Retainer for electrical connector

Abstract: An electrical connector (10) comprises a housing (12), a plurality of laterally-spaced parallel cavities (13) formed in the housing for receiving terminals, and a retainer (20) for holding the terminals within the cavities. A respective window (14) joins each of the cavities (13) to the exterior of the housing (12), the windows being positioned within a housing face overlying the cavities. The retainer (20) has a base (21), a pair of arms (22) extending away from the ends of the base, and a plurality of claws (23) positioned between the arms and extending away from the base in a given direction. The retainer (20) is such that, in use, its base (21) overlies said housing face, its arms (22) clamp a pair of housing faces adjacent to said housing face, and the claws (23) are aligned with the windows (14) . The retainer (20) is movable with respect to the housing (12) in a first direction from a first position in which the claws (23) lie outside the windows (14), to a second position, in which the claws have entered the windows. The retainer (20) and the housing (12) are provided with interengageagble locking means (24,25 and 17,18) for resisting movement of the retainer from the second position to the first position in a direction opposed to the first direction.

Description: Background of the Invention 1. Field of the Invention This invention relates to an electrical connector, and in particular to a connector having a C-shaped retainer. 2. Prior Art A conventional electrical connector has a retainer with arms projecting from both extremities of a base, the retainer being supported by inserting its arms into the housing of the connector. Interengageable means, that also serve as a guide, are formed on the arms and on the side faces of the housing. The retainer can be fixed at a fully-fitted position, where retainer claws come to rest after entering terminal fitting insertion chambers; and at an intermediate position, where the retainer claws are withdrawn from the terminal fitting insertion chambers. In the conventional connector described above, the retainer is arranged to be attached by engagement of the interengageable means as the retainer moves from the intermediate position to the fully-fitted position. There is a problem here in that the force which resists movement of the retainer from its intermediate position to its fully-fitted position is weak. Moreover, when the retainer is forced to the rear, it rotates, since the force applied is not necessarily parallel with respect to the housing. As a result, the arms tend to rise, and the force that resists movement to the rear decreases. EP-A-0644620 discloses an electrical connector according to the first part of claim 1 having a retainer with a guide ramp face to guide a terminal into a cavity of the connector housing. Latching means are provided on side arms of the retainer. EP-A-0596707 discloses an electrical connector having a retainer also having latching means on the side arms thereof. US-A-5316504 discloses an electrical connector having a retainer with latching projections formed on side arms of the retainer. The aim of the invention is to provide an electrical connector which resists an easy return to the intermediate position from the fully-fitted position. The present invention provides according to claim 1 an electrical connector comprising a rectangular housing, a plurality of laterally-spaced parallel cavities formed in the housing for receiving terminals, and a retainer for holding the terminals within the cavities, a respective window joining each of the cavities to the exterior of the housing, the windows being positioned within that housing face overlying the cavities, the retainer having a base, a pair of arms extending substantially at right angles from the ends of the base and in the same direction, and a plurality of claws positioned between the arms and extending away from the base in a given direction, the retainer being such that, in use, its base overlies said housing face, its arms clamp opposite housing faces adjacent to said housing face, and its claws are aligned with the windows, the retainer being movable with respect to the housing in a first direction from a first position in which the claws lie outside the windows, to a second position in which the claws have entered the windows, wherein the retainer and the housing are provided with interengageable locking means for resisting movement of the retainer from the second position to the first position in a direction opposed to the first direction, characterized in that said locking means is constituted by projections of the base which, in use, mate with cut-outs formed in the housing. When the retainer is subjected to a rotational force applied at its front, those portions of the retainer adjacent to the arms at the rear of the base try to move in response. However, the engagement of the locking means on the retainer base and on the housing