JPH09222535A - Relay adapter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a relay adapter which is superior in assembly and holds the coupling loss of optical fibers low. SOLUTION: A sleeve 40 into which a ferrule projecting atop of a connector is inserted and held is held in the relay adapter 10 which has engagement parts 14 for fitting and holding the connector at both the ends. At the center of the outer peripheral surface of the sleeve 20, a peripheral groove 42 is formed along the circumferential direction and at the center in the adapter main body 12, an engagement wall 27 which has a rectangular through-hole 25 formed is formed; and the sleeve 40 is loosely inserted and held in the through-hole 26 of the engagement wall 27 so that it is stopped from sliding out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a relay adapter for coupling optical fibers together.

[0002]

2. Description of the Related Art As a relay adapter for coupling optical fibers, there is, for example, one in which a sleeve is housed and held in an adapter body having fitting portions for fitting and holding a connector at both ends. A ferrule projecting from the tip of the connector is inserted into the sleeve, and the optical fiber held in the ferrule is axially aligned.

In many cases, such a sleeve is usually made of metal in order to improve the accuracy of axial alignment of the optical fiber and reduce the coupling loss.

Examples of such relay adapters include those disclosed in Japanese Utility Model Laid-Open No. 62-68107, Japanese Utility Model Laid-Open No. 63-35008, and Japanese Patent Laid-Open No. 7-35951.

The technique disclosed in Japanese Utility Model Laid-Open No. 62-68107 is such that a metal sleeve is press-fitted and fixed in a cylindrical adapter body.

The relay adapters disclosed in Japanese Utility Model Laid-Open No. 63-35008 and Japanese Patent Application Laid-Open No. 7-35951 are housed in such a manner that a metal sleeve is sandwiched between a pair of adapter division bodies, and then the two adapter divisions are made. The body is joined by screw fastening or the like.

[0007]

However, in the technique disclosed in Japanese Utility Model Laid-Open No. Sho 62-68107, the sleeve is fixed at a fixed position in the adapter body, so that vibration is applied to the relay adapter. In addition, there is a problem that a twisting force is generated between the sleeve and the ferrule of the connector inserted and held in the sleeve, shavings are generated in the sleeve, and the coupling loss is increased. Furthermore, if the optical fiber held in the ferrule is made of glass,
The optical fiber may be damaged.

Further, in the technique disclosed in Japanese Utility Model Laid-Open No. 63-35008 and Japanese Patent Laid-Open No. 7-35951, when the relay adapter is assembled, the sleeve is sandwiched between a pair of adapter divided bodies, Since the adapter divided bodies are joined by screw fastening or the like, there is a problem in that the number of parts to be assembled and the number of assembling steps are large, resulting in poor productivity.

Therefore, the present invention has been made to solve the above-mentioned problems, and is excellent in assemblability and
An object of the present invention is to provide a relay adapter that can keep the coupling loss between optical fibers low.

[0010]

In order to solve the above-mentioned problems, the relay adapter according to claim 1 of the present invention has a pair of connectors, each of which has an optical fiber accommodated and held in a ferrule projecting at its tip, at both ends. In a relay connector for fitting and holding the optical fibers held by the both connectors, a tubular adapter body having fitting portions at both ends for fitting and holding the both connectors,
A sleeve that is housed and held in the adapter body and that holds the end faces of the ferrules of the connectors that are fitted and held in the fitting portions at positions where they face each other, and the circumference of the sleeve is at the center of the outer peripheral surface of the sleeve. A peripheral groove is formed along the direction, and a locking wall having a through hole is formed in the center of the inside of the adapter body, and the sleeve is inserted into the through hole so that the peripheral groove of the sleeve fits into the through hole. It is characterized in that the sleeve is loosely inserted and held in the adapter body in a retaining state by being locked.

Further, as described in claim 2, the through hole may be formed in a rectangular shape.

Further, as described in claim 3, both end faces of the sleeve may be finished in a taper shape in which the outer peripheral face is gradually reduced in diameter toward the end portion of the sleeve.

According to a fourth aspect of the present invention, the adapter body has a symmetrical shape with the locking wall interposed therebetween, and
The sleeve may have a symmetrical shape with the circumferential groove portion sandwiched therebetween.

