Abstract:
A device for mixing at least two separate streams of components which, when mixed, form a combined fluid stream. The device comprises a conduit with at least two separate passageways leading to exit openings at an end face of the conduit. Each passageway communicates with a separate component stream and is arranged to direct the separate component stream in a downstream direction. The exit openings each have a predetermined cross-sectional flow area. A separate channel is located at a downstream end of each passageway exit opening. The channels are arranged to redirect the flow from each passageway to an axial direction. A single mixing chamber communicates with all of the separate channels, the mixing chamber being arranged to receive each of the component streams at an upstream end thereof and to permit a mixing of the component streams. An outlet is arranged downstream of the mixing chamber through which the combined fluid stream is dispensed.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of International Application PCT/FR2012/052209 filed Sep. 28, 2012, designating the United States and published on Apr. 4, 2013 as WO 2013/045861. This application also claims the benefit of the French patent application No. 1158805 filed on Sep. 30, 2011, the entire disclosures of which are incorporated herein by way of reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to an aircraft cockpit and more particularly to the arrangement of an instrument panel inside such a cockpit. 
         [0003]    The invention is in the field of commercial aircraft for the transport of passengers and/or freight. A cockpit of such an aircraft is most frequently positioned in the nose cone of the aircraft and accommodates a flight station occupied by a pilot, optionally a co-pilot and/or a crew member such as an instructor for example. Inside the cockpit, the pilot and/or the co-pilot have available a full set of display screens and control means known in this document as an instrument panel. 
         [0004]    The number of display screens in aircraft, or at least the display surface area, has a tendency to increase, leading naturally to an increase in the size of the instrument panels. The instrument panels thus have a tendency to become wider and wider, which results in a wider cockpit. This increasing cockpit width is detrimental when the outer aerodynamic shape of the nose cone of the aircraft is defined. 
         [0005]    An aircraft instrument panel contains instruments having different standards and sizes, which are included in the instrument panel even if the structure required to incorporate this varied equipment is complex and therefore costly. The set of varied equipment is bulky and heavy, sensitive to vibrations and awkward to install and inspect. 
       SUMMARY OF THE INVENTION 
       [0006]    The purpose of the present document is thus to propose a work environment for the pilot and optionally his co-pilot that is more ergonomic, and in particular an environment using a simplified structure, having greater accessibility and improved integration of the surrounding functions into the flight station. 
         [0007]    To this end, there is proposed firstly a display device for an aircraft cockpit comprising a screen and a support, characterized in that the screen is mounted on its support rotatable about a first, substantially horizontal pin, and in that the support comprises means allowing height adjustment of the screen. 
         [0008]    The screen, which is preferably a flat screen (i.e., the thickness of which is of the order of a few centimeters, for example less than 10 cm and preferably less than 2 cm), can then be adjusted as desired by its user (pilot or co-pilot) in order to avoid any reflection problems and especially in order to best adapt to the morphology of the user. Making the screen mobile can also, if the extent of the displacement is sufficient, allow access to the rear of the screen (the display face being considered the front face of the screen; on the other hand, by displacing the screen access can be gained to the space forward of the screen considering the direction of travel of the aircraft) in order to reach the connections and optionally devices installed there. 
         [0009]    In a preferred embodiment, the screen is an incurved concave screen. Thus, on the one hand, the visual comfort of the user is improved and, on the other hand, for a similar space requirement, the display surface can be increased compared with a flat screen. 
         [0010]    A variant embodiment of the present invention makes provision for the screen to comprise a flexible thin film for screen use, fixed on a stiff panel made from composite material. 
         [0011]    Advantageously, provision is made for the screen to have a frame on which control buttons are placed. This feature is particularly advantageous when the screen is a touch screen. In this case, it is preferable to have a screen in the proximity of the user. This proximity can then be exploited to provide control buttons around the screen, these buttons then being placed directly within reach of the user. 
         [0012]    In order to make the screen mobile, it is proposed that the support comprises a second, substantially horizontal, fixed pin and at least one arm having a first end rotatably mounted on the first pin and a second end bearing the second, fixed pin. By “fixed” is meant here that the second pin is preferably attached to the structure of the cockpit so that it is immobilized; the connection can nevertheless be dismantled if necessary. Preferably, the first pin and the second pin are parallel, so that the user (pilot or co-pilot) can easily bring the screen closer to him when the screen, in a fully retracted position, is situated facing the user. However, in a variant, the first pin and the second pin can define an angle between them, which allows other movement combinations. 
         [0013]    The present invention thus relates in particular to an aircraft cockpit, characterized in that it comprises at least one display device such as described above. Such an aircraft cockpit can moreover comprise a first seat intended to accommodate a pilot, a second seat intended to accommodate a co-pilot. Provision is then advantageously made for a single screen to be placed facing the first seat, for said screen to be a screen of a display device such as described above, for a single screen to be placed facing the second seat, and for said single screen to be a screen of a display device such as described above. 
         [0014]    The present invention relates moreover to an aircraft cockpit comprising a first seat intended to accommodate a pilot, a second seat intended to accommodate a co-pilot, at least one first display device comprising a first screen facing the first seat, at least one second display device comprising a second screen facing the second seat, and a windscreen. The display device is preferably a display device such as described above but it could also be another type of display device. 
         [0015]    The invention here provides that the cockpit also comprises a third display device having a third, mobile, screen and a support allowing the third screen to be displaced from a first position known as a deployed position to a position known as a retracted position, that in the deployed position the third screen is above the first screen and the second screen so as to be visible both for a person seated on the first seat and for a person seated on the second seat and obscures a portion of the windscreen both for a person seated on the first seat and for a person seated on the second seat, and that in the retracted position the third screen is lowered with respect to its deployed position so as to make the portion of the windscreen obscured in the deployed position at least partially visible for a person seated on the first seat and for a person seated on the second seat. 
