Field of the Invention The present invention relates to a plug and a receptacle that are electrically connected by inserting plug pins of the plug into pin receivers of the receptacle through insertion ports of the receptacle, respectively. Background of the Invention

A plug is usually used for being inserted into a receptacle. There is known a receptacle with a door body capable of pivoting to cover insertion ports of the receptacle for the purpose of preventing dust deposition on the insertion ports and protecting the insertion ports from an external atmosphere (see, e.g., Japanese Unexamined Patent Application Publication No. 11-185861) .

By the way, in such plug and receptacle, plug pins of the plug are inserted into pin receivers of the receptacle to come into contact with terminal plates of the receptacle, respectively, so that an electrical connection therebetween is made. However, in such plug and receptacle, it is difficult to prevent an infiltration of water into between the plug pins of the plug.

Summary of the Invention

In view of the above, the object of the present invention is to provide a plug and a receptacle capable of

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C0NFIRMATI0N COPY ensuring waterproof performance by preventing the infiltration of water into between the plug pins of the plug In accordance with a first aspect of the present invention, there is provided a plug including: a plug body; a plurality of plug pins protruding from a tip end surface of the plug body, the plug pins being adapted to be inserted into respective insertion ports formed on a plug insertion surface of a receptacle; and a waterproof seal member provided to the tip end surface through which the plug pins are extended, the waterproof seal member being in contact with the plug body, wherein the waterproof seal member is in contact with the plug insertion surface of the receptacle and surrounds the plug pins in the state where the plug pins are inserted into the respective insertion ports of the receptacle.

The plug body may include a tip end cover defining the tip end surface of the plug body and a body part coupled to the tip end cover, and the waterproof seal member may be protruded beyond the tip end surface of the plug body and interposed between the tip end cover and the body part.

With such configuration, the waterproof seal member is in contact with the plug body and the plug insertion surface of the receptacle unit and surrounds the plug pins in the state where the plug pins are inserted into the respective insertion ports of the receptacle. Therefore, the waterproof seal member prevents infiltration of water toward the plug pins. Accordingly, it is possible to ensure the waterproof performance because the water is prevented from infiltrating into between the plug pins of the plug.

In accordance with a second aspect of the present invention, there is provided a plug including: a plug body to be inserted into a recess formed in a receptacle; a plurality of plug pins protruding from a tip end surface of the plug body, the plug being connected to the receptacle by inserting the plug pins into respective insertion ports formed in a bottom surface of the recess of the receptacle; and a waterproof seal member provided on an outer peripheral surface of the plug body to contact with the plug body, the waterproof seal member being in contact with an inner surface of the recess of the receptacle and surrounding the plug pins in the state where the plug body is inserted into the recess of the receptacle.

The plug body may include a tip end cover defining the tip end surface of the plug body and the body part coupled to the tip end cover, and the waterproof seal member may be protruded beyond the outer peripheral surface of the plug body and interposed between the tip end cover and the body part .

With such configuration, the waterproof seal member achieves waterproofing between the tip end surface of the plug body and the recess in the state where the tip end portion of the plug body is inserted into the recess of the receptacle unit. Besides, the waterproof seal member prevents water from infiltrating into the plug body through between the tip end cover and the body part. In addition, in the state before the tip end portion of the plug body is inserted into the recess of the receptacle unit, the waterproof seal member also prevents water from infiltrating into the plug body through between the tip end cover and the body part. The waterproof seal member may be protruded beyond the tip end surface of the plug body to the tip end side.

With such configuration, even if waterdrops are stuck on the tip end surface of the tip end cover, the waterproof seal member prevents the waterdrops from flowing toward the plug body side. Therefore, the waterdrops are prevented from being stuck on a user's hand when the user holds the plug body. Accordingly, it is possible to avoid the use from connecting and disconnecting the plug to and from the receptacle in the state where the waterdrops are stuck on his/her hand.

In accordance with a third aspect of the present invention, there is provided a receptacle including: a receptacle unit provided with a recess into which a tip end portion of a plug is adapted to be inserted, the receptacle being connected to the plug by inserting plug pins protruding from a tip end surface of the plug into respective insertion ports formed in a bottom surface of the recess; and a waterproof seal member provided on the bottom surface and/or a side surface of the recess of the receptacle unit to contact with the receptacle unit, the waterproof seal member being in contact with the plug and surrounding the plug pins of the plug in the state where the tip end portion of the plug is inserted into the recess of the receptacle unit.

With such configuration, a gap is generated between the inner surface of the recess and the plug body in the state that the tip end portion of the plug body is inserted into the recess of the receptacle unit so that water would infiltrate to the plug pin through the gap. The waterproof seal member is in contact with the plug body and the receptacle unit and surrounds the plug pins while being interposed between an opening of the recess and the plug pins. Therefore, the waterproof seal member prevents infiltration of water flowing from the opening of the recess to the plug pins. Accordingly, it is possible to ensure the waterproof performance because the water is prevented from infiltrating into between the plug pins of the plug.

The receptacle unit may be provided with a door body pivotable between a closed position in which an opening of the recess is closed and an opened position in which the opening of the recess is exposed to the outside. In this case, the plug pins of the plug remain in the respective insertion ports of the receptacle unit in the state where the tip end portion of the plug is inserted into the recess of the receptacle unit when the door body is in the opened position.

With such configuration, the door body in the opened position holds the state where the plug pins are inserted into the respective pin receivers of the receptacle when the tip end portion of the plug body is inserted into the recess of the receptacle unit. From a viewpoint of ensuring waterproof performance, that is preferable.

In accordance with a fourth aspect of the present invention, there is provided a plug and receptacle including: a plug including a plug body, and a plurality of plug pins protruding from the plug body; and a receptacle including a receptacle unit provided with a recess into which a tip end portion of the plug body is adapted to be inserted, the plug and the receptacle being connected to each other by inserting the plug pins of the plug into respective insertion ports formed in a bottom surface of the recess; and a waterproof seal member provided to a tip end surface through which the plug pins of the plug are extended, the waterproof seal member being in contact with the plug body, wherein the waterproof seal member is in contact with an inner surface of the recess of the receptacle unit and surrounds the plug pins in the state where the tip end portion of the plug body is inserted into the recess of the receptacle unit.

