Patent Description:
In a conventional example, there is known an optical connector having an optical cable as an optical fiber, a ferrule which is arranged at one end of the optical cable and through which a core of the optical cable is inserted, a frame as a housing in which the ferrule is accommodated, and a first face plate and a second face plate as holders which are assembled to the frame and engaged with the frame through a first latch piece and a second latch piece to allow the frame to hold the ferrule (refer to PTL <NUM>).

In the conventional optical connector, the first face plate and the second face plate are assembled to the frame so as to cover upper and lower faces of the frame. Each of the first face plate and the second face plate is provided with a ferrule receiver which allows the frame to hold the ferrule through a coil spring.

Reference is made to <CIT>. Additionally, <CIT> and <CIT> disclose an optical connector. These documents, however, fail to disclose the use of interacting ribs and groove portions to suppress positional displacement of a cover when it is assembled to the housing of the optical connector. They also fail to disclose a temporary engagement portion that is configured to allow the holder to be held in the housing in a temporary engagement position and allow the ferrule to be accommodated in the housing.

The conventional optical connector according to <CIT> is provided with a positioning projection which determines the assembling position of the holders relative to the housing.

In this positioning projection, however, there is a possibility of causing positional displacements that the holders are pivoted or inclined to the housing in assembling the holders to the housing, causing inferior assembly.

Therefore, an object of the present invention is to provide an optical connector allowing the assembly to be improved.

According to the invention, there is provided an optical connector comprising: an optical fiber; a ferrule which is provided at an end of the optical fiber and through which a core of the optical fiber is to be inserted; a housing in which the ferrule is accommodated; a holder, provided with a ferrule retainer, which is inserted into the housing and engaged with the housing through an engagement portion, the ferrule retainer allowing the housing to hold the ferrule; a pair of ribs integrally connected to each other through the ferrule retainer, which are provided in the holder so as to extend along an inserting direction of the holder into the housing, the ferrule retainer provided between the pair of ribs; and a pair of fitting portions which are groove portions and are provided in the housing and to which the ribs are to be fitted to suppress a positional displacement where the holder may be pivoted or inclined to the housing when assembling the holder to the housing, the pair of ribs fitted to the pair of fitting portions when inserting the holder into the housing, wherein the engagement portion includes: a temporary engagement portion configured to allow the holder to be held in the housing in a temporary engagement position and allow the ferrule to be accommodated in the housing; and a formal engagement portion configured to allow the holder to be inserted into the housing under a condition that the ferrule is accommodated in the housing and allow the holder to be held in the housing in a formal engagement position.

Since the ribs are provided in one of the holder and the housing so as to extend along the inserting direction of the holder into the housing and the fitting portions to be fitted to the ribs are provided in the other of the holder and the housing, with the ribs fitted to the fitting portions, it is possible to suppress a positional displacement where the holder may be pivoted or inclined to the housing when assembling the holder to the housing.

Therefore, it is possible to suppress a positional displacement of the holder relative to the housing, allowing the assembly of the optical connector to be improved.

The engagement portion includes a temporary engagement portion configured to allow the holder to be held in the housing and allow the ferrule to be accommodated in the housing, and a formal engagement portion configured to allow the holder to be inserted into under a condition that the ferrule is accommodated in the housing and allow the holder to be held in the housing.

By the temporary engagement portion, it is possible to allow the holder to be held in the housing and allow the ferrule to be accommodated in the housing. In shifting from the engagement with the temporary engagement portions to the engagement with the formal engagement portions, with the ribs fitted to the fitting portions, it is possible to suppress the positional displacement of the holder relative to the housing, allowing the assembly to be improved.

The ribs are provided in the holder, and the holder is provided, between the ribs, with a ferrule retainer which allows the housing to hold the ferrule. Additionally, the ribs are connected to each other through the ferrule retainer integrally.

Since the ribs are connected to each other through the ferrule retainer integrally, it is possible to improve the rigidity of the ribs thereby allowing the suppression of deformation of the ribs and also possible to stabilize the fitting of the ribs to the fitting portions thereby allowing the assembly to be improved.

The optical fiber may be fixed to the ferrule through a crimping sleeve which allows the core to be inserted therethrough, and the holder may be configured to allow the housing to hold the ferrule through the crimping sleeve.

