Abstract:
A wedge device for use with a fiber optic connector comprises an insert body comprising a light transmissive material. The insert body defines a wedge portion integrally extending into a light pass structure, the light pass structure terminating in a single upper face distal from the wedge portion. For example, wedge device may be a unitary member formed entirely of the light transmissive material.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to fiber optic connectors. More particularly, the present invention relates to an attachment tool for use in fixing an optical connector to the end of a fiber optic cable. 
         [0002]    The ability of high-quality optical fiber to transmit large amounts of information without appreciable signal degradation is well known. As a result, optical fibers have found widespread use in many applications, such as voice and data transmission. Optical fibers are often terminated with connectors in the form of plugs that can be quickly mated with corresponding sockets. 
         [0003]    One common type of connector is a field installable optical connector. This type of connector can be attached in the field to the end of an optical fiber which has been cut to length. The optical fiber is mechanically spliced to a shorter optical fiber inside the connector housing by abutting end to end. The attachment of an existing optical fiber to the one inside the connector may be achieved using a wedge tool as described in U.S. Pat. No. 7,346,255 to Yamaguchi (“the &#39;255 patent”). The &#39;255 patent is incorporated herein by reference in its entirety for all purposes. 
         [0004]    As described in the &#39;255 patent, the wedge tool may include a wedge received in a corresponding hole in a holder which attaches to the optical connector. The holder is configured to allow the edge portion of the wedge to move towards and away from an aligned insertion recess of the connector. The wedge may have a VFI (Visual Fault Identify) function, which enables the installer to identify the mechanical splice connection inside the connector by checking applied visible light from the connector end. In particular, transmitted light is visible as it passes through a transparent wedge. Prior to inserting the fiber into the connector, the light is visible. Once the fiber is inserted, most of the light is channeled through the fiber and attenuates the amount of light present in the wedge. This difference in apparent brightness indicates a good or bad connection. VFI function for a field installable connector is described in European Patent Office published patent application EP 2138879 A1 (published Dec. 30, 2009), incorporated herein by reference in its entirety for all purposes. 
         [0005]    Because of the design and shape of the existing prior art wedge, visible light disperses and reduces prominent visibility. Thus, discerning between connected fiber and unconnected fiber is difficult especially in a well-lit environment. The existing design has oppositely-directed catches and an intervening gap that tends to diffuse, rather than concentrate light, which makes it difficult to determine when a fiber connection is complete. 
         [0006]    The present invention recognizes the foregoing considerations, and others, of the prior art. 
       SUMMARY OF THE INVENTION 
       [0007]    According to one aspect, the present invention provides a wedge device for use with a fiber optic connector. The wedge device comprises an insert body comprising a light transmissive material. The insert body defines a wedge portion integrally extending into a light pass structure, the light pass structure terminating in a single upper face distal from the wedge portion. For example, wedge device may be a unitary member formed entirely of the light transmissive material. 
         [0008]    Preferably, the upper face of the insert body is faceted to define a plurality of planar surfaces. For example, the upper face may comprise a central surface perpendicular to an axis of the insert body. A plurality (e.g., eight) of oblique surfaces surrounding the central surface may also be provided. The insert body may comprise a projection at which the wedge portion is located, having a width less than a width of the upper face. In this case, the light pass structure may preferably increase in width between the projection and the upper face. For example, the light pass structure may gradually and continuously increases in width until it has a width substantially equal to the width of the upper face. 
         [0009]    The wedge device may also comprise spaced apart first and second sidewalls delimiting the light pass structure. First and second lateral flanges may extend from the first and second sidewalls, respectively, to limit insertion of the wedge device into a holder. First and second catches projecting laterally from the first and second sidewalls, respectively, may also be provided. The catches are preferably spaced apart from a corresponding one of the first and second flanges along an axis of the insert body. 
         [0010]    An additional aspect of the present invention provides a wedge device for use with a fiber optic connector comprising an insert body comprising a light transmissive material. The insert body defines a wedge portion integrally extending into a light pass structure, the light pass structure terminating in an upper face distal from the wedge portion, the upper face being faceted to define a central surface perpendicular to an axis of the insert body and a plurality of oblique surfaces surrounding the central surface. 
         [0011]    According to an additional aspect, the present invention provides a combination comprising a wedge device for use with a fiber optic connector. The wedge device has a unitary insert body formed entirely of a light transmissive material. The insert body defines a wedge portion integrally extending into a light pass structure, the light pass structure terminating in an upper face distal from the wedge portion which is faceted to define a plurality of planar surfaces. The combination further includes a holder defining a hole in which a portion of the insert body is received. 
         [0012]    Various combinations and subcombinations of the disclosed elements, as well as methods of practicing same, discussed in greater detail below, provide other objects, features and aspects of the present invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    A full and enabling disclosure of the present invention, including the best mode thereof, to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying drawings, in which: 
           [0014]      FIG. 1  is a perspective view of a light transmissive wedge of a holder in accordance with the prior art. 
           [0015]      FIG. 2  is a perspective view of a holder in which the wedge is contained in accordance with the prior art. 
           [0016]      FIG. 3  is a perspective view of a wedge in accordance with an embodiment of the present invention. 
           [0017]      FIG. 4  is another perspective view of the wedge of  FIG. 3 . 
