Injection device including needle shield remover

Abstract

An injection device (1) comprises a housing (10); a syringe (2) having an injection needle (4) covered by a needle shield (5); and a cap assembly (3), the cap assembly comprising a cap body (15) covering the distal end of the syringe, and a shield remover (9) adapted to engage the needle shield (5), the shield remover (9) being axially fixed relative to the cap body (15). The cap assembly (3) also includes a lifting member (12) that can be rotated and axially moved relative to the cap body (15), wherein the lifting member (12) includes a first anti-rotational geometric structure (18, 28, 31) configured to prevent the lifting member (12) from rotating relative to the housing (10), and a cam interface (20) having engaging cam surfaces respectively arranged on the lifting member (12) and the cap body (15), the cam surfaces being configured to slidingly engage when the cap body (15) rotates relative to the housing (10) so as to cause the proximal surface (17) of the lifting member (12) to be axially pressed against the distal surface (16) fixedly arranged relative to the housing (10) while the cap body (15), the shield remover (9) and the needle shield (5) are moved distally relative to the housing (10).

Description

[0001] The present invention relates to an injection device for injecting one or more doses of a liquid drug. In particular, the present invention relates to an injection device for injecting one or more doses of a drug from a retained drug reservoir via an injection needle and improvements related to the safety of the injection device during storage, handling and administration. Background Art

[0002] For some diseases, patients must inject medicaments regularly, such as once a week, once a day, or even multiple times a day. In order to help patients overcome their fear of needles, some injection devices include a needle shield or needle cover to cover the injection needle before or after the dose is administered. Such a needle shield or needle cover generally hides the injection needle from the user's view and, in some forms, additionally provides a mechanical barrier to prevent an individual from accidentally touching the injection needle.

[0003] Some injection devices include a prefilled syringe (PFS) in which the injection needle is typically maintained in a sealed and sterile state prior to use by a needle shield or "boot". Different types of needle shields have been proposed, some of which include an elastomeric plug that fits over the needle and is attached relative to the neck of the barrel of the syringe. The force required to remove the needle shield from the syringe barrel can be considerable, making removal of the needle shield a cumbersome process, especially for those with impaired dexterity.

[0004] Even in the case where the prefilled syringe is included in an injection device housing (e.g. the housing of an autoinjector) and an external cap is coupled to the needle shield to serve as a tool for handling the needle shield, the removal force may be difficult to overcome. Typically, the needle shield is pulled out in an axial direction relative to the syringe barrel. The force may vary due to differences in part size and material properties in different cases. In order to alleviate these problems, shield-type injection devices have been proposed, which have a lifting feature that enables the cap to be screwed off to facilitate the removal of the needle shield. An example is disclosed in EP 2255842A1. These shield-type injection devices are characterized by visible technical lifting features on the housing and on the cap that are quite complex in appearance, which enable the cap to be lifted relative to the housing when the cap is rotated. Such visible lifting features conflict with the potential need to produce a shield-type injection device with a non-technical, human appearance. A related solution is disclosed in WO 2009 / 019440 A1, which involves a threaded shield pulling member in the external cap. Another reference, WO 2017 / 029515 A1, discloses an injection device in which a mechanism associated with the cap performs a combined priming and needle shield release function.

[0005] Known lifting features typically provide only limited axial movement of the needle shield, thereby failing to achieve a satisfactory degree of needle shield removal, or requiring a significant amount of rotation of the cap to achieve complete removal. Although the above references include disclosures of cap configurations intended to simplify the removal process of a needle shield from a syringe, there remains a need for injection devices having improved functionality for removing a needle shield from a syringe. Summary of the invention

[0006] It is an object of the present invention to provide an injection device characterized by improved uncapping of a shielded syringe.

[0007] The present invention provides a great deal of freedom in designing the exterior of a shield-type injection device, as any elevated features are hidden from the user. The present invention also includes the freedom to optimize the functionality of the hidden elevated features without compromising the aesthetic appearance of the device. Furthermore, the present invention can be implemented in many existing shield-type injection devices with limited design changes to existing components and limited impact on the assembly process.

[0008] In the disclosure of the present invention, a plurality of embodiments and aspects will be described, which will address one or more of the above-mentioned objects, or will address objects that will be apparent from the following disclosure and from the description of exemplary embodiments.

