Adaptor unit and optical plug

A screwing part 1220 is inserted into a large through-hole 1110 from its front side and is screwed together with a male screw part of a jig. A convex part 1230 in an approximately ring shape is formed at a back end part of the screwing part 1220. The convex part 1230 is adjacent to a fitting part 1111 which is made of an approximately ring convex part projecting toward inside of the large through-hole 1110. The back of the fitting part 1111 is adjacent to a front end opening part 1310 of a back tubular part 1300. In short, the fitting part 1111 of the adaptor main body 1110 is sandwiched between the convex part 1230 and the front end opening part 1310. By inserting and pressing the back end opening part 1210 of the front tubular part 1200 into the front end opening part 1310 of the back tubular part 1300, the front tubular part 1200 and the back tubular part 1300 are connected and fixed with each other. Sign β represents their pressing part.

TECHNICAL FIELD

The present invention relates to an adaptor unit comprising an optical plug which connects each front facet of two ferrules facing with each other and is installed at either male or female opening part.

BACKGROUND ART

Conventionally, a Japanese Utility Patent Application Laid-open No. H6-2306 has disclosed an adaptor unit comprising an optical plug which connects each front facet of two ferrules facing with each other and is installed at either male or female opening part in itsFIGS. 1 and 2.FIG. 9of the present application illustrates its structure. The adaptor (19) comprising components such as a dividing sleeve (22) disclosed in the Japanese Utility Patent Application Laid-open No. H6-2306 has been common and well-known.

Recently, as shown inFIGS. 10A-10C, a dividing sleeve unit (u1) is formed by using an approximately tubular dividing sleeve holder (K1, K2) comprising a dividing sleeve (S), and an assembly of components (referred as an adaptor unit hereinafter) in which the dividing sleeve is held indirectly by the main body of the insulation adaptor through a dividing sleeve holder of the dividing sleeve unit (u1) tends to be installed at an opening part of the optical plug or the optical connector.

In the Japanese Utility Patent Application Laid-open No. H6-2306A, a dividing sleeve unit comprising such a structure is illustrated as an alignment tube or an alignment device, and examples for constructing an elastic contact which is used along with the dividing sleeve are also disclosed.

FIG. 11is a side and sectional view of an adaptor unit19′ of a general optical connector (optical plug10′) which is consisted by using such dividing sleeve unit (alignment device; u1) and has been well-known widely in Japan. The dividing sleeve unit u1inFIG. 11is inserted and installed in a large through-hole h of the adaptor unit19′. A tubular main body2comprising a ferrule holder13which holds a ferrule18, or a contact point (: the optical contact unit), has a groove g2formed in an approximately ring shape on the external surface of the opening part of the front end part3. The dividing sleeve unit u1fits a projection part g1which is formed in an approximately ring shape at the back opening part of the dividing sleeve holder K1illustrated inFIG. 10Cwith the groove g2at a point γ illustrated inFIG. 11. As a result, the dividing sleeve unit u1is fixed in the large through-hole h of the adaptor unit19′.

A male screw K1aformed on the external surface of the dividing sleeve holder K1can screw together with a female screw which is formed at the end point of a jig in an approximately cylindrical bar shape. By pulling the jig while the male screw and the female screw remain screwing with each other, the groove g2and the projection part g1fitting together at the point γ can be released, and further the dividing sleeve unit u1can be pulled out of the optical plug10′ from the opening part10a. By employing that process, maintenance, or inspection for dirt or stain, and cleaning with tools such as a commercially available cotton-tipped swab can be carried out toward the front facet of the ferrule18.

The Japanese Patent Application Laid-open No. 2001-749776 discloses more detailed structure of the elastic contact point which holds the ferrule18in the optical axis direction with elasticity. That is, for example, sign12represents a hole of the groove formed in the tubular main body2.

DISCLOSURE OF THE INVENTION

Problems to be Solved

In order to use the conventional optical plug10′, however, each process for taking out the dividing sleeve unit u1from the opening part10ashould be carried out individually at each ferrule18. Accordingly, with respect to an optical connector comprising plural ferrules, process for releasing the dividing sleeve unit should be repeated for plural times to maintain the front facet of each ferrule. Consequently, efficiency for maintaining each ferrule front facet becomes worse.