With such configuration, a gap is generated between the inner surface of the recess and the plug body in the state that the tip end portion of the plug body is inserted into the recess of the receptacle unit so that water would infiltrate toward the plug pin through the -gap. The waterproof seal member is in contact with the plug body and the inner surface of the recess of the receptacle unit and surrounds the plug pins while being interposed between an opening of the recess and the plug pins. Therefore, the waterproof seal member prevents infiltration of water flowing from the opening of the recess to the plug pin. Accordingly, it is possible to ensure the waterproof performance because the water is prevented from infiltrating into between the plug pins of the plug.

In accordance with a fifth aspect of the present invention, there is provided a plug and receptacle including: a plug including a plug body, and a plurality of plug pins protruding from the plug body; and a receptacle including a receptacle unit provided with a recess into which a tip end portion of the plug body is adapted to be inserted, the plug and the receptacle being connected to each other by inserting the plug pins of the plug into respective insertion ports formed in a bottom surface of the recess; and a waterproof seal member provided on an outer peripheral surface of the plug body to contact with the plug body, the waterproof seal member being in contact with an inner surface of the recess of the receptacle unit and surrounding the plug pins in the state where the tip end portion of the plug body is inserted into the recess of the receptacle unit.

With such configuration, a gap is generated between the inner surface of the recess and the plug body in the state that the tip end portion of the plug body is inserted into the recess of the receptacle unit so that water would infiltrate to the plug pin through the gap. The waterproof seal member is in contact with the plug body and the inner surface of the recess of the receptacle unit and surrounds the plug pins while being interposed between an opening of the recess and the plug pins. Therefore, the waterproof seal member prevents infiltration of water flowing from the opening of the recess to the plug pin. Accordingly, it is possible to ensure the waterproof performance because the water is prevented from infiltrating into between the plug pins of the plug.

According to the present invention, there are provided a plug and a receptacle capable of preventing the infiltration of water into between the plug pins of the plug and ensuring waterproof performance. Brief Description of the Drawings The objects and features of the present invention will become apparent from the following description of embodiments, given in conjunction with the accompanying drawings, in which:

Fig. 1 is a perspective view of a plug and receptacle of a first embodiment of the present invention;

Fig. 2 is a longitudinal-sectional view of the plug and receptacle of the first embodiment;

Fig. 3 is an exploded perspective view of the receptacle of the first embodiment;

Fig. 4A is a perspective view showing an exploded perspective structure of a receptacle block of the first embodiment, and Fig. 4B is a plane view showing a front structure of pin insertion ports;

Fig. 5A is a perspective view showing a perspective structure of a door body viewed from above in the first embodiment, and Fig. 5B is a cross-sectional view showing a cross-sectional structure of the door body taken along line A-A in Fig. 5A;

Fig. 6 is a cross-sectional view showing a cross- sectional structure of the receptacle of the first embodiment ;

Fig. 7 is a perspective view of the plug adapted to be connected to the receptacle of the first embodiment, which is viewed from below;

Fig. 8 is a bottom view of the plug adapted to be connected to the receptacle of the first embodiment, which is viewed from below;

Fig. 9A is an exploded perspective view showing an exploded perspective structure of a plug adapted to be connected to the receptacle of the first embodiment, and Fig 9B is a plane view of the plug body viewed from its front side ;

Fig. 10A and 10B show the plug adapted to be connected to the receptacle of the first embodiment, wherein Fig. 10A is a plane view showing a front structure of a waterproof member, and Fig. 10B is a side view showing a side structure of the waterproof member;

Fig. 11 is a cross-sectional view of a tip end portion of the plug of the first embodiment;

Figs. 12A to 12D are views for explaining a process of inserting the plug into the receptacle of the first embodiment, wherein Fig. 12A is a schematic view showing a relation between the door body and the plug when the door body is in the closed state, Fig. 12B is a schematic view showing a relation between the door body and the plug when the door body is in the opened state, Fig. 12C is a schematic view showing a state where the plug is inserted from the state of Fig. 12B, and Fig. 12D is a schematic view showing a state where a protruding part is accommodated in a restricting part;

Figs. 13A to 13C are views for explaining a process of inserting the plug into the receptacle of the first embodiment, wherein Fig. 13A is a schematic view showing a state where a holding part is engaged with the protruding part, Fig. 13B is a schematic view showing a state where the protruding part stays on a top surface of the holding part, and Fig. 13C is a schematic view showing a state where the protruding part is accommodated in an engaging part; Figs. 14A and 14B are views for explaining a process of detaching the plug from the receptacle of the first embodiment, wherein Fig. 14A is a schematic view showing a state where a user pushes the door body down, and Fig.l4B is a schematic view showing a movement of the door body after detaching the receptacle;

Fig. 15 is a longitudinal-sectional view of a plug and receptacle of a second embodiment of the present invention;

Fig. 16 is a longitudinal-sectional view of a plug and receptacle of a third embodiment of the present invention;

Fig. 17 is a longitudinal-sectional view of a plug and receptacle of a fourth embodiment of the present invention;

Fig. 18 is a cross-sectional view showing a cross- sectional structure of a tip end portion of the plug body in accordance with another embodiment showing an appearance of the plug and receptacle of the present invention; and

Fig. 19 is a cross-sectional view showing a cross- sectional structure of a tip end portion of the plug body in accordance with still another embodiment showing an appearance of the plug and receptacle of the present invention .

Detailed Description of the Embodiments (First Embodiment)

With reference to Figs. 1 to 13C, there will be described a plug and a receptacle in accordance with a first embodiment of the present invention. In the present embodiment, a receptacle A installed on an outer wall of a house and a plug B to be inserted into the receptacle A are exemplified as shown in Figs. 1 and 2. Figs. 1 and 2 show the state where the plug B is inserted into the receptacle A As shown in Fig. 3, the waterproof receptacle (hereinafter, referred to as "receptacle A") includes: a receptacle unit 1A provided with insertion ports 75 (see Figs. 4A and 4B) into which plug pins 91 (see Fig. 7) of a plug B are inserted; and a door opening/closing mechanism IB for opening and closing the insertion ports 75 while being provided in the receptacle unit 1A.

