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RELATED APPLICATION 
       [0001]    This application claims priority to French patent application 1456336 filed Jul. 2, 2014, the entirety of which is incorporated by reference. 
       FIELD OF INVENTION 
       [0002]    The present invention relates to a case which comprises a vessel and a cover which pivots on the vessel. 
       BACKGROUND 
       [0003]    A case may include a vessel which has a base, an opening opposite the base and lateral walls which delimit the inner volume of the vessel. Objects may be placed in the inner volume through the opening. 
         [0004]    To ensure the protection of the objects in the inner volume, the case conventionally comprises a cover which is pivotably mounted on the vessel and which can be moved between an open position in which the opening is not closed by the cover and a closed position in which the opening is closed by the cover. A case may be used in an aircraft cockpit to enclose oxygen masks which are available for personnel in the cockpit. During maintenance of the aircraft, a technician in the cockpit may step on the cover of the case. Thus, the case should be able to support without deformation heavy loads, such due to a person standing on the case. Conventional covers for cases are typically rigid and heavy to withstand heavy loads. 
       SUMMARY OF INVENTION 
       [0005]    An invention has been conceived and is disclosed herein to provide a case which comprises a vessel and a cover which has a light cover that does not deformed under a load. The case may comprise: 
         [0006]    a. a vessel, 
         [0007]    b. a cover which is mounted so as to be able to be moved in rotation on the vessel via a hinge system which has a hinge axis and which comprises at least one hinge, 
         [0008]    c. the hinge system includes hinges which have a first portion fixedly joined to the vessel, a second portion fixedly joined to the cover, and 
         [0009]    d. a connector provided to assume alternately an operating position in which the connection means ensure, on the one hand, the connection between the second portion and the first portion and, on the other hand, the rotation of the second portion relative to the first portion about the hinge axis or a safety position in which the connector ensures the dissociation of the second portion and the first portion. If an excessively heavy load is applied to the cover, the connection means allow the cover to become detached from the vessel. The cover of the case may be less rigid and thus less heavy than conventional cases. 
         [0010]    Advantageously, the movement from the operating position to the safety position is carried out when there is applied to the cover a force which has a component perpendicular to the hinge axis and whose intensity is greater than a threshold intensity. 
         [0011]    Advantageously, the connector may include a spring-loaded ball type stop. 
         [0012]    Advantageously, the case further comprises a retainer provided to alternately assume a retention position in which they retain the cover in an open position and a released position in which they do not maintain the cover in an open position which thus allows it to return to a closed position. 
         [0013]    According to a specific embodiment of the case, the retainer includes at least one magnet and, for each magnet, a metal element, one from the cover or the vessel comprises at least one magnet and the other from the vessel or the cover comprises, for each magnet, a metal element, and each magnet and the associated metal element move into contact when the cover is in an open position. 
         [0014]    According to another specific embodiment of the case, the retainer may comprise: 
         [0015]    a. a block which has a counterpart and which is fixedly joined to the cover, and 
         [0016]    b. a lever which has a cavity, the lever being mounted so as to be movable in rotation on the vessel about a rotation axis parallel with the hinge axis and remote therefrom, between a non-engagement position in which the cavity and the counterpart do not cooperate in order to retain the cover in an open position and an engagement position in which the cavity and the counterpart cooperate in order to retain the cover in an open position, and 
         [0017]    c. a return means which urges the lever into contact against the block. 
         [0018]    According to another specific embodiment, the retainer may comprise: 
         [0019]    a. a leaf spring which has an end which is fixedly joined to the cover and a free end, 
         [0020]    b. a rod which is mounted so as to be movable in rotation on the vessel about a rotation axis parallel with the hinge axis and remote therefrom, which has a retention portion which is parallel with the rotation axis and which is placed between the leaf spring and the cover, 
         [0021]    wherein the leaf spring has a fold which is such that, on the one hand, the distance between the fold and the cover is less than the cross-section of the retention portion and, on the other hand, the retention portion is at one side of the fold when the cover is closed and the other side of the fold when the cover is open. 
         [0022]    Advantageously, the case may also comprise a shield which covers the leaf spring and the retention portion. 
