CA2242615A1 - Ferrule for connectors - Google Patents
Ferrule for connectors Download PDFInfo
- Publication number
- CA2242615A1 CA2242615A1 CA002242615A CA2242615A CA2242615A1 CA 2242615 A1 CA2242615 A1 CA 2242615A1 CA 002242615 A CA002242615 A CA 002242615A CA 2242615 A CA2242615 A CA 2242615A CA 2242615 A1 CA2242615 A1 CA 2242615A1
- Authority
- CA
- Canada
- Prior art keywords
- fibre
- ferrule
- hole
- guiding portion
- diameter
- 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.)
- Abandoned
Links
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
-
- 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
- G02B6/3861—Adhesive bonding
-
- 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
- G02B6/3835—Means for centering or aligning the light guide within the ferrule using discs, bushings or the like
-
- 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
- G02B6/3854—Ferrules characterised by materials
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- Mechanical Coupling Of Light Guides (AREA)
Abstract
A ferrule for connectors, particularly connectors of optical fibres, comprising a body (1) through which runs a hole for the passage of an optical fibre. The body (1) comprises a guide (2) for the fibre, in which the circumference of the straight portion of the hole forms a closed, non-circular line (3) enclosing and touching a circle (4) whose diameter depends on the diameter of the fibre. The form of the body (1) facilitates the ferrule's manufacture and better secures the fibre within the ferrule.
Description
CA 0224261~ 1998-07-09 (25727E.D~C ~ 5.~6.~998 VE:) FILE, Fa~3 ~ qE~
l:E~ T~l~Nl~;LQT~:)N
FERRULE FOR CONNECTORS
The lnvention relates to a ferrule for connectors, especially for connectors of optical fibres, said ferrule comprising a body traversed by a hole which is suitable for receiving an optical fibre.
Such a device is already known. Reversible connection of optical fibres, used for the transmission of luminous signals, is achieved by means of connectors of different kinds. Perfect allgnment of the two ends of the fibres to be connected is the omnipresent objective in the realisation of connectors for optical fibres. The mechanical workpiece on which the result of the connection depends the most and which reduces the intensity loss of a signal to a minimum, is the ferrule.
A ferrule is essentially a cylindrically shaped body having a diameter in the range of from 1.3 to 3.17 millimeter and a length of from 3 to 16 millimeter, depending on the nature of the connector to be used. The ferrule must have a hole which traverses the ferrule lengthwise and which is suitable for receiving the optical fibre which is typically glued therein. The diameter of the ferrule hole may vary from 0.124 millimeter to 0.150 millimeter according to the type of fibre to be introduced. At the time of assembling, the clearance between the ferrule hole and the optical fibre should be as small as possible in order to avoid alignment errors that would bring about intensity losses of the luminous signal; usual values of this clearance are inferior to 1 micrometer for monomodal connections and smaller than 3 to 4 micrometer for multimodal connections.
The position of the capillary hole is also very important for the results to be obtained when two ferrules, having i CA 022426l~ l998-07-os 125727L.WC l?rt: 15.06.199B Vl;) received the two ends of the fibre to be connected, are mechanically aligned by means of an elastic aligning sleeve which acts on their outer diameter. The concentricity deviation between the axis of the capillary hole and the axis of the ~errule itself should be as small as possible, ideally inferior to 1 to 1.4 micrometer for monomodal connections, and inferior to 3 to 4 micrometer for multimodal connections.
Still other properties of the ferrule may influence the quality of the connection, namely the thermal, chemical or mechanical stability of the material used and the degree of - surface finishing, more particularly of the contact surface of the ferrule and of its outer diameter.
There are several types of connectors commercially available. The connectors which are most widely used are those which comprise a single block ceramic ferrule (zirconium oxide, ZrO2). This material permits to obtain good performances as to material stabilityr and an optimal, nearly spectacular surface finishing which is the result of special polishing techniques. The material which is used for the manufacture of ceramic ferrules is a fritted "raw" body whose shape depends on the technique that is applied for moulding the body prior to the fritting treatment. There are two principal methods of manufacture: extrusion and injection moulding.
The extrusion method allows to obtain circular cylindrical bars having a capillary hole. It is not possible to obtain more complex shapes. The hardness of the material does not allow to remove material, excepted by special methods such as grinding with diamond fitted abrasive wheels or by polishing, always using abrasives on diamond basis.