Hereinafter, a direction indicating front and rear sides of a wall surface of the wall is defined as "front- rear direction X", a vertical direction is defined as "up- down direction Z", and a direction perpendicular to both the front-rear direction X and the up-down direction Z is defined as "left-right direction Y" . Further, in the front- rear direction X, a direction heading to the front side of the wall surface is defined as "forward", and a direction heading to the rear side of the wall surface is defined as "rearward" .

The receptacle unit 1A is provided with: a receptacle block 2 connected to an electric wire and serving to supply electric power from the wire to the plug connected thereto; and a body 3 in which the receptacle block 2 is accommodated In the rear side of the body 3, a waterproof packing (hereinafter, referred to as "packing 4") is interposed between the wall surface and the body 3 in the front-rear direction X. Both the body 3 and packing 4 are fastened to a mounting frame 5 disposed on the rear side of the wall surface by using screws SCI. The receptacle block 2 is fixed to the body 3 by using screws SC2. Further, a decorative cover 6 is attached to a front face of the body 3.

The body 3 includes a body part 20 as a substantially rectangular frame, and a holding section 21 protruding forwardly from the body part 20. The receptacle block 2 is accommodated in the holding section 21. Further, through holes 22 for inserting the screws SCI therethrough are formed at upper and lower ends of a central portion of the body 3 in the left-right direction Y. Over the through holes 22 at the lower end, a cover 23 for covering the screw SCI is attached.

The packing 4 includes a body part 30 as a substantially rectangular frame and a lid part 31 covering the front surface of the body part 30. In an upper portion of the lid part 31, there is provided a wire opening 32 having a substantially rectangular shape formed through the lid part 31 in the front-rear direction X. Electric wires are inserted into the wire opening 32 from the rear side of the wall surface. In a joint portion between an outer periphery of the lid part 31 and the body part 30, a step portion 33 is formed over the joint portion. The packing 4 and the body 3 are engaged with each other by the step portion 33. Further, through holes 34 for inserting the screws SCI are provided at positions of packing 4 corresponding to the through holes 22 of the body 3.

The mounting frame 5 includes a body part 40 configured as a substantially rectangular frame in which an opening 41 with an approximately rectangular shape is formed. In both sides of the opening in the up-down direction Z, mounting holes 42 formed through the body part 40 in the front-rear direction X are provided, so that screw members (not shown) are inserted thereinto to attach the body part 40 to a switch box (not shown) disposed in the rear side of the wall surface. Besides, in an upper and a lower side of the respective mounting holes 42, there are provided through holes 43 that are formed through the body part 40 in the front-rear direction X while corresponding to the through holes 34 of the packing 4.

The decorative cover 6 includes: a side wall portion

50 covering the holding part 21 from the front side and having a curved surface; and an upper wall 51 covering an upper portion of the side wall portion 50 and tilting upwardly as it goes backwardly. The decorative cover 6 is constituted by the side wall portion 50 and the upper wall

51 to be opened downwardly.

The door opening/closing mechanism IB includes a door body 7 for opening and closing the insertion ports 75, a shaft 8 attached to the door body 7, and a shaft support body 9 for accommodating and holding the shaft 8. The shaft support body 9 is attached to the body 3 with screws SC3. Further, a pair of coil springs (hereinafter, referred to as "springs 10") for biasing the door body 7 to the insertion ports 75 are attached to the shaft 8.

In the door opening/closing mechanism IB, the shaft 8 is inserted into a shaft through hole 9a formed in the shaft support body 9, and then the springs 10 are attached to both outer sides of the shaft 8 protruding from the shaft through hole 9a in the left-right direction Y. In this state, the door body 7 is attached to the shaft 8 at outer portions than the springs 10 in the left-right direction Y, so that the door body 7 can pivot about the shaft 8. Accordingly, the operation of opening and closing the door body 7 is carried out by pivoting the door body 7 about the shaft 8.

In the receptacle block 2, as shown in Fig. 4A, a receptacle body 11 and a receptacle cover 12 serving as a case held by the body 3 (see Fig. 3) are molded of a synthetic resin by injection molding. In an internal space defined by the receptacle body 11 and the receptacle cover 12, there are received three terminal plates 13, four locking springs 14, and two release buttons 15. Further, the receptacle block 2 includes a socket cover 16 for receiving plug pins 91 (see Figs. 7 and 8), which is a different member from the receptacle body 11 and the receptacle cover 12.

The receptacle body 11 and the receptacle cover 12 respectively have a fixing part 11a and a fixing part 12a to be fitted with the socket cover 16. In a bottom wall lib of the receptacle body 11, there are provided wire through holes 11c that are formed through the bottom wall lib in the front-rear direction X to communicate with the above internal space. Electric wires are inserted into the wire through holes 11c. Further, in the bottom wall lib, there are provided operation holes lid for manipulating the release buttons 15, the operation holes lid being formed through the bottom wall lib in the front-rear direction X.

Terminal plate 13 is constituted by two power terminal plates 13A and 13B arranged in the left-right direction Y, and one ground terminal plate 13B adjacent to the power terminal plates 13A and 13B in the front-rear direction X.

Each of the power terminal plates 13A and 13B includes: a flat-plate base 60 extending in the up-down direction Z and the left-right direction Y; a pin receiver 61 extending downwardly from the base 60; a pair of locking spring contact portions 62 extending rearwardly from a lower end of the base 60; and a pair of wire contact portions 63 extending rearwardly from an upper end of the base 60. The locking spring 14 is accommodated between the locking spring contact portion 62 and the wire contact portion 63 in the up-down direction Z, while being in contact with the base 60 The release button 15 is interposed between the locking springs 14 disposed adjacent to each other in the left-right direction Y. The pin receiver 61 is provided with a pair of first gripping pieces 64A, and a second gripping piece 64B disposed adjacent to the first holding pieces 64A in the left-right direction Y.

