GB1565038A - Creation of Inventions and Patents with Artificial Intelligence

GB1565038A – Single optical fibre connector
– Google Patents

GB1565038A – Single optical fibre connector
– Google Patents
Single optical fibre connector

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Publication number
GB1565038A

GB1565038A
GB9976/78A
GB997678A
GB1565038A
GB 1565038 A
GB1565038 A
GB 1565038A
GB 9976/78 A
GB9976/78 A
GB 9976/78A
GB 997678 A
GB997678 A
GB 997678A
GB 1565038 A
GB1565038 A
GB 1565038A
Authority
GB
United Kingdom
Prior art keywords
spheres
optical fiber
single optical
termination
recess
Prior art date
1977-03-23
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)

Expired

Application number
GB9976/78A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)

TDK Micronas GmbH

ITT Inc

Original Assignee
Deutsche ITT Industries GmbH
ITT Industries Inc
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1977-03-23
Filing date
1978-03-14
Publication date
1980-04-16

1978-03-14
Application filed by Deutsche ITT Industries GmbH, ITT Industries Inc
filed
Critical
Deutsche ITT Industries GmbH

1980-04-16
Publication of GB1565038A
publication
Critical
patent/GB1565038A/en

Status
Expired
legal-status
Critical
Current

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Classifications

G—PHYSICS

G02—OPTICS

G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

G02B6/24—Coupling light guides

G02B6/36—Mechanical coupling means

G02B6/38—Mechanical coupling means having fibre to fibre mating means

G02B6/3807—Dismountable connectors, i.e. comprising plugs

G02B6/3833—Details of mounting fibres in ferrules; Assembly methods; Manufacture

G02B6/3834—Means for centering or aligning the light guide within the ferrule

G02B6/3841—Means for centering or aligning the light guide within the ferrule using rods, balls for light guides

G—PHYSICS

G02—OPTICS

G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

G02B6/24—Coupling light guides

G02B6/36—Mechanical coupling means

G02B6/38—Mechanical coupling means having fibre to fibre mating means

G02B6/3807—Dismountable connectors, i.e. comprising plugs

G02B6/3873—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls

G02B6/3874—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls using tubes, sleeves to align ferrules

G—PHYSICS

G02—OPTICS

G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

G02B6/24—Coupling light guides

G02B6/36—Mechanical coupling means

G02B6/38—Mechanical coupling means having fibre to fibre mating means

G02B6/3807—Dismountable connectors, i.e. comprising plugs

G02B6/3873—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls

G02B6/3874—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls using tubes, sleeves to align ferrules

G02B6/3878—Connectors using guide surfaces for aligning ferrule ends, e.g. tubes, sleeves, V-grooves, rods, pins, balls using tubes, sleeves to align ferrules comprising a plurality of ferrules, branching and break-out means

G—PHYSICS

G02—OPTICS

G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS

G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

G02B6/24—Coupling light guides

G02B6/36—Mechanical coupling means

G02B6/38—Mechanical coupling means having fibre to fibre mating means

G02B6/3807—Dismountable connectors, i.e. comprising plugs

G02B6/381—Dismountable connectors, i.e. comprising plugs of the ferrule type, e.g. fibre ends embedded in ferrules, connecting a pair of fibres

G02B6/3818—Dismountable connectors, i.e. comprising plugs of the ferrule type, e.g. fibre ends embedded in ferrules, connecting a pair of fibres of a low-reflection-loss type

G02B6/3821—Dismountable connectors, i.e. comprising plugs of the ferrule type, e.g. fibre ends embedded in ferrules, connecting a pair of fibres of a low-reflection-loss type with axial spring biasing or loading means

Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC

Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Y10T29/00—Metal working

Y10T29/49—Method of mechanical manufacture

Y10T29/49826—Assembling or joining

Y10T29/49895—Associating parts by use of aligning means [e.g., use of a drift pin or a “fixture”]

Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC

Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Y10T403/00—Joints and connections

Y10T403/16—Joints and connections with adjunctive protector, broken parts retainer, repair, assembly or disassembly feature

Y10T403/1616—Position or guide means

Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC

Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

Y10T403/00—Joints and connections

Y10T403/16—Joints and connections with adjunctive protector, broken parts retainer, repair, assembly or disassembly feature

