Patent Publication Number: US-2010127817-A1

Title: Fuse assembly and fuse therefor

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a fuse assembly and a fuse for the fuse assembly. 
     U.S. Pat. No. 4,580,124 granted to John M. Bozoni Apr. 1, 1986 discloses a conventional flat fuse  2  comprising a fuse element  4  and a synthetic plastic housing  6 . The fuse element  4  which is secured in the housing  6  has two terminal blade portions  8  extending downwardly from the housing in spaced, juxtaposed, parallel relationships. 
     U.S. Pat. No. 5,645,443 granted to Thomas Schaller Jul. 8, 1997 discloses a fuse assembly comprising a plurality of conventional flat fuses  18  disposed in housing  16  that may comprise two housing halves. Each of the flat fuses  18  also has two terminal blade portions projecting downwardly from a fuse housing. A potential distributor  10  which includes a plurality of blade terminals  12 ,  12 ′ is disposed in the housing  16 . Each of the blade terminals  12 ,  12 ′ is connected to one of the terminal blade portions of one of the flat fuses  18  by a contact strip  17  that includes a plurality of sleeves. Each sleeve connects one of the blade terminals  12 ,  12 ′ to one of the terminal blade portions of one of the flat fuses  18 . The other terminal blade portion of each of the flat fuses  18  is connected to an electrical lead  39  via an individual flat plug sleeve  19 . 
     Bussed electrical centers having conventional flat fuses are also known. The flat fuses are enclosed in a housing having a lower housing and a removable upper cover that provides access to the fuses for replacement. The fuses are typically plugged into the lower housing and then enclosed by attaching the removable upper cover. 
     U.S. Pat. No. 6,062,916 granted to Joseph H. Gladd et al. May 16, 2000 also discloses a bussed electrical center  8  having an upper housing  10  for receiving conventional flat fuses (not shown). The electrical center  8  has a printed circuit board  14  sandwiched between upper housing  10  and a lower housing  12  that has a plurality of bays for receiving wiring harness connectors. The printed circuit board  14  carries pass through terminals  16  for connecting terminals of the conventional fuses to mating terminals in the wiring harness connectors. 
     In either of the above cases, the flat fuses are plugged into the bussed electrical connector or the fuse assembly so that one of the blade terminal portions is plugged into a bussed electrical connector that is either connected to a common power source or a common ground while the other blade terminal portion is plugged into an electrical connector that is attached to an electrical device via an electrical lead and/or one or more electrical connectors. See for instance, the Schaller &#39;443 patent described above where one blade terminal portion of each of the fuses  18  is plugged into a bussed electrical connector (a power strip  15 ,  20  via sleeves  17 ) and the other blade terminal portion of each of the fuses  18  is plugged into an electrical lead  39  that is attached to an electrical device or load. 
     SUMMARY OF THE INVENTION 
     The fuse assembly of the invention provides at least one of the following improvements in comparison to the known bussed electrical connectors and fuse assemblies of the type discussed above having conventional flat fuses wherein the two terminal blade portions of the flat fuses extend downwardly from a fuse housing in the same direction and plug into two electrical sleeves or female terminals that are arranged side by side in a spaced parallel relationship. 
     The fuse assembly reduces the distance required between the centerlines of the electrical sleeves or female terminals (and the conductor cables attached to the electrical sleeves or female terminals, if any) that plug onto the terminal blade potions of the flat fuses. 
     The fuse assembly reduces the footprint and/or height of the housing that holds the flat fuses resulting in weight and/or material savings. 
     The fuse assembly reduces the travel distance required for plugging the flat fuses and other components into the fuse assembly. 
     The fuse assembly increases the interior packaging space available for bussing component or components of the fuse assembly. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of a fuse assembly that illustrates an embodiment of the invention; 
         FIG. 2  is side view of the fuse assembly shown in  FIG. 1 ; 
         FIG. 3  is a fragmentary perspective view of the fuse assembly shown in  FIG. 1 ; 
         FIG. 4  is another view of the fuse assembly shown in  FIG. 1  with the housing removed to show internal relationships; 
         FIG. 5  is a section taken substantially along the line  5 - 5  of  FIG. 3  looking in the direction of the arrows; and 
         FIG. 6  is a perspective view of one of the fuses. 
         FIG. 7  is a perspective view of a battery connector having a fuse assembly that embodies the invention; 
         FIG. 8  is a side view of the battery connector shown in  FIG. 7 , and 
         FIG. 9  is a section taken substantially along the line  9 - 9  of  FIG. 8  looking in the direction of the arrows. 
     
    
    
     DETAILED DESCRIPTION OF A PREFERRED ENVIRONMENT 
     Referring now to  FIG. 1 , a fuse assembly  10  that illustrates an embodiment of the invention is disclosed. Fuse assembly  10  comprises a fuse holder  12  having a plurality of passages  14  that extend through the fuse holder and that are arranged in two rows. However, it should be understood that the fuse holder  12  may have any number of passages arranged in any number of rows. 
     Each passage  14  has a fuse chamber  16  at one end of the fuse holder  12 . The fuse chamber  16  is open at the one end of the fuse holder  12  for plugging a fuse  17  into the fuse chamber  16  from the one end of the housing. 
     Each passage  14  has a terminal cavity  18  at an opposite end of the fuse holder  12  that communicates with fuse chamber  16  and that opens at an opposite end of the terminal housing  12  for plugging an electrical sleeve or female terminal  19  into the fuse holder  12  from an opposite end of the fuse holder  12 . Each electrical sleeve or female terminal  19  may be attached to the end of an electrical lead  20  in a conventional manner for connecting the electrical sleeve or female terminal  19  to an electrical device or load. 
     Each of the flat fuses  17  comprises an electric insulator fuse body  22  and two terminals  24  and  26 . Terminals  24  and  26  are at opposite sides of the fuse body  22  and substantially parallel to each other. Terminals  24  and  26  project from portions of the fuse body  22  in opposite directions in a substantially parallel manner. That is terminal  24  projects upward and terminates in an exposed upper tip  28  while terminal  26  projects downward and terminates in an exposed lower tip  30 . Terminals  24  and  26  which are at opposite sides of the fuse body  22  are preferably within the overall height of the fuse body  22  as best shown in  FIG. 6 . Terminals  24  and  26  have respective ends that are embedded or otherwise disposed in the fuse body  22  and that are connected by a fusible link  32  that is disposed within the fuse body  22 . Flat fuse  17  operates in a well know manner to limit current flow between terminals  24  and  26  as determined by the characteristics of fusible link  32 . 
     Each of the flat fuses  17  is plugged into the fuse chamber  16  of a passage  14  with one of the fuse terminals  24  or  26  projecting down with its tip  28  or  30  aligned with and juxtaposed the terminal cavity  18  of the passage  14 . The other fuse terminal  24  or  26  projects up and is accessible via the upper open end of the fuse chamber  16  as best shown in  FIG. 5 . Each of the flat fuses  17  is preferably retained in the fuse chamber  16  for instance by flex arms  34  of the terminal body  12  or some other suitable retaining means. As shown in  FIGS. 2 ,  3  and  5 , each of the fuse chambers  16  have two flex arms  34  engaging the top of a respective flat fuse. The flex arms  34  are offset laterally and engage the top at opposite sides. 
     Fuse assembly  10  further comprises a bussed electrical connector  36  which is illustrated as a sub-assembly comprising a circuit board  38  that carries a plurality of terminals  40  that are arranged to plug onto the fuse terminals  24  or  26  of the flat fuses  17  in fuse chambers  16  that project upward. Terminals  40  are illustrated as tuning fork type terminals, however, any electrical sleeve or female terminal that mates with the fuse terminals  24  or  26  of the flat fuses may be used. 
     Fuse assembly  10  further comprises a stamped metal distributor strap  42  that has a plurality of connector feet  44  that plug into slots of the circuit board  20  for connecting the distributor strap  42  to the circuit board mechanically and electrically. The metal distributor strap  42  is connected to each of the terminals  40  in any well known manner, for instances by traces of copper or copper alloy (not shown) on the circuit board  38  connecting the feet  44  to the terminals  40  electrically. The distributor strap  42  includes a connector tab  46  at one end for connecting the distributor strap  42  to a power source such as a vehicle battery (not shown). 
