Fuse assembly including a two-piece fuse end bell with precast / premolded alignment slots and optional interfacial crush ribs, and the end bell

Abstract

To provide slots in an endbell for receipt of insertion pins, the slots enabling an endbell to be pre-cast / pre-molded without costly rework of molding tools.SOLUTION: A novel fuse assembly design utilizes a single-piece terminal assembly and a two-piece endbell. The two-piece endbell and terminal assembly have mating elements that enable fastening of the endbell portions to the terminal assembly without use of adhesives. The mating elements also provide positioning guidance for ease of assembly.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate to fuse assemblies, and more particularly, to fuse assemblies having two-piece end bells. [Background technology]

[0002] A fuse is a sacrificial device used in electrical systems for overcurrent protection, rupturing in the event of an overcurrent condition. A fuse includes a fuse element, such as a metal wire or strip, connecting two metal contact terminals, which melts / ruptures when excessive current flows through it. This rupture creates an open circuit, thereby protecting the device to which the fuse is connected. Fuses come in a variety of shapes and sizes and have many applications, from small circuit electronics to large-scale industrial applications. In addition to being component protection devices, fuses are also safety devices, such as when used in vehicles, providing fire protection in the event of a vehicle accident.

[0003] Some fuses may include end bells on either side of a fuse body within which a fuse element is disposed. The end bells are designed to support the fuse element and protect it from external forces and environmental stresses. Existing fuse technology utilizes two fully circular end bells, each of which is first engaged, such as by press-fitting or brazing, within its own separate terminal before attaching the fuse element. This assembly method therefore involves a secondary process, such as soldering or welding, to attach the fuse element between the two terminals, increasing manufacturing complexity and potentially introducing quality variations. Furthermore, the sliding interface between the conductive terminals and the end bells during assembly is not designed to create a sealed enclosure between the fuse contents and the environment.

[0004] The end bells are secured to the fuse body using insertion pins. Drilling holes in the end bells, which are generally made of a softer metal than that used for the fuse terminals, can be messy, resulting in debris remaining within the fuse body. Hermetically sealing the end bells to the fuse body ensures that the fuse assembly will operate as designed. Therefore, the end bells can be sealed to the fuse body using an adhesive material, which can also be messy.

[0005] With these and other considerations in mind, the present improvements may be useful. 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 or essential features of the claimed subject matter, nor is it intended as an aid in determining the scope of the claimed subject matter.

[0007] An exemplary embodiment of a fuse assembly according to the present disclosure may include a fuse body for housing a fuse element, a terminal assembly, and an end bell. The terminal assembly features a fuse element having opposing first and second faces and extending between first and second terminals. The end bell includes first and second end bell portions, each having a crush rib. When the two end bell portions are secured to each other with the terminal assembly sandwiched therebetween, the first crush rib engages the first face of the terminal assembly and the second crush rib engages the second face of the terminal assembly, thereby forming a seal around the terminal assembly.

[0008] An exemplary embodiment of an end bell according to the present disclosure is adapted to secure a terminal assembly, together with a second end bell, within a fuse housing and may include a first end bell portion and a second end bell portion. The first end bell portion has a first protrusion, a first receptacle, and a first crush rib. The first crush rib is adapted to engage with a first surface of the terminal assembly, including the fuse element. The second end bell portion has a second protrusion, a second receptacle, and a second crush rib. The second crush rib is adapted to engage with a second surface of the terminal assembly, opposite the first surface. In response to securing the first end bell portion to the second end bell portion, the first protrusion engages with the second receptacle and the second protrusion engages with the first receptacle, thereby forming a seal around the terminal assembly.

[0009] Another exemplary embodiment of a fuse assembly according to the present disclosure may include a fuse body, first and second end bell portions, and first and second insertion pins. The fuse body is molded with a first hole and a second hole. The first end bell portion is molded with a first slot formed radially into its peripheral edge, thereby forming a radial cavity within the first end bell. The second end bell portion is molded with a second slot formed radially into its peripheral edge, thereby forming a radial cavity within the second end bell. The first insertion pin extends through the first hole and the first slot, and the second insertion pin extends through the second hole and the second slot, and the first and second insertion pins secure the first and second end bell portions to the fuse body. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 illustrates a fuse assembly according to an exemplary embodiment.

[0011] [Figure 2A] 2 illustrates a terminal assembly for the fuse assembly of FIG. 1 according to an exemplary embodiment. [Figure 2B] 2 illustrates a terminal assembly for the fuse assembly of FIG. 1 according to an exemplary embodiment. [Figure 2C] 2 illustrates a terminal assembly for the fuse assembly of FIG. 1 according to an exemplary embodiment.

[0012] [Figure 3A] 2 illustrates an end bell portion for the fuse assembly of FIG. 1 according to an exemplary embodiment. [Figure 3B] 2 illustrates an end bell portion for the fuse assembly of FIG. 1 according to an exemplary embodiment.

[0013] [Figure 4A] 2 illustrates an end bell portion connection structure for the fuse assembly of FIG. 1 according to an exemplary embodiment. [Figure 4B] 2 illustrates an end bell portion connection structure for the fuse assembly of FIG. 1 according to an exemplary embodiment.

[0014] [Figure 5] FIG. 1 illustrates a fuse assembly according to an exemplary embodiment.

[0015] [Figure 6A] 6 illustrates a terminal assembly for the fuse assembly of FIG. 5 according to an exemplary embodiment. [Figure 6B] 6 illustrates a terminal assembly for the fuse assembly of FIG. 5 according to an exemplary embodiment. [Figure 6C] 6 illustrates a terminal assembly for the fuse assembly of FIG. 5 according to an exemplary embodiment.

[0016] [Figure 7A]6 illustrates an end bell portion and end bell portion coupling structure of the fuse assembly of FIG. 5 according to an exemplary embodiment. [Figure 7B] 6 illustrates an end bell portion and end bell portion coupling structure of the fuse assembly of FIG. 5 according to an exemplary embodiment.

[0017] [Figure 8A] 6 illustrates an end bell portion for the fuse assembly of FIG. 5 according to an exemplary embodiment. [Figure 8B] 6 illustrates an end bell portion for the fuse assembly of FIG. 5 according to an exemplary embodiment.

