Patent Description:
Used in electrical systems to protect against excessive current, fuses are sacrificial devices which break when an overcurrent condition occurs. Fuses include a fuse element, such as a metal wire or strip, that links two metal contact terminals together, and which melts/breaks if too much current flows. The breakage causes an open circuit, thus protecting devices 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 a component protection device, fuses are also safety devices, such as when used in vehicles, as they protect against fires in response to vehicle accidents.

Some fuses may include endbells at either side of the fuse body, with a fuse element disposed in the fuse body. The endbells are designed to support and protect the fuse element from external forces and environmental stresses. The existing fuse technology utilizes two fully circular endbells, each of which is engaged such as by first press-fitting or brazing into its respective separate terminal before the fuse element is attached. This assembly method thus involves a secondary process, such as soldering or welding, to attach the fuse element between the two terminals, increasing the complexity of manufacture and risking quality deviation. Further, the sliding interface between conductive terminal and endbell during assembly is not designed to produce a sealed envelope between fuse contents and the environment.

The endbells are secured to the fuse body using insertion pins. Drilling holes in the endbells, which are typically made of a softer metal than the metal used for the fuse terminal, can be messy, resulting in contaminants being left inside the fuse body. Tight sealing of the endbells to the fuse body ensures that the fuse assembly operates as designed. Thus, the endbells may be sealed to the fuse body using adhesive materials, which can also be messy. For instance, <CIT> discloses a fuse assembly comprising a fuse body, a terminal assembly disposed within the fuse body and having first and second opposing surfaces, the terminal assembly comprising a fuse element extending between a first terminal and a second terminal, an endbell to be coupled to the fuse body, the endbell comprising a first endbell portion and a second endbell portion, the first endbell portion and the second endbell portion being fastened to one another with the terminal assembly sandwiched therebetween. In this example, the first endbell portion comprises a first protrusion and a first receptacle, and the second endbell portion comprises a second protrusion and a second receptacle, wherein the first protrusion engages the second receptacle and the second protrusion engages the first receptacle.

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.

An exemplary embodiment of a fuse assembly in accordance with the present disclosure may include a fuse body to house a fuse element, a terminal assembly, and an endbell. The terminal assembly has first and second opposing surfaces and features a fuse element extending between a first terminal and a second terminal. The endbell includes first and second endbell portions, each having a crush rib. When the two endbell portions are fastened to one another with the terminal assembly sandwiched between them, the first crush rib engages the first surface of the terminal assembly and the second crush rib engages the second surface of the terminal assembly such that the first crush rib and the second crush rib form a seal around the terminal assembly.

An exemplary embodiment of an endbell in accordance with the present disclosure, along with a second endbell, is adapted to secure a terminal assembly inside a fuse housing and may include a first endbell portion and a second endbell portion. The first endbell 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 a terminal assembly, which includes the fuse element. The second endbell portion has a second protrusion, a second receptacle, and a second crush rib. The second crush is adapted to engage with a second surface of the terminal assembly opposite a first surface. In response to the first endbell portion being fastened to the second endbell portion, the first protrusion engages the second receptacle and the second protrusion engages the first receptacle, forming a seal around the terminal assembly.

Another exemplary embodiment of a fuse assembly in accordance with the present disclosure may include a fuse body, first and second endbell portions, and first and second insertion pins. The fuse body is molded with first and second holes. The first endbell portion is molded with a first slot formed radially into its circumferential edge, forming a radial cavity through the first endbell. The second endbell portion is molded with a second slot formed radially into its circumferential edge, forming a radial cavity through the second endbell. 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 endbell portions to the fuse body.

Novel fuse assembly designs are disclosed herein. Two-piece endbell designs enable the terminals and fuse element of the fuse assembly to be formed as a single piece, eliminating the manufacturing variability caused by having to separately attach the fuse element between the two terminals. The two-piece endbells as well as the terminal assembly feature elements that enable engagement of the endbell portions to the terminal assembly without use of adhesives. The elements also provide positioning guidance for ease of assembly. The endbell portions feature slots rather than cylindrical holes for receipt of insertion pins used to secure the endbells to the fuse body, thus avoiding costly rework of molding tools.

For the sake of 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 placement and orientation of the features and components of the fuse assemblies, each with respect to the geometry and orientation of the assemblies as they appear in the perspective, exploded perspective, and cross-sectional views provided herein. Said terminology is not intended to be limiting and includes the words specifically mentioned, derivatives therein, and words of similar import.

<FIG> is a representative perspective view of a novel fuse assembly <NUM>, according to exemplary embodiments. The fuse assembly <NUM> features a fuse body <NUM>, which is transparent for ease of viewing other elements of the fuse assembly. Disposed at either end of the fuse body <NUM> are two endbells, a first endbell 102a and a second endbell 102b (collectively, "endbells <NUM>"). A fuse element <NUM> is disposed between a first terminal 104a and a second terminal 104b (collectively, "terminals <NUM>"). The fuse element <NUM> may assume shapes and configurations other than is shown in <FIG>. As will be shown herein, the components of the fuse assembly <NUM> include features that facilitate secure affixation of the components as well as positioning guidance of the components during assembly, thus ensuring ease of manufacture.

<FIG> are representative perspective views of a terminal assembly along with endbells and endbell portions, which are part of the fuse assembly <NUM> of <FIG>, according to exemplary embodiments. <FIG> features a terminal assembly 200A consisting of a fuse element disposed between two fuse terminals; <FIG> features the fuse assembly 200B having two attached endbells; and <FIG> features the fuse assembly 200C with an attached bottom first endbell portion and top second endbell portion (collectively, "terminal assembly <NUM>").

