Patent Publication Number: US-9895492-B2

Title: Autoinjector

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an autoinjector. 
     Autoinjectors are well known in the prior art. The main aim of these devices is to carry out automatic injection of the contents of a syringe inside the body of a patient. There are various systems for automating penetration of the needle into the body of the patient as well as injection of the fluid product contained in the syringe. Autoinjectors are relatively complex devices which must respond to a certain number of requirements of stresses to be reliable. The robustness of the device, its handling, and its ease of use for the user are also important elements. In addition, as the majority of these autoinjectors is single use, the cost of manufacture and assembly is also a factor to be kept in mind. 
     There are numerous autoinjectors on the market, all of which however have some disadvantages. 
     Therefore, to prevent untimely triggering of the autoinjector, for example during transport or storage, devices must comprise reliable locking means. Similarly, when a user wants to utilise the autoinjector and unlocks the device, for example by removing the cap, the device must not actuate prematurely but only when the user really wants it, that is, at the moment when he applies it to the part of the body in which he wants to carry out the injection. Now, especially when those people using the autoinjector are elderly or handicapped people, it can happen that the user drops the device just when he wants to use it. It is preferable in such a case that the autoinjector does not actuate on its own. It is therefore important to provide a reliable triggering lock. From another viewpoint, using the autoinjector should not become too difficult, which would prevent weak people from using it. It is therefore difficult to find a good compromise between the security of the locking and the ease of use and actuation of the autoinjector. It is one of the aims of the present invention to respond to this problem. 
     In addition, according to the volume of the fluid product distributed during injection and also as a function of its viscosity, the time needed to complete this injection can be fairly substantial, and may especially exceed several second. It is very important that the user not remove the device from his body before the injection is complete. It is therefore preferable for the device to comprise means for indicating reliably to the user that the injection is finished. 
     It is also important to ensure that the product is injected to the correct depth in the body, that is, in the right tissue. So mastering the start of injecting, to ensure that the latter will start only when the needle reaches its definitive pricking position, is therefore also an important aspect. 
     Also, to avoid any risk of injury after use of the device, the autoinjector must comprise a needle safety device which prevents the needle from being conspicuous after use of the device. This safety device must obviously also be reliable and not be released too easily. It must also be functional even if the user improperly activates the autoinjector, for example if he removes it too early from his body, prior to completion of the injection. 
     Another important aspect of autoinjectors, especially when the volume of fluid product is relatively large and/or when the fluid product injected is relatively viscous, is to allow the product to diffuser from the injection site for a few seconds after said injection. If the user removes the autoinjector immediately after the end of the injection, part of the product can flow back out of the body of the user, which diminishes the efficacy of the treatment. It is therefore preferable to provide that the user holds the autoinjector against his body for a few more seconds after the end of the injection. This aspect is generally resolved by existing autoinjectors by the notice of use which asks the user to count in his head for a certain number of seconds before removing the device. This is not reliable and therefore unsatisfactory, as the system then depends on the user himself who in some cases can be perturbed or weakened by what he has just done. 
     Documents WO2012045833, EP1743666, WO2009095701, WO2012022810, EP2399632, FR2884722, WO9632974, WO2012000832, U.S.2008281271, WO2009040602, WO2009040604, WO2009040607, WO2010108116, WO2011048422, EP2399628, WO2008112472, WO2011101380, WO2011101382, U.S.2005273055, FR2905273, WO2009062508, WO2009037141 and GB2463034, describe devices of the prior art. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to provide an autoinjector which does not reproduce the abovementioned disadvantages and which responds to the different requirements and considerable restrictions for safe and reliable use of the autoinjector. 
     Another aim of the present invention aim is to provide an autoinjector which is reliable in use, which ensures distribution of all the fluid product at the planned site, which allows the user to determine when he must remove or when he can withdraw the autoinjector from his body after its use, which is safe and which avoids any risk of injury, and which is simple and not costly to manufacture and assemble. 
     The aim of the present invention is therefore to provide an autoinjector comprising a lower body receiving a reservoir, said reservoir containing fluid product and comprising a piston and a needle, such as a pre-filled syringe, said autoinjector comprising:
         an actuating sleeve provided with a contact end designed to make contact with the body of the user, said actuating sleeve being displaceable between projected positions and an actuation position, said actuating sleeve being in a first projected position prior to actuation of the autoinjector and in a second projected position after actuation of the autoinjector,   injection means to inject said fluid product through said needle when said needle is in the injection position,   an injection lock to block said injection means,   said actuating sleeve being automatically returned to said second projected position when the user removes the autoinjector from his body, said actuating sleeve ( 11 ;  1011 ) being locked in this second projected position, preventing any other actuation of the autoinjector,       

     wherein said autoinjector comprises an external shell comprising at least one display window for indicating visually to the user the actuation sequences of the autoinjector, at least one display window indicating to the user that the injection of the fluid product is finished. 
     Advantageously, the autoinjector comprises a reservoir displacement device on the one hand to displace the needle towards an injection position in which it is inserted in the body of the user and on the other hand to retract said needle out of the body of the user after injection of the fluid product, said actuating sleeve, in the actuation position, actuating said reservoir displacement device to move the needle towards its injection position, said reservoir displacement device unblocking said injection lock and actuating the injection means when the needle is in the injection position, in which said injection means actuate said reservoir displacement device after injection of the fluid product to retract said needle. 
     Advantageously, said reservoir displacement device comprises a control slide displaceable axially in said autoinjector during the actuation, said control slide comprising at least one indicator, such as a colour zone, evident through said at least one display window. 
     Advantageously, said injection means actuate a trigger which actuates the retraction of the needle after a predefined rotation, said trigger comprising at least one indicator, such as a colour zone, evident through said at least one display window. 
     Advantageously, said external shell comprises a first display window indicating to the user that the injection of the fluid product is finished and that the needle is in a retracted position. 
     Advantageously, said external shell comprises a second display window indicating to the user that the phases of pricking and injection of the fluid product are underway. 
     Advantageously, said external shell comprises a third display window indicating to the user that the actuating sleeve is in a projected position. 
     Advantageously, the autoinjector comprises a retarding device adapted to retard during a predetermined time the actuation of said reservoir displacement device by said injection means after injection of the fluid product, to delay retraction of said needle of said predetermined time after the end of the injection. 
     Advantageously, said external shell comprises a display window indicating the flow of said predetermined time to the user. 
     Advantageously, the autoinjector comprises a control sleeve displaceable axially relative to said external shell between a first locking position in which it locks the injection lock, and a second unlocking position, in which it allows unblocking of the injection lock and therefore the injection of the product through the needle, said control sleeve being displaced from its locking position towards its unlocking position by said actuating sleeve. 
     Advantageously, said control sleeve is also displaceable axially relative to said external shell between said second unlocking position and a third final position, in which it has actuated a sound and/or tactile indication device to inform the user of the end of injection. 
     Advantageously, said external shell comprises a display window adapted to indicate the different axial positions of said control sleeve. 
