Perfect coupling confirming mechanism for an electric connector

Abstract: A perfect coupling confirming mechanism for an electric connector having a first and second connector housings, capable of confirming the perfect coupling of the first and second connector housings and double-locking the first and second connector housings. The perfect coupling confirming mechanism comprises: a locking arm having a locking projection, formed on the first connector housing; a locking lever pivotally joined at its rear end to the first connector housing and provided at its front end with an insulating projection, and at its front end with locking fingers; locking projections formed on the second connector housing; a break contact formed of a pair of short-circuiting terminals disposed in a short-circuiting terminal chamber formed in the second connector housing. The locking fingers of the locking lever is able to engage the locking projections of the second connector housing and the insulating projection of the same is able to break the break contact only when the first and second connector housings are perfectly coupled. The first and second connector housings can be double-locked by the engagement of the locking projection of the locking arm and the second connector housing and by the engagement of the locking lever and the second connector housing only when the first and second connector housings are perfectly coupled.

Description: BACKGROUND OF THE INVENTION The present invention relates to a perfect coupling confirming mechanism for an electric connector for connecting contactors of an electric circuit on a vehicle. GB-A- 2180657 discloses a perfect coupling confirming mechanism according to the preamble of claim 1. However, the insulating projection according to that prior art does not function as lock means. Known electric connectors have a pair of connector housings, which are mated together to join electrically the male and female contactors contained therein, and is provided with locking means including flexible locking arm and a locking arm catching member between the pair of connector housings to lock the pair of connector housings to each other. In coupling the pair of connector housings by hand, the perfect coupling and exact locking of the pair of connector housings are confirmed through the tactile recognition of coupling, the auditory recognition of locking sound and the visual inspection of the appearance of the electric connector. However, since a large number of electric connectors need to be coupled on the vehicle and the working environment is not necessarily favorable for the sensational confirmation of the perfect coupling of the electric connectors, it is possible that some electric connectors are not perfectly coupled. To improve such a disadvantage, an electrically perfect coupling confirming mechanism as shown in Figs. 6 and 7 is proposed in Japanese Utility Model Laid-open (Kokai) No. 61-186180. This perfect coupling confirming mechanism comprises a pair of electrical contactors b₁ and b₂ contained in a first connector housing a in an electrically separate condition, and an elastic tongue e contained in a second connector housing d t bring forcibly the pair of electrical contactors b₁ and b₂ into contact with each other. The first connector housing a is provided with a protrusion c which prevents the connectors b ₁ and b ₂ from the forcible contact when the first connector housing a and the second connector housing d are imperfectly coupled. This perfect coupling confirming mechanism, however, has the following drawbacks. As shown in Fig. 6, since the pair of electrical contactors b₁ and b₂ are disposed close to each other in the first connector housing a and any insulating means is not provided between the pair of electrical contactors b₁ and b₂ , it is possible that the electrical contactors b₁ and b₂ remain in contact with each other before the coupling of the first connector housing a and the second connector housing d when either the electrical contactor b₁ or b₂ or both the electrical contactors b₁ and b₂ are deformed or are disposed incorrectly within the first connector housing a . Furthermore,, since the elastic tongue e is comparatively small and is formed of a synthetic resin integrally with the second connector housing d , the elasticity of the elastic tongue e is dependent on temperature and, under some condition, the elastic tongue 3 is unable to function properly, and the elastic tongue e makes the internal construction of the second connector housing d complex. The elastic tongue e does not serve as a safe lock means as the pivoted locking lever as claimed. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a perfect coupling confirming mechanism for an electric connector having first and second connector housings capable of detecting the imperfect coupling of the first and second connector housings and capable of surely double-locking the first and second connector housings. In one aspect of the present invention, a perfect coupling confirming mechanism for an electric connector having a first connector housing provided on its wall with a locking arm, a second connector housing provided with latching means for latching the locking arm when the first and second connector housings are coupled perfectly to lock the first and second connector housings to each other comprises a break contact consisting of a pair of short-circuiting terminals accommodated in a short-circuiting terminal chamber formed in the second connector housing, a locking lever pivotally joined to the first connector housing, capable of perfectly engaging the second connector housing when the first and second connector housings are coupled perfectly, and provided at its extremity with a breaking