WO1995011534A1

WO1995011534A1 - Female electric terminal with an auxiliary outer structure

Info

Publication number: WO1995011534A1
Application number: PCT/EP1994/003415
Authority: WO
Inventors: Alessandro Genta; Renzo Rampone
Original assignee: Framatome Connectors International S.A.
Priority date: 1993-10-18
Filing date: 1994-10-17
Publication date: 1995-04-27
Also published as: ITTO930767A0; ITTO930767A1; IT1261618B

Abstract

A female electric terminal (1), comprising an inner contact element (2) having a portion (6) for connection to an electric cable, and designed to cooperate with a male terminal (3a, 3b); and an auxiliary outer structure (4); the inner contact element (2) comprising first (9) and second (7, 8) contact blade means asymmetrical in relation to the plane (α) of the male terminal (3a, 3b) so as to define offset contact areas on respective faces of the male terminal; and the auxiliary structure (4) comprising first (45) and second (44) elastic blade means cooperating respectively with the first (9) and second (7, 8) contact blade means so as to form, with the same, respective elastic systems interacting with the opposite faces of the male terminal (3a, 3b) and having the same flexural rigidity; and first and second protective blade means (40) having respective end portions (41) turned inwards of respective front edges (48, 49) of the contact blade means (9, 7, 8).

Description

FEMALE ELECTRIC TERMINAL WITH AN AUXILIARY OUTER

STRUCTURE TECHNICAL FIELD

The present invention relates to an electric terminal, particularly a female electric terminal designed to mate with a male blade type terminal.

BACKGROUND ART

Female electric terminals made by blanking and bending conductive sheet metal are known, and comprise an inner contact element having one or more pairs of flexible contact blades cooperating with opposite faces of a male blade terminal, and a deformable portion for connection to an electric cable; and an auxiliary structure fitted to the inner contact element and in turn having additional elastic blades facing and cooperating with outer surfaces of respective contact blades to define elastic systems with predetermined elastic characteristics. The auxiliary structure also comprises protective blades extending frontwards beyond and outwards of the contact blades, and having an end portion turned inwards for protecting the end portions of the contact blades.

A female terminal of the type briefly described above is illustrated in U.S. Patent US-A- 5 035 661.

As the contact blades of known terminals define facing contact areas on the opposite faces of the male terminal, such terminals are only suitable for use with flat blade type male terminals as opposed to those with shaped, e.g. ridged cross section, blades, which are becoming increasingly popular by virtue of requiring less material for given mechanical characteristics.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a female terminal designed to overcome the limitations typically associated with known terminals of the aforementioned type, and which in particular is designed to cooperate indifferently with both flat and shaped blade male terminals.

According to the present invention, there is provided a female electric terminal made of conductive sheet metal and consisting of an inner contact element comprising a box portion, a portion for connection to an electric cable and integral with said box portion, and first and second contact blade means projecting from said box portion and cooperating elastically with respective opposite faces of a male terminal; and of an outer auxiliary structure in turn integrally comprising a box portion fitted to said box portion of said inner contact element, first and second elastic blade means projecting integrally from said box portion and cooperating respectively with said first and second contact blade means of said inner contact element, so as to respectively define with the same a first and second elastic system which are flexible upon insertion of said male terminal, and first and second protective blade means projecting integrally from said box portion and having respective end portions turned inwards of said terminal and about respective front edges of said first and second contact blade means; characterized by the fact that said first and second contact blade means are asymmetrical in relation to the plane of said male terminal, so as to define offset contact areas on respective faces of said male terminal; said first and second elastic systems presenting at least approximately the same flexural rigidity.

