Abstract:
An electric component includes: an insulating housing; a conductive member inserted into the housing until hitting a stop provided by the housing, the conductive member configured to mate with a conductive portion of a device that mates with the electrical component, the mating device thereby applying a force to the conductive portion, the conductive member including a wall, the wall defining a projection that is at least substantially coplanar with the wall; and wherein the housing includes a catch that flexes when the conductive member is inserted into the housing to allow the projection to move past the catch so that the conductive member can hit the stop, at which point the catch unflexes into locking engagement with the projection.

Description:
BACKGROUND 
     The present disclosure relates generally to electrical components and in particular to fuses, such as automotive fuses. 
     Automobile and other female fuse assemblies commonly include a two-piece assembly having an insulating housing and an all metal one-piece female fuse secured therein. The female fuse has a pair of spaced apart female terminals that are accessible from one end of the housing, into which male terminals are inserted. The male blade-type terminals or conductors extend typically from a mounting panel or male fuse block. The female terminals are typically held tightly within walls of the insulating housing. The female fuse also includes a fuse element that extends between the female terminals. The width of the fuse element is typically narrowed to create a fuse opening portion for the fuse. 
     The terminals need to be inserted into the housing during manufacturing, requiring an opening on one end, which is then capped. The other end of the housing is open for engagement with the fuse block terminals. Once the housing is in position relative to the terminals, the terminals need to be restrained from moving any further in the insertion direction relative to the housing. Once the fuse opens it needs to be replaced. An operator pulls the opened fuse from the fuse block and replaces the opened fuse with a new fuse. The force needed to remove the fuse is not inconsequential given that the fuse needs to be secured under vibrating operating conditions. Likewise, the force needed to reinsert the new fuse is not inconsequential. Accordingly, an apparatus is needed that allows the terminal to be inserted into the housing in one (fuse insertion) direction but prevents the housing from being further moved in the fuse insertion direction relative to the housing once the terminals are in a desired position relative to the housing. 
     U.S. Pat. No. 5,929,740 (“the &#39;740 Patent”), assigned to the assignee of the present disclosure, the entire contents of which are incorporated herein by reference, describes one such apparatus. FIGS. 1, 8 and 17 of the &#39;740 Patent perhaps best show what are termed “lances” 132 and 134 that secure the housing to the fuse terminals. Beginning at column 8, line 66, the &#39;740 Patent reads as follows: 
     For the purpose of securing the female fuse within main portion 106 of the housing 2, the first female terminal portion 6 includes a first lance 132. The first lance is defined by a first lance cutout portion 136 on the first face portion 10 of the first female terminal portion 6, and is substantially centered between the first and second ends 14, 18 of the first face portion 10 of the first female terminal portion 6. The first lance 132 includes a first lance edge 140. Likewise, the second female terminal portion 8 further includes a second lance 134. The second lance 134 is defined by a second lance cutout portion 138 on the second face portion 12 of the second female terminal portion 8, and is substantially centered between the first and second ends 16, 20 of the second face portion 12 of the second female terminal portion 8. The second lance 134 also has a second lance edge 142. When the female fuse 4 is inserted into the main portion 108 of the housing 2, the first lance edge locks into the first interior cutout portion 120, and engages with the first cutout upper wall 126. Likewise, the second lance edge 142 locks into the second interior cutout portion 122, and engages with the second cutout upper wall 130. The cap 108 of the housing 2 is preferably transparent, and locks into the main portion 108 through well known techniques. 
     The bent lances 132 and 143 have in certain cases caused problems due primarily to inconsistencies in the bending process. The lances 132 and 134 are quite small, making consistent bending somewhat problematic. If the lances 132 and 134 are not bent far enough, they will not engage the cutout walls 126 and 130 properly. If the lances 132 and 143 are overly bent, they lose too much force for resistance against the terminals being pushed up into the housing. 
     A need therefore exists for an improved fuse housing holder apparatus. 
     SUMMARY 
     The present disclosure addresses the above-described deficiency in the prior art. While fuses, such as female automotive fuses, provide one suitable application for the housing securing apparatus of the present disclosure, the apparatus can be applied in other electrical components, such as male blade and other types of fuses and fuse holders, circuit breakers, and electrical connectors. In one embodiment, the fuse or electrical component includes an insulating housing. A conductive member inserted into the housing until hitting a stop provided by the housing, wherein the conductive member is configured to mate with a conductive portion of a device that mates with the electrical component, the mating device thereby applying a force to the conductive portion. For example, the conductive member can include female terminals as shown in detail below, which mate with male terminals attached to a fuse block or other fuse center. The male terminals thereby apply a force, e.g., a spring-like clamping force that holds the fuse in place even under vibrating conditions. The present apparatus prevents the terminals from being pushed into the housing. The conductive member could alternatively include male blade-type terminals that mate with female terminals attached to the fuse block or center. 
