Patent Description:
In this application, the distal end of a component or of a device is to be understood as meaning the end furthest from the user's hand and the proximal end is to be understood as meaning the end closest to the user's hand. Likewise, in this application, the "distal direction" is to be understood as meaning the direction away from the user's hand, and the "proximal direction" is to be understood as meaning the direction toward the user's hand.

Automatic injection devices are designed for automatic injection of a medical product into an injection site. Autoinjectors usually comprise a top body and a bottom body assembled to each other to form a housing. The bottom body is usually configured for receiving a medical container, such as a prefillable or prefilled syringe. The medical container has a barrel defining a reservoir for containing the medical product, the barrel having a distal end provided with an injection needle and an opened proximal end receiving a plunger rod for pushing a stopper. The injection needle is usually protected by a rigid needle shield removably secured to a distal tip of the medical container.

Autoinjectors also include a safety shield mechanism moving from an extended to a retracted position to respectively shield or unveil the needle and a power pack for automatically injecting the medical product into an injection site. The power pack is usually arranged inside the top body and includes a plunger rod for pushing a stopper inside the barrel of the medical container. An initially compressed spring is configured for moving the plunger in the distal direction. Locking means are provided for maintaining the plunger rod in an initial position in which the plunger rod is axially blocked despite the action of the compressed spring. A release member is further provided to release the plunger rod from the locking means and allow the spring to push the plunger rod in the distal direction to perform injection. A predetermined displacement of the safety shield towards the retracted position is required to allow the release member to unlock the locking means and release the plunger rod.

Assembly of the top body and the bottom body may be realized by any appropriate means such as snap-fitting or friction fit means. When fully assembled, a rattling noise may however be heard if a user shakes the autoinjector. This rattling noise is due to axial gaps that may exist between the powerpack and the medical container and between the power pack and the top body in the radial direction. As can be seen in <FIG>, the powerpack <NUM>' may slightly move between a position (<FIG>) in which the powerpack abuts against the top body <NUM>' (and an axial clearance exists between the powerpack and the medical container <NUM>') and another position (<FIG>) in which the powerpack <NUM>' abuts against the medical container <NUM>' (and an axial clearance exists between the powerpack and the top body).

There is therefore a need for reducing these clearances and limiting the rattling noise.

The document <CIT> discloses a cap provided at a distal end of an autoinjector. The cap includes a retainer for removing a needle shield. The retainer has radial protrusions for engaging an axial gap arranged between the needle shield and a distal shoulder of the syringe barrel. During assembly, it may happen that the needle shield is inserted too far inside the retainer. Thus, the radial protrusions outwardly deflect and rest against a lateral surface of the syringe barrel instead of engaging the axial gap. It is necessary to carry out a so-called "push back" step in which a the needle shield is moved back in the proximal direction. The push-back step enables the axial gap between the needle shield and the syringe barrel to move at the level of the radial protrusions so that the deformed radial protrusions move back inward in the axial gap and engage the needle shield. To that end, the known autoinjectors have an opened distal end providing access to the needle shield, thereby allowing to proximally push the needle shield. This opening at the distal end of the autoinjector is sometimes confusing for the end user who is generally not a skilled healthcare worker and who may believe that the injection needle will emerge from this central hole. It may happen that the end user forgets to remove the cap prior to injection.

There is therefore a need for a cap allowing to perform the push-back step and to avoid confusion for the end user.

An aspect of the invention is a cap for removing a needle shield attached to a medical container arranged inside a body of an autoinjector, the cap including:.

As a result, the proximal abutment surface of the retainer pushes the medical container in the proximal direction. In turn, the medical container pushes the power pack against the body of the autoinjector. Thus, the axial clearances between the medical container, the power pack and the body of the autoinjector are suppressed or limited. The resulting rattling is also suppressed or limited.

The cap of the invention may further include some or all of the features below.

In an embodiment, the adjustment member includes a protrusion proximally extending from the proximal side of the sealing portion.

In an embodiment, the plug includes a single adjustment member.

The adjustment member may include two-diametrically opposite protrusions.

In an embodiment, the adjustment member includes a sloped surface configured to deform a distally extending resilient leg of the retainer.

In an embodiment, the adjustment member includes a resililently deformable element configured to exert a proximal pushing force on the retainer.