[0009] In a first aspect, the present invention relates to an injection device for expelling a drug from a syringe, the injection device comprising:

[0010] - a housing formed to be grasped by a subject user, the housing extending along a central longitudinal axis and defining a needle distal end and an opposite proximal end,

[0011] - a syringe holding device,

[0012] - a syringe comprising a syringe barrel, an injection needle, and a needle shield arranged on the injection needle, the syringe barrel being axially held relative to the syringe holding device; and

[0013] - a cap assembly comprising a cap body covering the distal end of the syringe, and a shield remover adapted to engage the needle shield, the shield remover being axially fixed relative to the cap body.

[0014] The injection device defines a distally facing surface axially fixedly arranged relative to the housing, and a shield removal mechanism including a cam interface, the cam interface being adapted to axially separate the needle shield from the injection needle when the cap body is rotated relative to the housing. The cap assembly also includes a lift member that is rotationally and axially movable relative to the cap body, wherein the lift member includes a proximally facing surface configured to engage the distally facing surface, and wherein the lift member includes a first anti-rotation geometry configured to prevent the lift member from rotating relative to the housing. The cam interface includes engaging cam surfaces disposed on the lift member and the cap body, respectively, the cam surfaces being configured to slidably engage when the cap body is rotated relative to the housing so as to cause the proximally facing surface of the lift member to axially press against the distally facing surface while causing the cap body, the shield remover and the needle shield to move distally relative to the housing.

[0015] In some embodiments, the injection device further comprises an expelling assembly configured to expel one or more doses of the drug held by the syringe.

[0016] In some embodiments, the syringe retaining device is prevented from moving proximally relative to the housing. In other embodiments, the syringe retaining device is prevented from moving proximally and distally relative to the housing. The syringe retaining device may be formed as a syringe barrel that partially or completely accommodates the syringe and is provided as a syringe holder or syringe carrier.

[0017] In some embodiments, the barrel of the syringe is axially fixedly mounted relative to the syringe retaining device, for example, such that the syringe is prevented from moving distally, and optionally, is prevented from moving proximally and distally relative to the syringe retaining device.

[0018] In other embodiments, the syringe is maintained in an axially fixed position relative to the housing in a storage state, and wherein the syringe is configured to move axially relative to the housing from a first position in which the needle does not protrude from the housing to a second position in which the needle protrudes from the housing by a predetermined distance. In such embodiments, the syringe can be configured to move from the first position to the second position during a dose administration process, such as when the expelling assembly is operated.

[0019] In further embodiments, the housing or a component fixedly mounted relative to the housing forms the distally facing surface.

[0020] The injection device can be configured so that it can be operated from a storage state to a ready-to-injection state, wherein when the injection device is in the storage state, the cap body and the lifting member are in corresponding axial storage positions, and wherein the cap body and the lifting member are prevented from moving proximally relative to their respective storage positions.

[0021] In some embodiments, the injection device includes a second anti-rotation geometry structure, which is configured to engage with the first anti-rotation geometry structure of the lifting member and is configured to prevent the lifting member from rotating relative to the housing when the cap body is rotated relative to the housing, at least during a portion of the rotational movement required to axially separate the needle shield from the injection needle.

[0022] In some embodiments, the injection device may further include a needle shield that is telescopically movable relative to the housing.

[0023] The injection device may be formed with a skin contact member configured to surround the hollow needle and the needle shield, the skin contact member configured to remain against the user's skin during drug expulsion. The skin contact member may be formed so that it includes a tubular slender section arranged coaxially with the injection needle, wherein the tubular slender section has a distal edge portion. In some forms, the skin contact member forms or defines the needle shield. In some variations, the needle shield is axially movable to allow the retained injection needle to protrude through the central needle hole in the needle shield. In other forms, the skin contact member forms the farthest side of the housing of the injection device. In such variations, the syringe barrel is axially slidable relative to the housing to allow the retained injection needle to protrude through the central needle hole of the skin contact member.

[0024] In embodiments comprising a needle shield, the needle shield may cooperate with the housing such that the needle shield is prevented from rotational movement relative to the housing, and wherein the needle shield comprises the second anti-rotation geometry.

[0025] In an alternative embodiment, the housing or a component fixedly attached to the housing comprises the second anti-rotation geometry.

