Patent Publication Number: US-6655013-B2

Title: Terminal applicator for attaching flag terminals

Description:
The present invention relates to an applicator machine for attaching an electrical terminal to a wire and more particularly to a wire guide carried by the ram of the machine for guiding a wire into position for crimping a single sided flag terminal thereto. 
     BACKGROUND OF THE INVENTION 
     Terminal applicator machines are widely used in the industry to attach electrical terminals to conductors. These terminal applicators are typically secured in a press which supplies the power and motion that operates the applicator. The applicator may be used manually where an operator inserts an already prepared wire end into the crimping area between a crimping tool and an anvil containing a terminal and holds the wire in place while activating the press to complete the termination. Alternatively, the terminal applicator and associated press may be attached to a host machine, such as a lead maker, where the prepared wire end is automatically presented to the applicator tooling for termination. These terminal applicators typically feed a strip of terminals along a guide rail into a workstation where one of the terminals is positioned over an anvil. The wire, its end having been previously stripped of insulation, is positioned in the workstation and the apparatus is activated to cause crimping tools to engage and crimp the tabs of the terminal onto the end of the wire. 
     The terminal typically has four tabs, two of which are on each side of the barrel. The tabs are rolled over onto the insulation and the conductor during the crimping process. Prior to crimping, the tabs on opposite sides form a lead in to help guide the wire from a target area within which the wire is placed, into crimping position in the barrel of the terminal. Additionally, the crimping tooling usually has a V-shaped lead in that helps to guide the wire as well. The target area within which the wire must be placed is relatively large, and the host machine typically can easily position the wire within this area. 
     However, certain types of terminals, known as flag terminals, are configured with the tabs to be crimped on only one side of the terminal. See, for example, FIGS. 3 and 4 where there is shown a flag terminal  2  having a receptacle contact  4 , a barrel  6 , an insulation tab  8  and a conductor tab  10 . The outer tip of the conductor tab  10  extends directly over a portion of the barrel  6 , as viewed in FIG. 3, which directly interferes with normal seating of the conductor within the barrel  6  unless the conductor is positioned within a very small target zone. This configuration requires that the crimping tooling be relieved on the side opposite the tabs, eliminating the normal V-shaped lead in. See FIG. 2A for a schematic representation of prior art crimping tooling of this type. 
     When positioning a wire with respect to the terminal  2  for crimping, it must be positioned within a well defined target zone  16  which falls between the two phantom lines  18  and  20 , in FIG.  2 A. The phantom line  18  defines the upper most position from which the wire can be guided into the barrel  6 , the tabs  8  and  10  define the left most position, while the phantom line  20  defines the right most position. An insulation crimping tool  26  includes a lead in angled surface  28  that extends on both sides of a crimping nest  30 . Similarly, a conductor crimping tool  34  includes a lead in angled surface  36  that extends on both sides of a conductor crimping nest  38 . During the downward crimping stroke of the ram these angled surfaces  28  and  36  will engage and guide the tips of the tabs  8  and  10  toward and into the nests  30  and  38 . 
     Note that, in the event that the wire is inadvertently positioned above the phantom line  18 , the wire will enter the nests  30  and  38  before the tips of the tabs, resulting in a failed crimp. The net result of this over extending tip  10  and the lack of lead in on the right most side of the tooling is that the area of the target zone  16 , the area within which the conductor must be placed in order for the crimping tooling to pick it up and center it in the barrel  6 , is substantially reduced from what it would be with conventional terminals having straight tabs on opposite sides of the terminal. This reduced target area is a serious detriment in an automated environment where the host machine must consistently and accurately position the conductor within that reduced target area. Achieving this accuracy substantially increases the cost of the host machine and can reduce its cycle time, thereby reducing its efficiency. 
     What is needed is a terminal applicator machine having a simple and inexpensive wire guide that permits a substantially larger target area while assuring that the wire is properly guided into the barrel during the crimping cycle. 
     SUMMARY OF THE INVENTION 
     A terminal applicator is provided for attaching an electrical flag terminal to a conductor. The flag terminal is of the type having a crimping tab extending from only a single side thereof. The terminal applicator includes a frame and an anvil supported by the frame and arranged to receive a flag terminal. A ram, having crimping tooling attached thereto, is in sliding engagement with the frame and is arranged to undergo reciprocating motion carrying the crimping tooling along a first axis in a crimping direction into crimping engagement with the flag terminal on the anvil and in an opposite return direction away from the anvil. The crimping tooling has a crimping nest for forming the crimping tab in cooperation with the anvil. The first axis extends at least from the crimping nest to the anvil. The crimping tooling includes a lead in surface that is adjacent the crimping nest and extends therefrom away from the first axis toward the anvil. A wire guide is attached to and carried by the ram adjacent the crimping tooling. The wire guide has a wire guiding surface on a side of the first axis opposite the lead in surface. The wire guiding surface is adjacent the crimping nest and extends therefrom away from the first axis toward the anvil. 