[0018] [Figure 9A] 6 illustrates an end bell portion for the fuse assembly of FIG. 5 according to an exemplary embodiment. [Figure 9B] 6 illustrates an end bell portion for the fuse assembly of FIG. 5 according to an exemplary embodiment.

[0019] [Figure 10] 1A and 1B illustrate drilling holes in a fuse assembly according to the prior art.

[0020] [Figure 11A] FIG. 10 illustrates an end bell portion having a cylindrical bore according to an exemplary embodiment;

[0021] [Figure 11B] FIG. 10 illustrates an end bell portion having a slot according to an exemplary embodiment;

[0022] [Figure 12] FIG. 1 illustrates a fuse assembly according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0023] A novel fuse assembly design is disclosed herein. The two-piece end bell design allows the terminal and fuse element of the fuse assembly to be formed as a single piece, eliminating manufacturing variability caused by having to separately attach the fuse element between the two terminals. The two-piece end bell and terminal assembly features elements that allow the end bell portion to be mated to the terminal assembly without the use of adhesives. These elements also provide positioning guidance for ease of assembly. The end bell portion features a slot rather than a cylindrical hole to accept an insertion pin used to secure the end bell to the fuse body, avoiding costly rework of molding tools.

[0024] For convenience and clarity, terms such as "top," "bottom," "upper," "lower," "vertical," "horizontal," "lateral," "transverse," "radial," "inner," "outer," "left," and "right" may be used herein to describe the relative locations and orientations of features and components of fuse assemblies, each of which refers to the geometry and orientation of those assemblies when they appear in the perspective, exploded perspective, and cross-sectional views provided herein. The foregoing terms are not intended to be limiting and include the specifically mentioned words, derivatives thereof, and words of similar import.

[0025] Fuse Assembly 100

[0026] FIG. 1 is a representative perspective view of a novel fuse assembly 100 according to an exemplary embodiment. The fuse assembly 100 features a fuse body 106. The fuse body 106 is transparent to facilitate visualization of the other elements of the fuse assembly. Two end bells, a first end bell 102a and a second end bell 102b (collectively, "end bells 102"), are disposed at opposite ends of the fuse body 106. A fuse element 108 is disposed between a first terminal 104a and a second terminal 104b (collectively, "terminals 104"). The fuse element 108 may take on shapes and configurations other than those shown in FIG. 1. As shown herein, the components of the fuse assembly 100 include features that facilitate stable fixation of the components and guidance in positioning the components during assembly, ensuring ease of manufacturing.

[0027] Figures 2A through 2C are representative perspective views of terminal assemblies and end bells and end bell portions according to example embodiments, which are part of fuse assembly 100 of Figure 1. Figure 2A features terminal assembly 200A consisting of a fuse element disposed between two fuse terminals, Figure 2B features fuse assembly 200B having two attached end bells, and Figure 2C features fuse assembly 200C with a first end bell portion at the bottom and a second end bell portion at the top (collectively, "terminal assemblies 200").

[0028] Terminal assembly 200A (FIG. 2A) comprises a fuse element 208 disposed between first terminal 204a and second terminal 204b (collectively, "terminals 204"). Fuse element 208 is known as the sacrificial portion of fuse assembly 100 because it breaks in response to a fault condition and is shown as a simple rectangular element without any bends or curves. In various alternative embodiments, fuse element 208 may assume other various shapes and sizes, may have twists or bends, may be thinner than or the same thickness as terminals 204, and may be comprised of multiple pieces not shown. The present disclosure is not limited in this respect.

[0029] Fuse terminal 204 optionally includes terminal apertures 206a and 206b (collectively, "terminal aperture 206") for fixedly attaching the fuse to an electrical circuit. Although shown as a circular opening, terminal aperture 206 may be any of a variety of shapes and sizes. As an example, fuse terminal 204 may be attached to a bus bar by inserting a conductive bolt into terminal aperture 206 to form an electrical connection between the fuse and the bus bar.

[0030] In one exemplary embodiment, the terminals 204 and fuse element are formed from a single metallic conductive material such as zinc, copper, silver, aluminum, or alloys or combinations thereof, although the terminal assembly 200 shown and described herein is not limited to such configurations. In other embodiments, the terminal assembly 200 of the fuse assembly 100 is formed by connecting the terminals 204 to opposite sides of the fuse element 208, such as by soldering, welding, or other means.

[0031] In one exemplary embodiment, terminal assembly 200 features a protruding lip formed proximate each terminal. A first lip 212a and a second lip 212b are located on opposite sides of terminal assembly 200 near first terminal 204a, and similarly, a third lip 212c and a fourth lip 212d are located on opposite sides of terminal assembly 200 near second terminal 204b (collectively, "lips 212"). As shown in FIG. 2C, in the exemplary embodiment, lips 212 are mating features that facilitate connection of end bells to terminal assembly 200. Lips 212 are described in more detail below in conjunction with the description of FIGS. 4A and 4B.

[0032] FIG. 2B shows end bells 202a and 202b (collectively, "end bells 202"). In an exemplary embodiment, each end bell 202 is made up of two sections or two equal sections. First end bell 202a is made up of first end bell portion 210a (bottom) and second end bell portion 210b (top), and second end bell 202b is made up of first end bell portion 210c (bottom) and second end bell portion 210d (top) (collectively, "end bell portions 210"). End bell portions 210 are designed to engage terminal assembly 200 at lip 212, such as by press fit. In one exemplary embodiment, end bell portions 210 are manufactured using a zinc alloy.

[0033] In conventional fuse designs, these end bells are a single-piece design with a rectangular slot in each end bell. A fuse element is slid through the slot in each end bell, and then terminals are attached to each end of the fuse element, such as by soldering or welding. In an exemplary embodiment, the two-piece end bell design of fuse assembly 100 allows the terminals and fuse element to be formed as a single piece, eliminating manufacturing variations caused by having to separately attach the fuse element between the two terminals.

