an auto-injector for automatically injecting the product into the injection site

Abstract

The automatic injector (1) comprises: a housing that accommodates a medication container having a needle at its distal end; a needle cover (200) axially movable within the housing, the needle cover (200) movable between a retracted position that shields the needle, a retracted position that exposes the needle, and a safe position that re-shields the needle; a retainer that is elastically deformable between a rest position that holds the plunger rod in an initial position and a deformed position that allows the plunger rod to move distally to press a stopper disposed within the barrel; and a locking member (400) rotatable about an axis (A1) within the housing, the locking member (400) rotatable between a locked position that holds the retainer in the rest position and a released position that allows deformation of the retainer, the rotation of the locking member being caused by movement of the needle cover from the retracted position to the safe position, the locking member (400) comprising a locking device (450) configured to lock the needle cover (200) in the safe position.

Description

[Technical Field]

[0001] The present invention relates to an auto-injector. [Background technology]

[0002] As used herein, the distal end of an element or device means the end furthest from the user's hand, and the proximal end means the end closest to the user's hand. Similarly, as used herein, the terms "distally" and "distally" mean in a direction away from the user's hand, and the terms "proximally" and "proximally" mean in a direction toward the user's hand.

[0003] An auto-injector (auto-injection device) is designed to automatically inject a medical product into an injection site. An auto-injector typically includes a housing that contains a medical container having a barrel defining a reservoir for containing the medical product, the barrel having a distal end provided with an injection needle and an open proximal end.

[0004] The automatic injector also includes a safety shield movable between an extended position to cover the needle and a retracted position to expose the needle, and an injection mechanism for automatically injecting the medical product into an injection site. A locking means is provided to hold the plunger rod in an axially constrained initial position despite the action of a compression spring. A release member is typically positioned to release the plunger from the locking means, allowing the spring to push the plunger rod distally to perform the injection. The injection mechanism typically includes a plunger rod housed in the open proximal end of the barrel of the medical container to press against a stopper within the barrel, and a spring in an initially compressed state to move the plunger distally. A locking means is provided to hold the plunger rod axially blocked in the initial position despite the action of the compression spring. A release member is typically positioned to release the plunger from the locking means, allowing the spring to push the plunger rod distally to perform the injection. A predetermined displacement of the safety shield toward the retracted position is required for the release member to unlock the locking means and release the plunger rod.

[0005] After the injection is completed, the auto-injector is removed from the injection site and the safety shield automatically returns to its extended position covering the needle.

[0006] Having and keeping the needle covered after an injection is extremely important to prevent needle injuries and contamination with medical products. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, there is a need for an auto-injector that provides a mechanism for reliably shielding the needle, yet is not overly complex and adds weight or cost. [Means for solving the problem]

[0008] To this end, and according to one embodiment, the present invention relates to an auto-injector for automatically injecting a product into an injection site, the auto-injector comprising: a housing configured to receive a medical container having an axis defining a longitudinal direction and including a barrel defining a reservoir for containing a medical product, the barrel having a distal end at which a needle is provided and an open proximal end configured to receive a plunger rod for pushing a stopper disposed within the barrel; an inner sleeve axially disposed within the housing and fixed to the housing; a needle cover coupled to the housing, the needle cover rotationally fixed relative to the housing and axially movable within the housing between a retracted position in which the needle cover projects beyond the distal end of the housing to shield the needle, a retracted position in which the needle cover moves proximally relative to the housing from the retracted position to at least partially expose the needle, and a safety position in which the needle cover moves distally relative to the housing from the retracted position and projects beyond the distal end of the housing to shield the needle; guide means fixedly disposed on the housing for guiding axial movement of the needle cover relative to the housing; a first biasing means for biasing the needle cover in a distal direction; a plunger rod axially movable within the housing between an initial position and an end-of-injection position distal to the initial position, the plunger rod configured to push the stopper to expel the medical product; a second biasing means for biasing the plunger rod in a distal direction; a retainer for holding the plunger rod in the initial position against the action of the second biasing means, the retainer being disposed in the distal portion of the inner sleeve, the retainer being resiliently deformable between a rest position in which the retainer axially abuts the plunger rod to lock the plunger rod in the initial position, and a deformed position in which the retainer is radially deflected to allow the plunger rod to move in the distal direction; and a locking member disposed within the housing, the locking member being axially fixed relative to the housing and rotatable about an axis relative to the housing between a locked position in which the locking member prevents deformation of the retainer and holds the retainer in a rest position, and a released position in which the locking member allows deformation of the retainer, the rotation of the locking member from the locked position to the released position being caused by the needle cover moving from the stored position to the retracted position, the locking member comprising a locking device configured to lock the needle cover in a safe position.

[0009] The locking member therefore performs both the function of activating the injection mechanism by deforming the retainer and allowing the plunger rod to be pushed distally, and the function of locking the needle shroud in a safe position.

[0010] By achieving these two functions in a single component, the locking member, the number of components constituting the auto-injector can be reduced, reducing complexity and saving materials. Furthermore, the present invention allows the overall volume of the auto-injector to be reduced, which is highly advantageous when using a smaller barrel capacity, a shorter needle, or smaller medical containers. This eliminates the need for a conventional large auto-injector designed to accommodate a conventional large medical container. Furthermore, the reduced number of components simplifies the manufacturing process and improves reliability, as fewer dimensional and positional adjustments between components are required.

[0011] In practice, the catch member and locking device are preferably formed integrally, for example by moulding from a plastics material.

[0012] The locking member not only functions to lock the plunger rod in the retracted position, but also to lock the needle cover in the safe position.

[0013] The needle cover extends in the retracted position and the safety position (which may be the same position). In the retracted position, which is more proximal than the retracted position, the needle cover allows injection. Therefore, this retracted position is determined so that the needle is inserted to an appropriate depth into the user's body for injection. The needle cover then moves to the safety position, which is more distal than the retracted position.

[0014] In one embodiment, when the retainer is disposed at the distal portion of the inner sleeve, the locking member is also disposed near the distal portion of the inner sleeve for cooperation with the retainer. Furthermore, the needle cover is provided with a portion for cooperation with the locking member so that axial movement of the needle cover rotates the locking member. Therefore, the needle cover must extend proximally to the locking member. According to the present invention, the locking member is disposed so distally within the housing because the retainer is disposed at the distal portion of the inner sleeve, thereby enabling the length of the needle cover to be reduced compared to conventional auto-injectors in which the retainer is disposed more proximally relative to the housing.

[0015] As a result, the present invention makes it possible to provide a shorter auto-injector, which is advantageous in terms of storage and transportation, and also reduces the amount of material required to manufacture the auto-injector.

[0016] Furthermore, the auto-injector according to the invention is particularly compact and robust due to at least one of the following features: The retainer is disposed on an inner sleeve that is a member fixed to the housing, The needle cover is axially movable within the housing but rotationally fixed relative to the housing, reducing restrictions; The locking member is rotatable relative to the housing but is axially fixed to the housing, thereby providing fewer restrictions.

[0017] The inner sleeve can be integrally formed with the housing, can be part of the housing, or can be initially formed separately and then secured to the housing, in either configuration, the inner sleeve is secured to the housing for rotation and sliding relative to the housing both longitudinally and circumferentially.

[0018] A plunger rod is disposed within the inner sleeve and is axially movable relative to the inner sleeve, thereby displacing the retainer outwardly from a rest position to a deformed position.

[0019] In one embodiment, the only movement of the needle cover is the aforementioned axial movement, and the only movement of the locking member is the aforementioned rotational movement.

[0020] In one embodiment, no part of the auto-injector other than the needle cover and locking member moves relative to the body for operation of the auto-injector, although this does not preclude the provision of non-moving but deforming members such as retainers and locking devices.

[0021] The retainer may be in the form of longitudinally extending legs.

[0022] The retainer may be provided with a holder, such as a protrusion, configured to cooperate with an auto-injector. The holder may be located at a distal end of the retainer.

[0023] The locking device preferably includes a first stopper extending substantially perpendicular to the axis, the first stopper cooperating with the needle cover in the safety position to prevent axial movement of the needle cover in the proximal direction.

[0024] In one embodiment, the locking member includes a body, and the locking device includes a tab having a base fixed to the body and a free distal end, the tab protruding obliquely (i.e., protruding outward, for example) from the body in a distal direction toward the needle cover, the tab being resiliently deflectable toward the body upon movement of the needle cover from the retracted position to the safe position, and the distal end of the tab forming the first stop. The body and the tab are preferably integrally molded.

[0025] The locking device preferably includes a second stopper extending in a plane substantially parallel to the axis, the second stopper cooperating with the needle cover in the safety position to prevent the locking member from rotating towards the locked position.

[0026] In one embodiment, the second stopper comprises a wall that extends substantially axially and projects toward (e.g., projects outward from) the needle cover. The second stopper may be circumferentially offset from the first stopper.

[0027] The locking member may have a cam surface that protrudes toward the needle cover and is inclined relative to the axis, the cam surface being configured to cooperate with the needle cover, and the locking member rotates from the locked position to the released position when the needle cover moves from the stored position to the retracted position.

