Source: http://www.google.com/patents/US7052185?ie=ISO-8859-1&dq=5,890,152
Timestamp: 2014-08-20 17:28:13
Document Index: 74186607

Matched Legal Cases: ['art 72', 'art 74', 'art 74', 'art 72', 'art 72', 'art 72']

Patent US7052185 - Fiber optic cable connector with a plurality of alignment features - Google PatentsSearch Images Maps Play YouTube News Gmail Drive More »Sign in<nobr>Advanced Patent Search</nobr>PatentsA connector for joining a first fiber optic cable end and a second fiber optic end includes first and second connector ends adapted to receive the first and second fiber optic cable ends. Each connector end houses a plurality of termini for terminating the fiber optic cable ends. The connector also includes...http://www.google.com/patents/US7052185?utm_source=gb-gplus-sharePatent US7052185 - Fiber optic cable connector with a plurality of alignment featuresAdvanced Patent SearchPublication numberUS7052185 B2Publication typeGrantApplication numberUS 10/772,091Publication dateMay 30, 2006Filing dateFeb 3, 2004Priority dateJun 15, 2000Fee statusPaidAlso published asCA2412625A1, CA2412625C, DE60139315D1, EP1290480A1, EP1290480B1, US6685361, US20040247251, WO2002025340A1, WO2002025340A8Publication number10772091, 772091, US 7052185 B2, US 7052185B2, US-B2-7052185, US7052185 B2, US7052185B2InventorsRobert A. Rubino, Nabil E. Mishriky, Daniel Caisse, Peter GumprechtOriginal AssigneeWeatherford/Lamb, Inc.Export CitationBiBTeX, EndNote, RefManPatent Citations (20), Non-Patent Citations (2), Referenced by (3), Classifications (14), Legal Events (3) External Links: USPTO, USPTO Assignment, EspacenetFiber optic cable connector with a plurality of alignment featuresUS 7052185 B2Abstract A connector for joining a first fiber optic cable end and a second fiber optic end includes first and second connector ends adapted to receive the first and second fiber optic cable ends. Each connector end houses a plurality of termini for terminating the fiber optic cable ends. The connector also includes a first alignment feature and a second alignment feature. The first alignment feature includes a plurality of flanges formed on the first connector end to define a plurality of key openings and a plurality of key protrusions formed on the second connector end adapted to fit into the plurality of key openings to ensure proper alignment of the first and second connector ends. The second alignment includes a plurality of termini keys with each termini key being disposed on each of the termini and fitting into a key termini slot formed in the first and second connector ends for receiving the termini. The first and second alignment features ensure that the first connector end is properly aligned with respect to the second connector end and that each termini disposed in the first connector end is properly aligned with each termini disposed in the second connector end.
1. A connector for joining a first fiber optic cable end and a second fiber optic end of a fiber optic cable, said connector comprising:
a first connector end adapted to receive said first fiber optic cable end;
a second connector end adapted to receive said second fiber optic cable end;
a first plurality of termini disposed within said first connector end for terminating said first fiber optic cable end, wherein the first plurality of termini is unbiasly fixed within the first connector;
a second plurality of termini disposed within said second connector end for terminating said second fiber optic cable end, each termini of said first plurality of termini mating with each respective termini of said second plurality of termini;
a first alignment feature for properly aligning said first connector end with respect to said second connector end; and
a second alignment feature for properly rotationally aligning each termini of said first plurality of termini with each termini of said second plurality of termini.
2. The connector according to claim 1 further comprising a nut disposed about said first connector end and being threadably attached to said second connector end.
3. The connector according to claim 1 wherein said first alignment feature comprises:
a plurality of flanges formed on said first connector end to define a plurality of key openings; and
a plurality of key protrusions formed on said second connector end adapted to fit into said plurality of key openings to ensure proper alignment of said first and second connector ends.
4. The connector according to claim 3 wherein said plurality of key openings include a first key opening and a second key opening with said first and second key openings having different sizes and wherein said plurality of key protrusions having a first key protrusion and a second key protrusion corresponding in size to said first and second key openings, respectively.
5. The connector according to claim 1 wherein said second alignment feature comprises a plurality of termini keys with each termini key being disposed on each of said plurality of termini, each said termini key fitting into a termini keyed hole formed in said first and second connector ends for receiving said termini.