The ground terminal plate 13C is provided with a base

(not shown), a pin receiver 65, a pair of locking spring contact portions 66, and a pair of wire contact portions 67, like the power terminal plate 13A and 13B. In the grounding terminal plate 13C, there are provided two spring contact portions 66 and two wire contact portions, which are separated from each other in the left-right direction Y respectively. Further, the locking spring 14 is accommodated between the locking spring contact portion 66 and the wire contact portion 67, and the release button 15 is interposed between 'the locking springs 14 disposed adjacent to each other in the left-right direction Y.

The socket cover 16 includes a body part 70 having a substantially square shape viewed from the up-down direction Z. In an upper portion of the body part 70, a side wall surface 71 for fitting with the fixing part 11a and the fixing part 12a is provided. Further, in a lower portion of the body part 70, a recess 73 formed into a circular shape viewed from the up-down direction Z and recessed upwardly from an under surface 72 is provided. In a bottom surface (plug insertion surface) 73a of the recess 73, insertion ports 75 are provided.

As shown in Fig. 4B, the insertion ports 75 include: a power-pin insertion port 75a having a substantially rectangular shape whose long side is extended in the left- right direction Y viewed from the up-down direction Z; a power-pin insertion port 75b with a substantially L-shape; and a ground-pin insertion port 75c with a substantially circular shape. The power-pin insertion ports 75a, 75b are arranged in the left-right direction Y, and the ground-pin insertion port 75c is positioned between the power insertion ports 75a, 75b in the left-right direction Y and rearward of the power insertion ports 75a, 75b. The tip end portion 90c of the plug body 90 can be inserted into the recess 73 of the receptacle unit 1A, and the plug pins 91 are detachably inserted through the insertion ports 75.

Hereinafter, a way of connecting and disconnecting an electric wire and the receptacle block 2 will be described schematically. When being connected to the receptacle block 2, the electric wire is inserted through the wire through hole 11c. Then, the electric wire comes into contact with the locking spring 14 and is pressed by the locking spring 14 against the wire contact portion 63. Thus, the connection of the electric wire and the terminal plate 13 is completed. When the electric wire is disconnected from the receptacle block 2, a tool such as a flat-blade screwdriver is inserted into the operation hole lid to push the release button 15 forwardly. Accordingly, the release button 15 pushes the locking spring 14 to decrease the force of the locking spring 14 pressing the electric wire. In this state, the electric wire is pulled backwardly to be disconnected from the receptacle block 2.

As shown in Fig. 5A, the door body 7 has a base 80 formed into a flat plate. In the base 80, a recess 81 recessed downwardly from a surface 80a of a center portion thereof is provided. At a rear end of the base 80, a pair of shaft support portions 82 having through holes for inserting the shaft 8 (see Fig. 3) therethrough is provided. At a front end and a center portion of the base 80 in the left-right direction Y, a depression 83 curved downwardly is provided.

The recess 81 includes a bottom 84 forming a lower portion of the recess 81 and joint portions 85 joining the bottom 84 and the surface 80a of the base 80. The joint portions 85 include a front slope face 85a joining the bottom 84 and the surface 80a of the base 80 in the front- rear direction X and tilting backwardly as it goes downward, and a pair of side slope faces 85b joining the bottom 84 and the surface 80a of the base 80 in the left-right direction Y and coming closer to each other as they go downward.

In the central portion of the recess 81 in the front- rear direction X, there is provided a partition wall 86 protruding upwardly from the bottom 84 and joining the side slope faces 85b that are opposed to each other in the left- right direction Y. A rear surface 86a (see Fig. 5B) of the partition wall 86 is formed into a plane shape extending along the left-right direction Y and the up-down direction Z Besides, the partition wall 86 divides the recess 81 into a restricting part 87 positioned forward of the partition wall 86 and a fixing part 88 positioned rearward of the partition wall 86.

In the bottom 84 corresponding to the restricting part 87, a plane 84a extending along the front-rear direction X and the left-right direction Y is provided. In the bottom 84 corresponding to the fixing part 88, a plane 84b (see Fig 5B) similar to the plane 84a and a slope 84c tilting upwardly as it goes rearward are provided. The slope 84c is formed to have a tilting angle smaller than those of the front slope face 85a and the side slope faces 85b.

On a front face 86b of the partition wall 86, there are provided, e.g., two slope portions 89 joining a top face 86c of the partition wall 86 and the plane 84a, and tilting downwardly as it goes forward from the front face 86b. The slope portions 89 are arranged spaced apart from each other in the left-right direction Y.

As shown in Fig. 6, the receptacle block 2 is fitted to a fitting part 24 provided in a lower end portion of the holding section 21 so that its position relative to the holding section 21 is determined. Specifically, the receptacle block 2 is inserted into an opening 25 provided in the fitting part 24 and comes into contact with a contacting face 26 around the peripheral edge of the opening 25, so that the bottom surface 73a of the socket cover 16 in which the insertion ports 75 are formed is positioned inwardly of the opening 25 of the receptacle A. In the state where the receptacle block 2 is fixed to the body 3, the recess 73 is arranged so as to tilt downwardly and rearwardly, while being opened downwardly. Accordingly, the bottom surface 73a of the recess 73 and the insertion ports 75 are exposed downwardly.

As for the receptacle A, "a closed state" is defined by a state where the door body 7 is in contact with a bottom end surface 52 of the side wall portion 50 in the decorative cover 6 (the door body 7 illustrated by the solid line in Fig. 6) . The position of the door body 7 in the closed state is referred to as "a closed position". Further, the bottom end surface 52 is formed so as to be parallel to the bottom surface 73a of the recess 73 in the socket cover 16.

The shaft 8 is disposed near the opening 25, so that the door body 7 can pivot downwardly from the closed position. Further, as indicated by a long dashed double- short dashed line, "an opened state" is defined by a state where the door body 7 is separated from the bottom end surface 52. The position of the door body 7 in the opened state is referred to as "an opened position". Hereinafter, a direction of operating the door body 7 to the closed state or the opened state is defined as "an opening/closing direction W" . The opening/closing direction W corresponds to a direction in which the spring 10 biases the door body 7. In the opening/closing direction W, a direction heading to the closed position is defined as "a close direction", and a direction heading to the opened position is defined as "an open direction". Further, in the closed position, the base 80 is kept pressed against the bottom end surface 52 of the decorative cover 6 by the spring 10 (see Fig. 3) .

