FEMALE ELECTRICAL TERMINAL WITH TORSION MEMBERS
The present invention concerns a female electrical terminal which engages a mating male terminal, such as a tab terminal .
The female terminal shown in Figures 5 and 6 is conventionally known as a female terminal with which tab terminals are engaged and connected. This terminal is disclosed in more detail in U.K. Patent 1,108,005. This prior art female terminal 100 is equipped with an upper plate 101, and a lower plate 102 which faces the upper plate 101. Furthermore, this female terminal 100 is formed with a substantially U-shaped cross section by punching out and bending a single metal plate. Moreover, a plurality of contact members 103, which protrude toward the lower plate 102, are formed by being cut out and caused to protrude from the upper plate 101. A plurality of contact members 104, which protrude toward the upper plate 101, are formed by being cut out and caused to protrude from the lower plate 102. Furthermore, a plurality of tab terminal insertion openings 105 which are wider than the plate thickness of the tab terminals 111 of the mating connector 110 are formed in a bent member 106 of the female terminal 100. The tab terminals 111 of the mating connector 110 are inserted between the contact members 103 of the upper plate 101 and the contact members 104 of the lower plate 102 via the openings 105 formed in the female terminal, and contact the contact members 103 and contact members 104 with a specified contact pressure. However, in the case of this conventional female terminal 100, the contact members 103 and contact members 104, which are respectively cut out from the upper plate 101 and lower plate 102 of the terminal 100, have a short spring length. As a result, when the tab terminals 111 of the mating connector are engaged and connected, the bending stress values of the respective
root portions of the contact members 103 and contact members 104 are increased, so that these root portions undergo plastic deformation.
Accordingly, the object of the present invention is to provide a female terminal with a high contact reliability, in which there is no plastic deformation of the contact members (formed by punching out and bending a flat metal plate) when the mating male terminal is engaged and connected, even in cases where the spring length of the contact members is short.
The female terminal of the present invention is characterized by the fact that [a] the terminal is equipped with [i] a metal plate, [ii] contact members which contact a mating male terminal, and which are formed by punching out and bending the metal plate, and [iii] torsion members which are formed by punching out areas near the roots of the contact members, and which connect the contact members to the metal plate, and [b] the torsion members are twisted when the mating male terminal contacts the contact members.
Furthermore, the female terminal is characterized by the fact that [a] the terminal is equipped with [i] a metal plate, [ii] a plurality of contact members which contact a mating male terminal, and which are formed facing toward the center from the left and right sides by punching out and bending the metal plate, and [iii] a pair of left and right torsion members which are formed by punching out areas near the roots of the contact members, and which connect the contact members to the metal plate, [b] the contact members extend toward the center from the left and right torsion members, with two contact members extending from each torsion member, and [c] both of the contact members on one side are positioned to the outside of both of the contact members on the other side. As a result, space can be saved in the area around the contact members of the female terminal, and the left-right balance of the contact
members is good, so that an appropriate contact force can be guaranteed with respect to the mating male terminal .
In the present invention, since torsion members which are formed by punching out areas in the vicinity of the roots of the contact members are twisted when the mating male terminal contacts the contact members, an elastic force generated by the twisting of the torsion members acts on the mating male terminal when the mating male terminal contacts the contact members.
Accordingly, even in cases where the spring length of the contact members formed by punching out and bending the flat metal plate are short, there is no plastic deformation of the contact members when the mating male terminal is engaged and connected. As a result, the contact members make highly reliable contact with the mating male terminal. Accordingly, the length of the contact members of the female terminal can be shortened so that a reduction in size is possible. Figures 1 and 2 illustrate one working configuration of the female terminal of the present invention. Figure 1 is a plan view which shows the female terminal insert-molded in a housing, and Figure 2 is a sectional view along line 2-2 in Figure 1. Figure 3 is a plan view of the female terminal shown in Figures 1 and 2, and shows the state of the female terminal immediately after the punching of the metal plate.
Figure 4 is a plan view which illustrates another working configuration of the present invention; this figure shows the state immediately following the punching of the metal plate.
Figures 5 and 6 illustrate a conventional female terminal . Figure 5 is a plan view showing a state in which mating male terminals engage and are connected by the female terminal , and Figure 6 is a sectional view along line 6-6 in Figure 5.