[0028] According to one embodiment, the needle cover comprises an operating element for cooperating with the first stop and / or the second stop and / or the cam surface, which can thus rotate the locking member when the needle cover is moved from the retracted position to the safe position and / or deflect a tab forming part of the locking device when the needle cover is moved from the retracted position to the safe position. The operating element may comprise at least one pin that protrudes towards the locking member, i.e., for example protrudes inward.

[0029] The retainer may include legs with bulges that are directed toward the plunger rod and can engage holes or recesses in the plunger rod. The legs are resiliently deflectable radially from the plunger rod. The legs may extend axially. The legs may extend distally from a proximal wall of the housing. The legs may be part of an inner sleeve of the housing, the sleeve protruding distally from a lateral wall that closes the proximal end of the housing.

[0030] The locking member may have an axial groove configured to receive the retainer when the retainer is in the deformed position, and the axial groove may be circumferentially offset relative to a locking surface of the locking member that holds the retainer in the rest position.

[0031] The automatic injector may include an axial holder for axially locking the locking member. According to an embodiment of the axial holder, an abutment is provided inside the housing, preferably in a plane substantially perpendicular to the axis, to prevent proximal movement of the locking member, and additional holding force is provided by friction between the peripheral wall of the locking member and the wall of the adjacent part. In another embodiment of the axial holder, the locking member may be clipped to the housing or another member axially fixed relative to the housing, thereby providing both proximal and distal locking functions. In this embodiment, the locking member may be provided with a hook.

[0032] The locking member may have a plane of symmetry that includes the axis of the auto-injector.

[0033] The locking member includes two sets symmetrical about a plane containing the axis of the auto-injector, each set comprising a cam surface, a first stopper (e.g., in the form of a resiliently deformable tab), and a second stopper, e.g., the locking member has a plane of symmetry that includes the axis of the auto-injector.

[0034] The locking member may have a generally cylindrical shape. The locking member may comprise a substantially cylindrical body. In one embodiment, the locking member is disposed outside the plunger rod and retainer and inside the needle cover. The locking member may be located proximally from an abutment surface of the auto-injector against which a proximal flange of the barrel of the medical container can abut.

[0035] The needle cover is provided with guide means configured to cooperate with guide means fixedly arranged on the housing to guide axial movement of the needle cover relative to the housing and preferably to limit radial or tangential movement of the needle cover relative to the housing.

[0036] Guide means for cooperating with the needle cover guide means may be arranged on the locking member.

[0037] For example, the needle cover may have a distal portion including a substantially cylindrical shield and at least one arm extending proximally from the shield. The needle cover preferably includes two opposing arms. The operating portion may be located near the proximal end of each arm.

[0038] The housing includes an axially extending channel for receiving the needle cover arms, with at least a portion of the lateral ends of the arms positioned against the inner surface of the channel, where "against" means in contact with or adjacent to a functional gap that allows relative sliding movement parallel to the axis.

[0039] Preferably, at least a portion of the side ends of the arms are positioned against two substantially perpendicular inner surfaces of the channel to prevent movement along two orthogonal directions.

[0040] In one embodiment, a first portion of the lateral end of the arm contacts one inner surface of the channel, and a second portion of the lateral end of the arm contacts another inner surface of the channel at a different axial location. Guides can be implemented at different locations along the length of the arm by different features or cooperation of features. For example, one axial location may have a guide to prevent tangential movement, another axial location may have a guide to prevent inward radial movement, and yet another axial location may have a guide to prevent outward radial movement.

[0041] The needle cover arm has a main wall and at least one rail extending axially and projecting outward from the main wall. The rail is configured to abut against an inner peripheral wall of the housing. This configuration prevents outward movement of the needle cover. Additionally or alternatively, the rail can be configured to abut against at least one rib projecting inward from the housing and extending axially. This configuration prevents tangential movement of the needle cover. The same rail may abut both the inner peripheral wall and the rib of the housing, or separate rails may be provided for these two functions.

[0042] The needle cover arm includes a tab having a base fixed to the arm main wall and a free distal end, the tab protruding obliquely from the main wall in a distal direction toward the housing, and the tab is resiliently deflectable axially to mount the needle cover to the housing. Furthermore, in the retracted and secure positions, the distal end of the tab is configured to abut against at least one axially extending rib projecting inward from the housing to prevent distal movement of the needle cover relative to the housing. The rib may be the same as the rib cooperating with the rail of the needle cover, or may be a separate rib.

[0043] When the rail abuts the inner peripheral wall of the housing, the main wall is forced radially inward against the inner peripheral wall of the housing, thereby forming a space between the main wall of the arm of the needle cover and the inner peripheral wall of the housing, and the tab can be located within that space.

[0044] In the retracted position, a portion of the lateral end of the arm abuts a surface of the locking member that extends in a plane substantially parallel to the axis, thereby preventing unintended tangential displacement and holding the needle cover arm in the proper position when the needle cover is in the retracted position, thereby ensuring proper sequence of movement of the components of the auto-injector and proper operation of the auto-injector.

[0045] In one embodiment, the locking member comprises a body; the body has a central bore, for example having a substantially cylindrical inner surface, in which the inner sleeve is received, and at least one axial groove opening into the central bore; In the locked position, the locking member is positioned so that the retainer radially faces the inner surface of the central bore, and in the released position, the locking member is positioned so that the retainer radially faces the axial groove.

[0046] The axial grooves are configured to initiate deformation of the retainer when the needle cover is moved axially along a predetermined length, and are preferably configured to control the rate of deformation of the retainer to the deformed position, particularly depending on the circumferential location and / or shape of the axial grooves.

[0047] The initiation of deformation of the retainer almost immediately accompanies the initiation of the injection. Initiating deformation of the retainer when the needle cover has moved axially a predetermined distance corresponds to timing the start of the injection relative to the puncture depth. Initiating the injection before the needle reaches the final puncture depth can be advantageous to ensure that all of the medication is expelled from the medication container and injected into the injection site when the user removes the automatic injector from the injection site.

[0048] For example, in one embodiment, the retainer may be allowed to deform after the locking member has rotated an angle of 22°, which corresponds to an axial movement of the needle cover of approximately 5 mm.

[0049] By controlling the rate at which the retainer deforms toward the deformed position, the actuation of the plunger rod can be controlled over the time interval from when the release of the retainer begins to occur until the plunger rod moves distally and the actual injection can be performed.

[0050] This time interval is preferably relatively short, but not too short, as too short a time interval may cause a perceived shock to the user. Additionally, assembly considerations of the auto-injector may limit the speed that can be achieved.

[0051] For example, the longitudinal edge between the inner surface and the axial groove is the last point of contact between the retainer and the inner surface before the retainer can deform as the locking member rotates, and the longitudinal edge is called the actuation edge.

[0052] In one embodiment, the axial groove includes a control surface that extends from the working edge toward the inner space of the axial groove (i.e., away from the inner surface) and away from the housing axis. The control surface is inclined at an angle of 25° to 50°, preferably 35° to 45°, relative to a radial segment of the housing that passes through the working edge, the angle being measured in a plane perpendicular to the housing axis.

[0053] The angle must be large enough to rapidly deform the retainer, thereby creating a control surface steep enough to rapidly release the plunger rod and initiate the actual injection. However, if the angle is too large, the action may be too abrupt, causing a shock that may adversely affect the proper operation of the auto-injector. Furthermore, if the angle is too large, it may be difficult or impossible to properly assemble the components of the auto-injector.

[0054] According to a second aspect, the present invention relates to a medical device comprising an automatic injector as described above and a medical container including a barrel defining a reservoir containing a medical product, the barrel having a distal end at which a needle is provided and an open proximal end configured to receive a plunger rod for pressing a stopper located in the barrel, the medical container being contained within a housing of the automatic injector.

[0055] According to a third aspect, the present invention relates to an auto-injector for automatically injecting a product into an injection site, the auto-injector comprising: a housing configured to receive a medical container having an axis defining a longitudinal direction and including a barrel defining a reservoir for containing a medical product, the barrel having a distal end at which a needle is provided and an open proximal end configured to receive a plunger rod for pushing a stopper disposed within the barrel; a needle cover coupled to the housing and axially movable within the housing, the needle cover being movable between a retracted position in which the needle cover projects from a distal end of the housing to cover the needle, a retracted position in which the needle cover moves from the retracted position proximally relative to the housing to at least partially expose the needle, and a safety position in which the needle cover moves from the retracted position back distally relative to the housing to project from the distal end of the housing to cover the needle; a first biasing means for biasing the needle cover in a distal direction; a plunger rod axially movable within the housing between an initial position and an end-of-injection position distal to the initial position, the plunger rod configured to push the stopper to expel the medical product; a second biasing means for biasing the plunger rod in a distal direction; a retainer for holding the plunger rod in an initial position against the action of the second biasing means, the retainer being configured to be in either an engaged state in which the plunger rod is held in the initial position, or a disengaged state in which the plunger rod can be moved distally; a movable locking member disposed within the housing, the locking member being movable between a locking position where the retainer is held in an engaged state and a release position where the retainer can be moved to a disengaged state, the movement of the locking member from the locking position to the release position being caused by the needle cover moving from the storage position to the retracted position; Equipped with the needle cover includes a shield portion at a distal end thereof configured to cover the needle in the storage position and the safety position, and an inner portion extending proximally from the shield portion into the housing; The needle cover has a shield portion at its distal end configured to cover the needle in the storage position and the safety position, and an inner portion extending proximally from the shield portion into the housing, the inner portion having a main wall and a stop protruding outward from the main wall, and in the storage position and the safety position, the stop is configured to abut against at least one rib protruding inward from the housing and extending axially, thereby preventing the needle cover from moving distally relative to the housing from the storage position or the safety position.

