JPH0554929A - Receptacle - Google Patents

Abstract

PURPOSE:To use a door for closing a plug blade insertion port commonly for different sorts of receptacles. CONSTITUTION:A door 15a is energized in such a direction as to close a plug blade insertion port 14a by a restoration spring 16a comprising a plate spring. An insertion force of a plug blade is converted into a force in a direction to open the door 15a against the spring force of the restoration spring 16a by an inclined surface 15f provided at the door 15a. A forward end edge of the inclined surface 14f is curved to be recessed. When the plug blade is pulled or inserted to the plug blade insertion port 14a, the door 15a moves to advance or retract by function of the inclined surface 15f. In rotating the plug blade along the plug blade insertion port 14a, the compression quantity of the restoration spring 16a is kept almost constant by the curvature of the forward end edge of the inclined surface 15f.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an outlet provided with a door for closing a blade insertion opening when the blade of the plug is not inserted.

[0002]

2. Description of the Related Art Conventionally, an outlet provided with a door for opening and closing the blade insertion opening so that foreign matter such as dust and water does not enter the blade insertion opening when the blade of the plug is not inserted Is provided. Especially, in the case of an outlet that is exposed on the floor and the blade insertion opening is open upward, foreign matter from above easily enters the blade insertion opening, so the door that closes the blade insertion opening when not in use Will be required.

[0003]

However, the conventional outlet provided with a door is usually of a type in which a flat blade-shaped plug blade is inserted and removed in a straight line, and the plug is rotated to prevent the plug from coming off. There is no such form. Although it is possible to form a door that corresponds to the type of blade that rotates the plug to prevent it from coming off, a door with a different shape will be designed depending on the type of blade, increasing the number of parts and manufacturing. There is a problem that it leads to an increase in cost.

SUMMARY OF THE INVENTION The present invention is intended to solve the above-mentioned problems, and can be either of a type in which a flat plate-shaped blade is inserted / removed in a straight line, or a type in which a plug is rotated to prevent it from coming off. Also aims to provide an outlet that is equipped with a door that can be handled by the same parts and that suppresses an increase in manufacturing cost by sharing the parts.

[0005]

According to a first aspect of the invention, a plurality of blade insertion holes into which the blades of the plug are inserted are opened on one surface of the case, and the opening of each blade insertion opening is formed inside the case. In an outlet provided with a door that moves in the direction along the surface to open and close each blade insertion port, at least the blade insertion port door into which the power supply blade is inserted closes the blade insertion port. And a biasing surface that is biased by a return spring made of a leaf spring in a direction toward each other and that converts the insertion force of the blade into a force for opening the door against the spring force of the return spring, The tip edge of the inclined surface is curved in a concave arc in a plane along the opening surface of the blade insertion opening.

According to the second aspect of the present invention, there is provided a blade insertion opening into which the ground blade is inserted, and the blade insertion opening is provided at a portion corresponding to the blade insertion opening into which the ground blade is inserted. A pair of doors that open and close on both sides of the blade insertion opening on a straight line are provided.Each door is biased by a return spring consisting of a coil spring in the direction of closing the blade insertion opening, and the blade insertion force is also increased. Is provided with an inclined surface that resists the spring force of the return spring and converts it into a force for opening the door.

According to the third aspect of the present invention, there is provided a pair of rectangular blade insertion holes into which flat plate blades for power feeding are inserted, and a blade insertion port into which a blade blade for grounding is inserted. There is.
According to the invention of claim 4, a pair of arc-shaped blade insertion holes into which a flat blade blade for power feeding is inserted and an arc-shaped blade insertion slot into which a blade blade for grounding is inserted are provided. The blade receiving spring that clamps and electrically connects the blade of the blade is a member that engages with a locking hole formed in the blade when the blade is inserted into the blade receiving spring and then rotated in a predetermined direction. It has a stop projection.

In the invention of claim 5, among the return springs for urging the pair of doors into which the blade for grounding is inserted, the locking hole of the blade is engaged with the locking projection of the blade receiving spring. One of the return springs, which expands at this time, is longer than the other spring that is compressed. According to the sixth aspect of the invention, at least a pair of arc-shaped blade insertion holes into which the hook blades are inserted are provided.