         [0016]    It is proposed here, in a totally original manner, to place a screen in front of the aircraft windscreen. The regulations allow (although explicit provision is not made) a screen to be placed as mentioned above, as it is provided that the pilot (and the co-pilot) may have a visual blind spot through the center of the windscreen. 
         [0017]    In such an aircraft cockpit, the third screen in its deployed position is preferably placed in a central position in the cockpit, and in its retracted position the third screen is for example placed partially behind the first screen and partially behind the second screen for an observer positioned on the first seat or the second seat. 
         [0018]    The third screen is for example mobile by means of being mounted on tracks, allowing it to translate between its deployed position and its retracted position. To allow improved visibility and adaptation to the pilots, the third screen is advantageously mounted rotatable about a substantially horizontal pin. 
         [0019]    A cockpit with a third screen such as described above can also comprise moreover a glare shield covering the first display device and the second display device. Provision is then advantageously made for the third screen, in its deployed position, to be above the glare shield, the third screen in its retracted position to be below the glare shield, and an opening to be made in the glare shield to permit the passage of the third screen when it passes from its deployed position to its retracted position or vice versa. 
         [0020]    For the same reasons as those given above for the screen of the display device, the third screen is advantageously concave. 
         [0021]    The present invention also proposes a glare shield of an aircraft cockpit, characterized in that it comprises a central portion and two lateral portions, and in that each lateral portion comprises, on the one hand, a piece of fabric and, on the other hand, tensioning means for holding said fabric. 
         [0022]    In a cockpit equipped according to the invention, the ergonomics conferred by the display devices makes it possible to dispense with at least part of the item of equipment known as the “glare shield” comprising control means. As standard, this item of equipment is situated at such a height that it acts as a glare shield for the screens to protect them from light which would prevent the display on the screens from being seen. A glare shield according to the invention also makes it possible to protect the display devices from such light, while allowing a weight saving and a reduced space requirement. It is preferably situated just above the first display device (and the second if applicable), so that the third screen defined previously, in its deployed position, is situated above the glare shield. 
         [0023]    Such a glare shield is very light, easy to install and remove, and has a very modest cost, while perfectly fulfilling its primary functions, namely preventing reflections on the display screens and protecting the electronic equipment over which it is placed. 
         [0024]    For such a glare shield, the central portion can be a stiff portion and partially serve as a structure for holding each fabric of the lateral portions. The central portion, like the lateral portions, can also be made from taut fabric. 
         [0025]    The tensioning means comprise for example a cable having an area with a low modulus of elasticity and at least one elastically deformable area with a substantially higher modulus of elasticity. In other words, the cable comprises a portion that does not elongate (or elongates very, very little) when placed under tension and a portion that elongates, like elastic webbing, to allow the tension of the cable to be adjusted, to hold the latter over time, and also to allow deformation of the cable in the event of impact on the latter so that it does not constitute a troublesome obstruction in the cockpit. 
         [0026]    In order to facilitate the mounting and removal of the glare shield, its tensioning means comprise for example a zip fastener. 
         [0027]    The present invention also relates to an aircraft cockpit, characterized in that it comprises a glare shield such as described above. Removal of the glare shield then makes it possible, for example, to gain access to a space situated behind the different display devices present in the cockpit, i.e., situated at the front of the cockpit. 
         [0028]    An aircraft cockpit is also proposed here comprising an instrument panel incorporating at least one display screen (which is preferably a screen of a display device such as described above but which can also be of a different type), characterized in that an avionics unit is placed forward of the display screen. Moreover, the display screen is preferably a flat screen. 
         [0029]    An avionics unit is here a unit (cabinet or similar) inside which electronic avionics equipment is housed. This arrangement for electronic avionics equipment is totally original and also advantageous. Here a space made available by the use of flat screens (the thickness of which is 10 cm at most) is used to place therein electronic avionics equipment which is moreover in a secure area there. 
         [0030]    A variant embodiment is proposed in which a support is used to bear the avionics unit. This support can be a substantially planar support. Provision is then made for example for an electronic board, known as a motherboard, to extend substantially perpendicularly to the support and to receive electronic boards, known as daughterboards, extending substantially perpendicular both to the motherboard and to the support. In this aircraft cockpit, the avionics unit support is shaped so as to be capable of supporting an input keyboard, or a work surface as described hereinafter. The avionics unit support can moreover comprise an upper face and a lower face, the upper face receiving said avionics unit, and the lower face being shaped to support at least one rudder bar. Advantageously, the support is mounted rotatable about a fixed pin. 