[0056] Such an arrangement allows the needle cover to be effectively retained against the housing when the auto-injector is drop tested, thereby ensuring robustness and proper operation of the auto-injector.

[0057] Furthermore, the needle cover is directly bonded to the housing, eliminating the need for intermediate parts, simplifying the design of the auto-injector and saving materials. Direct bonding of the needle cover and housing reduces the need for dimensional and alignment adjustments between the parts, simplifying the manufacturing process and improving reliability.

[0058] In one embodiment, the inner portion of the needle cover comprises a tab having a base fixed to the main wall and a free distal end, the tab protruding obliquely from the main wall in a distal direction toward the housing, the tab being resiliently deflectable toward the axis to attach the needle cover to the housing, and the distal end of the tab forming a stopper.

[0059] The inner portion of the needle cover includes at least one rail extending axially and projecting outwardly from the main wall, the rail configured to abut against the inner peripheral wall of the housing.

[0060] The rails allow the tabs to be received in an area formed between the main wall of the inner portion of the needle cover and the inner peripheral wall of the housing.

[0061] The shield portion is substantially cylindrical, and the inner portion has at least one arm, preferably two oppositely positioned arms.

[0062] The interior portion of the needle cover can guide axial movement of the needle cover and limit or prevent radial or tangential movement of the needle cover relative to the housing.

[0063] The interior portion may also include an actuator for cooperating with the locking member to move the locking member and / or lock the needle cover in the safe position.

[0064] The automatic injector may include any one or a combination of the aforementioned components. In particular, the retainer is resiliently deformable between an engaged state (also called a resting position) in which the retainer axially abuts the plunger rod and secures the plunger rod in an initial position, and a disengaged state (also called a deformed position) in which the retainer is radially deflected to allow the plunger rod to move distally. The locking member may be rotatable about an axis between the locked position and the released position. When the retainer is deformable as described above, the locking member can prevent deformation of the retainer when in the locked position and hold the retainer in the resting position. Furthermore, the locking member may include a locking device configured to lock the needle cover in a safe position.

[0065] According to a fourth aspect, the present invention relates to an auto-injector for automatically injecting a product into an injection site, the auto-injector comprising: a housing configured to receive a medical container having an axis defining a longitudinal direction and including a barrel defining a reservoir for containing a medical product, the barrel having a distal end at which a needle is provided and an open proximal end configured to receive a plunger rod for pushing a stopper disposed within the barrel; a needle cover coupled to the housing and axially movable within the housing, the needle cover being movable between a retracted position in which the needle cover projects from a distal end of the housing to cover the needle, a retracted position in which the needle cover moves from the retracted position proximally relative to the housing to at least partially expose the needle, and a safety position in which the needle cover moves from the retracted position back distally relative to the housing to project from the distal end of the housing to cover the needle; a first biasing means for biasing the needle cover in a distal direction; a plunger rod axially movable within the housing between an initial position and an end-of-injection position distal to the initial position, the plunger rod configured to push the stopper to expel the medical product; a second biasing means for biasing the plunger rod in a distal direction; a retainer for holding the plunger rod in an initial position against the action of the second biasing means, the retainer being configured to be in either an engaged state in which the plunger rod is held in the initial position, or a disengaged state in which the plunger rod can be moved distally; a locking member disposed within the housing, the locking member rotatable about an axis relative to the housing between a locked position that prevents deformation of the retainer and holds the retainer in a rest position, and a released position that allows deformation of the retainer, the rotation of the locking member from the locked position to the released position being caused by movement of the needle cover from the stored position to the retracted position, the locking member including a locking device configured to lock the needle cover in a safe position; Equipped with The locking member has a body, the body having a central hole with an inner surface and at least one axial groove opening into the central hole, and in the locked position, the locking member is arranged so that the retainer faces radially toward the inner surface of the central hole, and in the released position, the locking member is arranged so that the retainer faces radially toward the axial groove.

[0066] In one embodiment, the axial groove is configured to initiate deformation of the retainer when the needle cover is moved axially along a predetermined length, and is preferably configured to control the rate of deformation of the retainer to the deformed position.

[0067] In one embodiment, the axial groove comprises a control surface that extends from the working edge toward the inner space of the axial groove (i.e., away from the inner surface) and away from the housing axis, and the control surface is inclined at an angle of 25° to 50°, preferably 35° to 45°, relative to a radial line segment of the housing that passes through the working edge.

[0068] The automatic injector may further include an inner sleeve axially disposed within the housing and secured to the housing, the inner sleeve being received in the central bore of the locking member, and the retainer may be disposed at a distal portion of the inner sleeve.

[0069] The auto-injector may comprise one or more of the above features alone or in combination. [Brief explanation of the drawings]

[0070] One possible embodiment of the invention will now be described by way of non-limiting example with reference to the accompanying drawings, in which: [Figure 1] 1A and 1B illustrate a medical device including an automatic injector according to an embodiment of the present invention in a retracted position. [Figure 2] 1 shows a medical container housed in an automatic injector. FIG. [Figure 3] FIG. 1 is an exploded view of an auto-injector. [Figure 4]1 is a perspective side view of an upper housing of an automatic injector housing. FIG. [Figure 5] FIG. 5 is a perspective view of the upper housing of FIG. 4 from the distal end. [Figure 6] 1 is a perspective side view of a lower housing of the automatic injector housing; FIG. [Figure 7] FIG. 7 is a perspective view of the lower housing of FIG. 6 from the distal end. [Figure 8] FIG. 7 is a partial perspective view of the lower housing of FIG. 6, shown from the proximal end. [Figure 9] FIG. 1 is a perspective view of the upper plunger rod of the auto-injector. [Figure 10] FIG. 1 is a side perspective view of a needle cover for an automatic injector. [Figure 11] FIG. 11 is a perspective view of the needle cover of FIG. 10 from its distal end. [Figure 12] FIG. 1 is a side perspective view of a locking member of an automatic injector. [Figure 13] 13 is a perspective view of the locking member of FIG. 12 from the proximal end. FIG. [Figure 14] FIG. 13 is a detailed cross-sectional view of the locking member of FIG. 12. [Figure 15] FIG. 1 is a perspective view of a cap of an automatic injector. [Figure 16] FIG. 1 is a perspective view of a cap of an automatic injector. [Figure 17] 1A-1C are longitudinal cross-sectional views of the auto-injector in two mutually perpendicular planes in the retracted position. [Figure 18] 1A-1C are longitudinal cross-sectional views of the auto-injector in two mutually perpendicular planes in the retracted position. [Figure 19] FIG. 1 is a bottom view showing the auto-injector in the retracted position. [Figure 20] FIG. 1 is a partial perspective view showing the auto-injector in the retracted position. [Figure 21] 2 is a cross-sectional view of the auto-injector in the retracted position taken along line AA of FIG. 1. [Figure 22]2 is a cross-sectional view of the auto-injector in the retracted position taken along line BB in FIG. 1; [Figure 23] 2 is a cross-sectional view of the automatic injector in the retracted position taken along line CC in FIG. 1. [Figure 24] 2 is a cross-sectional view of the automatic injector in the retracted position taken along line DD in FIG. 1; FIG. [Figure 25] FIG. 1 is a partial perspective view of the auto-injector from its distal end in the retracted position. [Figure 26] 1 is a cross-sectional view showing the locking member in the locked position and the auto-injector in the retracted position; FIG. [Figure 27] 1A-1C are longitudinal cross-sectional views of a portion of an automatic injector illustrating the steps of use from a stored position. [Figure 28] 1A-1C are longitudinal cross-sectional views of a portion of an automatic injector illustrating the steps of use from a stored position. [Figure 29] 10A-10C are partial side views of the auto-injector illustrating movement of the locking member from a locked position to a released position. [Figure 30] 27 is a schematic view similar to FIG. 26 with the locking member in the released position; FIG. [Figure 31] 18 is a view similar to FIG. 17 showing the needle cover in the retracted position prior to injection. [Figure 32] FIG. 32 is a view similar to FIG. 31 showing the state after the injection is completed. [Figure 33] FIG. 10 is a partial side view of the auto-injector showing the locking member in the released position and the needle cover moving from the retracted position to the safe position. [Figure 34] 19 is a view similar to FIG. 18 showing the needle cover in the safe position. [Figure 35] FIG. 10 is a partial perspective view of an auto-injector according to another embodiment of the present invention in a retracted position. [Figure 36] FIG. 36 is a longitudinal cross-sectional view of the automatic injector shown in FIG. 35. [Figure 37] FIG. 5 is a partially cutaway perspective view of the upper housing shown in FIG. 4. [Figure 38] 36 is a perspective view of the upper housing of the auto-injector of FIG. 35. FIG. [Figure 39] 10 is a cross-sectional view of the auto-injector showing the locking member rotated from the locked position to hold the retainer in the rest position. FIG. [Figure 40] 1 is a cross-sectional view of the automatic injector showing the locking member rotated from the locked position and attempting to allow deformation of the retainer. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0071] FIG. 1 shows an auto-injector 1 according to one embodiment of the present invention.

