Abstract:
An arrangement for installing electric cables in the floor region of an aircraft includes longitudinal guide elements that form cable channels and essentially extend in the longitudinal direction of the aircraft parallel to seat rails that are arranged in the aircraft floor and serve for the mechanical attachment of seat legs. The longitudinal guide elements, which accommodate the data and supply cables to be installed, are not visible to aircraft passengers, but are still readily and easily accessible to the maintenance personnel. The floor plate features an elongate groove-shaped recess extending parallel to the seat rail in the longitudinal direction of the aircraft in the immediate vicinity of one of the two seat rails, wherein an elongate extruded profile is arranged in said recess. The extruded profile features an elongate drawer for transmitting shearing forces and an elongate cable shaft arranged above the drawer and serves for accommodating electric cables.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of the filing date of U.S. Provisional Patent Application No. 61/201,073 filed Dec. 4, 2008, the disclosure of which application is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The invention relates to an arrangement for installing electric cables in the floor region of an aircraft, wherein longitudinal guide elements are provided that form cable channels and essentially extend in the longitudinal direction of the aircraft parallel to seat rails that are arranged in the aircraft floor and serve for the mechanical attachment of seat legs, as well as to a method for manufacturing the arrangement. 
         [0003]    An arrangement of the initially cited type is known from German Patent Application No. DE 102 48 241 A1, wherein lateral guide elements that also form cable channels are provided in addition to longitudinal guide elements. The longitudinal and lateral guide elements are respectively composed of lower parts and upper parts, wherein the lower parts are mounted on the aircraft floor and the upper parts are arranged on the lower parts. A cable junction is provided on at least one intersecting point of longitudinal and lateral guide elements and forms a cable installation path with a longitudinal and a lateral guide element. All guide elements are arranged above the aircraft floor such that tripping hazards for aircraft passengers may be created. 
         [0004]    Furthermore, US Patent Publication No. 2002/0144835 A1 describes a protected cable installation path in the region of a seat rail of an aircraft, wherein the cable installation takes place within a cable guide in the form of a longitudinal guide element. This elongate guide element also consists of an upper part and a bottom part that is mounted above the floor of the aircraft, namely between the outer cabin wall and the seats situated directly adjacent to this wall. Consequently, a tripping hazard for aircraft passengers does not exist in the described application; however, the utilization of this guide element in seat areas that lie in the cabin interior may also result in tripping hazards. Furthermore the known cable installation path may entail an inflexible change of the layout in the cabin, an inferior accessibility to the installed electric lines, as well as a high expenditure for the preparation of construction documents that are dependent on the layout and for the incorporation of the technology into the aircraft cabin. There may also be optical and technical design disadvantages because the cable guide elements are visible to the passengers. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The invention may provide an arrangement of the initially cited type, in which the longitudinal guide elements that accommodate the data and supply cables to be installed are not visible to the aircraft passengers, but still readily and easily accessible to the maintenance personnel. 
         [0006]    According to the invention, an elongate groove-shaped recess is provided that extends in the longitudinal direction of the aircraft parallel to the seat rail in a floor plate that is arranged between two parallel seat rails and serves for attaching the legs of an assigned seat or several seats that lie behind one another in the longitudinal direction of the aircraft, namely in the immediate vicinity of one of the two seat rails, and in that an elongate extruded profile is arranged in the groove-shaped groove and features an elongate drawer for transmitting shearing forces and other possibly occurring forces, as well as an elongate cable shaft for accommodating electric cables that is arranged above the drawer. 
         [0007]    According to another embodiment of the invention, the floor plate is realized in the form of a sandwich component that consists of a honeycomb structure with two outer cover layers and the extruded profile is laminated into the groove-shaped recess of the honeycomb structure in such a way that the bottom of the drawer lies on and is bonded to the lower cover layer of the honeycomb structure and the intermediate spaces between the outer side walls of the extruded profile and the inner side walls of the groove-shaped recess are filled with core filler compound and/or adhesive. 
