Patent Application
20070293091
Exemplary embodiments of the present invention are described herein that provide convention installation and replacement of fuses, and protection of fuses for certain types of fuses that are incompatible with existing fuse holders.
One type of electrical system that presents particular challenges to fuse installation and replacement of opened fuses is a vehicle electrical system. Various types and configurations of fuses may be used in a modern vehicle, and large numbers of fuses are required to protect an ever increasing number of electrical components and accessories in the vehicle. Indeed, an entire industry of automotive fuses, fuse holders and accessories has been established to meet the needs of vehicle manufacturers and maintenance and repair firms.
Plug-in fuses having male contact blades, for example, have been developed for use with wiring harnesses in under-the-hood installations, or alternatively that may be used standard fuse blocks interior to the vehicle. A variety of in-line fuse holders have also been developed for convenience in installing such fuses.
Fuses having integral female terminals have also been developed and are increasingly being used in truck, bus, and automotive applications. Female fuses are typically used with compatible fuse blocks having contact blades that are inserted into the fuses, but it would be desirable in certain instances to connect them to wiring harnesses. In such a manner, a single fuse could be provided to a circuit without having to retool an existing fuse block or utilize an additional fuse block at another location in the vehicle, thereby adding flexibility to circuit protection at a reduced cost. However, connecting such female fuses to wiring harnesses is difficult and typically would require spliced line and load connections and separate connector components. Securing the female fuse housings in a desired location is also difficult when using them with wiring harnesses, as the female fuse housings generally lack any structure to mount them in place.
Additionally, known female fuses are not well suited for harsh operating environments encountered in, for example, under-the-hood installations in a vehicle. Protective enclosures, however, for such fuses may render the fuses difficult to locate for replacement, and may hide color-coded identification features and rating indicia commonly printed on outer surfaces of the fuses. Thus, when servicing the fuse, neither the location of the fuse nor the type of fuse may be apparent if the fuses are enclosed. Each of these factors can be an impediment to efficient replacement of fuses, and any delay in replacing an opened fuse is of course undesirable. Full operation and functionality of the electrical system will not occur until opened fuses are replaced.
The fuse 100, as those in the art will no doubt recognize, has achieved some acceptance in the automotive industry and is sometimes referred to as a J Case Style Cartridge Fuse in the industry. Such fuses are commercially available and provide high current circuit protection for automotive and vehicle applications. For example, one such commercially available fuse is a Female Maxi™ Fuse of Cooper/Bussmann, St. Louis, Mo.
As depicted in
The partition wall 120 subdivides the terminal cavity 118 into first and second terminal receiving portions, and the partition wall 120 extends vertically in the terminal cavity for a distance that is less than the vertical height of the side walls 110, 112, 114 and 116 measured from the bottom wall 108 toward a top edge of the side walls 110, 112, 114 and 116. The terminal cavity 118 is open at the top edges of the housing side walls 110, 112, 114 and 116, allowing the fuse element 106 to be inserted therein through the open top of the housing 102.
The bottom wall 108 of the housing 102 includes slots 122 (one of which is shown in
The fuse element 106 may be stamped and formed from a sheet of conductive material into female terminal portions 130 and a fusible link 132 extending therebetween. The female terminal portions 130 may be arranged in a generally parallel and spaced apart configuration, and the fusible link 132 may extend from an upper edge of each of the female terminal portions 130 and connect the female terminal portions 130 to one another.
The female terminal portions 130 may be formed into a generally rectangular configuration having a generally planar side wall 134 having side edges 136 that are curled or wrapped to define female terminals for receiving and engaging male terminal blades of a connecting component. The planar side wall 134 of the female terminal portions 130 may include a deflectable latch tab 138 extending obliquely therefrom. As the fuse element 106 is inserted into the terminal cavity 118 in the housing 102, the respective latch tabs 138 of the female terminal portions 130 are compressed by the opposing sides of the partition wall 120, and once the latch tabs clear a locking ledge (not shown) in the partition wall 120, the latch tabs 138 resiliently deflect outwardly and abut the locking ledge to secure the female terminal portions 130 to the housing 102. The fuse element 106 is therefore maintained in a predetermined location within the housing and is not intended to be removed from the housing 102.
The fusible link 132 is curved or bent between the female terminal portions 130 in a U-shaped configuration which bridges or joins the female terminal portions 130. The fusible link 132 is constructed to have a cross sectional area which may only withstand certain current conditions when coupled to an energized electrical circuit. When subjected to an overcurrent condition, for example, the fusible link 132 melts, disintegrates, or otherwise structurally fails and opens the electrical circuit between the female terminal portions 130. The fusible link may be constructed for ampere ratings, for example, from 20A to 80A.
