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 is provided for receiving a first optical fiber plug, and including a first latch molded integrally with the first connector housing. A second connector housing is provided for receiving a second optical fiber plug. A latch member is mounted on the second connector housing in loose engagement therewith and includes a second latch for interengagement with the first latch on the first connector housing. Therefore, the connector housings are held in a side-by-side relationship with float therebetween provided by the loosely engaged latch member.

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 and includes a first latch molded integrally with the first connector housing. A second connector housing is provided for receiving a second optical fiber plug. A latch member is permanently molded onto the second connector housing in loose engagement therewith. The latch member includes a second latch for interengagement with the first latch on the first connector housing to hold the connector housings in a side-by-side relationship with float therebetween. 
     Preferably, the first latch on the first connector housing and the second latch on the latch member are structured to provide a snap-latch means. As disclosed herein, the first latch comprises at least one locking flange and the second latch comprises at least one chamfered snap flange for snapping into locking engagement with the locking flange. 
     The second connector housing and the latch member each include at least one retention arm molded integrally therewith. The retention arms are permanently molded in loose interengagement with each other. The retention arm on the second connector housing is a hooked arm, and the retention arm on the latch member is a projecting arm extending beneath the hooked arm. The latch member is generally rectangular, and a pair of the interengaging retention arms are provided at each corner of the latch member, with the second latch being located intermediate opposite ends of the latch member. 
     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 pair of fiber optic connector housings maintained in a side-by-side relationship by the system of the invention; 
     FIG. 2 is a perspective view of the pair of connector housings separated; 
     FIG. 3 is a perspective view of the first connector housing; 
     FIG. 4 is a perspective view of the second connector housing and the intermolded latch member; 
     FIG. 5 is a perspective view of the latch member; 
     FIG. 6 is a perspective view of the opposite side of the latch member; 
     FIGS. 7 and 8 are perspective views looking at opposite ends of a mold assembly for intermolding the second connector housing and the latch member as seen in FIG. 4; and 
     FIGS. 9-11 are exploded perspective views of the components of the mold assembly surrounding the intermolded second connector housing and latch member. 
    
    
     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  12 , for maintaining a pair of fiber optic connectors in a side-by-side relationship with float therebetween. The entire connectors are not shown in the drawings. It is sufficient to state that the connectors include a first connector housing  14  and a second connector housing  16 . The connector housings include through receptacles  18  for receiving first and second optical fiber plugs, as is known in the art. Specifically, connector housings  14  and  16  are of the well known “SC” type based on a push-pull concept. Basically, the duplex interconnection system  12  of the invention is provided between connector housings  14  and  16 , and it is unnecessary to go into the details of the optical fiber plugs which are received by the housings. However, it should be understood that the duplex interconnection system of the invention is not limited to just “SC” type connectors. While FIG. 1 shows the connector housings interconnected, FIG. 2 shows the housings separated. 
     Referring to FIG. 3 in conjunction with FIGS. 1 and 2, first connector housing  14  is a one-piece structure unitarily molded of dielectric material such as plastic or the like. The housing is elongated and includes a pair of first latches, generally designated  20 , molded integrally therewith. Each first latch is formed by a locking flange  22  having an inner chamfered edge  22   a . The locking flanges are in the form of elongated bars having elongated openings  24  therebeneath. A pair of end flanges  26  project from the first connector housing beyond locking flanges  22  for aesthetic purposes as well as to provide standoffs between the two connector housings. Second connector housing  16  is a one-piece structure unitarily molded of dielectric material such as plastic or the like. The second connector housing has a latch member  28  permanently molded thereon in loose engagement therewith to provide relative floating movement therebetween. The latch member is elongated and generally rectangular, with four arms  30  projecting laterally outwardly from the four corners thereof. Second connector housing  16  has four hooked arms  32  beneath which arms  30  of the latch member project in a loose engagement as depicted in FIG.  4 . In essence, arms  30  and  32  define retention arms for maintaining latch member  28  in loose engagement with second connector housing  16 . It also can be seen that the width of latch member  28  is narrower than the distance between each pair of arms  32  at opposite ends of the latch member so that there is relative movement between the latch member and the second connector housing in the direction of arrow “A”. The latch member can float relative to the second connector housing in both lateral directions as indicated by arrows “A” and “B” (FIG.  4 ). The distances that flanges  22  project from housing  14  and hooked arms  32  project from housing  16  define the amount of float in the “B” direction. The width of flanges  26  between hooked arms  32  define or limit the amount of floating in the “A” direction. Therefore, the various gaps between latch member  28  and its arms  30  and housing  16  and its arms  32  can be larger than the amount of floating for better moldability. Relative longitudinal movement between the connector housings is generally not desirable. This is made a minimum by the length of flanges  22  and their abutment with hooked arms  32  as seen in FIG.  1 . 