         [0008]    Other embodiments of the invention are described in dependent claims  3  to  17 . 
         [0009]    An inventive method for manufacturing an arrangement according to the invention is claimed in claim  18 . 
         [0010]    One advantage of the invention may be seen in that an electrical system is integrated into a mechanical primary structure of an aircraft, especially in floor plates that are arranged between seat rails, such that applicable aircraft-specific regulations are fulfilled and the above-described disadvantages are avoided. The installation of a plurality of electric data and supply cables from one seat to another seat, preferably a seat that is situated directly adjacent in the longitudinal direction of the aircraft, is significantly simplified. This type of seat-to-seat cabling may serve, for example, for supplying electric connecting elements assigned to passenger seats or entertainment systems integrated into passenger seats. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    One embodiment according to the invention is illustrated in the drawings that are not true-to-scale, wherein: 
           [0012]      FIG. 1  shows a floor plate of approximately rectangular cross section that is arranged between two seat rails and features an integrated extruded profile, 
           [0013]      FIG. 2  shows a floor plate of approximately trapezoidal cross section that is arranged between two seat rails and features an integrated extruded profile, 
           [0014]      FIG. 3  shows an enlarged detail of the arrangement according to  FIG. 1 , and 
           [0015]      FIG. 4  shows an enlarged representation of an extruded profile that consists of two prepreg shells and is arranged in a floor plate. 
       
    
    
     DETAILED DESCRIPTION 
       [0016]    In  FIG. 1 , a floor plate  1  is realized in the form of a sandwich component that consists of a honeycomb structure  2  with two outer cover layers  3  and  4 , wherein the honeycomb structure  2  may consist of plastic and the cover layers  3  and  4  may consist of plastic that is reinforced with carbon fibers or glass fibers. For example, these outer cover layers may consist of a carbon fibre reinforced plastic (CFK)-layer that is situated adjacent to the honeycomb structure, a central CFK-layer and an outer glass fibre reinforced plastic (GFK)-layer that are not graphically illustrated. The floor plate  1  is arranged between the seat rails  5  and  6  that extend parallel to one another in the longitudinal direction of the aircraft and serve for attaching seat legs  7  of one or more passenger seat(s) by means of conventional tongue and groove clamping connections  8 . It may have a width, for example, of 493 mm between the seat rails  5  and  6  while its length may extend over one seat or several seats that are arranged behind one another in the longitudinal direction of the aircraft. In its central region, the honeycomb structure  2  of the sandwich component according to  FIG. 1  has a predetermined, approximately rectangular cross section  9  while the cross section  9  of the honeycomb structure  2  according to  FIG. 2  is realized in an approximately trapezoidal fashion. In this case, the maximum thickness of the trapezoidal cross section  9  may amount to approximately 27 mm in the immediate vicinity of an extruded profile  18  and the minimum thickness on the opposite side may amount to approximately 9.5 mm. In the edge regions  10  and  11  that extend parallel to the seat rails  5  and  6 , the honeycomb structures are respectively realized with cross sections  12  and  13  that are reduced in comparison with the predetermined cross sections  9  and have a thickness, for example, of 9.5 mm. The edge regions  10  and  11  with their reduced cross sections  12  and  13  lie on longitudinal surfaces and  15  of the assigned seat rails  5  and  6  and are mechanically mounted thereon, for example, by means of screw connections  16 . 