[0026] The first anti-rotation geometry of the raised member may include one or more axially extending shoulders, each shoulder rotationally locked relative to a corresponding axially extending shoulder of the second anti-rotation geometry.

[0027] In some variations, the second anti-rotation geometry is formed on a radially outwardly facing surface and cooperates with a first anti-rotation geometry disposed on a radially inwardly facing surface of the rise member. In other variations, the second anti-rotation geometry is formed on a radially inwardly facing surface and cooperates with a first anti-rotation geometry disposed on a radially outwardly facing surface of the rise member. In still other variations, the second anti-rotation geometry is formed on a distally facing surface and cooperates with a first anti-rotation geometry disposed on a proximally facing surface of the rise member. Such variations may include a distally facing flange, the distally facing flange including the second anti-rotation geometry provided by at least one recess or protrusion disposed at the distally facing flange, and wherein the first anti-rotation geometry of the rise member engages with at least one recess or protrusion at the distally facing flange to provide a rotational lock between the rise member and the housing.

[0028] In some variations, the elevation member is formed as a sleeve-shaped member coaxially disposed between the shield remover and the cap body. In embodiments including a needle shield, the sleeve-shaped member may in some embodiments be coaxially disposed between the needle shield and the cap body.

[0029] In some embodiments, when the injection device is in the storage state, the lifting member is completely included in the cap body. In some embodiments, when the cap body has been fully rotated relative to the lifting member, the lifting member is still completely included in the cap body. In other embodiments, when the cap body is rotated relative to the lifting member, the lifting member can protrude from the cap body.

[0030] In yet other embodiments, a distal portion of the elevation member is included within the cap body, and wherein a proximal portion of the elevation member extends proximally from the cap body even when the injection device is in the storage state.

[0031] To provide a rotation stop limit, the geometry of the cap body and the lifting member, such as the cam interface, may include a pair of cooperating end-of-rotation stops that define an end-of-rotation stop position between the cap body and the housing.

[0032] To provide a rotation start limit position, the geometry of the cap body and the lifting member, such as the cam interface, may include a pair of cooperating rotation start stops that define a rotation start stop position between the cap body and the housing.

[0033] To help guide the user to use the injection device correctly, the device can be formed to include a first indicator indicating the rotation of the cap body relative to the housing. Optionally, a second indicator indicating the axial pulling of the cap body relative to the housing can be provided. In such an embodiment, the injection device can be configured so that the second indicator is revealed in response to the rotation of the cap body.

[0034] In yet other embodiments, the cap assembly may include a ratchet mechanism, such as a snap mechanism, disposed between the cap body and the elevation member, wherein the ratchet mechanism is configured to provide a tactile feedback snap during the distal movement of the cap body relative to the elevation member during rotation of the cap body relative to the housing. Such a ratchet mechanism may be configured as a one-way ratchet mechanism or a two-way ratchet mechanism.

[0035] When the proximally facing surface of the lifting member axially engages the distally facing surface, the distally facing surface prevents the lifting member from moving proximally. In this way, it is ensured that the cap body performs a spiral motion relative to the housing when the cap body rotates relative to the housing.

[0036] In some forms of the cap assembly, the shield remover is mounted to be freely rotatable relative to the cap body. In other embodiments, the shield remover is either fixedly mounted relative to the cap body, or is formed as a single integral component with the cap body.

[0037] As used herein, the term "drug" is intended to encompass any drug-containing flowable formulation or a combination of multiple drug-containing flowable formulations held separately, such as liquids, solutions, gels or fine suspensions, that can be passed in a controlled manner through a delivery device such as a cannula or hollow needle. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Hereinafter, the present invention will be further described with reference to the accompanying drawings, in which

[0039] Figure 1 shows a perspective view of a first embodiment of an injection device 1 according to the invention during storage of the device prior to initial use,

[0040] Figure 2 Shows Figure 1 A partially exploded perspective view of the injection device 1, wherein the cap assembly 3 and the syringe 2 are separated from the housing 10,

[0041] Figure 3 yes Figure 1-2 A perspective view of the injection device 1 with the cap assembly 3 separated from the housing 10,

[0042] Figure 4 is corresponding to Figure 2 , but in which the cap assembly 3 and the syringe are shown exploded,

[0043] Figure 5a , 5b and 5c show perspective views of the first embodiment injection device 1 in three states during cap removal,

[0044] Figure 6a , 6b and 6c corresponds to Figure 5a , 5b and a perspective cross-sectional view of 5c,

[0045] Figure 7 Two different detailed perspective cross-sectional views showing the cap assembly of the first embodiment of the injection device 1 ,

[0046] Figure 8 Shows Figure 1-7 A partially cutaway perspective exploded view of components of the cap assembly 3 and the front portion of the injection device 1 shown in FIG.