     An embodiment of the invention will now be described by way of example with reference to the following drawings. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a terminal applicator incorporating the teachings of the present invention; 
     FIG. 2 is a front view of the applicator shown in FIG. 1; 
     FIG. 2A is a schematic representation of prior art crimping tooling; 
     FIG. 2B is a front view of a portion of the terminal applicator shown in FIG. 2; 
     FIG. 3 is a front or end view of an electrical flag terminal of the type utilized by the applicator shown in FIG. 1; 
     FIG. 4 is a side view of the terminal shown in FIG. 3; 
     FIG. 5 is an exploded parts view of the ram assembly shown in FIG. 1; 
     FIGS. 6,  7 ,  8 , and  9  are similar front views of a portion of the crimping tooling shown in FIG. 2, showing the tooling in various positions during its operating cycle. 
    
    
     DESCRIPTION OF AN EMBODIMENT OF THE INVENTION 
     There is shown in FIGS. 1 and 2 a terminal applicator  50  for crimping an electrical terminal  2  onto a conductor  52  of a wire  54 . The applicator includes a frame  56 , base  58  that supports an anvil  60 , and a ram assembly  62  that is in sliding engagement within an opening  64  in the frame, shown in FIG. 5, and is arranged to undergo reciprocating movement in a crimping direction toward the anvil and away therefrom along a vertical axis of movement  66  or first axis, as best seen in FIG.  2 . The ram assembly  62 , as best seen in FIG. 5, comprises a ram  68  which carries tooling that includes an insulation crimping tool  70 , a conductor crimping tool  72 , and a wire guide  74 , all of which are attached to the ram by means of a screw  76 . The screw  76  extends through a hole in the wire guide  74 , a spacer  78 , an elongated hole in the insulation crimping tool  70 , a hole in the conductor crimping tool  72 , and into a threaded hole in the ram  68 . A crimp height adjust mechanism  82  is coupled to the ram  68  by means of a shoulder coupling screw  84  that is threaded into a hole in the ram in the usual manner. The shoulder coupling screw  84  includes a coupling head  86  that couples the ram assembly  62  to a press ram of a host machine, not shown. When the press ram of the host machine is actuated, it imparts reciprocating motion to the ram  68 . A terminal feed mechanism  88  is coupled to the frame  56  and is actuated by the ram  68  to incrementally feed a strip of terminals  2 , in the usual manner, so that a new terminal  2  is positioned on the anvil for the next crimping cycle. 
     A portion of the terminal applicator  50 , taken from FIG. 2, is shown in FIG.  2 B. However, in FIG. 2B the crimping tooling is positioned just above the terminal  2  so that it is comparable to the schematic representation of the prior art tooling shown in FIG.  2 A. As best seen in FIGS. 2B and 5, the insulation crimping tool  70  includes an insulation crimping nest  90  having a vertical null surface  91  formed in an angled surface  92  that extends on both sides of the nest, the null surface  91  being spaced from the vertical axis of movement  66 . The portion of the angled surface  92  that extends from the null surface  91  of the nest  90  downwardly and to the left, as viewed in FIG. 2B, acts as a lead-in for guiding the insulation tab  8  into the crimping nest  90  during the crimping stroke of the ram  68 . The portion of the angled surface  92  that extends from the nest  90  upwardly and to the right, as viewed in FIG. 2B, is simply a clearance portion to prevent interference with the contact  4  as the tab  8  is being crimped. 
     Similarly, the conductor crimping tool  72  includes a conductor crimping nest  96  having a vertical null surface  97  formed in an angled surface  98  that extends on both sides of the nest. The vertical axis of movement  66  of the ram assembly  62  is adjacent the right most edge of the nest  96 , as viewed in FIG. 2B, and spaced from the null surface  97 . The portion of the angled surface  98  that extends from the null surface  97  of the nest  96  downwardly and to the left, as viewed in FIG. 2B, is on the left most side of the axis  66  and extends away from the axis and toward the anvil  60 . This portion of the angled surface acts as a lead in for guiding the conductor tab  10  into the crimping nest  96  during the crimping stroke of the ram  68 . In a manner similar to that of the prior art mechanism shown in FIG. 2A, the upper most limit and left most limit for properly guiding the wire are indicated by the phantom lines  18  and the tabs  8  and  10 , respectively, in both FIGS. 2A and 2B. The portion of the angled surface  98  that extends from the nest  96  upwardly and to the right, as viewed in FIG. 2B, is simply a clearance portion to prevent interference with the contact  4  as the tab  10  is being crimped. Note that the vertical axis of movement  66  is in a position with respect to the nest  96  similar to that of the phantom line  20  with respect to the nest  38  of the prior art mechanism. That is, the axis  66  and phantom line  20  are in identical positions with respect to their respective terminals and crimping tooling. 