     Advantageously, said external shell comprises at least one display window formed in the distal end edge of said external shell, by being evident at the same time in the axial direction and in the radial direction of said external shell. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These characteristics and advantages and others of the present invention will emerge more clearly from the following detailed description, given in reference to the attached drawings, given by way of non-limiting examples, and in which: 
         FIG. 1  is a schematic exploded view in perspective of the components of an autoinjector, according to a first advantageous embodiment, 
         FIGS. 2 a  to 2 f    are schematic views in transversal section illustrating the different sequences of use of the autoinjector of  FIG. 1 , 
         FIGS. 3 a    à  3   c  illustrate more precisely three different stages of an advantageous actuating sleeve, respectively before, during and after use, 
         FIG. 4  is a detailed view showing the actuating sleeve in the position of  FIG. 3   a,    
         FIGS. 5 and 6  are schematic views in transversal section according to two different sectional planes showing the actuating sleeve in the position of  FIG. 4 , 
         FIGS. 7 and 8  are partially cut schematic views in perspective illustrating the actuating sleeve in the position of  FIGS. 5 and 6 , 
         FIG. 9  is a view similar to that of  FIG. 4 , at the start of actuation of the autoinjector, during the pricking phase, 
         FIGS. 10 to 11  are views similar to  FIGS. 5 and 6 , in the position of  FIG. 9 , 
         FIG. 12  is a view similar to that of  FIG. 8 , in the position of  FIGS. 10 and 11 , 
         FIG. 13  is a view similar to that of  FIGS. 4 and 9  during actuation, in the injection phase, 
         FIGS. 14 and 15  are views similar to those of  FIGS. 10 and 11  illustrating the position of  FIG. 13 , 
         FIG. 16  is a view similar to that of  FIG. 12 , illustrating the position of  FIGS. 14 and 15 , 
         FIG. 17  is a view similar to that of  FIG. 13 , at the end of actuation, when the user removes the autoinjector from the injection site, 
         FIG. 18  is a view similar to that of  FIG. 17 , when the actuating sleeve is locked, 
         FIG. 19  is an exploded schematic view in perspective illustrating an advantageous injection lock, 
         FIG. 20  is a sectional transversal schematic view of the injection lock of  FIG. 19 , in the blocking position, 
         FIG. 21  is a view similar to that of  FIG. 20 , in the unblocking position, 
         FIG. 22  is a schematic plan view in horizontal section of the injection lock of  FIG. 19 , in the blocking position, 
         FIG. 23  is a partially cut schematic view in perspective of the injection lock of  FIG. 19 , in the blocking position, 
         FIG. 24  is a transversal sectional schematic view of the injection lock of  FIG. 19 , in the blocking position, 
         FIG. 25  is a view similar to that of  FIG. 23 , in the unblocking position, 
         FIG. 26  is a view similar to that of  FIG. 24  in the unblocking position, 
         FIG. 27  is an exploded schematic view in perspective of an advantageous retarding device, 
         FIG. 28  is a transversal sectional schematic view of the retarding device of  FIG. 27  before its actuation, 
         FIG. 29  is a sectional schematic view according to the cutting line X of  FIG. 28 , 
         FIG. 30  is a sectional schematic view according to the cutting line Y of  FIG. 28 , 
         FIG. 31  is a view similar to that of  FIG. 28 , at the end of actuation of the retarding device, 
         FIG. 32  is an exploded schematic view in perspective of an advantageous syringe displacement mechanism, 
         FIGS. 33 to 35  are partially cut schematic views in perspective of the displacement mechanism of  FIG. 32 , prior to actuation, according to three different orientations, 
         FIGS. 36 and 37  are views similar to  FIGS. 33 and 35 , during actuation of the displacement mechanism, 
         FIGS. 38 to 41  are partially cut partial schematic views in perspective of the displacement mechanism of  FIG. 32 , when the needle of the syringe has reached its injection position in the body of the user, 
         FIGS. 42 and 43  are schematic views of the displacement mechanism of  FIG. 32  at the start of retraction initiated by the retarder, 
         FIG. 44  is a schematic view of the displacement mechanism of  FIG. 32  at the start of retraction initiated by the actuating sleeve, 
         FIGS. 45 and 46  are view similar to  FIGS. 43 and 44 , on completion of injection, 
         FIG. 47  is an exploded schematic view in perspective of the components of an autoinjector, according to a advantageous second embodiment, 
         FIGS. 48 a    à  48   e  are schematic views in transversal section illustrating the different sequences of use of the autoinjector of  FIG. 47 , 
         FIGS. 49 a  and 49 b    are schematic views in perspective illustrating the lower body and the actuating sleeve of the autoinjector of  FIG. 47 , 
         FIGS. 50 a , 50 b  and 50 c    schematically illustrate the cooperation between the actuating sleeve and the lower body of the autoinjector of  FIG. 47 , respectively in position prior to actuation, after actuation but prior to injection and after injection, 
         FIG. 51  is a view similar to that of  FIG. 50 a   , illustrating a variant embodiment, 
         FIG. 52  is a detailed cut enlarged view in perspective, showing a variant of the actuating sleeve with breakable bridges, 
         FIGS. 53 a  and 53 b    illustrate schematic views of the autoinjector prior to injection, 
         FIGS. 54 a  and 54 b    are views similar to  FIGS. 53 a  and 53 b   , after injection, 
         FIG. 55  is a schematic view in perspective of a sound and/or tactile indication device according to an advantageous variant, 
         FIG. 56  is a view similar to  FIG. 55 , partially in section, 
         FIGS. 57 a , 57 b  and 57 c    show the autoinjector prior to injection, 
         FIGS. 58 a , 58 b  and 58 c    show the autoinjector after injection but prior to actuation of the sound and/or tactile indication device, 
         FIGS. 59 a , 59 b  and 59 c    show the autoinjector after injection and after actuation of the sound and/or tactile indication device, 
         FIG. 60  is a schematic view in perspective exploded illustrating a variant embodiment of the sound and/or tactile indication device, 
         FIGS. 61 and 62  are schematic views of the control sleeve of the sound and/or tactile indication device of  FIG. 61 , 
         FIGS. 63 a  and 63 b    are schematic views of the key of the sound and/or tactile indication device of  FIG. 61 , 
         FIGS. 64 a , 64 b  and 64 c    are schematic views of the autoinjector of  FIG. 60 , respectively before unlocking of the injection lock, after unlocking of the injection lock and on completion of injection, illustrating the sound and/or tactile indication device of  FIG. 61 , 
         FIG. 65  shows another variant embodiment of the sound and/or tactile indication device, 
         FIGS. 66 a  and 66 b    are schematic views of the support pellet of the sound and/or tactile indication device of  FIG. 65 , 
         FIGS. 67 a  and 67 b    are schematic views of the key of the sound and/or tactile indication device of  FIG. 65 , 
         FIGS. 68 a , 68 b  and 68 c    are views similar to  FIGS. 64 a , 64 b  and 64 c   , illustrating the sound and/or tactile indication device of  FIG. 65 , 
         FIGS. 69, 70 and 71  are detailed views of  FIGS. 68 b    and  68   c,    
         FIG. 72  schematically shows a variant embodiment of the actuating sleeve, 
         FIG. 73  shows another view of the variant embodiment of  FIG. 72 , and 
         FIGS. 74 a , 74 b  and 74 c    are views similar to  FIGS. 50 a , 50 b  and 50 c   , illustrating the variant embodiment of the actuating sleeve of  FIGS. 71 and 72 . 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The autoinjector will be described hereinbelow in reference to diverse variants of two advantageous embodiments of the latter. A first embodiment is shown in  FIGS. 1 to 46  and a second embodiment is shown in  FIGS. 47 to 74   c . It is however to be noted that these autoinjectors, which are complex devices, comprise several modules for carrying out several functions. These diverse modules can be used separately and independently of each other, without necessarily being combined with other modules, and could especially be used in autoinjectors of form different to that shown in the drawings. 
     In reference to  FIG. 1 , the different components of the autoinjector, according to a first advantageous embodiment, are shown exploded. In this first embodiment, and in the order of the reference numerals, the autoinjector comprises a central body  1 , a control ring  2 , a pricking spring  3 , a control sleeve  4 , a piston rod  5 , a pellet support  6 , three blocking elements  7 , here in the form of balls, an injection spring  8 , a control slide  9 , a lower body  10 , an actuating sleeve  11 , a spring  12  of the actuating sleeve, a reservoir housing  13 , a cap  14 , an upper body  15 , a plurality of planetaries  16 , a plurality of satellites  17 , a retardant spring  18 , a trigger  19 , a locking finger  20 , a wire  21 , an external shell  22  and a blocking ring  23 . All these elements form part of the embodiment described, but all are not indispensable to the operation of the autoinjector, as will be described more precisely hereinbelow. 
     The cap  14  especially locks the autoinjector during transport and storage. As this cap is assembled on the lower body  10 , it prevents any actuation of the actuating sleeve  11 , and therefore any triggering of the autoinjector. 
     A reservoir A can be inserted into said autoinjector. This reservoir contains fluid product, and comprises a piston and a needle. The piston is adapted to shift in said reservoir to inject the fluid product through said needle. The present description will be given in reference to a syringe A, which can be any type. More generally, it is understood that the term “syringe” in the present description covers any type of reservoir linked to a needle. 
     Preferably, the syringe A is a pre-filled syringe. It advantageously comprises a needle cap B which protects and isolates the needle prior to use of the autoinjector. Advantageously, this needle cap B is removed automatically at the moment when the cap  14  is withdrawn from the lower body  10 . 
