WO2008078156A1

WO2008078156A1 - Electrical connector with improved secondary locking means

Info

Publication number: WO2008078156A1
Application number: PCT/IB2006/055064
Authority: WO
Inventors: Sébastien DEUBEL
Original assignee: Fci
Priority date: 2006-12-27
Filing date: 2006-12-27
Publication date: 2008-07-03

Abstract

This connector comprises - an insulating housing (3) having at least one terminal accommodating chamber (4), a wall (25) adjacent said chamber and a flexible arm (27) provided to secure a terminal (5) in the chamber, a gap (23) being defined between the wall (25) and the flexible arm (27), and - a secondary locking member (41) having a locking beam (47), said secondary locking member (41) being mounted on the housing (3) so as to be axially moved between a neutral position, wherein the arm (27) can be deflected, and a locking position, wherein the locking beam (47) is inserted in the gap (23) thereby blocking the arm (27) in flexion. The flexible arm (27) and the secondary locking member (41) are designed such that, in the locking position of the locking member, the locking beam (47) contacts the flexible arm (27), with no clearance between the flexible arm and the locking beam.

Description

ELECTRICAL CONNECTOR WI TH IMPROVED SECONDARY LOCKING MEANS

BACKGROUND OF THE INVENT ION

The invention relates to an electrical connector comprising

- an insulating housing having at least one terminal accommodating chamber, a wall adjacent said chamber and a flexible arm essentially axially projecting from said wall into the chamber and provided to secure a suitable terminal in the chamber, a gap being defined between the wall and the flexible arm, and - a secondary locking member having a locking beam, said secondary locking member being mounted on the housing so as to be axially slideable between a neutral position, wherein the flexible arm can be deflected, and a locking position, wherein the locking beam is inserted in the gap thereby blocking the flexible arm in flexion.

Connectors of this type are known in the art. In spite of the presence of the locking beams, some arms may be deflected in such an extent that the respective terminals are not prevented from being forced out of the corresponding chambers .

In addition, the terminals to be accommodated within the chambers may be in a slightly inclined position with respect to the mating axis. Damages on those terminals may then occur upon mating with the counterpart connector. This axial alignment problem is of a particular importance for male terminals, such as pins, since a slight inclination of a terminal body in the chamber makes a substantial offset at the mating end of the pin. SUMMARY OF THE INVENTION

It is an object of the invention to provide an electrical connector of the above type, with an increased retention effect with no substantial modification of the existing moulds or additional complexity.

Accordingly, the invention provides an electrical connector of the above-mentioned type, wherein the flexible arm and the secondary locking member are designed such that, in the locking position of the locking member, the locking beam contacts the flexible arm, with no clearance between the flexible arm and the locking beam, in a normal use condition where a terminal is accommodated and secured in the chamber by the flexible arm. The invention will be better understood on reading the following description of one particular embodiment of the invention, given as a non-limiting example.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a perspective view from the front mating side of the housing of an electrical connector according to the invention;

Fig. 2 a perspective view from the rear side of the secondary locking member of an electrical connector according to the invention, suitable to be mounted on the housing shown on Fig.l;

Fig. 3 is a sectional view of the connector, the housing and the secondary locking member of which are shown respectively on Fig. 1 and Fig. 2, in an axial plane through a chamber, with the locking member in the locking position; and

Fig. 4 is a sectional view of the connector of Fig. 3, in the 4-4 direction. DETAILED DESCRIPTION OF ONE PREFERRED EMBODIMENT

A connector 1 according to the invention is shown on Figures 1 to 4.

In the example shown, the connector 1 is a female receptacle connector of a type used in an automotive application, equipped with male terminals. Such a connector is suitable to mate with a counterpart male connector including complementary female terminals. However, the invention may apply to different connector types.

For the sake of clarity, the Figures are orientated according to an X-axis, which represents the mating direction of the connector 1 with the counterpart connector (not shown) . The X-axis is supposed to be orientated from the connector 1 towards the counterpart connector in mating conditions .

Every direction- or orientation-related term in the following description, in particular the terms "rear" and "front", should be interpreted as referring to this axis. The connector 1 has a mating side 2.

