U.S. patent number RE42,094 [Application Number 11/291,018] was granted by the patent office on 2011-02-01 for optical fiber connector and associated methods of validating optical fiber continuity.
This patent grant is currently assigned to Corning Cable Systems LLC. Invention is credited to Brandon A. Barnes, Thomas A. Church, Michael de Jong, Markus A. Giebel, Sean M. Kerr.
United States Patent |
RE42,094 |
Barnes , et al. |
February 1, 2011 |
Optical fiber connector and associated methods of validating
optical fiber continuity
Abstract
Methods are provided for validating the continuity of one or
more optical fibers upon which a fiber optic connector is mounted.
Typically, the fiber optic connector is mounted upon an optical
field fiber by actuating a cam mechanism to secure the optical
field fiber in position relative to an optical fiber stub. If
subsequent testing indicates that the continuity of the optical
field fiber and the optical fiber stub is unacceptable, the cam
mechanism can be deactuated, the optical field fiber can be
repositioned and the cam mechanism can be reactuated without having
to remove and replace the fiber optic connector. In order to
determine if continuity has been established between the optical
field fibers and respective optical fiber stubs, a method is also
provided that introduces light into at least one of each pair of
optical field fibers and optical fiber stubs and that only secures
the position of each optical field fiber relative to the respective
optical fiber stub once the glow associated with .[.each pair of
optical field fibers and optical fiber stubs.]. .Iadd.the optical
field fiber and the optical fiber stub .Iaddend.dissipates, which
dissipation indicates the establishment of continuity. An improved
.[.multifiber.]. connector and installation tool are also provided
to facilitate the establishment and validation of the continuity of
.[.optical field fibers and optical fiber stubs.]. .Iadd.the
optical field fiber and optical field stub .Iaddend.in order to
reduce the time and cost required to connectorize optical .[.field
fibers.]. .Iadd.fiber .Iaddend.in the field.
Inventors: |
Barnes; Brandon A. (Ft. Worth,
TX), de Jong; Michael (Ft. Worth, TX), Kerr; Sean M.
(Trophy Club, TX), Church; Thomas A. (Saginaw, TX),
Giebel; Markus A. (Hickory, NC) |
Assignee: |
Corning Cable Systems LLC
(Hickory, NC)
|
Family
ID: |
24122880 |
Appl.
No.: |
11/291,018 |
Filed: |
November 30, 2005 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
09532722 |
Mar 22, 2000 |
06816661 |
Nov 9, 2004 |
|
|
Current U.S.
Class: |
385/134;
385/59 |
Current CPC
Class: |
G02B
6/3846 (20130101); G02B 6/3898 (20130101); G02B
6/26 (20130101); G02B 6/3807 (20130101); G02B
6/3833 (20130101); G02B 6/3869 (20130101); G02B
6/3843 (20130101); G02B 6/3885 (20130101); G02B
6/3806 (20130101) |
Current International
Class: |
G02B
6/00 (20060101) |
Field of
Search: |
;385/53,55,56,59,60,62,66,70-72,83,134 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Siecor.RTM. CAMLITE.TM. Multimode Connector Procedure for Laser
Usage, SRP-006-046, Circa 1991, 2 pages. cited by other .
Siecor.RTM. CAMLITE.TM. Connector Laser Assembly Aid Instructions,
SRP-006-048, Issue 3, Sep. 1991, 6 pages. cited by other.
|
Primary Examiner: Nguyen; Khiem
Attorney, Agent or Firm: Carroll, Jr.; Michael E.
Parent Case Text
.[.This is a divisional of application Ser. No. 09/532,772, filed
Mar. 22, 2000, now U.S. Pat. No. 6,499,672, which is a divisional
of application Ser. No. 09/433,299, filed Nov. 3, 1999, now U.S.
Pat. No. 6,244,521..].
Claims
That which is claimed:
1. A method of validating continuity of an optical fiber upon which
a fiber optic connector is mounted, the method comprising:
providing a fiber optic connector including a ferrule defining at
least one bore extending between opposed front and rear faces, an
optical fiber stub disposed within the bore and extending beyond
the rear face of the ferrule, and a cam mechanism; introducing
light into at least one of an optical field fiber .[.and.].
.Iadd.or .Iaddend.the optical fiber stub; advancing the optical
field fiber into the fiber optic connector such that a glow
emanates from an end portion of the at least one of the optical
field fiber and the optical fiber stub while the optical field
fiber is advanced into the fiber optic connector; actuating the cam
mechanism to secure the optical field fiber in position relative to
the optical fiber stub once the glow dissipates; evaluating the
continuity of the optical field fiber and the optical fiber stub
once the cam mechanism has been actuated; deactuating the cam
mechanism in instances in which the evaluated continuity of the
optical field fiber and the optical fiber stub is unacceptable such
that the optical field fiber can be repositioned relative to the
optical fiber stub; and reactuating the cam mechanism following the
repositioning of the optical field fiber relative to the optical
fiber stub.
2. A method according to claim 1 further comprising monitoring the
glow emanating from an end portion of at least one of the optical
field fiber and the optical fiber stub while the optical field
fiber is advanced into the fiber optic connector.
3. A method according to claim 2 further comprising halting further
advancement of the optical field fiber once the glow dissipates
during said monitoring step.
4. A method according to claim 1 further comprising cleaving and
cleaning the end portion of the optical field fiber following
deactuation of the cam mechanism.
5. A method according to claim 4 further comprising repositioning
the optical field fiber relative to the optical fiber stub
following said cleaving and cleaning and prior to said reactuation
of the cam mechanism.
6. A method according to claim 1 further comprising repeating the
evaluation of the continuity of the optical field fiber and the
optical fiber stub, the deactuation of the cam mechanism to permit
repositioning of the optical field fiber relative to the optical
fiber stub and the reactuation of the cam mechanism following the
repositioning until the continuity is acceptable.
7. A method according to claim 6 further comprising crimping at
least a portion of the fiber optic connector .[.onto the optical
field fiber.]. once the continuity of the optical field fiber and
the optical fiber stub is acceptable.
8. A method of validating continuity of a plurality of optical
fibers upon which a fiber optic connector is mounted, the method
comprising: providing a fiber optic connector including a ferrule
defining a plurality of bores extending between opposed front and
rear faces, a plurality of optical fiber stubs disposed within
respective bores and extending beyond the rear face of the ferrule,
and a cam mechanism; advancing a plurality of optical field fibers
into the fiber optic connector and toward respective optical fiber
stubs such that each optical field fiber is paired with a
respective optical fiber stub; introducing light into at least one
of each pair of optical field fibers and optical fiber stubs while
the optical field fibers are advanced into the fiber optic
connector such that a glow emanates from within the fiber optic
connector for each pair of optical field fibers and optical fiber
stubs; halting further advancement of each optical field fiber once
the glow associated with the respective optical field fiber
dissipates; and securing the position of each optical field fiber
within the fiber optic connector relative to the respective optical
fiber stub once the glow associated with each pair of optical field
fibers and optical fiber stubs is dissipated.
9. A method according to claim 8 further comprising monitoring the
glow associated with each pair of optical field fibers and optical
fiber stubs while the optical field fibers are advanced into the
fiber optic connector.
10. A method according to claim 8 wherein said securing comprises
actuating a cam mechanism to secure the optical field fibers in
position relative to the respective optical fiber stubs once the
glow dissipates.
11. A method according to claim 10 further comprising evaluating
the continuity of the optical field fiber and the optical fiber
stub once the cam mechanism has been actuated.
12. A method according to claim 11 further comprising: deactuating
the cam mechanism if the continuity of the optical field fibers and
the optical fiber stubs is unacceptable such that the optical field
fibers can be repositioned relative to the respective optical fiber
stubs; and reactuating the cam mechanism following the
repositioning of the optical field fibers relative to the
respective optical fiber stubs.
13. A method according to claim 12 further comprising repeating the
evaluation of the continuity of the optical field fibers and the
optical fiber stubs, the deactuation of the cam mechanism to permit
repositioning of the optical field fibers relative to the
respective optical fiber stubs and the reactuation of the cam
mechanism following the repositioning until the continuity is
acceptable.
14. A method according to claim 13 further comprising crimping at
least a portion of the fiber optic connector .[.onto the optical
field fibers.]. once the continuity of the optical field fibers and
the respective optical fiber stubs is acceptable.
