Patent Publication Number: US-2020287300-A1

Title: Connection Terminal, Method Of Connecting Wires Using The Same And Pressing Die

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of the filing date under 35 U.S.C. § 119(a)-(d) of Chinese Patent Application No. 201910170433.4, filed on Mar. 6, 2019. 
     FIELD OF THE INVENTION 
     The present invention relates to a connection terminal and, more particularly, to a connection terminal adapted to connect a plurality of wires. 
     BACKGROUND 
     In connecting electrical equipment, it is sometimes necessary to use a connection terminal to electrically connect a plurality of wires to each other in a crimped manner. For example, when connecting three wires for conveying three-phase AC current, one end of the three wires needs to be electrically connected together. To facilitate the connection, a terminal clip is crimped to one end of the three wires to achieve an electrical connection between the three wires. 
     In one type of connection, the terminal clip is made of a conductive material, and the terminal clip is electrically connected to at least a part of the connected wires, so that a reliable electrical connection between all the wires may be further ensured. In the process of connecting the wires with such a terminal clip, some of the wires may move relative to the other wires under the clamping force of the terminal clip, resulting in poor electrical contact, inconsistent cross-sectional structure of the finally formed wires, and/or inability to crimp the wire securely. 
     SUMMARY 
     A connection terminal made of a metal sheet includes a body portion having a first edge and a second edge extending in a longitudinal direction of the body portion and opposite to each other in a transverse direction of the body portion, a first wing extending from the first edge, and a second wing extending from the second edge. The first wing and the second wing are opposite to each other in the transverse direction of the body portion. A length of the first wing extending from the first edge is greater than a length of the second wing extending from the second edge. An inner surface of each of the first wing, the second wing, and the body portion has a plurality of first grooves. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described by way of example with reference to the accompanying Figures, of which: 
         FIG. 1  is a perspective view of a connection terminal according to an embodiment; 
         FIG. 2  is a sectional view of a body portion of the connection terminal of  FIG. 1 ; 
         FIG. 3  is a rear perspective view of the connection terminal of  FIG. 1  with a plurality of wires connected thereto and in an unbent state; 
         FIG. 4  is a front perspective view of the connection terminal of  FIG. 3 ; 
         FIG. 5  is a perspective view of the connection terminal of  FIG. 3  with a pressing die; 
         FIG. 6  is a perspective view of the connection terminal of  FIG. 1  with a plurality of wires connected thereto and in a bent state; 
         FIG. 7  is a sectional view of the connection terminal, taken along line A-A of  FIG. 6 ; 
         FIG. 8  is a sectional view of the connection terminal, taken along line B-B of  FIG. 6 ; 
         FIG. 9  is a perspective view of the connection terminal of  FIG. 1  connecting end portions of wires; 
         FIG. 10  is a perspective view of the connection terminal of  FIG. 1  connecting portions of wires between end portions; 
         FIG. 11  is a perspective view of the connection terminal of  FIG. 1  with a pressing die before bending; 
         FIG. 12  is a sectional view of the connection terminal of  FIG. 1  with bent wings connected to a plurality of wires; 
         FIG. 13  is a sectional view of the connection terminal of  FIG. 1  with bent wings connected to a plurality of wires; 
         FIG. 14  is a perspective view of a connection terminal according to another embodiment; 
         FIG. 15  is a sectional view of a body portion of the connection terminal of  FIG. 14 ; and 
         FIG. 16  is another sectional view of the body portion of the connection terminal of  FIG. 14 . 
     
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENT(S) 
     Although the present disclosure will be described hereinafter in detail with reference to the attached drawings showing the embodiments of the present disclosure, it should be appreciated by those of ordinary skill in the art that the invention described herein may be modified and the technical effect of the present disclosure may be achieved at the same time. It should be understood that the description to the embodiments of the present disclosure in conjunction with the attached drawings is to convey a general concept of the present disclosure to the person of ordinary skill in the art, and is not intended to limit the present disclosure to the described exemplary embodiments. 
     Furthermore, in the following detailed description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing. 
     A connection terminal  100  according to an embodiment, as shown in  FIG. 1 , is made of a metal sheet such as a single copper sheet or a single stainless steel sheet, and includes a body portion  1 , a first wing  2 , and a second wing  3 . 
