Abstract:
An aircraft heated floor panel ( 10 ) comprising a heat-generating layer ( 20 ) including an electric heater ( 52 ) having current supply lines ( 54 ) and a controller ( 60 ) which controls the current supplied to the heater ( 52 ) via the supply lines ( 54 ) to thereby control the heat generated by the layer ( 20 ). The controller ( 60 ) is integrated into the floor panel ( 10 ) whereby the panel has a stand-alone control system which need only be connected to the on-board power source of the aircraft, but can be connected to a main controller for networking or other purposes.

Description:
RELATED APPLICATION 
       [0001]    This application claims priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application No. 60/758,334 filed on Jan. 12, 2006. The entire disclosure of this earlier provisional application is hereby incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates generally to an aircraft floor panel and, more particularly, to a floor panel for installation in an area of an aircraft that is to be heated during flight. 
       BACKGROUND OF THE INVENTION 
       [0003]    An aircraft will commonly include a heating system in order to maintain the cabin at a comfortable temperature during flight. The floor of the aircraft is a particular area of concern whereby heater floor panels often are part of an aircraft&#39;s heating system. An aircraft heater floor panel can comprise a heat-generating layer including an electric heater having a current line for providing power to the heater. An aircraft typically has a plurality of heated floor panels and they are usually all connected to the same controller located in the cockpit of the aircraft. A sensor in or near the heat-generating layer provides panel temperature data to the controller and, based on this data, the controller regulates the amount of current supplied to the electric heater. Optionally, an ambient sensor can be used to provide temperature data to the controller to allow for closed-loop temperature control in the cabin. Additionally or alternatively, the controller can be connected to switch located outside the cockpit (e.g., the galley) to allow manual selection of power levels and/or temperature setpoints. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides an aircraft heated floor panel having an integrated controller. The panel may operate as part of a stand-alone control system which need only be connected to the on-board power source. Additionally or alternatively, the panels may be combined or networked in combination with a main and/or sub-controller. The present invention reduces and/or eliminates dependency on an aircraft power distribution unit and/or centralized control as each panel is capable of providing localized control via its integrated controller. Moreover, the ability to accommodate growth and/or operational flexibility, should panel needs grow or change, is enhanced by the integrated design of the present invention. 
         [0005]    These and other features of the invention are fully described and particularly pointed out in the claims. The following descriptive annexed drawings set forth in detail a certain illustrative embodiment of the invention, this embodiment being indicative of but one of the various ways in which the principles of the invention may be employed. 
     
    
     
