JP2010054945A - Cylindrical sleeve for connecting optical fiber - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cylindrical sleeve that reduces an axial shift in connecting optical fibers and achieves stable optical fiber connection, in a cylindrical sleeve for connecting optical fibers. <P>SOLUTION: The cylindrical sleeve for connecting optical fibers in the Claim 1 is characterized in that three cross sectionally circular arcuate small projections having equal protruding quantities inward are projectingly formed with equal spaces apart in the circumferential direction, and the three small projections protruding in the circumferential direction are arranged in four rows or more in the axial direction. Also, the Claim 2 is characterized in that, in the cylindrical sleeve for connecting optical fibers in the Claim 1, the small projections are arranged with equal spaces apart in the axial direction. The Claim 3 is characterized in that, in the cylindrical sleeve for connecting optical fibers in Claim 1 or the Claim 2, the small projections are formed in alignment in the axial direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a cylindrical sleeve used for an optical fiber connection adapter or the like.

  In constructing an optical communication network, it is a very important technique to suppress the loss / reflection of an optical fiber cable and to connect it, and today, as a means that an operator can easily and repeatedly attach and detach, Patent Document 1 As disclosed in (1), a connection method using a connector and an adapter (such as a connection adapter or an exchange adapter) is widely used.

  FIG. 13 shows a connector attached to the optical fiber cable and an adapter (connection adapter) for connecting the connectors. In the figure, reference numeral 1 denotes a known SC connector, and the tip of the optical fiber cable 3 inside the connector 1 formed in a prismatic shape. And the ferrule 5 are connected and fixed, and the front end of the ferrule 5 provided from the front end of the connector 1 protrudes.

  Further, on the upper surface of the connector 1, a protrusion 11 is provided so as to engage with a guide groove 9 formed on the upper surface of the adapter 7 to be described later, and regulate the direction of the connector 1 with respect to the adapter 7. On both side surfaces, there are provided locking recesses 15 for engaging the hooks 13 disposed inside the adapter 7 and fixing the connector 1 in the adapter 7.

  On the other hand, the adapter 7 connects the connectors 1 by inserting the connector 1 from both sides, and is formed in a substantially rectangular tube shape. The adapter 7 is inserted into the locking recess 15 of the inserted connector 1 and the connector 1 is inserted. A hook 13 for fixing to the adapter 7 is formed inside, and guide grooves 9 for guiding the convex portion 11 are provided at both ends of the upper surface in the longitudinal direction.

  As a method for connecting the optical fiber cables 3 between the connectors 1, a cylindrical sleeve 19 having a split slit structure in which slits 17 are provided in the axial direction is incorporated in the adapter 7 as shown in FIGS. The slit 17 opens in the circumferential direction in accordance with the outer diameter of the ferrule 5 between the connectors 1 to be inserted, thereby changing the inner diameter of the sleeve 19 as shown in FIG. .

As is well known, the sleeve 19 is made of a material having a spring effect such as phosphor bronze, and the optical fiber cable 3 is a protective coating of the surface of the optical fiber 21 composed of a core and a clad with a silicone resin. Is further covered with a jacket (outer skin) 23.
JP 2005-202380 A

  However, when the outer diameter of the ferrule 5L inserted as shown in FIG. 17 is large, the sleeve 19 becomes non-circular and the center axis between the ferrule 5L and the sleeve 19 is displaced, so that the fiber connection displacement is lost. There is a risk that light loss (transmission loss) and light reflection will increase.

  The present invention has been devised in view of such circumstances, and an object of the present invention is to provide a cylindrical sleeve for optical fiber connection that reduces axial misalignment during optical fiber connection and enables stable optical fiber connection.

  In order to achieve such an object, the cylindrical sleeve for optical fiber connection according to claim 1 is provided with three small projections having a circular arc cross section having the same amount of inward projection protruding in the circumferential direction at equal intervals, The three small protrusions protruding in the circumferential direction are arranged in four or more rows in the axial direction.

  According to a second aspect of the present invention, in the cylindrical sleeve for optical fiber connection according to the first aspect, the small protrusions are arranged at equal intervals in the axial direction. The invention is characterized in that in the cylindrical sleeve for optical fiber connection according to claim 1 or 2, the small protrusions are provided on the same line in the axial direction.

  Furthermore, in the invention according to claim 4, in the cylindrical sleeve for optical fiber connection according to any one of claims 1 to 3, slits of the same size are provided at the connection location of the inserted ferrule. The invention according to claim 5 is characterized in that, in the cylindrical sleeve for optical fiber connection according to claim 4, the slit is provided along the circumferential direction. Six slits and three slits are arranged on the same line as the small protrusions provided on the same line in the axial direction.

  According to the first and fifth aspects of the invention, the center axis of the ferrule can be kept stable and constant by the small protrusion group regardless of the outer diameter of the ferrule, so that the axis when the optical fiber is connected Deviation is reduced and stable optical fiber connection is possible.