         [0031]    Finally, the present invention relates to an aircraft, characterized in that it comprises a cockpit such as one of the above-described embodiments of a cockpit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0032]    Details and advantages of the present invention will become more clearly apparent from the following description, given with reference to the attached diagrammatic drawings in which: 
           [0033]      FIG. 1  is a diagrammatic side view of an aircraft cockpit of the prior art, 
           [0034]      FIG. 2  is a diagrammatic side view of an aircraft cockpit according to one aspect of the invention, 
           [0035]      FIG. 3  is a partial perspective view of the inside of the cockpit in  FIG. 2 , also including other aspects of the invention, 
           [0036]      FIG. 4  is another diagrammatic side view of an aircraft cockpit according to the present invention, 
           [0037]      FIGS. 5A to 5F  are diagrammatic side views showing an aircraft pilot seated on a seat facing an instrument panel in a cockpit according to the present invention, 
           [0038]      FIG. 6  is a perspective view of the rear face of a display device for a cockpit according to the present invention, 
           [0039]      FIG. 7  shows an enlarged view of a locking device for the display device shown in  FIG. 6 , 
           [0040]      FIGS. 8A to 8C  show, in three different positions, another display device able to be installed in a cockpit according to the present invention, 
           [0041]      FIG. 9  is an enlarged perspective view from another viewing angle of the display device in  FIGS. 8A to 8C , 
           [0042]      FIG. 10  shows the display device in  FIG. 9  from another angle and in another position, 
           [0043]      FIG. 11  shows the display device in  FIGS. 8 to 10  in side view, in two different positions, 
           [0044]      FIG. 12  is a diagrammatic top view of an aircraft cockpit according to the invention, 
           [0045]      FIG. 13  shows in perspective top view a glare shield of an instrument panel of a cockpit according to the invention and part of its surroundings, 
           [0046]      FIG. 14  shows only an instrument panel glare shield, 
           [0047]      FIG. 15  shows diagrammatically in side view the glare shield in  FIG. 14  in its surroundings, 
           [0048]      FIG. 16  shows the mounting principle of the glare shield in  FIGS. 13 to 15 , 
           [0049]      FIG. 17  shows diagrammatically an enlarged view of a mounting detail of an instrument panel glare shield, 
           [0050]      FIG. 18  shows diagrammatically tensioning means for a glare shield shown in  FIGS. 13 to 17 , 
           [0051]      FIG. 19  shows an avionics unit able to be installed in an aircraft cockpit according to the present invention, 
           [0052]      FIG. 20  is another diagrammatic side view of a pilot positioned facing an instrument panel in a cockpit according to the present invention, and 
           [0053]      FIG. 21  shows diagrammatically an avionics bay in two different positions in a cockpit according to the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0054]    The present description relates to an aircraft nose cone, or aircraft cockpit, intended for a commercial aircraft, i.e., intended more particularly for the transport of passengers and/or freight. It relates for example to an aircraft the fuselage of which, when fitted out for the transport of passengers, can transport approximately one hundred passengers or more. 
         [0055]    The front portion of an aircraft is fitted out to receive the aircraft pilots. In general, in an aircraft of the aforementioned type, a pilot and a co-pilot are at the controls of the aircraft. The controls are placed in a space also known as the cockpit, positioned in the fuselage nose cone. In the present description, the terms “cockpit” and “nose cone” are considered to be substantially synonymous. Conventionally, there are two seats in the cockpit, which face an instrument panel above which there is a windscreen. The pilot is accommodated in one seat, the co-pilot in the other, so that they are both seated in the direction of travel of the aircraft. The instrument panel faces them, grouping, on the one hand, control means allowing the aircraft to be piloted and, on the other hand, display means allowing the pilot and the co-pilot to be informed on the status of the aircraft, its condition and environment. The control means can be press buttons, thumb wheels, turn buttons or even input means such as tablets or keyboards. The display means are most frequently warning lights and screens. 
         [0056]    The number and dimensions of the various control and display means are important for dimensioning the cockpit and determining the aerodynamic shape of the whole of the front portion of the fuselage of the aircraft. 
         [0057]    The cockpit described hereinafter is an ergonomic cockpit, the design of which takes account of the development of the various avionics systems, allowing genuine progress in the work environment of the pilots (the pilot and his co-pilot). 
         [0058]    In  FIG. 1 , a cockpit of the prior art is shown diagrammatically, and more particularly the instrument panel of this cockpit and its environment. The instrument panel shown in this figure comprises a central unit  2  in which there are control screens for example. Above and overhanging the central unit, control units  4  with various control buttons form a visor above the screens, corresponding to the “glare shield” equipment mentioned previously. Below the central unit  2 , a console  6  accommodates other controls and also for example input means (keyboard or other). 
         [0059]      FIG. 1  does not show a seat for accommodation of the pilots. Such seats are intended for installation on each side of a central pylon  8  which is also used to accommodate avionics systems. 
         [0060]    Forward of all these various command and control elements, there are numerous connection cables as well as air ducts to provide good ventilation for all the electrical and electronic instruments of the instrument panel. 
         [0061]    The result is a complex structure for the instrument panel and the whole front portion of the aircraft. 
         [0062]      FIG. 2  shows a view similar to that in  FIG. 1  for a cockpit according to an aspect of the present invention. The use of flat display screens  10  and a console with control and/or input means is proposed here. In a preferred embodiment, each pilot (i.e., the pilot and the co-pilot) has an instrument panel with a single wide screen  10  and a work surface. Each screen located facing a pilot can be fully reconfigured. Preferably, these screens  10  are touch screens, which can thus also serve as control means. The corresponding structure is described in further detail hereinafter. 
         [0063]      FIG. 3  shows that there is a screen  10  facing each pilot. Thus there is a first screen  10  and a second screen  10  which are for example symmetrical with respect to a plane separating the flight stations, even preferably identical. Only one screen  10  will therefore be described hereinafter. Preferably, each pilot also has a work surface  26 . The cockpit in  FIG. 3  here also comprises a third, retractable, screen  28 , as well as a glare shield  46 . 
         [0064]    Also, in  FIG. 3  and  FIG. 6 , a reference mark makes it possible to define a horizontal plane along axes x and y, and a vertical plane along axes y and z. 
         [0065]    The screen  10  is preferably concave, i.e., the side of the screen  10  facing the pilot is concave. This side of the screen thus has the shape of a circular cylindrical surface. The concavity of the screen  10  is such that the focal line, i.e., the axis of symmetry of the circular cylindrical shape of the screen, passes through the theoretical position of the pilot&#39;s eyes. Thus, the pilot views the screen  10  perpendicularly, regardless of the screen area viewed (in side view as shown for example in  FIG. 4 ). In this way, it is possible to have a greater equivalent screen surface area (compared with a non-concave flat screen): the gain is estimated here at 6%. 
         [0066]    The screen  10  is adjustable. In a preferred embodiment, provision is made for rotating this screen about two horizontal axes. In this way, it is possible to adjust the tilt of the screen with respect to the pilot and to change the height position of the screen and its distance from the pilot as explained below. 
