Optical connector

An optical connector comprises: an inner housing including an engagement recess for engaging an optical adaptor on its surface; a boot connected to a rear side of the inner housing; a first outer housing covering the engagement recess; and a second outer housing covering a part of the first outer housing and provided freely movably in a front-rear direction relative to the first outer housing. When the second outer housing moves frontward, the engagement recess is exposed by the second outer housing and the inner housing moving relative to the first outer housing, and when the second outer housing moves rearward, the engagement recess is exposed by the second outer housing and the first outer housing moving relative to the inner housing.

TECHNICAL FIELD

An aspect of the present invention relates to an optical connector.

This application claims priority based on Japanese Patent Application No. 2016-048297, filed on Mar. 11, 2016, the content disclosed in the aforementioned Japanese application being incorporated by reference herein in its entirety.

BACKGROUND ART

In Patent Literature 1, an optical connector inserted into and pulled off from an optical connector adaptor is disclosed. This optical connector includes a connector body holding a ferrule attached to the tip of an optical fiber, a coupling movable frontward and rearward relative to the connector body, a coupling engagement member provided rearward of the connector body, a boot extending rearward from the coupling engagement member, and an operation stick extending rearward.

With this optical connector, when the operation stick is pushed frontward, the coupling engagement member and the connector body move frontward, latches of the optical connector adaptor engage with the connector body, and thereby, the optical connector is connected to the optical connector adaptor. Moreover, when the operation stick is pulled rearward, the coupling engagement member and the coupling move rearward, the above engagement of the latches is released, and thereby, the optical connector is pulled off from the optical connector adaptor.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

An optical connector according to an aspect of the present disclosure is an optical connector connected to an optical adaptor along a predetermined connecting direction, the optical connector comprising: an inner housing including an engagement part for engaging with the optical adaptor on its surface; a boot connected to one side of the inner housing in the connecting direction; a first outer housing covering the engagement part; and a second outer housing covering at least part of the first outer housing and provided freely movably in the connecting direction relative to the first outer housing, wherein when the second outer housing moves in a direction away from the boot, the engagement part is exposed by the second outer housing and the inner housing moving relative to the first outer housing, and when the second outer housing moves in a direction toward to the boot, the engagement part is exposed by the second outer housing and the first outer housing moving relative to the inner housing.

DESCRIPTION OF EMBODIMENTS

Problems to be Solved by Present Disclosure

In a conventional optical connector, a connector body, a coupling, a coupling engagement member and a boot extend to be long in the front-rear direction. Therefore, bending stress and tensile stress exerted on the optical connector when inserting and pulling-off the optical connector and during attachment thereof tend to be large, and there can be a case where a problem such as breakage arises. In order to prevent such a problem such as breakage, an expensive material has to be used, and hence, there also arises a problem that costs of materials and the like are high.

The present disclosure is made in view of such problems, and an object thereof is to provide an optical connector capable of realizing shortening.

Effect of Present Disclosure

According to the present disclosure, shortening can be realized.

DESCRIPTION OF EMBODIMENT

First, the contents of an embodiment of the present invention are listed and described. (1) An optical connector according to an aspect of the present invention is an optical connector connected to an optical adaptor along a predetermined connecting direction, the optical connector comprising: an inner housing including an engagement part for engaging with the optical adaptor on its surface; a boot connected to one side of the inner housing in the connecting direction; a first outer housing covering the engagement part; and a second outer housing covering at least part of the first outer housing and provided freely movably in the connecting direction relative to the first outer housing, wherein when the second outer housing moves in a direction away from the boot, the engagement part is exposed by the second outer housing and the inner housing moving relative to the first outer housing, and when the second outer housing moves in a direction toward to the boot, the engagement part is exposed by the second outer housing and the first outer housing moving relative to the inner housing.

In the optical connector according to an aspect of the present invention, the second outer housing is freely movable in the connecting direction relative to the first outer housing. Further, when the second outer housing moves in the direction away from the boot, both the second outer housing and the inner housing move, the engagement part is exposed, and hence, engagement with an external optical adaptor is possible. Moreover, when the second outer housing moves in the direction toward to the boot, both the second outer housing and the first outer housing move, and the engagement part is exposed. Therefore, by releasing engagement with the optical adaptor in the engagement part, the optical connector can be detached from the optical adaptor. In this way, since attachment and detachment to/from the optical adaptor can be performed only by moving the second outer housing, operability in attachment and detachment can be improved. Moreover, the at least part of the first outer housing is covered by the second outer housing. By covering a part of the first outer housing with the second outer housing in this way, the whole length of the first outer housing and the second outer housing in the connecting direction can be reduced. Accordingly, realizing shortening of an optical connector can be achieved.