       FIGS. 2 a  to 2 f    illustrate the sequences of the use of the autoinjector of  FIG. 1 . 
     In  FIG. 2 a   , the autoinjector is in the rest position prior to use, the cap  14  having been removed. 
     When the user wants to use the autoinjector, he takes the device, for example at the level of the external shell  22  and presses the actuating sleeve  11 , which in a first projected position projects out of the lower body  10 , against the part of the body where he wants to carry out the injection. In  FIG. 2 b   , it is evident that pressure exerted by the user on the actuating sleeve  11  causes the latter to slide towards the interior of the lower body  10 , with the effect of compression of the spring of the actuating sleeve  12 . 
     When the actuating sleeve  11  reaches its actuation position, which is its end position inside the lower body  10 , it causes triggering of the pricking lock and therefore displacement of the control sleeve  4  in the lower body  10  under the effect of the pricking spring  3 , consequently with displacement of the syringe A in the lower body  10  and therefore insertion of the needle of the syringe in the body of the user, as is evident in  FIG. 2   c.    
     When the needle reaches its injection position with complete insertion of the needle, the injection phase is triggered, which is shown in  FIGS. 2 c  and 2 d   . It is noted that the piston rod  5  slides inside the syringe A by pushing the piston of the latter under the effect of the injection spring  8 . The product is therefore distributed. 
     On completion of the injection, and with optionally a certain delay or time offset, as will be described later, the autoinjector provides retraction of the syringe A. The needle is therefore retracted out of the body of the user towards the interior of the autoinjector, as shown in  FIG. 2   e.    
     On completion of retraction, the actuating sleeve  11  is again displaced out of the lower body  10  towards a second projected position, under the effect of the spring  12  of the actuating sleeve, with locking of said actuating sleeve  11 , which ensures absolute safety for the user and avoids any risk injury with the needle after use of the device. It is evident that the first and second projected positions of the actuating sleeve, which in the example shown are different positions, could optionally be identical. 
     An advantageous actuating sleeve will be described in more detail hereinbelow in reference to  FIGS. 3 a    to  18 . 
     Said actuating sleeve  11  comprises a flexible tab  110  which has double flexibility. It is on the one hand flexible radially that is, it deforms towards the interior of the actuating sleeve  11 . It is then also flexible laterally that is, it deforms in the peripheral direction of the actuating sleeve  11 . An actuating sleeve  11  provided with such a flexible tab is simple to mould, which is favourable from the point of view of manufacturing costs. The flexible tab  110  advantageously comprises a rod part  111  which is flexible and which terminates in a head part  112 . Said flexible tab  110  is adapted to deform on the one hand radially and on the other hand laterally relative to said central body  1  when said actuating sleeve  11  is displaced from its first projected position towards its actuation position then from its return actuation position towards its second projected position. Preferably, said flexible tab  110  is deformed radially when said actuating sleeve  11  is moved from its first projected position, prior to actuation, towards its actuation position, and said flexible tab is deformed laterally when said actuating sleeve  11  is moved from its actuation position towards its second projected position, at the end of use. This is the variant which is shown in the figures. 
       FIGS. 3 a , 3 b  and 3 c    are three partial schematic views in perspective which show the end positions of the actuating sleeve  11 , specifically in  FIG. 3 a    the first projected position at rest prior to actuation, in  FIG. 3 b    the actuation position in which the actuating sleeve  11  has been inserted to the maximum inside the lower body  10 , and in  FIG. 3 c    the second projected position with the actuating sleeve  11  locked relative to the lower body  10 , at the end of use. 
     It is noted that the central body  1  comprises cutouts forming grooves and shoulders which are detailed hereinbelow. The central body  1  is fixed to the lower body  10  and the actuating sleeve  11  is arranged to slide inside said lower body  10 . 
     The central body  1  comprises a first groove  101 , substantially axial, and an opening  103 , separate from said first groove  101  but arranged in the axial extension of said first groove  101 . Said central body  1  also comprises a radial cam  102  arranged between said first groove  101  and said opening  103 . As evident especially in  FIGS. 6 and 7 , said radial cam  102  can be formed by inclined radial thickening of the wall of the central body  1 , said thickening being formed at the axial end of the first groove  101 . Said radial cam  102  cooperates with said head  112  of said flexible tab  110  to radially deform said flexible tab  110  and allow said head  112  to move from said first groove  10  to said opening  103  during displacement of the actuating sleeve  11  towards its actuation position. 
     Said central body  1  comprises a final reception zone  105  offset axially and laterally relative to said opening  103 . As evident in the figures, this final reception zone  105  is arranged axially around the level of said first groove  101 . The opening  103  is connected to said final reception zone  105  by a laterally inclined groove  104 . An axial shoulder  106  is provided between said final reception zone  105  and said inclined groove  104 . Therefore, when said actuating sleeve  11  returns from its actuation position towards its second projected position, said head  112  of the flexible tab  110  slides in said laterally inclined groove  104 , laterally deforming said flexible tab  110 . When said actuating sleeve  11  reaches its second projected position, after use, said head  112  clips in or snaps under said axial shoulder  106 , locking said actuating sleeve  11  relative to said central body  1  and relative to the lower body  10 . From this locked position, said actuating sleeve can no longer be displaced in the direction of its actuation position, due to the stop formed between the head  112  of the flexible tab  110  and the axial shoulder  106 . 
       FIGS. 4 to 8  represent the start position, that is, at the moment when the user will commence using the autoinjector. It is evident in these figures that the head  112  is arranged in said groove axial  101  of the central body  1 . When the actuating sleeve  11  slides towards the interior of the lower body  10 , said head  112  of the flexible tab  110  will slide inside said groove  101  of the central body. When the head  112  reaches the axial end of the first groove  101 , said radial cam  102  will cooperate with said head  112 . This radial cam  102  will therefore deform the flexible tab  110 , and especially its rod part  111 , radially towards the interior in the direction of its longitudinal central axis. 
       FIGS. 9 to 12  illustrate the position in which the flexible tab  110  is radially deformed. As evident especially in  FIG. 11 , after this radial deformation the head  112  of the flexible tab  110  will continue to move axially over an additional distance to reach said opening  103 . The actuating sleeve  11  reaches its actuation position, as shown in  FIG. 13 . 
     In this actuation position, the flexible tab  110  returns elastically to its radially non-deformed position. The head  112  of the flexible tab  110  returns inside said opening  103 , as is evident in  FIG. 14 . 
     The radial deformation of the flexible tab  110 , necessary to move the actuating sleeve from its first projected position towards its actuation position, generates some resistance. Combined with the compression force of the spring  12 , this resistance obliges the user to exert at least some predetermined force to perform displacement of the actuating sleeve  11  inside the lower body  10 . This avoids any risk of accidental or unwanted actuation after the cap  14  is removed. Actuation takes place only if the user exerts said predetermined force on the actuating sleeve  11 . This force threshold also creates some precompression in the hand of the user, the effect of which is that displacement of the actuating sleeve  11  towards its actuation position is ensured when this threshold is reached. 
     When the actuating sleeve  11  reaches its actuation position, that is, in the position of  FIGS. 13 to 16 , the spring  12  of the actuating sleeve has been compressed and the pricking lock is triggered by said actuating sleeve  11 , as will be described in more detail later, which causes displacement of the syringe A inside the lower body  10  and therefore pricking of the needle in the body of the user. Throughout this pricking phase and during the injection phase which follows said pricking phase, the actuating sleeve  11  does not move relative to the lower body  10 , since the user maintains his pressure on the part of the body in which he is injecting. 
