ES2953610T3 - Automatic injection device with timing means - Google Patents

Abstract

A device (1) for automatic injection, the injection device (1) comprising: a container (5), an injection needle (6), a housing (9, 11, 68, 72, 93) intended to receive, at less partially, the container (5), the container (5) being mobile in relation to the housing (9, 11, 68, 72, 93) between an initial position, in which the needle (6) is contained within the housing ( 9, 11, 68, 72, 93), an insertion position, spaced distally with respect to the initial position and in which the needle (6) is exposed at a predetermined length, and a final position in which the needle ( 6) is contained within the housing (9, 11, 68, 72, 93); and a folding chamber (26, 59, 79, 96) in which, with the container (5) in the initial position, the proximal wall is separated proximally from the sealing element (27, 29a, 60, 76, 97) and The chamber (26, 59, 79, 96) is filled with a fluid, where, with the container (5) in the insertion position, the fluid is at least partially expelled from the chamber (26, 59, 79, 96) and the proximal wall is made to engage the sealing element (27, 29a, 60, 76, 97) and, in which, with the proximal wall that engages the sealing element (27, 29a, 60 , 76, 97), the container (5) being caused to move from the insertion position to the final position. (Automatic translation with Google Translate, without legal value)

Description

DESCRIPTION

Automatic injection device with timing means

The present invention relates to a device for the automatic injection of a product in a very safe way, especially for self-injection.

In this application, the distal end of a component or device means the end furthest from the user's hand, and the proximal end means the end closest to the user's hand. Also, in this application, "distal direction" means the direction of injection, and "proximal direction" means the direction opposite to the direction of injection.

Some diseases require regular injections of medications or products, for example, daily. To simplify treatment, some auto-injectors have been provided to allow the patient to perform the injection themselves.

Of course, since the patient is usually neither a nurse nor a person educated in medical devices, such autoinjectors must be very simple to use and also very safe. In particular, the needle insertion must be made to the appropriate depth, the correct dose of product must be injected, i.e. a complete injection must be made, and the injector must be deactivated after use before being discarded. Preferably, the needle should not be exposed, either before or after use, to avoid accidental needle stick injuries.

For these reasons, most autoinjectors have a high degree of automation. Typically, the user only has to apply the device to the injection site and then press a button, for example, to activate needle insertion and automatic injection of the product. In some devices, in particular when the injection is automatic, some damping means are provided to control the injection speed and therefore limit a possible unpleasant sensation for the patient.

Documents EP 1586341 and EP 1588342 disclose injection devices provided with damping means to control the injection speed. *

In terms of protecting the needle after use, some devices are provided with a sleeve that extends over the needle once the user has removed the device from the injection site. Alternatively, the needle can automatically retract into the device at the end of the injection without any further action by the user. Therefore, when the user removes the device from the injection site, the needle is already retracted into the device and the user is not at risk of injury.

However, one of the problems with autoinjectors based on needle retraction is ensuring that all of the product has been injected before the needle retraction. In fact, in most of these devices, due to the dimensional tolerances of the assembled parts of the device, it is necessary to activate the needle retraction just before the end of the full injection, thus creating a dead volume in the lower part of the body. of the syringe. The result is that the product dose is not fully injected, which may result in inadequate dosing for the patient or user.

Consequently, there is a need for autoinjection devices that allow the needle to be retracted into the device at the end of an automatically actuated injection, with the assurance that the entire product has been injected before the needle is retracted.

The present invention responds to this need by proposing a device for automatic injection of a product at an injection site, said device allowing both the retraction of the needle at the end of an automatically actuated injection and the complete injection of the product.

The present invention relates to a device for the automatic injection of a product at an injection site, according to claim 1.

The device of the invention allows the needle guard to be removed prior to use of the device with limited or no rotation of the needle guard. Consequently, potential rotation of the needle tip within the rubber forming the needle guard is prevented and insertion that could result from such potential rotation is also prevented. Therefore, the integrity and sterility of the needle is preserved and product administration can be completed safely.

The device of the invention allows the injection of the entire product before the needle is retracted. Thanks to the timing means of the device of the invention, the retraction of the needle is not activated when there is still some product at the bottom of the container of the injection device. Some time, for example between 1 and 10 seconds, is allowed before needle retraction is activated.

The device of the invention is therefore very safe and easy to use. The user only needs to apply the device to the injection site and then activate the first deactivation means to start the operation. At the end of the full injection, and only when all the product has been injected, the needle retracts into the device and the user can safely remove the device from the injection site.

In one embodiment of the invention, said housing is coupled to a deguard comprising a cap to which said needle guard is attached, said housing comprising slots to guide the translation of said cap when said cap is removed along with the removal of said protector with a view to using said device.

In an embodiment of the invention, said timing means comprise a chamber comprising a ventilation outlet, said chamber being hermetically closed by a sealing cover in an initial state, and defining an initial volume of said chamber and in which a certain amount of fluid within said initial volume, said sealing cover can move within said chamber from said initial state to a final state in which at least part of said fluid has escaped through said vent outlet.

Said ventilation outlet can be a simple hole, of small diameter. For example, said diameter can range between 15 micrometers and 25 micrometers. Alternatively, said ventilation outlet may be an exhaust valve comprising a membrane that allows the passage of fluid. Said membrane may be made of a material selected from the group consisting of polytetrafluoroethylene, polyethylene, paper, tissue, foam, porous plastic and combinations thereof. The diameter of said membrane can be approximately 1 mm.

Said fluid can be a gas, such as air. Preferably, said fluid is pressurized. Alternatively, said fluid may be a viscous liquid, such as oil or grease.

Preferably, said device further comprises elastic return means coupled to said chamber for moving said sealing cover from said initial state to said final state, said deactivation means being coupled to said chamber such that said deactivation means releases said retaining means. only when said sealing cover is in said final state.

In one embodiment of the invention, said chamber comprises the proximal portion of a sleeve having a closed proximal end and an open distal end, said closed proximal end comprising a vent outlet and said open distal end comprising an outer radial edge, further comprising said device a piston provided in said container and movable with respect to said container, and a piston rod coupled to said piston to cause said piston to move with respect to said container, the movement of said piston causing said product to be expelled from said container through said injection needle,

- said sealing cover, in its initial state, closing the inner proximal space of said sleeve thus defining said chamber, said sealing cover being coupled to said piston rod,

- said outer radial edge being able to cooperate with said second retaining means and release them when said sealing cover comes into contact with said closed proximal end of said sleeve.

Advantageously, said device further comprises first elastic return means coupled to said housing to move said container from said initial position to said insertion position, second elastic return means coupled to said housing to move said container from said insertion position to said position. end, and a ring, said ring being coupled to said container at least from said insertion position to said end position of said container,

- said retention means comprise a flexible tongue provided in said housing and engaged in a support surface located on said ring, when said container is in said Insertion position,

- said outer radial edge deflecting said flexible tab and thus disengaging said tab from said ring, when said sealing cover comes into contact with said closed proximal end of said sleeve, thus releasing said second elastic return means and causing said container to move to said final position.