Therefore, it is important to avoid such expensive CA 0224261~ 1998-07-09 ~25~7E:.I~C e~t: 15~06_l99~
operations regarding the type of equipment that must be used and the fact that these operations must be carried out rather slowly in order not to damage the piece under machining and the tool.
The method of injection moulding allows to obtain more complex shapes and thus a "raw" body whose shape is closer to that of the finished product by integrating shapes required for the final product. A major problem of this technique, however, is the difficulty of correctly managing, within the interior of the matrix, the filament that will produce the capillary hole. The pressure exerted by the flux of the molten ceramic material unavoidably causes a curving of the filament and a displacement from its axis with respect to the mould opening that shapes the outer diameter of the ferrule. As a result, the best values of the concentricity that can presently be obtained in industrial manufacture, are between 20 and 40 micrometer . This fact implies that, for obtaining the required values on the finished product, excess material must be removed from the outer diameter by grinding in various manners and with a mechanical effect on the capillary hole. To that end, it is required that the hole traverses the ferrule over its entire length with a constant diameter.
The length of the ferrule hole is a parameter that may influence the performances of the connector. The length which must guide the fibre within the ferrule must not be inferior to about 1.5 millimeter in order to avoid an angular misalignment of the fibre with respect to the ferrule. The length of the guiding hole in the ferrule, presently about 10 millimeter, is considered to be greatly exaggerated as to the functionality of the connector. This length is due to ferrule manufacturing considerations and aspects.
CA 0224261~ 1998-07-09 ~2572~E.DOC P~t: 15.1)6.1991~ VE) The objective of the invention is to provide a ferrule which can easily and cheaply be manufactured and which guarantees a safe and reliable connection.
This objective is achieved by the ferrule according to the invention which is characterised in that the body of the ferrule comprises a first guiding portion for the fibre, this portion being shaped in such a manner that the periphery of the cross section of the hole is a closed, non-circular line that surrounds a virtual circle whose diameter is a function - of the diameter of the fibre, said closed line touching said virtual circle at least once, and a second, additional fibre guiding portion having a circular cross section whose diameter corresponds to the diameter of said virtual circle, which diameter is determined by the size of the fibre to be lodged within the first guiding portion.
On the one hand, the above defined profile of the first guiding portion for the fibre allows the use of a reinforced matrix core during manufacture of the ferrule, and this fact greatly reduces the necessary grinding operations after manufacture, improves the concentricity of the hole with respect to the outer diameter, and facilitates the washing of the hole, all in maintaining the precise guidance of the fibre. On the other hand, the ferrule according to the present invention reduces the difficulty of inserting the fibre into the ferrule, thus improving the automation possibilities of the process, and generates a space into which any glue excess may enter and find an increased contact surface which improves the fixation of the fibre at the connection site. The second, additional guiding portion for the fibre still improves its guidance and provides an CA 0224261~i 1998-07-09 ~25727E.DOC ~re 15.06.1991~ VE) extremity of the ferrule that is virtually free from any glue deposit.
The means which are defined ln the dependent claims allow to implement the invention according to preferred embodiments.
Now, an embodiment of the device according to the invention will be described as a non-limiting example. Reference will be made to the drawing wherein:
FIG. 1 shows a partially cross-sectioned side elevation view of the ferrule, FIG. 2 shows a cross-sectional view according to the plane II-II in FIG. 1, FIG. 3 is an enlarged cross-sectional view of the central portion of the ferrule, and ~0 FIG. 4 shows a cross-sectional view according to the plane IV-IV in FIG. 3.
FIG. 1 shows a partly sectioned side elevation view of the ferrule for connectors according to the invention, and FIG.
l:E~ T~l~Nl~;LQT~:)N
FERRULE FOR CONNECTORS
The lnvention relates to a ferrule for connectors, especially for connectors of optical fibres, said ferrule comprising a body traversed by a hole which is suitable for receiving an optical fibre.
Such a device is already known. Reversible connection of optical fibres, used for the transmission of luminous signals, is achieved by means of connectors of different kinds. Perfect allgnment of the two ends of the fibres to be connected is the omnipresent objective in the realisation of connectors for optical fibres. The mechanical workpiece on which the result of the connection depends the most and which reduces the intensity loss of a signal to a minimum, is the ferrule.