In the conventional optical plug10′, each adaptor unit19′ is left at the optical plug10′ side even after each dividing sleeve unit u1is released. In an urgent situation in its maintenance or operation, dirt or stain at the front facet of the ferrule18tends not to be easily and rapidly found out depending on its brightness condition. In short, the conventional optical plug10′ has not been desirable.

The present invention has been accomplished in order to overcome the aforementioned drawbacks. An object of the present invention is to provide an adaptor unit functioning as an optical connector which can be efficiently and easily maintained.

Here, each object listed above may be enough to be fulfilled individually by at least one of each method described above, and each invention in the present application is not necessarily secure that there is a solution which solves all the problems at once.

Means of Solving the Problem

In order to solve the above-described problems, the following methods may be effective.

That is, the first aspect of the present invention is an adaptor unit comprising an optical plug which connects each front facet of two ferrules facing with each other and is installed at either male or female opening part, comprising: a dividing sleeve which includes each front facet of two ferrules and holds each front ferrules facing with each other in connecting process; an approximately cylindrical dividing sleeve holder which includes and holds the dividing sleeve; and an adaptor main body which holds the dividing sleeve holder by including at least a portion of the dividing sleeve holder, wherein a fitting part which fits with the dividing sleeve holder to restrain movement of the driving sleeve holder at least in the optical axis direction is formed at the adaptor main body, the dividing sleeve holder comprises a front tubular part and a back tubular part which is adjacent and fixed to the front tubular part, and an engagement part which can be freely put on and taken off to connect with a predetermined jig is formed in at least one of the front tubular part of the dividing sleeve holder.

The second aspect of the present invention is that the adaptor unit includes plural dividing sleeve holders each of which is formed in an approximately cylindrical shape and includes and holds the dividing sleeve. Here, the engagement part may not be necessarily formed on all of the plural dividing sleeve holders. Alternatively, the engagement part may be comprised in only one dividing sleeve holder. At that time, the dividing sleeve holder comprising the engagement part may be recognized by coloring or marking. That enables to obtain actions and effects of the present invention.

The third aspect of the present invention is that a screwing part which screws the engagement part with the jig is formed and that the screw axis direction of the screwing part approximately corresponds to the optical axis direction.

The fourth aspect of the present invention is that the fitting part is made of a convex part which projects to the axis side of the dividing sleeve holder and that the convex part is sandwiched between the front tubular part and the back tubular part in the optical axis direction.

The fifth aspect of the present invention is that the convex part is formed in an approximately ring shape around the axis which corresponds to the axis of the dividing sleeve holder.

The sixth aspect of the present invention is that the back end opening part of the front tubular part is installed inside of the front end opening part of the back tubular part.

The seventh aspect of the present invention is that the front tubular part and the back tubular part are connected and fixed with each other by inserting and pressing the back end opening part into the front end opening part.

The eighth aspect of the present invention is that a rotational asymmetry part is formed at the external surface of the dividing sleeve holder which is asymmetric to rotation around the axis of the dividing sleeve holder and that a rotation preventing pat contacting to the rotational asymmetry part is formed at the adaptor main body. Here, rotational asymmetry is that a sectional plane vertical to the rotational axis is not a circular shape. Accordingly, rotational asymmetry includes rotational symmetry rotating at an angle of 180° or 90°.

The ninth aspect of the present invention is the rotational asymmetric part and the rotation preventing part are two parallel planes sandwiching the axis of the dividing sleeve holder.

The tenth aspect of the present invention is that the optical plug which connects each front facet of two ferrules facing with each other comprises the adaptor unit.

Through employment of the aforementioned aspects of the present invention, the aforementioned drawbacks can be overcome effectively and rationally.

EFFECT OF THE INVENTION

Effects to be obtained by the present invention are explained as follows.

That is, according to the first aspect of the present invention, the adaptor main body and the dividing sleeve holder are fit at the fitting part and the dividing sleeve holder and a predetermined jig are also fit at the fitting part. When the jig is connected to the dividing sleeve holder, the whole body of the adaptor unit can be taken out from the opening part of the optical connector only by pulling the jig.

Accordingly, by employing the first embodiment of the present invention, the portion around the front facet of the ferrule can be easily and rapidly opened remarkably wide in an urgent situation in its maintenance or operation, and that enables to find out dirt or stain at the front facet of the ferrule easily and rapidly. Consequently, maintenance efficiency of the optical plug or the optical connector can be remarkably improved.