(2) In the aforementioned optical connector, one of a slit and a claw may be provided on an outer surface of the first outer housing, the other of the slit and the claw may be provided on an inner surface of the second outer housing, and the second outer housing may be freely movable relative to the first outer housing in a state where the claw engages with the slit. In this case, since the second outer housing moves in the state where the claw engages with the slit, the movement of the second outer housing can be stabilized.

Details of Embodiment

Specific examples of an optical connector according to an embodiment of the present disclosure are described with reference to the drawings. Notably, the present invention is not limited to these exemplary illustrations but defined by the claims, and is intended to include any modifications within a range of equivalency of the claims. In the following description, the same or corresponding elements in the description of the drawings are given the same signs and the duplicated description thereof is omitted.

FIG. 1is a perspective view showing an optical connector1according to the present embodiment,FIG. 2is a plan view showing the optical connector1, andFIG. 3is a longitudinal cross-sectional view of the optical connector1. The optical connector1is an MPO connector. The optical connector1is a connector connected to an external optical adaptor.

As shown inFIG. 1toFIG. 3, the optical connector1includes a rectangular ferrule2, an inner housing3, a first outer housing4, a second outer housing5and a boot6as an appearance configuration. The ferrule2is positioned at one end of the optical connector1. The inner housing3covers the ferrule2, and the first outer housing4covers a part of the inner housing3. The second outer housing5covers a part of the first outer housing4. The boot6extends to the opposite side to the ferrule2. Moreover, inside the optical connector1, a coil spring7, a rear housing8, a caulking ring9, a ferrule spring (not shown), and the like are provided.

In the below, for convenience of description, the “front”, the “rear”, the “top”, the “bottom”, the “left” and the “right” directions are defined to perform the description. The longitudinal direction of the optical connector1is set to a front-rear direction, specifically, the front is set to the orientation to which the ferrule2is seen from the boot6, and the rear is set to the opposite direction thereto. Moreover, the longitudinal direction of the front face of the ferrule2is set to a right-left direction, and the short-side direction of the front face of the ferrule2is set to a top-bottom direction. These directions are merely for convenience of the description and do not limit the scope of the present invention.

The ferrule2has a box shape to include an expansion part2aon its rear side. Inside the ferrule2, a plurality of fiber holes extending in the front-rear direction is formed. Into each fiber hole, each of optical fibers constituting a fiber cord inserted from the rear of the boot6is inserted. A front face2bof the expansion part2aof the ferrule2is a contact face brought into contact with the inner housing3. Moreover, the ferrule spring urging the ferrule2frontward is provided between the ferrule2and the rear housing8.

The inner housing3has a stepped polygonal cylinder shape to include an expansion part3aon its rear side. A pair of engagement recesses (engagement parts)3bin the right-left direction, and a groove3care provided on the outer surface of the inner housing3. Latches of an external optical adaptor are engaged with the engagement recesses3b. The groove3ccontains the coil spring7urging the first outer housing4frontward. The engagement recesses3bare provided on the surface of the inner housing3. For example, the engagement recesses3bare formed to be trapezoidal on the outer surface of the inner housing3. By the latches of the optical adaptor fitting to the individual engagement recesses3b, the optical connector1is engaged with the optical adaptor in the front-rear direction, and the optical connector1is attached to the optical adaptor. Moreover, the groove3cextends in the front-rear direction. The coil spring7being extendable and shrinkable in the front-rear direction is contained in the groove3c.

Inside the inner housing3, the ferrule2and the rear housing8are contained. The inner surface of the inner housing3has a stepped shape. A contact face3dwhich the ferrule2is brought into contact with, and a contact face3ewhich the front end face of the rear housing8is brought into contact with are provided inside the inner housing3. The front face2bof the expansion part2aof the ferrule2urged frontward by the ferrule spring is brought into contact with the contact face3d.

The first outer housing4is attached freely movably in the front-rear direction outside the inner housing3. The first outer housing4exhibits a cylindrical shape, and a cross section of the first outer housing4has a curved shape in which the short sides of the rectangle expand outward.

On an outer surface4cof the first outer housing4, slits4awhich the second outer housing5engages with are provided. The slits4aextend to have a predetermined length in the front-rear direction. The first outer housing4includes, for example, a pair of slits4awith symmetry in the right-left direction. Contact parts4bbrought into contact with the second outer housing5are provided at the rear ends of each of the slits4aof the first outer housing4. The contact parts4bconstitute the rear end faces of the slits4a.

