Terminal fitting having a retracted portion extending from one side plate to another side plate

A rectangular tube (10) of a terminal fitting (T) includes a lid plate (16) extending substantially at a right angle from the extending end of a right side plate (15) and formed with a locking hole (20) extending over the entire width. A front plate (19F) is cantilevered from the right side plate (15) and arranged before the locking hole (20). A rear plate (19R) is cantilevered from the right side plate independently of the front plate (19F) and is behind and adjacent to the locking hole (20). A retracted portion (21) is formed over the entire width at the rear plate (19R), retracted inwardly of the rectangular tube (10) from the front plate (19F) to provide a height difference within the range of an engagement margin with a locking projection (34) and capable of facing a rear end of the locking projection (34).

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to a terminal fitting and to a connector provided therewith.

2. Description of the Related Art

U.S. Pat. No. 7,374,465 discloses a female terminal fitting with a rectangular tube at a front end and a wire crimping portion in the form of an open barrel at a rear end. The wire crimping portion defines an open barrel with a bottom wall and two side plates extending from left and right sides of the bottom wall. The rectangular tube has a base plate connected to the bottom wall of the wire crimping portion, two side plates extending at substantially right angles from left and right sides of the base plate and a lid plate extending at a substantially right angle from the end of at least one side plate opposite the base plate. The base plate is formed with a locking hole. The terminal fitting inserted into a terminal accommodating chamber of a housing from behind and a locking projection of a locking lance formed in the terminal accommodating chamber engages the edge of the locking hole to prevent the terminal fitting from coming out backward.

A part of the base plate behind the locking hole is indented inwardly of the rectangular tube to form a retracted portion. Thus the base plate has a height difference between the front and rear sides of the rear edge of the locking hole. A rear end part of the locking projection of the locking lance faces the outer surface of this retracted portion, and a part of the locking projection before the retracted portion is in the opening area of the locking hole. According to this configuration, a dimension of the locking hole in forward and backward directions can be reduced as compared with the case where an opening range of the locking hole in forward and backward directions extends from the front end to the rear end of the locking projection, and the terminal fitting can be made smaller by reducing a length of the rectangular tube in forward and backward directions by that much.

In the above-described terminal fitting, the retracted portion is formed by cutting a part of the base plate and bending the cut part. The side plates are connected to the left and right edges of this base plate. Thus, a formation range of the retracted portion in a width direction is limited to a range inwardly of the inner side surfaces of the side plates. That is, it is structurally impossible to form the retracted portion over the entire width of the rectangular tube including plate thickness ranges of the side plates. Since the locking projection of the locking lance is accommodated in a space secured by indenting the retracted portion inwardly of the rectangular tube, the width of the locking lance is limited to the entire width of the retracted portion or smaller. In other words, an engagement margin between the locking lance and the locking hole in the width direction is limited to the formation range of the retracted portion in the width direction.

The invention was completed in view of the above situation and an object thereof is to ensure a large engagement margin between a lock and a locking hole.

SUMMARY OF THE INVENTION

The invention relates to a terminal fitting with a tube at a front end part. A locking hole is formed is formed in the tube. A locking projection of a lock formed in a terminal accommodating chamber engages a front end edge of the locking hole when the terminal fitting is inserted properly in the terminal accommodating chamber to retain the terminal fitting. The tube comprises a base plate and first and second side plates extending from the base plate. A lid plate extends between the side plates and is formed with the locking hole. The lid plate includes a front and rear plates cantilevered from the first side wall. The front plate defines a part of the lid plate before the locking hole and the rear plate defines a part of the lid plate behind the locking hole. A retracted portion is formed in the rear plate and is retracted inwardly relative to the front plate to provide a height difference within the range of an engagement margin with the locking projection and capable of facing a rear end part of the locking projection.