According to the second aspect of the present invention, each dividing sleeve holder is fit to the fitting part of the adaptor main body. That enables to expose each front facet of all the ferrules at front side of the opening part of the optical plug by pulling the jig only once.

As a result, frequency of operating the jig may be decreased in fewer than half in maintenance of the optical plug comprising plural ferrules, and maintenance efficiency of the optical plug can be improved.

Alternatively, fitting structure in which a male screw and a female screw are screwed together (the third aspect of the present invention) can be employed for forming the fitting part described above concretely and easily. The fitting part, however, may not be necessarily have those structures in the present invention but can have other structure.

On carrying out the first and the second aspects of the present invention, however, the fitting part can also have, for example, the conventional structure shown inFIG. 11comprising the male screw K1a. When the fitting part has the conventional structure shown inFIG. 11, it becomes not necessary to develop any new jig and also it becomes easier and surer to form the fitting part. Those are desirable.

According to the fourth aspect of the present invention, the convex part is sandwiched between the front tubular part and the back tubular part in the optical axis direction and movement of the dividing sleeve holder in the optical axis direction is effectively restrained by simple structure. Accordingly, by employing the fourth aspect of the present invention, it becomes easier to design fitting structure of the adaptor main body and the dividing sleeve holder in concrete and in detail, to form each component and to compose members of the unit.

According to the fifth aspect of the present invention, the adaptor main body and the dividing sleeve holder can contact with each other around the dividing sleeve holder in the axis direction. That enables to fix the adaptor main body and the dividing sleeve holder more firmly with each other at least in the optical axis direction.

According to the sixth aspect of the present invention, the end part such as the end of the front end opening part of the back tubular part can be adjusted to the fitting part. Alternatively, the fitting part may be formed on the external surface of the front tubular part and then the side wall of backside of the fitting part can be adjusted to the fitting part.

Accordingly, by employing the sixth aspect of the present invention, the fitting part of the adaptor main body and the dividing sleeve holder can be obtained at a limited and small space in the adaptor main body.

Structure for connecting and fixing the front tubular part and the back tubular part may be arbitrary. For example, they can be fixed by pressing and screwing together. Especially, by inserting, screwing and pressing the back end opening part into the front end opening part (the seventh aspect of the present invention), it becomes easier to design, manufacture, and compose the dividing sleeve holder.

According to the eighth aspect of the present invention, the rotational asymmetric part is adjacent to the rotation preventing part, and rotation of the dividing sleeve holder can be prevented. As a result, the dividing sleeve holder (and the whole body of the dividing sleeve unit) can be fixed in the adaptor main body sufficiently.

According to the ninth aspect of the present invention, the rotational asymmetric part and the rotation preventing part which sufficiently prevent rotation of the dividing sleeve holder can be formed effectively and easily without restraining miniaturization of the adaptor main body. Also, because both planes which face sandwiching the axis of the cable adaptor and are approximately parallel with each other are formed in the same shape and the same size, two right angles (half-turn) around the axis shows rotational symmetry. And the cable adaptor can be composed at two positions, or both at 0° and 180° positions in the circle around the axis. Consequently, rotational direction for composing the cable adaptor may not be limited in one way, which enables to obtain excellent composing efficiency.

According to the tenth aspect of the present invention, maintenance, or inspection for dirt or stain, and cleaning toward the front facet of the ferrule can be carried out easily and rapidly. That improves efficiency of practical operation of the unit.

Moreover, other actions and effects of the optical contact unit described above can also be obtained.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will next be described based on concrete examples. The scope of the present invention, however, is not limited to the embodiment described below.

FIRST EMBODIMENT

FIG. 1Ais a side view of an adaptor unit1000in the first embodiment of the present invention. An adaptor main body1100is made of an insulator, and a shallow groove1104is formed in the optical axis direction at the upper portion of its′ external surface formed in an approximately cylindrical shape. And a further shallow step1105is formed at the external surface of the cylindrical main body in circular direction. From the bottom surface1100aof the adaptor main body1100, each back end part1320of two dividing sleeve holders1300in total, each of which formed in an cylindrical shape, sticks out backward. A hill part1321is formed in an approximately ring shape at the external surface of the back end part1320.

