GB2468442A - Method of installing a Subscriber Connection (SC) optical fibre connector - Google Patents
Method of installing a Subscriber Connection (SC) optical fibre connector Download PDFInfo
- Publication number
- GB2468442A GB2468442A GB1010181A GB201010181A GB2468442A GB 2468442 A GB2468442 A GB 2468442A GB 1010181 A GB1010181 A GB 1010181A GB 201010181 A GB201010181 A GB 201010181A GB 2468442 A GB2468442 A GB 2468442A
- Authority
- GB
- United Kingdom
- Prior art keywords
- optical fibre
- ferrule
- assembly
- sub
- ferrule holder
- Prior art date
- 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.)
- Granted
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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
- G02B6/3847—Details of mounting fibres in ferrules; Assembly methods; Manufacture with means preventing fibre end damage, e.g. recessed fibre surfaces
- G02B6/3849—Details of mounting fibres in ferrules; Assembly methods; Manufacture with means preventing fibre end damage, e.g. recessed fibre surfaces using mechanical protective elements, e.g. caps, hoods, sealing membranes
-
- 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
-
- 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
-
- 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
- G02B6/3855—Details of mounting fibres in ferrules; Assembly methods; Manufacture characterised by the method of anchoring or fixing the fibre within the ferrule
-
- 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
- G02B6/3869—Mounting ferrules to connector body, i.e. plugs
Abstract
The invention relates to a method of installing a Subscriber Connection (SC) -type push/pull optical fibre connector having a ferrule 14 onto an optical fibre 8. The connector 101 comprises an optical fibre connector sub-assembly (60, fig 6) including a ferrule holder 16 and a ferrule holder carrier 50. The carrier has a groove (78, figure 24) and assembled about the sub-assembly are an inner housing 120 and an outer housing 40, the inner housing having a radially inwardly projecting feature (82, figure 24). The method comprises the steps of terminating the optical fibre 8 at an end face (34, figure 6) of the ferrule 14, using the ferrule holder 16 to hold the, engaging the ferrule holder within a receiving portion 54 of the ferrule holder carder 50 and placing a spring biasing means 17 between the ferrule holder and ferrule holder carrier to form the sub-assembly such that the holder and carrier are spring biased apart and relatively moveable with respect to each other along the ferrule axis. The sub-assembly is inserted in a length of protective conduit (72, figure 19) and then assembled with the inner housing 120 by engaging the radially inwardly projecting feature (82) in the groove (78). An SC connector is then formed by engaging the outer housing 40 around the inner housing 120, the two being movable relative to each other for push/pull engagement/disengagement.
Description
INTELLECTUAL
. ... PROPERTY OFFICE Application No. GB1O1O181.4 RTM Date:29 June 2010 The following term is a registered trademark and should be read as such wherever it occurs in this document:
NTT
Intellectual Property Office is an operating name of the Patent Office www.ipo.gov.uk Optical Fibre Connector
BACKGROUND
a. Field of the Invention
The present invention relates to an optical fibre connector, for example an SC-style connector, and to a method of forming and using such a connector.
b. Related Art The niechancal tolerances involved in terminating single mode optical fibre are much tighter than those for multimode optical fibre. Therefore, while it is quite common for multimode optical fibre be terminated at the point of use, for example at a user's premises or at an outside junction box, in most product applications, single mode optical fibre is not terminated in the field. When single mode fibre must be terminated in the field, then it can take a skilled technician between about to 20 minutes to splice fibres together either by using a V-groove clamp or expensive fusion welding equipment.
Single mode fibre is therefore often provided in a range of different lengths, pre-terminated at both ends with a connector plug ready to plug into a matching receptacle. Commonly, eight or twelve single mode optical fibres may be bundled together in an optical fibre cable having an outer protective tube inside of which the optical fibres run.