According to a fifth aspect of the present invention, there is provided a relay adapter in which at least two or more through holes are formed in the locking wall of the adapter body and the sleeves are respectively loosely inserted and held in the through holes. It is preferable that the through holes are finished in the same shape and the sleeves are finished in the same shape.

In the relay adapter according to the sixth aspect, a pair of connectors having optical fibers housed and held in ferrules projecting at the respective tips are fitted and held at both ends,
In a relay connector for connecting optical fibers held by the both connectors, a tubular adapter body having fitting portions for fitting and holding the both connectors at both ends, and a housing and holding in the adapter body And a sleeve that holds the end faces of the ferrules of the connectors that are fitted and held in the fitting portions at positions where they face each other, and a collar-shaped protrusion is formed at the center of the outer peripheral surface of the sleeve along the circumferential direction thereof. And a pair of locking grooves parallel to the width direction of the adapter body are formed in the center of the inside of the adapter body so that the sleeve is inserted from one end side of the adapter body. The sleeve is loosely inserted and held in the adapter main body by locking the flange-shaped projections in the locking grooves.

Further, according to a seventh aspect of the present invention, a projecting edge portion projecting inwardly of the adapter body is formed at a peripheral edge of the both locking grooves, and the projecting edge portion facing the end portion side of the adapter body is formed. The side surface of the ridge may be finished as an inclined surface whose height dimension is gradually reduced toward the end of the adapter body.

In addition, as described in claim 8, both side surfaces of the collar-shaped protrusion of the sleeve may be finished in a tapered shape in which the outer peripheral surface is gradually reduced in diameter toward the end portion of the sleeve.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A first embodiment according to the present invention will be described below.

This relay adapter 10 is shown in FIGS.
As shown in FIG. 5, a cylindrical sleeve 40 is housed and held in the adapter body 12 having fitting portions 14 for fitting and holding the connector 50 at both ends.

The connector 50, as shown in FIG.
It has a connector main body 52 and a ferrule 54 provided in a protruding shape at the tip of the connector main body 52. A tapered surface 54a is formed on the outer peripheral portion of the ferrule 54 on the distal end side so that the diameter decreases in the distal direction. An optical fiber 70 is inserted and held in the ferrule 54, and the tip end surface of the optical fiber 70 and the tip end surface of the ferrule 54 are in a state of being aligned with each other.

A tubular portion 56 is extended from the tip of the connector body 52 so as to surround the ferrule 54 from four sides.
A tapered surface 56a is formed on the outer peripheral portion of the tubular portion 56 on the tip end side so as to reduce the diameter in the tip end direction. Also,
On the upper and lower surfaces of the outer periphery of the tubular portion 56, there are formed, respectively, hook-shaped engaging projections 58 which are engageable with and disengageable from engagement holes 16 on the side of the fitting portion 14, which will be described later. Guide ridges 60 that are slidably fitted into guide groove portions 18 on the fitting portion 14 side, which will be described later, are formed on both outer peripheral surfaces along the front-rear direction.

Further, on both sides of the connector main body 52, a square-shaped engaging mechanism 62 whose one end side is connected to the connector main body 52 is provided. On the other end side of both engagement mechanisms 62,
An inwardly projecting engagement portion 64 is formed so as to be engageable with and disengageable from an engagement recess 22 of the fitting portion 14 described later.
The engaging mechanism 62 is configured such that the engaging portion 64 is opened outward by pressing the inverted V-shaped folded-back portion inside the connector 50.

On the other hand, the relay adapter 10 is, as shown in FIGS. 1 to 5, a cylindrical adapter body 12 made of resin, and a cylindrical sleeve 40 which is removably accommodated in the adapter body 12. Composed of and.

The adapter body 12 has a symmetrical shape in the front-rear direction, and screw fastening portions 24 projecting outward are formed on both left and right sides of the central portion of the adapter body 12. Each screw fastening part 2
4 has a screw fastening groove portion 25 opened in a U shape, and the relay adapter 10 is screwed and fixed to a printed wiring board (not shown) or the like via the screw fastening groove portion 25.