FIG. 1Bis a back view of the adaptor unit1000in the first embodiment of the present invention. Each adaptor unit1000is formed approximately symmetrical to a sectional plane α. Six through-holes (1101,1102,1110) in total are formed in the adaptor main body1100in each size. Each kind of component such as a metal pin which constructs a contact point for electric wiring is inserted and installed in the through-holes1101and1102.

The dividing sleeve holder of the present invention is inserted and installed in the large through-hole1110having the largest diameter. A rotation preventing part1112is formed at a portion of the large through-hole1110. The rotation preventing part1112contacts to a rotational asymmetric part1330installed on the external surface of the back tubular part1300of the dividing sleeve. The rotation preventing part1112distributes to keep an equivalently wide area for forming the through-hole1101with predetermined durability. Here, signs S and1340represent a dividing sleeve and a leaning shoulder part of the back tubular part1300, respectively.

FIG. 2is a sectional view of the adaptor unit1000at a sectional plane α. The upper portion and the lower portion of the adaptor unit1000are formed approximately symmetric at the sectional plane α except for existence of a groove1104. As shown in the sectional view ofFIG. 2, the adaptor unit1000comprises one adaptor main body1100and two dividing sleeve units U. Here, one dividing sleeve unit U has a dividing sleeve S and a dividing sleeve holder comprising it, and a dividing sleeve holder has a front tubular part1200and a back tubular part1300.

The dividing sleeve S has a slit Sa which inns in the optical axis direction. A screwing part1220is a male screw which is formed on the external surface of the approximately cylindrical front tubular part1200, and its screwing axis corresponds to the axis of the dividing sleeve S formed in an approximately ring shape. The screwing part1220is inserted forward into the large through-hole1110and screws together with a female screw part of jig1225, shown schematically inFIG. 4. As the jig, a well-known jig which is formed in an approximately cylindrical bar and has a female part at its end can be used.

And an approximately ring convex part1230is formed at the back end part of the screwing part1220. The convex part1230is adjacent to the fitting part1111which is an approximately ring convex part projecting inward of the large through-hole1110. The back end of the fitting part1111is adjacent to a front opening part1310of the back tubular part1300. In short, the fitting part1111of the adaptor main body1100is sandwiched between the convex part1230and the front opening part1310.

By inserting, fitting and pressing the back end opening part1210of the front tubular part1200into the front end opening part1310of the back tubular part1300, the front tubular part1200and the back tubular part1300are connected and fixed with each other. Sign β shows an injection part in which the back end opening part1210is pressed.

FIG. 3is a sectional view of the adaptor main body1100of the adaptor unit1000at the sectional plane α. The fitting part1111exists almost in the center of the large through-hole1110of the adaptor main body1100, and its front surface is an adjacent plane1111awhich corresponds to a portion adjacent to the front end opening part1310. A rotation preventing part1112is parallel to the sectional plane α. The rotation preventing part1112makes an angle of about 40° in circumferential direction from the axis of the approximately ring fitting part1111, or the axis of the dividing sleeve S. When this angle is too small, rotation of the back tubular part1300can hardly be prevented sufficiently.

FIG. 4is a sectional view of the dividing sleeve unit U at the optical axis. Ua represents a concave part, which is a groove formed on the external surface of the dividing sleeve holder made of the front tubular part1200and the back tubular part1300. The bottom plane of the concave part Ua is formed with the external surface of the approximately cylindrical front tubular part1200, the front side plane of the concave part Ua is formed with the back end adjacent plane1230aof the convex part1230, and the back side plane of the concave part Ua is formed with the front end adjacent plane1310aof the front end opening part1310. In short, the concave part Ua sufficiently fits with the fitting part1111formed with the approximately ring convex part. Similar to the conventional invention, the concave part Ua efficiently fits with the fitting part1111leaving a proper amount of play in the diameter direction of the concave part Ua formed in an approximately ring shape. The play in the diameter direction helps to insert other ferrule B smoothly from the front end opening part1240of the front tubular part1200.