6. The connector according to claim 5 wherein said termini key is a pin inserted into a base part of each of said termini, said pin fitting into a keyed slot of said termini keyed hole.
7. The connector according to claim 1 wherein said termini includes an angled tip surface for mating with a corresponding termini, said angled tip surface being properly aligned with respect to each other when joined as a result of said second alignment feature.
8. The connector according to claim 1 wherein said connector is multi-channeled.
9. The connector according to claim 1 wherein said connector is rated to withstand temperatures ranging from approximately 0� C. to approximately 175� C.
10. The connector according to claim 1 wherein said connector is rated to withstand ambient pressures of approximately one thousand (1,000) atmospheres.
11. The connector according to claim 1 wherein said connector further comprises a back-shell welding feature to facilitate welding of each of said connector ends to protective tubing of said fiber optic cable.
12. The connector according to claim 11 wherein said back-shell welding feature comprises:
a welding opening formed within said connector end adapted to receive said protective tubing; and
a welding surface formed on one end of said connector end substantially adjacent said welding opening.
CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of U.S. patent application Ser. No. 09/594,645, filed Jun. 15, 2000 now U.S. Pat. No. 6,685,361, which is herein incorporated by reference.
The present invention relates to connectors for fiber optic cables and, more particularly, to multi-channel connectors therefor that can be used in downhole applications and withstand high temperature and pressure.
The fiber optic cable is typically housed in at least one protective tube to shield the fiber optic from the extremely harsh downhole environment. The fiber optic cable can be subjected to downhole ambient pressures of approximately one thousand (1,000) atmospheres and temperatures ranging from 0� C. to 175� C. (zero to one hundred seventy-five degrees Celsius). Additionally, the fiber optic cable is exposed to downhole corrosives such as water, sulfuric acid and others.
Besides harsh temperatures and pressures, there are a number of other requirements that must be taken into consideration for using fiber optic cable in the downhole applications. For example, packaging for fiber optic cable must be extremely compact for downhole use. Moreover, the fiber optic cable must come either in extremely long segments or be connected. For installation and assembly purposes, it is much easier to have smaller segments of fiber optic cable that connect to each other. However, the connectors for the fiber optic cable must ensure integrity of the transmitted data and information as well as withstand the harsh ambient conditions of the downhole environment.
Existing connectors are intended for the less harsh, surface environment and are typically either multi-channel or single channel. Commercially available multi-channel connectors use physical contact type pins or termini. One such termini is MIL-T-29504 which is manufactured by a number of vendors, one of which is Packard-Hughes Interconnect Corporation. However, these termini rely on the termini preload to cause the polished fiber surfaces to physically distort, thereby minimizing the glass-air interface as a strategy to improve the insertion and return loss performance of the termini. Unfortunately, prolonged exposure of the preloaded termini to temperatures in excess of the glass transition temperature of the epoxy used in bonding of the fiber to the termini will cause the fiber to push back, thereby compromising the geometric requirements for both return and insertion loss. Additionally, the connectors that would incorporate these termini do not meet temperature and pressure requirements for downhole use.
Certain single channel connectors are commercially available with angled termini to reduce the return loss of a physical contact connector. These connectors are manufactured with the end surface of the termini polished at an angle such that the Fresnel reflection at the glass-air interface of the termini is reflected at an angle that exceeds the numerical aperture of the fiber. This allows the return loss (reflected energy) of the connector to be reproducibly suppressed by more than one million times or 60 db. However, existing single-channel connectors are rated for temperatures ranging from −40� C. to 85� C., which is substantially inadequate for downhole use. Additionally, pressure rating of the single-channel angled physical contact connectors is not compatible for downhole use. Moreover, the diameter of the angled termini is at least 2.5 mm, which prohibits inclusion into multi-channel connectors that meet the dimensional requirements of the downhole environment.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a fiber optic cable connector for multi-channel use that can withstand the downhole harsh environment as well as satisfy dimensional requirements therefor.