[0072] The auto-injector 1 is designed for automatic injection of a product into an injection site. The auto-injector 1 extends along an axis A1 defining a longitudinal direction, which axis A1 is also the axis of each of the components of the auto-injector 1 in the mounted position.

[0073] As shown in FIG. 3, the auto-injector 1 comprises various components including a housing 100, a needle cover 200, a plunger rod 300, and a locking member 400.

[0074] The housing 100 has a longitudinal axis A100 and is configured to accommodate the medical container 2 shown in FIG. 3 . The medical container 2 has an axis A2 and includes a barrel 3 defining a reservoir for containing a medical product. The barrel 3 has a distal end 4 at which a needle 5 (also called a syringe needle) is provided and a proximal end 6 that is open to accommodate a plunger rod 300. A stopper 7 is disposed within the barrel 3 proximal to the medical product (see, for example, FIG. 17 ) and is configured to be pushed by the plunger rod 300 to expel the medical product through the needle 5. The medical container 2 also includes a flange 8 extending outward from the proximal end 6. A rigid needle shield 9 is removably attached to the barrel 3 to cover the needle 5 prior to use.

[0075] The housing 100 is shown in FIGS.

[0076] The housing 100 has two planes of symmetry P1 and P2 that contain an axis A100 and are perpendicular to each other.

[0077] The housing 100 comprises a lower housing 101 having an axis A101 and an upper housing 150 having an axis A150, which are assembled together by suitable fastening means, such as a snap-fitting means. The lower housing 101 and the upper housing 150 have corresponding cylindrical shapes, and when assembled, they form a cylindrical shape in which the axes A101, A150, and A100 substantially coincide. Preferably, the lower housing 101 and the upper housing 150 each have two planes of symmetry, which coincide with planes P1 and P2, respectively, in the assembled state. Therefore, the same reference numerals P1 and P2 are used to identify the planes of symmetry of the lower housing 101 and the upper housing 150.

[0078] The lower housing 101 will be described with reference to FIGS.

[0079] The lower housing 101 may be integrally formed, for example by injection molding of a plastic material.

[0080] Lower housing 101 includes a peripheral wall 102, which is preferably substantially cylindrical and has an inner surface 103, an outer surface 104, an open distal end 105, and an open proximal end 106. Lower housing 101 also includes an inner sheath 107, which is substantially cylindrical and coaxial with peripheral wall 102. An open distal end 108 of sheath 107 is located proximal to open distal end 105 of peripheral wall 102, and an open proximal end 109 of sheath 107 is located distal to open proximal end 106 of peripheral wall 102.

[0081] In one embodiment, on either side of axis A101, divider walls 110 extend substantially parallel to plane P2 from sheath distal end 108 to sheath proximal end 109. Divider walls 110 may be disposed approximately tangentially to sheath 107 or may be slightly offset relative to sheath 107 toward axis A101. The longitudinal edges 111 of the partition wall 110 may be directly connected to the inner surface 103 of the lower housing peripheral wall 102, except near the sheath proximal end 109 (see Figures 7 and 23), where each of the longitudinal edges 111 may be spaced apart from the inner surface 103, and in that case the longitudinal edges 111 are extended by side walls 112 that are at least partially perpendicular to the partition wall 110 and connected to the inner surface 103 of the lower housing peripheral wall 102 (see Figures 8, 20, and 22).

[0082] In this manner, two channels 115 are formed between the sheath 107 and the peripheral wall 102. The channels 115 extend axially along the entire sheath 107. The channels 115 are symmetrical to each other about the plane P2, and each channel is symmetrical about the plane P1. Each channel 115 has an inner surface 116 consisting of a continuous surface formed by the lower housing peripheral wall 102, the partition wall 110, optionally the sheath 107, and the side wall 112 (if present).

[0083] The sheath 107 is attached to the peripheral wall 102 by a partition wall 111 and preferably also by a first lateral wall 117 near the distal end 108 of the sheath and a second lateral wall 118 near the proximal end 109 of the sheath. The first and second lateral walls 117, 118 preferably extend across a ring-shaped cross-sectional area between the sheath 107 and the peripheral wall 102, excluding the cross-sectional area corresponding to the channel 115.

[0084] In one embodiment, a window 119 extends through the lower housing 101 and is parallel to the plane P2. The window 119 may form a substantially rectangular frame on either side of the lower housing peripheral wall 102. The window 119 is provided for inspecting the medical container 2 contained in the auto-injector 1.

[0085] The proximal portion of the peripheral wall 102 is provided with two notches 120 that face each other along a direction perpendicular to P1, and each notch 120 is symmetrical with respect to P2. Each notch 120 is square, has a base that is approximately flush with the second lateral wall 118, and has two longitudinal side edges 121. As shown in FIGS. 6, 8, and 22, the peripheral wall 102 extends circumferentially beyond the side wall 112 of the channel 115 from proximal to the second lateral wall 118 to form a lip 122.

[0086] Facing each notch 120 is a snap-fit ​​projection 123 that projects outwardly from the sheath 107. Preferably, the snap-fit ​​projections 123 do not extend radially beyond the cylindrical outline formed by the peripheral wall 102 of the lower housing.

[0087] The lower housing 101 may further include at least one axially extending rib 124 projecting inwardly from the peripheral wall 102. The rib 124 extends from the open distal end 105 of the peripheral wall, and a proximal surface 125 of the rib 124 is spaced from the distal end 108 of the inner sheath. The rib 124 may project from the peripheral wall 102 along a direction substantially parallel to P1.

[0088] For example, the lower housing 101 includes two sets of ribs 126, each consisting of two ribs 124, which are arranged symmetrically with respect to the plane P2. In each set 126, the ribs 124 may be arranged symmetrically with respect to the plane P1 and adjacent to each other. For example, when viewed in a plane perpendicular to the axis A101, the distance between the ribs 124 is substantially the same as the width of each rib 124.

[0089] Next, the upper housing 150 will be described with reference to FIGS.

[0090] The upper housing 150 may be unitarily molded, for example by injection molding of a plastic material.

[0091] Upper housing 150 is preferably substantially cylindrical and includes a peripheral wall 152 having an inner surface 153 , an outer surface 154 , an open distal end 155 , and a proximal end closed by a proximal lateral wall 156 .

[0092] The distal portion of the peripheral wall 152 is provided with two notches 159 facing each other along a direction perpendicular to P2, with each notch 159 symmetrical with respect to P1. Two protrusions 160 are formed between the notches 159 and configured to cooperate with the notches 120 of the lower housing 101. To obtain a housing 100 with a continuous peripheral wall, the shape of the protrusions 160 preferably matches the shape of the notches 120. Thus, each protrusion 160 may be square with two longitudinal side edges 161. Alternatively, as shown in FIGS. 5 and 22, the lip 162 may extend circumferentially beyond each longitudinal side edge 161 and be offset inward. The lip 162 of the upper housing 150 radially cooperates with the inner surface of the lip 122 of the lower housing 101, thereby ensuring proper positioning and joining of the upper housing 150 and the lower housing 101. Additionally, each projection 160 may include a hole 163 that receives a snap-fit ​​projection 123 to provide a secure connection between the upper housing 150 and the lower housing 101 .

[0093] The upper housing 150 may further include at least one rib 164 projecting inward from the peripheral wall 152 and extending in the axial direction. The rib 164 may project from the peripheral wall 152 along a direction substantially parallel to P1. For example, the upper housing 150 may include two sets 166 of two ribs 164, the sets being symmetrically arranged with respect to the plane P2. In each set 166, the ribs 164 may be symmetrically arranged with respect to the plane P1 and adjacent to one another. In one example, when viewed in a plane perpendicular to the axis A150, the width of the set 166 of ribs 164 is substantially the same as the width of the set 126 of ribs 124 of the lower housing 101. Each rib 164 may extend distally from the proximal lateral wall 156 substantially to the proximal end 158 of the corresponding notch 159.

[0094] 37, upper housing 150 includes a substantially cylindrical inner sleeve 167 coaxial with peripheral wall 152. Sleeve 167 extends from proximal lateral wall 156, with an open distal end 168 of sleeve 167 located proximal to proximal edge 158 of notch 159. The diameter of sleeve 167 may be smaller than the diameter of sheath 107.

[0095] In one embodiment, the distal portion of the sleeve 167 is provided with recesses 169 extending axially from the open distal end 168 of the sleeve 167. Thus, between the two recesses 169, an axially extending leg 170 is formed. This leg is preferably provided with a bulge 171 at its distal end, the bulge 171 being oriented toward the axis A150. The leg 170 is resiliently deflectable radially outward from a rest position (shown in solid lines in FIGS. 5 and 31) toward a deformed position (shown in dashed lines in FIG. 31). As will be described below, the leg 170 forms a retainer. Two legs 170 may be provided, arranged symmetrically with respect to the plane P1.