prevent this movement. Additionally, or alternatively, said locking means includes according to claim 1 a laterally-extending slot which, in use, mates with one or more laterally-extending locking projections formed in the housing. In this case, the interengaging locking means on the retainer and the housing can extend over a substantial proportion of the width of the connector, thereby increasing the resistance to movement of the retainer in relation to the housing. In a preferred embodiment, the locking means of the or each retainer is constituted by locking devices positioned at the ends of the base of that retainer and at regions of that base remote from the free ends of the claws. The housing may have retainers on opposite sides thereof to retain terminals in parallel rows of cavities. Preferably the free ends of the arms of the or each retainer define inclined end surfaces which are slidingly engageable with complementary inclined surfaces formed on the housing. Brief Description of the Drawings The invention will now be described in greater detail, by way of example, with reference to the drawings, in which:- Figure 1 is an exploded perspective view of a male connector constructed in accordance with the invention; Figure 2 is a perspective view of the connector of Figure 1 with its retainer in an intermediate position; Figure 3 is a perspective view of the connector of Figure 1 with its retainer in a fully-fitted position; Figure 4 is an exploded perspective view of a female connector constructed in accordance with the invention; Figure 5 is a perspective view of the connector of Figure 4 with its retainer in an intermediate position; and Figure 6 is a perspective view of the connector of Figure 4 with its retainer in a fully-fitted position. Description of Preferred Embodiments Referring to the drawings, Figure 1 shows a male connector 10 having a housing 12 formed with a hood 11 at its front end. The housing 12 is formed with a plurality of parallel, horizontal cavities 13 which are located in upper and lower rows. Each cavity 13 has a window 14 that opens out, either towards the upper face or the lower face of the housing 12 depending upon whether that cavity is in the upper or lower row. These upper and lower faces define retainer attachment faces 15a and 15b for attaching a two-part retainer 20 (20a and 20b). The upper face of the housing 12 is formed with a central recess 16, the upper retainer attachment face 15a being positioned on either side of this recess. The retainer member 20a has a laterally-extending base 21 which, in use, covers the upper face of the rear end of the housing 12. Similarly, the retainer member 20b has a base 21 for covering the lower face of the rear end of the housing 12. Arms 22 extend substantially at right-angles from both ends of each base 21, so that each retainer member 20a and 20b is generally C-shaped in cross-section. The arms of each retainer member 20a and 20b clamp, in use, the side faces of the housing 12 from both sides. The upper and lower faces of the housing 12 are formed with inclined edge portions which, in use, engage with inclined end surfaces of the arms 22 of the retainer members 20a and 20b to permit the retainer members to slide onto the housing 12, from the rear, into either an intermediate position or a fully-fitted position (to be described below). As each retainer member 20a and 20b approaches, or moves away from, its fully-fitted position (shown in Figure 3), claws 23 formed on its front end move into, or out of, the cavities 13 via the windows 14. In other words, the retainer claws 23 gradually enter the cavities 13 as they move from the rear ends of the windows to the front ends thereof. In the intermediate position (see Figure 2), the claws 23 are free of the cavities 13. A respective terminal fitting (not shown) is insertable into each of the cavities 13 from an opening located at the rear end thereof. Once the retainer members 20a and 20b are slid to the front end of the housing 12, the retainer claws 23 enter the cavities 13 via the windows 14 and make contact with respective inclined stop members (not shown) thereby doubly stopping it. The retainer attachment faces 15a, 15b are formed with cut-outs 17 in positions which are adjacent to the roots of the arms 22 when the retainer members 20a and 20b move to their fully-fitted positions, the roots of the arms constituting the rear ends of the bases 21 of the retainer members. The retainer members 20a and 20b, are formed with projections 24 that, in use, mate with the cut-outs 17. Alternatively, the cut-outs 17 could be formed on the retainer members 20a and 20b and the projections 24 could be formed on the retainer attachment faces 15a, 15b. Either way, the projections 24 will mate with the cut-outs 17 when an attempt is made to move the retainer members 20a and 20b to the rear, thereby inhibiting such a movement. The retainer attachment face 15a is also formed with projections 18 which extend