Patent Document

CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a national stage entry of PCT/EP2014/062482 filed Jun. 13, 2014, under the International Convention claiming priority over French Patent Application No. 1355563 Jun. 14, 2013. 
     
    
     TECHNICAL FIELD 
       [0002]    The invention relates to a method for arming/disarming an aircraft door evacuation slide connected to the cabin floor of the aircraft and a mechanism for implementing such a method. 
         [0003]    In airliners, the doors are generally equipped with an inflatable evacuation slide for the emergency exit of the passengers, for example in the event of an emergency landing. This is because the cabin floor of these aircraft is too high to enable the passengers and the crew to jump out without risking serious injury. 
         [0004]    The deployment of an evacuation slide proceeds in three steps:
       commanding arming of the evacuation slide on the door, which attaches a girt bar at the upper end of the evacuation slide to fittings integrated into the floor of the cabin;   emergency opening of the door by actuation of the interior handle of the door, which triggers its automatic opening and releases the uninflated evacuation slide, which falls out of the cabin; and   inflation of the evacuation slide triggered by Venturi effect thanks to the nitrogen pressure supplied by a tank provided for this purpose: the evacuation slide is deployed, its bottom part comes into contact with the ground outside the aircraft and the occupants then make use of the evacuation slide to exit the aircraft safely.       
 
         [0008]    A control is used to arm or disarm the evacuation slide and a visual indicator informs the operator of the arming status of each evacuation slide at all times. The operator therefore actuates the control before takeoff to verify that the status of the door changes correctly from the “disarmed” status (DISARM) in which the evacuation slide cannot be released to the “armed” status (ARM) enabling the evacuation slide to be released if necessary. 
       BACKGROUND OF THE INVENTION 
       [0009]    The ARM/DISARM commands correspond to two positions of a dedicated handle that also visually indicate the status of the door. An indicator lamp can confirm this status at all times. 
         [0010]    In the disarmed position, the evacuation slide is stored in a box fixed to the internal wall of the door in the form of a tube attached to and surrounding the girt bar, the box being arranged at the bottom of the door or in some installations in the fuselage, under the door threshold. The girt bar is held parallel to the floor of the cabin by U-shaped clamps provided with releasable clips in the form of leaf springs or the like. When the handle is moved to the door armed position (ARM), the rotation movement of the handle is converted into vertical translation movement by mechanical cables—for example “push-pull” cables—to lock handles attached to the bar to jaws of integrated fittings under the threshold of the floor. Conversely, of the bar is released by a mechanism for relaxing the jaws actuated by a cable connected to an ancillary handle, for example. A visual indicator reinforced by an audible warning device advises the operator that the evacuation slide of the door that they are attempting to open is armed. 
         [0011]    This type of solution has been described in numerous patent documents, such as U.S. Pat. No. 3,634,914, U.S. Pat. No. 4,715,562, EP 0743 246 or WO 8400786, for example. 
         [0012]    Improvements have been proposed in order to take into account particular issues in the perilous context of emergency opening of a cabin door. For example, to prevent the untimely deployment of the evacuation slide, US patent document 2011/0139934 provides human presence sensors facing the cabin door connected to a warning device indicating such presence in the vicinity of the internal handle of the door. 
         [0013]    Another example, referred to in the document U.S. Pat. No. 7,090,168, concerns the load supported by the girt bar attached at its ends when the evacuation slide is deployed and inflated. In order to prevent the generation of a bending moment at the centre of the bar, which might cause it to break, superposed flexible panels are provided to create a distribution of the forces from connection points on the girt bar or on the cabin floor fittings. 
         [0014]    However, the girt bar and the locking cables of such a bar have numerous disadvantages:
       the bar has a non-negligible weight and forms an obstacle to be overcome before jumping onto the evacuation slide;   anchoring the fittings under the threshold of the floor leads to accumulation of dust and other “detritus” (soil, small objects, etc.), which fouls the mechanics and can prevent correct deployment of the evacuation slide;   the transmission cables may jam or break because of the complexity of the system;   disarming can be difficult under difficult climatic conditions: frost, ice, snow, corrosion, jamming, etc.;   if it is not equipped with a “snap-action” type tensioning device, the ARM/DISARM handle can assume an intermediate position between the two command positions;   it is difficult to demount an evacuation slide in order to remount it at another door in the event of ditching.       
