Connector provided with a retainer

Abstract: [Object] To improve operability during the insertion of a retainer and a function of locking terminal fittings when the retainer is in its full locking position. [Solution] In a connector having a retainer 13 which is insertable through one side surface of a housing 11 and provided with forked locking arms, the width and/or thickness of partial locking arms 13a are set smaller than those of full locking arms 13b to thereby set the elastic forces of the partial locking arms 13a smaller than those of the full locking arms 13b.

Description: The present invention relates to a connector and is particularly designed to improve operability and functionability when a retainer for locking terminal fitting(s) is held in its partial locking position and full locking position. A known connector provided with a retainer is, as shown in FIG. 6, such that a retainer 3 is inserted through one side surface of a housing 1 in order to prevent a terminal fitting 2, which has been inserted into a cavity 1a formed in the housing 1 from a rear end portion of the housing 1, from moving in its withdrawing direction. Partial and full locking arm 3a and 3b which are fork-shaped project from the retainer 3. By engaging locking projections 3c, 3d projecting outward from the leading ends of the partial and full locking arms 3a, 3b with locking steps 1c, 1d formed on inner walls of a retainer insertion portion 1b, the retainer 3 can be held in two positions: a partial locking position 4 and a full locking position 5 (position in phantom line in FIG. 7). In the partial locking position 4 where the retainer 3 is not yet fully inserted, the retainer 3 does not interfere the insertion of the terminal fitting 2 into the cavity 1a as indicated in solid line in FIG. 6. On the other hand, in the full locking position 5 where the retainer 3 is fully inserted, a part of the retainer 3 is engaged with the terminal fitting 2 to prevent the movement of the terminal fitting 2 in its withdrawing direction as indicated in phantom line in FIG. 6. During the insertion of the retainer 3 to the partial locking position 4, the partial locking arm 3a is deflected inwardly when the locking projection 3c moves over the partial locking step 1c, with the result that the retainer 3 reaches the partial locking position 4. Here, the retainer 3 is positioned by the contact of the locking projection 3d of the full locking arm 3b with the lower surface of the full locking step 1d. Similarly, the retainer 3 reaches the full locking position 5 after the full locking arm 3b is deflected inward. In inserting the retainer 3, it is desirable to push the retainer 3 with a small force before reaching the partial locking position 4 and to stably hold the retainer 3 in the partial locking position thereafter. This is because the retainer 3 may be pushed straight to the full locking position 5 if an attempt is made to insert the retainer 3 to the partial locking position 4 with a strong force. In this case, the retainer 3 needs to be pulled back using a jig or like device, requiring extra time and labor. On the other hand, an external matter may strike against the retainer 3 during transportation or the like after the retainer 3 has reached the partial locking position 4 and before the terminal fittings 2 are inserted. Thus, it is an object of the present invention to provide a connector having an improved operability. This object is solved according to the invention by a connector according to claim 1. Preferred embodiments are subject of the dependent claims. According to the invention, there is provided a connector, comprising: a housing provided with one or more cavities for at least partly accommodating at least one terminal fitting to be inserted through a rear end portion of the housing, and a retainer which is partly insertable into the cavities through a retainer insertion portion and can be held in a partial locking position where the retainer permits the insertion and withdrawal of the at least one terminal fitting and in a full locking position where the retainer substantially engages the inserted at least one terminal fitting to prevent the movement thereof in a withdrawing direction, wherein one or more partial locking arms and one or more full locking arms project from the retainer, and locking steps for the partial and full locking arms to hold the retainer in the partial locking position and in the full locking position, respectively, are formed on inner walls of the retainer insertion portion, and wherein the width and/or thickness of the partial locking arms are set smaller than those of the full locking arms to thereby set the elastic forces of the partial locking arms smaller than those of the full locking arms. Accordingly, the retainer is pushed to the partial locking position with a smaller force, whereas it is pushed from the partial locking position to the full locking position with a larger force. This prevents the retainer from being inadvertently pushed straight to the full locking position when being pushed to the partial locking position. Simultaneously, the retainer may also be prevented from inadvertently falling while being in the partial locking position, before the terminal fittings are inserted. When the retainer is pushed to the full locking position, an operator preferably can properly feel the retainer having reached the full locking position and the retainer can stably keep locking the terminal fittings in its full locking position. Thus, operability during the insertion of the retainer and a function of locking the terminal fittings can be improved. According to a preferred embodiment, a pair of partial and full locking arms project from each of the substantially opposite sides of the retainer. Thus the retainer can be securely positioned in its partial and full lock positions. Preferably, the one