FIGS. 5A,5B and5C are a sectional view, a back view and a side view of the front tubular part1200of the dividing sleeve holder, respectively. By forming an approximately ring convex part which projects inward, or to the axis direction, at the front end opening part1240, the adjacent plane1240awhich prevents releasing the dividing sleeve unit S is formed. An inclined part1210bis formed uniformly in circumferential direction at the front end of the external surface1210cof the back end opening part1210which is pressed into the front end opening part1310of the back tubular part1300. Because the front end adjacent plane1310aof the front end opening part1310contacts to the inclined part1210b, inserting process can be completed without changing the shape of each component such as the front tubular part1200and the back tubular part1300.

FIGS. 6A,6B and6C are a sectional view, a back view and a side view of the back tubular part1300of the dividing sleeve holder, respectively. The adjacent planes1350and1360are steps each of which is a difference of the inner diameters of the internal surface of the back tubular part1300. A back-facet1210aof the back end opening part1210of the front tubular part1200shown inFIGS. 5A-5Cis adjacent to the adjacent plane1350, and a bottom plane of the dividing sleeve S is adjacent to the adjacent plane1360. Here,1340ais a plane which exists outside of the leaning shoulder part1340and is vertical to the optical axis direction.

A rotational asymmetric part1330is formed smoothly by grinding and polishing the cylindrical external surface1301. Each position, shape and size of the rotational asymmetric part1330is formed rotationally symmetrical and parallel to the axis of the back tubular part1300. The rotational asymmetric part1330makes a proper angle of about 40° in circumferential direction around the axis. When this angle is too large, the back end opening part1310tends to become too thin and that may reduce its durability. When this angle is too small, the area at which the rotational asymmetric part1330contact to the rotation preventing parts1112becomes too small and rotation of the back tubular part1300can hardly be restrained sufficiently. In short, the angle which the rotational asymmetric part1330make around the axis efficiently contributes to sufficient restrain of rotational operation of the dividing sleeve holder (dividing sleeve unit U), downsizing of the adaptor unit1000, and maintaining strength of each part of the adaptor unit1000.

A taper part1320bformed in an approximately ring shape guides the end (front end part) of the ferrule to be inserted smoothly into the back tubular part1300of the dividing sleeve holder. And a hill part1321formed at the back end opening part1320of the back tubular part1300functions to fit a main body of an elastic contact point which is installed independently of the adaptor unit1000in the first embodiment.

FIG. 7is a sectional view of the elastic contact point (an optical contact unit100) which is connected to the back tubular part1300. A ferrule A, a ferrule holder110, a coil spring120, a main body130, and a cable adaptor140are comprised in the optical contact unit100and are fixed in a shell of an objective optical plug. The ferrule A is inserted from the front facet Aa into the dividing sleeve S of the adaptor unit1000.

The main body130of the optical contact unit100is formed in an approximately cylindrical shape, and two slits S5and S6running in the optical axis direction are formed at its front opening part making an angle of 180° with each other, or symmetrical to the optical axis. A groove G in an approximately ring shape is formed on the internal surface of the cylindrical front opening part of the main body where the slits S5and S6are formed, and the groove G fits with the hill part1321. When the back end opening part1320of the back tubular part1300is inserted into the front opening part of the main body130of the optical contact unit100, the slits S5and S6help to fit the units by varying the shape of the front opening part of the main body130to a recoverable extent. As a result, the adaptor unit1000can be fit firmly in the optical plug shell. This fitting operation is carried out at each dividing sleeve unit U.

The conventional dividing sleeve unit u1shown inFIG. 11also fits at a point γ, which is similar to that of the present embodiment. But when the dividing sleeve unit u1picked out from the conventional optical plug10′ by using a jig, the adaptor19′ which is fixed in the opening part of the optical plug10′ is left there.

On the contrary, when the process same as that in the conventional optical adaptor19′ is carried out to the adaptor unit1000in the first embodiment of the present invention by using a jig, connection between the groove G and the hill part1321is released and further the whole body of the adaptor unit1000can be easily taken out from the opening part of the optical plug. In short, in the present invention, a female screw part of a jig which is an approximately cylindrical metal bar and has a female screw at its end is screwed together firmly with a male screw part (: screwing part1220) of the front tubular part1200. By pulling the jig forward until the hill part1321is released from the groove G, the adaptor unit1000can be released from the optical plug. By further pulling the jig forward, the whole body of the adaptor unit1000can be easily taken out from the opening part of the optical plug.

