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You are an expert at summarizing long articles. Proceed to summarize the following text: 
TECHNICAL FIELD 
     The present invention relates to a device for locking an opening portion of a turbojet nacelle relative to a fixed portion, and to a nacelle fitted with such a device. 
     BRIEF DISCUSSION OF RELATED ART 
     The prior art teaches of a system for locking an opening portion of a turbojet nacelle relative to a fixed portion, typically comprising:
         means for locking said opening portion relative to said fixed portion, and   means for actuating these locking means, mounted so as to be able to move on said opening portion between a closed position in which they allow the immobilization of said locking means and an open position in which they allow the release of these locking means.       

     Such a system typically makes it possible to lock together the half-cowls of a turbojet nacelle that are capable of opening upwards by pivoting about spindles substantially parallel to the spindle of the nacelle. 
     Once these two cowls are unlocked, specific means, such as hydraulic or electric cylinders, act on these two cowls so as to make it possible to open them. 
     These specific actuation means have a not inconsiderable weight and installing them inside the nacelle involves a certain complexity. 
     The following disclosure seeks to dispense with these drawbacks. 
     BRIEF SUMMARY 
     The disclosure provides a device for locking an opening portion of a nacelle of a turbojet relative to a fixed portion, comprising:
         means for locking said opening portion relative to said fixed portion,   means for actuating these locking means mounted so as to be able to move on said opening portion between a closed position in which they allow the immobilization of said locking means and an open position in which they allow the release of these locking means,
 
this device being noteworthy in that said actuation means comprise gripping means and in that it comprises means for immobilizing in the open position said gripping means relative to said opening portion at least in the direction of movement of said opening portion.
       

     By virtue of the presence of these gripping means and of the possibility of immobilizing them in the direction of movement of the opening portion, it is possible to manually move the opening portion relative to the fixed portion: it is therefore no longer necessary to provide actuation means dedicated to the movements of the opening portion, which makes it possible to save weight and complexity. 
     According to other optional features of the device according to the invention:
         said gripping means are able to move in rotation between said closed and open positions,   said gripping means can be moved in translation between said closed and open positions,   said locking means comprise at least one hook mounted so as to be able to move on said opening portion and capable of interacting with a counter-hook formed in said fixed portion,   said locking means comprise at least one finger mounted so as to be able to move on said opening portion and capable of interacting with an orifice formed in said fixed portion,   said immobilization means comprise at least one finger mounted so as to be able to move on said opening portion and capable of interacting with an immobilization notch secured to this opening portion,   said immobilization means comprise an immobilizing cam,   said immobilization means comprise a sheath in which said gripping means are mounted,   this device comprises a trigger for releasing said gripping means: this trigger makes it possible, with a slight pressure, to make the gripping means accessible,   this device comprises means for braking said opening portion relative to said fixed portion, and means for actuating these braking means, mounted on said gripping means: these braking means make it possible to prevent inadvertent movements of the opening portion during the maintenance operations,   said locking means are electrically controlled by said actuation means,   said locking means are geographically distinct from said actuation means: this makes it possible to reconcile the respective installations of the locking means and of the actuation means with the geometric constraints of the fixed and opening portions of the nacelle.       

     The present invention relates to a nacelle of a turbojet comprising a fixed portion and an opening portion, noteworthy in that it comprises a device for locking these two portions relative to one another according to the aforegoing. 
     According to an optional feature of this nacelle, said opening portion is mounted so as to slide relative to said fixed portion. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Other features and advantages of the present invention will appear in the light of the following description and on examination of the appended figures in which: 
         FIGS. 1 to 3  represent in perspective a nacelle according to the invention mounted beneath an aircraft wing, this nacelle being represented in three successive steps of movement of its opening portion relative to its fixed portion, 
         FIGS. 4 to 16  represent schematically an opening and closing sequence of a first embodiment of the locking device according to the invention, 
         FIGS. 17 and 18  represent schematically an opening sequence of a second embodiment of the locking device according to the invention, 
         FIGS. 19 to 25  represent schematically an opening sequence of a third embodiment of the locking device according to the invention, 
         FIGS. 26 and 27  represent schematically the two positions of a braking system incorporated into the embodiment of  FIGS. 17 and 18  and 
         FIGS. 28 and 29  represent schematically an opening sequence of yet another embodiment of the locking device according to the invention. 
     
