Abstract:
A plug housing for accommodating a plug for connecting to the adapter, includes a housing body having an inside surface, the inside surface forming a through hole accommodating the main body of the plug, a slope portion formed on the inside surface and configured to cause the main body of the plug to move forward by a reaction force received from a second lever formed on the side surface of the plug when the main body of the plug is accommodated in the through hole and the second lever is pushed down by the slope portion, and a restrict portion formed on the inside surface and configured to restrict the forward movement of the main body of the plug.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2009-079069, filed on Mar. 27, 2009, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The present embodiment relates to a plug housing and a plug apparatus. 
       BACKGROUND 
       [0003]    An adaptor for connecting optical connectors and an optical connector having an arm are disclosed in, for example, Japanese Laid-Open Patent Publication Nos. 2001-141961 and 10-307234. 
         [0004]    In such an adaptor, no axial play is set with respect to the optical connectors. For this reason, the distance between the optical connectors becomes too short according to production accuracies of the adapter and the optical connectors. This may cause an overload on ferrules that are to abut on each other. In contrast, when the distance between the optical connectors is too long, the connection loss between the ferrules sometimes increases. 
       SUMMARY 
       [0005]    According to an aspect of the embodiments, a plug housing for accommodating a plug for connecting to the adapter, includes a housing body having an inside surface, the inside surface forming a through hole accommodating the main body of the plug, a slope portion formed on the inside surface and configured to cause the main body of the plug to move forward by a reaction force received from a second lever formed on the side surface of the plug when the main body of the plug is accommodated in the through hole and the second lever is pushed down by the slope portion, and a restrict portion formed on the inside surface and configured to restrict the forward movement of the main body of the plug. 
         [0006]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0007]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0008]      FIGS. 1A and 1B  are explanatory views of an optical connector; 
           [0009]      FIGS. 2A to 2C  are explanatory views of a housing; 
           [0010]      FIGS. 3A and 3B  are explanatory views of an electronic device including the housing; and 
           [0011]      FIGS. 4A and 4B  are explanatory views of housing according to a modification. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0012]    An embodiment will be described below. 
         [0013]      FIGS. 1A and 1B  are explanatory views of an optical connector  1 .  FIG. 1B  schematically shows a side face of the optical connector  1 . The optical connector  1  is a dual LC optical connector. Ferrules  11  are respectively held by a pair of cylindrical portions  12 , and respectively hold optical fibers. A holding portion  13  is provided at base ends of the cylindrical portions  12 , and latch arms  14  are respectively provided on side faces of the cylindrical portions  12 . An operation arm  17  is provided on a side face of the holding portion  13 . 
         [0014]    A pair of optical fiber cables  19  is led in the holding portion  13  via a pair of boots  18 . The holding portion  13  holds the ferrules  11  together with the cylindrical portions  12 . The latch arms  14  are provided on the cylindrical portions  12  in a manner such as to be elastically deformable, and extend toward an axial base end of the optical connector  1 . The operation arm  17  is provided on the holding portion  13  in a manner such as to be elastically deformable, and extends toward an axial leading end of the optical connector  1 . A leading end of the operation arm  17  presses leading ends of the latch arms  14 . When the operation arm  17  is pushed, the latch arms  14  deform together with the operation arm  17  so as to follow the shapes of the cylindrical portions  12  and the holding portion  13 . The latch arms  14  are respectively provided with engaging projections  15 . The engaging projections  15  are normally engaged with engaging holes provided in an adapter in which the optical connector  1  is to be inserted, so that the portion of the optical connector  1  with respect to the adapter is determined. In  FIG. 1B , θ 1  represents the inclination angle of the operation arm  17  with respect to the holding portion  13  in a natural state. 
         [0015]    Next, a housing  2  will be described with reference to  FIGS. 2A to 2C . As shown in  FIG. 2A , the housing  2  includes cases  20  and  30 . The cases  20  and  30  correspond to a housing body, and are formed of, for example, synthetic resin. The housing  2  is fixed to a printed board  50 . More specifically, the cases  20  and  30  respectively have holes  24  and  34 , the printed board  50  has holes  54 , and screws  40  are inserted in the holes  24 ,  34 , and  54 . The cases  20  and  30  are fixed to the printed board  50  by the screws  40  and nuts  44 . Further, the cases  20  and  30  respectively have concave accommodating portions  22  and  32  for accommodating and holding the optical connector  1 . 
         [0016]      FIG. 2B  shows a cross section of the housing  2  that holds the optical connector  1 . The optical connector  1  is accommodated in the accommodating portions  22  and  32 . Leading ends of the ferrules  11  protrude from the accommodating portions  22  and  32 . In a state in which the optical connector  1  is accommodated in the accommodating portions  22  and  32 , the operation arm  17  and the latch arms  14  are pressed. More specifically, a pressing surface  37  provided on the accommodating portion  32  presses the operation arm  17  toward the holding portion  13  and the cylindrical portions  12 .  FIG. 2C  is an enlarged view of the pressing surface  37 . A ridge line of the pressing surface  37  is shaped like a gentle arc that is convex upward. The distance from a horizontal plane parallel to the printed board  50  to the pressing surface  37  decreases from the front side to the rear side in the axial direction. In other words, the pressing surface  37  is inclined in a manner such that a space defined in the accommodating portions  22  and  32  decreases from the front side to the rear side in the axial direction. The maximum angle θ 2  of the pressing surface  37  with respect to the horizontal plane is smaller than the angle θ 1  of the operation arm  17  in the natural state. Hence, the angle of the operation arm  17  is smaller than θ 1  in a state in which the optical connector  1  is held by the housing  2 . Thus, the operation arm  17  and the latch arms  14  attempt to return to their original portions by elastic restoring forces. The elastic restoring forces by which the operation arm  17  and the latch arms  14  attempt to return to their original portions move the optical connector  1  forward in the axial direction relative to the housing  2 . 
