WO2010102401A1

WO2010102401A1 - Elastically deformable cable connector, multi- connector block and methods of connecting cables

Info

Publication number: WO2010102401A1
Application number: PCT/CA2010/000351
Authority: WO
Inventors: Patrick Zivojinovic; Éric WEYNANT; Robin CÉRUTTI; Géraldine TROUILLARD
Original assignee: Phasoptx Inc.
Priority date: 2009-03-11
Filing date: 2010-03-10
Publication date: 2010-09-16

Abstract

A highly elastically deformable cable connector comprises a connector body that may be made of a shape memory alloy (SMA). The connector body deforms when a force is applied to the connector body. The connector body has a deformation cavity in an interior portion of the connector body to enable and then limit deformation of the connector body when the force is applied. The connector body has a fiber-receiving opening or conduit for receiving fibers to be connected together. Also disclosed herein are connector blocks having a plurality of connectors to enable multiple pairs of fibers to be spliced together. Also disclosed herein are methods of connecting cables that entail splicing fibers using elastically deformable connectors that may be formed of shape memory alloys.

Description

ELASTICALLY DEFORMABLE CABLE CONNECTOR, MULTI- CONNECTOR BLOCK AND METHODS OF CONNECTING CABLES

TECHNICAL FIELD

[0001] The present invention relates to connectors for telecommunications cables and, in particular, to connectors for fiber optic cables.

BACKGROUND

[0002] Optical communications systems, which provide the backbone of most modern long-haul telecommunications networks, use fiber optic cables to carry the optical signals from one node to another. Connecting fiber optic cables together remains a technical problem for which a fully satisfactory solution has yet to have been devised.

[0003] Two general optical fiber splicing techniques are known in the art, arc fusion splicing and mechanical splicing. Arc fusion splicing is accomplished by fusing the ends of optical fibers together with a spark generated by electrodes. This technique tends to be intricate and time-consuming to utilize. Mechanical splicing is a much quicker technique but it has a propensity to incur high optical losses (insertion losses) across the connection or coupling due to the bonded joint. Mechanically splicing fibers typically requires that the fibers be aligned and held together using a precision sleeve and gel adhesive having a carefully selected index of refraction that minimizes Fresnel reflection across the splice. Nonetheless, these mechanical splices typically have higher optical losses and are less robust than fusion splices, even if a protective enclosure is used.

[0004] In the case of mechanical connectors, it is common to place the fiber ends m a single "V" groove on a substrate in end-to-end abutment and then to build a packaging around the fibers with the use of optical gels and/or adhesives to complete the connection. When the fibers are not of the same diameter, the alignment of fibers in a groove in a substrate is not good. Technical solutions to this problem have been disclosed by Applicant in WO 2008/151445 Al entitled CONNECTOR FOR MULTIPLE OPTICAL FIBERS AND INSTALLATION APPARATUS.

[0005] The use of a glue or bonding agent (distinct from an index-matching gel) to bond the mechanical splices together is problematic because the bond may come undone, especially in the presence of thermal extremes (i.e. may melt or loosen in extreme heat or become brittle in extreme cold) . For many applications, therefore, a bonded connection is unsatisfactory. Furthermore, a bonded connection cannot be rotated inside the connector, i.e. one cable cannot be rotated relative to the other cable. For applications where the polarization of light matters, a bonded mechanical splice can be highly inflexible. Moreover, another significant disadvantage of bonded couplings is that they cannot be reused.

[0006] A mechanical splice for optical fibers that provides an easier way to connect fibers with greater rates of success than the rate of success associated with the previous state of the art has been developed by the Applicants of the present invention. In U.S. patent application publication 2005/0220418 published on Oct. 6, 2005, based on PCT/CA03/00232 published as WO 2003/071328, there is disclosed a mechanical splice made of shape memory alloy construction having an axial passageway or conduit that is expandable to receive an optical fiber end. The splice can then exert a moderate radial pressure to retain the optical fiber securely centered in the axial passageway and ensure an end-to-end coupling between two optical fiber ends . [0007] Such technology however requires special tooling for opening and closing the axial passageway in order to controllably secure and release the optical fiber ends to provide the desired optical coupling. Examples of instruments adapted to allow the controlled expansion and contraction of the axial passageway in the mechanical splice is known from Applicant's own previous PCT publications, WO 2004/015473 published Feb. 19, 2004 and WO 2005/040876 published May 6, 2005. In Applicant's commonly assigned U.S. Patent 7,490,995, an optical connector assembly is disclosed for interconnecting two optical fibers. In some embodiments of the invention disclosed m U.S. Patent 7,490,995, two corresponding ferrules are used for securing the fibers to lead into the splice, the ferrules being interconnected by a sheath to form a connector body. At least one of the ferrules has one or more fiber guiding members adapted to fit within the aperture of the first extremity of the first fiber conduit for aligning the first and second fiber conduits and for guiding the first fiber end into the first fiber conduit without catching an edge. In other embodiments, at least one of the ferrules is adapted to engage the mechanical splice with inter-engaging members that allow for mechanical expansion and contraction of a first fiber conduit of the splice by adjusting the position of the ferrule with respect to the splice by a suitable mechanism such as an adjustment nut acting between the sheath. In another embodiment, the first ferrule releases exerted compression against the splice forming a first gap between the first ferrule and the splice.