As shown on Figures 3 and 4, the connector 1 has an insulative housing 3, which is preferably integrally made of a moulded plastic material. The housing 3 is formed with terminal accommodating chambers 4 (two in number in the example shown) .

The housing 3 substantially has a parallelepiped shape with a body section 6, wherein the chambers 4 are formed, and a skirt section 7 defining a receptacle which is open at the mating side 2 for accommodating a corresponding portion of the counterpart connector.

The skirt section 7 has peripheral axial walls 8, 9 including a pair of opposed parallel lateral walls 8, and a pair of opposed parallel transversal walls 9. The housing 3 is formed with a locking projection 10 provided on one transversal wall 9 to be engaged by a complementary snap-fit securing member of the counterpart connector. The housing 3 also has fixing means 11 projecting from the other transversal wall 9, for fixing the connector 1 on a vehicle part or an equipment part (not shown) .

As it can be seen on Fig. 3, the chambers 4 are formed as through passages in the body section 6, extending according to the mating axis X from the rear side of the body to the receptacle 7.

Typically, the male terminal 5 is roughly composed of a crimping section (or more generally a connecting section to a cable) 15 at the rear side which is connected to a cable 16, a pin (or a tab) 17 at the front side, and an intermediate section 19 provided therebetween to ensure the guiding and the securing of the terminal in the housing.

To this end, the intermediate section 19 of the terminal has at least two spaced parallel walls 21, suitable to glide on inner walls of the chamber 4, each of said walls having an opening 23 suitable to be engaged by respective elastic latching means that will be described hereafter.

The chambers 4 are provided to partly accommodate respective male terminals 5, as visible on Fig. 3, and more precisely to accommodate the intermediate section 19 thereof.

In a normal use condition, such as illustrated on

Fig. 3, where a terminal 5 is fully inserted in the corresponding chamber 4, the pin 17 axially projects within the receptacle 7, the intermediate section 19 being accommodated and secured in the chamber 4.

Referring especially to Fig. 3 and 4, it can be seen that the body section 6 of the housing 3 is formed with two transversal opposed walls 25 adjacent the chamber 4 and two respective flexible arms 27, each of which essentially axially projecting from the respective wall 25 into the chamber 4.

As shown on Fig. 3, the flexible arms 27 and the adjacent walls 25 are arranged symmetrically with respect to an axial plane of the chamber 4.

Each of the flexible arms 27 associated with the chamber 4 projects forwards and essentially axially from the adjacent lateral wall 25 into the chamber 4. The arm 27 is a cantilevered arm with a free end 29 at the front side thereof, and a base section 31 which connects the arm 27 to the wall 25. The arm 27 further comprises a tooth 33 providing a stop member for engaging a corresponding opening 23 of the terminal. Oppositely to the tooth 33, the arm 27 has an outer surface 34 facing the wall 25. The flexible arm 27 and the adjacent wall 25 define a gap or recess 35 therebetween, which is open at the front side and closed at the rear side by the base section 31.

The front section of the flexible arm 27 can thus be deflected into the recess 35 upon the insertion of the terminal 5 in the chamber 4.

On Fig. 3 and 4, one terminal 5 is shown in its normal use condition, wherein it is fully engaged in the respective chamber 4 and secured therein by the respective flexible arms 27, said arm providing latching means with snap-fit effect.

In this normal use condition, the surface 34 is inclined with respect to the symmetry plane.

As shown on Fig. 2-4, the connector 1 also comprises a secondary locking member 41, which is also preferably made as one piece moulded from a plastic material.

The secondary locking member 41 is provided to be mounted in the housing 3 through the front receptacle 7, so as to be axially slideable between a neutral position, wherein the arms 27 can be deflected, and a locking position (shown on Fig. 3 and 4), wherein it blocks the arms in flexion .

The secondary locking member 41 essentially comprises a front plate 43, two opposed lateral locking legs 45, rearwards and axially projecting from said plate, and two opposed locking beams 47 for each chamber 4, also rearwards and axially projecting from the plate 43.

