Abstract:
The present invention provides a terminal ring assembly structured for engagement to a conductor post. The terminal ring assembly of the present invention includes a first ring element and a second ring element, each having a circular body and at least one grip having crimpable barrels for engaging a wire in electrical connectivity. The first and second ring elements further include an interlocking device, in which the interlocking components of the first and second ring elements engage each other so that the first and second ring elements are locked together.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to an electric terminal, and, more specifically, to a ring terminal assembly formed from two ring elements and having multiple wire couplings.  
       DESCRIPTION OF THE RELATED ART  
       [0002]     Ring terminals are typically used to couple a wire to a conductor. The ring terminal is made from an electrically conductive material and includes a flat ring-shaped body having a radial arm or “grip.” The grip is folded, or crimped, around the exposed end of an insulated electrical wire. The ring-shaped body is then disposed about a conductor post, such as a stud or a bolt. That is, the stud or bolt is passed through the ring-shaped body and the ring terminal is secured with a fastener. The stud or bolt is in electrical communication with an electrical system or circuit. Thus, following the installation of the ring terminal, the wire is also coupled to the electrical system or circuit. Such ring terminals are typically plated with a material such as, but not limited to, tin. The plating helps to resist corrosion.  
         [0003]     Generally, the grip includes a “barrel,” structured to be crimped about one, or two, wires. That is, the grip includes a generally flat member having two generally perpendicular connector tabs extending from opposite sides of the member. The tabs are initially, generally flat so that the entire tab is almost perpendicular to the member, thereby forming a U-shape or a V-shape. Hereinafter, the U-shaped or V-shaped tabs shall be referred to as an “open barrel.” The exposed tip of an insulated wire is placed in the open barrel and the tabs are bent, or crimped, to engage the exposed wire tip, hereinafter a “closed barrel.” The grip is typically an outer pair of support tabs which are substantially similar to the connector tabs. The support tabs are structured to be crimped over the portion of the wire having an insulator.  
         [0004]     While ring terminals are simple and inexpensive, they have several disadvantages. For example, a single grip can be crimped with one or two wires while maintaining an acceptable pull force. If three or more wires are crimped into a single grip, the wire(s) may be easily pulled out of the grip, creating an un-reliable connection between wire and ring terminal. Also, if more than three wires need to be coupled to a single location, multiple ring terminals must be used. As noted above, terminals are plated, usually with tin, to resist corrosion. If more than two plated terminals are stacked together, the plating on the terminals may be subject to cold-softening. Even with the cold-softening, the connection between the bolt and nut joint remains acceptably reliable, or tight, with two plated terminals. However, if more than three plated terminals are stacked, the bolt-nut joint may become loose and cause a thermal event and electrical failure due to accumulated cold-softening. In other words, a single stud is limited to a maximum of 4 wires as each plated terminals can be crimped to two wires.  
         [0005]     If more than four wires are needed to connect at a single stud point, three or more un-plated terminals could be stacked on the stud to avoid the accumulated cold-softening effect. However, the terminal then did not have corrosion protection. So, such a solution is limited to use in a non-corrosive area. This solution also has the disadvantage of costing more due to the use of additional terminals.  
         [0006]     There is, therefore, a need for a ring terminal assembly that is structured to accept a variable number of wires.  
         [0007]     There is a further need for a two-part terminal ring that may be interlocked and that is plated and structured to accept multiple wires.  
         [0008]     There is a further need for a terminal ring structured to accept multiple wires and which functions with existing crimping hardware.  
       SUMMARY OF THE INVENTION  
       [0009]     These needs, and others, are met by the present invention which provides a ring terminal assembly having two interlocking ring elements. Each ring element has at least one grip supporting a multi-wire barrel. The multi-wire barrel typically accepts one or two wires. Each ring element may have one or two grips. The ring elements are structured to interlock to each other to ensure contact between the ring elements. Preferably, the interlock device is a tab with a projection disposed on one ring element and a tab with an opening disposed on the other ring element. The two tabs are structured to engage each other so that the projection is disposed within the opening. By using either, or both, of the ring elements, the ring terminal assembly may be adapted to couple between one and eight wires to a stud without an empty grip.  
         [0010]     Preferably, each ring element includes a generally flat ring-like body, and the tabs are slightly offset, but generally parallel to, the ring-like bodies. The ring bodies are placed against each other and rotated so that the tabs move towards each other until the projection engages the opening. One ring element may include a collar about the central opening to assist in aligning the ring-like bodies. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     A full understanding of the invention can be gained from the following description of the preferred embodiments when read in conjunction with the accompanying drawings in which:  
         [0012]      FIG. 1A  is an isometric view of an exploded terminal ring with two grips prior to engaging any wires.  