The terminal assembly 200A (<FIG>) consists of a fuse element <NUM> disposed between a first terminal 204a and a second terminal 204b (collectively, "terminals <NUM>"). Known as the sacrificial portion of the fuse assembly <NUM> because it breaks in response to a fault condition, the fuse element <NUM> is shown as a simple, rectangular element having no bends or curves. In various alternative embodiments, the fuse element <NUM> may assume a variety of other shapes and sizes, may have twists or turns, may be thinner than or the same thickness as the terminals <NUM>, and may consist of multiple pieces which are not shown in the figures. The present disclosure is not limited in this regard.

The fuse terminal <NUM> optionally includes terminal apertures 206a and 206b (collectively, "terminal apertures <NUM>") for fixably attaching the fuse to an electrical circuit. Though they are shown as circular openings, the terminal apertures <NUM> may be any of a variety of shapes and sizes. As one example, the fuse terminal <NUM> may be attached to a busbar by inserting electrically conductive bolts through the terminal apertures <NUM>, thus forming an electrical connection between the fuse and the busbar.

In an exemplary embodiment, the terminals <NUM> and the fuse element are formed as a unitary metallic, conductive material, such as zinc, copper, silver, aluminum, or alloys or combinations thereof, though the terminal assembly <NUM> shown and described herein is not limited to such a configuration. In other embodiments, the terminal assembly <NUM> of the fuse assembly <NUM> is formed by connecting the terminals <NUM> to either side of the fuse element <NUM>, such as by soldering, welding, or other means.

In an exemplary embodiment, the terminal assembly <NUM> features protruding lips formed proximate to each terminal. A first lip 212a and a second lip 212b are located on opposing sides of the terminal assembly <NUM> close to the first terminal 204a; similarly, a third lip 212c and a fourth lip 212d are located on opposing sides of the terminal assembly <NUM>, close to the second terminal 204b (collectively, "lips <NUM>"). As illustrated in <FIG>, the lips <NUM> are mating features which facilitate connection of the endbells to the terminal assembly <NUM>, in exemplary embodiments. The lips <NUM> are described in more detail in conjunction with the description of <FIG>, below.

Endbells 202a and 202b are shown in <FIG> (collectively, "endbells <NUM>"). In exemplary embodiments, each endbell <NUM> consists of two parts or halves. The first endbell 202a consists of a first endbell portion 210a (bottom) and a second endbell portion 210b (top); the second endbell 202b consists of a first endbell portion 210c (bottom) and a second endbell portion 210d (top) (collectively, "endbell portions <NUM>"). The endbell portions <NUM> are designed to be engaged with, such as by press-fitting, into the terminal assembly <NUM> at the location of the lips <NUM>. In an exemplary embodiment, the endbell portions <NUM> are manufactured using a zinc alloy.

In legacy fuse designs, the endbells are a single-piece design having a rectangular slot in each endbell. The fuse element is slid through the slots of each endbell, followed by the attachment of the terminals to each end of the fuse element, such as by soldering, welding, and the like. In exemplary embodiments, the two-piece endbell design of the fuse assembly <NUM> enables the terminals and fuse element to be formed as a single piece, eliminating the manufacturing variability caused by having to separately attach the fuse element between the two terminals.

<FIG> shows the endbell portion 210a of the first endbell 202a and the endbell portion 210d of the second endbell 202b. In an exemplary embodiment, the endbell portions 210a, 210b, 210c, and 210d are substantially similar and interchangeable with one another. The endbell portions <NUM> are disposed next to the terminal <NUM> at the location of the lips <NUM>. Described in more detail in conjunction with the descriptions of <FIG> and 4A-4B, below, the endbell portions <NUM> include features that enable first and second endbell portions (e.g., 210a and 210b of endbell 202a or 210c and 210d of endbell 202b) to mate with one another. Further, the lips <NUM> facilitate both placement of the endbell portions <NUM> and coupling of the endbell portions to the terminal assembly <NUM> of the fuse assembly <NUM>.

In exemplary embodiments, the endbells <NUM> further include insertion pins (<FIG> and <FIG>). The first endbell 202a includes insertion pins 214a and 214b; the second endbell 202b includes insertion pins 214c and 214d (collectively, "insertion pins <NUM>"). In one embodiment, the insertion pins <NUM> are made of a metal or metal alloy, such as stainless steel. The number of insertion pins may vary. In one embodiment, each endbell portion <NUM> includes one insertion pin <NUM>. In an exemplary embodiment, the insertion pins <NUM> enable connection between the endbells <NUM> and the fuse body <NUM> (see also <FIG>). The insertion pins <NUM> are described in more detail in in conjunction with the description of <FIG>, below.

<FIG> are representative drawings of the endbell portions <NUM>, according to exemplary embodiments. The perspective views of the endbell portions <NUM> are given from different angles, making visible some additional details. Because each endbell portion <NUM> is substantially similar to each other endbell, whether disposed on top, on bottom, on the left side, or on the right side, of the terminal assembly <NUM>, the various features of the endbell portions are also substantially similar, in some embodiments.

Each endbell portion <NUM> includes a first diagonal surface <NUM>, a second diagonal surface <NUM>, a center (horizontal) surface <NUM>, a semi-circular surface <NUM>, and two flat side surfaces 324a and 324b (collectively, "side surfaces <NUM>"). With the exception of the semi-circular surface <NUM>, the other surfaces are substantially flat. The center surface <NUM> is formed on either side of the first and second diagonal surfaces <NUM>, <NUM>.