     The conductive member includes a wall that can for example be a wall bridging the female terminals located at the bottom of the housing and a fuse element located at the top of the housing. The wall defines or provides a projection that is at least substantially coplanar with the wall. The housing includes an internal catch that flexes when the conductive member is inserted into the housing to allow the projection to move past the catch, so that the conductive member can hit the stop, at which point the catch unflexes or snaps back into locking engagement with the projection. 
     The conductive member in one embodiment includes first and second terminals (or terminal pairs as shown in detail below), such as first and second female terminals. The first and second female terminals each extend from first and second terminal bodies. The first and second terminal bodies in one embodiment are four-sided, each having a front wall, rear wall, inner wall and outer wall. The terminals in one embodiment extend from the inner and outer walls of the terminal bodies. The projection(s) is formed on one of the front or rear walls of the terminal body. 
     A fuse element extends between the terminal bodies, for example from the outer wall of the first body to the outer wall of the second body. The fuse element includes a fuse link located in one embodiment above the first and second bodies and in the approximate center of the fuse element. The fuse link is narrowed and provides a high resistance point at which the fuse opens. To this end, the fuse link can be provided with one or more spot of dissimilar, low melting temperature metal commonly termed a Metcalf spot, which aids in the opening of the fuse at the fuse link. 
     The stop and the catch of the housing fix the conductive member (e.g., including terminal bodies, fuse element and terminals) relative to the housing in both a (manufacturing and application) insertion direction and a direction opposite the insertion direction (e.g., opened fuse removal direction). During manufacture, the housing is initially open at its top. The conductive member is inserted into the housing and snap-fitted over the catch. The housing is then capped at its top end, that is, the end into which the conductive member is inserted into the housing before being capped. The housing is open at the opposite or bottom end, so that the fuse and housing can be inserted onto (or receive) the mating device. The mating device in one embodiment includes first and second male terminals that extend from a fuse block or fuse center. The first and second male terminals slip into the first and second female terminals (or terminal pairs) for operation. 
     As shown in detail below, the projection of the front or rear wall is formed by removing a section of the front or rear wall and in one embodiment a section of the front wall. The metal removal is done while the conductive member is in a flat or unbent condition, that is, before the flat is bent to form the terminal bodies having the inner, outer, front and back walls. The metal removal can be via a process selected from the group consisting of: (i) stamping; (ii) laser cutting; and (iii) wire electrical discharge machining (“EDM”). After the metal sections are removed, the projection can have a shape that is at least one of: pointed, trapezoidal and triangular. 
     As shown below, the projection in one embodiment includes a lower or engaging edge that engages the catch as the conductive member is inserted into the housing. The engaging edge is angled so as to gradually and increasingly flex the catch as the conductive member moves along the catch. For example, the engaging edge can have an angle of about forty-five degrees relative to a horizontal line (parallel to cap or top of the housing). 
     The projection can also include an upper or catching edge that comes into locking engagement with the housing, the catching edge can also be angled so as to have a directional component that opposes an insertion direction of the conductive member into the insulating housing. In this manner, the catching edge knifes up into a mating surface of the (catch of the) housing, preventing further movement of the housing in the (manufacturing and application) insertion direction relative to the conductive member. 
     In one embodiment, the mating surface is also angled, so as to mate with the angle of the catching or upper edge of the projection. The angle of the catching or upper edge of the projection is in one embodiment less severe (e.g., thirty degrees relative to a horizontal line) than the angle of the engaging edge of the projection, so that the projection forms a somewhat pointed, triangular or trapezoidal shape for projecting upward into the mating surface of the housing. 
     As seen below, the front or rear (projection) walls of the terminal bodies are bent along bendlines from the outer walls of the terminal bodies. The inner walls are bent along separate bendlines to for the box-like shape of the terminal bodies. A section of the bendline between the outer and front (or rear) wall can be removed at a top portion of the bendline (portion opposing the projection), so that the upper portion of the front or rear (projection) wall can flex or bend slightly as the projection is pulled over the catch of the housing. Such flexing or bending in combination with the flexing of the catch helps to produce the snap-fit of the housing onto the conductive member. 