     
    
     
       SUMMARY OF THE DRAWINGS 
         [0023]    The features of the invention mentioned above, and others, will be appreciated more clearly from a reading of the following description of an embodiment, the description being given in relation to the appended drawings, in which: 
           [0024]      FIG. 1  shows a case according to the invention in section along the line I-I of  FIG. 2 , 
           [0025]      FIG. 2  shows the case of  FIG. 1  in section along the line II-II, when the cover is in a closed position, 
           [0026]      FIG. 3  shows the case of  FIG. 2 , when the cover is in an open position, 
           [0027]      FIG. 4  shows a variant of the case of  FIG. 1  in section along the line IV-IV, when the cover is in an open position, 
           [0028]      FIG. 5  shows the case of  FIG. 4 , when the cover is in a closed position, 
           [0029]      FIG. 6  shows a variant of the case of  FIG. 1  in section along the line IV-IV, when the cover is in an open position, 
           [0030]      FIG. 7  shows the case of  FIG. 6 , when the cover is in a closed position, and 
           [0031]      FIG. 8  is a view in accordance with the arrow VIII of  FIG. 6 . 
       
    
    
     DETAILED DESCRIPTION 
       [0032]      FIG. 1  shows a case  100  which comprises a vessel  102  and a cover  108 . The vessel  102  has a base, lateral walls  104  delimiting the inner space of the case  100  and an opening  106  which faces the base. The case  100  may be positioned in an aircraft cockpit to accommodate therein an oxygen mask for a pilot. The cover  108  is mounted so as to be able to be moved in rotation on the vessel  102  via a hinge system  110  between an open position in which the opening  106  is not closed by the cover  108  and a closed position in which the opening  106  is closed by the cover  108 . 
         [0033]      FIG. 2  shows the case  100  when the cover  108  is in the closed position and  FIG. 3  shows the case  100  when the cover  108  is in the open position. 
         [0034]    The hinge system  110  comprises in this instance two hinges  112  but it could have at least one. The hinge system  110  has a hinge axis  10  which is common to each hinge  112  which constitutes it. 
         [0035]    Each hinge  112  has a first portion  114  which is fixedly joined to the vessel  102  and a second portion  116  which is fixedly joined to the cover  108 . 
         [0036]    Each hinge  112  also has connection means  118 , e.g. a connector, which are provided to alternately assume an operating position in which the connection means  118  ensure, on the one hand, the connection between the second portion  116  and the first portion  114  and, on the other hand, the rotation of the second portion  116  relative to the first portion  114  about the hinge axis  10 , or a safety position in which the connection means  118  ensure the dissociation of the second portion  116  and the first portion  114 . 
         [0037]    In this manner, when the connection means  118  are in an operating position, the cover  108  can move from the open position to the closed position and vice versa by means of rotation about the hinge axis  10  and, when the connection means  118  are in a safety position, the cover  108  becomes dissociated from the vessel  102 . 
         [0038]    The connection means  118  are such that the dissociation of the second portion  116  and the first portion  114  is reversible, that is to say that the movement into the safety position is not destructive and they can be placed in the operating position again. 
         [0039]    The movement from the operating position to the safety position is carried out when there is applied to the cover  108  a force which has a component perpendicular to the hinge axis  10  and whose intensity is greater than a threshold intensity. 
         [0040]    That is to say that, if a technician climbs on the cover  108  and the intensity of the component perpendicular to the hinge axis  10  which he applies to the cover is greater than the threshold intensity, the connection means  118  will be placed in the safety position and the cover  108  will become separated from the vessel  102 . The cover  108  will then move relative to the vessel  102 , forcing the technician to climb down. 
         [0041]    The threshold intensity is determined in accordance with the force which the cover  108  can support without becoming damaged. 
         [0042]    In the embodiment of the invention which is set out in this instance, the connection means  118  are in the form of a spring-loaded ball type stop which is illustrated schematically here by a spring  122  and a ball  120  which is biased by the spring. The axis of the spring-loaded ball type stop  118  is aligned with the hinge axis  10 . 
