MXPA97010481A - Fiber optic connector element - Google Patents

Abstract

A device for interconnecting the bare ends of two or more optical fibers (18, 20) uses a common receptacle (12) having a fiber clamping element (66) therein and camming surfaces (70, 72) for actuating the element (66), and at least one plug having a camming finger (74, 76) for engaging one of the camming surfaces (70, 72). The camming surfaces (70, 72) are located such that, when only one of the camming surfaces (70, 72) is actuated, the clamping element (66) rocks to a side of the pocket opposite the one camming surface (70, 72) and remains in the open state, but when both of the camming surfaces (70, 72) are actuated, the clamping element (66) is forced to the closed state. The plug includes a fiber protector (22) free to slide within the plug housing (14, 16), substantially enclosing the bare end of the fiber (18, 20) when the plug housing (14, 16) is removed from the receptacle (12), but retracting when the plug housing (14, 16) is inserted into the receptacle (12) to direct the bare end of the fiber (18, 20) toward said guide tube (64). A fiber collet (26) biases the terminal end of the fiber (18, 20) toward the forward end of the plug to place a preload condition on the bare end of the fiber (18, 20). The connector (10) is particularly suited for cleave-and-bevel installations. The receptacle (12) preferably uses a novel clamping element (90) having two plate members (92, 94) with fiber-contacting surfaces, at least one of said fiber-contacting surfaces having a fiber-receiving groove (108). Edges (96, 98) of the plates (92, 94) are aligned and held together with a split tube spring (112). At least one of the plate members (92, 94) is provided with a wire-receiving groove (100, 102) and a wire (114) therein which acts as a fulcrum to allow the plates (92, 94) to pivot along an axis defined by the wire (114). The split tube spring (112) provides a precisely controlled load along the edges (96, 98) of the plates (92, 94) allowing the opposite ends to be clamped together (within the guide tube (64)) by a force sufficient to overcome the controlled load of the split tube spring (112).

Description

FIBER OPTIC CONNECTOR ELEMENT Background of the Invention 1. Field of the Invention The present invention is generally related to connectors / and more generally with dockable connectors for optical waveguides such as fibers used in telecommunications. 2. Description of the Previous Technique Many single-mode discrete fiber optic connector plug designs in use today contain precision cylindrical ceramic ferrules that are mounted on the connector pins. The bare glass optical fibers are joined at the narrow connecting axial holes in those ferrules, and the fiber and ferrule tips are joined together to provide low insertion loss and retroreflection connections. The connected housings used with those spigot connector pins may contain splicing ceramic sleeves which enter and align the splints when the pins of the connector are inserted into the opposite ends REF: 26512 of the housing. The alignment of the splints leads the center of the fibers to alignment providing relatively little insertion loss. The springs in the pins of the connector force the end faces of the polished fiber into intimate contact which provides a relatively low retroreflection. Also available are versions of ceramic ferrule connectors containing angled polished splint / fiber tips, which / when coupled with similar connector pins, provide extremely low retroreflection. Single-mode discrete fiber optic connectors, containing ceramic splints, have decreased their price and improved in operation in recent years. It is expected that this downward price trend will continue when the cost of ceramic splints and ceramic alignment sleeves falls; however, it is expected that there is a lower limit on the price of fiber optic connectors, which is related to the lower cost limit in ceramic splints and sleeves. Also, most single-mode ceramic ferrule connectors in use today are factory-installed in spiral fiber connections or jumper cables. Due to the difficulty of joining fibers in ceramic splints, and to the precise polishing of the fiber tips, very few ceramic splint-only connectors are installed in the field. In this way, the relatively high cost and lack of installation capacity in the field of single-mode ceramic ferrule connectors have been adequately addressed in the prior art. Another line of interconnect products, particularly adapted for permanent splices, uses a fiber fastener element that is etched with slots of various types to provide location and alignment to the fiber, and fiber cable in its characteristics. An example of such a product is the Fibrlok splice element, currently manufactured from a single sheet of ductile aluminum (Fibrlok is a trademark of Minnesota Mining and Manufacturing Co., would benefit from the present invention). The external shape of the element is usually rectangular, and is created by forming the element of its carrier strip. A bending focus slot divides the part of the rectangular element into two equal rectangular areas or plates. At least one of these plates contains a V-shaped fiber location and fastening groove which runs parallel to the bending focus slot. The depth of the V-shaped groove is such that a fiber of 125 μm located in this groove could project out of the groove approximately 50 μm. Funnel-shaped fiber conduction slots are provided at each end of the V-shaped fiber location slot. The opposing plate also contains funnel-shaped fiber conduction slots located at the same distance from the focusing slot Bending the funnel-shaped conductor in the slots in the first plate. The flat fibril piece is folded along the flexing bending slot until one plate is at an angle of approximately 5 to 10 degrees with respect to the other plate, creating a structure consisting of two essentially rigid plates containing V-shaped fiber gripping slots, oriented inwardly which are joined along an edge by a hinge which operates elastically for small intervals of plate movement . When used in a Fibrlok splice, this bent V-shaped element is located within a plastic sleeve having end holes that are aligned with the locating groove and V-shaped fastener in the element. A plastic cap fits over the edges of the outer side of the plates or legs of the open element. The layer contains a tapered recessed area that slides down on the outer side of the legs of the element when the lid is closed, causing the two legs of the element to move together with the fastening devices and centers a pair of fibers located within of the V-shaped groove Ductile aluminum was chosen as the material for the choice of Fibrlok elements due to its low cost, and its ability to be easily engraved and then folded without fracturing or breaking. In addition, the aluminum's ductility allows it to conform more easily to the fiber surfaces on the outer side without placing excessively high stress loads on the fiber during the fiber's hold in the V-shaped locating groove. Such material ductile, however, has certain disadvantages. For example, it is difficult to repeatedly use the element, that is, to activate and deactivate the clamping plates, since the multiple resurfacing of a fiber in a ductile element does not allow the fiber to be properly included by itself in the alignment slot. , and in this way the clamping forces of the fiber alignment element or potential in repeated closures is reduced. Therefore, such an element is generally suitable for use in a re-attachable connector. Another weakness identified for the aluminum elements was their relatively high coefficient of thermal expansion. This expansion can cause the end faces of the fastened fiber to separate at high temperatures. Although this is less concerning if the connection is mounted at room temperature, it is more concerning, if the connection is mounted at very low temperatures.

Another potential weakness of an aluminum element is the difficulty encountered when attempting to clean it after several engraving and bending operations. When V-shaped grooves and conductive cones are created in the aluminum element strip material, small aluminum flakes often adhere to the sidewalls and edges of the V-shaped groove. they generate small particles or aluminum flakes along the bending focus slot when the element is bent. If any of these aluminum flakes or particles are detached during the insertion of the bare fibers into the element, it can remain attached to one of the end faces of the fiber and block a portion of the core, severely affecting the insertion loss. Attempting to clean the V-shaped fiber location grooves in soft ductile aluminum before bending, often damages or scratches the V-shaped groove. Abrasive cleaners can not be used because they are embedded in the soft aluminum sidewalls on the V-shaped grooves. Cleaning the element after bending is virtually impossible due to the small spaces between the legs of the element. Another potential weakness of the bent aluminum element is that it is necessary to very carefully control the distance at which the legs of the element are closed during the fiber clamping operation. If the legs close too much, the articulation of the element can be opened, and the element will not be able to hold the fibers in subsequent drives. Furthermore, when fibers of different diameters are used in the articulated aluminum element, it is possible for one of the fibers to receive less clamping force than the other, which may result in the sliding of the fiber and the separation of the end of the fiber. fiber. Therefore it would be desirable to design a fastener that could overcome the above limitations. In addition, it could be advantageous to incorporate such an element in a bare, re-engagable fiber connector having a significantly lower initial cost than the ferrule connectors, and to provide such a connector for a single-mode use that is easily installable in the field with simple procedures and Low cost, easy to use, field installation tools, and still provide the same or better performance than existing ferrule connectors.

Brief Description of the Invention The present invention provides a bare fiber connector, without splints, generally comprising a receptacle and two pin assemblies, the receptacle includes a fiber clamping element that moves between the open and closed states, a guide tube having a recess for receiving the clamping element and cam surfaces for driving the clamping element, a base having an interior for receiving the guide tube, and a layer for securing the clamping element in the cavity and for securing the guide tube inside the base. Each pin assembly is adapted to mate with the receptacle, and includes a pin housing, a connector that secures a bare end portion of a fiber within the pin housing and places the bare end of the fiber at the rear end of the plug. housing of the plug, and a cam claw attached to the front end of the plug housing and extending outward thereof, located so that when the plug housing is fully inserted into the receptacle, the cam grip puts in forced contact with the cam surfaces. The retaining features are preferably provided on the housing of the plug and the receptacle to removably secure the housings from the plug to the receptacle, i.e., that the connector is re-engageable. The cavity in the receptacle guide tube can be dimensioned to allow the clamping element to swing within the cavity, and the cam surfaces located such that, when only one of the cam surfaces is actuated, the clamping element is swing at one side of the cavity opposite a cam surface and remain open, but when both cam surfaces are actuated, the clamping element is forced into the closed state. Each pin assembly preferably includes a fiber optic shield located in the pin housing and attached thereto so that the shield is free to slide into the pin housing, the fiber shield substantially enclosing the bare end of the fiber. Naked when the plug housing is removed from the receptacle, but retracts when the plug housing is inserted into the receptacle to direct the bare end of the fiber into the guide tube. The manifold is preferably biased toward the front end of the plug housing to place a preload condition on the bare end of the fiber when the plug housing is inserted into the receptacle. The size and shape of the cam claw is selected to drive the cam surfaces only after the bare end of the fiber has been fully inserted into the receptacle.

The connector of the present invention is particularly suitable for penetrating and beveling installations and, by compressively loading the end faces of the beveled fiber before being clamped, superior performance is achieved in terms of both insertion loss and retroreflection . The end faces are elastically flattened together, and exclude all air between the end faces of the fiber. The end faces can optionally be separated at an angle to further improve retroreflection. The receptacle may employ a prior art fastener, although here a novel element is presented which imparts additional advantages to the manufacture and use of the connector. This novel fastening element has two plate members each of which has a contact surface with the fiber, with at least one of the fiber contacting surfaces having a fiber receiving groove formed therein. The edges of the plates are aligned and held together with the slotted tube spring. At least one of the plate members is preferably tapered in its thickness towards the secured edge, so that the plates are separated at the opposite ends of the fastened edges. At least one of the plate members is provided with a wire receiving groove and a wire where, generally parallel to the fiber receiving groove, which acts as a fulcrum to allow the plates to rotate along the length of the fiber. axis defined by the wire. The slotted tube spring provides a precisely controlled load along the edges of the plates, allowing the opposite ends to be held together (inside the guide tube) by a force sufficient to overcome the controlled load of the tube spring with slit. The slot that receives the V-shaped fiber can be pre-formed at the factory by sliding another fiber into the clamping element, driving the element around the fiber, deactivating the element and then removing the fiber from the element. The plates can be constructed of a material having an appropriate coefficient of thermal expansion to prevent sliding of the fiber end faces during the temperature cycle. This novel element achieves improved performance for repeated reattachments, provides means for installing, holding and relieving the fiber tension on its shock absorbing coating, protects the bare glass fiber, and the separated fiber face / bevelled, and provides characteristics of guide and alignment that ensure that the end of the fiber can enter the fiber alignment element without holding it.

Brief Description of the Drawings The invention will be better understood by referring to the accompanying drawings, wherein; Figure 1 is a perspective view of one embodiment of the optical fiber connector of the present invention; Figure 2 is a side elevational view of the connector of Figure 1; Figure 3 is a top sectional view of the connector of Figure 1; Figure 4 is an exploded perspective view of the connector of Figure 1; Figure 5 is a side elevational view of an alternative fiber clamping and alignment element as taught in the present invention and which is useful with the connector of Figure 1; Figure 6 is a perspective view of a connector storage tray containing several of the connectors shown in Figure 1; Figure 7 is a perspective view of another connector constructed in accordance with the present invention and designed for panel mounting; Figure 8 is a perspective view of another connector constructed in accordance with the present invention in a duplex design; and Figure 9 is a perspective view of another connector more constructed in accordance with the present invention, having a plug and cavity in place of two pins and a common receptacle.