projection which enter the short-circuiting terminal chamber through an opening formed in the wall of the second connector housing to break the break contact when the first and second connector housings are coupled perfectly. The locking arm of the first connector housing locks the first and second connector housings to each other for primary locking when the first and second connector housings are coupled perfectly, and the locking lever pivotally supported on the first connector housing is allowed to engage the second connector housing to lock the first and second connector housings for secondary locking and to break the break contact only when the first and second connector housings are coupled perfectly. Thus, the first and second connector housings are double-locked and the perfect coupling of the first and second connector housings can be detected by electrically checking the condition of the break contact by a check circuit having an alarm lamp which is switched on when the first and second connector housings are coupled imperfectly. If the first and second connector housings are coupled imperfectly, the locking lever is unable to engage the second connector housing, the break contact remains closed, and hence the alarm lamp remains switched on. BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following description taken in connection with the accompanying drawings, in which: Figure 1 is an exploded perspective view of a perfect coupling confirming mechanism for an electric connector, in a preferred embodiment according to the present invention; Figure 2 is a longitudinal sectional view of the perfect coupling confirming mechanism of Fig. 1; Figures 3 and 4 are longitudinal sectional views of the perfect coupling confirming mechanism of Fig. 1 in a state where the electric connector is perfectly coupled and in a state where the same is imperfectly coupled, respectively; Figures 5A and 5B are circuit diagrams of a check circuit, showing the condition of the check circuit before and afar the perfect coupling of the electric connector; Figure 6 is an exploded sectional view of a conventional perfect coupling confirming mechanism in a state where the electric connector is not coupled; and Figure 7 is a sectional view of the conventional perfect coupling confirming mechanism in a state where the electric connector is coupled. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Shown in Figs. 1 and 2 are a first connector housing A formed of a synthetic resin and internally provided with a plurality of contactor chambers 1 accommodating female electrical contactors 3, respectively, a second connector housing B formed of a synthetic resin and internally provided with a plurality of contactor chambers 2 accommodating male electrical contactors 4, respectively, and a short-circuiting terminal chamber 2′ accommodating a pair of short-circuiting terminals C and C′. A flexible locking arm 5 having a locking projection 5a (Fig. 2) is formed in the lower wall of the first connector housing A. A locking lever 8 is pivotally supported at its rear end by a pin 7 on lugs 6 formed at the opposite sides of the rear end of the upper wall of the first connector housing A. The locking lever 8 is provided at the front end of the surface facing the upper surface of the first connector housing A with an insulating projection 9, and locking fingers 10 formed on the opposite sides of the insulating projection 9. The second connector housing B has a connector body 13 having the contactor chambers 2 and the short-circuiting terminal chamber 2′, and a hood 12 for receiving the first connector housing A, forming the front portion of the second connector housing B. An opening 13 for catching the locking projection 5a of the locking arm 5 is formed in the hood 12. The short-circuiting contactor chamber 2′ is formed in the connector body 11. The short-circuiting terminals C and C′ are the same in shape and are disposed symmetrically. The short-circuiting terminal C (C′) has a base 17 (17), a curled, elastic contact tongue 18 (18′) formed at the extremity of the base 17 (17), a crimp conductor fastener 19 (19) for fastening a conductor, formed in the rear portion of the base 17 (17), and a crimp cover fastener 20 (20) for fastening the insulation of the conductor, formed behind the crimp conductor fastener 19 (19). Cables 21 are fastened to the short-circuiting terminals C and C′ by crimping. A slot 14 is formed in the upper wall of the connector body 11 of the second connector housing B at a position corresponding to the joint of the contact tongues 18 and 18′ of the short-circuiting terminals C and C′ forming a break contact. Locking projections 16 which engage the locking fingers 10 of the locking lever 8 project from the rear edge of the hood 12 over an opening 15 merging into the slot 14. The perfect coupling confirming functions of the locking lever 8 and the short-circuiting terminals C and C′ will be described hereinafter. The locking projection 5a of the locking arm 5 engages the opening 13 of the hood 12 to lock the first connector housing A and the second connector housing B to each other in a primary locked state when the first connector housing A and the second connector housing B are coupled perfectly as shown in Fig. 3. In this state, the locking lever 8 is brought into engagement with the second connector housing B. Then, the insulating projection 9 of the locking lever 8 enter the short-circuiting terminal chamber 2′ through the slot 14 and thrusts itself into the joint of the pair of elastic contact tongues 18 and 18′ of the short-circuiting terminals C and C′ to disconnect the elastic contact tongues 18 and 18′, namely, to break the break contact. At the same time, the locking fingers 10 are caught by the