circuit breakers are in particular compliant with DIN EN IEC 60934 VDE 0642:2020-11.

[0015] Below, a tripping mechanism according to the invention for circuit breakers 1 - see Fig. 1a, Fig. 1b and Fig. 2a, Fig. 2b are described.

[0016] As can be seen from the Fig. As can be seen in Figures 3-6, a release mechanism according to the invention comprises a release lever T mounted on an axis B2, wherein the release lever T can be triggered by at least one actuator. Such an actuator can be, for example, a magnetic release, a bimetal, or another device that exerts force on the release lever T so that it rotates, for example, against a spring force.

[0017] Furthermore, a release mechanism according to the invention has an operating element S that can be rotated about an axis B1 in a predefined angular range, wherein a first switching position S1 and a second switching position S2 are defined. The switching positions are also shown in section in the Fig. 1a, Fig. 1b or 2a, Fig. 2b. It should be noted that a corresponding circuit breaker can also signal a switching state with additional optical elements in addition to the rotatable operating element S, for example, as shown in the Fig. 1b and Fig. As shown in Figure 2b, an additional optical display AZ may be provided, which, for example, provides a further optical and / or graphical display. For example, a red / green color change and / or a 0 / 1 display change may be provided.

[0018] The release mechanism according to the invention further comprises a pawl K, wherein the pawl K is fastened to the operating element S by means of a rotatably mounted pawl lever H, wherein the pawl lever H is rotatably mounted relative to the operating element S, wherein the pawl lever H is guided in a forced path Z when the rotatable operating element S is moved from the first switching position S1 to the second switching position S2, wherein the pawl K rotatably mounted on the pawl lever is also indirectly guided.

[0019] Furthermore, the release mechanism according to the invention has a translationally displaceable plunger ST, wherein switching contacts are arranged on the plunger ST, wherein at least two different switch positions are provided.

[0020] In the figures, the switching contact, ie the circuit to be switched, is shown as a contact bridge KB and two contacts K1 and K2, so that in the switched-on state ( Fig. 5) an electrically conductive connection is provided by the contact bridge KB from contact K1 to contact K2. This embodiment is exemplary. Other embodiments are not excluded. For example, instead of a contact bridge, a movable contact can also be provided. Likewise, it is immediately apparent to a person skilled in the art that not only the contact bridge KB can be moved relative to the contacts K1 and K2, but also the contacts K1 and K2 relative to the contact bridge KB.

[0021] In a first state Z1 corresponding to the Fig. 4, the latch K can rest on the release lever T when the release lever T is not actuated. In this case, the plunger ST is in a first position, providing a first switch position in which the electrical contact KB, K1, K2 is interrupted.

[0022] In a second state Z2 according to the Fig. 5 is moved into the second switching position S2 by actuating the rotatable operating element S and the plunger ST is moved from the first position to a second position, whereby a spring element D3 - shown in Fig. 3 as arranged inside the plunger ST - is tensioned, whereby a second switch position is provided in which the electrical contact KB, K1, K2 is connected.

[0023] In a third state Z3 corresponding to the Fig. 6 By actuating the release lever T, the pawl K can no longer be supported on the release lever T and under the effect of the tension of the spring element D3 and / or a return spring of the plunger (not shown), the plunger ST is moved back from the second position to the first position.

[0024] The plunger ST itself is coupled to the pawl K by frictional engagement in only one direction.

[0025] This means that in the invention, a rotary actuation of the release lever T is converted into a translatory contact movement of the plunger ST and thus of the contact bridge KB relative to the contacts K1, K2.

[0026] Triggering elements can act on the release lever T at different points of action WP1, WP2. For example, a magnetic release can act on point of action WP1, while a thermal switching element can act on point of action WP2. Obviously, other points of action can also be implemented, and the naming is therefore only exemplary. As soon as a rotation (counterclockwise) is effected at one point of action, this leads to triggering, so that under the action of the spring element D3 and / or a return spring (not shown) of the plunger, the plunger ST breaks the contact.

[0027] In the open position, no current flows through the switchable (movable) contact provided by contact bridge KB and contacts K1 and K2. Circuit breaker 1 cannot then conduct current.