Y10T403/1616—Position or guide means

Y10T403/1624—Related to joint component

Description

PATENT SPECIFICATION ( 11) 1 565 038
X ( 21) Application No 9976/78 ( 22) Filed 14 Mar 1978 ( 19) er ( 31) Convention Application No 780259 ( 32) Filed 23 Mar 1977 in ( 33) United States of America (US) ( 44) Complete Specification Published 16 Apr 1980
It ( 51) INT CL 3 G 02 B 5/14 _ ( 52) Index at Acceptance G 2 J GEA ( 72) Inventor: GEORGE RONALD DEACON ERRATUM SPECIFICATION NO 1565038
Page 2, line 10,for plastics read plastic Page 2, line 28, after fiber delete one Page 2, line 29, delete aspect of Page 2, line 62, after the (first occurrence) insert other Page 2, line 71, after by insert the Page 2, line 90, after optic delete ter insert terminations Page 2, line 91, delete minators Page 2, line 102, for termination read terminations Page 2, line 103, after on insert a Page 3, line 92, after the insert contact Page 3, line 106, delete termination insert contact Page 4, line 10, after recess for also, insert Also, Page 4, line 60, for terminations read termination Page 5, line 115, after termination insert as Page 6, line 6,for Asingle read A single Page 6, line 1 29, after 24 delete and insert or THE PATENT OFFICE Marc Jh 1986 Bas 265286/1 I PATENT SPECIFICATION ( 11) 1 565 038 ( 21) Application No 9976/78 ( 31) ( 33) ( 44) ( 51) ( 22) Filed 14 Mar 1978 Convention Application No 780259 ( 32) Filed 23 Mar 1977 United States of America (US) Complete Specification Published 16 Apr 1980
INT CL 3 ( 19) in X G 02 B 5/14 ( 52) Index at Acceptance G 2 J GEA ( 72) Inventor: GEORGE RONALD DEACON ( 54) SINGLE OPTICAL FIBER CONNECTOR ( 71) We, MTT INDUSTRIES INC, a Corporation organised and existing under the Laws of the State of Delaware, United States of America, of 320 Park Avenue, New York 22, State of New York, United States of America, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:
This invention relates to terminations and connectors for single optical fibers.
The use of fiber optic cables or light guides, also known as optical communication fibers, for the transmission of informationbearing light signals, is now an established art Much development work has been devoted to the provision of practical low-loss glass materials and production techniques For producing glass fiber cables with protective outer claddings or jackets The jackets make them resemble ordinary metallic-core electrical cable upon superficial external inspection Obviously, if fiber optic cables are to be used in practical signal transmission and processing systems, practical connectors for the connection and disconnection of fiber optic cables must be provided.
Some references will now be given for background in the state of fiber optic art in general An article entitled, “Fiber Optics”, by Narinder S Kapany, published in Scientific American, Vol 203, pgs 72-81, November 1960, provides a useful background for some theoretical and practical aspects of fiber optic transmission Of relevance to the problem of developing practical fiber optic connectors is the question of transfer efficiency at the connector Various factors, including separation at the point of abutment, and lateral separation or axial misalignment, are among the factors effecting light transfer efficiency In this connection, see Bell System Technical Journal, Vol.
50, No 10, December 1971, which contains an article by D L Bisbee, entitled, “Measurement of Loss Due to Offset, and End Separations of Optical Fibers” Another Bell System Technical Journal article of interest appeared in Vol 52, No 8, October 1973, and was entitled, “Effect of Misalignments on Coupling Efficiency on Single-Mode Optical Fiber Butt Joints “, by J S Cook, W.L Mammel, and R J Grow.
Fiber optic bundles are normally used for only short transmission distances in fiber optic communications networks On the other hand, fibers are used individually as optical data channels to allow transmission over many kilometers At present, most fiber optic cables are multi-fiber bundles due to the less stringent splicing requirements, greater inherent redundancy, and higher signalto-noise ratio The difficulty in achieving connections between single fibers in such a way that the connection is insensitive to axial misalignment has created an obstacle to the use of long run single data transmission systems Thus a connector or coupler is required to eliminate lateral tolerances if low-loss connections are to be obtained in the use of single fiber optical transmission arrangements “V” groove and metal sleeve arrangements have been used to interconnect single fibers See U S Patent No.
3,768,146, which discloses a metal sleeve interconnection for single fibers.
Another known device, as shown in U S.
Patent No 3,734,594, uses a deformable annular core having pressure plates at the ends The fiber ends are inserted into the core and an axial force is applied to the plates to deform the core radially, thereby aligning and securing the fibers.
