Abstract:
A series of electric terminals in which each member of the series has an identical receptacle portion at one end and a unique cable attachment portion at an opposite end is manufactured by forming a generic strip of partially formed terminals having a receptacle portion at one end in a first progressive die forming operation for all members of the series of electric terminals. Strips of completely formed electric terminals of particular members of the series of electric terminals are then completed in respective unique die progressive die forming operations using the generic strip of partially formed terminals. A modular die may be used for forming the strips of completely formed electric terminals from the intermediate generic the strip of partially formed terminals.

Description:
BACKGROUND OF THE INVENTION 
     This invention relates generally to a method of manufacturing a series of electric terminals. 
     Electric terminals generally comprise a contact portion at one end and an attachment portion at an opposite end. The contact portion is adapted for a temporary connection to a mating contact portion of another electric terminal while the attachment portion is adapted for permanent attachment to another electric element such as an electric cable or the like. 
     Thus a series of electric terminals may have identical contact portions at one end while having different attachment portions at an opposite end that are adapted for permanent attachment to different electric elements such as several different electric cables of various sizes and/or types. 
     In the past each member in a series of electric terminals for electric cables was manufactured with an identical contact portion at one end and a unique attachment portion at the other end for permanent attachment to a particular size or small size range of electric cables. Each member in turn required a unique set of progressive forming dies. For instance a typical female electric connector for an electric cable requires a set of progressive forming dies comprising forty to fifty individual dies. 
     This known method is satisfactory for manufacturing electric terminals that perform well. However, the known method is expensive from a manufacturing standpoint because of the requirement for several sets of unique progressive forming dies and the need for a large inventory storing each of the several members of the series of electric terminals. The expense is particularly notable when one or more member of the series has a relatively low volume of use. 
     SUMMARY OF THE INVENTION 
     This invention provides a method of manufacturing a series of electric terminals for electric cables that takes advantage of the fact that each member in the series of electric terminals has an identical contact portion at one end. 
     Basically the series of electric terminals is manufactured in a two stage manufacturing process where all members of the series have an identical contact portion formed in a primary operation in a common set of progressive forming dies. Each member of the series then has their unique attachment portions formed in a secondary operation in a unique set of progressive forming dies thereby reducing capital expenditures and inventory costs. 
     Savings in capital expenditures and inventory costs are particularly advantageous in electric terminals that have a contact portion that is progressively formed in a relatively large number of steps in comparison to a relatively few number of steps needed to form the attachment portion. This advantage increases with the complexity of the contact portion, and can result in considerable savings, particularly in the case of female terminals that often have complex contact portions. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a typical female electric terminal that can be manufactured in a series in accordance with the invention; 
         FIG. 2  is a front view of the electric terminal shown in  FIG. 1 ; 
         FIG. 3  is a top view of the electric terminal shown in  FIG. 1 ; 
         FIG. 4  is a longitudinal section of the electric terminal shown in  FIG. 1 ; 
         FIG. 5  is a plan view of a strip of electric terminals in various stages of manufacture in a progressive die forming operation resulting in an intermediate generic strip of partially formed terminals for manufacturing the electric terminal shown in  FIGS. 1-4 ; 
         FIG. 6  is a plan view of a strip of electric terminals in various stages of manufacture in a progressive die forming operation resulting in a unique strip of completely formed terminals made from the intermediate generic strip shown in  FIG. 5 ; 
         FIG. 7  is a plan view of a strip of electric terminals in various stages of manufacture in a progressive die forming operation resulting in another unique strip of completely formed terminals made from the intermediate generic strip shown in  FIG. 5 ; and 
         FIG. 8  is a plan view of a strip of electric terminals in various stages of manufacture in a progressive die forming operation resulting in yet another unique strip of completely formed terminals made from the intermediate generic strip shown in  FIG. 5 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings,  FIGS. 1-4  illustrate a typical female electric terminal  10  that can be manufactured by the method that is described in connection with  FIGS. 5-8 . Electric terminal  10  comprises a female receptacle portion  12  for receiving a male terminal (not shown) at one end and an attachment portion  14  at an opposite end for attaching terminal  10  to an electric cable  16 . Forming the attachment portion typically takes less than 10 steps. 
     Electric terminals such as the female electric terminal  10  are conventionally formed from a strip of metal is a series of dies that punch and form the strip in several steps usually on the order of 30-40 steps. Because of the need for a receptacle as well as a resilient contact tongue within the receptacle, the female receptacle portion  12  is much more complicated structurally than attachment portion  14  which typically merely comprises core wings  18  and insulation crimp wings  20  which are formed in barrels. The core and insulation crimp barrels are then crimped tightly around the exposed core end  22  and insulation jacket  24  of electric cable  16 . Female receptacle portion  12  on the other hand, is much more complex comprising several integrally connected parts in a one-piece construction. More specifically female socket portion  12  has a floor  26  with two laterally space side walls  28  and  30  connected to opposite longitudinal side edges of the floor respectively. A contact tongue  32  extends longitudinally from a support  34  that is cantilevered in a lateral direction from a rearward portion of side wall  28 . 