[0047] Figure 9a Shown in assembled state Figure 8 A partially cutaway perspective view of a component of wherein the component is shown in a stored state,

[0048] Figure 9b is corresponding to Figure 9a , but with the components shown in a state during cap removal,

[0049] Fig.10 Shows Figure 1-9b A partially cutaway perspective view of a front portion of an injection device shown in,

[0050] Fig.11 Shows Figure 1-10 Another perspective exploded view of the components of the cap assembly 3 and the front part of the injection device 1 shown in,

[0051] Fig.12a and 12b Two perspective exploded views showing components of the cap assembly 3 and the front part of a second embodiment of an injection device according to the invention,

[0052] Fig.13 is a perspective exploded view of components of a cap assembly 3 and a front portion of a third embodiment of an injection device according to the present invention,

[0053] Fig.14a is a perspective exploded view of components of the cap assembly 3 and the front portion of a fourth embodiment of an injection device according to the present invention, and

[0054] Fig.14b ,14c and 14d shows Fig.14a A perspective view of a fourth embodiment of an injection device shown in FIG. 4 , the device being shown in three states during cap removal.

[0055] Corresponding reference numerals indicate corresponding parts throughout the several views. Although the drawings represent embodiments of the invention, the drawings are not necessarily drawn to scale and certain features may be exaggerated or omitted in some of the drawings in order to better illustrate and explain the invention. DETAILED DESCRIPTION

[0056] In the context of the present disclosure, it may be convenient to define the term "distal end" in the drawings to refer to the end of the injection device that typically carries the injection needle, while the term "proximal end" refers to the opposite end of the injection device that is away from the injection needle. The figures shown are schematic diagrams and for this reason the configuration of the different structures as well as the relative dimensions are intended for illustrative purposes only.

[0057] Figure 1 A first embodiment of a shield-type injection device 1 is shown containing a pre-filled syringe 2, the pre-filled syringe comprising a needle 4 and a protective needle shield 5. The injection device 1 is shown in a storage state. The device comprises an elongated housing 10 extending along a central longitudinal axis and having a proximal end and a distal end. A cap assembly 3 is attached to the distal end of the housing 10.

[0058] Figure 2 The injection device 1 is shown in a view wherein the syringe 2 and the cap assembly 3 are shown separated from the housing 10. At different assembly levels, Figure 3 and 4 Further views of subassemblies and components of the injection device 1 are provided.

[0059] Figure 2 and 4 A standard prefilled syringe (PFS) widely used in the industry is shown. The syringe 2 comprises a tubular barrel 7 having a distally located neck 8, wherein the neck has a reduced diameter compared to the diameter of the barrel 7. An injection needle is mounted to the neck 8, and a removable cap provided in the form of a rigid needle shield (RNS) 5 is attached to the neck 8, so that the needle shield 5 seals the needle 4 in a sealing and aseptic manner. A slidably arranged piston 14 is arranged inside the barrel 7. A drug can be contained in the barrel between the piston 14 and the needle 4. Although the syringe shown includes only a single piston 14, other configurations may include multiple pistons for containing and expelling one or more drugs, including drugs to be reconstituted before administration. Figure 2 The syringe 2 shown in FIG. 2 also includes a proximally arranged finger-like flange extending radially from the wall of the barrel. For the syringe shown, there is a circumferential gap between the barrel 7 of the syringe and the needle shield 5 covering the needle 4.

