Abstract:
A fiber optic adapter releasably retains at least one optical fiber connector and includes a body portion having a first side, a second side, and a through-opening between the first side and the second side, a first housing projecting from the body portion first side, the first housing including a bore for receiving the at least one optical fiber connector and having at least one sidewall and an end wall, the housing overlying the through-opening, and a retainer mountable on the first housing and including first and second flexible arms for engaging opposite sides of the first housing to attach the retainer to the first housing, the retainer including at least one projection configured to block the removal of the at least one optical fiber connector from the bore when the flexible arms engage the opposite sides of the first housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present invention claims the benefit of U.S. Provisional Patent Application No. 61/233,587, filed Aug. 13, 2009, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention is directed to an adapter for securing an optical fiber connector to a body supporting the adapter, and, more specifically, toward an adapter comprising a housing having at least one bore for receiving an optical fiber connector and a retainer for selectively securing the connector to the housing. 
     BACKGROUND OF THE INVENTION 
     A fiber optic fan-out module is a product used in networks to split optical signals out from a high density cable into individual cables. It is generally desirable to make the module as small as possible so that a high density can be achieved in a patch panel. One hindrance to making smaller modules has been the size of the fiber optic connector used to secure cables to a housing. Conventionally, the same connectors are used inside the module as outside of the module. These connectors include, among other elements, a ferrule, a spring push, a spring and a connector body holding the ferrule, spring and spring push. If the structure of the connectors could be simplified, the size of the connectors could be reduced and this would allow for a higher density of connectors and in some cases the use of a smaller module. It would therefore be desirable to provide an adapter for connecting such a simplified connector to a module. 
     SUMMARY OF THE INVENTION 
     This problem and others are addressed by embodiments of the present invention, a first aspect of which comprises a fiber optic adapter configured to releasably retain at least one optical fiber connector. The adapter includes a body portion having a first side, a second side, and a through-opening between the first side and the second side. A first housing projects from the body portion first side around the through opening, and the first housing includes a bore for receiving the at least one optical fiber connector and has at least one sidewall and an end wall. The adapter also includes a retainer mountable on the first housing that has first and second flexible arms for engaging opposite sides of the first housing to attach the retainer to the first housing, and the retainer includes at least one projection configured to block the removal of the at least one optical fiber connector from the bore when the flexible arms engage opposite sides of the first housing. 
     Another aspect of the invention comprises a fiber optic adapter configured to releasably retain at least one optical fiber connector which adapter includes a body portion having a first side, a second side, and a through-opening between the first side and the second side, and a housing arrangement projecting from the body portion first side for receiving the at least one optical fiber connector. The housing arrangement has at least one sidewall and an end wall and overlies the through-opening. The adapter also includes a retainer device for engaging opposite sides of the housing arrangement to attach the retainer device to the housing arrangement. The retainer device includes a projecting arrangement for blocking the removal of the at least one optical fiber connector from the housing arrangement when the retainer device engages the opposite sides of the housing arrangement. 
     A further aspect of the invention comprises a fiber optic adapter configured to releasably retain at least one optical fiber connector, the adapter including a body portion having a first side, a second side, and a first through-opening between the first side and the second side and a first housing projecting from the body portion first side around the first through-opening with a bore in communication with the first through-opening. The housing has at least one sidewall and first and second slots extending into the at least one sidewall and into the bore, and the bore has a centerline and a cross-section perpendicular to the centerline between the first and second slots. A first retainer is mounted on the first cylindrical housing and includes a first pair of flexible arms configured to engage opposite sides of the first housing to attach the first retainer to the first housing. Each arm of the first pair of flexible arms including a tab extending through the first and second slots of the first housing and into the bore, the tabs of the first pair of flexible arms reducing an area of the cross-section. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and aspects of the invention will be better understood after a reading of the following detailed description of embodiments of the invention together with the attached drawings wherein: 
         FIG. 1  is perspective view of an optical fiber adapter according to a first embodiment of the present invention that includes first and second retainers securing first and second optical fiber connectors in an adapter body housing. 
         FIG. 2  is a side elevational view, partly in section, of a connector secured in one of the housings of  FIG. 1  by one of the retainers of  FIG. 1 . 
         FIG. 3  is a perspective view of a modified version of the optical fiber adapter of  FIG. 1  in which a bridge connects the first and second retainers. 
         FIG. 4  is a perspective view of an optical fiber adapter according to a second embodiment of the present invention that includes first and second retainers securing first and second optical fiber connectors to an adapter body. 
