Connector locking mechanism

Abstract: A device for locking a pair of connectors to each other, in which a locking unit which is attached to the housing of one of the connectors in a pivotable manner, and is biased by a spring in a direction tending to unlock the connectors from each other. The locking unit includes a pair of support portions and a plate spring engagement portion. Support members are provided on the housing for receiving the support portion and a plate spring is resiliently disposed between the engagement portion and the housing.

Description: Background of the Invention 1. Field of the Invention : The present invention relates to a mechanism for locking a pair of mating connectors together so that when the connectors are mated to each other, the pair is redundantly prevented from separating. 2. Description of the Prior Art : Fig. 14 illustrates a conventional device for preventing connectors attached to an electric connecting box and a wire harness respectively from being connected erroneously. In such a device, a plurality of fitting portions 102₁, 102₂, 102₃,..., each having a unique and independent shape, are provided on insulated box 101 of the electric connecting box A. A plurality of connectors 104₁, 104₂, 104₃,..., each corresponding to the respective fitting portions 102₁, 102₂, 102₃,..., are provided on an end portion of harnesses 103, respectively. Thereby, connectors 104₁, 104₂, 104₃,..., are prevented from being erroneously connected to respective fitting portions 102₁, 102₂, 102₃,.... In order to maintain a connected status between connectors 104 and fitting portions 102, locking arm 105 having projection 106 is provided on connector 104. In addition, connecting portion 107 operatively engages with projection 106 when connectors 104 are connected to fitting portions 102. In the above-mentioned conventional electric connecting box, confirmation of a connected status between connector 104 and fitting portion 102 is obtained through visual inspection by the person assembling the device as well as by the click sound being generated by the engagement of projection 106 with connecting portion 107. However, the entire connecting operation is conducted manually. Accordingly, human error can cause an incomplete connection and locking to be overlooked. It is desirable to eliminate the possibility of such an error, especially in a circuit directly relating to a person's life such as an air bag mechanism, or the like. From US-A-4,941,839 corresponding to the precharacterizing part of claim 1 a locking device is known for securing a pair of connectors in engagement with each other. Two support portions are formed in a housing. A locking unit is pivotally connected to said support portions and is engageable with another of the connectors. The locking unit can be pivoted to a first position, where the connectors are interengaged with each other and can be pivoted to a second position, where the locking unit is disengaged from the other connector. A coil spring is provided between the housing and the locking unit so that the locking unit is biased in the second position. Summary of the Invention It is an object of the present invention to provide an electric connecting box having a mechanism for preventing erroneous connections. Accordingly, it is an object of the present invention to provide a mechanism for locking a pair of connectors to each other wherein it is simple to attach the locking unit of the mechanism to the housing of one of the connectors. The locking unit is attached to the housing so as to be pivotable and is biased by a spring in a direction tending to unlock the connectors from each other. This object is solved by a locking device for securing a pair of connectors in engagement with each other, comprising: at least one support portion formed in a housing of one of the connectors; a locking unit pivotally connected to said support portion, said locking unit being engaged with the other of the connectors, when said locking unit is pivoted to a first position so as to lock said connectors into engagement with each other, said locking unit being disengaged from said another connector, when said locking unit is pivoted to a second position; and a spring resiliently disposed between said housing and the portion of said locking unit so as to bias said locking unit into said second position. In a first embodiment said locking device is characterized in that said spring is a plate spring; said locking unit has a pair of flexible support portions, each having a short column; said columns being engaged with pivot holes in said support plate; and an insert