Since the holder allows the housing to hold the ferrule through the crimping sleeve, even if an external force, such as tensile force, is applied to the optical fiber, it is possible to prevent the external force from being transmitted to the ferrule owing to the provision of the crimping sleeve.

In accordance with the aspect of the present invention, it is possible to produce an effect of providing an optical connector capable of improving its assembly.

Optical connectors according to embodiments will be described with reference to drawings.

A first example not falling within the scope of the claimed invention will be described with reference to <FIG>.

An optical connector <NUM> according to the first example, not falling under the scope of the claimed invention, includes two optical fibers <NUM>, two ferrules <NUM> arranged at respective ends of the optical fibers <NUM> to allow insertion of cores <NUM> of the optical fibers <NUM>, a housing <NUM> for accommodating the ferrules <NUM>, and a holder <NUM> inserted into and engaged with the housing <NUM> through a pair of engagement portions <NUM> to allow the ferrules <NUM> to be retained in the housing <NUM>.

In the holder <NUM>, a pair of ribs <NUM> are formed so as to extend toward an inserting direction of the holder <NUM> into the housing <NUM>. The housing <NUM> is provided with a pair of fitting portions <NUM> to be fitted with the ribs <NUM>.

Each of the engagement portions <NUM> includes a temporary engagement portion <NUM> which allows the holder <NUM> to be held in the housing <NUM> and allows the ferrules <NUM> to be accommodated in the housing <NUM>, and a formal engagement portion <NUM> which allows the holder <NUM> to be inserted into the housing <NUM> under a condition that the ferrules <NUM> are accommodated in the housing <NUM> and allows the holder <NUM> to be held in the housing <NUM>.

Each of the optical fibers <NUM> is formed by a solid type optical fiber cable where a cover is arranged on the periphery of the core <NUM>. In each of the optical fibers <NUM>, One end of each of the optical fibers <NUM> is connected to an instrument or the like. While on the other end of each of the optical fibers <NUM>, the core <NUM> is exposed and inserted into the ferrule <NUM>.

Two ferrules <NUM> are arranged in parallel with each other. The cores <NUM> of the optical fibers <NUM> are inserted into respective ferrules <NUM>, then completing a ferrule assembly <NUM>. In the ferrule assembly <NUM>, respective end faces of the optical fibers <NUM> are polished by such as a polishing jig (not illustrated) for holding the ferrule assembly <NUM> and a polishing machine (not illustrated) for polishing tip faces of the ferrules <NUM>. The ferrule assembly <NUM> part on the side of the ferrules <NUM> is accommodated in the housing <NUM>.

The housing <NUM> is shaped to be a rectangular tube and accommodates two ferrules <NUM> in parallel arrangement. The housing <NUM> can be mated with a mating housing (not illustrated) which accommodates mating ferrules arranged at leading ends of mating optical fibers (not illustrated). With the housing <NUM> mating with the mating housing, the ferrules <NUM> are connected to the mating ferrules, then effecting optical coupling between the mating optical fibers and the optical fibers <NUM>. The holder <NUM> is inserted and assembled into the housing <NUM>.

In assembling, the holder <NUM> is inserted into the housing <NUM> through the underside of the housing <NUM> part accommodating the ferrules <NUM>. In order to allow the ferrules <NUM> to be held in the housing <NUM>, the holder <NUM> serves to prevent the ferrule assembly <NUM> from slipping off the housing <NUM> through ferrule retainers <NUM> formed at a central part of the holder <NUM> in the axial direction. The holder <NUM> is engaged with the housing <NUM> through the engagement portions <NUM>.

The engagement portions <NUM> includes a lock arms <NUM> flexibly arranged on both sides of the holder <NUM> in the width direction and engaged portions <NUM> formed by openings penetrating through the holder <NUM> in the width direction. Each of the lock arms <NUM> is provided with a temporary engagement portion <NUM> and a formal engagement portion <NUM>. As illustrated in <FIG>, the engaged portion <NUM> has an engagement face formed on an upper side (in <FIG>) to engage with respective engagement faces of the temporary engagement portion <NUM> and the formal engagement portion <NUM> and an inclined face formed on the lower side to abut against respective inclined faces of the temporary engagement portion <NUM> and the formal engagement portion <NUM>.