[0028] In the closed position, current can flow through the moving contact and the circuit breaker 1 can carry the current.

[0029] In the event of a trip, the current flow is interrupted by the circuit breaker 1, i.e., the contact, switching from the closed to the open position. The actuator can be triggered under defined overcurrent conditions, and the actuator acts mechanically on the trip lever.

[0030] Preferably, the housing of the circuit breaker 1 consists of two housing halves (see Fig. 1a, Fig. 2a in side profile). The housing halves are preferably made of plastic, as this also provides insulation in the sense of contact protection.

[0031] The release mechanism according to the invention is then located within the two housing halves, along with other components that can trigger the release.

[0032] The actuator is actuated by the rotating control element S. The rotating control element S is mounted in the housing so that it can rotate about the axis B1. The rotating control element S can be preloaded with a (leg) spring (not shown). The (leg) spring (not shown) can be supported in the housing.

[0033] The preload of the (leg) spring (not shown) can cause the rotating control element S to move in the preload direction (counterclockwise). The movement of the rotating control element S can be limited by stops on the housing.

[0034] Eccentrically arranged on the rotatable operating element S is a U-shaped latch lever H. The first arm of the latch lever 2 is mounted rotatably about an eccentric axis in the rotatable operating element S. U-shaped elements can be manufactured particularly easily and allow for rapid assembly, since these elements are simply inserted into pre-formed openings on the side (ie in the Fig. 4-6 perpendicular to the plane of representation) and provide a connection as well as a bearing when installed.

[0035] In the present case, for example, the first arm of the ratchet lever H is inserted into an eccentric bore on the rotatable operating element S, while the second arm of the ratchet lever H is inserted into a pawl K. The second arm of the ratchet lever H is thus rotatably mounted in a bearing L, ie an opening in the pawl L.

[0036] It should be noted that the openings for the arms can be designed as through holes or as blind holes.

[0037] The ratchet lever can engage with the second arm in a link Z, which is formed, for example, in the housing, thereby providing a forced path Z in which the arm and thus all directly connected elements are guided.

[0038] Preferably, the link Z is designed so that a constant distance to the latching point, i.e. the point at which the pawl K rests on the release lever T, is provided.

[0039] When actuated and in the closed state, the latch K rests on the release lever T at the latching point. The movement of the latch K, like the movement of the rotatable operating element S, can be limited by stops in the housing.

[0040] The release lever T is rotatably mounted in the housing and, in particular, rotatable about the axis B2. The release lever T is preferably preloaded with a (leg) spring (not shown). The (leg) spring (not shown) can, in turn, be supported in the housing 9. The preload of the (leg) spring (not shown) can act in such a way that the release lever tends to move in the preload direction (here, clockwise).

[0041] The movement of the release lever T may be limited by stops on the housing.

[0042] At the end of the pawl K opposite the release lever T, the pawl K is “connected” to the plunger ST by frictional engagement in one direction.

[0043] It should be noted that the openings for the arms can be designed as through holes or as blind holes.

[0044] The plunger ST is preferably preloaded by a spring element (preferably a cost-effective compression spring) and is guided to be movable in a substantially translational direction.

[0045] The preload may act in such a way that the plunger ST tends to move in the preload direction (i.e., into an open contact position). The movement of the plunger ST may be limited by stops in the housing 9.

[0046] The plunger ST establishes or breaks the electrical contact. As already mentioned, this electrical contact can be designed in different ways.

[0047] An exemplary embodiment is shown in the figures. A contact bridge KB is movably mounted in the plunger ST. The contact bridge KB is supported by a spring element D3 ( Fig. ) is preloaded. The spring element D3 is supported in the plunger ST. The preload of the spring element D3 causes the contact bridge to move in the preload direction, i.e., toward the closed contact. In the closed position, the contact bridge KB sits on the contacts K1 and K2, with the spring element D3 generating a contact force such that the contact bridge KB and the contacts K1 and K2 press against each other.

[0048] In the closed position, a conductive connection is formed via the contact bridge KB between contact K1 and contact K2. In the open position, however, the conductive connection between contact K1 and contact K2 is interrupted.