According to the invention of claim 7, the door and the return spring are housed in a storage recess formed in the inner peripheral surface of the case in the vicinity of the blade insertion slot, and the storage recess is formed in the inner peripheral surface of the case. A pressing plate that closes is provided.

[0010]

According to the first aspect of the present invention, the door is biased in the direction of closing the blade insertion opening by the return spring made of a leaf spring, and the insertion force of the blade is resisted against the spring force of the return spring. Since the door is provided with an inclined surface that converts the force into the opening direction, and the tip edge of the inclined surface is curved in a concave arc shape in the plane along the opening surface of the blade insertion port, it is formed into a flat plate shape The door and the return spring with the same structure may be used not only in the case of inserting and removing in a straight line, but also in the case of the case where the flat blade blade or the hook blade is inserted into the blade insertion opening and then rotated. You can do it. That is, since the front edge of the door with which the blade abuts is curved in a concave arc shape, the blade can be smoothly rotated when the blade is rotated, and even when the blade is moved straight. You can open and close the door.

According to the second aspect of the present invention, a pair of opening and closing on both sides of the blade insertion opening on a straight line passing through the blade insertion opening at a portion corresponding to the blade insertion opening into which the ground blade is inserted. Doors are provided, each door is biased by a return spring consisting of a coil spring in the direction to close the blade insertion opening, and the insertion force of the blade is set against the spring force of the return spring to open the door. Since an inclined surface that converts into force is provided, a door can be provided at the blade insertion opening of the blade for grounding, which has not been considered in the past, and a blade can be inserted to insert the blade for grounding. It can prevent dust and water from getting into your mouth.

The structures of claims 3 to 6 are preferred embodiments. However, as in claim 5, in the type in which the blade is inserted into the blade insertion opening and then rotated, a state in which the blade is connected to the blade receiving spring among a pair of return springs for urging the door At this time, the door can be made to follow the rotation of the blade by adopting a configuration in which one of the expanding return springs is longer than the other compressed spring.

According to the structure of claim 7, the door and the return spring are housed in the housing recess formed in the inner peripheral surface of the case in the vicinity of the blade insertion opening, and the housing recess is housed in the inner peripheral surface of the case. Since the pressing plate to be closed is provided, at the time of assembly, after inserting the door and the return spring into the storage recess and then closing the storage recess with the pressing plate, the door and the return spring are separated from other members. Has an advantage that the case is held independently, which facilitates the assembling work.

[0014]

【Example】

(Embodiment 1) As shown in FIG. 1, a case 11 is arranged so as to close a rectangular parallelepiped-shaped body 11a in which a blade receiving spring 12, 13 for receiving a plug blade of a plug is opened and an opening of the body 11a. It is formed by combining with a cover 11b having plug blade insertion openings 14a and 14b into which plug blades of the plug are inserted. That is, an assembling protrusion (not shown) having an assembling hole is provided on the lower surface of the cover 11b, and an assembling claw piece 11c is provided on the upper end of the side surface of the body 11a.
By engaging with the assembly hole, the body 11a and the cover 11b are coupled. The outlet main body 10 is provided with a grounding electrode, and is configured so that a pair of flat plate-shaped parallel blades for power supply and a round bar-shaped blade for grounding can be connected. The two blade insertion openings 14a into which the blades are inserted and the one blade insertion opening 14b into which the ground blade is inserted are opened.

In the body 11a, three independent chambers are formed, and a pair of spring pieces 12a arranged to face each other and a terminal plate 12 arranged on the side of the spring piece 12a.
b and two blade receiving springs 12 integrally formed by a conductive metal plate, a pair of spring pieces 13a arranged to face each other, and a terminal plate 13b connected to a connecting portion of both spring pieces 13a. One blade receiving spring 13 integrally formed by a conductive sheet metal is housed in each chamber. Locking springs 12c and 13c are arranged to face the terminal plates 12b and 13b of the blade receiving springs 12 and 13, respectively. Locking spring 1
The terminals 2c and 13c are electric wires inserted through the electric wire insertion holes (not shown) formed in the lower wall of the body 11a to the terminal board 1
It is sandwiched between 2b and 13b, and the locking spring 1
The contact pieces 12d and 13d provided on the upper portions of 2c and 13c come into contact with the electric wire, and the locking pieces 12e and 13e provided on the lower portion bite into the electric wire to prevent the wire from coming off. Also, lock piece 1
Release buttons 12f and 13f are provided at positions corresponding to 2e and 13e.
When the release buttons 12f and 13f are pressed by a tool such as the tip of a driver inserted through a release hole (not shown) formed in the lower wall of the body 11a, the lock piece 1
2e and 13e are detached from the electric wire so that the electric wire can be pulled out. That is, the terminal boards 12b, 13
The b, the lock springs 12c and 13c, and the release buttons 12f and 13f constitute a known quick-connect terminal.