The temporary engagement portion <NUM> is formed so as to project from the leading end of the lock arm <NUM>. Again the temporary engagement portion <NUM> is provided, on the upper side (in <FIG>), with the inclined face which deflects the lock arm <NUM> with its abutment against the engaged portion <NUM> and also provided, on the lower side, with the engagement face which engages with the engaged portion <NUM> with return of the lock arm <NUM>. Since the holder <NUM> is inserted into the housing <NUM> so that the engagement face of the temporary engagement portion <NUM> engages with the engaged portion <NUM>, the temporary engagement portion <NUM> allows the holder <NUM> to be held in a temporary engagement position relative to the housing <NUM>.

In the temporary engagement position of the holder <NUM>, as illustrated in <FIG>, the ferrule retainers <NUM> of the holder <NUM> are positioned below the ferrules <NUM> to allow the ferrules <NUM> side of the ferrule assembly <NUM> to be inserted into the housing <NUM>.

As illustrated in <FIG>, under the temporary engagement portion <NUM>, the formal engagement portion <NUM> is formed so as to project from a main body of the lock arm <NUM>. Again the formal engagement portion <NUM> is provided, on the upper side (in <FIG>), with the inclined face which deflects the lock arm <NUM> with its abutment against the engaged portion <NUM> and also provided, on the lower side, with the engagement face which engages with the engaged portion <NUM> with return of the lock arm <NUM>. Since the holder <NUM> is further inserted from the temporary engagement position to the housing <NUM> so that the engagement face of the formal engagement portion <NUM> engages with the engaged portion <NUM>, the formal engagement portion <NUM> allows the holder <NUM> to be held in a formal engagement position relative to the housing <NUM> (see <FIG>).

In the formal engagement position of the holder <NUM>, as illustrated in <FIG>, the ferrule retainers <NUM> of the holder <NUM> are shifted upwardly to engage with the ferrules <NUM> of the ferrule assembly <NUM>, preventing the ferrule assembly <NUM> from slipping off the housing <NUM>.

The holder <NUM>, whose position relative to the housing <NUM> is changeable between the temporary engagement position and the formal engagement position, is provided with the ribs <NUM>. While, the housing <NUM> is provided with the fitting portions <NUM> for engagement with the ribs <NUM>.

The pair of ribs <NUM> are formed on both sides of the holder <NUM> in the axial direction so as to extend toward the inserting direction of the holder <NUM> into the housing <NUM>. When inserting the holder <NUM> into the housing <NUM> for assembling, the pair of ribs <NUM> are fitted to the pair of fitting portions <NUM>.

Corresponding to the pair of ribs <NUM>, the pair of fitting portions <NUM> are respective groove portions which are formed on respective inner faces of both lateral walls of the housing <NUM> so as to extend toward the inserting direction of the holder <NUM> into the housing <NUM>. Since the pair of ribs <NUM> are fitted to the pair of fitting portions <NUM>, the holder <NUM> is inserted into the housing <NUM>, effecting their assembling. Then, until the temporary engagement portion <NUM> is engaged with the engaged portion <NUM> in the engagement portion <NUM>, it is possible to prevent an occurrence of such a displacement that the holder <NUM> is pivoted or inclined to the housing <NUM>. In the temporary engagement position of the holder <NUM> to the housing <NUM>, additionally, it is possible to prevent the holder <NUM> from being inclined to the housing <NUM> due to the mating of the ribs <NUM> with the fitting portions <NUM>.

When moving the holder <NUM> from the temporary engagement position to the formal engagement position to the housing <NUM>, the mating of the ribs <NUM> with the fitting portions <NUM> enables the insertion of the holder <NUM> into the housing <NUM> to be conducted stably without any inclination of the holder <NUM> to the housing <NUM>. In the engagement portion <NUM>, therefore, there is no possibility that the formal engagement portion <NUM> makes partial contact with the engaged portion <NUM>, so that the formal engagement portion <NUM> can be engaged with the engaged portion <NUM> certainly.

In assembling the holder <NUM> to the housing <NUM>, the positional displacement of the holder <NUM> relative to the housing <NUM> can be prevented by fitting the ribs <NUM> to the fitting portions <NUM>, so that it is possible to avoid breakage of the housing <NUM> and the holder <NUM>.

