Connector containing front holder

Abstract: A connector is provided, which includes: a connector housing and a front holder, wherein the connector housing having: an insertion slot for receiving the front holder therein; a terminal receiving chamber for receiving the terminal therein; and a resilient locking arm which is resiliently deformed when pushed by the terminal and is resiliently recovered when the terminal is fully inserted into the terminal receiving chamber, the resilient locking arm having a detection end which is lowered toward the insertion slot when the resilient locking arm is resiliently deformed and is lifted toward the terminal receiving chamber when the resilient locking arm is recovered, and the front holder having: a holder end facing the detection end; and a stopper which stops the front holder at a provisional locking position where the holder end is apart from the detection end and is pushed into the insertion slot when the front holder passes through the provisional locking position, the front holder, the stopper of which is released, being shifted upward so that the holder end is movable in a direction to abut against the lowered detection end of the resilient locking arm. Thus, a secure locking of the terminal in the connector housing without overlooking the incomplete terminal insertion can be realized, even if there are some dimensional errors for the parts related accompanying by the fabrication thereof.

Description: BACKGROUND OF THE INVENTION (1) Field of the Invention This invention relates to a connector for use in connecting wire harness and the like in motor vehicles and, more specifically, relates to a connector containing a front holder for fastening terminals. (2) Description of the Related Art In Fig. 15 there is shown a longitudinal sectional view of a conventional connector containing a front holder. Such a connector is disclosed in document DE-A-19630754. In Fig. 16 there is shown a primary part of the longitudinal sectional view of the conventional connector for illustrating a problem encountered with the conventional connector. In a body a 1 of a connector housing a, there are provided a plurality of cylinders c each having a terminal receiving chamber b therein, a slit on an upper wall of an end portion c 1 of the cylinder c to form a cantilever-type resilient locking arm d, and a locking projection d 1 protruding toward the chamber b at a free end of the locking arm d. As to a terminal e to be inserted into the chamber b, there is formed a locking hole e 1 into which the projection d 1 fits when the terminal e is fully inserted into the chamber b. When the terminal e is inserted into the chamber b (see Fig. 16), the terminal e pushes the projection d 1 to deform the locking arm d, causing a detection end d 2 located at the end of the locking arm d protruding upward from the outer surface of the end portion c 1 of the cylinder c. When the terminal e is fully inserted into the chamber b (see Fig. 15), the projection d 1 fits in the hole e 1 so that the locking arm d is lowered at the end portion c 1 of the cylinder c. A front holder f is inserted from the end of the body a 1 (from left in Fig. 15) and that along the outer surface of the end portion c 1 of the cylinder c. When the locking arm d is lifted, the front holder f cannot be inserted into an end of the inserted position caused by abutting against the detection end d 2 . On the other hand, when the locking arm d is lowered, the front holder f can be inserted into the end of the inserted position, namely to a final inserted position. In the operation, the front holder f is half inserted into the cylinder c up to a provisional locking position where the front holder f does not contact with the detection end d 2 . Then, during the insertion of the terminal e into the chamber b, the locking arm d pushed by the terminal e is lifted from the cylinder c. When the terminal e is fully inserted, the locking arm d is lowered, then the front holder f can be inserted up to the end of the inserted position. Upon completion of the insertion, the front holder f is locked at the final inserted position by another locking projection (not shown in the figures). Consequently, the front holder f has one function to detect the full insertion of the terminal e and another function to keep the terminal e from coming off, since the front holder f restrains the locking arm d from lifting when the front holder f is inserted to the final inserted position. In order that the front holder f detects the full insertion of the terminal e, the detection end d 2 of the resilient locking arm d, which is lifted due to an incomplete insertion of the terminal e, must abut against a holder end f 1 , the end of the front holder f (see Fig. 16). Since the connector housing a and the front holder f are made of a synthetic resin and mold-shaped, there is some inevitable error in dimensions for these parts accompanied with the