Erroneous insertion prevention structure of electric connectors

Abstract

 In an erroneous insertion prevention structure of electric connectors in a fitting structure between a plug (3, 5, 12 or 14) and a receptacle (2, 4, 11 or 13) of each of the electric connectors provided with insulating housings (3a, 5a, 12a or 14a, and 2a, 4a, 11 a or 13a) and a plurality of contacts (6, 7, 8, 6a, 7a, 8a, 16, 16a) to be fixedly positioned on the insulating housings in a case where a plurality of the electric connectors at least having the same number of contacts and substantially the same shape and dimensions are mounted on an apparatus, the insulating housings of the plug and the receptacle are provided with a fitting portion including a key projection (3b, 5b, 12b or 14b) and a key groove (2b, 4b, 11 b or 13b) which allows the key projection to be fitted thereto respectively, and groups of the contacts of the connectors include combinations of the contacts having pitches in the vertical direction or in the lateral direction different from each other.

Description

[0001] The present invention relates to an erroneous insertion prevention structure of electric connectors.

[0002] In the related art, in a fitting structure between a plug and a receptacle of an electric connector, positioning for fitting thereof is achieved (key shape a) by for example, arranging a four-core contact equally on the left side and the right side with respect to a center axis "a", providing a key projection 10b on a plug 10 on one side, and providing a key groove 9b corresponding thereto on a receptacle 9 on the other side as illustrated in Fig. 5. As disclosed in JP-A-2010-165624, a configuration in which a pair of erroneous fitting preventing keys are provided is known.

[0003] In addition, as illustrated in Fig. 6, when mounting a plurality of electric connectors having the same number of contacts and substantially the same shape and dimension on an apparatus, the connectors are differentiated from other connectors by a key shape with key grooves 20 and key projections 21 at different positions respectively on insulating housings of the plugs and the receptacles. However, in this configuration, increase in types of key shape is limited due to limitations of space on the insulating housing, and there are limitations to the variety of configurations in a limited space.

[0004] An erroneous insertion prevention structure of an electric connector according to the invention is intended to solve the above-described problem, allow increase in type of a key shape in a limited space, and hence allow a variety of configurations of an electric connector while contributing to space saving.

[0005] Accordingly, there is provided an erroneous insertion prevention structure of electric connectors in a fitting structure between a plug and a receptacle of each of the electric connectors provided with insulating housings and a plurality of contacts to be fixedly positioned on the insulating housings in a case where a plurality of the electric connectors at least having the same number of contacts and substantially the same shape and dimensions are mounted on an apparatus, wherein the insulating housings of the plug and the receptacle are provided with a fitting portion including a key projection and a key groove which allows the key projection to be fitted thereto respectively, and groups of the contacts of the connectors include combinations of the contacts having pitches in the vertical direction or in the lateral direction different from each other.

[0006] The positions of the fitting portions each including the key groove and the key projection may be the same, or may be different from each other among the respective electric connectors. The configuration in which the positions of the fitting portions are different from each other provides a larger number of combinations of the key shapes.

[0007] Preferably, a pitch between the contacts is widened to an extent that allows a thick cable to be connected to one of the contacts on the plug side. In this configuration, the thick cable may be used even though the size of the connector is small, which contributes to improvement of apparatus performances.

[0008] According to the erroneous insertion prevention structure of the electric connector of the present invention, a larger number of combinations are achieved by combinations on the basis of the difference in pitches of the contacts in the lateral and vertical directions in addition to the number of combinations of the fitting portions formed on the insulating housings, whereby the number of types of the key shapes may be increased in a limited space. Therefore, the invention achieves a superior advantage that the electric connector which satisfies a variety of requirements in the configuration without changing the height or the width of the connector from those of the related art in a case where a plurality of number of the electric connectors having the same number of contacts and substantially the same shape and dimensions are mounted on the apparatus.

Fig. 1 is a front view of an erroneous insertion prevention structure of an electric connector according to a first embodiment of the invention;

Fig. 2 is a front view of an erroneous insertion prevention structure of an electric connector according to a second embodiment of the invention;

Fig. 3A is a front view illustrating a plug of the erroneous insertion prevention structure of the electric connector of the first embodiment;

Fig. 3B is a cross-sectional view taken along the line X-X in Fig. 3A;

Fig. 4A is a front view of a plug of a related art corresponding to Fig. 3A;

Fig. 4B is a cross-sectional view taken along the line Y-Y in Fig. 4A corresponding to Fig. 3B;

Fig. 5 is a front view illustrating an erroneous insertion prevention structure of an electric connector of the related art; and

Fig. 6 is a front view illustrating the erroneous insertion prevention structure of the related art when a plurality of the electric connectors is mounted.