An example of such a connector is the "Subscriber Connector', or SC connector, originally developed by NTT. SC connectors have convenient push/pull style mating, and are approximately square in cross-section and with a 2.5 mm diameter ferule at the termination of the optical fibre, surrounded by a plastic housing for protection. SC connectors are available in single or duplex configurations. The SC connector latches into a matching socket in a simple push motion. The push-puU design indudes a spring against which the ferrule sUdes within a plastic inner housing. This arrangement provides a reliable contact pressure at the ferrule end and resists fibre end face contact damage of the optical fibre during connection. The connector can be quickly disconnected by first pulling back an outer housing, which is slidable relative to the inner housing, to disengage a latch inside socket between the socket and the inner housing, before pulling the opUcal fibre connector from the socket. Until the latch is thus disengaged, the latch prevents withdrawal of the connector when the optical fibre cable is pulled in a direction away from the socket.
A different type of connector s the ST type connector has a key that prevents rotation of the ceramic ferrule and which connects with a socket using a bayonet lock wfth an outer shell. AU such bayonet type optical fibre connectors are referred to herein for convenience as "ST-style" optical fibre connectors.
An advantage of the SC connector over this type of bayonet connector is that the SC connector sockets can be more closely packed, as there is no need to get fingers fully around the connector to disengage the connector from the socket.
Other examples of push/pull type connectors are LC connectors or MU connectors. Often, the fibre-end is angled to reduce back reflections and this is usually described by adding APC (Ang'ed Physical Contact) to the name. All such push/puU type optical fibre connectors are for convenience referred to herein as "SC-style" optical fibre connectors. SC-style LC or MU connectors are also known as small form factor connectors, by virtue of having a 1.5 mm diameter ferrule and a p'astic housing.
It is important to avoid bending optical fibre around curves having too sharp a bend radius, as this will increase optical losses and can permanently damage the optical fibre. Optical fibre cables are therefore often routed inside a protective outer tube or conduit, which can have minimum bend-limiting properties.
Protective bend limiting conduits normally have an outer diameter of 8 mm or mm tubes. The cross-section of a standard SC connector has dimensions of about 7 mm x 9 mm, and even a smaU form factor SC connector is too large to fit inside the inner diameter of a typical protective conduit.
In one product application involving the provision of a single mode optical connection all the way to a service subscriber, the protective conduit may run for tens or hundreds of meters from a residential home to a curb-side connection box.
While it is relatively straight forward to blow or push a non-terminated length of optical fibre cable down the conduit, it is not possible to do this with cable pre-terminated with SC-style connectors owing to the mismatch in the size of the connector with the inner diameter of the conduit.
While, in principle, it would be possible to provide a length of optical cable pre-terminated at one end only, and then after blowing the cable down the conduit either splice or fuse the optical fibre to a terminated optical fibre stub, this adds significant time and cost to the job of providing a single mode optical fibre connection, particularly in product applications such as the provision of single mode optical fibre connection to a user's home.
It is an objection of the present invention to provide a more convenient optical fibre connector and optical fibre communication system and method for providing such a system.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, there is provided a method of installing a Subscriber Connection (SC) -type optical fibre connector, the connector comprising an optical fibre, an optical fibre connector sub-assembly and assembled about the sub-assembly an inner and an outer housing, the inner housing having a radially inwardly projecting feature, the method comprising the steps of: -terminating the optical fibre at an end face of the ferrule; -using the ferrule holder to hold the ferrule so that the ferrule extends away from the ferrule holder towards said end face; -engaging the ferrule holder within a receiving portion of the ferrule holder carrier and placing the spring biasing means between the ferrule holder and ferrule holder carrier to form said sub-assembly such that said holder and carrier are spring biased apart and relatively moveable with respect to each other along the ferrule axis between limits defined by an interaction between the ferrule holder carrier and the ferrule, the ferrule holder carrier having a groove; -inserting the optical fibre sub-assembly down a length of protective conduit; and -after said inserting, assembling the inner housing to said sub-assembly by engaging the inner housing to said sub-assembly while locating said radially inwardly projecting feature within said groove and then forming an SC-type optical fibre connector by engaging the outer housing around the inner housing, said inner and outer housings being movable relative to each other to provide SC-type push/pull engagement/disengagement functionality.
According to a second aspect of the invention, there is provided a method of making an optical fibre connection using a Subscriber Connection (SC) -type optical fibre connector, comprising the steps of: -installing a Subscriber Connection (SC) -type optical fibre connector according to the first aspect of the invention; and -mating said SC-type optical fibre connector with a matching optical fibre socket.