These prior devices, however, do not readily provide sufficient accuracy for joining and aligning small diameter cores of optical fibers.
Our Application No 37383/76 (Serial No 1497628) discloses a single optical fiber 00 1 f O 1,565,038 connector in which the ends of mating fibers are precisely aligned and coupled together in the interstice between three like contacting cylindrical rods mounted along and around the fibers within an adjustable assembly.
Means is provided to expand the interstice to insert the fiber ends and to clamp the rods in position around the fibers Our Application No 45912/76 (Serial No 1562728) discloses an optical fiber in which the plastics cladding thereof has three rounded indentations along its surface and a thin metal ferrule is formed around the cladding at the mating end of the fiber A pair of such fibers may be aligned in a three-rod arrangement of the type mentioned above.
Thus it is an object of this invention to overcome the above disadvantages of the known three-rod approach but still provide a controlled, accurate alignment of mating single optical fibers in a manner which minimizes light transmission losses, which is easily manufactured and assembled, relatively inexpensive, and practical for commercial field use.
According to one aspect of the invention, there is provided a single optical fiber one aspect of termination, including a set of equal diameter spheres arranged in closely adjacent, but not necessarily engaging, relationship defining an interstitial space therebetween; the centers of said spheres lying in a common plane; and means for supporting a single optical fiber so that the end portion thereof lies in said interstitial space, said spheres being dimensioned to closely confine a fiber in said space.
According to another aspect of the invention there is further provided a fiber optic connector for coupling single optical fibers, including a pair of like sets of equal-diameter spheres, the spheres of each set being arranged in closely adjacent, but not necessarily engaging, relationship defining an interstitial space therebetween; the centers of said spheres of each set lying in a common plane; means associated with each of said sets of spheres for supporting a single optical fiber so that the end portion of the fiber lies in the interstitial space of said set, said spheres of each set being dimensioned to closely confine a fiber therein; and means for mounting said sets of spheres closely together with the interstitial spaces therein aligned whereby fibers in said spaces will be optically coupled.
In the preferred embodiment, the mating terminations are abutted under an axial compression force which causes the spheres in one termination to nest with respect to the spheres in the termination so that the spheres cooperate to cause the optical fibers mounted therein to become precisely laterally aligned The spheres may be metal ball bearings which may be manufactured to extremely precise diameters, thus assuring that the interstitial space defined between the spheres of a set are precisely dimensioned so that a fiber of a sutiable cross section is not damaged by spheres Further, because the spheres may be metal, they will not be subject to creepage as are the plastics alignment rods in the aforementioned connector Thus, the connector of the present invention allows precise alignment of single optical fibers by the use of components which are readily available, inexpensive, and may be assembled at relatively low cost The invention also provides a connector which may be readily terminated to fiber optic cables in the field by relatively unskilled personnel.
Embodiments of the invention will now be described with reference to the drawings, in which:
Fig 1 is a partial longitudinal sectional view through a connector embodying the present invention, showing two pairs of contact cavities with one pair of fiber optic terminators mounted in one cavity in axial abutting relationship; Fig 2 is a perspective, fragmentary illustration of the internal portion of the connector of Fig 1 showing one fiber optic termination, with three spheres, mounted in a guide sleeve in an elastomeric sealing plate in the connector and the mating termination outside of the sleeve positioned to be inserted therein.
Fig 3 is a longitudinal sectional view of one of the termination of Figs 1 and 2 showing the terminations on fiber optic cable; Fig 4 is an enlarged front end view of the termination of Fig 3 showing the three engaging spheres; Fig 5 is an enlarged, partial longitudinal section of the forward ends of the mating terminations of Fig 1; Fig 6 shows how a spherical tool is used to appropriately position an optical fiber in the space defined by the three spheres; Fig 7 is a transverse sectional view taken through another termination embodying the invention wherein the spheres do not contact each other; Fig 8 is an enlarged, partial longitudinal sectional view of the forward end of another termination embodying the invention and using three sets of spheres; Fig 9 is an enlarged partial longitudinal section through the end portions of a pair of mating terminations, also embodying the invention; and Fig 10 is an enlarged front end view of still a further termination embodying the invention, using more than three alignment spheres to position a relatively large optical fiber in the interstitial space defined by the spheres.
