Abstract:
An adapter or connection comprises a plurality of adapter or connector sections ( 14 ) having plugging cavities ( 18 ) to which optical cable plugs ( 25 ) are detachably plugged. The plugging cavities ( 18 ) are arranged in a plane of a panel ( 32 ) at an acute angle to the plane thereby preventing light from entering the operator&#39;s eye upon plugging.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to optical cable adapters or connectors for connecting optical cables.  
           [0003]    2. Description of the Related Art  
           [0004]    An optical connectors are used to detachably connect optical cables or an optical cable and another optical device in an optical communication system. The optical connector comprises a plug to be connected to an end of the optical cable and an adapter for detachably holding the plug. The adapter is attached to an outer panel of equipment, such as an exchange, under downwardly tilted condition so as to prevent a high-power laser from entering the operator&#39;s eye upon connection of the plug into the adapter.  
           [0005]    An example of such adapter attachment is disclosed in Japanese patent application Kokai Nos. 10-239530 and 2000-147269.  
           [0006]    As FIG. 14 shows, a plurality of or four adapters  1  are attached to the outer panel  3  of equipment  2  under downwardly tilted condition. Each adapter occupies a separate space for attachment, keeping the mount density low. The separate attachment of the respective adapters  1  requires much labor in addition to the labor of making the outer panels by bending.  
           [0007]    Thus, there was proposed a multiple type adapter  5  consisting of a plurality of adapter sections  4  as shown in FIG. 15.  
           [0008]    However, the lowest adapter section  6  of the multiple type adapter  5  is retreated toward the inside of the equipment  2  so deep that the space of the equipment  2  is wasted, reducing the mount density inside the equipment. In addition, it is difficult to perform plugging operation for the lowest adapter section  6 .  
         SUMMARY OF THE INVENTION  
         [0009]    Accordingly, it is an object of the invention to provide an optical cable adapter or connector capable of protecting the operator&#39;s eye from laser upon plugging, making the plugging operation easy, and increasing the mount density.  
           [0010]    According to the invention there is provided an optical cable adapter or connector to which a plurality of optical cable plugs are detachably connected, which comprises a plurality of adapter or connector sections integrally formed and arranged in a plane of a panel; a plurality of plugging cavities provided in said adapter or connector sections, one for each section, so as to extend at an acute angle with said plane for receiving said optical cable plugs.  
           [0011]    It is preferred that said adapter or connector sections are arranged in a stepped fashion. The adapter or connector sections are separated by partition walls. The plugging cavities are adapted to receive two-prong plugs. The adapter or connector further comprises a pair of flange sections obliquely extending from opposite ends of said adapter or connector for securing said adapter or connector.  
           [0012]    According to the invention, entrance of the light into the operator&#39;s eye is prevented. Plugging to the adapter is made easy. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 is a side view of an adapter according to an embodiment of the invention;  
         [0014]    [0014]FIG. 2 is a rear view of the adapter viewed from an arrow A;  
         [0015]    [0015]FIG. 3 is a sectional view taken along line B-B of FIG. 1;  
         [0016]    [0016]FIG. 4 is a sectional view of a plug for the adapter;  
         [0017]    [0017]FIG. 5 is a side view of the adapter with detachable plugs;  
         [0018]    [0018]FIG. 6 a side view of an adapter according to another embodiment of the invention;  
         [0019]    [0019]FIG. 7 is a rear view of the adapter of FIG. 6 as viewed from an arrow C;  
         [0020]    [0020]FIG. 8 is a sectional view taken along line D-D of FIG. 6;  
         [0021]    [0021]FIG. 9 is a side view of the adapter of FIG. 6 with plugs to be inserted into the adapter;  
         [0022]    [0022]FIG. 10 is a side view of an adapter according to still another embodiment of the invention;  
         [0023]    [0023]FIG. 11 is a rear view of the adapter of FIG. 10 as viewed from an arrow E;  
         [0024]    [0024]FIG. 12 is a sectional view taken along line F-F of FIG. 10;  
         [0025]    [0025]FIG. 13 is a side view of an adapter according to yet another embodiment of the invention;  
         [0026]    [0026]FIG. 14 is a side view of a conventional adapter; and  
         [0027]    [0027]FIG. 15 is a side view of another conventional adapter. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0028]    Embodiments of the invention will now be described with reference to the accompanying drawings.  
         [0029]    In FIGS.  1 - 3 , an adapter  10  comprises a pair of adapter members  11  and  11 ′ made of a resin and a pair of cylindrical split sleeves  12  made of a metal. The adapter members  11  and  111  are joined together such that the respective front faces  13  and  131  abut each other. Both the adapter members  11  and  111  are identical in structure and, therefore, only the adapter member  11  will be described.  
         [0030]    The adapter member  11  has a plurality of adapter sections  14  arranged in a stepped fashion and a jaw-shaped flange section  15 . The adapter sections  14  are integrally molded at a certain angle, for example, 45 degrees with respect to the flange section  15 . Each adapter section  14  has first and second cantilevered engaging tongues  16  and  17  for engagement with engaging tongues  17 ′ and  16 ′ of the adapter section  14 ′ to connect the pair of adapter members  11  and  11 ′.  