     Contact tongue  32  is disposed in a receptacle formed by floor  26 , side walls  28  and  30  and top walls  36  and  40 . The forward top wall  36  extends laterally from side wall  30  and the forward top wall  36  has a tongue protector  38  folded inwardly and rearwardly from a forward edge to protect the free end of the contact tongue  32  within the receptacle. The rearward top wall  40  also extends laterally from side wall  30  to cover the rearward portion of contact tongue  32 . A forward portion of the rearward top wall  40  engages and stiffens the contact tongue  32 . 
     Terminals, such as female electric terminal  10  are typically attached to various sized wires. For instance electric terminal  10  might be attached to cables ranging in size from a cable having a core size of 0.35 mm and an insulation jacket size of 0.55 mm to a larger cable having a core size of 0.75 mm and an insulation jacket size of 1.0 mm to a still larger cable having a core size of 1.0 mm and an insulation jacket size of 1.5 mm. Even though the female socket portion  12  of the terminal  10  may be the same for all of these cables, the attachment portion  14  of the terminal, that is the core wings  18  and the crimp wings  18 , must be changed for each size cable in order to produce good electric and mechanical connections of the terminal  10  to the cable  16 . 
     The terminals are typically produced from very long strips of material that are unwound from a large reel and processed through a set of forming dies with the finished terminals still being attached to a carrier strip. The finished terminals may be attached to electric cables one at a time either at the end of the forming operation or in a separate secondary operation. When the terminals are attached in a separate secondary operation, the finished terminals attached to the carrier strip are wound on a reel and eventually used in the secondary operation where the reel is unwound and fed into a machine that attaches the terminals to electric cables one at a time. In either event, the end terminal is normally attached to the electric cable before it is severed from the carrier strip. Irrespective of when the terminals are attached to the electric cables, it is often necessary to produce several variations of the basically the same terminal for attachment to electric cables of different sizes. This in turn increases tooling and inventory costs. 
     Our invention provides a method for manufacturing electric terminals for attachment to electric cables of different sizes that reduces tooling and inventory costs. Basically this is accomplished by manufacturing the terminals in primary and secondary operations where a relatively complex contact portion is formed to provide a generic strip of partially formed terminals. The partially formed terminals of this generic strip are then finished for a particular size cable in a secondary operation. 
     Referring now to  FIGS. 5-8 ,  FIG. 5  is a plan view of a partially fabricated generic strip  100  for making the electric terminals like those shown in  FIGS. 1-4 . The generic strip  100  starts as an imperforate metal strip  102  shown at the right end of  FIG. 5 . The metal strip  102  progresses through a series of dies (not shown) from right to left as indicated by the arrow  104  in  FIG. 5 ; successive dies punching and forming the metal strip into a series of partially formed terminals until the generic strip  100  is formed with a plurality of partially formed electric terminals  106  preferably having completely formed contact portions such as the female receptacles indicated generally at  12  in  FIGS. 1-4 . The completely formed female receptacles being attached to a relatively wide carrier strip  110  in a spaced apart relationship as shown at the left hand end of  FIG. 5 . The carrier strip  108  is wide enough to provide a variety of predetermined attachment portions for the terminals  106  in a secondary operation with the partially formed terminal  106  being spaced apart a sufficient distance to accommodate the variety of predetermined attachment portions for attachment to cables of different sizes. 
     Briefly the generic strip  100  may be finished in a variety of ways as illustrated in  FIGS. 6 ,  7  and  8 . More specifically the generic strip  100  which is shown at the left in  FIG. 6  progresses through a series of dies (not shown) from left to right as indicated by the arrow  210  in  FIG. 6 , successive dies punching and forming the carrier strip  110  to form the attachment portions  214 , such as those indicated generally at  14  in  FIGS. 1-4 . These particular attachment portions  214  comprise core crimp wings  218  and insulation crimp wings  220  that are relatively narrow for attaching the terminals to a smaller cable, for instance a cable having a core size of 0.35 mm and a insulation jacket size of 0.50 mm. In the secondary operation shown in  FIG. 6 , a schematically illustrated stamping die  222  initially sizes a flat attachment portion while maintaining a carrier strip  230  that is considerably narrower than the starting carrier strip  110 . As the process continues from left to right, the core crimp wings and the cable crimp wings are formed into open barrels and then the open core crimp barrel and the open insulation crimp barrel are crimped around the exposed end of a cable core and the end of a cable insulation in a well know manner resulting in the end terminal being attached to an electric cable as shown at the right hand end of the strip  200  shown in  FIG. 6 . The attached end terminal may then be severed from the carrier strip  230  in a conventional manner. Alternatively, the end terminal can be severed and then attached to the cable. 