 
       SUMMARY OF THE INVENTION 
       [0021]    The invention aims to circumvent these disadvantages by decoupling the command and information aspect from the activation aspect and by eliminating the girt bar, which is replaced by a connection of the evacuation slide to attachment points. These attachment points are then moved by electrical means to grip fixed fittings in a reversible manner and with no anchoring. The mechanism driving the anchor points is then totally on the door side, well protected from environmental aggression. 
         [0022]    In this regard, the present invention consists in a method for arming/disarming an aircraft door evacuation slide connected to a cabin floor of the aircraft, this method consisting—in a so-called arming mode (ARM)—in lowering the door into a closed position to engage parts forming at least two releasable connections, the parts of each connection being rigidly connected to the door and to the cabin floor, respectively, locking the connections by a locking driving motion triggered by an energy source, in the event of an emergency evacuation, unfurling and inflating the evacuation slide attached only to each connection, and—in a so-called disarming mode (DISARM)—unlocking said connections by a reverse mechanical driving motion and then raising the door to decouple the connections before opening it. The energy source is preferably electrical, but it may alternatively be mechanical with manual actuation relayed by appropriate cables. 
         [0023]    In accordance with particular embodiments:
       the connecting parts rigidly connected to the cabin floor form extensions emerging from the floor;   the connecting parts rigidly connected to the door are aligned during the lowering of the door by fixing the connecting parts rigidly connected to the door via an elastic joint;   the locking motion consists of driving rotation at the level of each connection induced by driving each connection in translation;   the driving of rotation causes pivoting of a mobile subassembly of one of the parts of each connection between two angular positions, a locking position in which the subassembly is arranged in a housing of the other part in accordance with a locking configuration and a releasable position in which the subassembly and the housing have complementary configurations.       
 
         [0028]    The invention also relates to a mechanism for arming/disarming an aircraft door evacuation slide connected to a cabin floor of the aircraft adapted to implement the above method. This mechanism includes two releasable connectors disposed on respective opposite sides of the bottom of the door and each composed of two half-connectors coaxial with an axis perpendicular to the floor, a so-called upper half-connector rigidly connected to the door and having means of attachment to the evacuation slide, and a so-called lower half-connector fixed to the cabin floor, as well as a latch for locking/unlocking the upper half-connector and the lower half-connector. Each latch includes a part mobile in rotation about the axis of the half-connectors and adapted to be housed in the corresponding lower half-connector. The mechanism also includes a controlled electric motor coupled to two links, each link being adapted to drive the mobile part of each latch in rotation between two angular positions:
       a locking angular position in which said part is locked in a locking configuration of the walls of the corresponding lower half-connector, and   a releasable angular position in which said part and said base have walls of complementary configuration.       
 
         [0031]    In accordance with preferred embodiments:
       each lower half-connector is a threshold fitting that includes a base adapted to be fixed to the floor;   each lower half-connector has a so-called upper end of globally conical shape having walls forming shoulders that extend radially to form the base and, between the upper end and the base, a cylindrical intermediate portion radially smaller than the shoulders and adapted to form with the upper end a housing for the mobile part of the corresponding latch;   each upper half-connector includes a pillar adapted to be mounted perpendicularly to the floor in an arm for fixing it to the door and a control ring mobile in rotation mounted on the pillar and connected to a driving link,   each locking/unlocking latch, also mounted on the pillar, consists of a casing and the so-called mobile internal part adapted to be driven by the link via the control ring;   the mobile internal part and the control ring are coupled via connections by lugs and notches;   the pillar is mounted in the arm via an elastic joint adapted to absorb misalignments between the two half-connectors, notably in the event of relative movements in flight between the door and the fuselage or during their connection during the lowering of the door into the closed position;   position sensors are mounted on the mobile control ring in order to determine the angular position of said ring and to deduce therefrom the position of the latches and the armed/disarmed status of the evacuation slide;   the casing of the latch includes pins for attaching the evacuation slide;   the casing of the latch includes a cylindrical internal wall forming a face for centering and indexing the threshold fitting;   each mobile internal part is provided with a target for the position sensors of the latch;   the target of the mobile internal parts forms a pull-tab that can be maneuvered to arm or disarm the evacuation slide in the event of the electric motor stopping;   the motor is a bistable electrical actuator of solenoid type;   an indicator lamp informing the operator of the armed/disarmed status of the door and a door computer manage the arming/disarming operations, in particular   the arming/disarming angular positions of the upper half-connectors.       
