Fuses, protective devices and fusible devices

Abstract

The present invention is entitled "COILED ELEMENT LEAD FOR HIGH RELIABILITY SMD FUSES". A protection device such as a fuse is provided herein, which includes a coiled fusible element. In some embodiments, the fuse includes a body, the body including a central portion extending between a first end and a second end, and a first end cap surrounding the first end and a second end cap surrounding the second end. The fuse may also include a fusible element disposed within the central cavity of the body, wherein the fusible element includes a first coil disposed within the first end cap and a second coil disposed within the second end cap. The fusible element also includes a centerline extending diagonally between the first coil and the second coil.

Description

Background Art Technical Field

[0001] The present disclosure relates generally to fuses. More particularly, the present disclosure relates to fuses including a coiled fusible element.

[0002] Description of Related Art

[0003] Fuses are used as circuit protection devices and form an electrical connection with components in the circuit to be protected. One type of fuse includes a fusible element disposed within a hollow fuse body. Upon the occurrence of a particular fault condition, such as an overcurrent condition, the fusible element melts or otherwise opens to interrupt the circuit path and isolate the protected electrical component or circuit from potential damage. Such fuses can be characterized by the amount of time required to respond to the overcurrent condition. In particular, fuses including different fusible elements respond with different operating times because different fusible elements can accommodate different amounts of current passing through the fusible element. Therefore, by changing the size and type of the fusible element, different operating times can be achieved.

[0004] When an overcurrent condition occurs, an arc may form between the molten portions of the fusible element. If not extinguished, such an arc may further damage the circuit to be protected by allowing unwanted current to flow to circuit components. Therefore, it is desirable to manufacture fuses that can extinguish such arcs as quickly as possible. In addition, as fuses are reduced in size to accommodate smaller and smaller circuits, it is desirable to reduce the cost of manufacturing these fuses. This may include reducing the number of components and / or using less expensive components, as well as reducing the number and / or complexity of associated manufacturing steps.

[0005] Therefore, there is a need to reduce the number of components and / or manufacturing steps to produce a fuse with improved arc extinguishing characteristics.Due to these and other considerations, there is a need for the improvements of the present invention. Summary of the invention

[0006] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be an aid in determining the scope of the claimed subject matter.

[0007] In some methods according to the present disclosure, the fuse includes a body including a central portion extending between a first end and a second end, and a first end cap surrounding the first end and a second end cap surrounding the second end. The fuse may also include a fusible element disposed in the central cavity of the body, the fusible element including a first coil disposed in the first end cap and a second coil disposed in the second end cap. The fusible element may also include a centerline extending diagonally between the first and second coils.

[0008] In some methods according to the present disclosure, the protective device may include a body, and a first end cap surrounding a first end of the body and a second end cap surrounding a second end of the body. In some embodiments, the fusible element may extend between the first end of the body and the second end of the body, wherein the fusible element is disposed in a central cavity of the body. The fusible element may include a first coil disposed in the first end cap and a second coil disposed in the second end cap. The fusible element may also include a centerline extending diagonally between the first and second coils.

[0009] In some methods according to the present disclosure, a fusible device may include a hollow body, and a first end cap surrounding a first end of the hollow body and a second end cap surrounding a second end of the hollow body. The fusible device may also include a fusible element extending between the first end of the body and the second end of the body, wherein the fusible element is disposed in a central cavity of the hollow body. The fusible element may include a first coil partially disposed in the first end cap, the first coil having a plurality of loops wound around a central axis. The fusible element may also include a centerline having a first end integrally coupled to the first coil, the centerline extending diagonally through the central cavity relative to the central axis. The fusible element may also include a second coil having a second end integrally coupled to the second coil, the second coil having a plurality of loops wound around the central axis. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings illustrate exemplary methods of the embodiments disclosed thus far, which are designed for practical application of the principles thereof, and in which:

[0011] Figure 1 A fuse according to an embodiment of the present disclosure is shown;

[0012] Figure 2 A fuse according to an embodiment of the present disclosure is shown;

[0013] Figure 3 An exemplary fusible element according to an embodiment of the present disclosure is shown;

[0014] Figure 4 An exemplary fusible element according to an embodiment of the present disclosure is shown;

[0015] Figure 5 An exemplary fusible element according to an embodiment of the present disclosure is shown; and

[0016] Figure 6 A side cross-sectional view of a protection device according to an exemplary embodiment of the present disclosure is shown.