    
    
     DETAILED DESCRIPTION 
     In these figures, identical reference numbers designate identical or similar members. 
     With reference to  FIGS. 1 to 3 , it can be seen that the nacelle  1  placed beneath an aircraft wing  3  and incorporating a turbojet  5  comprises on the one hand a rear fixed portion  7 , and on the other hand a front opening portion  9  so as to allow access to the turbojet  5  for maintenance operations. 
     As can be seen in  FIG. 3 , the front portion of the nacelle  9  is opened by sliding relative to the rear fixed portion  7 . 
     Before carrying out this sliding action, it is necessary to act on at least one locking device  11  so as to place it in an open position that can be seen in  FIG. 2 , making it possible to separate the front opening portion  9  from the rear fixed portion  7  of the nacelle  1 . 
     The various ways of producing the locking device  11  will now be studied more closely. In the embodiment of  FIGS. 4 to 16 , this locking device comprises a hook  13  mounted so as to pivot about a spindle  15  inside the opening portion  9 . 
     In the closed position that can be seen in  FIG. 4 , this hook  13  interacts with a counter-hook  16  secured to a fixed portion  17  of the nacelle  1 , itself secured to the rear fixed portion  7 . 
     A gripping handle  21 , flush with the outer wall of the opening portion  9  in the closed position shown in  FIG. 4 , is mounted so as to pivot about the spindle  15  of the hook  13 . 
     A trigger  23  is mounted so as to pivot on the gripping handle  21  about a spindle  25  substantially parallel to the spindle  15 . 
     This trigger  23  comprises a notch  26  which, in the closed position shown in  FIG. 4 , interacts with a pin  27  secured to the hook  13 . 
     Elastic return means such as a spring  29  are interposed between the gripping handle  21  and the trigger  23  so as to return the latter to its position in which the notch  26  presses on the pin  27 . 
     A first link rod  31  is mounted so as to pivot about the spindle  15  and a second link rod  33  is itself mounted so as to pivot on this first link rod and on the hook  13 . 
     A pin  35  secured to the first link rod  31  interacts with a groove  37  formed in the gripping handle  21 . 
     A third link rod  39  is mounted so as to pivot on the trigger  23  and interacts with a finger  41  mounted so as to slide on the gripping handle  21 . 
     An immobilization notch  43  capable of interacting with the finger  41  is provided in the opening portion  9 . 
     The operating mode of the locking device that has just been described in the closed position is as follows. 
     The user begins by pressing on the trigger  23  so as to make it pivot about its spindle  25  and to disengage its recess  26  from the pin  27  (see  FIG. 5 ). 
     This disengagement makes it possible to leave the gripping handle  21  free to rotate (see  FIG. 6 ). 
     This therefore causes the latter to pivot about its spindle  15 . During this pivoting action, the groove  37  rotates the pin  35  and thereby the first and second link rods  31 ,  33  which allow the disengagement of the hook  13  from the counter-hook  16  (see  FIGS. 7 and 8 ). 
     The rotary movement of the gripping handle  21  continues until the finger  41  engages in the immobilization notch  43  against the elastic return force exerted by the spring  29  on the trigger  23  and therefore on the third link rod  39 . 
     This engagement of the finger  41  in the immobilization notch  43  makes it possible to immobilize the gripping handle  21  in the position that can be seen in  FIGS. 9 to 11 , and therefore to use this gripping handle to move the opening portion  9  relative to the fixed portion  7 , either in a direction allowing the opening of the former relative to the latter (see the arrow F 1  in  FIG. 10 ) or in the other direction (see the arrow F 2  in  FIG. 11 ). 
     To close the locking device that has just been described, the user presses on the trigger  23  so as to make it pivot about its spindle  25  and thereby to extract the finger  41  from the immobilization notch  43  by means of the third link rod  39  (see  FIG. 12 ). 
     This disengagement of the finger  41  relative to the immobilization notch  43  being completed, it is possible to make the gripping handle  21  pivot about its spindle  15  to its closed position, by virtue of which the hook  13  returns to its locking position on the counter-hook  16  (see  FIGS. 13 to 15 ). 