The front plate 43 is formed with through passages 49 arranged in correspondence with the respective chambers 4. In the normal use condition, the pins 17 of the terminals 15 axially project into the receptacle 7 through said passages 49.

The locking legs 45 are adapted to be engaged by a sliding movement in complementary axial groves 50 arranged in the body section 6 of the housing 3. Each locking leg 45 has a pair of axially offset first and second projections 52, 53. The first projections 52 constitute securing means adapted to engage complementary recesses (not shown) provided in the respective groves 50 for securing the locking member 41 in the housing 3 in the locking position. The second projections 53 constitute stopping means adapted to engage complementary recesses (not shown) provided in the respective groves 50 for provisory stopping the locking member 41 in the housing 3 in a pre-mounted neutral position, wherein the locking beams 47 are spaced apart from the respective flexible arms 27, whereby said arms can be deflected.

The locking beams 47 are arranged by pairs, the beams 47 of one pair (corresponding to one chamber 4) extending in a symmetric manner with respect to the axial plane. Each of the locking beam 47 has a free end 55 designed to be engageable in the respective recess 35 and is provided with internally formed axial ribs 57. The free ends have an outer surface 58 provided to contact a corresponding inner surface 36 of the wall 25 in the locking position of the secondary locking member 41.

The ribs 57 have an inner surface 59 facing the symmetry plane with an inclination angle substantially equal to the one of the surface 34. The surfaces 34 and 59 are corresponding contacting surfaces adapted to come into mutual engagement in the locking position of the secondary locking member 41. In the pre-mounted position of the locking member

41, the front plate 43 is axially spaced apart from the body portion 6 of the housing 3. The ribs 57, and more generally the locking beams 47, are spaced apart from the flexible arms 27, whereby said arms can be deflected. In this position of the locking member 41, terminals can thus be inserted in the chambers wherein no terminal is accommodated, and the locking member does not provide any additional retention force to the one provided by the arm 27, when a terminal is accommodated in the corresponding chamber.

As shown on Fig. 3 and 4, in the operative position

(or locking position) of the locking member 41, the front plate 43 engages the front face of the body portion 6.

Correspondingly, the ribs 57 come into engagement with the respective arms 27 with no any clearance in between, thereby preventing the arms from deflecting and disengaging from the respective terminals 5.

At the same time, in this position, the surface 58 engages the corresponding portion of the wall 25, also with no any clearance in between.

Optionally, the locking beams 47 may be designed so as to bias the flexible arms 27 in an engaged position with the respective terminals 5, and to slightly deform the arm 27 in flexion, in the locking position of the locking member 41.

In the case where a terminal 5 is attempted to be forced out of the chamber 4, for example by applying a withdrawal force to the corresponding cable 16, the locking beams 47 prevent the arm 27 from being submitted to any substantial deflection, due to the contacting relationship with no any clearance between the beam and the arm.

In addition, the contact with no any clearance between the surface 58 and the wall 25 ensures that no substantial deflection of the beam 47 occurs.

The terminal 5 is thus prevented from being withdrawn from the chamber 4 unless a sufficient force is exerted to break the arm 27. It will be appreciated that in some prior art connectors, the clearance between the locking beams 47 and the flexible arm 27, as well as the clearance between the locking beams 47 and the wall 25, permitted the arm to be deformed in flexion in such an extent that the terminal could be more easily forced out of the chamber, under a sufficient withdrawal force. Moreover, in prior art, clearances as described above, and also the clearance between the terminal walls 21 and the walls of chamber 4 as well as clearance between front plate passages 49 and terminals pins 17 allow some movement freedom of pin 17 relatively to mating X-axis, which makes the mating with the counterpart complementary female terminal difficult.

The invention provides a wedge effect which substantially increases the retention force on the terminals and minimizes the risks that the terminals could be withdrawn from their chambers, by simple means which do not involve complex manufacturing processes.

Moreover, the invention provides secondary locking means which, in use, holds the terminal 5 tight and in a symmetrical manner relatively to the mating X-axis and to the housing 3. This improves the axial alignment of the terminal in the chamber since the flexible arms are symmetrically forced in engagement with the terminal. This is of a particular interest for the small size electrical connections and more specifically for the male terminals .