On the other hand, in the cover 11b, the blade insertion slot 1
Doors 15a, 1 are provided on the lower surface of the portions corresponding to 4a, 14b.
5b is provided. One door 15a is provided for each blade insertion opening 14a, and two doors 15b are provided for each blade insertion opening 14b. The doors 15a are urged in directions toward each other by the antinodes of return springs 16a each of which is formed of an arc-shaped leaf spring, and close the blade insertion opening 14a. Further, the doors 15b are biased by the return springs 16b each made of a coil spring so as to approach each other to close the blade insertion opening 14b. A return spring 16 is provided on one end surface of the door 15b in the moving direction.
a spring seat projection 15c coupled to one end of b is provided,
Further, movement restriction protrusions 15d are provided on both side surfaces of the door 15b. Doors 15a, 15b, return springs 16a, 16
b is a storage recess 17 formed on the lower surface of the cover 11b.
a, 17b (see FIG. 2). The movement range of the door 15b is regulated by accommodating the movement regulation projections 15d in the movement regulation grooves 17c provided on both side surfaces of the storage recess 17b. An inclined surface 15f is formed on each of the doors 15a and 15b, and the force acting downward on the inclined surface 15f when the blade 20 is inserted causes the return spring 16a (16b) to return, as shown in FIGS. 3 and 4. The door 15a (15b) moves in the horizontal direction against the spring force of the above, and the blade insertion slot 14a (14b) is opened. Door 1
The tip edge of the inclined surface 15f of 5a is curved in a concave arc shape.
A pressing plate 18 is attached to the lower surface of the cover 11b in order to prevent the doors 15a and 15b and the return springs 16a and 16b housed in the housing recesses 17a and 17b from dropping downward. The pressing plate 18 is retained by the cover 11b by engaging a peripheral portion with a coupling claw (not shown) provided on the lower surface of the cover 11b. Further, when the cover 11b is coupled to the body 11a, the pressing plate 18 prevents the blade receiving springs 12a and 12b from rising. Through holes 18a and 18b, through which the plug blades 20 of the plugs are inserted, are formed in the pressing plate 18 in substantially the same shape as the plug blade insertion ports 14a and 14b.

(Embodiment 2) This embodiment will be described with reference to FIGS.
As shown in FIG. 5, a locking protrusion that engages with a locking hole (not shown) formed in the blade 20 on the spring piece 12a of the blade receiving spring 12 to which the flat blade 20 for power supply is connected. 12g is provided. The blade receiving spring 12 is inserted into the pair of spring pieces 12a from above at a portion where the locking projection 12g is not formed, and then the blade reception spring 12 is held between the spring pieces 12a. When 20 is rotated, the locking hole provided in the blade 20 is engaged with the locking projection 12g by the rotation of 20. When the blade 20 is engaged with the locking projection 12g, the blade 20 is prevented from coming off upward.
Since the blade 20 is rotated while being sandwiched between the pair of spring pieces 12a, the horizontal section of the spring piece 12a is curved in an arc shape. Also, with respect to the blade receiving spring 13 to which the blade for grounding is connected, the spring piece 13a faces in a direction in which the blade 20 can rotate.

The doors 15a and 15b have the same shape as in the first embodiment. Here, since the tip end line of the inclined surface 15f of the door 15a is curved in a concave arc shape,
While inserting the blade 20 as shown in FIG. 7 and rotating the blade 20 as shown in FIG. 8, since the compression amount of the return spring 16a is substantially constant, the blade 20 rotates smoothly. It can be done. Of the pair of return springs 16b for the door 15b, the return spring 16a (left side in FIG. 5) that is extended when the blade 20 is in the position of FIG. 8 has a natural length longer than that of the return spring 16b that is compressed. It is set long. This facilitates the door 15b to follow the rotation of the blade 20.

