ELECTRICAL CONNECTOR WITH INTEGRAL SECONDARY LOCKING MEMBER

Abstract: An electrical connector (2) comprises a bowed secondary locking arm (30) that is integrally formed with the housing. When engaging the secondary locking member into the fully locked position, the bowed section (36) is straightened out resiliently, to allow passage of the locking shoulder (48) into a channel (38) that extends across a top face of the housing. A rigid, robust, compact and cost-effective secondary locking member is thereby provided.

Description: ELECTRICAL CONNECTOR WITH INTEGRAL SECONDARY LOCKING MEMBER This invention relates to an electrical connector comprising a housing with cavities receiving electrical terminals therein, the connector further comprising a secondary locking member for securing the terminals within the housing. It is common to find electrical connectors comprising an insulative housing having cavities extending therethrough for receiving electrical terminals. Typically, the electrical terminals are locked within the cavities by resilient locking lances that are either formed on the terminals, or from the housing, engaging respective shoulders of the housing or of the terminal. For added security, it is known to provide a secondary locking mechanism, for example comprising a sliding plate that has shoulders engaging behind shoulders of the terminal. It is typical that the secondary locking member cannot be moved from a pre-assembly position, where terminals can be inserted into the cavities, to a fully locked position, where terminals are secured, unless the terminals are fully inserted in their respective cavities and locked with the primary locking means. The secondary locking provides a more reliable and robust securing of terminals within the connector housing. The provision of a separate sliding plate for secondary locking, increases the costs of manufacturing and handling in view of the additional part. It is known to provide more cost-effective secondary locking members that are integrally formed with the connector housing for example as shown in GB 1 525 046. The latter patent publication shows a flap integrally connected to a connector housing via a flexible hinge, the flap comprising locking shoulders thereon that can be rotated into position behind a shoulder of the terminal once it is mounted within the connector housing cavity. Latches engaging with the housing secure the flap to the housing in the fully locked position. In order to allow large pivoting movement the hinge is relatively thin and not very robust. A large pulling force on the terminal may cause the hinge to deform, possibly releasing the secondary locking member. Furthermore, the flap projects far out from the connector housing, which requires more volume and the flap easily gets caught on other objects during handling. It would be advantageous to provide an improved connector, with a robust and compact secondary locking member. It would also be desirable to provide a secondary locking member that can be very easily engaged. An object of this invention is therefore to provide an electrical connector having a robust, reliable, compact and cost-effective secondary locking member. Objects of this invention have been achieved by providing the electrical connector according to claim 1. In particular, the secondary locking member is integrally attached to the connector housing at one end, and extends in a bowed shape to a free end comprising a latch that engages a latch of the housing. The bow-shape of the secondary locking member is made straighter during engagement of the secondary locking latch with the housing to provide the resiliency that maintains the secondary locking member in the locked position. The secondary locking member can thus be formed extending almost parallel to a top or bottom wall of the connector housing to provide a compact connector. The avoidance of thin hinges, and the provision of a high elasticity due to the straightening out of the bow, produces a secure and robust secondary locking member. In addition, the secondary locking member can be very easily and quickly latched into position by merely applying pressure on the bowed region either manually, or with a machine. Further advantageous features of the invention will be apparent from the following description and the claims. Embodiments of this invention will now be described, by way of example, with reference to the accompanying figures: Figure l is an isometric view of a two row electrical connector according to this invention; Figure 2 is an isometric view of a single row connector according to this invention; Figures 3a and 3b are a cross-sectional view through the connector of Figure 2 showing a secondary locking member in the pre-assembly and fully locked positions respectively; and Figures 4 and 5 are similar views to Figures 1 and 2 respectively of another embodiment. Referring to Figures 2 and 3, an electrical connector 2 comprises an insulative housing 4 and electrical terminals 6 mounted in cavities 8 of the housing. The cavities 8 extend from a mating face 10 to a terminal receiving face 12. The connector further comprises top and bottom surfaces 14,16 respectively extending between the mating and terminal receiving surfaces 10,12, and lateral end surfaces 18 bounding lateral sides of the connector. Each terminal 6 comprises a connection section 20 for connection to a conducting wire, a contact section 22 for mating with a complementary terminal, and a primary retention section 24. In this embodiment, the retention section 24 comprises a resilient lance projecting obliquely outwards from the terminal and engaging a shoulder 26 of the connector housing. This is the primary locking means of the terminal within the housing. Such primary locking means could be designed otherwise, for example a resilient lance integral with the housing could engage a shoulder of the terminal , for example provided in a cut-out of the terminal body. Any conventional primary locking means could be imagined. The contact section 22 is provided in a contact body 23 that extends from a mating end 25, to a secondary locking shoulder 27 facing the connection section 20. The connector housing comprises a secondary locking member 30 integrally formed with the housing at an attachment end 32 that is proximate the conductor receiving face 12 of the housing. Secondary locking member 30 extends from the attachment end 32 to a free end 34 via a bowed resilient arm section 36. A channel 38, extending substantially parallel to the mating face 10, cuts into the top face 14 of the connector housing, and is provided with a latching shoulder 40 that engages a complementary latching shoulder 42 of the secondary locking member 30. The complementary latching shoulder 42 is provided proximate the free end 34 of the secondary locking member. The channel 38 cuts transversely across the terminal receiving cavities 8 of the housing at a position behind the secondary locking shoulder 27 of the terminals when they are fully inserted in the housing cavities. A secondary locking face 44 proximate the free end 34 of the secondary locking member 30 is thus engaged behind the terminal secondary locking shoulders 27 when the secondary locking member is latched in the channel 38. Prior to secondary locking, the secondary locking member 30 is in its free standing position (F) as shown in Figure 3 whereby the free end 34 projects above the top wall face 14. A shroud or extension on a complementary connector can be provided to abut the free end 34 in the free standing position, thereby preventing full coupling and indicating that the secondary locking member is not engaged. In the locked position (L) , the free end 34 of the secondary locking member is depressed into the channel 38 allowing the connectors to fully mate together. If a terminal is not fully mounted in the cavity, a bottom end 46 of the secondary locking member abuts a top wall 8 of the terminal contact body 23, thereby preventing latching of the secondary locking member in the fully locked position (L) . During engagement of the secondary locking member 30 from the free standing position to the locked position, the bowed resilient arm 38 is depressed towards the housing, and upon abutment of the bottom end 46 of the retention arm with an edge 50 forming a corner of the channel 38 with the top face 14, the resilient arm section 36 is straightened out thereby elongating the arm. The elongation allows passage of the secondary locking member shoulder 42 past, and into engagement with the secondary locking shoulder 40 of the housing. The resilient stretching of the bowed arm section of the secondary locking member securely holds it in latching engagement with the housing. Engagement of the secondary locking member can thus be affected in a very simple manner by merely applying pressure on the resilient bowed arm section 36, either manually or with a machine. In the free-standing position (F) , the secondary locking member is proximate the top face 14 of the housing therefore providing a compact connector even prior to secondary locking. In combination with the relatively rigid attachment portion 32, the secondary locking member is relatively well protected from engagement with external objects. A cost-effective connector is nevertheless provided due to the integral forming of the secondary locking member with the housing. In addition, a particularly robust secondary locking member is provided, as pulling force on a terminal engaging the secondary locking member locking shoulder 44 causes the free end 34 of the secondary locking member to engage an upstanding wall 52 of the channel 38. The secondary locking member free end 34 is thus securely blocked within the channel 38 i.e. the secondary locking force does not transit through the secondary locking member arm 36 or attachment portion 32. In Figure 1, an embodiment with two rows of terminal receiving cavities is shown, whereby the locking members 30 are provided on opposing faces of the connector. Referring now to Figures 4 and 5 , embodiments very similar to those described in Figures 1 and 2 respectively are shown. The main difference is in the free end 34' of the secondary locking member 30', which is attached via a hinge 51 to the bowed section 36'. This hinge gives the free end 34' greater pivoting flexibility in order to ease latching and unlatching of the secondary locking member. Unlatching is facilitated by provision of a ledge or grip extension 52 extending from the hinge 51 in an opposite direction to the free end locking end 44'. A protective extension 54 is provided projecting through and beyond the locking member 30' and provides some protection against external objects from pressing the secondary locking member in the locked position during handling and transport, prior to full assembly of terminals.