That is because each component in the adaptor unit1000is fixed to the adaptor main body1100either directly or indirectly as shown inFIG. 2. As explained by usingFIG. 2, each component in the adaptor unit1000is fixed to the adaptor main body1100according to the following processes:(1) First, the dividing sleeve S is inserted into the front tubular part1200.(2) Second, the front tubular part1200comprising the dividing sleeve S is inserted from forward into the large through-hole1110of the adaptor main body1100.(3) Third, the back tubular part1300is inserted from backward into the large through-hole1110of the adaptor main body1100.

Accordingly, the dividing sleeve S is comprised in the dividing sleeve holder (the front tubular part1200and the back tubular part1300). The back end opening part of the front tubular part1200is inserted and pressed into the front end opening part of the back tubular part1300.

According to this composing processes described above, composing the dividing sleeve unit U shown inFIG. 4is completed after pressing the dividing sleeve S into the large through-hole1110of the adaptor main body1100. Because this fitting is sufficiently firm, the process of composing the dividing sleeve unit U is an irreversible process. That is, the front tubular part1200and the back tubular part1300are connected and fixed firmly with each other and they may not be separated. And this composing process generates a concave part Ua at the dividing sleeve unit U as shown inFIG. 4, and the concave part Ua fits firmly with the fitting part1111formed in the large through-hole1110. Accordingly, the dividing sleeve unit U and the adaptor main body1100are composed to be one unit. In short, each components of the adaptor unit1000can be fixed to the adaptor main body1100either directly or indirectly through processes such as pressing and connecting.

Owing to that structure, the whole body of the adaptor unit1000can be taken out of the opening part of the optical plug easily at one time only by pulling the jig forward.

According to the first embodiment of the present invention, maintenance of the front facet of the ferrule can be carried out easily and effectively.

SECOND EMBODIMENT

FIGS. 8A and 8Bshow a front and top view and a sectional view of an optical plug4000in a second embodiment of the present invention. The optical plug4000comprises the adaptor unit1000in the first embodiment of the present invention. An agraffe4400, a cramp body4500, a pressure-bonding sleeve4600, and a gum tube GT consist of a cable fixing part of the optical plug4000. In the second embodiment, the central axis of an approximately cylindrical female plug shell4100is the z axis and the direction from the gum tube GT to an edge4000aof the female plug4000is the positive direction of the z axis.

A slide sleeve4150formed in an approximately cylindrical shape is supported by a screw4151resiliently and guided to the z axis direction by a guide pin PN3, which enables to shuttle in the z axis direction in a predetermined range. Accordingly, a latching sleeve LS is pumped in the slide sleeve4150in diameter direction of the female plug shell4100.

An insert of the female plug4000comprises a front part, a middle part and a rear part which are made of insulator. That is, an insulator1100which is formed in the same shape as that shown inFIGS. 1 and 2in the first embodiment consists of the front part of the insert, an insulator4220which is shown inFIG. 8Bconsists of the middle part of the insert, and an insulator4230shown inFIG. 8Bconsists of the rear part of the insert. These three insulators1100,4220and4230are collectively called an insert4200hereinafter. The insert4200formed in an approximately cylindrical shape is inserted and installed at the inside of the internal surface4100aof the female plug shell4100as illustrated inFIG. 8B, and is maintained in a condition that each end part of the transmission line can be freely fitted and separated with respect to each line to a certain male plug on which the female plug4000is coupled.

A concave part1103formed on the back1100aof the insulator1100shown inFIG. 1Bis formed to restrain relative rotational operation of the insulator1100and the insulator4220around the axis.

The groove1104and the groove4221formed at the insulator1100and the insulator4220, respectively, are connected with each other to be one straight line. That functions as a guiding line which guides the pin PN1in the z axis along the external surface of the insert4200.

The groove G2formed at the optical contact unit100as illustrated inFIG. 7, fits with the convex part4231awhich is formed in an approximately ring shape on the internal surface of the through-type hole4231comprised in the insulator4230. This fitting can be released by using a tool.

