FI130605B

FI130605B - Optical fiber connector for industrial conditions

Info

Publication number: FI130605B
Application number: FI20217054A
Authority: FI
Inventors: Matti Aula; Emilia Rontti; Mikko Jokinen
Original assignee: Luxmet Oy
Priority date: 2021-03-24
Filing date: 2021-03-24
Publication date: 2023-12-11
Also published as: FI20217054A1

Abstract

A fiber connector assembly is provided for industrial conditions. The fiber connector assembly comprises a first fiber connector unit (3), a second fiber connector unit (4) and a guiding washer (5). The first fiber connector unit has an external taper (118); the second fiber connector unit has an end with a cavity (119) for receiving the first fiber connector unit (3); and the guiding washer has a through-hole (127) for the first (116) or second fiber (117) connector unit.

Description

TITLE

Optical fiber connector for industrial conditions

TECHNICAL FIELD

The present specification relates to coupling of two or more optical fibers.

BACKGROUND

Utilizing light emitted from industrial processes can be used in many ways to diagnose the process. For example, infrared radiation emitted by the hot objects can be used to assess the temperature of the emitting object. Ideally, the emitted electromagnetic radiation should be analyzed remotely to avoid the sensor equipment to be subjected to the difficult environment near the process emitting the radiation. In order to transfer the electromagnetic radiation between the measurement head gathering the emitted radiation to the remotely placed sensor, an optical fiber is required.

In industrial conditions the equipment have to withstand high temperature and rough handling. For example, in steel industry the ambient temperature can exceed hundreds of degrees Celsius due to flames or splashing slag. Furthermore, the factory environment can be extremely dusty. In order to withstand the harsh industrial conditions, the optical fiber assembly and optical fiber connectors have to be specifically designed to suit these conditions.

US 2020221934 Al discloses a prior art optical connection device for optically connecting s first connector of a first optical fiber device with a second connector of a second optical fiber device. General state of the art is represented also by US 2016291260 AT, US 4795231 A, and US 2016011382 Al.

SUMMARY

According to the present specification, a fiber connector assembly is provided. The fiber connector assembly comprises a first inner fiber connector unit, a second inner fiber connector unit, and a guiding washer. The first inner fiber connector unit has an external taper, the second inner fiber connector unit has an end with a cavity for receiving the first inner fiber connector unit, and the guiding washer has a through- hole for the first or second inner fiber connector unit.

Due to self-aligning design the light guide can be quickly connected. In order to make sure the fibers are in line, male and female fiber connector units are employed. One or both of these connectors can be allowed to move, which allows coupling the fibers without production tolerances or accumulation of dust affecting the fiber alignment. The taper in the fiber connector unit guides the fiber connector units to couple and tightening the outer connector nut fixes the whole assembly firmly together.

Furthermore, the present specification allows utilization of materials capable of withstanding elevated temperature. The assembly can be connected only with threads.

Plastic clamps, rubber gaskets or other components susceptible to temperature damage are not required.

In an embodiment, one or more of the first fiber connection unit, the second fiber connection unit and the guiding washer comprises a temperature-tolerant material.

In an embodiment, the first inner fiber connector unit, second inner fiber connector unit and guiding washer are attached together in a connected state of the optical fiber assembly with a connector assembly comprising: a first outer connector unit, a second outer connector unit and means for attaching the first outer connector unit to the second 60 outer connector unit in a fluid-tight manner to restrict flow of fluid between the internal taper and external taper in the connected state.

In an embodiment, the first outer connector unit has an external threading, the second outer connector unit has a broader section; and the connector nut has a section narrower 65 than the broader section in second outer connector unit and an internal threading that can be connected to the external threading on the first outer connector unit.

In an embodiment, one of the first and the second outer connector unit comprises a cavity for receiving the other of the first and the second outer connector unit. 70

In an embodiment, the first inner fiber connector unit or the second inner fiber connector unit or both fiber connectors units have external and/or internal threading on their one end. 75 In an embodiment, a fluid channel for a fluid extends through one or more of the first connector unit, the second inner fiber connector unit, and the guiding washer.

In an embodiment, the first outer connector unit comprises a first support surface, the second outer connector unit comprises a second support surface, the first support surface 80 is configured to abut one of the second inner fiber connector unit and the guiding washer, and the second support surface is configured to abut the other of the second inner fiber connector unit and the guiding washer such that the second inner fiber connector unit and the guiding washer are held together in the connected state. 85 In an embodiment, the first support surface is fixed to the one of the second inner fiber connector unit and the guiding washer and/or the second support surface is fixed to the other of the second inner fiber connector unit and the guiding washer.

In an embodiment, a difference between the diameter of the through-hole and a broadest 90 section of the fiber connector unit going through the through-hole in the connected state is smaller than a difference in diameter of a widest and a narrowest part of the external taper of the first inner fiber connector unit.