[0008] Further improvements on this technology remain desirable in order to provide a cable connector and/or a method of mechanically connecting cables that simplify the connecting of fiber optic cables while minimizing optical losses across the connection. SUMMARY

[0009] In broad terms, the present invention provides a novel elastically deformable cable connector for connecting cables as well as an elastically deformable multi-connector assembly for connecting multiple pairs of cables. This invention also provides a number of related innovative methods for connecting cables, and for splicing fibers and packaging connected cables. As will be elaborated below, these various aspects of the invention enable cables, e.g. fiber optic cables, to be connected easily and efficiently without requiring bonding or adhesives while also minimizing signal losses (e.g. optical losses) across the resulting connection.

[0010] Accordingly, one main aspect of the present invention is a novel elastically deformable cable connector comprising a connector body made of a highly elastically deformable material, such as, for example, a shape memory alloy, that deforms elastically when a force is applied to an outer surface of the connector body, wherein the connector body includes a deformation cavity in an interior portion of the connector body to assist and then limit deformation of the connector body when the force is applied, and wherein the connector body has a fiber-receiving opening adapted for receiving and splicing respective fibers of the cables to be connected together.

[0011] Another main aspect of the present invention is a multi-connector assembly for connecting a plurality of pairs of cables. The assembly comprises a connector body made of a highly elastically deformable material such as, for example, a shape memory alloy, that deforms when a force is applied to an outer surface of the connector body, wherein the connector body has a plurality of deformation cavities disposed within an interior portion of the connector body to assist and then limit deformation of the connector body when the force is applied to an outer surface of the connector body, and wherein the connector body has a plurality of fiber-receiving openings each adapted for receiving and splicing respective fibers of the cables to be connected together.

[0012] Yet another main aspect of the present invention is an innovative method of connecting fiber optic cables. The method entails providing a highly elastically deformable connector, e.g. a shape-memory alloy connector, and then exerting a force on an outer surface of the connector to cause the connector to deform elastically from an original, undeformed shape to a deformed shape; inserting fibers extending from cables to be connected into an alignment hole within the connector; and releasing the force on the connector to cause the connector to return substantially to the undeformed shape thereby splicing the fibers and thus connecting the cables together.

[0013] A further main aspect of the present invention is a method of splicing and packaging fiber optic cables in which alignment and splicing of the fibers is performed using a tool and a separate case is used to enshroud the spliced cables. The method comprises providing an elastically deformable connector having a connector body having a deformation cavity in the connector body to assist and then limit deformation of the connector body when a force is applied to an outer surface of the connector body, applying the force to the connector body to cause deformation of the connector body, inserting fibers from respective cables to be connected through one or more alignment holes in the connector body, releasing the force to cause the connector body to splice the fibers, thus connecting the cables together, and packaging the cables to further connect the cables together. [0014] A further main aspect of the present invention is a method of splicing and packaging fiber optic cables in which alignment, splicing and packaging is done within a single case but wherein the application of force is done using a tool or external implement. This method comprises providing a cable- enshrouding case having an internal compartment for receiving an elastically deformable fiber connector, the cable case further having one or more alignment holes for aligning fibers of respective cables to be connected, and further having a tool access hole through which a tool may be inserted for exerting a force on the fiber connector to cause the fiber connector to deform elastically, applying the force on an outer surface of the fiber connector to cause elastic deformation of the fiber connector, thereby opening the fiber connector for receiving fibers, inserting the fibers through the one or more alignment holes in the cable case into the fiber connector, and releasing the force on the fiber connector to cause the fiber connector to splice the fibers together within the cable case.

[0015] A further main aspect of the present invention is a method of splicing and packaging fiber optic cables in which alignment, splicing, and packaging is also done in a single case that includes its own internal tool for automatically actuating the deformable connector. This method comprises providing a cable-enshrouding case having a movable cover and an internal compartment for receiving an elastically deformable fiber connector, the cable case further having alignment holes for aligning first and second fibers to be spliced together, and further having an access hole for exerting a force on an outer surface on the fiber connector to cause the fiber connector to deform elastically, opening the cover of the case to place within the fiber connector within the internal compartment, and closing the cover of the case, the cover having first and second internal abutments that sequentially actuate the elastically deformable fiber connector as the cover is moved from an open position to a closed position, the first abutment causing a first portion of the elastically deformable fiber connector to deform to enable insertion of the first fiber into the fiber connector, the second abutment subsequently causing a second portion of the elastically deformable fiber connector to deform to enable insertion of the second fiber, the first and second fibers being spliced together as the cover of the case is returned tothe closed position.