A ferrule is essentially a cylindrically shaped body having a diameter in the range of from 1.3 to 3.17 millimeter and a length of from 3 to 16 millimeter, depending on the nature of the connector to be used. The ferrule must have a hole which traverses the ferrule lengthwise and which is suitable for receiving the optical fibre which is typically glued therein. The diameter of the ferrule hole may vary from 0.124 millimeter to 0.150 millimeter according to the type of fibre to be introduced. At the time of assembling, the clearance between the ferrule hole and the optical fibre should be as small as possible in order to avoid alignment errors that would bring about intensity losses of the luminous signal; usual values of this clearance are inferior to 1 micrometer for monomodal connections and smaller than 3 to 4 micrometer for multimodal connections.
The position of the capillary hole is also very important for the results to be obtained when two ferrules, having i CA 022426l~ l998-07-os 125727L.WC l?rt: 15.06.199B Vl;) received the two ends of the fibre to be connected, are mechanically aligned by means of an elastic aligning sleeve which acts on their outer diameter. The concentricity deviation between the axis of the capillary hole and the axis of the ~errule itself should be as small as possible, ideally inferior to 1 to 1.4 micrometer for monomodal connections, and inferior to 3 to 4 micrometer for multimodal connections.
Still other properties of the ferrule may influence the quality of the connection, namely the thermal, chemical or mechanical stability of the material used and the degree of - surface finishing, more particularly of the contact surface of the ferrule and of its outer diameter.
There are several types of connectors commercially available. The connectors which are most widely used are those which comprise a single block ceramic ferrule (zirconium oxide, ZrO2). This material permits to obtain good performances as to material stabilityr and an optimal, nearly spectacular surface finishing which is the result of special polishing techniques. The material which is used for the manufacture of ceramic ferrules is a fritted "raw" body whose shape depends on the technique that is applied for moulding the body prior to the fritting treatment. There are two principal methods of manufacture: extrusion and injection moulding.
The extrusion method allows to obtain circular cylindrical bars having a capillary hole. It is not possible to obtain more complex shapes. The hardness of the material does not allow to remove material, excepted by special methods such as grinding with diamond fitted abrasive wheels or by polishing, always using abrasives on diamond basis.
Therefore, it is important to avoid such expensive CA 0224261~ 1998-07-09 ~25~7E:.I~C e~t: 15~06_l99~
operations regarding the type of equipment that must be used and the fact that these operations must be carried out rather slowly in order not to damage the piece under machining and the tool.
The method of injection moulding allows to obtain more complex shapes and thus a "raw" body whose shape is closer to that of the finished product by integrating shapes required for the final product. A major problem of this technique, however, is the difficulty of correctly managing, within the interior of the matrix, the filament that will produce the capillary hole. The pressure exerted by the flux of the molten ceramic material unavoidably causes a curving of the filament and a displacement from its axis with respect to the mould opening that shapes the outer diameter of the ferrule. As a result, the best values of the concentricity that can presently be obtained in industrial manufacture, are between 20 and 40 micrometer . This fact implies that, for obtaining the required values on the finished product, excess material must be removed from the outer diameter by grinding in various manners and with a mechanical effect on the capillary hole. To that end, it is required that the hole traverses the ferrule over its entire length with a constant diameter.
The length of the ferrule hole is a parameter that may influence the performances of the connector. The length which must guide the fibre within the ferrule must not be inferior to about 1.5 millimeter in order to avoid an angular misalignment of the fibre with respect to the ferrule. The length of the guiding hole in the ferrule, presently about 10 millimeter, is considered to be greatly exaggerated as to the functionality of the connector. This length is due to ferrule manufacturing considerations and aspects.
CA 0224261~ 1998-07-09 ~2572~E.DOC P~t: 15.1)6.1991~ VE) The objective of the invention is to provide a ferrule which can easily and cheaply be manufactured and which guarantees a safe and reliable connection.
This objective is achieved by the ferrule according to the invention which is characterised in that the body of the ferrule comprises a first guiding portion for the fibre, this portion being shaped in such a manner that the periphery of the cross section of the hole is a closed, non-circular line that surrounds a virtual circle whose diameter is a function - of the diameter of the fibre, said closed line touching said virtual circle at least once, and a second, additional fibre guiding portion having a circular cross section whose diameter corresponds to the diameter of said virtual circle, which diameter is determined by the size of the fibre to be lodged within the first guiding portion.