[0096] An elongated projection 175 projects distally from the proximal lateral wall 156 and extends perpendicular to the plane P2 within the sleeve 167. The elongated projection 175 has a small height along the axis A150 and, in particular, is offset proximally relative to the recess 169.

[0097] Additionally, upper housing 150 may include four ribs 176 projecting distally from proximal lateral wall 156, each connecting peripheral wall 152 to sleeve 167. Ribs 176 are spaced 90° apart from one another, with each rib 176 substantially contained within one of planes P1 and P2.

[0098] Please refer to Figure 9. Figure 9 shows plunger rod 300. Plunger rod 300 is mounted within housing 100, for example upper housing 150. Plunger rod 300 has a cylindrical wall 301 with axis A300, which in the mounted position substantially coincides with axis A1 of the auto-injector. Preferably, plunger rod 300 in the mounted position has two planes of symmetry that coincide with planes P1 and P2. Therefore, the same reference numerals P1 and P2 are used to identify the planes of symmetry of plunger rod 300.

[0099] The plunger rod 300 includes an inwardly directed collar 302 at its distal end 305, extending in a plane perpendicular to the axis A 300, the collar 302 defining an opening 303. The proximal end 306 of the plunger rod 300 is open. The cylindrical wall 301 includes a recess 304 extending axially from the proximal end 306, the recess 304 configured to receive the elongated protrusion 175 of the upper housing 150, thereby preventing the plunger rod 300 from rotating about the axis A 150 relative to the upper housing 150. Thus, in the above-described embodiment, the recesses 304 are opposite each other along a direction perpendicular to P2, and each recess 304 is symmetrical with respect to P1.

[0100] The cylindrical wall 301 includes at least one hole 310 for accommodating the bulge 171 of one leg 170 of the upper housing 150. Thus, in the above-described embodiment in which the upper housing 150 includes two legs 170, two holes 310 are provided opposite each other along a direction perpendicular to P1, and each hole 310 is symmetrical with respect to P2.

[0101] The needle cover 200 will be described with reference to FIGS.

[0102] The needle cover 200 is intended to be attached to the housing 100. The needle cover 200 has an axis A200 that, in the attached position, substantially coincides with the axis A1 of the automatic injector. Preferably, the needle cover 200, in the attached position, has two planes of symmetry that coincide with the planes P1 and P2. Therefore, the same reference signs P1 and P2 are used to identify the planes of symmetry of the needle cover 200.

[0103] The distal portion of the needle cover 200 forms a shield portion 201 having a substantially cylindrical peripheral wall 202 that is intended to shield the needle 5 to prevent injury and contamination. The peripheral wall 202 has an inner surface 203 and an outer surface 204. The distal end 205 of the needle cover 200 includes an abutment surface 207 that extends in a plane perpendicular to the axis A200. The abutment surface 207 has a portion that extends inward from the peripheral wall 202 and has a central opening 208, and a portion that extends outward and forms an annular flange 209. An annular flange 210 is disposed at the proximal end of the shield portion 201 and extends outward from the peripheral wall 202. Both flanges 209, 210 may have substantially the same outer diameter.

[0104] The needle cover 200 further includes at least one arm 220 extending proximally from the shield portion 201. In the embodiment shown in Figure 10, the needle cover 200 includes two arms 220 arranged symmetrically with respect to the plane P2. Preferably, each arm 220 is symmetric with respect to the plane P1.

[0105] The arm 220 includes a main wall 221, which, when viewed along the axis A200, has a curved portion that conforms to the cylindrical shape of the shield peripheral wall 202. A distal portion 222 of the main wall 221 has a longitudinal edge 223 and is extended by a proximal portion 224 having a longitudinal edge 225, the longitudinal edges 225 of the proximal portion 224 being closer to each other than the longitudinal edges 223 of the distal portion 222. That is, when the needle cover 200 is viewed in a direction perpendicular to the plane P2, the width of the distal portion 222 is greater than the width of the proximal portion 224. As a result, a lateral edge 226 is formed between the distal portion 222 and the proximal portion 224. The proximal end 206 of the needle cover 200 is also the proximal end of the arm 220.

[0106] The arms 220 further include at least one rail 230 extending axially and projecting outward from the main wall 221. In one embodiment, each arm 220 includes two rails 230. The rails 230 are disposed on longitudinal edges 225 of the proximal main wall portion 224. Preferably, the rails 230 define an outer diameter of the needle cover 200 around the arm 220 that is substantially the same as an outer diameter of the needle cover 200 around the shield portion 201. For example, the rails 230 and the annular flange 210 on the proximal end of the shield portion 201 can form a continuous rib.

[0107] The needle cover 200 also includes a pin 235 that protrudes from the arm 220 toward the axis A200. The pin 235 is located, for example, near the proximal end 206 of the proximal main wall portion 224. Preferably, the proximal surface 236 of the pin 235 is substantially perpendicular to the axis A200, and the distal surface 237 may be angled.

[0108] The needle cover 200 further includes a tab 240 disposed on each arm 220. The tab 240 preferably has a base 241 fixed to the arm main wall 221 between the rails 230 and a free distal end 242 extending perpendicular to the axis A200. The tab 240 protrudes obliquely distally and outwardly from the main wall 221. More specifically, as shown in FIGS. 10 and 18 , for example, the tab 240 has an inner surface 243 flush with the inner surface of the arm main wall 221 and an outer surface including an inclined portion 244 and a straight portion 245, the inclined portion 244 inclining distally and outwardly, and the straight portion 245 being substantially parallel to the outer surface of the main wall 221 but offset outwardly relative to the outer surface of the main wall 221.

[0109] From this position, tab 240 can be resiliently deflected toward axis A200, thereby attaching the needle cover to housing 100.

[0110] Next, the locking member 400 will be described with reference to FIGS.

[0111] The locking member 400 is attached to the housing 100. The locking member 400 has an axis A400 that is substantially aligned with the axis A1 of the automatic injector in the attached position. Preferably, the locking member 400 has a plane of symmetry P that includes the axis A1 of the automatic injector in the attached position.

[0112] The locking member 400 comprises a generally cylindrical body 401. The outer surface of the body 401 has two cylindrical portions 402 separated by a longitudinal edge 403. These portions 402 (hereinafter referred to as cylindrical portions 402) are arranged symmetrically with respect to an axis A400, and each portion 402 is symmetric with respect to a plane P. Between the cylindrical portions 402, the outer surface of the body 401 has a portion 404 that is recessed inwardly relative to the cylindrical portions 402. Thus, the outer surface of the body 401 has two recesses 404. Each recess 404 has a generally cylindrical outer surface 407.

[0113] The locking member 400 has an axially extending central bore 410 with a diameter equal to the inner diameter of the recess 404. Two opposing axial grooves 411 open into the central bore 410. Each axial groove 411 is disposed inside the corresponding cylindrical portion 402 in the same angular sector as the cylindrical portion 402. The locking member 400 has an open distal end 405 and an open proximal end 406. At the proximal end 406, a transverse wall 408 extends from the periphery of the body 401 to the edge of the opening formed by the combination of the bore 410 and the groove 411. Radially opposite the recess 404, i.e., circumferentially spaced from the axial grooves 411, the central bore 410 has a substantially cylindrical inner surface 413.

[0114] The locking member 400 can include an angled rib 435 projecting outward from the recess outer surface 407. The angled rib 435 has a distal end 431 disposed proximate the distal end 405 and one longitudinal edge 403 of the locking member, and a proximal end 432 disposed proximate the proximal end 406 of the locking member and away from the longitudinal edge 403. The distal surface 436 of the angled rib 435 thus forms a cam surface that is angled relative to the axis A400, defining an angled or substantially helical path from the distal end 431 to the proximal end 432. The angled rib 435 can form an angle α with the axis A400 that ranges from 20° to 45° when viewed perpendicular to the axis A400, as shown in FIG.

[0115] A longitudinal rib 437 protruding outward from the recess outer surface 407 and extending axially is arranged along the circumferential direction between the proximal end 432 of the inclined rib 435 and the longitudinal edge 403 facing the longitudinal edge 403 closer to the distal end 431 of the inclined rib 435.

[0116] Illustratively, the locking member 400 further includes an abutment wall 438 projecting outward from the recess outer surface 407. The abutment wall 438 extends generally axially from the distal end 405 of the locking member, with a proximal end of the abutment wall 438 spaced apart from the angled rib 435 in a direction parallel to axis A400. The abutment wall 438 is circumferentially disposed between the distal end 431 of the angled rib 435 and the longitudinal rib 437. A distal rib 439 projecting outward from the recess outer surface 407 can join the abutment wall 438 and the longitudinal rib 437 along the distal end 405 of the locking member.