Description of the Preferred Modality Referring now to the Figures, and in particular with reference to Figures 1 and 2, a mode 10 of the optical fiber connector of the connector of the present invention is described. The connector 10 is generally comprised of a housing or receptacle 12 having two open ends which respectively receive two pin assemblies 14 and 16. In the embodiment shown, the pin assembly 14 is designed for a 250 μm optical fiber. 18, while the plug assembly 16 is designed for a 900 μm optical fiber 20. Although the switch 10 is suitable for the interconnection of different fibers, it is of course equally useful for connecting fibers of identical size. The connector 10 can be used for single-mode or multi-mode fibers.

The details of the construction of the receptacle 12 and the pin assemblies 14 and 16 are shown in Figures 3 and 4. The pin assembly 14 includes a tubular fiber shield 22, a protective spring 24, a manifold 26, a housing manifold 28, a manifold ring 30, a manifold spring 32, a plug body 34, a plug body spring 36, a plug housing 38 and an effort releasing shoe 40 (not shown in FIGS. 2 and 3) . All of those components, except the compression springs, are preferably constructed of a durable injection moldable polymer, such as polyether sulfone (PES), polycarbonate (commercially known as LEXAN), polyarylsulphone (sold by Amoco under the trademark RADEL), polybutylene terephthalate (PBT), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyether imide (PET), liquid crystalline polymers, or acrylonitrile butadiene styrene. Those parts are placed together in the sequence illustrated in Figure 4. The fiber product 22 slides in and out of the body of the plug 34 and is deflected by the spring 24 towards the front end of the pin assembly 14, it is say, towards the receptacle 12. The projections or tongues 42 project from the skirt of the fiber protector 22 towards the coupling slots 44 formed on the sides of the body of the plug 34, to prevent the protector 22 from completely escaping from the body of the plug. pin 34, and to prevent guard 22 from rotating. The front tip of the fiber shield 22 has a wall with a hole that is concentric with the outer diameter of the front tip, and about 0.05 mm (0.002") longer than the diameter of the fiber. it slides through this hole and is located precisely when the shield 22 moves towards the body of the plug 34 when the pin assembly 14 is inserted into the receptacle 12. The narrow alignment of the end of the nude figure with the characteristic of entry on the fastener element prevents damage to the bare end of the fiber during insertion During the removal of the plug the force on the guard ensures complete retraction of the bare end of the fiber towards the protector before any removal of the guard from the fiber. receptacle, protecting the bare end of the fiber The 250 μm fiber buffer is held in the 3-jaw collector 26 which is placed inside the of the manifold 28. The manifold 26 and the collector housing 28 can be axially moved to approximately 1.3 mm (0.050") within the body of the plug 34 with the spring 32 providing a preload of the manifold assembly, towards the front tip of the manifold assembly. peg, approximately 0.9 N (0.2 pounds). The housing of the plug 38 snaps onto the outer side of the body of the plug 34 and slides with respect to the body of the plug 34 against the other preload spring 36. The shoe 40 provides release of the bending stress for the Fiber cushion eject the rear end of the plug. The plug assembly 16 includes a similar fiber protector 46, a protective spring 48, a plug body 50, a plug body spring 52, a manifold 54, a plug housing 56 and another strain release shoe 58 (not shown in Figures 2 and 3). All these components (again except the compression spring) are also preferably constructed of an injection moldable polymer. As with the pin assembly 14, the fiber shield 46 is retained in the body of the plug 50 by externally projecting snap-fit characteristics, and is allowed to slide but does not rotate. The spring 48 preloads the shield 46 towards the front end of the 900 μm pin assembly, ie towards the receptacle 12. The collector 54 is placed inside the body of the plug 50 and is clamped over the 900 μm fiber cushion. when the manifold sits axially complete in the rear part of the body of the plug 50. The housing of the plug 56 is also snapped onto the body of the plug 50 for restricted sliding movement, and the spring 52 provides a preload between the housing of the plug 56 and the body of the plug 50. The plug assemblies have characteristics on the internal coupling components that allow the complete assembly of the plug units to reduce part of the cost in the field and maximize the ease of installation. These features allow the installer to simply prepare the end of the fiber as prescribed and insert it into the pin assembly and, by means of a small tool, fully retract the guard that activates the manifold and secure the fiber to the pin assembly, terminating therefore that fiber for the connection. In the case of fiber breakage, these characteristics provide means for deactivating the termination by dislodging the collector in a mounting tool and allowing the fiber to be removed. The end of the fiber can then be prepared again and reinstalled as established above. The receptacle 12 includes a base 60, a cover 62, an internal guide tube 64 and a fastener 66. The base 60 and the cover 62 together form the outer portion of the receptacle, and can be constructed of any durable injection molded polymer. The guide tube 64 can also be formed of an injection moldable material. The guide tube 64 snaps into the center of the base of the receptacle 60, and has circular end holes that are aligned with the V-shaped groove in the clamping element 66 when the element is installed in the guide tube 64. The fastener 66 is preferably stamped from a metallic material, and utilizes a V-shaped groove technology similar to that shown in U.S. Patent No. 5,189,717. The fastening element 66 consists of two generally flat plates which are joined on the side of their longitudinal edge by means of an elastic joint. The plates could normally open slightly around the axis of the joint, preferably at an angle of about 1 to 8 degrees. The inner surface of one of the plates has a V-shaped fiber alignment slot and half of the fiber conductor (a funnel-shaped print) placed on each end of the V-shaped slot where the edge comes out on the outer side of the plate, at a distance from the joint about 1/4 the width of the plate. The V-shaped groove is parallel to the joint. The inner surface of the other plate is generally flat with the exception of the other half of the fiber conductor funnel that is aligned with the details of the conductor on the opposite plate. The fiber conductor ensures that the fiber is uniformly guided in the V-shaped groove in the element when the pin assemblies 14 and 16 are inserted into the connector receptacle. The V-shaped fiber clamping and alignment groove is engraved or stamped at a depth in the element plate so that the outer surface of the fiber projects out of the V-shaped groove approximately 20% of its length. diameter. In this way when the plates or legs of the element are in their open position or separate position, there is enough space between the flat surface of one of the plates and the sides of the V-shaped groove in the other plate to allow the fiber to be inserted into the ends of the V-shaped groove, and slide as far as possible. length of the V-shaped groove without significant resistance. The fit between the V-shaped groove and the surface of the opposite plate is not large enough, however, to allow the fiber to be outside the V-shaped groove, or for two beveled fibers to overlap when inserted. from the opposite ends of the V-shaped groove. When the upper edges of the two plates opposite the joint are pushed together, the spacing between the opposing plate and the V-shaped groove becomes smaller. In its relaxed (non-driven) mode, the two legs of the element are separated enough to allow an optical fiber to be inserted into the opposite ends of the V-shaped groove, so that the bond between the fibers is located approximately the center of the element. When the element is actuated or closed (as explained below), the legs of the element are pushed together around the elastic joint, and the fibers are clamped in the V-shaped groove. It is also possible to provide an element in which the fiber receiving slots are provided on both plates. It may be advantageous to preform those grooves by holding a single fiber between them at the factory to provide more uniform groove surface finishes and fiber alignment. Multiple slots can be formed for use with the fiber tape. The fiber clamping and alignment element 66 illustrated in Figure 4 has been designed to be fabricated from a single sheet of metallic or polymeric material using, for example, stamping, cutting and bending processes. This element is very similar to the element used in the Fibrlok fiber optic splice. However, it is possible to provide other designs, such as an element consisting of two separate plates that are joined by means of a spring tube, as detailed below. The fastening element 66 is placed in a cavity 68 in the upper part of the guide tube 64. Flexible hinged flaps are provided which contain cam surfaces 70 and 72 on their upper outer edges on either side of the cavity 68. The cam surfaces they come into contact with the corresponding cam surfaces on the drive jaws 74 and 76 which project from the front ends of the pin housings 14 and 16, respectively, when the pins are pushed towards the receptacle. The cam surfaces on the jaws on the pin 70 and 72 come into contact with the outer side of the cam flaps of the element 70 and 72 and push the flaps together when both the pin assemblies 14 and 16 are fully inserted into the receptacle 12. In its open position, there is sufficient space between the skirts for the element to rotate or swing from side to side, preferably through an angle of approximately 5 to 10 degrees. If only one pin assembly is inserted, the actuating claw of the pin housing pushes the corresponding cam skirt towards the center line of the cavity 68, but since the other skirt is not in contact with anything, the element 66 leaves of swinging towards one side of the cavity 68 and thus the element 66 does not close on the fibers or is held in the V-shaped groove. When the other pin is inserted, however, its drive claw pushes the skirt of cam opposite back towards the centerline of the cavity 68 and because the element is now forced to contact both camming flaps, the element plates are closed and clamped to the fibers resident in the groove in the form of V. From this, all protection operations occur, guide, centering and fastening during the process of insertion and removal of the plug. The retention features on the outer side of the base of the receptacle 60 of the housing of the pins 38 and 56 removably secure the pin assemblies 14 and 16 to the receptacle 12. The insertion of the pins of the connector the receiver makes the tabs on the sides of each pin housing 38 and 56 slide under the release lock retaining portions. When the tabs enter the fastener portions, they move back together and clamp the connector pin housings in their position within the receptacle. To release each plug from the connector, the lock holds are pressed into the body of the connector pin, decoupling the clamping portions of the tabs on the pin housings, and allowing the housings and pin bodies of the connector to move back to the connector receptacle. The lid of the receptacle 62 is snapped onto the base of the receptacle 60 by means of the clamping jaws 78, which capture the element 66 and the tube 64 within the base 60, and completing the assembly of the receptacle of the connector. The cover 62 also contains surfaces and wall structures 80 that support the flat, non-liftable opposite side of the drive jaws 74 and 76 to prevent the jaws from bending out due to the force of the contact. and elevation for closing the fastening element 66. This embodiment of the invention will allow the lid to be removed by replacing the cam element 66 in the event that, for example, a fiber breaks in it, or dust contamination in the element. A small tool may be required to press the clamps 78 together so that they can be uncoupled from their mating holes in the base 60, so that the lid 62 is released. The receptacle 12 and the pin 14 may be provided with edges. 82 and 84 (Figure 1), respectively, to provide a better holding action to the thumb and fingers. Referring now to Figure 5, there is described a novel design for a fastening element 90, which has several advantages over the one-piece element 66, mainly because the element 90 can be constructed from a wide variety of materials, particularly those with greater resistance to abrasion and hardness than the one-piece bent element 66. The novel element 90 is generally comprised of two substantially flat rectangular plates, 92 and 94 that are slightly beveled along an edge 96, 98. These edges are shown to be level with each other and, although this is preferred, they do not need to be perfectly aligned, but it is sufficient that the effective edges of the plates are aligned in a general manner to effect the turning action described below. . The shallow V-shaped slots 100 and 102 are formed in this bevelled area on each plate. On the flat back side of the element plates and at the bevelled end, deeper grooves 104 and 106 are formed slightly closer to the edge of the bevelled end of the element. One of the plates of the flat element 92 has a V-shaped fiber location and fastening groove 108 with a V-shaped conductive hole at each end of the V-shaped groove. The opposite plate of the element 94 has a pair of accompanying cone-shaped fiber conductor slots 110. The plates 92 and 94 are held together with a slotted tube spring 112, the legs of which fit into the slots 104 and 106 on the back side of the plates 92. and 94. As mentioned above in conjunction with element 66, two slots may be formed, one on each plate, instead of just one slot with a flat support surface. The tube spring 112 is preferably manufactured from a metallic material such as beryllium, copper or stainless steel, and remains slightly open to be placed on the element plates and in the locating slots. This design provides a light force preload condition occurring between the plates 92 and 94. An alignment and rotation wire 114 can optionally be inserted into the V-shaped 100 and 102 coupling slots located in the thickest section of the region. bevelled from the element plates. The wire 114 functions as a point of support for the hinge, and keeps both plates 92 and 94 properly aligned when the outer edges of the plates opposite the bevelled sections are forced during the fastening of the fiber. In its open condition, the tube spring pushes against the outer side of each plate and forces the plates to be in contact with the joint wire 114, and also along the edge of the thin portion of the bevelled section of the joint. each plate. In the open position, the inner edges of the plates 92 and 94 are preferably located at an angle of approximately 5 degrees with respect to each other. This amount of opening is large enough to allow a 125 μm optical fiber to be easily inserted from the opposite edges of the plates into the V-shaped fiber location groove 108. The fibers have approximately 15 to 25 μm of clearance between the two sides of the V-shaped groove, and the flat mating surface of the opposite plate. This amount of clearance ensures that the outer faces of the fiber (particularly the bevelled end faces) come into contact in the V-shaped groove without allowing the fibers to pass through another in the center of the V-shaped groove during insertion . The characteristics of the fiber conductor in the form of a half cone on the element plate ensures that the fibers easily enter the V-shaped groove during the insertion process. When used in the connector 10, the cut and beveled fibers are inserted from the opposite ends of the element 90, and their end faces in mutual contact at approximately the center of the element. The fibers are preferably pushed towards each other with a longitudinal load of about 0.9 N. { 0.2 lbs), causing the reduced area of the end faces of the cut fiber to elastically flatten each other, reducing insertion loss and retroreflections. To secure the fibers in the V-shaped groove, the non-beveled edges of the element plates are pushed together (as with element 66) causing the plates 92 and 94 to initially rotate around a turning wire, and causing the beveled edges of the