15. .[.A multifiber.]. .Iadd.An optical fiber .Iaddend.connector
comprising: a .[.multifiber.]. ferrule extending lengthwise between
opposed front and rear faces for receiving .[.a plurality of
optical fiber stubs.]. .Iadd.an optical fiber stub.Iaddend.; splice
components disposed proximate the rear face of said
.[.multifiber.]. ferrule for aligning a .[.plurality of optical
field fibers to respective ones of the plurality of optical fiber
stubs.]. .Iadd.field fiber to the optical fiber stub.Iaddend.;
.[.and.]. .Iadd.a sleeve in which said splice components are
disposed;.Iaddend. a cam mechanism for .[.urging.].
.Iadd.activating .Iaddend.said splice components together to
operably interconnect the aligned .[.optical field fibers.].
.Iadd.field fiber .Iaddend.and the optical fiber .[.stubs.].
.Iadd.stub.Iaddend., .Iadd.said cam mechanism disposed about said
sleeve, wherein movement of the cam mechanism relative to said
sleeve aligns the field fiber and the optical fiber stub;
and.Iaddend. wherein .[.at least one of said cam mechanism and said
splice components is translucent.]. .Iadd.the cam mechanism and at
least one of the splice components are translucent .Iaddend.such
that a glow emanating from therewithin .[.that.]. is indicative of
a discontinuity between .[.at least one pair of optical field
fibers.]. .Iadd.the field fiber .Iaddend.and optical fiber .[.stubs
is visible external to the multifiber connector.].
.Iadd.stub.Iaddend..
16. .[.A multifiber.]. .Iadd.An optical fiber .Iaddend.connector
according to claim 15 .[.wherein said cam mechanism comprises: a
sleeve in which said splice components are disposed,.]. said sleeve
defining a window through which said splice components are
exposed.[.; and a.]. .Iadd.and the .Iaddend.cam .[.member disposed
upon said sleeve for engaging.]. .Iadd.mechanism engaging
.Iaddend.said splice components via the window defined by said
sleeve.[., wherein movement of said cam member relative to said
sleeve urges said splice components together.]. .
17. .[.A multifiber.]. .Iadd.An optical fiber .Iaddend.connector
according to claim .[.16 wherein said cam member is translucent.].
.Iadd.15 wherein the connector is a multifiber
connector.Iaddend..
.Iadd.18. A method of validating the continuity of one or more
optical fibers upon which a fiber optic connector is mounted
comprising: providing a fiber optic connector including a ferrule
defining at least one bore extending between opposed front and rear
faces, an optical fiber stub at least partially disposed within the
bore and having an end portion extending beyond the rear face of
the ferrule, and at least one splice component; securing an end
portion of an optical field fiber relative to the end portion of
the optical fiber stub within the at least one splice component;
evaluating the continuity of the optical field fiber and the
optical fiber stub; repositioning and re-securing the end portion
of the optical field fiber relative to the end portion of the
optical fiber stub when the continuity of the optical field fiber
and the optical fiber stub is unacceptable; and re-evaluating the
continuity of the optical field fiber and the optical fiber stub
after repositioning and re-securing the end portion of the optical
field fiber relative to the end portion of the optical fiber
stub..Iaddend.
.Iadd.19. A method according to claim 18 wherein the step of
providing a fiber optic connector further comprises disposing the
fiber optic connector in an installation tool and wherein the step
of repositioning and re-securing the end portion of the optical
field fiber is accomplished without removing the fiber optic
connector from the installation tool..Iaddend.
.Iadd.20. A method according to claim 18 wherein the fiber optic
connector further comprises a cam mechanism and wherein the step of
securing the end portion of the optical field fiber relative to the
end portion of the optical fiber stub comprises actuating the cam
mechanism..Iaddend.
.Iadd.21. A method according to claim 18 wherein the step of
evaluating the continuity of the optical field fiber and the
optical fiber stub comprises introducing light into at least one of
the optical field fiber and the optical fiber stub such that a glow
emanates from at least one of the end portions of the optical field
fiber and the optical fiber stub..Iaddend.
.Iadd.22. A method according to claim 21 wherein the step of
evaluating the continuity and the step of re-evaluating the
continuity each further comprise monitoring the glow emanating from
the at least one of the end portions of the optical field fiber and
the optical fiber stub..Iaddend.
.Iadd.23. A method according to claim 18 further comprising
repeating the step of repositioning and re-securing and the step of
re-evaluating until the continuity of the optical field fiber and
the optical fiber stub is acceptable..Iaddend.
.Iadd.24. A method according to claim 23 further comprising the
step of introducing light into at least one of the optical field
fiber and the optical fiber stub such that a glow emanates from at
least one of the end portions of the optical field fiber and the
optical fiber stub and the step of monitoring the glow emanating
from the at least one of the end portions of the optical field
fiber and the optical fiber stub..Iaddend.
.Iadd.25. A method of validating the continuity of an optical field
fiber terminated to a fiber optic connector including a ferrule
defining at least one bore extending between opposed front and rear
faces and an optical fiber stub at least partially disposed within
the bore and having an end portion extending beyond the rear face
of the ferrule, the method comprising; positioning an end portion
of the optical field fiber in the fiber optic connector relative to
the end portion of the optical fiber stub; introducing light into
at least one the optical field fiber and the optical fiber stub
such that a glow emanates from at least one of the end portions of
the optical field fiber or the optical fiber stub; securing the end
portion of the optical field fiber relative to the end portion of
the optical fiber stub; evaluating the continuity of the optical
field fiber and the optical fiber stub by monitoring the glow
emanating from the at least one of the end portions of the optical
field fiber or the optical fiber stub; repositioning and
re-securing the end portion of the optical field fiber relative to
the end portion of the optical fiber stub when the continuity of
the optical field fiber and the optical fiber stub is unacceptable;
and re-evaluating the continuity of the optical field fiber and the
optical fiber stub after repositioning and re-securing the end
portion of the optical field fiber relative to the end portion of
the optical fiber stub..Iaddend.
.Iadd.26. A method according to claim 25 wherein the fiber optic
connector further comprises a cam mechanism and wherein the step of
securing the end portion of the optical field fiber relative to the
end portion of the optical fiber stub comprises actuating the cam
mechanism..Iaddend.
.Iadd.27. A method according to claim 26 further comprising the
step of deactuating the cam mechanism after the step of evaluating
the continuity and before the step of repositioning and re-securing
the end portion of the optical field fiber..Iaddend.
.Iadd.28. A method according to claim 27 wherein the step of
repositioning and re-securing the end portion of the optical field
fiber comprises reactuating the cam mechanism..Iaddend.
.Iadd.29. A method according to claim 25 further comprising the
step of disposing the fiber optic connector in an installation tool
and wherein the step of repositioning and re-securing the end
portion of the optical field fiber is accomplished without removing
the fiber optic connector from the installation tool..Iaddend.
.Iadd.30. A method according to claim 25 further comprising
repeating the step of repositioning and re-securing and the step of
re-evaluating until the continuity of the optical field fiber and
the optical fiber stub is acceptable..Iaddend.
.Iadd.31. A method according to claim 30 wherein the continuity of
the optical field fiber and the optical fiber stub is acceptable
when at least one of a measured amount of insertion loss is less
than a first predetermined value and a measured amount of
reflectance is greater than a second predetermined
value..Iaddend.
.Iadd.32. A method of validating the continuity of an optical field
fiber and an optical fiber stub mounted upon a fiber optic
connector including a cam mechanism, the method comprising:
disposing the fiber optic connector within an installation tool;
positioning an end portion of the optical field fiber in the fiber
optic connector relative to an end portion of the optical fiber
stub; introducing light into at least one of the optical field
fiber or the optical fiber stub such that a glow emanates from at
least one the end portions of the optical field fiber and the
optical fiber stub; actuating the cam mechanism to secure the end
portion of the optical field fiber relative to the end portion of
the optical fiber stub; evaluating the continuity of the optical
field fiber and the optical fiber stub by monitoring the glow
emanating from the at least one of the end portions of the optical
field fiber or the optical fiber stub; when the continuity of the
optical field fiber and the optical fiber stub is unacceptable,
deactuating the cam mechanism to release the end portion of the
optical field fiber relative to the optical fiber stub;
repositioning the end portion of the optical field fiber relative
to the end portion of the optical fiber stub without removing the
fiber optic connector from the installation tool; reactuating the
cam mechanism to secure the end portion of the optical field fiber
relative to the end portion of the optical fiber stub; and
re-evaluating the continuity of the optical field fiber and the
optical fiber stub after repositioning the end portion of the
optical field fiber relative to the end portion of the optical
fiber stub..Iaddend.
.Iadd.33. A method according to claim 32 further comprising
repeating the steps of deactuating the cam mechanism, repositioning
the end portion of the optical field fiber, reactuating the cam
mechanism, and re-evaluating the continuity until the continuity of
the optical field fiber and the optical fiber stub is
acceptable..Iaddend.