[0016] Yet another aspect of the present invention is an elastically deformable cable connector comprising an elevated support member and a connector body made of a shape memory alloy that deforms elastically when a force is applied to an outer surface of the connector body. The connector body is supported in an elevated position by the elevated support member, thereby defining a gap beneath the connector body to enable the connector body to deform downwardly when the force is applied. The connector body has a fiber-receiving opening adapted for receiving fibers when the connector body is deformed and then splicing respective fibers of the cables when the force is released. This fiber-receiving open may extend downwardly from a top surface of the connector body.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Further features and advantages of the present invention will become apparent from the following detailed description, taken in combination with the appended drawings, in which:

[0001] FIGS. IA and IB are side views of a shape memory alloy cable connector, in which FIG. IA shows the connector in an undeformed shape and FIG. IB shows the connector in a deformed shape;

[0002] FIG. 2 is an isometric view of a shape memory alloy cable connector with a dividing slit;

[0003] FIG. 3 is a side view of a multi-connector assembly that is assembled from three independent single-connector bodies which are partially separated by gaps between each adjacent pair of connector bodies;

[0004] FIG. 4 is an isometric view of a series of three cable connectors;

[0005] FIG. 5 is a cutaway view of another embodiment of a multi-connector assembly having two fiber slots (fiber- receiving openings) and opposed (back-to-back) cavities for separately actuating the flber-receivmg openings;

[0006] FIG. 6 is an isometric view of another embodiment of a multi-connector assembly, made from a single piece of alloy material, in which are cut two fiber slots, a central dividing slit and two deformation-assisting cavities that not only assist deformation but also limit the range of deformation;

[0007] FIG. 7 is an isometric view of another embodiment of a multi-connector assembly having twelve fiber slots (fiber- receiving openings) ;

[0008] FIG. 8 is a screen shot taken from a stress analysis software application for a finite element analysis model of a shape memory alloy cable connector undergoing deformation due an external force applied on a top right portion of the connector;

[0009] FIG. 9 is an example of a tool for aligning and splicing the fibers; [0010] FIG. 10 is an example of a packaging in which the connection is formed by using an external tool;

[0011] FIG. 11 is an example of a packaging for alignment and splicing fibers that includes its own internal tool for actuating the deformable connector;

[0012] FIGS. 12A-E together depict the pivotal cover of the cable-enshrouding case and how this cover automatically actuates the opening and closing of the flber-receivmg slots by sequentially abutting the connector body to cause sequential deformation of the flber-receivmg openings; and

[0013] FIG. 13 depicts another alternative embodiment of the connector wherein there is no deformation-assisting cavity but wherein the body of the connector is supported in an elevated manner to enable downward deformation of the body when a downward force is exerted.

[0014] It will be noted that throughout the appended drawings, like features are identified by like reference numerals. It should furthermore be noted that the drawings are not necessarily to scale.

DETAILED DESCRIPTION

[0015] In general, and by way of introduction, the present invention provides a novel cable connector a novel method of connecting cables such as fiber optic cables. The cable connector has a connector body made of a shape memory alloy that deforms when a force or pressure is exerted on an outer surface of the connector body. A related aspect of this invention is a novel method of connecting cables which entails exerting a force or pressure on a connector body, inserting the cables, and releasing the force or pressure on the connector body to cause the connector body to tend to return to its original, undeformed shape. When an external force or pressure is exerted on the outer surface of t-he connector body, the body deforms to expand a flber-receivmg opening (or slot or conduit) that, when the force or pressure is relieved, contracts to grip and hold the fiber in place. This splicing technique therefore can be easily performed by application of a force on the outer surface of the connector body using a finger, thumb or other implement. No wedge or prying instrument is required to open this connector.

[0016] References throughout the disclosure to an "original" or "undeformed" shape are to be understood as meaning a substantially, originally undeformed shape.

[0017] Specific embodiments and implementations of the present invention will now be described below, by way of example, with reference to the attached drawings.

[0018] FIG. 1 depicts an elastically deformable cable connector in accordance with one embodiment of the present invention. This cable connector comprises a connector body 4 made of a shape memory alloy that deforms elastically when a force is applied to the connector body. The connector body includes a deformation cavity 3 in an interior portion of the connector body that allows and limits deformation of the connector body when the force is applied. The connector body also has a flber-receivmg opening 1 (also referred to herein as a fiber slot or flber-splicmg channel) adapted for receiving and splicing respective fibers 6 of the cables to be connected together.