[0009] An erroneous insertion prevention structure 1 of an electric connector according to the invention allows an increase in key type not only by changing the key shape on insulating housings of a plug and a receptacle but also by changing an array pitch of the contacts as illustrated in Fig. 1 to Fig. 3B.

First Embodiment

[0010] Fig. 1 illustrates the erroneous insertion prevention structure 1 of the electric connector according to a first embodiment of the invention, including a key shape A and a key shape B. The key shape A is formed on a connector including a receptacle 2 having an insulating housing 2a and contacts 6, 7, and 8 fixedly positioned on the insulating housing 2a, and a plug 3 including an insulating housing 3a and contacts 6a, 7a, and 8a provided on the insulating housing 3a at positions corresponding to the contacts 6, 7, and 8.

[0011] In contrast, the key shape B is formed on a connector including a receptacle 4 having an insulating housing 4a and the contacts 6, 7, and 8 fixedly positioned on the insulating housing 4a, and a plug 5 including an insulating housing 5a and the contacts 6a, 7a, and 8a provided on the insulating housing 5a at positions corresponding to the contacts 6, 7, and 8.

[0012] As illustrated in Fig. 1, a fitting hole 2c of the insulating housing 2a on the receptacle 2 side is formed with a key groove 2b of a depressed shape at a position shifted leftward with respect to a center axis "a" thereof. In contrast, the projecting insulating housing 3a on the plug 3 side is formed with a key projection 3b at position symmetry with the key groove 2b of the fitting hole 2c of the receptacle 2. A key groove 4b and a key projection 5b formed on the receptacle 4 and the plug 5 of the key shape B are also formed at the same position as the key groove 2b and the key projection 3b, respectively.

[0013] The arrangement of the contacts 6, 7, and 8 of the fitting holes 2c and 4c on the receptacle 2 and 4 sides is as illustrated in Fig. 1. In the key shape A, the contacts 6 and 7 are arranged on the fitting hole 2c on the left side of the center axis "a" and the contact 8 is arranged thereon on the right side thereof. In the key shape B, the contact 6 is arranged on the fitting hole 4c on the left side of a center axis b, and the contacts 7 and 8 are arranged thereon on the right side thereof. Then, the contacts 6a, 7a, and 8a of the plugs 3 and 5 corresponding thereto are arranged at positions corresponding to the contacts 6, 7, and 8 of the receptacles 2 and 4. In this manner, the key shape A and the key shape B have array pitches of the contacts shifted from each other so as to prevent the erroneous insertion and allow identification thereof.

[0014] The arrangement of the key groove 2b in Fig. 1 is an example only, and three combinations are possible in addition thereto only by changing the arrangement of the key groove such as providing at the position of the center axis "a", or at the position shifted rightward with respect to the center axis "a". Also, in contrast to the example described above, the contact array in the key shape A may be varied, for example, by arranging the contact 6 on the left side of the center axis "a" and arranging the contacts 7 and 8 on the right side thereof. In this manner, there are three combinations including a case of arranging equally in the lateral direction with respect to the center axis "a". At this time, the arrangement in the key shape B is differentiated from that of the key shape A as a matter of course.

Second Embodiment

[0015] Fig. 2 illustrates an erroneous insertion prevention structure of an electric connector according to a second embodiment of the invention including a key shape C and a key shape D. The key shape C is formed on a connector including a receptacle 11 having an insulating housing 11a and four-core contacts 16 fixedly positioned on the insulating housing 11a, and a plug 12 including an insulating housing 12a and contacts 16a provided on the insulating housing 12a at positions corresponding to the contacts 16.

[0016] As illustrated in Fig. 2, a fitting hole 11c on the insulating housing 11a on the receptacle 11 side of the key shape C is formed with a key groove 11 b of a depressed shape at a position shifted leftward with respect to the center axis "a" thereof. The projecting insulating housing 12a on the plug 12 side is formed with a key projection 12b at position symmetry with the key groove 11b of the fitting hole 11c of the receptacle 11. In contrast, a fitting hole 13c on an insulating housing 13a of a receptacle 13 of the key shape D is formed with a key groove 13b of a depressed shape on the center axis "a" thereof, and a key projection 14b on an insulating housing 14a on a plug 14 side is also formed on the center axis.