     Finally, by completely folding down the gripping handle  21  into the plane of the outer wall of the opening portion  9 , the user engages the recess  26  of the trigger  23  on the pin  27 , and thereby replaces the locking device in its initial position (see  FIG. 16 ). 
     In the embodiment shown in  FIGS. 17 and 18 , the fixed portion  17  comprises an orifice  44  in which a locking finger  45  can be engaged, itself being mounted so as to pivot on a link rod  47 , which is in turn mounted so as to pivot on the gripping handle  21 . 
     In the closed position shown in  FIG. 17 , the recess  26  of the trigger  23  interacts with a pin  49  mounted on the link rod  47 . 
     Moreover, an immobilizing cam  51  mounted so as to pivot about the pin  49  is provided, this cam being returned by a spring  53  pressing against an abutment  55  secured to the gripping handle  21 . 
     To open this locking device, the user begins by pressing on the trigger  23  so as to disengage the recess  26  from the pin  49  by the rotation of this trigger about its spindle  25 . 
     This makes it possible to release the gripping handle  21  which can then be made to pivot about its spindle  15  in order to bring it to its position shown in  FIG. 18 . 
     In so doing, the link rod  47  extracts the finger  45  from its orifice  44 , which therefore makes it possible to unlock the opening portion  9  relative to the fixed portion  17 , and thus slide the former relative to the latter (see  FIG. 18 ). 
     It is also possible to note that, during the opening of the gripping handle  21 , the cam  51  passes over the abutment  55  under the action of the spring  53 , so that this cam is immobilized on the other side of this abutment as can be seen in  FIG. 18 : this immobilization of the cam relative to this abutment makes it possible to immobilize the gripping handle  21  in its position that can be seen in  FIG. 18 , by which it is possible to act manually on the movement of the opening portion  9 . 
     In the embodiment that can be seen in  FIGS. 19 to 25 , the gripping handle  21  is secured to a body  56  mounted so that it can move in translation and in rotation inside a sheath  57 , this body itself being extended by a finger  45 , in turn able to interact with an orifice  44  formed in the fixed portion  17 . 
     The body  56  comprises a lower portion  59  of smaller diameter, about which a spring  61  is placed pressing on the bottom of the sheath  57 . 
     On the top edge of the sheath  57  there is an abutment  63  capable of interacting with a bayonet-shaped groove  65  recessed into the body  56 . 
     Moreover, a trigger  23  similar to that of the previous embodiments is mounted flush with the gripping handle  21  and pivoting about a spindle  25  secured to this handle. 
     A spring  29  returns this trigger  23  to a position in which its recess  26  interacts with a pin  27  secured to the sheath  57  (see  FIG. 19 ). 
     To open the locking device that has just been described, the user proceeds in the following manner. 
     The user first of all begins by applying pressure to the trigger  23 , so as to disengage the recess  26  of this trigger from the pin  27  (see  FIG. 20 ). 
     Under the effect of the spring  61 , the body  56  and therefore the gripping handle  21  rise inside the sheath  57  until the abutment  63  reaches abutment in a first bend of the bayonet groove  65  (see  FIG. 21 ). 
     In this intermediate position, the finger  45  is still placed inside the orifice  44 , and a movement of the opening portion  9  relative to the fixed portion  17  is still not possible. 
     The next step consists in disengaging the abutment  63  from the first bend of the groove  65 : this is done by applying a slight pressure toward the bottom of the gripping handle  21 , as indicated by the arrow F 3  in  FIG. 22 . Doing this, the user imparts on the gripping handle  21  a quarter-turn movement, as indicated by the arrow F 4  in  FIG. 22 . 
     This quarter-turn movement makes it possible to run an intermediate portion of the groove  65  along the abutment  63  until this abutment is in the third and last portion of the groove  65  as can be seen in  FIG. 23 . 