     At the end of use, when the user is going to remove the autoinjector from his body, the spring  12  of the actuating sleeve  11  will stress said actuating sleeve  11  to return from its actuation position towards its second projected position, as is shown in  FIG. 3 c   . During this axial return deformation of the actuating sleeve  11  in the lower body  10 , the head  112  of the flexible tab  110  will cooperate with the inclined groove  104  as is evident in  FIGS. 17 and 18 . This will cause elastic deformation of the flexible tab  110 , and especially of its rod part  111 , to the extent where the actuating sleeve  11  will slide axially, the head  112  sliding in said inclined groove  104  laterally deforming said flexible tab  110  as clearly evident in  FIG. 17 . This inclined groove  104  terminates in a final reception zone  105  provided with an axial shoulder  106 . At the end of the return path of the actuating sleeve  11 , the head  112  of the flexible tab  110  will penetrate this final reception zone  105  and the upper edge  114  of the head  112  will cooperate with the axial shoulder  106 , which will block the actuating sleeve  11  relative to the lower body  10 . The actuating sleeve  11  can no longer slide axially towards the interior of the lower body  10 , and the safety device is then in the final locked position. Therefore, the needle is fully protected after use and the user can no longer utilise the autoinjector or injure himself with the needle. 
     Of course, the forms of the grooves, their dimensions and their inclinations can be modified as a function of the preferred needs and characteristics for the needle safety device. 
     The actuating sleeve described hereinabove is particularly effective and reliable, and is robust and easy and therefore inexpensive to mould. 
       FIGS. 32 to 46  describe more particularly the device for displacement of the syringe in the lower body  10 . This device for displacement ensures on the one hand the pricking, that is, insertion of the needle in the body of the user, and on the other hand retraction of the needle after injection. 
     As seen previously, at the start of actuation, the syringe A is displaced axially in said lower body  10  to perform insertion of the needle in the body of the user. After injection of the fluid product in the body of the user, and optionally after some delay provided by the retarding device described hereinabove, the syringe A is again displaced in the other direction inside the lower body  10  to be retracted and automatically withdraw the needle from the body of the user. In this way, when the user removes the autoinjector from his body, the needle no longer projects but instead is retracted inside said autoinjector. 
     To perform these reciprocal displacements of the syringe A in the lower body  10 , a control ring  2  is provided which cooperates with the control sleeve  4 , with the control slide  9  and with the actuating sleeve  11 . In addition, the trigger  19  intervenes to perform retraction of the syringe inside the body, as will be explained hereinbelow. 
       FIGS. 33 to 35  illustrate the start position before the syringe is displaced for pricking. It is noted that the control ring  2  is stressed in rotation by the pricking spring  3 , which here is a spring acting in torsion. Such a torsion spring performs painless pricking. 
     In this initial position of  FIGS. 33 to 35 , rotation of the control ring  2  is prevented by a projection  91  of the control slide  9 , as is more clearly evident in  FIG. 35 . 
     When the actuating sleeve  11  arrives in its end position inside the lower body  10 , as shown in  FIG. 3 b   , a shoulder  118  of said actuating sleeve  11  will cooperate with a shoulder  92  of the control slide  9  to axially move said control slide  9  upwards in  FIG. 36 . This axial deformation of the control slide  9  will release the rotation of the control ring  2  which will be able to turn under the effect of its loaded pricking spring  3 . 
     The control ring  2  comprises three inclined profiles  24 ,  25 ,  26  similar to ramps, whereof the functions will be explained hereinbelow. 
     The control ring  2  comprises a first inclined internal profile  24 , such as a, which will cooperate with a projection  44  of the control sleeve  4 . Therefore, rotation of the ring  2  will progressively axially move said control sleeve  4 . This control sleeve  4  cooperates with the syringe housing  13  which receives the syringe, and displacement of the control sleeve moves the syringe A in the lower body  10  to perform pricking of the needle. 
       FIG. 39  illustrates the position in which the needle is fully inserted, with the first inclined profile  24  which cooperates with the projection  44  of the control sleeve  4 . 
     During displacement of the control sleeve  4  and therefore insertion of the needle into the body of the user, the projection  91  of the control slide is also in contact with an external inclined profile  25  of the ring  2 , such as an external ramp, which will cause added axial deformation of said control slide  9  relative to the actuating sleeve  11 . This will displace the control slide  9  in the same direction as the actuating sleeve  11  during pricking. Because of this, the projection  92  of the control slide  9  comes close to an upper projection  119  of the actuating sleeve  11 , and the projection  95  of the control slide  9  comes close to a projection  191  of the trigger  19 , as is evident in  FIG. 44 . 
     The first internal inclined ramp  24  which cooperates with the projection  44  of the control sleeve  4  advantageously comprises a flat section  241 , that is, a non-inclined portion, evident in  FIG. 41 . This flat section  241  has a very important function since it ensures that the start of the injection will occur only after the total end of insertion of the needle into the body of the user. Whereas for many autoinjectors it is necessary to commence the injection slightly before the needle reaches its final insertion point, for reasons of manufacturing tolerance the flat section  241  on the ramp  24  avoids this phenomenon. In fact, while the ring  2  has already completely displaced the control sleeve  4  axially and therefore has completed total insertion of the needle of the syringe in the body of the user, it is necessary for the ring  2  to turn further on the arc of a circle formed by said flat section, for example around 30°, to trigger the injection lock. Therefore, the blocking ring  23  of the injection lock is displaced from its blocking position only after the extra rotation of the ring  2  on the arc of a circle formed by said flat section  241 . During this extra rotation, there is no axial deformation of the control sleeve  4 , and therefore of the syringe A, since the flat section  241  is not inclined. Even with manufacturing tolerances, this guarantees that insertion is finished before injection commences. In line with this, during this extra rotation of the control ring  2  a second internal inclined profile  26 , such as a ramp, of the control ring  2  will cooperate with a projection  235  of the blocking ring  23  of the injection lock and displace the latter from its blocking position to release the injection, when the control ring  2  arrives at the end of its extra rotation. This is also evident in  FIG. 41 . Advantageously, the control ring  2  comprises three second internal inclined profiles  26  arranged at 120° to each other, and the blocking ring  23  comprises three projections  235  also arranged at 120° to each other, a respective projection  235  cooperating with a respective second internal inclined profile  26 . 
     When the injection is triggered by the blocking ring  23 , the rotation of the control ring  2  is again blocked by the control slide  9 . 
     With the control slide  9  in the position of  FIG. 44 , if the user removes the autoinjector from his body while the injection is underway or after injection but before the end of the retarder, the spring  12  of the actuating sleeve  11  will stress said actuating sleeve  11  returning from the lower body  10 . This displacement of the actuating sleeve  11  will draw the control slide  9  axially downwards in  FIG. 44  by cooperation between the upper shoulder  119  and the projection  92  of the slider. Therefore, the control ring  2  will again be released in rotation by the control slide  9 , and the spring  3  will stress this control ring more in rotation, which will cause retraction of the syringe and of the needle inside the body. The actuating sleeve  11 , on completion of movement, will be locked as described previously. Therefore, even if the user removes the autoinjector before full distribution of the product, the needle safety device is operative. 
     In normal operation, the injection is terminated and as will be described hereinbelow the piston rod  5  will release the rotation of a trigger  19 , optionally with some delay if a retarding device is used. From the moment when the trigger  19  has performed predefined rotation, a projection  191  of the trigger  19  will cooperate with the upper shoulder  95  of the control slide  9 , and this control slide  9  will be displaced axially downwards in  FIG. 44 , which will release rotation of the control ring  2 , as described previously. 
       FIGS. 45 and 46  illustrate retraction of the needle with rotation of the ring  2  which will bring the projection  44  of the control sleeve opposite an internal groove of the ring  2 , which will cause, under the effect of the spring, axial return deformation of the control sleeve  4  inside the control ring  2  and therefore retraction of the syringe and of the needle. 
       FIGS. 19 to 26  schematically illustrate an advantageous injection lock. The autoinjector comprises injection means, comprising especially the piston rod  5 , the injection spring  8  and the blocking ring  23 , these injection means being blocked in a loaded position by said injection lock. The unblocking of said injection lock then causes actuation of said injection means and therefore injection of the fluid product through the needle. 
     As shown in  FIG. 19 , said injection lock comprises a control sleeve  4  arranged in said central body  1 , said control sleeve  4  containing said piston rod  5  and said injection spring  8 , said piston rod  5  comprising a radial recess  50  receiving at least one blocking element  7  mobile between a blocking position and an unblocking position. Said at least one blocking element  7  is preferably substantially spherical in shape. In the variant shown, there are three blocking elements  7  in the form of balls, but a different number of blocking elements and forms slightly different to these blocking elements are possible. The following description will be made however in reference to three balls, without this being limiting. Said balls  7  are stressed radially towards the exterior by said piston rod  5  and are held in the blocking position by a blocking member, which in this embodiment is formed by a blocking ring  23 . This blocking ring  23  is displaceable axially relative to said piston rod  5  between a locking position, in which if keeps the blocking elements  1007  in the blocking position, and an unlocking position, in which said blocking elements  1007  are released to unblock said injection lock, allowing said injection spring to displace said piston rod  5  towards its injection position. 