Also described is this specification is an optical fibre connector sub-assembly for an optical fibre connector, comprising an optical fibre, a cylindrical ferrule, a ferrule holder, a spring biasing means, and a ferrule holder carrier; wherein: -the optical fibre is held within the ferrule along an axis of the ferrule, the optical fibre being terminated at an end face of the ferrule; -the ferrule is held by the ferrule holder; -the ferrule holder is engaged within a receiving portion of the ferrule holder carrier, said holder and carrier being relatively moveable with respect to each other along the ferrule axis between limits defined by an interaction between the ferrule carrier and the ferrule holder, a portion of the ferrule leading to said end face of the ferrule projecting along the ferrule axis away from the ferrule carrier; and -the spring biasing means is provided between the ferrule holder and the ferrule holder carrier so that the projecting portion of the ferrule is spring biased along the ferrule axis away from the ferrule holder carrier.
The optical fibre connector sub-assembly may be suitable for inclusion in any type of optical fibre connection, for example, an ST-style optical fibre connector. In preferred embodiments the optical fibre connector sub-assembly is for an SC-style optical fibre connector.
The ferrule holder may include a base having a socket in which the ferrule is seated, and a hollow stem that projects axially from the base in a direction away from said projecting portion of the ferrule. The ferrule holder carrier receiving portion then extends around at least a portion of the stem and includes a feature that interacts with the ferrule holder base to limit the relative movement of the ferrule holder and the ferrule holder carrier along one direction of movement along the ferrule axis.
The optical fibre will normally lead to the ferrule through the stem.
The spring biasing means may be provided between the ferrule holder base and the ferrule holder receiving portion.
The spring biasing means is preferably a coil spring that is concentrically seated around the stem of the ferrule holder.
The optical fibre base may have a plurality of crenellations that extend circumferentially around the ferrule. The ferrule holder carrier can have at least two arms that sdeably engage with the creneUations.
The arms may terminate with circumferentially extending features that engage with the base to limit the relative movement along the ferrule axis of the ferrule holder away from the receiving portion of the ferrule holder.
The ferrule holder and ferrule holder carrier may be adapted to be assembled by a press-fitting operation in which the ferrule holder moves along the ferrule axis into the receiving portion of the ferrule holder.
The optical fibre wiU usually include a length of optical fibre extending away from the ferrule, the ferrule holder and the ferrule holder carrier. This length can be surrounded by a material for protection and/or reinforcement, in which case the ferrule holder carrier advantageously includes means for attaching said cladding to this material.
Also described herein is provided an SC-style optical fibre connector comprising an optical fibre, an optical fibre connector sub-assembly and assembled about the sub-assembly an inner and outer housing, the sub-assembly comprising a ferrule having and end face at which said optical fibre is terminated, the ferrule being spring biased along an optical axis defined by the terminated optical fibre, wherein the sub-assembly is mechanically integral prior to assembly of the inner and outer housing about the sub-assembly, the inner and outer housings when assembled about the sub-assembly serving to provide SC-style push/pull engagement! disengagement with a mating optical fibre socket.
The sub-assembly is mechanically integral in the sense of being a physically complete unit, or a whole, which is secure enough to be inserted inside a length of conduit, for example being blown or pushed down a length of bend-limiting conduit, without coming apart in the process. The sub-assembly can be formed with an outer diameter or other maximum external cross-sectional dimension significantly smaller than a corresponding dimension of the completed SC-style optical fibre connector, and can therefore be smaU enough to fit inside a wide range of commerciaUy avaUable conduits, for example 8 mm or 10 mm external diameter bend-limiting conduits. Then after insertion of the sub-assembly down the length of conduit, the inner and outer housings can be assembled about the sub-assembly to complete the SC-style optical fibre connector.
It is preferred if, the inner housing and then the outer housing in turn are inserted over the projecting ferrule and sub-assembly by press-fitting along an axial direction.