fabrication. Upon lifting of the locking arm d, lifted position g (see Fig. 16) of the detection end d 2 is influenced by various parameters such as the position and dimension of the terminal receiving chamber b, the diameter of the terminal e, and the dimension of the locking arm d and the projection d 1 thereof. On the other hand, internal diameter h of the front holder f has its own dimensional error accompanied with the above-mentioned fabrication. In addition, the inner diameter h must provide a clearance for allowing the front holder insertable with respect to the outer diameter of the end portion c 1 of the cylinder c (see Fig. 16). Therefore, when the following two situations simultaneously take place, the lifted position g of the detection end d 2 can be lower than the position h corresponding to the lowest portion of the holder end f 1 , as illustrated in Fig. 16. The one situation is that the lifted position g becomes significantly low within the tolerance of the connector housing a and the terminal e. The another situation is that the position h becomes significantly high within the tolerance of the holder f. In the above case, the front holder f can unfavorably be inserted to the final inserted position even if the locking arm d is in a lifted state, thereby causing a problem that the incomplete insertion of the terminal e cannot be detected. It is therefore an object of the present invention to solve the above problem. SUMMARY OF THE INVENTION In order to accomplish the above object, a first aspect of the present invention is to provide a connector composed in such a manner that it comprises a connector housing and a front holder, wherein the connector housing having: an insertion slot for receiving the front holder therein; a terminal receiving chamber for receiving the terminal therein; and a resilient locking arm which is resiliently deformed when pushed by the terminal and is resiliently recovered when the terminal is fully inserted into the terminal receiving chamber, the resilient locking arm having a detection end which is lowered toward the insertion slot when the resilient locking arm is resiliently deformed and is lifted toward the terminal receiving chamber when the resilient locking arm is recovered, and the front holder having: a holder end facing the detection end; and a stopper which stops the front holder at a provisional locking position where the holder end is apart from the detection end and is pushed into the insertion slot when the front holder passes through the provisional locking position, the front holder, the stopper of which is released, being shifted upward so that the holder end is movable in a direction to abut against the lowered detection end of the resilient locking arm. The front holder has a resilient wall which slides on the insertion slot, and said stopper is provided on a sliding surface of the resilient wall. According to this structure, when the stopper is pushed into the insertion slot, the front holder is shifted upward by a resilient force produced at the resilient wall, resulting in that the holder end of the front holder is movable in a direction to abut against the lowered detection end of the resilient locking arm. Thereby, the holder end can hit the detection end so that the incomplete insertion of the terminal can be inevitably detected. A second aspect of the present invention is the connector wherein a stopper face to abut on a stop end of the insertion slot is formed at the insertion side of the stopper. According to this structure, the front holder is securely locked at the provisional locking position. A third aspect of the present invention is the connector wherein the front holder has a resilient wall which slides on the insertion slot, said stopper being provided on a sliding surface of the resilient wall, and a stopper face to abut on a stop end of the insertion slot being formed at an insertion side of the stopper. The connector having the above structure can realize a secure locking of the terminal in the connector housing without overlooking the incomplete terminal insertion, even if there are some dimensional errors for the parts related accompanying by the fabrication thereof. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view illustrating the first example of a connector housing and a front holder according to the present invention. Figure 2 is a perspective view from the rear side of the front holder of Fig. 1. Figure 3 is a longitudinal sectional view illustrating an incomplete inserted state of a terminal and a provisional locking position of the front holder for the first example. Figure 4 is a longitudinal sectional view illustrating an opening between the front holder at the provisional locking position and an insertion slot, and a stopper of the front holder for the first example. Figure 5 is a longitudinal sectional view illustrating a change in an opening shown in Fig. 4 when the stopper is moved into