Optical connector

To extend the service life of a latch of a plug housing and facilitate assembly and aligning operations of an optical connector. The optical connector includes a latch provided in a cantilever form on an external surface of the optical connector and deformable for attachment/detachment with respect to an adaptor, and an excessive deformation preventing unit that prevents excessive deformation of the latch. Furthermore, the optical connector comprises: a ferrule including a flange having a largest width portion having directionality in a circumferential direction and a conical portion continuous to the front of the largest width portion; and a housing including a cavity having a cylindrical portion through which the largest width portion can pass freely, a housing unit arranged in front of the cylindrical portion for housing the largest width portion, and an inclined surface that is arranged at a junction between the cylindrical portion and the housing unit and inclines inward in the radial direction from the cylindrical portion toward the housing unit, wherein the point of the ferrule is protruded from the point of the housing by a predetermined amount and held, in the state that the ferrule is inserted into the housing from a rear end of the cylindrical portion and the largest width portion of the flange is housed in the housing unit.

CROSS-REFERENCE TO RELATED APPLICATION

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an optical connector fitted to an end of an optical fiber and attached to or detached from an adaptor.

2. Description of the Related Art

Generally, the above type of optical connectors include one which is fixed to the adaptor by a latch projected outward in a cantilever form on an external surface of the connector.

A conventional optical connector101shown inFIGS. 1 and 2includes a ferrule110formed of a ferrule body111and a flange115, and a plug housing120. The optical connector101includes a latch121deformable for attachment/detachment with respect to the adaptor, on the external surface of the plug housing120in the cantilever form.

InFIGS. 1 and 2, reference sign140denotes a spring,150denotes a stop ring,155denotes a retention member,160denotes a clip sleeve,165denotes a heat shrinkable tube, and170denotes a hood.

The optical connector is disclosed in Japanese patent No. 3066322, Japanese Patent Application Laid-Open No. H9-113762, Japanese patent No. 3103773, and Japanese Patent Application Laid-Open No. H8-327855.

However, the conventional optical connector has the following problems.

That is, when the connector is attached to and detached from the adaptor repetitively about 500 times, the latch121of the plug housing120is broken, and cannot maintain the function as the connector.

When the connector is assembled, it is difficult to insert the ferrule110in the plug housing120.

Furthermore, in an aligning operation, such a state that the ferrule110retracts and does not return to an original position occurs.

SUMMARY OF THE INVENTION

The present invention has been achieved in order to solve the above problems, and one object of the present invention is to extend the service life of the latch of the plug housing, and another object is to provide an optical connector that can facilitate assembling and aligning operations of the connector.

To achieve the objects, according to one aspect of the present invention, there is provided an optical connector that includes a latch provided in a cantilever form on an external surface of the optical connector and deformable for attachment/detachment with respect to an adaptor, and an excessive deformation preventing unit that prevents excessive deformation of the latch.

According to another aspect of the present invention, there is provided an optical connector, wherein the excessive deformation preventing unit is formed as a protrusion on the external surface of the optical connector, to which a free end of the latch approaches when the latch deforms.

According to a still another aspect of the present invention, there is provided an optical connector, comprising: a ferrule including a flange having a largest width portion having directionality in a circumferential direction and a conical portion continuous to the front of the largest width portion; and a housing including a cavity having a cylindrical portion through which the largest width portion can pass freely, a housing unit arranged in front of the cylindrical portion for housing the largest width portion, and an inclined surface that is arranged at a junction between the cylindrical portion and the housing unit and inclines inward in the radial direction from the cylindrical portion toward the housing unit, wherein the point of the ferrule is protruded from the point of the housing by a predetermined amount and held, in the state that the ferrule is inserted into the housing from a rear end of the cylindrical portion and the largest width portion of the flange is housed in the housing unit.

According to a still another aspect of the present invention, there is provided an optical connector, wherein the largest width portion of the flange is formed in a polygonal shape in cross section, and the housing unit of the housing is formed in a polygonal shape corresponding to the largest width portion.

According to a still another aspect of the present invention, there is provided an optical connector, wherein the diameter of the cylindrical portion is formed equal to the diameter of a circle circumscribing to the polygonal housing unit.