plate is formed on one of said housing and said locking unit and a groove is provided on the other of said housing and said locking unit, said groove being adapted to receive said insert plate so as to prevent relative lateral movement between said locking unit and said housing. In a second embodiment, the locking device is characterized in that said support portion has an engagement opening formed thereon; said locking unit has at least one engagement projection formed thereon, said engagement projection being adapted for operative engagement with said engagement opening so as to pivotally support said locking unit on said housing; said spring is a plate spring; and said housing is secured to a connection box having a aperture proximate each of said support portions, and a retaining member is adapted for insertion into each of said apertures so as to maintain operative engagement between said engagement projections and said engagement opening. The nature, principle and utility of the present invention will become apparent from the following detailed description of its operation and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is an exploded view of a connector locking mechanism of the first embodiment of the present invention; FIGURES 2(a), 2(b) and 2(c) are views of the first preferred embodiment illustrating how to attach the plate spring thereof; FIGURE 3 is a perspective view of the first preferred embodiment illustrating how to attach the locking unit thereof; FIGURE 4 is a cross-sectional view of the first preferred embodiment illustrating how to lock connectors; FIGURE 5 is a perspective view of the first preferred embodiment when the connectors are locked to each other; FIGURE 6 is a perspective view of a connector locking mechanism which is a modification of the first preferred embodiment; FIGURE 7 is a partial side view of a connector locking mechanism of another modification of the first preferred embodiment; FIGURE 8 is a perspective exploded view of a connector locking mechanism which is a second preferred embodiment of the present invention; FIGURE 9(a) is a partial side view of the second embodiment shown in FIGURE 8, illustrating how to engage the pivots in pivot support plates; FIGURE 9(b) is a partial side view of the second embodiment shown in FIGURE 8, illustrating how to fit the anti-disengagement members on the pivot support plates; FIGURE 10(a) is a perspective view of a connector locking mechanism which is a modification of the second preferred embodiment; FIGURE 10(b) is a partial side view of the modification shown in FIGURE 10(a); FIGURE 11 is a perspective view of a connector locking mechanism which is a modification of the second preferred embodiment; FIGURE 12 is an exploded view of a related connector locking mechanism; FIGURES 13(a) and 13(b) are partial side views of a connector illustrating how to lock the connectors; and FIGURE 14 is an exploded view of a conventional connector locking mechanism. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGURE 12 is an exploded view of a related device for locking a pair of connectors to each other (NOT PRIOR ART). FIGURES 13(a) and 13(b) are side views of this device illustrating the operation thereof. The device includes pivot support members 55, locking unit 56, helical spring 57, and pivot pin 59, as shown in FIGURE 12. Housing 53 of one of the connectors is provided on electric connection box 52. Pivot support members 55 are provided on wall 54 of housing 53. Locking unit 56 is pivotally supported by pivot pin 59 and pivot support members 55, so as to be rotatable about pin 59, and is biased by helical spring 57 in direction A so as to tend to unlock the connectors from each other. Upon assembly, helical spring 57 is placed between support members 58 and pivot pin 59 is then fed through pin holes 60 of pivot support member 55, holes 61 of support members 58 and spring 57. Locking unit 56 has engagement members 63 provided at both ends of the unit so as to be engaged with engagement projections 62 of the housing 53. Locking plate 65 is provided at the top of the unit so as to be engaged on the other connector 64 as shown in FIGURE 13(b). To lock the connectors to each other, connector 64 is fitted in housing 53 and locking unit 56 is pivoted so that locking plate 65 is engaged on overhangs 66 of connector 64, thus preventing connector 64 from separating from housing 53, as shown in FIGURES 13(a) and 13(b). Since engagement projection 67 of connector 64 is engaged with housing 53 and locking plate 65 is engaged with overhangs 66 of connector 64, both the connectors are redundantly engaged with each other and thus locked in a connected position. However, it is time-consuming and troublesome to attach locking unit 56 to housing 53, because it is necessary to set helical spring 57 and align pin holes 60 and 61 of pivot support members 55 and support members 58. Thus, assembly of this type of connector is difficult. Embodiments of the present invention are hereafter described in detail with reference to the drawings attached hereto. FIGURES. 