As shown in Fig. 5A, the bottom end surface 52 of the decorative cover 6 is formed to surround the recess 73. Specifically, the decorative cover 6 exposes the bottom surface 73a of the recess 73 downwardly and covers the receptacle block 2 from the front and the left and right side except for the bottom surface 73a. Further, in the closed position, the door body 7 covers the insertion ports 75 (formed in the bottom surface 73a) from below. At this time, the recess 81 is positioned to correspond to the insertion ports 75, and the base 80 comes into contact with the bottom end surface 52 along the circumference thereof.

A structure of the plug B will be described with reference to Figs. 7 to 11.

As shown in Figs. 7 and 8, the plug B includes: a plug body 90 with a substantially cylindrical shape for being held by a user; and plug pins 91 protruding forwardly of a tip end 90a of the plug body 90. Further, in the rear side of the plug body 90, there is provided a cable 92 for supplying an electric power received by the plug pins 91 to an apparatus (not shown) . The plug body 90 and a tip end cover 140 are molded of a synthetic resin by injection molding. Further, the tip end cover 140 and a waterproof seal member 97 are attached to the plug body 90 with screws SC10 and SC11.

The plug body 90 includes: holding portions 93 with a flat shape provided on left and right sides thereof in a center portion thereof in the front-rear direction X and held by the user's fingers; a protruding part 94 protruding downwardly from a lower portion thereof; and a position indicator 95 (see Fig. 1) provided in an upper portion thereof, for allowing the user to recognize visually the orientation of the plug B. Further, in the plug body 90, there is provided the tip end cover 140 with a substantially disc shape joined to the tip end portion 90c of the plug body 90.

The plug pins 91 include: a first power plug pin 91a and a second power plug pin 91b that are to be inse'rted into the power-pin insertion ports; and a ground plug pin 91c that is to be inserted into the ground-pin insertion port. The ground plug pin 91c is protruded further forwardly than the power plug pins 91a, 91b. Further, the power plug pin 91a is formed into a substantially rectangular shape whose long side extends in the left-right direction Y as viewed from the front-rear direction X, the power plug pin 91b is formed into a substantially L-shape as viewed from the front-rear direction X, and the ground plug pin 91b is formed into a round pin shape.

The position indicator 95 (see Fig. 1) is, e.g., a rectangular protrusion. In the case where the position indicator 95 is disposed in the upper portion of the plug B, the power plug pins 91a, 91b are arranged in the left-right direction Y.

The protruding part 94 includes: a lower end portion 94a; a front slope portion 94b tilting upwardly as it goes forward from the lower end portion 94a in the front direction; and side slope portions 94c tilting upwardly as it goes laterally from the lower end portion 94a in the left-right direction Y. Further, at a rear end of the lower end portion 94a, a holding face 94d extending upwardly is provided. A planar contact face 96 extending backwardly from the protruding part 94 is provided rearwardly of the protruding part 94 of the plug body 90. The external diameter of the portion of the plug body 90, corresponding to the contact face 96, is smaller than that of the other cylindrical portions. The front slope portion 94b is formed to have a larger width in the left-right direction Y as it goes forward. The front slope portion 94b is provided with a recess portion 94e that is recessed upwardly and has a substantially triangular shape as viewed from below (see Fig 8). The recess portion 94e serves to reduce the thickness of the protruding part 94, which prevents shrinkage or void from being formed in the protruding part 94 and around it.

The tip end 90a of the plug body 90 is provided with the waterproof seal member 97. The waterproof seal member

97 is made of a rubber or the like. As shown in Figs. 9A to 10B, the waterproof seal member 97 has: a seal member body

98 with an annular shape; a peripheral wall part 99 formed into a substantially cylindrical shape; and a bottom plate 100, and these members are formed integrally. The seal member body 98 is provided around one opening end of the peripheral wall part 99, and the bottom plate 100 is provided in the other opening end of the peripheral wall part 99. In the bottom plate 100, there are formed screw insertion holes 100a and 100b through which the screws SC10 and SCll are to be inserted, respectively. The peripheral wall part 99 of the waterproof seal member 97 is engaged with the cylindrical plug body 90, and then the screws SC10 and SCll are screwed into the plug body 90 through the screw insertion holes 100a and 100b, so that the waterproof seal member 97 is fixed to the plug body 90. In this state, as shown in Figs. 7 and 8, the seal member body 98 of the waterproof seal member 97 protrudes forwardly over an entire circumference of the tip end 90a of the plug body 90. The waterproof seal member 97 is in contact with the plug body 90.

As shown in Figs. 9A and 9B, at the tip end portion

90c of the plug body 90, there is provided an inward protrusion 90d being in contact with the bottom plate 100 of the waterproof seal member 97. The inward protrusion 90d is provided with: an annular protrusion 90e extending over an entire inner circumference 90g of the tip end portion 90c of the plug body 90; and three extension protrusions 90f protruding inwardly and separated from each other in a circumferential direction of the inner circumference 90g.

The tip end cover 140 includes: plug-pin insertion holes 141, 142, 149 formed through the tip end cover 140 in the front-rear direction X, for inserting the power plug pins 91a, 91b and the ground plug pin 91c, respectively; and screw insertion holes 143, 144 formed through the tip end cover 140 in the front-rear direction X, for inserting the screws SC10, SC11. The screw insertion holes 143, 144 are formed at portions corresponding to the screw insertion holes 100a, 100b in the bottom plate 100 of the waterproof seal member 97. The power plug pins 91a, 91b and the ground plug pin 91c protrude forwardly from a tip end surface 147 of the tip end cover 140, i.e., the tip end surface of the plug body 90 while passing through the plug-pin insertion holes 141, 142 and 149, respectively.

As shown in Fig. 11, in the state where the tip end cover 140 is assembled into the plug body 90, the peripheral wall part 99 of the waterproof seal member 97 is compressed by an outer peripheral surface 145 of the tip end cover 140 and the inner circumference 90g of the tip end portion 90c of the plug body 90 while being interposed therebetween. In addition, the bottom plate 100 of the waterproof seal member 97 is compressed by a rear surface 146 of the tip end cover 140 and the inward protrusion 90d, while being interposed therebetween.