At both front and rear ends of the adapter body 12,
The fitting portions 14 for fitting and holding the connector 50 are formed respectively. A taper surface 14a is formed at the inner peripheral edge of each fitting portion 14 so as to widen outward. Engagement recesses 22 are formed on the left and right outer surfaces of each fitting portion 14 so as to be engageable with and disengageable from the engagement portions 64 of the engagement mechanism 62 on the connector 50 side, and both sides of the connector 50 pressed against each other. A guide surface portion 21 for expanding the engaging portion 64 to the outside and guiding it to the engaging recess 22 is formed. Further, the guide protrusions 60 of the connector 50 are slidably inserted into the left and right inner side surfaces of the fitting portion 14, and a guide groove portion 18 for inserting and guiding the connector 50 in the front-rear direction is formed. Further, on the upper and lower surfaces of the inner circumference of the fitting portion 14, the engaging hole portion 16 that is engageable with and disengageable from the engaging projection portion 58 on the connector 50 side is formed, and the engaging projection portion 58 is engaged. A guide recess 17 for guiding to the hole 16 is formed.

In the center of the inside of the adapter body 12,
As shown in FIGS. 3 to 5, a locking wall 27 having a rectangular through hole 26 that penetrates the adapter body 12 in the axial direction and is horizontally long in the width direction of the adapter body 12 is formed.

A cylindrical sleeve 40 is loosely inserted and held in the through hole 26 in a state where it is not pulled out. The sleeve 40 is formed in a front-rear symmetrical shape with a circumferential groove portion 42 formed along the circumferential direction at the center of the outer peripheral surface thereof being sandwiched. The width dimension of the circumferential groove portion 42 is set to be slightly larger than the thickness dimension of the locking wall 27, and the diameter dimension of the circumferential groove portion 42 is set to be slightly smaller than the short side dimension of the through hole 26.
Further, the outer diameter dimension of the sleeve 40, which is obtained by adding the depth dimension of the circumferential groove portion 42 to the radial dimension of the circumferential groove portion 42, is larger than the short side dimension (vertical dimension) of the through hole 26 and the long side dimension of the through hole 26. It is set smaller than (width dimension). Further, tapered surfaces 44 are formed on the outer peripheral portions of both ends of the sleeve 40 so as to be reduced in diameter toward the respective end portions.

When the sleeve 40 is inserted from the one end side of the adapter body 12, first, the tapered surface 44 of the sleeve 40 is pressed against the through hole 26 of the locking wall 27 and the locking wall 27.
Is deformed so as to bend and the through hole 26 is expanded. Further, when the sleeve 40 is pushed in, the peripheral edge portion of the through hole 26 of the locking wall 24 is elastically returned to be locked in the circumferential groove portion 42 of the sleeve 40. At this time, the sleeve 40 is loosely inserted and held in the through hole 26 by a slight gap between the through hole 26 and the circumferential groove portion 42 of the sleeve 40.

When the connector 50 is inserted into the relay adapter 10 configured as described above, first, the connector 5
The 0 guide ridge 60 is guided by the guide groove 18 of the relay adapter 10, and the ferrule 54 is guided to the open end of the sleeve 40 and inserted into the sleeve 40. After that, when the connector 50 is further pushed, the connector 50
The engaging portion 64 and the engaging protrusion 58 are engaged with the engaging concave portion 22 and the engaging hole portion 16 of the relay adapter 10, respectively. In this state, the tip surface of the ferrule 54 is arranged at the center position inside the sleeve 40. That is, when the connectors 50 are fitted into the fitting portions 14 at both ends of the connector 10, the optical fibers 70 held in the ferrules 54 are held.
Are held in a state where the end faces of the are opposed to each other.

According to the relay adapter of the first embodiment configured as described above, the sleeve 40 is inserted from one end side of the adapter body 12, and the peripheral groove portion 4 of the sleeve 40 is inserted.
Since the relay adapter 10 can be assembled only by locking the peripheral portion of the through hole 26 of the locking wall 24 of the adapter body 12 to 2, the assembling property of the relay adapter 10 is excellent.

