1. Field of the Invention
This invention relates to production and assembly of aerospace vehicles. Particularly, this invention relates to the electrical connection system of a production aircraft.
2. Description of the Related Art
As is well known in the art, aerospace vehicles, e.g. aircraft, spacecraft, typically employ a large number electrical connections throughout their structures to facilitate communication between the various systems and components. In the production and assembly of aircraft, particularly large passenger aircraft, conventional production interconnects have had one basic function; they exist primarily for the ease of manufacturing.
Conventional circular and rectangular production interconnects are used in production aircraft. The conventional technique employed for production interconnects is to use numerous individual circular and/or rectangular connectors coupled together at specific bracket. While the conventional approach does provide a convenient specific location for the electrical connection of various systems and components, it is lacking in many significant respects. The conventional approach requires an excessive amount of volume for a specified number of electrical connections. In addition, in both cases custom brackets are created to serve as a centralized coupling station for the electrical interconnects. Thus, conventional interconnect systems are custom applications and often require unique configuration bracket designs for each location. Installation and use of the convention systems also typically entails a tedious, time-consuming tool procedure. The unique brackets combined with the current component cost and labor associated with the installation of the electrical connector to the application specific disconnect bracket drive high recurring cost in the conventional electrical interconnect system. Furthermore, as aerospace systems have evolved, there is a burgeoning need to accommodate a greater number of electrical connections that the conventional methods cannot adequately address.
The conventional rectangular production interconnects provide a greater packing ratio of electrical connectors than conventional circular production interconnects. From these two examples it becomes evident that using the circular connector will require larger brackets than the rectangular connector. This is generally due to the fact that wasted space is created by the interstices between circular interconnects disposed adjacent to one another. For example, conventional circular connector technology requires approximately one inch minimum clearance around each connector to aid in connector coupling and decoupling which increases the necessary spatial packaging volume. There is also another cost driver with the conventional circular connector. If for some reason another connector needs to be added, the bracket will need to be redesigned creating a new custom bracket configuration to be maintained in the drawing system.
The conventional rectangular connector can use one panel cutout to install up to six vertically stacked connectors. This can simplify the manufacturing of the bracket and the bracket design. If an additional connector needs to be added in a future provision, the additional connector can be more easily accommodated. Using the conventional rectangular connector provides some advantages over the conventional circular connector, but it still does not eliminate the need for unique interconnect panels and the labor associated with the installation of the electrical connectors. The labor associated with designing, fabricating and installation of the electrical connectors on the production conventional interconnect panel has not been eliminated.
A primary function for an electrical production interconnect assembly is to terminate the greatest number of electrical circuits in the smallest amount of space while providing an electrical ground path. In a conventional development, when optimal density cannot be achieved, there can be a range of negative consequences. For example, additional space may be required for larger brackets, increasing weight. Additionally, fanning out interconnects may sometimes increase wire weight. Furthermore, costs associated with designing and fabricating a larger and in the majority of situations, unique disconnect bracket are typically increased when this situation arises.
Production disconnect systems for the next generation of aircraft build requirements must meet requirements including reduced installed cost, weight, volume and airplane build cycle time. In addition, future airplane assembly sequences will require manufacturing flow times to be significantly reduced. The reduction in final assembly flow times requires a new electrical connector to be designed that enables the numerous manufacturing production breaks on the electrical wiring to be reliably joined, eliminating labor associated with the process and ultimately eliminating the unique production disconnect brackets and the use of numerous mechanical fasteners associated with the installation of the electrical connectors. Some key elements of the electrical production disconnect include the form factor, ease of mating and providing an inherent electrical ground path.
In view of the foregoing, there is a need in the art for systems and apparatuses for providing electrical interconnects in aerospace vehicles that are space efficient and light weight. There is further a need for such systems and apparatuses that reduce the excess wire weight otherwise necessary to fan out the disconnects. There is a also a need for such systems and apparatuses to reduce assembly flow times in production vehicles allowing quick and certain assembly and inspection. There is still further a need for such systems and apparatuses that can be efficiently designed and fabricated to accommodate new sets of interconnects at a reduced cost and build cycle time. These and other needs are met by the present invention as detailed hereafter.
The present invention discloses systems and apparatuses of a novel quick lock production interconnect that may be used in production aircraft. A typical quick lock production interconnect embodiment of the present invention can reduce the installed cost, weight, volume, and build cycle time in production airplane. The packaging volume of a novel quick lock production interconnect can be approximately thirty percent smaller than the conventional techniques used in the commercial airplane wiring today. Final assembly time may also be reduced as a result of a novel slide latch coupling mechanism that provides a positive visual indication of a fully coupled connector eliminating the need for specialized tools.