( 3 ‘ 1,565,038 The connector of Fig 1, generally designated 10, comprises a plug connector member 12 and mating receptacle member 14 The plug member 12 comprises a shell 16 having a coupling nut 18 rotatably mounted thereon A mounting member 20 for the fibre terminations is mounted in the shell 16, with an elastomeric sealing plate 22, in front of the member 20 The receptacle member 14 has a shell 24 with a mounting member 26 for the fibre terminations mounted therein.
The shell 24 is dimensioned so that the shell 16 of the plug member is slidably insertable therein The coupling nut 18 is threadedly engaged with the shell 24 so that, by rotating the nut, the plug and receptacle members may be drawn together into mating relationship.
The fibre terminations, generally designated 30, are mounted in aligned passages in the mating members, and each one comprises an elongated cylindrical body 32 with a reduced diameter forward portion 34 and an enlarged rear portion 35 (Fig 3) The forward portion 34 contains the alignment elements for the single optical fiber 36 of an optical fiber cable 38 The alignment elements will be described later.
The mounting members 20 and 26 have bores such as 40 therein aligned with bores such as 42 extending through the sealing plate 22 While two sets of said bores 40, 42 are shown in Fig 1 for receiving two pairs of mating terminations 30, obviously, additional bores may be provided for a greater number of light transmitting channels in the connector Each bore 42 has a central uniform diameter section 44 which receives the forward portions 34 of the terminations 30 Counterbores 46 are formed in the opposite end faces of the sealing plate 22 coaxial with the central section 44 of each bore 42.
Tapered transitional regions 48 join the counterbores 46 to the central sections 44 of the bores 42 The diameter of each counterbore 46 is slightly greater than the diameter of the rear portion 35 of each termination so as to slidably receive the body of the termination.
A counterbore 50 is formed in the flat face 52 of each member 20 and 26, defining between it and the bore 40 an annular forwardly-facing shoulder 54 An annular groove 56 is formed in the rear portion of each termination 30 The shoulders 54 in the members 20 and 26 and the grooves 56 in the terminations are so located that when a pair of terminations are fully mounted in mating relationship in a bore 42 in the sealing plate 22, the grooves 56 are in front of the shoulder 54 but just behind the faces 52 of members 20 and 26, respectively Springs 58 in the counterbores 50 surround the terminations and the rear convolution of each spring engages the shoulder 54 while the front convolution is reduced in diameter and is seated in the groove 56.
When the coupling nut 18 is threaded onto the shell 24 of the receptacle member 14, the members 20 and 26 will move axially toward each other causing the mating end faces of the terminations to engage in the central region of the bore 42, compressing the elastomeric sealing plate 22 and the springs 58.
Axial compression of the sealing plate causes the walls of the counterbores 46 to deform radially inwardly and contract around the bodies 32 of the terminations to provide a seal therebetween which prevents the intrusion of dust or other contaminants into the central region of the bore 42 where they may interfere with the optical coupling between the terminations Also, contraction of the bore wall around the terminations dampens vibration of the terminations during use of the connector Compression of the springs ensures that the mating end faces of the terminations, engage with an axial compression force Thus the terminations will be assured of being retained in their abutting relationship The spring arrangement also provides relief in manufacturing tolerances of the mounting members and the terminations.
A metal cylindrical guide sleeve 70 is mounted in the central section 44 of each bore 42 The sleeve has an inner diameter slightly greater than the diameter of the cylindrical forward portion 34 of each contact so that the contacts fit loosely into the sleeve As will be seen, the guide sleeve does not function to produce precise axial alignment between the optical fibers in the mating terminations 30 In fact, it is important that the sleeve not control the alignment of the termination bodies.