According to a still another aspect of the present invention, there is provided an optical connector, comprising: a ferrule including a flange having a largest width portion having directionality in a circumferential direction and a conical portion continuous to the front of the largest width portion; a housing including a cavity having a cylindrical portion through which the largest width portion can pass freely, a housing unit arranged in front of the cylindrical portion for housing the largest width portion, an inclined surface that is arranged at a junction between the cylindrical portion and the housing unit and inclines inward in the radial direction from the cylindrical portion toward the housing unit, and a support surface continuous to the housing unit and corresponding to the conical portion; and a pressing member that presses the largest width portion forward, when the ferrule is inserted into the housing from a rear end of the cylindrical portion, wherein the point of the ferrule is protruded from the point of the housing by a predetermined amount and held, in the state that the largest width portion of the flange is housed in the housing unit, and the conical portion is pressed against the support surface corresponding thereto by the pressing member.

According to a still another aspect of the present invention, there is provided an optical connector, wherein the pressing member is arranged in a space between the circumference of the flange at the back of the largest width portion and the cylindrical portion.

According to a still another aspect of the present invention, there is provided an optical connector, comprising: a latch provided in a cantilever form on an external surface of the housing and deformable for attachment/detachment with respect to an adaptor; and an excessive deformation preventing unit that prevents excessive deformation of the latch.

According to a still another aspect of the present invention, there is provided an optical connector, wherein the excessive deformation preventing unit is formed as a protrusion on the external surface of the housing, to which a free end of the latch approaches when the latch deforms.

According to a still another aspect of the present invention, there is provided an optical connector, wherein the largest width portion of the flange is formed in a polygonal shape in cross section, and the housing unit of the housing is formed in a polygonal shape corresponding to the largest width portion.

According to a still another aspect of the present invention, there is provided an optical connector, wherein the diameter of the cylindrical portion is formed equal to the diameter of a circle circumscribing to the polygonal housing unit.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 3is a front elevation of an embodiment of an optical connector according to the present invention, andFIG. 4is an elevational longitudinal section ofFIG. 3. An optical connector1includes a ferrule10and a housing (plug housing)20.

The ferrule10includes, as shown inFIG. 5, a ferrule body11and a flange15.

In the ferrule body11, an optical fiber is inserted into a central hole and fixed thereto, and a point of the ferrule body11is grinded so as to suit to optical connection.

A base of the ferrule body11is mounted on the point of the flange15. The flange15includes a largest width portion16in a hexagonal shape and a conical portion17continuous to the front of the largest width portion16. A notch18is formed at one position on the circumference of the conical portion17.

As shown inFIGS. 6A,6B,6C,7A, and7B, the plug housing20includes a latch21deformable for attachment/detachment with respect to the adaptor on an external surface thereof in a cantilever form. The plug housing20includes an excessive deformation preventing unit25that prevents an excessive deformation of the latch21.

The excessive deformation preventing unit25is formed as a protrusion on the external surface of the plug housing20, to which a free end of the latch21approaches when the latch21deforms.

In the plug housing20, a cavity30that passes through the opposite ends thereof is formed.

In the cavity30of the plug housing20, there is formed a cylindrical portion (cylindrical surface)31, into which the largest width portion16of the ferrule10can be freely inserted. A hexagonal housing unit33that houses the largest width portion16is formed in front of the cylindrical portion31. A support surface34corresponding to the conical portion17of the flange15is formed in front of the housing unit33, continuous to the housing unit33.

The diameter of the cylindrical portion31is formed equal to the diameter of a circle circumscribing to the hexagonal housing unit33. Therefore, the largest width portion16of the ferrule10can be inserted into the cylindrical portion31of the cavity30, regardless of the angle of the largest width portion16with respect to a central axis.

On the other hand, the largest width portion16of the ferrule10cannot be inserted into the housing unit33of the cavity30, unless the angle is relatively adjusted so that the hexagonal shape of the housing unit33agrees with the hexagonal shape of the largest width portion16.

When the largest width portion16of the ferrule10is housed in the housing unit33of the cavity30, the conical portion17continuous to the largest width portion16engages with and abuts against the support surface34continuous to the housing unit33.

An inclined surface32that inclines inward in the radial direction from the cylindrical portion31toward the housing unit33is formed at a junction of the cylindrical portion31and the housing unit33of the cavity30.

As shown inFIGS. 3 and 4, the optical connector1includes a spring40as a pressing member arranged in a space between the circumference of the flange15at the back of the largest width portion16and the cylindrical portion31of the cavity30, when the ferrule10is inserted into the plug housing20from the cylindrical portion31side.