[0019] As depicted in FIG. 1, the deformation cavity 3 (also referred to herein as a deformation-assisting cavity, a deformation-augmenting cavity, a deformation-enabling cavity or a deformation-assisting/limitmg cavity) 3 in the connector can be a thin rectangular slit, as shown, a V-shaped enclosure or effectively any other shaped gap. To facilitate or assist deformation, this cavity extends substantially orthogonally to a force vector 2 of the force applied to the connector body. The shape and size of this cavity determines the amount of flexure in the body, i.e. not only how easily it deforms but also how far it can deform until one side of the gap abuts the other side of the gap. As shown in FIG. 1, the slit 3 (i.e. the deformation-assisting/limiting cavity) defines a gap that may extend from a lateral surface of the connector body into the interior portion of the connector body. Alternatively, the cavity 3 may be simply an internal cavity that does not extend to an outer surface. Such an internal cavity may be produced by laser cutting, for example. For single connectors, either laser cutting or conventional machining can be used. For multiple connectors within the same integral piece of alloy, laser cutting is used. The case of multiple connectors within the same integral piece of memory allow shall be described in greater detail below. It should be noted that in other embodiments of the present invention, the applied force vector need not be perpendicular to the deformation cavity as noted in the embodiment described above. Other orientations of the cavity or cavities disposed within the connector body can be provided to enable forces to be exerted laterally (from the sides) or on other portions of the outer surface of the body that are not necessarily perpendicular to the deformation cavity.

[0020] As illustrated in FIG. 1, the fiber-receiving opening 1 comprises an opening slit 5 that widens or expands when the force is applied to the connector body. The opening 1 includes a substantially circular channel or slot defining an alignment hole for centering and splicing the fibers. This circular slot function as a self-centering hole for aligning and holding the fibers.

[0021] The connector body may be made of an alloy of copper and aluminum, which provides extremely high elasticity. As will be elaborated below, other shape memory alloys or highly elastic materials may also be contemplated. Shape memory materials provide high levels of elasticity, while at the same time, provide the desired levels of rigidity suitable for optic fiber coupling. It will be appreciated by a person skilled m the art of such materials that a shape memory material suitable for making such a splice can be polymer based, an alloy of copper and aluminum along with a wide variety of other shape memory materials. The essential property for a suitable material to make a mechanical splice that retains fiber ends in a fiber conduit in optical alignment is the ability for the material to expand and contract. With some shape memory materials, it will be appreciated that up to 8-10% deformation can be achieved. When deformations exceed approximately 5%, as is the case for many shape memory alloys, it is possible to use such materials to be controllably expanded and contracted to allow for positioning and securing of fibers m axial alignment in the fiber conduit. Applicants have found that the holding force of such a mechanical splice on a fiber is better than any adhesive and can allow for a fiber to be held and released without damage. Thus, the mechanical splice, as illustrated in FIG. 1, allows for the optical connector assembly to be reusable .

[0022] FIG. 2 depicts another embodiment of a cable connector in which the connector further includes a dividing slit 7 that divides a first portion of the connector body from a second portion of the connector body. The dividing slit can be disposed substantially orthogonally to both the deformation- augmenting/limiting cavity and the opening slit, as shown in FIG. 2. The dividing slit 7 enables the first and second portions of the connector body to be independently deformed. Thus, one fiber 6 can be inserted by deforming one portion of the connector body and then a second fiber can be inserted by deforming another portion of the connector body.

[0023] Optionally, the cable connector may further have a visually delineated actuation zone disposed on the connector body to visually indicate a predetermined optimal location for exerting the force on the connector body for causing deformation of the connector body, as shown by way of example m FIG. 9. For instance, buttons or other such elements may be provided on the connector as predetermined pressure- application points for optimally deforming the connector body. Optimally deforming the connector body is important since this ensure that the openings expand m a dimensionally acceptable manner, e.g. m a symmetrical manner, with minimal application of force or pressure. Alternatively, where the body contains a dividing slit, first and second visibly delineated actuation zones or actuation buttons can be provided on either side of the dividing slit. In other words, the first actuation zone or button can be disposed on the first portion of the connector body and the second zone or button can be disposed on the second portion of the connector body. The actuation zones or buttons indicate visually the optimal locations for exerting respective forces on the first and second portions of the connector body.

[0024] Force or pressure can be exerted manually, e.g. by finger or thumb, or by using a tool, or by driving an actuator such as a piezoelectric element by exploiting the reverse piezoelectric effect (inducing strain by application of an electric field) . [0025] FIG. 3 introduces a multi-connector assembly for connecting a plurality of pairs of cables m accordance with another embodiment of the present invention. By way of example only, the assembly depicted m this figure includes three flber-receivmg openings and two dividing slits. The multi-connector assembly includes a connector body 4 made of a shape memory alloy that deforms when a force is applied to the connector body. The connector body 4 has a plurality of deformation-assisting/limitmg cavities 3 disposed within an interior portion of the connector body to augment deformation of the connector body when the force is applied to an outer surface of the connector body. In this example, there are three such cavities. The connector body 4 has a plurality of fiber-receiving openings 1 each adapted for receiving and splicing respective fibers of the cables to be connected together. As noted above for the single connectors, the fiber-receiving openings of the multi-connector assembly each comprises an opening slit that widens when the force is applied to the connector body. Each of the openings can also further comprise a substantially circular channel or slot for centering and splicing the fibers.