In the optical connector <NUM> according to the first example, the ribs <NUM> and the fitting portions <NUM> are arranged on the side of an axial end of the housing <NUM>. Therefore, in the temporary engagement position of the holder <NUM> relative to the housing <NUM>, the holder <NUM> is slightly inclined to the housing <NUM> due to the holder's own weight. To the contrary, if an interference of these elements with the other members can be avoided, it is preferable to arrange the ribs <NUM> and the fitting portions <NUM> on the axial center of the housing <NUM> in view of suppressing such an inclination of the holder <NUM> to the housing <NUM>.

In the optical connector <NUM>, the holder <NUM> has the ribs <NUM> formed so as to extend along the inserting direction of the holder <NUM> into the housing <NUM>, while the housing <NUM> is provided with the fitting portions <NUM> to which the ribs <NUM> are to be fitted. Consequently, since the ribs <NUM> are fitted to the fitting portions <NUM> in assembling the holder <NUM> to the housing <NUM>, it is possible to suppress the positional displacement where the holder <NUM> is pivoted or inclined to the housing <NUM>.

In the optical connector <NUM>, accordingly, it is possible to suppress the positional displacement of the holder <NUM> relative to the housing <NUM> and improve the assembly of constituents.

The engagement portion <NUM> includes the temporary engagement portions <NUM> and the formal engagement portions <NUM>. Owing to the provision of the temporary engagement portions <NUM>, it becomes possible to allow the holder <NUM> to be held in the housing <NUM> and also allow the ferrules <NUM> to be accommodated in the housing <NUM>. During shifting from one engagement of the engaged portion <NUM> with the temporary engagement portions <NUM> to another engagement of the engaged portion <NUM> with the formal engagement portions <NUM>, the ribs <NUM> are fitted to the fitting portions <NUM>, so that it is possible to suppress the positional displacement of the holder <NUM> relative to the housing <NUM>, allowing the assembly to be improved.

A second embodiment, which is according to the claimed invention, will be described with reference to <FIG>.

In an optical connector <NUM> according to the second embodiment, a pair of ribs <NUM> are connected to each other through ferrule retainers <NUM> integrally.

The optical fibers <NUM> are fixed with the ferrules <NUM> through crimping sleeves <NUM> into which the cores <NUM> are to be inserted. The holder <NUM> allows the ferrules <NUM> to be held in the housing <NUM> through the crimping sleeves <NUM>.

In the second embodiment, elements identical to those of the first example are indicated with the same reference numerals respectively, and descriptions in both constitution and function of the same constituents are omitted with reference to those of the first example. Nevertheless, as a matter of course, respective effects brought by these constituents will be similar to those of the first example.

In a ferrule assembly <NUM> of the optical connector <NUM>, as illustrated in <FIG>, tensile strength fibers <NUM> are disposed on the periphery of the optical fibers <NUM> and the peripheries of the tensile strength fibers <NUM> are covered with secondary covers, providing a hollow type optical fiber cable.

While the cores <NUM> are inserted through the crimping sleeves <NUM> and crimping rings <NUM>, the optical fibers <NUM> are respectively inserted into the ferrules <NUM> and further fixed to the ferrules <NUM> through the crimping sleeves <NUM> and the crimping rings <NUM>, completing the ferrule assembly <NUM>.

A spring member <NUM> is accommodated in the housing <NUM> part on the side of the ferrules <NUM> of the ferrule assembly <NUM>. The spring member <NUM> is disposed between the ferrules <NUM> and the ferrule retainers <NUM> of the holder <NUM> to always urge the ferrules <NUM> against a mating housing (not illustrated).

In the optical connector <NUM>, the holder <NUM> is provided with the ribs <NUM>, while the housing <NUM> is provided with the fitting portions <NUM> to which the ribs <NUM> are to be fitted.

The pair of ribs <NUM> are formed on both sides of the holder <NUM> in the axial direction so as to extend toward the inserting direction of the holder <NUM> into the housing <NUM>. The ferrule retainers <NUM> are arranged between the pair of ribs <NUM>.

By allowing the crimping sleeves <NUM> to be held in the housing <NUM>, the ferrule retainers <NUM> operate to prevent the ferrule assembly <NUM> from slipping off the housing <NUM>, allowing the ferrules <NUM> to be retained in the housing <NUM>.

Since the ferrule retainers <NUM> allow the housing <NUM> to hold the ferrules <NUM> through the crimping sleeves <NUM>, even when an external force, such as tensile force, is applied to the optical fibers <NUM>, the external force could be absorbed by the fixing portion between the optical fiber <NUM> and the crimping sleeve <NUM>, so that it is possible to remarkably prevent the external force from being transmitted to insertion parts between the core <NUM> of the optical fibers <NUM> and the ferrules <NUM>.