     Latch member  28  has a pair of second latches  34  in the form of integrally molded flanges projecting outwardly from opposite sides of the latch member. The flanges are chamfered, as at  34   a . It can be seen that retention arms  30  project outwardly from the bottom of latch member  28 , and latch flanges  34  project outwardly from the top of the latch member so that a space  36  is provided beneath the latch flanges to accommodate locking flanges  22  (FIG. 3) on first connector housing  14 . This spacing is shown best in FIG.  1 . Reference also can be made to the isolated depictions of latch member  28  in FIGS. 5 and 6 to show that bottom surfaces  30   a  of retention arms  30  are offset below bottom surfaces  34   b  of latch flanges  34 . Another purpose for this offset is to make gap  36  (FIG. 4) larger for easy molding by a larger mold blade. 
     In connecting first connector housing  14  with second connector housing  16  in a side-by-side floating relationship, inner chamfered edges  22   a  of locking flanges  22  on first connector housing  14  (FIG. 3) are brought into engagement with chamfered sides  34   a  of latch flanges  34  of latch member  28  (FIG.  4 ), to snap the first connector housing into interengagement with the latch member on the second connector housing. Since the latch member is mounted for floating movement relative to the second connector housing as described above, the first connector housing, in turn, is mounted on the second connector housing for floating movement relative thereto. In other words, first connector housing  14  derives its floating movement relative to the second connector housing  16  through the floating latch member  28 . 
     FIGS. 7 and 8 show a mold assembly, generally designated  40 , for permanently molding latch member  28  onto second connector housing  16  in loose engagement therewith. In other words, the mold assembly facilitates loosely intermolding the latch member and the second connector housing, so that when the housing and the latch member are “intermolded”, they cannot be separated without breaking the components. The mold assembly includes a pair of major side molds  42  and  44 , a pair of minor side molds  46  and  48  and a core mold  50 . 
     FIGS. 9-11 show the major and minor side molds and the core mold of mold assembly  40  in positional relationship surrounding second connector housing  16  and latch member  28  to show how the latch member is molded in loose engagement with the second connector housing. More particularly, referring first to FIG. 9, major side mold  44  includes cavities  52  for forming hooked retention arms  32  of the connector housing and cavities  54  for forming latch flanges  34  of latch member  28 . A cavity  56  runs a substantial length of major side mold  44  to form the main body of latch member  28 . Core mold  50  forms the particular configuration of through receptacle  18  within second connector housing  16 . The core mold has a longitudinal rib  57  which is effective to form the main body portion of latch member  28  into a generally U-shaped configuration having generally uniform wall thicknesses which allow for generally uniform plastic shrinkage which, in turn, avoids warpage. 
     Referring to FIG. 10, major side mold  42  has a large cavity  58  for forming the bulk of second connector housing  16 . Each minor side mold  46  and  48  has end cavity configurations  60  which form projecting retention arms  30  of latch member  28 , and the surrounding portions of the minor side molds separate retention arms  30  from hooked retention arms  32  of the second connector housing. Cavities  62  form chamfered latch flanges  34  on the sides of latch member  28 . Minor side molds  46  and  48  have elongated projecting inner portions  64  which meet behind latch member  28  to separate the latch member from the second connector housing. The mold parts therefore form two separate cavities for the two components which are fed molten plastic material through separate insertion gates. FIG. 11 shows a depiction similar to that of FIG. 10 but looking in the opposite longitudinal direction. 
     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.