On the one hand, the above defined profile of the first guiding portion for the fibre allows the use of a reinforced matrix core during manufacture of the ferrule, and this fact greatly reduces the necessary grinding operations after manufacture, improves the concentricity of the hole with respect to the outer diameter, and facilitates the washing of the hole, all in maintaining the precise guidance of the fibre. On the other hand, the ferrule according to the present invention reduces the difficulty of inserting the fibre into the ferrule, thus improving the automation possibilities of the process, and generates a space into which any glue excess may enter and find an increased contact surface which improves the fixation of the fibre at the connection site. The second, additional guiding portion for the fibre still improves its guidance and provides an CA 0224261~i 1998-07-09 ~25727E.DOC ~re 15.06.1991~ VE) extremity of the ferrule that is virtually free from any glue deposit.
The means which are defined ln the dependent claims allow to implement the invention according to preferred embodiments.
Now, an embodiment of the device according to the invention will be described as a non-limiting example. Reference will be made to the drawing wherein:
FIG. 1 shows a partially cross-sectioned side elevation view of the ferrule, FIG. 2 shows a cross-sectional view according to the plane II-II in FIG. 1, FIG. 3 is an enlarged cross-sectional view of the central portion of the ferrule, and ~0 FIG. 4 shows a cross-sectional view according to the plane IV-IV in FIG. 3.
FIG. 1 shows a partly sectioned side elevation view of the ferrule for connectors according to the invention, and FIG.
2 is a cross-sectional view in the plane II-II of FIG. 1.
The ferrule comprises a body 1 which is essentially cylindrical or prismatic and which is traversed by a hole for receiving an optical fibre, which hole extends over the entire length of the body 1. The body 1 is thus a tubular one. The cross section of the hole is not circular over the entire length of the body 1. The latter has a guiding portion 2 for the fibre. This portion 2 is shaped in such a manner that the periphery of the cross section of the hole (see FIG. 2) forms a non-circular closed line 3 that surrounds and touches a virtual circle 4 (see FIG. 4) whose CA 0224261~ 1998-07-09 ~257275.WC Prt: 15.06.199~
diameter is a function of the diameter of the fibre. In the Example shown, line 3 is a closed curve which extends around the axis of the hole and has a varying radius whose value is never inferior to a minimum value which depends on radius of the fibre . Since the radius of the envisaged fibre is known, this miniml~m value (that is half the diameter of circle 4) corresponds to the radius of the fibre plus a clearance value which is necessary for the introduction of the fibre into the ferrule. As an example, for a fibre having a thickness of 0.127 millimeter, this clearance value is in the order of + 0.004 millimeter. The maximum value of the varying radius of the closed curve is preferably at least twice the minimllm value. This allows the use of a reinforced matrix core during manufacture of the ferrule and reduces the required grinding operations.
The term "cross section of the hole" means the section of this hole in a plane that is perpendicular to the axis 5 of the hole. This axis 5 is a symmetry axis of the body 1. The periphery of the cross section of the hole can be any closed line whatsoever which surrounds the circle 4 and touches its circumference at least once at a point or at a portion of this circumference. Preferably, line 3 that delimits the cross section of the hole within the guiding portion 2 touches the circle 4, determined by the fibre, at least three times in such a manner that every time a contact point or a contact line segment (or zone) for the fibre is established (the contact points or contact zones being discontinuous, that is, separated by non-contact zones).
Each contact point is part of a longitudinal contact line (which is also a generating line of the hole where the hole is prismatic or cylindrical, and its cross-section non-circular). For assembling the fibre, it is glued into the ferrule, and the glue is deposited within the clearance zone around the fibre and within the spaces created by the shape CA 022426l~ l998-07-os ~257271~ 0C E'~t: 15. 06. 199~
of the hole (whlch is for example prismatic or cylindrical and its cross-section non-circular; in this case, line 3 is the directrix). Thus, the precise guidance of the fibre within the ferrule is guaranteed.
FIG. 3 shows an enlarged longitudinal section of the central portion of the ferrule, and FIG. 4 is a cross-sectional view according to plane IV-IV in FIG. 3 (and which corresponds to the plane II-II in FIG. 1). In the example shown, the body 1 is shaped in such a manner that the cross section of the hole within the guiding portion 2 is like a four-leaf clover. This construction shape has proven to be advantageous for the manufacturing precision of the ferruler the assembling ease, and the safe and reliable fastening of the fibre in the ferrule.