One major advantage of the present invention is that a multi-channel connector is sufficiently compact to be used for downhole applications. Another major advantage of the present invention is that the connector can withstand high temperatures and pressures.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view of a fiber optic connector;
FIG. 3 is a cross-sectional view of the male connector end of FIG. 2 taken along line 3�3;
FIG. 6 is a cross-sectional view of the female connector end of FIG. 5 taken along line 6�6;
FIGS. 9A�B illustrate an exemplary prepared fiber end assembly and an exemplary terminated fiber assembly (TFA), respectively, for use in the fiber optic cable connector of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a fiber optic connector 10 has a male connector end 12 and a female connector end 14 for joining a first fiber optic cable end 16 and a second fiber optic cable end 18 of a fiber optic cable 19. The fiber optic connector 10 also includes a make-up nut 20. The fiber optic cable 19 is shielded by a capillary encapsulation tube 21.
As best seen in FIG. 3, each termini 24 is inserted into a keyed termini receiver hole 48 formed within the first connector end 12. The keyed termini receiver hole 48 includes a keyed slot 50, as best seen in FIG. 4. Each termini 24 is used to terminate the fiber optic cable end 16.
Referring to FIGS. 5, 6, and 7, the female connector end 14 includes a female housing 52 having an outside surface 54 and a plurality of threads 56. A plurality of female termini 58 are disposed within the female housing 52. The housing 52 includes an inside diameter 60 sized to accept the outside diameter 40 of the male housing 22. The female housing 52 also includes a first key protrusion 62 and a second key protrusion 64 adapted to be received within the first key opening 32 and the second key opening 34, respectively. The first key opening 32 and first key protrusion 62 are sized differently from the second key opening 34 and the second key protrusion 64 to ensure proper alignment between the male and female connector ends 12, 14 and, in combination, form a first alignment feature of the fiber optic connector 10. The key protrusions 62, 64 are of sufficient length to prevent engagement of the termini until proper angular alignment between the ends 12, 14 is achieved. The female housing 52 also includes a plurality of keyed termini holes 66 for accepting the plurality of female termini 58. Each termini hole 66 also includes a keyed slot 67 and has a sleeve 68 extending past the outward end of the termini 58.
Referring to FIG. 8, each termini 24, 58 has a central axis 70 and includes a base part 72 and a top part 74 with the top part 74 terminating with a tip surface 76. Each base part 72 of each termini 24, 58 includes a termini key 78. In the preferred embodiment of the present invention, the termini key 78 is a pin 80 inserted in an opening 82 formed within the base part 72 and protruding outwardly therefrom. The tip surface 76 of each termini 24, 58 is angled and forms an angle α with a line perpendicular to the axis 70 of the termini 24, 58. In the preferred embodiment of the present invention, the angle α is approximately eight degrees (8�). The angled tip surface 76 at each termini 24 is formed to mate with the corresponding termini 58 when both termini 24, 58 are properly keyed into respective connector ends 12, 14. For higher numerical aperture fiber the angle α can be increased to approximately fifteen degrees (15�).
Referring to FIGS. 1 and 3, the male and female housings 22, 52 also include a back-shell weld feature 86 that incorporates a welding surface 88 and a capillary opening 90 adapted to receive ends of the capillary encapsulation tube 21. Alternatively, the female housing 52 can include threads 91 for receiving threaded tube or other equipment that cannot be welded, as best seen in FIG. 6.
In the preferred embodiment of the present invention, the termini 24, 58 are a single channel termini, MIL-T-29504 equivalent, purchased from Packard-Hughes Interconnect Company that have a diameter of approximately two millimeters (2 mm) and have been further modified to include an approximately eight degree (8�) angle on the tip surface 76 thereof and to include the key 78 on the base part 72 thereof.
For some embodiments, the termini 24 and 58 may be prepared as part of a terminated fiber assembly (TFA), which may be pre-assembled and subsequently inserted into the ends 12 and 14, respectively, of the connector 10. Such a TFA may be assembled starting with a prepared fiber end assembly 900, such as that shown in FIG. 9A, having a length of bare fiber 904 exposed via removal of protective (e.g., teflon) coating 906. A protective tubing 904 (e.g., polyamide) may be threaded onto the bare fiber 904.
As illustrated in FIG. 9B, the fiber end assembly 900 may be inserted into a back shell 913 of a terminus 924, for example, until the protective tubing 904 contacts an inner wall 911 of the back shell 913 and a portion of the bare fiber 902 extends from an end of the terminus 924. Accordingly, the length of the bare fiber 902 and tubing 904 may depend on the dimensions of the terminus 924.