         [0013]      FIG. 1B  is an isometric view of an exploded terminal ring with one grip prior to engaging any wires.  
         [0014]      FIG. 2A  is an isometric view of a terminal ring assembly wherein each ring element has two grips and wherein the ring elements are not locked together.  FIG. 2B  is an isometric view of a terminal ring assembly wherein each ring element has two grips and wherein the ring elements are locked together.  
         [0015]      FIG. 3A  is an isometric view of a terminal ring assembly wherein one ring element has two grips and the other ring element has a single grip, and wherein the ring elements are not locked together.  FIG. 3B  is an isometric view of a terminal ring assembly wherein one ring element has two grips and the other ring element has a single grip, and wherein the ring elements are locked together.  
         [0016]      FIG. 4A  is an isometric view of a one-wire terminal ring assembly.  FIG. 4B  is an isometric view of a two-wire terminal ring assembly.  FIG. 4C  is an isometric view of a three-wire terminal ring assembly.  FIG. 4D  is an isometric view of a four-wire terminal ring assembly.  FIG. 4E  is an isometric view of a five-wire terminal ring assembly.  FIG. 4F  is an isometric view of a six-wire terminal ring assembly.  FIG. 4G  is an isometric view of a seven-wire terminal ring assembly.  FIG. 4H  is an isometric view of an eight-wire terminal ring assembly.  
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0017]     As used herein, directional terms, such as “upper” and “lower” relate to the terminal ring assembly as shown in the Figures and are not limiting upon the claims.  
         [0018]     As shown in  FIGS. 1A and 1B , a terminal ring assembly  10  includes a lower, first ring element  12  ( FIG. 1A ) and an upper, second ring element  14  ( FIG. 1B ). Both the first and second ring elements  12 ,  14  are, preferably, stamped from a flat sheet of conductive metal and shaped as follows. The terminal ring assembly first and second ring elements  12 ,  14  may be plated with a corrosion resistant material, such as tin. The first ring element  12  includes a generally circular, ring-like body  16 , that is, a torus, and at least one radial arm, hereinafter a “grip”  18 , described more fully below. Preferably, and as discussed hereinafter, the first ring element  12  includes two grips  18 A,  18 B. The first ring element body  16  includes a central opening  22 , a collar  24 , having an outer diameter, disposed about the central opening  22 , and a first component  26  of an interlock device  80 , described below. The first ring element body  16  is generally flat. The second ring element  14  also includes a generally circular, ring-like body  17 , that is, a torus, and at least one radial arm, hereinafter a “grip”  18 , described more fully below. Preferably, and as discussed hereinafter, the second ring element  14  includes either one grip  18 C ( FIG. 1B ) or two grips  18 D,  18 E ( FIG. 2A ). The second ring element body  17  includes a central opening  23 , and a second component  27  of an interlock device  80 , described below. The second ring element opening  23  has about the same diameter as the collar  24  outer diameter. Thus, the second ring element opening  23  is structured to engage, or abut, the collar  24 . The second ring element body  17  is also generally flat.  
         [0019]     The interlock device  80  includes the first and second components  26 ,  27  noted above, one component on each ring element  12 ,  14 . In the preferred embodiment, the first and second components  26 ,  27  are each flexible, arcuate tabs  82 ,  84  (respectively) stamped from the first and second ring element bodies  16 ,  17  having either an opening  86  or a projection  87 , such as a wedge  88 . The arcuate tabs  82 ,  84  are offset, but substantially parallel to, the plane of the first and second ring element bodies  16 ,  17 . Adjacent to each arcuate tab  82 ,  84  is a gap  89 . As shown in  FIG. 1 , the first arcuate tab  82  on the first ring element  12  is offset upwardly and the second arcuate tab  84  on the second ring element  14  is offset downwardly. The amount of the offset is about the thickness of the first and second ring element bodies  16 ,  17 . Thus, when the first and second ring elements  12 ,  14  are coupled, the first arcuate tab  82  on the first ring element  12  is, generally, in the plane of the second ring element body  17  and the second arcuate tab  84  on the second ring element  14  is, generally, in the plane of the first ring element body  16 . In this configuration, when the first and second ring elements  12 ,  14  are engaged, that is, coupled, and rotated, the first arcuate tab  82  will move over the second arcuate tab  84 . Thus, where the first arcuate tab  82  has an opening  86 , and the second arcuate tab  84  has a wedge  88 , the wedge  88  will engage the opening  86 , thereby interlocking the ring elements  12 ,  14 . In a preferred embodiment, each ring element  12 ,  14  includes two arcuate tabs. That is, the first ring element  12  includes two arcuate tabs  82 ,  83  and the second ring element includes two arcuate tabs  84 ,  85 . Where each ring element  12 ,  14  includes two arcuate tabs, one tab will have an opening  86  and the other tab will have a wedge  88 . The openings  86  and wedges  88  on opposing ring elements  12 ,  14  are structured to engage each other. That is, the first ring element  12  interlock device  80  includes a first flexible tab  82  having an opening  86  and a second flexible tab  83  having a projection  87 , and the second ring element  14  includes a third flexible tab  84  having a projection  87  and a fourth flexible tab  85  having an opening  86 .  
