CONNECTOR WITH TERMINAL POSITION ASSURANCE MEMBER

Abstract: An electrical connector (2) has primary locking means formed by terminal locking lances (28) engaging corresponding shoulders (30) of the connector housing (4), and secondary locking means formed by a resilient latch (52, 56) integrally formed with the housing. The secondary latch (52) is secured in the fully locked position by a terminal position assurance member (66), that can only be actuated if the terminals are fully inserted in their respective cavities. Extension of the secondary locking member from an attachment portion (58) directed towards the mating end of the connector, to a free end (60) directed towards a connection end of the connector, ensures that the secondary locking member acts in traction rather than compression. Buckling of the secondary locking member is thus avoided.

Description: CONNECTOR WITH TERMINAL POSITION ASSURANCE MEMBER This invention relates to an electrical connector with a housing and one or more terminals mounted therein, the terminals retained in a fully inserted position, and secured with a terminal position assurance member. In US 4,343,523, an electrical connector is shown comprising a plurality of electrical terminals retained in a fully inserted position in the housing by resilient locking lances integrally formed with the housing. The locking lances have locking projections that engage in holes of the terminal, cut out from a body section of the terminal. An insulative insert is inserted between the locking lances and a housing outer wall from a mating end of the connector. The insert blocks the locking lances from biasing outwards, thereby securely retaining the terminals in the connector. One of the problems of the latter design, is that the terminals are provided with cutouts for engaging the lances. Cutouts in the terminal body reduce the possibilities of providing functional or operational features such as an outer spring member, or contact arms at the position of the cutout. The lances integrally formed with the housing increase the volume of the housing, in order to allow movement of the lances within the housing, and to provide a certain thickness of the lance for sufficient robustness, particularly as the locking lances have free ends facing the mating end of the connector, and therefore risk buckling under excessive traction of the terminal towards the conductor receiving end of the connector. Another widely used design, is the provision of resilient locking lances on terminals that engage shoulders of a connector housing. The latter usually provides for a more compact connector design, however the risk of buckling of the lances of the terminal also exits. It is therefore also known to provide a secondary locking member that engages behind a shoulder of the terminals for additional security. As shown in US 4,284,320 for example, it is known to provide a secondary locking member that slides transversely engaging behind a shoulder of the terminal. The terminal is provided with a resilient locking lance that engages a shoulder of the housing, thereby forming the primary locking means. Secondary locking members are often relatively voluminous, and/or complicated to access or actuate m sealed connectors. It is an object of this invention to provide an electrical connector that is compact yet has terminals that are securely and robustly retained in the connector housing. It would be further desirable to provide a connector with locking means that can be easily accessed and actuated, and that also allow effective sealing of the connector. Objects of this invention have been achieved by providing the connector according to claim 1. Disclosed herein is an electrical connector comprising a housing with terminal receiving cavities extending from a terminal receiving end to a mating end, and one or more terminals mounted in respective said cavities and retained therein by locking lances, each lance attached to the housing at an attachment end and extending therefrom to a free end, each lance comprising a locking shoulder for engaging a complementary locking shoulder of said terminal, the connector further comprising a terminal position assurance member insertable in a gap between the locking lance and a portion of the housing for blocking the lance in the locked position, whereby the terminal position assurance member is blocked from full insertion in the gap if the terminal is not fully inserted, wherein the attachment end of the locking lance is positioned towards the mating end of the connector, and the free end is directed towards the terminal receiving end. Advantageously therefore, a particularly robust and compact locking lance is provided, with secure retention by the terminal position assurance member accessible from the connector mating end. The locking lance acts in traction which supports greater forces than in compression. The terminal may also be provided with locking lances engaging shoulders of the housing, thereby forming primary locking means, the housing locking lance forming secondary locking means engaging behind a shoulder of the terminal proximate a connection end of the terminal remote from a mating end thereof. Advantageously, cutouts within the terminal can be avoided if desired, whilst nevertheless providing a compact connector. The terminal position assurance member may extend in a mating direction of the connector, and slidably movable from a preassembly to a locked position in the mating direction. In the event of a terminal that is not fully inserted in its corresponding cavity, the housing locking lance is outwardly biased into the terminal position assurance receiving gap, thereby blocking full insertion of the terminal position assurance member. Coupling of connectors is prevented by projection of the terminal position assurance member in the mating direction. Further advantageous aspects of the invention are set forth in the claims, or will be apparent from the following description and drawings. An embodiment of this invention will now be described by way of example with reference to the Figures in which: Figure 1 is an isometric view of a connector according to this invention, viewed towards a mating face of the connector; Figure 2 is a view similar to Figure 1 with a terminal position assurance member of the connector m a preassembly position; Figure 3 is an isometric view of the terminal position assurance member; Figure 4 is a cross-sectional view through the connector, with the terminal position assurance member m a preassembly position; Figure 5 is a cross-sectional view similar to Figure 4, but with the terminal position assurance member m the fully locked position; Figure 6 is a view similar to Figure 4 where the terminal position assurance member is in the preassembly position, and a terminal is shown only partially inserted in the connector. Referring to the