Each surface of the endbell portion <NUM> includes a feature. The side surfaces <NUM> show an endbell aperture <NUM>, which is a transverse cylindrical void visible on either side of the endbell portion <NUM>. The endbell aperture <NUM> is used to fill the fuse assembly <NUM> with sand or other material once the two endbells are connected to the fuse body, after which the aperture is sealed with plugs <NUM> on both sides (<FIG>). The semi-circular surface <NUM> shows an insertion pin <NUM> extending radially from its surface.

Further, in exemplary embodiments, the first diagonal surface <NUM> features a receptacle <NUM> and the second diagonal surface <NUM> features a protrusion <NUM>. The receptacle <NUM> of one endbell portion <NUM> is designed to mate with the protrusion <NUM> of a second endbell portion. In exemplary embodiments, when the mating occurs, the diagonal surface <NUM> of one endbell portion <NUM> will be flush against the diagonal surface <NUM> of the other endbell portion.

The receptacle <NUM> includes a flat surface, known herein as a lip seat <NUM>, that extends from the center portion <NUM>, and a block receiver <NUM> orthogonal to the lip seat. Likewise, the protrusion <NUM> has a flat surface, a lip seat <NUM>, that extends from the center portion, and a block <NUM> orthogonal to the lip seat. In exemplary embodiments, two lips of the terminal assembly <NUM> mate with the endbell portion <NUM> so that one lip is disposed on the lip seat <NUM> of the receptacle <NUM>, while the second lip is disposed on the lip seat <NUM> of the protrusion <NUM> (see <FIG>). This enables the terminal assembly <NUM> to be seated between two engaged endbell portions <NUM> that form the endbell <NUM>, such that a seal is formed between the endbell portions and the terminal assembly. Further, the block <NUM> of one endbell portion <NUM> engages the block receiver <NUM> of the other endbell portion. Designers of ordinary skill in the art will recognize that the lip seat <NUM> and block receiver <NUM> of receptacle <NUM> and the lip seat <NUM> and block <NUM> of protrusion <NUM> may vary in shape and size, while still providing the desired mating properties to the endbell portions <NUM>. Further, where the receptacle <NUM> and protrusion <NUM> && are modified, the lips <NUM> of the terminal assembly <NUM> may be varied as well to facilitate mating of the components.

In exemplary embodiments, the center surface <NUM> features a crush rib <NUM> extending between (intermediate) the first diagonal surface <NUM> and the second diagonal surface <NUM>. In one embodiment, the crush rib <NUM> is disposed, not in the center of the center surface <NUM>, but to one side, closer to the side surface 324b than to the side surface 324a. The crush rib <NUM> is also placed so as to avoid the lip seats <NUM>, <NUM>, though the placement of the crush rib <NUM> may vary from what is illustrated. In an exemplary embodiment, when two endbell portions <NUM> are engaged with each other, the crush rib <NUM> of the upper endbell portion (e.g., endbell portion 210b, <FIG>) is disposed directly over the crush rib of the lower endbell portion (e.g., endbell portion 210a), with the terminal assembly <NUM> disposed between the two endbell portions. In exemplary embodiments, the crush ribs <NUM>, along with the lips <NUM>, facilitate placement of the terminal assembly <NUM> between the two endbell portions <NUM>. In one embodiment, the terminal assembly <NUM> includes depressions or other receiving structures for mating with the crush ribs <NUM>.

<FIG> are representative drawings of endbell portion coupling <NUM> for the fuse assembly <NUM> of <FIG>, according to exemplary embodiments. <FIG> is an exploded perspective view and <FIG> is a cross-sectional view of the endbell portion coupling <NUM>. The first endbell portion 210a and the second endbell portion 210b are disposed on either side of the fuse terminal <NUM>. Once the two endbell portions <NUM> are engaged with each other, such as by press-fitting together, with the lips <NUM> of the terminal assembly <NUM> disposed therebetween, the endbell portions are radially secured to one another, and a seal is formed between the endbell portions and the terminal assembly.

In exemplary embodiments, when the two endbell portions <NUM> are engaged with and radially secured to one another, the crush ribs <NUM> mate with the terminal assembly <NUM> and deform. A first crush rib 326a for endbell portion 210a and a second crush rib 326b for endbell portion 210b is shown. The terminal assembly <NUM>, which may be made from copper or copper alloy, is pressed firmly against the zinc or zinc alloy material of the endbell portions <NUM>, such that some compression and possibly deformation of the two materials occurs. In an exemplary embodiment, the pressure of connecting the crush ribs <NUM> against the terminal assembly <NUM> produces a sealed envelope between the contents of the fuse assembly <NUM> and the external environment.

Although a single crush rib <NUM> (per endbell portion <NUM>) is shown, there may be multiple crush ribs <NUM> on each endbell portion. Further, these features may be presented in different locations on the respective endbell portions <NUM> without limitation.

In an exemplary embodiment, the endbell portions <NUM> are pressed around the terminal assembly <NUM> during manufacture, resulting in a concentric circular endbell on each end of the fuse (<FIG> and <FIG>). The features of each endbell portion <NUM> (the protrusions <NUM>, the receptacles <NUM>, and the crush ribs <NUM>) can be used to both locate to mating features (the lips <NUM>) on the terminal assembly <NUM> as well as align the two endbell portions.

