Patent Publication Number: US-6984134-B1

Title: Terminal connector

Description:
BACKGROUND OF INVENTION 
     The present invention relates to electrical terminals, and in particular terminal blade connection systems. 
     It is known in the automotive industry to provide terminal and connector assemblies for distributing electrical current to various devices in the vehicle. Moreover, as vehicles employ more devices, which results in an even greater demand for electrical current, a need has arisen to provide multiple high current connections, in addition to low current connections. It is preferable that the connections, both high and low current, are provided in close proximity to one another. In order to accomplish this, some employ custom hybrid header connectors, which allow for the mixing of the high and low current connections. But these custom connectors are not desirable because of their relatively high cost. 
     Moreover, with these types of header connections, the routing on the printed circuit board must be from the high current connections to the high current header, whether the particular routings are convenient or not. This severely limits the ability to optimize a layout of a printed circuit board for routability. 
     Additionally, the existing printed circuit board and connector combinations are unidirectional. That is, the connection from the high current printed circuit board only allows for it to be oriented on one specific side of the low current printed circuit board. Additional flexibility can be provided if the mating between the boards could take place from either side. 
     Thus, it is desirable to have a connection system that can be employed to make both high and low current connections and that overcomes the drawbacks of the prior art. 
     SUMMARY OF INVENTION 
     In its embodiments, the present invention contemplates a terminal blade connection system. The terminal blade system has a first printed circuit board including a first terminal mounting passage, a second terminal mounting passage, spaced from the first terminal mounting passage, and a blade passage, located between the first and second terminal mounting passages and extending through the first printed circuit board. The terminal blade system also preferably includes a receptacle terminal having a first terminal support leg, a second terminal support leg, spaced from the first terminal support leg, and a side support arm connected between the first and second terminal support legs, with the first terminal support leg including a first foot portion mounted to the first terminal mounting passage, a first upper end spaced from the first foot portion, and a first contact portion located between the first foot portion and the first upper end, and the second terminal support leg including a second foot portion mounted to the second terminal mounting passage, a second upper end spaced from the second foot portion, and a second contact portion located between the second foot portion and the second upper end, and with the first contact portion being a distance from the second contact portion that is less than a distance between the first foot portion and the second foot portion and less than a distance between the first upper end and the second upper end. 
     An advantage of the present invention is that high and low current connections can be made without requiring the use of custom hybrid header connectors. 
     A further advantage of an embodiment of the present invention is that the blade insertion into receptacle terminals mounted on a printed circuit board can be achieved from either top side or bottom side blade entry. 
     An additional advantage of an embodiment of the present invention is that the different blade widths for high current blade connections and low current blade connections can be achieved with essentially the same design of receptacle terminals by employing a single receptacle terminal for the low current connections and a pair of side-by-side receptacle terminals for the high current connections. 
     Another advantage of an embodiment of the present invention is that the high and low current receptacle terminals can be located as desired on the printed circuit board, thus allowing for optimization of the design for routability of conductors on the printed circuit board. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view of a receptacle terminal, in accordance with an embodiment of the present invention. 
         FIG. 2  is a cross sectional view of the receptacle terminal, taken along line  2 — 2  in  FIG. 1 . 
         FIG. 3  is a partial elevation view of a pair of printed circuit boards assembled together with blades and receptacle terminals, in accordance with the present invention. 
         FIG. 4  is a partial perspective view, on an enlarged scale, of a portion of the assembly of  FIG. 3 . 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 2  illustrate a receptacle terminal, indicated generally at  10 , which includes a first terminal support leg  12  and a second terminal support leg  14  connected together by a side support arm  16 . Preferably, the receptacle terminal  10  is formed from a single piece of stamped metal, although it can be formed in other ways if so desired. 
     The first terminal support leg  12  has a first foot portion  18 , which is designed to be mounted to a circuit board, discussed below. The first terminal support leg  12  also has a first bottom guide portion  20 , adjacent to the first foot portion  18 , a first arm support portion  22 , adjacent to the first bottom guide portion  20 , a first contact portion  24 , adjacent to the first arm support portion  22 , and a first top guide portion  26 , which is adjacent to the first contact portion  24 . 
     The second terminal support leg  14  has a second foot portion  28 , which is also designed to be mounted to a circuit board, discussed below. The second terminal support leg  14  also has a second bottom guide portion  30 , adjacent to the second foot portion  28 , a second arm support portion  32 , adjacent to the second bottom guide portion  30 , a second contact portion  34 , adjacent to the second arm support portion  32 , and a second top guide portion  36 , which is adjacent to the second contact portion  34 . 
     The first and second bottom guide portions  20 ,  30  are spaced farther apart next to the foot portions  18 ,  28  and taper inward toward each other near the arm support portions  22 ,  32 , which, in turn, taper inward toward each other near the contact portions  24 ,  34 . By starting wide and tapering to narrow, the receptacle terminal  10  allows for misalignments due to tolerances in locating the receptacle terminal  10  or a terminal blade (discussed below) on a circuit board while guiding a terminal blade from under the circuit board into the narrow opening between the contact portions  24 ,  34 . Likewise, the first and second top guide portions  26 ,  36  are spaced farther apart at their upper ends  27 ,  37 , respectively, and taper inward toward each other near the contact portions  24 ,  34 . Again, misalignments during assembly are accounted for—but this time for instances where a terminal blade is inserted into the terminal receptacle  10  from above the board, rather than below. 
