Triggering mechanism for circuit breaker

Abstract

The invention relates to a triggering mechanism for a circuit breaker, comprising a latch which is fastened to the operating element by means of a rotationally supported latching lever, wherein the latch is supported in a rotational manner relative to the operating element, wherein the latching lever is guided in a forced path when the rotational operating element is transferred from the first switching position to the second switching position, wherein in a first state the latch can be supported on the triggering lever when the triggering lever is in the unactuated state, and wherein the tappet is in a first position, wherein a first switch position is provided, wherein in a second state by actuation of the rotational operating element into the second switching position the tappet is pressed into a second position, wherein a spring element is tensioned, wherein a second switch position is provided, wherein in a third state by actuation of the triggering lever the latch, under effect of the tension, the tappet moves back from the second position into the first position.

Description

[0001] Trigger mechanism for circuit breakers

[0002] background

[0003] 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 operating conditions. It should also be able to switch under specified exceptional conditions, such as a short circuit, at least for a specified duration.

[0004] Circuit breakers have two specific positions: an open position, which provides a 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.

[0005] Typically, circuit breakers also include an operating part that is part of the operating system and to which an external operating force can be applied so that the circuit breaker can be manually turned on or off.

[0006] Such circuit breakers have been developed and marketed for many years not only by the applicant but also by competitors of the applicant.

[0007] For example, the German patent DE 10 2019 209 747 B3 is known from the prior art. Furthermore, an overcurrent protection switch is known from the German patent DE 32 11 246 CI.

[0008] Task

[0009] It would therefore be desirable to provide a tripping mechanism for circuit breakers that allows for cost-effective use with a variety of different tripping elements. Summary of the invention

[0010] 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.

[0011] Brief description of the characters

[0012] 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.

[0013] They show:

[0014] Fig. 1a and 1b show views of a circuit breaker with tripping mechanisms according to embodiments of the invention in a switched-off state,

[0015] Fig. 2a and 2b are views of a circuit breaker with tripping mechanisms according to embodiments of the invention in a switched-on state,

[0016] Fig. 3 is a perspective view of a trigger mechanism according to embodiments of the invention, and

[0017] Fig. 4-6 a schematic view of a trigger mechanism according to embodiments of the invention in different states.

[0018] Detailed description of the invention

[0019] The invention will be presented in more detail below with reference to the figures. It should be noted that different aspects are described, each of which can be used individually or in combination. This means that each aspect can be used with different embodiments of the invention, unless explicitly presented as a pure alternative. Furthermore, for the sake of simplicity, reference will generally only be made to one entity in the following. Unless explicitly stated, the invention may also comprise several of the entities concerned. In this respect, the use of the words "a", "an" and "another" is to be understood only as an indication that in a simple embodiment at least one entity is used.

[0020] Numerical values ​​are generally not to be understood as exact values, but also include a tolerance of + / - 1% to + / - 10%.

[0021] To the extent that standards, specifications, or the like are mentioned in this application, reference is always made to at least 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.

[0022] Unless otherwise stated, circuit breakers are in particular compliant with DIN EN IEC 60934 VDE 0642:2020-11.

[0023] In the following, a tripping mechanism according to the invention for circuit breaker 1 - see Figures 1a, 1b and 2a, 2b - will be described.

[0024] As can be seen from 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.

[0025] Furthermore, a tripping mechanism according to the invention has 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. The switching positions can also be seen in section in Figures 1a, 1b and 2a, 2b. It should be noted that a corresponding circuit breaker can also signal a switching state with further optical elements in addition to the rotatable operating element S. For example, as shown in Figures 1b and 2b, a further optical display AZ can additionally be provided, which for example provides a further optical and / or graphic display. For example, a color change red / green and / or a display change 0 / 1 can be provided.

[0026] 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.

[0027] 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.

