WO1998033238A1

WO1998033238A1 - Female electric terminal

Info

Publication number: WO1998033238A1
Application number: PCT/EP1998/000338
Authority: WO
Inventors: Pier Carlo Bigotto
Original assignee: Framatome Connectors International S.A.
Priority date: 1997-01-24
Filing date: 1998-01-22
Publication date: 1998-07-30
Also published as: EP1012915A1; BR9807001A; ITTO970055A1; CA2278197A1; IT1291470B1

Abstract

A female electric terminal (1) for an electric connector, of the type having a connecting portion (2) fitted to an electric cable; and a tubular contact portion (3) engaged by a complementary male terminal (4), and in turn having a receptacle body (5), and a number of flexible contact blades (6, 7, 8) projecting from the receptacle body (5) and cooperating elastically with the male terminal (4) at respective end contact regions (10, 12); the contact blades (6, 7, 8) extending crosswise to the axis (A) of the female terminal (1) from lateral edges (9, 11) of the receptacle body (5) opposite the respective contact regions (10, 12).

Description

FEMALE ELECTRIC TERMINAL TECHNICAL FIELD

The present invention relates to a female electric terminal for a connector. BACKGROUND ART

Female electric terminals are known, which substantially comprise a connecting portion fitted to a cable, and a tubular contact portion engaged by a male terminal and in turn comprising a receptacle body and a number of flexible contact blades projecting from the receptacle body and cooperating elastically with the male terminal at respective end contact regions.

The terminal is blanked and pressed from flat conducting sheet metal, and the contact blades are normally cut into the lateral wall of the body and extend substantially axially.

Terminals of the type briefly described above have several drawbacks.

As is known, the Joule effect produces heating of the terminal by the current flowing through it in use; and, when heated, a pressed sheet metal part tends to revert to its undeformed shape (i.e. prior to being pressed) .

As a result, the receptacle body of known female terminals tends to "open" in use when heated, so that the flexible contact blades tend to "draw away" from the male terminal, the contact pressure between the blades and the male terminal is reduced, and the contact resistance, and hence the energy dissipated by the Joule effect, increases. In other words, the phenomenon is self-sustaining, and gradually impairs operation of the terminal to the extent of eventually impairing electric contact.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a female electric terminal designed to eliminate the aforementioned drawbacks typically associated with known terminals.

According to the present invention, there is provided a female electric terminal for an electric connector, of the type comprising a connecting portion fitted to an electric cable; and a contact portion in turn comprising a receptacle body having a longitudinal axis defining an insertion direction of a complementary male terminal, and at least a first flexible contact blade projecting from a first wall portion of said receptacle body and cooperating elastically with said complementary male terminal at a respective end contact region; characterized in that said first contact blade extends crosswise to said axis of said female terminal; said contact region being located on the opposite side of said axis of said female terminal with respect to said first wall portion.

BRIEF DESCRIPTION OF DRAWINGS A preferred, non-limiting embodiment of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a side view of a female electric terminal in accordance with the present invention; Figure 2 shows a plan view of the Figure 1 terminal;

Figure 3 shows a larger-scale view in perspective of the Figure 1 terminal engaged by a complementary male terminal; Figure 4 shows a section along line IV-IV in

Figure 1, of the female terminal engaged by the complementary male terminal;

Figure 5 shows a section along line V-V in Figure 2 , of the female terminal engaged by the complementary male terminal;

Figure 6 shows a larger-scale section along line VI-VI in Figure 5;

Figure 7 shows a larger-scale front view of the Figure 1 terminal; Figure 8 shows a side view of a variation of the

Figure 1 terminal.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figures 1, 2 and 7 indicates a female electric terminal for a known electric connector (not shown) .

Terminal 1 is blanked and pressed from flat conducting sheet metal (not shown) . Terminal 1 comprises a connecting portion 2 , which is fitted to an electric cable (not shown) ; and a substantially tubular contact portion 3, which is engaged by a cylindrical pin type complementary male terminal 4 (Figures 3 to 6) , and comprises a longitudinal axis A defining the insertion direction of terminal 4.

As shown in the accompanying drawings, contact portion 3 comprises a substantially semitubular receptacle body 5 of axis A, from which connecting portion 2 extends rearwards; and three flexible contact blades 6, 7, 8 extending crosswise to axis A, offset axially with respect to one another, and each curved with its concavity facing inwards of contact portion 3.

More specifically, blades 6 and 8 project from a first longitudinal lateral edge 9 of body 5, and each comprise an end contact region 10 cooperating elastically with terminal 4 and located on the diametrically opposite side of axis A with respect to lateral edge 9. Blade 7 is interposed axially between blades 6 and

8, projects from a second longitudinal lateral edge 11 of body 5 opposite lateral edge 9, and comprises an end contact region 12 cooperating elastically with terminal 4 and located on the same side as lateral edge 9 and on the diametrically opposite side of axis A with respect to lateral edge 11.

The contact region 10 or 12 of each blade 6, 7, 8 extends inwards of and partially over the lateral edge 11 or 9 of body 5 opposite the lateral edge (9 or 11) from which blade 6, 7, 8 extends, so as to be protected against accidental shock or deformation when handling terminal 1 (Figure 6) . When undeformed (as shown by the dotted lines in Figure 6) , contact regions 10, 12 of blades 6, 7, 8 define a transverse gap narrower than the diameter of the contact portion of terminal 4, so that blades 6, 7, 8 cooperate elastically with and exert a given preload on terminal 4.

Contact regions 10, 12 of blades 6, 7, 8 are defined by respective projections 13 on the blades, which project towards axis A and are elongated longitudinally so as each to define a respective substantially linear contact with terminal 4.