Prior to insertion, epoxy 907 (or other suitable adhesive) may be deposited into the back shell 913, for example, via a syringe or other type epoxy dispenser, to hold the bare fiber 902 in the terminus 924. A bead of epoxy 911, or other suitable type material, may be deposited at the rear of the back shell 913 to act as a strain relief. The epoxy may then be cured, for example, by heating the terminus assembly in some type of heating chamber, taking care to protect the bare fiber 902 from direct contact with a heating surface.
After the epoxy has cured and the terminus assembly has cooled, the bare fiber 902 may be cleaved (e.g., just above a bead of epoxy 909 formed at an end of the terminus 924) using any suitable cleaving means, such as a hand-held cleave tool. For some embodiments, the cleaved bare fiber 902 and terminus end 926 may be air polished (e.g., using a 12 u Al-Oxide Foam backed paper in small circular motion) until the epoxy bead 909 feels smooth to the touch.
The terminus end 926 may then be further polished by inserting the terminus assembly into a polishing puck and polishing the terminus end 926 on a polishing film deposited on a glass plate, for example, using a number of patterned motions (e.g., FIG. 8 turns) designed to ensure even polishing. In any of the aforementioned polishing operations, a light film of water may be initially sprayed onto the polishing film.
The terminus assembly may then be removed from the puck and inserted into an apparatus (e.g., another type of polishing puck) for forming an angled tip surface (e.g., similar to the angled tip surfaces 76 shown in FIG. 8). The terminus assembly may be clamped into the assembly and polished with a polishing machine using a suitable durometer pad (e.g., according to the material of the terminus 924) to ensure precise control of the polishing. The end 926 of the assembly may then be polished (or machined) with suitable pressure and duration to form the angled tip surface having the desired angle (e.g., 8� as previously described).
After the angled tip surface is formed, the light carrying properties of the terminus assembly may be tested using any suitable tests, such as white light interferometer inspection. The terminus assembly may be placed into a test fixture with white light transmitted therethrough, while comparing measured parameters to a set of expected parameters. Results of the test may be saved to file or printed and saved as quality documentation for the terminus assembly (or a batch of such assemblies).
Additional measurements, such as insertion and return loss measurements may also be taken, for example, using pin and socket termini-pairs inserted into a test fixture. The termini pairs may be inserted into the test fixture and aligned, with a proper radial force applied to bring the termini tips into physical contact. Insertion loss and/or return loss may then be measured using any suitable techniques, such as transmitting light of a known power from one end of the termini junction and detecting the power of the light received at the other end and/or detecting the power of light reflected back through the termini junction (e.g., reflected from Bragg gratings).
Any other type tests, such as temperature cycle tests may also be performed on the terminus assemblies. For example, termini pairs may be inserted into a connector or test housing and mated while subjecting the mated termini to a known temperature (e.g., 175�) for a predefined period of time (e.g., 6 hours minimum). The termini may then be re-inspected by taking any of the previously described measurements (e.g., white light interferometer, insertion and/or return loss).
While the terminated fiber assembly (TFA) of FIG. 9B is assembled by securing the fiber end assembly 900 to the terminus 924 via epoxy 907, for other embodiments, a terminus structure may be collapsed onto the fiber end assembly 900, thus eliminating or reducing the need for epoxy. One technique for collapsing a terminus structure onto a prepared fiber end assembly is described in the commonly assigned application Ser. No. 10/755,722 entitled �Low-Loss Large-Diameter Pigtail� filed Jan. 12, 2004, herein incorporated by reference in its entirety.
In any case, terminated fiber assemblies (TFAs) may be pre-assembled, tested, and later used to produce a final connector 10. By utilizing pre-assembled TFAs, a variety of different type TFAs may be produced and stocked, thus allowing for a modular connector design, in which the specific TFAs may be chosen, for example, according to a particular application. Utilizing pre-assembled TFAs may also facilitate field repair and replacement.
One major advantage of the present invention is that the fiber optic connector 10 has two alignment features that allow multiple termini connections be made while ensuring proper alignment of each of these termini connections. Another major advantage of the present invention is that this multi-channel connector can be used in downhole applications. The connector 10 of the present invention can operate for temperatures ranging approximately from 0� C. to 175� C. (zero to one hundred seventy-five degrees Celsius) and ambient pressures of approximately one thousand (1,000) atmospheres.