laterally away from the central recess 16. These projections 18 are aligned with the base 21 of the retainer member 20a when the latter moves into the fully-fitted position, the projections 18 mating with a laterally-extending slot 25 formed in the retainer member 20a in this position. Similarly, the retainer attachment face 15b is formed with a laterally-extending projection 18 (not shown) which mates with a laterally-extending slot 25 formed in the base 21 of the retainer member 20b. Alternatively, other means for controlling rotation of the retainer members 20a and 20b relative to the housing 12 could be provided in place of the laterally-extending projections 18 and slots 25. In use, the retainer members 20a and 20b are fixed in the intermediate position shown in Figure 2, by attaching these to the retainer attachment faces 15a and 15b of the housing 12. At this juncture, the projections 24 of the retainer members 20a and 20b have not entered the cut-outs 17 of the housing 12. Moveover, the projections 18 of the housing 12 have not entered the slots 25 of the retainer members 20a and 20b. When the retainer members 20a and 20b are moved to the fully-fitted position shown in Figure 3, from the intermediate position, the retainer claws 23 enter the windows 14 and doubly stop the terminal fittings inside. At the same time, the projections 24 of the retainer members 20a and 20b enter and mate with the cut-outs 17 of the housing 12. Moreover, the projections 18 of the housing 12 enter and mate with the slots 25 of the retainer members 20a and 20b. Now, assume that a force is applied which tends to return the retainer members 20a and 20b to the intermediate position. As described earlier, if an equal force is applied to the left and right sides of the retainer members 20a and 20b, this force is counteracted by the interengagement of the arms 22 and the housing 12. However, if unequal forces are applied to these sides, the retainer members 20a and 20b tend to tilt. As the retainer members 20a and 20b begin to rotate, the mating engagement of the projections 24 and the cut-outs 17 prevents rotation of the retainer members, and also prevent them from returning to the intermediate position. Moreover, the mating engagement of the projections 18 and the slots 25 of the retainer members 20a and 20b, also counteracts the rotational force, further resisting return to the intermediate position. In this way, the portions of the arms 22 constituting the rear ends of the bases 21 of the retainer members 20a and 20b, and the portions of the housing 12 facing said portions define interengageable means constituted by the projections 24 and the cut-outs members 17 respectively. This provides a counteracting force against any rotational force applied to the retainer members 20a and 20b and thereby holds these members in their fully-fitted positions. Moreover, each of the retainer members 20a and 20b is similarly prevented from rotating, and is maintained in the fully-fitted position since the projections 18 engage the slots 25 of the retainer members. In other words, any force tending to rotate the retainer members 20a and 20b is efficiently counteracted, thereby preventing rotation of these members. As a result, movement towards the intermediate position is prevented. Figure 4 shows a female connector 30 having a housing 32 which is insertable into the hood 11 of the male connector 10 from the front thereof. The housing 32 is formed with a plurality of parallel, horizontal cavities 33 which are located in upper and lower rows. Each cavity 33 has a window 34 that opens out, either towards the upper face or the lower face of the housing 32 depending upon whether that cavity is in the upper or lower row. The upper and lower faces define retainer attachment faces 35a, 35b for attaching a two-part retainer 40 (40a and 40b). A flexible locking arm 36 is formed on the upper side of the central portion of the housing 32, the locking arm being provided between the cavities 33 of the upper row, and the retainer attachment face 35a on the upper face of the housing being positioned on either side of the locking arm. The retainer member 40a is formed with a laterally-extending base 41 which, in use, covers the upper face of the rear end of the housing 32. Similarly, the retainer member 40b has a base 41 for covering the lower face of the rear end of the housing 32. Arms 42 extend substantially at right-angles from both ends of each base 41, so that each retainer member 40a and 40b is generally C-shaped in cross-section. The arms 42 of each retainer member 40a and 40b clamp, in use, the side faces of the housing 32 from both sides. The upper and lower faces of the housing 32 are formed with inclined edge portions which, in use, engage with inclined end surfaces of the arms 42 to permit the retainer members 40a and 40b to slide onto the housing 32 from the rear, into either an intermediate position or a fully-fitted position (to be described below). As each