Also described herein is an SC-style optical fibre connector comprising an optical fibre, a cylindrical ferrule, a ferrule holder, a spring biasing means, a ferrule holder carrier, a inner housing, and an outer housing, wherein: -the optical fibre is held within the ferrule along an axis of the ferrule, the optical fibre being terminated at an end face of the ferrule; -the ferrule is held by the ferrule holder; -the ferrule holder is engaged within a receiving portion of the ferrule holder carrier, said holder and carrier being relatively moveable with respect to each other along the ferrule axis between limits defined by an interaction between the ferrule carrier and the ferrule holder, a portion of the ferrule leading to said end face of the ferrule projecting along the ferrule axis away from the ferrule carrier; -the inner housing is fixedly connected to the ferrule holder carrier, the inner housing comprising a portion which coaxially extends around said projecting portion of the ferrule to define a receptacle for a socket to receive the projecting ferrule portion; -the spring biasing means is provided between the ferrule holder and the ferrule holder carrier so that the projecting portion of the ferrule is spring biased along the ferrule axis towards the receptacle portion of the inner housing; and -the inner housing is engaged within the outer housing, the inner housing and the outer housing being relatively moveable with respect to each other along the ferrule axis between limits defined by an interaction between the inner housing and the outer housing in order to provide SC-style push/pull engagement/disengagement with a mating optical fibre socket.
The ferrule housing assembly serves as an inner housing in relation to the outer housing in the provision of the SC-stye push/pull engagement/disengagement.
The ferrule is preferably rotationally fixed with respect to the ferrule holder about the ferule axis, with the ferrule holder bring rotationally aligned by means of one or more rotational keys with respect to the outer housing so that the rotational orientation of the ferrule with respect to the outer housing can be set during assembly of the connector at one of one or more predefined rotational orientations.
A first rotational key may be provided between the ferrule holder and the ferrule holder carrier. A second rotation& key may then be provided between the ferrule holder carrier and the inner housing. The ferrule holder and the ferrule holder carrier may have aligned features which provide a combined rotational key between, on the one hand, the ferrule holder and the ferrule holder carrier, and, on the other hand, the inner housing.
A further rotational key may be provided between the ferrule holder sub-assembly and the outer housing.
The ferrule holder and ferru'e holder carrier may be adapted to be assembled by a press-fitting operation in which the ferrule holder moves along the ferrule axis into the receiving portion of the ferrule holder.
The inner housing is adapted to be assembled to the ferrule ho'der and the ferrule holder carrier by a press-fitting operation in which the inner housing moves along the ferrule axis over the projection portion of the ferrule towards the ferrule holder carrier.
Also described in this disclosure is a method of making an optical fibre connection using an SC-style optical fibre connector, comprising the steps of: -forming an optical fibre connector sub-assembly comprising a spring-biased ferrule that terminates a length of optical fibre; -inserting the optical fibre sub-assembly down a length of protective conduit; -after said inserting, forming an SC-style optical fibre connector from the optical fibre connector sub-assembly by engaging around said sub-assembly an inner housing and an outer housing, said inner and outer housing being movable relative to each other to provide SC-style push/pull engagement/disengagement functionality and -mating said SC-style optical fibre connector with a matching optical fibre socket.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be further described, by way of example only, and with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of a prior art SC connector, comprising an optical fibre cable, optical fibre connector sub-assembly (including an inner housing) and an outer housing to provide SC-style push/pull engagement/disengagement with a mating optical fibre socket; Figure 2 is a an exploded perspective view of the optical fibre connector sub-assembly of Figure 1; Figure 3 is a perspective view of the optical fibre connector sub-assembly of Figure 1 when assembled; Figure 4 is a perspective view of the SC connector of Figure 1 when assembled; Figure 5 is an exploded perspective view of an SC connector for use in the method according to the invention, comprising an optical fibre cable, an optical fibre connector sub-assembly, and an inner housing and an outer housing to provide SC-style push/pull engagement/cfisengagement with a mating optical fibre socket; Figure 6 is a perspective view of the optical fibre connector sub-assembly of Figure 5 when assembled; Figure 7 is a perspective view of the SC connector of Figure 5 when assembled; Figures 8 and 9 show in perspective the components forming the fibre connector sub-assembly of Figure 5, namely a ferrule holder carrier, an optical ferrule held by a ferrule holder, and a helical spring; Figure 10 is another perspective view of the optical fibre connector sub-assembly of Figure 5 when assembled; Figure 11 is a perspective view of the inner housing of Figure 5 Figure 12 is a perspective view of a ferrule housing sub-assembly formed when the inner housing is press-fitted over the ferrule holder carrier; Figure 13 is another perspective view of the ferrule holder carrier of Figure 8, showing how the holder has a number of cylindrical or concentric surfaces; Figure 14 is a cross-sectiona' view a'ong a central axis of the ferrule holder carrier of Figure 13; Figure 15 is another cross-sectional view along the central axis of the ferrule holder carrier taken along line XV-XV of Figure 14. -11 -
Figure 16 is a perspective view of an alternative embodiment of ferrule holder canler, showing how the holder has a number of cylindrical or concentric surfaces; Figure 17 is a cross-sectional view along a central axis of the ferrule holder carrier of Figure 16; Figure 18 is another cross-sectional view along the central axis of the ferrule holder carrier, taken along line XVlll-XVlll of Figure 17.