In exemplary embodiments, once mated, the two endbell portions <NUM> become fixably attached without using an adhesive or sealant. This eliminates the need for endbell/terminal surface regularity. The crush ribs <NUM> in the endbell portions <NUM> bite into the terminal assembly <NUM>, deforming material in both the endbell portions and the terminal assembly. Thus, if the surface of either the endbell portion <NUM> or the terminal assembly <NUM> is not perfectly flat, the deformed-fit interface can still make a firm seal between the two materials. In an exemplary embodiment, the intentional interference of the crush ribs <NUM> with terminal assembly <NUM> provides mechanical support and a fixed connection between endbell portions <NUM> and the terminal assembly <NUM>. Further, in an exemplary embodiment, the pressure of connecting the crush ribs <NUM> with the terminal assembly <NUM> produces a sealed envelope between the fuse contents and the external environment. The mating elements of the novel fuse assembly <NUM> thus provide both secure affixation of the endbells to the fuse body and provide positioning guidance during assembly for ease of manufacturing the fuse assembly.

<FIG> is a representative perspective view of a novel fuse assembly <NUM>, according to exemplary embodiments. The fuse assembly <NUM> features a fuse body <NUM>, which is transparent for ease of viewing other elements of the fuse assembly. Disposed at either end of the fuse body <NUM> are two endbells, a first endbell 502a and a second endbell 502b (collectively, "endbells <NUM>"). A fuse element <NUM> is disposed between a first terminal 504a and a second terminal 504b (collectively, "terminals <NUM>"). The fuse element <NUM> may assume shapes and configurations other than is shown in <FIG>. As will be shown herein, both the endbells <NUM> and terminal assembly of the fuse assembly <NUM> include mating elements that provide secure affixation between the endbells and the fuse body, as well as providing positioning guidance for component assembly, thus facilitating ease of manufacture.

<FIG> are representative perspective views of a terminal assembly along with endbells and endbell portions, which are part of the fuse assembly <NUM> of <FIG>, according to exemplary embodiments. <FIG> features a terminal assembly 600A consisting of a fuse element disposed between two fuse terminals; <FIG> features the terminal assembly 600B having two attached endbells; and <FIG> features the terminal assembly 600C with an attached bottom first endbell portion and top second endbell portion (collectively, "terminal assembly <NUM>").

The terminal assembly 600A (<FIG>) consists of a fuse element <NUM> disposed between a first terminal 604a and a second terminal 604b (collectively, "terminals <NUM>"). The fuse element <NUM> is shown as a simple, rectangular element having no bends or curves but may assume a variety of shapes and sizes, as the particular shape or size of the fuse element <NUM> is not meant to be limiting. In an exemplary embodiment, the terminals <NUM> and the fuse element are formed as a unitary metallic, conductive material, such as zinc, copper, silver, aluminum, or alloys or combinations thereof. The present disclosure is not limited in this regard.

In an exemplary embodiment, the terminal assembly <NUM> features recesses disposed proximate to each terminal. A recess 612a and a recess 612b are located on opposing sides of the terminal assembly <NUM> close to the first terminal 604a; similarly, a recess 612c and a recess 612d are located on opposing sides of the terminal assembly <NUM>, close to the second terminal 604b (collectively, "recesses <NUM>"). As illustrated in <FIG>, the endbell portion 610a includes a projection <NUM> that mates with the recess 612b. The recesses <NUM> and projections <NUM> facilitate connection of the endbells to the terminal assembly <NUM>, in exemplary embodiments. The projections <NUM> are described in more detail in conjunction with the description of <FIG>, below.

Endbells 602a and 602b are shown in <FIG> (collectively, "endbells <NUM>"). In exemplary embodiments, each endbell <NUM> consists of two parts or halves. The first endbell 602a consists of a first endbell portion 610a and a second endbell portion 610b; the second endbell 602b consists of a first endbell portion 610c and a second endbell portion 610d (collectively, "endbell portions <NUM>"). The endbell portions <NUM> are designed to be engaged with respective surfaces of the terminal assembly <NUM> at the location of the lips <NUM> and the projections <NUM>. In an exemplary embodiment, the endbell portions <NUM> are formed of a zinc alloy.

<FIG> shows the first endbell portion 610a of the first endbell 602a and the second endbell portion 610d of the second endbell 602b. In an exemplary embodiment, the endbell portions 610a, 610b, 610c, and 610d are substantially similar and interchangeable with one another. The endbell portions <NUM> are disposed next to the terminal <NUM> at the location of the recesses <NUM>. Described in more detail in conjunction with the descriptions of <FIG> and <FIG>, below, the endbell portions <NUM> include features that enable first and second endbell portions (e.g., 610a and 610b of endbell 602a or 610c and 610d of endbell 602b) to mate with one another. Further, the recesses <NUM> facilitate both placement of the endbell portions <NUM> and coupling of the endbell portions to the terminal assembly <NUM> of the fuse assembly <NUM>.

Although <FIG> and <FIG> show endbell portions <NUM>, in an alternative embodiment, the terminal assembly <NUM> and the fuse assembly <NUM> may alternatively be fitted with endbell portions <NUM>, as illustrated and described in <FIG>, below.