A blade insertion port 14 formed in the cover 11b
a, 14b and through hole 18 formed in the pressing plate 18
The a and 18b are formed in an arc shape so that the blade can rotate. Here, the blade is designed to rotate counterclockwise and engage with the locking projection 12g.
The a and 14b and the through-holes 18a and 18b are formed at positions leftwardly displaced (see FIG. 6). Therefore, when the plug blade of the plug is inserted into the left end of the plug blade insertion openings 14a and 14b and the plug is rotated counterclockwise, the plug blade engages with the locking projection 12g to prevent the plug from coming off. is there.

The other structure and operation are the same as those in the first embodiment, and the description thereof will be omitted. (Embodiment 3) This embodiment corresponds to a plug having a hooking blade as shown in FIGS. The hook plug blade 21 has a well-known shape in which a hook piece 21a is projectingly provided on the side edge of the tip portion (see FIGS. 11 and 12), and has a cross section curved in an arc shape. The hook plug blade 21 is inserted through the plug insertion ports 14a and 14b and then rotated, so that the hook piece 21a is engaged with the inside of the case 11 to prevent the plug from coming off. Further, in this embodiment, the grounding blade is also the hook blade 21. The blade receiving springs 12a and 12b having the same shape as that of the second embodiment are used.
a, 14b and the through holes 18a, 18b are the hook plug blades 2.
1 is formed so that it can be inserted and rotated. In particular, the blade insertion port 14b and the through hole 18b into which the hooking blade 21 for grounding is inserted are formed to be narrower than those in the second embodiment.
Furthermore, since the grounding blade is the hook blade 21,
The door 15b is formed in the same shape as the door 15a, and is biased by a return spring 16a having the same shape as the door 15a in a direction to close the blade insertion opening 14b. The doors 15a and 15b have the first embodiment.
The same shape as the door 15a is used.

In this structure, when the hook blade of the plug is inserted into the left end of the blade insertion opening 14a, 14b and the plug is rotated counterclockwise, the blade is engaged with the locking projection 12a and The hooking pieces are locked to the peripheral edges of the openings of the through holes 18a and 18b to prevent the plug from coming off. That is, the peripheral edges of the openings of the through holes 18a and 18b function as locking portions.

The other structure and operation are the same as those in the first embodiment, and the description thereof will be omitted. As described above, the door 15a and the return spring 16a can be commonly used in various types of outlets.

[0023]

According to the structure of the first aspect of the present invention, the door is biased in the direction of closing the blade insertion opening by the return spring composed of the leaf spring, and the insertion force of the blade is resisted against the spring force of the return spring. Since the door is provided with an inclined surface that converts the force to open the door, and the tip edge of the inclined surface is curved in the plane along the opening surface of the blade insertion port, it is formed in a flat plate shape and straightened. The door and the return spring having the same configuration can be used not only in the case of inserting and removing on the line but also in the case of a plate blade or a hook blade inserted into the blade insertion opening and then rotated. Has the advantage. That is, by curving the leading edge of the door with which the blade comes into contact, when the blade is rotated, the blade can be smoothly rotated, and even when the blade is moved straight, the door is opened and closed. There is an effect that can be done.

According to the second aspect of the present invention, a pair of opening / closing members on both sides of the blade insertion opening on a straight line passing through the blade insertion opening at a portion corresponding to the blade insertion opening into which the ground blade is inserted. Doors are provided, each door is biased by a return spring consisting of a coil spring in the direction to close the blade insertion opening, and the insertion force of the blade is set against the spring force of the return spring to open the door. Since an inclined surface that converts into force is provided, a door can be provided at the blade insertion opening of the blade for grounding, which has not been considered in the past, and a blade can be inserted to insert the blade for grounding. It has the advantage of preventing dust and water from entering the mouth.

According to a fifth aspect of the present invention, in which the blade is inserted into the blade insertion opening and then rotated, the blade is connected to the blade receiving spring of the pair of return springs for urging the door. In the state, by adopting a configuration in which one expanding spring is made longer than the other compressed spring, the door can follow the rotation of the blade. According to the configuration of claim 7, the door and the return spring are housed in the storage recess formed in the inner peripheral surface of the case in the vicinity of the blade insertion opening, and the pressing member for closing the storage recess on the inner peripheral surface of the case. Since the plate is arranged, at the time of assembly, after inserting the door and the return spring into the storage recess, and closing the storage recess with the pressing plate, the door and the return spring can be isolated from other members. As a result, the case is held, which has the advantage of facilitating the assembly work.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment.

