|Publication number||US20060269194 A1|
|Application number||US 11/139,734|
|Publication date||Nov 30, 2006|
|Filing date||May 27, 2005|
|Priority date||May 27, 2005|
|Also published as||US7150567|
|Publication number||11139734, 139734, US 2006/0269194 A1, US 2006/269194 A1, US 20060269194 A1, US 20060269194A1, US 2006269194 A1, US 2006269194A1, US-A1-20060269194, US-A1-2006269194, US2006/0269194A1, US2006/269194A1, US20060269194 A1, US20060269194A1, US2006269194 A1, US2006269194A1|
|Inventors||James Luther, Thomas Theuerkorn, Hleu Tran|
|Original Assignee||Luther James P, Thomas Theuerkorn, Tran Hleu V|
|Export Citation||BiBTeX, EndNote, RefMan|
|Referenced by (23), Classifications (11), Legal Events (3)|
|External Links: USPTO, USPTO Assignment, Espacenet|
1. Field of the Invention
The present invention relates generally to fiber optic connectors, and more specifically, to a duplex fiber optic connector having positionable ferrules that allow the ferrules to be rotated between a first keyed position for simultaneous coplanar end face polishing, and a second keyed position for mating with a receptacle, optical device or another connector of complimentary ferrule configuration with proper end face contact.
2. Technical Background
A variety of optical connectors have been developed to facilitate the interconnection of optical fibers with other optical fibers, optical devices or the like. In this regard, a number of simplex, duplex and multi-fiber connectors including standard ferrules, such as SC, LC, FC, MU, MT and MTP, have been designed. A common type of connector includes an angled-physical-contact (APC) ferrule that is designed to make physical contact with another APC ferrule during the process of interconnecting optical fibers (i.e., mating opposing fiber optic connectors). The end face of an APC ferrule is disposed at a non-orthogonal angle, i.e., at an angle other than 90-degrees relative to the longitudinal axis defined by the ferrule. Typically, the end face of an APC ferrule is disposed at about an 8-degree angle relative to a plane that extends perpendicular to the longitudinal axis defined by the ferrule. In order to interconnect a pair of APC ferrules, the ferrules are positioned such that the angled end faces are complimentary to one another, that is, the forwardmost portion of the end face of one ferrule is preferably aligned with the rearward most portion of the end face of the other ferrule. In order to facilitate the proper alignment of the ferrules in this complimentary fashion, the connectors are mated in a specific manner. In certain APC connectors, a portion of the connector assembly includes a physical key, indicator or marking that is disposed in a predetermined relationship to the end face of the ferrule and is used to orient the connector relative to a mating connector.
APC ferrules may be preferred over physical-contact (PC) ferrules, as well as ultra-physical-contact (UPC) ferrules, because the angled end face of an APC ferrule advantageously reduces undesirable reflections of optical signals at the interface between the mating optical fibers, thereby decreasing losses and correspondingly increasing signal transmission. Conventional APC ferrules typically require that the amount of material removed from the ferrule to define the angled end face be precisely controlled so as to form the proper angled surface. In this regard, the removal of either too much or too little material during the process of polishing the end faces typically results in a misalignment of mating ferrules, which decreases signal transmission.
In conventional, industry standard LC or SC APC duplex connectors, the two ferrules are typically aligned parallel (side-by-side) such that the two end faces are not coplanar. This orientation is needed in order to mate the duplex connector with an industry standard connector having the same complimentary orientation. By aligning the ferrules side-by-side, with the ferrule end faces in different planes, it is not possible to simultaneously polish the two ferrule end faces in the same plane using conventional apparatus and processes. When assembling a hardened duplex fiber optic connector using conventional LC or SC APC ferrules, the design of the hardened connector does not allow the ferrules to be separated and their end faces oriented into the same plane for simultaneous polishing. By polishing the end faces individually, one end face may be polished differently than the other, thus resulting in connector-to-connector mating with improper end face contact and resulting signal loss. Accordingly, what is needed is a duplex hardened connector that allows the ferrules and their respective end faces to be aligned relative to one another for coplanar polishing, and thereafter moved to a mating position.