Each blade 6, 7, 8 comprises a respective strengthening rib 14 formed by permanent deformation, towards axis A, of a respective intermediate circumferential portion of the blade, and the inner profile of which is tangent to the inner profile of projection 13 (Figure 6) .

Contact portion 3 also comprises a tubular end portion 15 located at the opposite end of body 5 to connecting portion 2, and which acts as a guide for terminal 4.

More specifically, tubular portion 15 is smaller in diameter than body 5, and comprises three impressions 16, which are convex inwards of portion 15 to cooperate with and center terminal 4 during insertion (Figure 7) .

Blades 6, 7, 8 conveniently differ geometrically, so as to have different vibration frequencies. More specifically, blade 7 is wider than blades 6 and 8; and blade 6 is connected differently from blade 8 by being partly integral with tubular portion 15.

The Figure 8 variation comprises a second tubular portion 17 similar to portion 15 and interposed axially between contact portion 3 and connecting portion 2 to ensure male terminal 4 is coaxial with contact portion

3.

When inserted, terminal 4 contacts blades 6, 7, 8 successively to reduce the insertion force demanded by known terminals in which the contact blades are deformed _Q simultaneously.

In actual use, the heating of terminal 1 produced by the Joule effect tends to "open" contact portion 3 and so reduce the curvature of body 5 and part lateral edges 9 and 11. As each of blades 6, 7, 8, however, is 5 connected to the edge 9 or 11 opposite its contact region 10 or 12 , the contact pressure on terminal 4 is increased, thus reducing the contact resistance and the energy dissipated by the Joule effect. This not only provides for improving the efficiency of terminal 1 and establishing stable operating conditions as temperature increases, but also for reducing the cold preload and, hence, the force required to insert male terminal 4.

The substantially linear contact provided for between blades 6, 7, 8 and terminal 4 ensures at least one point of contact exists even in the event of misalignment of terminal 4. Moreover, the different vibration frequencies of blades 6, 7, 8 rule out any possibility of a given vibration field producing simultaneous resonance conditions, which might impair the stability of the contact between terminals l and 4. Finally, by virtue of the geometry of blades 6, 7,

8, terminal 1 may also be connected to a square-section terminal 4.

Clearly, changes may be made to terminal 1 as described and illustrated herein without, however, departing from the scope of the accompanying Claims.

In particular, male terminal 4 may be centered and guided along contact portion 3 in any other manner. And especially when the male terminal is guaranteed coaxial, as for example in the Figure 8 solution, the number of contact blades may be reduced to two or even one.

Claims

1) A female electric terminal (1) for an electric connector, of the type comprising a connecting portion (2) fitted to an electric cable; and a contact portion (3) in turn comprising a receptacle body (5) having a longitudinal axis (A) defining an insertion direction of a complementary male terminal (4) , and at least a first flexible contact blade (6, 8) projecting from a first wall portion (9) of said receptacle body (5) and cooperating elastically with said complementary male terminal (4) at a respective end contact region (10) ; characterized in that said first contact blade (6, 8) extends crosswise to said axis (A) of said female terminal (1) ; said contact region (10) being located on the opposite side of said axis (A) of said female terminal (1) with respect to said first wall portion

(9).

2) A terminal as claimed in Claim 1, characterized by comprising at least a second contact blade (7) offset axially with respect to said first contact blade (6, 8), extending from a second wall portion (11) of said receptacle body (5) opposite said first wall portion (9) of the receptacle body (5) , and having a respective end contact region (12) located on the same side as said first wall portion (9) .

3) A terminal as claimed in Claim 1 or 2, characterized in that said contact portion (3) is tubular .

4) A terminal as claimed in Claim 3, characterized in that said receptacle body (5) is substantially semitubular; said contact blades (6, 7, 8) being curved with respective concavities facing inwards of said contact portion (3) ; and said first and second wall portions being defined by respective opposite lateral edges (9, 11) of said receptacle body (5).

5) A terminal as claimed in Claim 4, characterized in that said contact region (10, 12) of each said contact blade (6, 7, 8) extends inwards of the lateral edge (11, 9) of said receptacle body (5) opposite the lateral edge from which the contact blade (6, 7, 8) extends . 6) A terminal as claimed in one of the foregoing

Claims, characterized in that said contact region (10, 12) of each said contact blade (6, 7, 8) is defined by a projection (13) of the contact blade (6, 7, 8), which projection is elongated axially to define a substantially linear contact with said complementary male terminal (4) .

7) A terminal as claimed in any one of the foregoing Claims from 2 to 6, characterized in that said contact blades (6, 7, 8) comprise respective longitudinal ribs (14) .

8) A terminal as claimed in any one of the foregoing Claims from 2 to 7, characterized by comprising two said first contact blades (6, 8) , and one said second contact blade (7) interposed between the first contact blades (6, 8) .

9) A terminal as claimed in any one of the foregoing Claims, characterized in that said contact portion (3) comprises first guide means (15) for guiding said complementary male terminal (4) and located at an opposite end of the contact portion (3) with respect to said connecting portion (2) .

10) A terminal as claimed in Claim 9, characterized in that said first guide means comprise a smaller-diameter tubular portion (15) of said contact portion (3) .

11) A terminal as claimed in Claim 10, characterized in that said tubular portion (15) comprises a number of impressions (16) , which are convex inwards of the tubular portion (15) .

12) A terminal as claimed in Claim 10 or 11, characterized in that said contact portion (3) comprises second guide means (17) for guiding said complementary male terminal (4) and located adjacent to said connecting portion (2) .

13) A terminal as claimed in any one of the foregoing Claims from 2 to 10, characterized in that said contact blades (6, 7, 8) have different vibration frequencies.