Connector for optical fiber

• US 5,481,634 A
• Filed: 06/24/1994
• Issued: 01/02/1996
• Est. Priority Date: 06/24/1994
• Status: Expired due to Term

• Current Assignee: Furukawa Electric North America Incorporated (Furukawa Electric Company Limited)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Mock, Robert W. Jr., Lampert, Norman R., Anderson, Jerry M.
• Primary Examiner(s): Healy, Brian
• Application Number:
  US08/265,291
• Time in Patent Office: 557 Days
• Field of Search: 385/76, 385/77, 385/78, 385/81, 385/84, 385/85, 385/86, 385/87, 385/88, 385/89, 385/92, 385/139, 385/55, 385/56, 385/60
• US Class Current: 385/76
• CPC Class Codes: G02B 6/3843 with auxiliary facilities for movably aligning or adjusting the fibre within its ferrule, e.g. measuring position or eccentricity testing the alignment of axes, including eccentricity, G01B11/27
• CPC Class Codes: G02B 6/3854 Ferrules characterised by materials
• CPC Class Codes: G02B 6/38875 Protection from bending or twisting
• CPC Class Codes: G02B 6/3888 Protection from over-extension or over-compression
• CPC Class Codes: G02B 6/3889 using encapsulation for protection, e.g. adhesive, molding or casting resin
• CPC Class Codes: G02B 6/3893 Push-pull type, e.g. snap-in, push-on

Abstract

A connector for optical fibers includes a cylindrical glass ferrule installed in a plastic base member to form a fiber-holding structure. This structure includes a small passageway along its central axis for holding an optical fiber, and is mounted within a dielectric housing that includes an opening at one end thereof from which the glass ferrule protrudes. A cylindrical spring surrounds the base member and interacts with an interior surface of the housing to urge the glass ferrule outward from the opening in the housing. The housing further includes a spring latch which is located on a single side surface thereof, which is manually operable and used to lock the connector to an associated receptacle.

Claims

1. A connector for terminating an optical fiber comprising:

a fiber-holding structure having an end face in which an associated fiber is to terminate the holding structure including an axial passageway which terminates in the end face and which is adapted to receive an end portion of the associated fiber;

a housing having internal surfaces that define a cavity and surround the fiber-holding structure, the housing including a first opening for receiving an optical fiber and a second opening for enabling the end face of the holding structure to protrude therethrough, said openings extending into the cavity and being positioned at opposite ends of the housing; and

a manually operated latch for securing the housing to an associated receptacle to preclude unintended decoupling therebetween, the latch being positioned on a single side surface of the housing and movable in a direction which is perpendicular to the axial passageway, said latch comprising a cantilever beam having its fixed end positioned toward the second opening of the housing.

2. The connector of claim 1 wherein the fiber-holding structure includes a spring member which interacts with the housing to urge said end face through the second opening in the housing.

3. The connector of claim 1 wherein the fiber-holding structure comprises

a cylindrical plug that includes the end face in which the associated fiber is to terminate and an axial passageway which terminates in said end face, said passageway being adapted to receive an uncoated end portion of the associated fiber;

and

a base member for holding an end portion of the plug, said base member including an axial passageway which is collinear with the axial passageway of the plug.

4. The connector of claim 3 wherein the cylindrical plug has a diameter of about 1.25 millimeters.

5. The connector of claim 3 further including an annular spring which is disposed about the base member and which presses against a flange thereof, said spring also pressing against one of the internal surfaces of the cavity.

6. The connector of claim 3 wherein the cylindrical plug comprises a drawn glass tube whose outer cylinder surface has a circular cross section and whose axial passageway is substantially concentric with the outer cylinder surface.

7. The connector of claim 6 wherein the glass tube comprises borosilicate glass.

8. The connector of claim 1 wherein the fiber-holding structure is adapted to be held within the housing in a plurality of stable angular positions;

whereby the angular position of the fiber-holding structure with respect to the housing can be varied.

9. The connector of claim 8 wherein the fiber-holding structure includes a square flange which is adapted to be held within the housing in four stable angular positions.