elements move out of contact. At some point when the element plates move very close together, the space between the V-shaped fiber clamping slot and the fibers is reduced, and the fibers are clamped. The additional closure of the upper parts of the element plates finally causes the plates to be in full contact with the fiber, and to move out of contact with the articulation wire. The clamping force on the tube spring now exactly controls the clamping forces on the fibers. In theory, any level of clamping force could be provided exactly on the fibers by dimensioning the spring tube to provide this force; a force of approximately 44.5 N (10 lbs) is preferred. If the fibers were slightly different in diameter, the tube spring could advantageously be elastically deformed a little more at one end than at the other to accommodate misalignments in the diameter of the fiber. Thus, the element 90 is particularly useful in bare fiber connectors such as the one of the present invention which uses axially preloaded and cut bevelled fibers. The fastening element 90 has numerous advantages over all existing aluminum elements especially when used in bare fiber connection applications. In the current Fibrlok element, the joint and the element are integrated and made of the same material. The formation of this articulation in the current element requires that the material of the element is initially very ductile, and consequently be able to work harder to provide the properties of elastic articulation over a very short interval of movement. This limits the number of materials that are available to manufacture the element in this design. In the novel two-plate element design with the tube spring and the articulation wire, the material of the element plate can be selected based on the most desirable properties for manufacturing to remove particles on the surface, for resistance to abrasion and hardness to prevent fiber impressions in the area of the V-shaped groove, for easy cleaning, for a low thermal expansion coefficient (12 x 10"6 inches / inch / ° F), and for resistance to Chemical attack With this design freedom, a wider range of materials for the element can be considered Some materials that have desirable properties for the 90 element include stainless steel, titanium, ceramics, glass and possibly some highly rigid polymers of CTE The element 90 can be manufactured easier than the existing element because a process of forming and bending the required joint is eliminated. gone that less material must be moved in the training process, and because the flat elements will be more robust and easier to clean. The separate tube spring is expected to provide more uniform fiber clamping force even when the plates are closed over a wide range of displacements. The tube spring 112 has the ability to provide the desired fiber clamping force on the fiber even if the element closes more than required. In the design of the prior art element, excessive closure can cause the joint to stretch or distort, which initially produces very high fiber clamping force. In subsequent closures, the distorted joint can not provide adequate forces to hold the fibers in the V-shaped groove. Although the concept of the novel element has been designed primarily for connection applications, it may also be useful in splice applications, that is, for the permanent interconnection of optical fibers. The previous aluminum element in the Fibrlok tie changes its length with temperature deviations. It is believed that this causes the end faces of the fiber to move apart and back together slightly when the element changes its length during a temperature cycle. It is also believed that the back and forward movement of the fiber end faces causes the gel to attach the index used in the splices to flow around the ends of the fibers, and possibly create air bubbles or transport dust particles. in the gel between the fiber cores and block some of the transmitted light. A material for the element with a very low coefficient of thermal expansion could therefore be beneficial to eliminate the movement potential of the gel and the associated formation of gas bubbles or transport of dust particles between the end faces of the fiber in the region of the core or center of the fibers. There have also been cases in which the initial performance of the assembled prior art splices has been reduced due to dust or manufacturing debris in the V-shaped fiber clamping groove in the aluminum element. An element, such as the element 90 constructed of a material that could withstand a more rigorous cleaning without damage to the V-shaped groove, could increase the initial assembly performance or the percentage of low splice losses produced. Due to the wide range of element plate materials that are possible with the novel design element, it is expected that a "cleaner" element can be provided for the splice. The connector of the present invention can be used in a variety of different applications. Figures 1-4 show a connector 10 adapted for tray mounting applications with both fiber plugs inserted at the ends of the receptacle. In this embodiment, the connector receptacle 12 does not have an externally projecting mounting flange, but contains an internal cavity that snaps onto the mounting posts 116 on a flat plate such as can be found in the lower part of the housing. a storage handling tray / connector fiber 118 as shown in Figure 6. The external shape of this tray mounting connector mode has been kept as small as possible so that the connectors can be placed adjacent to each other and occupy the smallest volume possible. Tray 118 can contain up to 4 connectors. The posts 116 are hollow so that a pin-like tool can be inserted through the hollow portion to lift the connector from the posts and out of the tray for easy access to an individual connector. This system is particularly suitable for fiber applications to the home. In the design illustrated in Figures 1-4 and 6, the 250 μm plug is preloaded by a spring, but the fiber in the 900 μm plug was mounted solidly on the plug, and could not be spring loaded. Although the two pins of Figures 1-4 are of different designs, they could be of the same design as long as at least one pin contains means for preloading one fiber against the other. The device preferably holds the end terminal loads of the fibers to a compressive load of at least 0.09 N. The interior of the tray 118 may be provided with one or more spools for storing excess loose fiber. Very thin coils can be provided which are stacked on a common post molded on the floor of the tray (not shown), so that the individual fibers can be rolled separately on the coils and subsequently accessed by removing the coils on top. of the desired fiber, without manipulating (and possibly damaging) the other individual fibers. Figure 7 illustrates another embodiment 120 of the connector of the present invention, configured with an externally projecting mounting flange 122 having mounting holes 124. The connector 120 is mounted on a connector panel (not shown) that is part of the connector. of the fiber distribution team. The panel mounting connector 120 can be placed over centered spacings that allow easy access of the finger to the individual connectors without disturbing the adjacent connectors or their fibers. Figures 1-4 and 6-7 illustrate designs according to the present invention which are useful for connecting discrete fibers mounted on pins of individual connectors *. Figure 8 illustrates another design in which two discrete connectors similar to the connector 10 have been integrated to create a double fiber connector 130. The pins of the connector 132 and 134 of the duplex connector 130 contain double spring-loaded fiber protectors, means of fiber preload (springs) and fiber fastening means (collectors). The housing or receptacle of the duplex connector 136 contains two alignment elements and two sets of inlet ports for the inner fiber guide portions of the fibers of the duplex connector. The separation of the fiber for this connector design is preferably about 8 mm. The designs of Figures 1-4 and 6-8 are designs of CLAVIJA-ACCOMMODATION-CLAVIJA; however, it could also be possible to design a connector according to the present invention that uses the same interconnection methods and the PLUG-HOUSING-PLUG design, but could have one of the permanently integrated plugs in the central housing. This style of connector 140 is known as PIPE AND PLUG design, as illustrated in Figure 9, it generally comprises a single plug 142 similar to pin 14 or 16, and a socket or cavity 144 that contains a fastening and alignment element. 