Abstract:
A system and method for creating fiber optic terminations includes a fiber optic connector tooling device and an improved hot plate termination plate or oven. The device cooperates with the oven to produce a fiber optic termination end with optimal light diffusion qualities. The device properly aligns a plastic fiber optic cable and connector with each other and perpendicularly aligns both with the oven. The device provides gradual forward pressure to seat the plastic cable in the connector to melt the second end of the cable and form an optical lens with optimal light diffusion qualities. A method of creating optically clear lens at a termination end of the plastic fiber optic cable uses the fiber optic connector tooling device to assist in holding and guiding the fiber optical cable to the improved oven in proper axial alignment to create a defect free lens.

Description:
PRIORITY AND RELATED APPLICATION 
     N/a 
     FIELD OF THE INVENTION 
     The present invention relates to optical fibers. More particularly, the present invention relates to a tooling device for preparing termination ends on optical fibers and a method of making the same. 
     BACKGROUND OF THE INVENTION 
     Plastic optical fibers used for data transmission are most often supplied in cable form where the cable comprises a plastic fiber core, a thin cladding, and a protective jacket which can include strengthening members. Optical fiber connectors and splices are used with said fibers and are an essential part of optical fiber communications systems. Connectors may be used to join lengths of optical fiber into longer lengths, or to connect optical fiber to active devices such as radiation sources, detectors, repeaters, or to passive devices such as switches or attenuators. 
     To prepare a termination end, a fiber end is exposed and a connector is clamped, crimped or molded onto the cable jacket with the bare fiber portion being exposed. There are many methods of terminating and finishing a termination end such as using adhesive, polishing or melting. 
     In the method using adhesive, adhesive is injected into a longitudinal bore of the connector. A fiber end of the cable is received into the connector body with the enclosed fiber projecting along the longitudinal bore of the connector. The adhesive wicks and adheres to the fiber, the connector, and other connector parts to permanently secure the connector and fiber together. 
     In the epoxy/polish method of connecting the fiber optic to the connector and forming a lens, epoxy is applied to an end of a fiber optic cable which is then inserted into the connector. An exposed portion of the fiber optic cable that extends past the second end or exit end of the connector is then finished by polishing with a grinder. This method is disadvantageous in that scratches are left on the fiber optic degrades quality of light transmission and causes loss of signal and signal distortion. 
     In the heat-reset method, the stripped portion of the fiber is inserted into the connector resting just within a chamfer adjacent an exit or second end of the connector and is melted in place to fill the chamfer. See U.S. Pat. No. 4,191,447. In another embodiments of the heat-reset method, a portion of exposed fiber optic may extend past an exit or second end of a connector. See for example, U.S. Pat. No. 5,097,522, where the exposed fiber optic end extending beyond the terminal face is melted using a conventional hot plate that advances into the plastic fiber optic cable that is made molten. The molten fiber optic cable tip forms a bulge that settles and lodges into a chamfer or recessed pocket to restrict movement of the fiber from the connector and to also create a lens. However, for each of these prior art reference outside variables caused by human contact can degrade the quality of lens formed at the termination end of the connector. 
     One type of heating device used in the prior art includes using a hot plate termination tool or hot plate termination oven such as the one distributed by FiberFin Inc. of Yorkville, Ill. This oven may have integrated circuitry to control two cycle functions, a melting cycle and a curing cycle. The heating cycle heats a hot plate of the tool/oven for about 17 seconds as indicated by a red light, while the curing cycle turns off the heat and uses a fan to cool the hot plate running about 5 seconds. In the heating cycle, the plastic fiber optic is made molten to fill the chamfer and then the curing cycle permits the molten plastic to solidify and create a lens at a second end of the connector, if done correctly. 
     One problem with this prior art device is that the two cycling events are automated and successive and thus no user control means exist. The user must wait for the next melt or red cycle in order to prepare the termination end. Another problem with the heating device of the prior art is identified in its use of malleable lens against which molten fiber optic cables are smoothed. Such malleable lens include lens made of brass or stainless steel. Once these malleable lens of the prior art are blemished, it becomes difficult to clean them without accidentally marking or nicking the surface. A blemish can then transfer undesired marks onto subsequent termination ends. Yet another problem with the prior art involves the fact that said malleable lens are soldered to the hot plate oven making the change or removal of the lens impossible by the end user. In order change or remove the soldered lens, the user must send the hot plate device back to the manufacturer. 