The locking hole preferably extends over the entire width of the lid plate. The retracted portion also preferably is formed over the entire width. Additionally, the front and the rear plates of the lid plate portion preferably are cantilevered from the side plate independently of each other. Thus, the position of a fold line along which the rear plate and the side plate are connected at a substantially right angle can be set at a position displaced inward of the rectangular tube from the position of a fold line along which the front plate and the side plate are connected at a substantially right angle, and the height difference can be provided between the front and the rear plates. The rear plate is cantilevered and hence can extend over the entire width of the rectangular tube if an extending dimension is set appropriately. Thus, it is possible to form the retracted portion over the entire width of the rectangular tube and to ensure a large engagement margin between the locking lance and the locking hole in the width direction.

At least one posture stabilizing portion preferably is formed behind an area of the retracted portion substantially facing the locking projection and projecting out of the rectangular tube from the outer surface of the retracted portion. The posture stabilizing portion enables the lid plate to be held in contact with the inner surface of the terminal accommodating chamber at two positions, i.e. a position before the locking hole and a position after the locking hole, thereby stabilizing the posture of the tube in the terminal accommodating chamber.

A distance from the rear end of the front plate to the front end of the rear plate preferably is shorter than a distance from the front end to the rear end of the locking projection in forward and backward directions.

A formation range of the retracted portion in forward and backward directions preferably extends substantially from the front end edge of the rear plate to a position slightly before a substantial center of the rear plate in forward and backward directions.

The retracted portion preferably is in a positional relationship to be retracted in a direction away from the outer surface of a main body of the lock and in an inward direction of the tube as compared with the front plate.

According to a further aspect of the invention, there is provided a connector comprising: at least one terminal accommodating chamber and at least one of the above-described terminal fittings to be inserted into the respective terminal accommodating chamber. A tube of the one a terminal fitting includes a locking hole formed at a front end part and which is be retained not to come off backward by the engagement of the front end edge of the locking hole with a locking projection of a locking portion formed in the terminal accommodating chamber in a state where the terminal fitting is properly inserted in the terminal accommodating chamber.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A terminal fitting in accordance with the invention is identified by the letter T inFIGS. 1,5to7. The terminal fitting T is a female terminal formed with a substantially rectangular tube10at a front and a wire crimping portion11at a rear end. A front part of a wire12is to be connected to the wire crimping portion11. As shown inFIG. 1, the terminal fitting T is to be inserted from behind into a terminal accommodating chamber31formed in a housing30. In the following, a connection side of the terminal fitting T with a mating terminal fitting (not shown) is referred to as the front.

A locking lance32is cantilevered forward from a lower wall of the terminal accommodating chamber31and is configured for holding and retaining the terminal fitting T that has been inserted properly inserted into the terminal accommodating chamber31. The locking lance32has a main body33that is resiliently deformable to retract out and down. A locking projection34projects up from the surface of the main body33and is in an insertion space for the terminal fitting T in the terminal accommodating chamber31for engaging the terminal fitting T when the locking lance32is not deformed resiliently, as shown inFIG. 1. However, the locking projection34is retracted from the insertion area for the terminal fitting T in the terminal accommodating chamber31when the locking lance32is deformed out and down in a direction DD intersecting an insertion direction ID of the terminal fitting T into the accommodating chamber31.

The locking projection34is arranged in a substantially in a central part of the main body33in forward and backward directions. A front receiving surface35F is defined at a front area of the upper surface of the main body33forward of the locking projection34and a rear receiving surface35R is defined at a rear area of the upper surface of the main body33behind the locking projection34. The front and rear receiving surfaces35F,35R are arranged to contact the properly inserted terminal fitting T from below when the locking lance32is not deformed resiliently. Thus, the front and rear receiving surfaces35F,35R are capable of supporting the terminal fitting T from below.

