Abstract:
A system for maintaining a pair of fiber optic connectors in a side-by-side relation with float therebetween, along with a method of fabricating the connectors. A first connector housing receives a first optical fiber plug, and includes a first latch molded integrally therewith. A second connector housing receives a second optical fiber plug and includes a second latch molded integrally therewith. The first and second latches are permanently and non-releasably molded in loose engagement to hold the connector housings in a side-by-side relationship with float therebetween.

Description:
FIELD OF THE INVENTION 
     This invention generally relates to the art of fiber optic connectors and, particularly, to a system for interconnecting a pair of individual fiber optic connectors, along with a method of fabricating the connectors. 
     BACKGROUND OF THE INVENTION 
     Fiber optic devices use single or multiple strands of fibers each having an inner circular glass core coated with a circumferential cladding having a different index of refraction. Light is transmitted along the core and reflected from the interface between the core and cladding. Such devices can be used as transmission lines for transmitting information bearing light energy. A transmission line can be formed from a single fiber or it can include a plurality of fibers bundled together. Additionally, several transmission lines can be arranged in parallel for the simultaneous transmission of information along each of the separate lines. 
     Originally, fiber optic systems utilized simplex interconnection systems with single connector plugs terminating single fiber optic cables. In a simplex system, either transmission or reception of information can take place at one time. Consequently, simplex systems are limited in the amount of information that they can transmit and receive during a given period of time. 
     To increase the amount of information that can be communicated over fiber optic systems, multi-channel systems were developed. Such multi-channel systems include, for example, duplex connector plugs and cables which are capable of simultaneous transmission and reception. Thus, using a duplex system enables information to be transmitted at a much higher rate. 
     In order to manage the duplex connector plugs and cables, structures have been designed for interconnecting two fiber optic connectors in a side-by-side relationship forming a duplex connector. For instance, adapter structures have been designed to provide a pair of side-by-side through receptacles for receiving the pair of fiber optic connectors in a side-by-side arrangement. Not only do such duplex adapters increase costs by requiring an additional, somewhat bulky component, but it also is difficult to maintain proper axial alignment which is necessary for optimum signal transmission. Misalignment in such duplex connectors or adapters are caused by manufacturing inaccuracies or tolerances. Consequently, interconnection systems, adapters or the like have been designed for mounting a pair of fiber optic connectors in a side-by-side alignment with lateral floating therebetween generally perpendicular to their longitudinal axes in order to compensate for misalignment due to manufacturing tolerances and the like. These systems may be provided directly between the connector housings. The present invention is directed to providing improvements in such a floating system directly between a pair of side-by-side fiber optic connectors and which also eliminates separate floating mechanisms in interconnecting adapters or the like. 
     SUMMARY OF THE INVENTION 
     An object, therefore, of the invention is to provide a new and improved system for maintaining a pair of fiber optic connectors in a side-by-side relation with float therebetween, along with a method of fabricating the connectors. 
     In the exemplary embodiment of the invention, a first connector housing is provided for receiving a first optical fiber plug. The first housing includes a first latch molded integrally therewith. A second connector housing is provided for receiving a second optical fiber plug. The second housing includes a second latch molded integrally therewith. The first and second latches are permanently and non-releasably molded in loose interengagement to hold the connector housings in a side-by-side relationship with float therebetween. 
     As disclosed herein, the first and second latches comprise complementarily loosely engaged retention arms. The retention arms comprise permanently interengaged hooked arms. A plurality of pairs of the first and second retention arms are located at spaced locations between the connector housings. 
     The invention also contemplates a method in which the connector housings are interconnected by the permanently molded, interengaging latches or retention arms. 
     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 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 pair of connector housings permanently interengaged by the duplex interconnection system of the invention; 
     FIG. 2 is a perspective view of one of the connector housings, although this isolated depiction of the housing could not occur in actual practice; 
     FIG. 3 is a perspective view of the other connector housing, although this isolated depiction could not happen in actual practice; 
     FIGS. 4 and 5 are perspective views of a mold assembly for molding the connector housings in permanent interengagement, the views looking at opposite ends of the mold assembly; and 
     FIGS. 6 and 7 are exploded perspective views of the components of the mold assembly surrounding the interengaged connector housings. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings in greater detail, and first to FIG. 1, the invention is embodied in a duplex interconnection system, generally designated  10 , for permanently interconnecting first and second fiber optic connector housings  12  and  14  in loose engagement to provide floating movement between the housings. The housings are of the well known “SC” type for receiving appropriate optical fiber plugs within through receptacles  16 . “SC” type fiber optic connectors are well known in the art and the optical fiber plugs are not shown herein. However, it should be understood that the duplex interconnection system of the invention is not limited to just “SC” type connectors. 