[0017] The accompanying drawings are not necessarily drawn to scale. The accompanying drawings are merely representations and are not intended to depict specific parameters of the present disclosure. The accompanying drawings are intended to depict typical embodiments of the present disclosure and therefore should not be considered limiting of the scope. In the accompanying drawings, similar reference numerals represent similar elements.

[0018] In addition, for the sake of clarity, some elements in some drawings may be omitted or not shown to scale. In addition, for the sake of clarity, some figure numerals may be omitted in some drawings. DETAILED DESCRIPTION

[0019] Embodiments according to the present disclosure will now be described more fully with reference to the accompanying drawings. The device / system / fuse may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to make this disclosure thorough and complete and to fully convey the scope of the systems and methods to those skilled in the art.

[0020] As will be discussed in more detail herein, the present disclosure provides a protection device such as a fuse having a fusible element including a coiled end and a centerline extending diagonally between the coiled ends. The fusible element can be used for high breaking capacity fuse applications and has at least the following features and technical advantages. First, the coiled fusible element free end promotes a solid element termination bond / connection, which is beneficial to thermal cycling reliability. For example, in one embodiment, the coiled free end provides good solder coverage for the nano fuse. In another embodiment, in the case of a solderless design, the coiled free end provides a good mechanical bond with a mechanical structure of an end cap such as a tube.

[0021] Second, coiling the fusible element effectively lengthens the wire element, which results in higher I2t values ​​suitable for high surge applications. The higher the I2t value, the higher the surge or starting current, and the longer the load cycle the fuse can withstand before opening, which is typical in LED lighting, AC / DC power adapters, and telecommunications equipment systems. Third, the coil ring generates a magnetic field when supplied with current, which helps to confine the arc plasma, improving the breaking capacity of the fuse.

[0022] Fourth, the interior area of ​​the coil ring provides an area to retain arc extinguishing material such as silicone for additional arc extinguishing capability. The diameter of the coil ring depends on the body / housing area and also helps with alignment of the fusible element.

[0023] Fifth, providing a straight diagonal centerline of the fusible element ensures that the weak point is located in the center of the fusible element, thereby providing a faster and safer breaking time. In addition, the diagonal orientation eliminates or minimizes the problem of the centerline contacting the body, which is a common root cause of failure of standard Nano OLs.

[0024] Figure 1A perspective view of a protection device such as a fuse 100 according to a non-limiting embodiment of the present disclosure is shown. As shown, the fuse 100 may include a body 102. The body 102 may be ceramic, plastic, or other suitable non-conductive material. In an exemplary embodiment, the body 102 is hollow. A first end cap 104 may be coupled to or assembled to a first end 106 of the body 102, and a second end cap 108 may be coupled to or assembled to a second end 110 of the body 102.

[0025] The fuse 100 also includes a fusible element 120, such as a wire. The fusible element 120 can be disposed within the body 102. As shown, the fusible element 120 includes a first coil 122 coupled to the first end cap 104 and a second coil 124 coupled to the second end cap 108. A centerline 128 extends diagonally between the first coil 122 and the second coil 124. In some embodiments, the centerline 128 can be substantially straight.

[0026] In some embodiments, solder 130 can be disposed within each of the first end cap 104 and the second end cap 108. More specifically, solder 130 can be disposed between the first end 106 of the body 102 and the first end cap 104, and between the second end 110 of the body 102 and the second end cap 108. As shown, solder 130 can electrically and mechanically connect to the first coil 122 and the second coil 124.

[0027] In some embodiments, the body 102 includes a central portion 132 extending between the first end 106 and the second end 110. The central portion 132 has an outer cross-sectional profile of a first size. In some embodiments, the first end 106 and the second end 110 of the body 102 have an outer cross-sectional profile of a second size, wherein the second size is smaller than the first size. However, in other embodiments, the first size and the second size can be the same.

[0028] The fusible element 120 extends through a cavity defined between the outer perimeter of the first end 106 and the inner surface of the first end cap 104. The fusible element 120 extends along a substantially diagonal path through the center of the cavity and terminates at the second end 110, which is at least partially covered by the second end cap 108. The cavity enables the solder 130 to completely surround at least a portion of the fusible element 120 disposed therein. In an exemplary embodiment, the fusible element 120 is not in direct contact with the inner surface of the body 102 defining the cavity.

[0029] Figure 2A perspective view of a protective device such as a fuse 200 according to a non-limiting embodiment of the present disclosure is shown. The fuse 200 may share many of the same features as the fuse 100 described above. Therefore, for the sake of brevity, some aspects of the fuse 200 may not be described in detail. As shown, the fuse 200 may include a body 202. The body 202 may be ceramic, plastic or other suitable non-conductive materials. In an exemplary embodiment, the body 202 is hollow. A first end cap 204 may be coupled to or assembled to a first end 206 of the body 202, and a second end cap 208 may be coupled to or assembled to a second end 210 of the body 202.