BRIEF DESCRIPTION OF DRAWINGS

Three preferred, non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a bottom plan view of a first embodiment of a female electric terminal in accordance with the teachings of the present invention;

Figure 2 shows a top plan view of the Figure 1 terminal;

Figure 3 shows a side view of the Figure 1 terminal;

Figure 4 shows a section along line IV-IV in Figure 2 of the female terminal engaged by a flat blade male terminal;

Figure 5 shows a section along line IV-IV in Figure 2 of the female terminal engaged by a ridged cross section blade male terminal;

Figure 6 shows a top plan view of the inner contact element of the Figure 1 terminal;

Figure 7 shows a bottom plan view of the Figure 6 element;

Figure 8 shows a flat sheet metal blank from which to produce the auxiliary outer structure of the Figure 1 terminal;

Figure 9 shows a bottom plan view of a second embodiment of a female electric terminal in accordance with the teachings of the present invention;

Figure 10 shows a top plan view of the Figure 9 terminal;

Figure 11 shows a top plan view of the inner contact element of the Figure 9 terminal;

Figure 12 shows a flat sheet metal blank from which to produce the auxiliary outer structure of the Figure 9 terminal;

Figure 13 shows a top plan view of the inner contact element of a third embodiment of the terminal according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figures 1 to 3 indicates a female electric terminal.

It should be stressed that terms such as "top", "bottom", "front", "rear" and similar in the following description are in no way limiting, and are used purely for reasons of clarity with reference to the position of terminal 1 as shown in Figure 3. Terminal 1 is made of conductive sheet metal, and substantially comprises an inner contact element 2 designed to cooperate indifferently with a flat blade male terminal 3a (Figure 4) or a ridged cross section blade terminal 3b (Figure 5); and an outer auxiliary structure 4 fitted to contact element 2 for the purpose described later on.

Inner contact element 2 (Figures 6, 7) comprises an intermediate box portion 5 from which project integrally, and respectively rearwards and frontwards, a deformable portion 6 for connection to an electric cable (not shown), and a number of contact blades 7, 8, 9 designed to cooperate with terminal 3a or 3b.

More specifically, box portion 5 presents a rectangular section open at the top along the center line, and comprises a bottom wall 10, a pair of lateral walls 11, and a top wall 12 composed of two half walls 12a, 12b integral with respective lateral walls 11 and having respective adjacent free edges 13. Edges 13 present respective intermediate rectangular recesses 15 forming a central square opening 16 in wall 12.

Bottom wall 10 of box portion 5 presents a central, substantially square opening 17 facing opening 16, and the edges of which, parallel to lateral walls 11, present respective recesses 17a for the purpose described later on.

Blades 7, 8 extend frontwards from top half walls

12a, 12b, are substantially in the form of an elongated rectangle, and are separated laterally from each other.

Blades 7, 8 (Figure 2) present respective substantially flat portions 18, 19 adjacent to wall 12 and inclined towards a mid plane α parallel to walls 10, 12 and defining, in use, the plane of male terminal 3a or 3b (Figure 3). Blades 7, 8 also present respective end portions 20, 21 curving outwards of terminal 1 and defining, at the point of maximum curvature, respective contacts 22, 23 which are preferably defined by spherical-bowl-shaped impressions formed on blades 7, 8 and symmetrical in relation to the mid longitudinal plane ß of terminal 1 perpendicular to plane α (Figure 2). Portions 18 and 19 form the part of respective blades 7, 8 designed to flex upon insertion of male terminal 3a or 3b.

Blade 9, facing blades 7 and 8, extends longitudinally from bottom wall 10 of box portion 5, and presents a width equal to the distance between the opposite lateral edges of blades 7, 8. Blade 9 presents a first substantially flat portion 24 adjacent to wall 10 and inclined towards plane a so as to converge with portions 18, 19 of blades 7, 8; and an end portion 25 curving outwards of the terminal and having a central contact 26 preferably defined by a spherical-bowl-shaped impression and located at the point of maximum curvature of portion 25 cooperating with that of blades 7, 8.

The center of contact 26 lies in plane ß and in a transverse plane T through the centers of contacts 22, 23 .

According to a first essential characteristic of the present invention, therefore, the blade means, defined respectively by blades 7, 8 and 9, acting on the opposite faces of male terminal 3a or 3b are asymmetrical in relation to plane α, so as to define offset contact areas - one central and two lateral - on the opposite faces of the male terminal.