     As mentioned above, the conductive member in one embodiment includes first and second terminal bodies, each having terminals extending downward from the bodies (to mate with separate, e.g., male terminals of a fuse box). Each of the bodies provides a projection, in which the projection is preferably formed from and thus at least substantially coplanar with one of the walls of the body. The catch flexes to accommodate each projection. Or, first and second catches are provided individually for the first and second projections so that the first and second catches can flex individually. In either case, to distribute the forces applied by the projections, the first and second projections can be: (i) disposed relative to each other so as to be adjacent to opposing sides of the housing and (ii) disposed relative to each other so as to be adjacent to diagonally spaced apart corners of the housing. It is also contemplated to form multiple projections on the same terminal body, e.g., one on the front wall and one on the rear wall of the terminal body. 
     It is accordingly an advantage of the present disclosure to provide an electric component including an insulating housing; a conductive member inserted into the housing and configured to mate with a conductive portion of a device that mates with the electrical component, the conductive member including a wall, the wall cut to form a projection that is at least substantially coplanar with the wall; and wherein the housing includes a catch that flexes when the conductive member is inserted into the housing to allow the projection to move past the catch, at which point the catch snaps into locking engagement with the projection. 
     It is another advantage of the present disclosure to provide an electric component including: an insulating housing; and a conductive member inserted into the housing and configured to mate with a conductive portion of a device that mates with the electrical component, the conductive member including a wall, the wall defining a projection that is at least substantially coplanar with the wall and that has an engaging edge angled so as to gradually and increasingly engage a portion of the housing as the conductive member is inserted into the housing, the projection eventually moving into locking engagement with the housing. 
     It is a further advantage of the present disclosure to provide an electric component including: an insulating housing; and a conductive member inserted into the housing and configured to mate with a conductive portion of a device that mates with the electrical component, the conductive member including a wall, the wall defining a projection that is at least substantially coplanar with the wall and that engages a portion of the housing as the conductive member is inserted into the housing, wherein at least one of the projection and the engaged portion of the housing flexes to allow the projection move eventually into locking engagement with the housing. 
     Additional features and advantages are described herein, and will be apparent from the following Detailed Description and the figures. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a perspective view of one embodiment of a conductive member having a portion of the housing securing apparatus of the present disclosure. 
         FIG. 2  is a plan view of one embodiment of the conductive member in a flat or pre-bent condition. 
         FIG. 3  is a perspective view of one embodiment of the conductive member in a partially bent or formed condition. 
         FIG. 4  is a perspective view of one embodiment of an electrical component having a securing apparatus of the present disclosure. 
         FIG. 5  is an elevation section view taken through one embodiment of an electrical component having a securing apparatus of the present disclosure, showing one alternative interaction of the projection of the conductive member and the catch of the housing. 
         FIG. 6  is an elevation section view taken through one embodiment of an electrical component having a securing apparatus of the present disclosure, showing another alternative interaction of the projection of the conductive member and the catch of the housing. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings and in particular to  FIGS. 1 to 3 , an embodiment of a conductive member  10  of an assembled electrical component (shown in  FIGS. 4 and 5 ) is illustrated. Conductive member  10  includes terminal pairs  12   a  and  12   b  that extend from each of terminal bodies  20   a  and  20   b . Terminal bodies  20   a  and  20   b  are connected together mechanically and electrically via a fuse element  30 . Conductive member  10  is made of metal, such as copper, a copper alloy or plated copper. Terminal pairs  12   a  and  12   b  are illustrated as female terminals but can alternatively be male terminals of an automotive blade fuse for example. Conductive member  10  is used for a fuse in the illustrated embodiment but is alternatively a conductive member (having a different configuration) for a different type of electrical component, such as a fuse holder, circuit breaker or electrical connector. 
     Each of terminal bodies  20   a  and  20   b  includes a front wall  14 , a rear wall  16 , an outer wall  18  and an inner wall  22  (formed via first and second inner wall panels  22   a  and  22   b  as seen best in  FIGS. 2 and 3 ). Front walls  14  and rear walls  16  are bent from outer walls  18 . Inner wall panels  22   a  and  22   b  are bent from front walls  14  and rear walls  16 , respectively, as seen best in  FIG. 2 . 
     Fuse element  30  includes fuse element legs  32   a  and  32   b  (each leg can have multiple extensions as illustrated in  FIGS. 1 ,  3  and  4  or only a single extension as seen in  FIG. 2 ), which extend from terminal bodies  20   a  and  20   b , respectively, to a single fuse link  34 . The illustrated embodiment shows multiple fuse element legs  32   a  and  32   b  extending from outer walls  18  of the respective terminal bodies  20   a  and  20   b.    