In an embodiment, the resiliently deformable member is in the form of a T-shaped blade.

In an embodiment, the plug further includes a push-back member for allowing to push the needle shield in a proximal direction.

In an embodiment, the push-back member is a through-hole extending through the sealing portion and configured to axially face a distal end of the needle shield.

In an embodiment, the push-back member includes a spring configured to push the needle shield in the proximal direction.

The adjustment member may include two proximal abutment surfaces and the push-back member is arranged between said two proximal abutment surfaces.

In an embodiment, the sealing portion is plate-shaped.

In an embodiment, the plug includes securing means for securing the plug to the housing. Thus, the plug is a separate component. The securing means are preferably configured to removably secure the plug to the housing.

In an alternative embodiment, the plug and the housing may be made of a single piece.

In an embodiment, the plug is made of a single piece.

Another aspect of the invention is an autoinjector including a cap having the aforementioned features.

Another aspect of the invention is a method for assembling said autoinjector, including the steps of :.

The above steps may be carried out in any chronological order. For instance, step (i) may occur before step (ii). In this case, the push-back member of the plug may be a through-hole providing acces to the distal end of the needle shield. In another instance, step (ii) may occur before step (i) : this may be the case when the plug is devoid of any push-back member. In another embodiment, steps (i) and (ii) occur at the same time. The plug automatically performs the push-back step (ii) when attached to the cap. This may be the case when the adjustment member of the plug includes a spring which pushes the needle shield.

The invention and the advantages arising therefrom will clearly emerge from the detailed description that is given below with reference to the appended drawings as follows :.

With reference to <FIG> is shown an autoinjector <NUM> according to an embodiment of the invention. The autoinjector <NUM> is designed for automatic injection of a product into an injection site. The autoinjector <NUM> extends along a longitudinal axis A. The autoinjector <NUM> includes a lower sub-assembly <NUM> and a top sub-assembly <NUM> assembled to each other by any appropriate securing means such as, for instance, snap-fitting means.

The lower sub-assembly <NUM> includes a bottom body <NUM> for receiving a medical container <NUM>, a cap <NUM> removably attached to a distal end <NUM> of the bottom body <NUM> and configured for removing a needle shield <NUM>, a needle cover <NUM> axially movable along the longitudinal axis A with respect to the bottom body <NUM> between a first extended position (pre-use position) in which the needle cover <NUM> at least partially or completely shields an injection needle, and a retracted position (injection position) proximally located relative to said first extended position, in which the needle cover <NUM> moves inside the autoinjector <NUM> to trigger the injection. Movement of the needle cover <NUM> from the first extended position to the retracted position is caused by a distal end of the needle cover <NUM> being pressed against an injection site during use of the autoinjector <NUM>. The needle cover <NUM> is further movable from the retracted position to a second extended position (safety position) in which the needle cover <NUM> moves back in the distal direction so as to safely shield the injection needle. The lower sub-assembly <NUM> may further include a safety spring <NUM> for urging the needle cover <NUM> in the distal direction towards the safety position and locking means for locking the needle cover <NUM> in said safety position. The locking means may include a locking element, such as an abutment ring <NUM> configured to be fixed to the medical container <NUM>, having a proximally extending resilient leg that engages a two-way slot arranged through the needle cover <NUM>.

The medical container <NUM> has a tubular barrel <NUM> defining a reservoir for containing a medical product to be injected. The barrel <NUM> has a distal end in the form of a distal shoulder and a longitudinally protruding tip provided with an injection needle. A needle shield <NUM> is removably attached to said distal end for protecting and sealing the injection needle. Opposite its distal end, the barrel <NUM> has an opened proximal end surrounded by a flange <NUM>. The opened proximal end is configured to receive a plunger rod <NUM> for pushing a stopper arranged inside the barrel <NUM>. The medical container <NUM> may be a prefilled or prefillable syringe.