1, 2(a), 2(b), 2(c), 3, 4 and 5 show the first preferred embodiment of the present invention. The device includes a pair of support plates 5, reinforcing insert plate 6, engagement projections 10, locking unit 11, and plate spring 23. Housing 3 of one of the connectors is integrally provided on main surface 2 of electric connection box 1 made of a synthetic resin, or the like. Support plates 5 are provided on main surface 2 of box 1 and front 4 of connector housing 3. Reinforcing insert plate 6 is provided on main surface 2 of box 1 and front 4 of the connector housing 3 at a position between support plates 5. Each of support plates 5 has groove 7 extending in an inner side 5a of each support plate 5 from the top thereof to an intermediate portion thereof. Pivot hole 8 is located at the bottom of groove 7 so as to serve for pivotal coupling of locking unit 11. Engagement projections 10 are provided on both sides 9 of connector housing 3. Locking unit 11 is thus pivotally coupled to housing 3. Locking unit 11 includes body 12, a pair of flexible support portions 13, a pair of short columns 15, fitting groove 16, locking plate 17, a pair of flexible engagement portions 18, and plate spring engagement portion 20. Flexible support portions 13 are provided on each of sides 14 of body 12. Each of support portions 13 has base part 13a on side 14, and flexible part 13b extended down from base part 13a. Short columns 15 are provided as pivotal coupling parts on the outer sides of the flexible parts 13b of and have lower oblique surfaces 15a so that the cross-sectional area of each of columns 15 gradually decreases from base part 13a toward the tip thereof. Thus, the insertion ease of column 15 is improved. Fitting groove 16 is provided in the lower portion of body 12 so that reinforcing insert plate 6 is accommodated therein. Flexible engagement portions 18 are provided at both ends of locking plate 17 so as to engage with engagement projections 10 on connector housing 3 when mating connector 33, shown in FIGURES 4 and 5, is engaged with locking plate 17. Spring engagement portion 20 is provided at front portion 19 of body 12, and has a pair of guide walls 21 parallel with the front portion 19, insertion slit 20a, between front portion 19 and guide walls 21, and engagement projection 22 provided on front portion 19 at a position between guide walls 21. Engagement projection 21 has oblique surface 22a on the top and both sides projection and flat surface 22b on the bottom thereof so that the cross-sectional area of engagement projection 21 gradually decreases from the base thereof toward the tip thereof. Tip portion 24 of plate spring 23 is shaped as a J and is inserted into insertion slit 20a of plate spring engagement portion 20 and is fixedly engaged therein. Tip portion 24 has engagement hole 25, opening 26, nicks 27, and clearance hole 28, for accommodating insert plate 6. Engagement projection 22 is fitted in engagement hole 25. Opening 26 extends from engagement hole 25 in the direction of the insertion of tip portion 24. Nicks 27 are provided at the outer end of opening 25 so that nicks 27 diverge outward. Fitting plate spring 23 in plate spring engagement portion 20 will now be described in detail with reference to FIGURES 2(a), 2(b) and 2(c). Tip portion 24 of spring 23 is inserted into insertion slit 20a of engagement portion 20, as shown in FIGURE 2(a). As a result, the width of opening 26 is increased, and edges 29 of tip portion 24, which extend along the opening, move up onto engagement projection 22, as shown in FIGURE 2(b). Subsequently, engagement projection 22 is fitted in engagement hole 25, the edges extending along opening 20 return to their original positions, and edges 25a of tip portion 24, which extend on the top of engagement hole 25 as shown in FIGURE 2(a), are engaged with flat surface 22b of engagement projection 22, as shown in FIGURE 2(c). FIGURE 3 shows the rear of locking unit 11. Body 12 of locking unit 11 has slope 31 at rear portion 30 so that flexible support portions 13 can be easily fitted in support plates 5 by pushing on slope 31 with jig rod 32, or the like. The angle α of the obliqueness of slope 31 is