     The side support arm  16  is sized and shaped so that the contact portions  24 ,  34  are spaced from each other a desired distance that is less than the thickness of the terminal blade to be inserted therein. In this way, during assembly of a terminal blade to its corresponding receptacle terminal  10 , the interference fit created between the terminal blade and the contact portions  24 ,  34  will cause the arm  16  and terminal support legs  12 ,  14  to flex somewhat. This elastic flexing of the receptacle terminal  10  will create a spring-like bias of the contact portions  24 ,  34  against a terminal blade, thus assuring a good electrical contact is maintained. 
       FIGS. 3 and 4  illustrate an assembly, indicated generally at  40 , of a first printed circuit board  42  with a second printed circuit board  44 . The first printed circuit board  42  includes several receptacle terminals, including the receptacle terminal  10  illustrated in  FIGS. 1 and 2 , as well as first and second receptacle terminals  10 ′ located on the first board  42  for a high current application. 
     The first printed circuit board  44  also includes a number of passages for mounting and receiving the various components. A pair of low current terminal mounting passages  46  extend through the first board  42  and receive the first and second foot portions  18 ,  28 . The foot portions  18 ,  28  are secured to the first board  42  via these passages  46  with solder (not shown) or other conventional means. A low current blade passage  48  extends through the first board  42  about mid-way between the low current terminal mounting passages  46 . The blade passage  48  has a width and length that is larger than the width and length of a low current terminal blade  50  in order to assure that the blade passage  48  will not interfere with the terminal blade  50  when inserted therethrough and into contact with the contact portions  24 ,  34  of the receptacle terminal  10 . The receptacle terminal  10  and terminal blade  50  together form a terminal blade assembly  56 . A conductive trace  52  is routed from the second (or first) foot portion  28  to a desired location (not shown) on the first board  42 . 
     The first printed circuit board  44  also includes a pair of high current terminal mounting passages  46 ′. These high current terminal mounting passages  46 ′ are significantly wider than the low current terminal mounting passages  46  because they are sized to receive the first and second foot portions  18 ′,  28 ′ of a pair of side-by-side receptacle terminals  10 ′. Again, the foot portions  18 ′,  28 ′ are secured to the first board  42  via these passages  46 ′ with solder (not shown) or other conventional means. As an alternative, the first and second foot portions can have smaller sections (not shown) at their bottom ends, with shoulders adjacent thereto. The smaller sections will then slide into correspondingly smaller mounting passages until the shoulders abut the surface of the board. 
     A high current blade passage  48 ′ extends through the first board  42  about mid-way between the high current terminal mounting passages  46 ′. The blade passage  48 ′ has a width and length that is larger than the width and length of a high current terminal blade  50 ′ in order to assure that the blade passage  48 ′ will not interfere with the terminal blade  50 ′ when inserted therethrough and into contact with the contact portions  24 ′,  34 ′ of the pair of receptacle terminals  10 ′. The receptacle terminal  10 ′ and terminal blade  50 ′ together form a terminal blade assembly  56 ′. A conductive trace  52 ′ is routed from the first (or second) foot portion  18 ′ to a desired location (not shown) on the first board  42 . 
     One will note that the terminal blade  50 ′ is much wider than the terminal blade  50 , with a much greater contact area with the two receptacle terminals  10 ′ than the terminal blade  50  has with the one receptacle terminal  10 . Consequently, terminal blade  50 ′ and receptacle terminals  10 ′ (that is, the terminal blade assembly  56 ′) better allow for high current flow. Yet, each of the receptacle terminals  10 ′ are very similar to (and in some applications may be exactly the same as) the receptacle terminal  10 . 
     The second printed circuit board  44  includes a mounting location  54  for the low current terminal blade  50  and another mounting location  54 ′ for the high current terminal blade  50 ′, with each being located and oriented to mate with its respective receptacle terminal  10 ,  10 ′. Each of the terminal blades  50 ,  50 ′ is secured to the second board  44  at these mounting locations  54 ,  54 ′ with solder (not shown) or other conventional means, with conductive traces (not shown) extending therefrom in a conventional manner. 
     As can be seen in  FIGS. 3 and 4 , multiple other terminal blade assemblies  156 ,  156 ′ that are very similar to or exactly the same as the terminal blade assemblies  56 ,  56 ′, respectively, can be located on the first and second printed circuit boards  42 ,  44  as needed for the particular application. 
     Since each terminal blade assembly  56 ,  56 ′,  156 ,  156 ′ is a stand alone structure, the high and low current terminal connections can generally be located on the first and second printed circuit boards  42 ,  44  wherever is desirable for optimizing routability of the conductive traces  52 ,  52 ′, thus being easily adapted for different applications. For example, if so desired, one can employ these terminal blade assemblies in an application with all high current connections. Moreover, each terminal blade assembly  56 ,  56 ′,  156 ,  156 ′, whether adapted for low current or high current, allows for bottom or top side mating terminal blade entry. Since the blades  50 ,  50 ′ can be inserted from either direction, one has a choice of which side to locate the first printed circuit board  42  relative to the second printed circuit board  44  when laying out the boards  42 ,  44  for a particular application. The result is a much improved terminal blade connection system  58  for making the connections between a first printed circuit board  42  to a second printed circuit board  44 . 
     While certain embodiments of the present invention have been described in detail, those familiar with the art to which this invention relates will recognize various alternative designs and embodiments for practicing the invention as defined by the following claims.