In exemplary embodiments, the endbells <NUM> further include insertion pins (<FIG> and <FIG>). The first endbell 602a includes insertion pins 614a, 614b, and 614c; the second endbell 602b includes insertion pins 614d, 614e, and 614f (collectively, "insertion pins <NUM>"). In exemplary embodiments, each endbell <NUM> further includes a fourth insertion pin (not shown). In one embodiment, the insertion pins <NUM> are made of a metal or metal alloy, such as zinc alloy. The number of insertion pins may vary. In one embodiment, each endbell portion <NUM> includes two insertion pins <NUM>. In an exemplary embodiment, the insertion pins <NUM> enable connection between the endbells <NUM> and the fuse body <NUM> (see also <FIG>). The insertion pins <NUM> are described in more detail in in conjunction with the description of <FIG>, below.

<FIG> are representative drawings of endbell portion <NUM> and endbell portion coupling <NUM>, respectively, according to exemplary embodiments. <FIG> shows an endbell portion <NUM>; <FIG> shows a cross-sectional view of the endbell portion coupling <NUM> for the fuse assembly <NUM> of <FIG>. Because each endbell portion <NUM> is substantially similar to each other endbell portion, whether disposed on top, on bottom, on the left side, or on the right side, of the terminal assembly <NUM>, the various features of the endbell portions are also substantially similar.

Each endbell portion <NUM> includes a feature surface <NUM>, including a raised portion <NUM>, a semi-circular surface <NUM> at a circumferential edge of the endbell portion, and two flat side surfaces 724a and 724b (collectively, "side surfaces <NUM>"). Side surface 724a shows an endbell aperture <NUM>, which is a transverse cylindrical void visible on either side of the endbell portion <NUM>. The endbell aperture <NUM> is used to fill the fuse assembly <NUM> with sand or other material once the two endbells are connected to the fuse body, after which the aperture is sealed with plugs on both sides (<FIG> and <FIG>).

In exemplary embodiments, the feature surface <NUM> includes a protrusion <NUM> while the raised portion <NUM> of the feature surface <NUM> includes a receptacle <NUM>. The receptacle <NUM> of one endbell portion <NUM> is designed to receive the protrusion <NUM> of a second endbell portion, thereby mating the two endbell portions. In exemplary embodiments, when the mating occurs, the raised portion <NUM> is raised up, relative to the feature surface <NUM>, thus allowing room for the terminal assembly <NUM> to be disposed between the two endbell portions <NUM>.

First introduced in <FIG>, the projection <NUM> of the raised portion <NUM> extends into the feature surface <NUM>. In exemplary embodiments, the recesses <NUM> of the terminal assembly <NUM> mate with respective projections <NUM> of the endbell portion <NUM> so that the endbell portions can successfully mate with the terminal assembly <NUM>. The recesses <NUM> and projections <NUM> thus provide a guide for positioning of the endbell portions <NUM> upon the upper and lower surfaces of the terminal assembly <NUM>. Designers of ordinary skill in the art will recognize that the recesses <NUM> and projections <NUM> may vary in shape and size, while still providing the desired mating properties to the endbell portions <NUM>.

In exemplary embodiments, the feature surface <NUM> further features two crush ribs 726a and 726b disposed at the edges of the feature surface (collectively, "crush ribs <NUM>"). In an exemplary embodiment, when two endbell portions <NUM> are engaged with one another, the crush rib 726a of the first endbell portion (e.g., endbell portion 610b, <FIG>) is disposed directly over the crush rib of the second endbell portion (e.g., endbell portion 610a), with the terminal assembly <NUM> disposed between the two endbell portions, thus forming a seal between the endbell portions and the terminal assembly. Similarly, the crush rib 726b of the one endbell portion is disposed directly over a second crush rib of another endbell portion. In exemplary embodiments, the projection <NUM> facilitates placement of the each endbell portion <NUM> upon the terminal assembly <NUM>.

In exemplary embodiments, the protrusion <NUM> of the endbell portion <NUM> further includes one or more ribs. Ribs 736a and 736b are visible in <FIG> (collectively, "ribs <NUM>"), though there may be more or fewer ribs than are shown. The ribs <NUM> on the protrusion <NUM> are another engagement feature which deform in the receptacle <NUM> during assembly to retain the relative positions of the two endbell portions <NUM>. Thus, when the endbells <NUM> are engaged with one another, the ribs <NUM>, like the crush ribs <NUM>, facilitate melding of the respective components together, resulting in an air-tight coupling and formation of a seal between the endbells <NUM> without use of adhesive. The recesses <NUM> and projections <NUM> similarly help seal the endbell portions <NUM> against the terminal assembly <NUM>.

In exemplary embodiments, as illustrated in the cross-sectional view of <FIG>, when the two endbell portions <NUM> are engaged with and radially secured to one another, the crush ribs <NUM> mate with the terminal assembly <NUM> and deform. First and second crush ribs 726a and 726b for endbell portion 610b and third and fourth crush ribs 726c and 726d for endbell portion 610a are shown. The terminal assembly <NUM>, which may be made from copper or copper alloy, is pressed firmly against the zinc or zinc alloy material of the endbell portions <NUM>, such that some compression and/or deformation of the two materials occurs. The optional ribs <NUM> also facilitate the fixed coupling of the two endbell portions <NUM>. In an exemplary embodiment, the pressure of connecting the crush ribs <NUM> with the terminal assembly <NUM> produces a sealed envelope between the contents of the fuse assembly <NUM> and the external environment.

In an exemplary embodiment, the endbell portions <NUM> are pressed around the terminal assembly <NUM> during manufacture, resulting in a concentric circular endbell on each end of the fuse (<FIG> and <FIG>). The features of each endbell portion <NUM> (the protrusions <NUM> and the receptacles <NUM>) can be used to align the two endbell portions while the projection <NUM> of each endbell portion is used to "locate" respective recesses <NUM> on the terminal assembly <NUM>.