90 and functional parts of the other plug, all combined in a single unit. The connector 140 is particularly useful for those applications in which fiber rearrangements occur only on one side of the connector (at the front of the panel, for example). The fiber on the other side of the connector (behind the panel) is permanent and may not be rearranged. Combining one of the pins with the alignment housing to create a connector cavity or plug partially reduces the contribution of the connector, the size of the connector, and potentially the cost of the connector. As used in the claims, the term "receptacle" encompasses both the dual plug receptacle 12 and the plug or cavity 144. The use of any of the above connectors is simple. When the fibers have been beveled, cleaned and inspected, they are installed on the pins of the connector. The beveling can be effected, for example, using the tools described in US Patent Application No. 08 / 122,755. This is done first by installing one of the empty connector plugs fully assembled (not containing a shoe) into a small tool or drive device. This tool (not shown) could provide means for 1) guiding the prepared fiber towards the plug of the connector, 2) providing a length stop at the tip of the fiber so that there is the correct amount of bare glass fiber inside the fiber. the connector pin, and 3) drive the inner manifold to the connector pin to clamp over the fiber cushion and secure the fiber in the connector pin without the use of adhesives or connecting tools. The prepared fiber is inserted through a brake flexing release shoe of the fiber, and the shoe slides down the fiber and away from it. A fully assembled connector pin is then loaded into the installation tool, and the cut and bevelled end of the fiber is inserted into the rear end of the connector pin. The fiber is pushed towards the protective end of the fiber of the connector until the end of the beveled tip of the fiber comes into contact with a stop mechanism located on the front of the fiber protector slightly retracted. With the fiber in the desired position, the worker operates a handle on the installation tool which axially forces the manifold into the manifold housing and permanently holds the fiber absorber in the body of the connector pin or in the assembly of the connector. collector loaded with spring, depending on what type of plug is being mounted. It is considered preferable to use the connectors of the present invention in conjunction with optical fibers whose end faces have been bevelled. The beveled angle is preferably about 45 °, that is, an included angle of about 90 °, although the angle of incidence may be in the range of 30 ° -160 °. The beveling leaves a flat, central area on the end face of the fiber, with preferable diameter of between 20 and 120 μm. The central portion can be angled, that is, not orthogonal to the axis of the fiber, to reduce retroreflections. The plug of the connector is removed from the tool, and any reinforcing member (Kevlar strands) can be secured directly to the plug body of the connector pin of the 900 μm type using standard clamping ring, etc. The 250-μm connector pin design could also be used with reinforcing cable types, but the body of the plug could have to be extended to allow the formation of an arc in the fiber between the place where it is held and the collector loaded by a spring, and the rear end of the connector. This region of the fiber arc is necessary because the spring-loaded collector is pushed back into the connector body against the preload spring of 0.9 N (0.20 lb) to create the desired level of compressive preload on the tips the fiber. A larger pin body (not shown) may have to provide sufficient internal space to accommodate the additional fiber length, such as a fiber arc, when the fiber is rigidly attached to the back of the connector pin, and then pushed back into the connector during insertion of the plug into the housing. The final step in the installation procedure of the fiber is to slide the release shoe upwardly straining the fiber and pressing it onto a hollow post through which the cushioned fibers pass towards the back of the plug body of the connector . As mentioned above, the fasteners of the damping manifold can be unhooked and the fibers can be removed in the event that the fibers break inside the connector and need to be replaced or cut and beveled. The connector pins could then be ready to be inserted into a connector or plug receptacle. The first plug (e.g., 14) is inserted into the receptacle until the fiber guard enters and rests on the receptacle on guide tube 64. Continuous movement of the plug causes the fiber guard to slide toward back towards the body of the pin against the compression spring, and the cut and bevelled fiber enters the V-shaped groove in the element. The additional push of the pin towards the housing results in the fiber continuing to slide towards the element until the tip of the fiber lies slightly beyond the center of the element. At this point, the body of the plug of the connector moves uniformly against the front face of the alignment receptacle. The continuous thrust of the cover of the plug of the connector causes the cam claw on the front of the cover to raise the actuating skirt of the element towards the element and try to close the element on the fiber. If another plug is not installed on the opposite side of the receptacle, the fiber clamping element will only be tilted on one side of the cavity or plug 68, and the bevelled fiberglass on the element will not be clamped. The plug housing (eg, 38) is pushed into the receptacle until the retainer in the receptacle engages the tabs on the sides of the plug housing, locking it into place. When the other plug (for example, 16) is inserted at the opposite end of the receptacle, its fiber guard is at the bottom and guides the fiber towards the end of the element 90. The continuous movement of the opposite pin in the housing pushes its Fiber down the V-shaped groove in the element towards the tip of the other fiber. When the two tips of the fiber come into contact with each other in the V-shaped groove, the compression spring that pushes against the sliding fiber collector on one of the pins begins to compress, and the tip of the fiber is pre-loaded to the desired load. The preload of the fibers continues until the pin body of the remaining connector pin moves uniformly against its end of the alignment receptacle. At this point, the fibers are preloaded with each other and the V-shaped groove of the element, but not clamped. The plug housing of the other plug may not continue to move, which could cause its drive claw to move toward the center of the housing and raise the closed element over the stationary fibers, preloaded. The retaining device for the other plug is coupled, the connection between the fibers is completed. The 900 μm 16 pin has been designed with an optional tensile feature that operates between the fingers or body of the plug 50 and the guide tube 64. These components have flexible coupling claws that engage with each other when the body the plug goes completely to the 900 μm end of the receptacle. Those claws hold the body of the plug to the alignment socket, and make the end of the 900 μm plug of the strain-proof connector. This tensile-proof feature could also be provided at the other end of the connector, but the body of the plug would have to be elongated to accommodate a gap in the fiber between the manifold loaded by the spring and the preload assembly and the rear end of the connector plug. Although the invention has been described with reference to specific embodiments, it does not mean that this description has been constructed in a limiting sense. Various modifications of the described modalities, as well as the alternative embodiments of the invention, will be apparent to those skilled in the art upon reference to the description of the invention. It was therefore contemplated that such modifications may be made without departing from the spirit or scope of the present invention as defined in the appended claims.