       FIG. 20  shows the injection lock in the blocking position. The injection spring  8  cooperates on the one hand with the piston rod  5  and on the other hand with a pellet support  6 . This pellet support  6  is formed by a ring arranged around said piston rod  5 . The piston rod  5  comprises a peripheral recess  50 , provided advantageously with an inclined surface  51 , formed by narrowing of the diameter of said piston rod  5 . This piston rod  5  is arranged inside the control body  4  and is likely to be displaced axially towards the left in  FIG. 20  to push the piston of the syringe A inside the syringe and distribute the fluid product contained in said syringe through the needle. 
     As evident in  FIG. 20 , the balls  7  are arranged in said recess  50  formed in the piston rod  5  and cooperate therefore on the one hand with the inclined wall  51  of the piston rod  5  and on the other hand with the upper surface  61  of said pellet support  6 . 
     The inclined surface  51  of the piston rod is in contact with the balls  7  such that under the effect of the compressed spring  8 , said inclined surface  51  exerts a reaction force F 1  on the balls  7 , this force F 1  not being exactly axial but directed slightly towards the exterior, stressing the balls  7  radially towards the exterior of the blocking position of  FIG. 20 . 
     The blocking ring  23  is provided radially outside the balls  7  to radially block said balls in the blocking position. In reference more particularly to  FIG. 22 , it is evident that the balls can be arranged in housings of the control sleeve  4 , the blocking ring  23  comprising projections  231 , one for each ball  7 , which are positioned in contact with the balls  7  to prevent the latter from being displaced radially towards the exterior. 
     The pellet  6  transmits the force F 3  of the spring  8  to the balls  7 , and the blocking ring  23  exerts a reaction force F 2  on the balls  7  to prevent radial displacement of the latter. Therefore, it is the balls  7  which support all the forces exerted on the lock in the blocking position, with balance at three points under the effect of forces F 1 , F 2  and F 3 . Such a lock is particularly stable and robust and especially resists drops tests. These tests simulate the fact of dropping the autoinjector to the floor after the cap  14  has been removed, the aim being to avoid triggering of the injection lock during this fall. In particular, no force is exerted on the structural pieces of the autoinjector, such as the central body  1  or the lower body  10 . This lock accordingly avoids the risk of untimely disassembly of the device during transport or handling. 
     It is evident that the balls  7  could be replaced by non-spherical elements but of rounded more complex shape, for example in the form of a cylinder or bean, to further improve the stability of the lock. In this case, these non-spherical mobile elements could be made of metal, for example by steel wire cutting. 
     When the needle of the syringe has fully penetrated the body of the user, and only after this total insertion, as will be described later, the blocking ring  23  is displaced according to arrow E 1  in  FIG. 21 . The effect of this is to release the balls  7  from their blocking position, the latter being displaced radially towards the exterior according to arrow E 2 . As a variant, the blocking ring  23  could also be displaced in rotation towards a position where it releases the balls. The pellet support  6  then stops against an internal edge of the control sleeve  4 , as shown by arrow E 3  in  FIG. 21 . In this position, the piston rod  5  is no longer held by the balls  7  and it is therefore displaced axially, that is, towards the left in  FIG. 21 , to perform injection of the product. The balls  7  can no longer return to the blocking position, prevented by the pellet  6 , as is evident in  FIG. 21 . 
     With slightly different views  FIGS. 23 to 26  illustrate the two positions of blocking and unblocking of the injection lock, as described hereinabove in reference to  FIGS. 20 and 21 . 
     The injection lock shown in  FIGS. 19 to 26  unlocks a substantial force exerted by a compressed spring, in this case the injection spring  8 , by exerting a relatively weak and easily controlled force on the blocking ring  23 . In particular, the force necessary to move said blocking ring  23  into the unblocking position can represent only 10%, or even only 5%, of the force exerted by the injection spring  8 . This represents a very large yield which ensures easy and reliable actuation of the device. 
     When the injection is finished, that is, when the piston rod  5  has reached its end position in which the piston of the syringe A has been displaced to inject the fluid product, a trigger  19  is actuated to retract the syringe and therefore the needle. 
     During the injection phase, a locking finger  20  extends through the trigger  19  and into the central channel  151  of the upper body  15 . A retardant spring  18 , here a spiral spring, stresses said trigger  19  in rotation. This rotation is blocked by the locking finger  20 , advantageously oblong in shape, which is adapted to turn together with said trigger  19 , but which is blocked in rotation by said central channel  151  of the upper body  15 . During the injection phase, the piston rod  5  moves axially, that is, towards the left in  FIG. 28 . As it moves, it will pull on the wire  21  which will therefore extend out of the channel  151 . As the locking finger  20  is arranged inside the central channel  151 , rotation of the trigger  19  is blocked. When the piston rod  5  approaches the end of the injection path, the wire  21  is completely taut and held between the piston rod  5  and the locking finger  20 , and any extra displacement of the piston rod  5  will therefore axially displace the locking finger  20  out of said central channel  151 . When the piston rod  5  reaches the end position of the end of injection, the locking finger stops cooperating with the central channel  151 , and the trigger  19  and the locking finger can turn under the effect of the retardant spring  18 . As evident in  FIG. 31 , the trigger  19  comprises an external inclined ramp  190  which can comprise a projection  191  to one side. When the trigger  19  will have described a predefined rotation, typically about one turn, this projection  191  will cooperate with the control slide  9 , which will displace the latter axially and trigger retraction of the needle, as has been described previously. 
       FIGS. 27 to 31  illustrate an advantageous retarding device. 
     The main aim of this retarding device, which is optional in an autoinjector, is to offset retraction of the syringe A in time and therefore of the needle out of the body of the user after completion of injection of the fluid product inside said body. This especially enables diffusion for a few seconds of the product after its injection. Such a retarder also produces a benefit for the user who no longer has to count, for example up to 10, after injection, the time taken for this counting varying widely from one user to another. A retarder makes the sequence of use of an autoinjector easy. 
     The mechanical retarder shown in  FIGS. 27 to 31  offsets this retraction by a few seconds, this delay being predeterminable. 
       FIG. 27  illustrates an exploded schematic view of this retarding device. This comprises the upper body  15 , several planetaries  16  with several satellites  17 , the retardant spring  18 , the trigger  19 , the locking finger  20 , the wire  21  and the piston rod  5 . It is this piston rod  5  which will perform actuation of the retarding device when it arrives at the end of the injection path with all the product which has been injected. 
       FIG. 28  shows the retarding device before its actuation. It is evident that the actuation rod  5  is connected to the locking finger  20  by means of the wire  21 . In this position, the wire  21  and the locking finger  20  extend inside a central channel  151  of the upper body  15  and into the trigger  19 . The upper body  15  comprises a gear  155  on its lateral internal surface, as clearly evident in  FIG. 30 . This internal gear  155  of the upper body  15  cooperates with a plurality of satellites  17  which are assembled on planetaries  16 . In the example shown in  FIG. 28 , there are several planetaries stacked axially on each other. The planetaries  16  comprise a plate in the form of a disc on which are formed to one side satellite support rods  161  which each rotatively receive a satellite  17 . In the example shown, there are three satellites  17  to each stage such that there are three rods  161 . Each planetary  16  associated with its satellites  17  forms one stage of the retarding device. On the other side of the plate in the form of a disc the planetary  16  comprises a gear  162  adapted to cooperate with the satellites  17  of the adjacent stage. Therefore, as is evident in  FIG. 30 , the retarding device utilises the principle of epicycloidal trains. Each stage of this device demultiplies and/or slows down the rotations of the previous stage. 