Further, in this state, the seal member body 98 of the waterproof seal member 97 is disposed forwardly of the tip end surface 147 of the tip end cover 140, i.e., the tip end surface of the plug body 90. Thus, the seal member body 98 is formed to cover the tip end 90a of the plug body 90 from its front side while being disposed forwardly of the tip end 90a.

Furthermore, as shown in Fig. 2, the waterproof seal member (packing) 97 is disposed between an inner surface of the recess 73 and the plug body 90, in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A.

With reference to Figs. 12A to 14B, a process of connecting the plug B to the receptacle A and a process of disconnecting the plug B from the receptacle A will be described. Figs. 12A to 12D show the process in which the plug B opens the door body 7 to be accommodated in the restricting part 87. Figs. 13A to 13C show the process in which the protruding part 94 of the plug B climbs and passes over the partition wall 86 to be accommodated in the fixing part 88 and then the connection of the receptacle A is completed. Figs. 14A and 14B show the process in which the plug B is disconnected from the receptacle A. Note that the cable 92 of the plug B is omitted in Figs. 12A to 14B.

With respect to the door body 7 in the closed position, as shown in Fig. 12A, the portion of the door body 7 that is protruded from the decorative cover 6 is hooked by the front end of the plug body 90, and the door body 7 is pivoted to the opened position. As another way of opening the door body 7, the user may open the door body 7 by his/her fingers.

As shown in Fig. 12B, the plug pins 91 are directed to the socket cover 16 to be inserted thereinto in the state where the plug pins 91 are located at the position corresponding to the bottom surface 73a of the recess 73 in the socket cover 16. Hereinafter, a direction of inserting the plug pins 91 is referred to as "a plug pin insertion direction V". In the plug pin insertion direction V, a direction of connecting the plug B to the socket cover 16 is referred to as "a connecting direction", and a direction of disconnecting the plug B from the socket cover 16 is referred to as "a disconnecting, direction".

As shown in Fig. 12C, when the plug B is inserted in the connecting direction, the protruding part 94 of the plug B comes into contact with the front end of the door body 7. When the plug B is further inserted in the connecting direction from this state, the door body 7 is further pivoted in the open direction by the front slope portion 94b of the protruding part 94. Accordingly, the lower end portion 94a comes into contact with the door body 7.

As shown in Fig. 12D, when the plug B is further inserted in the connecting direction from the state where the lower end portion 94a is in contact with the door body 7, the protruding part 94 is accommodated in the restricting part 87. Specifically, the protruding part 94 is guided into the restricting part 87 by the front slope face 85a of the door body 7 and then comes into contact with the bottom 84 of the restricting part 87. Thus, the door body 7 pivots in the close direction as the protruding part 94 is guided into the restricting part 87.

Besides, in this state, the plug pins 91 are positioned to correspond to the insertion ports 75 in the plug pins insertion direction V. Specifically, a tip end 91cl of the ground plug pin 91c is inserted into the corresponding insertion port 75 (the ground-pin insertion port 75c) . On the other hand, the power plug pins 91a, 91b are positioned in front of the corresponding insertion ports 75 in the plug pin insertion direction V.

As shown in Fig. 13A, when the plug B is further inserted in the plug pin insertion direction from the state where the protruding part 94 is accommodated in the restricting part 87, the front slope portion 94b of the protruding part 94 comes into contact with the slope portions 89 of the recess 81. Then, the protruding part 94 moves to the top face 86c while sliding on the slope portions 89. The contact of the protruding part 94 with the slope portions 89 makes the door body 7 move in the open direction. Further, the power plug pins 91a, 91b are inserted into the corresponding insertion ports 75 (power- pin insertion ports 75a, 75b) .

As shown in Fig. 13B, when the plug B is inserted into the receptacle A while the lower end portion 94a of the protruding part 94 is in contact with the top face 86c, the door body 7 comes to be moved to the greatest opened position. As shown in Fig. 13C, after passing over the top face 86c, the protruding part 94 is accommodated in the fixing part 88. At that time, the door body 7 pivots to the close direction. The holding face 94d of the protruding part 94 is brought into contact with the partition wall 86, and the contact face 96 comes into contact with the top face 86c. In this way, the connection of the plug B to the receptacle A is completed. In other words, the plug pins 91 are held by the pin receivers 61, 65 (see Fig. 4) .

As described above, the receptacle unit 1A is provided with the door body 7 capable of pivoting between the closed position in which the opening of the recess 73 is covered and the opened position in which the opening thereof is exposed to the outside. In state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A when the door body 7 is in the opened position, the respective plug pins 91 of the plug B are remained in the pin receivers 61, 65 of the receptacle A.

Further, in this state, the tip end portion 91c, which is a portion of the plug body 90 to be inserted into the recess 73, has an outer diameter substantially the same as an inner diameter of the recess 73. Accordingly, the plug body 90 and the recess 73 have a slight gap therebetween. Herein, "a slight gap" means that a gap does not allow a user to put his/her finger thereinto.

At this time, as shown in Fig. 2, the seal member body 98 of the waterproof seal member (packing) 97 provided in the plug B is pressed to the bottom surface 73a of the recess 73 of the receptacle unit 1A, so that they are in close contact with each other. Further, the seal member body 98 of the waterproof seal member (packing) 97 is also in close contact with the plug body 90. Therefore, the waterproof seal member 97 is in close contact with both the plug body 90 and the receptacle unit 1A to become watertight, thereby providing a waterproof seal. In detail, a gap is generated between the inner surface of the recess 73 and the plug body 90 in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A. Through the gap, there is formed a path in which water infiltrates from the opening of the recess 73 to the plug pins 91, and then the water would infiltrate into the path. Herein, the waterproof seal member 97, which is provided at the tip end 90a of the plug body 90 and is in contact with the plug body 90, comes into contact with the inner surface of the recess 73 of the receptacle unit 1A and surrounds the plug pins 91. Additionally, the waterproof seal member 97 is positioned between the opening of the recess 73 and the plug pins 91. Therefore, the waterproof seal member 97 prevents the water from infiltrating to the plug pins 91 from the opening of the recess 73. Accordingly, the infiltration of the water into between the plug pins of the plug B can be prevented. As a result, waterproof performance is ensured.

