This disclosure relates generally to the field of circuit protection devices and more particularly to high-current fuses.
Fuses can be used as circuit protection devices and can form an electrical connection between a power source and a component in a circuit to be protected. In particular, a fuse may be configured to protect against damage caused by an overcurrent condition. A fuse can be constructed to physically open or interrupt a circuit path and isolate electrical components from damage upon the occurrence of overvoltage and/or overcurrent conditions in the circuit. Electrical systems in vehicles typically include a number of circuit protection devices to protect electrical circuitry, equipment, and components from damage caused by these conditions.
In many circuit protection applications it is desirable to employ fuses that are compact and that have high “breaking capacities.” Breaking capacity (also commonly referred to as “interrupting capacity”) is the current that a fuse is able to interrupt without being destroyed or causing an electric arc of unacceptable duration. High-voltage applications require a fuse element (or fuse link) that can handle the energy and arcing associated with an opening of the element of the fuse or circuit. At lower voltages, the arc may not cause serious damage to the metal and plastic portions of the fuse and the fuse housing. However, at higher voltages, extensive damage to the metal and plastic portions of the fuse and its surroundings can occur.
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 as an aid in determining the scope of the claimed subject matter.
Various embodiments described herein provide a fuse with improved energy handling and arc quenching characteristics that can be provided in a relatively small package, suitable for the automotive environment.
Various embodiments provide a circuit protection device including a housing having a top section mounted to a bottom section. The circuit protection device can include a first arc barrier extending from the bottom section and a second arc barrier extending from the top section. The top and bottom sections mounted together can define a cavity that can include a spacing between the first arc barrier and the second arc barrier. A first terminal and a second terminal can be secured to the bottom section. A fuse element can be positioned within the housing and can be connected to the two terminals. The fuse element can be positioned to traverse over and/or under the arc barriers. The fuse element or a portion thereof can be surrounded by air. A portion of the cavity can be filled with an arc-quenching material.
By way of example, specific embodiments of the disclosed device will now be described, with reference to the accompanying drawings, in which:
The present disclosure will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments are shown. Circuit protection devices of the present disclosure, however, 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 so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements throughout.
As described herein, a circuit protection device can include a fuse and can form an electrical connection between a power source and a component in a circuit to be protected. In particular, the fuse may be configured to protect against damage caused by an overcurrent condition and/or an overvoltage condition. The fuse may be constructed to physically open or interrupt a circuit path and isolate electrical components from damage upon the occurrence of specified conditions in the circuit (e.g., overcurrent and/or overvoltage conditions). Upon the occurrence of a specified fault condition, such as an overcurrent condition, a fusible element melts, breaks or otherwise opens to interrupt the circuit path and isolate the protected electrical components or circuit from potential damage. More specifically, the circuit protection device may be a wire in air split fuse with built in arc quencher which includes a housing unit having a cover and a bottom holder. The circuit protection device may include one or more arc barriers with a first arc barrier extending from the housing and a second arc barrier extending from the bottom holder. A fuse element can be wrapped over one arc barrier and under the other arc barrier with terminals connected to the fuse element, secured at either end of the bottom holder. An arc-quenching material may also be included within the housing. In this manner, the first and second arc barriers prevent or reduce arcing between the ends of the fuse element and/or between the terminals to which the fuse element may be connected.
The circuit protection device 100 may include a first terminal 104A and a second terminal 104B. The first terminal 104A and the second terminal 104B can be secured to the bottom section 102B. In one embodiment, the top section 102A may include a second arc barrier (not shown in
In one embodiment, the circuit protection device 100 can include fuse element 112. The fuse element 112 may be positioned between the top section 104D of the first terminal 104A and the top section 104C of the second terminal 104B. The fuse element may have a serpentine shape as it traverses over and/or under at least one arc barrier, such as the first arc barrier 106A. Said differently, the fuse element 112, having a serpentine shape, can traverse at least one arc barrier, such as the first arc barrier 106A, by traversing up and over the at least one arc barrier, such as traversing up and over a peak 108A of the first arc barrier 106A, of the bottom section 102B.