         [0020]     The interlock device  80  may also include a stop device  90  structured to limit the rotation of the ring elements  12 ,  14  relative to each other. The stop device  90 , preferably, includes a pair of radial stops  92 ,  94  extending from the first ring element  12  and a perpendicular tab  96  extending from the perimeter of the second ring element  14 . When the ring elements  12 ,  14  are coupled, the perpendicular tab  96  is disposed between the radial stops  92 ,  94 . When the ring elements  12 ,  14  are rotated relative to each other, the perpendicular tab  96  will contact either radial stop  92 ,  94 , thereby limiting the rotation of the ring elements  12 ,  14  relative to each other. Further, tab  96  may be dropped into a slot of sheet metal and serve as anti-rotation during tightening a nut (not shown) to a stud.  
         [0021]     Each grip  18  is substantially similar. As such, a grip  18  will be described below and detailed on  FIG. 2A . It is understood that each separate grip  18  includes like components. Each grip  18  includes an arm  30  and a crimpable barrel  32 . The arm  30  is a flat member  34  extending radially from the associated ring-like body  16 ,  17 . The barrel  32  includes a flat member  36 , that is an extension of the arm flat member  34 , and at least one pair  40  of generally perpendicular tabs extending laterally from the barrel flat member  36 . Preferably, there are two sets of tabs, an inner pair of tabs  42 ,  44  and an outer pair of tabs  46 ,  48 . The pairs of tabs  42 ,  44 ,  46 ,  48  are bent upwardly, as shown in the figures, to form a U-shape or a V-shape. In this configuration, the tabs  42 ,  44 ,  46 ,  48  constitute an “open” barrel  32  as is known in the art. The use of four tabs  42 ,  44 ,  46 ,  48  are structured to cooperate with standard crimping tools so that the inner pair of tabs  42 ,  44  and the outer pair of tabs  46 ,  48  are coupled to one or two wires  1  ( FIG. 4A-4H ). That is, the barrel flat member  36  has a width sufficient to accommodate two wires placed thereon. As shown in  FIGS. 4A-4H , the tabs  42 ,  44 ,  46 ,  48  are structured to be crimped about the wire(s)  1 , with the inner pair of tabs  42 ,  44  contacting an exposed tip(s)  2  of the wire(s)  1 , and the outer pair of tabs  46 ,  48  contacting the wire insulation  3 . In this configuration the barrel  32  is “closed.” 
         [0022]     As noted above, and as shown in  FIG. 1A , the first ring element  12  preferably includes two grips  18 , a first grip  18 A, and a second grip  18 B. The first and second grips  18 A,  18 B are disposed about 90 degrees apart on the first ring element body  16 . As shown in  FIG. 3A , the second ring element  14 A,  14 B includes either one grip  18 , a third grip  18 C ( FIG. 1B ), or, as shown in  FIG. 2A , two grips  18 , an alternate third grip  18 D and a fourth grip  18 E. Hereinafter, a second ring element with two grips shall be identified by the reference number “ 14 A” and a second ring element with one grip shall be identified by the reference number “ 14 B” 
         [0023]     Thus, as shown in  FIG. 2A , a terminal ring assembly  10  having four grips  18 A,  18 B,  18 D,  18 E is assembled as follows. A first ring element  12  having two grips  18 A,  18 B is provided and a second ring element  14 A having two grips  18 D,  18 E is also provided. The ring elements  12 ,  14 A are coupled in an unlocked position with the first and second ring element bodies  16 ,  17  disposed adjacent to each other with the collar  24  extending through the second ring element opening  23 . Additionally, each arcuate tab  82 ,  83 ,  84 ,  85  is disposed in a gap  89  on the opposing ring element  12 ,  14 A and the perpendicular tab  96  is disposed between the two stops  92 ,  94 . As shown in  FIG. 2B , the first and second elements are then rotated relative to each other until the arcuate tabs  82 ,  83 ,  84 ,  85  overlay each other so that each wedge  88  engages an opening  86 . Rotation of the first and second ring elements relative to each other is halted by the perpendicular tab  96  contacting a stop  92 .  