[0034] FIG. 2C shows end bell portion 210a of first end bell 202a and end bell portion 210d of second end bell 202b. In one exemplary embodiment, end bell portions 210a, 210b, 210c, and 210d are substantially similar to one another and interchangeable. End bell portion 210 is positioned adjacent to terminal 204 at lip 212. As described in more detail below in conjunction with the descriptions of FIGS. 3A-3B and 4A-4B, end bell portion 210 includes features that allow first and second end bell portions (e.g., 210a and 210b of end bell 202a or 210c and 210d of end bell 202b) to mate with one another. Furthermore, lip 212 facilitates both placement of end bell portion 210 and coupling of the end bell portion to terminal assembly 200 of fuse assembly 100.

[0035] In an exemplary embodiment, the end bells 202 further include insert pins (FIGS. 2B and 2C). First end bell 202a includes insert pins 214a and 214b, and second end bell 202b includes insert pins 214c and 214d (collectively, "insertion pins 214"). In one embodiment, the insert pins 214 are made of a metal or a metal alloy, such as stainless steel. The number of insert pins can vary. In one embodiment, each end bell portion 210 includes one insert pin 214. In one exemplary embodiment, the insert pins 214 enable connection between the end bells 202 and the fuse body 106 (see also FIG. 1). The insert pins 214 are described in more detail below in conjunction with the description of FIG. 12.

[0036] 3A and 3B are representative illustrations of end bell portion 210 according to an exemplary embodiment. Perspective views of end bell portion 210 are provided from different angles, allowing some additional details to be visible. Because each end bell portion 210 is substantially similar to one another, in some embodiments, various features of the end bell portions are also substantially similar, regardless of whether the end bell is located on the top, bottom, left, or right side of terminal assembly 200.

[0037] Each end bell portion 210 includes a first inclined surface 316, a second inclined surface 318, a central (horizontal) surface 320, a semicircular surface 322, and two flat side surfaces 324a and 324b (collectively, "side surfaces 324"). Except for semicircular surface 322, the other surfaces are substantially flat. Central surface 320 is formed on one side of first inclined surface 316 and second inclined surface 318.

[0038] Each face of end bell portion 210 contains features. Side 324 shows end bell aperture 332, which is a transversely extending cylindrical void visible on both sides of end bell portion 210. Once the two end bells are connected to the fuse body, end bell aperture 332 is used to fill fuse assembly 100 with sand or other material, after which the aperture is sealed on both sides with plugs 338 (FIG. 3B). Semicircular face 322 shows insertion pins 214 extending radially from its surface.

[0039] Additionally, in the exemplary embodiment, first angled surface 316 features a receptacle 330, and second angled surface 318 features a protrusion 328. Receptacle 330 on one end bell portion 210 is designed to mate with protrusion 328 on the second end bell portion. In the exemplary embodiment, when mating occurs, angled surface 316 on one end bell portion 210 is flush with angled surface 318 on the other end bell portion.

[0040] The receptacle 330 includes a flat surface (referred to herein as a lip seat 334) extending from the central portion 320 and a block receiver 340 perpendicular to the lip seat. Similarly, the projection 328 has a lip seat 336, which is a flat surface extending from the central portion, and a block 342 perpendicular to the lip seat. In the exemplary embodiment, the two lips of the terminal assembly 200 mate with the end bell portions 210, with one lip positioned on the lip seat 334 of the receptacle 330 and the second lip positioned on the lip seat 336 of the projection 328 (see FIG. 2C ). This allows the terminal assembly 200 to be placed between the two mated end bell portions 210 that form the end bell 202, thus forming a seal between the end bell portions and the terminal assembly. Furthermore, the block 342 of one end bell portion 210 engages the block receiver 340 of the other end bell portion. Those skilled in the art will appreciate that the shape and size of lip seat 334 and block receiver 340 of receptacle 330 and lip seat 336 and block 342 of projection 328 can vary and still provide desired mating characteristics for end bell portion 210. Additionally, when modifying receptacle 330 and projection 328, lip 212 of terminal assembly 200 can also be changed to facilitate mating of the components.

[0041] In the exemplary embodiment, central surface 320 features an intervening crush rib 326 extending between first angled surface 316 and second angled surface 318. In one embodiment, crush rib 326 is positioned on one side of central surface 320, rather than in the center, closer to side 324b than to side 324a. Crush rib 326 is also positioned to avoid lip seats 334, 336, although the placement of crush rib 326 may vary from that shown. In one exemplary embodiment, when two end bell portions 210 are engaged with each other, crush rib 326 of the upper end bell portion (e.g., end bell portion 210b in FIG. 2B) is positioned directly above the crush rib of the lower end bell portion (e.g., end bell portion 210a) with terminal assembly 200 positioned between the two end bell portions. In the exemplary embodiment, crush rib 326, along with lip 212, facilitates placement of terminal assembly 200 between two end bell portions 210. In one embodiment, terminal assembly 200 includes a recess or other receiving structure for mating with crush rib 326.

[0042] 4A and 4B are representative diagrams of an end bell portion connection structure 400 for the fuse assembly 100 of FIG. 1, according to an example embodiment. FIG. 4A is an exploded perspective view of the end bell portion connection structure 400, and FIG. 4B is a cross-sectional view thereof. The first end bell portion 210a and the second end bell portion 210b are disposed on either side of the fuse terminal 204. When the two end bell portions 210 are engaged with one another, such as by press-fitting, with the lip 212 of the terminal assembly 200 disposed therebetween, the end bell portions are secured radially relative to one another and a seal is formed between the end bell portions and the terminal assembly.

[0043] In an exemplary embodiment, crush ribs 326 engage and deform terminal assembly 200 when two end bell portions 210 are engaged and radially secured relative to one another. A first crush rib 326a for end bell portion 210a and a second crush rib 326b for end bell portion 210b are shown. Terminal assembly 200 may be made from copper or a copper alloy and is pressed firmly against the zinc or zinc alloy material of end bell portions 210, causing some compression and possibly deformation of the two materials. In one exemplary embodiment, the pressure of connecting crush ribs 326 against terminal assembly 200 creates a sealed enclosure between the contents of fuse assembly 100 and the external environment.

[0044] Although a single crush rib 326 is shown (per end bell portion 210), each end bell portion may have multiple crush ribs 326. Furthermore, these features may be present in different locations on each end bell portion 210, without limitation.

[0045] In one exemplary embodiment, end bell portions 210 are pressed around terminal assembly 200 during manufacturing, resulting in concentric circular end bells at each end of the fuse (FIGS. 1 and 2B). Features on each end bell portion 210 (protrusion 328, receptacle 330, and crush rib 326) can be used both to locate the mating feature (lip 212) on terminal assembly 200 and to align the two end bell portions.