retainer member 40a and 40b approaches, or moves away from, its fully-fitted position (shown in Figure 6), claws 43 formed on its front end move into, or out of, the cavities 33 via the windows 34. In the intermediate position (shown in Figure 5), the claws 43 are free of the cavities 33. The retainer attachment faces 35a and 35b are formed with cut-outs 37 in positions which are adjacent to the roots of the arms 42 when the retainer members 40 and 40b move to their fully-fitted positions, the roots of the arms constituting the rear ends of the bases 41 of the retainer members. The retainer members 40a and 40b are formed with projections 44 that in use, mate with the cut-outs 37. Alternatively, the cut-outs 37 could be formed in the retainer members 40a and 40b, and the projections 44 could be formed on the retainer attachment faces 35a, 35b. Either way, the projections 44 mate with the cut-outs 37 when an attempt is made to move the retainer members 40a and 40b to the rear, thereby inhibiting such a movement. The retainer attachment face 35a is also formed with projections 38 which extend laterally away from the central locking arm 36. These projections 38 are aligned with the base 41 of the retainer member 40a when the latter is in the fully-fitted position (see Figure 6), the projections mating with a laterally-extending slot 45 formed in the base 41 of the retainer member 40a in this position. Similarly, the retainer attachment face 35b is formed with a central, laterally-extending projection 38 (not shown) which mates with a laterally-extending slot 45 formed in the base 41 of the retainer member 40b. Alternatively, other means for controlling rotation of the retainer members 40a and 40b relative to the housing 32 could be provided in place of the projections 38 and slots 45. Operation of the female connector 30 is essentially the same as that of the male connector 10. Thus, in the fully-fitted position shown in Figure 6, the projections 44 formed on the retainer members 40a and 40b fit into the cut-outs 37 of the housing 32; and the projections 38 formed on the housing 32 mate with the slots 45 of the retainer members. This counteracts any rotational force, thereby preventing the retainer members 40a and 40b from returning to the intermediate position shown in Figure 5.

Claims: An electrical connector (10,30) comprising a rectangular housing (12,32), a plurality of laterally-spaced parallel cavities (13,33) formed in the housing for receiving terminals, and a retainer (20,40) for holding the terminals within the cavities, a respective window (14,34) joining each of the cavities to the exterior of the housing, the windows being positioned within that housing face overlying the cavities, the retainer having a base (21,41), a pair of arms (22,42) extending substantially at right angles from the ends of the base and in the same direction, and a plurality of claws (23,43) positioned between the arms and extending away from the base in a given direction, the retainer being such that, in use, its base overlies said housing face, its arms clamp opposite housing faces adjacent to said housing face, and its claws are aligned with the windows, the retainer being movable with respect to the housing in a first direction from a first position in which the claws lie outside the windows, to a second position in which the claws have entered the windows, wherein the retainer and the housing are provided with interengageable locking means (24,25; 44,45; 17,18; 37,38) for resisting movement of the retainer from the second position to the first position in a direction opposed to the first direction, characterized in that said locking means (24,44) is constituted by projections of the base (24,44) which, in use, mate with cut-outs (17,37) formed in the housing (12,32), and or in that said locking means includes a laterally-extending slot (25,45) of a retainer (20,40) which, in use, mates with one or more laterally-extending locking projections (18,38) formed on the housing (12,32). An electrical connector as claimed in claim 1, wherein a locking means of the retainer (20,40) is positioned at the ends of the base (21,41) and at regions of said base remote from the free ends of the claws (23,43). An electrical connector as claimed in any one of claims 1 to 2, wherein the free ends of said arms (22,42) define inclined end surfaces which are slidingly engageable with complementary inclined surfaces formed on the housing (12,32). An electrical connector according to any preceding claim wherein said housing (12,32) includes first and second rows of cavities (13,33) and respective first and second windows (14,34) joining said cavities to opposite faces of said housing, one of said retainers being provided for each of said opposite faces of said housing.

Inventors: OKADA NAOHISA, OKADA, NAOHISA, Okada, Naohisa, c/o Sumitomo Wiring Sys., Ltd.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1996
Main classification: H01R13
IPC codes: H01R13