As shown in Fig. 14A, when a user disconnects the plug B from the receptacle A, the user pushes a proximal portion of the base 80 in the open direction so that the protruding part 94 is not overlapped with the partition wall 86 in the plug pin insertion direction V. In other words, the holding face 94d is in no contact with the partition wall 86. In the state, by pulling the plug B in the disconnecting direction, the user can disconnect the plug B from the receptacle A.

As shown in Fig. 14B, after the plug B is disconnected from the receptacle A, by the biasing force of the spring 10 (see Fig. 3), the door body 7 pivots to the bottom end surface 52 of the decorative cover 6, i.e., to the closed position .

According to the present embodiment, the following effects are expected.

(1) At the tip end 90a of the plug body 90, there is provided the waterproof seal member 97 being in contact with the plug body 90. In the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A, the waterproof seal member 97 comes into contact with the inner surface of the recess 73 of the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91. Accordingly, the waterproof seal member 97 prevents the infiltration of water into between the plug pins of the plug B, thereby ensuring waterproof performance.

(2) In the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A when the door body 7 is in the opened position, the plug pins of the plug B remain in the respective pin receivers 61, 65, which is desirable from a viewpoint of ensuring waterproof performance by the waterproof seal member 97.

(3) In the present embodiment, the seal member body 98 can ensure waterproof performance between the tip end 90a of the plug body 90 and the recess 73, in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A. Further, the peripheral wall part 99 prevents water from infiltrating into the plug body through between the plug body 90 and the tip end cover 140.

Additionally, in the state before the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A, the peripheral wall part 99 also prevents water from infiltrating into the plug body through between the plug body 90 and the tip end cover 140.

Furthermore, the seal member body 98, the peripheral wall part 99, and the bottom plate 100 are formed integrally That is, the seal member body 98, the peripheral wall part 99, and the bottom plate 100 are formed as a single member. Accordingly, the number of components can be reduced as compared with the case where the seal member body 98, the peripheral wall part 99, and the bottom plate 100 are formed individually .

(4) In the present embodiment, even if waterdrops are stuck to the tip end surface 147 of the tip end cover 140, the seal member body 98 prevents the waterdrops from flowing toward the plug body 90, and the waterdrops are prevented from being stuck to a user's hand when the user holds the plug body. Accordingly, it is possible to avoid the user from connecting and disconnecting the plug to and from the receptacle in the state where the waterdrops are stuck to his/her hand.

(5) In the present embodiment, also in the state before the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A, the bottom plate 100 is compressed by the inward protrusion 90d and the tip end cover 140. Accordingly, the infiltration of water into the plug body 90 through between the inward protrusion 90d and the tip end cover 140 can be suppressed.

(Second Embodiment)

Hereinafter, a second embodiment of the present invention will be described with respect to mainly differences between the second embodiment and the first embodiment .

Instead of the configuration shown in Fig. 2, in the present embodiment, a waterproof seal member (packing) 110 is provided on the bottom surface 73a of the recess 73 of the receptacle unit 1A, as shown in Fig. 15. In detail, an annular recess 111 is formed on the bottom surface 73a of the recess 73 of the receptacle unit 1A along the periphery thereof. Inside the recess 111, the waterproof seal member 110, such as an O-ring, is disposed. The waterproof seal member 110 is in contact with the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91.

Further, the waterproof seal member 110 is in contact with the plug body 90 in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A. In other words, the waterproof seal member 110, which is provided on the bottom surface 73a of the recess 73 of the receptacle unit 1A, is pressed by the tip end 90a of the plug body 90, so that the waterproof seal member 110 and the tip end 90a of the plug body 90 are in close contact with each other to become watertight. Further, the waterproof seal member 110 is also in close contact with an inner surface of the recess 111 to become watertight.

Accordingly, in the state where the tip end portion of the plug body is inserted into the recess of the receptacle unit, a gap is generated between the inner surface of the recess 73 and the plug body, so that water would infiltrate to the plug pins from the opening of the recess 73 through the gap. Now, the waterproof seal member 110, which is provided on the bottom surface of the recess 73 of the receptacle unit 1A, is in contact with the receptacle unit 1A and surrounds the plug pins 91. Additionally, the waterproof seal member 110 is interposed between the opening of the recess 73 and the plug pins 91, and is in contact with the plug body 90. Therefore, the waterproof seal member 110 prevents water from infiltrating to the plug pins 91 from the opening of the recess 73. Accordingly, the infiltration of the water into between the plug pins of the plug can be prevented, and waterproof performance is ensured (Third Embodiment)

Hereinafter, a third embodiment of the present invention will be described with respect to mainly differences between the third embodiment and the first embodiment .

Instead of the configuration shown in Fig. 2, in the present embodiment, a waterproof seal member (packing) 120 is provided on the outer peripheral surface 90b of the plug body 90, as shown in Fig. 16. In detail, a recess 121 is formed in the outer peripheral surface 90b of the tip end portion 90c of the plug body 90 to have an annular shape extending over its entire circumference. Inside the recess 121, the waterproof seal member 120, such as an O-ring, is disposed. The waterproof seal member 120 is in contact with the plug body 90.

Further, in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A, the waterproof seal member 120 is in contact with an inner surface of the recess 73 of the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91. In other words, the waterproof seal member 120, which is provided on the outer peripheral surface 90b of the plug body 90, is pressed against a side surface 73b of the recess 73 of the receptacle unit 1A, so that the waterproof seal member 120 and the side surface 73b of the recess 73 are in close contact with each other to become watertight. Further, the waterproof seal member 120 is also in close contact with an inner surface of the recess 121 to become watertight.

Thus, the waterproof seal member 120 is in contact with both the plug body 90 and the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91. Therefore, the waterproof seal member 120 prevents the infiltration of the water flowing from the opening of the recess 73 to the plug pins (it is possible to block the water flow to the plug pins) . Accordingly, the infiltration of the water into between the plug pins of the plug can be prevented, and waterproof performance is ensured.