At the time of this assembly, since the adapter body 12 is formed in a front-rear symmetrical shape and the sleeve 40 is also formed in a front-rear symmetrical shape, the sleeve 40 can be inserted from either the front side or the rear side of the adapter body 12, and Since the insertion direction of the sleeve 40 itself does not matter, the assembling property of the relay adapter 10 is also excellent in this respect.

Further, since the tapered surfaces 44 are formed on both end sides of the sleeve 40, the sleeve 40 is inserted through the through hole 26.
When inserting the relay adapter 10, the sleeve 40 is easily inserted even if the axes of the two are slightly deviated from each other, so that the relay adapter 10 can be easily assembled.

Further, since the sleeve 40 mounted inside the adapter body 12 is held in the through hole 26 in a loosely inserted state, the relay adapter 10, with the ferrule 54 of the connector 50 inserted and held in the sleeve 40, Connector 50
Or when an external force such as vibration acts on the optical fiber 70,
There is no undesired twisting force acting between the sleeve 40 and the ferrule 54, no shavings are produced in the sleeve 40, and the optical fiber 70 is not damaged. Can be kept low.

Next, a second embodiment according to the present invention will be described.

As shown in FIGS. 6 to 10, this relay connector is a two-pole type relay adapter 10b for connecting the connectors 50b holding two optical fibers 70b to each other. The difference from the adapter 10 will be mainly described.

That is, the connector 50b is the connector body 5
A pair of ferrules 54b, into which the optical fibers 70b are inserted and held, are provided on the tip side of 2b in a protruding shape. Each ferrule 54b is surrounded on four sides by a tubular portion 56b, and both tubular portions 56b are connected by a connecting portion 55b.

Guide ridges 60b having the same structure as the guide ridges 60 are formed on both outer peripheral surfaces of the cylindrical portions 56b, and a relay adapter 10b, which will be described later, is formed on the lower surface side of the connecting portion 55b. An engagement projection (not shown) is formed so as to be engageable with and disengageable from the engagement hole 16b of the fitting portion 14b.

An elastic engaging portion 65b extends from the center of the upper portion of the connector body 52b toward the space between the tubular portions 56b. An upwardly projecting engagement protrusion 66b is formed on the tip side of the elastic engagement portion 65b, and a fitting portion 14b described later is formed.
The engaging hole portion 20b is detachable. An operating portion 67b is formed at the center of the elastic engaging portion 65b. By pushing the operating portion 67b downward, the engaging protrusion 66b of the elastic engaging portion 65 and the engaging hole of the fitting portion 14b are formed. Part 2
It is configured so that the engagement with 0b can be released.

The relay adapter 10b includes the adapter body 12
Two sleeves 40b are housed and held in b.

The adapter body 12b is formed in a front-rear symmetrical shape, and on both sides thereof, the screw fastening portion 24b and the screw fastening groove portion 2 having the same structure as the screw fastening portion 24 and the screw fastening groove portion 25 are formed.
5b.

Further, the fitting portions 14b formed at the front and rear ends of the adapter body 12b are engaged with the engaging hole portion 2 which is engageable with and disengageable from the engaging protrusion 66b of the elastic engaging portion 65b on the inner peripheral upper surface side.
0b and a guide recess 21b that guides the engaging protrusion 66b to the engaging hole 16b. In addition, an engaging hole portion 16b and a guide concave portion 17b having the same structure as the engaging hole portion 16 and the guide concave portion 17 are provided on the inner peripheral lower surface side, and a guide having the same structure as the guide groove portion 18 is provided on both inner peripheral surfaces thereof. It has a groove 18b.

A locking wall 27b is formed at the center of the inside of the relay adapter 10b, and a pair of through holes 26b are provided upright in the locking wall 27b along the width direction of the relay adapter 10b. The through holes 26b are formed in the same shape, and the sleeves 40b having the same shape are loosely inserted and retained in a state of being prevented from coming off. Each of these through holes 26
The b and each sleeve 40b are configured similarly to the through hole 26 and the sleeve 40 of the first embodiment.

According to the relay adapter 10b of the second embodiment configured as described above, the same effect as in the case of the first embodiment described above is obtained, and the sleeve 40b is inserted into any through hole 26b. Because it is good, relay adapter 1
0b has excellent assemblability.