         [0067]    Adjustments to the screen  10  make it possible to reduce the reflections associated with the glare from outside that is often experienced in an aircraft cockpit during daytime flights. They also make it possible to change the position of the screen  10  and to orient it in relation to the position of the pilot, which may vary during a flight: for example while cruising, the pilot may adopt a position that is further back and more relaxed than that of the “theoretical” piloting position. When the screen  10  is a touch screen, it may also be preferable to be able to adjust the position of the screen to bring it closer to the user&#39;s hands. 
         [0068]    Whether or not the screen is a touch screen, provision can be made to place control buttons for specific commands on its periphery, or on one and/or several edges of the screen. In this case also, the screen  10  is preferably sufficiently close to the pilot so that he has easy access to these control buttons. 
         [0069]      FIGS. 5A to 5F  show the motion of a display device according to the invention comprising the screen  10 , and in particular a first pivot pin  16  and a second pivot pin  14  of the screen  10  and various positions that this screen  10  can adopt relative to a pilot. 
         [0070]    Each screen  10  is mounted on two arms  12 , preferably symmetrical or even identical, also shown in  FIG. 6 . Each arm  12  has a first end forming a bearing in which the first pivot pin  16  is fitted as well as a second end forming a bearing for a second pivot pin  14 . The second pin  14  is a pin that is fixed with respect to the structure of the aircraft cockpit and allows rotation of the assembly formed by the arms  12  and the screen  10  while the first pin  16  is a mobile pin which makes it possible to change the relative position between the arms  12  and the screen  10 . 
         [0071]    The second pin  14  is placed forward of the screen  10  (taking account of the orientation of the aircraft; the screen is therefore between the second pin  14  and the pilot and, in most positions of the screen  10 , the latter hides the second pin  14  from the pilot&#39;s view). The second pin  14  is for example a connecting rod with a relatively large cross section (for example a diameter greater than 50 mm) and forms part of the structure of the cockpit of the aircraft, or more generally of the structure of the aircraft. This connecting rod is for example used as a stiffener for the lower frame of the cockpit windscreen. 
         [0072]    The arms  12  are therefore rotatably mounted on this second pin  14 . As shown in  FIG. 6 , each arm  12  has the general shape of a Y, with a base  12   a  and two upper branches  12   b.  The free end of each of the upper branches has a housing forming a bearing to receive the second pin  14  so that it is able to rotate. The base  12   b,  here reduced in height, has a housing forming a bearing to receive a first pin  16 . The rear face of the screen  10  (i.e., the face opposite that on which images are formed) has two stirrups  18  in each of which will be installed a base  12   a  of an arm  12 , a first pin  16  passing through both the base  12   b  and the branches of the stirrup  18  so as to form a pivot link between the arm  12  and the screen  10 . Anti-friction washers (not shown) can be provided in each (or only some) of the housings of the arms  12  receiving either the second pin  14  or a first pin  16 . 
         [0073]    By combining the rotational movements, on the one hand, around the second pin  14  and, on the other hand, around the first pins  16 , the pilot can tilt the screen  10 , bring it closer to him and/or adjust its height. In  FIG. 5A , the screen  10  is in a distant position with respect to the pilot and the second pin  14  here acts as a positioning stop. Tilt adjustment is then possible by rotating the arms  12  and the screen  10  around the second pin  14  or by rotating the screen  10  around the first pins  16  as shown in  FIG. 5B . 
         [0074]      FIG. 5C  shows a position in which the screen  10  is raised and placed in a high position. This position is in particular intended to allow access forward of the screen (in the direction of travel of the aircraft) for accessing in particular connections and electronic equipment as explained below. 
         [0075]    Locking means are advantageously provided to allow the screen to be held in certain predetermined positions. 
         [0076]    Thus provision is made for example for the presence of locking catches  20  mounted on the rear face of the screen  10  to cooperate with the arms  12 . The locking catches  20  are curved so that when the screen  10  rotates in relation to the arms  12 , the locking catches  20  can enter and leave a bore  12   c  provided in each arm  12 . A locking device  22  mounted on each arm  12  on the side of the bore  12   c  makes it possible to hold the catch  20  in a given position in the bore  12   c.  Indexing can also be provided. In this event, the locking device  22  allows a locking catch  20  to be held in several predetermined positions. 
         [0077]    In order to hold the arms  12  in a predetermined position, it is possible to provide for retaining feet  24  which will hold the stirrups  18 , or only the pin  16 , in a predetermined position. For example, the retaining feet  24  comprise a hole  25  in which one end of the pin  16  is fitted, so that pulling on a lower part of the screen is sufficient to extract it therefrom. The arms  12  can then no longer rotate about the second pin  14 . According to another example, the retaining feet  24  cooperate with the stirrups  18  so that rotation about the first pin  16  can also be blocked, for example by means of cooperation between a loop and a hook, so that moving the retaining feet  24  away from one wall makes it possible to release the stirrups  18  and free the movement. The screen  10  can thus be held in a stowed position. 
         [0078]    The screen  10  can be formed by a stiff support, for example made from a composite material, in particular a carbon-based composite material, and a flexible film for screen use. The support has for example a thickness of 25 to 30 mm and makes it possible to give the screen a concave shape. 
         [0079]    As shown in particular in  FIGS. 4 and 5A  to  5 F, a work surface  26  is placed between each screen  10  and the corresponding pilot. These work surfaces  26  make it possible to input data and to interact with the screen  10  and other systems of the aircraft. As shown in  FIGS. 5A to 5F , the position of each work surface  26  can be adapted for improved ergonomics of the flight station, or according to the position of the pilot and/or the position of the screen  10 . 
         [0080]    Each work surface  26  has a width substantially equal to the width of the associated screen  10 . In this way, the work surface  26  offers a large work area for the pilot. The work surface  26  can incorporate a keyboard and also comprise a device such as a computer mouse. This can also be a touch screen tablet thus forming an interface with the various avionics systems. 