Figures 19 to 21 illustrate the insertion of the partially assembled SC connector of Figure 5 through and out from a protective conduit; Figure 23 is a cross-sectional view through the ferrule holder carrier of Figure 10; Figure 24 is a cross-sectional view of the ferrule holder carrier of Figure 23, including also a terminated optical fibre cable inside the ferrule and the inner housing connected about the ferrule holder carrier; and Figure 25 is a cross section at right angles to that of Figure 24.
DETAILED DESCRIPTION
Figures 1 to 4 show a prior art SC connector 1, comprising an optical fibre cable 2, a ferrule housing sub-assembly 4, and an outer housing 6 to provide SC-style push/pull engagement/disengagement with a mating optical fibre socket (not shown).
The cable 2 holds a single strand of 125 im diameter single mode optical fibre 8, protected by primary and secondary buffering layers 10, about 900 tm in diameter and an outer sheath 12, typically 3 mm to 5mm in diameter. The optical fibre 8 is terminated by the ferrule in a manner well-known to those skilled in the art, and defines a ferrule axis 5 which extends centrally through the SC connector 1.
The ferrule housing sub-assembly 4 includes a cylindrical ceramic ferrule 14, a ferrule holder 16 having a base 15 with a socket in which the ferrule is seated, a helical spring 17, a generally cylindrical cup 18 and an inner housing 20. The ferrule holder 16 has a cylindrical stem 22 which extends in an axial direction away from the ferrule 14 towards the cup 18. The spring 17 is seated around the stem 22 between an annular shoulder 24 on the ferrule holder 16 and a similar annular surface (not shown) within the cup. During assembly, the inner housing 20 is passed axially over the ferrule holder 16 and a forward part of the cup, and then rotated by 90° until a pair of slots 26 on opposite sides of the inner housing engage with a pair of ribs 28 projecting opposite sides of the cup 18. This engagement fixes the inner housing 20 in an axial direction, while at the same time leaving the spring 17 trapped under compression between the ferrule holder and the cup 18.
The inner housing has a forwards portion 30 which coaxially extends around the axially projecting ferrule 14 to define a receptacle 32 for a socket (not shown) to receive the projecting ferrule portion.
The connected cup 18 and inner housing 20 serve as a ferrule holder carrier inside of which the ferru'e holder 16 is free to move backwards when an end face 34 of the ferrule comes into contact with a simUar end face (not shown) of another optical fibre ferrule when making an optica' connection.
The cup 18 has a central aperture (not shown) through which the optical fibre and buffering 10 pass, and has in a rear-most portion a sleeve 36 sized to receive and be crimped to the cable sheathing 12.
Unusually a strain-relief sleeve 38 is provided around the junction of the optical fibre cable 2 and the ferrule housing sub-assembly 4.
An outer housing 40 is press-fitted axially over the assembled ferrule housing sub-assembly. Once the inner housing 20 and outer housing are engaged together, the inner and outer housings 20, 40 are relatively moveable with respect to each other along the ferrule axis 5 between imits defined by an interaction between the inner housing and the outer housing provided by projections 42 on a pair of opposite sides of the inner housing and a pair of apertures 44 in the outer housing. The projections 42 and apertures 44 interact with sprung features inside a matching socket (not shown) to provide SC-style push/pull 46 engagement/disengagement with a mating optical fibre socket.
Figure 5 is an exploded perspective view of an SC connector 101 for use in the method according to the invention, in which features corresponding with those of Figures 1 to 4 are indicated with the same reference numerals.