Portion 24 of blade 9 is designed to flex upon insertion of male terminal 3a or 3b, and conveniently presents a mid through slot 26a (Figure 7) by which it is divided into two longitudinal portions 24a, 24b respectively facing flexible portions 18, 19 of blades 7, 8, and having the same width and, hence, the same flexural rigidity as said portions.

Auxiliary structure 4 (Figures 1, 2 and 3) substantially comprises a box portion 30 surrounding box portion 5 of contact element 2; and a number of blades projecting frontwards from box portion 30 and cooperating with contact blades 7, 8, 9 as described in detail later on.

Figure 8 shows a flat blank 41 corresponding to auxiliary structure 4 and clearly showing the design of the various parts described below. For the sake of clarity, the parts of blank 41 corresponding to those of finished structure 4 are indicated using the same numbering system as in Figures 1 to 4.

Box portion 30 comprises a top wall 34 over wall 12 of box portion 5 and having an opening 37 at opening 16 of wall 12; a pair of lateral walls 35 contacting walls 11; and a pair of bottom walls 36a, 36b turned beneath wall 10 and forming a shaped opening. The facing edges of walls 36a, 36b present respective tabs 38 turned inside respective seats 17a of opening 17 (Figures 1 and 3) in wall 10 so as to lock auxiliary structure 4 in relation to inner contact element 2.

As shown clearly in Figure 2, from top wall 34 of box structure 30 and from one of the bottom walls (36b), there project frontwards, along the center line of terminal 1, respective blades 40 for protecting contact blades 7, 8, 9.

Protective blades 40 are elongated and narrow in shape, and present respective wider heads 41 turned inwards so as to respectively engage a center portion of front edge 48 of blade 9, and adjacent portions of respective front edges 49 of blades 7, 8.

On either side of protective blades 40, respective pairs of elastic blades 44, 45 extend frontwards from top wall 34 and each bottom wall 36a, 36b respectively.

Elastic blades 44 extend respectively along the center line of contact blades 7 and 8; and blades 45 along lateral longitudinal portions of blade 9.

Each blade 44, 45 is flat and elongated in shape, and is turned inwards of terminal 1 at the base so as to match the slope of and diverge slightly from the respective contact blade. Blades 44, 45 also present respective end portions 47 curved inwards and cooperating with the outer face of the respective contact blades in the concavity defined by the respective end portions.

Elastic blades 44 and 45 are identical and so present the same flexural rigidity.

On the basis of the above description of the elastic characteristics of blades 7, 8 and 9, therefore, elastic blades 44 and 45 respectively define, with contact blades 7,8 and contact blade 9, two elastic systems designed to cooperate with and, despite being asymmetrical, exert balanced elastic reactions on the opposite faces of male terminal 3a or 3b.

Figure 4 shows a cross section of terminal 1 engaged by a flat blade terminal 3a, and wherein contact 26 cooperates with a central portion of one face of terminal 3a, and contacts 22, 23 with lateral portions of the opposite face.

Figure 5 shows a cross section of terminal 1 engaged by a terminal 3b with a shaped blade, in particular, having a ridged cross section with a central rib 42 and two lateral wings 43 offset in relation to rib 42. Though made of thinner material as compared with terminal 3a, terminal 3b presents the same mechanical characteristics by virtue of its ridged structure. In this case, contact 26 cooperates with rib 42, on the face projecting in relation to wings 43, while contacts 22, 23 cooperate with the opposite face of respective wings 43. Since the distance between the planes of the contact faces of terminal 3b is typically equal to the thickness of terminal 3a, deformation of the elastic systems defined by blades 7, 8, 44 on the one hand and blades 9, 45 on the other upon insertion of terminal 3a or 3b is identical in both cases and hence results in the same contact pressure. Consequently, electric and mechanical performance of terminal 1 is identical in both cases.

Figures 9 to 12 show a terminal 50 according to a further embodiment of the present invention, and the following description of which is limited solely to the characteristics differing from those of terminal 1, and using the same numbering system for any parts similar or corresponding to those already described with reference to terminal 1.

More specifically, terminal 50 comprises an inner contact element 2 (Figure 11) having two contact blades 7, 8 extending from bottom wall 10, and one mid contact blade 9 originating from one of the top half walls (12a). When viewed laterally, contact blades 7, 8, 9 present the same shape as those of terminal 1, and present respective contacts 22, 23, 26.

In this case, when viewed from above, blade 9 presents the same size as each of blades 7, 8 which are, however, lightened along respective flexible portions 18, 19 by respective elongated through slots 51 which reduce their flexural rigidity to substantially half that of blade 9.

Auxiliary structure 4 is also accordingly modified (Figures 9, 10 and 12). In particular, the side of terminal 50 featuring blades 7, 8 (Figure 9) remains unchanged as compared with terminal 1, and structure 4 presents a mid protective blade 40, and two elastic blades 44 cooperating with blades 7, 8 as already described.

On the blade 9 side, structure 4 comprises one mid elastic blade 52 projecting from top wall 34. Blade 52 presents twice the width and hence twice the rigidity of elastic blades 44, and presents an end portion 53 curving inwards of the terminal and cooperating with blade 9 at the outer concavity defined by end portion 25 of blade 9.

Finally, structure 4 comprises a substantially

U-shaped protection element 54 surrounding elastic blade

52, and which is connected at its ends integral with top wall 34, and presents an end appendix 55 turned inwards of front edge 48 of blade 9.

The elastic performance of the elastic systems defined by blades 7,8 and 44 on the one hand and blades 9 and 52 on the other is qualitatively the same as that of terminal 1.

Figure 13 shows a further variation of inner contact element 2.

In this case, inner contact element 2 differs from that of terminal 50 described with reference to Figure 11 substantially as regards the design of blades 7, 8, which are substantially T-shaped, and present respective narrow flexible portions 18, 19 to define a total rigidity equal to that of blade 9.

More specifically, blade 9 and portions 18, 19 of blades 7, 8 are conveniently tapered, and the width of portions 18, 19 is equal to half the width of blade 9 measured in the same transverse plane.

The auxiliary outer structure may be the same as that of terminal 50 described with reference to Figures 9 , 10, 12, and is therefore not shown.

To those skilled in the art it will be clear that changes may be made to the terminals as described and illustrated herein without, however, departing from the scope of the present invention.

In particular, contact blades 7, 8, 9 need not necessarily present impressions defining the contacts.

In the case of blades with a flat cross section, the contact regions may be defined by simply curving the blades longitudinally, and contact with the flat surface of the male terminal is effected substantially along a generating line. The blades may also be curved transversely, in which case, contact is theoretically punctiform and in practice located in a circular area of tangency.

Moreover, with no change in the mutual arrangement of the contacts, blades 7, 8 may be so sized as to define a total flexural rigidity differing from that of blade 9, providing the flexural rigidity of the elastic systems acting on the opposite faces of the male terminal is made equal by compensating the difference by appropriately sizing elastic blades 44, 45 or 52 of auxiliary structure 4.

Finally, the female terminal according to the present invention permits the use of ridged-section male terminals turned over 180° in relation to that described, by appropriately adjusting the preload on the contact blades to achieve the required in-service contact pressure.

Claims

1) A female electric terminal (1; 50) made of conductive sheet metal and consisting of an inner contact element (2) comprising a box portion (5), a portion (6) for connection to an electric cable and integral with said box portion (5), and first (9) and second (7, 8) contact blade means projecting from said box portion (5) and cooperating elastically with respective opposite faces of a male terminal (3a, 3b); and of an auxiliary outer structure (4) in turn integrally comprising a box portion (30) fitted to said box portion (5) of said inner contact element (2), first (45; 52) and second (44) elastic blade means projecting integrally from said box portion (30) and cooperating respectively with said first (9) and second (7, 8) contact blade means of said inner contact element (2), so as to respectively define with the same a first and second elastic system which are flexible upon insertion of said male terminal (3a, 3b), and first (40; 54) and second (40) protective blade means projecting integrally from said box portion (30) and having respective end portions (41; 55) turned inwards of said terminal (1; 50) and about respective front edges (48, 49) of said first (9) and second (7, 8) contact blade means; characterized by the fact that said first (9) and second (7, 8) contact blade means are asymmetrical in relation to the plane (α) of said male terminal (3a, 3b), so as to define offset contact areas on respective faces of said male terminal (3a, 3b); said first and second elastic systems presenting at least approximately the same flexural rigidity.