locking projections 16 to lock the first connector housing A and the second connector housing B in a secondary locked state. Thus, the first connector housing A and the second connector housing B are double-locked. If the first connector housing A and the second connector housing B are coupled imperfectly as shown in Fig. 4, the insulating projection 9 of the locking lever 8 is unable to reach the slot 14, and hence the locking lever 8 is unable to exert its locking function and the elastic contact tongues 18 and 18′ remain in contact with each other, namely, the break contact remains closed and, naturally, the locking arm 5 is unable to engage the second connector housing B for locking. In Figs. 3 and 4, the female electrical contactors 3 and the male electrical contactors 4 are omitted for simplicity. Fig. 5A shows the condition of a check circuit 22 for confirming the perfect coupling of the first connector housing A and the second connector housing B when the first connector housing A and the second connector housing B are not coupled or are imperfectly coupled. Since the elastic contact tongues 18 and 18′ of the short-circuiting terminals C and C′ are in contact with each other, namely, the break contact is closed, the check circuit is made to switch on an alarm lamp 23. Fig. 5B shows the condition of the check circuit 22 when the first connector housing A and the second connector housing B are perfectly coupled. Since the elastic contact tongues 18 an 18′ are disconnected from each other by the insulating projection 9, the check circuit 22 is broken and hence the alarm lamp 23 is switched off, which indicates that the first connector housing A and the second connector housing B are perfectly coupled and double-locked. Accordingly, the perfect coupling of the connector housings A and B can exactly be confirmed without depending on auditory, tactile and visual sensations. The elastic tongues 18 and 18′ are disconnected from each other only by the insulating projection 9 of the locking lever 8 and, normally, remains stably in contact with each other. Thus, the break contact formed of the short-circuiting terminals C and C′ functions with a high reliability. The locking lever 8 pivotally supported by the pin 7 on the first connector housing A may be formed integrally with the first connector housing A and hinged to the first connector housing A. The locking fingers 10 may be formed apart from the insulating projection 9, for example, on the opposite sides of the front edge of the locking lever 8, and the locking projections 16 may be formed on the opposite side walls of the connector body 11 or the hood 12 at positions respectively corresponding to the locking fingers 10. Such an arrangement of the locking fingers 10 and the locking projections 16 enables the omission of the opening 15. The locking lever 8 may be biased away from the second connector housing B with a spring, not shown, to prevent the locking lever 8 from falling naturally onto the second connector housing B. Although the invention has been described in its preferred form with a certain degree of particularity, obviously many changes and variations are possible therein. It is therefore to be understood that the present invention may be practiced otherwise than as specifically described herein without departing from the scope and spirit of the claims.

Claims: A perfect coupling confirming mechanism for an electric connector, the mechanism comprising: a first connector housing (A) and a second connector housing (B), first lock means (5,13) provided between the first connector housing and the second connector housing for locking the first and second connector housings when assembled with each other; a pair of short-circuiting terminals (C) disposed in said second connector housing; a normally closed contact (18,18′) formed between said pair of short-circuiting terminals; and an insulating projection (9) adapted to extend within said second connector housing to open said normally closed contact and disconnect the pair of short-circuiting terminals from each other only when the first and second connector housings are perfectly coupled, characterised in that the mechanism further comprises second lock means (8,9,10) including a locking lever (8) which is pivotally attached to the first connector housing (A), for assuming the assembly of the first and second connector housings when said locking lever is pivoted onto said second connector housing (B), and in that the insulating projection is formed on the locking lever and extends within said connector housing when said locking lever is pivoted onto the second housing. A perfect coupling confirming mechanism as claimed in Claim 1, wherein said locking lever has a finger (9) formed thereon and engaging a slit (14) formed in said second connector housing when said locking lever is pivoted onto said second connector housing. a perfect coupling confirming mechanism as claimed in Claim 1, further comprising: alarm means (23) operatively connected to the pair of short-circuiting terminals (C) for alarming an imperfectly coupling condition of the first and second connector housings when the normally closed contact is closed.

Inventors: INABA SHIGEMITSU C O YAZAKI PA, MURAOKA KAUNIHIKO C O FUJI JUK, NAKAZATO WATARU C O FUJI JUKOG, OHTAKA KAZUTO C O YAZAKI PARTS, TAKAGISHI TAKASHI C O YAZAKI P, INABA, SHIGEMITSU, C/O YAZAKI PARTS CO. LTD., MURAOKA, KAUNIHIKO, C/O FUJI JUKOGYO KABUSHIKI K., NAKAZATO, WATARU, C/O FUJI JUKOGYO KABUSHIKI K., OHTAKA, KAZUTO, C/O YAZAKI PARTS CO. LTD., TAKAGISHI, TAKASHI, C/O YAZAKI PARTS CO. LTD.
Applicants: FUJI HEAVY IND LTD, YAZAKI CORP, FUJI JUKOGYO KABUSHIKI KAISHA, YAZAKI CORPORATION
Application year: 1990
Main classification: H01R13
IPC codes: G01R31, H01R13, A47G9