     When a retarding device is used, the trigger  19  cooperates with a first planetary  16 , whereof the rods  161  extend inside said trigger  19 . The gear  162  of this first planetary  16  cooperates with the satellites of a second adjacent planetary, which cooperate with the lateral gear  155  of the upper body  15 , demultiplying the rotation of the first planetary and therefore of the trigger, and therefore braking this rotation. Each additional stage of the epicycloidal train forming the retarder will further demultiply these rotations, and therefore further brake the rotation of the trigger  19 . Therefore, with four stages as shown in the figures, the rotation of the trigger  19  can be made as a single turn, whereas the last planetary  16  arranged at the very bottom of the upper body  15  will describe around fifty turns simultaneously. 
     According to the number of stages and/or according to the number of satellites and/or according to the form of the planetaries and/or according to the dimensions of the gears in play, the delay between the moment when the retarding device is triggered and the moment when the trigger  19  will have performed its predefined rotation to trigger retraction of the syringe can be adjusted fairly precisely, as will be explained later. Friction braking can also be provided, for example between the satellites  17  and the internal gear  155  of the upper body  15 . 
     The retarding device therefore offsets the moment when said trigger will actuate retraction of the needle by a predetermined time, from the moment when the injection phase is finished. 
     It is evident that the deployable wire principle connected on the one hand to the piston rod  5  and on the other hand to the locking finger  20  can be used without the train epicycloidal system such as shown in  FIGS. 27 to 31 , as will be especially described hereinbelow in reference to the second embodiment. This wire, of minimal bulk, ensures that retraction of the needle commences only once the injection phase is fully finished, especially compensating any manufacturing tolerances. More generally, the use of a wire reduces the bulk of the device. Because of this, it can be used advantageously for various functions in an autoinjector, as there is a need to pull one piece relative to another. 
     According to an advantageous aspect, the external shell  22  comprises several indicators which inform the user of the advance of sequences for pricking, injection and retraction. In case of use of a retarding device, display of said delay can also be provided. 
     Therefore, as evident in  FIGS. 2 a  to 2 f   , the external shell  22  can comprise several display windows, in this case three windows  221 ,  222 ,  223 , which display mobile elements during different phases of actuation, these elements comprising indicators, typically colours. 
     Therefore, the control slide  9 , which at rest is in a first position relative to the central body  1 , moves axially towards a second position during displacement of the actuating sleeve  11 . It remains in this second position throughout the injection phase, and returns in the direction of its first position during retraction of the needle. It is only when the actuating sleeve returns to its second projected position that the control slide reaches this first position. This control slide  9  can comprise one or more colour indicators, for example a red zone as evident in  FIG. 1 . This slider can therefore be used to indicate on the one hand the projected position of the actuating sleeve  11  (first position) and on the other hand the pricking and injection phase (second position). 
     The trigger  19 , which triggers the retraction of the needle on completion of injection, can also comprise an indicator, for example a red zone which displays when said trigger has performed its predefined rotation and actuated retraction of the needle. 
     Therefore, the first display window  221  can be the window for completion of injection, that is, when a predefined colour, red for example, appears in the window  221 , the injection is finished and the syringe has been retracted. The user therefore knows that when this first display window is red he can remove the autoinjector from his body in complete safety. This indication can be supplied for example by the trigger  19 . 
     The second display window  222  can be that of the phases of pricking and injection, which changes to red at the start of the pricking phase at the end of the injection phase. This prevents the user from removing the autoinjector from his body during these phases, which can last several seconds. This indication can be supplied by the actuator slider  9 . 
     The third display window  223  can be that of the actuating sleeve  11 , with the red displayed when the actuating sleeve  11  is in a projected position out of the lower body. This third display window  223  is therefore red prior to actuation, then again after use when the actuating sleeve  11  is locked in the safety position. This indication can be supplied by the control slide  9 . In the example shown, the red zone of the actuator slider  9  moves from the third display window  223 , prior to actuation ( FIG. 2 a   ), to the second display window  222  ( FIG. 2 c   ) when the actuating sleeve is in the actuation position where it triggers the pricking phase. During this transition, said red zone is not evident as it is located between said windows  223  and  222  ( FIG. 2 b   ). During the phases of pricking and injection, the control slide stays in its second position ( FIG. 2 c    &amp;  FIG. 2 d   ). When the control slide  9  is again displaced axially towards its first position by the trigger  19 , to actuate retraction of the needle, the red zone changes back from the second window  222  to the third window  223 , being invisible again ( FIG. 2 e   ), to finally reappear in the third window  223  when the actuating sleeve is locked in the second projected position ( FIG. 2 f   ). 
     In this configuration, the combination of red in the first and third display windows  221  and  223  ensures the end of the process of use of the autoinjector, with the needle retracted and the actuating sleeve  11  locked, ensuring optimal safety. 
     Of course, other means of display or indication are also possible and said external shell  22  can comprise any number of display windows, of any form and dimension, and which could be positioned differently to the variant shown in the figures. The same window can especially display several different functions. 
     Optionally, in the first display window  221  or in another display window, for example an additional display window, the state of the retarding device can be displayed, for example with a count. This could be done for example with numerical values inscribed on the lateral external edge of the trigger which moves progressively into an appropriate display window and which in seconds displays the count of the retarder. Other variants are of course also possible. 
     This external shell  22  can also comprise a button or buttons for pricking and/or retraction of the needle if the autoinjector provides such buttons to perform pricking and/or retraction of the needle. 
     The external shell  22  could also comprise a temperature indicator of the product to be injected. In fact, many products to be injected are stored at 8° and it is often recommended to bring them out 30-60 minutes in advance. If the product is too cold at the moment of the injection, this can cause pain for the patient. For example, the shell  22  could comprise temperature display of the reservoir containing the product to be injected. As a variant, a label could also be provided which changes colour with temperature. This temperature indicator could be provided on the shell, or on the reservoir, especially the syringe, and be visible through a window of the shell. 
       FIGS. 47 to 74   c  illustrate several variants of a second embodiment of the invention. This second embodiment relates to a simplified autoinjector, comprising fewer pieces, and therefore simpler and less costly to make and assemble. 
     In the variant of  FIG. 47  of this second embodiment, the autoinjector comprises a lower body  1010 , an actuating sleeve  1011 , a spring  1012  of the actuating sleeve, a cap  1014 , a control sleeve  1004 , a piston rod  1005 , a pellet support  1006 , three blocking elements  1007 , here in the form of balls, an injection spring  1008 , a click member  1500 , a wire  1021 , and an external shell  1022 . 
     The cap  1014  especially locks the autoinjector during transport and storage. As this cap is installed on the lower body  1010 , it prevents any actuation of the actuating sleeve  1011  and therefore any triggering of the autoinjector. 
     As for the first embodiment, the syringe A is a pre-filled syringe. It comprises advantageously a needle cap B which protects and isolates the needle prior to use of the autoinjector. Advantageously, this needle cap B is removed automatically at the moment when the cap  1014  is removed from the lower body  1010 . 
     It is evident that this second embodiment has several elements similar to the first embodiment, these similar elements being designated by reference numerals similar to those of the first embodiment, augmented by  1000 . Therefore, for example, the actuating sleeve reference  11  in the first embodiment is now reference  1011 . Consequently, in the description of this second embodiment, it is mainly the differences relative to the first embodiment which will be described, given that the other elements and functions remain similar, if not identical, between the two embodiments. 
     The principal difference in this second embodiment is that the reservoir, in this case the syringe A, is fixed relative to the lower body  1010 , relative to the control sleeve  1004  and relative to the external shell  1022 . Therefore, to perform pricking of the needle only the actuating sleeve slides relative to the rest of the autoinjector. In this second embodiment there is therefore no device for syringe displacement. 
       FIGS. 48 a  to 48 e    illustrate the sequences of the use of the autoinjector of  FIG. 47 . 
     In  FIG. 48 a   , the autoinjector is in a rest position prior to use, the cap  1014  having been removed. 
     When the user wants to use the autoinjector, he takes the device, for example at the level of the external shell  1022  and presses the actuating sleeve  1011 , which in a first projected position projects out of the lower body  1010 , against the part of the body where he wants to perform the injection. In  FIG. 48 b   , it is evident that the pressure exerted by the user on the actuating sleeve  1011  causes sliding of the latter towards the interior of the lower body  1010 , which reveals the needle and therefore its pricking due to the pressure exerted by the user on the autoinjector. 