 
         [0046]    The invention also relates to an aircraft door equipped with two upper half-connectors, latches and an energy source coupled to the links for driving the mobile parts of each upper half-connector in rotation according to locking and releasable angular positions of the arming/disarming mechanism defined above. The upper half-connectors are adapted to be associated with the threshold fittings of said mechanism. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0047]    Other data, features and advantages of the present invention will become apparent on reading the following non-limiting description with reference to the appended figures which show: 
           [0048]      FIG. 1 , a partially cutaway front view of an aircraft door seen from inside the aircraft, equipped with one example of an arming/disarming mechanism in accordance with the invention; 
           [0049]      FIG. 2 , a lateral view of the door and one of the releasable connectors of the mechanism from  FIG. 1 ; 
           [0050]      FIG. 3 , a sectional view of the connector according to  FIG. 2 ; 
           [0051]      FIGS. 4 a  and 4 b   , a sectional view and a partially exploded view of the upper half-connector of the example of a connector in accordance with the invention connected to a driving link and position sensors; 
           [0052]      FIGS. 5 a  to 5 c   , perspective, sectional and exploded views of an example of a half-connector latch in accordance with the invention; 
           [0053]      FIGS. 6 a  to 6 c   , two lateral views and a top view of an example of a threshold fitting in accordance with the invention; 
           [0054]      FIGS. 7 a  and 7 b   , a part-sectional top view of one of the connectors and a view of the arming/disarming mechanism in accordance with the invention in the disarming or DISARM position, and 
           [0055]      FIGS. 8 a  and 8 b   , part-sectional top views of the connector and the arming/disarming mechanism in accordance with  FIGS. 7 a  and 7 b    in the arming or ARM position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0056]    Throughout the text, the terms “upper” and “lower”, “vertical” and “horizontal” and their derivatives relate to locations of elements or parts of elements positioned relative to the level of the (land or water) landing or takeoff surface in the broad sense considered as a horizontal reference plane. 
         [0057]    Referring to  FIG. 1 , a partially cutaway front view of an aircraft door  1  as seen from inside the aircraft is shown. This door  1  is the usual passenger front entry/exit door. It is notably equipped with a raising/lowering handle  11 , an arm  12  for opening the door  1  in order to enable passengers to enter or exit and an arming/disarming mechanism  2  in accordance with the invention. 
         [0058]    This arming/disarming mechanism  2  enables use of an evacuation slide  3  stored in the box  4  formed at the bottom of the door  1  in the event of emergencies that necessitate evacuation of the occupants of the aircraft. This mechanism  2  is triggered by pressing a DISARM control button  51  or an ARM control button  52 . Light-emitting diodes  5   a  and  5   b  are disposed facing the buttons  51  and  52  to indicate the armed or disarmed status, respectively, of the mechanism. Alternatively, back-lit or equivalent buttons may replace the diodes. 
         [0059]    The lower face  4   i  of the box  4  is situated at substantially the same level as the lower face  1   i  of the structure of the door. The mechanism  2  includes two releasable connectors  21  and  22  disposed on respective opposite sides of the bottom of the door. Each connector  21 ,  22  comprises two half-connectors, a so-called upper half-connector  21   s,    22   s  fixed to a reinforcing structure  16  of the door  1  and a so-called lower half-connector  21   i,    22   i.  Each lower half-connector  21   i,    22   i  is formed by a so-called threshold fitting fixed to the cabin floor  6 . In  FIG. 1 , the door  1  has been lowered into the closed position and the half-connectors  21   s  and  22   s  are engaged on the threshold fittings  21   i  and  22   i.  In the figures in which a single connector  21  or half-connector  21   i,    21   s  is shown, the description is valid for the other connector  22  or half-connector  22   i,    22   s.    