Referring again to Fig 3, the termination body 32, which may be made of plastics or metal, has a bore 72 coaxial with the axis of the body and opening at the rear end 74 thereof The bore is dimensioned to slidably receive the optical fiber cable 38 The optical fiber 36 of the cable has an inner jacket 76 and an outer jacket 78 The forward portion of the outer jacket is removed from the cable to expose the inner jacket 76, and the forward section of the inner jacket is removed to expose the optical fiber 36 The bore 72 in the body has a reduced diameter forward section 80 which receives the inner jacket 76.
As best seen in Fig 5, a cylindrical recess 82 is formed in the front end 84 of the termination body coaxial with the axis of the bores 72 and 80 A small diameter bore 86, which leads from the bore 80 to the bottom 88 of the recess, is coaxial with the center axis of the cylindrical recess and is dimensioned to loosely receive the optical fiber 36 therein.
The cylindrical recess 82 provides a circular ring 90 which extends forwardly from the body 32.
1,565,038 The fiber alignment elements comprise equal diameter spheres 94 in the recess 82, preferably three in number, although a greater number of spheres may be used as will be explained later with reference to Fig 10 Preferably the spheres are so dimensioned as to engage the cylindrical wall 95 of the recess 82 Such wall forms a circular race which embraces the spheres and allows the spheres to rotate in a circular path in the recess also, the spheres are so dimensioned as to engage each other, Fig 4, and can rotate about their center axes These spheres are preferably steel ball bearings which may be made to precise dimensions, thus permitting the foregoing engagement between the spheres and the race 95 to be achieved at relatively low cost As well known, ball bearings may be manufactured to dimensions varying only about 5-50 millionths of an inch.
As seen in Fig 4, the adjacent circular surfaces of the spheres 94 define a tricuspid interstitial space 96 therebetween Preferably, the spheres are dimensioned so that the optical fiber 36 is not engaged thereby, but is slightly loose in the space 96 Thus, no forces are applied laterally against the fiber which may cause it to fracture To retain the spheres 94 in the recess 82, the forward end of the circular ring portion 90 of the contact is spin-formed to provide a forward inwardly extending annular lip 98.
As stated above, by the use of the connector arrangement of Fig 1, the mating terminations 30 in the connector are caused to engage under axial compression force.
Further, the forward end portions of the terminations are slightly loose in the guide sleeve 70 so they are capable of minor lateral movement When the sets of spheres in the forward ends of the terminations are engaged under an axial compression force, the spheres nest with respect to each other, see Fig 5 Such nesting occurs even though the spheres may not be properly oriented for nesting when the terminations are initially inserted into the guide sleeve The axial compression force between the sets of spheres, plus the fact that the spheres are rotatable about their own centers and are rotatable within the circular races 95 defined by the recesses 82, cause the spheres to become self-nested Hence, the optical fibers 36 mounted in the interstitial spaces 96 defined by the spheres in the terminations will become precisely laterally aligned Thus, two sets of spheres co-operate with each other to produce alignment of the fibers.
There is no reliance whatsoever upon the outer surfaces of the terminations bodies to achieve alignment between the optical fibers mounted therein, which is normally the case in prior art single fiber connectors.
It is noted that the centers C of the spheres 94 in each termination lie on a common plane Pl (see Fig 5) which is transverse to the center axis of the recess 82 The forwardmost surfaces 100 of the spheres lie in a second common plane P 2 which is parallel to the plane P 1.
Since the two sets of spheres 94 in the mating terminations nest with respect to each other, it will be appreciated that the forward end of the retention lip 98 of each termination must be positioned behind the plane P 2 a sufficient distance so as not to interfere with the nesting of the spheres This requires that the lip be positioned behind the plane P 2 a minimum distance X as indicated in Fig 5.
X is equal to 0 367 R, where R is the radius of the spheres Also, because the two sets of spheres nest with respect to each other when the terminations are mated in the embodiment of Figs 1 to 5, the end face 102 of each optical fiber must be positioned behind its respective plane P 2 a sufficient distance so that the fibers to be mated will not abut or will just barely touch so that scratching or chipping of the fiber faces is avoided.
To properly position a fiber 36 in its respective set of spheres 94, a large diameter spherical tool 104 may be used, see Fig 6.