     When the actuating sleeve  1011  reaches its actuation position, which is its end position inside the lower body  1010 , it causes triggering of the injection phase which is shown in  FIGS. 48 c  and 48 d   . It is noted that the piston rod  1005  slides inside the syringe A by pushing the piston of the latter under the effect of the injection spring  1008 . The product is therefore distributed. 
     On completion of the injection, when the user removes the autoinjector from the injection site, the actuating sleeve  1011  is again shifted out of the lower body  1010  towards a second projected position, under the effect of the spring of the actuating sleeve, with locking of said actuating sleeve  1011 , which ensures absolute safety for the user and avoids any risk of injury with the needle after use of the device. It is evident that the first and second projected positions of the actuating sleeve, which, in the example shown, are different positions, could optionally be identical. 
     In this second embodiment, as evident especially in  FIGS. 49 a    to  52 , said actuating sleeve  1011  also comprises a flexible tab  1110  which is flexible laterally only, that is, it deforms in the direction peripheral of the actuating sleeve  1011  only. An actuating sleeve  1011  provided with such a flexible tab is even simpler to mould than the flexible tab with double flexibility of the first embodiment, which is favourable from the point of view of manufacturing costs. With a tab flexible laterally only, there is also a gain in radial bulk, which especially improves the aesthetics of the autoinjector. The flexible tab  1110  advantageously comprises a rod part  1111  which is flexible and which terminates in a head part  1112 . 
     In a first variant, illustrated in  FIG. 51 , said flexible tab  1110  is adapted to deform laterally relative to said lower body  1010  on the one hand when said actuating sleeve  1011  is displaced from its first projected position towards its actuation position and on the other hand when said actuating sleeve  1011  is displaced from its return actuation position towards its second projected position. In this case, the head  1112  of the flexible tab must overcome resistance to deform laterally at the start of the actuation, to create a sort of precompression which ensures that when the actuating sleeve will slide towards the interior of the lower body  1010 , the needle will suddenly penetrate the injection site as far as its planned injection position. In the example of  FIG. 51 , this resistance is formed by a shoulder  1019  of the lower body  1010 . 
     Preferably however, in a second variant shown in  FIGS. 50   a, b, c  and  52 , said flexible tab  1110  is not deformed when said actuating sleeve  1011  is moved from its first projected position, prior to actuation, towards its actuation position, and said flexible tab is deformed laterally only when said actuating sleeve  1011  is moved from its actuation position towards its second projected position, at the end of use. In this variant, prior to actuation, the actuating sleeve  1011  is connected to said lower body  1010  by at least one breakable bridge  1500 . This embodiment especially allows easy moulding, and therefore reduced manufacturing costs, adaptation and management of the breaking force of the breakable bridges facilitated by the dimensioning of these bridges, and an evidence of use function. 
       FIG. 52  illustrates two breakable bridges  1500 , adapted to break and therefore enable sliding of the actuating sleeve  1011  relative to the lower body  1010  when the user presses the autoinjector on the injection site using predetermined pressure. 
     When the actuating sleeve  1011  returns from its second actuation position towards its projected position, under the effect of the spring  1012 , when the user removes the autoinjector from the injection site, the operation of the flexible tab  1110  can be identical to that described within the scope of the first embodiment, with an inclined groove, a final reception zone and an axial shoulder cooperating with the head of the flexible tab to block it in the second projected position. 
     In a variant, the lower body  1010  can comprise a shoulder  1019  which extends axially towards the interior by a ramp  1018 , for example formed by a groove, which is at least partially inclined. Therefore, when the actuating sleeve  1011  returns from its actuation position towards its second projected position the head  1112  of the flexible tab  1110  will be deformed laterally by said ramp  1018 , to finally returns to clip in or snap under the projection  1019  in the second projected position to block the actuating sleeve. 
     In the variant of  FIG. 51 , this same projection  1019  can cooperate with the head  1112  of the flexible tab  1110  at the same time at the start of actuation to create precompression and at the end of actuation to block the actuating sleeve in the second projected position. Of course, two different shoulders can also be provided to carry out these two functions. 
     It is evident that the flexible tab  1110  can be fixed to said actuating sleeve  1011  only at the level of its rod part  1111 , with in this case the head  1112  forming a free end of said flexible tab. By way of variant, the flexible tab could also be fixed to said actuating sleeve on two sides, with the head  1112  arranged between the two fastening points. This execution reinforces especially the robustness of the flexible tab. This variant could also be adapted to the flexible tab of the first embodiment. 
     In the variants of  FIGS. 49 a    to  52 , the flexible tab  1110  of the actuating sleeve  1011  cooperates advantageously with an opening  103 , an inclined groove  104 , a final reception zone  105  and an axial shoulder  106  of the body  1010  which are similar to these same elements described previously in reference to  FIGS. 4 to 18 . 
       FIGS. 72 to 74   c  illustrate another variant embodiment of the actuating sleeve. In this variant, the reference numerals will be similar to those hereinabove, but augmented by  1000 . Therefore for example, the actuating sleeve will be referenced  2011 . In this particular variant, the functions of the actuating sleeve  2011  and of the body  2010  are reversed, the body  2010  comprising the flexible tab  2110 , and the actuating sleeve  2011  comprising the profile which will cooperate with said flexible tab  2110 . The operation however remains similar to that described previously, with the flexible tab  2110  which will progressively slide in said profile, and especially in an inclined groove  2104  which connects an opening  2103  to a final reception zone  2105 . To lock the device at the end of actuation in the final reception zone  2105 , the flexible tab  2110  will clip or snap onto the shoulder  2106 , as is evident in  FIG. 74 c   . As described previously, the flexible tab must advantageously overcome resistance to deform at the start of the actuation to create a sort of precompression which ensures that when the actuating sleeve  2011  will slide towards the interior of the lower body  2010  the needle will suddenly penetrate the injection site as far as its planned injection position. In the example of  FIGS. 72 to 74C , this resistance is formed by a shoulder  2019  of the actuating sleeve  2011 . It is evident that the flexible tab  2110  can be formed monobloc on the body  2010 , or as a variant be formed on a separate piece assembled on said body  2010 , for example for reasons of simplicity and/or moulding. 
       FIGS. 53 a, b   ,  54   a, b ,  57   a, b, c  and  58   a, b, c  illustrate adaptation to the second embodiment of the injection lock described in the first embodiment. 
     As described previously, the autoinjector comprises injection means, comprising especially the piston rod  1005  and the injection spring  1008 , these injection means being blocked in a loaded position by said injection lock. The unblocking of said injection lock causes actuation of said injection means and therefore injection of the fluid product through the needle. 
     As shown in the different  FIGS. 53, 54, 57 and 58  said injection lock comprises a control sleeve  1004  arranged in said external shell  1022 , said control sleeve  1004  containing said piston rod  1005 , said injection spring  1008  and a pellet support  1006 . In the blocking position shown in the different  FIGS. 53 and 57 , the injection spring  1008  cooperates on the one hand with the piston rod  1005  and on the other hand with said pellet support  1006 . This pellet support  1006  is formed by a ring arranged around said piston rod  1005 . Said piston rod  1005  comprises at least one radial recess  1050  receiving at least one blocking element  1007  mobile between a blocking position and an unblocking position. Advantageously, there are three blocking elements  1007 , preferably substantially spherical in shape, especially in the form of balls, but a different number of blocking elements and rounded forms different to these blocking elements are possible. Said blocking elements  1007  are stressed radially towards the exterior by said piston rod  1005  and are held in the blocking position by a blocking member, which in this second embodiment is formed by said control sleeve  1004 . This control sleeve  1004  is displaceable axially relative to said piston rod  1005  between a locking position in which it holds the blocking elements  1007  in the blocking position, and an unlocking position in which said blocking elements  1007  are released to unblock said injection lock, allowing said injection spring to displace said piston rod  1005  towards its injection position. 
     As evident more particularly in  FIGS. 57 a  and 58 a   , the control sleeve  1004  comprises one or more windows  1400  which allow the blocking elements  1007  to move when the control sleeve has been displaced towards its unlocking position, shown especially in  FIG. 58 . The displacement of the control sleeve  1004  from its locking position towards its unlocking position is performed by a projection  1411  of the actuating sleeve  1011 , which will cooperate with a shoulder  1410  of the control sleeve  1004  such that the control sleeve  1004  is in the unlocking position when the actuating sleeve  1011  is in the actuation position. Since said piston rod  1005  is now not blocked by said blocking elements  1007 , it is displaced out of the control sleeve by said precompressed injection spring  1008  to move the piston into the reservoir and inject product through the needle. This type of lock enables unblocking with little effort, ensuring sound and tactile comfort for the user during injection. 