The body 1 further comprises a second, additional guiding portion 6 for the fibre. This portion 6 has a circular cross section. The diameter of the circular cross section of this additional guiding portion 6 corresponds to that of the circle 4, determined by the fibre within the first guiding portion 2 (i.e. the desired nominal diameter of a ferrule hole: fibre diameter plus clearance). According to the present example, the additional guiding portion 6 guides the fibre by a length of about 0.3 millimeter whereas the first guiding portion 2 guides the fibre by a length of about 1.3 millimeter, the total length of both guiding portions thus being about 1.6 millimeter. This guiding length is sufficient for avoiding an angular misalignment of the fibre with respect to the ferrule. The ferrule according to the invention has thus a length of the guiding hole for the fibre which is reduced to a minimum.
The body 1 has a third portion 7 where the cross section of the hole is circular and has a diameter greater than the CA 022426l~ l998-07-os ~5~2-~;.DOC er~: 15.06.~99~
greatest diameter of the guiding portion 2. The guiding length of the two guiding portions 2 and 6 being sufficient, this third portion 7 does not serve as a fibre guide and further renders the assembling easier.
The "raw" ferrule body, namely the original piece as such, is manufactured by injection moulding and does not require any removal of material for obtaining the correct hole diameter, nor any grinding of the external diameter of the ferrulei this avoids any detrimental mechanical effect on the inner diameter. The core of the matrix used which is stressed for bending during injection by the flux of the ~ molten material may be reinforced thanks to the profile of the guiding portion 2 and of the third portion 7.
Preferably, the ferrule is made of ceramics by Ceramic Injection Moulding (CIM), of metal by Metal Injection Moulding (MIM), or of suitable thermoplastic materials.
The dimension conditions of the capillary hole as well as the concentricity of the hole with respect to the outer diameter are improved. Moreover, the washing operations for cleaning the capillary hole and for avoiding its obstruction are rendered substantially easier.
- - - - -
The ferrule comprises a body 1 which is essentially cylindrical or prismatic and which is traversed by a hole for receiving an optical fibre, which hole extends over the entire length of the body 1. The body 1 is thus a tubular one. The cross section of the hole is not circular over the entire length of the body 1. The latter has a guiding portion 2 for the fibre. This portion 2 is shaped in such a manner that the periphery of the cross section of the hole (see FIG. 2) forms a non-circular closed line 3 that surrounds and touches a virtual circle 4 (see FIG. 4) whose CA 0224261~ 1998-07-09 ~257275.WC Prt: 15.06.199~
diameter is a function of the diameter of the fibre. In the Example shown, line 3 is a closed curve which extends around the axis of the hole and has a varying radius whose value is never inferior to a minimum value which depends on radius of the fibre . Since the radius of the envisaged fibre is known, this miniml~m value (that is half the diameter of circle 4) corresponds to the radius of the fibre plus a clearance value which is necessary for the introduction of the fibre into the ferrule. As an example, for a fibre having a thickness of 0.127 millimeter, this clearance value is in the order of + 0.004 millimeter. The maximum value of the varying radius of the closed curve is preferably at least twice the minimllm value. This allows the use of a reinforced matrix core during manufacture of the ferrule and reduces the required grinding operations.
The term "cross section of the hole" means the section of this hole in a plane that is perpendicular to the axis 5 of the hole. This axis 5 is a symmetry axis of the body 1. The periphery of the cross section of the hole can be any closed line whatsoever which surrounds the circle 4 and touches its circumference at least once at a point or at a portion of this circumference. Preferably, line 3 that delimits the cross section of the hole within the guiding portion 2 touches the circle 4, determined by the fibre, at least three times in such a manner that every time a contact point or a contact line segment (or zone) for the fibre is established (the contact points or contact zones being discontinuous, that is, separated by non-contact zones).
Each contact point is part of a longitudinal contact line (which is also a generating line of the hole where the hole is prismatic or cylindrical, and its cross-section non-circular). For assembling the fibre, it is glued into the ferrule, and the glue is deposited within the clearance zone around the fibre and within the spaces created by the shape CA 022426l~ l998-07-os ~257271~ 0C E'~t: 15. 06. 199~
of the hole (whlch is for example prismatic or cylindrical and its cross-section non-circular; in this case, line 3 is the directrix). Thus, the precise guidance of the fibre within the ferrule is guaranteed.