[0046] In the exemplary embodiment, once mated, the two end bell portions 210 are securely attached without the use of adhesives or sealants. This eliminates the need for regular end bell / terminal surfaces. The crush ribs 326 of the end bell portion 210 bite into the terminal assembly 200, deforming the material in both the end bell portion and the terminal assembly. Therefore, even if the surfaces of the end bell portion 210 or the terminal assembly 200 are not perfectly flat, the deformed mating interface can create a tight seal between the two materials. In one exemplary embodiment, the crush ribs 326 are intentionally inserted into the terminal assembly 200 to provide mechanical support and a secure connection between the end bell portion 210 and the terminal assembly 200. Furthermore, in one exemplary embodiment, the pressure of connecting the crush ribs 326 to the terminal assembly 200 creates a sealed enclosure between the fuse contents and the external environment. Therefore, the mating elements of the novel fuse assembly 100 facilitate the manufacture of the fuse assembly by providing both stable fixation of the end bell to the fuse body and positioning guidance during assembly.

[0047] Fuse Assembly 500

[0048] FIG. 5 is a representative perspective view of a novel fuse assembly 500 according to an exemplary embodiment. The fuse assembly 500 features a fuse body 506 that is transparent to facilitate visualization of the other elements of the fuse assembly. Two end bells, a first end bell 502 a and a second end bell 502 b (collectively, “end bells 502”), are disposed at opposite ends of the fuse body 506. A fuse element 508 is disposed between a first terminal 504 a and a second terminal 504 b (collectively, “terminals 504”). The fuse element 508 may take on shapes and configurations other than those shown in FIG. 5 . As shown herein, both the end bells 502 and the terminal assembly of the fuse assembly 500 include mating elements that provide a stable fixation between the end bells and the fuse body and provide positioning guidance for assembly of the components, thereby helping to facilitate manufacturing.

[0049] Figures 6A through 6C are representative perspective views of terminal assemblies and end bells and end bell portions according to example embodiments, which are part of fuse assembly 500 of Figure 5. Figure 6A features terminal assembly 600A consisting of a fuse element disposed between two fuse terminals, Figure 6B features terminal assembly 600B having two attached end bells, and Figure 6C features terminal assembly 600C with a first end bell portion at the bottom and a second end bell portion at the top attached (collectively, "terminal assemblies 600").

[0050] Terminal assembly 600A ( FIG. 6A ) consists of a fuse element 608 disposed between a first terminal 604 a and a second terminal 604 b (collectively, “terminals 604”). While fuse element 608 is shown as a simple rectangular element without any bends or curves, it can take on a variety of shapes and sizes, and the particular shape or size of fuse element 608 is not intended to be limiting. In one exemplary embodiment, terminal 604 and fuse element are formed of a single metallic conductive material, such as zinc, copper, silver, aluminum, or an alloy or combination thereof. The present disclosure is not limited in this respect.

[0051] In one exemplary embodiment, terminal assembly 600 features a recess disposed proximate each terminal. Recesses 612a and 612b are located on opposite sides of terminal assembly 600 near first terminal 604a, and similarly, recesses 612c and 612d are located on opposite sides of terminal assembly 600 near second terminal 604b (collectively, "recesses 612"). As shown in FIG. 6C, end bell portion 610a includes a protrusion 616 that mates with recess 612b. In the exemplary embodiment, recess 612 and protrusion 616 facilitate connection of the end bell to terminal assembly 600. Protrusion 616 is described in more detail below in conjunction with the description of FIG. 7A.

[0052] FIG. 6B shows end bells 602a and 602b (collectively, "end bells 602"). In an exemplary embodiment, each end bell 602 is made up of two sections or two equal sections. First end bell 602a is made up of first end bell portion 610a and second end bell portion 610b, and second end bell 602b is made up of first end bell portion 610c and second end bell portion 610d (collectively, "end bell portions 610"). End bell portions 610 are designed to engage respective surfaces of terminal assembly 600 at recesses 612 and protrusions 616. In one exemplary embodiment, end bell portions 610 are formed of a zinc alloy.

[0053] FIG. 6C shows first end bell portion 610a of first end bell 602a and second end bell portion 610d of second end bell 602b. In one exemplary embodiment, end bell portions 610a, 610b, 610c, and 610d are substantially similar to one another and interchangeable. End bell portion 610 is positioned adjacent to terminal 604 at recess 612. As described in more detail below in conjunction with the description of FIGS. 7A-7B and 8A-8B, end bell portion 610 includes features that allow first and second end bell portions (e.g., 610a and 610b of end bell 602a or 610c and 610d of end bell 602b) to mate with one another. Furthermore, recess 612 facilitates both placement of end bell portion 610 and coupling of the end bell portion to terminal assembly 600 of fuse assembly 500.

[0054] While Figures 6B and 6C show end bell portion 610, in an alternative embodiment, terminal assembly 600 and fuse assembly 500 may alternatively be mated to end bell portion 810, as shown and described below in Figures 8A and 8B.

[0055] In the exemplary embodiment, the end bells 602 further include insert pins (FIGS. 6B and 6C). The first end bell 602a includes insert pins 614a, 614b, and 614c, and the second end bell 602b includes insert pins 614d, 614e, and 614f (collectively, "insertion pins 614"). In the exemplary embodiment, each end bell 602 further includes a fourth insert pin (not shown). In one embodiment, the insert pins 614 are made of a metal or a metal alloy, such as a zinc alloy. The number of insert pins can vary. In one embodiment, each end bell portion 610 includes two insert pins 614. In one exemplary embodiment, the insert pins 614 enable connection between the end bells 602 and the fuse body 506 (see also FIG. 5). The insert pins 614 are described in more detail below in conjunction with the description of FIG. 12.

[0056] 7A and 7B are representative diagrams of an end bell portion 610 and an end bell portion connection structure 700, respectively, according to an example embodiment. Figure 7A shows an end bell portion 610, and Figure 7B shows a cross-sectional view of the end bell portion connection structure 700 for the fuse assembly 500 of Figure 5. Because each end bell portion 610 is substantially similar to one another, in some embodiments, various features of the end bell portions are also substantially similar, regardless of whether the end bell portion is located on the top, bottom, left, or right side of the terminal assembly 600.