     The wire guide  74  includes a lead in wire guiding surface  100  that is closely adjacent the upper right edge of the crimping nests  90  and  96 , as viewed in FIG. 2B, and extends downwardly away from the vertical axis of movement  66  to the right and toward the anvil  60 , thereby forming an angle  104  to the axis  66 . Preferably, the angle  104  is from 15 to 45 degrees, most preferably about 25 degrees. This wire guiding surface  100  is on a side of the axis  66  opposite the angled surfaces  92  and  98  of the insulation and conductor crimping tools, as viewed in FIGS. 2 and 2B. The wire guide  74  is positioned to the left of both the conductor crimping tool and the insulation crimping tool, as shown in FIGS. 1 and 5. Therefore, the wire guide will remain clear of the terminal  2  during the entire crimping cycle. However, the wire guiding surface  100  of the wire guide can engage the wire  54 , in the event that the wire is positioned to the right of the nests  90  and  96 , and guide it toward and into alignment with the barrel  6  of the terminal  2 . The lower right edge of the surface  100 , as viewed in FIG. 2B, defines a right most limit, identified by the phantom line  102 , from which the wire  54  can be properly guided toward and into alignment with the barrel  6 . 
     As with the prior art apparatus shown in FIG. 2A, when positioning the wire  54  for crimping a terminal  2  thereto, the wire must be placed within a target zone that includes the target zone  16  that is limited on the top by the phantom line  18 , on the left by the tabs  8  and  10 , and on the right by the vertical axis of movement  66 . However, in the case of the terminal applicator  50  shown in FIG. 2B, the area between the axis  66  and the phantom line  102  defines an additional target zone  106  within which a wire can be properly guided toward and into alignment with the barrel  6 . The additional target zone  106  coupled with the target zone  16  provides an area within which the wire is to be positioned that is about three times as large as the area of the prior art target zone. This has a substantial positive affect on the design and construction of a host machine that must accurately position the wire  54  within the expanded target zone. Because of this expanded target zone, the positioning mechanism of the host machine can have wider tolerances and, in some cases, a shorter cycle time. 
     The operation will now be described with reference to FIGS. 1 and 6 through  9 . As shown in FIG. 1, a terminal  2  is in crimping position on the anvil  60 . A wire  54  is then positioned so that it&#39;s conductor  52  is directly over the crimping barrel  6  and within either of the target zones  16  or  106 , in the present example the conductor is shown in the target zone  106  in FIG.  6 . As the ram assembly  62  is made to move in the crimping direction toward the anvil  60 , the angled surface  92  of the insulation crimping tool  70  engages the tip of the insulation tab  8  and begins to cam it toward the right and into alignment with the insulation crimping nest  90 , as shown in FIG.  7 . Concurrently, the wire guiding surface  100  of the wire guide  74  engages the outer surface of the insulation of the wire  54  in the target zone  106  and begins to cam the wire toward the left toward the axis  66  into vertical alignment with the barrel  6  and toward the anvil  60 . As the ram assembly  62  continues to move toward the anvil  60  the insulation tab  8  is urged further to the right so that it enters the crimping nest  90  while the angled surface  98  of the conductor crimping tool  72  engages and cams the tip of the conductor tab  10  into the conductor crimping nest  96 . Concurrently, the surface  100  of the wire guide  74  cams the wire  54  into direct alignment between the barrel  6  and the crimping nests  90  and  96 , as shown in FIG.  8 . As the ram assembly is moved to the bottom of its stroke, as shown in FIG. 9, the insulation tab  8  and the conductor tab  10  are crimped onto the wire  54  and its conductor  52 , respectively. The ram assembly  62  is then returned to its starting position, as shown in FIG. 1, and the process repeated as desired. 
     An important advantage of the present invention is that the cost of the host machine can be reduced because the larger target zone permits wider tolerances of the wire placement mechanism. Additionally, this wider tolerance will sometimes permit the machine to operate at a higher speed thereby reducing its cycle time. This is accomplished without a significant increase in the cost of the present terminal applicator. The wire guide of the present invention is simple to make and economical to maintain because it attaches to and is carried by the ram without any additional parts or supporting mechanisms.