     Fuse link  34  forms a ring between legs  32   a  and  32   b . Lower melting temperature (Metcalf) spots  36   a  and  36   b  are placed at desired areas of the ringed fuse link  34 .  FIG. 3  illustrates one embodiment in which apertures  38   a  and  38   b  are formed in the ring of fuse link  34 . Metal spots  36   a  and  36   b  fill apertures  38   a  and  38   b , respectively. Metal spots  36   a  and  36   b  can be made for example from tin or tin-alloy, which has a lower melting temperature than the, e.g., copper, ring. Spots  36   a  and  36   b  thereby melt more quickly and diffuse into the ring of link  34  surrounding apertures  38   a  and  38   b , causing the ring to open at one of the spots  36   a  and  36   b  upon a fuse link opening event (e.g., short circuit or low overload event). 
     Projections  50  are formed during the cutting (e.g., stamping; (ii) laser cutting; or (iii) wire electrical discharge machining (“EDM”)) and bending of conductive member  10 . Each projection  50  includes an engaging edge  52  and a catching edge  54 . Engaging edge  52  is formed at an angle, e.g., from about forty to sixty (forty-five as illustrated) degrees, via a slot  56   a  cut into both inner wall panel  22   a  (or inner wall panel  22   b ) and front wall  14  (or rear wall  16 ). Engaging edge  52  engages a catch of the housing shown below in  FIG. 4  for example, which gradually and increasingly moves the catch as the conductive member  10  is slid into position within the housing. Eventually, engaging edge  52  slides past the catch. At this point, the catch is flexed fully. A flat tip  58  of projection  50  then engages and slides along the catch. Once tip  58  of projection  50  has slid completely past the catch, the catch snaps back into place, locking catching edge  54  of projection  50  into position with a mating surface (shown below) of the housing. 
     Catching edge  54  is formed at an angle, e.g., between ten and thirty (twenty as illustrated) degrees, via a slot  56   b  cut again into both inner wall panel  22   a  (or inner wall panel  22   b ) and front wall  14  (or rear wall  16 ). Catching edge  54  in the illustrated embodiment has a less severe angle than does engaging edge  52 , such that edges  52  and  54  and tip  58  form a trapezoidal shape. Tip  58  is alternatively rounded or at least substantially pointed, such that projection  50  is more triangular than trapezoidal. In both cases, projection  50  forms a knife or lance in which the projection is angled so as to be against the direction that the conductive member  10  is moving as the member is inserted into the housing. This angle causes the projections  50  to knife up into the housing when conductive member  10  is fully assembled to prevent the conductive member from being pushed further up into the housing, e.g., upon fuse insertion into a fuse block. In the fuse example, it is desirable to maintain space between the fuse element  30  and the top of the housing for proper operation and opening of the element. Projections  50  ensure that the space between the top of the housing and fuse element  30  is maintained. 
       FIGS. 1 to 4  also illustrate that a third slot  56   c  is made at the bendline between front wall  14  (or rear wall  16 ) and outer wall  18 . Slot  56   c  allows front wall  14  (or rear wall  16 ) and thus projection  50  to flex in a plane of the front wall  14  (or rear wall  16 ) in addition to the flexing of the housing catch. In this manner, once tip  58  of projection  50  has slid completely past the catch, the catch and projection  50  snapback into place, locking catching edge  54  of projection  50  into position with a mating surface (shown below) of the housing. 
     Referring now to  FIG. 4 , in one embodiment electrical component  100  is a fuse, such as a female automotive fuse. Fuse  100  includes an housing  110 , which is made of a suitable electrically insulating material, such as nylon, polybutylene terephthalate (“PBT”), liquid crystal polymer (“LCP”) or phenylpropanolamine (“PPA”). Housing  100  includes a catch  112 , which extends from a stop  114 . Conductive member  10  is inserted into housing  110  in the direction of the arrow shown in  FIG. 4  prior to a cap (not illustrated) being placed onto the top of housing  110 . Conductive member  10  is in the final assembled position in  FIG. 4 , such that a desired space is maintained between fuse element  30  and the cap when applied to housing  110 . The snapped-fit engagement of projections  50  and catch  112  of housing  110  ensures that conductive member  10  does continue to slide further into the housing, compromising the space maintained between fuse element  30  and the cap (which would also slide the terminals  12   a  and  12   b  too far into housing  110 ). 
     Stops  114  engage the bottoms  14   a  and  16   a  (see also  FIG. 2 ) of front walls  14  and rear walls  16  in the final assembled position in  FIG. 4 , preventing housing  110  from being removed from conductive member  10  when fuse  100  is pulled in a direction opposite the arrow (e.g., when fuse  100  is removed after fuse element  30  has opened). 