Preferably, the device of the invention further comprises first retention means, arranged to maintain said container in said initial position, and first deactivation means, arranged to release said first retention means and cause the insertion of said needle at the injection site. , wherein said first retaining means comprises a flexible tooth provided in said housing, said flexible tooth being engaged with said outer radial edge of said sleeve when said container is in said initial position,

- said first deactivation means comprise a push button comprising at least one distal leg,

- said distal leg cooperating with at least said flexible tooth to deflect and disengage said flexible tooth from said outer radial edge, under the effect of manual pressure exerted on said push button, thus releasing said first elastic return means and causing said container to move from said initial position to said insertion position.

In another embodiment of the invention, said sleeve forms said first deactivation means, said first retaining means comprising an external projection provided on said sleeve, said external projection being supported against a stop provided on said housing and preventing distal translation of said sleeve. when said container is in said initial position, said stop can be overcome by said external projection under the manual pressure exerted on said sleeve, thus releasing said first elastic return means and causing said container to move from said initial position to said position of insertion.

In another embodiment of the invention, said device further comprises a piston provided in said container and movable with respect to said container, a piston rod coupled to said piston to cause said piston to move with respect to said container, causing the movement of said piston that said product is expelled from said container through said injection needle, second elastic return means coupled to said housing to move said container from said insertion position to said final position, and automatic injection means, arranged to cause automatically causing said piston rod to distally push said piston,

- said deactivation means being formed in the proximal part of said piston rod and said retaining means being partially formed in said housing,

- said piston rod being provided in two parts, a proximal part and a distal part, when said piston comes into contact with the distal end of said container, under the force exerted by said automatic injection means on the proximal part of said rod of the plunger, wherein said distal portion of said plunger rod is stopped and said proximal portion of said plunger is allowed to continue its distal movement under the force exerted by said automatic injection means for a certain time until said deactivation means cooperate with said retaining means to cause said container to move from said insertion position to said final position with said proximal part forming part of said piston rod of said timing means.

Advantageously, said device further comprises a ring, said ring being coupled to said container when said container moves from said Insertion position to said final position,

- said retaining means comprise a radially flexible leg located on the inner wall of said casing, hooked on a support surface of said ring, when said container is in said insertion position,

- said deactivation means comprise a head of said proximal part of said piston rod, said head of the piston rod deflecting said radially flexible leg under the force exerted by said automatic injection means, thus disengaging said radially flexible leg from said surface of support, releasing said second elastic return means and causing said container to move from said insertion position to said final position.

Preferably, said distal part of said piston rod comprises a cylinder capable of receiving a portion of said proximal part of said piston rod, and said distal part of said piston rod comprises softening means designed to reduce the speed of distal movement of said proximal portion of said piston rod within said distal portion of said piston rod.

In an embodiment of the invention, said softening means comprise a rubbery material that covers the internal wall of said cylinder, said proximal part of said piston rod is provided at its distal end with at least one radial projection that makes contact with said material rubbery when said proximal portion of said piston rod moves distally. Upon coming into contact with said rubbery material, the proximal part of the piston rod slows down and therefore time is given for the rest of the product to be completely expelled through the needle before the second deactivation means release the second retaining means and cause the container to move to its final position.

In another embodiment of the invention, said softening means comprise a compressible material provided at the bottom of said cylinder, the speed of said proximal part of said piston rod being reduced when the distal end of said proximal part of said piston rod enters contact with said compressible material. Said compressible material may be a spring. By reducing the velocity of the proximal portion of the plunger rod, some time is allowed for all of the product to be expelled before the container moves to its final position.

In another embodiment of the invention, the inner diameter of said cylinder decreases towards the bottom of said cylinder and the distal end of said proximal part of said piston rod is provided with flexible tabs that rub against the internal walls of said cylinder as that said proximal portion of said piston rod moves distally.

In another embodiment of the invention, the internal walls of said cylinder are provided with longitudinal flexible legs that come into contact with a radial projection arranged at the distal end of said proximal part of said piston rod, thus reducing the velocity of said proximal part. of said piston rod, as said proximal portion of said piston rod moves distally.

In another embodiment of the invention, said internal walls of said cylinder are provided with a thread that cooperates with a screw provided at the distal end of said proximal part of said piston rod, thus reducing the speed of said proximal part of said piston rod. plunger, as said proximal portion of said plunger rod moves distally.

In another embodiment of the invention, said cylindrical walls are provided with a number of steps and the distal end of said proximal part of said piston rod is provided with a number of radial fins, increasing the number of radial fins that interact with said steps. as said proximal portion of said piston rod moves distally. Consequently, the more the proximal portion of said piston rod is displaced distally, the greater the resistance force resulting from the interaction of the fins with the steps. Therefore, the proximal part of the plunger rod is slowed down and therefore time is allowed for the entire product to be expelled before the container moves to its final position.

In an embodiment of the invention, the device further comprises first retention means arranged to maintain said container in said initial position, and first deactivation means arranged to release said first retention means and cause the insertion of said needle into the injection site. , in which said first deactivation means are manually operated.

In another embodiment of the invention, the device further comprises means for indicating to a user that substantially all of the product contained within said container has passed through said outlet port and said injection needle.

In another embodiment of the invention, the device further comprises a tamper evident means removably coupled with said housing to protect said needle prior to use of said device, said tamper evident means being in a pre-use condition and a post-use condition, said post-use condition preventing the reuse of said tamper evident means with said device.

Preferably, said post-use condition provides a visual indication that said tamper evident means has been removed from said device.

In one embodiment of the invention, said tamper evident means comprises a deguard and a needle protector, said post-use condition demonstrating an indication that said tamper evident means has been removed from said device.

In one embodiment of the invention, the device further comprises a needle guard coupled with said housing and covering the needle prior to use of said device, removal of said needle guard being carried out with limited or no rotation of said needle guard. the needle.

In another embodiment of the invention:

- said device further comprising a piston arranged in said container and mobile within said container, the distal movement of said piston causing said product to be expelled from said container through said injection needle,

- said chamber being partially defined by the interior part of the container located proximal to said piston and partially defined by the proximal part of said housing, said sealing cover joining the proximal end of said interior part to said housing through a friction force of absolute value F,

- said chamber being filled in said initial state of said sealing cover with a pressurized fluid that exerts a pressure of absolute value Pc on said container in the distal direction, with the intermediation of the piston,

- said device further comprising elastic return means to move said container from the insertion position to the final position, said elastic return means are coupled to said container to exert on said container a return force of absolute value Pe when said elastic means return are at least in a partially compressed state,

- in which Pc is strictly greater than (Pe F) in the initial state of the sealing cover,

- in which Pc decreases as some of the pressurized fluid is escaping from the chamber through the vent outlet,

said retention means are formed by Pc being greater than (Pe F), said retention means being released when Pe is equal to or greater than (Pc F).

Preferably, said pressurized fluid is provided to said chamber from a container present within said chamber, said container being sealed when said container is in its initial position, said device being provided with a piercing button capable of creating an opening in said container when A manual force is exerted on said piercing button, then allowing said pressurized fluid to escape from said container and fill said chamber.