[0026] FIG. 4 is an isometric view of a series of three cable connectors. This illustrates how a group of these connectors can be used to connect respective cable segments together in series (as m FIG. 4) or in parallel (as m FIG. 3), or combinations thereof.

[0027] FIG. 5 depicts another embodiment of the multi- connector assembly in which two fiber-receiving slots are provided along with respective deformation-assistmg/limiting cavities. This assembly can be used to connect two pairs of cables in parallel with the same connector. [0028] FIG. 6 is an isometric view of another embodiment of a multi-connector assembly having two fiber slots, a central dividing slit and two deformation-assisting/limiting cavities. The dividing slit 7 is disposed between each adjacent pair of opening slits. The dividing slits are, in this example, disposed parallel to the opening slits to enable each opening slit to be operated independently of each of the other opening slits in the connector body. It should be understood that multiple connectors can be connected together or, alternatively, as depicted in this figure, a single piece of alloy can be used as the body and multiple fiber-receiving openings can be cut within this same body, i.e. multiple fiber-receiving openings can be cut from a single integral alloy structure.

[0029] FIG. 7 is an isometric view of another embodiment of a multi-connector assembly having twelve fiber slots (fiber- receiving openings) . This illustrates that virtually any number, configuration, or arrangement of connectors can be provided in the multi-connector assembly.

[0030] The connector body of these various multi-connector assemblies can be made of an alloy of copper and aluminum or other functionally eguivalent material. The horizontal cavity shown in this figure can be produced by laser cutting.

[0031] FIG. 8 is a screen shot taken from a stress analysis software application for a finite element analysis model of a shape memory alloy cable connector undergoing deformation due an external force applied on a top right portion of the connector. In other words, this finite element model shows the strain in the connector body when it is stressed by the application of a downward force on the top right corner of the connector body. Stress analysis of the connector body ensures that the body does not undergo stresses that exceed the fatigue strength of the alloy. It is also worthwhile noting that there is almost no strain or displacement of the left side of the opening when the pressure is applied.

[0032] This invention also provides a method of connecting fiber optic cables where the method involves providing a shape-memory alloy connector of the type described herein, exerting a force (or pressure) on the shape-memory alloy connector to cause the shape-memory alloy connector to deform elastically from an original, undeformed shape to a deformed shape. An example of what the deformed shape may look like was presented above in FIG. 8. The method then involves inserting fibers extending from cables to be connected into an alignment hole within the shape-memory alloy connector and then (once the fibers are fully and properly inserted) releasing the force on the shape-memory alloy connector to cause the shape-memory alloy connector to return substantially to the undeformed shape thereby splicing the fibers. Splicing the fibers thus connects the cables together. The spliced fibers can then optionally be packaged or wrapped for further protection. The method is best performed by sequentially inserting the two fibers to be connected. In other words, the force is exerted, the first fiber is inserted, the force is released, and then a second force is exerted, the second fiber inserted and then the second force is released. This sequential technique separately and sequentially actuates independently deformable portions of the shape memory alloy connector. Similarly, exerting the force, inserting the fibers and releasing the force can be performed repeatedly to connect in parallel a plurality of cable pairs to a common multi-connector assembly having multiple, independently operable fiber-receiving openings.

[0033] FIG. 9 depicts a tool for aligning and splicing fibers. This tool has pressure-point buttons above respective, independently deformable portions of the connector. This tool can be used m a method of splicing fiber cores for subsequently optionally packaging fiber optic cables. Such a method comprises providing an elastically deformable connector having a connector body having a deformation-assisting/limitmg cavity in the connector body to augment and limit deformation of the connector body when a force is applied to the connector body, applying the force to the connector body to cause deformation of the connector body, inserting fibers from respective cables to be connected through one or more alignment holes in the connector body, releasing the force to cause the connector body to splice the fibers, thus connecting the cables together. The cables can then be packaged to further protect the splice together. Once spliced, the connected cables can be are further packaged, sheathed or wrapped m a separate operation not involving this tool. Thus, the tool of FIG. 9 is not meant to remain with the spliced fibers but rather the spliced fibers and their respective cables are removed from this tool and either used m an unprotected state or wrapped or packaged in a further step or operation.

[0034] FIG. 10 is an example of a tool for aligning, splicing and packaging the fibers. Unlike the tool of FIG. 9, the tool of FIG. 10 is actually a hybrid tool and casing. This tool/casing can be used in conjunction with a method of splicing and packaging fiber optic cables. The method comprises providing a cable-enshrouding case having an internal compartment for receiving an elastically deformable fiber connector, the cable case further having one or more alignment holes for aligning fibers of respective cables to be connected, and further having a tool access hole through which a tool may be inserted for exerting a force on the fiber connector to cause the fiber connector to deform elastically, applying the force to cause elastic deformation of the fiber connector, thereby opening the fiber connector for receiving fibers, inserting the fibers through the one or more alignment holes in the cable case into the fiber connector, and releasing the force on the fiber connector to cause the fiber connector to splice the fibers together within the cable case. In other words, this tool/case has a tool or finger access hole that enables a user to exert a downward force on the deformable connector body to receive the optical fiber. When the force on the tool or finger is released, the fiber is gripped/restrained. The enshrouding case (or casing, encasement, or box) serves as the sheath, packaging, wrapper or protective outer cover for the connected cables. Thus, a further operation of packaging the connected cables is eliminated.

[0035] FIG. 11 and FIG. 12 together present yet another hybrid tool and case that can be used to efficiently align and splice fibers and then package the connected cables. In particular, FIG. 11 shows an example of a tool that can accomplish the alignment, splicing and packaging of the fibers, and which includes its own internal mechanism for actuating the deformable connector.

[0036] This tool/casing can be used in conjunction with a method of splicing and packaging fiber optic cables that involves providing a cable-enshrouding case having a pivoting cover and an internal compartment for receiving an elastically deformable fiber connector, the cable case further having alignment holes for aligning first and second fibers to be spliced together, and further having an access hole for exerting a force on the fiber connector to cause the fiber connector to deform elastically, opening the cover of the case to place within the fiber connector within the internal compartment, and closing the cover of the case, the cover having first and second internal abutments that sequentially actuate the elastically deformable fiber connector as the cover is pivoted from an open position to a closed position, the first abutment causing a first portion of the elastically deformable fiber connector to deform to enable insertion of the first fiber into the fiber connector, the second abutment subsequently causing a second portion of the elastically deformable fiber connector to deform to enable insertion of the second fiber, the first and second fibers being spliced together as the cover of the case is returned to the closed position.

[0037] FIG. 12 depicts how the pivotal cover of the cable- enshrouding case automatically actuates the opening (expanding) and closing (contracting) of the flber-receivmg slots by sequentially abutting the connector body to cause sequential deformation of the fiber-receiving openings. In other words, there are internal protuberances, shoulders or abutments protruding from the underside of the pivoting cover. When the cover is pivoting toward the closed position, the first abutment hits the corner of the deformable body, causing the body to squeezed laterally, which has the effect of opening the fiber slot (shown extending inwardly into the body of the connector from the right-hand side) . At this point, the fibre is inserted. Once the fibre has been fully inserted, the cover can then be pivoted further toward the closed position which has the effect of releasing the pressure on the body. Consequently, the fiber slot contracts, gripping the first fiber in place. The cover is then further pivoted toward the closed position until the second abutment hits the connector body. The second abutment hits an independently deformable portion of the connector body so that deformation of this second portion of the connector body does not expand the fiber slot holding the first fiber (i.e. the fiber that has already been inserted) . The second fiber-receiving opening expands due to the deformation of the second portion of the connector body. The second fiber is then fully inserted into the second opening. The cover is then further pivoted toward the fully closed position. This further pivoting of the cover relieves the pressure of the abutment against the second portion of the deformable connector body. The second opening contracts as the second portion elastically returns to its original shape, thus gripping the second fibre in aligned contact with the first fibre. As a result, the second fibre is spliced to the first fibre. With its lid (pivoting cover) shut, and optionally also locked, the cable- enshrouding case serves to protect the splice (connection) . As will be noted, all steps (alignment, splicing and packaging) are performed using the same device. This device and the related method is thus very useful for quickly mechanically splicing optical fibers.

[0038] FIG. 13 depicts another alternative embodiment of the connector wherein there is no deformation-assisting cavity but wherein the body of the connector is supported in an elevated manner to enable downward deformation of the body when a downward force is exerted. As shown m FIG. 13, the deformable body of the connector is restrained or clamped by a C-shaped restraint that has the effect of immobilizing one side of the deformable connector body while leaving the other side free and elevated above the support surface (i.e. the body is effectively cantilevered) . The application of a downward force causes deformation of the connector body, even in the absence of a deformation-assisting cavity, that the fiber-receiving slot expands sufficiently to enable insertion of an optical fiber into the slot. In other words, since the connector body is elevated, the body can deform downwardly even m the absence of an internal cavity or slit. [0039] As will be appreciated, the novel connector and novel splicing technique enabled by this novel connector can be used in a variety of ways to facilitate splicing of optical fiber and packaging of fiber optic cables.

[0040] In each of the foregoing embodiments of this invention, the resultant splice overcomes problems associated with prior-art mechanical splices. This novel technology enables precisely aligned claddings of the fibres. This technology can furthermore be useful for aligning fibers of different diameters, which is difficult to do with conventional splicing techniques. In other words, these novel shape memory alloy connectors can be used to align and splice together two optical fibers of different diameters. Where there is a minor variation in the diameter between two similarly sized fibres, the self-centering fiber slots or conduits have the effect of aligning the fibers. However, where the diameters of the fibres to be spliced are substantially different, it is preferable to utilize the novel techniques disclosed by Applicant m WO 2008/151445 Al entitled CONNECTOR FOR MULTIPLE OPTICAL FIBERS AND INSTALLATION APPARATUS. One of the embodiments of the novel connector disclosed in this PCT publication has fibre- receiving conduits of different diameters, i.e. a first fibre- receivmg conduit has a first diameter that is different from a second diameter of a second fibre-receiving conduit.