FIG. 3 shows an enlarged longitudinal section of the central portion of the ferrule, and FIG. 4 is a cross-sectional view according to plane IV-IV in FIG. 3 (and which corresponds to the plane II-II in FIG. 1). In the example shown, the body 1 is shaped in such a manner that the cross section of the hole within the guiding portion 2 is like a four-leaf clover. This construction shape has proven to be advantageous for the manufacturing precision of the ferruler the assembling ease, and the safe and reliable fastening of the fibre in the ferrule.
The body 1 further comprises a second, additional guiding portion 6 for the fibre. This portion 6 has a circular cross section. The diameter of the circular cross section of this additional guiding portion 6 corresponds to that of the circle 4, determined by the fibre within the first guiding portion 2 (i.e. the desired nominal diameter of a ferrule hole: fibre diameter plus clearance). According to the present example, the additional guiding portion 6 guides the fibre by a length of about 0.3 millimeter whereas the first guiding portion 2 guides the fibre by a length of about 1.3 millimeter, the total length of both guiding portions thus being about 1.6 millimeter. This guiding length is sufficient for avoiding an angular misalignment of the fibre with respect to the ferrule. The ferrule according to the invention has thus a length of the guiding hole for the fibre which is reduced to a minimum.
The body 1 has a third portion 7 where the cross section of the hole is circular and has a diameter greater than the CA 022426l~ l998-07-os ~5~2-~;.DOC er~: 15.06.~99~
greatest diameter of the guiding portion 2. The guiding length of the two guiding portions 2 and 6 being sufficient, this third portion 7 does not serve as a fibre guide and further renders the assembling easier.
The "raw" ferrule body, namely the original piece as such, is manufactured by injection moulding and does not require any removal of material for obtaining the correct hole diameter, nor any grinding of the external diameter of the ferrulei this avoids any detrimental mechanical effect on the inner diameter. The core of the matrix used which is stressed for bending during injection by the flux of the ~ molten material may be reinforced thanks to the profile of the guiding portion 2 and of the third portion 7.
Preferably, the ferrule is made of ceramics by Ceramic Injection Moulding (CIM), of metal by Metal Injection Moulding (MIM), or of suitable thermoplastic materials.
The dimension conditions of the capillary hole as well as the concentricity of the hole with respect to the outer diameter are improved. Moreover, the washing operations for cleaning the capillary hole and for avoiding its obstruction are rendered substantially easier.
- - - - -
Claims (11)
1. Ferrule for connectors, especially for connectors of optical fibres, comprising a body (1) traversed by a hole which is suitable for receiving an optical fibre, said ferrule being characterised in that the body (1) of the ferrule comprises (a) a first guiding portion (2) for the fibre, this portion (2) being shaped in such a manner that the periphery of the cross section of the hole is a closed, non-circular line (3) that surrounds a virtual circle (4) whose diameter is a function of the diameter of the fibre, said closed line (3) touching said virtual circle (4) at least once, and (b) a second, additional fibre guiding portion (6) having a circular cross section whose diameter corresponds to the diameter of said virtual circle (4), which diameter is determined by the size of the fibre to be lodged within the first guiding portion (2).
2. A ferrule according to claim 1, characterised in that said first guiding portion (2) is shaped in such a manner that in that portion the hole is prismatic or cylindrical and its cross-section non-circular.
3. A ferrule according to claim 1 or 2, characterised in that in the first guiding portion (2) the line (3) which delimits the cross section of the hole, touches at least three times said virtual circle (4) determined by the fibre, in such a manner that each time at least one contact point with the fibre is established.
4. A ferrule according to any one of claims 1 to 3, characterised in that said closed line (3) extends around the axis of the hole and has a varying radius whose minimum value corresponds to the radius of the fibre plus a clearance value.
5. A ferrule according to claim 4, characterised in that the maximum value of the varying radius of the closed line (3) is at least twice its minimum value.
6. A ferrule according to any one of claims 1 to 5, characterised in that in the first guiding portion (2) the cross section of the hole has the shape of a four-leaf clover.
7. A ferrule according to any one of claims 1 to 6, characterised in that the axis of the hole (5) is a symmetry axis of said body (1).
8. A ferrule according to any one of claims 1 to 7, characterised in that said first guiding portion (2) and said second, additional guiding portion (6) have a total length of about 1.6 millimeter.
9. A ferrule according to any one of claims 1 to 8, characterised in that said body (1) further comprises a third portion (7) wherein the cross section of the hole is circular and has a diameter greater than the greatest diameter of the first guiding portion (2).