In another embodiment of the invention, said sealing cover is porous and forms said ventilation outlet. Preferably said device further comprises:

- a piston arranged in said container and mobile within said container, the distal movement of said piston causing said product to be expelled from said container through said injection needle,

- a piston rod provided with a head and a distal end, said piston rod being independent of said piston,

said chamber is defined by the volume delimited by the interior part of the container located proximal to said piston, the wall of the housing and the head of the piston rod, the proximal end of said container joining the wall of the housing through a first porous sealing cover and joining the piston rod head to the casing wall through a second porous sealing cover.

In one embodiment of the invention, the two sealing covers have a friction force against the wall of said housing of absolute value F,

- said chamber is filled in the initial state of said second sealing cover with a pressurized fluid, exerting a pressure of absolute value Pc on said container in the distal direction, with the intermediation of the piston, - said device also comprising first elastic return means to move said container from the initial position to the Insertion position, said first elastic return means being coupled to said piston rod to exert on said piston rod a return force of absolute value Pi when said first elastic return means are at least in a partially compressed state,

- said device further comprising second elastic return means for moving said container from the insertion position to the final position, said second elastic return means being coupled to said container to exert on said container a return force of absolute value Pe when said second elastic return means are at least in a partially compressed state,

wherein (Pc Pi) is greater than (Pe F) in the initial state of said second sealing cover, wherein Pc decreases as part of the pressurized fluid escapes from the chamber through the vent outlet, said sealing means retention means are formed by (Pc Pi) being greater than (Pe F), said retention means are released when Pe becomes equal to or greater than (Pc F Pi).

In another embodiment of the invention, the deactivation means comprise a valve located in said first porous sealing cover, said valve being closed when said second porous sealing cover is in its initial state and open when said second porous sealing cover is in its final state, releasing the opening of said valve part of said retention means.

Another aspect of the invention is a kit for a device for automatic injection of a product at an injection site, the product being transported by a container having an open proximal end and a substantially closed distal end and having a reservoir defined between them, and a needle arranged at the distal end and in fluid communication with the container to provide an exit port for the product from the container, and a piston arranged in the container and movable with respect to the container, causing movement of the piston that the product is expelled from the container through the needle, characterized in that said kit comprises:

- a housing assembly comprising:

- a set of upper casing,

- a lower housing assembly, at least one of said upper and lower housing assembly being adapted to receive part of the container, the container being mobile, when received within said at least one of said upper and lower housing assembly, between an initial position, in which a tip of said needle does not extend beyond a distal end of said lower housing assembly, spaced distally with respect to said initial position and in which the tip of the needle extends beyond said distal end of said set of lower housing, and a final position in which said needle is contained within one of said upper and lower housing assemblies, and

- means for connecting said upper casing and said lower casing together.

Preferably, said kit further comprises means for transporting at least one of said upper housing assembly and said lower housing assembly, said transport means carrying said upper housing assembly and said lower housing assembly in a predetermined orientation.

The device of the invention will now be described in more detail with reference to the following description and accompanying drawings in which:

- Figure 1 is an exploded perspective view of an embodiment of the device of the invention, - Figure 2 is a cross-sectional view of the device of Figure 1 before use.

- Figure 3 is a partial section view of the device of Figure 1 showing the deactivation of the first retention means,

- Figure 4 is a cross-sectional view of the device of Figure 1 with the container in the insertion position, - Figure 5 is a cross-sectional view of the device of Figure 1 in the injection stage, before timing ,

- Figure 6 is a cross-sectional view of the device of Figure 1 at the end of the timing,

- Figure 7 is a cross-sectional view of the device of Figure 1 with the container in the final position, - Figure 8 is a cross-sectional view of a variant of the device of the invention,

- Figures 9 to 11 are cross-sectional views of another variant of the device of the invention, respectively during the injection step, during the timing step and in the final position,

- Figures 12 to 16 are partial cross-sectional views of various mechanical timing means,

- Figure 17a is a front view of the distal end of the proximal part of a piston rod suitable to form part of the timing means of the device of the invention,

- Figure 17b is a side view of the distal end of the proximal part of the piston rod of Figure 17a, - Figure 17c is a perspective cross-sectional view of the distal part of the piston rod of Figure 17a,

- Figures 18 to 21 are cross-sectional views of an alternative of the device of the invention, respectively in the initial position, in the insertion position, in the final injection position and in the final position,

- Figures 22 to 25 are cross-sectional views of another variant of the device of the invention, respectively in the initial position, in the insertion position, in the final injection position and in the final position,

- Figures 26 and 27 are partial side views of a tamper evident means suitable for the device of the invention, respectively in the pre-use condition and in the post-use condition,

- Figures 28 and 29 are perspective views of means for carrying at least one of the upper casing and the lower casing of a device of the invention,

- Figures 30 to 33 are section views of another variant of the device of the invention, respectively in the initial position, in the insertion position, in the final injection position and in the final position.

Figure 1 shows an exploded perspective view of a device for automatic injection according to an embodiment of the present invention and generally designated with reference number 1. The ingenious device 1 comprises a housing 300 composed of an upper housing assembly 100 and a lower housing assembly 200 which can be connected to each other by means of a snap connection (110, 210) such as screw type connection, bayonet connection, or other means of joining two parts together, so that they cannot come loose or not. When the injection device is of the single-use type, the means for connecting the upper housing assembly 100 to the lower housing assembly 200 are made unreachable to the user. A container 5 like, for For example, a syringe, is housed in at least one of the upper and lower housing assemblies (100, 200). Preferably, the container 5 is partially received in each of the upper and lower housing assemblies (100, 200), as discussed in more detail herein.

With reference to Figures 1 and 2, the injection device comprises a container 5 which is intended to receive a product 3 to be injected. The container 5 has a distal end 5a and an open proximal end, which is provided, in the example shown, with a flange 5b. Said tab 5b may be useful for gripping said container 5. The distal end 5a of the container 5 is substantially closed and is provided with an injection needle 6. This injection needle 6 provides an exit port of said container 5 for the product 3. In Figures 1 and 2, the distal end of said container 5 is also provided with a needle guard 2 that covers and protects the needle 6. before use of device 1. Needle guard 2 also provides a means of sealing the distal end of container 5 before use.

The device 1 of Figures 1 and 2 also comprises a piston 7 which is provided in the container 5 and which is movable with respect to said container 5. A piston rod 8 is coupled to said piston 7 to cause said piston to move With respect to said container 5, the movement of said piston 7 is intended to cause said product 3 to be expelled from said container 5 through the injection needle 6 during the injection step and thus perform the injection, as will be seen in Figures 4 to 6. As used here, the term "coupled" refers to any permanent or temporary connection between two parties. For example, by way of illustration and not limitation, two parts can be attached to each other by means of a screw-type connection, by mere contact with each other, or with adhesive. Other types and ways of connecting two parts will be apparent to a person skilled in the art and from the disclosure provided herein.

The container 5 is received within a support 21 having an overall tubular shape: said support 21 is open at both ends. Said support 21 is provided at its proximal end with at least two claws 21a in which the tab 5b of the container 5 is fixed.