[0117] The locking member 400 further includes a tab 440 disposed within the recess 404, the tab 440 being located between the abutment wall 438 and the longitudinal rib 437, and between the inclined rib 435 and the distal end 405 of the locking member (or the distal rib 439, if present). The tab 440 has a base 441 fixed to the main body 401 of the locking member 400 and a free distal end 442 that preferably extends perpendicular to the axis A400. The tab 440 protrudes obliquely distally and outwardly from the main body 401. More specifically, as shown in FIGS. 12 and 14 , for example, the tab 440 has an outer surface including an inclined portion 444 inclined distally and outwardly and a straight portion 445 that is substantially parallel to the recess outer surface 407 but offset outwardly relative to said outer surface 407. From this position, tab 440 can be resiliently deflected toward axis A400.

[0118] Tab 440, abutment wall 438, and distal rib 439 are part of a locking device 440 of locking member 400, which is configured to lock needle cover 200 in a safe position, as described below.

[0119] In one embodiment, the auto-injector 1 includes a cap 500, which is described below with reference to FIGS.

[0120] The cap 500 can be realized in one piece, for example by injection molding of a plastic material.

[0121] The cap 500 is configured to be attached to the distal end of the housing 100. The cap 500 has an axis A500 that substantially coincides with the axis A1 of the automatic injector in the attached position. Preferably, the cap 500 has two planes of symmetry that coincide with planes P1 and P2 in the attached position. Accordingly, the same reference symbols P1 and P2 are used to identify the planes of symmetry of the cap 500.

[0122] Cap 500 is preferably substantially cylindrical and includes a peripheral wall 502 having an inner surface 503, an outer surface 504, an open proximal end 506, and a distal end closed by a lateral wall 505. Outer surface 504 may be provided with beads 501 or equivalent structure to prevent a user's fingers from slipping on peripheral wall 502 when removing cap 500.

[0123] The cap 500 may include at least one protrusion 507 protruding from the inner peripheral wall surface 503 toward the axis A500. The protrusion 507 protrudes perpendicular to the plane P1 at a fixed distance from both the lateral wall 505 and the proximal end 506. Preferably, two protrusions 507 are provided, diametrically opposed, and symmetrically disposed with respect to the plane P1.

[0124] The cap 500 may include at least one axially extending rib 508 projecting inwardly from the peripheral wall 502. The rib 508 may project from the lateral wall 505, and a proximal surface 509 of the rib 508 may be spaced apart from the proximal end 506. Preferably, the cap 500 includes a plurality of ribs 508, for example, four ribs 508 spaced 90° apart from one another, each rib 508 being substantially contained within one of the planes P1 and P2.

[0125] In one embodiment, an inner ring 510 projects coaxially from the transverse wall 505 along the axis A500. Extending from the inner ring 510 are two legs 520 symmetrically arranged relative to a plane P2, with each leg 520 being symmetrical relative to a plane P1. Each leg 520 extends axially and has a partially cylindrical curvilinear profile that follows the shape of the inner ring 510. The proximal ends of the legs 520 are located proximal to the proximal end 506 of the peripheral wall 502. The proximal end of each leg 520 may include a bulge 521 that is oriented toward the axis A500. The legs 520 are preferably resiliently deflectable radially outward from the rest position shown in FIGS. 15 and 16 .

[0126] The auto-injector 1 in its storage position, ie the position where it is packaged, stored and sold to a user prior to use, is shown in Figures 1, 17 to 28 and will be described as follows.

[0127] The medical container 2 with the rigid needle shield 9 is engaged with the sheath 107 of the lower housing 101 with the flange 8 abutting the proximal end 109 of the sheath 107 as shown in FIG.

[0128] The needle cover 200 is attached to the lower housing 101 with the arm 220 received in the channel 115 and extending proximally beyond the proximal end 106 of the lower housing peripheral wall 102, so that the pin 235 is located proximally beyond the proximal end 106. The needle cover 200 is therefore positioned between the sheath 107 and the lower housing peripheral wall 102. The needle 5 then extends distally beyond the lower housing proximal end 105, as shown in FIG. 18. The annular flange 210 of the needle cover shield portion 201 serves to center the lower housing peripheral wall 102, as shown in FIG. 17.

[0129] In the attached or stowed position, the snap-fit ​​engagement between the needle cover 200 and the lower housing 101 prevents the needle cover 200 from moving distally relative to the housing 100. More specifically, as shown in FIG. 18 , the distal end 242 of the tab 240 abuts the proximal surface 125 of the rib 124 on the lower housing 101.

[0130] Furthermore, the needle cover 200 is prevented from rotating about the axis A1 relative to the housing 100, and the arm 220 is prevented from moving in the tangential and radial directions relative to the housing 100. The reasons for this are as follows: The rail 230 of the needle cover 200 contacts or is in close proximity to the inner surface 103 of the lower housing peripheral wall 102, thereby preventing or significantly limiting outward deflection of the arm 220 (FIGS. 22-24). The rails 230 of the needle cover 200 contact or are adjacent to the ribs 124 of the lower housing 101, e.g., located on either side of a set 126 of ribs 124, thereby preventing or significantly limiting rotational and tangential movement of the needle cover 220 (FIG. 24); The rails 230 of the needle cover 200 contact or are adjacent to the ribs 164 of the upper housing 150, e.g., located on either side of a set 166 of ribs 164, thereby preventing or significantly limiting rotational and tangential movement of the needle cover 220 (FIG. 21); The arms 220 contact or are adjacent to the partition wall 110 that forms the inner wall of the channel 115, thereby preventing or significantly limiting inward deflection of the arms 220 (FIGS. 22 and 23); The arm 220 contacts or is adjacent to the side wall 112 that forms the side wall of the channel 115 proximal to the second lateral wall 118, thereby preventing or significantly limiting rotational and tangential movement of the needle cover arm 220 (FIG. 22).

[0131] In the retracted position, the needle cover 200 projects beyond the distal end 105 of the housing and covers the needle 5, as shown in FIGS.

[0132] The automatic injector 1 further comprises a first biasing means for biasing the needle cover 200 in a distal direction. The first biasing means may comprise, for example, a first spring 250, also referred to as a "safety spring." The first spring 250 may be a helical spring having an axis that, in the mounted position, substantially coincides with the axis A1 of the automatic injector. The first spring 250 may be arranged inside the needle cover 200, more specifically, between the inside of the shield part 201 and the distal part of the arm 220. In the illustrated embodiment, the first spring 250 abuts against an abutment surface 207 of the needle cover distal end 205, and at its distal part abuts against the partition wall 110.

[0133] The plunger rod 300 is attached to the sleeve 167 of the upper housing 150, the elongated protrusions 175 of the upper housing 150 fit into the recesses 304 of the plunger rod 300, and the bulges 171 of each leg 170 engage with the corresponding holes 310 of the plunger rod 300. This places the plunger rod 300 in its initial position.

[0134] The automatic injector 1 further comprises a second biasing means for biasing the plunger rod 300 in a distal direction relative to the upper housing 150. The second biasing means may comprise, for example, a second spring 260, also referred to as an "injection spring." The second spring 260 is a helical spring having an axis that, in the mounted position, substantially coincides with the axis A1 of the automatic injector. The second spring 260 may be disposed inside the plunger rod 300. In the illustrated embodiment, a distal portion of the second spring 260 abuts against the collar 302 of the plunger rod 300, and a proximal portion of the second spring 260 abuts against the lateral wall 156 of the upper housing 150.

[0135] The locking member 400 is mounted in the housing 100, which is formed by combining the upper housing 150 and the lower housing 101. The sleeve 167 of the upper housing 150 is received in the central hole 410 of the locking member 400.

[0136] In the retracted position, the locking member 400 is longitudinally disposed between the rib 176 and the flange 8 of the medical container 2. The locking member 400 abuts the rib 176 and is maintained in that position by friction with the inner surface 153 or lip 162 of the upper housing peripheral wall 152, or by an outward force exerted by the legs 170 due to the force of the second spring 260.

[0137] Regarding the angular position of the locking member 400 around the axis A1 in the storage position, as shown by the dashed lines in Figure 29, the pin 235 arranged on each arm 220 of the needle cover 200 is positioned longitudinally between the distal end 405 of the locking member and the distal surface 436 of the inclined rib 435, and circumferentially between the abutment wall 438 and the distal end 431 of the inclined rib 435.

[0138] In this angular position, one of the longitudinal edges 225 of the proximal portion 224 of the arm 220 abuts the longitudinal edge 403 of the corresponding cylindrical portion 402 of the locking member body 401, and the longitudinal edge 403 is adjacent to the distal end 431 of the inclined rib 435. This prevents the locking member 400 from rotating in an undesired direction about the axis A1. Furthermore, the arm 220 is preferably positioned so as not to face the tab 440 along the radial direction. For example, the opposite longitudinal edge 225 of the proximal portion 224 of the arm 220 is positioned circumferentially between the abutment wall 438 and the tab 440.

[0139] Furthermore, in this angular position, the legs 170 of the upper housing 150 abut against the generally cylindrical inner surface 413 of the central bore 410 of the locking member 400, i.e., are circumferentially offset relative to the axial grooves 411, as shown in FIG.

[0140] Thus, in the retracted position, the legs 170 are in a rest position and are prevented from deflecting radially outward by the locking member 400. In the absence of the locking member 400, the force exerted distally by the second spring 260 would disengage the bulge 171 of the legs 170 from the hole 310 in the plunger rod 300, allowing the plunger rod 300 to move freely distally. Each leg 170 thus forms a retainer for holding the plunger rod 300 in its initial position against the action of the second spring 260, and this retainer is held in its rest position by the locking member 400. As a result, when the needle cover 200 is in the retracted position, the locking member 400 is in its locked position.