or more partial locking arms and the one or more full locking arms are fork-shaped and arranged along forward and backward directions of the retainer. Further preferably, the locking steps engage one or more partial locking projections and one or more full locking projections projecting preferably outward from the partial and full locking arms, respectively, to hold the retainer in the partial locking position and in the full locking position, respectively. Thus the locking arms have a simple but effective construction. Most preferably, the one or more partial locking projections are engageable with the corresponding locking steps after the partial locking arms are deflected preferably inwardly, when the retainer is pushed to the partial locking position, and the one or more full locking projections are engageable with the corresponding locking steps after the full locking arms are deflected preferably inwardly, when the retainer is pushed from the partial locking position to the full locking position. According to a further preferred embodiment, there is provided a connector, comprising: a housing provided with cavities for accommodating at least one terminal fitting to be inserted through a rear end of the housing, and a retainer which is partly insertable into cavities through a retainer insertion portion, which is open in one side surface of the housing, and can be held in a partial locking position where the retainer permits the insertion and withdrawal of the at least one terminal fitting and in a full locking position where the retainer engages the inserted at least one terminal fitting to prevent the movement thereof in a withdrawing direction, wherein a pair of partial and full locking arms which are fork-shaped and arranged along forward and backward directions project from each of the opposite sides of the retainer, and locking steps for engaging partial and full locking projections projecting outward from the partial and full locking arms to hold the retainer in the partial locking position and in the full locking position, respectively, are formed on inner walls of the retainer insertion portion, the partial locking projections being engageable with the corresponding locking steps after the partial locking arms are deflected inwardly when the retainer is pushed to the partial locking position and the full locking projections being engageable with the corresponding locking steps after the full locking arms are deflected inwardly when the retainer is pushed from the partial locking position to the full locking position, wherein the width and/or thickness of the partial locking arms are set smaller than those of the full locking arms to thereby set the elastic forces of the partial locking arms smaller than those of the full locking arms. With this construction, the retainer can be inserted to the partial locking position with a small force since the elastic forces of the partial locking arms are set smaller than those of the full locking arms and, accordingly, there is no likelihood that the retainer is pushed straight to the full locking position. On the other hand, since the elastic forces of the full locking arms are set larger, it prevents the retainer held in the partial locking position from inadvertently moving to the full locking position by an impact from an external matter. Further, when the retainer is pushed from the partial locking position to the full locking position, an operator can strongly feel the movement of the full locking projections over the locking steps and can securely notice that the retainer has reached the full locking position. Preferably, the lengths of the partial and full locking arms are set substantially equal to each other. The elastic forces of the partial and full locking arms can be differed according to the application even if the lengths thereof are equal to each other. Since the height of the retainer can be set lower if the partial and full locking arms have the same length, it can contribute to making the connector smaller. Further preferably, the retainer insertion portion is substantially open in one side surface of the housing. Most preferably, the full locking arm, preferably its full locking projection is substantially in contact with a receiving surface of the corresponding locking step when the retainer is arranged in the partial locking position. Accordingly, a loose movement of the retainer in its partial lock position can be prevented. These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and accompanying drawings in which: FIG. 1 is an exploded perspective view of a connector according to one embodiment of the present invention, FIG. 2 is a section of the connector when a retainer is inserted, FIGS. 3(A) and 3(B) are sections showing a state where the retainer is located before a partial locking position and a state where the retainer is located in the partial locking position, FIGS. 4(A) and 4(B) are sections showing a state where the retainer is located before a full locking position and a state where the retainer is located in the full locking position, FIG. 5 is an enlarged perspective view showing an essential portion of the retainer, FIG. 6 is a section showing an essential portion of a prior art connector, and FIG. 7 is a section of the prior art connector. Hereinafter, one embodiment of the present invention is described with reference to the accompanying drawings. FIGS. 1 to 5 shows a connector 10 according to this embodiment. The connector 10 is comprised of a housing 11 made e.g. of synthetic resin and a retainer 13 to be mounted in the housing 11. The housing 11 is provided with a plurality of cavities 11a arranged substantially side by side e.g. in two stages for at least partially accommodating terminal fittings 12 to be inserted preferably from a rear portion of the housing 11, and is formed with a substantially rectangular retainer