The fuse element 112 may be comprised of nickel, copper, tin, or an alloy or mixture comprising nickel, copper, silver, gold, and/or tin. With some examples, the fuse element 112 may have a thickness between 0.02 and 5 mils (a mil being a thousandth of an inch). The fuse element 112 may comprise a body of metallic material arranged in one of a plurality of geometric configurations. The fuse element 112 may be mounted and/or make contact with the first terminal 104A and the second terminal 104B. The fuse element 112 may be disposed on and electrically connected or coupled to both top sections 104D, 104C of each of the first terminal 104A and the second terminal 104B, respectively. In other words, each end of the fuse element 112 may be disposed on and electrically connected or coupled to both the first terminal 104A and the second terminal 104B. The fuse element 112 can traverse at least one arc barrier, such as the first arc barrier 106A. During an overcurrent condition, the fuse element 112 can melt (or break or split). At least one arc barrier, such as the first arc barrier 106A, can be configured to prevent or reduce arcing upon activation/melting of the fuse element 112.
As shown in
As can be seen in
For example, the wall defined by the first arc barrier 106A can include a sloping sidewall and a vertical sidewall opposite the sloping sidewall, and the sloping sidewall and/or the peak 108A can support a first portion of the fuse element 112. The wall defined by the second arc barrier 106B can include a sloping sidewall and a vertical sidewall opposite the sloping sidewall, and the sloping sidewall and/or the peak 108B can support another portion of the fuse element 112.
In one embodiment, the first arc barrier 106A may be molded onto (or formed as part of) the bottom section 102B and the second arc barrier 106B may be molded onto (or formed as part of) the top section 102A. The first arc barrier 106A and the second arc barrier 106B may create a high breaking capacity of greater than 350 volts direct current (VDC). In one embodiment, the first arc barrier 106A and the second arc barrier 106B can be configured to prevent or reduce arcing upon activation of the circuit protection device 100 (e.g., when the fuse element 112 melts or breaks in response to an overcurrent condition).
In one embodiment, the fuse element 112 may be coplanar at each end portion of the fuse element 112 and coupled to and connecting with the first terminal 104A and the second terminal 104B. In one embodiment, all or a portion of the fuse element 112 may be of a serpentine or serpentine-like shape. The fuse element 112 connects to the first terminal 104A and may traverse around and along the first arc barrier 106A and the second arc barrier 106B, such as traversing over one (e.g., over 106A) and under the other (e.g., under 106B) in a different plane to connect the first terminal 104A to the second terminal 104B. Said differently, the fuse element 112 having a serpentine shape may traverse up and over the first arc barrier 106A of the bottom section 102B and down and under the second arc barrier 106B of the top section 102A. The fuse element 112 may include at least 3 sections; one section defined from the first arc barrier 106A to an edge of housing 102 where the top section 102A and the bottom section 102B meet or join, a second section between the first arc barrier 106A and the second arc barrier 106B, and a third section between the second arc barrier 106B and an opposite edge of housing 102 where the top section 102A and the bottom section 102B meet or join. In general, the fuse element 112 can be shaped in any manner to traverse between the first terminal 104A and the second terminal 104B while negotiating around the first and second arc barriers 106A and 106B.
In one embodiment, the portion of the fuse element 112 that is supported by the peak 108A of the first arc barrier 106A and the peak 108B of the second arc barrier 106B may be one of a variety of geometrical configurations, such as a curve or triangle shape. For example, with the first arc barrier 106A defined by the ramped shaped wall extending upwardly from the bottom section 102B, the fuse element 112 traverses horizontally from the first terminal 104A and then changes directions moving diagonally upward and over the first arc barrier 106A. The portion of the fuse element 112 that is supported by the peak 108A may be a triangle shape so as to allow the fuse element 112 to reverse directions. The fuse element 112 then diagonally traverses downward through a portion of the cavity 110 and down and under the second arc barrier 106B. The portion of the fuse element 112 that is supported by the peak 108B may be a triangle shape so as to allow the fuse element 112 to reverse directions. The fuse element 112 reverses direction at the peak 108B and diagonally traverses upward and then traverses horizontally to the second terminal 104B. The fuse element 112 can be coplanar at one end connected and coupled to the first terminal 104A and the opposite end connected and coupled to the second terminal 104B. Also, the fuse element 112 may connect and/or rest upon the peak 108A of the first arc barrier 106A and/or connect and/or rest upon the peak 108B of the second arc barrier 106B.
