Circuit breaker lever

Abstract

A trip lever for a circuit breaker includes a hub, a cam arm extending away from the hub in a first radial direction, and a release arm extending away from the hub in a second radial direction and extending longitudinally in an axial direction of the hub. The cam arm may include a hardened portion at a distal end, and the release arm may include an open grid structure.

Description

Background Art

[0001] Circuit breakers are used in power supply networks as switches and safety elements. They ensure safe shutdown in the event of a short circuit and protect consumers and systems from overloads. For example, they protect cables from overheating caused by excessive current flow. They are designed to automatically disconnect the monitored circuit in the event of a short circuit or overload, thereby isolating it from the line network.

[0002] Circuit breakers are required to interrupt short-circuit currents within a given time period. Generally, the disconnection time should be less than twice the current frequency. In a 50 Hz network, a target disconnection time of 40 milliseconds (ms) is required, and therefore, a target disconnection time of 40 milliseconds (ms) must be achieved. In a 60 Hz network, a target disconnection time of 33 milliseconds is required. Therefore, minimizing the circuit breaker disconnection time is desirable. Summary of the Invention

[0003] In one aspect, a trip lever for a circuit breaker includes a hub, a cam arm extending away from the hub in a first radial direction, and a release arm extending away from the hub in a second radial direction and extending longitudinally in an axial direction of the hub.

[0004] The foregoing has summarized the technical features of the present disclosure so that those skilled in the art may better understand the detailed description that follows. The following describes additional features and advantages of the present disclosure that form the subject matter of the claims. Those skilled in the art will appreciate that they may use the disclosed concepts and specific embodiments as a basis for modifying or designing other structures for achieving the same purposes of the present disclosure. Those skilled in the art will also appreciate that such equivalent structures do not depart from the spirit and scope of the present disclosure in its broadest form.

[0005] Furthermore, before proceeding with the following detailed description, it should be understood that various definitions are provided for certain words and phrases in this patent document, which those skilled in the art will understand to apply in many, if not most, instances to prior and future uses of such defined words and phrases. While some terms may include a wide variety of embodiments, the appended claims may limit these terms to specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] To easily identify the discussion of a particular element or act, the most significant digit or digits in a reference number refer to the figure in which the element is first introduced.

[0007] Figure 1 An aspect of the subject matter according to one embodiment is shown.

[0008] Figure 2 An aspect of the subject matter according to one embodiment is shown. DETAILED DESCRIPTION

[0009] Before describing in detail any embodiments of the present invention, it should be understood that the present invention is not limited in its application to the details of construction or arrangement of components described in this specification or illustrated in the accompanying drawings. The present invention is capable of other embodiments or of being practiced or implemented in various ways. It should also be understood that the expressions and terminology used herein are for descriptive purposes only and should not be construed as limiting.

[0010] Various techniques related to the systems and methods will now be described with reference to the accompanying drawings, in which like reference numerals represent like elements throughout the drawings. The drawings discussed below and the various embodiments used to describe the principles of the present disclosure in this patent document are intended to be illustrative only and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any suitably arranged device. It should be understood that the functions described as being implemented by a particular system element can be performed by multiple elements. Similarly, for example, an element can be configured to perform the functions described as being implemented by multiple elements. A large number of innovative teachings of the present application will be described with reference to exemplary, non-limiting embodiments.

[0011] It should also be understood that, unless explicitly limited in some examples, the words or phrases used herein should be interpreted in a broad manner. For example, the terms "include," "have," and "include," as well as derivatives thereof, are intended to include without limitation. Unless the context clearly indicates otherwise, the singular forms "one," "an," and "the" are intended to include the plural forms as well. In addition, the term "and / or" used herein refers to and includes any one of one or more of the listed associated items and all possible combinations. Unless the context clearly indicates otherwise, the term "or" is inclusive, meaning "and / or." The phrases "associated with..." and "associated with it," as well as derivatives thereof, may mean to include, be included within, be interconnected with, include, be included within, be connected to, or be connected with, be coupled to, or be coupled with, be communicable with, collaborate with, interlace, be in parallel, be close to, be bound to, or be bound with, have, have the property of, or similar meanings of, Furthermore, although multiple embodiments or configurations are described herein, any features, methods, steps, components, etc. described with respect to one embodiment are equally applicable to other embodiments unless explicitly stated to the contrary.

