Abstract:
A fiber optic connector assembly with a fiber optic connector mounted to a fiber optic cable and including a ferrule with an end face terminating the fiber. A plug is configured to fit about and engage the ferrule of the fiber optic connector to seal the end face from contaminants. An adhesive tape is releasably attached to the connector about the plug, holding the plug to the connector. Further, a cover assembly for a fiber optic connector mounted to an end of and terminating a fiber optic cable. The cover includes an open sided box and a lid sized to engage the open side. The box and the lid define a cavity sized to fit about and receive a fiber optic connector. The cavity has an open end adapted to receive the optical fiber cable. The fiber optic connector is held within the cavity and the cable extends through the open end, with the lid engaging the open side and sealing the cavity from contaminants outside the cavity.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates generally to protective devices for telecommunications connectors.  
       BACKGROUND  
       [0002]     Telecommunications cables are often pre-terminated by a manufacturer or a supplier. These pre-terminated cables may be configured to standard or customs lengths and may have one or both ends terminated. The connectors attached to the ends of these cables may be susceptible to damage or contamination during transportation from the manufacturer or supplier to a warehouse, storage facility or installation site. Damage to these connectors and cable ends may result in lost time to repair the connectors as well as possible signal degradation.  
         [0003]     Improvements to protecting the ends of telecommunications cable connectors are desirable.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention relates to a cover assembly for a fiber optic connector mounted to an end of and terminating a fiber optic cable. The cover includes an open sided box and a lid sized to engage the open side. The box and the lid define a cavity sized to fit about and receive a fiber optic connector. The cavity has an open end adapted to receive the optical fiber cable. The fiber optic connector is held within the cavity and the cable extends through the open end, with the lid engaging the open side and sealing the cavity from contaminants outside the cavity.  
         [0005]     Further, the present invention relates to a fiber optic connector assembly with a fiber optic connector mounted to a fiber optic cable and including a ferrule with an end face terminating the fiber. A plug is configured to fit about and engage the ferrule of the fiber optic connector to seal the end face from contaminants. An adhesive tape is releasably attached to the connector about the plug, holding the plug to the connector.  
         [0006]     Further, the present invention relates to a sleeve, the first end of which fits about a ferrule of a telecommunications connector with the end face of the ferrule within an axial opening of the sleeve. A plug is inserted into a second opposing end of the sleeve. The sleeve fits closely about both the ferrule and the plug to prevent entry of airborne contaminants into the axial opening through either end.  
         [0007]     Still further, the present invention relates to a body including an axial opening with a first end and an opposing second end. A ferrule of a fiber optic connector is placed within the axial opening through the first end so that a polished end face of the ferrule is within the axial opening. A removable adhesive sealing member is placed over the second end of the axial opening. The body fits about the ferrule to prevent entry of airborne contaminants into the axial opening through the first end and the sealing member prevents entry of airborne contaminants into the axial opening through the second end.  
         [0008]     The present invention also relates to a method of sealing a telecommunications connector against airborne contaminants comprising terminating a fiber optic cable with a fiber optic connector in a clean environment protected against airborne contaminants. An end of an optical fiber within the cable is terminated at a polished end face of a ferrule of the connector. Within the clean environment, a seal is placed about the ferrule to protect the polished end face of the ferrule including the end of the optical fiber against airborne contaminants. The connector is then transported to a location where a fiber optic communications linkage is desired. The seal is then removed from the connector and the communications linkage is made without cleaning the end face of the connector. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the invention and together with the detailed description, serve to explain the principles of the invention. A brief description of the drawings is as follows:  
         [0010]      FIG. 1  is a perspective view of a telecommunications connector clamshell protective device according to the present invention.  
         [0011]      FIG. 2  is a side view of the protective device of  FIG. 1  with the lid closed and the foam sealing blocks and the telecommunications cable and connector indicated with dashed lines.  
         [0012]      FIG. 3  is a side view of a second embodiment of a telecommunications connector protective device according to the present invention with the lid closed and the foam sealing blocks and the telecommunications cable and connector indicated with dashed lines.  
         [0013]      FIG. 4  is a perspective view of a third embodiment of a telecommunications connector plug protective device according to the present invention.  