Further, the connector coupling mechanism can eliminate the need for specific torque values and the need for any tools to be used in the assembly sequence and the use of mechanical fasteners for mounting the receptacle to bracket may also be eliminated. The connector receptacles may be designed to “snap” onto an aluminum extrusion providing an inherent electrical ground path. The elimination of the mechanical fasteners reduces both the cost associated with the parts and the labor associated with the preparation and installation of the fasteners.
In addition, embodiments of the quick lock production interconnect can also incorporate a polarization feature to prevent the cross-mating of adjacent connectors to one another. The polarization keys can be made independent from a shell that supports the connector and can be reconfigurable.
A quick lock production interconnect may be fabricated from thermoplastic materials and plated with a metallic finish to provide the required electrical conductivity necessary for electrical bonding and electrical shielding. Employing thermoplastic materials that have been plated with conductive finish can yield an additional weight and piece part savings of approximately twenty to twenty-five percent over conventional techniques. Further cost savings may also be achieved by eliminating conventional application-unique disconnect brackets which are replaced with an efficient stamped and formed rail or metallic, e.g. aluminum, rail extrusion.
A typical embodiment of the invention comprises a system including a structural support, a plurality of electrical connector shells each supporting one or more couplable electrical conductors and a modular bracket affixed to each of the plurality of electrical connector shells, each modular bracket manually engaged to the structural support. Each modular bracket may employ a catch and a spring latch mechanism for manually engaging the structural support. The structural support may comprise a rail such that the catch engages a first edge of the rail and the spring latch mechanism engages an opposite edge of the rail.
In further embodiments, each of the plurality of electrical connector shells may be adapted for coupling the one or more electrical conductors through a plug, where the plug engages the electrical connector shell with a manual slide-and-latch mechanism. The manual slide-and-latch mechanism may include a visual indication that the plug and the electrical connector shell are engaged. In addition, each of the plurality of electrical connector shells may include a polarization key for engaging the plug, such that only a particular plug will engage a particular connector shell.
Also, each modular bracket may be capable of individual engagement. Thus, the one or more coupled electrical conductors for a particular connector can be coupled or decoupled without interfering with any adjacent connectors. In addition, engagement of the modular bracket to the structural support can conveniently provide an electrical connection between the modular bracket and the structural support. Typically, the plurality of electrical connector shells and each modular bracket comprise a metal plated polymer to yield a combination of light weight and electrical conductivity.
In one particular embodiment, the structural support is part of an aircraft fuselage section and the plurality of electrical connector shells each support the one or more electrical conductors coupled between separate fuselage sections. Thus, assembly efficiency of the aircraft is greatly improved through application of a modular quick lock production interconnect. As will be detailed hereafter, embodiments of the invention may encompass an integral system or an individual production interconnect device adapted to function as part of the integral interconnect system.
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
1. Overview
Electrical connection devices and systems for the electrical interconnection of systems and components within an aerospace vehicle, such as a production airplane, are disclosed. A typical quick lock production interconnect embodiment of the present invention comprises a manually installed and coupled modular electrical connector. The connector receptacles may be designed to “snap” onto a structural support, such as a stamped and formed or extruded rail, providing an inherent electrical ground path. A typical quick lock production interconnect may be fabricated from thermoplastic materials and plated with a metallic finish to provide for electrical bonding and shielding. The connector device may also include a novel slide latch coupling mechanism that provides a positive visual indication of a fully coupled connector eliminating the need for specialized tools. The structural support may be part of an aircraft fuselage section where the plurality of electrical connector shells each support the one or more electrical conductors coupled between separate fuselage sections.
As previously mentioned, embodiments of the present invention eliminate the necessity of designing unique interconnect brackets for a production aerospace vehicle. Embodiments of the invention can also provide an inherent electrical ground path. Furthermore, some embodiments of the invention employ plated thermoplastic materials that are lighter and less expensive to manufacture than conventional metal parts. The novel interconnect design is lighter weight, eliminates numerous mechanical fasteners, and the design provides an inherent electrical ground path. This eliminates numerous installation and assembly hours from the factory. In addition, the novel interconnect does not require any unique tools or procedures for the assembly or installation.
Embodiments of the present invention also eliminate the need for a variety of mechanical interconnect brackets as with conventional systems. The novel interconnect design can employ a simple aluminum extrusion which provides the structural and electrical interface to an airframe. This enables a significant reduction in the labor associated with the installation of the receptacle-to-bracket and bracket-to-airframe interface. Thus, employing such a quick lock production interconnect design in accordance with the present invention supports reduced final assembly time.