         FIG. 5  is side elevational view, partly in section, of a connector secured in one of the housings of  FIG. 4  by one of the retainers of  FIG. 4 . 
         FIG. 6  is a perspective view of a modified version of the optical fiber adapter of  FIG. 4  in which a bridge connects the first and second retainers. 
         FIG. 7  is a perspective view of an optical fiber adapter according to a third embodiment of the present invention. 
         FIG. 8  is a sectional side elevational view taken along line VII-VII in  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     The present invention now is described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. 
     Like numbers refer to like elements throughout. In the figures, the thickness of certain lines, layers, components, elements or features may be exaggerated for clarity. 
     The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the specification and relevant art and should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. Well-known functions or constructions may not be described in detail for brevity and/or clarity. 
     As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. As used herein, phrases such as “between X and Y” and “between about X and Y” should be interpreted to include X and Y. As used herein, phrases such as “between about X and Y” mean “between about X and about Y.” As used herein, phrases such as “from about X to Y” mean “from about X to about Y.” 
     It will be understood that when an element is referred to as being “on”, “attached” to, “connected” to, “coupled” with, “contacting”, etc., another element, it can be directly on, attached to, connected to, coupled with or contacting the other element or intervening elements may also be present. In contrast, when an element is referred to as being, for example, “directly on”, “directly attached” to, “directly connected” to, “directly coupled” with or “directly contacting” another element, there are no intervening elements present. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature. 
     Spatially relative terms, such as “under”, “below”, “lower”, “over”, “upper”, “lateral”, “left”, “right” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is inverted, elements described as “under” or “beneath” other elements or features would then be oriented “over” the other elements or features. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the descriptors of relative spatial relationships used herein interpreted accordingly. 
       FIG. 1  illustrates an adapter body  10  having a first side  12 , a second side  14 , and a plurality of through-openings  16  (only one of which is illustrated) between the first side  12  and second side  14 . Each through-opening  16  is surrounded by a generally cylindrical housing  18 , two of which are illustrated in  FIG. 1 . Dashed line  20  in  FIG. 1  shows where a third cylindrical housing  18  has been removed to show the through-opening  16  therebehind. The cylindrical housings  18  may be attached to the adapter body  10  in any conventional manner or may be molded or otherwise formed with the adapter body  10  as a unitary portion thereof. Cylindrical housings  18  each include a sidewall  22  having a curved outer surface  24  and an end wall  26  spaced from the adapter body  10 . A bore  28  extends from end wall  26  into the cylindrical housing  18  to one of the through-openings  16 , and bore  28  is generally larger than and aligned with the one of the through-opening  16  and configured to receive a connector, such as connector  32  illustrated in  FIG. 2 . The cylindrical housings  18  also include first and second opposed slots  30  that extend through sidewall  22  from outer surface  24  into bore  28  which first and second slots  30  are located on the left and right sides of the cylindrical housing  18  as viewed in  FIG. 1 . 
     A retainer  34  snaps onto each of the cylindrical housings  18  to secure a connector  32  in the housing  18  as described hereafter. Each of the retainers  34  includes a body portion  36  that can be gripped by a user to manipulate the retainer  34  and first and second flexible, arcuate, arms  38  that extend from body portion  36  and have concave portions  40  facing one another. The arms  38  that terminate in free ends  42  spaced apart from one another by a distance less than a width of cylindrical housing  18 . The distance between the first and second arms  38  along the concave portions  40  thereof is slightly less than the width of housing  18  so that the arms  38  grip housing  18  when the retainer  34  is installed on the housing  18 . Each arm also includes a tab  44  on concave portion  40  that projects toward the other one of the first and second arms  38 , which tabs  44  project through the slots  30  in housing sidewall  22  and into bore  28  when the retainers  34  are mounted on the housings  18 . 
     A connector  32  configured to be received and retained in cylindrical housing  18  is illustrated in  FIG. 2 . Connector  32  includes a ferrule barrel  50  with a hexagonal body portion  52 , a ferrule  54 , a tapered portion  56  between the hexagonal body portion  52  and the ferrule  54 . Connector  32  also includes a strain relief section  58  on the side of hexagonal body portion  52  opposite from ferrule  54 , and a wall  59  between hexagonal body portion  52  and strain relief section  58 . A sleeve  60  aligns ferrule  54  with an opposing mated ferrule (not illustrated), and an optical fiber fanout cable  62  extends from the strain relief section  58 . 