[0060] In the embodiment shown, the syringe retaining feature 11 in the injection device 1 (only Figure 6a-6c 10) is configured to hold the syringe 2 fixedly when it is contained in the housing 10. An ejection mechanism, such as a spring-driven ejection mechanism (not shown) contained in the housing 10, will be configured to push the piston of the installed syringe distally, while the syringe holding feature 11 prevents the syringe barrel from moving distally. For simplicity, the ejection mechanism will not be discussed further, but the ejection mechanism can be configured as a manual ejection mechanism or an automatic ejection mechanism, such as a spring-driven or electrically driven ejection mechanism. In addition, the syringe holding feature will not be discussed further in this disclosure, but the syringe holding feature can be configured as a part of the housing 10 or as a separate syringe holder mounted relative to the housing. Different exemplary syringe holder principles can be adopted, such as those disclosed in WO 2019 / 081578A1 and WO 2013 / 089620 A1. The housing 10 or a separate syringe holder can keep the syringe 2 from moving distally by cooperating with a neck with a reduced diameter arranged at the distal end of the syringe barrel and / or by cooperating with a flange arranged at the proximal end of the syringe barrel. In further embodiments, a syringe retaining feature may be provided as part of a syringe carrier that retains the syringe from distal movement relative to the syringe carrier, wherein the syringe carrier is mounted for axial movement relative to the housing, such as disclosed in WO 2009 / 019440 A1.

[0061] In the embodiment shown, the needle cover 6 covers the needle 4 before and after injection. In the storage state of the injection device, and after the dose is administered, the cap assembly 3 covers the needle 4 and the needle cover 6. As described above, in the embodiment shown, the needle 4 is covered by a protective needle shield 5 (e.g., a rigid needle shield (RNS)) that fits tightly around the neck 8 of the barrel 7 of the syringe of the prefilled syringe 2 to prevent bacteria from passing between the barrel 7 of the syringe and the protective needle shield 5 in the area where the protective needle shield is connected to the barrel 7 part of the syringe of the prefilled syringe 2.

[0062] The cap assembly 3 comprises a cap body 15 shaped to be grasped by the user's fingers and sized to fit over the needle shield 5 and the needle shield 6. The cap assembly 3 also features a shield remover 9 which grips the protective needle shield 5 in such a way that when the user initiates a dose administration, the protective needle shield 5 is removed from the syringe's barrel 7 by removing the cap assembly 3 from the injection device 1, thereby exposing the needle 4. To enable the cap body 15 to rotate, the shield remover 9 is mounted to be freely rotatable within the cap body 15, but in a manner that prohibits axial movement between the cap body 15 and the shield remover 9. Thus, when the shield remover is coupled to the needle shield 5, axial movement of the cap body 15 relative to the housing 10 will cause axial movement of the needle shield 5 relative to the syringe's barrel 7.

[0063] Although not mandatory in conjunction with the broadest aspects of the invention, the exemplary injection device 1 shown comprises a needle shield 6 which protects the needle 4 in a manner that generally makes the needle invisible. The needle shield 6 is telescopically mounted in the housing 10 such that in an initial storage state, a distal portion of the needle shield 6 extends from the housing 10. Fig.10 , the needle shield 6 and the housing 10 include spline features 6a, 10a, so that the needle shield 6 can be axially moved relative to the housing but is prevented from rotating. The needle shield 6 can be axially moved relative to the housing 10 from an extended position in which the needle 4 is covered and hidden to a retracted position in which the needle 4 is exposed so that the needle extends a predetermined distance from the distal end face of the needle shield. In the illustrated embodiment, the needle shield 6 is reversibly movable relative to the housing so that the needle shield can be moved from an extended position to a retracted position and further moved back to an extended position.

[0064] In use, the needle shield 6 is pushed against the body to initiate (eg trigger) an injection. Once the pressure pushing the needle shield 6 against the body is released, the needle shield spring 13 enables the needle shield 6 to be forced back to the extended position where the needle 4 is covered again.

[0065] In addition to the cap body 15 and the shield remover 9, the cap assembly 3 also includes a lifting member 12 so that the cap assembly 3 can be unscrewed from the protective needle shield 5 to be removed from the needle 4 when the cap body 15 is unscrewed relative to the housing 10. The shield remover 9 is shown as a separate component, which is permanently attached to the cap body 15 in such a way that once the cap body is unscrewed, the shield remover 9 can be kept in a stationary rotational position relative to the needle shield 6, the syringe barrel 7 and the housing 10, while the cap body 15 changes its rotational position and axial position. Once the cap body is unscrewed, the shield remover 9 remains in the same axial position as the cap body 15. Therefore, the shield remover 9 is a separate component of the cap assembly 3, which is attached to the cap body 15 to be able to perform only rotational movement. The purpose of the rotationally attached shield remover 9 is to enable the protective needle shield 5 to be removed from the needle 4 and the syringe barrel neck 8 in the axial direction once the cap body 15 is twisted. In the embodiment shown, the raising member 12 is formed as a sleeve-like member, which is coaxially arranged between the shield remover 9 and the cap body 15, i.e. arranged in such a way that the raising member is completely accommodated in the cap body 15. In the embodiment shown, although it cannot be recognized in the figure, the raising member 12 is mounted to be axially slidable in the cap body between axial end limits. Figure 4 The proximal edge of the raised member 12 forms a proximally facing surface 17 that is configured to engage a distally facing surface 16 that is provided as a distally facing edge portion of the housing 10 .

