1. Field of the Invention
The invention relates to a terminal structure, and more particularly to a terminal structure of an electrical connector having two horizontal contact surfaces opposite to each other.
2. Description of the Related Art
Referring to FIG. 1, a conventional terminal structure of an electrical connector includes an extension 11, a connection 12, and a contact 13, wherein the plate surfaces of the extension 11 and the connection 12 are in the same vertical plane. The contact 13 has two elastic arms 14 opposite to each other with a gap therebetween. The two elastic arms 14 have contact surfaces 15 close to each other. In addition, the two elastic arms 14 further have two twisted portions 16 to make the plate surfaces of the two elastic arms 14 opposite to each other.
The two elastic arms 14 of the conventional structure have twisted portions 16, respectively, to make the plate surfaces of the two elastic arms 14 opposite to each other so that wider plate surfaces may be utilized to form the contact surfaces 15. Instead of side surfaces 19 of a male terminal 17, the two contact surfaces 15 may contact top and bottom surfaces 18 of the inserted male terminal 17. Because the side surfaces 19 of the male terminal 17 are the cut-off surfaces that are rougher and the top and bottom surfaces are the smooth metal plate surfaces, it is preferred to contact the top and bottom surfaces in order to protect the gold-plated layers of the contact surfaces 15.
Although the prior art structure has the above-mentioned advantage, the following drawbacks will be caused.
1. The plate surfaces of the extension 11 and connection 12 are the vertical surfaces, a row of continuous terminals with gaps cannot be manufactured.
2. Because the two elastic arms 14 are twisted to make the plate surfaces thereof opposite to each other, it is labor-consuming and difficult to control the precision of the twisted elastic arms. Thus, the two elastic arms may be slanted, and the gap between the contact surfaces is too small or too large to cause normal contacts with the inserted terminals.
As shown in FIG. 2, the two elastic arms are slanted, wherein the phantom line represents the hole 20 on the connector. In this case, the male terminal 17 can only be in point-contact with the contact surfaces 15 but not in normal surface-contact with the contact surfaces 15. As shown in FIG. 3, the gap between the contact surfaces of the two elastic arms is too large, and the male terminal 17 cannot be in contact with the contact surfaces 15. As shown in FIG. 4, the gap between the contact surfaces of the two elastic arms is too small, and the male terminal 17 cannot be easily inserted.
Referring to FIG. 5, another conventional terminal structure of an electrical connector includes an extension 21, a connection 22, and a contact 23. The plate surface of the extension 21 is a horizontal surface and the plate surface of the connection 22 is a vertical surface. The contact 23 has two elastic arms 24 with a gap therebetween. The two elastic arms 24 have contact surfaces 25 close to each other. In addition, the two elastic arms 24 have twisted portions 26, respectively, to make the plate surfaces of the elastic arms 24 opposite to each other.
Although the above-mentioned terminal structure may be utilized to form continuous terminals with gaps and facilitate the assembly, it also has the following drawbacks.
1. Because the contact surfaces 25 of the two elastic arms 24 are vertical surfaces, they are in contact with the rough side surfaces 19 of the inserted male terminal 17, and the gold-plated layers of the contact surfaces 25 tends to be scratched.
2. Because the two elastic arms 24 are respectively twisted to make the plate surfaces opposite to each other, it is labor-consuming and the precision of the two twisted elastic arms cannot be easily controlled.