Patent Publication Number: US-6669144-B2

Title: Access apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 09/987,311, filed Nov. 14, 2001, now U.S. Pat. No. 6,484,449, and assigned to the common assignee of the present invention. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to access apparatus, e.g., door openers, and more specifically, to access apparatus that opens an access device, e.g., a door or window or the like, upon a pressure difference between opposite sides of the access device. 
     BACKGROUND OF THE INVENTION 
     Passenger planes or other aircraft may be equipped with cockpit doors. The cockpit door may be a simple door that provides privacy to the pilot, copilot or flight crew. (It is noted that the term “cockpit” refers to the portion of the aircraft where the pilot, copilot or flight crew sit, this also being referred to as the “flight deck”.) 
     In many aircraft, it may be required that the ambient air pressure in the cockpit be generally the same as the ambient air pressure in the passenger cabin of the aircraft. A dangerous situation may arise if there is a sufficiently great pressure difference between opposite sides of the cockpit door. The pressure difference may cause the cockpit to break away from the rest of the fuselage. Accordingly, the cockpit door is generally a low security door that easily opens in the presence of a sufficiently great pressure difference between opposite sides of the door. Once the door opens the pressure equalizes between the flight deck and the passenger cabin, thereby reducing or eliminating the dangerous pressure difference. 
     However, because of the need to equalize the pressure, cockpit doors are generally low security doors, as mentioned above, and may be prone to attempted entry by would-be hijackers. 
     SUMMARY OF THE INVENTION 
     The present invention seeks to provide access apparatus that opens an access device, e.g., a door or window or the like, upon a pressure difference between opposite sides of the access device. For example, the access apparatus may be a door opener that retracts and opens a door bolt in the presence of a sufficiently great pressure difference between opposite sides of the door. Another embodiment of the present invention opens a portion of a door, such as vanes or slats, in the presence of a sufficiently great pressure difference between opposite sides of the door. Another embodiment of the present invention permits installation of a high security door in the cockpit of an aircraft, such as a bullet-proof door that withstands attempted entry by would-be hijackers. 
     There is thus provided in accordance with a preferred embodiment of the present invention access apparatus including an access device including at least one of a door and a window, the access device including at least one openable element, and opening apparatus adapted to open the at least one openable element in a presence of a pressure difference of a predefined magnitude between opposite sides of the access device. 
     In accordance with a preferred embodiment of the present invention the opening apparatus includes an opening orientation adapted to bring the access device into an open position with respect to an access passageway in a presence of a pressure difference of a predefined magnitude between opposite sides of the access device. 
     Further in accordance with a preferred embodiment of the present invention the at least one openable element includes a locking device. 
     Still further in accordance with a preferred embodiment of the present invention the at least one openable element includes a vane pivotally mounted in the access device, the vane when in an open position permitting fluid flow therethrough. 
     In accordance with a preferred embodiment of the present invention the opening apparatus includes a trigger device adapted to urge the opening apparatus to the opening orientation. 
     Further in accordance with a preferred embodiment of the present invention the trigger device includes a flap arranged to move in the presence of the pressure difference, wherein a predefined movement of the flap actuates the trigger device. 
     Still further in accordance with a preferred embodiment of the present invention a guard is provided and adapted to generally prevent access to the opening apparatus. 
     In accordance with a preferred embodiment of the present invention the access device includes at least one of an anti-terrorist door and an anti-terrorist window. 
     There is also provided in accordance with a preferred embodiment of the present invention an access system including an access passageway formed in at least one of a wall, ceiling and floor, an access device including at least one of a door and a window mounted for providing access through the access passageway, the access device including at least one openable element, and opening apparatus adapted to open the at least one openable element in a presence of a pressure difference of a predefined magnitude between opposite sides of the access device. 
     In accordance with a preferred embodiment of the present invention the opening apparatus includes an opening orientation adapted to bring the access device into an open position with respect to the access passageway in a presence of a pressure difference of a predefined magnitude between opposite sides of the access device. 
     Further in accordance with a preferred embodiment of the present invention the at least one openable element includes a locking device. 
     Still further in accordance with a preferred embodiment of the present invention the at least one openable element includes a vane pivotally mounted in the access device, the vane when in an open position permitting fluid flow therethrough. 