         [0043]    The first portion  114  has a first bore which is coaxial with the hinge axis  10  and the second portion  116  has a second bore which is coaxial with the hinge axis  10 . The two bores open opposite each other. 
         [0044]    The spring-loaded ball type stop  118  is arranged in this instance in the bore of the first portion  114  but it may be arranged in the bore of the second portion  116 . 
         [0045]    In an operating position, the ball  120  projects from the bore in which the spring-loaded ball type stop  118  is accommodated and is accommodated partially in the other bore in abutment against the edges of the other bore in order to ensure the retention of the cover  108  in the vessel  102  and the rotation of the cover  108  on the vessel  102 . 
         [0046]    When a force is applied to the cover  108 , this force tends to move the cover  108  and therefore the edges of the bore of the portion (in this instance the second portion  116 ) in which the spring-loaded ball type stop  118  is not accommodated. These edges then press on the ball  120  and cause it to return into the bore of the portion (in this instance the first portion  114 ) in which the spring-loaded ball type stop  118  is accommodated. In this manner, the ball  120  retracts and the cover  108  becomes separated from the vessel  102 . 
         [0047]    In order to ensure the closed position of the cover  108 , one from the cover  108  or the vessel  102  comprises at least one magnet  202  and the other from the vessel  102  or the cover  108  comprises, for each magnet  202 , a metal element  204 . The magnet  202  and the metal element  204  which are associated move into contact when the cover  108  is in the closed position. 
         [0048]    In order to ensure the open position of the cover  108 , the case  100  comprises retention means  250 , e.g., a retainer, which are provided in order to alternately assume a retention position in which they retain the cover  108  in an open position and a released position in which they do not retain the cover  108  in an open position which thus allows it to return to a closed position. The retention means  250  thus prevents the cover  108  from falling onto the hand of a person who has opened the cover  108 . In this manner, when a person, in particular an aircraft pilot, wishes to take the contents of the case  100 , he can open and take the contents of the case  100  with one hand. 
         [0049]    In  FIGS. 2 and 3 , the retention means  250  comprise at least one magnet  206  and, for each magnet  206 , a metal element  208  and one from the cover  108  or the vessel  102  comprises at least one magnet  206  and the other from the vessel  102  or the cover  108  comprises, for each magnet  206 , a metal element  208 . Each magnet  206  and the associated metal element  208  move into contact when the cover  108  is in the open position. In the embodiment set out here, the magnet  206  is integrated in the first portion  114  and the metal element  208  is integrated in the cover  108 . 
         [0050]      FIGS. 4 and 5  show retention means  350  according to another embodiment. The retention means  350  comprise a lever  352  which has a cavity  356  (in this instance a female cavity) and a block  354  which has a counterpart  358  (in this instance a male counterpart) and is fixedly joined to the cover  108 . The counterpart  358  may be a detent in a fixed position on the cover and positioned to engage counterpart  358 , e.g., a ridge, on the lever  352 . 
         [0051]    The lever  352  is mounted so as to be able to be moved in rotation on the vessel  102  about a rotation axis  20  which is parallel with the hinge axis  10  and remote therefrom. The rotation axis  20  is arranged in this instance between the base of the vessel  102  and the hinge axis  10 . The differentiation between the rotation axis  20  and the hinge axis  10  enables an intersection zone to be created between the two rotation movements of the cavity  356  and the counterpart  358 . 
         [0052]    The lever  352  can be moved between a non-engagement position and an engagement position. In the non-engagement position, the cavity  356  and the counterpart  358  do not cooperate which results in the cover  108  not being retained in an open position. In the engagement position, the cavity  356  and the counterpart  358  cooperate which results in the cover  108  being retained in an open position. 
         [0053]    The engagement position corresponds to the open position of the cover  108  and the non-engagement position corresponds to all the positions of the cover  108  apart from the open position. 
         [0054]    A return means forces the lever  352  into contact against the cover  108  and in particular against the block  354  whether this be in the engagement position or in the non-engagement position. The return means is, for example, a torsion spring which is mounted in the region of the rotation axis  20 . 
         [0055]    The operation is as follows: 
         [0056]    a. When a person opens the cover  108 , the lever  352 , which is urged by the return means, follows the cover  108  and pivots about the rotation axis  20 . 