         [0060]    The mechanism  2  also includes a bistable electric motor  23  of solenoid type controlled by a door computer  14  and actuated by the control buttons  51  and  52 . The motor  23  is coupled to two links  31  and  32 , each link driving a respective upper half-connector  21   s,    22   s  in rotation between a so-called arming locking position (ARM) and a so-called disarming releasable position (DISARM), which positions are described in detail hereinafter. 
         [0061]      FIG. 2  shows a side view of the door  1  and the releasable connector  21 ,  FIG. 3  providing a sectional view of the connector  21 . The door  1  consists of a panel  15  and a reinforcing structure  16  in which is notably housed the equipment that controls, actuates and manages the door  1 . 
         [0062]    The upper half-connector  21   s  includes attachment pins  33  for the evacuation slide  3  stored in the box  4  and an arm  41  fixing it to the box  4 . This female half-connector  21   s  is coupled to a male threshold fitting  21   i  fixed to the cabin floor  6  to form the releasable connector  21  as explained hereinafter. 
         [0063]    The upper half-connector  21   s  includes a pillar  42  mounted vertically and perpendicularly to the floor  6  by the fixing arm  41 , a control ring  43  mobile in rotation mounted on the pillar  42  and connected to the driving link  31 , and a locking/unlocking latch  7  also mounted on the pillar  42 . 
         [0064]    In the  FIG. 3  sectional view, there are more specifically distinguished the elastic material—for example silicone—joint  45  by means of which the pillar  42  is mounted in the annular support  41   a  of the fixing arm  41 . This elastic joint  45  is intended to absorb misalignments between the half-connectors, for example during their connection during lowering of the door into the closed position or during relative movements between the door and the fuselage in flight. 
         [0065]    In this  FIG. 3  sectional view there also appears a mobile part  72  internal to the latch  7  which is coupled to the mobile control ring  43  to be driven in rotation as described below. 
         [0066]    Referring to the sectional and partly exploded views of the upper half-connector  21  in  FIGS. 4 a  and 4 b   , position sensors  47  and  48  are advantageously mounted on the pillar  42  of the upper half-connector  21   s  via a support  40   c.  These sensors  47  and  48  associated with a target  72   c  on the latch  7  (see  FIG. 5 c   ) make it possible to track the movement of the latch, to ensure it functions correctly, to determine the angular position of the ring  43  (cf.  FIGS. 7 a  and 7 b   ), and to deduce therefrom the armed/disarmed status of the evacuation slide. 
         [0067]    Moreover, these views show the coupling of the driving link  31  to the mobile ring  43  by an annular end fitting  31   a  formed at the end of the link  31  connected with a lug  43   a  on a base  40  fixed to the upper face  43   s  of the ring  43 .  FIG. 4 b    also shows three lugs  43   e  on a lower face  43   i  of the control ring  43 , these lugs being intended to be coupled to the mobile internal part  72  of a latch  7 . 
         [0068]    The latch  7  is described in detail now with reference to the perspective, sectional and exploded views of  FIGS. 5 a  to 5 c   , respectively. The latch  7  comprises an external casing  71  and the mobile internal part  72 . The external casing  71  has pins  33  for attaching the evacuation slide and advantageously an internal wall  73  including a cylindrical central bore  73   a  for centering the threshold fitting  21  i (cf.  FIGS. 6 a  to 6 c   ). 
         [0069]    Moreover, a system for indexing the position of the mobile part  72  is advantageously provided: here this known indexing system is mounted in a housing  49  formed in the example shown in the casing  71  at the root of a pin  33 . The indexing system functions in conjunction with a recessed marker  46  formed in a vertical annular wall  72   v  of the part  72 . 
         [0070]    Once mounted, the vertical annular wall  72   v  is integrated into a corresponding interstice of the casing  71 . This annular wall  72   v  has on its upper face  72   s  three depressed notches  72   e,  each of these notches being able to accept a lug  43   e  formed on the lower face  43   i  of the control ring  43  (cf.  FIG. 4 b   ). Each lug can then move along a circular opening  721  on the upper face  71   s  of the casing  71 . 
