Optical fiber ferrule connector having enhanced provisions for tuning

• US 5,212,752 A
• Filed: 05/27/1992
• Issued: 05/18/1993
• Est. Priority Date: 05/27/1992
• Status: Expired

• Current Assignee: Fitel USA Corporation
• Original Assignee: AT&T, Inc.
• Inventors: Stephenson, Daniel L., Subh, Naif T., Travieso, Ruben
• Primary Examiner(s): Healy, Brian
• Application Number:
  US07/889,203
• Time in Patent Office: 356 Days
• Field of Search: 385/53, 385/55, 385/56, 385/60, 385/66, 385/67, 385/76, 385/77, 385/78, 385/81, 385/84, 385/139
• US Class Current: 385/78
• CPC Class Codes: G02B 6/3821 with axial spring biasing or loading means G02B6/3847 takes precedence
• CPC Class Codes: G02B 6/3831 comprising a keying element on the plug or adapter, e.g. to forbid wrong connection keying element on the ferrule G02B6/3851; keying element for electrical coupling H01R13/64
• 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 6/3851 Ferrules having keying or coding means
• CPC Class Codes: G02B 6/3871 Ferrule rotatable with respect to plug body, e.g. for setting rotational position adjusting fibre within the ferrule, G02B6/3843; Fixation of ferrules after rotation
• 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
• CPC Class Codes: G02B 6/3893 Push-pull type, e.g. snap-in, push-on

Abstract

An optical connector (20) includes a ferrule assembly (22) which is adapted to be received in a plug frame (70). The ferrule assembly is held in the plug frame by a cable retention assembly (40) which is adapted to be secured to said plug frame. A leading end of the plug frame is symmetrical in an end cross-section which is normal to a longitudinal axis of the connector. After the ferrule assembly has been assembled to the plug frame, the direction of any eccentricity of the plug passageway or of an optical fiber terminated by the ferrule assembly is determined. Then the plug frame is assembled to a housing of a grip (90) such that the direction of eccentricity is aligned with a key (92) of the grip. The plug frame is capable of being assembled to the grip notwithstanding the rotational orientation of the plug frame with respect to the grip. An optical connection between optical fibers terminated by two connectors is made by inserting the grip of each of the two connectors into a coupling housing (100) so that the keys are aligned. Advantageously, portions of the connector may be factory assembled which facilitates field use of the connector to terminate optical fiber.

Claims

1. An optical fiber connector, said connector comprising:

a ferrule assembly including a ferrule portion having a passageway for an optical fiber, and a barrel;

a plug frame in which is disposed said ferrule assembly, said barrel of said ferrule assembly projecting toward a latching end portion of said plug frame and said ferrule projecting toward an opposite end portion of said plug frame, said opposite end portion of said plug frame being symmetrical with respect to a cross section of said plug frame which is normal to a longitudinal axis of said connector;

spring means disposed about said portion of said ferrule assembly which projects toward said latching end portion of said plug frame;

a cable retention member which is assembled to said plug frame and which includes a pocket for said spring means and said barrel, said cable retention member including outwardly projecting tabs each of which is received in a slot in said latching end portion of said plug frame to secure said cable retention member to said plug frame, said cable retention means being effective to preload said spring means, and

a housing in which said plug frame is disposed and which has a longitudinal axis, said plug frame capable of being assembled to said housing in any one of a plurality of rotational orientations with respect to the longitudinal axis of said connector.

2. The optical fiber connector of claim 1, which also includes a crimp portion which includes a sleeve which includes a large diameter portion which is capable of being crimped about a portion of said cable retention member with portions of a cable sheath system disposed between said large diameter portion of said crimp portion and said cable retention member and a small diameter portion which is capable of being crimped about a portion of a cable.

3. The optical fiber connector of claim 2, wherein said crimp portion includes a mandrel having a portion which becomes disposed in said large diameter portion of said sleeve, through which extends optical fibers of a cable being terminated and about which is disposed strength members of the cable so that the strength members may be secured between the large diameter portion of the sleeve and an outer surface of the cable retention member.