The device 1 of Figures 1 and 2 further comprises a housing (9, 11) intended to receive the container 5. In the example shown, said housing has an overall tubular shape and is formed by two cylinders, a proximal cylinder 9 and a 11 distal which, as shown in Figure 2, snap together when the device is in use. In an embodiment of the invention not shown, the housing (9, 11) could be made in one piece. The needle protector 2 is attached to the housing (9, 11) and covers the needle 6 before the use of the device 1. In particular, as is clear from Figure 2, the device 1 is provided with a deprotector 2a at the which the needle protector 2 is fixed. Such a protector 2a is shown in greater detail in Figures 26 and 27. The housing (9, 11) of device I is coupled to the protector 2a which comprises a cover 90 to which the needle protector 2 is fixed. As shown in Figure 27, the housing comprises slots 95 to guide the translation of said cover 90 when the cover 90 is removed together with the removal of said protector 2a with a view to using said device 1. Consequently, when the user remove the protector 2a to use the device 1, the cover 90 follows the slots 95 and does not rotate. The needle guard 2, which is attached to the cover 90, does not rotate either. Therefore, rotation of the needle tip 6 within the rubber forming the needle guard is prevented and insertion that could result from such potential rotation is also prevented. Therefore, the integrity and sterility of the needle 6 is preserved and the administration of the product can be completed safely.

As will be seen later, the container 5 is mobile with respect to said housing (9, 11) between an initial position, in which said needle 6 is contained within said housing (9, 11), an insertion position, separated distally with respect to said initial position and in which said needle 6 is exposed at a predetermined length, and a final position in which said needle 6 is contained within said housing (9, 11).

The proximal cylinder 9 of the housing is provided at its distal end with at least two flexible teeth 10 that can be deflected radially and outwardly.

As shown in Figure 2, the distal cylinder 11 of the housing is provided at its distal part with at least two flexible tabs 12 that are capable of being deflected radially and outwardly. The distal end of said distal cylinder I I is provided with an inner rim 13: the distal face 13a of said inner rim forms a support surface for the device 1 at the injection site 4 (see figure 4).

The device 1 of Figures 1 and 2 further comprises a sleeve 16 having a closed proximal end 17 and an open distal end 18. Said sleeve 16 is intended to at least partially receive said support 21. The proximal end 17 of the sleeve 16 comprises a ventilation outlet 19. The ventilation outlet 19 may be a small hole. For example, the diameter of said hole can range between 15 micrometers and 25 micrometers. Alternatively, the hole is replaced by a membrane vent. In such case, the diameter of said membrane can be approximately 1 mm. The distal end 18 of said sleeve 16 is provided with an outer radial edge 20.

The device 1 of Figures 1 and 2 further comprises a sealing cover 27 which is intended to engage the head 8a of the piston rod 8.

The device 1 of Figures 1 and 2 also comprises a ring 14 that is intended to receive the distal part of said support 21 and couple to said container 5 at least from the insertion position to the final position of said container 5. The ring 14 has a proximal part and a distal part, the diameter of said proximal part being less than the diameter of said distal part, said proximal and distal parts being joined by a radial wall 15. The radial wall 15 has a proximal face 15a and a distal face 15b.

The device 1 of Figures 1 and 2 further comprises a push button 22 intended to be housed between the proximal cylinder 9 of said housing and said sleeve 16. The push button 22 has the overall shape of a cylinder closed at its proximal end: the proximal end of the push button 22 forms a pushing surface 22a for the user to exert manual pressure to trigger the device 1. The inner wall of the proximal part of the push button 22 is provided with an inner edge 22b. The push button 22 is further provided in its distal part and with at least two distal legs 23.

In the device 1 according to Figures 1 and 2, a first helical spring 24 is provided between the push button 22 and the sleeve 16. As can be seen from Figure 2, the distal end of the first helical spring rests on the proximal face of said outer radial edge 20 of said sleeve 16, and the proximal end of the first helical spring rests on the distal face of the inner edge 22b of the push button 22. A second helical spring 25 is provided between said support 21 and said ring 14: as shown in Figure 2, the distal end of the second helical spring 25 rests on the proximal face 13b of the inner rim 13 of the distal cylinder 11 and the end proximal of said second helical spring 25 rests on the distal face 15b of said radial wall 15 of said ring 14

The device 1 of Figures 1 and 2 is finally provided with a protector 2a to remove the protector 2 from the needle when the user decides to perform the injection. As will be seen later, the deguard 2a and the needle guard 2 are removably coupled with the housing (9, 11) and act as tamper evident means to protect the needle 6 prior to use of the device 1, said tamper evident means may adopt a pre-use condition and a post-use condition, said post-use condition avoiding reuse of the tamper evident means with device 1.

Next, the operation of device 1 will be explained with reference to Figures 2 to 7.

Figure 2 shows device 1 before use, as provided to the user. In this position, the sealing cover 27 is in an initial state in which it seals and seals the proximal portion of said sleeve 16, thus defining a chamber 26 having an initial volume. In the position of Figure 2, said initial volume of said chamber 26 contains a certain amount of pressurized fluid, for example, pressurized air. Alternatively, the fluid could be another gas or a viscous liquid, such as oil or grease. As will be seen later, the sealing cover 27 is movable between said initial state and a final state in which at least part of said pressurized fluid has escaped through the ventilation outlet 19.

In the position before use as shown in Figure 2, the container is in its initial position. It is retained in said initial position by the engagement of said flexible teeth 10 of said proximal cylinder 9 on said outer radial edge 20 of said sleeve 16, said flexible teeth 10 and said outer radial edge 20 acting as first retaining means, under pressure. of said first helical spring 24, which is in a pressurized state.

In this position, needle 6 is protected by needle guard 2 which is attached to guard 2a. Consequently, the deguard 2a and the needle guard 2 form the tamper evident means that are in their pre-use condition.

When the user decides to perform the Injection, he first removes the protector 2a: through this operation, he also removes the protector 2 from the needle. The tamper evident means, formed by the deprotector 2a and the needle protector 2, are therefore in their post-use state. Removal of needle guard 2 is completed with limited or no rotation of needle guard 2. Possible nucleation caused by the tip of the needle 6 rotating in the rubber forming the needle guard 2 is therefore avoided.

After unprotecting, the container 5 continues to be retained in its initial position by the first retention means that are in the same position as described in Figure 2.

In a step not shown, the user then applies the device 1 on the injection site 4 through the support surface 13a of said distal cylinder 11. Next, manually operate the push button 22 by exerting a distal force on the pushing surface 22a to cause said push button 22 to move distally.

As shown in Figure 3, during this movement, the distal legs 23 come into contact with said flexible teeth 10, causing said flexible teeth 10 to deflect radially and outward. Consequently, said flexible teeth 10 are disengaged from said outer radial edge 20 to which they were previously engaged.

The first helical spring 24 is therefore free to return to its normal state and extends distally, dragging with it the sleeve 16. The sleeve 16 being coupled to said piston rod 8 by means of the sealing cover 27 that is fixed on the head 8a of the piston rod 8, the piston rod 8 is pulled distally by the sleeve 16. Furthermore, with the distal end of the piston rod 8 being threaded inside the piston 7, the piston rod 8 is coupled to said container 5, at least from the initial position to the insertion position of the container, by means of the friction force exerted by the outer walls of said piston 7 on the inner walls of said container 5. Consequently, the container 5 is also dragged distally causing the needle 6 penetrates the injection site 4 until the distal end of said support 21 rests on the proximal face 13b of the inner rim 13 of said distal cylinder 11, as shown in Figure 4.