     Catch  112  includes a mating surface  116  and an engagement surface  118 . When conductive member  10  has been inserted fully into housing  110  in the direction of the arrow of  FIG. 4 , engaging edge  52  of each projection  50  engages engagement surface  118  of catch  112 , which gradually and increasingly bends the catch (in  FIG. 4  to the left). Bendline slot  56   c  also allows the projection  50  and front wall  14  (and rear wall  16 ) to flex (in  FIG. 4  to the right). Eventually, engaging edge  52  slides past engagement surface  118 , at which point tip  58  of projection  50  engages engagement surface  118  of the catch. At this point, the catch  112  and projection  50  are flexed fully. Once tip  58  of projection  50  has slid completely past engagement surface  118  of catch  112 , the catch and projection  50  snap back into place, locking catching edge  54  of projection  50  into position with mating surface  116  of the catch. 
     Although not seen, catch  112  including the mating surface  116  and the engagement surface  118  are repeated on the rear wall  16  side of component  100 . On the rear wall side, catch  112  extends vertically down to stop  114  at the terminal body  20   b  side of housing  110  as opposed to the catch  112  extending vertically downwardly to stop  114  at the terminal body  20   a  side of housing  110  as shown from the front in  FIG. 4 . Such arrangement allows catch  112  to be twisted by the two projections  50  (in  FIG. 4  in a clockwise rotation around the arrow) before snapping into engagement with the projections (in  FIG. 4  catch  112  snaps back in a counterclockwise rotation around the arrow). In the illustrated embodiment, projections  50  are provided in opposite corners relative to housing  110 . 
     In one alternative embodiment, catch  112  is split into separate catches, one for each projection  50 . In another alternative embodiment, catch  112  is split into separate catches, one for each projection  50 . In a further alternative embodiment, a projection  50  is provided for each front wall  14  and rear wall  16  of the same terminal body  20   a  or  20   b , but for only one of the terminal bodies. In still another alternative embodiment, a projection  50  is provided for each front wall  14  and rear wall  16  of the same terminal body  20   a  or  20   b  and for both terminal bodies. In yet another alternative embodiment, only a single projection  50  is needed. 
     It should be appreciated that projection  50  is at least substantially coplanar with (and in the illustrated embodiment is part of the same wall as) front wall  14  or rear wall  16 . In one alternative embodiment, projection  50  is welded or soldered to wall  14  or  16 . Here, the weld could be a spot type weld such that the projection would not be coplanar with wall  14  or  16  but instead be abutted up against the wall, so as to be at least substantially parallel with wall  14  or  16 . Given the smaller size of component  100  and the cost and precision required for such welding, however, a one-piece, coplanar projection  50  is preferred. 
     Referring now to  FIG. 5 , an alternative arrangement includes projection  150  (coplanar with wall  14  or  16 ) and catch  212 . Projection  150  is the same or similar to projection  50  and includes an engaging edge  152 , a catching edge  154  and a tip  158 . Wall  14  or  16  is again allowed to flex via bendline slot  56   c . Here, catch  212  includes an engagement surface  218  that is similar to surface  118 . Catch  212  includes a mating lower mating surface  216  that is angled to allow projection  150  to move up into the catch. In the illustrated embodiment lower mating surface  216  is angled to match the angle of catching edge  154 , so as to allow projection  150  to move up into the catch  212  and to maximize surface area contact between the projection and the catch. A second lower mating surface  216  and a second upper engagement surface  218  (left side of catch  212  and not sectioned) are shown for the second projection  150  located on the other terminal body  120   a  or  120   b , behind the illustrated projection  150 . 
     Referring now to  FIG. 6  a further alternative arrangement includes projection  250  (coplanar with wall  14  or  16 ) and catch  250 . Here, projection  150  extends horizontally out from the top of wall  14  or  16 . Notch  56   b  ( FIG. 2 ) is not made as it is with projections  50  and  150 . Mating surface  316  of alternative catch  312  is also at least substantially horizontal, so as to match the at least substantially horizontal catching edge  254  of projection  250 . A second difference is that bendline slot  56   c  is not provided. Bendline slot  56   c  may not be needed for various versions of projections and catches, e.g., when the catch itself can provide the needed flexing or if a separate catch is provided for each projection. 
     It should be understood that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications can be made without departing from the spirit and scope of the present subject matter and without diminishing its intended advantages. It is therefore intended that such changes and modifications be covered by the appended claims.