.Iadd.34. A method according to claim 33 further comprising the
step of removing the fiber optic connector from the installation
tool once the continuity of the optical field fiber and the optical
fiber stub is acceptable..Iaddend.
.Iadd.35. A method according to claim 34 wherein the continuity of
the optical field fiber and the optical fiber stub is acceptable
when at least one of a measured amount of insertion loss is less
than a first predetermined value and a measured amount of
reflectance is greater than a second predetermined
value..Iaddend.
.Iadd.36. A method of validating continuity of an optical fiber
upon which a fiber optic connector is mounted, the method
comprising: providing a fiber optic connector including a ferrule
defining at least one bore extending between opposed front and rear
faces, an optical fiber stub disposed within the bore and extending
beyond the rear face of the ferrule, and a cam mechanism;
introducing light into at least one of an optical field fiber or
the optical fiber stub, while the optical field fiber and the
respective optical stub fiber are in optical contact; actuating the
cam mechanism to secure the optical field fiber in position
relative to the optical fiber stub when any glow emanating from an
end portion of the at least one of the optical field fiber or the
optical fiber stub is at a dissipated level; evaluating the
continuity of the optical field fiber and the optical fiber stub
once the cam mechanism has been actuated; deactuating the cam
mechanism in instances in which the evaluated continuity of the
optical field fiber and the optical fiber stub is unacceptable such
that the optical field fiber can be repositioned relative to the
optical fiber stub; and reactuating the cam mechanism following any
repositioning of the optical field fiber relative to the optical
fiber stub..Iaddend.
.Iadd.37. A method according to claim 36 further comprising:
repeating said evaluating, said deactuating, and said reactuating
following any repositioning of the optical field fiber relative to
the optical fiber stub..Iaddend.
.Iadd.38. A method according to claim 37 further comprising:
crimping at least a portion of the fiber optic connector once the
continuity of the optical field fiber and the optical fiber stub is
acceptable..Iaddend.
.Iadd.39. A method of validating continuity of a plurality of
optical fibers upon which a fiber optic connector is mounted, the
method comprising: providing a fiber optic connector including a
ferrule defining a plurality of bores extending between opposed
front and rear faces, a plurality of optical fiber stubs disposed
within respective bores and extending beyond the rear face of the
ferrule, and a cam mechanism; introducing light into at least one
of each pair of optical field fibers and optical fiber stubs while
the optical field fibers and the respective optical fiber stubs are
in optical contact; and securing the position of each optical field
fiber within the fiber optic connector relative to the respective
optical fiber stub when any glow emanating from within the fiber
optic connector for each pair of optical field fibers and optical
fiber stubs is at a dissipated level by actuating the cam mechanism
to secure the end portion of the optical field fiber relative to
the end portion of the optical fiber stub; and deactuating the cam
mechanism after said actuating when any glow emanating from within
the fiber optic connector for each pair of optical field fibers and
optical fiber stubs is not at a dissipated level..Iaddend.
.Iadd.40. A method according to claim 39 further comprising:
reactuating the cam mechanism after repositioning the end portion
of the optical field fiber..Iaddend.
.Iadd.41. A method according to claim 39 further comprising:
evaluating continuity of the optical field fiber and the optical
fiber stub following said actuating the cam mechanism..Iaddend.
.Iadd.42. A method according to claim 41 further comprising:
crimping at least a portion of the fiber optic connector onto the
optical field fibers once the continuity of the optical field
fibers and the respective optical fiber stubs is
acceptable..Iaddend.
.Iadd.43. A method of validating continuity of an optical fiber
upon which a fiber optic connector is mounted, the method
comprising: providing a fiber optic connector including a ferrule
defining at least one bore extending between opposed front and rear
faces, an optical fiber stub disposed within the bore, and a cam
mechanism; introducing light into at least one of an optical field
fiber and the optical fiber stub, while the optical field fiber and
the respective optical fiber stub are in optical contact; actuating
the cam mechanism to secure the optical field fiber in position
relative to the optical fiber stub; and evaluating the continuity
of the optical field fiber and the optical fiber stub once the cam
mechanism has been actuated by observing an amount of dissipated
light; deactuating the cam mechanism in instances in which the
evaluated continuity of the optical field fiber and the optical
fiber stub is unacceptable such that the optical field fiber can be
repositioned relative to the optical fiber stub; reactuating the
cam mechanism following any repositioning of the optical field
fiber relative to the optical fiber stub; and reevaluating the
continuity of the optical field fiber and the optical fiber stub
once the cam member has been reactuated by observing dissipated
light..Iaddend.
.Iadd.44. A method according to claim 43, wherein the amount of
dissipated light is no dissipated light..Iaddend.
.Iadd.45. A method according to claim 1 wherein at least one of
said cam mechanism or at least one splice component is
translucent..Iaddend.
.Iadd.46. A method according to claim 1 wherein the continuity of
the optical field fiber and the optical fiber stub is acceptable
when at least one of a measured amount of insertion loss is less
than a first predetermined value and a measured amount of
reflectance is greater than a second predetermined
value..Iaddend.
.Iadd.47. A method according to claim 8 wherein at least one of
said cam mechanism or at least one splice component is
translucent..Iaddend.
.Iadd.48. A method according to claim 8 wherein the continuity of
the plurality of optical field fibers and the plurality of optical
fiber stubs is acceptable when at least one of a measured amount of
insertion loss is less than a first predetermined value and a
measured amount of reflectance is greater than a second
predetermined value..Iaddend.
.Iadd.49. A method according to claim 18 wherein the continuity of
the plurality of optical field fibers and the plurality of optical
fiber stubs is acceptable when at least one of a measured amount of
insertion loss is less than a first predetermined value and a
measured amount of reflectance is greater than a second
predetermined value..Iaddend.
.Iadd.50. A method according to claim 18 wherein at least one of a
cam mechanism or the at least one splice component is
translucent..Iaddend.
.Iadd.51. A method according to claim 25 wherein at least one of a
cam mechanism or at least one splice component is
translucent..Iaddend.
.Iadd.52. A method according to claim 32 wherein at least one of
the cam mechanism or at least one splice component is
translucent..Iaddend.
.Iadd.53. A method according to claim 36 wherein at least one of
the cam mechanism or at least one splice component is
translucent..Iaddend.
.Iadd.54. A method according to claim 39 wherein at least one of
the cam mechanism or at least one splice component is
translucent..Iaddend.
.Iadd.55. The fiber optic connector connectorized according to the
method of claim 1..Iaddend.
.Iadd.56. The fiber optic connector connectorized according to the
method of claim 8..Iaddend.
.Iadd.57. The fiber optic connector connectorized according to the
method of claim 18..Iaddend.
.Iadd.58. The fiber optic connector connectorized according to the
method of claim 25..Iaddend.
.Iadd.59. The fiber optic connector connectorized according to the
method of claim 32..Iaddend.
.Iadd.60. The fiber optic connector connectorized according to the
method of claim 36..Iaddend.
.Iadd.61. The fiber optic connector connectorized according to the
method of claim 39..Iaddend.
.Iadd.62. The fiber optic connector connectorized according to the
method of claim 43..Iaddend.
.Iadd.63. An optical fiber connector according to claim 15, wherein
the cam mechamism is reversible for releasing the splice
components..Iaddend.
.Iadd.64. An optical fiber connector according to claim 15, wherein
both splice components are translucent..Iaddend.
.Iadd.65. An optical fiber connector according to claim 15, wherein
the sleeve is a ferrule holder..Iaddend.
.Iadd.66. An optical fiber connector according to claim 15, further
including a spring..Iaddend.
.Iadd.67. An optical fiber connector according to claim 15, further
including a crimp band..Iaddend.
.Iadd.68. An optical fiber connector according to claim 15, further
including a boot..Iaddend.
Description
FIELD OF THE INVENTION
The present invention relates generally to the connectorization of
optical fibers and, more particularly, to multifiber connectors,
installation tools and associated methods for validating optical
fiber continuity during the connectorization process.
BACKGROUND OF THE INVENTION
Although fiber optic connectors can generally be most efficiently
and reliably mounted upon the end portions of optical fibers in a
factory setting during the production of fiber optic cable, many
fiber optic connectors must be mounted upon the end portions of
optical fibers in the field. As such, a number of fiber optic
connectors have been specifically developed to facilitate field
installation. One advantageous type of fiber optic connector that
is specifically designed to facilitate field installation is the
UNICAM.RTM. family of fiber optic connectors provided by Siecor
Corporation of Hickory, N.C. While the UNICAM family of fiber optic
connectors includes a number of common features including a common
splicing technique, the UNICAM family of fiber optic connectors has
several different styles of connectors including UNICAM connectors
adapted to be mounted upon a single optic fiber and UNICAM
connectors adapted to be mounted upon two or more optical fibers,
such as the MT-RJ UNICAM connector. See, for example, U.S. patent
application Ser. No. 09/108,451 filed Jul. 1, 1998 and assigned to
Siecor Corporation, which describes a multifiber connector, such as
an MT-RJ UNICAM connector, adapted to be spliced onto the end
portions of a plurality of optical fibers. The contents of this
patent application are hereby incorporated by reference in their
entirety.
