This invention relates to an electrical connector assembly comprising mating male and female connectors having housings for lodging male and female electrical contacts respectively therein, the housings having flexible locking lances for retaining the terminals within the housings, the housing further comprising complementary walls engaging between the locking lances and complementary walls of the mating connector for preventing deflection of the locking lances when the connectors are mated, and also preventing mating of the connectors if a terminal is not fully inserted within one of the connector housings. For certain applications in the electrical connector industry, in particular in the automotive field, it is desirable to provide connector assemblies that have safe and reliable means for retaining the terminals within cavities of their corresponding housings, and furthermore to ensure that if terminals are not correctly inserted into their housing cavities, that the connectors can not be mated without detection of this fault. It is of course also a continuous desire to provide more cost-effective and compact connector assemblies having a higher density of electrical connections, the electrical connections being sealed from the environment, particularly those, for example, within an automobile engine compartment.

It is therefore an object of this invention to provide a connector with a terminal locking means for retaining electrical terminals within a connector housing, such that incomplete insertion of a terminal within the housing will prevent mating of a connector to the complementary connector, the connector being cost- effective, compact and reliable. The objects of this invention have been achieved by providing an electrical connector assembly comprising first and second connectors matable together, the first and second connectors each having a housings and terminals

mounted in cavities extending through the housings from terminal receiving faces to mating faces thereof, the housings further comprising resilient locking lances for engaging shoulders of the terminals for retention thereof in the cavities, wherein the housings comprise wall portions extending from the mating faces in the mating direction, the wall portions of one of the connectors engageable against locking lances of the other connector when the connectors are coupled together to prevent the locking lances from biasing open and releasing the terminals.

The preferred embodiment of this invention will now be described in detail with reference to the figures, whereby; Figures 1 and 2 are isometric views of a connector assembly comprising mated complementary male and female connectors mounted on a support member;

Figures 3 and 4 are isometric views of the male and female connectors disconnected; Figures 5 and 6 are exploded isometric views of the male connector and the support member;

Figures 7 and 8 are partial cross-sectional views of the male and female connectors about to be connected, and in the fully mated position respectively, whereby Figure 7 shows a terminal which is not fully inserted into it's cavity.

Referring to Figures 1-6, a connector assembly 2 is shown comprising a support plate 4, a pin receiving male connector 6 and a receptacle terminal receiving female connector 8. The female connector 8 comprises a housing 10, elasto eric seal member 12, a cover 14, and a lever 16 mounted to the housing 10 via springs 18. The male connector 6 comprises a housing 20, a seal member 22 and a cover 24. The male housing 10 comprises a base portion 26 for mounting to the support plate 4, and a terminal receiving portion 28 comprising a plurality of terminal receiving cavities 30 extending from a terminal receiving face 32 to

a mating face 34. The female connector housing 20 comprises a plurality of cavities 36 extending from a terminal receiving face 38 to a mating face 40.

The male housing 10 further comprises integrally moulded resilient locking lances 42 for engaging a shoulder 44 of a pin terminal 46 for retention thereof within the cavity 30. Similarly, the female housing 20 comprises integrally moulded resilient locking lances 48 that engage behind a shoulder 50 of a receptacle terminal 52 for locking thereof into the cavity 36. The male housing further comprises wall portions 54 extending in the mating direction towards the female connector, the wall portions 54 insertable into a slot 57 formed in the female housing 20 by the locking lance 48 on one side and a wall portion 56 extending up to the mating face 40 from within the connector housing. The wall portion 56 and a wall 58 forming the receptacle cavity 36, forms a further slot 60 for receiving a mating end extension 43 of the male locking lance 42. As shown in Figure 7, if a terminal 46' is not fully inserted and locked in it's cavity 30, the resilient locking lance 42 is outwardly biased and upon mating the female and male connectors, abuts the female wall portion 56 thereby preventing coupling of the connectors. Similarly, if a receptacle terminal 52' is not fully inserted into it's cavity 36, the resilient locking lance 48 is outwardly biased and abuts the male wall portion 54 upon coupling thereof. If the terminals are correctly inserted and locked as shown in Figure 8, the wall portions 54,56 of the male and female connectors respectively, interengage into slots 55,57 of the female and male connectors respectively, thereby allowing full mating and furthermore blocking the locking lances 42,48 from outward biasing. As shown in Figure 3, the wall portions 54 of the female housing 20 are arcuate webs that span between adjacent receptacle terminal walls 47 that form the cavities 36 and surround the receptacle terminals 52 (also

see Figures 7 and 8) . The arcuate webs 56 span between adjacent receptacle terminal walls 47 of the same column 70,72. Terminals adjacent columns 70,72 are vertically offset (i.e. in the direction of the column) such that the receptacle terminal walls 47 of one of the columns 70 are positioned opposite the arcuate webs 56 of the adjacent column 72 (when considering a direction orthogonal to that of the column) , such that the slots 57 are formed therebetween. More particularly, it is the locking lances 48 that form part of walls 47, that are opposite the arcuate web wall portions 56. The latter enables a very compact arrangement (i.e. a high density) of the terminals.

Referring to Figure 4, the wall portions 54 of the male connector 6 are arcuate in shape for complementary insertion into the arcuate slots 57 of the female connector 8. The wall portions 54 extend beyond the tips of the pin terminals 46, and thus also act as a means of protecting the pin terminals from damage. The locking lances 43 are insertable into the slots 60 of the female connector 8, which are formed by the convex side of the arcuate webs of one column 70, and the receptacle terminal walls 47 of the adjacent column 72 as shown in Figure 3.

The use of integrally moulded resilient locking lances 42,48 of the connector housings 10,20 enable the terminals 46,52 to have smooth outer profiles, contrary to terminals which have resilient locking lances stamped therefrom. This is particularly advantageous for use in sealed connectors where the terminals can be pushed through corresponding holes in the seal member 12, and pulled out again (e.g. for repair) without damaging the seal member. A single seal member 12,14 can thus be used for each connector housing, making such a design very cost-effective in comparison with provision of single wire sealing (i.e. one seal grommet per terminal) which is typically used with terminals having stamped locking lances therefrom. In connectors where the locking lances are provided on the connector housing, it is known to

provide a separate housing member that is insertable between the locking lances and housing walls to block the lance in position for secure retention of the terminal in the connector housing. Such secondary housing members may typically be mounted in a preassembled position to the main housing allowing reception of the terminals within the cavities. Once the terminals are fully assembled to the main housing, the secondary housing can be moved to its fully locked position thus blocking the locking lances for secure retention of the terminals. If one or more of the terminals are not fully inserted, the lances are outwardly biased and prevent movement of the secondary housing from the preassembled to the fully locked position. Although such connectors provide a locking function of the locking lances, they have the disadvantage of requiring additional housing members. The latter relates to an increase in manufacturing, inventory and assembly costs. These are overcome by the present invention where the locking function is performed by interengagement of the wall portions and slots 54,55,56 of the complementary mating connectors 6,8. Furthermore, the use of less parts also enables a more compact design to be provided, for example because no latching means are required for the positioning of secondary housings, or no space is required for the material volume of a secondary housing.

Advantageously therefore, the invention provides a cost-effective connector assembly for sealed or unsealed connectors that is very compact and furthermore ensures correct and safe retention of terminals within the connector housings.