         [0014]      FIG. 5  is a cross-sectional view of the protective device of  FIG. 4  mounted on a fiber optic connector.  
         [0015]      FIG. 6  is a partial cross-sectional view of the protective device of  FIG. 4 .  
         [0016]      FIG. 7  is a side view of a fourth embodiment of a telecommunications connector protective device.  
         [0017]      FIG. 8  is a side view of a fifth embodiment of a telecommunications connector protective device.  
         [0018]      FIG. 9  is an end view of the protective device of  FIG. 8 . 
     
    
     DETAILED DESCRIPTION  
       [0019]     Reference will now be made in detail to exemplary aspects of the present invention which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or similar parts.  
         [0020]     When a telecommunications connector is installed in an operational environment, dust and other contaminants may degrade the level of signal that is transmitted through the connector and the communications circuit to which the connector is attached. These contaminants may be introduced into the communication circuit at any time from when the connector is assembled (such as in a factory) to when the connector is inserted within a mating adapter (such as in an interconnect panel or other connection device). By assembling connectors in a relatively clean factory environment and providing a secure and removable shield for the connector, the potential for contaminants being introduced into such a communications circuit may be minimized.  
         [0021]     Referring now to  FIG. 1 , a telecommunications connector  16  is shown within a clamshell protective device  10 . Clamshell device  10  includes a box  12  and a lid  14  hingedly mounted to each other by hinge  13 . Alternatively, box  12  and lid  14  may be separate elements without hinge  13  or other connection extending between them. Connector  16  is mounted to the end of and terminates a telecommunications cable  18 . As shown, connector  16  is an optical fiber connector commonly referred to as an FC connector and cable  18  is an optical fiber cable including a strand of optical fiber terminated at a ferrule  17 . Other styles and formats of optical fiber connectors and high speed copper connectors are also contemplated within the scope of the present invention. The amount of data that may be transmitted through any of these connector types may be impeded by contaminants and use of a protective device such as device  10  may provide protection from the introduction of such contaminants.  
         [0022]     Connector  16  is received within a recess  20  of box  12 . A slot  22  receives cable  18 . Cable  18  also passes across a first foam block  24  mounted within recess  20  adjacent slot  22 . Block  24  may be formed of a deformable resilient foam to permit block  24  to conform the diameter of cable  18  and prevent entry of contaminants into recess  20  through slot  22 . A mating foam block  26  is included on lid  14  which cooperates with block  24  to assist in sealing around cable  18 . Alternatively, either of blocks  24  or  26  may be made of a material capable of conforming to the full diameter of cable  18  so that the other mating block may be formed of a relatively non-deformable material. The non-deformable block may be integrally formed as part of either lid  14  or box  12  so that fewer components are needed to assemble device  10 .  
         [0023]     Block  26  is within a mating recess  32  of lid  14 . Recess  32  includes perimeter walls  34  extending about lid  14 . Walls  34  engage mating surfaces  30  of box  12  about recess  20  and cooperate to seal recesses  32  and  20  against contaminants reaching connector  16  when device  10  is closed as shown in  FIG. 2 . Walls  34  and mating surfaces  30  may be snap fit with each other when lid  14  is mated with box  12 , as shown in  FIG. 2 , and the snap fit may be close enough to prevent entry of contaminants. Alternatively, walls  34  and mating surfaces  30  may be bonded to each other, such as with glue, heat sealing, ultrasonic welding or other techniques, to provide additional protection against the entry of contaminants.  FIG. 2  also shows foam blocks  24  and  26  of protective device  10  of  FIG. 1  cooperating to seal about cable  18  to prevent entry of contaminants into device  10 .  
         [0024]     Adjacent mating surfaces  30  about recess  20  are flanges  36 . Adjacent perimeter walls  34  about recess  32  are flanges  38 . As an alternative to bonding perimeter walls  34  to mating surfaces  30 , flanges  32  and  34  may be bonded to each other, such as with glue, heat sealing, ultrasonic welding or other techniques.  
