Abstract:
A method and apparatus for securing a workpiece during a polishing operation are described. More particularly, embodiments of the present invention provide a support fixture for securing a workpiece. The support fixture includes a gripping member that is configured to grip a workpiece and configured to release the workpiece. The support fixture also includes a ferrule that is configured to tighten the gripping member around the workpiece and configured to release the gripping member from the workpiece.

Description:
FIELD OF THE INVENTION 
   The present invention relates to polishing fixtures, and more particularly to a method and system for securing a workpiece during a polishing operation. 
   BACKGROUND OF THE INVENTION 
   Planar polishing fixtures hold workpieces during polishing operations. Such workpieces can be configured to hold a single or multiple optical fibers. 
   Before the optical fibers are connected, they are typically treated, e.g., polished, for a better optical connection. A planar polishing fixture can be used in conjunction with a polisher or lapper to treat the end faces of the optical fibers. 
     FIG. 1  is a side view of a conventional planar polishing fixture  10  in which a workpiece  12 , or connector, can be secured. The workpiece  12  holds, or “terminates,” one or more optical fibers  14 . The planar polishing fixture  10  includes a base  16  and a clamp  18 , both of which are sized according to the size of the workpiece  12 . A screw  20  secures the clamp  18  to the base  16  thereby securing the workpiece  12  within the planar polishing fixture  10 . 
     FIG. 2  is a top view of the planar polishing fixture  10  of FIG.  1 . For ease of illustration, the clamp is not shown in FIG.  2 . 
   In operation, the workpiece  12  is inserted into the planar polishing fixture  10 . Then a polisher (not shown) polishes the end faces of the optical fibers  14 . The lengths of the optical fibers  14  should comply with geometric and surface requirements so that when the workpiece  12  mates with another connector, all of the ends of the corresponding optical fibers make contact with minimal optical loss. When the lengths do not meet geometric and surface requirements, however, optical losses are incurred. 
   A problem with the conventional planar polishing fixture  10  is that it does not reliably enable the optical fibers to be polished such that geometric and surface requirements are met. The optical fiber end faces might appear to be properly polished while in the planar polishing fixture  10 , but the optical fiber end faces do not meet geometric and surface requirements when taken out of the planar polishing fixture  10 . As a result, not all of the optical fibers  14  will make contact with their corresponding optical fibers end faces when the workpiece  12  mates with another connector. 
   One cause of this problem is that the workpiece  12  can be out of tolerance. That is, the workpiece  12  can have irregularities on its surface. For example, the workpiece  12  can become deformed by the clamping force. In addition, any irregularities in the workpiece  12  can cause it to be inadequately supported by the planar polishing fixture  10 . As a result, the workpiece  12  can distort within the planar polishing fixture  10 , thereby causing the optical fibers  14  to not meet geometric and surface requirements. Precision in fiber optic processes is critical because optical fiber core diameters are so small. For example, the core of a single optical fiber is about 8.3 microns in diameter. Accordingly, a small mismatch in an optical fiber is problematic. 
   Accordingly, what is needed is a method and system for reliably securing a connector during a polishing operation. The system and method should be able to secure a connector during a polishing procedure so that any optical fibers being held by the connector are polished so that the optical fiber end faces meet geometric and surface requirements. The present invention addresses such a need. 
   SUMMARY OF THE INVENTION 
   The present invention achieves the above needs and others with a method and system for securing one or more workpieces during a polishing operation. More particularly, embodiments of the present invention provide a support fixture for securing the one or more workpieces, each workpiece holding one or more fiber optic termini. The support fixture includes a gripping member that is configured to grip the workpiece evenly 360 degrees around the workpiece. The support fixture also includes a ferrule that is configured to tighten the gripping member around the workpiece and configured to release the gripping member from the workpiece. 
   Consequently, any optical fibers being held by the workpiece are polished so that the optical fiber end faces meet geometric and surface requirements. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side view of a conventional planar polishing fixture; 
       FIG. 2  is a top view of the planar polishing fixture  10  of  FIG. 1 ; 
       FIG. 3  is a perspective view of a support fixture in accordance with the present invention; 
       FIG. 4  is a top view of the support fixture of  FIG. 3  in accordance with the present invention; 
       FIG. 5A  is a side view of the support fixture of  FIG. 3  in accordance with the present invention; 
       FIG. 5B  is a side view of a gripping member in accordance with another embodiment of the present invention; 
       FIG. 6  is a top view of a support assembly including a plurality of support fixtures assembled on a platform in accordance with the present invention; and 
       FIG. 7  is a side view of the support assembly of  FIG. 6  in accordance with the present invention. 
   

   DETAILED DESCRIPTION 
   The present invention relates to polishing fixtures, and more particularly to a method and system for securing a connector during a polishing operation. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein. 
   Generally, embodiments of the present invention provide a support fixture for securing a connector. The support fixture includes a plurality of support members, each of which engages the connector thereby reliably securing the connector during a polishing operation.  FIG. 3  describes an embodiment of the present invention. 
     FIG. 3  is a perspective view of a support fixture  30  in accordance with the present invention. The support fixture  30  has a plurality of support members  32 ,  34 ,  36 ,  38 ,  40 ,  42 ,  44 ,  46 ,  48 , and  50 , which moveably connect to a ferrule  52 . The support members  32 - 50  are arranged to form an aperture, in which a connector ferrule  54  (hereinafter referred to as connector  54 ) can be secured. The number of support members is not limited to eight. The exact number of support members can vary and will depend on the specific application. For example, there can be as few as two support members. Also, there can be more than eight support members. 
