A circuit breaker trip mechanism

Abstract

The invention relates to a circuit breaker release mechanism comprising a catch which is attached to an operating element by means of a rotatably mounted catch lever, which is pivotably mounted relative to the operating element and is guided along a guide slot path when the rotatable operating element is moved from a first switching position to a second switching position, in a first state, when the release lever is in an unbraked state, the catch is supported on the release lever and the plunger is in a first position, thereby providing the first switching position, in a second state, when the rotatable operating element is braked to the second switching position, the plunger is moved to a second position, thereby the spring element is tensioned and the second switching position is provided, in a third state, when the release lever is braked, the catch is moved from the second position back to the first position under the action of the plunger.

Description

Technical Field

[0001] This invention relates to a circuit breaker tripping mechanism. Background Technology

[0002] Overcurrent circuit breakers are used to protect electrical equipment. A circuit breaker is a mechanical switching device capable of making, carrying, and breaking current under normal operating conditions of a circuit. Circuit breakers are also designed to make, carry, and break current for at least a specific duration under specific abnormal conditions such as short circuits.

[0003] The circuit breaker has two specific positions: open and closed. In the open position, an air gap is provided between the disconnecting contacts of the main current path to disconnect the circuit; in the closed position, a conductive connection is provided to allow current to flow.

[0004] Typically, circuit breakers also include an operating element, which is part of a braking system and can be subjected to external braking force, enabling the circuit breaker to be manually turned on and off.

[0005] Such circuit breakers have been developed and marketed by the applicant and its competitors for many years.

[0006] For example, German patent DE 10 2019 209 747 B3 is known in the prior art. Furthermore, an overcurrent circuit breaker is known from German patent DE 3211 246 C1.

[0007] In each case, a simple mechanical design is disclosed; however, it is limited to a single tripping function. Furthermore, in these designs, it is possible for the user to be unaware of contact welding. Moreover, once such welding occurs, it cannot be easily separated.

[0008] Fusion welding can cause problems with the protective function, rendering it ineffective. Furthermore, in known products, the lack of indication for welded contacts can create a false sense of security for users. It should also be noted that such fusion welding in known products renders the circuit breaker unusable. Consequently, end users will incur significant costs associated with the installation, removal, and replacement of the circuit breaker, as well as potential system downtime. Summary of the Invention

[0009] The object of the present invention is to provide a circuit breaker tripping mechanism that can be used effectively with a variety of tripping elements of different costs, and / or can reliably indicate welded contacts and / or allow welded contacts to separate again.

[0010] This objective is achieved by the arrangement according to claim 1. Further advantageous embodiments are the subject of the dependent claims, drawings, and description. Attached Figure Description

[0011] The invention will now be described in more detail with reference to the accompanying drawings and exemplary embodiments. The drawings are schematic illustrations and are not drawn to scale. The drawings do not limit the invention in any way.

[0012] The attached diagram shows:

[0013] Figure 1a and 1b A view of a circuit breaker with a tripping mechanism in the open state according to an embodiment of the present invention;

[0014] Figure 2a and 2b A view of a circuit breaker with a tripping mechanism in the on state according to an embodiment of the present invention;

[0015] Figure 3 A perspective view of the tripping mechanism according to an embodiment of the present invention; and

[0016] Figure 4-7 A schematic diagram of the tripping mechanism according to an embodiment of the present invention in various states.

[0017] List of reference numerals in the attached diagram:

[0018] 1. Circuit breaker;

[0019] B1, B2 First and Second Rotary Shafts;

[0020] T-type release lever (repeatable operation, rotatable);

[0021] S-rotatable operating element;

[0022] S1 First switch position;

[0023] S2 second switch position;

[0024] K-lock;

[0025] H is a pivotally mounted locking lever;

[0026] L-shaped support section;

[0027] Z-guide groove;

[0028] ST linearly displaceable plunger;

[0029] Z1 First State (Open Position);

[0030] Z2 Second State (Closed Position);

[0031] Z3 Third State (Opening position after free tripping operation);

[0032] Z4 fourth state (middle position, welded contact);

[0033] D3 spring element;

[0034] KU hinge;

[0035] KB touch bridge;

[0036] Contacts K1 and K2;

[0037] AZ optical indicator. Detailed Implementation

[0038] The invention will now be described in more detail with reference to the accompanying drawings. It should be noted that different aspects are described, each of which can be used alone or in combination. That is, any aspect can be used with different embodiments of the invention unless explicitly stated as a simple alternative.