     There is also provided in accordance with a preferred embodiment of the present invention a method for depressurizing an enclosure in an aircraft, the method including forming an access passageway in at least one of a wall, ceiling and floor of the enclosure, installing an access device adapted for providing access through the access passageway, the access device including at least one openable element, and providing opening apparatus adapted to open the at least one openable element in a presence of a pressure difference of a predefined magnitude between opposite sides of the access device. 
     There is also provided in accordance with a preferred embodiment of the present invention a method for increasing security of a cockpit of an aircraft against a terrorist attack, the method including assembling a door in a door frame of a cockpit of an aircraft, the door including an anti-terrorist door, providing a bolt that is throwable and retractable from the door to the door frame, and providing bolt retractor apparatus adapted to retract the bolt in a presence of a pressure difference of a predefined magnitude between opposite sides of the door. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings in which: 
     FIG. 1 is a simplified pictorial illustration of a door opener, constructed and operative in accordance with a preferred embodiment of the present invention; 
     FIG. 2 is a simplified pictorial illustration of the door opener of FIG. 1 with a cover removed to expose operating elements of the door opener; 
     FIG. 3 is a simplified pictorial illustration of the door opener of FIG. 1 with a housing removed to expose a retaining device and a biasing device of the door opener; 
     FIG. 4 is a simplified sectional illustration of the door opener of FIG. 1, FIG. 4 being taken along lines IV—IV in FIG. 1; 
     FIG. 5 is a more detailed pictorial illustration of the retaining device and housing of the door opener of FIG. 1, constructed and operative in accordance with a preferred embodiment of the present invention; 
     FIG. 6 is a simplified pictorial illustration of the door opener of FIG. 1 with pressure apparatus actuating bolt retractor apparatus so as to retract a door bolt in accordance with a preferred embodiment of the present invention; 
     FIGS. 7 and 8 are simplified pictorial and sectional illustrations of a guard for guarding the door opener of FIG. 1, constructed and operative in accordance with a preferred embodiment of the present invention, FIG. 8 being taken along lines VIII—VIII in FIG. 7; and 
     FIGS. 9-12 are simplified pictorial illustrations of access apparatus that opens a portion of a door, such as vanes or slats, in the presence of a sufficiently great pressure difference between opposite sides of the door (FIGS. 9 and 10 showing opposite sides of the door with the vanes closed and FIGS. 11 and 12 showing opposite sides of the door with the vanes open), constructed and operative in accordance with a preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present invention is directed to an access device, e.g., a door or window, and opening apparatus that opens one or more openable elements of the access device in a presence of a pressure difference of a predefined magnitude between opposite sides of the access device. The present invention will first be described with reference to an embodiment wherein the access apparatus comprises a door opener, as seen in FIGS. 1-8. Further embodiments will be described with reference to FIGS. 9-12. 
     Reference is now made to FIGS. 1-4, which illustrate a door opener, constructed and operative in accordance with a preferred embodiment of the present invention. 
     The door opener may comprise bolt retractor apparatus  10  (also referred to as a trigger device) adapted to retract a bolt  12  of a door  14  in a presence of a pressure difference of a predefined magnitude between opposite sides of the door. Door  14  may be installed in a door frame  16 . Door  14  may comprise a cockpit door for an aircraft, but the invention is not limited to aircraft, and the door  14  is suitable for any application requiring operation due to pressure differences between two sides of a door. Door  14  may comprise, for example, an anti-terrorist door that is reinforced with anti-ballistic structure. 
     It is noted that the term door is used to mean not only a door but also any kind of openable and closable structure used to open or close a room or enclave, such as but not limited to a window. 
     Bolt  12  (also referred to as a latch or any other kind of opening, closing and locking device, all the terms being used interchangeably throughout the specification and claims) may slide in an outer cover  18  and may be slid by means of a knob  20  which may be constrained to move in a groove  22  formed in outer cover  18  (FIG.  1 ). As seen in FIG. 2, knob  20  may be attached to a housing  28  that slides in outer cover  18  (as seen in FIG.  4 ). Bolt  12  may be thrown by means of knob  20  in the direction of an arrow  24  into a bolt receiving member  26  mounted on door frame  16  (FIG.  1 ). Conversely, bolt  12  may be retracted by means of knob  20  in the direction of an arrow  30  out of bolt receiving member  26  (FIG.  1 ). FIGS. 1-4 illustrate the door opener from the side of the room or enclave that is to be protected from unauthorized entry. Thus, only the authorized personnel in the room or enclave may have access to the knob  20  to throw or retract bolt  12 . 