The connector 101 comprises an optical fibre cable 2, ferrule housing sub-assembly 104, and an outer housing 40 to provide SC-style push/pull engagement/disengagement with a mating optical fibre socket (not shown).
The cable 2 holds a single strand of 125 im diameter single mode optical fibre 8, protected by primary and secondary buffering layers 10, about 900 pm in diameter and an outer sheath 12, typicaUy 3 mm to 5 mm in diameter. The optical fibre 8 is -14-terminated by the ferrule in a manner weU-known to those skiUed in the art, and defines a ferrule axis 5 which extends centraUy through the SC connector 1 The ferrule housing sub-assembly 104 includes a cylindrical ceramic ferrule 14, a ferrule holder 16 in which the ferrule is seated, a helical spring 17, a ferrule holder carrier 50 and an inner housing 120. The ferrule holder 16 has a cylindrical stem 22 which extends in an axial direction away from the ferrule 14 towards a sleeve 136 of the ferrule holder carrier 50 used to make a crimp connection around the optical fibre cable. With reference now also to Figures 8 and 9, the spring 17 is seated around the stem 22 between an annular shoulder 24 on the ferrule holder 16 and a similar annular surface 52 within the a cylindrical recess 54 of the ferrule holder carrier 50. As shown in Figure 23, the stem is slideably seated in a closely fitting bore 55 of the ferrule holder carrier.
During assembly, the ferrule holder 16 and seated ferrule 14 are inserted axially into the recess 54 of the ferule holder carrier 50. The carrier 50 has a pair of arms 56 that extend axially forwards and around a portion of the stem 22 nearest the ferrule 14 and also around the base 15 of the ferrule holder. A pair of circumferentially extending fingers 58 are provided at the end of each arm 56. The ferrule base 15 has four cycles of crenellations 62 around the base, and the arms 56 are each seated in radially low regions of these crenellations, and reach axially forwards of the base 15 to engage with the intervening radially high regions on a side 61 of the base 15 opposite the annular surface 24 against which the spring 17 is engaged. The axial movement of the ferrule holder is therefore limited in one direction by the compression of the spring between the two annular surfaces 24, 52 and in the other axial direction by the contact of the fingers 58 with the base 15 of the ferrule holder 16.
The rotational orientation of the ferrule holder carrier 50 may be set at one of four orientations relative to the ferrule 14 in the ferrule holder 16 owing to the seating of the arms 56 in the crenellations. In this way, a first rotational key is provided between the ferrule holder 16 and the ferrule holder carrier 50.
The optical fibre 8 is therefore terminated in a sub-assembly referred to herein as an optical fibre connector sub-assembly 60. As can be appreciated by an inspection of Figures 8 to 10, during assembly of the optical fibre connector sub-assembly 60 the arms 56 and fingers 58, which each have a chamfered taper 64 on an inner forwards surface, flex outwardly over the base 15 of the ferrule holder 14 until the fingers 58 snap radially inwards into engagement with the forwards surface 61 of the ferrule holder base 15.
Figures 13 to 15 show various views of the ferrule holder carrier 50 described above.
Figures 16 to 18 show similar views of a variant design of the ferrule holder carrier 150, which works in the same way as that described above, but which has a smaller diameter sleeve 236 over which an outer sheath 12 of the optical fibre cable may be crimped.
In both cases, the resulting optical fibre connector sub-assembly 60 is therefore mechanically whole or integral, both as regards the components forming the sub-assembly and as regards the mechanical connection of the sub-assembly to the optical fibre cable 2. The sub-assembly cannot come apart without first prising the fingers 58 back over the ferule holder base 15. The ferrule holder carrier has an outer diameter which is preferably no more than that of the widest portion of the ferrule holder 14, i.e. the ferrule holder base 15.
With reference now also to Figures 19 to 22, the benefit of this arrangement is that the optical fibre connector sub-assembly 60 is thin enough in a radial direction to be inserted down a length of protective conduit 72, as shown in Figure 19, even after first placing over the optical fibre connector sub-assembly 60 a temporary protective outer sleeve 74, in order to prevent damage to the optical fibre connector sub-assembly 60. The outer sleeve is preferably formed in a low friction material, such as PTFE, in order to facilitate smooth insertion of sub-assembly -16-down the length of conduit 72.