[0049] Contacts K1 and K2 are part of the current path within circuit breaker 1. Please note that the complete current path is not shown. This includes other components such as conductors, terminals, and tripping devices.

[0050] Not shown is the actuator of the circuit breaker. When triggered, this acts mechanically on the release lever (arrows pointing to WP1 / WP2).

[0051] The release lever T is rotated counterclockwise (opposite the preload direction) by the action of an actuator. The actuator can be a magnetic release, a bimetal, a shape memory alloy, hydraulic, or another type of actuator, but this list is not exhaustive.

[0052] In Fig. 4 shows the rest position of the circuit breaker 1. The latch K is not supported on the release lever T. When closing the circuit breaker 1, i.e. when moving from the open position ( Fig. 4) into the closed position ( Fig. 6), the rotating operating element S is rotated against the pre-tensioning direction. The ratchet lever H is guided in the linkage on a forced path Z and transfers the actuating force from the rotating operating element S to the ratchet K. The ratchet K then rests on the release lever T at the latching point ( Fig. 5).

[0053] Upon further actuation, the latch K rotates around this latching point. This causes the latch K to press against the plunger ST, and the plunger ST moves toward the closed electrical contact. At the same time, a plunger return spring (not shown) is tensioned as the plunger ST moves.

[0054] During the closing process, a relative movement occurs between the contact bridge KB and the contacts K1, K2, so that the distance decreases and finally a mechanical and thus electrically conductive contact is established.

[0055] It can be provided that the plunger ST passes through a low point during closing and then even moves back a bit until a stable end position (closed position, Fig. 6). However, this is not harmful, since, for example, a spring - here spring element D3 - maintains the necessary contact between the contact bridge KB and the contacts K1, K2 in a partial range of the travel.

[0056] From the closed position, the circuit breaker 1 can return to the open position in two ways: by opening (operating the rotating control element S) or by tripping.

[0057] When opened (operating the rotating control element S), the described closing process occurs in reverse order. Thus, the circuit breaker 1 is moved from the closed to the open position.

[0058] When triggered, the trigger lever T is turned by an actuator against the pre-tension direction ( Fig. 6). This releases the latch at the latching point. The latch K can then rotate about the axis of rotation of the bearing L, releasing the movement of the plunger ST in the separating direction. The plunger ST moves upwards in this case and the electrical contact is separated, i.e. the switching state is open. The current flow is thus interrupted. The force for moving the plunger ST and thus for opening the contact is provided by the plunger return spring, which is tensioned during closing and tends to move the plunger in the separating direction. The contact should preferably open as quickly as possible. This can be achieved by appropriately dimensioning the plunger return spring.

[0059] The opening of the contacts is independent of whether the rotating control element S is in the working position I or a position between the rest position O and the working position I - as in Fig. 6 - is located (trip-free). This means that with the trip-free function, movable contact elements move into the open position and remain there if an opening initiated by the actuator is initiated after a closing, even if a subsequent closing is immediately attempted.

[0060] After release with free release and as soon as the rotating operating element S is freely movable, the rotating operating element S rotates in the pre-tensioning direction, driven by a (leg) spring (not shown). In doing so, the rotating operating element S takes the pawl K with it via the pawl lever H guided in the forced path Z of the link, until finally the open position in the rest position ( Fig. 4) is reached again.

[0061] In one embodiment of the invention, the predefined angular range for actuating the rotatable control element S is 80° and more, in particular approximately 90° and also up to (and including) 100°. Without limiting the generality, the angular range can also be up to 180°. Even larger angular ranges are conceivable.

[0062] The rotating control element S has two positions between which it can rotate. The rest position O ( Fig. 1a, Fig. 1b and Fig. 3) and the work situation I ( Fig. 6). These positions are clearly distinguishable. This is achieved by a large angle of rotation during operation. The switching mechanism allows a large angle of rotation of approximately 90° (see Fig. 1a and Fig. 2a in comparison). This allows the two states to be clearly distinguished visually.