[0057] Each end bell portion 610 includes a feature surface 720 including a ridge 718, a semicircular surface 722 at the peripheral edge of the end bell portion, and two flat side surfaces 724a and 724b (collectively, "side surfaces 724"). Side surface 724a reveals an end bell aperture 732, which is a transversely extending cylindrical void visible on both sides of end bell portion 610. Once the two end bells are connected to the fuse body, end bell aperture 732 is used to fill fuse assembly 500 with sand or other material, after which the aperture is sealed on both sides with plugs (FIGS. 5 and 6B).

[0058] In the exemplary embodiment, feature surface 720 includes a protrusion 728, and ridge 718 of feature surface 720 includes a receptacle 730. Receptacle 730 of one end bell portion 610 is designed to receive protrusion 728 of a second end bell portion so that the two end bell portions mate. In the exemplary embodiment, when mating occurs, ridge 718 is raised relative to feature surface 720, thereby providing space for terminal assembly 600 to be positioned between the two end bell portions 610.

[0059] 6C , the protrusions 616 of the ridges 718 extend into the feature surface 720. In the exemplary embodiment, the recesses 612 of the terminal assembly 600 mate with the respective protrusions 616 of the end bell portion 610, thereby enabling successful mating of the end bell portion to the terminal assembly 600. The recesses 612 and protrusions 616 thus provide guides for positioning the end bell portion 610 on the upper and lower surfaces of the terminal assembly 600. Those skilled in the art will appreciate that the shapes and sizes of the recesses 612 and protrusions 616 can vary and still provide the end bell portion 610 with the desired mating characteristics.

[0060] In the exemplary embodiment, the feature surface 720 further features two crush ribs 726a and 726b (collectively, "crush ribs 726") located at the ends of the feature surface. In one exemplary embodiment, when the two end bell portions 610 are engaged with each other, with the terminal assembly 600 positioned between the two end bell portions, the crush rib 726a of a first end bell portion (e.g., end bell portion 610b in FIG. 6B) is positioned directly above the crush rib of a second end bell portion (e.g., end bell portion 610a), thereby forming a seal between the end bell portions and the terminal assembly. Similarly, the crush rib 726b of one end bell portion is positioned directly above the second crush rib of the other end bell portion. In the exemplary embodiment, the protrusions 616 facilitate positioning of each end bell portion 610 on the terminal assembly 600.

[0061] In the exemplary embodiment, the protrusion 728 of the end bell portion 610 further includes one or more ribs. While ribs 736a and 736b (collectively, “ribs 736”) are visible in FIG. 7A , there may be more or fewer ribs than shown. The rib 736 of the protrusion 728 is another engagement feature that deforms within the receptacle 730 during assembly to maintain the relative position of the two end bell portions 610. Thus, when the end bell portions 610 are engaged with each other, the rib 736, like the crush rib 726, facilitates integration of the respective components, resulting in an airtight connection between the end bells 602 and the formation of a seal therebetween without the use of adhesives. The recess 612 and protrusion 616 similarly help seal the end bell portion 610 against the terminal assembly 600.

[0062] In an exemplary embodiment, as shown in the cross-sectional view of FIG. 7B , crush ribs 726 engage and deform terminal assembly 600 when the two end bell portions 610 are engaged and radially secured relative to one another. First and second crush ribs 726a and 726b are shown for end bell portion 610b, as well as third and fourth crush ribs 726c and 726d for end bell portion 610a. Terminal assembly 600 may be made from copper or a copper alloy and is pressed firmly against the zinc or zinc alloy material of end bell portions 610, causing some compression and / or deformation of the two materials. Optional rib 736 also facilitates secure connection of the two end bell portions 610. In one exemplary embodiment, the pressure connecting crush ribs 726 to terminal assembly 600 creates a sealed enclosure between the contents of fuse assembly 500 and the external environment.

[0063] In one exemplary embodiment, end bell portions 610 are pressed around terminal assembly 600 during manufacturing, resulting in concentric circular end bells at each end of the fuse (FIGS. 5 and 6B). Features on each end bell portion 610 (protrusion 728 and receptacle 730) can be used to align the two end bell portions, and protrusions 616 on each end bell portion are used to "locate" the respective recesses 612 on terminal assembly 600.

[0064] In an exemplary embodiment, once mated, the two end bell portions 610 are securely attached without the use of adhesives or sealants. This eliminates the need for regular end bell / terminal surfaces. The crush ribs 726 on the end bell portion 610 dig into the terminal assembly 600, deforming the material in both the end bell portion and the terminal assembly. Therefore, even if the surfaces of the end bell portion 610 or the terminal assembly 600 are not perfectly flat, the mating interface can create a tight seal between the two materials. In one exemplary embodiment, the crush ribs 726 intentionally interfere with the surface of the terminal assembly 600 to provide mechanical support and a secure connection between the end bell portion 610 and the terminal assembly. Furthermore, in one exemplary embodiment, the pressure of connecting the crush ribs 726 to the terminal assembly surface creates a sealed enclosure between the fuse contents and the external environment.

[0065] 8A and 8B are representative diagrams of an end bell portion 810 according to an exemplary embodiment. FIG. 8A is a perspective view of the end bell portion 810, and FIG. 8B is a cross-sectional view thereof. The end bell portion 810 may be a portion of the fuse assembly 500 of FIG. 5. The end bell portion 810 features a feature surface 820 with a ridge 818, which includes a protrusion 828, and the ridge includes a receptacle 830. In the exemplary embodiment, the protrusion 828 and the receptacle 830 facilitate connection of the end bell 610 to the terminal assembly 600. The end bell portion 810 also features a protrusion 816, which is designed to mate with the recess 612 ( FIG. 6C ) of the terminal assembly 600. In the exemplary embodiment, the recess 612 and the protrusion 816 facilitate positioning guidance when connecting the end bell portion to the terminal assembly 600.