FIG. 2 is a bottom view of the cover showing the first embodiment.

3A and 3B show a state before inserting a blade of Embodiment 1, FIG. 3A is a cross-sectional view of a main part, and FIG. 3B is a bottom view of the main part.

4A and 4B are views showing a state after inserting the blade of Embodiment 1, in which FIG. 4A is a sectional view of a main part and FIG. 4B is a bottom view of the main part.

FIG. 5 is an exploded perspective view showing a second embodiment.

FIG. 6 is a bottom view of the cover according to the second embodiment.

7A and 7B show a state before rotating a blade according to Example 2, where FIG. 7A is a sectional view of a main part and FIG. 7B is a bottom view of the main part.

FIG. 8 is a cross-sectional view of essential parts showing a state after rotation of a blade of Example 2;

FIG. 9 is an exploded perspective view showing a third embodiment.

FIG. 10 is a bottom view of the cover showing the third embodiment.

FIG. 11 shows the state before inserting the blade of Example 3, (a)
Is a cross-sectional view of a main part, and (b) is a bottom view of the main part.

FIG. 12 shows a state after inserting the blade of Example 3, (a).
Is a cross-sectional view of a main part, and (b) is a bottom view of the main part.

[Explanation of symbols]

 11 Case 12 Blade Receiving Spring 12g Locking Protrusion 14a Plug Blade Inserting Port 14b Plug Blade Inserting Port 15a Door 15b Door 15f Inclined Surface 16a Return Spring 16b Return Spring 17a Storage Recess 17b Storage Recess 18 Presser Plate 20 Plug Blade 21 blade

[Procedure amendment]

[Submission date] November 5, 1991

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Claim 5

[Correction method] Change

[Correction content]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

In the invention of claim 5, among the return springs for urging the pair of doors into which the blade for grounding is inserted, the locking hole of the blade is engaged with the locking projection of the blade receiving spring. One of the return springs, which is compressed at that time, has a longer natural length than the other return spring .

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

The structures of claims 3 to 6 are preferred embodiments. However, as in claim 5, in the type in which the blade is inserted into the blade insertion opening and then rotated, a state in which the blade is connected to the blade receiving spring among a pair of return springs for urging the door When, when one of the compression is restored
By adopting a configuration in which the natural length of the bed is longer than that of the other return spring , the stroke of the door can be reduced when opening and closing the door.
It can be made large and the door can follow the rotation of the blade.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0014

[Correction method] Change

[Correction content]

[0014]

(Embodiment 1) As shown in FIG. 1, a case 11 has a rectangular parallelepiped body 11a having a top opening and accommodating blade receiving springs 12 and 13 for receiving plug blades of a plug, and the opening of the body 11a is closed. And a cover 11b having plug blade insertion openings 14a and 14b into which plug blades of the plug are inserted are formed. That is, an assembling protrusion (not shown) having an assembling hole is provided on the lower surface of the cover 11b, and an assembling claw 11e is provided on the upper end of the side surface of the body 11a.
By engaging with the assembly hole, the body 11a and the cover 11b are coupled. The outlet main body 10 is provided with a grounding electrode, and is configured so that a pair of flat plate-shaped parallel blades for power supply and a round bar-shaped blade for grounding can be connected. The two blade insertion openings 14a into which the blades are inserted and the one blade insertion opening 14b into which the ground blade is inserted are opened.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Correction content]

The doors 15a and 15b have the same shape as in the first embodiment. Here, since the tip end line of the inclined surface 15f of the door 15a is curved in a concave arc shape,
While inserting the blade 20 as shown in FIG. 7 and rotating the blade 20 as shown in FIG. 8, since the compression amount of the return spring 16a is substantially constant, the blade 20 rotates smoothly. It can be done. Further, of the pair of return springs 16b with respect to the door 15b, the blade 20 is set to the position shown in FIG.
Return spring 1 extended when returning to the position of FIG. 7 (b)
6a (left side in FIG. 5) is a return spring 16b that is compressed.
The natural length is set longer than that. This facilitates the door 15b to follow the rotation of the blade 20.