By way of example of an advantageous fiber optic connector designed
for field installation, FIG. 1 depicts an MT-RJ UNICAM.RTM.
connector 10. The connector generally includes a ferrule 12
defining one or more bores for receiving respective optical fiber
stubs. The optical fiber stubs are preferably sized such that one
end of the optic fiber stubs extends rearwardly beyond the ferrule.
The MT-RJ UNICAM.RTM. connector also includes splice components, at
least one of which defines a groove for receiving an end portion of
each optical field fiber upon which the fiber optic connector is to
be mounted. In order to mount the fiber optic connector upon
optical field fibers, the splice components arc positioned
proximate the rear end of the ferrule, such that the end portions
of the optical fibers stubs that extend rearwardly beyond the
ferrule are disposed within the respective grooves defined by the
splice components. Thereafter, end portions of the optical field
fibers can also be inserted into the respective grooves defined by
the splice components. By inserting the optical field fibers into
the grooves defined by the splice components until respective end
portions of the optical fiber stubs and the optical field fibers
make contact, optical connections can be established between
respective pairs of the optical fiber stubs and the optical field
fibers. In this regard, the contact between the end portions of the
optical fiber stubs and the optical field fibers establishes
optical continuity between respective pairs of the optical fiber
stubs and the optical field fibers. The splice components can then
be actuated, such as by means of a cam member 20, in order to force
the splice components together and to secure the end portions of
the optical fiber stubs and the optical field fiber in position
within the respective grooves defined by the splice components.
In order to facilitate the connectorization of optical fibers in
the field, installation tools have also been developed. For
example, U.S. Pat. No. 5,040,867 to Michael de Jong et al. and U.S.
Pat. No. 5,261,020 to Michael de Jong et al. describe installation
tools for facilitating the connectorization of optical fibers in
the field. In addition, a UNICAM.RTM. installation tool kit is
provided by Siecor Corporation of Hickory, N.C., to facilitate the
mounting of the UNICAM.RTM. family of connectors upon the end
portions of optical field fibers in the field. An installation tool
holds a number of components of the fiber optic connector including
the ferrule and the splice components while the optical field
fibers are inserted into the fiber optic connector and aligned with
the respective optical fiber stubs.
In this regard, one conventional installation tool includes a base
and a tool housing mounted upon the base. The installation tool
also includes an adapter disposed within the tool housing. The
adapter has a first end for engaging the fiber optic connector that
is to be mounted upon the optical field fibers and an opposed
second end that is a dust cap. The installation tool also includes
a bias member mounted within the tool housing that engages a
shoulder defined between the first and second ends of the adapter
in order to secure the adapter in position within the tool housing.
Typically, the bias member includes a slide member slidably
connected to the tool housing and a biasing element, such as a
spring, for urging the slide member into engagement with the
shoulder defined by the adapter. The slide member generally
includes an engagement portion having a U-shape through which the
second end of the adapter extends. In addition, a conventional
slide member includes a base portion disposed between the tool
housing and the base and connected to the engagement portion by
means of a connecting element that extends through a lengthwise
extending slot defined by the tool housing. Thus, the movement of
the connecting element through the slot defined by the tool housing
guides the corresponding movement of the slide member in a
lengthwise direction relative to the tool housing in order to
engage the shoulder defined by the adapter, thereby securing the
adapter in position within the tool housing.
In order to mount the fiber optic connector upon the end portions
of the optical field fibers, the fiber optic connector is mounted
within the installation tool. In particular, the forward end of the
fiber optic connector is engaged by the first end of the adapter
which, in turn, is secured within the tool housing once the slide
member is biased into engagement with the shoulder defined by the
adapter. The end portions of the optical field fibers are then
inserted into the rear end of the fiber optic connector and the
splice components are subsequently actuated, such as by being
cammed together, in order to secure the optical field fibers
relative to respective optical fiber stubs. The crimp tube 24 of
the fiber optic connector is then crimped about the optical field
fibers and, in some applications, a crimp band 26 is crimped to the
strength members surrounding the optical field fibers in order to
provide strain relief and otherwise protect the splice connections
of the optical field fibers and the optical fiber stubs.
Once fiber optic connectors have been mounted upon the opposed end
portions of the optical field fibers, the resulting fiber optic
cable assembly is preferably tested end-to-end. Among other things,
this testing is designed to insure that optical continuity has been
established between the optical fiber stubs and respective optical
field fibers. While fiber optic cables can be tested in different
manners, one test involves the introduction of light having a
predetermined intensity into each optical fiber stub. By measuring
the light following its propagation through the fiber optic cable
assembly and, more particularly, by measuring the insertion loss
and back reflectance onto each optical fiber stub with a power
meter, the continuity of each optical field fiber and the
respective optical fiber stub can be determined. If the testing
indicates that the optical fibers are not sufficiently continuous,
the technician must either scrap the entire fiber optic cable
assembly or, more commonly, replace one or both fiber optic
connectors in an attempt to establish the desired continuity. In
order to replace the fiber optic connectors, a technician generally
removes, i.e., cuts off, one of the fiber optic connectors and
repeats the connectorization process described above by mounting a
new fiber optic connector within the installation tool and
inserting the optical field fibers into the new fiber optic
connector. Once the new fiber optic connector has been mounted upon
the end portions of the optical field fibers, the new fiber optic
connector is removed from the installation tool and the fiber optic
cable assembly is again tested. If the optical fibers are still not
sufficiently continuous, the fiber optic connector mounted upon the
other end of the fiber optic cable assembly is typically removed
and replaced as described above, prior to further testing of the
resulting fiber optic cable assembly.
While fiber optic connectors and associated installation tools have
been developed to facilitate the mounting of the fiber optic
connectors upon the end portions of optical field fibers in the
field, conventional field connectorization techniques can be quite
time consuming and expensive. In this regard, since the continuity
testing is not performed until after the fiber optic connectors
have been completely mounted to the optical field fibers, one or
both of the fiber optic connectors must typically be replaced if
the testing indicates a discontinuity between the optical field
fibers and the respective optical fiber stubs. This process not
only requires additional time to effect the reconnectorization, but
also increases the cost of the resulting fiber optic cable assembly
by causing a number of potentially functional fiber optic
connectors to be disadvantageously scrapped since the testing
generally does not indicate which of the fiber optic connectors
should be replaced. In this regard, the technician generally
randomly picks one of the fiber optic connectors to replace,
thereby insuring that a fiber optic connector that has been
appropriately mounted upon the optical field fibers is replaced
almost half of the time.
The reconnectorization of one or both ends of a fiber optic cable
assembly is particularly troublesome for fiber optic cable
assemblies that include a plurality of optical field fibers. In
this regard, if the testing indicates a discontinuity involving any
one of the optical field fibers, the fiber optic connectors mounted
upon one or both ends of the fiber optic cable assembly must
generally be replaced, even if the other optical field fibers and
the optical fiber stubs have the desired continuity.
In order to facilitate continuity testing while the fiber optic
connector remains mounted within the installation tool, Siecor
Corporation previously developed a modified installation tool for a
single fiber CamLite.TM. ST connector that permitted continuity
testing. The installation tool included an adapter having opposed
first and second ends, the first end of which was adapted to engage
a single fiber CamLite ST connector. In order to test the
continuity of the optical fiber, a laser, such as an HeNe gas
laser, was provided that delivered red light to the optical fiber
stub of the single fiber CamLite ST connector. More particularly,
the red light was delivered via an optical fiber upon which another
ST connector was mounted, This other ST connector was, in turn,
inserted into the second end of the adapter such that the red light
was delivered to the optical fiber stub of the single fiber CamLite
ST connector. By monitoring the glow emanating from the end portion
of the optical fiber stub within the fiber optic connector through
a translucent connector body, the technician could determine when
contact was established between the optical fiber stub and the
optical field fiber based upon the dissipation of the glow, i.e.,
continuity is presumed to have been established once the glow
dissipates. Thereafter, the cam member of the single fiber CamLite
ST connector could be actuated to fix the relative positions of the
optical field fiber and the optical fiber stub prior to making a
final check of continuity.