[0066] Similar to end bell 610 (FIGS. 7A and 7B), end bell 810 also features two crush ribs 826a and 826b (collectively, "crush ribs 826") located at the ends of feature surface 820. In one exemplary embodiment, when two end bell portions 810 are engaged with one another, such as by press-fitting, crush rib 826a of the upper end bell portion is positioned directly above the crush rib of the lower end bell portion with terminal assembly 600 positioned between the two end bell portions. Similarly, crush rib 826b of the upper end bell portion is positioned directly above the second crush rib of the lower end bell portion. In the exemplary embodiment, the two crush ribs 826, together with protrusion 816, facilitate positioning of each end bell portion 810 on terminal assembly 600.

[0067] Additionally, in the exemplary embodiment, end bell 810 features troughs adjacent crush ribs 826. Trough 844a is adjacent to crush rib 826a, and trough 844b is adjacent to crush rib 826b (collectively, "troughs 844"). In the cross-sectional view of FIG. 8B, crush ribs 826 are shown as protrusions and troughs 844 are shown as depressions. When end bell portions 810 are engaged, crush ribs 826 may be substantially compressed and / or deformed, allowing excess compressed / deformed material to be contained within trough 844. If the compression / deformation interference is less, the excess material may be less and trough 844 may not be used. Thus, end bell portions 810 provide additional flexibility in the assembly of fuse assembly 500. Unlike the mating elements of fuse assembly 100, the mating elements of novel fuse assembly 500 also provide both stable fixation of the end bells to the fuse body and positioning guidance during assembly, thereby facilitating manufacture of the fuse assembly.

[0068] 9A and 9B are representative diagrams of an end bell portion connection structure 900 according to an exemplary embodiment. FIG. 9A is a perspective view of the end bell portion connection structure 900, and FIG. 9B is a cross-sectional view thereof. A terminal assembly 902 is shown disposed between a first end bell portion 910a and a second end bell portion 910b (collectively, "end bell portions 910"). The elements shown in FIGS. 9A and 9B may be part of fuse assembly 500 (FIG. 5). In the exemplary embodiment, second end bell portion 910b is substantially similar to first end bell portion 910a, although it shows fewer features. Terminal assembly 902 shares some similarities with terminal assemblies 200 and 600 described above, and end bell portion 910 shares some similarities with end bell portions 610 and 810 described above.

[0069] The end bell portions 910 feature both a protrusion 928 and a receptacle 930. The protrusion 928 of one end bell portion 910 is designed to fit into the receptacle of the second end bell portion. The terminal assembly 902 features recesses 912a and 912b (collectively, "recesses 912") located on opposite ends of the terminal assembly. The bottom end bell portion 910a exhibits a protrusion 916, and the end bell portion 910b, which is substantially similar to end bell portion 910a, also includes a protrusion. In the exemplary embodiment, these protrusions 916 are designed to fit into respective recesses 912 of the terminal assembly 902. When the two end bell portions 910 are engaged with each other, the protrusion 916 of end bell portion 910a fits into the recess 912a, and the recess (not shown) of end bell portion 912b fits into the recess 912b.

[0070] In the exemplary embodiment, end bell portion 910a further includes a pair of crush ribs 926a and 926b (collectively, “crush ribs 926”). Each crush rib 926 has a trough on either side. Thus, crush rib 926a is disposed on one side of troughs 944a and 944b, and crush rib 926b is disposed on one side of troughs 944c and 944d (collectively, “troughs 944”). When end bell portions 910 are engaged, crush ribs 926 may be substantially compressed and / or deformed, allowing excess material from the compression / deformation to be contained in troughs 944 on one side of the crush rib, a second side of the crush rib, or both sides of the crush rib. If the compression / deformation interference is small, there may be less excess material, and one or more of troughs 944 may not be used.

[0071] In the exemplary embodiment, terminal assembly 902 includes mating grooves for coupling with crush ribs 926 of end bell portion 910. On a first surface of terminal assembly 902, a first mating groove 942a is on one side of recess 912 and a second mating groove 942b is on the other side of the recess, and on a second surface of terminal assembly, a third mating groove 942c is on one side of the recess and a second mating groove 942d is on the other side of the recess (collectively, "mating grooves 942"). In the exemplary embodiment, mating grooves 942 are spaced apart by a distance d, and crush ribs 926 are also spaced apart by a distance d. Thus, mating grooves 942 of terminal assembly 902 are receiving structures for mating with crush ribs 926 of end bell portion 910.

[0072] Terminal assembly 902, which may be made from copper or a copper alloy, is pressed firmly against the zinc or zinc alloy material of end bell portion 910, causing some compression and possibly deformation of the two materials. In one exemplary embodiment, the pressure of connecting crush ribs 926 against respective mating grooves 942 of terminal assembly 910 creates a sealed enclosure between the contents of the fuse assembly and the external environment. Crush ribs 926 and mating grooves 942 facilitate integration of the respective components, resulting in an airtight connection within the end bell without the use of adhesives. Recesses 912 and protrusions 916 similarly help seal end bell portion 910 against terminal assembly 902.

[0073] In the exemplary embodiment, protrusions 916 on end bell portions 910 and recesses 912 on terminal assembly 902 provide positioning guidance during manufacturing of fuse assembly 500. The addition of mating grooves 942 on terminal assembly 902 enhances this positioning guidance in the exemplary embodiment because crush ribs 926 on end bell portions 910 can "find" the mating grooves on terminal assembly 902, facilitating manufacturing of the fuse assembly.

[0074] Insertion pin slot

[0075] The fuse assembly described above features an insert pin that is used to secure the end bell to the fuse body. In conventional fuse assemblies, cylindrical holes are drilled in both the end bell and the fuse body. These holes axially retain the end bell within the cylindrical tube of the fuse body.

[0076] 10 is an illustration of a conventional drilling process for a prior art fuse assembly. This drilling operation can be very messy and can cause contamination inside the fuse assembly, which can adversely affect the operation of the fuse element. For example, if conductive material from the drilling operation remains inside the fuse assembly, it can allow current to flow between the two terminals even if the fuse element ruptures due to a fault condition. Thus, material from the drilling operation can prevent the fuse from functioning as designed.

