Patent Application
20090245736
1. Field
The present invention pertains generally to the field of mechanical connectors.
2. Background
Most generally modules are used in data communications. The modules may be located in data centers in a building, airplanes and satellites. The modules may be used for remote sensor read out in box-to-box communications. A module may have an interface that allows connection between itself and another module, or itself and an “interface card” or “interface board” that is integrated in a module or computer. The modules may come in various sizes, and have varying heights. The modules may also be interconnected in a number of ways. Coaxial cables, fiber optic cables, or sometimes free space wireless links may interconnect modules. The interface that allows the interconnection of modules using cables may include connectors to connect the cables. For modules with a height of around fifteen millimeters or more, commercial standard connectors may be used to connect cables and/or ribbons of wires to the modules. When using fiber optic cables or thin wires, the commercial standard connectors come with a jacket that protects the fibers or wires. The jacket has a metal ring that anchors the jacket to the connector. The commercial connector also usually has a strain relief for the jacket. Having the jacket and strain relief for the jacket sometimes makes the connectors as long as the modules themselves.
When fitting multiple boards into a small limited space in the module, the height available for a connector is often below fifteen millimeters. Modules below fifteen millimeters are often called “low profile” modules. For low profile modules, it is not possible to find a commercial standard connector, because the jacket size and strain relief for the jacket have a greater height than that of the height of the module.
Low profile modules, particularly optical modules, are usually connected just using “pigtails”—the fiber cables are exposed and are not protected by any jacket and are “glued” to the module's interface, with the “other” end of the fiber cable fitted with a commercial connector to allow connectability of the module to other systems. The fibers are usually just part of a ribbon of fibers and being only glued to the module often result in being detached when the commercial connector is handled. Also, having a bare fiber or ribbon of fiber cables during assembly or production test increases the chance that the fiber gets damaged. If the fiber is damaged, the whole module has to be discarded because the attached fiber can no longer efficiently couple into the module. Thus, it is desired to find a way to better protect the ribbon of fibers in the connector for low profile modules.
The foregoing needs are met, to a great extent, by the present disclosure, which describes in various embodiments a connector attachment for a low height profile module.
In one of various aspects of the disclosure, a connector for a low profile module attachment is provided, comprising: a lid adapted for placement on a low profile module, a spring extension attached to the lid, the spring attachment extending from the lid in a substantially co-planar orientation, wherein the spring extension at a non-attached end of the spring extension contains a spring head that is capable of abutting an external mechanically transferable (MT) ferrule to secure it to a side of the low profile module.
In another one of various aspects of the disclosure, a method for securing an external mechanically transferable (MT) ferrule to a side of the low profile module, is provided, comprising: placing a lid on the low profile module, the lid having a spring extension attached to the lid, the spring attachment extending in a substantially co-planar orientation from the lid, wherein the spring extension at a non-attached end of the spring extension contains a spring head that is capable of abutting a side of the external MT ferrule; and securing the lid to the low profile module by tightening retainers into holes placed in the lid and in the low profile module.
In yet another one of various aspects of the disclosure, a connector for a low profile module attachment is provided, comprising: a means for covering a low profile module, the means for covering having a means for extension attached to the means for covering, the means for extension extending in a substantially co-planar orientation from the means for covering, wherein the means for extension at a non-attached end of the means for extension contains a means for compression that is capable of abutting an external mechanically transferable (MT) ferrule to secure it to a side of the low profile module.
It should be noted that while the exemplary embodiments herein are discussed in the context of an optical module and/or optical fibers/ribbons, the teachings disclosed herein may be utilized for other types of modules and cables or connection paradigms that require a low profile attachment mechanism. That is, the teachings provided herein may be applied to non-optical systems and/or devices, without departing from the spirit and scope of this disclosure.
In some embodiments, the external ferrule 30 may attach to an optical component (not shown) rather than the module 4. In such an embodiment, the internal MT ferrule 34 may be optional, as according to design preference.
Of note in the above FIGS. is that the spring extension 18 is sized to allow the spring 22 to fit over the end of the external MT ferrule 30. In doing so, pressure from the spring 22 can be exerted on the external MT ferrule 30 rather than on the fibers 26, thus avoiding damage to the fibers 26. When the module lid 10 is secured to the module case 8, the configuration of
Several benefits are evident by these exemplary embodiments. First, the low profile height (5 mm) of the exemplary connector allows this connector to be used in many aircraft printed circuit boards, as their module sizes or heights are typically restricted to 5 mm. Because of the configuration shown, the exemplary connector has been shown to keep the MT ferrule/pigtail ribbon assembly mated during thermal cycle ranging from −55° C. to 125° C., as required for Military standard aircraft. Also, the exemplary connector has been shown to keep the MT ferrule/pigtail ribbon assembly mated during aircraft vibrations of up to 30 Gs.
Second, the retention mechanism formed by the lid 10, spring extension 18 and spring 22 is very robust in that it is secured to the module case 8 (or to a firm portion of the module), rather than to the internal MT ferrule 34. Thus, it is resistant to breakage. Third, by the use of screws (presuming an embodiment using screws), no “special” tools other than a screwdriver is needed for securing the connector/external MT ferrule 30. Fourth, the configuration of the spring 22 allows it to be easily removed or placed over the external MT ferrule 30 without damaging it or the fibers 26. Another benefit of the spring 22 is that by “unscrewing” the lid 10, the spring 22 will move in the same plane as the lid 10, thus avoiding twisting of the fibers 26 during attachment or un-attachment. Numerous other advantages can be found, such as, for example, the ability in some embodiments using the spring head 46 configuration shown, to have the applied tension adjusted by appropriate bending of the spring head(s) 46.
It will be understood that many additional changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 61/041,234, filed Mar. 31, 2008, the contents of which are hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61041234 | Mar 2008 | US |