While the installation tool developed by Siecor Corporation for the
single fiber CamLite ST connector advantageously monitored the
continuity of an optical field fiber and an optical fiber stub
while the single fiber CamLite ST connector remained within the
installation tool, this installation tool provided no mechanism for
uncamming and repositioning the optical field fiber relative to the
optical fiber stub if the continuity was inadequate after cam
actuation. As such, the fiber optic connector would still have to
be removed from the end portion of the optical fiber and replaced
by a new single fiber CamLite ST connector if testing subsequently
determined that the optical field fiber and the optical fiber stub
were actually discontinuous. In addition, the modified installation
tool developed by Siecor Corporation was only capable of mounting a
fiber optic connector upon a single optical fiber and, more
particularly, mounting a CamLite ST connector upon a single optical
fiber and did not permit multifiber connectors to be mounted upon
the end portions of a plurality of optical field fibers. As such,
improved techniques for mounting multifiber connectors upon optical
field fibers in the field and for testing the resulting fiber optic
cable assembly are desired in order to reduce the overall time
required for the mounting and testing procedures and to
correspondingly reduce the cost of the resulting fiber optic cable
assembly.
SUMMARY OF THE INVENTION
Methods are therefore provided according to the present invention
for validating the continuity of one or more optical fibers upon
which a fiber optic connector is mounted. According to one
embodiment, the fiber optic connector can be mounted upon an
optical field fiber by actuating a cam mechanism to secure the
optical field fiber in position relative to an optical fiber stub.
If subsequent evaluation indicates that the continuity of the
optical field fiber and the optical fiber stub is unacceptable, the
cam mechanism can be deactuated, the optical field fiber can be
repositioned and the cam mechanism can be reactuated without having
to remove and replace the fiber optic connector. In order to
determine if continuity has been established between the optical
field fibers and respective optical fiber stubs, a method is also
provided that introduces light into at least one of each pair of
optical field fibers and optical fiber stubs and that only secures
the position of each optical field fiber relative to the respective
optical fiber stub once the glow associated with each pair of
optical field fibers and optical fiber stubs dissipates, which
dissipation indicates the establishment of continuity. An improved
multifiber connector and installation tool are also provided to
facilitate the establishment and validation of the continuity of
optical field fibers and optical fiber stubs in order to reduce the
time and cost required to connectorize optical field fibers in the
field.
According to one advantageous embodiment, a method is provided for
validating the continuity of an optical fiber upon which a fiber
optic connector is mounted. In this regard, the fiber optic
connector includes a ferrule defining at least one bore extending
between opposed front and rear faces, an optical fiber stub
extending through the bore and beyond the rear face of the ferrule,
and a cam mechanism. According to this embodiment, an optical field
fiber is advanced into the fiber optic connector while light is
introduced into at least one of the optical field fiber and the
optical fiber stub. So long as the optical field fiber and the
optical fiber stub are discontinuous, a glow will emanate from an
end portion of the optical field fiber or the optical fiber stub
into which light is introduced. The glow is monitored while the
optical field fiber is advanced into the fiber optic connector and
further advancement of the optical field fiber is halted once the
glow dissipates. The cam mechanism is then actuated to secure the
optical field fiber in position relative to the optional fiber
stub. Once the cam mechanism has been actuated, the continuity of
the optical field fiber and the optical fiber stub is evaluated,
preferably while the fiber optic connector remains within the
installation tool. If the continuity of the optical field fiber and
the optical fiber stub is unacceptable, the cam mechanism is
deactuated. The optical field fiber is then repositioned relative
to the optical fiber stub. In this regard, the optical field fiber
is typically cleaved and cleaned prior to the repositioning to
improve the resulting connection. Once the optical field fiber has
been repositioned, the cam mechanism is reactuated. The evaluation
of the continuity of the optical field fiber and the optical fiber
stub as well as any necessary deactuation of the cam mechanism,
repositioning of the optical field fiber and reactuation of the cam
mechanism can be repeated as necessary to achieve continuity. Once
acceptable continuity is obtained, the fiber optic connector can be
crimped onto the optical field fibers and, more typically, to the
strength members surrounding the optical field fibers.
By permitting repeated repositioning of the optical field fiber
prior to crimping the fiber optic connector onto the optical field
fibers, the method of this embodiment prevents otherwise acceptable
fiber optic connectors from being replaced in an attempt to
establish continuity between optical field fibers and optical fiber
stubs. Thus, the total lime required to mount the fiber optic
connectors upon the optical field fibers and to validate the
resulting continuity of the optical fibers is decreased according
to the method of this embodiment of the present invention.
Correspondingly, the cost of the resulting fiber optic cable
assembly, on average, is also decreased since fewer fiber optic
connectors are removed and scrapped.
In order to permit the glow emanating from the end portion of at
least one optical fiber stub or optical field fiber that is
indicative of a discontinuity to be viewed, a multifiber connector
is also provided according to another embodiment of the present
invention. The multifiber connector of this embodiment includes a
multifiber ferrule extending lengthwise between opposed front and
rear faces for receiving a plurality of optical fiber stubs. The
multifiber connector also includes splice components positioned
proximate the rear face of the multifiber ferrule for aligning a
plurality of optical field fibers with respective ones of the
plurality of optical fibers stubs. The multifiber connector also
includes a cam mechanism for urging the splice components together
to operably interconnect respective pairs of the optical field
fibers and the optical fibers stubs. According to this embodiment
of the present invention, at least one of the cam mechanism and the
splice components is translucent such that the glow emanating from
therewithin that is indicative of a discontinuity between at least
one pair of optical field fibers and optical fibers stubs is
externally visible.
In one embodiment, the cam mechanism of the multifiber connector
includes a sleeve in which the splice components are disposed. The
sleeve of this embodiment also defines a window through which the
splice components are exposed. In addition to the sleeve, the cam
mechanism of this embodiment includes a cam member disposed upon
the sleeve for engaging the splice components via the window
defined by the sleeve. As such, movement of the cam member relative
to the sleeve urges the splice components together. In this
embodiment, the cam member is typically translucent. As such, the
multifiber connector of this embodiment of the present invention
permits the connectorization process to be monitored to ensure that
continuity is established between each optical field fiber and the
respective optical fiber stubs prior to actuating the cam mechanism
to secure the optical field fibers in position relative to the
respective optical fiber stubs.
An installation tool is also provided according to another
embodiment of the present invention for mounting the fiber optic
connector upon one or more optical field fibers. The installation
tool of this embodiment is capable of being converted between a
first configuration that facilitates validation of the continuity
of the optical fibers and a second configuration in which the
continuity of the optical fibers is untested.
According to this embodiment, the installation tool includes a tool
housing extending lengthwise between first and second opposed ends.
The installation tool also include first and second adapters
capable of being alternately mounted within the tool housing to
configure the installation tool in the first and second
configurations, respectively. The first adapter has a first end
adapted to engage the fiber optic connector that is being mounted
upon the optical field fiber and an opposed second end adapted to
engage a fiber optic connector that is mounted upon another optical
fiber that delivers light for continuity testing. While the second
adapter also has a first end adapted to engage the fiber optic
connector that is mounted upon the optical field fiber, the second
end of the second adapter serves as a dust cap. Each adapter
further defines a shoulder between the opposed first and second
ends. The installation tool of this embodiment of the present
invention also includes first and second bias members capable of
being alternately mounted within the tool housing to configure the
installation tool in the first and second configurations,
respectively. The bias members are adapted to be biased into
engagement with the shoulder defined by the respective adapter to
thereby secure the respective adapter in position within the tool
housing.
According to this embodiment of the present invention, the first
and second adapters and the first and second bias members can be
interchanged to convert the installation tool between the first and
second configurations without otherwise disassembling the
installation tool. In this regard, the first adapter and the first
bias member can be mounted within the tool housing such that the
installation tool has the first configuration that permits testing
of the continuity of the optical fibers upon which the fiber optic
connector is mounted. Alternatively, the second adapter and the
second bias member can be mounted within the tool housing such that
the installation tool has the second configuration that does not
support continuity testing, but appears and functions in the same
manner as a conventional installation tool.
According to this embodiment of the present invention, each bias
member preferably includes a slide member and a biasing element for
urging the respective slide member into engagement with the
shoulder defined by the respective adapter to thereby secure the
respective adapter and connector in position within the tool
housing. Moreover, each slide member can include an engagement
portion capable of being disposed within the tool housing for
engaging the shoulder defined by the respective adapter and a base
portion disposed on the opposite side of the tool housing from the
engagement portion. In addition, each slide member can include a
removable connector interconnecting the engagement portion and the
base portion. The removable connector extends through a slot
defined by the tool housing such that the removable connector rides
within the slot as the slide member moves relative to the tool
housing. Each slide member preferably includes a common base
portion. As such, by removing the removable connector, the
engagement portions of the first and second adapters can be
interchanged and mounted to the common base portion without
otherwise disassembling the installation tool.