[0039] Furthermore, for simplicity, reference will generally be made to only a single entity below. However, unless explicitly stated otherwise, the invention may also include multiple corresponding entities. In this regard, the terms “a,” “an,” and “an” should be understood only to indicate that at least one such entity is used in a simple embodiment.

[0040] Numerical values ​​should not be interpreted as exact values, but rather include tolerances of ±1% to ±10%.

[0041] References to standards, specifications, etc., in this application are intended to refer at least to those that were in effect as of the filing date. If a standard or specification is updated or replaced by a subsequent alternative version, the present invention also applies to such updated or subsequent alternative versions of the standard or specification.

[0042] Unless otherwise specified, the circuit breaker conforms in particular to DIN EN IEC 60934 VDE 0642:2020-11.

[0043] The tripping mechanism of the circuit breaker 1 according to the present invention will be described below, see below. Figure 1a , 1b And 2a, 2b.

[0044] from Figures 3 to 7 As can be seen, the tripping mechanism according to the present invention includes a tripping lever T mounted on the second rotating shaft B2, wherein the tripping lever T can be triggered by at least one brake.

[0045] Furthermore, the tripping mechanism also includes an operating element S that can rotate around the first pivot B1 within a predetermined angle range, defining a first switch position S1 and a second switch position S2 for the operating element. The switch position can be... Figure 1a , 1bThis is seen in sections 2a and 2b. It should be noted that the corresponding circuit breaker can also indicate the switching status using additional optical elements besides the rotatable operating element S. Therefore, as... Figure 1b and 2b As shown, an additional optical indicator AZ may be provided, which provides, for example, further optical and / or graphic indication. For example, color changes (red / green) and / or display changes (0 / 1) may be provided.

[0046] The tripping mechanism according to the invention further includes a latch K, wherein the latch K is attached to the operating element S by a rotatably mounted latch rod H, the latch rod H being rotatably mounted relative to the operating element S, wherein when the rotatable operating element S moves from the first switch position S1 to the second switch position S2, the latch rod H is guided along the guide groove Z, thereby indirectly guiding the latch K rotatably mounted on the latch rod.

[0047] Furthermore, the tripping mechanism of the present invention also includes a linearly displaceable plunger ST, on which switch contacts are arranged, and provides at least two different positions for the movement of the switch contacts.

[0048] In the attached diagram, the switch contact (i.e., the circuit to be switched) is shown as a contact bridge KB and two contacts K1 and K2, such that in the ON state ( Figure 5 In this embodiment, the contact bridge KB provides a conductive connection from contact K1 to contact K2. This embodiment is exemplary; other embodiments are not excluded. For example, instead of the contact bridge, movable contacts may be provided. It will also be apparent to those skilled in the art that not only can the contact bridge KB move relative to contacts K1 and K2, but contacts K1 and K2 can also move relative to the contact bridge KB.

[0049] In corresponding Figure 4 In the first state Z1, when the trip lever T is in the unbraked state, the latch K is supported on the trip lever T. In this case, the plunger ST is in the first position, thereby providing a first switching position, in which the electrical contacts KB, K1, and K2 are open.

[0050] In corresponding Figure 5 In the second state Z2, the rotatable operating element S is moved to the second switch position S2, thereby moving the plunger ST from the first position to the second position, whereby the spring element D3 (such as...) Figure 3 The arrangement shown (within the plunger ST) is tensioned to provide the second position, where an electrical connection is established between KB, K1, and K2.

[0051] In corresponding Figure 6In the third state Z3, pulling the release lever T causes the latch K to be unable to support itself on the release lever T, and under the tension of the spring element D3 and / or the force of the plunger's return spring (not shown), the plunger ST moves from the second position back to the first position.