the insertion slot. Figure 6 is a longitudinal sectional view illustrating a fully inserted state of the terminal for the first example. Figure 7 is a longitudinal sectional view illustrating a state when the front holder is fully inserted in succession from the state shown in Fig. 6. Figure 8 is a perspective view illustrating the second example of a connector housing and a front holder according to the present invention. Figure 9 is a perspective view from the rear side of the front holder of Fig. 8. Figure 10 is a longitudinal sectional view illustrating an incompletely inserted state of a terminal and a provisional locking position of the front holder for the second example. Figure 11 is a longitudinal sectional view illustrating a stopper in the provisional locking state for the second example. Figure 12 is a longitudinal sectional view illustrating a stopper moved into an insertion slot after escaped from the provisional locking state. Figure 13 is a longitudinal sectional view illustrating a fully inserted state of the terminal and the provisional locking position of the front holder. Figure 14 is a longitudinal sectional view illustrating a state when the front holder is fully inserted in succession from the state shown in Fig. 13. Figure 15 is a longitudinal sectional view illustrating an example of conventional connector containing front holder. Figure 16 is a primary part of a longitudinal sectional view of the conventional connector for illustrating a problem encountered therewith. DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following, the preferred embodiments of the present invention are explained with reference to the attached drawings. Figures 1 to 7 illustrate the first example of the present invention. In Fig. 1, there are shown each perspective view of a female-type connector housing 1 and a front holder 2, in Fig. 2, a perspective view from the rear side of the front holder 2, and in Fig. 3 a longitudinal sectional view illustrating a state when a male-type terminal 3 and the front holder 2 are incompletely inserted into the connector housing 1. The connector housing 1 has a square tube body 1a at the forepart and a plurality of cylindrical parts, in which each terminal receiving chamber 5 is provided, at the rear. (In Fig. 1, there are shown two pairs of the terminal receiving chamber 5 provided up and down in the connector housing 1.) As shown in Fig. 3, inside of the body 1a, there is formed an inner surface 6 along which a male-type counter connector housing (not shown) is fitted and a front wall surface 7 against which an end surface of the counter connector housing abuts. There are formed an stop end 8 located on the left side of the wall surface 7 in Fig. 3 and insertion slots 9a and 9b, each has a pair of slots up and down, which extend from the stop end 8 toward the rear of the housing 1. Inside the insertion slots 9a and 9b, there are formed insertion guide walls 10a and 10b, respectively, each of which extends from the bottom of the insertion slot toward the front of the housing 1. In the upper terminal receiving chamber 5 in Fig. 3, there are formed a hole 11 which opens at the front wall surface 7 and a notch 12 which extends from the chamber 5 to the insertion slot 9a, and a cantilever-type resilient locking arm 13 extended from the notch 12 toward the front of the housing 1. The lower terminal receiving chamber 5 in Fig. 3 has the same structure with that of the upper one. As shown in Fig. 6, a locking projection 14 is formed on the upper surface of the locking arm 13 and a detection end 15 is formed at the end of the locking arm 13. As for the terminal 3 to be inserted into the chamber 5, at the end there is formed a tub-shaped electrically connecting portion 16 which protrudes through the hole 11 to fit in a counter terminal (not shown), and at the intermediate portion there is formed a locking hole 17 in which the locking projection 14 fits when the terminal 3 is fully inserted, and at the rear end there is formed a electrically connecting portion 19 which connects an electric wire 18. A seal 20 is also provided for the terminal 3 to seal an opening between the wire 18 and the terminal receiving chamber 5 thereby to ensure the waterproof (see Fig. 6). As shown in Fig. 1, in the front holder 2, there are formed insertion walls 21a and 21b, each of which protrudes frontward at the upper end and at the intermediate portion of the holder 2, respectively, and there is formed a lower wall 22 at the lower end of the holder 2. The insertion wall 21a at the upper end is inserted into the insertion slot 9a to slide on the upper surface of the insertion guide wall 10a. The insertion wall 21b at the intermediate portion is inserted into the insertion slot 9b to slide on the upper surface of the insertion guide wall 10b. Two hollow portions of notch 23 are formed at the end surface of the insertion walls 21a and 21b. The bottom surface of each hollow