     In addition to the above cited problems, prior art hot plate termination ovens are further problematic by the fact that it employs malleable albeit smooth and flat lens. Such malleable lens which are conventionally used in the prior art include plated brass lens or stainless steel lens. In the process of creating the termination lens at the termination end of the connector, these brass or stainless steel lens employed in the prior art hot plate termination ovens often become blemished with residue or other material. If the residue is not removed from the lens, the residue may impair the quality of the termination lens and such impairment will then be transferred to termination ends of subsequent termination ends on cable and connector connections. However, the malleable nature of such brass or steel lens make them prone to scratches, thus making cleaning of such lens become futile. Also, once the lens is marred, subsequent termination lens prepared using the tarnished lens are also defective. 
     Many of the problems associated with the prior art are attributed to manual labor or human error. Thus, though the heat-reset method does not leave scratches on the cable, problems still exist such as alignment issues. Misalignment of fiber optic lens with the connector is one such example of error due to manual labor. When a fiber optic cable is not properly axially aligned with the connector the entire system can cause degrade the quality of light transmission. Also, traditionally, users guide the cable into a connector and then the hot plate oven using only their hand. Thus the chances of impairing alignment due to human action is very high. Another problem with the prior art involves the amount of manual pressure applied to the fiber optic cable as the termination end is prepared. Excess pressure applied to the cable as it is heated and made molten increase the chance that the fiber optic cable can be defective. Yet another uncontrolled problem present to the prior art involves a lack of control over the timing of heat cycle of the hot plate oven. This variable attributes to termination ends having poor light transmission qualities as uncontrolled timing of heat may cause cables to burn or even bubble. 
     Another problem with use of hot plate ovens of the prior art is that manual preparation of the termination ends lack inconsistency due to human error. Users find it difficult to create termination ends on fiber optic cables wherein the user has to manually guide the cable onto the hot plate tools without assistance. Also, attaining consistency when preparing numerous termination ends is difficult to achieve using the prior art methods and devices. These uncontrolled variables affect the quality of the termination lens created at the termination end. 
     There is a growing demand, for a system and method for facilitating the creation of fiber optic terminations. Such a system and method should be easy to use. Such a system should enable a user to attain consistent results. For instance, a device is desired that cooperates with a hot plate tool or hot plate oven. A device is further desired that will permit a user to properly align both the fiber optic cable and connector to the hot plate tool or oven to create a lens with little-to-no manual interference. A device is desired that will permit a user to control the activation of the heat cycle of a hot plate tool or oven. A device is also desired that will permit an appropriate amount of pressure to be applied on the fiber optic cable to create a lens with little-to-no manual labor. A device is desired that permits the production of defect free lens with optimal optical qualities. A device is desired that repeatedly and consistently permits the production of defect free lens with optimal optical qualities. Further what is desired is an improved hot plate tool used to create said termination end with optimal optical qualities. Accordingly, what is sought, and what is not provided by the prior art, is a fiber optic connector tooling device that is easy to use and that can provide consistent results. Also what is sought is an improved method of creating termination ends with optimal optical qualities. 
     BRIEF SUMMARY OF THE INVENTION 
     The system and method for creating fiber optic terminations includes a fiber optic connector tooling device and an improved hot plate termination plate or oven. The device cooperates with the oven to produce a fiber optic termination end with optimal light diffusion qualities. The device supports each a plastic fiber optic cable and connector and properly aligns each with an opening of an oven to create a termination end. The properly aligned cable and connector produces an tightly fixed connector/cable termination as a result of the cable having been melted and solidified within a chamfer of the connector. The device also provides gradual forward pressure to ease the plastic fiber optic cable through the connector wherein an optical lens with optimal light diffusion qualities is created at the termination end. 
     The fiber optic connector tooling device cooperates with a hot plate oven permitting a user to repeatedly and consistently produce defect free lens at a termination end of plastic fiber optic cables. A method of creating optically clear lens at a termination end of plastic fiber optic cable uses the fiber optic connector tooling device to hold a fiber optic cable in proper axial alignment with the improved oven in to create a defect free lens. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         FIG. 1  shows a system for creating fiber optic termination ends including a fiber optic connector tooling device and an improved hot plate termination oven with a fiber optic cable and connector disposed on the system. 
         FIG. 2  shows an exploded view of the system of  FIG. 1 , wherein the improved hot plate termination oven is exploded from the fiber optic connector tooling device. 
         FIG. 3A  shows an fiber optic cable and connector before being formed as a termination lens. 
         FIG. 3B  shows the fiber optic cable and connector after being formed into a termination lens. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  show a system  150  for creating fiber optic terminations including a fiber optic connector tooling device  100  for use with an improved hot plate oven  50 . The device  100  has a frame  102 , a hot plate oven receiving cavity  104 , connector seat  106 , fiber optic cable guide  108 , first solenoid  110 , second solenoid  112 , activator  114  and air pressure regulator  116 . The frame  102  defines the cavity  104  to hold the hot plate oven  50 .  FIG. 1  shows a plastic fiber optic cable  10  and a connector  20  disposed in the guide  108  and the seat  106 , respectively, while  FIG. 2  shows the oven  50  exploded from the device  100 . 
     The cavity  104  is perpendicularly adjacent to the connector seat  106  and fiber optic cable guide  108 . The connector seat  106  and fiber optic cable guide  108  are disposed adjacent and axially aligned with each other to axially align a cable  10  and connector  20  with the hot plate oven  50  retained in the cavity  104 . Specifically, the seat  106  is aligned with the opening  56  of the oven  50  while the guide  108  is axially aligned with both the opening  56  of the oven  50  and the seat  106 . More specifically, the axially aligned guide  108  and seat  106  are perpendicularly aligned with the opening  56 . 
     Two solenoids,  110 ,  112  are employed with the device  100  to automatically control the orientation and movement of the cable  10  once the cable  10  and connector  20  are set in the system  150 . The solenoid  110  serves as a horizontal clamping solenoid that clamps or grips the connector  20  and fiber optic cable  10  to the device  100 . The solenoid  110  properly aligns each the cable  10  and connector  20  into a “position ready” orientation with the opening  56  of the oven  50 . The gripping pressure provide by solenoid  110  assists in maintaining said connector  20  and said fiber optic cable  10  in perpendicularly alignment with said oven  50 . Accordingly, due to the solenoid  110 , the guide  108  can receive the width of any fiber optic cable  10  as the width of the guide  108  is adjustable and controlled by the first solenoid  110 . 
     The second solenoid  112  provides a consistent and controlled forward pressure to gradually push the fiber optic cable  10  forward in the guide  108  through the connector  20  until the fiber optic cable  10  is fully seated in the connector  20 . Both solenoids  110 ,  112  are controlled by the air pressure regulator  116 . The regulator  116  provides appropriate forward and horizontal pressure on the cable and connector  20  using the solenoids  110 ,  112 , respectively. Accordingly, once the cable  10  and connector  20  are placed on the device  100 , little to no manual intervention is needed to align the cable  10  to the oven  50  or to apply sufficient pressure to fully seat the cable  10 . Any type of solenoid may be employed with the invention, some non-limiting examples include a pancake solenoid and a cylinder solenoid such as those manufactured by Bimba Manufacturing Company of Monee, Ill. 
     The activator  114  cooperates with a relay  113  of device  100  and to provide a manual on/off switch to selectively activate and deactivate the oven  50 . In some embodiments, the activator  114  also controls the solenoids  110 ,  112 . Referring back to  FIG. 2 , the oven  50  cycles between a melting and curing cycle as indicated by a red light  52  and green light  54 , respectively. The plastic fiber optic  10  becomes molten during a melt cycle and is then cured in the cure cycle. The hot plate oven  50  shown in the figures is one non-limiting embodiment, other types of ovens  50  may equally be employed with the device  100 . Using the system  150 , the activator  114  in the “on” position initiates the heat cycle of the oven  150  for a period of time, as indicated by red light  52  and is followed by the curing cycle which is run for another period of time, as indicated by the green light  54 . 
     The improved hot plate oven  50  as shown uses a lens  58  that is made of non-malleable heat conducting material. The preferred non-malleable heat conducting material is glass. Some suitable, yet non-limiting, types of glass include borosilicate or quartz. The glass lens  58  can conduct heat produced by the oven  50  and can be easily removed for cleaning as the glass lens selectively releasable from the oven. The glass lens  58  is retained in the hot plate oven  50  by releasable fasteners, such as clips, disposed inside the oven  50  adjacent the heat generating part of the oven  50 . These fasteners are permanently secured to the oven to allow the fastener to releasably receive and hold the glass lens  50 . 