         [0081]    As previously described, in the cockpit described here, each pilot thus advantageously has available a screen  10  capable of adopting several working positions, but also at least one storage position, i.e., stowed position. This screen  10  as described above can be tilt-adjusted in order to prevent the pilot experiencing unwanted reflections. It is also incurved (concavity oriented towards the pilot) so as to optimize the display surface and allow the pilot a better view. The position of the screen with respect to the pilot is optimized depending on the nature of the screen: if the screen is a touch screen, it will preferably be placed closer to the pilots in order to facilitate the pilots&#39; access to their screen. Finally, this screen is retractable (as in  FIG. 5C ) in order to allow access to the area located forward of the screen (in the direction of flight). 
         [0082]    This screen  10  is associated with a work surface  26 , also mobile in order to improve the ergonomics of each pilot&#39;s workstation. With the screen  10  and its work surface  26 , the pilot can undertake not just the piloting but also the flight management of his aircraft. 
         [0083]    The volume of the instrument panel is limited. This makes it possible to free space inside the cockpit. This freed space can be used to accommodate systems previously housed in other parts of the aircraft and/or to optimize the volume of the cockpit and its external aerodynamic shape. 
         [0084]    The preferred embodiment described above makes provision for two mobile screens, one for each pilot, without providing any other screen at the same height as these two screens. It could however also be envisaged to have a fixed screen in the central area of the instrument panel, accessible and/or perfectly visible for both pilots, and a mobile screen  10 , such as the screen  10  described above and as shown in particular in  FIG. 6 , on each side of this fixed screen. 
         [0085]    A variant embodiment of a cockpit such as described above makes provision, in an original manner, for placing a third screen  28  in the central upper portion of the instrument panel. Provision is made for this third screen  28  to be positioned above the two previously described screens  10  and preferably straddling both, preferably equidistant from both flight stations. This positioning in an aircraft cockpit is totally original. In fact, this position is such that this third screen  28  partially obscures the pilot&#39;s view through the windscreen of the aircraft. Provision is made for retracting this third screen  28  so that the pilot can benefit, when necessary, from the best possible view through the windscreen. Such a third screen  28 , its incorporation into an instrument panel and its possible use are described in greater detail in the remainder of the description. 
         [0086]    It should be noted firstly that the regulatory requirements concerning visibility for pilots allow for the presence of a central “blind spot” for both pilots (or more accurately for the pilot and the co-pilot). Regulations therefore provide for a visual blind spot for the pilot and the co-pilot which is exploited in a totally original manner for installing a screen.  FIGS. 3 ,  4 , and  8  to  12  show how such a screen can be installed in an aircraft cockpit. 
         [0087]    The presence of this screen  28  makes it possible to have in the cockpit an additional display surface in the field of view of the pilot and the co-pilot. Provision is made for retracting this screen so as to improve their view through the windscreen, by increasing their field of view therethrough. Thus, during the phases of flight for which visibility through the windscreen is not critical, the additional screen (or third screen  28 ) can be viewed by the pilots and during the phases of flight for which visibility through the windscreen is more critical, the additional screen is retracted as explained below.  FIG. 12  shows the cockpit very diagrammatically in top view. This figure shows only, very diagrammatically, the shape of the cockpit, the third screen  28  in a deployed position in which it partially obscures a pilot&#39;s view through the cockpit windscreen, a pilot and a corresponding seat back, a work surface and, in dotted lines, a diagrammatic representation of the field of view of the pilot shown. 
         [0088]    It is proposed here to render the third screen  28  mobile by means in particular of two curved and parallel tracks  30 . Translational displacement of the third screen  28  with respect to the two tracks  30  is preferably carried out using a motor (not shown) but manual displacement can also be envisaged. Provision can also be made here for displacement toward the retracted position or toward the deployed position to be done automatically, without action by the pilots. Purely by way of illustrative example, provision can be made for example for the third screen  28  to retract (and be hidden from the pilots&#39; view) as soon as the aircraft descends below a predetermined altitude. Conversely, still purely for the purposes of illustration, provision can be made for the third screen  28  to pass from a retracted position in which the pilots cannot see it from their seats to a deployed position, in which the third screen  28  is between the windscreen and the pilots, when the aircraft enters a cruising flight phase. A safety device can for example also be provided so that it is not possible for the third screen  28  to be in deployed position during the phases of takeoff, landing and taxiing. 
         [0089]    The third screen  28  is preferably also mounted rotatable about a third pin  32 , also horizontal. Just as for the two screens  10 , the ability to rotate the third screen  28  makes it possible for the pilots to avoid seeing reflections on this screen and to adopt a good position suitable for reading the information displayed on said screen.  FIGS. 8A to 8C  show various positions that can be adopted by the third screen  28 . It is noted that this third screen  28  can translate along the tracks  30  and can also rotate about the third pin  32 , which is a horizontal pin, close to the upper edge of the third screen  28 . 
         [0090]    The third screen  28  reproduces substantially the same features as the screens  10  described above. This is preferably an incurved screen with a concavity oriented toward the pilots and, advantageously, the screen is obtained by bonding or any other suitable means of fastening—a flexible film for screen use onto a support, such as for example a sandwich panel made from a carbon-based composite material. However, a third screen  28  having different features would not exceed the scope of the present invention. 
         [0091]      FIGS. 9 and 10  show in greater detail the means used to allow the displacement of the third screen  28 . As shown in these figures, the third screen  28  is rotatably mounted on a carriage  34  that slides on the tracks  30 . 