The tool 104 has a diameter D equal to at least 2 72 R, where R is the radius of one of the spheres 94 By positioning the tool 104 centrally in the front cavity defined by the three spheres 94, the fiber 36 may be positioned properly with accuracy by inserting it into the interstitial space between the spheres 94 until it abuts the tool 104 By using such a tool having a diameter D equal to 2 72 R, the end face 102 of the fiber will be so positioned that when a pair of mating terminations are abutted with their spheres in nesting relationship, the fiber end faces will lie in a common plane For example, if the radius R of each sphere 94 is 03125 inch and the diameter D of the tool 104 is 085 inch, the end faces of the fibers will just touch in a common plane If D is equal to 3 R, the end faces of the fibers will be slightly spaced apart, but not so far as to cause significant light transmission losses.
Whereas in the embodiment of Figs 1 to 5, the optical fiber 36 is positioned in an interstitial space defined by three engaging spheres, the spheres need not contact each other in order to center the fiber As seen in Fig 7, the spheres 94 a and the circular race a are so dimensioned that the spheres do not touch each other, but do touch the fiber 36 a at three points Even though the spheres do not touch each other and are spaced apart from each other different distances, they co-operate with the race 95 a to center the fiber 36 a When a pair of terminations as illustrated in Fig 7 are mated, the spheres in the two terminations nest with respect to each other, bringing the fibers therein into precise lateral alignment.
l I 1,565,038 In the embodiment of Fig 8, three sets of spheres 94 b are mounted in a recess 82 b of the termination body 32 b The centers of the spheres of each set define planes which are parallel and spaced from each other As seen in Fig 8, the spheres in the three sets are arranged to nest with respect to each other.
The termination of Fig 8 functions in the same manner as that of Figs 1 to 5, but the spherical alignment mechanism for the optical fiber 36 b is longer.
Since the spheres in the mating terminations in the arrangements of Figs 1 to 5, 7, and 8, nest with each other, it is not necessary for the terminations to be keyed into alignment in the connector body On the contrary, the terminations not only may be mounted loosely in the guide sleeve 70 for slight lateral adjustment, they may be free to rotate slightly about their longitudinal axis to facilitate nesting of the spheres at the mating ends of the contacts.
In the embodiment of Fig 9, the spheres 94 c in the respective bodies 32 c are potted into place by a suitable epoxy 106 after the fibers 36 c are mounted in the interstitial spaces between the sets of spheres so as to make the spheres immovable The termination bodies 32 c have means for keying the terminations in the connector body (not shown), which causes the spheres in the two terminations to abut at their forwardmost surfaces 100 c, see Fig 9, to achieve alignment between the fibers 36 c Thus in this embodiment the nesting of the two sets of spheres is not used to achieve alignment between the optical fibers Therefore, unlike the arrangements of Figs 1 to 5, 7 and 8, the termination bodies 32 c must be accurately aligned with each other to produce alignment of the optical fibers 36 c Such alignment may be provided by eliminating the metal sleeve in the bore 42 in the sealing plate 22 so that axial compression of the elastomeric plate causes contraction of the wall of the center section 44 of the bore 42, thereby aligning the ends of the terminations It will be appreciated that since the sets of spheres 94 c abut each other at their forwardmost surfaces 100 c, the end faces of the optical fibers 36 c must be closely adjacent to the surfaces 100 c to minimize light transmission losses.
We now refer to Fig 10, which shows the end of an alternative form of contact which is preferred for use with a relatively large fiber 36 d If three spheres were used to align the fiber 36 d, it will be appreciated that the diameter of the spheres would be very large, requiring a termination having a large cross section Hence, in Fig 10, six smaller diameter spheres 94 d are used, each of which contacts each adjacent sphere, the inner race d of the termination and the optical fiber 36 d Thus the spheres 94 d align the optical fiber in the same manner as do the spheres 94 in the arrangement of Figs 1 to 5.
While we prefer that the alignment spheres be metal ball bearings, since they are readily available and are precise in their dimensions, it will be appreciated that the spheres may be made of other materials, e g.
hard plastics or glass.
It is, therefore, seen that by the present invention there is provided a relatively simple and inexpensive disconnectable coupling arrangement for single optical fibers The connector provides a controlled, accurate alignment of the mating optical fibers in a manner which minimizes light transmission losses to levels required for efficient long run single data transmission systems, yet is easily assembled and practical for commercial field use.