The top sub-assembly <NUM> includes a top body <NUM> arranged for receiving a power pack <NUM>. The power pack <NUM> is the unit that stores the energy and contain the features necessary to hold and release said energy so as to expel the medical product from the medical container. The power pack <NUM> may include a holder <NUM>, a plunger rod <NUM> and an injection spring <NUM> configured to push the plunger rod <NUM> in the distal direction to perform injection. The plunger rod <NUM> is axially movable between an initial position, in which the plunger rod <NUM> is blocked axially in spite of the action of the retracted injection spring <NUM>, and a final position, distally located with regard to said initial position, in which injection is completed. In the initial position, the plunger rod <NUM> may be axially away from the stopper, but in the final position the plunger rod <NUM> is engaged with the stopper and the injection spring <NUM> has extended in such a way that the plunger rod <NUM> has pushed the stopper to the distal end of the barrel <NUM> and the medical product is expelled from the reservoir. The power pack <NUM> may include blocking means for blocking the plunger rod <NUM> in the initial position, said blocking means including for instance an axially movable blocking ring <NUM> configured to maintain or release blocking balls <NUM> arranged for engaging radial cavities of the plunger rod <NUM>.

The holder <NUM> is configured for triggering the injection operation. The holder <NUM> is axially movable inside the top body <NUM> between an initial position, in which the autoinjector <NUM> stays inactive, and a triggering position, proximally located with regard to said initial position, in which the holder <NUM> releases the plunger rod <NUM> so that the autoinjector <NUM> becomes activated. In the initial position, the holder <NUM> may stay axially away from the blocking ring <NUM>, but in the triggering position the holder <NUM> may have pushed the blocking ring <NUM> in the proximal direction such that the blocking <NUM> balls are no longer blocked inside the cavities of the plunger rod <NUM> and can move outside said cavities in such a way that the plunger rod <NUM> is released. The proximal movement of the holder <NUM> from the initial to the triggering position may be caused by the needle cover <NUM> abutting against the holder <NUM> when the needle cover <NUM> moves towards the retracted position.

The power pack <NUM> may, or may not, includes a locker <NUM> arranged for preventing inadvertent movement of the holder <NUM> to the triggering position. The locker <NUM> may be in the form of a rotatable ring arranged around the holder <NUM>. The locker <NUM> is axially movable between a an initial position, in which a proximal abutment surface <NUM> of the locker <NUM> axially faces a distal abutment surface which may be defined by an axial rib <NUM> of the top body <NUM>, and an intermediate blocking position, proximally located with regard to said initial position, in which said proximal abutment surface <NUM> of the locker <NUM> abuts against the distal abutment surface of the top body <NUM> such that the locker <NUM> and the holder <NUM> (which axially abuts against the locker <NUM>) are blocked in the proximal direction and cannot transition towards the triggering position. This prevents inadvertent activation of the autoinjector <NUM>. However, the locker <NUM> is further rotationally movable around the longitudinal axis A between said intermediate blocking position and a release position, in which the proximal abutment surface <NUM> of the locker <NUM> is circumferentially shifted away from the distal abutment surface of the top body <NUM> such that the locker <NUM> does not any longer block the holder <NUM> and allows said holder <NUM> to move towards the triggering position. Translation and then rotation of the locker <NUM> are caused by a proximal end <NUM> of the needle cover <NUM> abutting against a cam portion <NUM> of the locker <NUM>.

The cap <NUM> includes a housing <NUM>, a retainer <NUM> arranged inside the housing <NUM>, and a plug <NUM> arranged at a distal end <NUM> of the housing <NUM> for at least partially closing the opened distal end <NUM> of the housing <NUM>.

With reference to <FIG> and <FIG>, the cap housing <NUM> is arranged at a distal end <NUM> of the bottom body <NUM> and may include securing means for removable attachment to the bottom body <NUM>, such as snap-fitting or friction fit means. The cap housing <NUM> may be tubular and may define an inner cavity <NUM> leading to a distal opening <NUM> allowing for insertion of the retainer <NUM> and/or the plug <NUM> inside the cap <NUM>. The cap housing <NUM> may include two opposite axial shoulders <NUM>, <NUM> extending inside the inner cavity <NUM> for limiting an axial movement of the retainer <NUM> with respect to the cap housing <NUM>.