appropriately set to prevent engagement portions 18 from interfering with engagement projections 10 when flexible support portions 13 are fitted in support plates 5 by pushing on slope 31 with jig rod 32. At this time, oblique surfaces 15a of columns 15 face downward to ease fitting of columns 15 in grooves 7 of support plates 5. At the same time, flexible support portions 13 are flexed inward so that columns 15 are slid and fitted into pivot holes 8 of support plates 5. FIGURE 4 illustrates locking unit 11 after attachment to connector housing 3. Spring plate 23 is engaged at one end thereof in locking unit 11 and disposed at the other end thereof in contact with front portion 4 of connector housing 3 so as to bias locking unit 11 in a direction A tending to unlock the housing 3 and mating connector 33. After mating connector 33 is inserted into housing 3 of the other connector so as to engage projections 35 and 36 with each other, locking unit 11 is pivoted in direction B so as to engage locking plate 17 on front surface 34 of connector 33. As a result, housing 3 and mating connector 33 are locked to each other, as illustrated in FIGURE 5. Even if an external force thereafter acts to locking unit 11 in a longitudinal direction C thereof, reinforcing insert plate 6 keeps locking unit 11 from being moved laterally so as to undesirably disengage from the support plates 5. FIGURE 6 illustrates a modification of the first embodiment described above. Reinforcing insert plate 6′ is provided on locking unit 11, and fitting hole 16′ is provided in electric connection box 1. When locking unit 11 is installed, as described above, on connector 3′, insert plate 6′ fits into fitting hole 16′ so as to increase resistance to lateral movement by locking unit 11. FIGURE 7 shows a mechanism which is another modification of the embodiment described above. Plate spring engagement projection 22′ is provided on rear 30′ of locking unit 11, and a plate spring 23′ is resiliently disposed between the rear of the unit and connector housing 3′. This modification insures that plate spring 23′ is positively secured. FIGURES 8, 9(a) and 9(b) illustrate a second preferred embodiment of the invention. The second embodiment includes a pair of pivot support plates 42, a pair of rectangular holes 44, a pair of anti-disengagement rectangular members 45, locking unit 46, and a plate spring not shown in the drawings. Housing 40 of one of the connectors is provided on main surface 39 of an electric connection box in which bus bar circuit boards 38 are housed. Pivot support plates 42 are provided on main surface 39 of box 37 and front 41 of connector housing 40. Each of support plates 42 has engagement opening 43 extending obliquely downward from front end 42a of plate 42. Engagement openings 43 are shaped substantially as a J. Main surface 39 of box 37 has rectangular holes 44 adjacent to front ends 42a of support plates 42. Anti-disengagement rectangular members 45 are set up on upper circuit board 38 and inserted up into rectangular holes 44 so that pivots 48 of locking unit 46, which are provided at outer sides 47 of other portions of the unit, are prevented from moving out of engagement openings 43 of support plates 42. Locking unit 46 is attached to connector housing 40. Pivots 48 are put into engagement openings 43 of support plates 42 (as shown by the arrow in FIGURE 9(a)), and are then fitted in inner end portions 49 of openings 43. When circuit boards 38 are disposed in connection box 37, anti-disengagement members 45 on the upper circuit board are inserted into rectangular holes 44 of connection box 37 so as to close the outer ends of engagement openings 43 as shown in FIGURE 9(b). This prevents pivots 48 from moving out of engagement openings 43. FIGURES 10(a) and 10(b) show a device which is a modification of the second preferred embodiment. In the modification shown in FIGURES 10(a) and 10(b), rectangular holes 44′ are provided in an electric connecting box adjacent to outer sides 42a′ of pivot support plates 42, and anti-disengagement rectangular members 45′ are inserted into rectangular holes 44′ and placed in contact with pivots 48 fitted in inner end portions 49′ of engagement openings 43 of pivot support plates 42. This arrangement also insures that pivots 48 will not move out of end portions 49. FIGURE 11 shows a mechanism which is another modification of the second embodiment. An anti-disengagement member 51 having a pair of engagement hooks 50 is provided so that the hooks are fitted in rectangular holes 44″. This is yet another arrangement that insures that pivots 48 are secured in end portions 49.