figures, an electrical 2 comprises an msulative housing 4 having a plurality of terminal receiving cavities 6 extending therethrough from a terminal receiving end 8 to a mating end 10, for receiving electrical terminals 12 of the connector therein. The terminal 12 is connected (crimped) to an electrical wire 14. Each cavity 6 is sealed proximate the terminal receiving end 8 by a single wire seal 15, that is retained by crimping tabs 16 to the terminal 12 and wire 14. The terminal 12 comprises a connection section 18 for connection to the wire 14, a body section 20, and a contact section 22 directed towards the mating end 10. The contact section 22 is a receptacle contact section comprising a pair of opposed contact arms for receiving a mating tab terminal therebetween. The terminal 12 further comprises an outer spring body 24 having spring arms 26 that apply pressure on the contact arms 23 of the contact section 22 for increasing the contact pressure thereof. The terminal 12 is further provided with primary locking members 28 in the form of resilient cantilever beam locking lances obliquely projecting out of the body section 20 for engaging complementary primary locking shoulder 30 of the housing 4. In this embodiment, the locking lances 28 are stamped out of the outer spring body 24. The terminal body section 20 extends from a rear end 32 facing the connection section 18, to a front end 34 facing the contact section 22. The housing 4 comprises a connection section 36, and a mating section 38. The connection section 36 receives the terminal connection section 18 and seal 15. The mating section 38 receives substantially the body and contact sections 20,22 of the terminals. The mating section 38 comprises an outer shroud 40 surrounding a housing terminal receiving portion 42, separated therefrom by a gap 44 for receiving the shroud of a mating connector therein. The mating connectors are provided with a seal member 46 that seals the connection area between mating terminals. In this embodiment, the seal member 46 is provided in the shroud receiving gap 44 of the connector 2, against an intermediate wall 46 arranged proximate the interface between the housing connection section 36 and mating section 38. The shroud of the mating connector (not shown) abuts against a forward sealing face 50 of the seal member 46. The shroud of the mating connector thus encloses the terminal receiving section 42 of the housing. The connector 2 comprises a locking member 52 attached to the housing 4 and having a locking shoulder 54 provided on a locking portion 56 in the form of a protrusion of the locking member, for engaging a complementary locking shoulder of the terminal, which in this embodiment is provided by the rear end 32 of the body section 20. In this embodiment, the locking member 52 is integrally formed with the housing 4, and in particular with the terminal receiving section 42 of the housing. The locking member 52 is attached to the housing at an attachment portion 58 proximate the mating end 10, and extends therefrom in a cantilever beam manner to a free end 60 directed towards the connection section 36. The locking portion 56 is provided proximate the free end 60. Adjacent an outer side 62 of the locking member 52, is a slot 64 in which a terminal position assurance member 66 of the connector is receivable. The gap 64 also enables the locking member 52 to bias into the gap during insertion of the terminal in the terminal receiving cavity 6, whereby as best seen in Figure 6, the locking protrusion 56 rides along the terminal side wall until it latches behind the body section end wall 32 as shown in Figure 4. In Figure 4, the terminal is fully inserted into the connector whereby the primary locking members 28,30 are engaged, as well as the locking member 32, which forms part of a secondary locking member. The secondary locking member 52 comprises a pair of spring arms extending in the mating direction M, separated by a slot 53. The arms are joined at an end 68 proximate the locking portion 56. The slot 53 between the spring arms of the locking member 52 enables the locking member to bias outwardly into the gap 64 when the terminal position assurance member 66 is in the gap in a preassembly position as shown in Figure 4. Locking extensions 70 (see Figure 3) of the terminal position assurance member are received in the gap 53 between the locking member spring arms. When the terminal position assurance member 66 is moved in the mating direction M to the fully locked position as shown in Figure 5, the locking extensions 70 insert behind the locking portion 56 thereby blocking the locking member 52 from outwardly biasing. The terminal is thus securely retained in the housing. The retention is particularly robust and compact, in particular due to the extension of the locking member 52 from an attachment end 58 directed towards the connector mating end 10, towards a locking portion 56 directed towards the connection end. The locking member 52 thus acts in traction rather than compression. The risk of buckling is thus eliminated. In addition, the locking portion 56 engages behind a rear end 32 of the body section. This avoids provision of a cutout within the body section, which increases the expense or reduces the functionality of the terminal. The terminal position assurance member 66 is in this embodiment in the shape of a generally planar plate with a base wall 72 from which the locking projections 70 extend. The base wall 72 is provided with locking portions 74 in the form of resilient beams for engaging a complementary locking portion 78 of the connector housing. The locking portion 74 is provided with two locking shoulders, a preassembly locking shoulder 75 and a full assembly locking shoulder 77, that determine respectively the preassembled and fully locked position of the terminal position assurance member with respect to the housing. The terminal position assurance member 66 is further provided with a grip 80 at a mating end 81 that is substantially flush with a mating end 82 of the housing terminal receiving portion 42 when the terminal position assurance member 66 is in the fully locked position as shown in Figure 5. In the preassembly position as shown in Figure 4, the mating end 81 projects beyond the mating end 82 of the terminal receiving section 42 thereby preventing a complementary connector from coupling with the connector 2. The terminal position assurance member 66 cannot be displaced into the fully locked position unless the terminals 12 of the connector are fully inserted, in view of engagement of the connection end 83 of the extension 70 against the end 68 of the locking portion 56 as best seen in Figure 6. The terminal position assurance member is thus particularly simple to access and actuate, yet nevertheless ensures a particularly reliable and robust secondary locking of terminals in the connector.