The cavity 110 may be defined to include several chambers (e.g., parts), such as a first chamber, a second chamber, and/or a third chamber. The first chamber may be the open space of the cavity 110 between one end of the top section 102A and the bottom section 102B and the first arc barrier 106A. The second chamber may be defined as the open space of the cavity 110 between the first arc barrier 106A and the second arc barrier 106B. The third chamber may be defined as the open space of the cavity 110 between the second arc barrier 106B and another end of the top section 102A and the bottom section 102B.
The fuse element 112 can traverse through all or a portion of the cavity 110. In one embodiment, the cavity 110 can provide for all or a portion of the fuse element 112 to be surrounded by air. Also, in order to prevent, reduce, or minimize arcing, all or a portion of the cavity 110 may be filled with a filler that minimizes the likelihood of arcing. For example, the filler can be an arc-quenching material. The arc-quenching material may assist with at least one arc barrier, such as the first arc barrier 106, in preventing an arcing between the ends of the fuse element 112 and/or between terminals 104A, 104B. The arc-quenching material can be an inorganic, dry, granular, nonconductive material. Examples include quartz sand, silica, ceramic powders, and calcium sulfate. This material is preferably placed into the housing before the housing is closed. Said, differently, an arc quenching material may be injected into the cavity 110 as the bottom section 102B is connected to the top section 102A. As an example, the first part and the third part of the cavity 110 may include the arc quenching material. In an alternative configuration, the first part, the second part, and/or the third part of the cavity 110 may include the arc quenching material.
The top section 102A can also include one or more positioning guides 114, 116 (e.g., “weld extensions”) so as to aid placement of the top section 102A onto the bottom section 102B of the housing unit 102. It should be noted that the top section 102A and the bottom section 102B collectively form the housing unit 102.
The fuse element 112 may electrically be connected to the first terminal 104A and the second terminal 104B by, for example, soldering. For example, a first end of the fuse element 112 may connect to the first terminal 104A and a second end of the fuse element 112 may connect to the second terminal 104B as depicted in
A portion of the positioning guides 114 and 116 can be considered to be mounting extensions. The mounting extensions 114 and 116 can aid in the placement and alignment of the top section 102A onto the bottom section 102B during assembly. Further, the bottom section 102B can include a recessed portion 320. The recessed portion 320 can be positioned on opposite lateral sides of the bottom section 102B. The recessed portion 320 can be positioned within an inner perimeter of the bottom section 102B. The recessed portion 320 can be positioned and shaped to mate and align with the portion of the mounting extensions 114 and 116 when the top portion 102A is positioned on top of the bottom portion 102B as shown in
In one embodiment, the bottom section 102B is disposed beneath the top section 102A. The fuse element is disposed over the bottom section 102B and underneath the top section 102A. On each side of the bottom section 102B, the first terminal 104A and the second terminal 104B are secured thereto.