  According to the invention of claim 2, since the small protrusions are arranged at equal intervals in the axial direction, the amount of deformation of the curved surface between the small protrusions is uniform and can be accurately centered, and according to claim 3 According to the invention, since the small protrusions are arranged on the same line in the axial direction of the sleeve, there is an advantage that the curved surface between the small protrusions is easily deformed linearly.

  Furthermore, according to the invention according to claim 4, even when ferrules having different outer diameters are inserted from both ends, each slit absorbs a difference in deformation amount between both ends of the sleeve sandwiching the slit, and thus both ends sandwiching the slit. The small protrusions and the curved surface between the small protrusions move freely, and even if there is a difference in the outer diameter of the ferrule, the central axis of the ferrule can be kept stable and constant, and the shaft misalignment when connecting the optical fiber is reduced and stable Optical fiber connection becomes possible.

  And according to the invention which concerns on Claim 5, each slit can absorb the difference of the deformation amount of the both ends of the sleeve which pinched | interposed the slit reliably, and the more stable optical fiber connection is attained.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same thing as the prior art example of FIG. 13, and those description is abbreviate | omitted.

  1 to 5 show an embodiment of the invention according to claims 1 to 3, in which 31 is a sleeve incorporated in the adapter 7 instead of the sleeve 19 of FIG. The sleeve 31 is formed in a cylindrical shape from a material having a spring effect such as phosphor bronze.

  As shown in FIGS. 1 to 3, the circumferential wall of the sleeve 31 is provided with three protrusions (dowels) 33 having an arcuate cross section projecting inwardly at equal intervals in the circumferential direction. Four groups of three small protrusions 33 projecting in the direction are arranged at equal intervals in the axial direction of the sleeve 31, and each small protrusion 33 is arranged on the same line in the axial direction as shown in FIG.

  Further, the inward protrusion amounts of the small protrusions 33 are all set to be the same, and the inner diameter (hereinafter referred to as “the inner diameter of the sleeve 31”) of a circle (reference numeral 35 in FIG. 2) connecting the tips of the respective small protrusions 33. Is set to have the same diameter as that of the smallest diameter of the ferrules 5 to be inserted. Then, by inserting the connector 1 into the adapter 7 from the left and right (both sides) as shown in FIG. 13, the ferrule 5 protruding from the tip of the connector 1 is inserted into the sleeve 31 and the connectors 1 are connected to each other. The ferrule 5 is stably held by the small projections 33 grouping to the left and right two rows arranged in four rows at equal intervals in the axial direction.

  Since the sleeve 31 according to the present embodiment is configured in this way, as described above, when the connector 1 is inserted into the adapter 7 from the left and right (both sides) as shown in FIG. 13, the ferrule 5 is inserted into the sleeve 31. The optical fibers 21 are connected to each other, but the small projections 33 grouped in the left and right rows arranged in four rows at equal intervals in the axial direction stably hold the ferrules 5 of both connectors 1 at the front and rear two locations.

  Thus, in this case, as shown in FIG. 4, when the outer diameter of the ferrule 5 between the connectors 1 to be inserted is equal to the inner diameter of the sleeve 31, the small protrusions 33 arranged at equal intervals in the circumferential direction and the axial direction. Since the group contacts the outer periphery of the ferrule 5 evenly to center the ferrule 5, no misalignment occurs in the central axis between the ferrule 5 and the sleeve 31, and no fiber connection misalignment occurs.

  On the other hand, when a connector equipped with a ferrule 5L having an outer diameter larger than the inner diameter of the sleeve 31 is inserted into the adapter 7 and the ferrule 5L is inserted into the sleeve 31, they are arranged in the circumferential direction as shown in FIG. Since the curved surface between the small projections 33 is linearly deformed and the three small projections 33 are evenly pushed outward, they are evenly pressed against the outer periphery of the ferrule 5L to center the ferrule 5L. The center axis between 5L and the sleeve 31 is not displaced.

  Since the small projections 33 are arranged on the same line in the axial direction of the sleeve 31, the curved surface between the small projections 33 is easily linearly deformed, and the small projections 33 are arranged at equal intervals in the axial direction. Therefore, the amount of deformation of the curved surface between the small protrusions 33 is uniform, and the centering can be accurately performed.

  As described above, according to the adapter 7 using the sleeve 31 according to the present embodiment, the central axis of the ferrules 5 and 5L is always stabilized by the small protrusions 33 group regardless of the outer diameter of the ferrules 5 and 5L. Therefore, the shaft misalignment at the time of optical fiber connection is reduced and stable optical fiber connection is possible.

  6 to 11 show a sleeve according to an embodiment of claims 1 to 5. As shown in FIGS. 6 and 7, the sleeve 37 according to this embodiment includes an inner side in addition to the configuration of the sleeve 31. In the middle of the sleeve 37 between the two rows of small projections 33, that is, at the connection place of the inserted ferrule, six long hole-shaped slits 39 of the same size are provided at equal intervals along the circumferential direction. The three slits 39 are arranged on the same line as the small protrusion 33 provided on the same line in the axial direction.