Claims (1)

WHAT WE CLAIM IS:
1 A single optical fiber termination, including a set of equal diameter spheres arranges in closely adjacent, but not necessarily engaging, relationship defining an interstitial space therebetween; the centers of said spheres lying in a common plane; and means for supporting a single optical fiber so that the end portion thereof lies in said interstitial space, said spheres being dimensioned to closely confine a fiber in said space.
2 A single optical fiber termination as claimed in claim 1, and including a circular ring embracing said set of spheres, the center axis of said ring being perpendicular to said common plane.
3 A single optical fiber termination as claimed in claim 2, wherein the forwardmost surfaces of said spheres lie in a second common plane parallel to said first-mentioned plane; and wherein said ring embodies a forward inwardly-extending annular lip restraining said spheres from forward movement of said ring, said lip terminating behind said second common plane.
4 A single optical fiber termination as claimed in claim 3, and wherein said lip terminates behind said second common plane a distance of at least 0 268 R, where R is the radius of each of said spheres.
A single optical fiber termination claimed in claim 2, 3 or 4, and wherein said ring is connected to said supporting means.
6 A single optical fiber termination as claimed in claim 2, 3 or 4, and wherein said ring is integral with said supporting means.
7 A single optical fiber termination as claimed in claim 1, 2, 3, 4, 5 or 6, and wherein each sphere engages the next adjacent spheres.
8 A single optical fiber termination as claimed in claim 2 or in any claim dependent thereon, and wherein said spheres and said ring are so dimensioned as to permit the spheres to shift in a circular path inside said ring.
6 6 1,565,038 9 A single optical fiber termination as claimed in any preceding claim, and wherein said set comprises three of said spheres, whereby the interstitial space has a generally tricuspid configuration.
Asingle optical fiber termination as claimed in claim 1, and wherein there are a plurality of said sets of spheres arranged with their interstitial spaces aligned and adapted to receive a single optical fiber therein.
11 A single optical fiber termination as claimed in any preceding claim, and including a single optical fiber mounted in said support means with its end portion in said interstitial space.
12 A single optical fiber termination as claimed in claim 11, wherein the forwardmost surfaces of said spheres lie in a common plane, and the end face of said fiber is positioned behind said common plane.
13 A single optical fiber termination as claimed in claim 12, wherein the end face of said fiber is positioned behind said common plane a distance such that when a pair of said terminations are abutted with the spheres of one nesting with respect to the spheres of the other termination, the ends of the fibers will be immediately adjacent to, but not contacting, each other.
14 A single optical fiber termination as claimed in claim 1 or in any claim dependent thereon, and wherein said fiber supporting means includes an elongated body having a forward end and a rear end; a cylindrical recess in the forward end of said body, said recess receiving said set of spheres, and a bore extending from the rear end of said body to the bottom of said recess coaxial with the center axis of said recess, said bore being dimensioned to receive a single optical fiber therein.
A single optical fiber termination including a body having a front end and a rear end; a cylindrical recess in said body at its said front end; three equal-diameter spheres in said recess arranged in closely adjacent relationship defining a tricuspid interstitial space therebetween; the centers of said sphercs lying in a plane transverse to the center axis of said recess whereby said axis passes through said interstitial space; the cylindrical wall of said recess engaging said spheres, and a bore in said body, coaxial with said axis and extending from said rear to the bottom of said recess, said bore being dimensioned to receive an optical fiber therein.
16 A single optical fiber termination as claimed in claim 15, and wherein said spheres are retained in the recess by an inwardly-extending lip on the front end of said body, which lip engages the forwardfacing surfaces of the spheres.
17 A single optical fiber termination as claimed in claim 15 or 16, wherein said spheres engage each other.
18 A single optical fiber termination as claimed in claim 15, 16 or 17, and wherein each said sphere can rotate about its center axis, and can rotate in a circular path in said recess 70 19 A single optical fiber termination, wherein:
(a) there is provided an elongated cylindrical body which has a bore therethrough extending from the front to the rear 75 of said body, said bore being dimensioned to receive an optical fiber therein; (b) there is a set of three equaldiameter identical spheres adjacent to the front of said body and arranged in closely 80 adjacent, but not necessarily engaging, relationship defining a tricuspid interstitial space therebetween; (c) said spheres are so positioned that their centers lie in a plane transverse to 85 the center axis of said bore and said interstitial space is aligned with said axis, and (d) a circular ring extending from the front of said body coaxial with said axis embraces said spheres 90 A single optical fiber termination including means providing a circular race; a plurality of spheres embraced by said race and defining an intersititial space therebetween, and an optical fiber extending into said 95 space coaxial with the center axis of said race.
21 A termination as claimed in any preceding claim and wherein said spheres are ball bearings.
22 A fiber optic connector for coupling 100 single optical fibers including a pair of like sets of equal-diameter spheres, the spheres of each set being arranged in closely adjacent, but not necessarily engaging, relationship defining an interstitial space therebet 105 ween; the centers of said spheres of each set lying in a common plane; means associated with each of said sets of spheres for supporting a single optical fiber so that the end portion of the fiber lies in the interstitial space of 110 said set, said spheres of each set being dimensioned to closely confine a fiber therein, and means for mounting said sets of spheres closely together with the interstitial spaces therein aligned whereby fibers in said spaces 115 will be optically coupled.
23 A fiber optic connector as claimed in claim 22, and wherein said sets of spheres are nested with respect to each other.
24 A fiber optic connector as claimed in 120 claim 22 or 23, and including means providing a pair of circular races each embracing one of said sets of spheres.
A fiber optic connector as claimed in claim 22, 23 or 24, and wherein each said set 125 comprises three spheres defining a tricuspid interstitial space therebetween.
26 A fiber optic connector as claimed in claim 22, 23, 24 and 25, and wherein said mounting means abuts said sets of spheres 130 I’ 7 1,565,038 7 under an axial compression force causing said spheres of said sets to become nested with respect to each other.
27 A fiber optic connector for coupling single optical fibers, including a pair of terminations each comprising a body having a front end and a rear end; a cylindrical recess in the front of each said body containing a set of equal diameter spheres defining an interslo titial space therebetween; the centers of the spheres of each said set lying in a common plane transverse to the center axis of its said recess; a bore in each termination body extending from said rear end to said recess and aligned with said space and dimensioned , to receive an optical fiber therein, and means It for positioning said terminations with said sets of spheres abutting each other.
28 A fiber optic connector as claimed in claim 27, and wherein said positioning means includes a sleeve loosely receiving said terminations in its opposite ends.
I 29 A fiber optic connector as claimed in E 5 claim 27 or 28, and including means abutting said sets of spheres in said terminations under an axial compressive force to cause said spheres in said terminations to nest with respect to each other.
A fiber optic connector for coupling single optical fibers, including two sets of three equal-diameter spheres each defining a tricuspid interstitial space therebetween; the centers of the spheres of said sets lying in two parallel planes; each said set of spheres having a forward face and a rear, said forward faces abutting each other with said interstitial spaces aligned, and a single optical fiber extending from the rear forwardly into the interstitial space in each said set of spheres.
31 A fiber optic termination substantially as described with reference to the accompanying drawings.
32 A fiber optic connector substantially as described with reference to the accompanying drawings.
For the Applicants S R CAPSEY Chartered Patent Agent Printed for tir N>lesl S Stationer) Office.
bx Cros don Printing Coripany Limited Cro Ydon, Surrey 1980.
fubblhed h, The Patinr Officc 25 Southampton Buddings, London W( 2 A IAN from ‘hich copies nma be obtained.