     Advantageously, the autoinjector comprises a sound and/or tactile indication device  1500  to indicate by an audible or by a tactile indication to the user that the injection phase is finished. This device will be described hereinbelow in relation to three variants of the second embodiment, but it could also be adapted to an autoinjector made according to the first embodiment. 
     According to a first variant embodiment, this sound and/or tactile indication device  1500  comprises a central piece  1501  provided with at least one lateral piece  1502  connected to said central piece  1501  by a pliable and/or breakable link  1503 . In the example shown in  FIGS. 55 to 59   c , there are two lateral pieces  1502 , each connected to the central piece by a breakable link. 
     The central piece  1501  is connected to said piston rod  1005  by said wire  1021 , which is fixed on the one hand to said central piece  1501  and on the other hand to said piston rod  1005 . In the blocking position of the injection lock, before the start of the injection, the wire  1021  is wound around the piston rod and the central piece  1501  is arranged outside the control sleeve  1004 . When the control sleeve  1004  is displaced towards its unlocking position, shown especially in  FIG. 58 a   , an upper edge of said control sleeve  1004  makes contact with said lateral pieces  1502 . During the injection, when the piston rod  1005  moves relative to the control sleeve  1004 , the wire  1021  will progressively unwind until it is stretched on completion of injection, as shown in  FIG. 58 b   . From this moment, the wire  1021  will exert traction on the central piece  1501 , under the effect of the reaction of the upper edge of the control sleeve  1004  causing displacement and/or deformation of the lateral pieces. In the example shown with breakable links  1503 , the latter break, allowing the lateral pieces  1502  to move above the central piece  1501 , and therefore the control sleeve  1004  to move axially relative to the external shell  1022 , as evident especially in  FIG. 59 a   . As this displacement happens under the pressure exerted by the injection spring  1008  on the control sleeve  1004 , it is relatively brusque and creates a shock between the control sleeve  1004 , the lateral pieces  1502  and/or the external shell  1022 . This shock is audible and/or tactile for the user who therefore receives information on the completion of injection. After actuation of this sound and/or tactile indication device, the wire  1021  is no longer fully stretched, as illustrated schematically in  FIGS. 59 a    and  59   b.    
       FIGS. 60 to 64   c  illustrate a second variant of the sound and/or tactile indication device. In this second variant, the central piece is omitted. The sound and/or tactile indication device  1500  comprises a mobile element which is here formed by the control sleeve  1004 , which comprises at its distal end relative to the needle one or more deformable feet  1510 , which on completion of injection will stop against the external shell  1022 . This control sleeve  1004  is in a first position relative to the external shell  1022  prior to actuation of the autoinjector, as shown in  FIG. 64 a   . During actuation, the opening of the injection lock, and therefore the start of the injection phase, causes displacement of the control sleeve  1004  towards a second position, evident in  FIG. 64B . Here a central piece called a key  1120  advantageously replaces the wire of the preceding first variant. This key  1120 , especially evident in  FIGS. 63 a  and 63 b   , comprises a rod part  1121  which extends inside the piston rod  1005 , this rod part being similar to the wire of the first variant. The key  1120  also comprises a head part  1122 , arranged at the upper end (or distal end relative to the needle) of said key. This head part cooperates with said deformable feet  1510  of the control sleeve  1004  to prevent it from deforming radially towards the interior. Because of this, these deformable feet  1510  block said control sleeve in its second position relative to said external shell  1022 . The lower end (or proximal end relative to the needle) of the rod part  1121  cooperates with the piston rod  1005  on completion of injection, causing sliding of said key  1120  relative to the control sleeve  1004  and to the external shell  1022 . Therefore, after this sliding, the head part  1122  no longer cooperates with the feet  1510  of the control sleeve, which can deform radially towards the interior. The effect of this is to unblock the control sleeve  1004  which is then shifted towards a third position against said external shell  1022  under the effect of the force exerted by the injection spring  1008 . This creates an audible shock or otherwise detectable by the user who now knows that the injection is finished. 
     Advantageously, the external shell  1022  comprises one or more, especially three, display windows  1023  in which said deformable feet  1510  become visible at the same time as they tap against the external shell. This allows visual indication simultaneously to the sound and/or tactile indication. 
     Advantageously, said at least one display window  1023  is formed on or in the distal end edge of said external shell  1022 , being visible at the same time in the axial direction and in the radial direction of said shell. This execution avoids masking the display window or the windows  1023  when the autoinjector is handled by the user, ensuring proper display of information displayed in said at least one display window  1023  throughout the phase of use, from start to finish. With several display windows  1023 , especially three, distributed around the distal end edge of the body  1022 , this ensures perfect display irrespective of the orientation of the autoinjector at the moment of its use. 
     The variant embodiments of the second embodiment of the autoinjector described hereinabove therefore define a control sleeve  1004  having three different positions: prior to injection when it is in the locking position, during injection when it is in the unlocking position, and after injection when it has actuated the sound and/or tactile indication device. This easily displays these three distinct positions in a suitable display window  1221 . Of course, the external shell  1022  of this second embodiment could also comprise several display windows, as described in the first embodiment. 
       FIGS. 65 to 71  illustrate a third variant embodiment of the sound and/or tactile indication device. In this variant, which is similar to the second variant hereinabove, the mobile element of the sound and/or tactile indication device is not formed by the control sleeve  1004  but by the support pellet  1006  on which the injection spring  1008  is supported.  FIGS. 66 a  and 66 b    shows this support pellet, which comprises one or more deformable feet  1520 , which are similar to the deformable feet  1510  of the control sleeve  1004  of the second variant hereinabove. The operation is also similar, with the key  1120  which blocks by its head  1122  the radial deformation of said feet  1520 , which blocks the pellet support relative to the external shell. When the piston rod has the key  1120  slide on completion of injection, by traction on the rod part  1121 , the head part  1122  of the key  1120  will release said feet  1520 , which deform radially towards the interior and will allow said pellet support  1006  to be projected against said external shell, creating a sound and/or tactile indication. Advantageously, as described previously, a visual indication is also supplied by a display window or windows  1023  of the external shell which show the deformable feet  1520  of the pellet support  1006 . 
       FIGS. 69 to 71  illustrate in more detail the operation of the sound and/or tactile indication device. In  FIG. 69 , the deformable tab  1520  is prevented from deforming radially towards the interior by the presence of the head part  1122  of the key  1120 . In  FIG. 70 , the key has been displaced by the piston rod and consequently the deformable tab  1520  has deformed radially towards the interior. This has caused displacement of the support pellet  1006  in the external shell, with a shoulder  1521  of the deformable tab which stops on a part of said external shell, generating the sound and/or tactile indication, for example an audible or sensitive vibration. Simultaneously, the end of the deformable tab  1520  has been positioned in the window  1023  of the external shell  1022 , as is evident in  FIG. 70 .  FIG. 71  illustrates the end of the injection, with the piston rod  1005  which will pull on the rod part  1121  of the key  1120  to move the latter. 
     The present invention applies to devices used especially for treatment of auto-immune diseases, for example of rhumatoid arthritis, multiple sclerosis, Crohn&#39;s disease type, for treatments against cancer, for antiviral treatment, for example of hepatitis type, for treatment against diabetes, for treatments against anaemia or for treatment of stress, for example in the event of anaphylactic shock. 
     Even though the present invention has been described in reference to several advantageous modes and variant embodiments, which combine several functional modules, it is understood that the different modules described can be used independently of each other. In particular, the actuating sleeve and/or the device for displacement of syringe for pricking and/or retraction and/or the injection lock and/or the retarding device and/or the sound and/or tactile indication device could be used independently of each other. Pricking of the needle and/or retraction of the needle after injection could be controlled by one or more button(s). The sound and/or tactile indication device of the second embodiment could be used with an autoinjector of the type described in the first embodiment. Other modifications are also possible for the expert without departing from the scope of the present invention such as defined by the attached claims.