(Fourth Embodiment)

Hereinafter, a fourth embodiment of the present invention will be described with respect to mainly differences between the fourth embodiment and the first embodiment .

Instead of the configuration shown in Fig. 2, in the present invention, a waterproof seal member (packing) 130 is provided on a side surface 73b of the recess 73 of the receptacle unit 1A, as shown in Fig. 17. In detail, a recess 131 is formed in the side surface 73b of the recess 73 of t the receptacle unit 1A to have an annular shape extending over its entire circumference. Inside the recess 131, the waterproof seal member 130, such as an 0-ring, is disposed. The waterproof seal member 130 is in contact with the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91.

Further, the waterproof seal member 130 is in contact with the plug body 90, in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A. In other words, the waterproof seal member 130, which is provided on the side surface 73b of the recess 73 of the receptacle unit 1A, is pressed by an outer peripheral surface 90b of the plug body 90, so that the waterproof seal member 130 and the outer peripheral surface 90b of the plug body 90 are in close contact with each other to become watertight. Further, the waterproof seal member 130 is also in close contact with an inner surface of the recess 131 to become watertight.

Thus, the waterproof seal member 130 is in contact with both the plug body 90 and the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91. Therefore, the waterproof seal member 130 prevents the infiltration of the water flowing from the opening of the recess 73 to the plug pins (it is possible to block the water flow to the plug pins). Accordingly, the infiltration of the water into between the plug pins of the plug can be prevented, and waterproof performance is ensured.

The present invention is not limited to the above embodiments, and the above embodiments may be modified as follows. In the first embodiment, although the bottom plate 100 is provided in the waterproof seal member 97, the bottom plate 100 may be omitted. In this case, the rear surface 146 of the tip end cover 140 and the inward protrusion 90d come into contact with each other.

In the first embodiment, although the waterproof seal member 97 is formed as a single member, the configuration thereof is not limited thereto. For example, the seal member body 98, the peripheral wall part 99, and the bottom plate 100 may be formed individually. Alternatively, the seal member body 98 and the peripheral wall part 99 may be formed as a single member, and the bottom plate 100 may be formed as a separate member. Alternatively, the peripheral wall part 99 and the bottom plate 100 may be formed as a single member, and the seal member body 98 may be formed as a separate member.

In the first embodiment, the seal member body 98 of the waterproof seal member 97 is disposed forwardly of the tip end surface 147 of the tip cover 140. The seal member body 98, however, may be disposed at the same position or rearwardly of the tip end surface 147 of the tip end cover 140 in the front-rear direction X. In the third embodiment, although the waterproof seal member 120 with an annular shape is provided on the outer peripheral surface of the plug body 90, the shape of the waterproof seal member 120 is not limited thereto. For instance, as shown in Fig. 18, there may be provided a waterproof seal member 150 including: a peripheral wall part 151 attached on the outer peripheral surface of the plug body 90; and a seal member body 152 covering both the tip end 90a of the plug body 90 and the outer peripheral surface of the tip end surface 147 of the tip end cover 140 from its front side. The peripheral wall part 151 and the seal material body 152 are formed as a single unit. That is, the waterproof seal member 150 is formed of a single member. Accordingly, the effect (3) in the first embodiment is expected. In addition, since the seal member body 152 covers a gap between the tip end cover 140 and the plug body 90, it is possible to suppress water from infiltrating into the plug body through the gap between the tip end cover 140 and the plug body 90. In addition, since the seal member body 152 covers an outer periphery of the tip end surface 147 of the tip end cover 140 from its front side, the effect (4) in the first embodiment is expected.

Further, the waterproof seal member 150 is interposed between the inner surface of the recess 73 and the plug body 90 in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A. Accordingly, the waterproof seal member 150 and the inner surface of the recess 73 are in close contact with each other to become watertight.

Further, as shown in Fig. 19, there may be provided a waterproof seal member 160 including: a seal member body 161 protruding outwardly from an outer peripheral surface of the plug body 90; a top plate 162 interposed between the tip end 90a of the plug body 90 and the tip end cover 140; a peripheral wall part 163 interposed between an inner circumference of the tip end portion 90c of the plug body 90 and the tip end cover 140; and a bottom plate 164 interposed between the inward protrusion 90d and the tip end cover 140. The seal member body 161, the top plate 162, the peripheral wall part 163, and the bottom plate 164 are formed as a single unit. That is, the waterproof seal member 160 is formed of a single member. Accordingly, the effect (3) in the first embodiment is expected.

Further, the waterproof seal member 160 is disposed between the inner surface of the recess 73 and the plug body 90 in the state where the tip end portion 90c of the plug body 90 is inserted into the recess 73 of the receptacle unit 1A. Accordingly, the waterproof seal member 160 and the seal member body 161 are in close contact with each other to become watertight.

In the respective embodiments, only one waterproof seal member is provided. A plurality of waterproof seal members, however, may be provided by combining the waterproof seal members in accordance with the respective embodiments. For instance, each of the waterproof seal members may be provided at the tip end of the plug and on the side surface of the recess of the receptacle. The provision of the plurality of waterproof seal members results in increased waterproof performance.

As described above, the waterproof seal member, which is in contact with the plug body 90, may be provided at the tip end and/or on the outer peripheral surface of the plug body 90. Further, the waterproof seal member may be provided on the bottom surface and/or the side surface of the recess 73 of the receptacle unit 1A, so that the waterproof seal member is in contact with the receptacle unit 1A and surrounds the plug pins 91 while being interposed between the opening of the recess 73 and the plug pins 91.

In the above respective embodiments, the receptacle A is exemplified as an outdoor receptacle. The receptacle A, however, may be an indoor receptacle. Further, the receptacle A may be applied to a charging system for a secondary battery of the electrical vehicle (E.V.). That is, the receptacle A may be applied to a system in which the secondary battery of the electrical vehicle is charged by connecting a plug connected to a charging device of the vehicle to a receptacle.

While the invention has been shown and described with respect to the embodiments, it will be understood by those skilled in the art that various changes and modification may be made without departing from the scope of the invention as defined in the following claims.