As shown in Figure 4, the container 5 is therefore in the insertion position and the injection of the product 3 can begin. The injection is automatically actuated by means of the first helical spring 24 which continues to extend distally towards its normal state. Once the container 5 is prevented from moving distally by said support 21 stopping against the inner rim 13, the force of the first helical spring 24 overcomes the friction force and the piston 7 is caused to move distally within from said container 5, thus expelling said product 3 through said injection needle 6.

Once the piston 7 is close to said distal end 5a of the container 5 and rests more or less on said distal end 5a, the force of said first helical spring 24 overcomes the friction force of the sealing cover 27 against the walls. internals of said sleeve 16 and said sleeve continues to move distally, causing part of the pressurized fluid present in said chamber 26 to escape through the ventilation outlet 19, as shown in Figure 5.

As shown in Figure 5, in the device 1 of the invention, although the piston 7 has reached the distal end of the container 5, said container 5 is prevented from moving from its insertion position to its final position, as long as it does not substantially all of the product has been expelled, and especially while said sealing cover 27 has not reached its final state (see figure 6): in fact, as is clear from figure 5, the second helical spring 25, which is intended To move said container from its insertion position to its final position, it is still prevented from extending proximally by engaging said flexible tabs 12 on the support surface 15a.

The time it takes for the sealing cover 27 to go from its initial state to its final state allows all of the liquid to be expelled through the injection needle 6.

As shown in Figure 6, the sleeve 16 continues to move distally, under the force exerted by said first helical spring 24, until the sealing cover 27 comes into contact with the proximal end of said sleeve 16 and substantially all of the pressurized fluid present in chamber 26 has escaped through ventilation outlet 19. During this movement, the outer radial edge 20 comes into contact with said flexible tabs 12 which are then deflected radially and outward, as shown in Figure 6. Therefore, the radial wall 15 is disengaged from said flexible tabs 12 and the second helical spring 25 is free to move soon. The force of said second helical spring 25 being greater than the force of the first helical spring 24, said second helical spring 25 pushes said ring 14, which couples to said support 21 in the proximal direction, thanks to an outer edge 21c provided on said support 21 on which the proximal end 14a of said ring rests.

With the container 5 fixed to said support 21, it is made to move proximally and retract within said distal cylinder 11 to reach its final position, within said casing (9, 11), as shown in Figure 7.

Thanks to the timing means of the device of the invention, the retraction of the needle within the housing is an indication to a user that substantially all of the product contained within the container has been passed through the needle exit port 6 injection.

In the final position, the needle 6 is contained within said casing (9, 11) and, therefore, the device 1 is ready to be discarded, without any risk of accidental puncture injury.

In an alternative embodiment of the invention not shown, the friction force of the sealing cover 27 against the internal walls of said sleeve 16 is such that it allows said sealing cover 27 to begin moving from its initial state as soon as the injection.

In another embodiment of the invention not shown, the force of the first helical spring 24 is reduced by adding a third spring to move said sealing cover 27 from its initial state to its final state. Such an embodiment makes it possible to reduce the force with which the support 21 or the container 5 touches the inner rim 13 or the injection site 4, especially the skin, and provides some comfort to the user.

Figure 8 shows a variant of device 1 of Figures 1 to 7, in which the sleeve that forms the chamber is confused with the push button. The references corresponding to the same elements as in Figures 1 to 7 have been maintained.

As can be seen in Figure 8, the deactivation means and the chamber are provided as a sleeve 30 which is closed at its proximal end. Said proximal end forms a pushing surface 30a for the user to exert manual and distal pressure when they wish to activate the device 1. The proximal end comprises a ventilation outlet 29b. A sealing cover 29a is provided on the head of a piston rod 8.

The sleeve 30 is provided with at least one external projection 31 and said casing 9 is provided with a stop 32. In the initial position of the container 5, said external projection 31 rests against said stop 32, forming said external projection 31 and said stop 32 first means of retaining said container 5 in the initial position.

In steps not shown, after removing the needle guard and deshield, the user applies the device 1 to the injection site and pushes distally on the pushing surface 30a causing said sleeve 30 to move distally. The manual pressure exerted on the sleeve 30 by the user exceeds said stop 32 and the first helical spring 24 is then free to move distally. The first helical spring 24 pushes the outer radial edge 20 of said sleeve 30, thus performing the insertion of the needle 6, the injection and the timing as seen for the device 1 of Figures 1 to 7. The container 5 moves from its insertion position to its final position by the second helical spring 25 only when the sealing cover 29a has reached its final state upon contact with the proximal end of said sleeve 30.

Figures 9 to 11 show another variant of device 1 of the invention, in which the piston rod is provided in two parts, a proximal part and a distal part, which separate when said piston comes into contact with the end. distal of said container. The references corresponding to the same elements as in Figures 1 to 7 have been maintained.

Figure 9 shows a device 1 according to the invention comprising a piston rod 40 provided with two parts, a proximal part 41 and a distal part 42. The proximal part 41 of the piston rod 40 is provided at its proximal end with a head 49 and at its distal end with a radial projection 44. The distal part 42 of the piston rod comprises a cylinder, the internal walls of which are coated with a rubbery material 43.

The housing 9 is provided on its inner wall with at least two radially flexible legs 46.

The device 1 further comprises a ring 48, said ring 48 being coupled to said container 5 when said container moves from its insertion position to its final position. Said ring 48 comprises a support surface 47.

In Figure 9, device 1 is in the injection position, said container 5 being in the Insertion position. The first helical spring 24 performs the injection automatically by pushing the head 49 of the piston rod 40 distally. In this position, the force exerted by the first helical spring 24 on the piston rod 40 is not large enough to separate said piston rod into two parts. The piston 7 is caused to move distally, thereby expelling the products through the injection needle 6.

When said piston is close to the distal end of said container 5, as shown in Figure 10, said distal part 42 of said piston rod 40 is stopped, but said proximal part 41 of said piston rod 40 is allowed to continue its distal movement under the force exerted by said automatic injection means, that is, the first helical spring 24. The radial projection 44 then comes into contact with the rubbery material 43 and the distal movement of the proximal part 41 of the piston rod 40 is slowed down, due to the interaction between the radial projection 44 and the rubbery material 43. A period of time is then allowed to pass for all of the product 3 to be expelled before the container 5 is retracted into the casing 9.

In fact, during the distal movement of the proximal portion 41 of the piston rod 40, the head 49 contacts the flexible legs 46 of the housing 9 and causes them to deflect radially. The support surface 47 is thus disengaged from said flexible legs 46 and the second helical spring 25 is free to return to its normal state and extend in the proximal direction, as shown in Figure 11.

Only then is the container 5 made to move from its insertion position to its final position.

12 to 17c show alternative provisional means in the form of a piston rod 40 provided in two parts, a proximal part 41 and a distal part 42. The references corresponding to the same elements as in Figures 9 to 11 have been maintained.