         [0057]    b. When the cover  108  and the lever  352  reach the engagement position, the cavity  356  and the counterpart  358  engage one in the other in order to ensure the open position of the cover  108 . 
         [0058]    c. In order to close the cover again, it is simply necessary to use one hand to move the lever  352  away and to lower the cover  108 . 
         [0059]    d. The return means allows the cover  108  to be followed automatically by the lever  352  without the user having to intervene, thereby avoiding any need for both hands in order to open and engage the cavity  356  and the counterpart  358 . 
         [0060]      FIGS. 6 ,  7  and  8  show retention means  650  according to another embodiment. The retention means  650  comprises a rod  652  and a leaf spring  654  which has one end which is fixedly joined to the cover  108  and a free end. 
         [0061]    The rod  652  is mounted so as to be movable in rotation on the vessel  102  about a rotation axis  30  which is parallel with the hinge axis  10  and which is remote therefrom. The rotation axis  30  is arranged in this instance between the base of the vessel  102  and the hinge axis  10 . 
         [0062]    The rod  652  has a retention portion  656  which is parallel with the rotation axis  30  and which is placed between the leaf spring  654  and the cover  108 . 
         [0063]    The leaf spring  654  has a fold  658  which is such that, on the one hand, the distance between the fold  658  and the cover  108  is less than the cross-section of the retention portion  656  and, on the other hand, the retention portion  656  is at one side of the fold  658  when the cover is closed ( FIG. 7 ) and at the other side of the fold  658  when the cover is open ( FIGS. 6 and 8 ). In the last case, the fold  658  and the retention portion  656  cooperate in order to keep the cover  108  open. 
         [0064]    The operation is as follows: 
         [0065]    a. When a person opens the cover  108  with one hand, the retention portion  656  is located between the leaf spring  654  and the cover  108  and is therefore driven in rotation about the rotation axis  30 . 
         [0066]    b. When the cover  108  reaches an intermediate position between the closed position and the open position, the retention portion  656  reaches the fold  658  and moves it progressively away from the cover  108  in order to pass beyond it. 
         [0067]    c. The retention portion  656  is then located at the other side of the fold  658  and maintains the open position of the cover  108 . 
         [0068]    d. In order to close the cover again, it is simply necessary to use one hand to push down on the cover  108  so that the retention portion  656  passes between the fold  658  and the cover  108  in order to return to its initial position. 
         [0069]    The rod  652  in this instance is in the form of an Omega (Ω) whose two ends are inserted into bores of the vessel  102  provided for this purpose and produce the pivot connection about the rotation axis  30  and whose central portion constitutes the retention portion  656 . 
         [0070]    A shield  660  may cover the leaf spring  654  and the retention portion  656  in order to improve the visual appearance of the assembly and to prevent the leaf spring  654  from striking and potentially damaging the objects present in the case  100 . 
         [0071]    While at least one exemplary embodiment of the present invention(s) is disclosed herein, it should be understood that modifications, substitutions and alternatives may be apparent to one of ordinary skill in the art and can be made without departing from the scope of this disclosure. This disclosure is intended to cover any adaptations or variations of the exemplary embodiment(s). In addition, in this disclosure, the terms “comprise” or “comprising” do not exclude other elements or steps, the terms “a” or “one” do not exclude a plural number, and the term “or” means either or both. Furthermore, characteristics or steps which have been described may also be used in combination with other characteristics or steps and in any order unless the disclosure or context suggests otherwise. This disclosure hereby incorporates by reference the complete disclosure of any patent or application from which it claims benefit or priority.

Summary:
A case including: a vessel, a cover mounted to be moved in rotation on the vessel via a hinge system which has a hinge axis and at least one hinge, wherein each hinge has a first portion which is fixedly joined to the vessel, a second portion) which is fixedly joined to the cover and a connector which assumes alternately an operating position in which the connector ensures the connection between the second portion and the first portion to allow for rotation of the second portion relative to the first portion about the hinge axis and, alternatively, a safety position in which the connector dissociates the second portion and the first portion.