Abstract:
Door systems and methods of making a door that provide added security in a vehicle, such as a commercial aircraft. An example door system includes a door, a source of pressurized fluid, and a frame. The door includes an injection-molded polycarbonate base, a plurality of hinge inserts embedded within the injection-molded polycarbonate base, and an inflatable seal. The source inflates the inflatable seal. The frame includes hinges that attach to the plurality of hinge inserts.

Description:
FIELD OF THE INVENTION  
       [0001]     This invention relates to doors, and, more particularly, to security doors with observation measures.  
       BACKGROUND OF THE INVENTION  
       [0002]     Recent events have shown a need for additional cockpit security in commercial aircraft. Secured doors that provide for crew safety is a concern for pilots, crew members, and passengers. There is an additional desire by aircraft manufacturers to not add additional weight to an aircraft, such as might occur if the cockpit doors were heavy metal doors. Increased aircraft weight typically results in increased operational costs (e.g. greater fuel consumption).  
         [0003]     Therefore, there exists a need to provide security to airplane cockpits without significantly increasing the weight and cost of the airplane, thereby decreasing payload revenue.  
       SUMMARY OF THE INVENTION  
       [0004]     The present invention provides door systems and methods of making a door that provide added security in a vehicle, such as a commercial aircraft. An example door system includes a door, a source of pressurized fluid (e.g. a pump), and a frame. The door includes an injection-molded polycarbonate base, a plurality of hinge inserts embedded within the injection-molded polycarbonate base, and an inflatable seal. The source of pressurized fluid inflates the inflatable seal. The frame includes hinges that attach to the plurality of hinge inserts.  
         [0005]     In one aspect of the invention, the system includes a switch for activating the pneumatic pump. The switch is activated when the door is in a locked position relative to the frame.  
         [0006]     In another aspect of the invention, the door includes lock inserts that are embedded within the injection-molded polycarbonate base. The frame includes locking pins that are slideably received by a corresponding one of the locking inserts when the door is in a closed position. A locking device controls the position of the locking pins.  
         [0007]     In a further aspect of the invention, the door includes a door handle device having a door handle insert embedded within the injection-molded polycarbonate base, and a door handle that is attached to the door handle insert.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings.  
         [0009]      FIG. 1  illustrates a cut-away side elevational view of a cabin door and corresponding systems formed in accordance with embodiment of the present invention;  
         [0010]      FIGS. 2 and 3  are perspective views of a cabin door formed in accordance with an embodiment of the present invention;  
         [0011]      FIG. 4  illustrates an enlarged side elevational view of a hinge edge of the cabin door illustrated in  FIGS. 2 and 3 ;  
         [0012]      FIG. 5  illustrates a side elevational view of door handles and a corresponding edge of the cockpit door of  FIGS. 2 and 3 ; and  
         [0013]      FIG. 6  illustrates a top-down cross-sectional view of the components of the cockpit door illustrated in  FIGS. 2 and 3  and the bulkheads that attach to the door. 
     
    
     DETAILED DESCRIPTION  
       [0014]     The present invention relates to apparatus and methods for providing a lightweight, secure barrier between an aircraft cockpit and cabin. Many specific details of certain embodiments of the invention are set forth in the following description and in  FIGS. 1-6  to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the present invention may have additional embodiments, or that the present invention may be practiced without several of the details described in the following description.  
         [0015]      FIG. 1  illustrates a cut-away side elevational view of an aircraft fuselage  20  as viewed towards a cockpit  24  of the aircraft  20 . In this embodiment, the cockpit  24  is separated from the cabin  22  by the bulkhead  30  having a door  32 . The door  32  is a polycarbonate door (e.g. an injection-molded polycarbonate door) that in one embodiment includes an inflatable seal that is coupled to a source  40  (e.g. a pneumatic pump system, a pressurized vessel, engine bleed air, etc.). In one embodiment, the source  40  is activated by a switch that senses when the door  32  is in a closed position. The door  32  is described by example and more detail below with regard to  FIGS. 2-6 .  
         [0016]      FIGS. 2 and 3  illustrate perspective views of an example of the door  32 . The door  32  includes a first edge  44 , a second edge  52 , and interior and exterior handles  58  and  60 . The first edge  44  includes or is attached to a plurality of hinges  50 . The second edge  52  includes a plurality of locking devices  56 .  
         [0017]      FIG. 4  illustrates an enlarged side elevational view of the first edge  44  of the cockpit door  32 . During the molding process of the door  32 , hinge inserts  62  are molded into a first side  64  of the door  32  at or near the first edge  44 . The hinge inserts  62  are exposed at the surface of the first side  64 , but are not removable from the door  32  because the hinge inserts  62  expand in width from the surface of the side  64 . A hinge  66  is attached to each of the hinge inserts  62 . The hinges  66  and hinge inserts  62  are described in more detail below with regard to  FIG. 6 .  
         [0018]     The outer perimeter of the door  32  (i.e., the first and second edges  44  and  52 , a base edge and top edge) includes a groove for receiving an inflatable seal  70 . The inflatable seal  70  is pneumatically connected to the source  40  as shown in  FIG. 1 . In alternate embodiments of the present invention, the inflatable seal  70  may be attached to the bulkhead  30  rather than to the door  32 .  