The locking projection34has a wide substantially rectangular shape and is longer in forward and backward directions than in a height direction when viewed laterally. A locking surface36is defined at the front end of the locking projection34and is substantially perpendicular to the inserting direction ID of the terminal fitting T when the locking lance32is not deformed. The upper surface of the locking projection34is substantially parallel to the inserting direction ID of the terminal fitting T when the locking lance32is not deformed. An inclined surface37is formed at the rear end of the locking projection34and inclines out and down toward the back with respect to the inserting direction ID of the terminal fitting T when the locking lance32is not deformed. The entire area of the locking surface36from the lower end to the upper end defines an engagement margin with the terminal fitting T in the vertical direction.

References to the vertical direction in the following paragraphs are based on the state where the terminal fitting T is inserted in the terminal accommodating chamber31. As shown inFIGS. 1 to 7, the rectangular tube10has a substantially flat rectangular horizontal base plate13, a substantially flat rectangular left side plate14extending substantially perpendicularly down from the left side of the base plate13, a substantially flat rectangular right side plate15extending substantially perpendicularly down from the right side of the base plate13and a substantially flat rectangular lid16extending substantially perpendicularly leftward from the extending lower end of the right side plate15. The front and rear ends of the rectangular tube10are open toward the outside. As shown inFIGS. 1,5to7, a rear end of the base plate13is connected to the front end of a bottom wall17of the wire crimping portion11, and rear ends of the left and right side plates14,15are connected to base end parts of lateral walls of the left and right crimping pieces18extending from both lateral sides of the bottom wall17.

As shown inFIGS. 1,5to7, the lid16comprises a front plate19F connected to a front part of the right side plate15and a rear plate19R connected to a rear part of the right side plate15. Left edges of the front and rear plates19F and19R contact or proximately face the lower end of the opposite left side plate14from below. A locking hole20is formed through the lid16between the front and rear plates19F and19R. As shown inFIG. 7, the locking hole20is a substantially rectangular opening that extends across an entire width of the rectangular tube10from an outer surface of the left side plate14to an outer surface of the right side plate15. As shown inFIG. 1, the locking projection34is in the locking hole20when the terminal fitting T is inserted properly in the terminal accommodating chamber31and a front edge of the locking hole20(rear edge of the front plate19F) engages the locking surface36of the locking projection34of the locking lance32from the front to retain the terminal fitting T.

A dimension of an opening area of the locking hole20in forward and backward directions (distance from the rear end of the front plate19F to the front end of the rear plate19R) is less than a distance from the front end (locking surface36) to the rear end of the locking projection34in forward and backward directions, as shown inFIG. 1, to make the length of the rectangular tube10in forward and backward directions shorter. That is, the front edge of the rear plate19R is located to correspond to a substantially central part of the inclined surface37of the locking projection34in forward and backward directions when the locking surface36of the locking projection34engages the front edge of the locking hole20(state where the terminal fitting T is retained). On the other hand, a part of the locking projection34is in the opening area of the locking hole20when the terminal fitting T is retained. Thus, the rear plate19R of the lid16is formed with a retracted portion21to avoid interference of the lid16and the locking projection34.

As shown inFIGS. 1 and 7, the retracted portion21extends in forward and backward directions from the front edge of the rear plate19R to a position slightly before a substantial center of the rear plate19R in forward and backward directions. As shown inFIG. 1, the rear end of the retracted portion21is behind the rear end of the locking projection34when the terminal fitting T is retained. Further, as shown inFIGS. 3 and 7, the retracted portion21extends from the outer surface of the left or right side of the rear plate19R of the lid16to a position inward of the outer surface of the other of the left and right side of the rear plate19R.

As shown inFIG. 1, the lower surface of the retracted portion21facing the outside of the rectangular tube10is higher than the lower surface of the front plate19F when the terminal fitting T is retained. That is, the retracted portion21is retracted away from the upper surface of the main body portion33of the locking lance32as compared with the front plate19F. A retracting direction of the retracted portion21is the same as a projecting direction of the locking projection34from the upper surface of the main body portion33. Further, there is a height difference between the retracted portion21and the front plate19F within the range of a vertical engagement margin between the locking projection34and the locking hole20. Note that, in the state where the terminal fitting T is retained, the upper surface (surface facing the interior of the rectangular tube10) of the retracted portion21is at the same height as or slightly lower than the upper surface of the locking projection34. The height difference between the retracted portion21and the front plate19F prevents interference of the rear plate19R with the locking projection34.

As shown inFIG. 1, the retracted portion21is arranged to face the inclined surface37at the rear of the locking projection34. As shown inFIG. 7, the retracted portion21forms an area of the rear plate19R of the lid16behind and adjacent to the locking hole20over the substantially an entire width of the rear plate. In this way, an area in which the retracted portion21can be formed in the width direction is over the entire width of the rectangular tube10. Such formation over the entire width could be realized for the following reason.

As shown inFIG. 7, the locking hole20is a through hole formed over an entire width in the lid16between the left and right sides of the lid, and the front plate19F (area of the lid16before the locking hole20and where the retracted portion21is not formed) and the rear plate19R (area of the lid16behind the locking hole20and where the retracted portion21is formed) are cantilevered from the right side plate15independently of each other. Thus, as shown inFIG. 6, the position of a rear fold line22R between the rear plate19R and the right side plate15can be higher (inward) from the position of a front fold line22F between the front plate19F and the right side plate15. Thus, the height difference can be provided between the front and rear plates19F and19R. The rear plate19R is cantilevered and hence can extend over the entire width of the rectangular tube10if an extending dimension is set appropriately. Thus, the retracted portion21can extend over substantially the entire width of the rectangular tube10to ensure a large engagement margin between the locking lance32and the locking hole20in the width direction.

As shown inFIGS. 1,5to7, an area of the rear plate19R behind the retracted portion21is hammered, deformed or bent to project in or down to form a posture stabilizer23that extends in forward and backward directions substantially from the rear end of the retracted portion21to the rear end of the rear plate19R. Further, as shown inFIG. 7, the posture stabilizer23is formed in a widthwise central part of the rear plate portion19R. As shown inFIGS. 1,5and6, the lower surface of the posture stabilizer23is lower than the lower surface of the retracted portion21and substantially at the same height as the lower surface of the front plate19F. In a state where the terminal fitting T is inserted in the terminal accommodating chamber31to be retained, the front plate19F is placed on and in contact with the front receiving surface35F and the posture stabilizer23is placed on and in contact with the rear receiving surface35R, as shown inFIG. 1. Since the terminal fitting T is supported by the main body33of the locking lance32from below at positions before and behind the locking hole20(locking projection34) to prevent the terminal fitting T from being inclined down or up toward the front.

As shown inFIGS. 1 to 4, a resilient contact piece24is accommodated in the tube10and resiliently contacts a tab of a male terminal fitting T (not shown) inserted into the rectangular tube10from the front. As shown inFIG. 1, the resilient contact piece24comprises a resilient displacing portion25curved to project up or in when viewed sideways and is arranged along the upper surface of the lid16. A flat plate-shaped link26extends back from the rear end of the resilient displacing portion25and is connected at a substantially right angle to the extending lower end of the left side plate14. A contact portion27for engaging the tab is defined at a highest or most projecting part of the resilient displacing portion25. A support28is defined at a boundary between the rear end of the resilient displacing portion25and the front end edge of the link26and projects down like a rib for contacting or proximately facing the upper surface of the retracted portion21. The resilient contact piece24is pressed out or down by the tab when the tab is inserted into the rectangular tube10and is displaced resiliently out or down about the support28. The support28is supported from below by the retracted portion21to ensure a predetermined contact pressure between the resilient contact piece24and the tab.

The invention is not limited to the above described embodiment. For example, the following embodiments are also included in the scope of the invention.

Although the lid extends only from the right side plate in the above embodiment, two lids may extend from the left and right side plates and may be both formed with a retracted portion.

Although the posture stabilizer is formed by hammering in the above embodiment, it may be formed by cutting and bending.

Although the posture stabilizer is arranged at one position in the widthwise center in the above embodiment, it may be provided at a plurality of positions spaced apart in the width direction.