In particular, a new approach is needed for a hardened duplex fiber optic connector that allows the ferrules to be rotated such that the end faces may be positioned in the same plane for simultaneous coplanar polishing. Thus, a multi-position ferrule or ferrule holder is needed that allows each ferrule to be rotated between a first position in which the end faces of the ferrules are coplanar for polishing, and a second position that properly aligns the end faces for connector-to-connector mating with a corresponding duplex connector of like ferrule configuration. The first keyed ferrule position preferably allows both ferrule end faces to be polished at the same time using conventional apparatus and processes. Once the polish is complete, the ferrules are rotated to the second keyed position for connector mating.
One aspect of the invention is a duplex fiber optic connector including a first single fiber ferrule and a second single fiber ferrule arranged side-by-side, wherein the first and the second single fiber ferrules may be independently rotated between a first keyed position and a second keyed position. The first keyed position properly aligns the end face of the first ferrule and the end face of the second ferrule substantially in the same plane for simultaneous coplanar end face polishing using conventional polishing apparatus and processes. The second keyed position properly aligns the end face of the first ferrule and the end face of the second ferrule for mating with a receptacle, connector or optical device of like ferrule type in which the end faces of the ferrules are not coplanar. The second keyed position may also be used to align the end face of the first ferrule and the end face of the second ferrule with a connector of like ferrule configuration and with proper end face contact.
In another aspect, the present invention provides a fiber optic connector in which each ferrule holder may be rotated between a first keyed position for end face polishing, and a second keyed position for mating with a receptacle, optical device or another connector of like ferrule type with proper end face contact. The keyed ferrule holder design may be used with any known simplex, duplex or multi-fiber connector in which it is desired to independently position or rotate each ferrule of the connector. The first keyed position may be used to arrange the end faces of the ferrules in a common plane for simultaneous end face polishing. Polishing may be performed using conventional polishing apparatus and processes. The second keyed position may be used to independently arrange the alignment of the end face of each ferrule in order to properly mate the connector with a receptacle, optical device or another connector having a predetermined ferrule arrangement, such as an industry standard connector of like ferrule type.
In yet another aspect, the present invention provides a fiber optic connector assembly including one or more keyed ferrule holders that may be rotated between a first keyed position for end face polishing and a second keyed position for mating with a receptacle, optical device or another connector. In one particular embodiment, the fiber optic connector is a duplex connector including a first APC ferrule and a second APC ferrule. In an exemplary embodiment, the duplex connector includes a plug housing defining an internal cavity opening through opposed first and second ends, a section of heat shrinkable tubing, a flexible boot, a coupling nut, a protective/pulling cap assembly, a crimp body, a crimp band, an connector inner housing, an connector outer housing and one or more ferrules having a keyed ferrule holder. In a specific embodiment, the ferrules are APC ferrules. In a further embodiment, the connector assembly includes a biasing member that operably engages and biases the respective ferrule toward the mating ferrule during connector mating. To mate the fiber optic connector with a like fiber optic connector or a receptacle including a like ferrule arrangement, the externally threaded coupling nut of the connector assembly is received, for example, within an internally threaded receptacle, an internally threaded coupling nut of another connector or an internally threaded alignment sleeve.
In yet another aspect, the present invention provides a fiber optic connector assembly including one or more keyed ferrule holders that may be rotated between a first keyed position for end face polishing and a second keyed position for mating with a receptacle, device or other connector. In one particular embodiment, the fiber optic connector is a duplex connector including a first APC ferrule and a second APC ferrule. The duplex connector includes a connector housing defining an internal cavity opening through opposed first and second ends, a section of heat shrinkable tubing, a flexible boot, a coupling nut, a protective/pulling cap assembly, a crimp body, a crimp band, an connector inner housing, an connector outer housing, one or more ferrules having a keyed ferrule holder, and a biasing member that operably engages a respective ferrule. The mating position of the ferrules may be reconfigured for polishing by pushing the ferrule inwards, clearing a key and rotating the ferrule holder to an alternate key slot position. In a particular embodiment in which the ferrule is an APC ferrule, the first and second key slots may be located about 90-degrees apart.