portion of notch 23 is a holder end 23a which abuts against the detection end 15. The detection end 15 is lowered toward the insertion slot 9a when the locking arm 13 is resiliently deformed (see Figs. 1, 2, 3 and 6). As shown in Fig. 4, in the front holder 2, there is formed a resilient wall 24 slidable on the lower surface of the insertion slot 9a and a stopper 25 is formed on the sliding surface of the resilient wall 24. The stopper 25 has a stopper face 25a which stops the front holder 2 at a provisional locking position when the stopper face 25a abuts against the stop end 8. Now, the function of the above-composed connector housing 1 and the front holder 2 is explained with referring to Figs. 3 to 7. As shown in Fig. 3, when the front holder 2 is inserted into the insertion slots 9a and 9b, the front holder 2 stops at the provisional locking position where the stopper 25 abuts against the stop end 8. In the provisional locking state, the holder end 23a of the front holder 2 is located at the position where the surface 23a does not hit against the detection end 15 of the locking arm 13. When the terminal 3 is inserted into the terminal receiving chamber 5, the terminal 3 pushes the locking projection 14 to allow the locking arm 13 to be deformed, causing the detection end 15 to be lowered toward the insertion slot 9a. When the front holder 2 is at the provisional locking position, an opening of size x is formed between the upper insertion wall 21a and the insertion slot 9a, and an opening of size y is formed between the lower wall 22 and the insertion slot 9b (see Fig. 4). After the complete insertion of the terminal 3, when the front holder 2 is pushed toward the inserting direction from the provisional locking position, the resilient wall 24 is deformed to allow the stopper 25 to run onto the lower surface of the insertion slot 9a, causing the front holder 2 to lift up due to the resilient force of the resilient wall 24. Accordingly, the opening size x' between the upper insertion wall 21a and the insertion slot 9a is reduced to be almost zero and the opening size y' between the lower wall 22 and the insertion slot 9b is enlarged (see Fig. 5), that is, the holder end 23a of the front holder 2 is significantly lifted up. On the other hand, when the terminal 3 is not fully inserted so that the detection end 15 is lowered toward the insertion slot 9a (see Fig. 3), the holder end 23a inevitably hits the detection end 15 upon the insertion of the front holder 2, resulting in that the incomplete insertion of the terminal 3 is securely detected, even if there are some dimensional errors for the parts related accompanying with the fabrication thereof. When the terminal 3 is fully inserted, the locking hole 17 of the terminal 3 fits with the locking projection 14 of the resilient locking arm 13, that is, the locking arm 13 resiliently recovers to its original shape (see Fig. 6) from its deformed shape (see Fig. 3). Consequently, the front holder 2 can be fully inserted into the insertion slot 9a by pushing from the lifted position as described above (see Fig. 7). The fully inserted holder 2 prevents the locking arm 13 from being deformed downward so that the fitting between the locking hole 17 of the terminal 3 and the locking projection 14 of the resilient locking arm 13 is maintained to prevent the terminal 3 from coming off. Figures 8 to 14 illustrate the second example of the present invention concerned with a male-type connector housing 26 having a front holder 27. This connector housing is different in shape from that of the first example, nevertheless the function is the same. Consequently, each part having the same function with that of the corresponding part in the first example is given the same number so that the detailed description of such parts is omitted in the following. In Fig. 8, there are shown each perspective view of the male-type connector housing 26, the front holder 27 and a sealing member 28, in Fig. 9, a perspective view from the rear side of the holder 27, and in Fig. 10, a longitudinal sectional view illustrating a state when a female-type terminal 29 and the holder 27 are incompletely inserted into the connector housing 26. The sealing member 28 seals the contact surface between the end surface of the body 1a of the female-type connector housing 1 and the connector housing 26, thereby ensuring the waterproof. Similar to the first example, in the connector housing 26, there are formed the terminal receiving chamber 5, the notch 12 which extends from the terminal receiving chamber 5 to the insertion slots 9a and 9b, and the resilient locking arm 13 having the locking projection 14 and the detection end 15 (see Fig. 10). A female-type terminal 29, which is received in the chamber 5 to be electrically connected to the male-type terminal 3, has the locking hole 17. Similar to the first example, in the front holder 27, there is provided the holder end 23a to the insertion