With reference to <FIG> and <FIG>, the upper axial shoulder <NUM> may define a proximally oriented surface for abutting against a first abutment surface <NUM> of the retainer <NUM>, thus preventing the retainer <NUM> from being pulled off the cap housing <NUM> in the distal direction. The lower axial shoulder <NUM> may define a distally oriented blocking surface for abutting against a second abutment surface <NUM> of the retainer <NUM>, thus preventing disassembly of the retainer <NUM> and the cap housing <NUM>. To that end, the retainer <NUM> may include a radial flange <NUM> defining the first and second abutment surfaces <NUM>, <NUM> as visible in <FIG>. The radial flange <NUM> may also include a chamfer <NUM> which may be arranged on the opposite side of the first abutment surface <NUM> for allowing the retainer <NUM> to pass beyond the lower axial shoulder <NUM> during assembly of the retainer <NUM> inside the cap housing <NUM>.

The cap <NUM> is configured so that withdrawal of the cap housing <NUM> from the bottom body <NUM> of the autoinjector <NUM> causes withdrawal of the needle shield <NUM> from the medical container <NUM> by means of the retainer <NUM>. More specifically, due to the abutment between the lower axial shoulder <NUM> and the second abutment surface <NUM>, the cap housing <NUM> drives the retainer <NUM> in the distal direction. The clamping member <NUM> of the retainer <NUM> engages the proximal end <NUM> of the needle shield <NUM>. The needle is accordingly withdrawn from the medical container <NUM>. As visible in <FIG>, the cap housing <NUM> may have a flared distal end <NUM> so that a user can firmly grasp the cap <NUM> and thus easily pull the cap <NUM> off the bottom body <NUM>.

With reference to <FIG> is shown the retainer <NUM>. The retainer <NUM> is arranged within the cap housing <NUM> and may be in the form of a longitudinal sleeve defining an inner cavity for receiving the needle shield <NUM>. The retainer <NUM> is configured to remove the needle shield <NUM> when the user removes the cap <NUM> from the autoinjector <NUM>. To that end, the retainer <NUM> has a clamping member <NUM>, such as a flexible hook arranged at a proximal end <NUM> of the retainer <NUM>, and more specifically at the proximal end of distally extending resilient legs <NUM>. The resilient legs <NUM> are configured to deform outwardly to allow insertion of the needle shield <NUM> within the retainer <NUM>. At the end of the push-back step, the resilient legs <NUM> flex back towards the central longitudinal axis A to engage the axial gap <NUM> (<FIG>) between the needle shield <NUM> and the syringe barrel <NUM>. The clamping member <NUM> may be provided with a distal stop <NUM> for abutting against a proximal end <NUM> of the needle shield <NUM>.

The retainer <NUM> further has an opened distal end <NUM>. The opening defined by said opened distal end <NUM> is configured for allowing the push-back step. The push-back step ends when the distal stop <NUM> abuts against the proximal end <NUM> of the needle shield <NUM>. The distal end <NUM> of the retainer <NUM> is further configured to abut against the plug <NUM> so that the plug <NUM> can move the retainer <NUM> in the proximal direction when the plug <NUM> is assembled to the cap, as will be explained in further details below. More specifically, the distal end <NUM> of the retainer <NUM> may include at least one resilient leg <NUM> configured to abut against the plug <NUM>.

The retainer <NUM> may be axially movable with respect to the cap housing <NUM> between a first position, in which the retainer <NUM> abuts against the upper axial shoulder <NUM> of the cap housing <NUM>, and a second position, proximally located with regard to the first position, in which the retainer <NUM> abuts either against the lower axial shoulder <NUM> or against the bottom body <NUM> (<FIG>). Before assembly of the cap <NUM> to the bottom body <NUM>, the second position is defined by the retainer <NUM> abutting against the lower axial shoulder <NUM>. When the cap <NUM> is assembled to the bottom body <NUM>, the second position is defined by the proximal end <NUM> of the retainer <NUM> abutting against the bottom body <NUM>. More specifically, as illustrated in <FIG>, the bottom body <NUM> may include a distal stop <NUM> for blocking the retainer <NUM> in the second position. The distal stop <NUM> may be arranged at a distal end of an inner cavity <NUM> which is configured for receiving the medical container <NUM>. Thus, the retainer <NUM> cannot move further in the proximal direction. The retainer <NUM> is maintained in abutment against the bottom body <NUM> by the plug <NUM> whose anti-rattling member <NUM> pushes or abuts against the retainer <NUM>.