Figures 12 and 16 show piston rods 40 similar to those of Figures 9 to 11, in which the rubbery material has been replaced by a compressible material (50, 51): in Figure 16, the compressible material is a spring 51. When the distal end of the proximal part 41 of the piston rod 40 comes into contact with the material compressible (50, 51), the velocity of the proximal portion 41 of the piston rod 40 is reduced and therefore some time is allowed for substantially all of the product to be expelled 3 before the head of the piston rod cooperates with the second retention means to cause retraction of the container.

A two-part piston rod 40 is shown in Figure 13, in which the diameter of the cylinder 42, which forms the distal part of the piston rod, decreases towards the bottom of said cylinder. The distal end of the proximal part 41 of said piston rod 40 is provided with flexible tabs 52 that rub against the internal walls of said cylinder, causing the proximal part 41 to brake when it moves distally.

In Figure 14, a piston rod 40 is shown for which the internal walls of said cylinder 42 are provided with a thread 55 cooperating with a screw 56 provided at the distal end of said proximal part 41 of said piston rod, thereby reducing the velocity of said proximal portion 41 of said piston rod, as said proximal portion of said piston rod moves distally.

Figure 15 shows a piston rod 40 for which the internal walls of said cylinder 42 are provided with flexible longitudinal legs 53 that come into contact with a radial projection 54 provided at the distal end of said proximal part 41 of said rod. of the plunger, thereby reducing the velocity of said proximal portion 41 of said piston rod, as said proximal portion of said piston rod moves distally.

Figures 17a to 17c show a piston rod for which said cylindrical walls are provided with a series of steps 57 and the distal end of said proximal part of said piston rod is provided with a series of radial fins 58, increasing the number of radial fins interacting with said steps as said proximal portion of said piston rod moves distally.

An alternative embodiment of device 1 of the invention is shown in Figures 18 to 21. The reference numbers that refer to the same elements as for Figures 1-7 have been retained.

The device 1 of Figures 18-21 comprises a chamber 59 partially defined by the interior part 61 of the container located next to the piston 7. The rest of the chamber 59 is defined by the walls of the housing 68 that receives the container 5. A Sealing cover 60 joins the proximal end 5b of said inner part 61 to the housing 68 by means of a friction force of absolute value F. At its proximal end, the chamber 59 comprises a ventilation outlet 63. The chamber 59 also comprises a container 65, preferably made of rigid walls.

In the initial position of the container, as shown in Figure 18, this container 65 is sealed and filled with a fluid 64 under pressure.

The device of Figures 18-21 further comprises a piercing button 66 capable of creating an opening 67 in said container when a manual force is exerted on said piercing button 66. The size of the opening 67 is much larger than the size of the ventilation outlet 63.

Furthermore, the device 1 of Figures 18-21 comprises a sleeve 69 received within said housing 68 and receiving said container 5. The sleeve 69 comprises in its distal area an inner radial edge 70. A helical spring 62 is placed between said container 5 and said sleeve 69, the proximal end of said spring 62 resting on the distal face of said proximal end of said container 5 and the distal end of said spring resting on the proximal face of said edge. 70 inner radial of said sleeve 69. The absolute value of the return force exerted by the spring 62 on said container 5 when said spring is at least in a partially compressed state is called Pe.

Next, the operation of device 1 of Figures 18-21 will be described.

The device 1 is provided to the user in its initial position shown in Figure 18.

In this position, the needle 6 is protected by a needle guard 2 and a deguard 2a.

The container 65 is filled with the fluid 64 under pressure. When the user wishes to proceed with the administration of product 3, he removes the deprotector 2a and the needle protector 2, applies the device 1 to the injection site 4 and exerts manual force on the puncture button 66. The puncture button 66 penetrates a wall of the container 65 and creates an opening 67 as shown in Figure 19.

The pressurized fluid 64 is then allowed to escape from the container 65 through the opening 67 and begins to fill the chamber 59. As shown in Figure 19, as the pressurized fluid 64 spreads in the chamber 59, it pushes on the sealing cover 80 and therefore on the container 5 that moves distally. Consequently, the needle 6 penetrates the injection site and the device 1 is in the insertion position. Once the distal movement of the container 5 has stopped, thanks to the support of the proximal end 5b of said container 5 on the distal end of the sleeve 69, the pressure exerted by the pressurized fluid 64 in the chamber 59 causes the piston 7 to move distally. .

As the piston 7 moves distally, the product 3 is injected into the injection site 4 through the needle 6 until the piston 7 is close to the distal end of the container 5, as shown in Figure 20.

During the insertion and injection steps, some of the pressurized fluid 64 has been allowed to escape from the chamber 59 through the vent 63. However, since the size of the vent 63 is much smaller than the opening 67, only a negligible amount of pressurized fluid 64 has escaped from said chamber 59.

When the piston 7 is close to the distal end of the container 5, as shown in Figure 20, the pressurized fluid 64 exerts a pressure on said container 5 of absolute value Pc.

During the injection stage and until the piston 7 is close to the distal end of the container 5, Pc is greater than (Pe F). As the pressurized fluid 64 escapes through the vent 63, Pc decreases.

Furthermore, during the insertion step, the spring 62 has been compressed and its return force Pe has increased.

Therefore, during the injection stage, the retention means are formed by Pc greater than (Pe F). When Pe becomes equal to or greater than (Pc F), the retaining means is released and the spring 62 is allowed to return to its expanded state. The time required for Pe to be equal to or greater than (Pc F) allows the Injection to be fully completed.

The return of the spring 62 to its expanded state is subject to the flow of fluid 64 out of the chamber 59 through the vent 63.

Consequently, due to the small size of the ventilation outlet 63, the return of the spring to its expanded state will occur slowly and the needle 6 will slowly retract into said housing 68.

An alternative to the embodiment of Figures 18-21 is shown in Figures 22 to 25.

The device 1 of Figures 22-25 comprises a chamber 79 partially defined by the internal part 71 of the container 5 located next to the piston 7. The rest of the chamber 79 is defined by the walls of the housing 72 that receives the container 5 and by the head 73 of a rod 74 the piston. The distal end 77 of the piston rod 74 is not fixed to the piston 7.

A first sealing cover 75 joins the proximal end 5b of said inner part 71 to the housing 72. A second sealing cover 76 joins the head 73 of the piston rod 74 to the housing 72 and therefore seals the chamber 79. The two sealing covers (75, 76) are porous sealing covers. Consequently, both form an outlet vent for any pressurized fluid contained in chamber 79. The two sealing covers (75, 76) together present a friction force against the housing wall 72 of absolute value F.

The device 1 of Figures 22-25 comprises a sleeve 78 received within said housing 72 and receiving said container 5. The sleeve 78 comprises in its distal area an inner radial edge 80. A helical spring 81 is placed between said container 5 and said sleeve 78, the proximal end of said spring 81 resting on the distal face of said proximal end of said container 5 and the distal end of said spring resting on the proximal face of said inner radial edge 80 of said sleeve 78. The absolute value of the return force exerted by the spring 81 on said container 5 when said spring is at least in a partially compressed state is called Pe.

The device 1 of Figures 22-25 further comprises a stop 82 provided on the inner wall of said housing 72. The device 1 also comprises a push button 83 having two distal legs 84.