     As shown in  FIGS. 1 and 6-8 , the body portion  1  has a substantially rectangular shape when unfolded into a plane, and has a first edge  11  and a second edge  12  extending in a longitudinal direction thereof and opposite to each other in a transverse direction thereof. The first wing  2  and the second wing  3  extend from the first edge  11  and the second edge  12 , respectively. The first wing  2  and the second wing  3  are opposite in the transverse direction of the body portion  1 , and a length of the first wing  2  extending from the first edge  11  of the body portion  1  is greater than a length of the second wing  3  extending from the second edge  12 . Thus, as shown in  FIGS. 6 and 8 , in the case where the first wing  2  and the second wing  3  are bent so as to crimp the wires  200 , the second wing  3  is held between the first wing  2  and the wires  200  by the first wing  2 , so that the wires  200  is crimped by two layers of wings and thus may be securely held in the connection terminal  100  and all of the wires  200  are electrically connected to each other. 
     In an exemplary embodiment, as shown in  FIGS. 1 and 2 , an inner surface of each of the first wing  2 , the second wing  3 , and the body portion  1  have a plurality of first grooves  8 . By providing the first grooves  8 , the friction force applied to the wires  200  by the body portion  1 , the first wing  2 , and the second wing  3  may be increased, and the friction between the first wing  2  and the second wing  3  may also be increased, thereby retaining the wire  200  more securely in the connection terminal  100 . 
     In an embodiment, each of the first grooves  8  is formed as a slot extending in the transverse direction on the first wing  2 , the second wing  3 , and the body portion  1 . For example, nine slots, which are formed in a serration shape and each of which is symmetrical in the transverse direction, are arranged in the longitudinal direction. In this way, the retention of the connection terminal  100  in the longitudinal direction may be increased, preventing the wires  200  from being detached from the connection terminal  100  in the longitudinal direction. In an alternative embodiment, the first grooves  8  may be configured as a plurality of circular protrusions or a plurality of circular recessions. 
     As shown in  FIGS. 12 and 13 , in an exemplary embodiment, the connection terminal  100  is adapted to retain more than three wires  200 , such as ten wires. The wires  200  include a plurality of (e.g. seven) bare wires  201  and a plurality of (e.g. three) varnished wires  202 . The varnished wire  202  includes a conductor and an insulating layer that covers the conductor. 
     An edge of each first groove  8 , as shown in  FIG. 2 , has first burrs  7  extending away from the inner surfaces. Each varnished wire  202  is disposed to be in contact with at least one of the first wing  2 , the second wing  3 , and the body portion  1 . Thus, in the case where the wires  200  are crimped by the first wing  2 , the second wing  3  and the body portion  1  by a pressing die  300  (described in detail below), the burrs  7  pierce the insulating layer of the varnished wire  202  so that the connection terminal  100  may be electrically connected to the varnished wire  202 . Further, by direct contact between the connection terminal  100  and the bare wires  201  and direct contact between the bare wires  201 , all of the wires  200  including the bare wires  201  and the varnished wires  202  are electrically connected to each other. The varnished wire  202  is electrically connected to other wires when the insulation layer thereof is pierced, thereby avoiding the use of welding technology, reducing the cost of crimping, and reducing environmental pollution. 
     As shown in  FIG. 1 , the connection terminal  100  further includes at least one third wing  4  (for example, two third wings  4  are shown in  FIG. 1 ) and at least one fourth wing  5  (for example, two fourth wings  5  are shown in  FIG. 1 ) extending from the second edge  12  and the first edge  11  of the body portion  1 , respectively. Each third wing  4  is opposite a respective fourth wing  5  in the transverse direction of the body portion  1 , and a length of the third wing  4  extending from the second edge  12  of the body portion  1  is greater than a length of the fourth wing  5  extending from the first edge  11 . Further, the first wing  2  and the at least one fourth wing  5  are alternately arranged on the first edge  11 , and the second wing  3  and the at least one third wing  4  are alternately disposed on the second edge  12 . For example, as shown in  FIG. 3 , the first wing  2  having a longer length is located between two fourth wings  5  having a shorter length, and the second wing  3  having a shorter length is located between two third wings  4  having a longer length. 
     The connection terminal  100  according to an embodiment has a two-dimensional structure, and the wings  2 - 5  perform overlapping and crimping on the wires  200  from two dimensions, and the wings  2 - 5  at the front end (for example, the third wing  4  and the fourth wing  5 ) overlap towards one side of the body portion  1  to crimp the wires  200 , and the wings  2 - 5  at the rear end (for example, the first wing  2  and the second wing  3 ) overlap towards the other side of the body portion  1  to crimp the wires  200 . In this way, a plurality of wires  200  are subjected to balanced force, and are pressed by a plurality of wings  2 - 5  at a plurality of points to prevent the plurality of wires  200  from being concentrated or twisted toward a certain portion during the crimping process, thereby more reliably retaining the plurality of wires  200  together mechanically. The poor electrical contact between the wires  200  may be avoided, and the cross-sectional structure of the finally formed wires  200  is substantially uniform. 