         [0017]    As described above, the pressing surface  37  is inclined in a manner such that the space in the accommodating portion  32  decreases from the front side to the rear side in the axial direction. For this reason, when the optical connector  1  moves rearward in the axial direction while being held in the housing  2 , the operation arm  17  is pressed by the pressing surface  37 , whereby the elastic restoring forces of the operation arm  17  and the latch arms  14  increase. As described above, the elastic restoring forces act so that the optical connector  1  moves forward in the axial direction relative to the housing  2 . Hence, the more the optical connector  1  moves rearward in the axial direction relative to the housing  2 , the more the elastic restoring forces of the operation arm  17  and the latch arms  14  become, so that the optical connector  1  attempts to move forward in the axial direction. 
         [0018]    As shown in  FIG. 2B , the case  20  is provided with a contact portion  23 . The contact portion  23  restricts the axial forward movement of the optical connector  1  by contact with an end of the holding portion  13 . However, the contact portion  23  does not have a function of restricting the axial rearward movement of the optical connector  1 . In a state in which the optical connector  1  is held by the housing  2 , it is moved by the elastic restoring forces of the operation arm  17  and the latch arms  14  to a portion where the holding portion  13  comes into contact with the contact portion  23 , whereby the portion of the optical connector  1  with respect to the housing  2  is determined. 
         [0019]    As described above, play that allows axial movement of the optical connector  1  is set in the housing  2 . For example, when the optical connector  1  held by the housing  2  is connected to the other optical connector, the ferrules  11  of the optical connector  1  are brought into contact with ferrules of the other optical connector. In this case, the optical connector  1  is allowed to move in the axial direction relative to the housing  2 , more specifically, rearward in the axial direction. This avoids an overload on the ferrules. 
         [0020]    If the axial play between the connected optical connectors is too large, rattling in the axial direction occurs there between, which may increase the connection loss between the ferrules. However, since the optical connector  1  attempts to move forward in the axial direction because of the elastic restoring forces of the operation arm  17  and the latch arms  14 , as described above, the axial play between the optical connectors is absorbed, and the connection loss is suppressed thereby. 
         [0021]    A description will now be given of an electronic device that adopts a printed board  50  on which the above-described housing  2  is mounted.  FIGS. 3A and 3B  are explanatory views of an electronic device having housing.  FIG. 3A  schematically shows a rack mount apparatus in which electronic devices are mounted. Referring to  FIG. 3A , a rack mount apparatus  3 , such as a server apparatus, includes a casing  4  and a plurality of electronic devices  5  stored in the casing  4 . The electronic devices  5  can be inserted into and removed from the casing  4 . A printed board  50  on which a housing  2  is mounted is adopted in each of the electronic devices  5 . 
         [0022]      FIG. 3B  shows a connecting method for an optical connector. In the rack mount apparatus  3 , a backplane  60  is provided, and an adapter  64  is mounted on the backplane  60 . The adapter  64  has, at one end; an opening  65  in which a leading end of an optical connector  1  held by the housing  2  can be inserted. Further, the other optical connector is inserted in the other end of the adapter  64 . A side of the one end of the adopter  64  is where the electronic device  5  is inserted, and a side of the other side of the adapter  64  is a back side of the rack mount apparatus  3 . 
         [0023]    In the rack mount apparatus  3 , a printed board  70  having guide rails  72  is also provided. Along the guide rails  72 , the printed board  50  is inserted, so that the optical connector  1  is inserted in the opening  65 . Also, when the other optical connector is inserted in the adapter  64 , it is connected to the optical connector  1 . 
         [0024]    Next, a modification of housing will be described.  FIGS. 4A and 4B  are explanatory views of a housing of the modification.  FIG. 4A  corresponds to  FIG. 2B . As shown in  FIG. 4A , an accommodating portion  32   a  of a case  30   a  has a substantially linear pressing surface  37   a . An angle θ 3  formed between the pressing surface  37   a  and a horizontal plane is smaller than an angle θ 1  of an operation arm  17  with respect to a holding portion  13 . The case  30   a  also has a contact portion  33  that restricts axial forward movement of an optical connector  1 . The contact portion  33  is to be in contact with a leading end of the operation arm  17 . An accommodating portion  22   a  of a case  20   a  has a contact portion  23   a  that restricts axial rearward movement of the optical connector  1 . The contact portion  23   a  is to be in contact with a base end of the holding portion  13 . 
         [0025]    Such a contact portion for restricting the axial forward movement of the optical connector  1  may be provided in the case  30   a . In this way, the acceptable moving range in the axial direction of the optical connector  1  is defined by the contact portions  23   a  and  33 . 
         [0026]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.