4. The optical fiber connector of claim 2, wherein a central portion of said cable retention member includes circumferentially extending tabs each of which is adapted to be received in an opening of said plug frame to secure said cable retention member to said plug frame.

5. The optical fiber connector of claim 4, wherein said connector comprises a grip which includes said housing and which includes a leading end portion having outer surfaces and a central cavity for receiving said plug frame assembly and a key projecting from one of the outer surfaces of the leading end portion of said housing, said opposite end portion of said plug frame including four outer orthogonal surfaces and being capable of being assembled to said grip such that any one of said outer surfaces of said opposite end portion of said plug frame is aligned with said key.

6. The optical fiber connector of claim 5, wherein said plug frame is assembled to said grip to cause the direction of any eccentricity of said passageway in said ferrule to be in the same quadrant as said key.

7. The optical fiber connector of claim 6, wherein said ferrule assembly includes a segmented collar with said barrel and said ferrule portion extending from opposite sides thereof, said plug frame including inwardly radially projecting, circumferentially spaced splines, said ferrule assembly being disposed in said plug frame such that grooves formed between segmented portions of said collar receive splines of said plug frame therebetween to prevent relative rotation between said plug frame and said ferrule assembly.

8. The optical fiber connector of claim 7, wherein two opposed inner portions of said grip of said leading end portion of said grip are provided with inwardly projecting latching nubs, said opposite end portion of said plug frame including a beveled surface at the intersection of each two outer surfaces of said opposite end portion of said plug frame, each said beveled surface being an invert of a groove formed by sidewalls which connect to said orthogonal surfaces of said opposite end portion of said plug frame, whereupon assembly of said plug frame to said housing of said grip, one of said latching nubs of said housing of said grip becomes disposed in one of said grooves and the opposed one of said latching nubs becomes disposed in a diagonally opposite one of said grooves.

9. The optical fiber connector of claim 8, wherein each of said orthogonal surfaces of said opposite end portion of said plug frame is provided with a detent and a leading end portion of said housing of said grip includes opposed walls and opposed openings, said assembly of said plug frame with said housing of said grip to cause said latching nubs of said grip to become disposed in two of said grooves of said plug frame and the assembly of said grip with a coupling housing causing latching fingers of said coupling housing to snap-lock behind each of two opposed detents to secure said connector to the coupling housing.

10. The optical fiber connector of claim 9, wherein the arrangement of said latching nubs and said grooves in said opposite end portion of said plug frame is such that the application of compressive forces to diagonally opposed outer corner portions of said housing of said grip which are aligned with said latching nubs causes disengagement of said latching nubs with said grooves and allows withdrawal of said plug frame from said grip.

11. The optical fiber connector of claim 9, which also includes a cable strain relief portion having a small diameter cable entry portion which transitions to a large diameter end portion which is adapted to be disposed about said crimp portion and connected to said cable retention member.

12. The optical fiber connector of claim 10, wherein said plug frame is adapted to be assembled to said housing of said grip when any one of said orthogonal surfaces of said opposite end portion of said plug frame is aligned with the outer surface of said housing of said grip which includes said key.

13. The optical fiber connector of claim 12, which is adapted to become assembled to a coupling housing with said passageway of said ferrule being aligned with a passageway of a ferrule of another such connector which is aligned coaxially therewith in the coupling housing.

14. A terminated optical fiber, which includes:

a length of optical fiber; and

an optical fiber connector which terminates said length of optical fiber, said optical fiber connector comprising;

a ferrule assembly including a ferrule portion having a passageway for an optical fiber, and a barrel;

a plug frame in which is disposed said ferrule assembly, said barrel of said ferrule assembly projecting toward a latching end portion of said plug frame and said ferrule projecting toward an opposite end portion of said plug frame, said opposite end portion of said plug frame being symmetrical with respect to a cross section of said plug frame which is normal to a longitudinal axis of said connector;

spring means disposed about said portion of said ferrule assembly which projects toward said latching end portion of said plug frame;

a cable retention member which is assembled to said plug frame and which includes a pocket for said spring means and said barrel portion, said cable retention member including outwardly projecting tabs each of which is received in a slot in said latching end portion of said plug frame to secure said cable retention member to said plug frame, said cable retention means being effective to preload said spring means; and

a housing in which said plug frame is disposed and which has a longitudinal axis, said plug frame capable of being assembled to said housing in any one of a plurality of rotational orientations with respect to the longitudinal axis of said connector.