The retainer <NUM> includes a proximal abutment surface <NUM> configured to abut against the medical container <NUM> when the retainer <NUM> moves in the proximal direction. The proximal abutment surface <NUM> may be defined by the proximal side of the hooks forming the clamping member <NUM>, while the distal side of these hooks defines the distal stop <NUM>. The proximal abutment surface <NUM> of the retainer <NUM> permits to push the medical container <NUM>, and consequently the power pack <NUM>, in the proximal direction so that the power pack <NUM> abuts against the top body <NUM> of the autoinjector <NUM>. This limits or cancels the axial clearances and the rattling noise. Movement of the retainer <NUM> in the proximal direction is caused by the plug <NUM>.

With reference to <FIG> is shown a plug <NUM> according to an embodiment of the invention. The plug <NUM> is configured to delete the operating clearances between the power pack <NUM> and the medical container <NUM>, thereby avoiding rattling noises. The plug <NUM> is arranged at the distal end <NUM> of the cap housing <NUM> and may include a sealing portion <NUM> for partially or completely closing the distal opening <NUM>, an adjustment or anti-rattling member <NUM> for adjusting the axial position of the power pack <NUM> and the medical container <NUM> and thus cancelling clearances between the power pack <NUM> and the medical container <NUM>, a push-back member <NUM> enabling to perform the push-back step, and securing means for securing the plug <NUM> to the rest of the cap <NUM>. The plug <NUM> may be made of a single piece.

Still with reference to <FIG>, the sealing portion <NUM> may be in the form of a transversal plate extending orthogonal to the longitudinal axis A, such as for instance a plate-shaped disc, having a proximal side <NUM> and an opposite distal side <NUM>. The sealing portion <NUM> and the distal opening <NUM> of the cap housing <NUM> may have complementary shapes, more specifically complementarily shaped outlines, so that the sealing portion <NUM> closes the inner cavity <NUM> of the cap <NUM>, thereby avoiding confusion and misuse of the autoinjector <NUM> by the end user. The sealing portion <NUM> may include a notch <NUM> arranged at a lateral edge for properly positioning the plug <NUM> relative to the cap housing <NUM> during assembly of the plug <NUM> within the cap housing <NUM>. The securing means for securing the plug <NUM> to the housing <NUM> may include snap-fitting means, such as two or more diametrically opposite flexible hooks <NUM> axially extending from the proximal side <NUM> of the transversal plate and configured for engaging complementary features of the cap housing <NUM>.

The anti-rattling member <NUM> is configured to suppress the axial clearance between the power pack <NUM> and the medical container <NUM>, thus cancelling the rattling noise that is due to said axial clearance. To that end, the anti-rattling member <NUM> is arranged at a proximal side <NUM> of the plug <NUM> for abutting against the retainer <NUM>. The anti-rattling member <NUM> is intended to push the retainer <NUM> in the proximal direction when the plug <NUM> is secured to the cap housing <NUM>. In turn, this causes the medical container <NUM> to move together with the retainer <NUM> in the proximal direction. Thus, the medical container <NUM> abuts against the power pack <NUM> and pushes the power pack <NUM> in abutment against the top body <NUM>. The resilient legs <NUM> of the retainer <NUM> may then slightly deform in a radial outward direction until the proximal end <NUM> of retainer <NUM> abuts against the distal stop <NUM> of the bottom body <NUM> ; the clamping member <NUM> however remains engaged in the axial gap <NUM> and still faces the proximal end <NUM> of the needle shield <NUM>. The anti-rattling member <NUM> thus axially maintains the medical container <NUM> against the power pack <NUM> and the power pack <NUM> against the top body <NUM> (as schematically illustrated in <FIG>). The axial clearance and the consequent rattling noise are suppressed.

In the embodiment of <FIG>, the anti-rattling member <NUM> is in the form of a protrusion such as a tranversal rib which may be orthogonal to the longitudinal axis A and which is arranged on the proximal side <NUM> of the plug <NUM>. The protrusion has a proximal abutment surface <NUM> which may be in the form of a sloped surface inclined with regard to the longitudinal axis A and configured to abut against the resilient legs <NUM> of the retainer <NUM> to outwardly deflect said resilsient legs <NUM>. Deformation of the resilient legs <NUM> and their abutment againts the sloped surface <NUM> causes the retainer <NUM> to be pushed in the proximal direction. The plug <NUM> may include one, two or more anti-rattling members <NUM> which may be arranged diametrically opposite to each other. The anti-rattling members <NUM> are arranged at a distance from the lateral edge of the sealing portion <NUM>. As illustrated in <FIG>, the anti-rattling members <NUM> may have a proximal end <NUM> which may define a flat transversal surface orthogonal to the longitudinal axis A.