walls 21a and 21b (see Fig. 8), and the stopper 25 to the resilient wall 24 (see Figs. 10 and 11). Now, the function of the above-composed connector housing 26 and the front holder 27 is explained with referring to Figs. 10 to 14. As shown in Fig. 10, when the front holder 27 is inserted into the insertion slots 9a and 9b, the front holder 27 stops at the provisional locking position where the stopper 25 abuts against the stop end 8. In this provisional locking state, the holder end 23a of the front holder 27 is located at the position where the surface 23a does not hit against the detection end 15 of the locking arm 13. When the terminal 29 is inserted into the terminal receiving chamber 5, the terminal 29 pushes the locking projection 14 to allow the resilient locking arm 13 to be deformed, causing the detection end 15 to be lowered toward the insertion slot 9a. After the complete insertion of the terminal 29, when the front holder 27 is pushed toward the inserting direction from the provisional locking position, the resilient wall 24 is deformed to allow the stopper 25 to run onto the lower surface of the insertion slot 9a, causing the front holder 27 to be lifted up due to the resilient force of the resilient wall 24, that is, the holder end 23a of the front holder 27 is significantly lifted up, similar to the first example. On the other hand, when the terminal 29 is not fully inserted so that the detection end 15 is lowered toward the insertion slot 9a (see Fig. 10), the holder end 23a inevitably hits the detection end 15 upon the insertion of the front holder 27, resulting in that the incomplete insertion of the terminal 29 is securely detected, even if there are some dimensional errors for the parts related accompanying with the fabrication thereof. When the terminal 29 is fully inserted, the locking hole 17 of the terminal 29 fits with the locking projection 14 of the resilient locking arm 13, that is, the locking arm 13 resiliently recovers to its original shape (see Fig. 13) from its deformed shape (see Fig. 10). Consequently, the front holder 27 can be fully inserted into the insertion slot 9a by pushing from the lifted position as described above (see Fig. 14). The fully-inserted holder 27 prevents the locking arm 13 from being deformed downward so that the fitting between the locking hole 17 of the terminal 29 and the locking projection 14 of the resilient locking arm 13 is maintained to prevent the terminal 29 from coming off.

Claims: A connector comprising a connector housing (1) and a front holder (2), the connector housing (1) having: insertion slots (9a, 9b) for receiving the front holder (2) therein, in which insertion guide walls (10a, 10b), respectively, are formed, each of said insertion guide walls (10a, 10b) extending from the bottom of the insertion slots (9a, 9b); a terminal receiving chamber (5) for receiving the terminal (3) therein; and a resilient locking arm (13) which is resiliently deformed when pushed by the terminal (3) and is resiliently recovered when the terminal (3) is fully inserted into the terminal receiving chamber (5), wherein the resilient locking arm (13) has a detection end (15) which is lowered toward the insertion slot (9a) when the resilient locking arm (13) is resiliently deformed and is lifted toward the terminal receiving chamber (5) when the resilient locking arm (13) is recovered, the front holder (2) having: insert walls (21a, 21b) surrounding said insert guide walls (10a, 10b), and being adapted to be slidingly moved along surfaces on said insertion guide walls (10a, 10b) to be received into said insertion slots (9a, 9b); a resilient interior wall (24) being slidable on a lower surface of the insertion slot (9a) and being provided with an stopper (25); a holder end (23a) facing the detection end (15); wherein the stopper (25) stops the front holder (2) at a provisional locking position where the holder end (23) is apart from the detection end (15) and is pushed into the insertion slot (9a) when the front holder (2) passes through the provisional locking position, wherein the front holder (2), the stopper (25) of which is released, is lifted upward due to the resilient force produced at the resilient interior wall (24) so that the holder end (23a) is movable in a direction to abut against the lowered detection end (15) of the resilient locking arm (13) when the terminal (3) is incompletely inserted in the terminal receiving chamber (5). A connector according to claim 1, wherein a stopper face to abut on a stop end of the insertion slot is formed at an insertion side of the stopper. A connector according to claim 2, wherein a stopper face to abut on a stop end of the insertion slot is formed at an insertion side of the stopper.

Inventors: IWAHORI YOSHIHIRO, IWAHORI, YOSHIHIRO, IWAHORI, YOSHIHIRO, C/O YAZAKI PARTS CO., LTD.
Applicants: YAZAKI CORP, YAZAKI CORPORATION
Application year: 1999
Main classification: H01R13
IPC codes: H01R13