[0066] Cam interface 20 is arranged between cap body 15 and raising member 12. Cam interface in the embodiment shown is formed as raising track, and described raising track is provided as spiral cam surface provided on cap body 15 and raising member 12 respectively. Cam interface 20 enables cap body 15 to rise in distal direction during the process that user rotates cap body 15. Because raising member 12 is rotationally locked to needle shield 6 by ridge 18 on the inner side of raising member 12 is assembled in recess 19 in the outer surface of needle shield 6, when cap body 15 is twisted relative to housing 10, spiral cam surfaces are forced to slide and engage with each other, and thus raising member 12 is pushed toward proximal side relative to cap body 15. Because the proximal-facing surface 17 on raising member 12 is pushed toward the distal-facing edge portion of housing 10, cap body 15 is pushed axially in distal direction relative to housing 10 and syringe barrel 7. Therefore shield remover 9 and needle shield 5 are axially disengaged from the neck 8 of syringe barrel 2.

[0067] The ridges 18 and recesses 19 are formed in such a way that the cap assembly 3 including the lifting member 12 can be interconnected to the needle shield 6 in the axial direction during assembly and can also be completely removed from the rest of the injection device 1 by pulling the cap assembly 3 including the lifting member 12 in the axial direction after sufficient rotation of the cap body 15, or at any time when the user wants to take off the cap assembly 3 instead of unscrewing the cap assembly 3. In the first embodiment shown, the fact that the lifting member 12 is rotationally locked when the cap body 15 is twisted relative to the housing is a prerequisite for the needle shield 6 to be rotationally locked to the housing 10.

[0068] Now refer to the reference Figures 5a to 5c , which show the injection device and cap assembly in three consecutive states during cap removal. The accompanying cross-sectional views are in Figure 6a-6c . When the housing 10 of the injection device is held with one hand and the cap assembly 3 is held between the fingers of the other hand during removal of the cap assembly 3, removal of the cap assembly is intended to be performed by twisting the cap body 15 relative to the housing. For the embodiment shown, the lifting member 12 is rotationally locked relative to the needle shield 6 and further rotationally locked relative to the housing 10. Common ways of rotationally locking the needle shield 6 to the housing 10 are tracks and grooves in the inner surfaces of the needle shield 6 and the housing 10, respectively, and vice versa, such as Fig.10 As shown in . In order to evenly distribute the force when twisting the cap assembly 3, the cap body 15 and the lifting member 12 are forced away from each other by two sets of lifting tracks positioned 180 degrees apart in rotation (i.e., in a symmetrical manner). The lifting tracks in the cap body 15 and the lifting member 12 are formed with a lifting geometry that is optimized to overcome the force required to move the protective needle shield 5 from the needle 4 and the syringe barrel neck 8. The cap assembly 3 is twisted in one direction, so the two sets of lifting tracks can be as long as possible, considering the simplicity of tooling for manufacturing the parts and considering that the best possible transmission device for overcoming the force of removing the protective needle shield 5 requires a good balance between the length of the lifting tracks and the lifting slope.

[0069] In order to provide the user with tactile feedback that the cap assembly 3 has been sufficiently rotated and it is time to remove the cap assembly 3 by simply pulling the cap assembly 3 away from the housing 10, the cam interface may include an end-of-rotation stop, which in the illustrated embodiment is formed as a cooperating axially extending shoulder 21 (see Figure 9b In order to enable the cap assembly 3 to be twisted in only one direction at the start of the twisting action, the cam interface 20 will additionally be provided with a rotation start blocking member, which in the embodiment shown is formed as a cooperating axially extending shoulder 22 (see Figure 9a ).