[0028] In the figures, the switching contact, i.e. the circuit to be switched, is shown as a contact bridge KB and two contacts Kl and K2, so that in the switched-on state (Fig. 5), an electrically conductive connection is provided by the contact bridge KB from the contact Kl to the contact K2. This embodiment is exemplary. Other embodiments are not excluded. For example, a movable contact can be provided instead of a contact bridge. 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 Kl or K2, but also the contacts Kl or K2 relative to the contact bridge KB.

[0029] In a first state ZI according to Figure 4, the pawl K can be supported on the release lever T in the unactuated state of the release lever T. In this case, the plunger ST is in a first position, providing a first switch position in which the electrical contact KB, Kl, K2 is interrupted.

[0030] In a second state Z2 according to Figure 5, by actuating the rotatable operating element S, the switch is moved into the second switching position S2 and the plunger ST is moved from the first position into a second position, wherein a spring element D3 - shown in Figure 3 as being arranged inside the plunger ST - is tensioned, whereby a second switch position is provided in which the electrical contact KB, Kl, K2 is connected.

[0031] In a third state Z3 according to Figure 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 (not shown) of the plunger, the plunger ST is moved back from the second position to the first position.

[0032] The plunger ST itself is coupled to the pawl K by frictional connection in only one direction.

[0033] 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 Kl, K2.

[0034] 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.

[0035] 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.

[0036] In the closed position, current can flow through the moving contact and the

[0037] Circuit breaker 1 can conduct current. When triggered, 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.

[0038] The housing of the circuit breaker 1 preferably consists of two housing halves (see Figures 1a and 2a in side profile). The housing halves are preferably made of plastic, as this also provides insulation in the sense of contact protection.

[0039] The release mechanism according to the invention is then located within the two housing halves, along with other components that can trigger the release.

[0040] 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 Bl. 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.

[0041] 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.

[0042] A latch lever H, for example of a U-shape, is arranged eccentrically on the rotatable operating element S. The first arm of the latch lever 2 is mounted rotatably about an eccentric axis in the rotatable operating element S. U-shaped elements, for example, can be manufactured particularly easily and allow rapid assembly, since these elements can simply be inserted into pre-formed openings laterally (ie, in Figures 4-6, perpendicular to the plane of the illustration) and, when installed, provide a connection as well as a bearing.

[0043] 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, i.e., an opening in the pawl L. It should be noted that the openings for the arms can be designed as either through bores or blind holes.

[0044] 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.

[0045] Preferably, the link Z is designed in such a way that a constant distance is provided to the latching point, ie the point at which the pawl K rests on the release lever T.

[0046] 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.

[0047] 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).

[0048] The movement of the release lever T may be limited by stops on the housing.

[0049] 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.

[0050] It should be noted that the openings for the arms can be designed as either through holes or blind holes. The plunger ST is preferably preloaded by a spring element (preferably a cost-effective compression spring) and guided for movement in a substantially translational direction.

[0051] 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.

[0052] The plunger ST establishes or breaks the electrical contact. As already mentioned, this electrical contact can be designed in different ways.

[0053] An example design is shown in the figures. A contact bridge KB is movably mounted in the plunger ST. The contact bridge KB is preloaded by a spring element D3 (Figure 3). 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 Kl and K2, with the spring element D3 generating a contact force such that the contact bridge KB and the contacts Kl, K2 press against one another.

[0054] 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.

[0055] 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.

[0056] Not shown is the actuator of the circuit breaker. When triggered, this acts mechanically on the trip lever (arrows pointing to the WP1 / WP2 action points).

[0057] The release lever T is rotated counterclockwise (opposite the preload direction) by 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.

[0058] Figure 4 shows the rest position of the circuit breaker 1. The latch K is not supported on the release lever T. When the circuit breaker 1 is closed, i.e., when moving from the open position (Figure 4) to the closed position (Figure 6), the rotating operating element S is rotated counter to the preload direction. The latch lever H is guided in the guide on a forced path Z and transfers the actuating force from the rotating operating element S to the latch K. The latch K then rests on the release lever T at the latching point (Figure 5).

[0059] 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.

[0060] During the closing process, a relative movement occurs between the contact bridge KB and the contacts Kl, K2, so that the distance decreases and finally a mechanical and thus electrically conductive contact is established.