   The actual number of support members will vary and will depend on the specific application. For example, in this specific embodiment, there are eight support members. In another embodiment, there can be two support members. There can also be up to and beyond eight support members, depending on the configuration, e.g., size, shape, etc., of the connector. 
   The actual shape of the support members will vary and will depend on the specific application. For example, in this specific embodiment, the support members are substantially triangular. They can also be other shapes such as substantially rectangular. 
   The support fixture  30  can secure different types of connectors. In this specific embodiment, the connector  54  is connected to a plurality of optical fibers (not shown). In this specific embodiment, the optical fibers are enclosed in a protective jacket  56 . The optical fibers are exposed on the underside of the support fixture  30 . 
   The support fixture  30  is versatile and can be used with different types of machines and processes. For example, the support fixture  30  can be used with lapping machines, polishing machines, and as well as with other kinds of machines, adaptable to current and future machines. 
     FIG. 4  is a top view of the support fixture  30  of  FIG. 3  in accordance with the present invention. For ease of illustration, the support fixture  30  is shown without a connector in order to show an aperture  60 . 
     FIG. 5A  is a side view of the support fixture  30  of  FIG. 3  in accordance with the present invention. The support fixture  30  is shown with the connector  54  in order to show a plurality of optical fibers  62 , which are exposed. Also shown is a base  63 . 
   In one embodiment, the optical fiber end faces can be perpendicular to the surface of the base. In another embodiment, the optical fiber end faces can be angled relative to the surface of the base. The specific embodiment used will depend on the specific application. 
   In operation, referring to both  FIGS. 4 ,  5 A, and  5 B, the connector  54  is inserted into the aperture  60  of the support fixture  30 . Pressure is applied to the support members  32 - 50  to actuate them to close and open the aperture. The ferrule  52  as described below can apply the pressure. Other means of actuation, e.g., a clamp, a lever, etc., can apply the pressure. 
   In this specific embodiment, the ferrule  52  is a nut having threads on its interior. The treads engage with corresponding threads on the support members  32 - 50 . If the ferrule  52  is turned in one direction, e.g., clockwise, the aperture  60  closes. As shown in  FIGS. 5A and 5B , in this specific embodiment, the outside of the support members  32 - 50  are tapered and meet the inside of the ferrule  52 , which is tapered. As the ferrule  52  is turned, e.g., clockwise, such that it moves toward the support members  32 - 50 , the tapered portion of the ferrule  52  exerts an inward force against the support members  32 - 50  causing the aperture  60  to contract. As the aperture  60  closes, opposing forces provided by the support members  32 - 50  secures the connector  54 . If the ferrule  52  is turned in the other direction, e.g., counter-clockwise, the aperture  60  opens. The specific directions in which the ferrule is turned to either close or open the aperture  60  will depend on the configuration of the threads, which of course will depend on the specific application. The turning of the ferrule  52  can be automated or controlled manually. 
   In another embodiment, the threads can be on the exterior of the ferrule  52 . In such an embodiment, the threads of the ferrule  52  engage with corresponding threads in the base  63 . 
   The connector  54  is reliably secure when the aperture  60  closes because all of the support members  32 - 50  make contact with the connector  54  and are tightened by the ferrule  52 . Furthermore, the connector  54  is supported at multiple locations; i.e., the support fixture  30  grips the connector  54  around it, 360 degrees. Furthermore, the forces applied by the support members  32 - 50  onto the connector  54  are distributed evenly. 
   Once the connector  54  is secured in the support fixture  30 , a polisher (not shown) polishes the ends of the optical fibers  62 . Because the connector is well secured, the optical fiber end faces can be polished to meet geometric and surface requirements. As a result, when the connector  54  is removed from the support fixture  30  to be mated with another connector, all of the ends of corresponding optical fibers will make contact. 
     FIG. 5B  is a side view of a gripping member  64  in accordance with another embodiment of the present invention. In this specific embodiment, the gripping member  64  includes support members  32 ′,  34 ′,  36 ′,  38 ′,  40 ′,  42 ′,  44 ′,  46 ′,  48 ′, and  50 ′, which are formed as one piece. While the support members are integrally connected as one gripping member, they can be flexed inwardly and outwardly to cause the aperture to close and open. In this specific embodiment, the support members  32 ′- 50 ′ are spring biased such that they move inwardly when a force is exerted against them by the ferrule and they move outwardly when the force is removed. 
   In another embodiment, the gripping member can be elastomeric. 
     FIG. 6  is a top view of a support assembly  70  including a plurality of support fixtures  72 ,  74 ,  76 ,  78 ,  80 ,  82 , and  84  assembled on a platform  86  in accordance with the present invention. The platform  86  is universal. As such, the platform  86  can be used with different types of machines and processes. For example, the universal platform  86  can be used with lapping machines, polishing machines, and as well as with others types of machines. In this specific embodiment, the platform  86  is a hub, which has an opening  87  that can receive an axle (not shown). Each of the support fixtures  72 - 84  is similar to the support fixture  30  of FIG.  3 . The number of support fixtures can vary, depending on the application. For example, there can be as few as one support fixture. There can also be up to and beyond seven support fixtures. 
     FIG. 7  is a side view of the support assembly  70  of  FIG. 6  in accordance with the present invention. For simplification, only two support fixtures  74  and  80  are shown. This embodiment includes support inserts  88  and  90 . 
   According to the method and system disclosed herein, embodiments of the present invention provide numerous benefits. For example, they reliably secure connectors so that optical fibers held by the connectors can be polished to meet geometric and surface requirements. Furthermore, a support fixture in accordance with the invention can be tightened to better secure a connector. Furthermore, the support fixture compensates for deviations in connector dimensions. 
   Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.