  Since the sleeve 37 according to the present embodiment is configured in this way, even if ferrules 5 and 5L having different outer diameters are inserted from both ends, the small diameter is reduced according to the outer diameter of the ferrules 5 and 5L. Since the position of the protrusion 33 follows, the central axes of the ferrules 5 and 5L are kept constant at both ends across the slit 39.

  In addition, as described above, in the present embodiment, six slits 39 having the same dimension of the long hole shape are provided in the center of the sleeve 37 at equal intervals along the circumferential direction. 37, each of the slits 39 absorbs the difference in deformation amount between the both ends (left and right) of 37, so that the small protrusion 33 on both ends sandwiching the slit 39 and the curved surface between the small protrusions 33 freely move, and the outside of the ferrules 5 and 5L. Even if there is a difference in diameter, the centering is not hindered.

  In particular, in this embodiment, six slits 39 are provided at equal intervals along the circumferential direction, and the three slits 39 are arranged on the same line as the small protrusions 33. Therefore, deformation of both ends of the sleeve sandwiching the slits is performed. Each slit reliably absorbs the difference in quantity.

  As described above, according to the adapter 7 using the sleeve 37 according to the present embodiment, even if the ferrules 5 and 5L having different outer diameters are inserted from both ends, the position of the small protrusion 33 according to the outer diameter of the ferrules 5 and 5L. As in the above embodiment, the central axis of the ferrules 5 and 5L can be kept stable and constant by the small protrusions 33 group, and the axial displacement at the time of optical fiber connection can be reduced and the stable optical fiber connection can be achieved. Is possible.

  In the embodiment, since the center of the group of small protrusions 33 arranged in four rows at equal intervals in the axial direction is the connection place of the ferrules 5 and 5L, the slit 39 is provided in the center of the sleeve 37. When the small protrusions 33 are arranged in five rows at equal intervals in the axial direction, and the connection location of the ferrule is displaced left or right, a slit 39 may be provided in accordance with the connection location.

  In each of the above-described embodiments, the present invention is applied to a sleeve incorporated in a connection adapter. However, the present invention can also be applied to a sleeve incorporated in an exchange adapter, for example, TOSA (Transmitter optical sub). It can also be applied to so-called optical device modules such as -assembly) and ROSA (Receiver optical sub-assembly).

  That is, as shown in FIG. 12, in this type of TOSA 41, a sleeve 45 is incorporated in the device 43, and a ferrule 47 in which the optical fiber 21 is arranged in the center is inserted in advance from one end side thereof. Then, a connector is inserted into the tip of the device 43, and a ferrule of the connector is inserted into the sleeve 45. The invention of claims 1 to 5 can be applied to the sleeve 45.

  Thus, this embodiment can also achieve the intended purpose, reduce the axial misalignment when connecting the optical fiber, and keep the connection loss and reflection low. is there.

It is a whole perspective view of the sleeve which concerns on one Embodiment of Claim 1 thru | or 3. It is a front view of a sleeve. It is sectional drawing of a sleeve. It is sectional drawing of the sleeve in which the ferrule of the same diameter as the internal diameter of a sleeve was inserted. It is sectional drawing of the sleeve in which the ferrule larger in diameter than the inner diameter of the sleeve was inserted. FIG. 6 is an overall perspective view of a sleeve according to an embodiment of claims 1 to 5. It is a front view of a sleeve. It is sectional drawing of a sleeve. It is sectional drawing of the sleeve in which the ferrule was inserted. It is sectional drawing of the sleeve in which the ferrule of the same diameter as the internal diameter of a sleeve was inserted. It is sectional drawing of the sleeve in which the ferrule larger in diameter than the inner diameter of the sleeve was inserted. It is sectional drawing of TOSA. It is a whole perspective view of the connector and adapter which connect an optical fiber cable. It is a whole perspective view of the conventional sleeve integrated in the adapter and the ferrule inserted in this. It is a front view of a sleeve. It is sectional drawing of the sleeve in which the ferrule was inserted. It is sectional drawing of the sleeve in which the ferrule with a large diameter was inserted.

Explanation of symbols

1 Connector 3 Optical fiber cable 5, 5L, 47 Ferrule 7 Adapter 21 Optical fiber 31, 37, 45 Sleeve 33 Small protrusion 39 Slit 41 TOSA

Claims (5)

  Three small projections having a circular arc section with the same amount of inward projection projecting at equal intervals in the circumferential direction, and four or more rows of the three small projections projecting in the circumferential direction are arranged in the axial direction A cylindrical sleeve for optical fiber connection.   The cylindrical sleeve for optical fiber connection according to claim 1, wherein the small protrusions are arranged at equal intervals in the axial direction.   The cylindrical sleeve for optical fiber connection according to claim 1 or 2, wherein the small protrusions are provided on the same line in the axial direction.   The optical fiber connecting cylinder according to any one of claims 1 to 3, wherein a plurality of slits having the same size are provided at equal intervals along a circumferential direction at a connecting portion of the inserted ferrule. Sleeve. The optical fiber connection according to claim 4, wherein six slits are provided along the circumferential direction, and three slits are arranged on the same line as the small protrusions provided on the same line in the axial direction. Cylindrical sleeve for use.

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