         [0092]    The carriage  34  is presented in the form of a substantially rectangular plate. It thus has two main faces, an inner face, facing the third screen  28 , and an outer face, opposite the inner face. The tracks  30  each extend in a plane that is substantially vertical (and longitudinal with respect to the axis of the aircraft). The carriage  34  has two long substantially horizontal edges linked joined by two short edges also in a substantially vertical plane parallel to the tracks  30 . The third pin  32  is level with the horizontal upper edge of the carriage  34 . The carriage  34  and the third screen  28  are connected in a hinged manner, the third pin  32  corresponding to the pin of said hinge. 
         [0093]    The carriage  34  has on its face opposite its short edges, bearings  36 , in which the tracks  30  slide. The bearings  36  are for example formed by open race ball bearings so as to ensure satisfactory sliding on the tracks  30 . In the embodiment shown in the figures, four bearings  36  are placed on the outer face of the carriage  34 , approximately at the four corners of the outer face. 
         [0094]    The lower long edge of the carriage  34  ( FIG. 10 ) is connected to the third screen  28  by a cross brace  38  which makes it possible, on the one hand, to better hold the third screen  28  with respect to the carriage  34  and therefore also with respect to the tracks  30  and, on the other hand, to lock the third screen  28  in relation to the carriage  34  in one (or more) predetermined position(s). 
         [0095]      FIGS. 9 and 10  also show in particular the presence of fixing lugs  40  which allow the tracks  30  to be mounted on the structure of the cockpit. 
         [0096]      FIG. 11  shows a side view of the third screen  28  in a deployed position and in a retracted position. It also shows the lower attachment of the tracks  30 . In the lower portion, each track  30  has two fixing lugs  40  connected to a structural part (described below) via a connecting triangle  42 . In the upper portion, each track  30  has for example a fixing lug  40  intended to be fixed on a central V-post  44  of the cockpit windscreen ( FIG. 13 ). 
         [0097]    Some possible uses of a third screen  28  described above are proposed hereinafter. The examples are of course purely illustrative and other uses can of course be envisaged for this screen. 
         [0098]    The third screen  28  can be considered as a secondary screen and is then used for displaying non-essential information (for example Internet access, cabin surveillance camera screen, etc.). The essential information relating to piloting is given on the screens  10 . 
         [0099]    This third screen  28  can also be used as an emergency screen in the event of failure of one of the screens  10  facing the pilots. This use can of course complement the use provided for in the previous paragraph. 
         [0100]    It can also be envisaged to provide reversible fixing means of the third screen on its carriage. In such a scenario, the third screen could for example be detached and used in the aircraft, or outside the aircraft at a stopover, as a mobile tablet. 
         [0101]    For the cockpit described above, it is also proposed here to produce a glare shield  46  which makes it possible essentially to avoid reflections on the main screens  10  as well as solar reflections which could disturb the pilots. This glare shield  46 , in an original manner, is designed so that it does not constitute a dangerous obstacle for the pilots during sudden deceleration. 
         [0102]    In a cockpit of the prior art, as shown in  FIG. 1 , the above-mentioned functions are performed by a control unit  4  which is placed overhanging the various screens, thus forming a visor. This control unit  4  is fixed below a stiff upper plate which is difficult to remove. The edge of the upper plate facing the pilots is protected by a foam overmolding intended to absorb frontal impacts in the event of sudden deceleration. The upper plate prevents, or makes very difficult, any access forward of the instrument panel (in the direction of flight of the aircraft) and therefore to all the connections and devices placed between the instrument panel and the front end of the cockpit. 
         [0103]    It is proposed here to produce a glare shield  46  in three portions: a central portion  48  and two side portions  50 . 
         [0104]    The central portion  48  is for example stiff. It is placed in front of the pilots and between them. It extends backwards from the lower frame of the windscreen while partially covering the screens  10  in their working position ( FIGS. 5A  or  5 B for example). The width of this central portion is limited so that it is located outside any area at risk in the event of a crash. In this way, in the event of sudden deceleration, there is no risk of collision between a pilot, in particular a pilot&#39;s head, and the central portion  48  of the glare shield. 
         [0105]    This central portion  48  is for example made from a composite material that has the advantage of being strong and light. It can thus be constituted by a carbon-based sandwich panel and have a thickness of the order of 10 to 12 mm. Two lateral metal structures  52  (one of which is shown in  FIG. 15 ), for example comprising a truss, advantageously contribute to the support and stiffening of the central portion  48  when positioned in the cockpit, preferably just above the screens  10 , and so that the third screen  28  in its deployed position is above the glare shield  46 . In the embodiment shown, the central portion has a front edge (in the direction of travel of the aircraft) that adopts the shape of the windscreen at the level of its lower frame, and a rear transverse edge on the side of the pilots. Lateral edges join the ends of the front edge to the ends of the rear edge. The metal lateral structures  52  support the lateral edges of the central portion  48  or extend parallel to these lateral edges and close to them (from a few millimeteres to a few centimeteres, for example from 1 to 10 centimeteres). 
         [0106]    Preferably, the width of the central portion  48  is, at least locally, greater than the width of the third screen  28 . An opening can then be made in the central portion  48  to allow the passage of the third screen  28  when it passes from a retracted position to a deployed position. 
         [0107]    The two lateral portions  50  of the glare shield  46  are symmetrical with respect to the central portion  48 . These lateral portions  50  are made from a flexible material which is held taut so as to form a substantially planar surface. These lateral portions  50  can thus for example be made from a fabric. This fabric is partially fixed on its surround (frame of windscreen glass, stiff central portion  48  of the glare shield) and partially by a thin cable itself held taut by a suitable device. The chosen fabric used is preferably a thin, light fabric; strong and flexible so that it can be held taut with moderate force. The fact that the parts opposite the pilots are flexible thus makes it possible to reduce the risk of frontal impacts in the event of sudden deceleration. 
         [0108]    The lateral portions  50  and the central portion  48  preferably have an upper face with a non-reflective appearance. They can for example have an upper face that is matte black in color. 
