Termination of a fiber optic transmission member and method therefore

• US 4,773,725 A
• Filed: 12/24/1986
• Issued: 09/27/1988
• Est. Priority Date: 05/24/1982
• Status: Expired due to Fees

• Current Assignee: AMP Limited
• Original Assignee: AMP Limited
• Inventors: Ashman, John J., Caron, Bernard G.
• Primary Examiner(s): Sikes, William L.
• Assistant Examiner(s): HEALY, BRIAN
• Application Number:
  US06/946,114
• Time in Patent Office: 643 Days
• Field of Search: 350/96.10, 350/96.20, 350/96.21, 350/96.22, 350/96.23, 350/96.34, 350/320
• US Class Current: 385/87
• CPC Class Codes: G02B 6/322 and having centering means being part of the lens for the self-positioning of the lightguide at the focal point, e.g. holes, wells, indents, nibs
• CPC Class Codes: G02B 6/3825 with an intermediate part, e.g. adapter, receptacle, linking two plugs
• CPC Class Codes: G02B 6/3841 using rods, balls for light guides
• CPC Class Codes: G02B 6/3855 characterised by the method of anchoring or fixing the fibre within the ferrule G02B6/3854 takes precedence
• CPC Class Codes: G02B 6/3857 Crimping, i.e. involving plastic deformation
• CPC Class Codes: G02B 6/3861 Adhesive bonding adhesives in general C09J
• CPC Class Codes: G02B 6/3863 fabricated by using polishing techniques grinding of the fibre ends B24B19/226
• CPC Class Codes: G02B 6/3865 fabricated by using moulding techniques shaping techniques of plastic materials in general B29C; producing plastic optical fiber connectors B29D11/0075
• CPC Class Codes: G02B 6/3869 Mounting ferrules to connector body, i.e. plugs
• CPC Class Codes: G02B 6/3874 using tubes, sleeves to align ferrules
• CPC Class Codes: G02B 6/3888 Protection from over-extension or over-compression

Abstract

A connector for a fiber optic member comprises a ferrule member in which is positioned an insert having rods surrounding a section of an exposed end of the fiber optic member, the exposed end extending along a front bore of the ferrule member. A crimping ferrule on the ferrule member is controllably crimped thereon thereby moving the rods into mechanical engagement with the fiber optic member with no or minimum deformation to the fiber optic member and securing the fiber optic member in the ferrule member. The method of terminating the fiber optic member includes surrounding the exposed end section with protective viscous material to protect the exposed end section from moisture and from becoming brittle, such as by filling the ferrule bore and the insert with the viscous material prior to inserting the fiber end thereinto.

Claims

1. A method for terminating a fiber optic transmission member of a fiber optic cable means, comprising the steps of:

preparing an end portion of the fiber optic cable means for termination including removal of a selected end length of jacket material of the cable means surrounding the fiber optic transmission member, exposing an end length of said fiber otic transmission member;

selecting a viscous material having the property of being moisture resistant;

surrounding said exposed fiber end length with said viscous material;

disposing said exposed fiber end length in a bore of a ferrule means such that a front end of said exposed fiber end length is disposed within a front bore in a front ferrule section for optical connection with a mating connector means, and the remaining length of said exposed fiber end length is disposed along a bore portion of said ferrule means rearward from said front ferrule section; and

mechanically securing said ferrule means at least to said fiber optic cable means whereby said exposed fiber end length is protected by said viscous material from moisture and from becoming brittle.

2. A method as set forth in claim 1 wherein said viscous material is disposed in said bore of said ferrule means, and said surrounding step comprises insertion of said exposed fiber end length into said bore.

3. A method as set forth in claim 1 wherein a fiber-engaging insert is placed within said bore portion of said ferrule means in a rearward ferrule section thereof, said viscous material is disposed in said bore of said ferrule means and within said fiber-engaging insert prior to insertion of said exposed fiber end length through said fiber-engaging insert and said bore of said ferrule means, and said fiber-engaging insert is moved into mechanically securing engagement with said exposed fiber end length.

4. A method as set forth in claim 3 wherein said mechanical securing step includes placing a crimping sleeve around said rearward ferrule section containing said fiber-engaging insert and around an end section of said jacket material of said fiber optic cable means, and crimping said crimping sleeve at both locations, thereby securing said fiber-engaging insert to said exposed fiber end length and securing said ferrule means both to said fiber-engaging insert and to said fiber optic cable means.

5. A termination of a fiber optic transmission member of a fiber optic cable means comprising:

an end portion of a fiber optic cable means having a selected end length of jacket material removed therefrom exposing an end length of a fiber optic transmission member;

ferrule means including a front section having a front end face and a rear section having a rear end face and further including a profiled bore therethrough from said front end face to said rear end face, said exposed fiber end length extending along said profiled bore from said rear end face to said front end face;

means mechanically securing said ferrule means to at least said fiber optic cable means; and

viscous moisture-resistant material surrounding said exposed fiber end length at least within said rear section of said ferrule means protecting said exposed fiber end length from moisture and from becoming brittle.

6. A termination as set forth in claim 5 further including a fiber-engaging means secured within said profiled bore in said rear ferrule section and mechanically securing said exposed fiber end length within said ferrule means, and viscous material surrounds said exposed fiber end length within said fiber-engaging means.

7. A termination as set forth in claim 5 wherein said viscous material is selected to have the property of remaining viscous over the wide temperature range to which the termination will be subjected during in-service use.

8. A terminal assembly for terminating a fiber optic transmission member of a fiber optic cable means comprising:

a ferrule member including a front section having a front end face and a rear section having a rear end face and further including a profiled bore therethrough from said front end face to said rear end face, said profiled bore adapted to receive therethrough an exposed fiber end length of said fiber optic transmission member of said fiber optic cable means inserted thereinto from said rear end face;

fiber-engaging insert means secured within said rear section of said ferrule means and having a fiber-receiving passageway therethrough coaxial with said profiled ferrule bore and adapted to receive therethrough said exposed fiber end length inserted from a rear end thereof, and further adapted to be moved into mechanically securing engagment with said exposed fiber end length after said fiber end length has been inserted therethrough;

means to secure said ferrule member to said fiber optic cable means; and

viscous moisture-resistant material disposed at least within said rear section of said ferrule member and within said fiber-engaging insert means to protect an exposed fiber end length inserted and secured therewithin from moisture and from becoming brittle.

9. A terminal assembly as set forth in claim 8 wherein said viscous material has sufficient viscosity to retain itself within said rear section of said ferrule member and within said fiber-engaging insert means.

10. A terminal assembly as set forth in claim 9 wherein said viscous material is selected to have the property of remaining viscous over the wide temperature range to which the termination will be subjected during in-service use.