Optionally, time delay tabs 140 may be integrally formed with the fusible link 132 and are folded upon one another in a T-shaped configuration at a distance from the upper edge of each of the female terminal portions 130, and the fusible link 132 is curved between the time delay tabs 140. The fusible link 132 may be of substantially constant cross sectional area between the time delay tabs 140 and may extend continuously and directly between the time delay tabs 140. Alternatively, the fusible link 132 may include lateral bends, sidewardly extending portions which would otherwise deviate from a longitudinal axis of the fusible link 132 and/or areas of reduced cross sectional area between the female terminal portions 130. Positive temperature coefficient materials, or other treatments known in the art may be applied to the fusible link 132 to modify the fusing characteristics thereof.
When the fuse element 106 is located within the housing 102, the female terminal portions 130 are placed in the respective subdivisions of the terminal cavity 118 on opposite sides of the partition wall 120, and the fusible link 132 extends and curves over the top of the wall 120 and joins the female terminal portions 130. The female terminal portions 130 are located proximate the slots 122 in the housing bottom wall 108 so that when blade terminals of a connecting component are inserted in the slots in the housing bottom wall, the female terminal portions 130 engage the blade terminals and complete an electrical connection through the fusible link 132.
The cover 104 may be fabricated from a plastic material and may be mounted to the top of the housing 102 via a latch protrusion 150 formed in the housing 102 near an upper edge thereof, and a latch recess 152 formed in the cover 104. The cover 104 may be engaged to the housing 102 with snap-fit engagement and encloses the top end of the terminal cavity 118 after the fuse element 106 has been inserted therein and retained to the locking ledges of the partition wall 120. The cover may be transparent to allow visual observation of the fusible link 132 through the cover 104, and the cover 104 may be marked with amperage and/or voltage ratings for the fuse element 106.
As shown in the Figures, the fuse holder 200 may include a housing 202 defining a fuse receptacle portion 204 and a connector portion 206. The housing 202 may be formed integrally with the fuse receptacle portion 204 and the connector portion 206, and may be fabricated from heavy duty plastic according to a known molding operation, although other materials and fabrication techniques known in the art may alternatively be used.
The fuse receptacle portion 204 and the connector portion 206 face in opposite directions to one another and are generally aligned along a longitudinal axis 208 of the fuse holder 200. That is, in an exemplary embodiment the fuse receptacle portion 204 and the connector portion 206 are oriented about 180° from one another and are generally centered upon the longitudinal axis 208. In alternative embodiments, however, it understood that the fuse receptacle portion 204 and the connector portion 206 may be staggered or offset from one another along the axis 208 of the fuse holder 200, or the fuse receptacle portion and the 204 and the connector portion 206 may be oriented relative to one another at another orientation in lieu of the opposing, 180° separation illustrated in the Figures.
As best seen in
A series of sealing ribs 219 may be formed in the fuse receptacle portion 204 and project outwardly from the side walls 209, 210, 212 and 214 adjacent the front surface 215 of the housing 202. The sealing ribs 219 circumscribe the fuse receptacle portion 204 and cooperate with a protective cover, described below, to provide a buffer and some degree of protection for the fuse receptacle portion 204 from harsh operating environments. While three sealing ribs 219a, 219b, and 219c are illustrated in
As best seen in
Contact blades 230a, 230b protrude from the housing 202 into the cavity 228 in the connector portion 206 The contact blades 230a, 230b are extensions of the respective contact blades 218a, 218b in the fuse receptacle portion 204 and establish pass-through electrical connection between the fuse receptacle portion 204 and the connector portion 206. The contact blades 230a and 230b are dimensioned and positioned relative to one another for mating engagement with terminals of the connector component 229 and establish electrical connection between the contact blades 230a, 230b and the terminals of the connector component 229. The terminals of the connector component 229 may, for example, be electrically connected to conductors of a wiring harness in a known manner.
As one example, the connector portion 206 may be configured for compatibility with a known connector 229 having, for example, Series 800 terminals that are commercially available from Delphi/Packard Electrical Systems of Troy, Mich. Using such a connector 229, line and load connections to output wires, cables, or harnesses connected to electrical components, circuitry, or equipment in a vehicle may be established conveniently and quickly with snap-fit engagement. The connector 229 may be sealed to provide moisture-proof connections to the fuse holder 200, which can be particularly advantageous in specialty vehicle applications operated in extreme environments. Other connectors may be used in lieu of the connector 229, however, in alternative embodiments.