It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects that it refers. Having described the invention as above, property is claimed as contained in the following:

Claims (20)

1. An article for aligning and securing the terminal ends of two optical fibers, characterized in that it comprises: a first flat member having a fiber contact surface and an edge; a second plate member having a fiber contact surface and an edge, at least one of the fiber contact surfaces has a fiber receiving groove formed therein, and the fiber contact surface of the first plate member is positioned adjacent the fiber contact surface of the second plate member with the edge of the first plate member generally aligned with the edge of the second plate member; and means for holding the plate members longitudinally along the edges thereof.

2. The article according to claim 1, characterized in that: the first plate member has an external surface, opposite the fiber contact surface thereof, the outer surface of the first plate member has a slot therein extending longitudinally next to the edge of it; the second plate member has an outer surface, opposite the fiber contact surface thereof, and the outer surface and the second plate member has a slot therein extending longitudinally close to the edge thereof; and fastening means comprising a slit tube spring having first and second edges engaged in the slots on the outer surfaces of the first and second plate members, respectively.

3. The article according to claim 1, characterized in that at least one of the plate members is bevelled in its thickness towards the edge thereof, the plate members are separated at the opposite ends of the edges,

4. The article according to claim 1, characterized in that at least one of the plate members is provided with support point means which allow the plates to rotate along the axis which is generally parallel to the fiber receiving groove.

5, The article according to claim 1, characterized in that each of the plate members was constructed of a material having a coefficient of thermal expansion less than 12 x 10"6 inches / inches / ° F.

6. The article according to claim 3, characterized in that the fastening means provide a precisely controlled load along the edges, thereby allowing the ends of the plate members, opposite the edges, to be clamped together by a force sufficient to overcome the fastening means.

7. The article according to claim 4, characterized in that each of the plate members has an end opposite the edge thereof, and the ends are separated open at an angle in the range of 1 ° to 8 ° when the edges of the plate members are completely in contact with each other.

8. The article according to claim 6, characterized in that: a first plate member has an external surface, opposite the contact surface of the fiber thereof, and the outer surface of the first plate member has a groove therein that is extends longitudinally near the edge thereof; the second plate member has an outer surface, opposite the fiber contact surface thereof, the outer surface of the second plate member having a slot therein extending longitudinally close to the edge thereof; and the fastening means comprise a slotted tube spring having first and second edges engaged in the slots on the outer surfaces of the first and second plate members, respectively.

9. The article according to claim 8, characterized in that the ends of the plate member are separated open in the range of Io to 8o when the edges of the plate members are completely in contact with each other, and the slot receiving the fiber is dimensioned and separated allowing sufficient tolerance to insert the fiber therein when the ends of the plate members are separated open, so that the tolerance of the groove received by the fiber is still sufficiently small to prevent the end faces of two bevelled fibers from passing each into the groove.

10. A receptacle for interconnecting two optical fibers, characterized in that it comprises: a housing; a fastener located in the housing, the fastener includes a first plate member having a surface in contact with the fiber, an edge and an end opposite the edge, a second plate member also has a surface in contact with the fiber, an edge and an end opposite the edge, at least one of the surfaces in contact with the fiber has a fiber receiving groove formed therein and the surface in contact with the fiber of the first plate member is positioned adjacent to the fiber. the surface in contact with the fiber of the second plate member with the edge of the first plate member generally aligned with the edge of the second plate member, and first means for holding the plate members longitudinally along the edges thereof , so that the ends are separated in an open position; second means in the housing for holding the ends of the plates together to move the clamping element to a closed position.