In an embodiment, a difference between the diameter of the through-hole and a broadest 95 section of the fiber connector unit going through the through-hole in the connected state is greater thanor equal to 0,2 mm or greater than or equal to 0,5 mm and/or less than or equal to 2 mm, or lessthan or equal to 5 mm.

BRIEF DECRIPTION OF THE DRAWINGS

100 Figure 1 is a longitudinal section view of the present specification in connected state.

Figure 2 is an exploded view of the components presented in Figure 1.

Figure 3 is a longitudinal section view of first inner fiber connector unit (3).

Figure 4 is a longitudinal section view of second inner fiber connector unit (4).

105 Figure 5 is a cross section view of guiding washer (5).

Figure 6 is a cross section view of first inner fiber connector unit (3).

Figure 7 is a cross section view of second inner fiber connector unit (4).

DETAILED DESCRIPTION

110

In the following, fiber connector assembly presented in Fig. 2. is explained.

The optical connector assembly contains first (1) and second (2) outer connector units, first (3) and second (4) inner fiber connector units, guiding washer (5), connector nut (6) 115 and optical fiber connectors (7).

Any of the first outer connector unit (1), second outer connector unit (2), first inner fiber connector unit (3), second inner fiber connector unit (4), guiding washer (5) or connector nut (6) may comprise of a temperature-tolerant material. ”A “temperature-tolerant 120 material” may refer to a material having a glass-transition temperature or a melting point at a pressure of 1 atm of at least 200°C, or at least 400°C, or at least 600°C, or at least 800°C, or at least 10009C,”).

The first outer connector (1) contains external threading (101) for connecting to second 125 outer connector (2) and internal threading (102) for connecting to hose connector. In addition, the first outer connector (1) contains internal taper towards its end (103) that allows the first connector to lock into to the second outer connector (2) that has external taper towards its end (104). Alternatively, the first connector can have external taper and the second connector internal taper. 130

The second outer connector (2) internal threading (105) allowing fixing the hose connector to it. The second outer connector (2) has a broader section (106) that is larger than the narrow end (107) of the connector nut (6) diameter. In order to fix the second outer connector (2) to the first outer connector (1), the second connector has internal or 135 external taper, as described earlier. Preferably, the length of the tapers in both outer connectors are defined so that in the bottom of the internal taper there is space (108) for the guiding washer (5) and the second inner connector (4) to fit inside in connected state.

The support surface in one outer connector (109) abuts the guiding washer and one of the fiber connector units against the support surface (110) on the other outer connector.

140 Alternatively, the distance 108 can vary depending on the tolerance of the assembly.

The first (1) and second (2) outer connector may also contain rectangular section (111) or other geometric shape that allows holding the outer connector with a spanner or similar tool. 145 The first outer connector (1) can be fixed on the female outer connector (2) with a connector nut (6). The connector nut (6) contains a narrowed section (107) in one end that abuts the broader section (106) in the second outer connector (2) when the inner threading (112) of the connector nut is connected on the outer threading on the first outer connector (101). Alternatively, protrusions on the second connector or other similar 150 mechanisms as narrowed section (107) and broader section (106) can be utilized to ensure the connector nut tightens the first outer (1) connector and the second outer connector (1) together. Alternatively, the outer connectors can be attached together with another type of a mechanism, for example with one outer connector having a hole and another outer connection having a hole with a threading and the outers connectors being 155 attached together with a bolt being through the hole in one connector and turned into the threaded hole in another. Additionally, the outer connectors can be attached together with a clamping mechanism, in which the outer connectors are tightened together with a lever or levers. 160 Two optical fiber connectors (7) are aligned with the first inner connector (3), the second inner connector (4), and guiding washer (5). Preferably, the optical fiber connected to optical fiber connector (7) in the assembly is a multimode mode fiber. Alternatively, a single mode fiber or a bundle of single-mode or multi-mode fibers can be used. The optical fiber connectors (7) are made of ceramic, steel or other temperature resistant 165 material. The fiber connectors are fixed on the fibers with epoxy, crimp sleeve or other fiber attaching mechanism. The optical fiber connectors have connector tip (113), which goes inside the first (3) and the second inner fiber connector unit (4). The optical fiber connector contains the fiber nut (114), which has inner threading (115) allowing its connection to the external threading on the first (116) and second (117) inner connector. 170

The first inner fiber connector unit (3) has external taper towards its one end (118) and external threading (116) on the other end. The second inner fiber connector unit (4) has a cavity or taper in the middle (119) that is larger than the widest part (120) of the first inner connector. In addition, the second inner fiber connector unit has external threading (117) 175 on its other end to enable connecting it to the internal threading in optical fiber connector nut (115). Alternatively, the first inner connector can have a cavity in the middle and the second inner connector external taper towards its end. Preferably, the length of the first inner connector (121), the length of the second (122) fiber connector unit and depth of the cavity (123) are defined so that the fiber tip (113) of one of optical fiber connector 180 protrudes from the first or second inner fiber connector unit hole (124) and the other fiber connector tip (113) is correspondingly inside the hole in the other fiber connector unit (125). Preferably, the second inner fiber connector unit has gas channels (126) to enable flow of fluid through the connector assembly. 185 The guiding washer (5) is installed between optical fiber connector and the first or the second inner fiber connector unit. The guiding washer contains a through-hole (127) in the middle higher in diameter than the maximum diameters of threading in the first (116) and second (117) inner connectors. Preferably, the guiding washer has gas channels (128) to enable flow of cooling fluid through the connector. The gas channels can be of 190 any geometry providing that there is enough material thickness between gas channels to keep the structure rigid.