GB9976/78A
1977-03-23
1978-03-14
Single optical fibre connector

Expired

GB1565038A
(en)

Applications Claiming Priority (1)

Application Number
Priority Date
Filing Date
Title

US05/780,259

US4087155A
(en)

1977-03-23
1977-03-23
Single optical fiber connector utilizing spherical alignment elements

Publications (1)

Publication Number
Publication Date

GB1565038A
true

GB1565038A
(en)

1980-04-16

Family
ID=25119079
Family Applications (1)

Application Number
Title
Priority Date
Filing Date

GB9976/78A
Expired

GB1565038A
(en)

1977-03-23
1978-03-14
Single optical fibre connector

Country Status (10)

Country
Link

US
(1)

US4087155A
(en)

JP
(1)

JPS53122436A
(en)

AU
(1)

AU512234B2
(en)

CA
(1)

CA1105303A
(en)

DE
(1)

DE2812284C2
(en)

FR
(1)

FR2385109A1
(en)

GB
(1)

GB1565038A
(en)

IT
(1)

IT1192551B
(en)

NZ
(1)

NZ186755A
(en)

ZA
(1)

ZA781171B
(en)

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1977

1977-03-23
US
US05/780,259
patent/US4087155A/en
not_active
Expired – Lifetime

1978

1978-02-28
ZA
ZA00781171A
patent/ZA781171B/en
unknown

1978-03-14
AU
AU34124/78A
patent/AU512234B2/en
not_active
Expired

1978-03-14
GB
GB9976/78A
patent/GB1565038A/en
not_active
Expired

1978-03-16
IT
IT21276/78A
patent/IT1192551B/en
active

1978-03-21
DE
DE2812284A
patent/DE2812284C2/en
not_active
Expired

1978-03-21
NZ
NZ186755A
patent/NZ186755A/en
unknown

1978-03-22
CA
CA299,504A
patent/CA1105303A/en
not_active
Expired

1978-03-22
JP
JP3280678A
patent/JPS53122436A/en
active
Granted

1978-03-23
FR
FR7808445A
patent/FR2385109A1/en
active
Granted

Also Published As

Publication number
Publication date

IT7821276D0
(en)

1978-03-16

IT1192551B
(en)

1988-04-20

JPS5635848B2
(en)

1981-08-20

AU3412478A
(en)

1979-09-20

AU512234B2
(en)

1980-10-02

ZA781171B
(en)

1979-02-28

DE2812284C2
(en)

1986-07-24

FR2385109B1
(en)

1982-12-10

CA1105303A
(en)

1981-07-21

NZ186755A
(en)

1981-12-15

US4087155A
(en)

1978-05-02

JPS53122436A
(en)

1978-10-25

DE2812284A1
(en)

1978-09-28

FR2385109A1
(en)

1978-10-20

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