[0077] To retain the end bells on the opposing ends of the fuse, holes are drilled radially through the fuse body to a specified depth into the end bells. A metal pin is then inserted into the hole to securely hold the end bells in place. Drilling holes in most fuse body materials is fast, efficient, and does not easily dull the drill bit. Drilling blind holes in the end bell section is dangerous because of uncertainty about whether the drill hole is in the correct position. Furthermore, drilling blind holes in zinc is difficult, time-consuming, and rapidly dulls the drill bit, damaging it with high regularity, which is a hindrance for mass production. Because they are made of zinc or a zinc alloy, drilling holes in the end bell section 210, 610, or 910 is problematic in some embodiments.

[0078] Instead of drilling holes, the end bell portion can be made using a molding operation such as injection molding. A core and cavity are formed in one half of the mold tool that gives the end bell portion its final shape. In this way, it is possible to mold cylindrical holes used for insertion pins.

[0079] However, using a molding operation for cylindrical holes can have drawbacks. Figure 11A is a representative illustration of an end bell portion having cylindrical holes, according to an example embodiment. End bell portion 1100 may be similar to end bell portion 210 of fuse assembly 100 or end bell portions 610 or 910 of fuse assembly 500. Two cylindrical holes 1104a and 1104b are shown (collectively "holes 1104") radially disposed at the peripheral edge of end bell portion 1100 to form a radial cavity.

[0080] The upward vertical arrow indicates the pulling of the tool cavity for the molding operation, and the downward vertical arrow indicates the pulling of the tool core. The diagonal arrow indicates the tooling slide for hole 1104. Unfortunately, during tooling of hole 1104, the interrupted surface profile presented by parting lines 1106a and 1106b poses a risk to uniform assembly of the fuse body.

[0081] Adding die-cast / molded holes (as opposed to slots) requires additional sliding action in the tool, which creates an uneven surface due to an additional parting line. A uniform surface is preferred for the end bell, since this is the mating surface between the outside of the end bell and the inside of the body. Thus, Figure 11A shows an inefficient tooling layout. The diagonal lines indicate tooling "slides" that are not aligned with the tool pull direction, which adds both cost and an additional parting line to the final part.

[0082] Instead, in an exemplary embodiment, the molding operation forms the end bells with slots rather than cylindrical holes, and these slots are specifically designed to eliminate the need for lateral movement in the molding tool and to maintain a smooth, unobstructed end bell surface.

[0083] 11B is a representative diagram of an end bell portion 1150 with slots according to an exemplary embodiment. Using a molding operation rather than drilling, two slots 1112a and 1112b are radially formed in the peripheral edge (e.g., semicircular surface) of the end bell portion 1150 to form radial cavities (collectively, "slots 1112"). Again, the upward vertical arrow indicates the pull of the tool cavity, and the downward vertical arrow indicates the pull of the tool core. Unlike the holes 1012, the slots 1112 allow for a straight pull direction from the tool cavity. In some embodiments, the added slots are specifically designed to eliminate the need for lateral movement in the molding tool and maintain a smooth, unobstructed end bell surface. In exemplary embodiments, the non-conductive material that makes up the fuses, such as fuse body 106 (FIG. 1) and fuse body 506 (FIG. 5), is also created using a molding process, with the holes being part of the core and cavity of the fuse body, eliminating the need to drill holes in the fuse body.

[0084] Parting lines 1114a and 1114b are shown in slot 1112a, and parting lines 1114c and 1114d are shown in slot 1112b (collectively, "parting lines 1114"). In contrast to parting line 1106 in FIG. 11A, parting line 1114 of end bell 1110 does not affect the surface of the end bell, but only the slot itself, which will receive the insertion pin during assembly. Thus, in some embodiments, the alternative molding operation of FIG. 11B improves assembly of the fuse body by ensuring a uniform surface profile with minimal interruptions. Thus, in an exemplary embodiment, FIG. 11B shows an improved tooling layout compared to that of FIG. 11A. By using slots rather than cylindrical holes, the slots are made in the tooling using the same pull direction as the rest of the tool.

[0085] Fuse Assembly 1200

[0086] 12 is a representative exploded perspective view of a fuse assembly 1200 featuring end bells with pre-molded alignment slots, according to an exemplary embodiment. A fuse body 1206 and a cross section of a single end bell 1202 are shown. End bell 1202 may be a two-part end bell, such as end bell 102 of fuse assembly 100 and end bell 502 of fuse assembly 500. Fuse terminals 1204a and 1204b on opposite ends of fuse body 1206 are shown.

[0087] The fuse body 1206 includes fuse body holes 1216a, 1216b, 1216c, and 1216d shown in cross section of the end bell 1202, as well as fuse body hole 1216e shown on the opposite side of the fuse body for securing a second end bell (not shown) (collectively, "fuse body holes 1216").

[0088] In an exemplary embodiment, a die-cast / molded slot of predetermined size and orientation is located in each end bell 1202, eliminating the need for drilling holes. Alignment slots 1212a, 1212b, 1212c, and 1212d, such as those shown in FIG. 11B, are pre-molded into the peripheral surface of end bell 1202 (collectively, "alignment slots 1212" or "slots 1212"). In some embodiments, a cross-sectional view shows that slot 1212 has a somewhat trapezoidal shape, with the top of the slot near the peripheral surface of end bell 1202 being wider than the bottom. In some embodiments, slot bottom 1218 visible in alignment slot 1212b is circular, but is shown as a semicircle in the cross-sectional view.

[0089] Fuse assembly 1200 also features insert pins 1214a, 1214b, and 1214d for securing end bell 1202, and insert pins 1214e, 1214f, and 1214g (collectively, “insertion pins 1214”) for securing a second end bell (not shown). It is envisioned that invisible insert pins 1214 are insertable into fuse body holes 1216c and slots 1212c for end bell 1202 and the invisible end bell. In one embodiment, insert pins 1214 are made of a metal or metal alloy material, such as stainless steel. In one exemplary embodiment, four insert pins 1214 are used to secure each end bell, although the number of insert pins can vary.

[0090] The fuse body holes 1216 and slots 1212 together receive insertion pins 1214 to secure the end bells 1202 and invisible end bells to the fuse body 1206. The pre-cast / pre-molded alignment slots 1212 significantly simplify the fuse manufacturing process by eliminating the need to drill holes in the fuse end bells without adding tooling complexity. The use of slots 1212 (rather than cylindrical holes) in the end bells 1202 allows the end bell tooling to remain basic with a simple core / cavity block, thereby avoiding costly lateral movement features in the tooling. Thus, in some embodiments, the use of slots minimizes the impact on tooling costs and part cycle time. Furthermore, having pre-cast / pre-molded end bell slots allows holes to be drilled separately in the fuse body prior to assembly.