Accordingly, the installation tool can be configured to support
continuity testing of a fiber optic connector that remains mounted
within the installation tool. Alternatively, the installation tool
can be configured as a conventional installation tool that does not
support continuity testing. By permitting continuity testing
without removing the fiber optic connector from the installation
tool, however, the installation tool of this embodiment of the
present invention further facilitates the rapid repositioning of
the optical field fibers relative to the optical fiber stubs in
order to achieve continuity without having to scrap the fiber optic
connector as required by conventional techniques.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of an MT-RJ UNICAM.RTM.
fiber optic connector.
FIG. 2 is an exploded perspective view of an installation tool
according to one embodiment of the present invention.
FIG. 3 is a perspective view of the installation tool of FIG. 2
following assembly thereof.
FIG. 4 is a fragmentary perspective view of the installation tool
of FIGS. 2 and 3 having at least portions of the MT-RJ UNICAM fiber
optic connector of FIG. 1 mounted therein.
FIG. 5a is an exploded perspective view of a portion of the
installation tool of FIGS. 2-4 illustrating the adapter and slide
member that define the first configuration of the installation
tool.
FIG. 5b is an exploded perspective view of a portion of the
installation tool of FIGS. 2-4 illustrating the adapter and slide
member that define the second configuration of the installation
tool.
FIG. 6 is a flow chart illustrating the operations performed in
order to validate the continuity of one or more optical field
fibers with respective optical fiber stubs according to one
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention now will be described more fully hereinafter
with reference to the accompanying drawings, in which preferred
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout.
A method is provided according to the present invention for
validating the continuity of one or more optical field fibers with
respective optical fiber stubs carried by a fiber optic connector
mounted upon end portions of the optical field fibers. While the
method of the present invention can be utilized to perform
continuity testing following the mounting of a variety of different
fiber optic connectors upon the end portions of the optical field
fibers, the method will be hereinafter described by way of example,
and not of limitation, in conjunction with continuity testing
performed following the mounting of a MT-RJ UNICAM.RTM. connector
upon the end portions of a pair of optical field fibers.
As depicted in FIG. 1 and described in more detail in U.S. patent
application Ser. No. 09/108,451, an MT-RJ UNICAM connector 10 is a
multifiber connector having a multifiber ferrule 12. A number of
optical fiber stubs extend through and are secured within the
multifiber ferrule. Depending upon the eventual application of the
multi fiber connector and the type of optical fibers upon which the
connector will be mounted, the optical fiber stubs can be either
multi-mode or single mode optical fiber stubs. In any event, the
ferrule defines a plurality of bores that open through a front face
of the ferrule for receiving respective optical fiber stubs. While
the multifiber ferrule of the illustrated embodiment includes two
bores, the multifiber ferrule can include any number of bores
depending upon the number of optical field fibers upon which the
fiber optic connector is to be mounted. The optical fiber stubs are
preferably secured within the multifiber ferrule and, more
particularly, within respective bores defined by the ferrule by
means of an epoxy or other adhesive.
Once the optical fiber stubs have been secured within the
multifiber ferrule 12, the front face of the multifiber ferrule,
including the end portions of the optical fiber stubs that are
exposed via the bores opening through the front face of the
ferrule, is precision polished. Although the multifiber connector
10 is particularly well-suited for field installation, the optical
fiber stubs are preferably secured within the multifiber ferrule
and the front face of the multifiber ferrule are preferably
polished in the factory. The optical fiber stubs also preferably
extend rearwardly beyond the rear face of the multifiber ferrule.
In this regard, the ends of the optical fiber stubs that extend
rearwardly beyond the rear face of the multifiber ferrule have
typically been precision cleaved in order to facilitate subsequent
splicing to respective optical field fibers.
The multifiber connector 10 also generally includes a sleeve 22,
typically termed a ferrule holder, defining a lengthwise extending
passageway for at least partially receiving the ferrule 12. For
example, the second end of the ferrule is typically secured within
one end of the passageway defined by the ferrule holder by means of
an epoxy or other adhesive or by means of ultrasonic welding or the
like. The multifiber connector also includes splice components
disposed within the ferrule holder. As described in copending U.S.
patent application Ser. No. 09/108,451, the splice components are
commonly formed of first and second splice portions or splice
halves which are urged together to securely engage end portions of
the optical fiber stubs and the optical field fibers. In this
regard, at least one of the splice components defines grooves for
receiving the end portions of the optical fiber stubs and the
optical field fibers.
Once assembled as shown in FIG. 1, the ferrule holder 22 secures
the splice components within the lengthwise extending passageway
such that the insertion of the rear end of the multifiber ferrule
12 into the passageway correspondingly inserts the end portions of
the optical fiber stubs that extend beyond the rear face of the
multifiber ferrule into respective grooves defined by the splice
components. The assembled components of the fiber optic connector
10 can then be inserted into a housing 30. In addition, the fiber
optic connector can include a spring 32 and an annular spring push
member 34 that are mounted upon the ferrule holder and that engage
the housing in order to resiliently bias the ferrule forwardly in a
longitudinal direction relative to the housing. In order to
fabricate a male connector, the fiber optic connector may also
include a pin keeper 16 that retains a pair of guide pins 18.
During assembly, the forward end of the ferrule can be extended
through an opening defined by the pin keeper prior to inserting the
ferrule and the ferrule holder into the housing. As such, the guide
pins are positioned in respective guide pin passageways 14 defined
by the ferrule and extend beyond the front face of the housing.
Once in the field, the end portions of the optical field fibers can
also be inserted into respective grooves from the opposite end of
the splice components so as to be aligned with and optically
connected with respective optical fibers stubs. In this regard, the
multifiber connector 10 can also include a crimp tube 24 through
which the end portions of the optical field fibers are extended
prior to insertion into respective grooves defined by the splice
components, thereby facilitating the insertion of the optical field
fibers into the respective grooves defined by the splice
components.
The ferrule holder 22 preferably defines a window (not shown) and
the splice components preferably include a keel. As such, the
splice components can be disposed within the passageway defined by
the ferrule holder such that the keel is positioned within the
window defined by the ferrule holder and is exposed through the
window for facilitating actuation of the splice components. The
multi fiber connector also includes a cam member 20 that is mounted
upon the ferrule holder. The cam member is designed to engage the
keel of the splice components that is exposed through the window
defined by the ferrule holder. In addition to engaging the exposed
keel, the cam member is adapted to actuate the splice components,
such as by urging the first and second portions of the splice
components toward one another as the cam member is rotated relative
to the ferrule holder from a first unactuated position to a second
actuated position. Upon actuation of the splice components, the end
portions of the optical fiber stubs and the optical field fibers
are mechanically coupled or spliced. Further details regarding the
manner in which the cam member actuates the splice components are
provided by U.S. patent application Ser. No. 09/108,451, the
contents of which have been incorporated herein by reference.
Once the splice components have been actuated and the continuity of
the optical fiber stubs and the optical field fibers has been
validated as described below, the crimp tube 24 can be crimped
about the optical field fibers and the remainder of the components
of the fiber optic connector 10 can be assembled. For example, the
fiber optic connector can include an annular crimp band 26 that is
mounted over the crimp tube and upon the end portion of the ferrule
holder 22 proximate the cam member 20. The crimp band can also be
crimped inwardly in order to engage strength members associated
with the optical field fibers that are positioned between the crimp
band and the ferrule holder. A boot 36 that has that been
previously mounted upon the optical field fibers can also be
inserted into the rear end of the housing 30 so as to provide
strain relief for the optical field fibers.
The method for validating the continuity of the optical field
fibers and the optical fiber stubs according to the present
invention is particularly advantageous for applications in which
the fiber optic connector 10 is mounted upon the optical field
fibers in the field. As such, an installation tool 40 is provided
according to one embodiment of the present invention to facilitate
mounting of the fiber optic connector upon the end portions of the
optical field fibers. In this regard, FIGS. 2 and 3 depict an
exploded perspective view and an assembled perspective view,
respectively, of an installation tool. The installation tool
typically includes a base 42. Mounted to the base, typically by
means of set screws 44, are a fiber holder 46 for holding the
optical field fibers, an anvil 48 for facilitating the crimping of
crimp tube 24 during assembly of the fiber optic connector, and a
tool housing 50. The installation tool also includes a wrench 52
mounted to the tool housing for engaging the cam member 20 of the
fiber optic connector and permitting actuation thereof. The
installation tool further includes an adapter 54 that is mounted
within the tool housing and a bias member 57 that is also mounted
within the tool housing for securing the adapter in position
therewithin.