[0030] The fuse 200 also includes a fusible element 220, such as a wire. The fusible element 220 can be disposed within the body 202. As shown, the fusible element 220 includes a first coil 222 coupled to the first end cap 204 and a second coil 224 coupled to the second end cap 208. A center line 228 extends diagonally between the first coil 222 and the second coil 224. In some embodiments, the center line 228 can be substantially straight.

[0031] In this non-limiting embodiment, the fuse 200 can be solderless. Instead, the first coil 222 is coupled to or wrapped around the first tube 234 of the first end cap 204. The second coil 224 is coupled to the second tube 236 of the second end cap 208. The first tube 234 and the second tube 236 can be a kind of column or support extending from the respective end caps 204, 208 toward the body 202. In one embodiment, the first tube 234 and the second tube 236 can each be a metal tube.

[0032] The fusible element 220 extends through the cavity defined between the outer perimeter of the first end 206 and the inner surface of the first end cap 204. The fusible element 220 extends along a substantially diagonal path through the center of the cavity and terminates at the second end 210, which is at least partially covered by the second end cap 208. In an exemplary embodiment, the fusible element 220 is not in direct contact with the inner surface of the body 202 defining the cavity.

[0033] Now go to Figure 3, a fusible element 320 according to an embodiment of the present disclosure will be described in more detail. The fusible element 320 may be the same or similar to the fusible element 120 and the fusible element 220 described above. As shown, the fusible element 320 may include a first coil 322 opposite to a second coil 324. A center line 328 extends diagonally between the first coil 322 and the second coil 324. As shown, each of the first coil 322 and the second coil 324 may include a plurality of loops wound generally around a central axis AA. Depending on the application, each of the first coil 322 and the second coil 324 may have any number of loops. In an exemplary embodiment, the center line 328 is not parallel to the central axis AA.

[0034] During use, the first coil 322 and the second coil 324 can produce a bottle-like configuration of magnetic field lines 340, which can confine the arc 344 to about the approximate midpoint of the centerline 328. With the arc 344 confined to the center between the first coil 322 and the second coil 324, damage to the first coil 322, the second coil 324, the body, and the end caps (not shown) is mitigated. In this non-limiting embodiment, the first coil 322 and the second coil 324 are wound in the same direction (e.g., clockwise).

[0035] like Figure 4 As shown, the first coil 322 and the second coil 324 of the fusible element can be wound in opposite directions. In this embodiment, the magnetic field lines 340 generate magnetic repulsion between the first coil 322 and the second coil 324. This repulsion helps separate the fusible element 320 after disconnection. In some embodiments, the fusible element 320 can include an arc-extinguishing material 350 (e.g., silicone) within and / or around the first coil 322 and the second coil 324, such as Figure 5 shown.

[0036] Figure 6A cross-sectional view of an exemplary fuse 400 is shown. The body 402 may include a center portion 432 disposed between the first end 406 and the second end 410. As shown, the center portion 432 may have an outer square cross-sectional profile. However, embodiments of the present disclosure are not limited to any particular shape or cross-sectional profile. For example, in some embodiments, the body 402 may have a generally circular cross-sectional profile, for example, when viewed from the first end 406 and the second end 410. The center portion 432 includes a central cavity 455 extending between the first end 406 and the second end 410, and a plurality of outer surfaces defining an outer cross-sectional profile of a first size. In a non-limiting embodiment, the body 402 includes four (4) generally flat outer surfaces. The body 402 may be ceramic, plastic, or other suitable non-conductive material. The first end cap 404 may be mounted on the first end 406 of the body 402, and the second end cap 4081164 may be mounted on the second end 410 of the body 402.

[0037] As shown, the solder 430 can be disposed within the central cavity 455 and along the first end surface 456 of the first end 406 of the body 402. The first coil 422 can have a free end (not shown) that is surrounded by the solder 430 near the first end 406 of the body 402. Similarly, the solder 430 can extend along the second end surface 458 of the second end 410 of the body 402. The second coil 424 can have a free end that is surrounded by the solder 430 near the second end 410 of the body 402. In some embodiments, an arc extinguishing material (e.g., silicone) can be disposed within the central cavity 455.