Even in the case of a multi-pole type relay adapter having three or more poles, similarly, if each through hole is formed in the same shape and a sleeve of the same shape is loosely inserted and held in each through hole. The same effect as described above can be obtained.

Next, a third embodiment according to the present invention will be described.

This relay adapter is shown in FIGS.
The relay adapter 10c is a one-pole type relay adapter 10c similar to that of the first embodiment, and the differences from the first embodiment will be mainly described.

That is, the fitting portions 1 at both ends of the relay adapter 10c
A connector having the same structure as the connector 50 of the first embodiment is fitted in 4c.

The relay adapter 10c is composed of an adapter body 12c and a sleeve 45c held therein, and has a front-back symmetrical shape. The adapter body 12c has an engaging hole portion 16 having the same structure as that of the first embodiment.
c, a guide concave portion 17c, a guide groove portion 18c, a guide surface portion 21c, and a fitting portion 14c having an engaging concave portion 22c, and a screw fastening groove portion 25c having a screw fastening portion 24c.

A pair of upper and lower engaging grooves 28c are formed in the center of the adapter body 12c along the width direction thereof. Along the edge of each locking groove 28c, the adapter body 12
A projecting ridge edge portion 29c is formed toward the inside of c. The side surface of each protruding edge portion 29c facing the end portion side of the adapter body 12c is finished as an inclined surface 30c whose height dimension gradually decreases toward the end portion side.

A cylindrical sleeve 45c made of metal is retained in the retaining groove 28c in a state where it is not pulled out. The sleeve 45c has a symmetrical shape with a collar-shaped protrusion 46c formed along the circumferential direction at the center of the outer peripheral surface of the sleeve 45c. Both side surfaces of the collar-shaped protrusion 46c face the end of the sleeve 45c. The inclined surface 47c is finished so as to reduce the diameter. However, the inclination angle of the inclined surface 47c with respect to the sleeve axial direction is formed slightly more gently than the inclination angle of the inclined surface 30c.

The outer diameter of the flange-shaped projection 46c is set to be slightly smaller than the height of the internal space of the fitting portions 14c at both ends of the adapter body 12c, and the adapter body 1
It is formed to be larger than the dimension between the pair of upper and lower protruding edge portions 47c protruding inside 2c. Further, the outer diameter dimension of the sleeve 45c obtained by subtracting the height dimension of the collar-shaped protrusion 46c from the outer diameter dimension of the collar-shaped protrusion 46c is determined by the distance between the pair of upper and lower projecting edge portions 47c protruding inside the adapter body 12c. It is set smaller than the size. Also, the upper and lower locking grooves 2
The groove width dimension of 8c is set to be slightly larger than the width dimension of the protruding edge portion 29c of the sleeve 45c.

Adapter body 12c formed in this way
When the sleeve 45c is inserted from the one end side, first, the taper surface 47c of the flange-shaped projection 46c of the sleeve 45c is pressed against the inclined surface 30c of the projection edge portion 29c, and the projection edge portion 29c and the adapter body 12c. The whole is deformed so as to bend outward, and the space between the upper and lower projecting edge portions 29c is widened. After that, when the sleeve 45c is further pushed in, the rib protrusion 4
The adapter body 12 elastically returns to the position where 6c has passed over the protruding edge portion 29c, and the collar-shaped protruding portion 46c of the sleeve 45c.
Fits into the locking groove 28c between the upper and lower projecting edge portions 29c, and the sleeve 45c is retained in the adapter body 12c in a retaining state. At this time, due to a slight gap between the sleeve 45c and the locking groove 28c, the sleeve 45c
c is held in a loosely inserted state.

When connectors are fitted to both ends of the relay adapter 10c, the ferrules of both connectors are held in the sleeve 45c with their end faces facing each other, and the respective optical fibers are joined together. This is the same as the case of the first embodiment.

According to the relay adapter of the third embodiment configured as described above, the sleeve 45c is inserted from one end side of the adapter body 12c, and the flange-shaped protrusion 46c of the sleeve 45c is engaged with the adapter body 12c. Since the relay adapter 10c can be assembled only by locking it in the stop groove 28c, the ease of assembly of the relay adapter 10c is excellent.