As shown in FIGS. 5a and 5b, the adapter 54 has opposed first and
second ends 56, 58 and defines a shoulder 60 therebetween. The
first end of the adapter is designed to engage the fiber optic
connector 10 that is being mounted upon the end portions of the
optical field fibers. In embodiments in which an MT-RJ UNICAM
connector is to be mounted upon the end portions of the optical
field fibers, the first end of the adapter is designed to engage
the housing 30 of the MT-RJ UNICAM connector, such as by being
sized and shaped to receive the housing of the MT-RJ UNICAM
connector and defining windows for receiving and engaging
corresponding tabs that extend outwardly from the housing.
According to the present invention, the installation tool 40
includes first and second adapters 54 that can be alternately
mounted within the tool housing 50 to configure the installation
tool to have first and second configurations, respectively. As
shown in FIG. 5a, the second end 58 of the first adapter is also
sized and shaped to engage another fiber optic connector, typically
of the same type engaged by the first end 56 of the adapter. As
will be described below, the fiber optic connector engaged by the
second end of the first adapter is mounted upon the end portion of
an optical fiber that serves to deliver light for testing the
continuity of the optical fiber stubs and the optical field fibers.
Even though the first and second ends of the first adapter are both
typically designed to engage the same type of fiber optic
connectors, the first and second ends of the first adapter are
preferably sized differently so as to thereby define a shoulder 60
that can be engaged by the bias member 57. In contrast to the first
adapter, the second adapter is of a more conventional design and
has a closed second end that functions as a dust cap. Since the
second end of the second adapter is not designed to engage another
fiber optic connector, the second adapter is generally smaller than
the first adapter.
By providing two different adapters 54, the installation tool 40 of
the present invention can be differently configured depending upon
its application. For example, the first adapter can be mounted
within the tool housing 50 in order to facilitate continuity
testing of the optical fiber stubs and the optical field fibers
while the fiber optic connector 10 is mounted within the
installation tool as will be described in more detail hereinafter.
By mounting the second adapter within the tool housing, however,
the installation tool of the present invention can operate in a
more conventional manner by facilitating the mounting of the fiber
optic connector upon the end portions of the optical field fibers
without permitting continuity testing of the optical fiber stubs
and the optical field fibers. Also, as described below, the second
adapter could be used if the light source is attached to the
optical field fibers rather than the optical fiber stubs.
Since the first and second adapters 54 are generally of different
sizes, the installation tool 40 of the present invention also
generally provides first and second bias members 57 adapted to
engage the first and second adapters, respectively. In this regard,
each bias member generally has a U-shape and defines a channel 67
through which the respective adapter extends. In this regard, the
channel defined by the first bias member is preferably larger than
the channel defined by the second bias member since the first
adapter is also generally larger than the second adapter.
Each bias member 57 includes a slide member 62 capable of being
mounted within the tool housing 50 and a biasing element 64 for
urging the respective slide member into engagement with the
shoulder 60 defined by the respective adapter 54. As shown in FIGS.
2, 5a and 5b, each slide member typically includes an engagement
portion 66 disposed within the tool housing for engaging the
shoulder of the respective adapter. In this regard, the engagement
portion is generally U-shaped and defines the channel through which
the second end 58 of the respective adapter extends. Each slide
member also includes a base portion 68 disposed on the opposite
side of the tool housing from the engagement portion. In this
regard, the base portion is typically disposed between the tool
housing and the base 42. In addition, each slide member includes a
removable connector 70 interconnecting the engagement portion and
the base portion. As depicted in FIG. 2, the tool housing
preferably defines a lengthwise extending slot 72. As such, the
removable connector can extend through the slot defined by the tool
30 housing in order to connect the engagement portion and the base
portion and can ride within the slot as the slide member moves
lengthwise relative to the tool housing.
The biasing element 64, such as a spring, typically engages the
base portion 68 of each slide member 62 so as to bias or urge the
slide member in a predetermined direction, such as to the right in
FIG. 4. Thus, the adapter 54 can be secured in position between an
upstanding portion of the tool housing and the slide member. For
example, the slide member depicted in FIG. 4 can be moved to the
left by a technician and an adapter inserted between the slide
member and an upstanding portion of the tool housing. Once the
slide member is released by the technician, the biasing clement
urges the slide member to the right and into contact with the
shoulder 60 of the adapter, thereby securing the adapter and
connector housing 30 against the upstanding portion of the tool
housing.
By utilizing a common base portion 68 and a common biasing element
64, the installation tool 40 can be readily converted between the
first and second configurations without substantially disassembling
the installation tool. In order to change from the first
configuration of the installation tool to the second configuration,
the first adapter 54 is removed from the installation tool and the
removable connector 70 is removed in order to disconnect the
engagement portion 66 and the base portion 68. The engagement
portion of the first bias member 57 is then replaced with the
engagement portion of the second bias member and the removable
connector is reinserted. Thereafter, the second adapter is inserted
into the tool housing 50 to complete the reconfiguration process.
By reversing these steps, the installation tool can also be easily
converted from the second configuration to the first configuration,
if so desired. Accordingly, the installation tool need not be
disassembled, such as by removing the tool housing or any other
component from the base 42, in order to be reconfigured. Thus, the
same installation tool can function as a conventional installation
tool in the second configuration in which a dust cover is mounted
to the fiber optic connector 10 that is being mounted upon the end
portions of the optical field fibers and which does not support
continuity testing while the fiber optic connector is mounted
within the installation tool, as well as a modified installation
tool in the first configuration which permits continuity testing to
be performed while the fiber optic connector is mounted within the
installation tool, as described in more detail below.
In order to test the continuity of the optical field fibers and the
optical fiber stubs during the process of mounting a fiber optic
connector 10, such as a MT-RJ UNICAM.RTM. connector, upon the end
portions of the optical field fibers, at least portions of the
fiber optic connector are initially mounted within the installation
tool 40 that is assembled to have the first configuration. See
block 80 of FIG. 6. In this regard, the fiber optic connector with
the exception of the crimp band 26 and the boot 36 are assembled
and the forward end of the housing 30 is inserted into the first
end 56 of the adapter 54 for engagement therewith. While the crimp
band and the boot are not assembled to the remainder of the fiber
optic connector, the crimp band and the boot are mounted upon the
optical field fibers prior to inserting the optical field fibers
into the fiber optic connector. In addition to the engagement of
the housing within the first end of the first adapter, the wrench
52 of the installation tool engages the cam member 20 of the fiber
optic connector that has previously been mounted upon the ferrule
holder 22.
In order to test the continuity of the optical fiber stubs and the
optical field fibers, a light source is provided, such as a diode
laser, for producing light signals having predetermined
characteristics, such as a predetermined intensity and/or
wavelength. The light produced by the light source is introduced
into at least one of each pair of the optical fiber stubs and the
optical field fibers. See block 82. As described hereinafter, the
light is typically introduced into the optical fiber stubs. For
example, in the illustrated embodiment in which a multifiber
connector 10 is to be mounted upon a pair of optical field fibers,
light is introduced into each of the two optical fiber stubs. While
the light source can include a separate source for providing the
light that is introduced into each optical fiber stub, a single
light source is typically utilized with the light generated thereby
being split prior to its introduction into the respective optical
fiber stubs.
The light produced by the light source is typically delivered to
the optical fiber stubs by means of one or more optical fiber
jumpers upon which a fiber optic connector is mounted. Although not
necessary, the fiber optic connector that is mounted upon the
optical fiber jumpers from the light source is typically of the
same type as the fiber optic connector 10 to be mounted upon the
optical field fibers, such as an MT-RJ UNICAM.RTM. connector. The
fiber optic connector associated with the optical fiber jumpers can
therefore be inserted into the second end 58 of the adapter 54,
i.e., the first adapter, such that light generated by the light
source is introduced into each optical fiber stub of the fiber
optic connector to be mounted to the optical field fibers.
Alternatively, the light source could be introduced from the
opposite end of the optical field fibers, rather than from the
connector end. In this manner, the light would emanate from the
ends of the optical field fibers rather than the optical fiber
stubs. With the light emanating from the optical field fibers,
either of the adapters 54 could be used.