2) A terminal as claimed in Claim 1, characterized by the fact that Sάid first (9) and second (7, 8) contact blade means comprise respective flexible portions (24; 18, 19) having at least approximately the same flexural rigidity; and said first (45; 52) and said second (44) elastic blade means present at least approximately the same flexural rigidity.

3) A terminal as claimed in Claim 1 or 2, characterized by the fact that said first contact blade means (9) define a first contact (26) with its center in the mid longitudinal plane (ß) of said terminal (1; 50); and said second contact blade means (7, 8) define two contacts (22, 23) symmetrical in relation to said mid longitudinal plane (ß) of said terminal (1; 50), and the respective centers of which lie in a transverse plane (τ) through the center of said first contact (26).

4) A terminal as claimed in Claim 3, characterized by the fact that said first contact blade means (9) and said second contact blade means 7, 8) comprise respective end portions (25; 20, 21) defining respective said contacts (26; 22, 23); said flexible portions (24; 18, 19) integrally connecting said end portions (25; 20, 21) to respective walls (10, 12) of said box portion (5) of said contact element (2), parallel to said plane (α) of said male terminal (3a, 3b).

5) A terminal as claimed in Claim 3 or 4, characterized by the fact that said first contact blade means consist of a first contact blade (9) defining said respective first contact (26); and said second contact blade means comprise a pair of second contact blades (7, 8) respectively defining said two contacts (22, 23).

6) A terminal as claimed in Claim 5, characterized by the fact that said flexible portion (24) of said first contact blade (9) presents an opening (26a) dividing a portion of it into two side by side, flexible longitudinal portions (24a, 24b), each presenting the same rigidity as the flexible portion (18, 19) of said second blades (7, 8).

7) A terminal as claimed in Claim 5 or 6, characterized by the fact that said first elastic blade means consist of a pair of first elastic blades (45) cooperating with respective lateral portions of said first contact blade (9); and said second elastic blade means comprise a pair of second elastic blades (44), each cooperating with a respective said second contact blade (7, 8); said first and second elastic blades (45, 44) being identical.

8) A terminal as claimed in Claim 7, characterized by the fact that said first protective blade means and said second protective blade means comprise respective elongated protective blades (40) extending along the center line of said terminal (1; 50); said first and second elastic blades (45, 44) being located on either side of respective said protective blades (40).

9) A terminal as claimed in Claim 5 or 6, characterized by the fact that said first elastic blade means consist of a first elastic blade (52) cooperating with said first contact blade (9); and said second elastic blade means comprise a pair of second elastic blades (44) . each cooperating with a respective said second contact blade (7, 8); said first elastic blade (52) presenting twice the flexural rigidity of said second elastic blades (44).

10) A terminal as claimed in Claim 9, characterized by the fact that said first protective blade means (54) comprise a substantially U-shaped protective element surrounding said first elastic blade (52) and connected at its ends integral with said box portion (30) of said auxiliary structure (4); and said second protective blade means comprise an elongated protective blade (40) extending along the center line of said terminal (1; 50); said second elastic blades (44) being located on either side of said protective blade (40).

11) A terminal as claimed in Claim 9 or 10, characterized by the fact that said flexible portions (18, 19) of said second contact blades (7, 8) are so lightened as to present a flexural rigidity equal to half that of said first contact blade (9).

12) A terminal as claimed in Claim 11, characterized by the fact that said flexible portions (18, 19) of said second contact blades (7, 8) present respective longitudinal slots (51).

13) A terminal as claimed in Claim 11, characterized by the fact that said second contact blades (7, 8) are substantially T-shaped.

14) A female electric terminal, substantially as described and illustrated herein with reference to the accompanying drawings.