     Adapter body  10  would generally comprise part of or be mounted on a module (not illustrated) which is configured to contain a plurality of optical fibers (not illustrated). The adapter body  10  would be used to attach a connector such as connector  32  to the module. In use, ferrule  54  of connector  32  is inserted into bore  28  and subsequently sleeve  60  of cylindrical housing  18 —into the page as viewed in FIG.  1 —until the hexagonal body portion  52  and/or tapered portion  56  engage an angled inner wall portion  64  ( FIG. 2 ) of bore  28 . The sizes and shapes of bore  28  and connector  32  are selected to mate in a manner that places connector  32  in a desired location when fully inserted into bore  18 , and other connector and bore shapes can be used. When connector  32  is inserted in bore  18  with tapered portion  56  of connector  32  in contact with angled inner wall portion  64  of bore  28 , wall  59  of connector  32  is located slightly inward of opposed slots  30  in sidewall  22  relative to the front of the bore at end wall  26 . 
     Connector  32  is retained in bore  28  by retainer  34 . With connector  32  inserted in bore  28  as described, retainer  34  is snapped onto cylindrical housing  38  by pressing first and second flexible arms  38  of retainer  34  against an upper portion of sidewall  22 . This forces the arms  38  away from each other as they slide over curved outer surface  24  and allows the retainer body portion  36  to approach sidewall  22  and tabs  44  to enter opposed slots  30 . As the free ends  42  of the flexible arms  38  pass the midpoint of housing  18 , the resiliency of the retainer  34  causes the free ends  42  begin to move back toward each other until the concave portions  40  of the arms rest against the curved outer surface  24  of sidewall  22 . The retainer  34  is sized so that, in this position, the flexible arms  38  exert a compressive force on sidewall  22  of the housing  18  to hold retainer  34  securely in place. As seen in  FIG. 2 , tabs  44  extend into bore  28  and partially overlie wall  59  of connector  32 . In this manner, the tabs  40  reduce the cross-section of bore  28  in the vicinity of the opposed slots  30  and block connector  32  from being removed from the bore  28 . Retainer  34  is removed from housing  18  by pulling on retainer body portion  36  and reversing the above-described actions. 
       FIG. 3  illustrates a modified version of the retainer  34  of  FIG. 1 . While  FIG. 1  illustrates a plurality of retainers  34  each securing a single connector  32  to adapter body  10 , in  FIG. 3 , the individual retainers  34  are connected by a bridge  66  so that multiple retainers can be attached to and removed from adapter body  10  as a unit. While only two cylindrical housings  18  are illustrated in  FIG. 1 , in use twelve or more cylindrical housings might be present on an adapter body, and it may be advantageous to gang together all twelve of the retainers  34  with bridges  66  or subsets thereof (groups of three or four retainers  34  connected by bridges  66 ) to allow groups of retainers  34  to be removed and attached in a single step. 
       FIG. 4  illustrates a second embodiment of the present invention and includes an adapter body  70  having a first side  72 , a second side  74 , and a plurality of through-openings  76  (only one of which is illustrated) between the first side  72  and second side  74 . Each through-opening  76  is surrounded by a generally cylindrical housing  78 , two of which are illustrated in  FIG. 4 . Dashed line  80  in  FIG. 4  shows where a third cylindrical housing  78  has been removed to show the through-opening  76  therebehind. The cylindrical housings  78  may be attached to the adapter body  70  in any conventional manner or may be molded or otherwise formed with the adapter body  70  as a unitary portion thereof. Cylindrical housings  78  each include a sidewall  82  having a curved outer surface  84  and an end wall  86  spaced from the adapter body  70 . A bore  88 , illustrated in  FIG. 5 , extends from end wall  86  into the cylindrical housing  78  to one of the through-openings  76 , and bore  88  is generally larger than and aligned with the one of the through-opening  76  and configured to receive a connector, such as connector  92  illustrated in  FIG. 5 . The cylindrical housings  78  also include first and second opposed bosses  90 , only one of which is visible in  FIG. 4 , that project from opposite sides of sidewall  82 . 
     A retainer  94  snaps onto each of the cylindrical housings  78  to secure a connector  92  in the housing  78  as described hereafter. Each of the retainers includes a split-cylindrical body portion  96  configured to engage one of the cylindrical housings  78  to hold the retainers  94  on the cylindrical housing  78  and a fork portion  98  configured to block the withdrawal of the connector  92  from the bore  88 . Body portion  96  comprises first and second arcuate, flexible arms  100  having concave inner portions  101 , and each arm  100  includes a circumferentially extending groove  102  extending into each arm from an arm free end  103 . Fork portion  98  is connected to body portion  96  by a tongue  104  and comprises first and second fingers  106  defining a gap  108  therebetween. Fork portion  98  is spaced from body portion  96  by a distance equal to the length of tongue  104 . 
