Optical fiber connector

Abstract

An optical fiber connector, which comprises a pre-assembled ceramic ferrule assembly (10), a front sleeve (1), and a rear sleeve (2) detachably connected to the front sleeve (1), wherein the pre-assembled ceramic ferrule assembly (10) comprises a shank (3), a ceramic ferrule (4) mounted at the front end of the shank (3), and a spring (5) which is sleeved on the shank (3) and has one end abutting against a mounting portion (32) of the tail handle (3); a limiting member, which only abuts against the other end of the spring (5) when pre-assembled, is provided on the rear end of the shank (3); after a pulling operation is completed, the pre-assembled ceramic ferrule assembly (10) is mounted in front and rear axial channels (11, 21) formed from assembling the front and rear sleeves (1, 2); a tapered tube (22) extends from a rear end face of the rear sleeve (2), the outer diameter of the tapered tube gradually decreasing from front to back; an inner bore of the tapered tube (22) is connected to and in communication with the rear axial channel (21); a radial channel (25) penetrating a front end face of the rear sleeve (2) and a rear end face of the tapered tube (22) is formed in side walls of the rear sleeve (2) and the tapered tube (22); and the pre-assembled ceramic ferrule assembly (10) can enter the rear axial channel (21) and the inner bore of the tapered tube (22) via the radial channel (25). The optical fiber connector incorporating the tapered tube (22), the limiting member and the radial channel (25) improves the construction efficiency and reduces the optical loss.

Description

A fiber optic connector Technical Field

[0001] The utility model relates to the technical field of optical fiber equipment, and specifically refers to an optical fiber connector. Background Art

[0002] When laying fiber optic cables, the traditional practice is to pre-attach fiber optic connectors to the cables. Then, using a conduit threader, the cables with connectors are clamped and threaded through pipelines or walls. This ensures a high-quality connection between the cables and connectors, as they are pre-attached at the factory. However, due to the bulk of the connectors themselves, they are difficult to thread through small-diameter conduits. Furthermore, if fiber optic connectors are reassembled on-site, construction efficiency is compromised and the connection between the two cannot be guaranteed.

[0003] To address this issue, new fiber optic connectors have been designed, such as the one disclosed in Chinese Patent Publication No. CN215005981U. This design includes a pre-installed ceramic ferrule assembly, a pull cap, an inner retaining shell, and an outer shell. When the fiber optic connector is being pulled through a wall or pipe, the pull cap is placed over the pre-installed ceramic ferrule assembly. After the pulling operation is complete, the inner retaining shell and outer shell are sequentially placed over the pre-installed ceramic ferrule assembly from the inside out, completing the assembly. This design improves installation efficiency due to the relatively small size of the pre-installed ceramic ferrule assembly, while also ensuring a high-quality connection between the fiber optic connector and the optical cable.

[0004] However, because the pre-assembled ceramic ferrule assembly includes a retaining tube to accommodate the extension of the ceramic ferrule holder and the spring, the outer diameter of the retaining tube is still relatively large, making it difficult to install the pre-assembled ceramic ferrule assembly in the pipeline. Furthermore, the retaining tube has a complex structure, which increases production costs to a certain extent.

[0005] To this end, a new structure has been designed. The rear end of the tail handle of this new optical fiber connector features a stopper that, during pre-installation, only abuts against the other end of the spring. The sidewall of the rear sleeve (equivalent to the aforementioned inner retaining housing) includes radial passages extending through the front and rear end faces of the rear sleeve. The pre-installed ceramic ferrule assembly can enter the rear axial passage through these radial passages. During use, since the stopper's outer diameter only needs to be slightly larger than the tail handle to axially retain the spring, the pre-installed ceramic ferrule assembly is no longer restricted by the conventional retaining tube. This allows for a smaller size, smoother passage through pipelines of the same size, and allows for application in pipelines with smaller inner diameters, thereby improving installation efficiency and reducing installation costs. Furthermore, thanks to the radial passages in the rear sleeve, after the pulling operation is complete, the pre-installed ceramic ferrule assembly can be assembled into the rear sleeve through the radial passages, and then the rear sleeve and front sleeve are assembled. This new structure improves assembly efficiency and simplifies operation.