[0052] The plunger ST is connected to the latch K via a hinge KU.

[0053] In other words, in this invention, the rotational braking of the trip lever T is converted into the translational motion of the plunger ST, and thus into the translational motion of the contact bridge KB relative to the contacts K1 and K2.

[0054] In this context, the tripping element can act on the tripping lever T at different points of action, WP1 and WP2. For example, a magnetic tripping unit can act at point WP1, while a thermal switch element, for example, can act at point WP2. Of course, other points of action can also be provided; in this respect, such designations are merely exemplary. Once a (counterclockwise) rotation occurs at any point of action, tripping occurs, causing the plunger ST to open the contacts under the force of the spring element D3 and / or the return spring of the plunger (not shown).

[0055] This improves safety because it ensures that the contacts are open when the rotatable operating element S is rotated to the indicated rest position (position 0, FIG. 1). Furthermore, it extends service life because the welded contacts can be freely broken off by braking, allowing the circuit breaker 1 to continue operating. Therefore, the present invention provides this simple and cost-effective structure.

[0056] This invention also enables the circuit breaker 1 to have a free-tripping mechanism. In the case of free-tripping operation, when the circuit breaker is closed and the tripping operation is initiated by the brake, even if an attempt is made to immediately reclose, the movable contact element will still move to the tripping position and remain in that position. The circuit breaker 1 has a closed position and a tripping position. The rotatable operating element S moves between the rest position O and the operating position I.

[0057] In the open position, no current flows through the switchable (movable) contacts formed by the contact bridge KB and contacts K1 and K2. At this time, circuit breaker 1 cannot carry current.

[0058] In the closed position, current can flow through the movable contact, and circuit breaker 1 can carry current.

[0059] If tripping occurs, circuit breaker 1 (i.e., the contacts) changes from the closed position to the open position, and the current is interrupted. The brake can be triggered under limited overcurrent conditions and acts mechanically on the trip lever.

[0060] Preferably, the casing of circuit breaker 1 consists of two half-casings (see...). Figure 1a and2a (Side view). The half-shell is preferably made of plastic, which also provides insulation in the sense of preventing contact.

[0061] According to the invention, the tripping mechanism is arranged together with other components that enable tripping within two half-shells.

[0062] Braking is achieved by a rotatable operating element S. The rotatable operating element S is rotatably mounted in the housing about a first pivot B1. The rotatable operating element S can be biased by a spring (not shown), particularly a torsion arm spring. This (torsion arm) spring can be supported on the housing.

[0063] The preload of a spring (not shown), particularly a torsion spring, causes the rotatable operating element S to tend to move in the preload direction (counterclockwise). The movement of the rotatable operating element S can be limited by a stop on the housing.

[0064] For example, a U-shaped locking lever H is eccentrically arranged on a rotatable operating element S. The first arm of the locking lever H is rotatably mounted in the rotatable operating element S about an eccentric axis. For example, U-shaped elements can be manufactured particularly easily and allow for rapid assembly because these elements can be laterally inserted into pre-made openings (i.e., Figures 4 to 7 (The plane perpendicular to the attached drawing) and provides both connection and support in the assembled state.

[0065] In this configuration, for example, the first arm of the locking lever H is inserted into the eccentric hole of the rotatable operating element S, while the second arm of the locking lever H is inserted into the latch K. Therefore, the second arm of the locking lever H is rotatably mounted in the support L, i.e., in the opening of the latch.

[0066] It should be noted that the openings used for the arm can be configured as through holes and blind holes.

[0067] The second arm of the locking lever can engage in the guide groove Z, which is integrally formed with the housing, thereby providing the guide groove Z path to guide the arm and all directly connected components.

[0068] Preferably, the guide groove Z is configured such that the distance from the locking point (i.e., the point where the latch K is supported on the release lever T) remains constant.

[0069] When braked and in the closed position, the latch K is supported on the release lever T at the locking point. The movement of the latch K and the movement of the rotatable operating element S can be limited by the limit block in the housing.