[0091] Additionally, in exemplary embodiments, the risk of metal particles getting into the functional area of ​​the fuse due to the drilling of the end bells is eliminated due to the presence of pre-cast / pre-molded alignment slots 1212. In exemplary embodiments, the end bell slot design of FIG. 12 guides the alignment of the pin insertion and allows the drilling of holes in the fuse body to be done at any time independent of other assembly.

[0092] It is to be understood that, as used herein, the singular and the prefaces of elements or steps such as "a" or "an" do not exclude a plurality of elements or steps unless the context clearly states otherwise. Furthermore, references to "one embodiment" of the present disclosure are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features.

[0093] While this disclosure refers to particular embodiments, numerous modifications, substitutions, and variations to the described embodiments are possible without departing from the breadth and scope of the disclosure as defined by the appended claims. Accordingly, it is intended that the disclosure not be limited to the described embodiments, but rather have the full scope defined by the language of the following claims and equivalents thereof.

Claims

1. Fuse body and a terminal assembly disposed within the fuse body and having opposing first and second faces, the terminal assembly having a fuse element extending between the first and second terminals; an end bell for connecting to the fuse body, a first end bell portion including a first crush rib that engages the first surface of the terminal assembly; and a second end bell portion including a second crush rib that engages the second surface of the terminal assembly; an end bell having Equipped with the first end bell portion and the second end bell portion are fixed to each other with the terminal assembly therebetween, and the first crush rib and the second crush rib surround the terminal assembly to form a seal. Fuse assembly.

2. The first end bell portion is a first receptacle formed in the first end bell portion; a first projection extending from the first end bell portion; Further comprising: the second end bell portion includes a second receptacle formed in the second end bell portion and a second protrusion extending from the second end bell portion; the first protrusion matingly engages with the second receptacle, and the second protrusion matingly engages with the first receptacle; 10. The fuse assembly of claim 1.

3. a first slot formed in a periphery of the first end bell portion; a second slot formed in a periphery of the second end bell portion; a first hole formed in the fuse body; a second hole formed in the fuse body; a first insertion pin extending through the first hole and the first slot; a second insertion pin extending through the second hole and the second slot; Further provided with the first and second insertion pins secure the end bell to the fuse body; 3. The fuse assembly of claim 1 or 2.

4. the first crush rib is disposed on a surface of the first end bell portion interposed between the first receptacle and the first projection; 3. The fuse assembly of claim 2.

5. the first end bell portion is identical to the second end bell portion; 3. The fuse assembly of claim 1 or 2.

6. The end bell is made of a zinc alloy material.

3. The fuse assembly of claim 1 or 2.

7. the first crush rib deforms and penetrates the first surface, and the second crush rib deforms and penetrates the second surface, thereby forming an airtight seal between the first end bell portion, the terminal assembly, and the second end bell portion.

3. The fuse assembly of claim 1 or 2.

8. a first mating groove and a second mating groove on the first surface of the terminal assembly; a third mating groove and a fourth mating groove on the second surface of the terminal assembly; a third crush rib on the first end bell portion; and a fourth crush rib on the second end bell portion; and Further provided with the first crush rib is fitted into the first fitting groove, the second crush rib is fitted into the third fitting groove, the third crush rib is fitted into the second fitting groove, and the fourth crush rib is fitted into the fourth fitting groove; 3. The fuse assembly of claim 1 or 2.

9. The first end bell portion is a first feature surface including a first ridge and a first protrusion, the first ridge defining a first receptacle; Further comprising:

9. The fuse assembly of claim 8.

10. the second end bell portion further includes a second feature surface including a second ridge and a second protrusion, the second ridge defining a second receptacle, and in response to the first end bell portion being secured to the second end bell portion, the second protrusion engages with the first receptacle and the first protrusion engages with the second receptacle.

10. The fuse assembly of claim 9.

11. a plurality of troughs disposed adjacent to each crush rib, the troughs allowing excess material from each crush rib to flow into the respective trough when the first end bell portion is secured to the second end bell portion; 11. The fuse assembly of claim 10.

12. an end bell adapted to secure a terminal assembly within a fuse body, a first end bell portion having a first projection, a first receptacle, and a first crush rib, the first crush rib adapted to engage a first surface of the terminal assembly; a second end bell portion having a second projection, a second receptacle, and a second crush rib, the second crush rib adapted to engage a second surface of the terminal assembly opposite the first surface; Equipped with the first protrusion engages the second receptacle, and the second protrusion engages the first receptacle to form a seal around the terminal assembly; End bell.

13. a first lip sheet formed on the first projection; a second lip sheet formed on the second projection; and Further provided with The terminal assembly extends in a first direction, a first lip of the terminal assembly is located on a first side of the terminal assembly in a second direction intersecting the first direction and adjacent to a first terminal provided at one end of the terminal assembly in the first direction, and a second lip of the terminal assembly is located on a second side of the terminal assembly opposite to the first side in the second direction and adjacent to the first terminal of the terminal assembly. The end bell according to claim 12.

14. In response to the first end bell portion being fixed to the second end bell portion, the first lip of the terminal assembly engages with the first lip seat, and the second lip of the terminal assembly engages with the second lip seat. The end bell according to claim 13.

15. The first end bell portion is a feature surface including a ridge; The third crush rib and and the first crush rib is formed at an end of the feature surface, and the third crush rib is formed at a second end of the feature surface; the first protrusion is disposed on the feature surface, and the first receptacle is disposed on the raised portion; An end bell according to claim 12 or 13.

16. a protrusion extending from the raised portion, the protrusion adapted to fit into a recess in the terminal assembly; The end bell according to claim 15.

17. a first slot formed in a periphery of the first end bell portion; a second slot formed in a second periphery of the second end bell portion; and Further provided with a first insertion pin is inserted into a first cylindrical hole and the first slot of the fuse body, and a second insertion pin is inserted into a second cylindrical hole and the second slot of the fuse body, thereby fixing the end bell to the fuse body; An end bell according to claim 12 or 13.

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