At the time of this assembly, since the adapter body 12c is formed in the front-rear symmetrical shape and the sleeve 45c is also formed in the front-rear symmetrical shape, the sleeve 45c can be inserted from either the front side or the rear side of the adapter body 12c. Since the inserting direction of the sleeve 45c does not matter, the assembling property of the relay adapter 10c is excellent also in this respect.

Further, since both side surfaces of the flange-shaped protrusion 46c of the sleeve 45c are finished as tapered surfaces 47c and the projecting edge portion 29c of the adapter body 12c is formed with the inclined surface 30c, the sleeve 45c can be inserted. It becomes easy and the assembling property of the relay adapter 10c is excellent.

Further, since the flange projection 46c of the sleeve 45c is held in a state where the adapter body 12c is loosely inserted,
When an external force such as vibration is applied to the relay adapter 10c, the connector or the optical fiber while the ferrule of the connector is inserted and held in the sleeve 45c, an unreasonable twisting force acts between the sleeve 45c and the ferrule. Without causing shavings in the sleeve 45c or damaging the optical fibers, the coupling loss between the optical fibers can be maintained in a low state.

In the third embodiment described above, the outer diameter dimension of the flange-shaped protrusion 46c is set larger than the height dimension of the internal space of the fitting portion 14c without forming the protruding edge portion 29c. The same effect can be obtained by locking the flange-shaped protrusion 46c in the locking groove 28c.

[0059]

As described above, according to the relay adapter according to the first and second aspects of the present invention, the peripheral groove portion of the sleeve is locked to the peripheral edge portion of the through hole formed in the locking wall in the adapter body. As a result, the sleeve is held loosely inside the adapter body in a state that it is not pulled out, so it is easy to assemble the relay adapter, and when vibration is applied to the relay adapter, forcible twisting force between the sleeve and ferrule. Does not act, and the coupling loss between optical fibers can be maintained in a low state.

If the outer peripheral portions of both ends of the sleeve are finished as tapered surfaces having a diameter decreasing toward the end portion of the sleeve, the sleeve can be easily inserted into the through hole. .

According to a fourth aspect of the present invention, the adapter body has a symmetrical shape with the locking wall interposed therebetween, and
If the sleeve has a symmetrical shape with the circumferential groove portion interposed,
When inserting the sleeve into the through hole, the inserting direction does not matter, so that the assembling property of the relay adapter is excellent.

Further, as described in claim 5, a plurality of through holes are formed in the locking wall of the adapter body, and
In the relay adapter in which the plurality of sleeves are respectively loosely inserted and held in the respective through holes, if the respective through holes are finished in the same shape and the respective sleeves are finished in the same shape, the insertion positions of the sleeves can be determined. Since it is not present, it is easy to assemble the relay adapter.

Further, according to the relay adapter of the sixth aspect, a flange-shaped protrusion is formed along the circumferential direction at the center of the outer peripheral surface of the sleeve, and at the center of the inside of the adapter body.
A pair of locking grooves that are parallel to the width direction of the adapter body are formed to face each other, and the sleeve is inserted from one end side of the adapter body to fit and lock the brim-shaped protrusion into the locking groove. As a result, the sleeve is held loosely in the adapter body in a state that it is not pulled out.Therefore, it is easy to assemble the relay adapter, and in the event that vibration etc. is applied to the relay adapter, it is not possible to force between the sleeve and the ferrule. The twisting force does not act, and the coupling loss between the optical fibers can be kept low.

According to a seventh aspect of the present invention, a ridge edge projecting inward of the adapter body is formed along the edges of the both locking grooves, and a surface is formed on the end side of the adapter body. If the side surface of the protruding edge portion is finished to be an inclined surface whose height dimension gradually decreases toward the end direction of the adapter body,
It facilitates insertion of the sleeve into the adapter body.

Further, as described in claim 8, even if both side surfaces of the collar-shaped protrusion of the sleeve are finished as inclined surfaces whose diameter decreases toward the end portion of the sleeve, the sleeve is inserted into the adapter body. Insertion becomes easier.