In exemplary embodiments, once mated, the two endbell portions <NUM> become fixably attached without using an adhesive or sealant. This eliminates the need for endbell/terminal surface regularity. The crush ribs <NUM> in the endbell portions <NUM> bite into the terminal assembly <NUM>, deforming material in both the endbell portions and the terminal assembly. Thus, if the surface of either the endbell portion <NUM> or the terminal assembly <NUM> is not perfectly flat, the engagement interface can still make a firm seal between the two materials. In an exemplary embodiment, the intentional interference of the crush ribs <NUM> with the surfaces of the terminal assembly <NUM> provides mechanical support and a fixed connection between endbell portions <NUM> and the terminal assembly. Further, in an exemplary embodiment, the pressure of connecting the crush ribs <NUM> the terminal assembly surfaces produces a sealed envelope between the fuse contents and the external environment.

<FIG> are representative drawings of endbell portion <NUM>, according to exemplary embodiments. <FIG> is a perspective view and <FIG> is a cross-sectional view of the endbell portion <NUM>. The endbell portion <NUM> may be part of the fuse assembly <NUM> of <FIG>. The endbell portion <NUM> features a feature surface <NUM> with a raised portion <NUM>, where the feature surface <NUM> includes a protrusion <NUM> and the raised portion includes a receptacle <NUM>. The protrusion <NUM> and receptacle <NUM> facilitate connection of the endbells <NUM> to the terminal assembly <NUM>, in exemplary embodiments. The endbell portion <NUM> also features a projection <NUM>. The projection <NUM> is designed to mate with the recess <NUM> of the terminal assembly <NUM> (<FIG>). The recesses <NUM> and projections <NUM> facilitate positioning guidance when connecting the endbell portions to the terminal assembly <NUM>, in exemplary embodiments.

As with the endbell <NUM> (<FIG>), the endbell <NUM> also features two crush ribs 826a and 826b disposed at the edges of the feature surface <NUM> (collectively, "crush ribs <NUM>"). In an exemplary embodiment, when two endbell portions <NUM> are engaged with one another, such as by press-fitting, the crush rib 826a of the upper endbell portion is disposed directly over the crush rib of the lower endbell portion, with the terminal assembly <NUM> disposed between the two endbell portions. Similarly, the crush rib 826b of the upper endbell portion is disposed directly over a second crush rib of the lower endbell portion. In exemplary embodiments, the two crush ribs <NUM>, along with the projection <NUM>, facilitate placement of the each endbell portion <NUM> upon the terminal assembly <NUM>.

Further, in exemplary embodiments, the endbell <NUM> features troughs which are adjacent to the crush ribs <NUM>. Trough 844a is adjacent to crush rib 826a while trough 844b is adjacent to crush rib 826b (collectively, "troughs <NUM>"). In the cross-sectional view of <FIG>, the crush ribs <NUM> are shown as projections while the troughs <NUM> are shown as depressions. When the endbell portions <NUM> are engaged together, sometimes the crush ribs <NUM> are substantially compressed and/or deformed, such that the excess material of the compression/deformation is able to fit into the troughs <NUM>. Where the compression/deformation causes a smaller interference, there may be less excess material, rendering the troughs <NUM> unused. The endbell portion <NUM> thus offers additional flexibility for the assembly of the fuse assembly <NUM>. The mating elements of the novel fuse assembly <NUM>, different from those of the fuse assembly <NUM>, also provide both secure affixation of the endbells to the fuse body and provide positioning guidance during assembly for ease of manufacturing the fuse assembly.

<FIG> are representative drawings of endbell portion coupling <NUM>, according to exemplary embodiments. <FIG> is a perspective view and <FIG> is a cross-sectional view of the endbell portion coupling <NUM>. A terminal assembly <NUM> is shown disposed between a first endbell portion 910a and a second endbell portion 910b (collectively, "endbell portions <NUM>"). The elements shown in <FIG> may be part of the fuse assembly <NUM> (<FIG>). The second endbell portion 910b, though showing fewer features, is substantially similar to the first endbell portion 910a, in exemplary embodiments. The terminal assembly <NUM> shares some similarities to the aforementioned terminal assemblies <NUM> and <NUM> and the endbell portions <NUM> share some similarities to the aforementioned endbell portions <NUM> and <NUM>.

The endbell portions <NUM> feature both a protrusion <NUM> and a receptacle <NUM>. The protrusion <NUM> of one endbell portion <NUM> is designed to fit into the receptacle of a second endbell portion. The terminal assembly <NUM> features a recess 912a and a recess 912b (collectively, "recesses <NUM>"), which are disposed on opposing edges of the terminal assembly. The bottom endbell portion 910a shows a projection <NUM>, and the endbell portion 910b, which is substantially similar to endbell portion 910a, also includes a projection. These projections <NUM> are designed to mate with respective recesses <NUM> of the terminal assembly <NUM>, in exemplary embodiments. When the two endbell portions <NUM> are engaged with one another, the projection <NUM> of the endbell portion 910a will fit into the recess 912a, with the recess (not shown) of the endbell portion 912b fitting into the recess 912b.