     In one embodiment, as shown in  FIG. 9 , the connection terminal  100  may be crimped at the end portions of the plurality of wires  200  such that the plurality of wires  200  extend out of the connection terminal  100  from the same end of the connection terminal  100 . In another embodiment, as shown in  FIG. 10 , the connection terminal  100  may be crimped at portions of the plurality of wires  200 , each of which is located between the two end portions of the wire  200 , that is, both end portions of each wire  200  extend out of the connection terminal  100 . This increases the application flexibility of the connection terminal  100 . In a further embodiment, the connection terminal  100  may crimp the wires  200  inserted therein from both ends of the body portion  1  such that one end of one wire  200  faces one end of the other wire  200 . 
     A connection terminal  100 ′ according to another embodiment is shown in  FIGS. 14-16 . As shown  FIG. 14 , a first wing  2  and a second wing  3  extend from the first edge  11  and the second edge  12 , respectively. The first wing  2  and the second wing  3  are opposite in the transverse direction of the body portion  1 , and a length of the first wing  2  extending from the first edge  11  of the body portion  1  is greater than that of the second wing  3  extending from the second edge  12 . Inner surfaces of the first wing  2 , the second wing  3  and the body portion  1  have a plurality of first grooves  8 . Each of the first grooves  8  is formed as a slot extending in the transverse direction on the first wing  2 , the second wing  3 , and the body portion  1 . An edge of each first groove  8  is provided with first burrs  7  extending away from the inner surfaces. 
     The connection terminal  100 ′, as shown in  FIGS. 14-16 , further includes one third wing  4  and one fourth wing  5  extending from the second edge  12  and the first edge  11  of the body portion  1 , respectively. The third wing  4  is provided to be opposite to the fourth wing  5  in the transverse direction of the body portion  1 , and a length of the third wing  4  extending from the second edge  12  of the body portion  1  is greater than that of the fourth wing  5  extending from the first edge  11 . Further, the first wing  2  and the fourth wing  5  are alternately arranged on the first edge  11 , and the second wing  3  and the third wing  4  are alternately disposed on the second edge  12 . Inner surfaces of the third wing  4  and the fourth wing  5  have a plurality of second grooves  9 . Each of the second grooves  9  is formed as a slot extending in the transverse direction on the third wing  4 , the fourth wing  5 , and the body portion  1 . An edge of each second groove  9  has second burrs  10  extending away from the inner surfaces. 
     As shown in  FIGS. 14 and 15 , in one embodiment, no slot is provided at a portion of the body portion  1  between the first wing  2  and the fourth wing  5  (or between the second wing  3  and the third wing  4 ). As shown in  FIGS. 14 and 16 , in an alternative embodiment, slots further are provided at a portion of the body portion  1  between the first wing  2  and the fourth wing  5  (or between the second wing  3  and the third wing  4 ). 
     As shown in  FIGS. 1 and 14 , in one embodiment, the body portion  1  is pre-bent to have a substantially U-shaped cross section to facilitate placement of multiple wires within a generally U-shaped configuration. A slope  13  is provided on an outer surface of a free end of each of the first wing  2 , the second wing  3 , the third wing  4 , and the fourth wing  5 . The slope  13  may direct the wings  2 - 5  to move smoothly relative to a pressing die (described in detail below). 
     In an embodiment shown in  FIG. 5 , a pressing die  300  is adapted to press the connection terminal  100  according to any one of above-mentioned embodiments. The pressing die  300  has an opening  301  having a substantially U-shaped cross section, into which the first wing  2 , the second wing  3 , the third wing  4 , and the fourth wing  5  of the connection terminal  100  are adapted to enter. As the pressing die  300  presses the connection terminal  100  against a support portion  400 , the first wing  2 , the second wing  3 , the third wing  4 , and the fourth wing  5  are all bent toward the body portion  1  so as to retain and crimp the wires  200  within the connection terminal  100 . The first wing  2  is located outside the second wing  3  and the fourth wing  5  is located outside the third wing  4  (as shown in  FIGS. 5 and 6 ). 