The second outer housing5covers a part of the rear side of the first outer housing4and is freely movable in the front-rear direction relative to the first outer housing4. The second outer housing5is separate from the first outer housing4. The second outer housing5exhibits a cylindrical shape. A cross section of the second outer housing5has a curved shape in which the short sides of the rectangle expand outward.

In the second outer housing5, the rear housing8is contained. Claws5bengaging with the slits4aof the first outer housing4are formed on an inner surface5aof the second outer housing5. The claws5bprotrude inward of the second outer housing5from the inner surface Sa of the second outer housing5. The second outer housing5includes, for example, a pair of claws5bwith symmetry in the right-left direction.

A protruding part Se which a rear end3fof the inner housing3is brought into contact with from the front is provided at the rear end of the second outer housing5. At the rear end of the second outer housing5, the protruding part Se protrudes inward of the second outer housing5. By moving the second outer housing5frontward and by the front face of the protruding part Se coming into contact with the rear end3fof the inner housing3from the rear, both the second outer housing5and the inner housing3move frontward.

The rear housing8includes a cylindrical insertion part8ainserted into the rear side of the inner housing3, and a cylindrical part8bengaged with the caulking ring9on the rear side of the insertion part8a. The insertion part8ahas a shape expanded at the front end of the cylindrical part8b. The rear housing8is engaged with the inner housing3in the state where the front end of the insertion part8ais in contact with the contact face3eof the inner housing3. A convex and concave part8cis formed on the outer circumferential surface of the cylindrical part8bof the rear housing8.

The caulking ring9exhibits a stepped cylindrical shape in which its front side is expanded in diameter. The caulking ring9is expanded in diameter into a stepped shape in such a way that the inner diameter meets the outer diameter as going from the rear to the front. The caulking ring9includes a large diameter part9apositioned on its front side, and a small diameter part9bpositioned on the rear side of the large diameter part9a. The caulking ring9engages with the rear housing8and is fixed thereto, tensile strength fibers, a covering and the like which constitute an optical fiber cord being pinched between the outer circumferential surface of the cylindrical part8band the inner circumferential surface of the caulking ring9. Moreover, optical fibers which constitute the optical fiber cord are held inside the caulking ring9.

The boot6exhibits a cylindrical shape extending in the front-rear direction. The boot6is attached to the caulking ring9in the state of containing the cylindrical part8bof the rear housing8and the caulking ring9. The boot6protects the optical fiber cord such that a drastic bend does not arise on the optical fiber cord. The front end of the boot6is in contact with the rear end of the insertion part8aof the rear housing8, and the boot6extends rearward from this contact portion. Rearward of the portion in which the boot6contains the caulking ring9, a diameter reducing part6bwhich is reduced in diameter as going to the rear is provided. A plurality of through holes6awhich have long hole shapes extending in the circumferential direction of the boot6are formed in the diameter reducing part6b.

Now, for example, assuming the first outer housing4and the second outer housing5to be one integrated outer housing as in conventional ones, an optical connector would be attached to an external optical adaptor by pushing a boot frontward, and the optical connector would be detached from the optical adaptor by moving the outer housing rearward. Namely, there has been room for improvement in operability since the place of holding in attachment and the place of holding in detachment are different from each other, the boot being held for attachment in attaching the optical connector to the optical adaptor, the outer housing being held for detachment in detaching the optical connector from the optical adaptor. On the contrary, for the optical connector1according to the present embodiment, its operability is improved in an attachment operation and a detachment operation to/from the optical adaptor. Operations in attaching and detaching the optical connector1to/from the optical adaptor are described below.

First, an operation of attaching the optical connector1to the optical adaptor is described. In the state shown inFIG. 1toFIG. 3, the operation of attaching the optical connector1to the optical adaptor is performed by pushing the second outer housing5frontward. When pushing the second outer housing5frontward, the front face of the protruding part5eof the second outer housing5presses the rear end3fof the inner housing3, and the inner housing3moves frontward along with the second outer housing5.

When the second outer housing5moves frontward along with the inner housing3, the first outer housing4does not move frontward since the first outer housing4is restricted from moving frontward by the latches of the optical adaptor. Namely, when the second outer housing5moves frontward along with the inner housing3, the first outer housing4relatively moves rearward.