         [0025]     Referring now to  FIG. 3 , a second embodiment of a protective device  110  is shown with a lid  114  and a box  112  connected by hinge  13 . Device  110  differs from device  10  in that box  12  and lid  14  are approximately equal in depth, whereas box  12  is substantially deeper than lid  14 . Recess  32  of lid  14 , as shown in  FIG. 2 , may only extend to the depth needed to define perimeter walls  34 . Recess  132  of lid  114  extends to a greater depth than required to define perimeter walls  34 , as shown in  FIG. 3 . As shown in  FIG. 2 , connector  16  is positioned substantially within recess  20  of box  12  and only a small portion of connector  16  extends within recess  32  of box  14 . As shown in  FIG. 3 , connector  16  extends within both recess  132  and a recess  120  of box  112  approximately equally. A pair of foam blocks  124  and  126  are positioned adjacent an end of device  110  opposite hinge  13  to permit entry of cable  18  into device  110  and to seal about cable  18  against the entry of contaminants.  
         [0026]     While devices  10  and  110  protect an end of cable  18  terminated at ferrule  17  from contaminants as described above, these devices also provide some protection from impact or other physical damage that may adversely affect the ability of connector  16  to interface with other elements of the telecommunications circuit. As is well known in the prior art, telecommunications connectors such as connector  16  include features which mate with adapters or other components and which may provide a secure and sealed interface for the transmission of signals, either optical or electrical. These mating features also need to be protected from contaminants as well as from physical damage. Devices  10  and  110  provide protection to these mating and locking features of connector  16  as well as to ferrule or cable termination  17 .  
         [0027]     Referring now to FIGS.  4  to  6 , a plug protective device  52  for protecting an end face  50  of ferrule  17  of telecommunications connector  16  is shown. Plug  52  includes a body  58  and a larger diameter portion  60  defining a shoulder  64  between. An inner cylindrical opening  56  is defined within plug  52  for receiving and sealing about ferrule  17 . When plug  52  is positioned about ferrule  17  as shown in  FIG. 5 , the seal between an inner wall  59  of body  58  within a cylindrical cavity  56  forms an air-tight seal, so that air is compressed within cavity  56  between end face  50  and an inner end wall  66 . To prevent this compressed air from forcing plug  52  from about ferrule  17  and allowing contaminants to come into contact with end face  50 , a tape  54  is positioned about plug  52  to hold plug  52  to connector  16 . Tape  54  may include an anti-tamper feature which will indicate of tape  54  has been removed and replaced or otherwise disturbed. If this anti-tamper feature indicates that tape  54  has been disturbed, this may indicate the seal between plug  52  and ferrule  17  has been broken and that end face  50  may have been exposed to contaminants. Tape  54  may also be mounted to connector  16  and plug  52  with a tail  55  to facilitate the removal of tape  54  and plug  52  from connector  16 .  
         [0028]     As shown, ferrule  17  is inserted within cavity  56  of plug  52  through an opening  62 . To assist in the alignment and entry of ferrule  17  into cavity  56 , a tapered entry  63  into opening  62  may be provided. At the inner end of taper  63 , adjacent inner wall  59 , a smaller diameter ledge  68  is formed. It is anticipated that plug  52  will be made of a resilient deformable material such as a thermoplastic elastomer. Ledge  68  should promote the formation of an airtight seal about ferrule  17  by deforming to closely match the outer surface of ferrule  17  as plug  52  is mounted to connector  16 . Ledge  68  may also serve to brush off surface contaminants from the outer surface of ferrule  17  as plug  52  is placed about ferrule  17  and ensure that these contaminants do not enter cavity  56 . Shoulder  64  provides a finger hold to aid in the removal of plug  52  from connector  16 .  
         [0029]     Referring now to  FIG. 7 , a fourth embodiment of a protective device  70  includes a plug  72  and a sleeve  74 . A first end  82  of sleeve  74  is sized to be received about ferrule  17  of connector  16  so that end face  50  is within an axial opening  75  of sleeve  74 . Axial opening  75  is defined by an interior wall  73 . In  FIG. 7 , axial opening  75  is shown enlarged greater than the diameter of ferrule  17  for clarity. However, axial opening  75  is sized to fit closely to ferrule  17  to prevent contaminants from passing through first end  82  along ferrule  17  to reach end face  50 . As shown, axial opening  75  is consistent in diameter from first end  82  to a second end  84 . Plug  72  includes a shaft  78  which similarly sized to ferrule  17  and is inserted through second end  84  into axial opening  75 . Shaft  78  includes a mating portion  76  sized and shaped to approximate the polished shape of end face  50 . Mating portion  76 , as shown, is concave and forms a contour to match the polished convex shape of end face  50 . Mating portion  76  is shown offset from end face  50  for clarity in  FIG. 7 . However, in use, mating portion  76  will be in close proximity or contact with end face  50  to further provide protection against contaminants reaching end face  50 .  