The plug <NUM> may advantageously include a push-back member <NUM> for allowing to perform the push-back step, i.e. to push the needle shield <NUM> in the proximal direction until the distal stop <NUM> of the retainer <NUM> engages the axial gap <NUM> between the needle shield <NUM> and the syringe barrel <NUM> and thus faces the proximal end <NUM> of the needle shield <NUM>. In the embodiment of <FIG>, the push-back member <NUM> includes a through-hole <NUM> which may be arranged at the center of the transversal plate forming the sealing portion <NUM> and which is configured to face the distal end <NUM> of the needle shield <NUM>. The through-hole <NUM> is shaped to allow a machine to extend through the plug <NUM> so that the machine can push the retainer <NUM> in the proximal direction. The through-hole <NUM> may be arranged between the sloped surfaces <NUM> of the anti-rattling members <NUM>. The anti-rattling members <NUM> may be arranged at a distance from the through-hole <NUM>.

In the embodiment of <FIG>, the plug <NUM> is similar to the plug <NUM> of <FIG> except that the securing means for securing the plug <NUM> to the housing <NUM> include four diametrically opposite flexible hooks <NUM> axially extending from the proximal side <NUM> of the transversal plate of the sealing portion <NUM> and configured for engaging complementary features of the cap housing <NUM>. Besides, the anti-rattling member <NUM> is in the form of a circumferential rib extending around the central longitudinal axis A. The anti-rattling member <NUM> still has a proximal abutment surface in the form of a sloped surface <NUM> which is inclined with regard to the longitudinal axis A and which is configured to abut against the resilient legs <NUM> of the retainer <NUM> to outwardly deflect said resilsient legs. Deformation of the resilient legs <NUM> and their abutment againts the sloped surface <NUM> causes the retainer <NUM> to be pushed in the proximal direction. The plug <NUM> may include one, two or more anti-rattling members <NUM> which may be arranged diametrically opposite to each other. The anti-rattling members <NUM> are arranged at a distance from the lateral edge. The plug <NUM> of <FIG> does not include a push-back member <NUM> for allowing to perform the push-back step. The push-back step accordingly needs to be performed before assembly of the plug <NUM> within the cap housing <NUM>.

<FIG> show the interference between the plug <NUM> and the retainer <NUM>. As can be seen in these Figures, the anti-rattling member <NUM> of the plug <NUM> abuts against the distal end <NUM> of the resilient legs <NUM> of the retainer <NUM>, thereby causing deformation of the resilient legs <NUM>. The elastic deformation of the resilient legs <NUM> suppresses the clearances between the components and thus cancels the rattling noise.

With reference to the embodiment illustrated in <FIG>, the plug <NUM> includes a single anti-rattling member <NUM>. The anti-rattling member <NUM> has two diametrically opposite sloped surfaces <NUM> which are inclined with regard to the longitudinal axis A and which are configured to abut against the resilient legs <NUM> of the retainer <NUM> to outwardly deflect said resilsient legs <NUM>. Deformation of the resilient legs <NUM> and their abutment againts the sloped surface <NUM> causes the retainer <NUM> to be pushed in the proximal direction. As illustrated in <FIG>, the single anti-rattling member 91may have a proximal end <NUM> which may define a flat transversal surface orthogonal to the longitudinal axis A. Furthermore, the plug <NUM> advantageously includes a push-back member <NUM> for allowing to perform the push-back step, i.e. to push the needle shield <NUM> in the proximal direction until the distal stop <NUM> of the retainer <NUM> engages the axial gap <NUM> between the needle shield <NUM> and the syringe barrel <NUM> and thus axially faces the proximal end <NUM> of the needle shield <NUM>. In the embodiment of <FIG>, the push-back member <NUM> is formed by a resilient element, such as a spring, which may be arranged at the center of the anti-rattling member <NUM> or the center of the transversal plate forming the sealing portion <NUM> and which is configured to face the distal end <NUM> of the needle shield <NUM>. The resilient element <NUM> extends axially and is configured to automatically perform the push-back step, i.e. without need for a machine and an additional time-consuming step to push the retainer <NUM> in the proximal direction. The resilient element <NUM> may be arranged between the sloped surfaces <NUM>. The resilient element <NUM> is preferably integral with the plug <NUM> which may thus be made of a single piece.