[0070] The trip lever T is pivotally mounted in the housing, particularly around the second pivot B2. The trip lever T is preferably biased by a spring (not shown), particularly a torsion arm spring. The torsion arm spring can in turn be supported on the housing 9. The preload of the torsion arm spring causes the trip lever to tend to move in the preload direction (clockwise in this case).

[0071] The movement of the trip lever T can be limited by a limit stop on the housing.

[0072] At the end of the latch K that is away from the release lever T, there is a hinge KU. This hinge can also be configured to be U-shaped and connect the latch K to the plunger ST.

[0073] In this configuration, for example, the first arm of the coupling member KU is inserted into the bore of the movable plunger ST, while the second arm of the hinge member KU is inserted into the latch K, which is offset relative to the support L. Therefore, both the first and second arms of the hinge member KU can be pivotally mounted.

[0074] It should be noted that the openings used for the arm can be configured as through holes and blind holes.

[0075] The plunger ST is preferably biased by a spring element (preferably a cost-effective compression spring), and its movement is directed as a substantially translational motion.

[0076] Preload allows the plunger ST to tend to move in the preload direction (i.e., toward the contact disconnect position). The movement of the plunger ST can be limited by a stop block in the housing 9.

[0077] The plunger ST establishes or disconnects electrical contact. As already explained, this electrical contact can be configured in different ways.

[0078] The accompanying drawings illustrate an exemplary configuration. In this configuration, the contact bridge KB is movably mounted within the plunger ST. The contact bridge KB is biased by the spring element D3. Figure 3 Spring element D3 is supported in plunger ST. The preload of spring element D3 causes the contact bridge to tend to move in the preload direction, i.e., toward the closed contact. In the closed position, the contact bridge KB is attached to contacts K1 and K2, thereby generating a contact force from spring element D3, which causes the contact bridge KB and contacts K1 and K2 to press against each other.

[0079] Therefore, in the closed position, a conductive connection is established between contact K1 and contact K2 via contact bridge KB. Conversely, in the open position, the conductive connection between contact K1 and contact K2 is broken.

[0080] Contacts K1 and K2 are part of the current path within circuit breaker 1. It should be noted that the complete current path, including conductors, terminals, brakes, and other components, is not shown.

[0081] The circuit breaker's brake is not shown. In the event of tripping, the brake acts mechanically on the trip lever (arrows indicate the points of action WP1 / WP2).

[0082] The trip lever T rotates counterclockwise (opposite to the preload direction) under the action of the brake. The brake can be a magnetic trip unit, bimetallic strip, shape memory alloy, hydraulic brake, or other types of brake, and is not limited to the types listed.

[0083] Figure 4 The image shows the rest position of circuit breaker 1. In this state, the latch K is not supported on the trip lever T. When circuit breaker 1 is closed, i.e., from the open position (… Figure 4 Transition to the closing position ( Figure 5 During this period, the rotatable operating element S rotates in the opposite direction to the preload direction. The locking lever H is guided along the guide path Z in the guide groove and transmits the braking force from the rotatable operating element S to the locking lever K. The locking lever K then abuts against the release lever T at the locking point. Figure 5 ).

[0084] Upon further braking, latch K rotates around the locking point. As a result, latch K, with hinge KU as the transmission element, presses against plunger ST, and plunger ST moves toward the closed electrical contact. Simultaneously, as plunger ST moves, plunger return spring (not shown) is tensioned.

[0085] During the closing process, the contact bridge KB moves relative to the contacts K1 and K2, reducing the distance between them and eventually establishing mechanical contact and thus establishing conductive contact.

[0086] It can be configured so that the plunger ST passes through the lowest point during closing, and then even slightly moves back until it reaches the stable final position (closing position). Figure 6 This is not harmful, because, for example, the spring element (in this case, spring element D3) maintains the required contact between the contact bridge KB and the contacts K1 and K2 within a portion of the travel range.