     Referring to FIG. 2 in conjunction with FIG. 1, first connector housing  12  is a one-piece structure unitarily molded of dielectric material such as plastic or the like. The housing has four latches in the form of hooked retention arms  18  molded integrally therewith and projecting inwardly from an inner face  20  thereof. In essence, the hooked retention arms are located at the corners of an elongated rectangular interface between the connector housings. It can be seen that the hooked arms are directed radially outwardly in a direction transverse to the longitudinal axis of the connector housing. A pair of elongated ribs  22  are molded integrally with the housing between the opposite pairs of hooked retention arms and project radially inwardly from inner face  20 . These ribs are for aesthetic purposes, but the ribs also function to prevent an operator&#39;s fingers from projecting between the two connector housings. 
     Referring to FIG. 3 in conjunction with 1, second fiber optic connector housing  14  also has four latches in the form of generally “rectangularly” spaced, hooked retention arms  24  projecting inwardly from an inside face  26  of the housing. The second connector housing is a one-piece structure unitarily molded of dielectric material such as plastic or the like, and retention arms  24  are molded integrally therewith. It can be seen that the hooked retention arms are directed longitudinally of the elongated connector housing. 
     It should be understood that first and second connector housings  12  and  14 , respectively, cannot be separated from each other as shown in the isolated depictions of FIGS. 2 and 3. These depictions are used herein simply to provide a better illustration of the configuration and spacing of the latches or hooked retention arms  18  and  24  between the two housings. The hooked retention arms are permanently and non-releasably molded in loose interengagement as shown in FIG.  1  and as described hereinafter, and the housings cannot be disengaged after molding. 
     Specifically, referring back to FIG. 1, it can be seen that the transversely directed hooked retention arms  18  of first connector housing  12  are loosely interengaged behind the longitudinally directed hooked retention arms  24  of second connector housing  14 . It also can be seen that the lengths of the hooked arms and the thickness of the hooks on the ends of the arms are such as to provide a significant amount of lost motion or float between the interengaged retention arms and, consequently, between the two connector housings, and prevents the two housings from becoming disengaged. With the two housings being in permanent interengagement, subsequent assembly steps are totally eliminated. This also reduces the problem of maintaining separate inventories for separate parts. 
     FIGS. 4-7 show a mold assembly, generally designated  30  (FIGS.  4  and  5 ), for molding fiber optic connector housings  12  and  14  with hooked retention arms  18  and  24  in permanent but loose interengagement. The mold assembly includes a pair of major side molds  50 , a pair of minor side molds  52 , an end mold  54  and a core mold  56 . Major side molds  50  are movable toward and away from assembled condition in the direction of arrows “A”. Minor side molds  52  are movable toward and away from assembled condition in the direction of arrows “B”. End mold  54  is movable toward and away from assembled condition in the direction arrow “C”. Core mold  56  is movable toward and away from assembled condition in the direction of arrow “D”. 
     Core mold  56  includes a pair of plug portions  58  which are effective to form through receptacles  16  within the connector housings. A center partition  60  of the core mold cooperates with a plug portion  62  of end mold  54  to effectively form the gap or spacing between connector housings  12  and  14 , as well as laterally between elongated ribs  22  and the side pairs of interengaged hooked retention arms  18  and  24 . Major side molds  50  are identical in construction and have major elongated cavities  64  which form the outside configuration of connector housings  12  and  14 . 
     Finally, minor side molds  52  are identical in construction and include ribs  66  which are effective to form side ribs  22  on connector housing  12 . The minor side molds have multiple boss arrangements  68  which are effective to form the loosely interengaged hooked retention arms  18  and  24  at one end of the interconnected housings (the left-hand end as viewed in FIG.  6 ). The minor side molds also have boss arrangements  70  which are effective to form the loosely interengaged hooked retention arms  18  and  24  located more centrally of the interengaged housings. Boss arrangements  68  close onto shut-off surface arrangements  76  on core mold  56 , and boss arrangements  70  close onto surface arrangements  78  on end mold  54 . In essence, two separate cavities are formed for the two housings. Other portions, such as bosses  72 , on the opposite ends of minor side molds  52  are effective to form the specific configuration of the noses  74  of the connector housings, such as notches  76 . 
     When side molds  50  and  52 , end mold  54  and core mold  56  as shown in FIGS. 6 and 7 are closed to form the mold assembly  30  shown in FIGS. 4 and 5, molten dielectric or plastic material is injected through two distinct gates into the two cavities formed by the various mold components to mold connector housings  12  and  14  with hooked retention arms  18  and  24  in permanent but loose interengagement as shown in FIG.  1 . The invention includes molding this duplex interconnection system by such techniques and by such a molding apparatus or its equivalent. 
     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.