[0041] With these novel connectors, no glue is required to hold the fibers inside the connectors, thus making the splices temperature resistant. In some cases, the connection also does not require adhesive gel at the joint. The absence of adhesive at the joint means that the connection can be rotated to correct polarization issues. The absence of adhesive also means that the connector can be reused. [0042] The connector body should be made of a highly elastic material, e.g. a shape memory material (SMM) such as a shape memory alloy (SMA) or other such material that is capable of being easily deformed and whose elasticity is high enough to return to its original, undeformed shape when the force or pressure is released from the connector body In main implementations of this technology, a shape-memory alloy is used for the connector body since shape memory alloys exhibit unusually high elasticity and are thus perfectly suited for this application. A Copper-Aluminum shape memory alloy has been found to provide excellent results. However, as will be appreciated by those of ordinary skill in the art who have had the benefit of reading this disclosure, other functionally equivalent shape-memory alloys can also be used. Indeed, any highly elastic material that has an elasticity comparable to the copper-aluminum alloy could be utilized to provide similar results. The optical fiber connector device of the present invention may, for example, be made from a polymeric material such as isostatic polybutene, shape ceramics such as zirconium with some addition of Cerium, Beryllium or Molybdenum, copper alloys including binary and ternary alloys, such as Copper - Aluminum alloys, Copper - Zinc alloys, Copper - Aluminum - Beryllium alloys, Copper - Aluminum - Zinc alloys and Copper - Aluminum - Nickel alloys, Nickel alloys such as Nickel - Titanium alloys and Nickel - Titanium - Cobalt alloys, Iron alloys such as Iron - Manganese alloys, Iron - Manganese - Silicon alloys, Iron - Chromium - Manganese alloys and Iron - Chromium - Silicon alloys, Aluminum alloys, and high elasticity composites which may optionally have metallic or polymeric reinforcement.

[0043] From the foregoing, it should now be evident that this novel cable connector provides a number of significant advantages over the prior art. For example, this novel connector is easy to use, thus simplifying the task of connecting cables. The optical losses measured over this connector have been found to be very low. Furthermore, since no bond or adhesive is required, the connectors are more temperature resistant. Therefore, this connector may be used in a variety of temperature-sensitive applications such as, for example, aerospace applications where temperature cycling is extreme or laser applications where the heat of the laser is extreme. The absence of a bonded coupling enables the connectors to be rotated which is useful for situations where the polarization of the light is important. The absence of adhesive or bonding material enables the connector to be reused. The design of this connector is furthermore amenable to miniaturization.

[0044] While the primary application of this technology is connecting fiber optic cables, it should be appreciated that it can also be applied to other types of telecommunications cable, small tubing, micro-fluidic piping, etc. where two substantially identical tubular or cylindrical structures are to be joined, spliced or connected together.

[0045] The present invention has been described in terms of specific embodiments, examples, implementations and configurations which are intended to be exemplary or illustrative only. Other variants, modifications, refinements and applications of this innovative technology will become readily apparent to those of ordinary skill in the art who have had the benefit of reading this disclosure. Such variants, modifications, refinements and applications fall within the ambit and scope of the present invention. Accordingly, the scope of the exclusive right sought by the Applicant for the present invention is intended to be limited solely by the appended claims and their legal equivalents.

Claims

CLAIMS :

1. An elastically deformable cable connector comprising: a connector body made of a highly elastic material that deforms elastically when a force is applied to an outer surface of the connector body, wherein the connector body includes a deformation cavity in an interior portion of the connector body to assist and then limit deformation of the connector body when the force is applied, and wherein the connector body has a fiber-receiving opening adapted for receiving and splicing respective fibers of the cables to be connected together.

2. The cable connector as claimed in claim 1 wherein the cavity extends substantially orthogonally to a force vector of the force applied to the connector body.

3. The cable connector as claimed in claim 2 wherein the slit extends from a lateral surface of the connector body into the interior portion of the connector body.

4. The cable connector as claimed in claim 1 wherein the opening comprises an opening slit that widens when the force is applied to the connector body, the opening further comprising a substantially circular channel defining an alignment hole for centering and splicing the fibers.

5. The cable connector as claimed in claim 1 further comprising a dividing slit that divides a first portion of the connector body from a second portion of the connector body, the dividing slit being disposed substantially orthogonally to both the deformation cavity and the opening slit, the dividing slit enabling the first and second portions of the connector body to be independently deformed.