[0070] In addition, the cap assembly 3 and the housing 10 may show visual indication features to guide the user to the steps of removing the cap assembly 3. The rotation arrow 23 on the front of the cap body 15 or on both the front and rear sides of the cap body 15 tells the user how to rotate the cap assembly 3. As shown in the first embodiment, the pull arrow 24 may be arranged on the radial outer surface of the housing 10. Once the cap body 15 is rotated to its end position, along with the axial movement of the cap body, the pull arrow 24 on the housing 10, which was initially hidden by the cap body 15, appears and aligns with the end of the longer horizontal line portion of the rotation arrow 23. This indicates to the user that it is time to completely remove the cap assembly 3 by pulling the cap assembly 3 away from the rest of the injection device 1. In order to enable the lifting member 12 to always be positioned below the cap assembly 3 in a clear manner, a support rib 25 on the inner side of the cap body 15 and a corresponding lifting member upper edge 26 are formed to keep the lifting member 12 in place. Once the cap assembly 3 is rotated, the support ribs 25 provide tactile feedback to the user and serve as an invisible indication that the two elements are moving relative to each other as the upper edge 26 of the raised member will slide over the support ribs 25 (see Figure 7 ).

[0071] As described above, the cap assembly 3 is provided with a lifting member 12, which is rotationally locked relative to the needle shield 6 by physical engagement between the lifting member 12 and the needle shield 6, thereby providing a rotational lock between the two components, and also enabling the lifting member 12 to be axially disengaged from the needle shield 6. In a first embodiment, the lifting member 12 is rotationally locked to the needle shield 6 by fitting the ridges 18 on the radially inward surface of the lifting member 12 into the recesses 19 in the radially outward surface of the needle shield 6. As described, there are two ridges 18 and two recesses 19 in order to obtain good kinematics of the structure compared to, for example, one ridge 18 and one recess 19. However, in alternative embodiments, the geometric structure can be provided by making, for example, three or more groups of ridges 18 and recesses 19. Alternatives to the ridges 18 and recesses 19 can be regular triangular, square, pentagonal or hexagonal shapes, or other equilateral shapes or variations of any other shapes that can achieve the above-mentioned rotational lock and axial disengagement. Furthermore, since the ridge 18 can be provided on the outer surface of the needle shield 6, the ridge 18 on the inside of the raised member 12 that fits into the recess 19 in the outer surface of the needle shield 6 can be selected differently. Instead of forming a suitable geometric structure on the outer side of the needle shield 6, any geometric structure that enables rotational locking and axial disengagement can be located on the radially inward surface of the needle shield 6. Fig.12a and 12b A second embodiment of the injection device 1 is shown, wherein the geometry of the inner edge 27 of the distal facing surface 12a is formed with two recesses 29 cooperating with two protruding flanges 28 on the inner side of the elevation member 12, wherein the two protruding flanges 28 point in the proximal direction.

[0072] The shield remover 9 in the figure is shown as a separate component, which is permanently attached to the cap body 15 in such a way that once the cap assembly 3 is unscrewed, the shield remover 9 can remain in a stationary rotational position relative to the needle shield 6, the barrel 7 of the syringe and the housing 10, while the cap body 15 changes its rotational position and axial position relative to the housing 10. Once the cap assembly 3 is unscrewed, the shield remover 9 remains in the same axial position as the cap body 15. Therefore, the shield remover 9 is a separate component, which is attached to the cap body 15 in a way that allows the shield remover to rotate freely relative to the cap body 15. The purpose of the rotation function associated with the shield remover 9 is to enable the protective needle shield 5 to be removed from the needle 4 and the neck 8 of the barrel 7 of the syringe in the axial direction once the cap assembly 3 is twisted. Shield removers 9 of this type are well known in the art. Other embodiments of the injection device 1 may be formed with a cap assembly 3 in which the shield remover 9 is a non-separate component integrated in the cap body 15, which is formed in such a way that it will hook onto the protective needle shield 5 during assembly and will remove the protective needle shield 5 from the neck 8 of the barrel 7 of the syringe and the needle 4 once the cap assembly 3 is rotated or simply removed. In such an embodiment, the cap body 15, including the integrated shield remover 9, may be rotated relative to the protective needle shield 5 during removal of the cap assembly 3, and thus the protective needle shield 5 is rotated with the axial movement of the cap. Therefore, also in this case, the protective needle shield 5 will be removed in the axial direction.