         [0030]     Other polish profiles for end face  50  are known and it is anticipated that mating portion  76  may be shaped as appropriate to match these known polish profiles. It is also anticipated that mating portion  76  may be shaped to match new polish profiles that may be developed, within the scope of the present invention. Plug  72  also includes an enlarged end  80  opposite shaft  78 . Enlarged end  80  provides a finger grip for removing device  70  from ferrule  17  of connector  16 .  
         [0031]     As shown, mating end  76  is offset from end face  50  for clarity. However, end face  50  and mating face  76  would be positioned directly adjacent each other so that mating face  76  may block contaminants from reaching end face  50 . As axial opening  75  is uniform in diameter and shaft  78  is similarly sized to ferrule  17 , contaminants are prevented from entering axial opening  75  through second end  84  as well.  
         [0032]     Referring now to  FIGS. 8 and 9 , a fifth embodiment of a protective device  90  includes a body  96  with a flange  94  at a second end  104 . Body  96  includes an inner wall  98  which defines an interior opening  100  extending between a first end  102  and second end  104 . Interior opening  100  is sized to be received about ferrule  17  so that end face  50  is within opening  100  and inner wall  98  fits closely about ferrule  17  to prevent contaminants from entering opening  100  through first end  102 . With such an air-tight or near air-tight seal between ferrule  17  and inner wall  98 , second end  104  of body  96  is open to permit ferrule  17  to be inserted within opening  100  and allowing displaced air to escape. Once ferrule  17  has been placed within opening  100 , an adhesive member  92 , such as tape, is then placed across end  104  to provide an air-tight seal of second end  104  and prevent contaminants from entering opening  100  through second end  104 .  
         [0033]     As shown, member  92  extends beyond a flanged portion  94  of body  96 , so that member  92  may be removed to permit protective device  90  to be withdrawn from ferrule  17 . Flanged portion  94  provides a finger grip to aid in the removal of body  96  from ferrule  17 . Alternatively, member  92  could be sized to more closely match the size and shape of flanged portion  94  with a single tab extending beyond flanged portion  94  to permit removal of member  92 .  
         [0034]     While several embodiments of protective devices have been described herein, a generalized procedure for protecting telecommunications connectors from airborne contaminants applicable to many of these embodiments is within the scope of the present invention as well. This generalized procedure begins with a fiber optic cable being terminated with a fiber optic connector in a clean factory environment. An optical fiber within the cable is positioned within a ferrule of the connector and an end face of the ferrule and the end of the fiber adjacent the end face are polished to the desired polish profile. Once the end face has been finished and before the connector is removed from the clean factory environment, a seal is applied to the connector to protect the end face from airborne contaminants.  
         [0035]     The protection procedure also includes transporting the protected connector to a location where a fiber optic communications linkage is desired. This location may be in an environment where the air is not as protected from airborne contaminants as the factory environment. Further, during transportation or storage, it is desirable that the end face of the connector be protected from airborne or other contaminants as well. Once at the location of the desired telecommunications connection, the seal may be removed from the connector and the linkage may be completed without the need for cleaning of the end face in the field.  
         [0036]     The creation of the seal about the end face and removal of the seal prior to making the linkage may be performed by the methods and devices described above.  
         [0037]     The embodiments of the inventions disclosed herein have been discussed for the purpose of familiarizing the reader with novel aspects of the present invention. Although preferred embodiments have been shown and described, many changes, modifications, and substitutions may be made by one having skill in the art without unnecessarily departing from the spirit and scope of the present invention. Having described preferred aspects and embodiments of the present invention, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.