Claims: CLAIMS 1. An electrical connector (2) comprising a housing (4) with at least one terminal receiving cavity (6) extending from a terminal receiving end (8) to a mating end (10), and at least one terminal (12) mounted in the cavity (6) and retained therein by a locking lance (64) attached to the housing at an attachment end (58) and extending therefrom to a locking portion (56) , the lance comprising a locking shoulder (54) for engaging a complementary locking shoulder (32) of said terminal, the connector further comprising a terminal position assurance member (66) insertable in a gap (64) between the locking lance (52) and a portion of the housing for blocking the lance in the locked position, whereby the terminal position assurance member is blocked from full insertion in the gap (64) if the terminal is not fully inserted, wherein the attachment end (58) of the locking lance is positioned towards the mating end (10) of the connector, and the locking portion (56) is positioned towards the terminal receiving end (8). 2. The connector of claim 2 wherein the locking lance (64) is a cantilever beam having a free end (60) proximate the locking portion (56) . 3. The connector of claim 1 or 2 wherein the locking lance comprises a gap (53) separating the lance into a pair of beams joined together at an end (68) at the locking portion (56) , the gap receiving an extension (70) of the terminal position assurance member (66) therein when outwardly biased in the terminal position assurance member receiving gap (64) . 4. The connector of claim 3 wherein the extension (70) of the terminal assurance member (66) is adapted to abut the end (68) of the locking lance slot (53) when the lance is outwardly biased in the terminal position assurance member receiving gap (64) thereby preventing full locking. 5. The connector of any one of the preceding claims wherein the terminal position assurance member (66) extends in a mating direction (M) , and is slidable in the gap (64) in the mating direction (M) , the terminal position assurance member (66) having an extension (70) at one end for engaging the connector lance locking portion (56), and a grip (81) at an opposed end directed towards the mating end (10) of the connector, the grip (81) projecting beyond a mating face (82) of a terminal receiving portion (42) of the housing, when the terminal position assurance member (66) is in a preassembly position enabling insertion of terminals (12) in their cavities (6), and wherein the grip (81) is substantially flush with the terminal receiving portion end (82) when the terminal position assurance member is in the fully locked position. 6. The connector of any one of the preceding claims wherein the complementary locking shoulder (32) of the terminal is provided on a rear end of a receptacle body section (20) of the terminal, adjacent the connection section (18) of the terminal. 7. The connector of any one of the preceding claims wherein the connector comprises primary locking means provided by resilient locking lances (28) stamped out of - l i ¬ the terminal, engaging behind complementary locking shoulders (30) in the connector housing. 8. The connector of any one of the preceding claims wherein a body and contact section (20,22) of the terminal (12) is received in a terminal receiving portion (42) of the housing, the housing further comprising a shroud (40) surrounding the terminal receiving portion (42) with a gap (44) that receives a shroud of a mating connector therein in a mating direction (M) . 9. The connector of the preceding claim wherein a seal member (46) with a sealing face (50) facing the .mating end (10) is provided against an end wall (48) of the shroud (40), for sealing the terminal receiving portion (42) .

Inventors: PAMART OLIVIER, PAMART, OLIVIER
Applicants: PAMART OLIVIER, WHITAKER CORP, PAMART, OLIVIER, THE WHITAKER CORPORATION
Application year: 1998
Main classification: H01R13
IPC codes: H01R13