Abstract:
A dual-function dust cover is provided for a fiber optic connector having a mating end. The dust includes a securing portion for facilitating securing the dust cover to the fiber optic connector to protecting at least a portion of the mating end thereof. The dust cover also includes a pulling portion for attachment thereto of a pulling device to facilitate pulling the connector through an appropriate structure.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to the art of fiber optic connector assemblies and, particularly, to a dual-function dust cover which performs multiple functions of protecting a mating end of a fiber optic connector as well as providing a pulling eye for the connector. 
     BACKGROUND OF THE INVENTION 
     Fiber optic connectors of a wide variety of designs have been employed to terminate optical fiber cables and to facilitate connection of the cables to other cables or other optical fiber transmission devices. A typical fiber optic connector includes a ferrule which mounts and centers an optical fiber or fibers within the connector. The ferrule may be fabricated of such material as ceramic. A ferrule holder or other housing component of the connector embraces the ferrule and may be fabricated of such material as molded plastic. A spring may be disposed within the housing or ferrule holder such that the ferrule is yieldably biased forwardly for engaging another fiber-mounting ferrule of a mating connecting device. 
     A pair of fiber optic connectors or a connector and another optical fiber transmission device often are mated in an adapter which centers the fibers to provide low insertion losses. The adapter couples the connectors together so that their encapsulated fibers connect end-to-end. The adapter may be an in-line component, or the adapter can be designed for mounting in an opening in a panel, backplane, circuit board or the like. 
     Various problems are encountered when terminating optical fibers in fiber optic connectors versus terminating electrical conductors in electrical connectors, when situations arise wherein a fiber end of an “active” fiber optic connector is exposed. A typical situation might arise when one of the fiber optic connectors at one end of an adapter is removed, leaving the other “active” fiber optic connector in the adapter. 
     In particular, an exposed fiber end may be damaged by adverse environmental hazards, and the accumulation of dust and dirt may impair the optical transmission capabilities of the fiber. Another very important problem is to protect an operator&#39;s eyes from dangerous light beams from the exposed end of an active optical fiber. For instance, an operator&#39;s eyes may be damaged from dangerous light beams exiting an unprotected receptacle or adapter. 
     Heretofore, dust covers, end caps or spring-loaded shutters have been used to close an open end of a connector to, thereby, cover the exposed fiber ends to protect the fiber ends from adverse environmental hazards, dust or dirt and to prevent light energy from the fiber ends from exiting the connector. 
     Another problem with fiber optic connectors involves feeding the connector and its terminated optical fiber cable through various structures such as subfloors, walls, ducts, vents or the like. It would be undesirable to provide a pulling portion, such as a pulling eye, directly on the connector itself, because this would increase the size of the connector. Therefore, various housings have been proposed to encapsulate the connector, with the housing having a pulling portion or pulling eye to facilitate pulling the connector and terminated cable through an appropriate structure. These pulling housings increase installation expenses of fiber optic connectors, increase inventory and otherwise are often undesirable. 
     The present invention solves these diverse problems by providing a unique dust cover for a fiber optic connector, wherein the dust cover performs an additional function of providing a pulling device for the connector. 
     SUMMARY OF THE INVENTION 
     An object, therefore, of the invention is to provide a fiber optic connector assembly with a new and improved dust cover which performs a dual function of protecting the mating end of a fiber optic connector as well as providing a pulling device for the connector. 
     In the exemplary embodiment of the invention, the fiber optic connector assembly includes a fiber optic connector for termination to an optical fiber cable and including a mating end. A dust cover is securable to the fiber optic connector for protecting at least a portion of the mating end thereof. The dust cover includes a pulling portion for attachment thereto of a pulling device to facilitate pulling the connector and terminated optical fiber cable through an appropriate structure. 
     As disclosed herein, the pulling portion of the dust cover comprises a pulling eye. The dust cover includes the pulling eye at one end thereof and a mating face at an opposite end thereof for mating with the mating end of the fiber optic connector. 
     Other features of the invention include the dust cover having at least one hole for receiving a guide pin projecting from the mating end of the fiber optic connector. The dust cover includes a receptacle for receiving a plug portion at the mating end of the fiber optic connector. The dust cover further includes a recess in a base of the receptacle for accommodating an end of a ferrule at the mating end of the fiber optic connector. 