Preferably, the second inner fiber connector unit (4) and guiding washer (5) are attached to the halves of the outer connector (1 and 2). The attaching can be conducted by gluing, 195 soldering, welding or equivalent attachment method. Alternatively, the second inner fiber connector unit (4) and guiding washer (5) can be left unattached. The possible attachment of either second inner fiber connector unit or guiding washer to the outer connector halves is done to the support surface on the first outer connector (109), second fiber connector (110) or both. 200

When the first (1) and second (2) outer connectors are connected, the external taper (118) in the inner connector goes into the cavity (119) in the second inner connector.

The fiber tip (113) protruding from one fiber tip hole (124) goes into the another fiber tip hole (125) having the fiber tip (113) farther inside. Tightening the connector nut 205 inner thread (112) on the outer thread (101) in the first outer connector tightens the first inner fiber connector unit (3), second inner fiber connector unit (4) and guiding washer (5) tightly together, thus preventing movement of parts of the assembly.

Claims

1. A fiber connector assembly, comprising: a first inner fiber connector unit (3), a second inner fiber connector unit (4) and a guiding washer (5); wherein the first inner fiber connector unit has an external taper (118); the second inner fiber connector unit has an end with a cavity (119) for receiving the first inner fiber connector unit (3); and the guiding washer has a through-hole (127) for the first fiber connector unit (3); characterized in that a fluid channel (126, 128) for a fluid extends through the second inner fiber connector unit (4) and the guiding washer to enable flow of cooling fluid through the fiber connector assembly.

2. A fiber connector assembly of claim 1, wherein one or more of the first fiber connection unit, the second fiber connection unit and the guiding washer comprises a temperature- tolerant material.

3. A fiber connector assembly of claim 2, wherein the one or more of the first fiber connection unit, the second fiber connection unit and the guiding washer comprises a metal, such as stainless steel, as the temperature-tolerant material.

4. A fiber connector assembly of any of the preceding claims, wherein the first inner fiber connector unit, second inner fiber connector unit and guiding washer are attached together in a connected state of the optical fiber assembly with an outer connector comprising: a first outer connector unit (1), a second outer connector unit (2) and means for attaching the first outer connector unit to the second outer connector unit in a fluid- tight manner to restrict flow of fluid between an internal taper (103) arranged towards an end of the first outer connector (1) and an external taper (104) arranged towards an end of the second outer connector (2) in the connected state.

5. A fiber connector assembly of claim 4, wherein the first outer connector unit has an external threading (101), the second outer connector unit has a broader section (106); and the fiber connector assembly comprises a connector nut (6) having a section

(107) narrower than the broader section (106) in the second outer connector unit and an internal threading (112) that can be connected to the external threading (101) on the first outer connector unit.

6. A fiber connector assembly in accordance with claim 4 or 5, wherein one of the first outer connector unit and the second outer connector unit comprises a cavity for receiving the other of the first and the second outer connector unit.

7. A fiber connector assembly of any of the preceding claims, wherein the first inner fiber connector unit or the second inner fiber connector unit or both fiber connector units have external and/or internal threading on their one end.

8 A fiber connector assembly of any of claims 4 to 7, wherein the first outer connector unit (1) comprises a first support surface (109), the second outer connector unit (2) comprises a second support surface (110), the first support surface (109) is configured to abut one of the second inner fiber connector unit (4) and the guiding washer (5), and the second support surface (110) is configured to abut the other of the second inner fiber connector unit (4) and the guiding washer (5) such that the second inner fiber connector unit (4) and the guiding washer (5) are held together in the connected state.

9. A fiber connector assembly of claim 8, wherein the first support surface (109) is fixed to the one of the second inner fiber connector unit (4) and the guiding washer (5) and/or the second support surface (110) is fixed to the other of the second inner fiber connector unit (4) and the guiding washer (5).

10. A fiber connector assembly in accordance with any of the preceding claims, wherein a difference between the diameter of the through-hole (127) and a broadest section (130) of the fiber connector unit going through the through-hole in the connected state is smaller than a difference in diameter of a widest (120) and a narrowest (129) part of the external taper (118) of the first inner fiber connector unit.

11. A fiber connector assembly in accordance with any of the preceding claims, wherein a difference between the diameter of the through-hole (127) and a broadest section (130) of the fiber connector unit going through the through-hole in the connected state is greater than or equal to 0,2 mm or greater than or equal to 0,5 mm and/or less than or equal to 2 mm, or less than or equal to 5 mm.