Additional features and advantages of the invention will be set forth in the following detailed description, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein, including the accompanying drawings and the appended claims.
It is to be understood that both the foregoing general description and the following detailed description present exemplary embodiments of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, and are incorporated into and constitute a part of this specification. The drawings illustrate various embodiments of the invention, and together with the detailed description, serve to explain the principles and operations thereof.
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Whenever possible, the same reference numerals will be used throughout the drawings to refer to the same or like parts. An exemplary embodiment of a duplex fiber optic connector according to the invention is shown in
Referring now specifically to the accompanying drawings,
Referring specifically to
The duplex fiber optic connector 20 is shown with the combination protective dust/pulling cap 30 removed. The protective dust/pulling cap 30 is secured to a portion of the connector 20 by a flexible lanyard 32. A threaded coupling nut 34 on the connector 20 may be operable for securing the connector 20 to a receptacle (not shown), optical device (not shown) or another connector (not shown) upon engagement and may also be used to secure the dust/pulling cap 30 on the connector 20 during shipping and deployment of the duplex cable 36. The coupling nut 34 may be replaced with a bayonet or push-pull mechanism to secure the connector 20 within the receptacle, optical device or another connector. Alternatively, a spring clip or similar device may be added to engage the connector 20 with the receptacle, optical device or another connector to secure them together. Sealing may be removed or relaxed based upon the extent of the adverse environment to which the connector assembly is exposed. Although not shown, the dust/pulling cap 30 may define a pulling loop at its forward end. In preferred embodiments, the pulling loop should be able to withstand cable-pulling forces up to about 600 lbs. The fiber optic connector 20 and dust/pulling cap 30 provide a fully sealed design that prevents moisture and contamination from reaching the ferrule end faces 26, 28. In all embodiments, elastic seals, grommets or O-rings may be used to provide static seals, and their position combined with relief features to minimize vacuum build-up during unplugging the connector or pressure build-up when mating the plug with a receptacle, optical device or another connector. Generally speaking, most of the components of the connector 20 are formed from a suitable polymer. Preferably, the polymer is a UV stabilized polymer such as ULTEM 2210 available from GE Plastics. However, other suitable materials may also be used. For example, stainless steel or any other suitable metal may be used for various components without departing from the spirit of the invention.
In the embodiments shown and described herein, different types of fiber optic cables may function as the connector cable, also referred to herein as the “drop cable”, such as, but not limited to, monotube, loose tube, central tube, ribbon, flat dielectric and the like. However, in the exemplary embodiments shown, the drop cable is a duplex cable 36 and comprises a cable jacket 38 with a strength component and an optical transmission component disposed within the cable jacket. In one embodiment, the strength component comprises two glass-reinforced plastic (GRP) strength components (indicated at reference numeral 40 in
At the end of the connector 20 opposite the dust/pulling cap 30, a pre-formed, elastomeric boot 44 covers the rear of the connector 20 and generally inhibits kinking while providing bending strain relief to the cable 36 near the connector 20. Disposed immediately underneath the elastomeric boot 44 is a section of heat shrinkable tubing 46 that is secured over a portion of the cable 36 and a portion of a plug housing 48. The heat shrinkable tubing 46 protects the rear of the connector 20 from the environment and provides a sealing function. The boot 44 may be pre-manufactured (e.g., molded) and assembled onto cable 36, or may be overmolded using a technology available from Corning Cable Systems LLC of Hickory, N.C. Further, the heat shrinkable tubing 46 may be used to fulfill the same purpose as the boot 44 when aesthetics are less important and bend characteristics less stringent.