     In the preferred embodiment of the invention, the dust cover is secured to the mating end of the fiber optic connector by taking advantage of the securing means of the connector itself. Specifically, the dust cover includes an internally threaded hole for receiving a jack screw of the fiber optic connector to secure the dust cover to the connector. The cover simply is removed by unscrewing the jack screw which remains with the connector. 
     Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: 
     FIG. 1 is a perspective view of a fiber optic connector assembly including a fiber optic connector and a dust cover according to the invention; 
     FIG. 2 is a perspective view of the fiber optic connector assembly, looking in a direction opposite that of FIG. 1; 
     FIG. 3 is a perspective view of the mating face of the dust cover; and 
     FIG. 4 is a perspective view of the assembly, with the dust cover secured to the connector. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in greater detail, and first to FIGS. 1 and 2, the invention is embodied in a fiber optic connector assembly, generally designated  10 . The assembly includes a fiber optic connector, generally designated  12 , and a dual-function dust cover, generally designated  14 , which is securable to the connector. 
     Still referring to FIGS. 1 and 2, fiber optic connector  12  includes a multi-part housing  15  surrounding a ferrule holder  16  (FIG. 2) which mounts a plurality of ferrules  18  which project slightly beyond a front face  16   a  of holder  16 . Actually, holder  16  forms a plug portion at a mating end  20  of the connector, the plug portion being surrounded by a step or shoulder  20 . Connector  12  terminates an optical fiber cable  22  which includes a plurality of optical fibers  24  (FIG. 2) terminated in ferrules  18 . A pair of alignment pins  26  project forwardly of mating end  20  of the connector for insertion into a pair of alignment holes in a complementary mating fiber optic connector or other connecting device, as is known in the art. 
     Finally, a pair of jack screws  28  extend through housing  15  in the mating direction of connector  12 . As is known in the art, jack screws  28  include externally threaded ends  28   a  which project forwardly of mating end  20  of the connector for threading into appropriate internally threaded holes of the complementary mating device to which connector  12  is mated. The jack screws may be threaded into a wide variety of other structures to which connector  12  is secured. 
     Referring to FIG. 3 in conjunction with FIGS. 1 and 2, dust cover  14  includes a mating face  30  for mating with mating end  20  of fiber optic connector  12 . The dust cover may be a one-piece structure molded of such material as plastic or the like. Mating face  30  includes a receptacle  32  for receiving plug portion  16  at mating end  20  of the connector. A recess  34  is formed in a base  32   a  of the receptacle for accommodating the ends of ferrules  18  and to prevent the ferrules and the ends of optical fibers  24  from abutting against any extraneous surfaces. A pair of holes  36  are formed in the base of receptacle  32  for receiving alignment pins  26  projecting from the connector. A pair of internally threaded holes  38  are provided in the base of receptacle  32  for receiving externally threaded ends  28   a  of jack screws  28 . Therefore, dust cover  14  is secured to mating end  20  of the connector as seen in FIG. 4 by rotating jack screws  28  to tighten ends  28   a  thereof within internally threaded holes  38  of the dust cover to draw mating face  30  of the dust cover into secure engagement with mating end  20  of the connector. 
     When dust cover  14  is secured to the mating end of connector  12  as seen in FIG. 4, the dust cover protects the exposed ends of optical fibers  22  from damage by adverse environmental hazards as well as the accumulation of dust and dirt which may impair the optical transmission capabilities of the fibers. In addition, an operator&#39;s eyes are protected from dangerous light beams from the exposed ends of the optical fibers should the fibers be “active”. 
     Dust cover  14  is a unique structure in that it performs a dual function of both protecting mating end  20  of connector  12  and the ends of optical fibers  24 , as well as providing a pulling device to facilitate pulling the connector and terminated optical fiber cable  22  through an appropriate structure. Specifically, dust cover  14  includes a pulling portion in the form of a pulling eye  40 . An appropriate pulling device, such as a pulling line or cable can be attached to dust cover  14  through pulling eye  40  and the entire fiber optic connector assembly  10  can be easily pulled or fed through various structures, as necessary. Therefore, dust cover  14  completely eliminates the need for any other extraneous pulling apparatus which might be attached to or encompass connector  12 . 
     It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.