[0017] The four-core contacts 16 --- on the receptacle 11 side of the key shape C are arranged in such a manner that duplex contacts 16 and 16 on the upper side are arranged at a pitch "p" wider than those on the lower side. The contacts 16a on the plug 12 side are arranged at a pitch corresponding thereto. In contrast, in the key shape D, the four-core contacts 16 on the receptacle 13 side are arranged in such a manner that the duplex contacts 16 and 16 on the lower side are arranged at a pitch wider than those on the upper side, and the contacts 16a on the plug 14 side are arranged also at a pitch corresponding thereto, so that the erroneous insertion of the electric connectors of the key shape C and the key shape D is prevented, and the identification thereof is enabled.

[0018] As described above, in the case of the contacts having three or more cores, the types of the key shape may be increased by changing the arrangement by changing the pitch from pair to pair or by changing the arrangement by changing the pitch from one contact to another. In the same manner, in the contacts having three or more cores, the number of combinations of the key shape may be increased by combining different pitches on the upper side and the lower side. Accordingly, the fitting structures of the receptacle and the plug having a number of different arrangements may be obtained.

[0019] By selecting combinations of the plug and the receptacle having key shapes different from each other from among the combinations of the plug and the receptacle which can be fitted to each other and which are obtained in a manner described above arbitrarily, mounting of the plurality of electric connectors on the apparatus in a form which does not allow the erroneous insertion is facilitated and, in addition, a number of configurations within a saved space are allowed as illustrated later.

[0020] Figs. 3A and 3B are drawings explaining an example of usage of the electric connector having the erroneous insertion prevention structure according to the invention configured as described above with an example of the plug 3 of the key shape A in the first embodiment described above. In other words, in the plug 3 in the case of the key shape A illustrated in Figs. 3A and 3B (see Fig. 1), unlike the configuration of the related art in which the contacts 6a and 8a are arranged equally on the left side and the right side with respect to the center axis "a" (see Figs. 4A and 4B), the contact 7a at the center is shifted rightward with respect to the center axis "a" to widen the pitch with respect to the contact 8a, whereby a thick cable is allowed to be connected to the contact 8a provided in a wide space. This is because a radial dimension B of a mounting hole 15a of the plug 3 of the key shape A may be set to be larger than a radial dimension A (see Fig. 4B) of a contact insertion hole 15 of the related art so as to satisfy the relationship of B>A as illustrated in the vertical cross-sectional view of Fig. 3B.

[0021] In this manner, according to the invention, by changing the pitch of the contacts, in a case where a plurality of the same type of connectors are mounted, various demands in configuration such as increasing the thickness of a cable as well as increasing the types of the key identification in a limited space are achieved without changing the height or the width of the connectors.

[0022] The erroneous insertion preventing structure of the electric connector according to the invention may be applied widely as a structure of an electric connector contributing to space saving.

Claims

1. An erroneous insertion prevention structure of electric connectors in a fitting structure between a plug (3, 5, 12 or 14) and a receptacle (2, 4, 11 or 13) of each of the electric connectors provided with insulating housings (3a, 5a, 12a or 14a, and 2a, 4a, 11a or 13a) and a plurality of contacts (6, 7, 8, 6a, 7a, 8a, 16, 16a) to be fixedly positioned on the insulating housings in a case where a plurality of the electric connectors at least having the same number of contacts and substantially the same shape and dimensions are mounted on an apparatus, characterized in that: the structure is provided with:

a fitting portion including a key projection (3b, 5b, 12b or 14b) and a key groove (2b, 4b, 11b or 13b) that allows the key projection to be fitted thereto respectively, in the insulating housings of the plug and the receptacle, wherein

groups of the contacts of the connectors include combinations of the contacts having pitches in the vertical direction or in the lateral direction different from each other.

2. The erroneous insertion prevention structure of an electric connector according to claim 1, wherein the positions of the fitting portions each including the key groove (2b, 4b, 11 b or 13b) and the key projection (3b, 5b, 12b or 14b) are the same among the respective electric connectors.

3. The erroneous insertion prevention structure of an electric connector according to claim 1, wherein the positions of the fitting portions each including the key groove (2b, 4b, 11b or 13b) and the key projection (3b, 5b, 12b or 14b) are different from each other among the respective electric connectors.

4. The erroneous insertion prevention structure of an electric connector according to claim 1, wherein a pitch between the contacts (6, 7, 8, 6a, 7a, 8a, 16, 16a) is widened to an extent that allows a thick cable to be connected to one of the contacts on the plug side.

Drawing