         [0024]     As shown in  FIG. 3A  a terminal ring assembly  10  having three grips  18 A,  18 B,  18 C is assembled as follows. A first ring element  12  having two grips  18 C is provided and a second ring element  14 B having two grips  18 C is also provided. The ring elements  12 ,  14 B are coupled in an unlocked position with the first and second ring element bodies  16 ,  17  disposed adjacent to each other with the collar  24  extending through the second ring element opening  23 . Additionally, each arcuate tab  82 ,  83 ,  84 ,  85  is disposed in a gap  89  on the opposing ring element  12 ,  14 B and the perpendicular tab  96  is disposed between the two stops  92 ,  94 . As shown in  FIG. 3B , the first and second ring elements  12 ,  14 B are then rotated relative to each other until the arcuate tabs  82 ,  83 ,  84 ,  85  overlay each other so that each wedge  88  engages an opening  86 . Rotation of the first and second ring elements  12 ,  14 B relative to each other is halted by the perpendicular tab  96  contacting a stop  92 .  
         [0025]     Given these ring elements  12 ,  14 A,  14 B, the terminal ring assembly  10  may be adapted to couple between one and eight wires  1  to a stud (not shown). That is, as shown in  FIGS. 4A and 4B , a single second ring element  14 B having one grip  18 C may be coupled to one wire  1  ( FIG. 4A ) or two wires  1  ( FIG. 4B ). As shown in  FIG. 4C , a single first ring element with two grips  18 A,  18 B may be coupled to three wires  1 ; one wire coupled to one grip  18 A and two wires  1  coupled to the other grip  18 B. Alternatively, as shown in  FIG. 4D , a single first ring element with two grips  18 A,  18 B may also be coupled to four wires  1 ; two wires  1  coupled to one grip  18 A and two wires  1  coupled to the other grip  18 B. As shown in  FIG. 4E , a terminal ring assembly  10  having a single first ring element with two grips  18 A,  18 B and a second ring element  14 B having one grip  18 C may be used to couple five wires  1  to a stud. That is, on the first ring element  12 , two wires  1  are coupled to one grip  18 A and two wires  1  are coupled to the other grip  18 B and, on the second ring element  14 B, one wire  1  is coupled to the grip  18 C. As shown in FIG. F, this same configuration of a first ring element  12  and a single grip second ring elements  14 B may be used to couple six wires  1  to a stud. That is, on the first ring element  12 , two wires  1  are coupled to one grip  18 A and two wires  1  are coupled to the other grip  18 B and, on the second ring element  14 B, two wires  1  coupled to the grip  18 C. As shown in  FIG. 4G , a terminal ring assembly  10  having a single first ring element  12  with two grips  18 A,  18 B and a second ring element  14 A having two grips  18 D,  18 E may be used to couple seven wires  1  to a stud. That is, on the first ring element, one wire  1  is coupled to one grip  18 A and two wires  1  are coupled to the other grip  18 B and, on the second ring element  14 A, two wires  1  are coupled to each grip  18 D,  18 E. This same configuration of a first ring element  12  and a single grip second ring elements  14 A may be used to couple eight wires  1  to a stud. That is, on the first ring element  12 , two wires  1  are coupled to each grip  18 A,  18 B and, on the second ring element  14 A, two wires  1  coupled to each grip  18 D,  18 E. Of course, the location of the single and double wires  1  on a particular grip  18 A- 18 E may vary as needed.  
         [0026]     While specific embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details could be developed in light of the overall teachings of the disclosure. For example, the stop device  90  could also be a perpendicular tab  96  on one ring element disposed in a slot on the other ring element. Accordingly, the particular arrangements disclosed are meant to be illustrative only and not limiting as to the scope of invention which is to be given the full breadth of the claims appended and any and all equivalents thereof.