The plug housing 48 defines an internal cavity opening through opposed first 50 and second 52 ends. The plug housing 48 generally protects the ferrules 22, 24 and in preferred embodiments also aligns and keys engagement of the connector 20 with the mating receptacle, alignment sleeve, optical device or another connector. In the embodiment shown, the first end 50 of the plug housing 48 defines alignment and keying features 54 that permit mating in only one orientation and also provide access to the end faces of the ferrules 22, 24 from the sides of the connector 20. In preferred embodiments, this orientation may be marked on the features 54 using alignment indicia so that a less skilled field technician can readily mate the connector 20 with the receptacle, alignment sleeve, optical device or other connector. Any suitable indicia may be used. After alignment, the field technician engages the coupling nut 34 to secure the connector 20 to the mating component. The plug housing 48 may further define a shoulder 56 that serves as a mechanical stop for a conventional elastomeric O-ring (not shown), as well as the coupling nut 34. The O-ring provides an environmental seal when the coupling nut 34 engages the mating component. Preferably, the coupling nut 34 has an interior passageway sized to loosely fit over the second end 52 of the plug housing 48 so that the coupling nut 34 rotates without any significant resistance about the plug housing 48.
Referring now to
Referring now to
As is well known to one of ordinary skill in the relevant art, the two optical fibers 74 of the duplex cable 36 terminate within longitudinally extending optical fiber bores of the two single fiber ferrules 22, 24. The connector outer housings 62, 64 are not secured by the crimp body 58, but are free to be pulled away from the crimp body 58, rotated to the desired, keyed position and pushed back into place against the crimp body 58. The connector inner housings 76 are received within recesses 78 defined by the crimp body halves 58 and are held between the two halves. The ferrules 22, 24 are rotated between their first and second keyed positions by pulling the connector outer housings 62, 64 out away from the crimp body 58 sufficiently to clear the corresponding connector inner housing 76, and rotating the outer housings to either their first or second keyed position. Once positioned, the connector outer housings 62, 64 are then pressed back in towards the crimp body 58 and the key slot 66 formed in the connector outer housing receives the key defined by the connector inner housing 76. As shown, the first and second keyed positions are separated by and are achieved by rotating the connector outer housings 62, 64 about 90-degrees in either the clockwise or counter-clockwise direction. Movement of the outer housings 62, 64 relative to the crimp body 58 is represented by reference numbers 80 and 82 in
The connector outer housings 62, 64 define key slots 66 on two adjacent sides. The underlying connector inner housings 76 define a key (not shown) that is received within the key slot 66 of the connector outer housings 62, 64. As shown in
Referring specifically to
In further embodiments, the entire connector housing assembly, any component thereof or the one or more ferrules themselves may be rotated between a first keyed position for end face polishing and a second keyed position for mating with a receptacle, optical device or another connector. Thus, designs for several types of connectors having rotatable ferrule assemblies may be derived from the basic design shown and described herein. In all embodiments, the polishing position aligns the end faces of the one or more ferrules in a coplanar configuration for simultaneous polishing, and the mating configuration aligns the end faces of the ferrules for interconnection with other optical fibers, such as for extending an all optical communications network to a subscriber premises, such as a residence or business. Ferrule holders having specific key slot shapes and connector components having specific key shapes may be created for each type of ferrule. While certain generic connector components may be used for all ferrule types, crimp bodies and connector housing components may have specific shapes to accommodate specific ferrules and cable types.