[0087] Circuit breaker 1 can return to the open position from the closed position in two ways: by tripping (by braking the rotatable operating element S) or by tripping.

[0088] When the circuit breaker is opened (by braking the rotatable operating element S), the closing process described above is reversed. Therefore, the circuit breaker 1 moves from the closed position to the open position.

[0089] If tripping occurs, the trip lever T rotates via the brake in the opposite direction to the preload direction. Figure 6As a result, the lock at the locking point is released. Therefore, the latch K can rotate about the axis of the support L, thereby releasing the movement of the plunger ST in the opening direction. In this case, the plunger ST moves upward, the electrical contacts open, and the switch is in the open state. The current is thus interrupted. The force required for the movement of the plunger ST, and therefore the force required to open the contacts, is provided by the plunger return spring, which is tensioned during closing and tends to move the plunger in the opening direction. Preferably, the opening of the contacts should occur as quickly as possible. This can be achieved by appropriately determining the dimensions of the plunger return spring.

[0090] The opening of the contact is independent of whether the rotatable operating element S is in operating position I or stationary position O, and the position between operating position I and operating position O. Figure 6 As shown.

[0091] After tripping via a free-trip operation, once the rotatable operating element S is free to move, it rotates in the preload direction driven by a (torsion arm) spring (not shown). During this process, the rotatable operating element S is carried along the latch K via the latch rod H guided in the guide groove Z, until it reaches the open position in the rest position again. Figure 4 ).

[0092] If an overcurrent occurs, an electric arc may form when the electrical contacts (in this case, the contact bridge KB and contacts K1 and K2) close or open. This can cause melting in the contact area. It is also possible that the movable and fixed contacts may fuse together (welding). In this case, circuit breaker 1 is typically no longer operable.

[0093] In known solutions, the contacts may weld together while the operating element remains in the resting position O. In this situation, the user cannot perceive that the contacts are still closed (welded) and therefore conductive. This poses a safety risk.

[0094] With the aid of the hinge KU, in the case of welding the movable contact, the rotatable operating element S is held in an intermediate position between the rest position O and the operating position I (see Figure 7 This provides the user with a clear visual indication of a malfunction. Alternatively, another optical indicator (AZ) can also provide corresponding indications, for example, by displaying different colors or symbols, or, during transitional states, by displaying red and green areas, and / or areas where 0 is partially visible and areas where 1 is partially visible.

[0095] When tripping / disconnecting with welded contacts, the plunger ST moves as far as possible in the return direction until it is stopped from further movement by the welded contact bridge.

[0096] The rotatable operating element S can continue to rotate further in the preload direction under the drive of the preload force. This rotation can be limited, for example, by the latch K striking the limiting stop (not shown) on the left side of the housing 9.

[0097] As a result, the rotatable operating element S cannot be moved to a stationary position because it is directly connected to the welded (and therefore immovable) electrical contacts via the locking lever H, locking K, coupling element KU, and plunger ST. Therefore, the welded contacts can be identified from the position of the rotatable operating element S. This improves safety.

[0098] Conversely, if the rotatable operating element S is in the stationary position O, the user can be certain that the contacts have opened and the current has been interrupted. This improves safety.

[0099] Furthermore, when the rotatable braking element S is opened, a force can be applied to the normally movable but currently welded contacts, allowing the weld to be manually broken. The manually applied force can be greater than the force of the plunger return spring ST. By separating the welded contacts, service life can be extended.

[0100] In one embodiment of the invention, the predetermined angle range for braking the rotatable operating element S is 80° or greater, particularly about 90°, or up to and including 100°. Without limitation, this angle range can also be up to 180°. Even larger angle ranges are possible.

[0101] The rotatable operating element S has two positions: a stationary position O ( Figure 1a , 1b and 3) and operation position I ( Figure 6 The operating element can rotate between these two positions. These positions are clearly distinguishable. This is achieved through a large rotational angle during braking. The switching mechanism allows a large rotational angle of approximately 100° (see comparison). Figure 1a and 2a As a result, the two states can be clearly distinguished visually.