         [0071]    The lower part of the annular wall  72   v  of the mobile part  72  is extended by a horizontal wall  72   h.  This horizontal wall  72   h  includes a central bore  72   a  with a configuration adapted to the configuration of the threshold fitting in order to define locking and releasable positions as described in detail hereinafter. 
         [0072]    Moreover, the mobile part  72  includes a target  72   c  for the position sensors  47 ,  48  of the latch (cf.  FIGS. 4 a  and 4 b   ). The target  72   c  forms a pull-tab that can be maneuvered by hand to arm or disarm the door in the event of failure of the electric motor. 
         [0073]    The lateral views and the top view of  FIGS. 6 a  to 6 c    show a threshold fitting  21  i of the connector  21  (cf.  FIGS. 2 and 3 ) adapted to be connected to the upper half-connector  21   s  described above. This threshold fitting  21   i  includes a base  8  intended to be fixed to the cabin floor  6  (cf.  FIG. 1 ), the base  8  resting on this floor  6  so that no cavity is formed between the base  8  and the threshold. 
         [0074]    The threshold fitting  21   i  has a so-called upper end  9  of globally conical shape including four shoulders  91  that extend radially and above a cylindrical base  9   b.  A cylindrical intermediate portion  10  radially smaller than the shoulders  91  extends axially between this cylindrical base  9   b  and the base  8 . This smaller intermediate portion  10  houses the horizontal wall  72   h  of the bore  72   a  in the mobile part  72  (cf.  FIG. 5 b   ): the configuration of this wall  72   h  is complementary to that of the cylindrical base  9   b  so that: 
         [0075]    in certain angular positions of the part  72 , the wall  72   h  of this part is in corresponding relationship with that of the base  9   b —releasable positions for the part  72  and therefore for the latch  7 —and, once the part  72  is at the level of the intermediate portion  10 , 
         [0076]    +/−45° rotations of the mobile part  72  from the preceding positions lock this part between the shoulders  91  of the base  9   b  and the base  8  of the threshold fitting  21  i: the latch  7  is then locked to the threshold fitting (locking positions). 
         [0077]    The top views of  FIGS. 7 a  and 7 b    show the connector  2  partly in section and the arming/disarming mechanism  2  in the disarming position DISARM. To reach this position, the motor  23  is actuated by the control button  51  and the door computer  14  ( FIG. 1 ) so that the movement in translation T 1  of the driving links  31  and  32  causes pivoting in rotation R 1  of the control ring  43  by a disarming angle Ad (relative to a reference R 0 ) for which the latches  7  are not in a locking position on the threshold fitting  21   i.  In this position, the latches  7  and therefore the connections  21 ,  22  are released: the door can be raised to decouple the connections and then opened with the arm  12  ( FIG. 1 ) in the normal way. 
         [0078]    In order to place the mechanism  2  in the arming mode ARM, a reverse motion—reverse movement in translation of the links  31 ,  32  driving reverse rotation of the control ring  43 —is triggered by the control button  51  of the motor  23  and the door computer  14  ( FIG. 1 ). 
         [0079]    Refer to  FIGS. 8 a  and 8 b   , which repeat the top views of  FIGS. 7 a  and 7 b    in the ARM position. In this position, the door  1  is in the closed position and the latches  7  are locked in a locking angular position on the threshold fittings  21  i by rotation of the control ring  43  by an arming angle i. To this end, the links  31 ,  32  are actuated in accordance with a locking motion triggered via the electric motor  23  by the control button  52  and the door computer  14  ( FIG. 1 ). 
         [0080]    By virtue of this motion, the movement in translation T 2  of the driving links  31  and  32  causes pivoting in rotation R 2  of the control ring  43  by the angle Aa: the connectors  21  and  22  are locked and raising and then opening the door causes unfurling and inflation of the evacuation slide  3  ( FIG. 1 ). 
         [0081]    The driving in rotation causes pivoting of a mobile subassembly of one of the parts of each connection between two extreme positions, a locking position in which the subassembly is arranged in a housing of the other part in accordance with a locking configuration and a releasable position in which the subassembly and the housing have complementary configurations. 
         [0082]    The invention is not limited to the embodiments described and shown.

Technology Category: 7