insertion portion 11b. The retainer insertion portion 11b is a recess which is open preferably in one side surface of the housing 11 substantially along the entire transverse direction thereof and extends inward. The retainer 13 has substantially rectangular parallelepipedic lattice-like shape so as to be fitted into the retainer insertion portion 11b and is provided with holding portions 13e which extend along forward and backward directions and substantially communicate with the cavities 11a when being mounted in the retainer insertion portion 11b. A terminal locking projection 13f engageable with a stepped portion 12a of the corresponding terminal fitting 12 projects from each holding portion 13e. A pair of partial and full locking arms 13a, 13b which are preferably fork-shaped and arranged along forward and backward directions and have flexibility project at the opposite sides of the retainer 13. Partial and full locking projections 13c, 13d project outwardly from the leading ends of the partial and full locking arms 13a, 13b, respectively. Slanted guide surfaces 13g, 13h are formed at the leading ends of the partial and full locking projections 13c, 13d, respectively. On the other hand, locking steps 11c, 11d engageable with the partial and full locking projections 13c, 13d project from inner walls of the retainer insertion portion 11b of the housing 11, and slanted guide receiving surfaces 11e, 11f similar to the guide surfaces 13g, 13h of the partial and full locking projections 13c, 13d are formed on the inner wall surfaces to be opposed to the guide surfaces 13g, 13h. As shown in FIGS. 3(A) and 3(B), the locking steps 11c, 11d project in vertically different positions or in positions spaced along the insertion direction ID of he retainer into the retainer insertion portion 11b. When the retainer 13 is inserted to an intermediate position in the retainer insertion portion 11b, the partial locking projections 13c move over the locking steps 11c and, at the substantially same time, the full locking projections 13d come into contact with the other locking steps 11d. This state is referred to as a partial locking position 14. On the other hand, as shown in FIGS. 4(A) and 4(B), when the retainer 13 is further inserted, the full locking projections 13d move over the locking steps 11d and, at the substantially same time, a lid 13i of the retainer 13 preferably comes substantially into contact with an inlet surface 11g of the retainer insertion portion 11b. This state is referred to as a full locking position 15. The partial locking position 14 of the retainer 13 is, as shown in FIG. 2, such a position where the terminal locking projections 13f are substantially retracted from the cavities 11a so as not to interfere the insertion and withdrawal of the terminal fittings 12. The full locking position 15 is such a position where the terminal locking projections 13f are substantially engaged with the stepped portions 12a of the inserted terminal fittings 12 to prevent the terminal fittings 12 from moving in their withdrawing direction. A clearance 13j between the partial and full locking arms 13a and 13b of the retainer 13 has a width necessary for the partial locking arm 13a or the full locking arm 13b to be deflected inwardly when the retainer 13 reaches the partial locking position 14 or the full locking position 15. The widths of the partial and full locking arms 13a, 13b are differed without widening width W of the entire retainer 13 while ensuring the above width of the clearance 13. In other words, width W1 of the partial locking arm 13a is preferably set smaller than width W2 of the full locking arm 13b by locating the clearance 13j toward the partial locking arm 13a, thereby setting the elastic force of the partial locking arm 13a smaller and that of the full locking arm 13b larger. In order to provide this difference in the elastic force, thickness t1 of the partial locking arm 13a may be set smaller than thickness t2 of the full locking arm 13b as shown in FIG. 5. In order to mount the retainer 13 dimensioned as above in the housing 11, the retainer 13 is inserted into the retainer insertion portion 11b from the side of the locking arms 13a, 13b, and the lid 13i is pushed. Then, when the partial locking projections 13c of the partial locking arms 13a move over the locking steps 11c of the retainer insertion portion 11b, the partial locking arms 13a are deflected inwardly and the retainer 13 reaches the partial locking position 14. Since the partial locking arms 13a are narrower and have a smaller elastic force, they can be engaged with the locking steps 11c by a small pushing force. In the partial locking position 14 of FIG. 3(B), the full locking projections 13d are held in contact with the full locking steps 11d before moving over them. Further, since the full locking arms 13b are wider and have a stronger force, it prevents the retainer 13 from being pushed straight to the full locking position 15 when being inserted to the partial locking position 14. Subsequently, the terminal fittings 12 are inserted through the rear portion of the housing 11 with the retainer 13 in its partial locking position 14 and are locked by locking portions L in the cavities 11a (as in the prior art of FIG. 6). If the retainer 13 in its partial locking position 14 is strongly pushed as shown in FIG. 4(A) after the insertion of all terminal fittings 12 is completed, the full locking arms 13b are deflected inwardly while the full locking projections 13d move over the locking steps 11d. Then, as shown in FIG. 4(B), the retainer 13 reaches the full locking position 15 and, at the substantially same time, the lid 13i thereof preferably comes into contact with the inlet surface 11g of the retainer insertion portion 11b and becomes in flush with the side surface of the housing 11 and preferably substantially closes the opening