[0038] As further shown, the centerline 428 of the fusible element 420 can be disposed within the central cavity 455 of the body 402. The centerline 428 is a diagonal line extending between the first coil 422 and the second coil 424. More specifically, the centerline 428 includes a first end 460 integrally coupled to a first end 462 of the first coil 422. A second end 464 of the centerline 428 is integrally coupled to a second end 466 of the second coil 424. The first coil 422 and the second coil 424 are positioned within the first end cap 404 and the second end cap 408, respectively. In some embodiments, the first coil 422 also extends within the central cavity 455 near the first end 406 of the body 402, and the second coil 424 extends within the central cavity 455 near the second end 410 of the body 402. As described above, according to the winding direction of the first coil 422 and the second coil 424, when the loops of the first coil 422 and the second coil 424 are provided with current, a magnetic field is generated, which helps to limit the arc plasma, thereby enhancing the breaking capacity of the fuse 400. Although not shown, the loop area of ​​the first coil and / or the second coil may also maintain silicone material to obtain additional arc extinguishing ability. It should be understood that the number of coils, the thickness of the material and the diameter of the loop, as well as other parameters, can vary and may depend in part on the geometry of the body 402 and the central cavity 455 and the rating of the fuse 400.

[0039] Although not shown, in some embodiments, the free ends of the first coil 422 and / or the second coil 424 can extend along the respective first end surface 456 and second end surface 458. In still other embodiments, the fusible element 420 can also extend partially along one or more of the plurality of outer surfaces of the body 402.

[0040] In summary, a fusible element is provided herein having coils disposed at opposite ends of a diagonal. The first and second coils can be wound in the same direction, thereby creating a magnetic bottle configuration (also known as a magnetic mirror), which can advantageously confine the arc to the center of the diagonal. With the arc confined to the center, damage to the fuse terminal / cover and body will be mitigated. Alternatively, the first and second coils can be wound in opposite directions. As a result, once a strong magnetic field is generated, such as in the case of an overcurrent condition, the first and second coils will advantageously repel each other.

[0041] The foregoing discussion is presented for the purpose of illustration and description and is not intended to limit the present disclosure to one or more forms disclosed herein. For example, in order to simplify the present disclosure, various features of the present disclosure may be combined together in one or more aspects, embodiments or configurations. However, it should be understood that various features of certain aspects, embodiments or configurations of the present disclosure may be combined in alternative aspects, embodiments or configurations. In addition, the following claims are hereby incorporated by reference into this detailed description, and each claim is independently a separate embodiment of the present disclosure.

[0042] As used herein, unless such exclusion is explicitly stated, an element or step stated in the singular and beginning with the word "a" or "an" should be understood as not excluding multiple elements or steps. In addition, reference to "one embodiment" of the present disclosure is not intended to be interpreted as excluding the existence of additional embodiments that also include the described features.

[0043] The "includes," "comprising," or "having," and variations thereof used herein are intended to include the items listed thereafter and their equivalents as well as additional items. Therefore, the terms "includes," "comprising," or "having," and variations thereof are open-ended expressions and can be used interchangeably herein.

[0044] As used herein, the phrases "at least one," "one or more," and "and / or" are open-ended expressions that are conjunction and disjunction in operation. For example, each of the expressions "at least one of A, B, and C," "at least one of A, B, or C," "one or more of A, B, and C," "one or more of A, B, or C," and "A, B, and / or C" refers to A alone, B alone, C alone, A and B together, A and C together, B and C together, or A, B, and C together.

[0045] All directional references (e.g., proximal, distal, upper, lower, upward, downward, left, right, lateral, longitudinal, front, rear, top, bottom, above, below, vertical, horizontal, radial, axial, clockwise, and counterclockwise) are used for identification purposes only to assist the reader in understanding the present disclosure and are not intended to be limiting, particularly with respect to the position, orientation, or use of the present disclosure. Unless otherwise indicated, connection references (e.g., attachment, coupling, connection, and engagement) are to be understood broadly and may include intermediate members between a range of elements and relative movement between elements. Thus, connection references do not necessarily infer that two elements are directly connected and in fixed relation to each other.

[0046] Furthermore, identifying references (e.g., primary, secondary, first, second, third, fourth, etc.) are not intended to imply importance or priority, but rather are used to distinguish one feature from another. The drawings are for illustration purposes only, and the dimensions, positions, order, and relative sizes reflected in the attached drawings may vary.

[0047] In addition, the terms "substantially" or "essentially" and the terms "approximately" or "about" can be used interchangeably in some embodiments and can be described using any relative measure acceptable to those of ordinary skill in the art. For example, these terms can be used as a comparison to a reference parameter to indicate a deviation from being able to provide the intended function. Although not limiting, the deviation from the reference parameter can be, for example, an amount of less than 1%, less than 3%, less than 5%, less than 10%, less than 15%, less than 20%, etc.