In one embodiment, the first terminal 104A and the second terminal 104B each may be one of a variety of geometric configurations, such as c-shaped. In one embodiment, the first terminal 104A and the second terminal 104B being c-shaped can wrap around opposite ends of the bottom section 102B. For example, the first terminal 104A and the second terminal 104B may have a c-shape and can extend into a top edge of the bottom section 102B and/or wrap around a lower edge of the bottom section 102B. The first terminal 104A may have a top edge 104D that may bend, extend and/or wrap around a top edge of a bottom section 102B for receiving the fuse element 112. The top edge 104D is then secured, coupled, and/or connected to the bottom section 102B. The first terminal 104A may also have a bottom edge 104E. The bottom edge 104E can be connected and/or secured to the bottom section 102B. The bottom edge 104E may traverse along a portion of the bottom section 102B and/or bend, extend and/or wrap around a bottom edge of the bottom section 102B. In one embodiment, the top edge 104D and the bottom edges 104E may be orthogonal to a portion of the first terminal 104A, thus forming the substantially C-shape, and secured into at least a portion of the bottom section 102B. The top edge 104D and the bottom edge 104E may be connected by a section of the first terminal 104A that wraps around the bottom section 102B.
In one embodiment, the second terminal 104B may have the top edge 104C that may bend, extend and wrap around a top edge of a bottom section 102B for receiving the fuse element 112. The top edge 104C is then secured, coupled, and/or connected to the bottom section 102B. The second terminal 104B may also have a bottom edge 104F. The bottom edge 104F is connected and/or secured to the bottom section 102B. The bottom edge 104F may traverse along a portion of the bottom section 102B and/or bend, extend and wrap around a bottom edge of the bottom section 102B. In one embodiment, the top edge 104C and the bottom edges 104F may be orthogonal to a portion of the second terminal 104B, thus forming the substantially c-shape, and secured into at least a portion of the bottom section 102B. The top edge 104C and the bottom edge 104F may be connected by a section of the second terminal 104B that wraps around the bottom section 102B. After assembly, the top edges 104C and 104D may be positioned between the top portion 102A and the bottom portion 102B of the housing 102.
In one embodiment, the circuit protection device 100 may be fabricated in two parts, such as a cover (e.g., the top section 102A) and housing (e.g., the bottom section 102B). After the first terminal 104A and the second terminal 104B are connected, and the fuse element 112 is connected, it may be necessary to close the fuse. The two parts (e.g., the top section 102A and the bottom section 102B) of the circuit protection device 100 may be closed in many ways.
In one embodiment, when using plastic parts, assembly may include placing the top section 102A over the bottom section 102B and sealing the top section 102A to the bottom section 102B by ultrasonic welding. An alternative approach can include plastic welding the parts (e.g., the top section 102A and the bottom section 102B) together, such as by running a bead of polypropylene “welding” bead around the split line between the parts. The positioning guides 114 (see
As more clearly illustrated in
In one embodiment, the bottom section 102B and the top section 102A may be a molded plastic part, with the internal walls and with the openings in the internal and external walls for receiving the first terminal 104A and the second terminal 104B.
Also, it should be noted that in one embodiment the top section 102A and the bottom section 102B can be made of made of a variety of polyamides, such as Ultramid TKR4365G5. The first terminal 104A and the second terminal 104B may be made of one of a variety of conductive materials, such as, for example, tin plated copper. Additionally, the fuse element 112 may be made of a copper alloy.
While the present disclosure has been disclosed with reference to certain embodiments, numerous modifications, alterations and changes to the described embodiments are possible without departing from the sphere and scope of the present disclosure, as defined in the appended claims. Accordingly, it is intended that the present disclosure not be limited to the described embodiments, but that it has the full scope defined by the language of the following claims, and equivalents thereof.
It is emphasized that the Abstract of the Disclosure is provided to allow a reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively. Moreover, the terms “first,” “second,” “third,” and so forth, are used merely as labels, and are not intended to impose numerical requirements on their objects.
What has been described above includes examples of the disclosed architecture. It is, of course, not possible to describe every conceivable combination of components and/or methodologies, but one of ordinary skill in the art may recognize that many further combinations and permutations are possible. Accordingly, the novel architecture is intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.
This application claims priority to U.S. Provisional Patent Application No. 62/106,378, filed Jan. 22, 2015, the entirety of which is hereby incorporated by reference.
Number | Date | Country | |
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62106378 | Jan 2015 | US |