The connector portion 206 may be formed with a latch element 232 on one of the side walls 224. The latch element 232 cooperates with a complementary latch feature of the connector 229 to provide terminal position assurance between the mating connector terminals and the contact blades 230a and 230b in known manner. Additionally, the cavity 228 may include polarizing or rejection features, 234a and 234b, sometimes referred to as keys, that cooperate with complementary features on the connector 229 in a tongue and groove or slot and key arrangement so as to frustrate any attempt to install the wrong connector or install the connector backwards into the connector portion 206. Stated another way, the features 234a and 234b permit only a one-way installation of the correct connector, while positively resisting installation of the connector in another way, and while resisting installation of the wrong connector to the fuse holder 200.
Comparing
The housing 202 may further include a cover abutment flange 240 spaced from the fuse receptacle portion 204 and projecting outwardly form the housing 202. The cover abutment flange 240 may be formed with a gap 242 that may be used to secure a protective cover to the housing 202. A second flange 244 may also be provided and may project outwardly form the housing 202 in a spaced relation to the cover abutment flange 240. Optionally, a tie wrap (not shown) may be positioned between the flanges 240 and 242 and wrapped around the housing for mounting of the housing 202 in a desired location. The second flange 244 may not include a gap similar to the gap 242 in the cover abutment flange 240. The second flange 244 may also serve to secure a protective cover to the housing 202 in the manner explained below.
Mounting lugs 246a and 246b may be provided and may extend from the side walls 220 and 222 at lower edges thereof. The mounting lugs 246a and 246b extend generally perpendicular to the longitudinal axis 208 of the fuse holder 200 and at right angles to the fuse receptacle cavity 216 and the connector receptacle cavity 228. Using the mounting lugs 246a and 246b, the fuse holder 200 may be surface mounted to, for example, a vehicle chassis, the mounting lugs 246a and 246b may be used to through-hole mount the fuse holder 200 using known fasteners (such as screws or bolts), or alternatively the lugs 246a and 246b may serve as cable ties to secure the fuse holder 200 in place.
As seen in
The shroud 254 may be formed in a generally hollow rectangular shape in an exemplary embodiment, and may be of a substantially larger dimension than the fuse receptacle portion 204 of the fuse holder 200. The larger dimension of the shroud 254 may define a clearance or gap 260 between outer surfaces of the fuse receptacle portion 204 and inner surfaces of the shroud 254 when the shroud 254 is inserted over the fuse receptacle portion 204 of the fuse holder 200. An inwardly tapered lip 262 may be formed on a forward edge of the shroud 254, and the lip 262 may resiliently engage the outer surfaces of the fuse holder 200 adjacent the cover abutment flange 240.
A retaining deflectable retaining tab 264 may be formed with and extend from the forward end of the shroud 254. When the shroud 254 is fully inserted over the fuse receptacle portion 204 and the lip 262 is in abutting contact with the flange 240, the tab 264 may be pressed downwardly into the space between the flanges 240 and 244. Resilient deformation of the tab 264 between the flanges 240 and 244 maintains the shroud 254 in position relative to the fuse holder 200. Further, the flanges 240 and 244 are taller than the tab 264, and some effort is required to remove the tab 264 from between the flanges 240 and 244, thereby reducing, if not eliminating, inadvertent or accidental separation of the shroud 254 from the fuse holder 200.
The lid 256 may include a cover plate 270, an open-ended hood 272 extending from the cover plate 270, and a finger pull tab 274 extending from one end of the hood 272. The hood 272 includes an outwardly flared conical portion 275 extending from one side of the cover plate 270, and a generally rectangular shaped head portion 276 extending on the opposite side of the cover plate 270. The conical portion 275 is complementary in shape to the fuse receptacle portion 204 of the fuse holder 200, and the conical portion 275 includes sealing ribs 278a, 278b, 278c that engage the sealing ribs 219a, 219b, 219c (
From the closed position shown in
Additionally, when used with the connector 229 (shown in phantom in
The shroud 254 and/or the lid 256 may be color coded to match color coded ratings for the fuse 100, and as shown in the Figures, the shroud may include indicia corresponding to a rating of the fuse, such as the “50” rating shown in the illustrative embodiment. Thus, the type and rating of the fuse may be apparent for maintenance of the electrical system even while the lid 256 is closed and the fuse 100 is concealed within the lid 256 and the shroud 254. The keys 234 and 234b (
An embodiment of a fuse holder is disclosed herein that comprises a housing comprising a fuse receptacle portion and a connector portion, wherein the fuse receptacle portion is configured to receive a female fuse.