In exemplary embodiments, the endbell portion 910a further includes a pair of crush ribs 926a and 926b (collectively, "crush ribs <NUM>"). On either side of each crush rib <NUM> are troughs. Thus, crush rib 926a is disposed on either side of trough 944a and 944b, while crush rib 926b is disposed on either side of trough 944c and 944d (collectively, "troughs <NUM>"). When the endbell portions <NUM> are engaged with one another, sometimes the crush ribs <NUM> are substantially compressed and/or deformed, such that the excess material of the compression/deformation is able to fit into the troughs <NUM>, whether to one side of the crush rib, to a second side of the crush rib, or to both sides of the crush rib. Where the compression/deformation causes a smaller interference, there may be less excess material, rendering one or more of the troughs <NUM> unused.

In exemplary embodiments, the terminal assembly <NUM> includes mating grooves for coupling with the crush ribs <NUM> of the endbell portions <NUM>. On a first surface of the terminal assembly <NUM>, a first mating groove 942a is in one side of the recesses <NUM> and a second mating groove 942b is in another side of the recesses; on a second surface of the terminal assembly, a third mating groove 942c is in one side of the recesses and a second mating groove 942d is in another side of the recesses (collectively, "mating grooves <NUM>"). In exemplary embodiments, the mating grooves <NUM> are spaced a distance, d, apart and the crush ribs <NUM> are also spaced a distance, d, apart. The mating grooves <NUM> of the terminal assembly <NUM> are thus receiving structures for mating with the crush ribs <NUM> of the endbell portions <NUM>.

The terminal assembly <NUM>, which may be made from copper or copper alloy, is pressed firmly against the zinc or zinc alloy material of the endbell portions <NUM>, such that some compression and possibly deformation of the two materials occurs. In an exemplary embodiment, the pressure of connecting the crush ribs <NUM> against respective mating grooves <NUM> of the terminal assembly <NUM> produces a sealed envelope between the contents of the fuse assembly and the external environment. The crush ribs <NUM> and the mating grooves <NUM> facilitate melding of the respective components together, resulting in an air-tight coupling into the endbells without use of adhesive. The recesses <NUM> and projections <NUM> similarly help seal the endbell portions <NUM> against the terminal assembly <NUM>.

In exemplary embodiments, the projection <NUM> of the endbell portions <NUM> and the recesses <NUM> of the terminal assembly <NUM> provide positioning guidance during manufacture of the fuse assembly <NUM>. With the addition of mating grooves <NUM> in the terminal assembly <NUM>, this positioning guidance is enhanced, in exemplary embodiments, as the crush ribs <NUM> of the endbell portions <NUM> are able to "find" the mating grooves of the terminal assembly <NUM> for ease of manufacturing the fuse assembly.

The fuse assemblies described above feature insertion pins, which are used to secure the endbells to the fuse body. In legacy fuse assemblies, cylindrical holes are drilled into both the endbells and the fuse body. The holes retain the endbells axially within the cylindrical tube of the fuse body.

<FIG> is an illustration of a legacy drilling process of a fuse assembly according to the prior art. The drilling operation can be quite messy and may cause contamination inside the fuse assembly, which can negatively impact operation of the fuse element. For example, conductive materials from the drilling operation, if left inside the fuse assembly, may cause current to flow between the two terminals, even though the fuse element has been broken due to a fault condition. The material from the drilling operation may thus cause the fuse to not function as designed.

To retain the endbells at opposing ends of the fuse, holes are to be drilled radially to a specified depth through the fuse body and into the endbells. Metal pins are then inserted into the holes, rigidly retaining the endbells in place. Drilling into most fuse body materials is fast, efficient, and does not easily dull the drill bit. Drilling a blind hole into the endbell portion is risky because there is uncertainty about whether the drill hole is in the correct location. Further, drilling a blind hole into zinc is difficult, slow, and dulls the drill bit quickly and damages the drill bit with high regularity, which poses a problem for mass production. Because they are made from zinc or zinc alloy, drilling holes in the endbell portions <NUM>, <NUM>, or <NUM> is problematic, in some embodiments.

As an alternative to drilling, the endbell portions may be made using molding operations, such as injection molding. The core and cavity are the shaped sections in either half of the mold tool that give the endbell portion its final shape. The cylindrical holes used for the insertion pins can be molded in this way.

There may be drawbacks with using molding operations for the cylindrical holes, however. <FIG> is a representative drawing of an endbell portion with cylindrical holes, in accordance with exemplary embodiments. Endbell portion <NUM> may be similar to endbell portions <NUM> of fuse assembly <NUM> or endbell portions <NUM> or <NUM> of fuse assembly <NUM>. Two cylindrical holes 1104a and 1104b are shown, radially disposed in the circumferential edge of the endbell portion <NUM>, forming radial cavities (collectively, "holes <NUM>").

The upward vertical arrow indicates tool cavity pull while the downward vertical arrow indicates tool core pull of the molding operation. The diagonal arrows indicate tooling slide for the holes <NUM>. Unfortunately, during the tooling of the holes <NUM>, an interrupted surface profile, given by parting lines 1106a and 1106b, adds risk for consistent assembly to the fuse body.

Adding diecast/molded holes (as opposed to slots) require additional slides to be added to the tool, which in turn create an inconsistent surface due to the additional parting-lines. As this is the mating surface between the endbell exterior and the body interior, a consistent surface for the endbell is preferred. <FIG> thus shows an inefficient tooling layout. The diagonal lines indicate tooling "slides" that are not aligned with the tool pulling direction, which adds both cost and additional parting lines to the final part.

As an alternative, in exemplary embodiments, the endbells are formed in a molding operation with slots, rather than cylindrical holes. The slots are designed specifically to eliminate the need to add side actions in the molding tool and maintain a smooth uninterrupted endbell surface.