         [0109]      FIG. 16  shows the assembly of a lateral portion  50 . The bottom part of  FIG. 16  is a diagrammatic side view while the top part of this figure is a diagrammatic perspective view. Arrows between the two parts of the figure show the correspondence between these two parts of the figure. 
         [0110]    It is proposed here for example to fix each lateral portion  50  to the surrounding structure using zip fasteners  55  (such as for example those sold under the “Eclair” trade mark). Such a fastener  55  comprises two parallel tapes edged with a toothed rack the teeth of which (made of metal or synthetic material) engage by means of a slider (small movable sliding element) that merely needs to be pulled. In the present case, for a first zip fastener  55 , a first tape  54  is fixed to the central portion  48  of the glare shield and the other tape is formed by the lateral portion  50  the corresponding edge of which has a toothed rack complementary to the toothed rack of the corresponding first tape. The first tape  54  is for example fixed by bonding (symbolized in  FIG. 16  by dots). The lateral portion  50  is also fixed on the lower structure, or lower frame  56 , of the windscreen. This fixing is also carried out by a zip fastener  55 ′. A first tape  54 ′ of the zip fastener  55 ′ is fixed on the lower frame  56  using, for example, a self-gripping ribbon  58 . A self-gripping ribbon comprises a surface provided with hooks and another surface provided with corresponding loops. It is proposed here that the first tape  54 ′ bears, on the one hand, hooks or loops and, on the other hand, a toothed rack on one of its edges. The other surface of the self-gripping ribbon  58 , with the loops or the hooks, is fixed onto the lower frame  56 . The corresponding lateral portion  50  also comprises on its edge facing the lower frame  56  a toothed rack capable of cooperating with the toothed rack of the first tape  54 ′ to form, with a slider, a zip fastener  55 ′. 
         [0111]    Holding the free edge of the lateral portion  50 , i.e., the edge facing a pilot (or co-pilot), is shown in  FIGS. 17 and 18 . The free edge of the lateral portion  50  is shown in an enlarged cross section in  FIG. 17 . This edge has a hem  59  which is shown as being produced by bonding (dots representing blobs of glue). However, other methods of realization—sewing, self-gripping tape, stapling, etc.—could of course be envisaged here. The hem  59  contains a tension cable  60  protected by a foam covering  62 . 
         [0112]    The tension cable  60  is formed of two separate parts: a first part is formed by a strand or braid that is flexible but made from a material with a low modulus of elasticity and a second part with a much higher modulus of elasticity. The first part of the tension cable  60  behaves like a metal cable that is flexible but does not stretch—or stretches very little—when subjected to traction. This first part is shown by a solid line then a dotted line (because it is inside the hem  59 ) in  FIG. 18 . The second part of the tension cable  60  is much more elastic and deforms like rubber for example. This second part is shown by a dash-dotted line in  FIG. 18 . 
         [0113]    The two ends of the tension cable  60  are fastened to a fixed point. A first fixed point is for example produced by a micro strut  64  which is located for example on a windscreen post. The second fixed point is an attachment point produced on a lateral edge of the central portion  48 . A pulley  66  is used to change the orientation of the tension cable  60 . 
         [0114]    During the mounting of the tension cable assembly  60 , its length is adapted to obtain the desired tension. The second part of the tension cable makes it possible to hold this tension over time and ensures a taut fabric for producing the lateral part  50  of the glare shield  46 . Moreover, this second cable part allows the fabric to deform in the event of impact. 
         [0115]    The glare shield  46  thus produced allows its primary functions to be performed (preventing the various reflections and improving the pilots&#39; view of their screens). It does not form a troublesome obstacle in the event of a frontal impact as it is deformable. Finally, it has the advantage that it can be dismantled and easily allows access forward of the screens of the instrument panel. In a totally original manner, it becomes possible with a glare shield such as described above to gain access from above to the connections and items of equipment located forward of the instrument panel. Moreover, the glare shield thus produced is very light in comparison with the glare shields of the prior art and has a greatly reduced space requirement. It is also highly adjustable (shape, position, etc.). 
         [0116]    In a variant embodiment, a glare shield can also be envisaged that is made entirely from flexible material. The fixing principle remains similar, with the ability to also use the lateral metal supports to tension the fabric. 
         [0117]    As is apparent from the preceding description, in particular by using flat screens and simplifying the instrument panel, space is available forward of the screens  10 . In addition, access to this space is doubly facilitated as it is possible to gain access, on the one hand, by displacing the screens  10  and, on the other hand, by removing the glare shield  46 , which is easily dismantled, at least as far as its lateral parts  50  are concerned. 
         [0118]    Finally, as shown in  FIG. 15  for example, the glare shield  46  is preferably slightly tilted so that its front edge is slightly lowered, limiting the presence of the upper face of the glare shield  46  in the pilots&#39; field of view. 
         [0119]    It is proposed here to accommodate behind the screens  10  electronic equipment that is usually located (for the aircraft to which the present invention relates) in a hold below the cockpit. As shown in particular in  FIG. 20 , an avionics unit is advantageously located at the front of the cockpit. The location of this unit, shown only in  FIG. 19 , is described hereinafter. 
         [0120]    The chosen site is suitable for receiving a rack of the IMA (Integrated 
         [0121]    Modular Avionics) type. This novel avionics format aims to group software functions together in identical modular calculators. These software functions have each hitherto been performed by dedicated calculators. 
         [0122]    An example of an IMA type rack is shown in  FIG. 19 . A motherboard  68  is installed at the base of the unit and receives electronic cards, or daughter cards,  70 . The daughter cards  70  are all arranged in parallel, side by side, and extend perpendicularly to the motherboard  68 . 