     A connector  92  configured to be received and retained in cylindrical housing  78  is illustrated in  FIG. 5 . Connector  92  includes a ferrule barrel  110  with a hexagonal body portion  112 , a ferrule  114 , a tapered portion  116  between the hexagonal body portion  112  and the ferrule  114 . Connector  92  also includes a strain relief section  118  on the side of hexagonal body portion  112  opposite from ferrule  114 , and a wall  119  between hexagonal body portion  112  and strain relief section  118 . A sleeve  120  aligns ferrule  114  with an opposing mated ferrule (not illustrated), and an optical fiber fanout cable  122  extends from the strain relief section  118 . 
     In use, ferrule  114  of connector  92  is inserted in bore  88  of cylindrical housing  78 —from left to right as viewed in  FIG. 4 , until the tapered portion  116  of connector  92  engages angled inner wall  124  of bore  88 . In this embodiment, the tapered body portion  116  of the connector  92  and the angled inner wall  124  of bore  88  are configured to leave at least a portion of hexagonal body portion  112  of connector  92  outside bore  88  when the connector  92  is fully inserted in bore  88 . However, if tongue  104  were made shorter or eliminated, fork portion  98  would be closer to end wall  86  and could secure connector  92  in a position with wall  119  of connector  92  close to end wall  86  of cylindrical housing  78 . 
     Connector  92  is retained in bore  88  by retainer  94 . With connector  92  inserted in bore  88  as described, retainer  94  is pressed against the top of cylindrical housing  78  causing free ends  103  of first and second flexible arms  100  of retainer  94  to slide over curved outer surface  84  of cylindrical housing  78  and move away from one another. As retainer  94  is pressed further onto housing  78 , bosses  90  on housing  78  enter grooves  102  in the flexible arms  100 . The retainer  94  is sized so that, in this position, the flexible arms  100  cannot return to their original configuration and thus they exert a compressive force on sidewall  82  of the housing  78  to hold retainer  94  in place in this position. As body portion  96  of retainer  94  snaps over cylindrical housing  88 , the strain relief portion  118  of connector  94  enters gap  108  between the fingers  106  of fork  98 . Tongue  104  is sized so that fork portion  98  will be spaced from end wall  86  of cylindrical housing by a distance approximately equal to the amount of connector hexagonal body portion  112  that remains outside housing  78  when connector  94  is fully inserted in the housing  78 . When body portion  96  of retainer is in position on housing  78 , fork portion  98  engages wall  119  of connector  94  and blocks the removal of connector  94  from bore  88 . The presence of bosses  90  in grooves  102  of retainer  94  substantially prevents retainer  94  from moving axially or circumferentially relative to cylindrical housing  78 . 
       FIG. 6  illustrates a modified version of the retainer  94  of  FIG. 4 . While  FIG. 4  illustrates a plurality of retainers  94  each securing a single connector  92  in adapter body  70 , in  FIG. 6 , the individual retainers  94  are connected by a bridge  126  so that multiple retainers can be attached to and removed from adapter body  70  as a unit. While only two cylindrical housings  78  are illustrated in  FIG. 4 , in use twelve or more cylindrical housings might be present on an adapter body, and it may be advantageous to gang together all twelve of the retainers  94  with bridges  126  or subsets thereof to allow groups of retainers  94  to be removed and attached in a single step. 
       FIG. 7  illustrates an adapter according to an additional embodiment of the present invention and includes an adapter body  130  having a first side  132 , a second side  134 , and a plurality of through-openings  136  (only one of which is illustrated) between the first side  132  and second side  134 . Each through-opening  136  is surrounded by a generally cylindrical housing  138 , two of which are illustrated in  FIG. 7 . Dashed line  140  in  FIG. 7  shows where a third cylindrical housing  138  has been removed to show the through-opening  136  therebehind. The cylindrical housings  138  may be attached to the adapter body  130  in any conventional manner or may be molded or otherwise formed with the adapter body  130  as a unitary portion thereof. Cylindrical housings  138  each include a wall  142  having a curved outer surface  144  and an end wall  146  spaced from the adapter body  130 . A bore  148  extends from end wall  146  into the cylindrical housing  148  to one of the through-openings  146 , and bore  148  is generally larger than and aligned with the one of the through-opening  136  and configured to receive a connector, such as connector  152 . The cylindrical housings  138  also include a circumferential groove  150 , illustrated in  FIG. 8 , adjacent to adapter body  130 . 