Working configurations of the present invention will be described with reference to the attached figures. Figure 1 illustrates one working configuration of the female terminal of the present invention. Figure 1 is a plan view which shows the female terminal insert - molded in a housing, and Figure 2 is a sectional view along line 2-2 in Figure 1. Figure 3 is a plan view of the female terminal shown in Figure 1, and shows the state of the female terminal immediately after the punching of the metal plate, prior to bending the contact members .
In these figures, the female terminal 1 has a metal plate 2, a plurality of contact members 4 which contact the mating terminal 20, and which are formed by punching out and bending the metal plate 2, and torsion members 6 which are formed by punching out areas in the vicinity of the roots of the contact members 4.
Immediately after the metal plate 2 has been punched out, as is shown in Figure 3, the contact members 4 extend toward the center from the torsion members 6, 6 formed on the left and right sides, as shown in Figure 3, with two contact members 4 extending inward from each torsion member 6. The right-side contact members 4, 4 in Figure 3 are positioned to the outside of the left-side contact members 4, 4 (i. e., above and below the left-side contact members 4, 4 in Figure 3) . Furthermore, as is shown in Figure 2, the left- and right-side contact members 4, 4 are bent upward so that the width W of the gap between the tip ends of the contact members 4, 4 is slightly smaller than the thickness h of the mating male terminal 20.
The torsion members 6 are formed by punching out areas on the left and right to the rear of the roots of the left- and right-side contacts 4, 4, and are formed continuously with the same specified width in the vertical direction of the metal plate 2 (i. e., in the vertical direction in Figure 3) , so that these torsion
members 6 connect the contact members 4, 4 to the metal plate 2. Punched-out holes 5 are formed to the rear of the torsion members 6 on the left and right.
Furthermore, as is shown in Figures 1 and 2, the female terminal 1 is fastened in place by being insert- molded inside a housing 10 (e. g., the housing of a connector used in an automobile anti-lock braking system) . The metal plate 2 has a connecting member (not shown in the figures) which is connected to the outside, so that (for example) a solenoid- outside connection is established by contact with the male terminal 20.
As is shown in Figure 2, the mating male terminal 20 (for example, a solenoid tab terminal) is inserted into the space between the tip ends of the left- and right-side contact members 4, 4 via a punched-out hole 3 from the back side (lower side in Figure 2) of the female terminal 1, so that the male terminal 20 contacts these contacts 4, 4. In this case, since the width W of the gap between the tip ends of the left- and right-side contacts 4, 4 is smaller than the thickness h of the mating male terminal 20, the contacts 4, 4 rotate about the root portions, so that a torsional stress is generated in the left- and right-side torsion members 6, 6. Consequently, what acts on the mating male terminal 20 is mainly an elastic force generated by the torsion members 6 rather than an elastic force generated by the bending of the contacts 4, 4. Accordingly, even in cases where the spring length of the contacts 4, 4 is short, the stress acting on the root portions of the contacts 4, 4 when the male terminal 20 is engaged and connected is small, so that there is very little possibility of plastic deformation of these root portions. Thus, the contact reliability of the contacts 4, 4 with respect to the mating male terminal 20 is high.
Figure 4 is a unit plan view which illustrates another working configuration of the present invention;
this figure shows the state immediately following the punching of the metal plate.
In Figure 4, the female terminal 51 has a metal plate 52, a plurality of contact members 54 which contact the mating male terminal, and which are formed by punching out and bending the metal plate 52, and torsion members 56 which are formed by punching out areas in the vicinity of the roots of the contact members 54. The point of difference between the female terminal 51 shown in Figure 4 and the female terminal 1 shown in Figure 1 is that the contact members 54 extend toward the center from four torsion members 56, 56, 56, 56 formed above and below and on the left and right in Figure 5, with one contact member 54 extending from each torsion member 56. Furthermore, these contacts members 54 are bent upward (in the direction perpendicular to the plane of the page in Figure 5) in order to accommodate the mating male terminal (not shown in the figures) . As a result, a mating male terminal (not shown in the figures) which has a substantially rectangular or round cross section can be accommodated, so that the four contact members 54, 54, 54, 54 contact the male mating terminal. As in the case of the female terminal 1 shown in Figure 1, the main force acting on the mating male terminal when the mating male terminal contacts the contact members 54 is an elastic force generated by the torsion of the torsion members 56; accordingly, the stress acting on the root portions of the contact members 54 is small, so that there is very little possibility of plastic deformation of these root portions .