     In an embodiment, as shown in  FIG. 5 , a plurality of guiding grooves  303  and  304  having different slopes are provided on sidewalls of the U-shaped opening  301  of the pressing die  300 . The plurality of guiding grooves  303  and  304  are configured such that the second wing  3  is bent toward the body portion  1  prior to the first wing  2  and, meanwhile, the fourth wing  5  is bent toward the body portion  1  prior to the third wing  4  as the pressing die  300  presses the connection terminal  100  against the support portion  400 . For example, in the state shown in  FIG. 5 , the guiding groove  303  is adapted to guide the second wing  3  or the fourth wing  5  having a shorter length, and the guiding groove  304  is adapted to guide the first wing  2  or the third wing  4  having a longer length, and an angle of the guiding groove  303  with respect to a vertical axis and/or a height of the guiding groove  303  protruding into the opening  301  is larger than an angle of the guiding groove  304  with respect to a vertical axis and/or a height of the guiding groove  304  protruding into the opening  301 . Thus, as shown in  FIGS. 6-8 , in the case where the first  2 , second  3 , third  4 , and fourth  5  wings are bent so as to retain the wires  200 , the second wing  3  is held between the first wing  2  and the wires  200  by the first wing  2 , and the fourth wing  5  is held between the third wing  4  and the wires  200  by the third wing  4 . 
     As shown in  FIGS. 3-5 , an embodiment of the present disclosure further provides a method for connecting a plurality of wires  200  by the connection terminal  100  according to any of the above embodiments. The method includes the following steps: as shown in  FIGS. 3 and 4 , pre-bending the body portion  1  of the connection terminal  100  so as to have a substantially U-shaped cross-section; placing a portion of the plurality of wires  200  within the bent body portion  1  having a substantially U-shaped cross-section; and pressing the connection terminal  100  by a pressing die  300 . The pressing die  300  has an opening  301  having a substantially U-shaped cross section, into which the first wing  2 , the second wing  3 , the third wing  4 , and the fourth wing  5  of the connection terminal  100  are adapted to enter. As the pressing die  300  presses the connection terminal against a support portion  400 , the first wing  2 , the second wing  3 , the third wing  4 , and the fourth wing  5  are all bent toward the body portion  1  so as to retain and crimp the wires  200  within the connection terminal  100 , and the first wing  2  is located outside the second wing  3 , and the fourth wing  5  is located outside the third wing  4 . 
       FIG. 11  shows the connection terminal  100  when a plurality of wires  200  are connected thereto, wherein wings  2 - 5  of the connection terminal  100  haven&#39;t been bent yet. The connection terminal  100  is adapted to retain more than three (for example, ten) wires  200 . The wire  200  includes a plurality of (e.g. seven) bare wires  201  and a plurality of (e.g. three) varnished wires  202 . The operation of connecting the ten wires shown in  FIG. 11  is similar to the operation of connecting the three wires shown in  FIG. 5 , and will not be described again. 
     The connection terminal  100 ,  100 ′ according to the invention may achieve a firm mechanical connection and a reliable electrical connection of a plurality of wires  200  having different overall outer diameters, which widens the usage of the connection terminal  100 ,  100 ′ and simplifies the structure of the connection terminal  100 ,  100 ′. The wires  200  may include, for example, varnished wires  202  and/or bare wires  201  adapted to coils of a three-phase motor. The connection terminal  100 ,  100 ′ is adapted to crimp wires  200  with different conductor cross-sections (for example, Circular Mil Area (CMA)). In one embodiment, the milli-inch area (diameter (mm)/25.4)2*106) of the wire  200  may be in the range of 600 to 7000, for example, 600 to 3000 (model 62304-2), 1500 to 5000 (model 62306-2) and 3000-7000 (model 62304-2). 
     Therefore, the connection terminal  100 ,  100 ′ of the embodiment may crimp the wires  200  having different outer diameter ranges, reducing the management cost of the wires  200 . The burrs  7 ,  10  are used to pierce the insulating layer of the wire  200  when crimping the wire  200 , avoiding the process of melting the insulating layer and soldering the wire  200 . 
     It should be appreciated for those skilled in this art that the above embodiments are intended to be illustrative, and not restrictive. For example, many modifications may be made to the above embodiments by those skilled in this art, and various features described in different embodiments may be freely combined with each other without conflicting in configuration or principle. Although several exemplary embodiments have been shown and described, it would be appreciated by those skilled in the art that various changes or modifications may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.