[0141] Finally, the cap 500 is attached to the distal end of the auto-injector. More specifically, the cap 500 is not attached to the housing 100 but rather to the needle cover 200 via, for example, a protrusion 507 that cooperates with the annular flange 209. The protrusion 507 is designed to allow for manual attachment and detachment of the cap 500 and to prevent movement of the needle cover during drop testing. In the retracted position, the rib 508 of the cap 500 cooperates with the distal end 105 of the housing 100 to prevent the cap 500 from moving proximally toward the lower housing 101. Furthermore, as shown in FIGS. 17 and 18 , the bulge 521 of the leg 520 is positioned proximal to the proximal end of the rigid needle shield 9 of the medical container 2.

[0142] The operation of the automatic injector during use will be described with reference to Figures 27 to 34.

[0143] 27, starting from the stowed position, the user pulls the cap 500 distally away from the housing 100 (arrow S1). Due to the action of the bulge 521 engaging the proximal end of the rigid needle shield 9, the rigid needle shield is automatically removed as the cap is removed.

[0144] The user then places the auto-injector 1 at the injection site and, while holding the housing 100, presses the auto-injector 1 towards the injection site, which causes the needle cover 200 to be pushed in (arrow S2 in FIG. 28). Because the needle cover 200 is axially movable within the housing 100, it moves proximally within the housing against the force of the second spring 260 until it reaches the retracted position shown in FIG. 31. In this retracted position, the needle cover 200 at least partially exposes the needle 5 and the first spring 250 is compressed.

[0145] 29, as the needle cover 200 moves from the stored position to the retracted position, the pin 235 located on each arm 220 of the needle cover 200 first contacts the distal surface 436 of the corresponding angled rib 435 of the locking member 400. Cooperation between the pin 235 and the distal surface 436 of the angled rib causes the pin 235 to follow a path along the distal surface 436 (arrow S3) as the needle cover 200 moves further proximally.

[0146] The automatic injector 1 includes means for guiding the axial movement of the needle cover 200 relative to the housing 100 (i.e., the arms 220 and rails 230 on the needle cover 200, and the channels 115 and ribs 124, 164 on the housing 100), thereby preventing the needle cover 200, and in particular the arms 220, from rotating relative to the housing 100. Meanwhile, the locking member 400 is rotatable about axis A1 relative to the housing 100. Thus, when the needle cover 200 moves proximally from the stored position to the retracted position, the locking member 400 rotates from the locked position to the released position (arrow S4 in FIG. 29 ). The locking member 400 can rotate from the locked position to the released position through an angle ranging from 20° to 45°.

[0147] After the locking member 400 has been rotated relative to the housing 100, the auto-injector 1 is in the configuration shown in Figures 30 and 31.

[0148] Legs 170 of upper housing 150 no longer face radially against inner surface 413 of locking member central bore 410, but rather face axial grooves 411. Thus, locking member 400 no longer forms a radial abutment against legs 170, but rather allows legs 170 to deflect outward.

[0149] The force of second spring 260 pushes plunger rod 300 distally relative to upper housing 150. This forces bulge 171 out of bore 310, which was previously impossible because it required legs 170 to deflect outward, which was prevented by their abutment against inner surface 413 of locking member central bore 410. Thus, legs 170 deflect outward into axial groove 411 (arrow S5 in FIGS. 30 and 31 ). In the deflected position, legs 170 allow plunger rod 300 to move distally relative to housing 100, as shown by the dashed lines in FIG. 31 .

[0150] The plunger rod 300 is then moved distally within the housing 100 from the initial position to the end-of-injection position shown in Figure 32. During this movement, the plunger rod 300 presses against the stopper 7, expelling the medical product from the barrel 3 and through the needle 5. In one example, when the legs 170 are no longer being pushed outward by the plunger rod 300, the legs 170 resiliently return to their rest position.

[0151] Upon completion of the injection, the user can remove the automatic injector 1 from the injection site. With the needle cover 200 no longer abutting the injection site and the first spring 250 compressed, the first spring 250 causes the needle cover 200 to move distally relative to the housing 100 and into a safe position where it projects beyond the distal end of the housing to again cover the needle 5. This safe position is shown in FIG. 34. In this safe position, the distal end 242 of the tab 240 again abuts the proximal surface 125 of the rib 124 of the lower housing 101. Alternatively, the position of the needle cover relative to the housing 100 in the safe position may be different from its position in the retracted position.

[0152] As shown in FIG. 33, when the needle cover 200 moves from the injection position to the safety position, the pins 235 disposed on each arm 220 of the needle cover 200 move in the distal direction as indicated by arrows S6.

[0153] The auto-injector 1 is designed so that the position of the pin 235 in the injection position is longitudinally aligned with the tab 440 of the locking member 400. Thus, the pin 235 reaches the tab 440 and moves further distally until the pin 235 is distal to the tab 440. This movement is limited by a distal rib 439 located on the locking member 400. Providing the pin 235 with a sloped distal surface 237 facilitates cooperation with and inward deflection of the tab 440 as the needle cover 200 is moved distally from the retracted position toward the safety position.

[0154] In the safety position, the needle cover 200 is prevented from moving proximally by cooperation of the pin 235 and the tab 440. More specifically, the pin proximal surface 236 abuts the tab distal end 442. Preferably, the pin proximal surface 236 and / or the tab distal end 442 are substantially perpendicular to the axis A1 to enhance the locking effect. Thus, the distal end 442 of the tab 440 forms a first stop that cooperates with the needle cover 200 in the safety position to prevent axial movement of the needle cover in the proximal direction.

[0155] Furthermore, in the safety position, the needle cover 200 can be prevented from returning to the retracted position again by rotating the locking member 400 to the blocking position. This is achieved by an abutment wall 438 arranged on the locking member. The abutment wall 438 forms an abutment for the pin 235. The abutment wall 438 therefore forms a second stop that cooperates with the needle cover 200 in the safety position.

[0156] The first and second stops, here the distal end 442 of the tab 440 and the abutment wall 438, are part of a locking device 450 disposed on the locking member 400 for locking the needle cover 200 in a safe position. In one embodiment, the locking device 450 is configured to cooperate with an actuator (here including the pin 235) disposed on the needle cover.

[0157] The locking device improves the safety of the auto-injector by ensuring that the needle remains shielded. Locating the locking device on the locking member offers the advantages of simplified design, compactness, material savings, and reliability.

[0158] Reference is now made to Figures 35, 36 and 38, which illustrate another embodiment of an auto-injector according to the present invention.

[0159] Only the differences from the first embodiment will be described below, and the operation of this auto-injector will not be described here as it is the same or similar to the operation of the previous embodiment.

[0160] 36 , most of the upper housing 150 is disposed inside the lower housing 101, with substantially only its proximal lateral wall 156 disposed outside the lower housing 101. Furthermore, the snap-fit ​​arrangement is reversed, with the portion including the snap-fit ​​protrusion 180 being the upper housing 150, while the hole 140 that receives the snap-fit ​​protrusion 180 is provided in the lower housing 101.

[0161] The upper housing 150 also includes a collar 185 configured to interlock with a hook 485 provided on the locking member 400. The hook 485 can protrude proximally from the proximal end 406 of the locking member body 401. This allows the collar 185 to be sandwiched between the hook 485 of the proximal end 406 of the locking member body 401 and the lateral wall 408, thereby preventing axial movement of the locking member 400 in both the proximal and distal directions.

[0162] The automatic injector 1 may further comprise means for limiting the range of rotational movement of the locking member 400. To this end, the lateral wall 408 may comprise a notch 490 adjacent the recess 404. The notch 490 may be bounded by the longitudinal edge 403 adjacent the distal end 431 of the angled rib 435 and a matching first edge 491 and a second edge 492 adjacent the proximal end 432 of the angled rib 435. Furthermore, the upper housing 150 may comprise a tongue 190 that extends distally beyond the locking member lateral wall 408 in the mounted position. The tongue 190 may thereby abut against the first edge 491 or the second edge 492 of the notch 490, limiting the rotational movement of the locking member 400 about the axis A1 relative to the housing 100.

[0163] Reference is now made to Figures 39 and 40, which illustrate an embodiment in which the point in time at which the retainer release begins and the duration of the actual injection actuation are controlled.

[0164] Therefore, the automatic injector 1 can be configured to set the injection start position according to the puncture depth, ensuring that all of the medical product is expelled from the medical container and injected into the injection site. More specifically, the axial groove 411 is configured to start deformation of the retainer 170 when the needle cover 200 has moved a predetermined distance in the axial direction, and preferably is configured to control the speed at which the retainer 170 is deformed to the deformed position.

[0165] The longitudinal edge between the inner surface 413 of the locking member body 401 and the axial groove 411, which is the last part where the retainer 170 and the inner surface 413 come into contact before the retainer 170 deforms as the locking member 400 rotates, is called the operating edge 414.