[Brief description of drawings]

FIG. 1 is a perspective view showing a relay connector according to a first embodiment of the present invention.

FIG. 2 is an exploded perspective view of the above relay connector.

FIG. 3 is a front view of the above relay connector.

FIG. 4 is a sectional view taken along line IV-IV of FIG. 3;

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a perspective view showing a relay connector of a second embodiment according to the invention.

FIG. 7 is a front view of the above relay connector.

FIG. 8 is a plan view of the relay connector of the above.

9 is a sectional view taken along line IX-IX in FIG.

FIG. 10 is a sectional view taken along line XX of FIG. 7;

FIG. 11 is an exploded perspective view showing a third embodiment according to the present invention.

FIG. 12 is a sectional view taken along line XII-XII of FIG. 11;

13 is a sectional view taken along line XIII-XIII in FIG.

FIG. 14 is an enlarged sectional view of a main part of FIG.

[Explanation of symbols]

 10 Relay Adapter 12 Adapter Body 27 Through Hole 28 Locking Wall 40 Sleeve 42 Circumferential Groove 50 Connector 54 Ferrule 70 Optical Fiber

Claims (8)

[Claims] 1. A relay connector for fitting and holding a pair of connectors having optical fibers accommodated and held in ferrules projecting at their respective ends at both ends and connecting the optical fibers held by the both connectors. In a tubular adapter body having fitting portions for fitting and holding the both connectors at both ends, and the adapter body accommodated in the adapter body so as to be attachable and held in the fitting portions. A sleeve for holding the end faces of the ferrules of both connectors at a position where they face each other, and a peripheral groove portion is formed along the circumferential direction in the center of the outer peripheral surface of the sleeve, and a through hole is formed in the inner center of the adapter body. A sleeve is formed, and the sleeve is inserted into the through hole to lock the peripheral edge of the through hole of the sleeve with the circumferential groove portion of the sleeve. Relay adapter being characterized in that loosely inserted held in retaining state in the adapter body. 2. The relay adapter according to claim 1, wherein an opening shape of the through hole is a rectangle. 3. The relay adapter according to claim 1, wherein a tapered surface is formed on an outer peripheral portion of both ends of the sleeve so as to reduce a diameter toward an end portion of the sleeve. 4. The adapter body has a symmetrical shape with the locking wall sandwiched therebetween, and the sleeve has a symmetrical shape with the circumferential groove portion sandwiched therebetween. The relay adapter described in 3. 5. The adapter body according to claim 1, wherein a plurality of through holes are formed in the locking wall of the adapter body, and the plurality of sleeves are respectively loosely inserted and held in the respective through holes. In the relay adapter, each of the through holes is finished in the same shape, and each of the sleeves is finished in the same shape. 6. A relay connector for connecting optical fibers held by both connectors by fitting and holding a pair of connectors having optical fibers accommodated and held in ferrules projecting at respective tips, at both ends. In a tubular adapter body having fitting portions for fitting and holding the both connectors at both ends, and the adapter body accommodated in the adapter body so as to be attachable and held in the fitting portions. A sleeve for holding the end faces of the ferrules of both connectors at a position where they face each other, and a flange-shaped projection is formed along the circumferential direction at the center of the outer peripheral surface of the sleeve, and at the center of the inside of the adapter body. , A pair of locking grooves that are parallel to the width direction of the adapter body are formed to face each other, and the sleeve is inserted from one end side of the adapter body so that the flange-shaped protrusion is formed in both the locking grooves. A relay adapter characterized in that the sleeve is loosely inserted and held in the adapter body by fitting and locking. 7. A side surface, which is formed along the edges of the both locking grooves, with a projecting edge portion projecting inward of the adapter body, the side surface of the projecting edge portion facing an end portion side of the adapter body. 7. The relay adapter according to claim 6, wherein the relay adapter is finished as an inclined surface whose height is gradually reduced toward the end of the adapter body. 8. The relay according to claim 6, wherein both side surfaces of the collar-shaped protrusion of the sleeve are finished to be inclined surfaces so as to reduce a diameter toward an end portion of the sleeve. adapter.