Connector with locking device

Abstract: To prevent the disengagement of a retainer from a housing during the shift of the retainer from its first locking position to its second locking position, a connector comprises a housing (1), a retainer (8) having a pair of side members (12) which are so deformable as to widen a spacing therebetween, first and second locking projections (17,18) formed on each of the surfaces of the housing (1) facing the side members (12), and a window (13) formed in each side member (12) for holding the retainer (8) in a first locking position in which the windows (13) are engaged with the first locking projections (17) and in which the insertion and withdrawal of terminal fittings (5) into and from the housing (1) are permitted, and for holding the retainer (8) in a second locking position in which the windows (13) are engaged with both of the first and second locking projections (17,18) and in which the terminal fittings (5) are securely retained in the housing (1), the side members (12) of the retainer (8) undergoing a deformation when the retainer (8) is shifted between the first and second locking positions, wherein the height of at least one of the second locking projections (18) is lower than that of the first locking projections (17).

Description: The present invention relates to a connector provided with a retainer and, particularly to a connector having a retainer which is engageable with two types of projections to shift between a first locking position and a second locking position. The EP 0 596 707 discloses a connector having a retainer shiftable between two locking positions, which is guided by guide projection engaging with windows of the retainer. The connector further comprises two lock bosses, the first of which is engaged with the window in the first locking position while the second lock boss is engaged with the window in second locking position of the retainer. In the first locking position the retainer is fixed between the guide projection and the second lock boss and in the second locking position the retainer is fixed between the guide projection and the first lock boss. The guide projections are higher than the lock bosses or projections so that the retainer is continuously guided during the shifting operation between the first and second locking positions. For shifting the retainer from the first locking position to the second locking position the retainer has to move over both locking bosses. It is the object of the invention to provide an improved connector which is not disengageable from a housing while it is moved from a first locking position to a second locking position and which is stably engageable in the locking position. The above object is accomplished by the invention defined in claim 1. The engaging portions formed in the wing members are engaged with the first locking projections when the retainer is in its first locking position. At this stage, the insertion and withdrawal of the terminal fittings into and from are permitted. In order to shift the retainer to its second locking position, the wing members are deformed to widen the spacing therebetween so that the engaging portions are engaged with the second locking projections as well. During the deformation of the wing members, since the height of at least one of the second locking projections is lower than that of the first locking projections, at least the corresponding engaging portion is still partially engaged with the respective first locking projection until the at least one second locking projection is engaged by the engaging portion. Thus, the retainer can shift to its second locking position without being disengaged from the housing, since the retainer is constantly engaged with the housing while being shifted from its first locking position to its second locking position. Thus, the disengagement of the retainer from the housing can be securely 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 a partially enlarged side view of the connector when a retainer is in its first locking position, FIG. 2 is a partially enlarged side view of the connector when the retainer is in its second locking position, FIG. 3 is a side view in section of the connector when the retainer is in its first locking position, FIG. 4 is a side view in section of the connector when the retainer is in its second locking position, FIG. 5 is a perspective view showing first and second engagement projections, and FIGS. 6(a) to 6(b) are sections showing a process of engagement of a side member with the projections. Hereafter, one embodiment of the invention is described in detail with respect to FIGS. 1 to 6. A housing 1 of a connector is unitarily formed of synthetic resin. The illustrated housing 1 is a female connector housing and is formed at its front part with a fitting portion 2 fittable with an unillustrated male connector housing. The housing 1 is formed with a multitude of cavities 3 for accommodating terminal fittings 5, the cavities 3 extending in a forward/backward direction and opening in the opposite front and rear walls. The respective cavities 3 are separated by partition walls 4. An engaging member or lance 6 engageable with the inserted terminal fitting 5 is deflectably formed in each cavity 3. The leading end of each engaging member 6 is partially cut away to form an engaging portion 7 so that the engaging member 6 engages the corresponding terminal fitting 5. The terminal fittings 5 are female terminal fittings and are each formed at its leading end with a