[0166] The axial groove 411 includes a control surface 415 that extends from the actuating edge 414 toward the interior space of the axial groove 411 and away from the housing axis A100. As shown in FIG. 40, the control surface 415 is inclined at an angle α relative to the radial segment 195 of the housing 100 that passes through the actuating edge 414. The angle α can be in the range of 25° to 50°, and preferably in the range of 35° to 45°. This allows for a quick start of injection while also providing a smooth transition of the plunger rod from its initial position to its end-of-injection position.

[0167] The invention is not limited to the embodiments described above by way of example, but rather includes all technical equivalents and modifications of the means described, as well as combinations thereof.

[0168] It will be obvious to those skilled in the art that the present invention is not limited to the embodiments described above and shown in the drawings, but rather that many variations and modifications are possible within the scope of the appended claims.

Claims

1. An automatic injector (1) for automatically injecting a product into an injection site, comprising: The automatic injector (1) comprises: a housing (100) configured to house a medical container (2) having an axis (A100) defining a longitudinal direction and including a barrel (3) defining a reservoir for containing a medical product, the barrel (3) having a distal end (4) provided with a needle (5) and an open proximal end (6) configured to house a plunger rod (300) for pushing a stopper (7) disposed within the barrel (3); an inner sleeve (167) axially disposed inside the housing (100) and fixed to the housing (100); a needle cover (200) coupled to the housing (100), the needle cover (200) being rotationally fixed relative to the housing (100) and axially movable within the housing (100) between a retracted position in which the needle cover (200) projects beyond the distal end (105) of the housing to shield the needle (5), a retracted position in which the needle cover (200) moves proximally relative to the housing (100) from the retracted position to at least partially expose the needle (5), and a safety position in which the needle cover (200) moves distally relative to the housing (100) from the retracted position to shield the needle (5) and projects beyond the distal end (105) of the housing; guide means (103, 115, 124, 164) fixedly arranged on the housing (100) for guiding axial movement of the needle cover (200) relative to the housing (100); a first biasing means (250) for biasing said needle cover (200) in a distal direction; a plunger rod (300) axially movable within the housing (100) between an initial position and an end-of-injection position distal to the initial position, the plunger rod (300) configured to push the stopper (7) to expel the medical product; second biasing means (260) for biasing said plunger rod (300) in a distal direction; a retainer (170) for holding the plunger rod (300) in the initial position against the action of the second biasing means (260), the retainer (170) being disposed in a distal portion of the inner sleeve (167), the retainer (170) being elastically deformable between a rest position in which the retainer (170) axially abuts the plunger rod (300) to lock the plunger rod (300) in the initial position, and a deformed position in which the retainer (170) is radially deflected to allow the plunger rod (300) to move in a distal direction; a locking member (400) disposed within the housing (100), the locking member (400) being axially fixed relative to the housing (100) and rotatable about the axis (A100) relative to the housing (100) between a locked position where the locking member (400) prevents deformation of the retainer (170) and holds the retainer (170) in the rest position, and a released position where the locking member (400) allows deformation of the retainer (170), the rotation of the locking member (400) from the locked position to the released position being caused by movement of the needle cover (200) from the stored position to the retracted position, the locking member (400) comprising a locking device (450) configured to lock the needle cover (200) in the safety position; An automatic injector comprising:

2. 2. The automatic injector of claim 1, wherein the locking device (450) preferably comprises a first stop (442) extending substantially perpendicular to the axis (A100), the first stop (442) cooperating with the needle cover (200) in the safety position to prevent axial movement of the needle cover (200) in the proximal direction.

3. 3. The automatic injector of claim 2, wherein the locking member (400) comprises a body (401), the locking device (450) comprises a tab (440) having a base (441) fixed to the body (401) and a free distal end (442), the tab (440) protruding obliquely from the body (401) in a distal direction toward the needle cover (200), the tab (440) being resiliently deflectable toward the body (401) by movement of the needle cover (200) from the retracted position to the safety position, and the distal end (442) of the tab (440) forming the first stopper.

4. 4. The automatic injector according to claim 1, wherein the locking device (450) comprises a second stop (438), preferably extending in a plane substantially parallel to the axis (A100), the second stop (438) cooperating with the needle cover (200) in the safety position to prevent the locking member (400) from rotating towards the locked position.

5. 5. The automatic injector of claim 4, wherein the second stopper (438) comprises a wall extending substantially axially and projecting toward the needle cover (200).

6. 6. The automatic injector according to claim 1, wherein the locking member (400) has a cam surface (436) that protrudes toward the needle cover (200) and is inclined relative to the axis (A100), the cam surface (436) being configured to cooperate with the needle cover (200), and the movement of the needle cover (200) from the storage position to the retracted position causes the locking member (400) to rotate from the locked position to the released position.

7. 7. The automatic injector according to claim 2, wherein the needle cover (200) comprises an operating portion (235) that cooperates with the first stopper (442), and / or the second stopper (438), and / or the cam surface (436), and the operating portion (235) comprises at least one pin that protrudes towards the locking member (400).

8. 8. The automatic injector according to any one of claims 1 to 7, characterized in that the needle cover (200) comprises guide means (220, 230) configured to cooperate with the guide means (103, 115, 124, 164) fixedly arranged on the housing (100) to guide axial movement of the needle cover (200) relative to the housing (100) and preferably to limit radial or tangential movement of the needle cover (200) relative to the housing (100).

9. 9. The automatic injector according to claim 1, wherein the needle cover (200) has a distal portion including a substantially cylindrical shield portion (201) and at least one arm (220) extending proximally from the shield portion (201).

10. 10. The automatic injector according to claim 9, wherein the housing (100) comprises an axially extending channel (115) for receiving the needle cover arm (220), and at least a portion of the lateral end of the arm (220) is positioned against an inner surface (116) of the channel (115).

11. 11. The automatic injector according to claim 9 or 10, wherein the needle cover arm (220) has a main wall (221) and is provided with at least one rail (230) extending axially and projecting outward from the main wall (221), the rail (230) being configured to abut against an inner peripheral wall (103) of the housing (100).

12. the needle cover arm (220) comprises a tab (240) having a base (241) fixed to the arm main wall (221) and a free distal end (242), the tab (240) protruding obliquely distally from the main wall (221) towards the housing (100), the tab (240) being resiliently deflectable towards the axis (A100) to enable the needle cover (200) to be attached to the housing (100); 12. The automatic injector of claim 11, wherein in the retracted position and the safety position, the distal end of the tab is configured to abut at least one axially extending rib projecting inward from the housing to prevent distal movement of the needle cover relative to the housing.

13. 13. The automatic injector according to any one of claims 9 to 12, wherein the needle cover arm (220) has a main wall (221) and is provided with at least one rail (230) extending axially and projecting outwardly from the main wall (221), the rail (230) projecting inwardly from the housing (100) and configured to abut at least one axially extending rib (124, 164).

14. 14. The automatic injector according to any one of claims 9 to 13, characterized in that in the retracted position, a portion of the lateral end (225) of the arm (220) abuts against a face (403) of the locking member (400) extending in a plane substantially parallel to the axis (A100).

15. The locking member (400) comprises a body (401), The body (401) a central bore (410) having an inner surface (413) in which the inner sleeve (167) is received; At least one axial groove (411) opening into said central hole (410); Equipped with In the locked position, the locking member (400) is arranged so that the retainer (170) faces radially toward the inner surface (413) of the central hole (410), and in the released position, the locking member (400) is arranged so that the retainer (170) faces radially toward the axial groove (411); 15. The automatic injector according to any one of claims 1 to 14, wherein the axial groove (411) is configured to initiate deformation of the retainer (170) when the needle cover (200) is moved axially along a predetermined length, and preferably configured to control the speed of deformation of the retainer (170) to the deformed position.

16. The locking member (400) comprises a body (401), The body (401) a central bore (410) having an inner surface (413) in which the inner sleeve (167) is received; At least one axial groove (411) opening into said central hole (410); Equipped with In the locked position, the locking member (400) is arranged so that the retainer (170) faces radially toward the inner surface (413) of the central hole (410), and in the released position, the locking member (400) is arranged so that the retainer (170) faces radially toward the axial groove (411); the longitudinal edge between the inner surface (413) and the axial groove (411) is the last contact between the retainer (170) and the inner surface (413) before the retainer (170) is able to deform with rotation of the locking member (400), and this longitudinal edge is called the actuation edge (414); 16. The automatic injector according to any one of claims 1 to 15, characterized in that the axial groove (411) comprises a control surface (415) extending from the actuating edge (414) towards the interior space of the axial groove (411) in a direction away from the housing axis (A100), the control surface (415) being inclined at an angle (α) of 25° to 50°, preferably 35° to 45° with respect to the radial segment (195) of the housing passing through the actuating edge.

17. 17. A medical device comprising an automatic injector (1) according to any one of claims 1 to 16, and a medical container (2) including a barrel (3) defining a reservoir for containing a medical product, said barrel (3) having a distal end (4) provided with a needle (5) and an open proximal end (6) configured to receive a plunger rod (300) for pushing a stopper (7) disposed within said barrel (3), said medical container (2) being received in a housing (100) of said automatic injector (1).

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