[0012] In addition, although the terms "first," "second," and "third" are used herein to refer to various elements, information, functions, or actions, these elements, information, functions, or actions should not be limited by these terms. On the contrary, these numerical adjectives are used to distinguish different elements, information, functions, or actions. For example, a first element, information, function, or action can be referred to as a second element, information, function, or action, and similarly, a second element, information, function, or action can be referred to as a first element, information, function, or action without departing from the scope of this disclosure.

[0013] Additionally, unless the context clearly indicates otherwise, the term "adjacent to..." means that an element is relatively close to another element, but not in contact with the other element, or that the element is in contact with another portion. Furthermore, unless otherwise clearly indicated, the phrase "based on" is intended to mean "based at least in part on." The terms "approximately" or "substantially" or similar terms are intended to encompass variations in values ​​within the normal industry manufacturing tolerance range for that dimension. If there is no industry standard, a variation of 20% will fall within the meaning of these terms unless otherwise indicated.

[0014] Figure 1 FIG. 1 shows a diagrammatic representation of a circuit breaker 102 according to an embodiment of the present invention, the circuit breaker 102 having a trip mechanism 104. The tripping or opening movement of the circuit breaker 102 is triggered at Figure 1 The trip mechanism 104 is actuated by actuator 106. Actuator 106 may include an electromagnetic trigger, such as a solenoid, for moving actuator rod 108 outward when power is applied to actuator 106. Trip mechanism 104 may include supporting elements, such as a trip lever 110, a shift lever 112, a trip spring 114, and a return spring 116. Actuator 106 moves trip lever 110. The force of the trip spring is supported by trip lever 110. Rotating trip lever 110 releases the force of the tensioned trip spring 114, and the tripping action is achieved by separating contacts 118. After switching, actuator 106 and trip lever 110 can be moved back to their initial positions to reliably maintain the force of trip spring 114 after the circuit breaker 102 is next closed or reset. In order to reset the moving parts of the actuator 106 and the trip lever 110 , a return spring 116 can be used, which can be preloaded during the release process by the force of the trip spring 114 .

[0015] According to the present invention, at least one of the moving parts of circuit breaker 102 is manufactured using an additive manufacturing process. In this case, it is particularly advantageous if the moving parts produced using the additive manufacturing process are as light as possible and / or have a low moment of inertia, thereby reducing the force of return spring 116. This ensures that the moving parts of actuator 106 and trip lever 110 can be strongly accelerated in the shortest possible time and that return spring 116 is preloaded at the front. Lightweight components advantageously reduce the power consumption of electromagnetic actuator 106. For example, the reduced power requirement of actuator 106, while simultaneously requiring high acceleration of the moving parts and preloading of return spring 116, is achieved by using moving parts that are as light as possible or have a low moment of inertia, such as by using additively manufactured components, which allows the tripping stroke to be kept short.

[0016] In one embodiment of the present invention, for example, the force of trip spring 114 can act directly on switch lever 112 and be held and triggered by trip lever 110, but reduced several times by lever gear 120. The full force of trip spring 114 is then held by trip lever 110 within lever gear 120. Trip lever 110 must be accelerated by actuator 106, but when the force of trip spring 114 acting on trip lever 110 is reduced by lever gear 120, the force of return spring 116 can be lower. In this case, actuator 106 can accelerate faster or consume less power.

[0017] For example, by additively manufacturing the movable parts of lever gear 120, it is possible to reduce the force required by trip spring 114 to accelerate the movable parts of lever gear 120. Consequently, the force acting on trip lever 110 can be reduced, and the force required by return spring 116 is advantageously reduced. The functions of trip lever 110 and return spring 116 can still be performed safely, and actuator 106 can significantly accelerate them with less power. Actuator 106 must overcome the force of return spring 116 to push trip lever 110. Therefore, it is advantageous to design the movable parts of trip lever 110 and actuator 106 to be particularly lightweight or to have the lowest possible moment of inertia. This is achieved by using components produced using additive manufacturing processes.

[0018] Using additive manufacturing processes, such as three-dimensional or 3D printing, offers several ways to optimize the moving parts in circuit breaker 102 and lever gear 120. As a result, circuit breaker 102 achieves the shortest possible switching times while using the lowest possible tripping power. These advantages are sometimes impossible to achieve using previous manufacturing processes. Using additive manufacturing processes, such as powder-bed 3D printing using selective laser melting, components can be designed in a way that exploits the material's strength properties, and exploits them at every point. Considerations such as mold release properties of castings and forgings, maximum formability of forgings, and ease of use of machining tools no longer need to be considered.