[0006] However, during use, it was found that in the above-mentioned new structure optical fiber connector, when the optical cable is subjected to tension in a direction perpendicular to the axis of the rear sleeve, since the tail of the rear sleeve is designed as a square tube (the outer contour of the cross section is basically square), the deformation is small, resulting in a small bending half of the optical cable at this location, which makes the stress at the bending point of the optical cable greater and the optical loss greater.

[0007] Utility Model Content

[0008] The technical problem to be solved by the utility model is to provide an optical fiber connector which is beneficial to improving construction efficiency and reducing optical loss in view of the current status of the existing technology.

[0009] The utility model solves the above technical problems by adopting the following technical solutions: an optical fiber connector, comprising a pre-installed ceramic ferrule assembly, a front sleeve and a rear sleeve that can be detachably connected to the front sleeve, wherein the front sleeve has a front axial channel, and the rear sleeve has a rear axial channel corresponding to the front axial channel, the pre-installed ceramic ferrule assembly comprises a tail handle, a ceramic ferrule mounted on the front end of the tail handle, and a spring sleeved on the tail handle and having one end abutting against the mounting portion on the tail handle, and a limiter is provided on the rear end of the tail handle that only abuts against the other end of the spring when pre-installed. The positioning part, after the pulling operation is completed, the pre-installed ceramic ferrule assembly is installed in the front and rear axial channels assembled by the front and rear sleeves, and is characterized in that: a tapered tube with an outer diameter gradually decreasing from front to rear extends from the rear end face of the rear sleeve, and the inner hole of the tapered tube is connected and connected with the rear axial channel. The side walls of the rear sleeve and the tapered tube are provided with a radial channel that passes through the front end face of the rear sleeve and the rear end face of the tapered tube. The pre-installed ceramic ferrule assembly can enter the rear axial channel and the inner hole of the tapered tube through the radial channel.

[0010] In order to allow the tapered tube to have a greater deformation after being subjected to force, it is better that the wall thickness of the tapered tube gradually decreases from the front to the back.

[0011] In the above scheme, the limiting member can adopt an existing limiting sleeve, which is also tightly fitted on the tail handle, and the end face of the limiting sleeve abuts against the other end of the spring. At this time, while ensuring the strength and abutment of the limiting sleeve, a further improvement is that the outer diameter of the rear end of the tail handle is reduced to form a small diameter end, and the limiting sleeve is arranged on the small diameter end to further reduce its outer diameter. However, it is more preferred that the limiting member is a heat shrink tube. The use of a heat shrink tube is easier to assemble and has lower cost. In addition, the heat shrink tube can be appropriately lengthened so that it partially exposes the rear end face of the tapered tube, that is, it can be simultaneously sleeved on the optical cable, so that the optical cable is not easy to fall off when pulled by external force, and it also plays a certain protective role to prevent the surface of the optical cable from being worn.

[0012] Similarly, in order to avoid excessive increase in the outer diameter of the rear end of the tail handle due to the installation of the thermoplastic sleeve, the outer diameter of the rear end of the tail handle is also reduced to form a small diameter end, and the front end of the heat shrink tube is sleeved on the small diameter end.

[0013] In the above schemes, the cross-section of the mounting portion of the tail handle is designed to be D-shaped, and the inner wall of the front sleeve has a first inner hole with a D-shaped cross-section for accommodating the mounting portion. The D-shaped structure can not only improve the strength of the mounting portion, but also prevent the tail handle from rotating relative to the front sleeve.

[0014] In order to achieve better concentricity between the tail handle and the front sleeve, a straight cylindrical positioning column is extended from the front end of the tail handle, and the inner wall of the front sleeve has a second inner hole matching the positioning column.

[0015] In each of the above solutions, the pre-assembled ceramic ferrule assembly is provided with a protective cover that can at least cover the ceramic ferrule, so as to protect the ceramic ferrule and avoid wear during the pulling process.