The head 73 of the piston rod 74 is provided with two proximal flexible tabs 85. The proximal end of the housing 72 is provided with two bearing surfaces 86.

A coil spring 87 is provided within the push button 83 and the proximal portion of the head 73 of the piston rod 74. The proximal end of the spring 87 rests on the distal face of the push button 83, and the distal end of the spring 87 rests on the proximal face of the proximal part of the head 73 of the piston rod 74. The absolute value of the return force exerted by the spring 87 on said piston rod 74 when said spring is at least in a partially compressed state is called Pi.

Next, the operation of device 1 of Figures 22-25 will be described.

The device 1 is provided to the user in its initial position shown in Figure 22.

In this position, the needle 6 is protected by a needle guard 2 and a deguard 2a. The proximal tabs 85 of the head 73 of the piston rod 74 are engaged in the bearing surfaces 86 of the housing 72. The spring 87 is in a compressed state.

When the user wishes to continue with the administration of product 3, he removes the protector 2a and the needle protector 2, applies the device 1 to the injection site 4 and exerts manual force on the push button 83. Therefore, the push button 83 moves distally and its distal legs 84 come into contact with the flexible tabs 85 of the housing 72. Under the pressure of the distal legs 84, the flexible tabs 85 deflect radially and disengage from the support surfaces 86. The spring 87 is then free to return to its expanded state and pushes the piston rod 74 in the distal direction. The friction F of the sealing covers (75, 76) being less than the friction force of the piston 7 against the internal wall of the container 5, said container 5 is dragged in the distal direction, thus performing the insertion of the needle 6 in injection site 4, as shown in figure 23.

Once the distal movement of the container 5 has stopped, thanks to the support of the proximal end and 5b of said container 5 on the distal end of the sleeve 78, the force of the spring 87 exceeds the friction force and the piston 7 is pushed distally by the end distal of the piston rod 74, thus carrying out the injection of the product 3 at the injection site 4.

As the piston 7 and piston rod 74 move distally, the volume defining the chamber 79 decreases, as shown in Figure 24. Consequently, the fluid, for example, gas or air, present within of said chamber 79 is pressurized. Furthermore, before the piston 7 approaches the distal end of the container, as shown in Figure 24, the distal movement of the piston rod 74 is stopped by the stop 82 provided on the inner wall of said housing 72. The fluid pressure, referenced 88 in Figure 24, therefore fills the space located between the piston 7 and the distal end 77 of the piston rod 74, therefore holding the piston 7 against the distal end of the container 5 and allowing time extra for the injection to be fully completed. The pressure of the pressurized fluid 88 is called Pc.

During the insertion stage, the spring 81 has been compressed and its return force Pe has increased.

During the injection step, and after the piston 7 approaches the distal end of the container 5, the pressurized fluid escapes through the porous sealing covers (75, 76). Therefore, once the piston 7 has reached the end of the distal end of the container 5 and substantially all of the product has been passed through the outlet port of the injection needle 6, Pc decreases as a result of the fluid escapes from chamber 79 through porous sealing covers (75, 76).

During the injection stage, the retention means are formed by (Pc PI) being greater than (Pe F). When Pe becomes equal to or greater than (Pc F Pi), the retaining means is released and the spring 81 is allowed to return to its expanded state. The time required for Pe to be equal to or greater than (Pc F Pi) allows the injection to be fully completed.

Returning to its expanded state, the spring 81 draws the needle 6 into the housing 72 and the device 1 is secure.

With reference to Figures 26 and 27, partial views are shown of a deshield 2a suitable as a tamper evident means for a device of the invention. The deprotector 2a is made of a cap 90 and a ring 91 connected to each other by breakable tapes 92.

In the pre-use condition, as shown in Figure 26, the protector 2a is fixed on the housing 93 of a device according to the invention. The lid 90 and the ring 91 are manufactured in one piece, for example, by injection molding, and are connected to each other by the breakable tapes 92.

The housing 93 is provided with stops 94 that prevent a user from breaking the tapes 92 by applying a proximal force on the cover 90.

When a user is ready to use the device of the invention, he or she removes the protector 2a by pulling distally on the cap 90 to remove it from the housing 93, thereby breaking the breakable tapes 92.

As can be seen in Figure 27, the housing 93 is provided with slots 95 that guide the translation of the cover 90 as it is removed. In this manner, the remover and the needle guard (not shown) inside the cap 90 are removed with limited or no rotation of the needle (not shown). Therefore, nucleation caused by the rotation of the needle tip in the rubber that forms the needle guard is prevented.

In Figure 27, the tamper evident means formed by the deprotector 2a is in its state after use. Any user, provided with the device with the protector 2a in this state, can immediately notice, thanks to the broken tapes 92, that the device has been tampered with. The post-use condition of the deprotector proves an indication that the tamper evident media has been removed from the device.

Additionally, due to the broken 92 tapes, it is impossible for anyone to replace the cap in its pre-use state.

A tray 400 for transporting upper casing assemblies 100 in a predetermined direction is shown in Figure 28. The transport means 400 of Figure 28 may especially carry a plurality of upper casings 100, all arranged in the same direction. Said tray comprises a plurality of holes 402 intended to receive the upper casing assemblies 100. Said tray 400 is useful for transporting and/or handling upper casings of a device of the invention during all the various stages of manufacturing, filling, packaging, etc...

A tray 401 similar to the tray 400 of Figure 28 is shown in Figure 29, with the tray 401 carrying, in the example shown, a plurality of lower housing assemblies 200 of a device of the invention, in a predetermined orientation.

A variant of the device of Figures 22-25 is shown in Figures 30-33. The references that design the same elements as in figures 22-25 have been maintained.

The device 1 of Figures 30-33 comprises a chamber 96 partially defined by the internal part 71 of the container 5 located next to the piston 7. The rest of the chamber 96 is defined by the walls of the housing 72 that receives the container 5 and by the head 73 of a rod 74 the piston. The distal end 77 of the piston rod 74 is not fixed to the piston 7.

A first sealing cover 97 joins the proximal end 5b of said Inner Part 71 to the housing 72. A second sealing cover 98 joins the head 73 of the piston rod 74 to the housing 72 and therefore seals the chamber 96. The two Sealing covers (97, 98) are porous sealing covers. Consequently, both form an outlet vent for any pressurized fluid contained in chamber 96. The two sealing covers (97, 98) together present a friction force against the housing wall 72 of absolute value F.

The device 1 of Figures 30-33 comprises a sleeve 102 received within said housing 72 and receiving said container 5. The sleeve 102 comprises in its distal area an inner radial edge 103 and at its proximal end a flexible tongue 104 provided with a support surface 105. A helical spring 106 is placed between said container 5 and said sleeve 102, the proximal end of said spring 106 resting on the distal face of said support surface 105 by means of a ring 107 and the distal end of said spring 106 resting on the proximal face of said inner radial edge 103 of said sleeve 102.

The device 1 of Figures 30-33 further comprises a push button 83 having two distal legs 84.

The head 73 of the piston rod 74 is provided with two proximal flexible tabs 85. The proximal end of the housing 72 is provided with two bearing surfaces 86.

A coil spring 87 is provided within the push button 83 and the proximal portion of the head 73 of the piston rod 74. The proximal end of the spring 87 rests on the distal face of the push button 83, and the distal end of the spring 87 rests on the proximal face of the proximal part of the head 73 of the piston rod 74.

Next, the operation of device 1 of Figures 30-33 will be described.

The device 1 is provided to the user in its initial position shown in Figure 30.

In this position, the needle 6 is protected by a needle guard 2 and a deguard 2a. The proximal tabs 85 of the head 73 of the piston rod 74 are engaged in the bearing surfaces 86 of the housing 72. The spring 87 is in a compressed state.

When the user wishes to continue with the administration of product 3, he removes the protector 2a and the needle protector 2, applies the device 1 to the injection site 4 and exerts manual force on the push button 83. Therefore, the push button 83 moves distally and its distal legs 84 come into contact with the flexible tabs 85 of the housing 72. Under the pressure of the distal legs 84, the flexible tabs 85 deflect radially and disengage from the support surfaces 86. The spring 87 is then free to return to its expanded state and pushes the piston rod 74 in the distal direction. The friction F of the sealing covers (97, 98) being less than the friction force of the piston 7 against the inner wall of the container 5, said container 5 is dragged in the distal direction, thus performing the insertion of the needle 6 in injection site 4, as shown in figure 31.

Once the distal movement of the container 5 is stopped, for example, when the distal end of the container 5 comes into contact with the injection site 4, the force of the spring 87 overcomes the friction force and the piston 7 is pushed distally by the distal end of the piston rod 74, thus carrying out the injection of the product 3 at the injection site 4.

As the piston 7 and piston rod 74 move distally, the volume defining the chamber 96 decreases. Consequently, the fluid, for example, gas or air, present within said chamber 96 is pressurized. This fluid fills the space between the piston and the distal end 77 of the piston rod 74. Due to this gap, when the piston 7 approaches the distal end of the contents 5, the head 73 of the piston rod 74 is not in contact with the sealing cover 97. The porosity of the sealing covers (97, 98) allows said sealing covers to act as a ventilation outlet and part of the pressurized fluid present in the chamber 96 can slowly escape from said chamber 96, giving sufficient time for it to be substantially expelled. all of the product 3. As substantially all of the product is expelled, the piston rod 74 is allowed to move slowly in a distal direction, and the head 73 of the piston rod 74 contacts the valve 99 of the cover 97 sealing. Valve 99 is pushed distally and comes into contact with flexible tab 104 which deflects radially, releasing ring 107 and spring 106. The released spring 106 begins to move proximally, but is slowed by the force of the pressurized fluid present in the valve. chamber 96. With proximal movement of spring 106, ring 107 contacts valve 99 and opens it. The pressurized fluid still present in chamber 96 is then allowed to escape through open valve 99 and spring 106 quickly returns to its expanded state.

Upon returning to its expanded state, the spring 106 attracts the needle 6 toward the housing 72 and the device is secured as shown in Figure 33.

The device of the invention is very easy to use and very safe. Allows a patient to self-inject a product without any risk of needle stick injury, before, during and after use. In particular, it allows retraction of the needle into the device only once substantially all of the product has been injected. Therefore, injections of incorrect doses of product are avoided.

Claims (8)

1. A device (1) for automatic injection of a product at an injection site, the injection device (1) comprising: a container (5) having an open proximal end and a substantially closed distal end and which is intended to receive a product, an injection needle (6) being provided at the distal end; a piston (7) provided in the container (5) and mobile with respect to said container (5); a piston rod (8) coupled to said piston (7); a housing (9, 11, 68, 72, 93) intended to receive, at least partially, the container (5), the container (5) being mobile with respect to the housing (9, 11, 68, 72, 93) between an initial position, in which the injection needle (6) is contained within the housing (9, 11, 68, 72, 93), an insertion position, distanced distally with respect to the initial position and in which the injection needle (6) is exposed at a predetermined length, and a final position in which the injection needle (6) is contained within the housing (9, 11, 68, 72, 93); retaining means (12, 15), arranged to maintain said container (5) in said insertion position; deactivation means (20), arranged to automatically release said retaining means and cause said container (5) to move to said final position; and a needle protector (2) coupled with said housing (9, 11, 68, 72, 93) and covering the injection needle (6) before the use of said device, the removal of said needle protector (2) being with limited or no rotation of said needle guard (2), characterized by said device by timing means (19, 26, 27), arranged to control the release of said retention means by said deactivation means until substantially all of the product contained within said container (5) has passed through said needle (6) injection before said container (5) moves to said final position, wherein the provisional means comprise a sleeve (16) having a closed proximal end (17) and an open distal end (18), the closed proximal end (17) comprising a ventilation outlet (19); a sealing cover (27) coupled to a head (8a) of a piston rod (8); a first helical spring (24) having a distal end that rests on the sleeve (16) and a proximal end that rests on a push button (22); wherein, in an initial state, the sealing cover (27) closes the proximal end of the sleeve (16), thus defining a chamber (26) having an initial volume of pressurized fluid, gas or viscous liquid, said cover ( 27) sealing being mobile between an initial state and a final state in which at least part of said pressurized fluid, gas or viscous liquid has escaped through the ventilation outlet (19), and in which once the piston (7) is close to a distal end (5a) of the container (5) and rests on said distal end (5a) of the container (5), the first helical spring (24) is configured to overcome the friction force of the sealing cover (27) against the internal walls of the sleeve (16) so that the sleeve (16) continues to move distally under the force exerted by the first helical spring (24), causing part of the pressurized viscous fluid, gas or liquid present in the chamber (26) escapes through the vent outlet (19), until the sealing cover (27) comes into contact with the proximal end of the sleeve (16) and substantially the entire pressurized fluid, gas or viscous liquid present in the chamber (26) has escaped through the vent outlet (19), causing the container (5) to move from the insertion position to the final position. 2. The device (1) according to claim 1, wherein the product contained within the container (5) is expelled through the injection needle (6) with the container (5) in the insertion position, and in which, the chamber (26, 59, 79, 96) begins to collapse during the expulsion of the product from the container (5). 3. The device (1) according to claim 2, wherein the proximal wall engages the sealing element (27, 29a, 60, 76, 97) after complete expulsion of the product from the container (5). 4. The device (1) according to claim 2, wherein the piston (7) is slidably arranged within the container (5) and is configured to eject the product and the sleeve (16, 30, 69, 78, 102) is configured to push the piston (7). 5. The device (1) according to claim 4, wherein sufficient distal movement of the sleeve (16, 30, 69, 78, 102) causes collapse of the chamber (26, 59, 79, 96). 6. The device (1) according to claim 4, wherein, with the piston ⁽ 7 ⁾ located in the most distal position in the container (5) without the possibility of additional distal movement with respect to the container (5), the Sleeve (16, 30, 69, 78, 102) is configured to move distally to cause the proximal wall to engage the sealing element (27, 29a, 60, 76, 97). 7. The device (1) according to claim 6, wherein the sleeve (16, 30, 69, 78, 102) defines the proximal wall. 8. The device (1) according to claim 4, wherein the sleeve (16, 30, 69, 78, 102) defines the proximal wall.