Claims: -1- CLAIMS 1. An electrical connector comprising a housing (4) having a secondary locking member (30) and terminal receiving cavities (8) extending through the housing from a terminal receiving end (12) to a mating end (10) , further comprising terminals (6) secured in the cavities by primary locking means (24) , the terminals each having a secondary locking shoulder (27) for engagement with the secondary locking member, the secondary locking member having a free-standing position (F) allowing assembly of the terminals in the cavities, and a locked position (L) engaging behind the terminal secondary locking shoulders for secondary securing of the terminals in their respective cavities, characterized in that the secondary locking member extends from an attachment portion (32) attached to the housing, to a free end (34) having a locking shoulder (44) engageable in a channel (38) extending across the top face (14) of the connector housing for insertion behind the terminal locking shoulders (27) , the secondary locking member comprising a resilient bowed section (36) between the attachment and free ends. 2. The connector of claim 1 wherein the resilient bowed section (36) extends roughly parallel over the top face (14) of the connector in the free-standing position (F) . 3. The connector of claim 1 or 2 wherein the attachment portion (32) of the secondary locking member is proximate the housing terminal receiving end (12) . 4. The connector of any one of the preceding claims wherein the free end (34) of the secondary locking member is bent approximately orthogonally to the resilient bowed section (36) . 5. The connector of any one of the preceding claims wherein the secondary locking member free end (34) comprises a latching shoulder (42) engageable with a latching shoulder (40) in the channel (38) to secure the secondary locking member in the locked position (L) . 6. The connector of any one of the preceding claims wherein a lower end (46) of the secondary locking member free end (34) abuts the housing top face (14) at a corner (50) with the channel (38) during biasing of the member into the locked position (L) , the engagement of the lower end (46) and corner (50) causing the bowed section to be resiliently bent and thereby elongated such that complementary latching shoulders (42,40) of the secondary locking member (30) and housing channel (38) respectively engage each other.

Inventors: HOWELLS RICHARD JOHNATHON, HOWELLS, RICHARD, JOHNATHON
Applicants: HOWELLS RICHARD JOHNATHON, WHITAKER CORP, HOWELLS, RICHARD, JOHNATHON, THE WHITAKER CORPORATION
Application year: 1997
Main classification: H01R13
IPC codes: H01R13