[0016] In the above solutions, it is more practical that the front and rear sleeves are designed with matching clamping feet and clamping holes.

[0017] Compared with the prior art, since the tapered tube extends from the rear end face of the rear sleeve of the present invention, when the optical cable is subjected to a pulling force perpendicular to the axis of the rear sleeve, the pulling force will be transmitted to the tapered tube, causing the tapered tube to slightly deform. That is, the support and deformation of the tapered tube can be used to increase the turning radius of the optical cable, thereby dispersing the stress of the optical cable at that location, thereby helping to reduce the optical loss of the optical cable. At the same time, with the help of the limiter, the pre-installed ceramic ferrule assembly is made smaller in size and passes smoothly through the pipeline, which also helps to improve construction efficiency and save construction costs. In addition, the radial channels on the rear sleeve and the tapered tube can also be used. After the pulling operation is completed, the pre-installed ceramic ferrule assembly only needs to be assembled into the rear sleeve and the tapered tube through the radial channels, and then the rear sleeve and the front sleeve are assembled. Therefore, the present invention is easy to install and thread into the pipeline while ensuring the transmission performance of the optical cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] FIG1 is a schematic diagram of the three-dimensional structure of an embodiment of the present utility model;

[0019] FIG2 is a schematic diagram of the three-dimensional structure of the front cover after being decomposed in FIG1;

[0020] FIG3 is a perspective schematic diagram of the front cover in FIG2 ;

[0021] FIG4 is a schematic perspective cross-sectional view of FIG1 ;

[0022] FIG5 is a perspective exploded schematic diagram of FIG1 . DETAILED DESCRIPTION

[0023] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0024] In the description of the following embodiments, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "top", "bottom", "axial", "circumferential", etc., indicating directions or positional relationships, are based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Since the embodiments disclosed in the present invention can be set in different directions, these terms indicating directions are only for explanation and should not be regarded as limitations. For example, "upper" and "lower" are not necessarily limited to directions opposite to or consistent with the direction of gravity. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of such features.

[0025] As shown in Figures 1 to 5, the optical fiber connector includes a pre-installed ceramic ferrule assembly 10, a front sleeve 1, and a rear sleeve 2 that can be removably connected to the front sleeve 1. The front sleeve 1 has a front axial channel 11, and the rear sleeve 2 has a rear axial channel 21 corresponding to the front axial channel 11. A tapered tube 22 with a gradually decreasing outer diameter extends from the front to the rear end of the rear sleeve 2. The inner hole of the tapered tube 22 is connected to and communicates with the rear axial channel 21. When the front sleeve 1 and the rear sleeve 2 are combined, they can accommodate the pre-installed ceramic ferrule assembly 10. The removable connection method of the front and rear sleeves can adopt existing technology. In this embodiment, the front and rear sleeves are designed with matching elastic clamping feet and clamping holes. Specifically, the rear end of the front sleeve 1 is sleeved on the outside of the front end of the rear sleeve 2. Two clamping feet 23 are located on the outer side wall of the front end of the rear sleeve 2 at intervals along the circumference. There are also two locking holes 12, each located on the sidewall of the rear end of the front sleeve 1. When the front sleeve 1 is inserted and fitted onto the front end of the rear sleeve 2, the deformation and recovery of the rear sleeve's wall allow the locking pins to be inserted into the locking holes, thereby connecting the front and rear sleeves into a single piece. To prevent mismatching, the outer surface of the rear sleeve 2 is provided with two guide blocks 24. As shown in FIG5 , these guide blocks 24 are located at the upper and lower positions of the outer surface of the rear sleeve 2. Correspondingly, guide grooves 13 are provided on the upper and lower inner walls of the rear end of the front sleeve 1, respectively, to mate with the guide blocks 24. Of course, if desired, the rear sleeve 2 can also be fitted onto the rear end of the front sleeve 1, with the locking holes located on the rear sleeve and the locking pins located on the front sleeve.