In the process of releasing the adaptor unit1000in the first embodiment of the present invention, the adaptor unit1000is released from its front part, or the insert4200. Because the shoulder part4100c, which is a difference between the large diameter and the small diameter of the female plug shell4100, the pin PN1, and the connecting member4300completely restrict motion of the middle part (insulation4220) and the back part (insulator4230) of the insert4200in the female plug shell4100, the process of releasing the adaptor unit1000is a reversible process. In short, after the adaptor unit1000is pulled out from the optical plug4000, the insert4200can be put back to be connected in the female plug4000by reversing the process: pushing the adaptor unit1000into the optical plug4000.

OTHER MODIFIED EMBODIMENT

While the present invention has been described with reference to the above embodiments as the most practical and optimum ones, the present invention is not limited thereto, but may be modified as appropriate without departing from the spirit of the invention. By applying and modifying the embodiment, effect of the present invention can be obtained.

In the first embodiment, for example, it is preferable that the adaptor main body1100is made of resin and the front tubular part1200and that the back tubular part1300consisting the dividing sleeve holder are made of metal concerning strength, elasticity, durability, and compatibility to the tools of each member. On carrying out the present invention, however, material for forming each member can be arbitral and may not be necessarily limited thereto.

In the first embodiment, two dividing sleeves U are comprised in the adaptor unit1000. Alternatively, the adaptor unit in the present invention may comprise only one dividing sleeve or three or more dividing sleeves.

Number of the through-holes for electric line, e.g., the through-holes1101and1102shown inFIG. 1B, can be arbitrary, and alternatively, any through-hole may not be necessarily formed.

InFIG. 1B, both sides of the adaptor unit1000is symmetrical to the sectional plane α. And inFIG. 2, both upper and lower sides of the adaptor unit1000is symmetrical. Alternatively, the adaptor unit of the present invention may not be necessarily formed symmetrical. Structure of the adaptor unit may be designed concerning each object and specification.

In the first embodiment, the front tubular part1200and the back tubular part1300are pressed and screwed together with each other. Alternatively, that fitting can be carried out by screwing a male screw and a female screw together.

Alternatively, the through-hole the adaptor main body to which one dividing sleeve unit is inserted and arranged may comprise only one rotational preventing part or three or more rotational preventing parts. Eight rotational preventing parts, which form the through-hole in an octagon shape, may be comprised to provide sufficient rotational preventing action.

Here, proper and optimum position and number of rotational preventing parts depend on processing accuracy of the dividing sleeve holder and the adaptor main body toward the through-holes and strength of the materials of the rotational preventing parts. Although the rotational preventing part in the first embodiment which is made of assumable kinds of materials always satisfies those conditions, conditions with respect to positions and numbers of the rotational preventing part may not be limited to those in the first embodiment.

Alternatively, the rotational-preventing part which prevents rotation of the dividing sleeve unit can be formed at the front tubular part. It is sufficient that the rotational preventing part is formed either at the front tubular part or at the back tubular part. Accordingly, by limiting that the rotational preventing part is formed at either one portion, it becomes easier to form the rotational preventing part on the dividing sleeve holder.

Alternatively, the rotational preventing part can also be formed to cover the entire length of the dividing sleeve holder in the optical axis direction.

Alternatively, the convex part which is the fitting part formed at the adaptor main body may not be necessarily formed in an approximately ring shape. It may be formed, for example, partially at the internal surface in circumferential direction. That is, the fitting part may not be necessarily formed around a circle in circumferential direction, but the convex part can be formed only at one portion of the circle.

Alternatively, the fitting part formed at the adaptor main body may use a conventional screwing part which fits a male screw and a female screw by screwing together. Further alternatively, the fitting part may be formed by using other conventional screwing part or arbitrary unique screwing part.

Alternatively, structure of the dividing sleeve unit (the back tubular part) and the optical contact unit which is to be fitted at the back of the dividing sleeve unit may be the conventional structure shown inFIG. 11.

The present invention relates to an adaptor unit comprising an optical plug which connects each front facet of two ferrules facing with each other and is installed at either male or female opening part. The optical plug may be either male or female and may be hybrid-type structure which connects electric lines as explained in the first embodiment of the present invention.

While the present invention has been described with reference to the above embodiments as the most practical and optimum ones, the present invention is not limited thereto, but may be modified as appropriate without departing from the spirit of the invention.

The present invention comprises all the contents in the priority claiming Japanese patent application No. 2004-120752.