         [0123]    It is therefore proposed to have such a rack available forward of the screens  10  of the instrument panel, said rack being borne by a support  72 . The latter is fixed to the structure of the aircraft so as to receive the IMA type rack. The support  72  has an upper face bearing the IMA type rack. The motherboard extends perpendicularly to the upper face of the support  72  and the daughter cards  70  are connected and disconnected by a translational movement parallel to the upper face of the support  72 . As shown for example in  FIG. 20 , the upper face of the support  72  is tilted toward the front of the cockpit. The motherboard  68  is in a forward position, i.e., toward the front of the cockpit and the daughter cards  70  disconnect from their motherboard  68  in an upward translational movement toward the rear of the aircraft. 
         [0124]    The support  72 , due to its position in particular, can perform many other functions. Thus for example, the lower face of the support can be used to support a rudder bar  76 . The latter is a flight control by which the pilot acts on the rudder units and can control rotation of the aircraft about its yaw axis. Conventionally, a rudder bar  76 ′ is operated by the pilot with both feet. The control means, most frequently pedals, are mounted on the floor of the cockpit. In order to simplify the structure of the cockpit and free up the floor, it is advantageously proposed here to fix the pedals of the rudder bar  76  below the support  72 , as shown in dotted lines in  FIG. 20 . 
         [0125]    As shown in  FIG. 21 , the support  72  is preferably mounted rotatable about a substantially horizontal fixed pin  74 . In order to simplify the structure of the assembly formed by the support  72  and the control pedals  76  of the rudder bar, the axis of rotation of these pedals  76  corresponds to the pivot pin  74  of the support  72 . 
         [0126]    The support  72  bears a housing  82  described in greater detail below. The assembly formed by the support  72  and the housing  82  is advantageously used to receive the work surfaces  26 . The support  72  and the housing  82  thus bear a mobile pair of arms  78  that is positioned in front of each pilot, at the level of the corresponding screen  10 . As shown in  FIG. 20 , a pair of arms  78  is rotatably mounted with respect to the support  72  and a cylinder  80  allows adjustment of the relative position between the support  72  and the arms  78 . The work surface  26  can also be displaced in translation and in rotation with respect to the corresponding pair of arms  78 . Numerous adjustments are thus possible and each pilot can then adapt his work surface to the best position depending on his morphology, the adjustment of his seat, his position, or other factors.  FIGS. 5A to 5F  show various positions which can be adopted by the work surface  26 . 
         [0127]    Provision is made for the work surface  26  to connect the two arms of a pair of arms  78  each time. Provision can also be made to mount a plate on each pair of arms  78  and to displace the work surface  26  with respect to the plate connecting the corresponding arms. In the former instance a maximum of space is freed in front of the pilot, in the latter, the plate forms a surface on which the pilot can place various objects, thus forming a work surface. 
         [0128]    Between the two pairs of arms  78  (one in front of the pilot and the other in front of the co-pilot), provision can be made for two fixed arms (not shown) to form a work surface between the two pilots. It is not necessary a priori to make provision for adjusting the position of such a work surface but of course it is possible to provide either full adjustment of the position of this work surface, or simply to provide the ability to fold it back in order to free space. 
         [0129]    As is usual for this type of equipment, the IMA type rack also incorporates ventilation of the electronic components. This ventilation is obtained by forced blowing and by forced extraction of air. The housing  82  is provided on the support  72 . This is a sealed hollow housing  82 , intended to fulfill the function of distributing pressurized air. Aspiration is provided by an element  84  placed over the whole of the upper face of the IMA type rack. This element  84  thus serves both as a cover for the aspiration and as an umbrella, thus ensuring protection of the computer equipment against any leakage that may occur as a result for example of condensation. To provide the function of cooling the electronic equipment of the IMA type rack, the housing  82  and the element  84  are connected to the independent circuits (not shown) provided as standard in an aircraft for the blowing and extraction of air dedicated only to the electrical systems. 
         [0130]    In an original manner, it is proposed here to also incorporate the function of air conditioning of the front end of the cockpit into the housing  82 . The latter is then divided into two parts ( FIG. 20 ). One part is then dedicated to blowing air toward the electronic components while the other part is dedicated to the air conditioning of the front portion, in particular the lower front portion, of the cockpit. Diffusers are then provided to send conditioned air toward the feet of the pilots. The second part of the housing  82  is here connected to a branch (not shown) of the air conditioning circuit of the aircraft. This integration makes it possible to simplify the installation in this area of the cockpit and thus ensure savings, with respect to volume, cost of production and integration and finally weight, for the aircraft. 
         [0131]    Access to the daughter cards  70  can easily be provided by placing the screens  10  in the position shown in  FIG. 5C . For access to the connections at the rear of the IMA type rack, as already mentioned above, provision is made to tilt the support  72  as shown in  FIG. 21 , the support  72  being rotatable about the pivot pin  74 . This figure also shows the one of the support brackets  86  that bears the pivot pin and the support  72 . These support brackets  86  are mounted directly on the structure of the aircraft. 
         [0132]    The solution described allows the space at the front of a cockpit to be optimized. The avionics equipment placed forward of the screens is in a site that is very secure due to its location close to the pilots. 
         [0133]    The proposed solution also allows simplification of the arrangement of the front portion of the cockpit despite the incorporation of a large number of functions. 
         [0134]    The novel cockpit concept as described above makes it possible to achieve a very innovative aircraft flight station allowing savings to be made in particular in respect of weight, volume and production costs, for maintenance and also in terms of security. This solution allows in particular better integration of avionics systems of the aircraft. 
         [0135]    The present invention is not restricted to the preferred embodiment described above as a non-limitative example and shown in the drawings, nor to the variants mentioned. It relates to all the variant embodiments available to a person skilled in the art within the framework of the claims hereinafter. 
         [0136]    As is apparent from the foregoing specification, the invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. It should be understood that I wish to embody within the scope of the patent warranted hereon all such modifications as reasonably and properly come within the scope of my contribution to the art.