Optionally, the housing may extend along a longitudinal axis, and the fuse receptacle portion may extend opposite the fuse connector portion along the longitudinal axis. Each of the fuse receptacle portion and the connector portion may comprise a pair of contact blades, with the contact blades being differently configured from one another. Each of the fuse receptacle portion and the connector portion comprise a pair of contact blades, each of the contact blades in each pair being spaced a distance from one another, wherein the spacing of the contact blades in the fuse receptacle portion is different from the spacing of the contact blades in the connector portion. The fuse receptacle portion may be substantially rectangular, and the fuse receptacle portion may comprise a sealing rib. The housing may include an abutment flange, with the abutment flange having a gap therein. A protective cover may be provided, with the cover attached to the fuse receptacle portion, and the cover may comprise at least one sealing rib. A shroud may extend over the fuse receptacle portion, and a lid may be connected the shroud. The shroud may extend over the fuse receptacle portion, and the shroud may comprise indicia corresponding to a rating of the fuse. At least one mounting lug may extend from the housing, and the mounting lug may extend at an angle from the fuse receptacle portion.
An embodiment of a fuse holder is also disclosed herein. The fuse holder comprises a housing; a fuse receptacle portion extending from one side of said housing, the fuse receptacle portion being configured to receive a female fuse; and a connector portion extending from another side of said housing, the connector portion defining a receptacle having a pair of contact blades therein.
Optionally, the fuse receptacle portion and the connector portion are oriented substantially 180° from one another. The fuse receptacle portion may be substantially rectangular. The fuse receptacle portion may include at least one sealing rib circumscribing the receptacle portion. The fuse receptacle portion may be conical. The fuse receptacle portion may define a receptacle having a pair of contact blades, with the contact blades of the fuse receptacle portion being spaced a first distance from one another, wherein the contact blades in the connector portion are spaced a second distance from one another, and wherein the first and second distances are unequal. A protective cover may be attached to the fuse receptacle portion, with the cover comprising a shroud portion and a lid portion, the shroud portion and the lid portion being connected by a tether.
The shroud may be hollow and may extend over the fuse receptacle portion, and the lid may comprise a cover plate being substantially coextensive with an opening in the shroud when the lid is closed. The shroud may be separately provided from the housing and may comprise indicia corresponding to a rating of the fuse. At least one mounting lug may extend from the housing, with the mounting lug extending at an angle from the fuse receptacle portion.
An embodiment of a fuse holder assembly is also disclosed. The assembly comprises a housing comprising opposed first and second sides; a fuse receptacle portion extending from the first side of said housing, the fuse receptacle portion defining a first receptacle and a first set of contact blades in the first receptacle; a connector portion extending from the second side of the housing, the connector portion defining a second receptacle and second set of contact blades therein; a female fuse inserted in the first receptacle and partly exposed therefrom; a shroud coupled to the fuse receptacle portion over the fuse; and a lid selectively positionable relative to the shroud between an opened position and a closed position.
Optionally, the fuse receptacle portion is substantially rectangular. The fuse receptacle portion may include a first sealing rib circumscribing the receptacle portion, and the lid may comprise a second sealing rib engaging the first rib when the lid is closed. The first set of contact blades may be spaced a first distance from one another, wherein the second set of contact blades is spaced a second distance from one another, and wherein the first and second distances are unequal. The shroud portion and the lid portion may be connected by a tether. The lid may comprise a cover plate and a finger pull tab, with the cover plate being substantially coextensive with an opening in the shroud when the lid is closed. The shroud may comprise indicia corresponding to a rating of the fuse. Mounting lugs may extend from the housing, with the mounting lugs extending at an angle from the fuse receptacle portion.
An embodiment of an in-line fuse holder system is also disclosed. The system comprises a fuse comprising a housing and female terminal portions therein; a housing comprising first and second receptacles each having contact blades therein, the first receptacle adapted to receive the fuse with plug-in connection and establish electrical contact therewith, and the second contact receptacle adapted to receive a connector with plug-in connection.
Optionally, the first and second receptacles may be located 180° from one another on the housing. The housing may comprise a flange projecting outwardly therefrom, and the system may further comprise a shroud, with a portion of the shroud resiliently deflected over the flange to secure the shroud to the housing. The fuse receptacle may comprise a series of sealing ribs, and the system may further comprising a lid, the lid comprising a second series of sealing ribs, and the lid being fitted over the fuse receptacle portion. The connector may be coupled to a wiring harness. 36. The fuse may be color coded to indicate a rating of the fuse, and the housing may be color coded to match the fuse, thereby providing visual indication of the rating of the housing A lid may be coupled to the housing, with the lid being color coded to match the fuse.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