     As indicated above, the generic strip blank  100  may be rolled up into a reel after completing the primary operation illustrated in  FIG. 5  and then transported to a secondary operation where the reel is unwound and processed through the secondary operation. This secondary operation may result in the terminals being attached progressively to the terminal at the end of the carrier strip  230  as shown in  FIG. 6  or to the terminal that is severed from the end of the carrier strip  230  as stated above. It is also possible to roll up a completed strip  200  before attaching the terminals to electric cables and do the attachment in a third operation. 
     Referring now to  FIG. 7 , the generic strip  100  may be finished in a variety of ways as stated above. Here the generic strip  100  which is shown at the left in  FIG. 7  progresses through a series of dies (not shown) from left to right as indicated by the arrow  310  in  FIG. 7 , successive dies punching and forming the carrier strip  110  to form the attachment portions  314 , such as those indicated generally at  14  in  FIGS. 1-4 . These particular attachment portions  314  comprise core crimp wings  318  and insulation crimp wings  320  that are wider than those shown in  FIG. 6  for attaching the terminals to a larger cable, for instance a cable having a core size of 0.75 mm and an insulation jacket size of 1.0 mm. In the secondary process shown in  FIG. 7 , a schematically illustrated stamping die  322  that is narrower than die  222  initially sizes a flat attachment portion while maintaining a carrier strip  230  that is considerably narrower than the starting carrier strip  110 . As the process continues from left to right, the core crimp wings and the cable crimp wings are formed into open barrels and then the open core crimp barrel and the open insulation crimp barrel are crimped around the exposed end of a cable core and the end of a cable insulation in a well know manner resulting in the end terminal being attached to an electric cable as shown at the right hand end of the strip in  FIG. 7 . The attached end terminal may then be severed from the strip  330  in a conventional manner. Alternatively, the end terminal can be severed and then attached to the cable. 
     As indicated above, the generic strip  100  may be rolled up into a reel after completing the primary operation illustrated in  FIG. 5  and then transported to a secondary operation where the reel is unwound and processed through the secondary operation. This secondary operation may result in the terminals being attached progressively to the terminal at the end of the carrier strip  330  as shown in  FIG. 7  or to the terminal that is severed from the end of the carrier strip  330  as stated above. It is also possible to roll up a completed strip  300  before attaching the terminals to electric cables and do the attachment in a third process. 
     Referring now to  FIG. 8 , the generic strip  100  may be finished in a variety of ways as stated above. Here the generic strip  100  which is shown at the left in  FIG. 8  progresses through a series of dies (not shown) from left to right as indicated by the arrow  410  in  FIG. 8 , successive dies punching and forming the carrier strip  110  to form the attachment portions  414 , such as those indicated generally at  14  in  FIGS. 1-4 . These particular attachment portions  414  comprise core crimp wings  418  and insulation crimp wings  420  that are still wider than those shown in  FIG. 7  for attaching the terminals to an even larger cable, for instance a cable having a core size of 1.0 mm and an insulation jacket size of 1.5 mm. In the secondary process shown in  FIG. 8 , a schematically illustrated stamping die  422  that is even narrower than die  322  initially sizes a flat attachment portion while maintaining a carrier strip  430  that is considerably narrower than the starting carrier strip  110 . As the process continues from left to right, the core crimp wings and the cable crimp wings are formed into open barrels and then the open core crimp barrel and the open insulation crimp barrel are crimped around the exposed end of a cable core and the end of a cable insulation in a well know manner resulting in the end terminal being attached to an electric cable as shown at the right hand end of the strip in  FIG. 8 . The attached end terminal may then be severed from the strip  430  in a conventional manner. Alternatively, the end terminal can be severed and then attached to the cable. 
     As indicated above, the generic strip  100  may be rolled up into a reel after completing the primary operation illustrated in  FIG. 5  and then transported to a secondary operation where the reel is unwound and processed through the secondary operation. This secondary operation may result in the terminals being attached progressively to the terminal at the end of the carrier strip  430  as shown in  FIG. 8  or to the terminal that is severed from the end of the carrier strip  430  as stated above. It is also possible to roll up a completed strip  400  before attaching the terminals to electric cables and do the attachment in a third process 
     Thus it can be seen that the method of the invention provides for attaching female terminals to a variety of different sized electric cables thus avoiding high inventory costs. 
     It will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many embodiments and adaptations of the present invention other than those described above, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the following claims and the equivalents thereof.