The pair of ribs <NUM> are connected to each other through the ferrule retainers <NUM> integrally, providing one continuous member. Thus, due to the integration of the pair of ribs <NUM> through the ferrule retainers <NUM>, the rigidity of the ribs <NUM> is improved to allow the prevention of the pair of ribs <NUM> from being deformed by such as external force.

The pair of ribs <NUM> are fitted to the pair of fitting portions <NUM> as respective groove portions which are formed on respective inner faces of both lateral walls of the housing <NUM> so as to extend toward the inserting direction of the holder <NUM> into the housing <NUM>, corresponding to the pair of ribs <NUM>.

Since the ribs <NUM> are fitted to the fitting portions <NUM>, it is possible to prevent the positional displacement of the holder <NUM> relative to the housing <NUM> in assembling the holder <NUM> to the housing <NUM>, allowing the prevention of the housing <NUM> and the holder <NUM> from being damaged.

Here, it is noted that the pair of ribs <NUM> and the pair of fitting portions <NUM> are positioned on the center of the housing <NUM> in the axial direction. Therefore, in the temporary engagement position of the holder <NUM> relative to the housing <NUM> illustrated in <FIG>, it is possible to suppress a slight inclination of the holder <NUM> to the housing <NUM> due to the holder's own weight.

In the optical connector <NUM>, the pair of ribs <NUM>, <NUM> are connected to each other through the ferrule retainers <NUM> integrally. Thus, it is possible to improve the rigidity of the ribs <NUM> to allow the suppression of deformation of the ribs <NUM> and also possible to stabilize the fitting of the ribs <NUM> to the fitting portions <NUM>, allowing the assembly to be improved.

The holder <NUM> allows the ferrules <NUM> to be held in the housing <NUM> through the crimping sleeves <NUM>. Therefore, even when an external force, such as tensile force, is applied to the optical fibers <NUM>, it is possible to prevent the external force from being transmitted to the ferrules <NUM> by the crimping sleeves <NUM>.

In common with the optical connector according to each of the embodiments, the ribs are provided in the holder, while the fitting portions are provided in the housing. However, the rib may be provided in the housing on condition of providing the fitting portions in the holder in the modification.

Claim 1:
An optical connector ( <NUM>) comprising:
an optical fiber (<NUM>);
a ferrule (<NUM>) which is provided at an end of the optical fiber (<NUM>) and through which a core (<NUM>) of the optical fiber (<NUM>) is to be inserted;
a housing (<NUM>) in which the ferrule (<NUM>) is accommodated;
a holder (<NUM>), provided with a ferrule retainer (<NUM>), which is inserted into the housing (<NUM>) and engaged with the housing (<NUM>) through an engagement portion (<NUM>), the ferrule retainer (<NUM>) allowing the housing (<NUM>) to hold the ferrule (<NUM>);
a pair of ribs (<NUM>) integrally connected to each other through the ferrule retainer (<NUM>), which are provided in the holder (<NUM>) so as to extend along an inserting direction of the holder (<NUM>) into the housing, the ferrule retainer (<NUM>) provided between the pair of ribs; and
a pair of fitting portions (<NUM>) which are groove portions and are provided in the housing (<NUM>) and to which the ribs (<NUM>) are to be fitted to suppress a positional displacement where the holder (<NUM>) may be pivoted or inclined to the housing (<NUM>) when assembling the holder to the housing, the pair of ribs (<NUM>) fitted to the pair of fitting portions (<NUM>) when inserting the holder (<NUM>) into the housing (<NUM>),
wherein
the engagement portion (<NUM>) includes:
a temporary engagement portion (<NUM>) configured to allow the holder (<NUM>) to be held in the housing (<NUM>) in a temporary engagement position and allow the ferrule (<NUM>) to be accommodated in the housing (<NUM>); and
a formal engagement portion (<NUM>) configured to allow the holder (<NUM>) to be inserted into the housing (<NUM>) under a condition that the ferrule (<NUM>) is accommodated in the housing (<NUM>) and allow the holder (<NUM>) to be held in the housing (<NUM>) in a formal engagement position;
wherein the pair of ribs (<NUM>) are configured to mate with the fitting portions (<NUM>) in the temporary engagement position.