       DRAWINGS 
         [0006]      FIG. 1  is a schematic perspective view of aircraft floor panels according to the present invention installed in an aircraft. 
           [0007]      FIG. 2  is a cross-sectional view of one of the aircraft floor panels. 
           [0008]      FIG. 3  is a schematic illustration of a heat-generating layer of the aircraft floor panel. 
           [0009]      FIG. 4  is a schematic illustration of the connection and/or control of a plurality of the floor panels on the aircraft. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Referring now to the drawings, and initially to  FIG. 1 , a plurality of aircraft floor panels  10  according to the present invention are shown installed in an aircraft  12 . The floor panels  10  are provided in order to maintain an area  14  (e.g., the cabin) at a comfortable temperature and, to this end, are heated floor panels. The aircraft  12  includes structural members  16  below the area  14  by which the panels  10  are supported. 
         [0011]    Referring now to  FIG. 2 , one of the aircraft floor panels  10  is shown in detail. The panel  10  comprises a heat-generating layer  20  and, in the illustrated embodiment, also includes a support level  22 , and a cover layer  24 . An adhesive layer  26  may be situated between the support level  22  and the heat-generating layer  20 , and an adhesive layer  28  may be situated between the heat-generating layer  20  and the cover layer  24 . 
         [0012]    The support level  22  is mounted to the aircraft structural members  16  below the area  14 . The support level  22  can comprise a honeycomb layer  30 , upper and lower layers  32  and  34 , and sandwiching layers  36 - 39  and  40 - 43 . The upper and lower layers  32  and  34  can each comprise a prepreg layer, that is a fiber reinforced polymer layer formed of a plurality of filamentary materials (e.g., fiberglass, carbon, aramid) in a matrix of thermoset polymeric material (e.g., phenolic, epoxy). For example, the layers  32  and  42  can comprise fiberglass/phenolic prepreg layers. The sandwiching layers  36 - 39  and  40 - 34  can also each comprise prepreg layers, such as carbon/epoxy prepreg layers. 
         [0013]    The cover layer  24  forms the upper surface of the panel  10  and thus must be able to receive (and resist) impacts caused by floor traffic in the area  14 . The cover layer  24  can comprise, for example, a thin sheet of aluminum or titanium. If the cover material is thermally conductive (as would be the case with aluminum and/or titanium), the layer  24  can also function as a heat-distributing layer. 
         [0014]    The adhesive layers  26  and  28  can each comprise a film adhesive (e.g., epoxy) capable of withstanding elevated curing temperatures such as, for example, the epoxy film adhesive sold as AF-126 from 3M. The adhesive layer  26 / 28  may incorporate a scrim (not shown) if necessary or desired for adhesive-spreading purposes. 
         [0015]    Turning now to the heat-generating layer  20 , it is shown in more detail in  FIG. 3 . The layer  20  comprises a dielectric base material  50  and an electric heater  52  encapsulated therein. The heater  52  may be an etched foil type element or a resistance wire element made of an electrically conductive material (e.g., metal). In any event, the heater  52  has current lines  54  connected to a controller  60 . In the illustrated embodiment, the heater  52  has three current lines  54  connected respectively to three heating elements. A multi-element arrangement such as this allows switch selection of different power level settings (e.g., high, medium, low). That being said, a heater  52  with a single heating element and/or a single current line is certainly possible with and contemplated by the present invention. 
         [0016]    According to the present invention, a controller  60  is integral to the floor panel  10  and, in the illustrated embodiment, integral to the heat-generating level  20 . The panel-integrated controller  60  can be of any suitable configuration, such as that shown in U.S. Patent Application Publication US 2005/0150968. The invention disclosed in this publication is assigned to the assignee of the present invention and its entire disclosure is hereby incorporated by reference. 
         [0017]    The panel  10 , via the controller  60 , receives electrical power from an on-board power supply (not shown). The power preferably is 3-phase AC power, but could instead be single phase AC power. Alternatively, the panel  10  can be designed to receive DC power. 
         [0018]    A sensor  62 , in or near the heat generating level  20 , provides panel temperature data to the controller  60  and, based on this data, the panel-integrated controller  60  regulates the amount of current supplied to the electric heater  52 . An ambient sensor  64  can also be used to provide temperature data to the panel-integrated controller  60  to allow for closed-loop temperature control in the cabin. The sensor  64  is situated, for example, in the area  14  of the cabin. Although not specifically shown in the drawing, an overheat-prevention device can be provided as a precaution against temperature sensor and/or controller malfunction. 
         [0019]    The panel-integrated controller  60  can be connected to a switch  66  which, for example, is accessible by flight crew members (e.g., in the galley) to allow manual selection of power levels (e.g., low, medium, high) and/or temperature set-points. In the exemplary embodiment, the switch  66  has an output connected to the panel-integrated controller  60  for indicating the desired heating power. For example, if a flight crew member switches the switch  66  to select either off, low, medium or high power, the panel-integrated controller  60  may be configured to activate none, one, some or all of the heating elements via their respective current lines  54 . 
         [0020]    As shown in  FIG. 4 , a plurality of panels  10  on the aircraft  12  can be networked and/or connected to a main controller  70  via a control-data bus  72 . The control-data bus  72  may be a CANbus or any other type of control-data bus. 
         [0021]    In the illustrated embodiment, the main controller  70  communicates with the integrated controller  60  of each panel  10  through a secondary controller  74 . As shown in  FIG. 3 , each panel  10  can be associated with its own ambient sensor  64 , power level switch  66  and/or secondary controller  74 . Alternatively, as shown in  FIG. 4 , all of the panels  10  could share the same sensor  64 , switch  66  and/or secondary controller  74 , and they could be coupled to the main power source via a power/switching bus  80 . Although not specifically shown in the drawings, the floor panels  10  within the aircraft may be defined within different zones, with each zone having its own ambient temperature sensor  64 , switch  66  and/or secondary controller  74 . 
         [0022]    The main controller  70  can, for example, use a primary temperature control algorithm to provide temperature set-points to the panel-integrated controller  60 . In the exemplary embodiment, the secondary controller  74  receives the switch status information from the switch  66  and temperature data from the ambient sensor  64 . The secondary controller  74  provides such information to the main controller  70  so that overall temperature control may be carried out via information (control set-points, fault detections, etc.) communicated between the main controller  70  and the panel-integrated controller  60 . 
         [0023]    The panel-integrated controllers  60  can each be configured to provide local temperature information (via their sensors  62 ) to the main controller  70 . The main controller  70  can process this local temperature data, along with data from the ambient temperature sensor(s)  64 , and then provide a desired temperature profile in different locations in the aircraft. For example, the main controller  70  can initially provide temperature set-point information to each of the floor panels  10 . Based on the temperature values obtained by the ambient temperature sensors  64  received, the main controller  72  can provide revised set-point temperature information to some or all of the floor panels  10  in the affected location(s). 
         [0024]    The panel-integrated controllers  60  can be also be configured to provide set point temperature values, fault information, and other health/maintenance information to the main controller  70 . In the event the main controller  70  receives fault information from a given panel  10 , the main controller  70  may deactivate the faulty panel. In addition, the main controller  70  may provide revised control information (e.g., new temperature set-points, power levels, etc) to one or more floor panels  10  in the vicinity of the faulty panel  10  in order to compensate for the faulty panel. 
         [0025]    One may now appreciate that the present invention provides a heated floor panel with an integrated controller. Although the invention has been shown and described with respect to a certain preferred embodiment, it is obvious that equivalent and obvious alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such alterations and modifications and is limited only by the scope of the following claims.