     Two types of passages  14  with eccentric terminal cavities  18  are preferably used. In one, the terminal cavity is offset to the right while in the other the terminal passage is offset to the left. 
     Each row of passages  14  can be alternated so that a passage of the first type having a terminal cavity offset laterally in one direction is followed by a passage of the second type having a terminal cavity offset laterally in an opposite direction. For instance as shown in  FIG. 3 , the front passage  14   a  in the right hand row has a terminal cavity  18  that is offset laterally to the right while the second passage  14   b  in the right hand row behind the front terminal passage  14   a  has a terminal cavity  18  that is offset to the left. Thus the right front fuse  17   a  is inserted into the right front passage  14   a  so that the fuse terminal  24  projects upward and the fuse terminal  26  projects downward into the right front terminal passage  18  to engage the terminal  19  as shown in  FIG. 5 . The second fuse  17   b  is then inserted upside down (or rotated 180 degrees about a vertical axis) and inserted into the second terminal passage  16   b  so that the fuse terminal  26  projects upward and the fuse terminal  24  projects downward into the second terminal passage  18  which is offset to the left to engage another terminal  19 . 
     For fuse holders having more than two passages or more than one row, this right/left alternating arrangement may be repeated in each row as indicated in  figure 4  where the fuse holder  12  has been removed to show the arrangement of the flat fuses  17 , the terminals  19  that are plugged up into the terminal cavities of the fuse holder  12  and the terminals  40  that are plugged down into the fuse chambers  16  more clearly. Where more than one row is used, the side-by side passages are preferably offset in the same direction as shown in  FIG. 4 . This right/left alternating arrangement provides several advantages. The spacing between the centerlines of the terminals  19  engaging the flat fuses  17  from one direction (and the conductors  20  as well, if any) and of the spacing between the centerlines of the terminals  40  engaging the fuses  17  from an opposite direction can be reduced in a longitudinal and/or a lateral direction. This in turn results in a smaller foot print for the terminal housing  12 . Moreover, the height of the terminal housing  12  can be reduced due to the fuse terminals  24  and  26  being located at the opposite sides of the fuse body  22  and within the height of the fuse body  22 . The smaller foot print and reduced height of the terminal housing  12  each result in a saving in weight and material which is even better if the footprint and the height of the fuse holder  12  are both reduced. 
     The fuse assembly  10  of the invention also reduces the travel distance required for plugging the components into the fuse assembly  10  in comparison to current designs where the printed circuit board is located between conventional flat fuses and wiring harness terminals which require an intermediate terminal such as the pass through terminals  16  shown in the Gladd et al. &#39;916 patent. This is turn reduces the height “h” of the fuse assembly  10  shown in  FIG. 1 . 
     The fuse assembly  10  also may increase the interior packaging space available for the bussing sub-assembly by reducing the distance “d” between the fuse centerline as best shown in  FIG. 3 . 
     Fuse assembly  10  may also include a housing  48  for the bussed electrical connector sub-assembly  36  as shown for example in  FIGS. 7 ,  8  and  9  in connection with a battery connector  50  which comprises a lower housing  52  and an upper housing  54  that houses the bussed electrical connector sub-assembly  36  as best shown in  FIG. 9 . Upper housing  54  has a socket portion  56  that receives the fuse holder  12  and flexible lock arms  58  that retain the fuse holder  12 . The flat fuses  17  carried by the fuse holder  12  plug into the circuit board terminals  40  when the terminal housing  12  is plugged into the upper housing  54 . The lower housing  52  of the battery connector  50  supports a stud  58  that is connected to the connector tab  46  of the distributor strap  46  that is inside the housing of the battery connector formed by lower and upper housings  52  and  54 . Stud  58  is secured to a battery cable terminal  60  by a nut  62 . 
     While the forms of the invention herein disclosed constitute presently preferred embodiments, many others are possible. It is not intended herein to mention all of the possible equivalent forms or ramifications of the invention. It is understood that the terms used herein are merely descriptive rather than limiting and that various changes may be made without departing from the spirit or the scope of the invention.