[0048] The scope of the present disclosure is not limited by the specific embodiments described herein. In fact, in addition to those described herein, various other embodiments and modifications of the present disclosure will be apparent to those of ordinary skill in the art from the foregoing description and the accompanying drawings. Therefore, such other embodiments and modifications are intended to fall within the scope of the present disclosure. In addition, the present disclosure has been described herein in the context of a specific embodiment in a specific environment for a specific purpose. Those of ordinary skill in the art will recognize that usefulness is not limited thereto, and that the present disclosure can be beneficially implemented in many environments for any purpose. Therefore, the claims set forth below will be understood in light of the full breadth and spirit of the present disclosure as described herein.

Claims

1. A fuse, include: a body including a central portion extending between a first end and a second end; a first end cap surrounding the first end and a second end cap surrounding the second end; as well as A fusible element, the fusible element being disposed in the central cavity of the main body, the fusible element comprising: a first coil disposed in the first end cover and a second coil disposed in the second end cover; and a center line extending diagonally between the first coil and the second coil, The first coil has a free end coupled to a first end surface in the first end of the body by solder, and the second coil has a free end coupled to a second end surface in the second end of the body by solder. 2 . The fuse of claim 1 , further comprising solder disposed within the first end cap and the second end cap.

3. The fuse according to claim 2, in, The solder is also disposed between the first end and the first end cap, and between the second end and the second end cap.

4. The fuse according to claim 1, further comprising a first tube of the first end cap and a second tube of the second end cap, in, The first coil is coupled to the first tube, and wherein the second coil is coupled to the second tube.

5. The fuse according to claim 4, in, The first coil is partially wrapped around the first tube, and wherein the second coil is partially wrapped around the second tube.

6. The fuse of claim 1 further comprising an arc extinguishing material within the body.

7. The fuse according to claim 1, in, The first coil and the second coil are wound in the same direction.

8. The fuse according to claim 1, in, The first coil and the second coil are wound in opposite directions.

9. The fuse according to claim 1, in, The centerline of the fusible element is substantially straight.

10. A protective device, include: main body; a first end cap surrounding a first end of the body and a second end cap surrounding a second end of the body; as well as a fusible element extending between the first end of the body and the second end of the body, wherein the fusible element is disposed within a central cavity of the body, and wherein the fusible element comprises: a first coil disposed in the first end cover and a second coil disposed in the second end cover; and a center line extending diagonally between the first coil and the second coil, The first coil has a free end coupled to a first end surface in the first end of the body by solder, and the second coil has a free end coupled to a second end surface in the second end of the body by solder.

11. The protection device of claim 10, further comprising solder disposed within the first end cap and the second end cap.

12. The protection device according to claim 10, further comprising a first tube of the first end cap and a second tube of the second end cap, in, The first coil is coupled to the first tube, and wherein the second coil is coupled to the second tube.

13. The protection device according to claim 12, in, The first coil is wrapped around the first tube, and wherein the second coil is wrapped around the second tube.

14. The protection device according to claim 10, in, The first coil and the second coil are one of: wound in the same direction, and wound in opposite directions.

15. The protection device according to claim 10, in, The centerline of the fusible element is substantially straight.

16. A fusible device, include: Hollow body; a first end cap surrounding a first end of the hollow body and a second end cap surrounding a second end of the hollow body; as well as a fusible element extending between the first end of the hollow body and the second end of the body, wherein the fusible element is disposed within a central cavity of the hollow body, and wherein the fusible element comprises: a first coil, the first coil being partially disposed within the first end cap, The first coil has a plurality of loops wound around a central axis; a centerline having a first end integrally coupled to the first coil, the centerline extending through the central cavity diagonally relative to the central axis; and a second coil having a second end integrally coupled to the second coil, the second coil having a plurality of loops wound around the central axis, The first coil has a free end coupled to a first end surface in the first end of the body by solder, and the second coil has a free end coupled to a second end surface in the second end of the body by solder.

17. The fusible device according to claim 16, further comprising: include: A solder is disposed between the first end cap and the first end of the hollow body, and between the second end cap and the second end of the body.

18. The fusible device according to claim 16, further comprising: include: a first support member extending from an interior of the first end cap toward the first end of the hollow body; and A second support extends from an interior of the second end cap toward the second end of the hollow body, wherein the first coil is wound around the first support, and wherein the second coil is wound around the second support.

19. The fusible device according to claim 16, in, The first coil and the second coil are one of: wound around the central axis in the same direction, and wound around the central axis in opposite directions.

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