     Referring particularly to FIGS. 3 and 4, bolt retractor apparatus  10  may comprise a biasing device  32 , such as but not limited to, a coil spring mounted on bolt  12 , for example, adapted to urge bolt  12  in the direction of arrow  30  to a retracted position. Biasing device  32  may abut against a ring  34  mounted on bolt  12 . A retaining device  36  may be provided that comprises a first orientation, shown in FIGS. 1-5, wherein retaining device  36  may retain bolt  12  in a non-retracted position. Retaining device  36  may comprise without limitation a pin secured in a hole through bolt  12 . 
     As seen more clearly in FIG. 5, housing  28  may comprise without limitation an abutment  38  and one or more recesses  40 . In the first orientation shown in FIGS. 1-5, retaining device  36  abuts against abutment  38 . Although bolt  12  is free to slide and rotate about its longitudinal axis  42  in housing  38 , nevertheless retaining device  36  remains abutted against abutment  38  and may not normally rotate out of the first orientation if there is no pressure difference between the two sides of door  14 . Knob  20  is constrained in groove  22 , and may not be used to rotate bolt  12  about axis  42 . 
     Referring again to FIGS. 1-4, bolt retractor apparatus  10  may comprise a flap  44  secured to bolt  12 , such as by means of a flange  46 , for example. A pressure difference (in the ambient atmosphere) of a predefined magnitude between opposite sides of the door  14  pushes flap  44 , thereby causing bolt  12  to rotate about axis  42  (either clockwise or counterclockwise), as indicated by double arrow  48  in FIG. 2. A predefined movement, e.g., rotation, of flap  44  actuates bolt retractor apparatus  10 . Referring to FIGS. 5 and 6, this may be accomplished by flap  44  rotating bolt  12  so that retaining device  36  is aligned with and receivable in one of the recesses  40  (indicated, for example, by an arrow  50 ). Once retaining device  36  is aligned with one of the recesses  40 , biasing device  32  urges retaining device  36  into a second orientation by urging and pulling retaining device  36  into the recess  40 , thereby retracting bolt  12  (direction of arrow  30  in FIG.  1 ). Door  14  may be formed with an aperture  52  that permits at least a portion of flap  44  to move into aperture  52  when moved by the pressure difference. 
     Reference is now made to FIGS. 7 and 8. The door opener may further comprise a guard  56  adapted to generally prevent access to flap  44 . For example, on the inside of the door  14 , guard  56  may comprise a grille with openings to allow the air pressure to move flap  44 . On the outside of the door, as seen in FIG. 8, a robust guard  58  may be placed that prevents unauthorized personnel to push or otherwise move flap  44  and yet allows air pressure to move flap  44 . It is noted that a reset mechanism (not shown) may be provided for resetting the door opener after the door opener has been used to open the door. 
     Reference is now made to FIGS. 9-12, which illustrate access apparatus  60 , constructed and operative in accordance with a preferred embodiment of the present invention, which opens a portion of an access device  62 , such as a door or window, in the presence of a sufficiently great pressure difference between opposite sides of the access device  62 . 
     Access apparatus  60  may include a trigger device  63 , which is actuable by a flap  64 , and a guard  66 , as similarly described hereinabove for bolt retractor apparatus (trigger device)  10 , flap  44  and guard  58  in FIGS. 1-8. One or more openable elements  68  may be provided in access device  62 , such as but not limited to, one or more vanes  70  pivotally mounted in access device  62 . Vanes  70  may be arranged for opening vertically or horizontally or any other orientation. (“Vane” encompasses any kind of vane, slat, bar, shutter and the like, and the terms are used interchangeably.) When vanes  70  are in an open position, fluid (gas or liquid, such as but not limited to, air) may flow therethrough. The openable elements  68  may be actuated by trigger device  63  may any suitable linking apparatus  72 . Accordingly, trigger device  63  may open openable elements  68  in the presence of a pressure difference of a predefined magnitude between opposite sides of access device  62 , as seen in FIGS. 11 and 12 Alternatively or additionally, trigger device  63  may open the access device  62  itself in the presence of a pressure difference of a predefined magnitude between opposite sides of access device  62 , as similarly described hereinabove for bolt retractor apparatus  10 , which opens the door  14 . 
     It will be appreciated by person skilled in the art that the present invention is not limited by what has been particularly shown and described herein above. Rather the scope of the present invention is defined only by the claims that follow: