WO2012022854A1

WO2012022854A1 - Secure single-use injection device

Info

Publication number: WO2012022854A1
Application number: PCT/FR2011/000436
Authority: WO
Inventors: Marc Brunel
Original assignee: Marc Brunel
Priority date: 2010-07-26
Filing date: 2011-07-22
Publication date: 2012-02-23
Also published as: FR2962915A1; FR2962915B1

Abstract

The invention relates to a secure single-use injection device, including a syringe body (2, 10, 13, 16, 19) having an injection needle (21), and a protective case adapted such that said protective case and said syringe body are capable of sliding, relative to one another, between an injection position, in which the injection needle (21) extends at least partially away from the protective case, and a protection position for after use, in which the injection needle (21) is entirely housed within the protective case. According to the invention, the protective case comprises at least two concentric tubular elements (23, 28) capable of being nested within one another and sliding relative to one another between a retracted position determining the injection position and a deployed position determining the protection position for after use, achieved after the sequential deployment of the tubular elements (23, 28) and the relative sliding of the proximal tubular element (23) and the syringe body.

Description

Secure injection device for single use

The invention relates to a secure disposable injection device comprising:

A syringe body comprising a container containing a piston, a base carrying an injection needle arranged to allow the emptying of the container, and injection means able to manually generate a relative sliding of the piston and the container for emptying the said container,

A protective case adapted so that said protective case and the syringe body are able to slide relative to one another between an injection position in which the injection needle extends to less partially in the extension of the protective case and a position of protection after use in which the injection needle is entirely housed in the protective case,

Locking means adapted to present a locked state for holding the syringe body and the protective case in their injection position, and to switch to an unlocked state capable of authorizing, at the end of the emptying of the container, the relative sliding of the syringe body and the protective case towards their protective position after use,

And elastic means arranged to be held compressed between the syringe body and the protective case in the locked state of the locking means, and to relax and cause relative sliding of said syringe barrels and holster. protection in the unlocked state of the locking means.

Such secure injection devices are commonly used for obvious reasons of safety, because they lead to avoid any risk of puncture with the injection needle soiled, after injection, because the latter is fully housed in a case protection.

It turns out, however, that the design of today's secure injection devices requires dimensional data concerning the relative lengths of the various constituent elements to be respected, namely mainly the lengths of the syringe body, the injection needle and the protective case, for effective protection of the injection needle inside the protective case, after use. In practice, these dimensional constraints lead to the impossibility of making secure injection devices for injecting small volumes and / or having injection needles of great length, because of the short relative length of the bodies of syringe relative to the length of the injection needles.

At present, although totally irrational, the common solution used to solve this problem is a second-hand solution that consists of partially filling syringe bodies designed to contain higher volumes of liquid to be injected than the required small volumes, and whose dimensions thus meet the requirements for the realization of a secure injection device.

Against this traditionally traditional practice, the present invention has the main objective of providing a secure injection device of a design adapted to be equipped with:

containers having useful volumes covering a very wide range of volumes including all the volumes conventionally injected and in particular the very small volumes,

and / or injection needles of considerable length relative to the length of the containers.

For this purpose, the invention is directed to a secure disposable injection device of the type described above, the protective case of which consists of a telescopic protective case comprising at least two concentric tubular elements, including a distal element and a proximal element, able to fit and slide into each other between a retracted position determining the injection position and an extended position determining the protective position after use,

The distal element comprising a locking member having a locked state for holding the syringe body and the protective case in an injection position in which the tubular elements are fitted into each other and extend over the along the syringe body,

^• the injection means having an unlocking member of the locking member to the distal member, adapted to switch said locking member toward a stroke end in unlocked state of said injection means, ^• the distal member having abutment means of elastic means, and the tubular elements having, in pairs, complementary axial abutment members, said abutment means and axial abutment members being adapted to allow the elastic means to generating a successive deployment of the tubular elements and the relative sliding of the proximal tubular element and the syringe body,

^• and the proximal tubular member and the syringe body comprising complementary axial abutment means adapted to limit the relative sliding of said proximal tubular member and the syringe body.

(Note that for purposes of clarity and brevity, the terms such as proximal / distal, back / forward, posterior / anterior are used in the present application with reference to the end of the device. injection with the injection needle, the distal term, for example, designating a portion or a face of an element oriented towards this reference or the closest to it).

The secure injection device according to the invention therefore comprises in particular a telescopic protective case and elastic means adapted to allow, at the end of the stroke of the injection means corresponding to the end of emptying the container, an automatic deployment of the protective case between:

a retracted position in which the tubular elements of the protective case are nested one inside the other, and extend along the syringe body,

and an extended position in which the syringe body and the tubular elements of the protective case are deployed in the extension of each other.

According to this principle, the protective case can be designed, by varying the number of tubular elements and the lengths thereof, so as to accommodate the injection needle regardless of the length ratio between the said injection needle and the syringe body, the only constraint of providing a protective case whose length, in the nested position of the tubular elements, allows to release a useful length of injection of preselected length. Such a principle therefore leads to a rational solution of the problem of the protection after use of injection needles of injection devices intended for the injection of small volumes and / or with injection needles of great length.

It should be noted that it is known, in particular patent applications WO2004014458 and WO200220074, to make telescopic protective cases. However, these current protective cases are designed to be secured to a base equipped with an injection needle and adapted to be subsequently mounted on a syringe body, and are provided with a locking member requiring a specific manual action, for unlocking.

The principle according to the invention may, in addition, be adapted for the production of injection devices of various designs.

Thus, according to a first advantageous embodiment, the injection device may comprise a protective case adapted to partially house the syringe body in the injection position, and injection means comprising a piston rod integral with the piston. , equipped with a push button for actuating said piston, constituting the unlocking member of the locking means at the end of stroke of said push button.

On this basis, the injection devices can, moreover, advantageously be divided into two families:

the first family consisting of so-called "passive protection" injection devices, comprising injection means provided with finger support members secured to the syringe body, capable of generating a deployment of the cartridge case; protection in the extension of the syringe body at the end of the push button stroke,

and the second family consisting of so-called "active protection" injection devices, comprising injection means provided with finger-support members integral with the protective case, able to allow the syringe body to retract. in the rear extension of the protective case during the deployment of said protective case at the end of travel of the push button.

According to a second advantageous variant embodiment, the injection device comprises: ^• a tubular outer body,

Support means for the base adapted to maintain it inside the tubular outer body, said support means, said base and said tubular outer body being adapted so that an annular volume is formed in the body external annular around the periphery of the base,

^• a tubular container closed by a piston having a weakened central region, and a base provided with means for opening the central region of the piston, said tubular container and base being adapted so that the tubular container:

is positioned in the annular outer body in a position where the piston is attached to the base, with its central zone open by the opening means of said base,

moves in a sealed manner relative to the piston, so as to slide in the annular internal volume delimited around the base, inside the tubular outer body, and to constitute the unlocking member of the locking means at the end of stroke of said container.

Such an injection device has the particular advantage of having a container, on the one hand, serving as injection means, and secondly, consisting of a simple tubular container very simple design and therefore a price very advantageous.

It should be noted, moreover, concerning this variant embodiment, that the weakened zone of the piston and the associated opening means of the base can be of any type known per se, and for example consist of:

a zone of lesser thickness of the piston that can be pierced by opening means consisting of the posterior tip of a two-point needle,

- A central region of the piston forming a neck closed by a "plug" adapted to be pushed by aperture means of a shape adapted to penetrate the neck.

Moreover, on the basis of the concept of this variant embodiment, the invention advantageously makes it possible to produce an injection device of which: ^• the base of the support means comprises a tubular inner body disposed concentrically inside the tubular outer body, so as to delimit, inside said outer tubular body, an annular internal volume extending in the extension the annular volume formed around the periphery of the base,

The telescopic protective case extends, in its retracted position, inside the tubular internal body and houses elastic means extending around the injection needle, between the base and stop means positioned within the distal tubular section of said protective case.

According to this design, the telescopic protective case is thus integrated inside the syringe body and the external appearance, and especially the size of the injection device, are similar to those of an injection device current classic.

In addition, the injection device can be realized by means of two distinct components consisting of:

a simple tubular container containing the liquid to be injected and sterilized in the laboratory,

and a set of syringe body / protective case made for example by plastic injection and closed by a single seal, particularly paper, preserving sterility.

On the basis of this concept, the tubular elements of the protective case further advantageously have sections of decreasing diameter from the proximal tubular member to the distal tubular member. This arrangement makes it possible, in particular, to produce a distal tubular element having at least one distal section of internal section adapted to constitute an intermediate point of support for the injection needle.

Moreover, the locking means of this second type of injection device according to the invention advantageously comprise:

Radially deformable locking tabs provided with internal locking notches, said tabs being formed at the distal end of the outer tubular body of the syringe body so as to be deformed radially outwardly by the container at the end race of the latter, And a locking member integral with the distal end of the distal tubular element of the protective case adapted to lock in the notches of the locking tabs in the undistorted state of the latter.

Moreover, whatever the embodiment variant of the injection device according to the invention, and in order to prevent a retraction of the tubular elements of the protective case in the deployed position of the latter after injection, the stop members axial formed on said tubular elements and on the syringe body advantageously consist of irreversible locking members in translation.

This arrangement makes it possible to size the elastic means only so that they ensure the deployment of the telescopic protective case, without requiring these elastic means a residual force able to oppose the retraction of said telescopic protective case.

Other features, objects and advantages of the invention will emerge from the detailed description which follows with reference to the accompanying drawings which show by way of non-limiting examples three preferred embodiments. On these drawings:

- Figure 1 is a longitudinal section through an axial plane of a first embodiment of a secure injection device according to the invention shown before use,

FIG. 2 is a longitudinal section through an axial plane representing this first embodiment of an injection device at the end of injection, with the addition of a partial detail view in perspective of a portion of this injection device. ,

FIGS. 3a and 3b are diagrammatic longitudinal sections through two orthogonal axial planes A and B showing a second embodiment of an injection device according to the invention before use,

FIGS. 4a and 4b are diagrammatic longitudinal sections through the axial planes A and B showing this second embodiment of the injection device at the end of the injection,

FIG. 5 is a schematic longitudinal section showing a third embodiment of an injection device according to the invention before use, FIG. 6 is a diagrammatic longitudinal section showing this third embodiment of an injection device at the end of the injection,

The disposable secure injection devices shown in the figures consist of injection devices particularly, but not exclusively, designed to include containers having very small working volumes, and / or equipped with injection needles of considerable length. relative to the length of said containers.

According to the embodiment shown in FIGS.

2, the syringe body 1 comprises, firstly, a tubular outer body 2 having digital gripping members 3 at a rear end portion of said outer body.

This outer body 2 further comprises two diametrically opposed tabs 4, 5 extending from its front end.

As shown in Figure 2, these two lugs 4, 5 are delimited, each by two longitudinal slots 6, 7, conferring on them the ability to deform elastically radially outwardly.

Each of these tabs 4, 5 further comprises two internal transverse ribs delimiting a transverse notch: an anterior rib 8 of retentive shape, and a posterior rib 9 having a retentive radial anterior face and a posterior face 9a forming an inclined ramp. access to the notch.

The syringe body 1 further comprises a tubular inner body 10 of external diameter less than the internal diameter of the outer body 2, adapted to define an annular volume between said outer and inner body.

This inner body 10 further comprises a transverse internal rib 12 at its front end.

In addition, the front end of this inner body 10 is connected to the outer body 2 by a transverse wall 11 of annular shape adapted to close the front end of said annular volume, and to define a circular orifice of the same diameter as the diameter. internal of the said internal body. This transverse connecting wall 11 is positioned near the front end of the outer body 2, and it has a peripheral notch 11a facing each tab 4, 5, leading to separate said legs of said transverse wall, so that to allow the free deformations of these tabs 4, 5.

The annular inner body 10 extends substantially over three quarters of the length of the tubular outer body 2, from the transverse wall 11, and the rear face of this inner body 10 is closed by a base 13 pierced axially with a longitudinal bore 13a, composed of a circular transverse wall 14 for closing the inner body 10, extended posteriorly by an axial cylindrical stud 15 of diameter smaller than that of said closing wall.

The syringe body 1 also comprises a container 19, for example made of glass, consisting of a cylindrical tube closed by a rear end wall 20.

This receptacle 19 also houses, in a sealed manner, a piston 16 whose front end face comprises a cylindrical recess 17 conjugated with the cylindrical stud 15, adapted to fit on the latter, and whose rear face also comprises a cylindrical recess 18 delimiting, with the front recess 17, a piston portion of smaller thickness adapted to be pierced by a needle tip.

The syringe body 1 also comprises a two-point injection needle 21 sealed in the longitudinal bore 3a of the base 13, so as to comprise:

a distal injection section 21a extending in the extension of the syringe body 1,

- And a proximal piercing portion 2b adapted to pierce the piston 16 and lead into the rear recess 18 of the latter.

This syringe body 1 comprises, finally, a needle cover cap 22 adapted to cap the anterior end of the outer body 2 and to protect the needle before use of the injection device.

The protective case of this injection device consists, according to the principle of the invention, in a telescopic protective case, in the example adapted to be housed, in its retracted position, inside the inner body 10.

This telescopic protective case consists of two tubular elements consisting of a proximal element 23 of greater diameter, adapted to slide inside the inner body 10, and inside which is slidably mounted a distal element 28.

In addition, the proximal element 23 has posterior lumens 24 of a shape adapted to accommodate the rib 12 of the inner body 10, previously bordered by a rib 25 having an anterior ramp crossing the rib 12 of the inner body 10, and a posterior retentive face for blocking this rib 12.

This proximal element 23 also includes anterior lumens 26 bordered posteriorly by a rib 27 subsequently provided with a crossing ramp, and previously with a radial retentive face.

The distal element 28 comprises, meanwhile, an anterior end section 29 of smaller external and internal diameters, on which is secured an annular transverse wall 30 of external diameter adapted to be housed in the notches of the tabs 4, 5, in the absence of deformation of the latter.

This distal element 28 further comprises a posterior external rib 31 of shape adapted to be housed in each lumen 26 after crossing the ribs 27.

Finally, the injection device shown in FIGS. 1 and 2 comprises a spring 32 extending inside the tubular elements 23, 28, around the injection needle 21, between the base 13 and the anterior section 29 of the distal element 28.

Initially, this injection device consists of two distinct elements consisting of:

a tubular container 19 enclosing the liquid to be injected and closed by a piston 16,

- And a syringe body assembly 1 / protective case 23, 28 closed by a single seal seal including paper, wherein the protective case 23, 28 is held in its retracted position, to against the force exerted by the spring 32, by locking the annular transverse wall 30 inside the notches of the tabs 4, 5.

For injection, the container is positioned, as shown in Figure 1, so as to engage the piston 16 and the base 13 and to drill, during this interlocking, said piston by means of the piercing section 21b of the injection needle 21.

The injection is then performed by exerting an antagonistic force on the rear wall 20 of the container 19 and on the digital gripping members 3, so as to cause the container 19 to slide inside the outer body 2.

At the end of the injection, and as shown in FIG. 2, the front end of the receptacle 19 causes the tabs 4, 5 to move apart, causing the release of the transverse wall 30, and, under the effect of the force exercised by the spring 32, the successive deployments:

of the distal element 28 with respect to the proximal element

23, limited at the end of the race by the irreversible blocking of the ribs 31 in the lights 26,

- Then the proximal element 23 relative to the inner body 10, limited at the end of the race by the irreversible blocking of the ribs 12 in the slots 24.

The two other embodiments, shown schematically respectively in FIGS. 3a, 2b, 4a, 4b and in FIGS. 5 and 6, are directed to injection devices comprising a protective case adapted to partially house the syringe body in the position of FIG. injection, and a syringe body comprising a syringe 35 of conventional type forming a container housing a piston 40 integral with a piston rod 41 having a rear push button 42 for actuating said piston and unlocking the locking means at the end of the race of the said push button.

In addition, the syringe 35 comprises a base 37 in which is sealed an injection needle 39, and at the junction between container and base 37, an outer transverse rib 38 formed on the periphery of said container.

According to the embodiment shown in FIGS. 3a, 3b, 4a, 4b, the injection device consists of a so-called "passive protection" injection device, and the digital capture devices intended to enable to exert an antagonistic force to that exerted on the push button 42, for an injection, consist of posterior digital gripping members 36 integral with the syringe 35.

According to this embodiment, the telescopic protective case consists of two tubular elements consisting of a proximal element 43 of smaller diameter, adapted to slide externally along the syringe 35, and outside of which is slidably mounted a distal element 48.

In addition, the proximal element 43 has two posterior transverse ribs 44, 45 delimiting a transverse notch of a shape adapted to accommodate the anterior external rib 38 formed on the periphery of the syringe 35.

This proximal element 43 also comprises two transverse anterior ribs 46, 47 delimiting a transverse notch,

The distal element 48 comprises, meanwhile, a posterior internal transverse rib 49 adapted to be housed in the notch defined by the ribs 46, 47 of the proximal section 43.

This distal member 48 also has an anterior internal transverse rib 50.

This distal element 48 carries, in addition, a cylindrical skirt

51 concentrically positioned around said distal element and connected substantially at mid-height thereof, by an annular transverse wall

52 adapted to close the annular volume 55 delimited between said distal element and cylindrical skirt.

This cylindrical skirt 51 further includes, in the posterior extension of the distal element 48, radially deformable elastic tabs 53 provided, at their posterior end, with hooks 54 adapted to hook onto the digital gripping members 36 of FIGS. the syringe 35, in the retracted position of the protective case.

Finally, the injection device comprises a spring

56 housed in the annular volume 55 delimited between the distal element 48 and the cylindrical skirt 51, abutting between the digital gripping members 36 and the annular transverse wall 52.

According to this embodiment, and as shown in FIGS. 3a and 3b, the tubular elements 43, 48 of the protective case are initially held in their retracted position, against the force exerted by the spring 56, by locking the hooks 54 on the digital gripping members 36.

In addition, the anterior rib 50 of the distal element 48 prevents any sliding of the proximal section 43.

The injection is then performed by exerting an antagonistic force on the push button 42 and on the digital gripping members 36, so as to cause the piston 40 to slide inside the syringe 35.

At the end of the injection, and as represented in FIGS. 4a and 4b, the push button 42 causes the hooks 54 to move away, resulting, under the effect of the force exerted by the spring 56, on the successive deployments:

of the distal element 48 with respect to the proximal element 43, limited at the end of the stroke by the irreversible blocking of the rib 49 in the notch delimited by the ribs 46, 47 of the proximal section 43,

then the proximal element 43 with respect to the syringe

35, limited at the end of the race by the irreversible locking of the rib 38 in the notch defined by the ribs 44, 45 of said proximal section.

According to the embodiment shown in FIGS. 5 and 6, the injection device consists of a so-called "active protection" injection device, and the digital gripping members intended to make it possible to exert an antagonistic force to that exerted on the push button 42, for injection, consist of digital gripping members 69 integral with the protective case. The syringe 35 has in turn a flange 36 intended not to form finger grips but to allow the locking of the protective case.

Apart from this difference, this injection device is similar to that described above and comprises a telescopic protective case consisting of two tubular elements consisting of a proximal element 60 of smaller diameter, adapted to slide outwardly along. the syringe 35, and outside which is slidably mounted a distal member 65.

In addition, the proximal element 60 has two posterior transverse ribs 61, 62 delimiting a transverse notch of a shape adapted to accommodate the anterior external rib 38 formed on the periphery of the syringe 35. This proximal element 60 also comprises two anterior transverse ribs 63, 64 delimiting a transverse notch.

The distal element 65 comprises, meanwhile, a posterior internal transverse rib 66 adapted to be housed in the notch defined by the ribs 63, 64 of the proximal section 60.

This distal member 65 also has an anterior internal transverse rib 67.

This distal element 65 carries, in addition, a cylindrical skirt 68 concentrically positioned around said distal element and connected substantially at half height thereof, by an annular transverse wall 70 adapted to close the annular volume 73 delimited between said distal element and cylindrical skirt.

This cylindrical skirt, 68 further comprises, in the posterior extension of the distal element 65, resilient tabs 71 radially deformable, provided, at their rear end, hooks 72 adapted to hook on the flange 36 of the syringe 35, in the retracted position of the protective case.

In addition, the digital gripping members 69 are secured to the cylindrical skirt 68.

Finally, the injection device comprises a spring

74 housed in the annular volume 73 delimited between the distal element 65 and the cylindrical skirt 68, abutting between the collar 36 and the annular transverse wall 70.

The course of an injection by means of this injection device is identical to that described above, except that, at the end of injection, the deployment of the protective case is obtained during the release of the pressure exerted on the push button 42, and is translated, under the effect of the force exerted by the spring 74, successively by:

the recoil of the syringe 35 with respect to the proximal element 60, limited at the end of the stroke by the irreversible blocking of the rib 38 in the notch delimited by the ribs 61, 62 of the proximal section 60,

- Then the recoil of the proximal element 60 relative to the distal member 65, limited at the end of stroke by the irreversible locking of the rib 66 in the notch defined by the ribs 63, 64 of the proximal section 60. The above described exemplary injection devices therefore all comprise, according to the invention, a telescopic protective case adapted to be deployed between a retracted position and an extended position in which the syringe body and the tubular elements of the protective case are deployed in the extension of each other, said telescopic case can, therefore, equip containers with useful volumes covering a very wide range of volumes.

Claims

1 / Secure disposable injection device comprising:

A syringe body (1-22; 35-42) having a container (19,20; 35,36) enclosing a plunger (16; 40); a base (13; 37) carrying an injection needle (21; 39) arranged to allow the emptying of the container (19, 20; 35, 36), and injection means (3, 19, 20; 36, 41, 42; 41, 42, 69) adapted to allow manually generating a relative sliding of the piston (16; 40) and the container (19, 20; 35, 36) for the purpose of emptying said container,

A protective case (23, 28, 43, 48, 60, 65) adapted for said protective case and the syringe body (1-22; 35-42) to be slidable relative to one another relative to to the other between an injection position in which the injection needle (21; 39) extends at least partially in the extension of the protective case (23, 28; 43, 48; 60, 65 ) and a post-use protection position in which the injection needle (21; 39) is fully accommodated in the protective case (23, 28; 43, 48; 60, 65),

Locking means (4, 5, 30, 53, 54, 71, 72) adapted to have a locked state for holding the syringe body (1- 22; 35-42) and the protective case (23; , 28; 43, 48; 60, 65) in their injection position, and to switch to an unlocked state able to allow, at the end of emptying the container (19, 20; 35, 36), the relative sliding of the body syringe (1-22; 35-42) and the protective case (23, 28; 43, 48; 60, 65) to their protective position after use,

And elastic means (32; 56; 74) arranged to be held compressed between the syringe body (1-22; 35-42) and the protective case (23,28; 43,48; 60; 65) in the locked state of the locking means (4, 5, 30; 53, 54; 71, 72), and to relax and cause relative sliding of said syringe bodies and protective case in the unlocked state locking means (4, 5, 30; 53, 54; 71, 72),

said secure injection device being characterized in that the protective case consists of a telescopic protective case comprising at least two concentric tubular elements (23, 28, 43, 48, 60, 65), including a distal element ( 28; 48; 65) and a proximal member (23; 43; 60), able to fit and slide into each other between a retracted position determining the injection position and an extended position determining the protective position after use,

^• the distal member (28; 48; 65) having a locking member (30; 53, 54; 71, 72) having a locked state for holding the syringe body (1-22; 35-42) and the protective case (23, 28; 43, 48; 60, 65) in an injection position in which the tubular elements (23, 28; 43, 48; 60, 65) are nested within each other and 'extend along the syringe body,

· The injection means (3, 19, 20; 36, 41, 42; 41, 42, 69) comprising an unlocking member (19; 42) of the locking member (30; 53, 54; 72) of the distal member (28; 48; 65), adapted to switch said locking member to an unlocked state at the end of stroke of said injection means,