     The glass lens  58  is visible through the opening  56 , which is dimensioned and configured to accept the connector  20  with fiber optic cable  10 . The glass lens  58  is used to melt an exposed portion  14  of the plastic fiber optic  10 . See  FIGS. 3A and 3B . The hot plate oven  50  is an improvement to the oven distributed by FiberFin Inc. of Yorkville, Ill. The improved oven  50  identified herein could also be embodied in other prior art ovens by employing a glass lens  58  as described above. 
     Using the system  150  a lens  12  is created at the termination end  25  having optimal light conducting properties. See  FIG. 3B . Optimal light conducting properties are achieved in the lens  12  as little outside variables are present during creation of the termination end to impair the lens  12 . For example, solenoid provides controlled, gradual progression of the cable  10  to the oven  50  while fully seating the cable  10  in the connector  20 . By using the solenoid  112 , there is no opportunity to impart excess pressure on the cable  10  as it is pressed against the glass lens  58 . Excess pressure can causes bubbles to arise in the lens  12 . Also, solenoid  110  provides controlled horizontal pressure on the cable  10  and connector  20  to ensure proper alignment in creating the lens  12  at the termination end  25  to further ensure optimal light emitting properties at the lens  12 . 
     The method of creating fiber optic terminations using the system  150  includes preparing the cable  12  prior to being disposed in the tooling device  100 . A pre-determined portion of the cable jacket is stripped off of the cable  10  to create the exposed fiber portion  14 . The length of jacket stripped off is determined by the amount of material necessary to completely fill the chamfer in the end of the connector. The user then fits the exposed portion  14  through the first end  23  of the connector  20  and out a second end or exit end  25  of the connector  20 . See  FIG. 3A . The second end  25  is called the termination end  25  once the exposed portion  14  extending past the second end  25  of the connector  20  is prepared into a lens  12 , see  FIG. 3B . 
     The cable  10  and connector  20  are then placed on the tooling device  100  so that the connector  20  is disposed in the seat  106  and the cable  10  is disposed through the guide  108 . The user clamps the cable  10  and connector  20  in a ready position using the solenoid  110  thereby aligning it with the opening  56  of the oven  50 . The seat  106  and guide  108  steadies the cable  10  and connector  20  without the need for manual or human intervention that could easily cause misalignments and impair the termination end. 
     With the cable  10  and connector  20  in proper axial alignment, the user is ready to activate the system  150 . Here, unlike with prior art methods, the user may control the start time for preparing the termination end using the activator  114 . The user turns the activator  114  “on” to start the melt cycle, indicated by the red light. In the melt cycle of the system  150 , the solenoid  112  eases the fiber optic cable  10  forward through the connector  20  until the cable is fully seated and melts the exposed portion  14  thereby filling a chamfer (not shown) of the connector  20 . In some embodiments, the solenoid  112  is turned on when the activator  114  is started, while in other embodiments the solenoid  112  may be turned on independent of the activator  114 . As the exposed portion  14  is melted it is smoothed against a glass lens to form the lens  12 . After the melt cycle, the cure cycle is initiated to solidify the molten plastic fiber optic  10  into a lens  12 . See  FIG. 3B . The lens  12  defines the termination end on the connector  20  and cable  10  connection and also serves to retain the cable  10  in the connector  20  by lodging the lens  20  within the chamfer of the connector  20 . 
     On occasion, in the process of creating the lens  12  the glass lens  58  in the oven  50  may be blemished with residue or other material. Unlike, with prior art lens, the improved oven  50 , of the present invention, uses a non-malleable glass lens  58  that can easily be cleaned of residue or other extraneous material. The glass lens  58  is removed from the oven  50  and it is wiped clean using any cleaning solution. 
     The system  150  of the present invention may be employed with any type of connector  20  or any fiber optic cable  10  width as the seat  106  and the guide  108  are adjustable and may be dimensioned and configured to receive any type of connector  20  or any fiber optic cable  10  width. Also, the present invention may be used to prepare one termination end on one cable  10  and connector  20  or a plurality of termination ends on a plurality of cables  10  and connectors  20  at one time. 
     The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and accompanying Figures. Such modifications are intended to fall within the scope of the appended claims.