         [0017]    The enlarged illustrations according to  FIGS. 3 and 4 , in particular, clearly show that the floor plate  1  features an elongate groove-shaped recess  17  that is arranged in the immediate vicinity of the seat rail  5  and extends parallel to the seat rail  5  in the longitudinal direction of the aircraft, wherein an elongate extruded profile  18  is arranged in said recess. The extruded profile  18  may have a width of approximately 75 mm and consists of an elongate drawer  20  for transmitting shearing forces and other possibly occurring forces, as well as an elongate cable shaft  22  that is arranged above the drawer  20  and serves for accommodating electric cables. The drawer  20  with a depth, for example, of 11 mm and the cable shaft  22  that may have a depth, for example, of 13 mm are separated from one another by an intermediate wall  23  extending in the longitudinal direction of the aircraft. The extruded profile  18  is integrated into the groove-shaped recess  17  of the honeycomb structure  2  in such a way that the bottom  21  of the drawer  20  lies on the bottom cover layer  4  and is bonded to this cover layer while the intermediate spaces between the outer side walls  19  of the extruded profile  18  and the inner side walls of the groove-shaped recess  17  are filled with core filler compound and/or adhesive  31 . 
         [0018]    The extruded profile  18  that may be manufactured of glass fiber-reinforced plastic, carbon fiber-reinforced plastic or aluminum is equipped with flanges  24  and  25  in the upper region of the cable shaft  23  such that it can be additionally fixed on the honeycomb structure  2 . These flanges extend from the outer side walls  19  of the extruded profile  18  in the direction of the respectively adjacent honeycomb structure  2  and are bonded to the upper cover layer  3  and to the honeycomb structure  2  underneath this upper cover layer. However, the flanges  24  and  25  may also lie on the upper cover layer  3  and be bonded to this cover layer, preferably in the directly adjacent region of the seat rail  5 . The flanges  25  are mechanically mounted on the longitudinal surface  14  of the seat rail  5  together with the edge region  10  of the honeycomb structure  2  by means of a screw connection  16 . According to  FIG. 3 , it may be practical to also fill the intermediate spaces between the outer cover layers  3  and  4 , for example a CFK-layer, and the honeycomb structure  2  or the flange  25  with core filler compound and/or adhesive  31 . 
         [0019]      FIG. 4  shows that the extruded profile  18  consists of two prepreg shells of carbon fiber-reinforced plastic that are bonded to one another, wherein the upper CFK part  33  forms the cable shaft  22  and the lower CFK part  34  forms the drawer  20 . In this case, the aforementioned intermediate wall  23  and the flanges  24  and  25  of the extruded profile  18  are integrated into the upper CFK part  33 . 
         [0020]      FIGS. 1 ,  2 ,  3  and  4  show that the elongate opening of the cable shaft  22  is closed by means of an elongate cover  26  with angled side walls  27 , wherein the side walls  27  engage into the cable shaft  22  and adjoin the inner side walls thereof. If an extruded profile  18  of aluminum is used, it may be advantageous to apply a non-conductive layer that is not graphically illustrated on the aluminum surface of the cable channel  22  in the cable shaft  22  because the cables, lines or the like to be arranged in the cable channel  22  cannot lie on a bare metal surface. The insulating layer may consist of glass fiber-reinforced plastic. It would also be possible for the upper cover layer  3  or the outer GFK-layer of this cover layer  3  to extend through the cable channel  22  as an insulating layer. Sealing means  32  are advantageously provided between the adjoining surfaces of the side walls of the cover and the cable shaft  22  in order to realize a protection against moisture and unauthorized access. The side walls  27  of the cover  26  advantageously consist of plastic and are preferably arranged perpendicular to the undesignated longitudinal surface of the cover  26 . Other angled bends are possible and dependent on the relative position between the elongate inner surfaces of the side walls of the cable shaft  22 . The elongate cover  26  is mounted in the cable shaft  22  by means of a snap-on system  28  that consists of several clamping pins  29  that are mounted on the intermediate wall  23  between the drawer  20  and the cable shaft  22 , protrude into the cable shaft  22  and are preferably equipped with mounting flanges  29   a,  as well as of clamping sleeves  30  that cooperate with these clamping pins  29 . For this purpose, the clamping sleeves  30  are mounted on the inner surface of the cover  26  that faces the cable shaft  22  and the mounting flanges  29   a  of the clamping pins  29  are mounted on the bottom of the cable shaft  22  or the insulating layer covering this bottom, for example, by means of an adhesive connection. Alternatively, the clamping sleeves  30  may be mounted on the bottom of the cable shaft  22  and the clamping pins  29  may be mounted on the inner surface of the cover  26 . The snap-on system  28  may extend over the entire length of the cover  26  on one hand and over the entire length of the cable shaft  22  on the other hand. In this case, several covers  26  lie behind one another edge-to-edge over the entire length of the groove-shaped recess  17  that corresponds to the seat rail length. 