hollow connecting portion 5a into which the leading end of an unillustrated corresponding male terminal fitting 5 is inserted. An engaging hole 5b formed at the lower surface of the connecting portion 5a engages the engaging member 6. A jaw portion 5c engageable with a corresponding locking portion 9 of a retainer 8 is formed at the upper surface of the connecting portion 5a. In each of the upper and lower surfaces of the housing 1, a plurality of slits 10 extend in parallel relationship over a specified distance backward from the fitting portion 2. The slits 10 are as many as the cavities 3, and communicate with the respective cavities 3. The slits 10 permit the respective locking portion 9 formed on the bottom surface of the retainer 8 to enter the cavities 3 when the retainer 8 is in its second locking position as described later, thereby enabling the engagement of the locking portions 9 with the terminal fittings 5. The retainers 8 are located above and below the housing 1 and are coupled therewith via elastically deformable hinge members 11. Both of the retainers 8 are unitarily formed with the housing 1 vertically symmetrically. On the surfaces of the retainers 8 facing the upper and lower surfaces of the housing 1, there are formed the locking portions 9 projectable into the cavities 3 through the openings 10. The locking portions 9 are arranged at the same pitch as the cavities 3 along the longitudinal direction of the retainers 8. The locking portions 9 are in the form of projections tapered toward their leading ends which project into the respective cavities 3. The locking portions 9 do not project into the cavities 3 when the retainers 8 are in their first locking positions, thereby permitting the insertion and withdrawal of the terminal fittings 5. When the retainers 8 are in their second locking positions, the locking portions 9 deeply project into the cavities 3 and engage with the jaw portions 5c of the corresponding terminal fittings 5 as shown in FIG. 4. In this way, the terminal fittings 5 are doubly locked by the engagements with the engaging members 6 and with the locking portions 9 of the retainers 8, and thus can be securely retained in the cavities 3. A pair of side members 12 are formed at the opposite sides of each retainer 8, and the spacing between the pair of side members 12 is set such that they can engage recesses 15 in the side walls of the housing 1. Further, each pair of side members 12 are permitted to undergo an elastic deformation in such directions as to widen the spacing therebetween, and a window 13 in the form of an oblong hole is formed in each of the side members 12. Furthermore, a pair of projections 14 are formed on the surface of each retainer 8 facing the fitting portion 2. The projections 14 engage recesses (not shown) formed at the housing 1 when the retainers 8 are in their second locking positions, thereby preventing an undesired lifting of the retainers 8. The retainers 8 are mounted on the housing 1 in a partially (first) locking state (where the retainers 8 do not hinder the insertion and withdrawal of the terminal fittings 5 into and from the cavities 3) and in a fully (second) locking state. Therefore, on the opposite side surfaces of the housing 1, there are formed the recesses 15 in positions where the side members 12 are fitted. The bottom surface (in a vertical direction) of each recess 15 is a slanted surface having a specified downward inclination, and acts as a guide surface 16 for guiding the shifting of the corresponding retainer 8. In each recess 15, projections 17 and 18 project in a horizontal direction for holding the retainer 8 in its first and second locking positions and are formed in parallel with the inclination of the guide surface 16. The recesses 15 are arranged symmetrically so as to correspond to the vertically symmetrically disposed retainers 8. The projections 17 and 18 are so formed as to have the same width (dimension W shown in FIG. 1), which is substantially equal to a width of the window 13. Further, a distance defined by the outer ends of the projections 17 and 18 is substantially equal to the entire length of the window 13. Accordingly, the window 13 is engageable only with the projection 17 as shown in FIG. 1 (first locking position) and is also stably engageable with both of the projections 17 and 18 as shown in FIG. 2 (second locking position). In order to conform to arcuate ends of the window 13, the parts of the projections 17 and 18, i.e., the both ends of the projection 17 and a lower end of the projection 18 in FIGS. 1 and 2, are formed to have an arcuate shape. Further, a height (H2) (in the projection direction) of the projection 18 is slightly smaller than a thickness of the side member 12, and is lower than a height of the projection 17 (H1 > H2). Thus, even while the side member 12 moves over the projection 18 so as to fit the projection 18 in the window 13 (see FIG. 6(b)), the window 13 is engaged with the projection 17 by a specified engagement margin. This engagement margin is set such that the disengagement of the retainer 8 can be effectively prevented. Furthermore, the surface of the projection 18 facing the projection 17 is a slanted surface 18a for enabling the retainer 8 to smoothly move on the projection 18. The action and effect of the thus constructed embodiment are specifically described. When the connector is formed, the retainers 8 are held in positions away from the housing 1 as shown in FIG. 1. The retainers 8 are brought to their first locking positions prior to the insertion of the terminal fittings 5. More specifically, the hinge members 11 are bent to bring the retainers 8 closer to the housing 1, and the side members 12 are engaged with the recesses 15 to fit the projections 17 in the windows 13 (state shown in FIG. 6(a)). As a result, the retainers 8 are held in their first locking positions. Since the respective locking portions 9 do not enter the cavities 3 at this stage, the terminal fittings 5 can be smoothly inserted into the cavities 3. The inserted terminal fittings 5 cause the respective engaging members 6 to move (deflect) in a direction out of the cavities 3, but the engaging members 6 return to their original shape thereafter because of their elasticity, with the result that the engaging portions 7 of the engaging members 6 engage the engaging holes 5b, thereby partially locking the terminal fittings 5. Subsequently, the retainers 8 are moved further closer to the housing 1 to fit both of the projections 17 and 18 in the windows 13. As a result, the retainers 8 are fixed in their second locking positions. Since the respective locking portions 9 of the retainers 8 project into the cavities 3 and engage the jaw portions 5c of the corresponding terminal fittings 5 in this state, the terminal fittings 5 are retained in such a manner that they cannot come out of the cavities 3. While the retainers 8 shift from their first locking positions to their second locking positions, the side members 12 are displaced while being guided by the guide surfaces 16 of the recesses 15 and move on the projections 18 while undergoing a deformation to widen the spacing between them. During this period, since the windows 13 are still engaged with the projections 17 by the specified engagement margin, the undesired disengagement of the retainers 8 during the shift to their second locking positions can be avoided. When the windows 13 pass over the projections 18, the side members 12 return to their original shape because of their elasticity. As a result, the windows 13 are engaged with both of the projections 17 and 18 and thus the retainers 8 can be securely held in their second locking positions. As described above, according to the foregoing embodiment, the retainers 8 are not inadvertently disengaged from the housing 1 while shifting from their first locking positions to their second locking positions, thereby advantageously enabling a smooth sliding movement of the retainers 8. Various changes and modifications may be made in the invention. The following modifications are also embraced by the technical scope of the invention. (1) Although the projections 17 and 18 are fitted in one window 13 in the foregoing embodiment, separate windows 13 may be formed for the projections 17 and 18, respectively. In this case, the window 13 for the projection 17 needs to be an oblong hole having a length for permitting the sliding movement of the retainer 8. (2) The invention may be applied to male connectors. The number of contacts of the connector, the number of the hinge members 11, etc. may be suitably changed.

Claims: A connector, comprising: a housing (1), a retainer (8) having a pair of wing members (12) which are so deformable as to widen a spacing therebetween when the retainer is shifted between first and second locking positions, first and second locking projections (17,18) formed on each of the surfaces of the housing (1) facing the wing members (12), the height of the second locking projections (18) being lower than that of the first locking projections (17), and an engaging portion (13) formed in each wing member (12) for holding the retainer (8), characterized in that there are provided only two locking projections (17,18), and that the engaging portions (13) are engaged only with the first locking projections (17) in a first locking position in which the insertion and withdrawal of terminal fittings (5) into and from the housing (1) are permitted, and that the engaging portions (13) are engaged with both of the first and second locking projections (17,18) in a second locking position in which the terminal fittings (5) are securely retained in the housing (1), whereby a distance defined by the outer ends of the first locking projections (17) and the second locking projections (18) is substantially equal to the entire length of the engaging portion (13). A connector according to claim 1, wherein the surface of the second locking projection (18) facing the first locking projection (17) is a slanted surface (18a). A connector according to claim 1 or 2, wherein the engaging portions are windows (13) formed in the wing members (12). A connector according to claim 3, where the width of the windows (13) corresponds to the width of the first and/or the second locking projections (17, 18), so that the projections act as guide members when shifting the retainer from the first to the second locking position. A connector according to any of claims 1 to 4, wherein the wing members are side members (12) provided at its opposite sides. A connector according to any of claims 1 to 5, wherein the retainer (8) is connected with the housing (1) by a connection member (11). A connector according to any of claims 1 to 6, wherein the height of each of the second locking projections (18) is lower than that of the first locking projections (17).

Inventors: SASAI OSAMU, SASAI, OSAMU, SASAI, OSAMU, C/O SUMIMOTO WIRING SYSTEMS, LTD.
Applicants: SUMITOMO WIRING SYSTEMS, SUMITOMO WIRING SYSTEMS, LTD.
Application year: 1995
Main classification: H01R13
IPC codes: H01R13