The embodiments described above provide advantages over conventional connector assemblies. In contrast to conventional hardened duplex fiber optic connectors that do not provide the ability to move the ferrules, the connectors of the present invention allow the ferrules to be independently positioned, thus allowing simultaneous polishing using conventional apparatus and processes. In addition, the keyed ferrule holders described herein do not increase the overall package size of the connector, thus allowing the connectors to be interconnected with conventional receptacles. Further, the keying features of these connectors makes them fully APC capable.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
|Citing Patent||Filing date||Publication date||Applicant||Title|
|US7641398 *||Mar 14, 2008||Jan 5, 2010||O'riorden Stephen||Single boot for duplex fiber optic connectors|
|US8267596||Aug 23, 2010||Sep 18, 2012||Corning Cable Systems Llc||Fiber optic cable assemblies with fiber access apertures and methods of assembly|
|US8285096||Sep 30, 2008||Oct 9, 2012||Corning Cable Systems Llc||Fiber optic cable assemblies and securing methods|
|US8376629 *||May 20, 2011||Feb 19, 2013||Corning Cable Systems Llc||Fiber optic connector assembly employing fiber movement support and method of assembly|
|US8408815||Dec 11, 2009||Apr 2, 2013||Senko Advanced Components, Inc.||Optical fiber connector and adapter|
|US8465317||Nov 1, 2011||Jun 18, 2013||Senko Advanced Components, Inc.||Latching connector with remote release|
|US8523455 *||Aug 3, 2009||Sep 3, 2013||Corning Cable Systems Llc||Ruggedized fiber optic connector assembly|
|US8724943 *||Dec 13, 2011||May 13, 2014||Electronics And Telecommunications Research Institute||Angled physical contact receptacle stub and angled physical contact transmitter optical sub-assembly having the same|
|US8974124||Aug 16, 2012||Mar 10, 2015||Senko Advanced Components, Inc.||Fiber optic connector|
|US9020320||Jan 22, 2013||Apr 28, 2015||Corning Cable Systems Llc||High density and bandwidth fiber optic apparatuses and related equipment and methods|
|US9038832||Nov 29, 2012||May 26, 2015||Corning Cable Systems Llc||Adapter panel support assembly|
|US9042702||Sep 18, 2012||May 26, 2015||Corning Cable Systems Llc||Platforms and systems for fiber optic cable attachment|
|US9059578||Feb 18, 2010||Jun 16, 2015||Ccs Technology, Inc.||Holding device for a cable or an assembly for use with a cable|
|US9075216||Nov 5, 2010||Jul 7, 2015||Corning Cable Systems Llc||Fiber optic housings configured to accommodate fiber optic modules/cassettes and fiber optic panels, and related components and methods|
|US9075217||Nov 23, 2010||Jul 7, 2015||Corning Cable Systems Llc||Apparatuses and related components and methods for expanding capacity of fiber optic housings|
|US20090310916 *||Dec 17, 2009||Luther James P||Ruggedized Fiber Optic Connector Assembly|
|US20110217008 *||Sep 8, 2011||Corning Cable Systems Llc||Fiber optic connector assembly employing fiber movement support and method of assembly|
|US20120106906 *||Jun 9, 2011||May 3, 2012||Sumitomo Electric Industries, Ltd.||Stranded optical cable with connectors|
|US20120148191 *||Dec 13, 2011||Jun 14, 2012||Electronics And Telecommunications Research Institute||Angled physical contact receptable stub and angled physical contact transmitter optical sub-assembly having the same|
|CN102177453B||Sep 30, 2009||Jul 2, 2014||康宁光缆系统有限责任公司||Fiber optic cable assemblies and securing methods|
|WO2010039830A2 *||Sep 30, 2009||Apr 8, 2010||Corning Cable Systems Llc||Fiber optic cable assemblies and securing methods|
|WO2012027309A2 *||Aug 23, 2011||Mar 1, 2012||Corning Cable Systems Llc||Fiber optic cable assemblies with fiber access apertures and methods of assembly|
|WO2012058185A1 *||Oct 25, 2011||May 3, 2012||Corning Cable Systems Llc||Fiber optic connector employing optical fiber guide member|
|U.S. Classification||385/78, 385/85|
|Cooperative Classification||G02B6/3849, G02B6/3851, G02B6/3863, G02B6/3871, G02B6/3878, G02B6/3822|
|European Classification||G02B6/38D6P, G02B6/38D6K|
|May 27, 2005||AS||Assignment|
Owner name: CORNING CABLE SYSTEM LLC, NORTH CAROLINA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:LUTHER, JAMES P.;THEUERKORN, THOMAS;TRAN, HIEU V.;REEL/FRAME:016620/0437
Effective date: 20050527
|Jun 7, 2010||FPAY||Fee payment|
Year of fee payment: 4
|May 27, 2014||FPAY||Fee payment|
Year of fee payment: 8