While the light source is introducing light into the optical fiber
stubs, the optical field fibers are inserted into the rear end of
the fiber optic connector 10 and advanced therethrough until
contact is established with the respective optical fiber stubs. See
block 84. In the embodiment in which an MT-RJ UNICAM.RTM. connector
is to be mounted upon a plurality of optical field fibers, the end
portions of the optical field fibers are inserted through the crimp
tube 24 and into respective grooves defined by the splice
components. While the end portions of the optical field fibers are
spaced apart from the optical fiber stubs, the light introduced
into the optical fiber stubs generates a glow that emanates from
the end portions of the optical fiber stubs within the splice
components. Once the optical field fibers have made optical contact
with the respective optical fiber stubs, either through direct
physical contact or via index matching gel that is also disposed
within the grooves defined by the splice components, the glow will
dissipate since the light will be transmitted from the optical
fiber stubs to respective optical field fibers. As such, the glow
emanating from the end portions of the optical fiber stubs is
preferably monitored as the optical field fibers are advanced into
the fiber optic connector since the glow provides an indication of
optical continuity. In order to permit the glow to be monitored, at
least one of the cam mechanism and the splice components of the
multifiber connector is translucent. Although one or all components
could be translucent, the multifiber connector of one advantageous
embodiment includes a cam member 20, a ferrule holder 22 and splice
components that are each translucent to permit the technician to
monitor the glow emanating from the end portions of each optical
fiber stub.
Once the optical field fibers appear to have made optical contact
with the respective optical fiber stubs as indicated by the
dissipation of the glow associated with each optical fiber stub,
the optical field fibers are no longer advanced and the cam
mechanism is actuated to secure the optical field fibers in
position relative to the optical fiber stubs. See blocks 86 and 88.
In the embodiment in which an MT-RJ UNICAM connector 10 is mounted
upon the end portions of a plurality of optical field fibers, the
cam mechanism is actuated by rotating the cam member 20 relative to
the ferrule holder 22 which, in turn, actuates the splice
components and forces the splice components together. In order to
facilitate the rotation of the cam member relative to the ferrule
holder, the outwardly extending handle of the wrench 52 can be
grasped by the technician and moved so as to rotate the cam member
relative to the ferrule holder.
Once the cam mechanism has been actuated to secure the optical
field fibers in position relative to the optical fiber stubs, the
fiber optic connector 10 is evaluated to determine if the glow that
previously emanated from the optical fiber stubs completely
disappears, thereby indicating that the optical field fibers and
the optical fiber stubs are continuous. See block 90. If the glow
has not been extinguished and the continuity is therefore
unacceptable, the cam mechanism is deactuated. See block 92. For
example, the cam member 20 of an MT-RJ UNICAM.RTM. connector can be
rotated relative to the ferrule holder 22 in order to deactuate the
splice components by returning the wrench 52 to its original
position. Thereafter, the optical field fibers can be repositioned
relative to the optical fiber stubs. In addition to repositioning
the optical field fibers, the optical field fibers can be withdrawn
from the fiber optic connector, recleaved and cleaned prior being
reinserted into the fiber optic connector and repositioned. See
block 94. In this regard, the optical field fibers are generally
cleaned of any index matching gel prior to being recleaved and
thereafter recleaned with alcohol or the like.
During the repositioning of the optical field fibers, light
continues to be introduced, typically into the optical fiber stubs,
and the glow emanating from the end portions of the optical fiber
stubs is again monitored to determine when continuity appears to
have been established between each of the optical field fibers and
the optical fiber stubs. Once the glow emanating from the end
portion of each optical fiber stub dissipates, the cam mechanism
can be reactuated to secure the optical field fibers in position
relative to the optical fiber stubs. The fiber optic connector 10
can then again be inspected to determine if the glow has been
completely extinguished. The repositioning and retesting of the
continuity of the optical field fibers and the optical fiber stubs
can be repeated as many times as necessary in order to obtain
acceptable continuity between each pair of optical field fibers and
optical fiber stubs.
Once the continuity of each pair of optical field fibers and
optical fiber stubs has been verified by the extinguishment of the
glow, the fiber optic connector 10 can be physically secured to the
optical field fibers. In this regard, the crimp tube 24 is
generally crimped about the optical fibers and, more commonly,
about the buffer tubes. In order to crimp the crimp tube, the
installation tool can include an arm 78 pivotally connected to the
tool housing. By rotating the arm downwardly, the crimp tube can be
compressed between the underside of the arm and the anvil 48,
thereby crimping the crimp tube radially inward about the ferrule
holder and securing the strength members therebetween. Sec block
96. Following crimping of the crimp tube, the arm is lifted and the
fiber optic connector 10 is removed from the installation tool. See
block 98. A crimp band 26 is then typically slid over the optical
field fibers and the crimp tube and about the rear end of the
ferrule holder 22 such that the strength members that extend
lengthwise along with the optical field fibers are positioned
between the crimp band and the ferrule holder. Once properly
positioned, the crimp band is crimped radially inward so as to
securely couple the strength members of the fiber optic cable and
the fiber optic connector. See block 100. The boot 36 is then slid
along the optical field fibers and inserted into the rear end of
the housing so as to provide strain relief for the optical field
fibers. See block 102.
Although the continuity of the optical field fibers and the optical
fiber stubs is confirmed by the extinguishment of the glow
emanating from the optical fiber stubs, the continuity of the
optical field fibers and the optical fiber stubs can be further
and/or alternatively evaluated by an additional test. In this
regard, the fiber optic connector 10 is removed from the
installation tool 40 after the cam mechanism has been actuated to
secure the optical field fibers and the optical fiber stubs, but
prior to crimping the crimp tube 24 about the optical fibers. The
fiber optic connector is removed from the installation tool by
disengaging the housing 30 and the adapter 54 from the slide member
62. The continuity of the optical field fibers and the optical
fiber stubs can then be evaluated in a conventional manner. For
example, a power meter, such as a JDS power meter, can be connected
to the fiber optic connector through adapter 54 (functioning as a
regular connector adapter) in order to introduce light into each
pair of optical fiber stubs and optical field fibers and to measure
attenuation of the light, typically by measuring the insertion loss
and the back reflectance. If the insertion loss is unacceptably
high or if the back reflectance is unacceptably low, it will
generally be determined that the optical fiber stubs and the
optical field fibers arc not sufficiently continuous.
Alternatively, if the insertion loss is relatively low and the back
reflectance is relatively high, the testing will confirm that
optical field fibers and the optical fiber stubs are
continuous.
In either instance, the fiber optic connector 10 is then remounted
within the installation tool 40 such as by inserting the housing 30
at least partially within the first end 56 of the first adapter 54.
If the continuity of the optical field fibers and the optical fiber
stubs is unacceptable, the cam mechanism can be deactuated and the
optical field fibers can be repositioned as described above and as
shown in blocks 92 and 94. If the continuity of the optical field
fibers and the optical fiber stubs is acceptable, however, the
crimp tube 24 is crimped about the optical fibers prior to removing
the fiber optic connector from the installation tool and completing
the assembly process as also described above and depicted in blocks
96-102.
By monitoring the continuity of the optical field fibers and the
optical fiber stubs while the optical field fibers are inserted
into the fiber optic connector 10, a technician can visually
determine when continuity appears to have been established between
each of the optical field fibers and the respective optical fiber
stubs. In addition, by permitting the continuity to be further
evaluated in the manner described above after actuating the cam
mechanism and securing the optical field fibers in position
relative to the optical fiber stubs, the continuity can be
validated and, if it is determined that continuity has not actually
been established between one or more of the optical field fibers
and their respective optical fiber stubs, the cam mechanism can be
deactuated, the optical field fibers can be repositioned, the cam
mechanism reactuated and the process repeated until continuity is
confirmed between each optical field fiber and the respective
optical fiber stub.
Only once continuity is established between each optical field
fiber and the respective optical fiber stub, as indicated by the
extinguishment of the glow emanating from the optical fiber stubs,
is the fiber optic connector 10 crimped onto the optical field
fibers as described above. As such, the method and associated
multifiber connector and installation tool 40 of the present
invention reduce the time required to mount fiber optic connectors
upon optical field fibers in the field and to test the continuity
of the resulting optical connection. In addition, the method and
the associated multifiber connector and installation tool of the
present invention reduce the number of fiber optic connectors that
must be scrapped, thereby reducing the overall costs associated
with the connectorization of optical field fibers in the field.
Many modifications and other embodiments of the invention will come
to mind to one skilled in the art to which this invention pertains
having the benefit of the teachings presented in the foregoing
descriptions and the associated drawings. Therefore, it is to be
understood that the invention is not to be limited to the specific
embodiments disclosed and that modifications and other embodiments
are intended to be included within the scope of the appended
claims. Although specific terms are employed herein, they are used
in a generic and descriptive sense only and not for purposes of
limitation.
* * * * *