formed by the retainer insertion portion 11b. The retainer 13 is pushed to the full locking position 15 with a stronger force as compared with the force used to push it to the partial locking position 14. Accordingly, an operator can sufficiently feel the movement of the full locking projections 13d over the locking steps 11d due to inertial forces acting during this time and notice that the retainer 13 has reached the full locking position 15 by a clicking sound given out when the lid 13i comes into contact with the inlet surface 11g of the retainer insertion portion 11b. In the full locking position 15, the terminal fittings 12 are substantially locked so as not to come out of the cavities 11a by the engagement of the terminal locking projections 13f and the stepped portions 12a. This state is stably maintained by the enlarged elastic forces of the full locking arms 13b. As is clear from the above description, the retainer is pushed to the partial locking position with a smaller force, whereas it is pushed from the partial locking position to the full locking position with a larger force. This prevents the retainer from being inadvertently pushed straight to the full locking position when being pushed to the partial locking position. Simultaneously, the retainer may also be prevented from inadvertently falling while being in the partial locking position, before the terminal fittings are inserted. When the retainer is pushed to the full locking position, an operator preferably can properly feel the retainer having reached the full locking position and the retainer can stably keep locking the terminal fittings in its full locking position. Thus, operability during the insertion of the retainer and a function of locking the terminal fittings can be improved. LIST OF REFERENCE NUMERALS 11 ... Housing 11a ... Cavity 11b ... Retainer Insertion Portion 11c, 11d ... Locking Step 12 ... Terminal Fitting 13 ... Retainer 13a ... Partial Locking Arm 13b ... Full Locking Arm 13c ... Partial Locking Projection 13d ... Full Locking Projection 14 ... Partial Locking Position 15 ... Full Locking Position

Claims: A connector (10), comprising: a housing (11) provided with one or more cavities (11a) for at least partly accommodating at least one terminal fitting (12) to be inserted through a rear end portion of the housing (11), and a retainer (13) which is partly insertable into the cavities (11a) through a retainer insertion portion (11b) and can be held in a partial locking position (14; FIGS. 2; 3B) where the retainer (13) permits the insertion and withdrawal of the at least one terminal fitting (12) and in a full locking position (15; FIG. 4B) where the retainer (13) substantially engages the inserted at least one terminal fitting (12) to prevent the movement thereof in a withdrawing direction, wherein one or more partial locking arms (13a) and one or more full locking arms (13b) project from the retainer (13), and locking steps (11c, 11d) for the partial and full locking arms (13a, 13b) to hold the retainer (13) in the partial locking position (14; FIGS. 2; 3B) and in the full locking position (15; FIG. 4B), respectively, are formed on inner walls of the retainer insertion portion (11b), and wherein the width (W1) and/or thickness (t1) of the partial locking arms (13a) are set smaller than those (W2; t2) of the full locking arms (13b) to thereby set the elastic forces of the partial locking arms (13a) smaller than those of the full locking arms (13b). A connector according to claim 1, wherein a pair of partial and full locking arms (13a, 13b) project from each of the substantially opposite sides of the retainer (13). A connector according to one or more of the preceding claims, wherein the one or more partial locking arms (13a) and the one or more full locking arms (13b) are fork-shaped and arranged along forward and backward directions of the retainer (13). A connector according to one or more of the preceding claims, wherein the locking steps (11c, 11d) engage one or more partial locking projections (13c) and one or more full locking projections (13d) projecting preferably outward from the partial and full locking arms (13a, 13b), respectively, to hold the retainer (13) in the partial locking position (14; FIGS. 2; 3B) and in the full locking position (15; FIG. 4B), respectively. A connector according to claim 4, wherein the one or more partial locking projections (13c) are engageable with the corresponding locking steps (11c) after the partial locking arms (13a) are deflected (FIG. 3A) preferably inwardly, when the retainer (13) is pushed to the partial locking position (14; FIGS. 2; 3B), and the one or more full locking projections (13d) are engageable with the corresponding locking steps (11d) after the full locking arms (13b) are deflected (FIG. 4A) preferably inwardly, when the retainer (13) is pushed from the partial locking position (14; FIGS. 2; 3B) to the full locking position (15; FIG. 4B). A connector according to one or more of the preceding claims, wherein the lengths of the partial and full locking arms (13a, 13b) are set substantially equal to each other. A connector according to one or more of the preceding claims, wherein the retainer insertion portion (11b) is substantially open in one side surface of the housing (11). A connector according to one or more of the preceding claims, wherein the full locking arm (13b), preferably its full locking projection (13d) is substantially in contact with a receiving surface (11f) of the corresponding locking step (11d) when the retainer (13) is arranged in the partial locking position (14; FIGS. 2; 3B).

Inventors: MAKINO HIROTAKA, OKADA HAJIME, MAKINO, HIROTAKA, OKADA, HAJIME, Makino, Hirotaka, Sumitomo Wiring Systems, Ltd., Okada, Hajime, Sumitomo Wiring Systems, Ltd.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1999
Main classification: H01R13
IPC codes: H01R13