6. The cable connector as claimed in claim 1 further comprising a visually delineated actuation zone disposed on the connector body to visually indicate a predetermined optimal location for exerting the force on the connector body for causing deformation of the connector body.

7. The cable connector as claimed in claim 5 further comprising first and second visibly delineated actuation zones, the first actuation button being disposed on the first portion of the connector body and the second button being disposed on the second portion of the connector body, the actuation zones indicating visually the optimal locations for exerting forces on the first and second portions of the connector body.

8. The cable connector as claimed in claim 1 wherein the connector body is made of a shape memory alloy.

9. A multi-connector assembly for connecting a plurality of pairs of cables, the assembly comprising: a connector body made of a highly elastic material that deforms when a force is applied to an outer surface of the connector body, wherein the connector body has a plurality of deformation cavities disposed within an interior portion of the connector body to assist and then limit deformation of the connector body when the force is applied to an outer surface of the connector body, and wherein the connector body has a plurality of fiber- receivmg openings each adapted for receiving and splicing respective fibers of the cables to be connected together.

10. The multi-connector assembly as claimed in claim 9 wherein the flber-receivmg openings comprise an opening slit that widens when the force is applied to the connector body, the opening further comprising a substantially circular channel for centering and splicing the fibers.

11. The multi-connector assembly as claimed in claim 10 further comprising a dividing slit between each adjacent pair of opening slits, the dividing slits being disposed parallel to the opening slits to enable each opening slit to be operated independently of each of the other opening slits m the connector body.

12. The multi-connector assembly as claimed in claim 9 wherein the connector body is made of a shape memory alloy.

13. A method of connecting fiber optic cables, the method comprising: providing an elastically deformable connector; exerting a force on an outer surface of the connector to cause the connector to deform elastically from an original, undeformed shape to a deformed shape; inserting fibers extending from cables to be connected into an alignment hole within the connector; and releasing the force on the connector to cause the connector to return substantially to the undeformed shape thereby splicing the fibers and thus connecting the cables together.

14. The method as claimed in claim 13 wherein exerting the force, inserting the fibers and releasing the force is performed sequentially for each of the two cables by separately and sequentially actuating independently deformable portions of the connector.

15. The method as claimed in claim 13 wherein exerting the force, inserting the fibers and releasing the force is performed repeatedly to connect in parallel a plurality of cable pairs to a common multi-connector assembly having multiple, independently operable flber-receiving openings .

16. A method of splicing and packaging fiber optic cables, the method comprising: providing an elastically deformable connector having a connector body having a deformation cavity m the connector body to assist and then limit deformation of the connector body when a force is applied to the connector body; applying the force to an outer surface of the connector body to cause deformation of the connector body; inserting fibers from respective cables to be connected through one or more alignment holes in the connector body; releasing the force to cause the connector body to splice the fibers, thus connecting the cables together, and packaging the cables to further connect the cables together.

17. A method of splicing and packaging fiber optic cables, the method comprising: providing a cable-enshrouding case having an internal compartment for receiving an elastically deformable fiber connector, the cable case further having one or more alignment holes for aligning fibers of respective cables to be connected, and further having a tool access hole through which a tool may be inserted for exerting a force on the fiber connector to cause the fiber connector to deform elastically; applying the force to an outer surface of the fiber connector to cause elastic deformation of the fiber connector, thereby opening the fiber connector for receiving fibers; inserting the fibers through the one or more alignment holes in the cable case into the fiber connector; and releasing the force on the fiber connector to cause the fiber connector to splice the fibers together within the cable case.

18. A method of splicing and packaging fiber optic cables, the method comprising: providing a cable-enshrouding case having a movable cover and an internal compartment for receiving an elastically deformable fiber connector, the cable case further having alignment holes for aligning first and second fibers to be spliced together, and further having an access hole for exerting a force on the fiber connector to cause the fiber connector to deform elastically; opening the cover of the case to place within the fiber connector within the internal compartment; and closing the cover of the case, the cover having first and second internal abutments that sequentially actuate the elastically deformable fiber connector as the cover is moved from an open position to a closed position, the first abutment causing a first portion of the elastically deformable fiber connector to deform to enable insertion of the first fiber into the fiber connector, the second abutment subsequently causing a second portion of the elastically deformable fiber connector to deform to enable insertion of the second fiber, the first and second fibers being spliced together as the cover of the case is returned to the closed position.

19. An elastically deformable cable connector comprising: an elevated support member; a connector body made of a highly elastic material that deforms elastically when a force is applied to an outer surface of the connector body, wherein the connector body is supported in an elevated position by the elevated support member, thereby defining a gap beneath the connector body to enable the connector body to deform downwardly when the force is applied, and wherein the connector body has a fiber-receiving opening adapted for receiving fibers when the connector body is deformed and then splicing respective fibers of the cables when the force is released.

0. The connector as claimed in claim 19 wherein the fiber- receiving opening extends downwardly from a top surface of the connector body into an interior portion of the connector body.