When the second outer housing5moves frontward along with the inner housing3as above, as shown inFIG. 4andFIG. 5, in the slits4aof the first outer housing4, the claws5bof the second outer housing5move frontward. In this stage, since the inner housing3and the second outer housing5move frontward relative to the first outer housing4, the engagement recesses3bstart to be exposed.

Then, when pushing the second outer housing5frontward, the inner housing3is also pushed frontward, and the latches of the optical adaptor engage with the engagement recesses3bof the inner housing3. After the engagement of the latches is completed, the first outer housing4urged frontward by the coil spring7contained in the groove3con the outer circumference of the inner housing3moves frontward to cover the latches of the optical adaptor and the engagement recesses3bwhich are engaged with each other. Thereby, the attachment of the optical connector1to the optical adaptor is completed.

Next, an operation of detaching the optical connector1from the optical adaptor is described. The operation of detaching the optical connector1from the optical adaptor is performed by pulling the second outer housing5rearward. When pulling the second outer housing5rearward, the claws5bof the second outer housing5press the contact parts4bof the first outer housing4, and after that, the first outer housing4moves rearward along with the second outer housing5.

When the second outer housing5moves rearward along with the first outer housing4as above, the inner housing3does not move rearward. Accordingly, when the second outer housing5moves rearward along with the first outer housing4, as shown inFIG. 6andFIG. 7, the engagement recesses3bof the inner housing3are exposed. Then, when further pulling the second outer housing5rearward, the latches of the optical adaptor with respect to the engagement recesses3bare released. When further pulling the second outer housing5rearward, the inner housing3is pulled along with the first outer housing4, and thereby, the optical connector1can be pulled off from the optical adaptor.

As described above, in the optical connector1, the first outer housing4and the second outer housing5are separate from each other, and the second outer housing5is freely movable in the front-rear direction relative to the first outer housing4. Accordingly, when the second outer housing5moves frontward, since both the second outer housing5and the inner housing3move frontward and the engagement recesses3bare exposed, the latches of the optical adaptor can be engaged with the engagement recesses3b.

Moreover, when the second outer housing5moves rearward, both the second outer housing5and the first outer housing4move rearward, and the engagement recesses3bare exposed. Therefore, by releasing the engagement with the optical adaptor at the engagement recesses3b, the optical connector1can be detached from the optical adaptor. In this way, since the optical connector1can be attached and detached to/from the optical adaptor simply by moving the second outer housing5in the front-rear direction, its operability in attachment and detachment can be improved.

Moreover, since at least part of the first outer housing4is covered by the second outer housing5, the whole length of the first outer housing4and the second outer housing5in the front-rear direction can be reduced. Accordingly, realizing shortening of the optical connector1can be achieved.

For the optical connector1, since bending stress and tensile stress exerted particularly on these portions when inserting and pulling-off the optical connector1and during attachment thereof can be reduced by realizing the shortening, costs of materials and the like can also be reduced. As the material of the inner housing3and the rear housing8, other than PEI (polyetherimide) which has been generally used, for example, PBT (polybutylene terephthalate) or PPS (polyphenylene sulfide) which costs less and is relatively lower in strength can be used. Notably, as the material of the first outer housing4and the second outer housing5, the same one as that of the inner housing or the rear housing8can be used.

Moreover, in the optical connector1, the slits4aare provided on the outer surface4cof the first outer housing4, the claws5bare provided on the inner surface5aof the second outer housing5, and the second outer housing5is freely movable relative to the first outer housing4in the state where the claws5bengage with the slits4a. Therefore, since the second outer housing5moves in the state where the claws5bengage with the slits4a, the movement of the second outer housing5can be stabilized.

As above, while an embodiment of the present invention has been described, the present invention is not limited to the aforementioned embodiment but various modifications thereof can occur without departing from the spirit of the present invention. For example, it can also be widely applied to various multicore and single-core optical connectors. Moreover, the optical connector1may be, for example, a so-called field-assembled optical connector which is attached to an optical fiber cord on site.

Moreover, in the aforementioned embodiment, the pair of slits4aare provided on the outer surface4cof the first outer housing4, and the pair of claws5bare provided on the inner surface5aof the second outer housing5. Nevertheless, the number, arrangement and shape of slit(s)4acan be properly modified. The number, arrangement and shape of claw(s)5bof the second outer housing5can also be properly modified. Furthermore, in place of the first outer housing4including the slit(s)4aand the second outer housing5including the claw(s)5b, a first outer housing including a claw and a second outer housing including a slit may be used.

REFERENCE SIGNS LIST