         [0021]    An inventive method for manufacturing an arrangement of the above-described type by utilizing a floor plate  1  that is realized in the form of a sandwich construction and arranged between two seat rails  5  and  6  extending in the longitudinal direction of an aircraft is characterized by the following process steps:
       the floor plate  1  is slit open in the region of the seat rail  5  in such a way that an elongate groove-shaped recess  17  is created that is arranged parallel to the seat rail  5  and serves for accommodating an extruded profile  18  provided with mounting flanges  24  and  25 ,   the extruded profile  18  that forms a drawer  20  and a cable shaft  22  is fitted into the groove-shaped recess  17  and baked in an autoclave for lamination purposes in such a way that the underside of the extruded profile  18  lies on and is bonded to the lower cover layer  4  of the sandwich component and the intermediate spaces between the side walls of the extruded profile  18  and the honeycomb structure  2  and, if applicable, the intermediate spaces between the mounting flanges  24  and  25  and the honeycomb structure  2  are filled with core filler compound and/or adhesive  31 , and   the mounting flanges  25  situated adjacent to the predetermined cross section  9  of the honeycomb structure are bonded to the upper cover layer  3  and to the honeycomb structure  2  underneath this upper cover layer. In this case, the mounting flanges  24  arranged in the adjacent region of the seat rail  5  may be alternatively placed on the upper cover layer  3  in the edge region  10  of the honeycomb structure  2  and bonded to the cover layer  3  at this location.       
 
         [0025]    As a supplement, it should be noted that “comprising” does not exclude other elements or steps, and that “an” or “a” does not exclude a plurality. It should furthermore be noted that characteristics or steps that were described with reference to one of the above exemplary embodiments can also be used in combination with other characteristics or steps of other above-described exemplary embodiments. The reference symbols in the claims should not be interpreted in a restrictive sense. 
       LIST OF REFERENCE SYMBOLS 
       [0000]    
       
           1  Floor plate 
           2  Honeycomb structure 
           3  Outer cover layer of honeycomb structure  2   
           4  Outer cover layer of honeycomb structure  2   
           5  Seat rail 
           6  Seat rail 
           7  Leg of a seat 
           8  Tongue and groove clamping connection 
           9  Cross section of honeycomb structure  2   
           10  Edge region of honeycomb structure  2   
           11  Edge region of honeycomb structure  2   
           12  Cross section of an edge region of honeycomb structure  2   
           13  Cross section of an edge region of honeycomb structure  2   
           14  Longitudinal surface of seat rail  5   
           15  Longitudinal surface of seat rail  6   
           16  Screw connection 
           17  Groove-shaped recess in honeycomb structure  2   
           18  Extruded profile 
           19  Outer side walls of extruded profile  18   
           20  Drawer 
           21  Bottom of drawer  20   
           22  Cable shaft 
           23  Intermediate wall between drawer  20  and cable shaft  22   
           24  Flange of extruded profile  18   
           25  Flange of extruded profile  18   
           26  Elongate cover 
           27  Side wall of cover  26   
           28  Snap-on system 
           29  Clamping pin with mounting flange  29   a  of snap-on system  28   
           30  Clamping sleeve of snap-on system  28   
           31  Core filler compound and/or adhesive 
           32  Sealing means for side walls of the cover  26  and the cable shaft  22   
           33  Upper CFK part of bonded prepreg shells 
           34  Lower CFK part of bonded prepreg shells