10. The connector of claim 1 wherein the housing comprises first and second interconnecting members, the first interconnecting member being generally U-shaped with a channel for receiving the fiber-carrying structure, the second interconnecting member being generally fiat and shaped to mate with the first part, said first and second interconnecting members substantially enclosing the fiber-holding structure when they are joined together.

11. The connector of claim 10 wherein the first and second interconnecting members are made from a dielectric material.

12. The connector of claim 11 wherein the dielectric material comprises thermoplastic.

13. In combination, an optical cable and a connector, the optical cable comprising a glass fiber enclosed within a plastic buffer material;

and the connector comprising (i) a fiber-holding structure having an axial passageway which receives the optical fiber and which terminates in a planar end face that is perpendicular to the passageway, (ii) a housing having internal surfaces that define a cavity and surround the fiber-holding structure, the housing including a first opening at its back end which receives the optical cable and a second opening at its front end that enables the end face of the fiber-holding structure to protrude therethrough, said openings extending into the cavity and being positioned at opposite ends of the housing, and (iii) a manually operated latch for securing the housing to an associated receptacle to preclude unintended decoupling therebetween, said latch being positioned on a single side surface of the housing and movable in a direction which is perpendicular to the axial passageway, said latch comprising a cantilever beam having its fixed end positioned toward the front end of the housing.

14. The combination of claim 13 wherein the optical cable further comprises a plurality of filamentary strength members surrounding the buffered fiber and a plastic jacket surrounding the filamentary strength members.

15. The combination of claim 13 wherein the fiber-holding structure includes an annular spring which interacts with the housing and urges the end face of the fiber-holding structure through the second opening in the housing.

16. The combination of claim 14 further including a strain-relief boot having a longitudinal passageway which holds the optical cable, a front portion of the strain-relief boot surrounding the back end of the housing and capturing the filamentary strength members of the optical cable therebetween;

whereby tensile forces applied to the optical cable are transferred to the connector.

17. The combination of claim 16 wherein the strain relief boot is adapted to limit the minimum bending radius of the optical cable in the region where it joins the connector.

18. A connector for terminating an optical fiber including a fiber-holding structure which terminates in an end face and is adapted to receive an end portion of the optical fiber.

CHARACTERIZED BY:

a housing having a plurality of internal surfaces that define a cavity and surround the fiber-holding structure, the housing including a first opening for receiving an optical fiber and a second opening for enabling the end face of the fiber-holding structure to protrude therethrough, said openings extending into the cavity and being positioned at opposite ends of an axial passageway through the housing; and

a manually deformable latch for securing the housing to an associated receptacle in order to preclude unintended decoupling therebetween, the latch being positioned on a single side surface of the housing and movable in a direction which is perpendicular to the axial passageway, said latch comprising a cantilever beam having its fixed end positioned toward the second opening of the housing.

19. The connector of claim 18 wherein the fiber-holding structure includes a compression spring which presses against one of the interior surface of the housing to urge the end face of the fiber-holding structure through the second opening in the housing.

20. An optical fiber connector for effecting optical end-to-end coupling between two optical fibers, each of which terminates in a ferrule having a precision cylindrical outside surface, one end of the ferrule being held within an opening of a base member, said base member being generally cylindrical and having a flange which is disposed around the circumference of the base member and interacts with one end of an annular spring which is also disposed around the base member, said ferrule and base member and spring being mounted within a dielectric housing that is

CHARACTERIZED BY:

a plurality of internal surfaces that surround the ferrule and base member and spring, the housing including a first opening for receiving an optical fiber and a second opening for enabling an end portion of the ferrule to protrude therethrough, said openings extending into the cavity and being positioned at opposite ends of the housing; and

a spring latch for securing the housing to an associated receptacle in order to preclude unintended decoupling therebetween, the latch being positioned on a single side surface of the housing and being manually movable in a direction which is perpendicular to a longitudinal central axis of the cylindrical ferrule, said latch comprising a cantilever beam having its fixed end positioned toward the second opening of the housing.

21. The connector of claim 20 wherein the latch comprises a cantilever beam which is attached to the single side surface of the housing, and includes a groove at the free end thereof to facilitate manual operation.