2. Quick Lock Production Interconnect
A novel quick lock production interconnect embodiment of the present invention can eliminate the traditional metal interconnect bracket and machined aluminum circular or rectangular connectors and numerous fasteners employed in a conventional interconnect. The quick lock production interconnect can be clamped to either an extruded or stamped and formed metallic, e.g. aluminum, rail. A receptacle shell mounts to the rail by capturing a first edge of the rail as a fixed hinge point and then manually actuating a spring latch mechanism on an opposing edge of the rail that firmly attaches the receptacle shell to the rail. The receptacle fixed hinge point and the spring latch mechanism provide both a mechanical and electrical interface to the mounting rail. This interface is accomplished without the use of ancillary hardware of with any pre-installation preparations to obtain the low resistance ground path.
The interconnect 200 also includes a modular bracket 206 affixed to the electrical connector shell 202. The modular bracket 206 and the electrical connector shell 202 can be produced as separate pieces and then attached or manufactured as a single integral element. The bracket 206 is modular because certain features of its design are standardized to allow duplication and reuse in a range of applications, e.g. engagement features to a structural support. In particular, the standardized design features allow a plurality of adjacent interconnects to be employed together in an overall assembly. At the same time, other aspects of the interconnect are customizable to accommodate variation in their application, e.g. the number and type of electrical conductors carried.
The electrical connector shell 202 is adapted for coupling the one or more electrical conductors 204 through a plug 218. The plug 218 supports a second plurality of electrical conductors 222 that include the matching end connectors couplable to the end connectors of the first plurality of electrical connectors 204 supported by the electrical connector shell 202. The plug 218 can engages the electrical connector shell employing a manual slide-and-latch mechanism 220 that engages features on the electrical connector shell 202 and assists in drawing the plug 218 and electrical connector shell 202 together to couple the electrical conductors 204, 222. Similar to the spring latch mechanism 210, the slide-and-latch mechanism 220 may be manually engaged without tools. In addition, the manual slide-and-latch mechanism 220 may include a visual indicator that the plug 218 and the electrical connector shell 202 are fully engaged (indicating that the conductors 204, 222 are coupled). For example, the slide-and-latch mechanism 220 indicates that the plug 218 and the electrical connector shell 202 are fully engaged after the slide-and-latch mechanism 220 is seated flush with the tops of both the electrical connector shell 202 and plug 218. Note that although the mating connector is defined here as a “plug”, embodiments of the invention do not require male electrical connectors; male or female electrical connectors may be interchanged or intermingled between the electrical connector shell 202 on one side and the plug 218 on the other side, so long as the connectors are appropriate to be coupled when the components are engaged.
In addition, embodiments of the invention can incorporate features to prevent accidental misconnection among the pluralities of electrical connector shells 202 and plugs 218 which may be used close together. Each of the plurality of electrical connector shells 202 may include a polarization key 224 for engaging the plug 218. The polarization key 224 can comprise one or more keyways which mate to a particular key 226 in a specified orientation, e.g. a variable of four orientations ninety degrees apart. If more than one keyway is used for each connector, a large number of combinations are readily available to distinguish connectors employing even the same keyway and key. For example, employing two separate but identical keyways for the same connector, each having four possible orientations, enables sixteen distinct combinations. Of course many more combinations are possible with the addition of different keyways. The use of the polarization key 224 allows for a modular bracket 206 to engage the structural support 208 adjacent to a plurality of other modular brackets without confusion among the connectors. Also note that although the key and keyway that accepts it may be attributed in the present description to either the connector shell or plug they may be interchangeably applied to either element; the term polarization key only indicates a feature of some type on a component that may be altered in orientation to properly engage a matching feature on a mating component.
In the example embodiment, the connector shell is a molded part available in electrical plug and receptacle versions. The connector shell incorporates an integral strain relief with provisions to accept an EMI enclosure for zero length cable shield terminations as will be understood by those skilled in the art. The shells are constructed to mechanically retain the electrical conductor support inserts and permit their removal. The plug shell incorporates a slide latch coupling mechanism as previously described. The receptacle incorporates features that produce a mechanically rigid assembly when engaged with the plug slide latch mechanism.
The receptacle shell design also incorporates features that provide a mechanical and electrical interface to the mounting rail as previously described. The electrical ground path established by the mounting feature incorporated in the receptacle shell maintains a stable, low resistance electrical ground path for the life of the installation. This electrical ground path that is provided by the mechanical mounting feature requires no special preparation or tools during the initial assembly processes or maintenance once in service. For example, the connector shells are typically electrically grounded to the aircraft structure. The reason for this is that the wiring, which is usually shielded from both EMI and lightning threats, has this shield terminated at or on the connector shell. The connector shell may be grounded to the aircraft structure by mounting the connector shell to a metallic panel by use of mechanical fasteners. In this case, the ground path may be accomplished through the structural mounting rail which will then use ground straps to couple into the current return network. Some type of grounding feature is critical in the functionality of such electrical systems. The grounds provide an important function of draining the electrical currents off the shields that are protecting the core wires. Although, a standard flat blade screw driver may be used to uncouple the mechanical latch mechanism enabling the receptacle to be disengaged from the mounting rail.