[0061] It can be provided that the plunger ST passes through a low point during closing and then even moves back a bit until it finally reaches a stable end position (closed position, Figure 6). However, this is not harmful, since, for example, a spring mechanism—here, spring element D3—maintains the necessary contact between the contact bridge KB and the contacts K1, K2 over a portion of the travel.

[0062] 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.

[0063] When opened (operating the rotating operating element S), the described closing process takes place in reverse order. The circuit breaker 1 is therefore moved from the closed to the open position. When tripped, the trip lever T is turned by an actuator against the pretensioning direction (Figure 6). This releases the latch at the latching point. The pawl K can then rotate about the axis of rotation of the bearing L and the movement of the plunger ST in the breaking direction is released. In this case, the plunger ST moves upwards 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 breaking direction. Preferably, the contact should open as quickly as possible.This can be achieved by appropriate dimensioning of the plunger return spring.

[0064] The opening of the contacts is independent of whether the rotating operating element S is in the operating position I or a position between the rest position 0 and the operating position I - as shown in Figure 6 (trip-free). This means that with the trip-free function, the movable contact elements move to the open position and remain there if an opening initiated by the actuator is initiated after a closing, even if a subsequent closing is attempted immediately.

[0065] After release with the free release mechanism 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). The rotating operating element S drives the pawl K via the pawl lever H, which is guided in the forced path Z of the gate, until the open position in the rest position (Figure 4) is finally reached again.

[0066] 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.

[0067] The rotatable operating element S has two positions between which it can rotate: the rest position O (Figures 1a, 1b and 3) and the operating position I (Figure 6). These positions are clearly distinguishable. This is achieved by a large angle of rotation during actuation. The switching mechanism allows a large angle of rotation of approximately 90° (see comparison of Figures 1a and 2a). This allows the two states to be clearly distinguished visually. Furthermore, it is possible to apply clearly legible printing to the rotatable operating element S. Figures 1b and 2b show the top side of the circuit breaker 1. In Figure 1b the rotatable operating element S can be seen in an off position (corresponding to Figures 1a, 3) and in Figures 1b and 6 in an on position.

[0068] 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.).

[0069] Circuit breaker 1 can also be used as a switch.

[0070] Without limiting its generality, the tripping mechanism according to the invention can be used to implement 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.

[0071] 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.

[0072] 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.

[0073] Other elements such as the ratchet lever K can be bent or stamped from steel.

[0074] Contact elements, such as the contact bridge KB and the contacts K1, K2, can also be made of steel, or, due to their lower resistance, of copper, silver, or an alloy containing copper and / or silver (e.g., stamped and bent). Likewise, other elements—such as spring elements as preload elements—can be provided by similar elements. 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 generally has a width of more than 6 mm.

[0075] List of designations

[0076] 1 circuit breaker

[0077] Bl, B2 axis

[0078] T Release lever (multi-operation, rotatable) S Rotatable control element

[0079] 51 first switching position

[0080] 52 second switching position

[0081] K Jack

[0082] H rotatable ratchet lever L bearing

[0083] Z forced railway

[0084] ST translationally movable plunger

[0085] ZI first state (open position)

[0086] Z2 second state (closed position) Z3 third state (open position after release)

[0087] D3 spring element

[0088] KB contact bridge

[0089] Kl, K2 Contact

[0090] AZ optical display

Claims

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 released by at least one actuator, • an operating element (S) which can be rotated about an axis (Bl) in a predefined angular range, wherein a first switching position (Sl) 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 (ZI) the pawl (K) can be supported on the release lever (T) in the unactuated state, 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 in that the predefined angular range is 80° and more.

3. Release mechanism according to one of the preceding claims, characterized in that the release mechanism is designed for a nominal current of up to 20 A.

4. Release mechanism according to one of the preceding claims, characterized in that the release mechanism has a width of less than 10 mm.

5. Release mechanism according to one of the preceding claims, characterized in that the release mechanism has a width of more than 5 mm.

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