OptionaUy, the projecting end of the ferrule 14 may be additionaUy protected by a disposable end cap 76.
After the insertion has been performed, the assembly of the SC-style optical fibre connector is completed as follows. With reference to Figures 11, 12, 23 and 24, an inner housing 120 is inserted in an axial direction over the projecting ferrule 14 and surrounding ferrule holder carrier 50. The ferrule holder carrier 50, 150 has an annular groove 78. The inner housing has a pair of arms 80 each having at an end a radially inwardly projecting detent 82. The detents 82 are initially deflected radially outwards and then snap into engagement with the groove 78 as the inner housing is slid over the sub-assembly 60. This engagement prevents relative axial movement of the inner housing and the sub-assembly 60 in one direction.
Relative movement in the opposite direction is prevented by abutting of surface 52 and an end surface 83 of a rib 84 that engages as a rotational key with an inner radial region of the crenellations 62. In this way, a second rotational key is provided between the ferrule holder carrier 50, 150 and the inner housing 120.
The external shape of the inner housing 120 where this interacts with the outer housing 6 is the same as with the prior art. The outer housing therefore is snap-fitted over the inner housing, after which the SC-style connector 101 is fully
compatible with the prior art connector 1.
It should be noted that although the specific example described above relate to an SC-style connector, the optical fibre connector sub-assembly can be adapted for use with other types of optical fibre connector systems, for example the ST-style connectors.
The invention therefore provides a convenient optical fibre connector and optical fibre communication system and method for providing such a system.
Claims (8)
- CLAIMS1. A method of instaUing a Subscriber Connection (SC) -type optical fibre connector, the connector comprising an optical fibre, an optical fibre connector sub-assembly including a ferrule holder and a ferrule holder carrier, said carrier having a groove, and assembled about the sub-assembly an nner and an outer housing, the inner housing having a radially inwardly projecting feature, the method comprising the steps of: -terminating the optical fibre at an end face of the ferrule; -using the ferrule holder to hold the ferrule so that the ferrule extends away from the ferrule holder towards said end face; -engaging the ferrule holder within a receiving portion of the ferrule holder carrier and placing a spring biasing means between the ferrule holder and ferrule holder carrier to form said sub-assembly such that said holder and carrier are spring biased apart and relatively moveable with respect to each other along the ferrule axis between limits defined by an interaction between the ferrule holder carrier and the ferrule; -inserting the optical fibre sub-assembly down a length of protective conduit; and -after said inserting, assembling the inner housing to said sub-assembly by engaging the inner housing to said sub-assembly while locating said radially inwardly projecting feature within said groove and then forming an SC-type optical fibre connector by engaging the outer housing around the inner housing, said inner and outer housings being movable relative to each other to provide SC-type push/pull engagement/disengagement functionality.
- 2. A method as claimed in Claim 1, said groove being an annular groove, and said radially inwardly projecting feature being a radially inwardly projecting detent, in which during said engagement of the inner housing to said sub-assembly said detent is initially deflected radially outwards and then snaps radially inwards into engagement with the groove as the inner housing is slid over the sub-assembly.
- 3. A method as daimed in Claim 1 or Claim 2, in which the method comprises placing a temporary protective outer sleeve over the optical fibre connector sub-assembly prior to insertion of the optical fibre sub-assembly down said length of protective conduit, and then removing said outer sleeve after said insertion and prior to said assembly of the inner housing to said sub-assembly.
- 4. A method as claimed in Claim 3, comprising placing a temporary end cap over the projecting end of the ferrule prior to insertion of the optical fibre sub-assembly down said length of protective conduit, and then removing said end cap after said insertion and prior to said assembly of the inner housing to said sub-assembly.
- 5. A method of making an optical fibre connection using a Subscriber Connection (SC) -type optical fibre connector, comprising the steps of: -installing a Subscriber Connection (SC) -type optical fibre connector according to the method of Claim 1; and -mating said SC-type optical fibre connector with a matching optical fibre socket.
- 6. A method as claimed in any preceding claim, in which the inner housing and then the outer housing in turn are inserted over the projecting ferrule and sub-assembly by press-fitting along an axial direction.