     A connector  152  is configured to be received and retained in cylindrical housing  138 . Connector  152  includes a ferrule barrel  160  with a hexagonal body portion  162 , a ferrule  164 , a tapered portion  166  between the hexagonal body portion  162  and the ferrule  164 . Connector  152  also includes a strain relief section  168  on the side of hexagonal body portion  162  opposite from ferrule  164 , and a wall  169  between hexagonal body portion  162  and strain relief section  168 . A sleeve  170  aligns ferrule  164  with an opposing mated ferrule (not illustrated). 
     A retainer  172  snaps onto each of the cylindrical housings  138  to secure a connector  152  in the housing  138  as described hereafter. Retainer  172  includes a body portion  174  having one U-shaped opening  176  for each cylindrical housing  138  to which it will connect. Retainer  172 , illustrated in  FIG. 7 , is configured to connect to two cylindrical housings  138  and includes two U-shaped openings  176 ; however, a retainer  172  may be configured to work with a single cylindrical housing  138  or more than two cylindrical housings  138  depending on the configuration of the adapter body with which it is used. Each U-shaped opening  176  has a width at its open end wide enough to allow one of the cylindrical housings  138  to pass therethrough, and the bight  178  of the U-shaped opening  176  includes a cutout  180  along its length forming a flange  182  extending from leg to leg of the U. First and second flexible arms  184  project perpendicularly from body portion  174  on opposite sides of each U-shaped opening  176 , and the free ends  186  of the first and second flexible arms  184  each include an inwardly facing protrusion  188  with opposed cam surfaces  190  angled toward each other in the direction of body portion  174  and inner walls  192  facing toward body portion  174 . 
     Retainer  172  is connected to adapter body  130  by placing U-shaped openings  176  over cylindrical housings  138  and moving the bight  178  of each U-shaped opening toward the cylindrical housings  138  until flange  182  of the retainer  182  enters groove  150  of the cylindrical housing  138  and the retainer  172  is supported on the cylindrical housing  138 . The bight  178  of the U-shaped opening prevents the retainer  172  from moving beyond its intended position on the cylindrical housing  138  in a radial direction of the cylindrical housing  138  and the presence of flange  182  in groove  180  prevents the retainer  172  from being removed from the cylindrical housing  138  in an axial direction. Alternately, retainer  172  could be glued or otherwise permanently attached to the adapter body  130 . When mounted in this manner, inner walls  192  overlie end wall  146  of cylindrical housing  138  and partially block bore  148 . 
     Retainer  172  can be attached to adapter body  130  before or after connectors  152  are inserted into the bores  148 . Before the retainer  172  is attached to the retainer body  130 , connectors  152  may be inserted into bores  148  until tapered portions  166  of the connectors come into contact with angled inner walls  149  of bores  148 . In this position, wall  169  of connector  152  is generally aligned with end wall  146  of cylindrical housing  138 . When retainer  152  is attached to the cylindrical housing  138  as described above, the inner walls  192  of flexible arms  184  overlie wall  169  of the retainer  152  and block the withdraw of the connector  152  from the bore  148 . If the retainer  172  is attached to the adapter body  130  before the connectors are inserted, the connectors are aligned with the bores  148  and moved toward bores  148  until the tapered portion  166  of the connectors  152  engage the inwardly angled opposed cam surfaces  190  of the first and second flexible arms  184 . Because arms  184  are flexible, pressing the tapered portion  166  of the connectors  152  against cam surfaces  190  and further into bores  148  causes the flexible arms  184  to move away from one another and allow the passage of the connector  152 . When wall  169  of the connector passes beyond the inner walls  192  of the flexible arms  184 , the resiliency of the flexible arms  184  causes them to snap back to their original position, partially blocking bore  148  to block the removal of connector  152  therefrom. Connectors  152  can be removed from bores  148  either by removing retainer  172  from cylindrical housings  138  or by forcing the flexible arms  184  away from one another so that inner walls  192  do not block bore  148 . 
     The present invention has been described herein in terms of several preferred embodiments. However, additions and modifications to these embodiments may become apparent to those of ordinary skill in the art upon a reading of the foregoing description. It is intended that all such additions and modifications form a part of the present invention to the extent they fall within the scope of the several claims appended hereto.