<FIG> is a representative drawing of an endbell portion having slots <NUM>, in accordance with exemplary embodiments. Using a molding operation rather than drilling, two slots 1112a and 1112b are formed radially into the circumferential edge of the endbell portion <NUM> (e.g., the semi-circular surface), forming radial cavities (collectively, "slots <NUM>"). Again, the upward vertical arrow indicates tool cavity pull while the downward vertical arrow indicates tool core pull. Unlike the holes <NUM>, the slots <NUM> allow for direct pull direction from the tool cavity. In some embodiments, added slots are designed specifically to eliminate the need to add side actions in the molding tool and maintain a smooth uninterrupted endbell surface. In exemplary embodiments, the non-conductive material making up the fuse, such as fuse body <NUM> (<FIG>) and fuse body <NUM> (<FIG>), are also made using a molding process with the holes being part of the core and cavity of the fuse body, thus eliminating the need to drill holes in the fuse body.

Parting lines 1114a and 1114b are shown in slot 1112a and parting lines 1114c and 1114d are shown in slot 1112b (collectively, "parting lines <NUM>"). In contrast to the parting lines <NUM> in <FIG>, the parting lines <NUM> of endbell <NUM> do not affect the surface of the endbell, but only the slots themselves, which will receive insertion pins during assembly. The alternative molding operation of <FIG> thus ensures a consistent minimally interrupted surface profile for improved assembly to the fuse body, in some embodiments. <FIG> thus shows the improved tooling layout, relative to that of <FIG>, in exemplary embodiments. By using slots rather than cylindrical holes, the slots are produced by tooling with the same pull direction as the rest of the tool.

<FIG> is a representative exploded perspective drawing of a fuse assembly <NUM> featuring endbells with pre-molded alignment slots, according to exemplary embodiments. A fuse body <NUM> and a cross-section of a single endbell <NUM> are shown. The endbell <NUM> may be a two-part endbell, such as the endbells <NUM> and <NUM> of the fuse assemblies <NUM> and <NUM>, respectively. Fuse terminals 1204a and 1204b are shown at either end of the fuse body <NUM>.

The fuse body <NUM> includes fuse body holes 1216a, 1216b, 1216c, and 1216d, shown in the cross-section of the endbell <NUM>, as well as fuse body hole 1216e, shown on the opposing side of the fuse body, for securing a second endbell (not shown) (collectively "fuse body holes <NUM>").

In exemplary embodiments, diecast/molded slots of predetermined size and orientation are located on each endbell <NUM>, removing the need to drill. Alignment slots 1212a, 1212b, 1212c, and 1212d are pre-molded into the circumferential surface of the endbell <NUM>, such as is shown in <FIG> (collectively, "alignment slots <NUM>" or "slots <NUM>"). The cross-sectional view shows that the slots <NUM> are somewhat trapezoid-shaped, with the top of the slots near the circumferential surface of the endbell <NUM> being wider than at the bottom, in some embodiments. Visible in the alignment slot 1212b, a slot bottom <NUM> is circular, in some embodiments, though shown as a semi-circle in the cross-sectional view.

Also featured in the fuse assembly <NUM> are insertion pins 1214a, 1214b, and 1214d for securing the endbell <NUM> as well as insertion pins 1214e, 1214f, and <NUM>, for securing the second unshown endbell (collectively, "insertion pins <NUM>"). Not visible insertion pins <NUM> are presumed to be insertable in the fuse body hole 1216c and slot 1212c for the endbell <NUM> and for the not visible endbell. In one embodiment, the insertion pins <NUM> are made of a metal or metal alloy material, such as stainless steel. In an exemplary embodiment, four insertion pins <NUM> are used to secure each endbell, though the number of insertion pins may vary.

Together, the fuse body holes <NUM> and the slots <NUM> receive the insertion pins <NUM> to secure the endbell <NUM> and not visible endbell to the fuse body <NUM>. The pre-cast/pre-molded alignment slots <NUM> significantly simplify the fuse manufacturing process by removing the need to drill into the fuse endbells without adding tooling complexity. Using slots <NUM> in the endbells <NUM> (rather than cylindrical holes) allow the endbell tooling to remain basic with simple core/cavity blocks, avoiding costly side-action features in the tooling. The use of slots thus minimally impacts tooling cost and piece part cycle time, in some embodiments. Further, having pre-cast/pre-molded endbell slots allow for the fuse body to be independently drilled prior to assembly.

Further, in exemplary embodiments, the presence of the pre-cast/pre-molded alignment slots <NUM> eliminates the risk of metal particulate entering the functional region of the fuse due to endbell drilling. The endbell slot design of <FIG> both guides pin insertion alignment and permits the action of drilling holes into the fuse body to be performed at any time separately from the rest of the assembly, in exemplary embodiments.

Claim 1:
A fuse assembly (<NUM>) comprising:
a fuse body (<NUM>);
a terminal assembly (<NUM>) disposed within the fuse body and having first and second opposing surfaces, the terminal assembly comprising a fuse element (<NUM>) extending between a first terminal (104a) and a second terminal (104b);
an endbell (<NUM>) to be coupled to the fuse body, the endbell comprising:
a first endbell portion (210a) having a first crush rib (<NUM>) engaging the first surface of the terminal assembly; and
a second endbell portion (210b) having a second crush rib (<NUM>) engaging the second surface of the terminal assembly, the first endbell portion and the second endbell portion being fastened to one another with the terminal assembly sandwiched therebetween, the first crush rib and the second crush rib forming a seal around the terminal assembly.