· The distal member (28; 48; 65) having abutment means (29; 51; 68) resilient means (32; 56; 74), and the tubular members (23; 28; 43,48; 65) comprising, in pairs, axial abutment members (26, 27, 31, 46, 47, 49, 63, 64, 66) complementary, said abutment means and axial abutment members being adapted to allow the means elastic members (32; 56; 74) for generating a successive deployment of the tubular members (23,28; 43,48; 60,65) and the relative sliding of the proximal tubular member (23; 43; 60) and the body syringe (1-22; 35-42),

And the proximal tubular member (23; 43; 60) and the syringe body (1-22; 35-42) having axial abutment members (12,24;

38, 44, 45; 38, 61, 62) adapted to limit the relative sliding of said proximal tubular member and said syringe body.

21 injection device according to claim 1 characterized in that the axial stop members (12, 24, 26, 27, 31; 38, 44, 45, 46, 47, 49; 38, 61, 62, 63, 64 66) formed on the tubular members (23,28; 43,48; 60,65) of the protective case and on the syringe body (1-22; 35-42) consist of irreversible locking members in translation of said tubular elements and syringe body.

3 / injection device according to one of claims 1 or 2 wherein: ^• the protective case (43, 48; 60, 65) partially accommodates the syringe body (35-42) in the injection position,

• the injection means comprise a piston rod (41, 42) integral with the piston (40), provided with a push button (42) for actuating said piston, constituting the unlocking member of the locking means (53, 54, 71, 72) at the end of the stroke of said push button.

4 / injection device according to claim 3 characterized in that the injection means comprise finger support members (36) integral with the syringe body (35-42), able to generate a deployment of the protective case (43, 48) in the extension of said syringe body at the end of stroke of the push button.

5 / injection device according to claim 3 characterized in that the injection means comprise finger-support members (69) integral with the protective case (60, 65), adapted to allow the syringe body (35) 42) to retract into the rear extension of the protective case (60, 65) during the deployment of said protective case at the end of travel of the push button (42).

6 / injection device according to one of claims 1 or 2 characterized in that the syringe body (1-22) comprises:

A tubular outer body (2),

Support means (10, 11) of the base (13) adapted to hold it inside the tubular outer body (2), said support means, said base and said tubular outer body being adapted so that an annular volume is formed in the annular outer body (2) on the periphery of the base (13),

A tubular container (19, 20) closed off by a piston (16) having a weakened median zone, and a base (13) provided with means for opening (21b) the median zone of the piston (16), said container tubular and base being adapted so that the tubular container (19, 20):

- is positioned in the annular outer body (2) in a position where the piston (16) is attached to the base (13), with its central zone open by the opening means (21b) of said base,

- moves in a sealed manner relative to the piston (16), so as to slide in the annular internal volume defined around the base (13), inside the tubular outer body (2), and to constitute the unlocking member of the locking means (4, 5, 30) at the end of travel of said container.

7 / injection device according to claim 6 characterized in that:

· The support means of the base comprise a tubular inner body (10) arranged concentrically inside the tubular outer body (2), so as to delimit, inside said tubular outer body, an annular internal volume extending in the extension of the annular volume formed on the periphery of the base,

The telescopic protective case (23, 28) extends, in its retracted position, inside the tubular inner body (10) and houses elastic means (32) extending around the needle; injection (21), between the base (13) and abutment means (29) positioned within the distal tubular section (28) of said protective case.

8 / injection device according to claim 7 characterized in that the tubular elements (23, 28) of the protective case comprise sections of decreasing diameter of the proximal tubular element (23) to the tubular element distal (28).

9 / injection device according to one of claims 7 or 8 characterized in that the locking means comprise:

Radially deformable locking tabs (4, 5) having internal locking notches, said tabs being formed at the distal end of the outer tubular body (2) of the syringe barrel (1-22) so as to to be deformed radially outwardly by the container (19, 20) at the end of its travel,

And a locking member (30) integral with the distal end of the distal tubular element (28) of the protective case, adapted to lock in the notches of the locking tabs (4, 5) in the undistorted state of the latter.