10. A ferrule according to any one of claims 1 to 9, characterised in that it is manufactured by injection moulding.
11. A ferrule according to any one of claims 1 to 10, characterised in that it is made of ceramics by Ceramic Injection Moulding (CIM), of metal by Metal Injection Moulding (MIM), or of a thermoplastic material.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| EP96810021A EP0784219A1 (en) | 1996-01-10 | 1996-01-10 | Optical connector ferrule |
| EP96810021.4 | 1996-01-10 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2242615A1 true CA2242615A1 (en) | 1997-07-17 |
Family
ID=8225532
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002242615A Abandoned CA2242615A1 (en) | 1996-01-10 | 1997-01-09 | Ferrule for connectors |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0784219A1 (en) |
| JP (1) | JP2000502817A (en) |
| KR (1) | KR19990077119A (en) |
| AU (1) | AU1187997A (en) |
| CA (1) | CA2242615A1 (en) |
| IL (1) | IL125087A0 (en) |
| WO (1) | WO1997025640A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102018204387A1 (en) * | 2018-03-22 | 2019-05-23 | Sumida Flexible Connections Gmbh | Guide element for a lightwave connector and method for its manufacture |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3128510B2 (en) * | 1996-04-22 | 2001-01-29 | セイコーインスツルメンツ株式会社 | Ferrule for optical connector |
| JP3516256B2 (en) | 1998-07-31 | 2004-04-05 | 矢崎総業株式会社 | Optical fiber fixing structure of ferrule |
| DE19923416C2 (en) * | 1999-05-21 | 2002-01-17 | Tyco Electronics Logistics Ag | Ferrule for an optical waveguide, method for producing such a ferrule and method for fastening a ferrule to an optical waveguide |
| KR100368436B1 (en) * | 2000-05-15 | 2003-01-24 | (주)이탑스테크놀로지 | Ferrule for end of optical fiber and Method thereof |
| JP2004045805A (en) * | 2002-07-12 | 2004-02-12 | Yazaki Corp | Ferrule for optical fiber connection and welding method of optical fiber and ferrule |
| JP2007264424A (en) * | 2006-03-29 | 2007-10-11 | Kyocera Corp | Optical fiber component and optical device |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS589114A (en) * | 1981-07-08 | 1983-01-19 | Ritsuo Hasumi | Connector made of plastic for optical fiber |
| EP0130513A3 (en) * | 1983-06-26 | 1986-12-30 | Allied Corporation | Fiber optic connector |
| JPS6087304A (en) * | 1983-10-20 | 1985-05-17 | Fujitsu Ltd | Optical connector |
| JPH0616126B2 (en) * | 1986-11-06 | 1994-03-02 | 日本電気株式会社 | Ferrule for optical fiber connection |
| JPH02253207A (en) * | 1989-03-28 | 1990-10-12 | Miwa Denki Kogyo Kk | Production of ferrule for optical fiber connector |
| DE4219901A1 (en) * | 1992-06-17 | 1993-12-23 | Amp Inc | Optical fiber end sleeve |
-
1996
- 1996-01-10 EP EP96810021A patent/EP0784219A1/en not_active Withdrawn
-
1997
- 1997-01-09 IL IL12508797A patent/IL125087A0/en unknown
- 1997-01-09 AU AU11879/97A patent/AU1187997A/en not_active Abandoned
- 1997-01-09 CA CA002242615A patent/CA2242615A1/en not_active Abandoned
- 1997-01-09 WO PCT/CH1997/000006 patent/WO1997025640A1/en not_active Application Discontinuation
- 1997-01-09 JP JP9524707A patent/JP2000502817A/en active Pending
- 1997-01-09 KR KR1019980705255A patent/KR19990077119A/en not_active Application Discontinuation
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102018204387A1 (en) * | 2018-03-22 | 2019-05-23 | Sumida Flexible Connections Gmbh | Guide element for a lightwave connector and method for its manufacture |
Also Published As
| Publication number | Publication date |
|---|---|
| AU1187997A (en) | 1997-08-01 |
| WO1997025640A1 (en) | 1997-07-17 |
| EP0784219A1 (en) | 1997-07-16 |
| KR19990077119A (en) | 1999-10-25 |
| IL125087A0 (en) | 1999-01-26 |
| JP2000502817A (en) | 2000-03-07 |
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| Date | Code | Title | Description |
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| FZDE | Discontinued |