[0019] In embodiments of the present invention, components produced using additive manufacturing processes can have a structure. This structure can, for example, reduce the weight of the component without compromising its stability. Examples of such structures include honeycomb structures or lattice structures. However, other structural forms are also possible, whereby the structure is already formed during the component production process.

[0020] In an embodiment of the present invention, a component manufactured using an additive manufacturing process comprises at least segments of different materials. The use of several materials within a component is particularly advantageous, thereby optimally adapting individual regions of the component to the mechanical requirements. Plastics, synthetic resins, ceramics, carbon materials, graphite materials, and / or metals can be used as materials, in particular. Depending on the materials used, different additive manufacturing processes may be advantageous. The most important technologies are laser beam melting and electron beam melting for metals, laser sintering for polymers, ceramics, and metals, stereolithography and digital light processing for liquid synthetic resins, and polyjet modeling and fused layer modeling for plastics and some synthetic resins.

[0021] Using different materials and additive manufacturing processes, it is possible to create areas of a component with lower strength requirements that have a significant impact on the moment of inertia. For example, areas at a large distance from the axis of rotation can be created from low-density materials. Furthermore, areas with high strength requirements can be specifically and locally limited. For example, these areas can be made of high-strength metal materials. For example, these high-strength metal materials have high hardness, so they can also be used for mechanical contact points in circuit breakers. At these mechanical contact points, such as where rolling elements roll off, a layer of hard or curable material can be applied and subsequently hardened if necessary. It is also possible to mechanically reprocess the material to achieve high shape accuracy.

[0022] When using different materials, it is particularly advantageous if the regions of different materials are connected to one another in a form-fitting manner. In embodiments of the present invention, this can be achieved, for example, by toothing, by a wedge-shaped mold, or by a taper. Depending on the manufacturing technology used, it is also conceivable that the regions of different materials are fused together during production. Both methods can be used to create structures that cannot be produced using traditional manufacturing processes.

[0023] Figure 2 The circuit breaker trip mechanism 104 is shown and includes a trip lever 110 including a hub 202, a cam arm 122 extending radially away from the hub 202, and a release arm 204 extending radially away from the hub 202. The longitudinal axis 216 of the release arm 204 is offset from the hub rotation axis 206. In one aspect, the release arm 204 can include an open grid structure 208. Figure 1 As shown, actuator 106 can selectively apply force to release arm 204 to rotate hub 202 about hub rotation axis 206. Lever gear 120 can be selectively restrained by cam arm 122 and can be released from cam arm 122 when force applied by actuator 106 to release arm 204 causes hub 202 to rotate.

[0024] In one aspect, the cam arm 122 includes a hardened portion 212 at a distal end 214 that is configured to resist contact stresses applied thereto, such as Hertzian forces from the cam portion 124 of the shift lever 112. The hardened portion 212 may include an end hardness greater than the hardness of the cam arm 122. The cam arm 122 may also include an intermediate portion below the hardened portion 212, having an intermediate hardness between the end hardness and the cam hardness. In another aspect, the hardened portion 212 of the cam arm 122 may include a cold spray coating. In one embodiment, the cold spray coating may include tungsten carbide. In another embodiment, the cam arm 122 may include an aluminum alloy, wherein the hardened portion 212 includes an anodized coating.

[0025] In another aspect, the open lattice structure 208 can be configured to define an opening, such as 210, in a portion of the release arm 204 distal from the hub rotational axis 206 to maintain the lever's center of gravity near the hub rotational axis 206. The open lattice structure 208 can also include a plurality of beams 218 interconnected at vertices, such as 202a. In another aspect, at least one of the beams 218 can extend diagonally away from the hub 202. Such beams 218 can include an end vertex 220c at each end. In yet another aspect, at least one of the vertices can include a surface 226 configured to receive an end of the actuator rod 108 thereon, thereby converting a force applied by the actuator rod 108 at the surface 226 into a rotational force applied to the hub 202 about its hub rotational axis 206, thereby rotating the cam arm 122 away from the cam portion 124 of the shift lever, thereby triggering the opening contact 118.

[0026] In another aspect, the open lattice structure 208 can include a first lattice portion 222 having a pair of intersecting beams 218. In yet another aspect, the open lattice structure 208 can include a second lattice portion 224 having a triangular arrangement of beams 218 extending in a longitudinal direction away from the end of the hub 202. In yet another aspect, the beams 218 can include one or more cross-sectional configurations for reducing the weight of one or more of the beams 218 while maintaining a desired stiffness of the release arm 204. For example, the beams 218 can include at least one of an "I"-shaped cross-section, a double "T"-shaped cross-section, a "C"-shaped cross-section, or an hourglass-shaped cross-section.