Since the conical portion17is pressed on the support surface34by the spring40, in the state with the largest width portion16being housed in the housing unit33, the optical connector1holds the ferrule10with the point thereof protruded from the plug housing20by a predetermined amount.

A protective tube19is fitted to the flange15of the ferrule10, and the ferrule10is inserted into the plug housing20from the cylindrical portion31side. The spring40is then positioned by arranging it at the back of the largest width portion16and by fitting a stop ring50to the plug housing20.

The optical connector1is assembled and integrally formed by mounting a clip ring60and a boot70on the circumference of the stop ring50, allowing a clip80including a trigger lever81to pass over the outer circumference of the junction of the stop ring50and the boot70, and fitting the clip80to the plug housing20.

FIGS. 8 to 11show one example of an adaptor90, and indicating how the optical connector1is attached and detached with respect to the adaptor90. The adaptor90includes a ferrule housing unit91that stores the ferrule10protruding from the point of the plug housing20of the optical connector1.

The adaptor90includes a projection92that presses a protrusion22of the latch21downward in a process in which the optical connector1is inserted and the ferrule10is housed in the ferrule housing unit91to a predetermined depth. The projection92presses the protrusion22downward so that the latch21is collapsed (deformed) once in a direction approaching to the plug housing20.

The projection92releases the downward pressing towards the protrusion22of the latch21at a position immediately before the ferrule10is housed in the ferrule housing unit91to the predetermined depth. As a result, the latch rises toward the original state due to a spring force of the latch21(the deformation is restored to the original state).

The adaptor90includes an engaging unit93, with which the protrusion22engages, when the protrusion22passes the projection92and the latch21rises due to its own spring force (when the deformation is restored). Since the protrusion22of the latch21engages with the engaging unit93, the optical connector1is attached to the adaptor90.

When the optical connector1is detached from the adaptor90, the trigger lever81is pressed down to bring the latch21down, thereby detaching the protrusion22from the engaging unit93of the adaptor90. The protrusion22of the latch21is allowed to pass below the projection92, and the optical connector1is pulled out, thereby detaching the optical connector1from the adaptor90.

When the trigger lever81is pressed down, a free end of the latch21abuts against the excessive deformation preventing unit25on the upper surface of the plug housing20. As a result, the latch21is prevented from deforming largely.

In other words, the excessive deformation preventing unit25restricts the collapsed amount of the latch21, so that the latch21is sufficiently brought down up to a height required for the protrusion22to pass below the projection92of the adaptor90, but is not brought down more than necessary.

As a result, even when attachment and detachment of the optical connector1with respect to the adaptor90is repeated, the deformed amount of the latch21is kept to a required amount at all times, and the latch21is not largely deformed more than necessary. Accordingly, the service life of the latch21is extended, and resistance against attachment/detachment of the optical connector1can be greatly improved, as compared to a conventional optical connector having no excessive deformation preventing unit25.

That is, in the case of the optical connector101shown inFIGS. 1 and 2, when attachment/detachment of the optical connector101with respect to the adaptor is repeated 500 times, the latch121of the plug housing120is broken.

On the other hand, in the case of the optical connector1, when such an experiment is executed that attachment/detachment of the optical connector1with respect to the adaptor90is repeated until the latch21of the plug housing20is broken, the latch21was not broken, even when attachment/detachment operations are repeated 3000 times.

When the optical connector1is to be assembled, the ferrule10is inserted into the plug housing20from the cylindrical portion31side and the stop ring50is fitted to the plug housing20, while pressing the ferrule10in a direction of the point thereof by the spring40.

At this time, it is necessary to insert the hexagonal largest width portion16of the ferrule10into the hexagonal housing unit33of the plug housing20, while adjusting the angle thereof.

A cylindrical portion31of a size circumscribing to the hexagonal housing unit33is formed on this side of the housing unit33of the plug housing20, at the time of an assembly operation.

In the conventional optical connector101, as shown inFIG. 12B, the junction of a cylindrical portion131and a housing unit133of the plug housing120has been connected by a plane orthogonal to the axial direction of the plug housing120. Therefore, at the time of assembling the optical connector101, when a hexagonal largest width portion116of the ferrule110is inserted into a hexagonal housing unit133of the plug housing120, insertion is not possible unless the angles of these hexagonal shapes match with each other.