Claims: A locking device for securing a pair of connectors in engagement with each other, comprising: at least one support portion (5) formed on a housing (3;3′) of one (1) of the connectors (1,33); a locking unit (11,11′) pivotally connected to said support portion (5), said locking unit (11;11′) being engaged with the other (33) of the connectors (1,33), when said locking unit (11;11′) is pivoted to a first position so as to lock said connectors into engagement with each other, said locking unit (11;11′) being disengaged from said another connector, when said locking unit (11;11′) is pivoted to a second position; and a spring (23;23′), resiliently disposed between said housing (3;3′) and the portion of said locking unit (11;11′) so as to bias said locking unit (11;11′) into said second position characterized in that said spring (23;23′) is a plate spring; said locking unit (11;11′) has a pair of flexible support portions (13), each having a short column (15); said columns (15) being engaged with pivot holes (8) in said support plates (5); and an insert plate (6;6′) is formed on one of said housing (3;3′) and said locking unit (11;11′) and a groove (16;16′) is provided on the other of said housing (3;3′) and said locking unit (11,11′), said groove (16;16′) being adapted to receive said insert plate (6;6′) so as to prevent relative lateral movement between said locking unit (11;11′) and said housing (3;3′). A locking device for securing a pair of connectors in engagement with each other, comprising; at least one support portion (42) formed on a housing (40) of one of the connectors; a locking unit (11) pivotally connected to said support portion (42), said locking unit (46) being engaged with the other of the connectors, when said locking unit (46) is pivoted to a first position, so as to lock said connectors into engagement with each other, said locking unit (46) being disengaged from the other connector when said locking unit (46) is pivoted to a second position; and a spring (23;23′), resiliently disposed between said housing (40) and a portion of said locking unit (46) so as to bias said locking unit (46) into said second position characterized in that said support portion (42) having an engagement opening (43) formed thereon; said locking unit (46) having at least one engagement projection (48) formed thereon, said engagement projection (48) being adapted for operative engagement with said engagement opening (43) so as to pivotally support said locking unit (46) on said housing (40); said spring (23;23′) is a plate spring; and said housing (46) is secured to a connection box having an aperture (44;44′;44″) proximate each of said support portions (42), and a retaining member (45;45′;51) is adapted for insertion into each of said apertures (44;44′;44′′) so as to maintain operative engagement between said engagement projections (48) and said engagement opening (43). A locking device as claimed in claim 1 or 2 further comprising: means (20) for securing an end portion of said spring (23;23′) to said locking unit (11;11′;46) comprising an insertion slit (20a) and a salient portion (22) formed on said locking unit (11;11′;46), said spring (23;23′) having an opening (26) formed thereon at said end portion; said end portion being received in said slit (20a) and said salient portion (22) being received in said opening (26) when the locking device is assembled. A locking device as claimed in any of claims 1 to 3, further comprising: a slope (31) for receiving a jig rod (32) so as to allow said locking unit (11) to be pivotally attached to said housing (3) by a force placed on said slope (31) by said rod (32), said force being applied while said locking unit (11) is oriented at an angle associated with said second position.

Inventors: ARAKI MAMORU C O YAZAKI PARTS, SUEHISA TOSHIO C O YAZAKI PART, SUGIYAMA MASAAKI C O YAZAKI PA, ARAKI, MAMORU, C/O YAZAKI PARTS CO., LTD., SUEHISA, TOSHIO, C/O YAZAKI PARTS CO., LTD., SUGIYAMA, MASAAKI, C/O YAZAKI PARTS CO., LTD.
Applicants: YAZAKI CORP, YAZAKI CORPORATION
Application year: 1991
Main classification: H01R13
IPC codes: H01R13