[0027] To reduce the weight of the trip lever 110, it can include a different material in the lever portion 228 that is primarily subjected to tension stress, such as the force of the actuator 106 along one side of the release arm 204, than in the portion that is primarily subjected to compression forces. Such a different material portion can advantageously be manufactured using an additive manufacturing process.

[0028] Although the exemplary embodiments of the present disclosure have been described in detail, those skilled in the art will understand that they can make various changes, substitutions, alterations, and improvements as disclosed herein without departing from the spirit and scope of the disclosure in its broadest form.

[0029] Nothing in this application should be interpreted as implying that any particular element, step, act, or function is essential to the scope of the claims: the scope of the claimed subject matter is limited only by the allowed claims. Furthermore, these claims are not intended to trigger a "means-plus-function" claim construction unless the phrase "means for..." is followed by a participle.

[0030] Reference Signs List

[0031] 102 circuit breaker

[0032] 104 tripping mechanism

[0033] 106 actuators

[0034] 108 actuator rod

[0035] 110 trip lever

[0036] 112 shift lever

[0037] 114 disconnect spring

[0038] 116 return spring

[0039] 118 contact

[0040] 120 lever gear

[0041] 122 cam arm

[0042] 124 cam part

[0043] 202 wheels

[0044] 204 release arm

[0045] 206 wheel hub rotation axis

[0046] 208 open grid structure

[0047] 210a opening

[0048] 210b opening

[0049] 210c opening

[0050] 212 hardened part

[0051] 214 remote

[0052] 216 longitudinal axis

[0053] 218 beam

[0054] 220a Vertex

[0055] 220b vertex

[0056] 220c Vertex

[0057] 222 first grid part

[0058] 224 Second grid section

[0059] 226 surface

[0060] 228 Leverage

[0061] 230 first radial direction

[0062] 232 second radial direction

[0063] 234 axial direction

Claims

1. A trip lever for a circuit breaker, comprising: wheel hub; a cam arm extending away from the hub in a first radial direction; as well as A release arm extends away from the hub in a second radial direction and extends longitudinally in an axial direction of the hub.

2. The lever according to claim 1, wherein The cam arm includes a hardened portion at a distal end thereof, the hardened portion having an end hardness value greater than a hardness value of the cam arm, configured to resist contact stress applied thereto. 3 . The lever according to claim 2 , further comprising a middle portion below the hardened portion, the middle portion having a hardness value intermediate between the end hardness value and the cam hardness value.

4. The lever according to claim 2, wherein: The hardened portion includes a cold sprayed coating.

5. The lever according to claim 4, wherein The cold spray coating comprises tungsten carbide.

6. The lever according to claim 2, wherein: The cam arm comprises an aluminum alloy, wherein the hardened portion comprises anodizing.

7. The lever according to claim 1, wherein The release arm comprises a lattice structure including a plurality of beams interconnected at vertices, the lattice structure including openings in portions of the arm remote from the hub's axis of rotation for maintaining the lever's center of gravity close to the hub axis.

8. The lever according to claim 7, wherein: At least two of the vertices are longitudinally aligned relative to the hub axis of rotation.

9. The lever according to claim 7, wherein: At least one of the vertices includes a surface configured to receive an actuator plunger thereon to convert a lateral force applied by the actuator at the surface into a rotational force applied to the hub about a hub rotational axis of the hub.

10. The lever according to claim 7, wherein At least one of the beams includes at least one of an "I" shaped cross-section, a double "T" shaped cross-section, a "C" shaped cross-section, or an hourglass shaped cross-section.

11. The lever according to claim 7, wherein: At least one of the beams extends diagonally away from the hub.

12. The lever according to claim 11, wherein At least one of the beams extending diagonally away from the hub includes an end vertex disposed at a respective end thereof.

13. The lever according to claim 9, wherein The open lattice structure includes a first lattice portion having a pair of intersecting beams and a second lattice portion having a triangular arrangement of beams extending in a longitudinal direction away from an end of the hub.

14. The lever according to claim 1, wherein The longitudinal axis of the release arm is offset from the hub rotation axis.

15. The lever according to claim 1, wherein The lever comprises different materials in the portion of the lever which is subjected to tensional stress.

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