In the locking position, the contact area between the surface 58 of locking beam 47 and the inner surface 36 of wall 25 can extend to all the available surface portions. As represented on the embodiment fig. 1, advantageously this inner surface 36 can alternatively have a small projection 37 on which the extremity of surface 58 come first into contact during the movement of member 41 to its locking position. This way the contact area between surfaces 58 and 36 is limited during a first phase of the movement. This allows, during a second phase as the pressure on the arm 27 increases, a small bending deformation of locking beam 47, which limits the pressure on arm 27 and terminal section 19 and corresponding deformations. This way it is possible to push member 41 along X-axis until abutment against some portion of housing 3 without the risk of too great a deformation of arm 27 and terminal. Abutment can for instance be made on surface portion 60 of member 41. In the shown embodiment the relatively to X-axis inclined contact surfaces 59 of locking beam 47 and 34 of arm 27 are engaged on all of the available area. Alternatively a recess of small depth can be made along either one or both of the facing sides of locking beam 47 and arm 27, thus building up limited contact surfaces, leaving at least one contact bump near each extremity, such a way that the contact area is smaller. In a similar way as previously explained, this allows some deformation of both parts which limits the forces between the different parts and the pressure on the terminal, especially when member 41 is pushed into abutment.

Claims

1. Electrical connector comprising an insulative housing (3) having at least one terminal accommodating chamber (4), a wall (25) adjacent said chamber and a flexible arm (27) essentially axially (X) projecting from said wall (25) into the chamber (4) and provided to secure a suitable terminal (5) in the chamber, a gap (35) being defined between the wall (25) and the flexible arm (27), and

- a secondary locking member (41) having a locking beam (47), said secondary locking member (41) being mounted on the housing (3) so as to be axially slideable between a neutral position, wherein the arm (27) can be deflected, and a locking position, wherein the locking beam (47) is inserted in the gap (23) thereby blocking the arm (27) in flexion, characterized in that the flexible arm (27) and the secondary locking member (41) are designed such that, in the locking position of the locking member, the locking beam

(47) contacts the flexible arm (27), with no clearance between the flexible arm and the locking beam, in a normal use condition where a terminal (5) is accommodated and secured in the chamber (4) by the flexible arm (27) .

2. Electrical connector as claimed in claim 1, characterized in that said secondary locking member (41) is adapted to be mounted on the housing (3) by a sliding movement in an axial direction (X) from a front mating side

(2) of the connector (1) .

3. Electrical connector as claimed in claim 1 or 2, characterized in that said locking member (41) and said housing (3) have complementary securing means (52) for securing the locking member (41) on the housing (3) in the locking position, and complementary stopping means (53) for provisory stopping the locking member (41) on the housing (3) in a pre-mounted neutral position, wherein the locking beam (47) is spaced apart from the flexible arm (27), whereby said arm can be deflected.

4. Electrical connector as claimed in claim 3, characterized in that the locking member (41) is axially slideable on the housing (3) between the pre-mounted position and the locking position.

5. Electrical connector as claimed in anyone of claims 1 to 4, characterized in that the locking beam (47) and the flexible arm (27) have corresponding contacting surfaces (34, 59) adapted to come into mutual engagement in the locking position of the secondary locking member (41), said contacting surfaces being inclined with respect to the sliding axis (X) of the secondary locking member (41) .

6. Electrical connector as claimed in claim 5, characterized in that the contacting surfaces (34, 59) have substantially the same inclination angle with respect to the sliding axis (X) of the secondary locking member (41) .

7. Electrical connector as claimed in anyone of claims 1 to 6, characterized in that the housing (3) is provided, for each chamber (4), with two substantially symmetrical flexible arms (27), and the locking member (41) is correspondingly provided with a pair of respective symmetrical locking beams (47), said symmetry being defined with respect to an axial symmetry plane of the chamber (4) .

8. Electrical connector as claimed in anyone of claims 1 to 7, characterized in that in the locking position of the locking member (41), the locking beam (47) biases the flexible arm (27) in an engaged position with the respective terminal (5), so as to deform the arm in flexion.