EMI ground springs can be made integral to the shell designs. The EMI spring can form an integral part of the plug shell and make contact with the receptacle shell prior to electrical contact engagement. To provide a good ground path between plug and receptacle, the EMI spring or ground fingers (formed as an integral part of the plug shell) applies sufficient pressure onto the receptacle shell. This pressure is generated by the elasticity of these ground fingers. A continuous circumferential spring design is not required (i.e. corners may be open) provided that the EMI requirements are met.
The connector shell incorporates ground block provisions for terminating shield cable ground wires to the connector shell. The grounding clip and retention system is designed to accept known rear release, crimp, pin contacts. The crimp barrel location is defined to ensure that a strain relief is provided to prevent the wire termination from bending at the crimp joint.
The receptacle shell shall be fully bottomed in the plug shell providing not only a mechanically rigid assembly but a 360 degree enclosure important to the EMI shielding performance. The coupling mechanism and connector shell design incorporate a means for providing a visual reference that the slide latch mechanism is in a fully down and locked position. No tools are required to activate the slide latch mechanism to the fully down and lock position, although a standard flat blade screw driver may be used to uncouple the slide latch enabling the plug to be disengaged from the receptacle.
Embodiments of the present invention can employ a stable electrical resistance ground path from shell to shell and receptacle shell to the metal extrusion interface yielding a low resistance ground path from the receptacle shell to the supporting metal rail. A low resistance electrical path from shell to shell can be produced through selection of the appropriate metallic plating thickness. Thus, the interface provides both a mechanical and electrical interface. For example, a modified spring finger design can be employed provide the electrical path to rail interface.
Furthermore, in order to optimize the weight and cost, the shells of the quick lock production interconnect can be constructed of a metal plated polymer. The use of metal plated polymers is quickly gaining acceptance in the military and aerospace markets. Plated thermoplastic parts are currently being used for circular connectors. Thus, migration of this technology to embodiments of the present invention can be readily implemented. The plating thicknesses of the metal finishes are selected depending upon the intended application. As is known in the art, the shell to shell conductivity, shielding performance and the ability to survive an indirect lightning strike are some defining requirements in selecting and developing the appropriate plating.
For example, the connector shell may be made from high grade thermoplastic or thermoset materials known in the art. The material used for the connector housing may be a durable, resilient plastic material with sufficient stiffness to minimize deflection and distortion when mated and will not deteriorate under normal conditions of operation and aging. One attribute that should be considered when selecting the material for the connector shell, is the ability to accept a conductive metallic finish. For example, the connector shell may be plated with an electrically conductive finish of electrolytic nickel (e.g. per SAE-AMS QQ-N-290) over an electroless nickel (e.g. per SAE-AMS 2404 Class 3024). The spring catch of the spring latch mechanism 210 may be Beryllium Copper and include a gold plated grounding clip. Accessory members of the grounding clip assembly need not be gold plated, but should comply with the requirements for avoidance of dissimilar metals in intimate contact.
3. Aircraft Assembly Using Quick Lock Production Interconnect
The proposed manufacturing technique for a new aircraft program incorporates pre-integration of the structural elements, fully integrated with all the transport utilities, before shipping to a final assembly facility. This may require additional production interconnects or modifications to various wiring trays to optimize the weight, cost and ease of maintenance of the electrical wiring interconnect system. The electrical wiring system may be designed with common major airframe interfaces consistent with a final assembly plan for major component integration. The major production interconnects should be designed to achieve the highest possible level of commonality of electrical parts and processes. In addition, the design of the electrical wiring interconnect system should enable the inclusion of customer options and technology upgrades based on common parts, processes and provisioning of the product envelope.
The airplane fabrication may be designed and fabricated in sections 602A-602F. For example, the nose 602A, fuselage 602B, 602D and 602E, wing/body center section 602C, wings and empennage 602F. Each of these airplane sections 602A-602F can be assembled by a structure supplier who will then install as much of the internal systems and equipments as possible. The final assembly factory will receive these pre-integrated sections 602A-602F and the electrical wiring will be connected at the junction locations 604A-604I which employ standard interconnects as previously detailed.
This concludes the description including the preferred embodiments of the present invention. The foregoing description including the preferred embodiment of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible within the scope of the foregoing teachings. Additional variations of the present invention may be devised without departing from the inventive concept as set forth in the following claims.
This application claims the benefit under 35 U.S.C. § 119(e) of the following U.S. provisional patent application, which is incorporated by reference herein: United States Provisional Patent Application No. 60/754,228, filed Dec. 27, 2005, and entitled “ELECTRICAL QUICK LOCK INTERCONNECT”, by Johnson et al.
Number | Date | Country | |
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60754228 | Dec 2005 | US |