     This last portion of the groove  65  allows an additional travel in translation of the gripping handle  21  making it possible to bring this handle from the position shown in  FIG. 23  in which the finger  45  still interacts with the orifice  44  to the position shown in  FIG. 24  in which this finger  45  has come out of this orifice, thereby allowing the opening portion  9  to slide relative to the fixed portion as shown in  FIG. 25 . 
     In the variant shown in  FIGS. 26 and 27 , established on the basis of the embodiment of  FIGS. 17 and 18 , a braking handle  67  connected to a braking device  69  via a braking cable  71  has been incorporated into the gripping handle  21 . 
     The braking device  69  may typically comprise two shoes  73  capable of pinching the fixed portion  17  under the action of the cable  71 . 
     A return spring  75  tries to place the braking handle  67  in a position in which the brake shoes are activated (see  FIG. 26 ), thereby preventing the inadvertent movements of the opening portion  9  relative to the fixed portion  17 . 
     In order to deactivate these brake shoes, the user folds down the braking handle  67  toward the gripping handle  21 , as can be seen in  FIG. 27 , thereby making it possible to move the opening portion  9  at will relative to the portion  17 . 
     The presence of these braking means that are active by default makes it possible, once the opening portion  9  has been moved relative to the fixed portion  17  for the purpose of carrying out turbojet maintenance operations, to prevent this opening portion  29  from closing again inadvertently at the risk of injuring an operator. 
     The embodiment shown in  FIGS. 28 and 29  differs from that shown in  FIGS. 17 and 18  in that the finger  45  does not directly lock the opening portion  9  relative to the fixed portion  17 : this locking action is carried out by an electromagnetic bolt  77  connected via an electric cable  79  to a switch  81  placed at the bottom of a socket  83  capable of receiving the finger  45 . 
     The electromagnetic bolt  77  comprises a latch  85  capable of interacting with a catch  87  secured to the opening portion  9 . 
     When the gripping handle  21  moves from the closed position that can be seen in  FIG. 28  to the open position that can be seen in  FIG. 29 , the finger  45  disengages from the socket  43  thereby causing the closure of the switch  81 , and the translation of the latch  85  from a position in which it interacts with the catch  87  ( FIG. 28 ) to a position in which this latch is disengaged from this catch (see  FIG. 29 ) thereby allowing the opening portion  9  to be moved relative to the fixed portion  17  by means of the gripping handle  21 . 
     As will have been understood in the light of the aforegoing description, the gripping handle  21  allows, on the one hand, the locking device to be opened, and, on the other hand, the opening portion to be moved manually relative to the fixed portion. 
     These movements are allowed because, in the open position, the movements of this gripping handle in the direction of movement of the opening portion relative to the fixed portion are immobilized. 
     Naturally, it should be understood that this gripping handle  21  is designed in an appropriate manner, that is to say so as to be able to withstand the actuation forces applied by the operator in order to carry out the opening and closing movements of the opening portion relative to the fixed portion. 
     The present invention is in no way limited to the embodiments described and shown, which are provided purely as examples.

Summary:
This device for locking an opening part ( 9 ) of a jet engine nacelle with respect to a fixed part ( 7, 17 ) comprises: means ( 13, 16 ) for locking said opening part ( 9 ) with respect to said fixed part ( 7, 17 ), means for actuating ( 21 ) these locking means that are mounted such that they can move on said opening part ( 9 ) between a closed position, in which they enable said locking means ( 13, 16 ) to be immobilized, and an open position, in which they enable these locking means ( 13, 16 ) to be released. Said actuating means comprise gripping means ( 21 ). This device comprises means ( 41, 43 ) for immobilizing, in the open position, said gripping means ( 21 ) with respect to said opening part ( 9 ) at least in the direction of movement of said opening part ( 9 ).