           [0018]      FIG. 5  is a cross-sectional view as taken along line  5 - 5  of  FIG. 3 . 
           [0019]      FIG. 6A  is a perspective view of a holder in accordance with an embodiment of the present invention. 
           [0020]      FIG. 6B  is a perspective view of a holder with logo removed in accordance with an embodiment of the present invention. 
           [0021]      FIGS. 7A and 7B  show transmission of light through the prior art wedge of  FIG. 1  before and after a good mechanical splice, respectively. 
           [0022]      FIGS. 8A and 8B  show transmission of light through the wedge of  FIG. 3  before and after a good mechanical splice, respectively. 
       
    
    
       [0023]    Repeat use of reference characters in the present specification and drawings is intended to represent same or analogous features or elements of the invention. 
       DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0024]    It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary constructions. 
         [0025]    Referring first to  FIGS. 1 and 2 , a wedge  10  in accordance with the prior art is adapted to be received in one of two receiving holes (labeled “1” and “2”) in holder  12 . The structure of wedge  10  and holder  12  is described in detail in the &#39;255 patent, and need not be repeated here. In this case, wedge  10  is made of a light transmissive (i.e., transparent) plastic material to facilitate the determination of whether the mechanical splice was successful. 
         [0026]    This is illustrated in  FIG. 7A , which shows the end portion  14  of wedge  10  before the mechanical splice. In comparison, a lower level of illumination, after a successful mechanical splice, is seen in  FIG. 7B . While the difference between illumination in  FIGS. 7A and 7B  can be readily discerned in many cases, it is not so apparent when ambient light is bright. Moreover, the oppositely-directed catches  16   a  and  16   b,  and the intervening gap  18 , tends to diffuse, rather than concentrate, the light. Thus, there is room for improvement. 
         [0027]    Referring now to  FIGS. 3-5 , an improved wedge device (or simply “wedge”)  50  in accordance with the present invention is illustrated. As can be seen, wedge  50  is preferably formed as a unitary structure of a suitable light transmissive material, such as a suitable clear polymeric material. Wedge  50  includes a projection  52  at the lower portion thereof. A wedge member  54  is located at the distal end of projection  52 . As one skilled in the art will appreciate, projection  52  and wedge member  54  are similar to corresponding portions of prior art wedge  10 . 
         [0028]    The upper portion of wedge  50  defines a pair of side walls  56   a  and  56   b  between which a light pass structure  58  is located. As shown, sidewalls  56   a  and  56   b  include flanges  60   a  and  60   b  which serve to limit insertion of wedge  50  into the holder. Catches  62   a  and  62   b  are also located on side walls  56   a  and  56   b,  spaced apart from the flanges. One skilled in the art will appreciate that catches  56   a  and  56   b  serve a similar function to the upper catches  16   a  and  16   b  of wedge  10 . 
         [0029]    Structure  58  serves to guide the light emitted by the optical fiber end inside the connector up through wedge  50 . As can be seen in  FIG. 5 , structure  58  is configured in this embodiment having a gradual increase in width as it extends to the top of wedge  50 . As one skilled in the art will appreciate, the light is not divided as occurred in wedge  10  due to the separate arms carrying upper catches  16   a  and  16   b.  Moreover, the upper face  64  of wedge  50  may be faceted as shown (having a plurality of planar faces), or otherwise configured, to enhance the brilliance of the transmitted light. In this embodiment, for example, upper face  64  defines a central surface  64   a  that is perpendicular to the axis of wedge  50 , and a plurality of oblique surfaces (such as surface  64   b ) that surround central surface  64   a.  Eight such oblique surfaces are provided in the illustrated embodiment, although a greater or lesser number of such oblique surfaces may be employed as necessary or desired. 
         [0030]    Advantageously, upper face  64  is prominent in the single hole  66  of the holder  68  in  FIG. 6A  through which light is transmitted, as opposed to the three holes in holder  12 . As shown in  FIG. 6B , holder  68  may also define a second hole  70 , which is revealed by removing a cover  72 . The cover  72  may seat in a recess  74  defined in the upper surface of holder  68 , to resist movement of the cover but also to enhance overall aesthetics of holder  68 . For example, a logo of the manufacturer or other suitable indicia may be provided on cover  72 . As one skilled in the art will appreciate, holder  68  is configured is configured to allow the edge portion of the wedge  50  to move towards and away from an aligned insertion recess of the connector. 
         [0031]    Referring now to  FIGS. 8A and 8B , it can be seen that the difference between light intensity levels in good and bad connection situations has been enhanced in comparison with the prior art. 
         [0032]    One skilled in the art will appreciate that embodiments of the present invention offer various advantages in comparison with the prior art. For example, a wedge embodiment as described above achieves the following advantages: 
         [0033]    1. The new design provides clear brilliant visible light, which is significantly attenuated when mechanical splice connection is made. 
         [0034]    2. The new design passes VFI light through the wedge more efficiently. 
         [0035]    3. The new design uses a faceted shape on top of wedge to display the channeled light as brilliantly as possible. 
         [0036]    While preferred embodiments of the invention have been shown and described, modifications and variations may be made thereto by those of ordinary skill in the art without departing from the spirit and scope of the present invention. For example, the wedge may be formed as a structure unitary with the holder in some embodiments. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to be limitative of the invention.