11. The receptacle according to claim 10, characterized in that: the first plate member has an external surface, opposite the surface in contact with the fiber thereof, the outer surface of the first plate member has a groove extending longitudinally in her near the edge of it; the second plate member has an outer surface, opposite the surface in contact with the fiber thereof, the outer surface of the second plate member having a slot therein extending longitudinally close to the edge thereof; and the first fastening means comprise a slotted tube spring having first and second means engaged in the grooves on the outer surfaces of the first and second plate members, respectively.

12. The receptacle according to claim 11, characterized in that at least one of the plate members is bevelled in its thickness towards the edge thereof.

13. The receptacle according to claim 12, characterized in that the ends of the plate members are separated open at an angle in the range of Io to 8 ° when the edges of the plate members are completely in contact with each other, and the groove The fiber receiver is dimensioned and separated allowing sufficient tolerance to insert a fiber therein when the ends of the plate members are separated open, but such tolerance of the fiber receiving groove is still small enough to prevent the end faces of the fiber. the two beveled fibers each pass into the slot.

14. The receptacle according to claim 13, characterized in that at least one of the surfaces in contact with the fiber of the plate member is provided with a wire receiving groove which is generally parallel to the fiber receiving groove, and further comprises a wire located in the wire receiving slot, the wire is long enough to act as a fulcrum to allow the plates to rotate along an axis defined by the wire.

15. The receptacle according to claim 14, characterized in that: the housing includes a base member and a cap member which is releasably attached to the base member, the housing provides direct access to the fastener after releasing the cap member. top; and the fastening element is removable from the housing when the lid member is released therefrom.

16. A receptacle for interconnecting two optical fibers, characterized in that it comprises: a clamping element moving between the open and closed position and having means for securing the bare ends of the fibers in an optical connection in the closed position; a housing, the fastening element is located in the housing, and the housing includes a base member and a cover member which is releasably attached to the base member, the housing provides direct access to the fastener after releasing the cap member, and the fastener is removable from the housing when the cap member is released therefrom; and means in the housing for operating the fastening element.

17. The receptacle according to claim 16, characterized in that the clamping element further comprises: a first plate member having a surface in contact with the fiber, an edge and an end opposite the edge; a second plate member also having a surface in contact with the fiber, an edge and an end opposite the edge, at least one of the surfaces in contact with the fiber has a fiber receiving groove formed therein and the contacting surface with the fiber of the first plate member is adjacent to the surface in contact with the fiber of the second plate member with the edge of the first plate member generally aligned with the edge of the second plate member; and means for holding the plate members longitudinally along the edges thereof, so that the ends are separated in the open position.

18. The receptacle according to claim 17, characterized in that: the first plate member has an outer surface, opposite the surface in contact with the fiber thereof, the outer surface of the first plate member has a groove therein extending longitudinally close to the edge thereof; the second plate member has an outer surface, opposite the surface in contact with the fiber thereof, and the outer surface of the second plate member has a slot therein extending longitudinally close to the edge thereof; the fastening means comprises a slotted tube spring containing first and second edges coupled in the grooves on the outer surfaces of the first and second plate members, respectively; at least one of the plate members is bevelled in its thickness towards the edge thereof; and at least one of the plate members is provided with support means which allow the plates to rotate along an axis which is generally parallel to the receiving groove of the fiber.

19. The receptacle according to claim 18, characterized in that: the clamping means provide a precisely controlled load along the edges thereof allowing the ends of the plate members, the opposite edges, to be held together by a sufficient strength to overcome the fastening means; the ends of the plate means are separated open at an angle in the range of 1 ° to 8 ° when the edges of the plate members are completely in contact with each other, and the receiving groove of the fiber is dimensioned and separated allowing sufficient tolerance for inserting a fiber into it when the ends of the plate members are separated open, but the tolerance of the fiber receiving groove is still sufficient to prevent the end faces of the two bevelled fibers from each passing into the groove .

20. The receptacle according to claim 19, characterized in that each plate member is constructed of a material having a coefficient of thermal expansion of less than 12 x 104 inches / inches / ° F. SUMMARY OF THE INVENTION A device for interconnecting the bare ends of two or more optical fibers (18, 20) uses a common receptacle (12) having a fiber fastener element (66) thereon and cam surfaces (70, 72) for actuating the elements. (66), and at least one pin having a cam claw (74, 76) for coupling one of the cam surfaces (70, 72). The cam surfaces (70, 72) are located so that, when only one of the cam surfaces (70, 72) is actuated, the clamping element (66) swings to one side of the cavity opposite a cam surface (70, 72) and remains open, but when both cam surfaces (70, 72) are operated, the fastening element (66) is forced to close. The plug includes a free fiber shield (22) for sliding into the plug housing (14)., 16), substantially enclosing the bare end of the fiber (18, 20) when the pin housing (14, 16) is removed from the receptacle (2), but retracts when the pin housing (14, 16) it is inserted into the receptacle (12) to direct the bare end of the fiber (18, 20) towards the guide tube (64). A fiber collector (26) deflects the terminal end of the fiber (18, 20) towards the front end of the pin to place a preload condition on the bare end of the fiber (18, 20). The connector (10) is particularly suitable for penetrating and beveling installations. The receptacle (12) preferably uses a novel fastening element (90) having two plate members (92, 94) with surfaces in contact with the fiber, at least one of the surfaces in contact with the fiber has a groove that receives the fiber (108). The edges (96, 98) of the plates (92, 94) are aligned and are held together with a slotted tube spring (112). At least one of the plate members (92, 94) is provided with a wire receiving slot (100, 102) and a wire (114) therein, which acts as a fulcrum to allow the plates (92 , 94) rotate along an axis defined by the wire (114). The spring of the slit tube (112) provides a precisely controlled load along the edges (96, 98) of the plates (92, 94) allowing the opposite ends to be clamped (inside the guide tube (64) ) by a force sufficient to overcome the controlled load of the spring of the slotted tube (112).