15. The terminated optical fiber of claim 14, wherein a central portion of said cable retention member includes circumferentially extending tabs each of which is adapted to be received in an opening of said plug frame to secure said cable retention member to said plug frame.

16. The terminated optical fiber of claim 15, which also includes a grip which includes said housing in which said plug frame is disposed, said housing of said grip including a leading end portion which includes outer surfaces and which includes a central cavity for receiving said plug frame and a key projecting from one of said outer surfaces of said housing of said grip, said opposite end portion of said plug frame including four outer orthogonal surfaces and being capable of being assembled to said grip such that any one of said outer surfaces of said opposite end portion of said plug frame is aligned with said key.

17. The terminated optical fiber of claim 16, wherein said plug frame is assembled to said grip to cause the direction of eccentricity of said passageway in said ferrule to be in the same quadrant as said key.

18. The terminated optical fiber of claim 17, wherein two opposed inner portions of said grip of said leading end portion of said grip are provided with inwardly projecting latching nubs, said opposite end portion of said plug frame including a beveled surface at the intersection of each two surfaces of said opposite end portion of said plug frame, said beveled surface being an invert of a groove formed by sidewalls which connect to orthogonal surfaces of said opposite end portion of said plug frame, whereupon assembly of said plug frame to said housing of said grip, one of said latching nubs of said housing of said grip becomes disposed in one of said grooves and the opposed one of said latching nubs becomes disposed in a diagonally opposite one of said grooves.

19. An optical fiber connection, which includes:

a coupling housing; and

two terminated optical fibers, each being a terminated optical fiber as set forth in claim 14.

20. The optical fiber connection of claim 19, wherein a central portion of said cable retention member includes circumferentially extending tabs each of which is adapted to be received in an opening of said plug frame to secure said cable retention member to said plug frame.

21. The optical fiber connection of claim 20, which also includes a grip which includes said housing in which said plug frame is disposed, said housing which includes outer surfaces and which includes a central cavity for receiving said plug frame assembly and a key projecting from one of said outer surfaces of a leading end portion of said housing of said grip, said opposite end portion of said plug frame including four outer orthogonal surfaces and being capable of being assembled to said grip such that any one of said outer surfaces of said opposite end of said plug frame is aligned with said key.

22. The optical fiber connection of claim 21, wherein said plug frame is assembled to said grip to cause the direction of eccentricity of said passageway in said ferrule to be in the same quadrant as said key.

23. The optical fiber connection of claim 22, wherein two opposed inner portions of said grip of said leading end portion of said grip are provided with inwardly projecting latching nubs, said opposite end portion of said plug frame including a beveled surface at the intersection of each two orthogonal surfaces of said opposite end portion of said plug frame, said beveled surface being an invert of a groove formed by sidewalls which connect to orthogonal surfaces of said opposite end portion of said plug frame, whereupon assembly of said plug frame to said housing of said grip, one of said latching nubs of said housing of said grip becomes disposed in one of said grooves and the opposed one of said latching nubs becomes disposed in a diagonally opposite one of said grooves.

24. The optical fiber connection of claim 23, wherein said grip is provided with ports spaced about the circumference of an intermediate portion thereof, said ports exposing the plug frame which is inserted into said grip, said ports of said grip being enclosed by said coupling housing when said grip is seated fully in said coupling housing.

25. The optical fiber connection of claim 24, wherein said coupling housing includes opposed latching fingers at each end portion thereof and said plug frame includes a detent disposed along each of said four outer orthogonal surfaces such that when said grip is inserted into one end of said coupling housing, the latching fingers associated with said one end of said housing are moved into openings in said housing of said grip and snap-lock behind detents of said plug frame to secure said grip to said coupling housing.