Patent CitationsCited PatentFiling datePublication dateApplicantTitleUS3945700Aug 6, 1974Mar 23, 1976Boston Insulated Wire & Cable Co.Connector with fluid-resistant sleeve assemblyUS4140367Apr 19, 1977Feb 20, 1979Bunker Ramo CorporationMultiple channel connector for fiber optic cablesUS4225214Sep 18, 1978Sep 30, 1980Trw Inc.Connector constructionUS4252406Sep 5, 1978Feb 24, 1981The United States Of America As Represented By The Secretary Of The ArmyConnector for optical fibersUS4759601Jun 24, 1985Jul 26, 1988Schlumberger Technology CorporationFiber optic connector assemblyUS4801191Aug 7, 1986Jan 31, 1989The Furukawa Electric Co., Ltd.Connecting section for optical fiber cableUS4802861Jun 15, 1987Feb 7, 1989Boeing Vertol CompanySelf-aligning electrical connectorUS4829407Nov 6, 1987May 9, 1989Oxley Developments Company LimitedIndicator lampsUS5018822Dec 11, 1989May 28, 1991Litton Systems, Inc.Environmentally sealed multichannel fiber optic connectorUS5064268Dec 7, 1990Nov 12, 1991The United States Of America As Represented By The Secretary Of The NavyHigh pressure fiber optic connector plugUS5067783 *Oct 16, 1990Nov 26, 1991At&T Bell LaboratoriesOptical fiber connector buildout systemUS5293581Apr 16, 1993Mar 8, 1994Alcoa Fujikura Ltd.Flexible connector assembly for fiber opticsUS5301213Jun 8, 1993Apr 5, 1994Combustion Engineering, Inc.Method of field replacement of an electrical connector for nuclear reactor instrumentationUS5384885Oct 28, 1993Jan 24, 1995At&T Corp.Variable attenuation optical fiber couplingUS5433275Jul 19, 1994Jul 18, 1995Baker Hughes IncorporatedDouble-threaded anchor tubing assemblyUS5590229Apr 22, 1994Dec 31, 1996Litton Systems, Inc.Multichannel fiber optic connectorUS5925879May 9, 1997Jul 20, 1999Cidra CorporationOil and gas well packer having fiber optic Bragg Grating sensors for downhole insitu inflation monitoringUS5928034Jul 29, 1997Jul 27, 1999Sumitomo Wiring Systems, Ltd.Connector with terminal locking and locking assurance featuresUS5997362Mar 19, 1998Dec 7, 1999Yazaki CorporationConnectorUS6234683Sep 13, 1999May 22, 2001Stratos Lightwave, Inc.Field repairable hermaphroditic connector* Cited by examinerNon-Patent CitationsReference1International Search Report for PCT/US01/15792, dated Mar. 14, 2002.2Packard-Hughes Interconnect Fiber Optic Connectors, Fiber Optic Termini, MIL-T-29504, pp. 1-9.Referenced byCiting PatentFiling datePublication dateApplicantTitleUS7572063 *Sep 12, 2005Aug 11, 2009Stratos International, Inc.Opto-electric connectorUS7634168Jul 9, 2007Dec 15, 2009Schlumberger Technology CorporationApparatus and method for forming an optical fiber deviceUS7836959Jun 25, 2007Nov 23, 2010Schlumberger Technology CorporationProviding a sensor array* Cited by examinerClassifications U.S. Classification385/58, 385/60International ClassificationG02B6/38Cooperative ClassificationG02B6/3878, G02B6/3894, G02B6/3847, G02B6/3831, G02B6/3822, G02B6/3816, G02B6/3851, G02B6/3883European ClassificationG02B6/38D10A6, G02B6/38D10C2, G02B6/38D2S5Legal EventsDateCodeEventDescriptionOct 30, 2013FPAYFee paymentYear of fee payment: 8Oct 28, 2009FPAYFee paymentYear of fee payment: 4Aug 20, 2004ASAssignmentOwner name: WEATHERFORD/LAMB, INC., TEXASFree format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:RUBINO, ROBERT A;MISHRIKY, NABIL E;CAISSE, DANIEL;AND OTHERS;REEL/FRAME:015011/0469;SIGNING DATES FROM 20040719 TO 20040729RotateOriginal ImageGoogle Home - Sitemap - USPTO Bulk Downloads - Privacy Policy - Terms of Service - About Google Patents - Send FeedbackData provided by IFI CLAIMS Patent Services©2012 Google