[Procedure Amendment 6]

[Document name to be amended] Statement

[Name of item to be corrected] 0019

[Correction method] Change

[Correction content]

A blade insertion port 14 formed in the cover 11b
a, 14b and through hole 18 formed in the pressing plate 18
The a and 18b are formed in an arc shape so that the blade can rotate. Here, the blade is designed to rotate clockwise and engage with the locking projection 12g.
The a and 14b and the through-holes 18a and 18b are formed at positions leftwardly displaced (see FIG. 6). Therefore, when the plug blade of the plug is inserted into the right ends of the plug blade insertion openings 14a and 14b and the plug is rotated clockwise , the plug blade engages with the locking projection 12g to prevent the plug from coming off. is there.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

In this structure, the hook blade of the plug is inserted into the center of the blade insertion opening 14a, 14b, and the plug is rotated clockwise when the blade is engaged with the locking projection 12a. At the same time, the hooking pieces are engaged with the peripheral edges of the openings of the through holes 18a and 18b to prevent the plug from coming off. That is, the peripheral edges of the openings of the through holes 18a and 18b function as locking portions.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

According to a fifth aspect of the present invention, in which the blade is inserted into the blade insertion opening and then rotated, the blade is connected to the blade receiving spring of the pair of return springs for urging the door. If the natural length of one of the compressed return springs is longer than that of the other spring, the door will open and close
The stroke of the door at the time of opening can be made large, and the door can follow the rotation of the blade. According to the configuration of claim 7, the door and the return spring are housed in the storage recess formed in the inner peripheral surface of the case in the vicinity of the blade insertion opening, and the pressing member for closing the storage recess on the inner peripheral surface of the case. Since the plate is arranged,
At the time of assembly, if the door and the return spring are inserted into the storage recess and then the storage recess is closed by the pressing plate, the case holds the door and the return spring independently of other members. There is an advantage that the assembling work becomes easy.

Claims (7)

[Claims] 1. A plurality of blade insertion holes into which plug blades of a plug are inserted are opened on one surface of a case, and each blade is moved inside the case in a direction along an opening surface of each blade insertion opening. In an outlet provided with a door that opens and closes the insertion opening, at least the door of the blade insertion opening into which the blade for power supply is inserted is closer to each other than the leaf spring in the direction of closing the insertion opening of the blade. It is biased by a return spring and has an inclined surface that converts the insertion force of the blade into a force that opens the door against the spring force of the return spring. An outlet characterized by being curved in a concave arc in a plane along the opening surface. 2. A plug blade insertion opening into which a ground blade is inserted, and a plug corresponding to the blade insertion opening into which the ground blade is inserted is plugged on a straight line passing through the blade insertion opening. A pair of doors that open and close on both sides of the blade insertion opening are provided.Each door is biased by a return spring consisting of a coil spring in the direction of closing the blade insertion opening, and the insertion force of the blade is returned to the spring of the return spring. The outlet according to claim 1, further comprising an inclined surface that converts force into force for opening the door against the force. 3. A pair of rectangular blade insertion holes into which a flat blade blade for feeding power is inserted, and a blade insertion port into which a blade blade for grounding is inserted. The outlet according to claim 2. 4. A plug for power supply, comprising a pair of arc-shaped plug blade insertion ports into which flat plate-shaped plug blades for power feeding are inserted and arc-shaped plug blade insertion ports into which ground blades are inserted. The blade receiving spring that clamps the blade and electrically connects is a locking projection that engages with the locking hole formed in the blade when the blade is inserted into the blade receiving spring and then rotated in a predetermined direction. The outlet according to claim 2, further comprising: 5. Of the return springs for urging the pair of doors into which the blade for grounding is inserted, one of the return springs is extended when the locking hole of the blade is engaged with the locking projection of the blade receiving spring. 5. The outlet according to claim 4, wherein the return spring is longer than the other compressed spring. 6. The outlet according to claim 1, comprising at least a pair of arc-shaped blade insertion holes into which hooking blades are inserted. 7. The door and the return spring are housed in a housing recess formed in the inner peripheral surface of the case in the vicinity of the blade insertion opening, and a pressing plate for closing the housing recess is formed on the inner peripheral surface of the case. The outlet according to claim 1 or 2, wherein the outlet is provided.