[0102] In addition, clearly identifiable markings can be applied to the rotatable operating element S. Figure 1b and 2b The top side of circuit breaker 1 is shown. Figure 1b In the diagram, the rotatable operating element S is shown in the OFF position (corresponding to...). Figure 1a and 3 ), and in Figure 2b In the diagram, the rotatable operating element S is shown in the ON position (corresponding to...). Figure 6 ).

[0103] The switching mechanism is not limited to using the contact bridge KB as the movable contact. Other forms of translational movable contacts can also be used (e.g., single contact, double contact (parallel current path) etc.).

[0104] Circuit breaker 1 can also be used as a switch.

[0105] Without limitations, switches, particularly circuit breakers for AC and DC voltages, can be implemented using the tripping mechanism according to the invention. In this context, rated currents up to about 20 A or greater can be switched independently of the switching mechanism. Similarly, AC voltages far exceeding 280 V and DC voltages exceeding 50 V can be switched without difficulty.

[0106] Furthermore, without limitation, the materials used for the components of the present invention may be selected as appropriate. It is preferable to use as many identical components as possible, and to use components made of the same material to the greatest extent possible.

[0107] For example, the rotatable operating element S, the latch K, the release lever T, the housing (and therefore also the limit stop and the guide groove of the guide path Z), the plunger ST, etc., can all be made of plastic, especially injection-moldable plastic.

[0108] Other components, such as the locking lever H or the hinge KU, can be formed from steel, for example, by bending or stamping. The locking lever H and the hinge KU can also be provided from the same mechanical components, thereby reducing the number of parts required for the tripping mechanism, which saves on production and storage costs.

[0109] Contact elements, such as contact bridge KB and contacts K1, K2, can also be made of steel, or, due to their lower resistance, of copper, silver, or alloys containing copper and / or silver (e.g., formed by stamping and bending).

[0110] Similarly, other components (such as spring elements used as biasing elements) can also be supplied from the same parts.

[0111] This invention provides a space-saving tripping mechanism with a width of less than 10 mm. Typically, the width of the tripping mechanism is greater than 6 mm.

Claims

1. A tripping mechanism for a circuit breaker (1), characterized in that, The tripping mechanism includes: • A trip lever (T), rotatably mounted on a second shaft (B2), said trip lever (T) being actuated by at least one brake. • A rotatable operating element (S) that rotates about a first axis (B1) within a predetermined angle range, thereby defining a first switch position (S1) and a second switch position (S2). • A latch (K) • The latch (K) is connected to the operating element (S) via a rotatably mounted latch rod (H). The latch rod (H) is rotatable relative to the operating element (S). When the rotatable operating element (S) moves from the first switch position (S1) to the second switch position (S2), the latch rod (H) is guided along the guide groove (Z), thereby guiding the latch (K) rotatably mounted on the latch rod (H). • A linearly displaceable plunger (ST) on which a switch contact is arranged, and provides at least two distinct positions for movement of the switch contact. • In the first state (Z1), when the trip lever (T) is in the unbraked state, the latch (K) is supported on the trip lever (T), and the plunger (ST) is in the first position, thereby providing a first switching position. • In the second state (Z2), when the operating element (S) is braked to the second switch position (S2), the plunger (ST) moves from the first position to the second position, thereby tensioning the spring element (D3) to provide the second position. • In the third state (Z3), pulling the release lever (T) causes the latch (K) to no longer be supported on the release lever (T). Under the force of the spring element (D3) and / or the return spring, the plunger (ST) moves from the second position back to the first position. • The plunger (ST) is hinged to the latch (K) via a hinge (KU).

2. The tripping mechanism according to claim 1, characterized in that, The predetermined angle range is 80° or greater.

3. The tripping mechanism according to any one of the preceding claims, characterized in that, The tripping mechanism is designed for rated currents up to 20A.

4. The tripping mechanism according to any one of the preceding claims, characterized in that, The width of the tripping mechanism is less than 10 mm.

5. The tripping mechanism according to any one of the preceding claims, characterized in that, The width of the tripping mechanism is greater than 6 mm.

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