         [0019]      FIG. 5  illustrates the cockpit door  32  at the second edge  52 . Embedded into the edge  52  are a plurality of lock sockets  80 . The lock sockets  80  are similar in shape to the hinge inserts  62  ( FIG. 4 ) and are exposed at the edge  52 . Embedded into the first side  64  and a second side  84  of the door  32  are handle inserts  90  and  92 , respectively. The handle inserts  90  and  92  are shaped similarly to the lock sockets  80  such that once they are embedded into the door  32 , they cannot be removed without destruction of the door  32 . The handle-locking sockets  90  and  92  are exposed at the respective side for receiving the corresponding handles  60  and  58 , respectively. Attachments of the handles  60  and  58  to the handle inserts  90  and  92  are shown in more detail below with regard to  FIG. 6 .  
         [0020]      FIG. 6  illustrates a top-down cut-away view of the door  32  hingedly attached to the bulkhead  30 . Each hinge  66  is attached by a threaded bolt  98  that is received by a threaded cavity formed by the hinge insert  62 . The hinges  66  are also fastened to the bulkhead  30  in a conventional manner. Other mechanisms for attaching the hinges  66  to the hinge inserts  62  and to the bulkhead  30  may be used, such as rivets, other fastening mechanisms or adhesives.  
         [0021]     As further shown in  FIG. 6 , each lock socket  80  forms a cavity for receiving a locking pin bayonet  100  that is partially recessed within the bulkhead  30 . Each locking pin bayonet  100  may be spring-loaded into a locked position, i.e., a position that would allow it to be received by the cavity formed by the lock socket  80 . Each locking pin bayonet  100  may be manually operated or may include an opening device, such as an electromechanical device (e.g. a solenoid actuator). The electromechanical device may be activated by a switch  104  accessible from the cockpit  24  and/or a switch  106  accessible from the cabin  22 . The switches  104  and  106  may be coded for more secure access. The locking pin bayonets  100  and the opening device may also be coupled to a switch located elsewhere within the cockpit  24 .  
         [0022]     The handle inserts  90  and  92  may include threaded cavities for receiving threaded bolts  108  and  110 , respectively, that pass through an opening in the handles  60  and  58 , thereby affixing the handles  60  and  58  to the respective inserts  90  and  92 .  
         [0023]     A pneumatic line  120  pneumatically connects the seal  70  with the source  40 . In one embodiment, an electromechanical switch  130  produces a signal sensing that the door  32  is in the closed position and sends that signal to the source  40 , thereby instructing the source  40  to send pressurized fluid (e.g. air) through the pneumatic line  120  to inflate the seal  70 . When the seal  70  is pressurized, it provides an environmental seal between the cockpit  24  and the cabin  22 . Other switching mechanisms can be linked to the source for activating the source  40 . For example, the switches  104  and  106  can produce signals that indicate when the locking pin bayonets  100  are in a locked position. As previously noted, in alternate embodiments, the seal  70  may be coupled to the bulkhead  30  and disposed about the perimeter of the door  32 , and may be inflated using the source  40  in substantially the same manner to provide the desired environmental seal.  
         [0024]     The injection-molded polycarbonate door described above may provide significant advantages over prior art door systems. For example, the polycarbonate door may provide the desired degree of strength, yet may be very light weight. The door may also provide ballistic resistance to prevent intrusion by handguns, rifles, or other types of break-in, while being transparent. The transparent feature allows the flight crew visual indication of flight cabin conditions.  
         [0025]     Furthermore, the pneumatic seal allows for independent cockpit pressurization in the event of accidental or man-made pressure loss in the cabin. The pneumatic seal allows for an independent air supply to be provided to the cockpit in the event of accidental or man-made disruptions in the cabin breathing air. The seal may also provide air crew separation if the cabin were to be infused with an airborne aerosol sedative for temporarily incapacitating cabin occupants in the event of a security risk.  
         [0026]     In one embodiment, the door includes a one way mirror for allowing flight crew to see into the cabin and not allow passengers to view into the cockpit. Alternatively, the door may be coated with a film, such as an electrically charged coating, that when charged makes the door opaque and when uncharged makes the door transparent, including, for example, an electrochromic device of the type generally disclosed in co-pending, commonly-owned U.S. Patent Application No. (undetermined) entitled “Low Vapor Pressure Solvent for Electrochromic Devices”, filed under Attorney Docket No. BING-1-1066 on Mar. 12, 2004, and in co-pending, commonly-owned U.S. Patent Application No. 60/552,589 entitled “Multi-Color Electrochromic Device” filed on Mar. 12, 2004, and in co-pending, commonly-owned U.S. Patent Application No. 60/552,453 entitled “Dimming Window Control Systems and Methods” filed on Mar. 12, 2004, which applications are hereby incorporated by reference.  
         [0027]     While preferred and alternate embodiments of the invention have been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of these preferred and alternate embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.