<FIG> illustrate the plug <NUM> mounted within the cap housing <NUM> and the resilient element <NUM> automatically pushing against the distal end <NUM> of the needle shield <NUM> so that the needle shield <NUM> and the medical container <NUM> move axially with regard to the retainer <NUM> until the distal stop <NUM> of the retainer <NUM> abuts against the proximal end <NUM> of the needle shield <NUM>.

<FIG> schematically illustrates the anti-rattling member <NUM> pressing the retainer <NUM>, the medical container <NUM> and the power pack <NUM> against the top body <NUM> to suppress the clearances and thus the rattling noise.

As illustrated in the embodiment of <FIG>, the anti-rattling member <NUM> may be a resiliently deformable member which may be in the form of a T-shaped blade. The T-shaped blade <NUM> has one transversal arm <NUM> extending orthogonal to the longitudinal axis A between two free ends <NUM>. A connecting rod <NUM> extends in the axial direction for connecting the transversal arm <NUM> to the proximal side <NUM> of the plug <NUM>. The T-shaped blade <NUM> has a proximal abutment surface <NUM> which may be defined by the upper surface of the transversal arm <NUM>, opposite the connecting rod <NUM>. The proximal abutment surface <NUM> is configured to abut against the distal end <NUM> of the retainer <NUM> to push said retainer <NUM> in the proximal direction. The plug <NUM> may include one, two or more T-shaped blades <NUM> which may be arranged diametrically opposite to each other. The T-shaped blades <NUM> are arranged at a distance from the lateral edge of the sealing portion <NUM>. As illustrated in <FIG>, the connecting rod <NUM> may be arranged at the middle of the transversal arm <NUM>.

As visible in <FIG>, the plug <NUM> may further include a push-back member <NUM> for automatically performing the push-back step, in the same way as the push-back member <NUM> of the plug <NUM> illustrated in <FIG>. Thus, the push-back member <NUM> includes a resilient element, such as a spring, which may be arranged at the center of the the transversal plate of the sealing portion <NUM> and which is configured to face the distal end <NUM> of the needle shield <NUM>. The resilient element <NUM> extends axially and is configured to automatically perform the push-back step, i.e. without need for a machine and an additional time-consuming step to push the retainer <NUM> in the proximal direction. The resilient element <NUM> may be arranged between the T-shaped bladed <NUM>, at a distance from the T-shaped blades <NUM>. The resilient element <NUM> is preferably integral with the plug <NUM>, which may thus be made of a single piece.

Claim 1:
Cap (<NUM>) for removing a needle shield (<NUM>) attached to a medical container (<NUM>) arranged inside a body (<NUM>) of an autoinjector (<NUM>), the cap (<NUM>) including:
a housing (<NUM>) extending along a longitudinal axis A, the housing (<NUM>) having a distal end (<NUM>) and an opposite proximal end configured to be removably attached to the body (<NUM>) of the autoinjector (<NUM>),
a retainer (<NUM>) arranged inside the housing (<NUM>) and axially movable with respect to said housing (<NUM>), the retainer (<NUM>) including an inner cavity (<NUM>) for receiving the needle shield (<NUM>), a clamping member (<NUM>) configured to remove the needle shield (<NUM>) from the medical container (<NUM>), an opened distal end (<NUM>) configured to provide access to a distal end (<NUM>) of the needle shield (<NUM>), and a proximal abutment surface (<NUM>) configured to abut against the medical container (<NUM>),
a plug (<NUM>) arranged at the distal end (<NUM>) of the housing (<NUM>), the plug (<NUM>) including a sealing portion (<NUM>) configured for closing the distal end (<NUM>) of the housing (<NUM>) and at least one anti-rattling member (<NUM>) arranged at a proximal side (<NUM>) of the sealing portion (<NUM>) for abutting against the retainer (<NUM>) and move the retainer (<NUM>) in the proximal direction.