         [0031]    A plugging cavity  18  is provided in each adapter section  14 , and the respective plugging cavities  18  are separated by partition walls  19 . Two sets of plug locks  20 , each consisting of a couple of plug locks, are provided in the plugging cavity  18 . Each plug lock  20  is formed as a cantilevered beam and has an engaging projection  21  inwardly extending from the free end. Two split sleeve receiving cavities  22  are provided at the front end of the plugging cavity  18 . A stop ridge  23  is provided near each opening of the sleeve receiving cavity  22  such that when the adapter members  11  and  11 ′ are connected, two complete sleeve receiving cavities  24  are formed to hold the split sleeve  12  for sliding movement between the stop ridges  23  and  23 ′.  
         [0032]    In FIG. 4, a two-prong plug  25  pluggable into the plugging cavity  18  is shown. The plug  25  comprises a pair of ferrules  26  for accommodating the core wires (not shown) of optical cables  30  (FIG. 5), a pair of springs  27  for forwardly biasing the ferrules  26 , and a pair of housings  28  for accommodating the ferrules  26  and the springs  27 . A pair of engaging projections  29  are provided on opposite sides of the housing  28 .  
         [0033]    In FIG. 5, to attach the adapter  10  to the outer panel  32  of equipment  31  having an opening  33 , the adapter sections  141  are inserted into the opening  33  from outside such that the plugging cavities  18  face outside downwardly, and the flange sections  15  and  15 ′ are secured to the outer panel  32  with bolts  34 . Since the respective adapter sections  14  are tilted by 45 degrees with respect to the flange section  15 , the plugging cavities  18  are secured at 45 degrees relative to the outer panel  32 .  
         [0034]    To connect the two-prong plug  25  into the adapter  10  on the outer panel  32 , the plugs  25  and  25 ′ attached to the optical cables  30  and  30 ′ are inserted into the plugging cavities  18  and  18 ′ in obliquely upward and downward directions, respectively. With advance of the plugs  25  and  25 ′, the plug locks  20  and  20 ′ are flexed outwardly by the engaging projections  29  and  29 ′, which abut against the engaging projections  21 , and  21 ′. When the plug locks  20  and  20 ′ pass over the engaging projections  29  and  29 ′, the plug locks  20  and  2 ′ return inwardly, engaging the engaging projections  21  and  21 ′ with the engaging projections  29  and  29 ′. Consequently, the plugs  25  and  25 ′ are locked in the plugging cavities  18  and  18 ′. The ferrules  26  and  26 ′ of the plugs  25  and  25 ′ are inserted into the split sleeves  12  and retained in alignment. To unplug the plugs  25  from the adapter  10 , the above operation is made in reverse order.  
         [0035]    Alternatively, the plugs  25 ′ within the equipment  31  may be fixed to the adapter and only the outer plugs  25  may be made detachable from the connector sections of the equipment  31 . These connector sections are made identical with the adapter sections  14 .  
         [0036]    In FIGS.  6 - 9 , according to another embodiment of the invention, a plurality of jaw sections  35  are provided on each side of the adapter member  11  (two in this embodiment) and a plurality of adapter lock tabs  36  on each side of the adapter member  11 ′. Each cantilevered adapter lock tab  36  extends toward the corresponding jaw section  35  and has a step-down portion  37  at the free end. When the adapter member  11 ′ of the adapter  10  is inserted into the opening  33  of an outer panel  32 , the adapter lock tabs  36  are flexed inwardly by the periphery of the opening  33 . When the step-down portions  37  reach the opening  33 , the adapter lock tabs  36  return to the original condition and engage the opening  33  to secure the adapter  10  to the outer panel  32 .  
         [0037]    In FIGS.  10 - 12 , according to the third embodiment, a pair of attaching members  38  are provided on the adapter members  11  and  11 ′ one for each side instead of the integrated attaching sections of the adapter members  11  and  11 ′. It is made of a metal, for example, so as to provide a panel abutment member  39  and two cantilevered adapter lock tabs  40 . Both ends of the panel abutment member  39  are formed in cantilevered beam. When the adapter  10  is inserted into the outer panel  32  through the opening  33 , the adapter lock tabs  40  are flexed inwardly by the periphery of the opening  33 . Past the opening  33 , the adapter lock tabs  40  return to the original condition so that the periphery of the opening  33  is retained between the panel abutment members  39  and the adapter lock tabs  40 , with the result that the adapter  10  is secured to the outer panel  32  by spring forces of the panel abutment members  39 .  
         [0038]    In FIG. 13, according to the fourth embodiment, a pair of attaching members  43  are provided separately from the adapter members  11  and  11 ′. The corresponding number of panel abutment members  44  to the number of adapter lock tabs  40  (two in this embodiment) are provided on each attaching member  43 . How to attach the adapter  10  to the outer panel  32  is the same as the procedure of the attaching member  38  and, therefore, the description will be omitted.  
         [0039]    Alternatively, the adapter  10  has a stepped form in the above embodiments but, as long as the plugging cavities  18  are arranged under upwardly and downwardly tilted conditions along the panel, it may take another form.  
         [0040]    The invention is applicable to a single or multi-prong plugs as well as the illustrated two-prong plugs.  
         [0041]    As has been described above, according to the invention, the adapter is attached to the panel under tilted condition so that entrance of light into the operator&#39;s eye upon plugging is prevented. Also, the plugging cavities are arranged along the panel so that plugging into the adapter is made easy. In addition, a plurality of plugging cavities are integrated so that the mount density is increased. Moreover, it is not necessary to bend a panel material, thus simplifying the panel production.