On the other hand, in the optical connector1of the present invention, as shown inFIG. 12A, the plug housing20includes the inclined surface32that inclines inward in the radial direction from the cylindrical portion31toward the housing unit33at the junction of the cylindrical portion31and the housing unit33. The ferrule10also includes the conical portion17in front of the hexagonal largest width portion16continuous thereto.

Therefore, when the hexagonal largest width portion16of the ferrule10is inserted into the hexagonal housing unit33of the plug housing20, and it is tried to relatively adjust the angle of the ferrule10and the plug housing20, the conical portion17of the ferrule10can freely adjust the angle along the inclined surface32of the plug housing20.

Consequently, at the time of assembling the optical connector1, the optical connector1can be easily assembled, even when there is some angular displacement between the hexagonal largest width portion16of the ferrule10and the hexagonal housing unit33of the plug housing20.

In some cases, an aligning operation of the optical connector1is performed for adjusting the center of the axis between the optical fiber on the adaptor90side and the optical fiber of the optical connector1. In this case, after the ferrule10protruding from the point of the optical connector1is pushed into the plug housing20once, the pushing force is released. Then, the ferrule10returns to the original protruded state due to the thrust of the spring40.

FIG. 13Ashows a normal state before the ferrule10is pushed in the plug housing, andFIG. 13Bshows a state when the ferrule10is pushed therein.

When the ferrule10returns from the pushed state, the angle can be adjusted by the conical portion17of the ferrule10along the inclined surface32of the plug housing20. Therefore, even when there is some angular displacement at the time of pushing the ferrule10in the plug housing20, the ferrule10does not stay in the pushed state, and movement to return to the normal position can be facilitated.

According to the present invention, the shape of the largest width portion16in the flange15of the ferrule10is not limited to the hexagonal shape, as in the embodiment, and may be an optional polygonal shape. In this case, the shape of the housing unit33of the plug housing20that stores the largest width portion16can be formed in an optional polygonal shape, matched with the shape of the largest width portion16.

Furthermore, according to the present invention, the shape of the largest width portion16of the ferrule10can be formed, for example, in a shape having directionality in a circumferential direction by appropriate means. In this case, the shape of the housing unit33of the plug housing20that stores the largest width portion16is also formed in the shape having directionality in a circumferential direction by the same means, matched with the shape of the largest width portion16.

The object of the present invention is not limited to achieve compatibility between realization of extended service life of the latch21and realization of easiness of assembly and the aligning operation of the optical connector1.

That is, if it is the only object to extend the service life of the latch21, the inclined surface32of the cavity30is not necessary, and the excessive deformation preventing unit25that prevents excessive deformation of the latch21needs only to be provided. The present invention is realized only by this configuration.

Furthermore, if it is the only object to facilitate assembly and the aligning operation of the optical connector1, the excessive deformation preventing unit25of the plug housing20is not necessary, and the inclined surface32that inclines inward in the radial direction from the cylindrical portion31toward the housing unit33needs only to be formed at the junction of the cylindrical portion31and the housing unit33of the cavity30. The present invention is realized only by this configuration.

The configuration of the present invention includes the latch deformable for attachment/detachment with respect to the adaptor, provided in a cantilever form on the external surface of the connector, and the excessive deformation preventing unit that prevents excessive deformation of the latch. As a result, the service life of the latch of the plug housing can be extended.

Furthermore, according to the present invention, the optical connector comprises: the ferrule including the flange having the largest width portion having directionality in a circumferential direction and the conical portion continuous to the front of the largest width portion; and the housing including the cavity having the cylindrical portion through which the largest width portion can pass freely, the housing unit arranged in front of the cylindrical portion for housing the largest width portion, and the inclined surface that is arranged at a junction between the cylindrical portion and the housing unit and inclines inward in the radial direction from the cylindrical portion toward the housing unit, wherein the point of the ferrule is protruded from the point of the housing by a predetermined amount and held, in the state that the ferrule is inserted into the housing from a rear end of the cylindrical portion and the largest width portion of the flange is housed in the housing unit. Accordingly, the assembly and the aligning operation of the connector can be facilitated.

While preferred embodiments of the present invention have been described above, the foregoing description is in all aspects illustrative. It is therefore understood that numerous modifications can be devised without departing from the spirit or scope of the appended claims of the invention.