[0026] In this embodiment, the pre-installed ceramic ferrule assembly 10 is a ceramic ferrule assembly that can be pre-installed with an optical cable. It includes a stem 3, a ceramic ferrule 4, and a spring 5. The stem 3 has an axial through-hole 31 formed of a large diameter section and a small diameter section, as in the prior art. The large diameter section is located at the front end of the stem 3, and the small diameter section is located at the rear end of the stem 3. The ceramic ferrule 4 is mounted within the front end of the stem 3, i.e., inserted into the axial through-hole 31 of the large diameter section. The small diameter section of the axial through-hole 31 is used to insert the optical cable 7. Specifically, the optical fiber in the optical cable 7 is inserted through the axial through-hole 31 of the small diameter section and then into the center hole 41 of the ceramic ferrule 4, thereby securing the connection in accordance with the prior art. The stem 3 has a mounting portion 32 on its outer wall. The rear end of the stem 3 is inserted into the spring 5 (i.e., the spring 5 is sheathed over the rear end of the stem 3), so that one end of the spring 5 abuts against the mounting portion 32. In order to axially limit the spring 5, a limiting member is provided on the rear end of the tail handle 3. In this embodiment, the limiting member is a heat shrink tube 6. The front end of the heat shrink tube 6 is sleeved on the rear end of the tail handle 3, and the rear end of the heat shrink tube 6 can be sleeved on the optical cable 7. After being heated, the heat shrink tube 6 is tightly fitted on the rear end of the tail handle 3 and the optical cable 7. After pre-installation, the end face of the heat shrink tube 6 is against the other end of the spring 5. In this way, the outer diameter of the heat shrink tube 6 after being heated is slightly larger than the outer diameter of the rear end of the tail handle 3, as long as it can resist the spring 5. In this way, the overall outer diameter of the pre-installed ceramic ferrule assembly 10 is smaller, and after being pre-installed with the optical cable 7, it can also pass through smaller pipelines. Of course, if conditions permit, the limiting member can be a raised portion on the tail handle 3, and the raised portion is integrally formed with the tail handle. Such a structure is simpler and has a smaller appearance.

[0027] Furthermore, while ensuring the strength of the heat shrink tube 6, in order to minimize its outer diameter after heat assembly, in this embodiment, the outer diameter of the rear end of the tail handle 3 is further reduced to form a small-diameter end 33, and the front end of the heat shrink tube 6 is sleeved onto this small-diameter end 33. In this way, the outer diameter of the heat shrink tube 6 can be reduced while maintaining the same wall thickness, and the cost is lowered. In this case, as needed, the stopper can also be a stop sleeve that fits tightly onto the small-diameter end 33.

[0028] When the pre-installed ceramic ferrule assembly with the optical cable is passed through a pipeline, a protective cover 8 is provided on the pre-installed ceramic ferrule assembly 10 to at least shield the ceramic ferrule 4 in order to prevent damage to the ceramic ferrule 4. Of course, if the pipe threader has a protective structure, the protective cover can also be omitted.

[0029] After the pre-installed ceramic ferrule assembly 10 is pulled, a radial passage 25 is formed on the sidewalls of the rear sleeve 2 and the tapered tube 22, penetrating the front end of the rear sleeve 2 and the rear end of the tapered tube 22, to facilitate faster assembly with the rear sleeve 2. The pre-installed ceramic ferrule assembly with the optical cable can enter the rear axial passage 21 and the tapered tube 22 through the radial passage 25. In other words, the pre-installed ceramic ferrule assembly 10 and the optical cable can be inserted directly into the rear sleeve 2 and the tapered tube 22 with a single radial insertion motion. The front sleeve 1 is then fitted over the front end of the rear sleeve 2, so that the pre-installed ceramic ferrule assembly 10 is installed within the front and rear axial passages and the inner bore of the tapered tube formed by the assembly of the front and rear sleeves. At this time, the pre-installed optical cable is supported by the tapered tube. In this way, during use, when the optical cable is subjected to a pulling force in a direction that forms an angle with the axis of the rear sleeve (the maximum angle is 90 degrees, that is, perpendicular to the axis of the rear sleeve at this time), this pulling force will be transmitted to the tapered tube, causing the tapered tube to deform slightly to support the optical cable and make it bend with a smaller bending radius, thereby reducing light loss and ensuring the optical transmission performance in this state.