[0063] It is also possible to apply a clearly legible print to the rotating control element S. In Fig. 1b and Fig. 2b shows the top side of the circuit breaker 1. In the Fig. 1b the rotating control element S in an off position (according to Fig. 1a, Fig. 3) or in Fig. 1b, Fig. 6 can be seen in an on position.

[0064] The switching mechanism is not limited to the use of a contact bridge KB as a moving contact. Other forms of translationally moving contacts are conceivable (single contact, double contacts (parallel current conduction), etc.).

[0065] Circuit breaker 1 can also be used as a switch.

[0066] Without limiting its generality, the tripping mechanism according to the invention can be used to create switches, and in particular circuit breakers, for both AC and DC voltages. Rated currents of up to 20 A and more can be switched independently of the switching mechanism. Likewise, AC voltages well above 280 volts and DC voltages above 50 volts can be switched without any problems.

[0067] Furthermore, without limiting the generality, the material selection for the components of the invention can be made appropriately. It is preferred that as many identical parts as possible be used and that identical material components be used as far as possible.

[0068] For example, the rotatable operating element S, the latch K, the release lever T, the housing and thus also stops or a link for the forced path Z, the plunger ST, etc. can be made of plastic, in particular an injection-moldable plastic.

[0069] Other elements such as the ratchet lever K can be bent or stamped from steel.

[0070] Contact elements, such as the contact bridge KB and the contacts K1, K2 can also be made of steel, or because of the lower resistance, of copper, silver, or of an alloy containing copper and / or silver (e.g. stamped and bent).

[0071] Likewise, other elements - such as spring elements as preload elements - can be provided by similar elements.

[0072] The invention makes it possible to provide space-saving release mechanisms, with the release mechanism having a width of less than 10 mm. The release mechanism typically has a width of more than 6 mm. List of designations 1 circuit breaker B1, B2 axis T Release lever (multi-operation, rotatable) S rotating control element S1 first switching position S2 second switching position K Jack H rotatable ratchet lever L bearing Z compulsory railway ST translationally movable plunger Z1 first state (open position) Z2 second state (closed position) Z3 third state (open position after release) D3 spring element KB contact bridge K1, K2 Contact AZ optical display QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2019 209 747 B3

[0005] DE 32 11 246 C1

[0005]

Claims

[1] Having a tripping mechanism for circuit breakers • a release lever (T) mounted on an axis (B2), wherein the release lever (T) can be triggered by at least one actuator, • an operating element (S) which can be rotated about an axis (B1) in a predefined angular range, wherein a first switching position (S1) and a second switching position (S2) are defined, • a latch (K), • wherein the pawl (K) is attached to the operating element (S) by means of a rotatably mounted pawl lever (H), wherein the pawl (H) is rotatably mounted (L) relative to the operating element (S), wherein a pawl lever (H) is guided in a forced path (Z) when the rotatable operating element (S) is moved from the first switching position (S1) to the second switching position (S2), wherein the pawl (K) rotatably mounted on the pawl lever is also indirectly guided, • a translationally displaceable plunger (ST), wherein switching contacts are arranged on the plunger (ST), wherein at least two different switch positions are provided, • wherein in a first state (Z1) the pawl (K) can be supported on the release lever (T) in the unactuated state of the release lever (T), and wherein the plunger (ST) is in a first position, whereby a first switch position is provided, • wherein in a second state (Z2) by actuating the rotatable operating element (S) into the second switching position (S2) the plunger (ST) is pressed from a first position into a second position, wherein a spring element (D3) is tensioned, wherein a second switching position is provided, • wherein in a third state (Z3) by actuating the release lever (T) the pawl (K) can no longer be supported on the release lever (T), but under the effect of the tension of the spring element (D3) and / or a return spring the plunger (ST) moves back from the second position to the first position. [2] Release mechanism according to claim 1, characterized by that the predefined angle range is 80° and more. [3] Release mechanism according to one of the preceding claims, characterized by that the trigger mechanism is designed for a rated current of up to 20 A. [4] Release mechanism according to one of the preceding claims, characterized by that the trigger mechanism has a width of less than 10 mm. [5] Release mechanism according to one of the preceding claims, characterized by that the trigger mechanism has a width of more than 5 mm.

Images