- 7. A method of installing a Subscriber Connection (SC) -type optical fibre connector through a protective conduit, substantially as herein described, with reference to or as shown in Figures 5 to 25 of the accompanying drawings.
- 8. A method of making an optical fibre connection using an SC-style optical fibre connector through a protective conduit, substantially as herein described, with reference to or as shown in Figures 5 to 25 of the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1010181A GB2468442B (en) | 2007-05-04 | 2007-05-04 | Method of installing a push/pull type optical fibre connector |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB1010181A GB2468442B (en) | 2007-05-04 | 2007-05-04 | Method of installing a push/pull type optical fibre connector |
| GB0708709A GB2448935B8 (en) | 2007-05-04 | 2007-05-04 | Opticle fibre connector |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| GB201010181D0 GB201010181D0 (en) | 2010-07-21 |
| GB2468442A true GB2468442A (en) | 2010-09-08 |
| GB2468442B GB2468442B (en) | 2011-01-19 |
Family
ID=42471807
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB1010181A Active GB2468442B (en) | 2007-05-04 | 2007-05-04 | Method of installing a push/pull type optical fibre connector |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB2468442B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017156385A1 (en) * | 2016-03-10 | 2017-09-14 | Corning Optical Communications LLC | Fiber optic connectors having a ferrule insertion stop |
| EP3299858A1 (en) * | 2016-09-23 | 2018-03-28 | Hexatronic Group AB | Method of assembling a fibre connector |
| EP3830619A4 (en) * | 2018-08-03 | 2022-04-27 | PPC Broadband, Inc. | Fiber optical connector with retention feature |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102841411B (en) * | 2012-09-05 | 2014-07-23 | 武汉隽龙科技有限公司 | SC type optical fiber connector with light filtering function and manufacturing technology thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0819960A2 (en) * | 1996-07-15 | 1998-01-21 | Seiko Instruments Inc. | Universal optical fiber connectors and basic plugs thereof |
| WO2002052310A2 (en) * | 2000-12-27 | 2002-07-04 | Adc Telecommunications, Inc. | Tunable fiber optic connector and method for assembling |
-
2007
- 2007-05-04 GB GB1010181A patent/GB2468442B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0819960A2 (en) * | 1996-07-15 | 1998-01-21 | Seiko Instruments Inc. | Universal optical fiber connectors and basic plugs thereof |
| WO2002052310A2 (en) * | 2000-12-27 | 2002-07-04 | Adc Telecommunications, Inc. | Tunable fiber optic connector and method for assembling |
Cited By (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2017156385A1 (en) * | 2016-03-10 | 2017-09-14 | Corning Optical Communications LLC | Fiber optic connectors having a ferrule insertion stop |
| US9921375B2 (en) | 2016-03-10 | 2018-03-20 | Corning Optical Communications LLC | Ferrule-based fiber optic connectors with ferrule retraction balancing using axial gap geometry |
| US10126508B2 (en) | 2016-03-10 | 2018-11-13 | Corning Optical Communications LLC | Fiber optic connectors having a ferrule with an integral ferrule insertion stop |
| US11555969B2 (en) | 2016-03-10 | 2023-01-17 | Corning Optical Communications LLC | Ferrule-based fiber optic connectors with ferrule retraction balancing |
| US11719894B2 (en) | 2016-03-10 | 2023-08-08 | Corning Optical Communications LLC | Ferrule-based fiber optic connectors with ferrule retraction balancing |
| EP3299858A1 (en) * | 2016-09-23 | 2018-03-28 | Hexatronic Group AB | Method of assembling a fibre connector |
| WO2018055045A1 (en) * | 2016-09-23 | 2018-03-29 | Hexatronic Group Ab | Method of assembling a fibre connector |
| US10890721B2 (en) | 2016-09-23 | 2021-01-12 | Hexatronic Group Ab | Method of assembling a fibre connector |
| EP4086677A1 (en) * | 2016-09-23 | 2022-11-09 | Hexatronic Group AB | Ferrule assembly |
| EP3830619A4 (en) * | 2018-08-03 | 2022-04-27 | PPC Broadband, Inc. | Fiber optical connector with retention feature |
Also Published As
| Publication number | Publication date |
|---|---|
| GB2468442B (en) | 2011-01-19 |
| GB201010181D0 (en) | 2010-07-21 |
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