[0030] In order to allow the tapered tube to have a greater deformation when subjected to the above-mentioned tensile force, in this embodiment, the wall thickness of the tapered tube 22 gradually decreases from front to back.

[0031] To prevent rotation of the tail handle 3 relative to the front sleeve 1 after installation, the mounting portion 32 of the tail handle 3 is also designed to have a D-shaped cross-section. The inner wall of the front sleeve 1 has a first inner hole 14 with a D-shaped cross-section to accommodate the mounting portion. Furthermore, a straight cylindrical positioning post 34 extends from the front end of the tail handle 3, and the inner wall of the front sleeve 1 has a second inner hole 15 with a straight cylindrical shape that matches the positioning post 34. (See Figures 3 and 4 for details.) This improves the performance of the assembled optical fiber connector.

Claims

1. An optical fiber connector, comprising a pre-installed ceramic ferrule assembly (10), a front sleeve (1) and a rear sleeve (2) that can be detachably connected to the front sleeve (1), wherein the front sleeve has a front axial channel (11), and the rear sleeve has a rear axial channel (21) corresponding to the front axial channel, wherein the pre-installed ceramic ferrule assembly comprises a tail handle (3), a ceramic ferrule (4) installed at the front end of the tail handle, and a spring (5) sleeved on the tail handle and with one end abutting against the mounting portion (32) on the tail handle, wherein a limiting member is provided on the rear end of the tail handle and abuts only against the other end of the spring during pre-installation, and wherein the pre-installed ceramic ferrule assembly is installed in the front and rear axial channels assembled by the front and rear sleeves after completing the pulling operation, characterized in that: A tapered tube (22) with an outer diameter gradually decreasing from front to rear extends from the rear end face of the rear sleeve, the inner hole of the tapered tube (22) is connected and connected with the rear axial channel (21), and a radial channel (25) penetrating the front end face of the rear sleeve and the rear end face of the tapered tube is opened on the side wall of the rear sleeve (2) and the tapered tube (22), and the pre-installed ceramic ferrule assembly (10) can enter the rear axial channel and the inner hole of the tapered tube through the radial channel (25).

2. The optical fiber connector according to claim 1, wherein: The wall thickness of the tapered tube (22) gradually decreases from front to back.

3. The optical fiber connector according to claim 1, wherein: The limiting member is a heat shrink tube (6).

4. The optical fiber connector according to claim 3, wherein: The heat shrink tube (6) partially exposes the rear end surface of the tapered tube (22).

5. The optical fiber connector according to claim 3, wherein: The outer diameter of the rear end of the tail handle is reduced to form a small-diameter end (33), and the front end of the heat shrink tube (6) is sleeved on the small-diameter end (33).

6. The optical fiber connector according to claim 1, wherein: The outer diameter of the rear end of the tail handle is reduced to form a small-diameter end (33), and the limiting member is a limiting sleeve, which is tightly fitted on the small-diameter end (33).

7. The optical fiber connector according to any one of claims 1 to 6, wherein: The cross section of the mounting portion (32) of the tail handle is designed to be D-shaped, and the inner wall of the front sleeve (1) has a first inner hole (14) with a D-shaped cross section for accommodating the mounting portion.

8. The optical fiber connector according to claim 7, wherein: A straight cylindrical positioning column (34) is also extended from the front end of the tail handle, and the inner wall of the front sleeve (1) has a second inner hole (15) matching the positioning column.

9. The optical fiber connector according to any one of claims 1 to 6, wherein: The pre-installed ceramic ferrule assembly is provided with a protective cover (8) capable of at least shielding the ceramic ferrule.

10. The optical fiber connector according to any one of claims 1 to 6, characterized in that: The front and rear sleeves are designed with matching clamping feet (23) and clamping holes (12).

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