[0073] Whether the shield remover 9 is an integrated component of the cap body 15 or a separate component attached to the cap body 15, the raising member 12 can be integrated in either concept. The accompanying drawings show two sets of raised tracks positioned 180 degrees rotated from each other, and the raised tracks terminate at an end stop wall 21 parallel to the central longitudinal axis of the injection device 1. In order to enable the cap assembly 3 to be twisted in only one direction when the cap assembly 3 is started to be twisted, the start stop wall 22 provides such a rotation block. The end stop wall 21 can be selected to be omitted, resulting in less preferred user feedback. It is also possible to form a raised track only in the cap body 15 or only in the raising member 12. In this case, once the cap assembly 3 rotates, the ridges in the cap body 15 or the raising member 12 can follow the raised track so that the cap assembly 3 is pushed away from the injection device 1. Instead of two raised tracks or two sets of raised tracks, an alternative embodiment with three raised tracks or three sets of raised tracks can be provided. The track can also be formed as a mirror track, thereby forming a V shape. In this case, the cap assembly 3 can be removed by rotating in either direction (clockwise or counterclockwise).

[0074] Instead of linking the lift member 12 to the needle shield 6 to achieve rotational locking and relative axial displacement, the lift member 12 may be linked directly to the housing 10 . Fig.13 A third embodiment of the injection device 1 is shown in which a flange 31 extends proximally from the proximal edge of the rise member 12. The flange 31 cooperates with a recess 32 on the inner surface of the housing 10 to provide a rotational lock and enable the rise member to be pulled axially relative to the housing 10.

[0075] Fig.14a A fourth embodiment of the injection device 1 is shown in which the riser member 12 has a section that fits over the distal portion of the housing 10. This section of the riser member 12 will extend proximally from the cap body 15 and is therefore visible. The cap assembly 3 thus represents a two-piece cap. Fig.14b The device is shown in a storage state prior to removal of the cap assembly 3, showing the natural transition from the cap body 15 to the lifting member 12. After the initial rotation ( Fig.14c ), the cap body 15 will be axially separated from the lifting member 12 by a predetermined distance. Typically, depending on the specific embodiment, this axial distance will be sufficient to completely disengage the needle shield from the neck 8 of the syringe. However, in other embodiments, the predetermined distance corresponds to only a major portion of the axial movement required to completely disengage the neck. When the cap body 15 is subsequently pulled axially relative to the housing 10, the lifting member 12 will follow the axial movement of the cap body, and the cap body 15, the lifting member 12, the shield remover 9 and the needle shield 5 will be removed from the rest of the device as a single entity ( Fig.14d ).

[0076] The rotation lock is secured by a geometric structure that ensures that the lifting member 12 is rotationally locked relative to the housing 10 while allowing axial movement therebetween. Figures 14a-14d In the embodiment of the present invention, the ridges on the radially outwardly facing surface of the housing 10 cooperate with the recesses (not shown) provided on the inner side of the raised member 12. Figures 14a-14d As shown in , the raised member mounted on the main housing may alternatively have a flange that cooperates with a recess on the inside of the housing 10 rather than cooperating with the external geometry 33 of the housing.

[0077] The above description with respect to the drawings has been provided to give background information about the use of an exemplary injection device suitable for use with the present invention. However, the injection device described is one of many different available injection devices that can be used with the principles of the present invention. It should be emphasized that the present invention is not limited to the illustrated embodiments and the described variations, but may be implemented in other ways within the subject matter defined in the following claims and within the remaining disclosure.

Claims

1. An injection device (1) for discharging a drug from a syringe, the injection device comprising: - a housing (10) formed to be grasped by a subject user, the housing extending along a central longitudinal axis and defining a needle distal end and an opposite proximal end, - a syringe holding device (11), - a syringe (2) comprising a barrel (7) mounted relative to the syringe holding device (11), an injection needle (4), and a needle shield (5) arranged on the injection needle; and - a cap assembly (3) comprising a cap body (15) covering the distal end of the syringe, and a shield remover (9) adapted to engage the needle shield (5), the shield remover (9) being axially fixed relative to the cap body (15); The injection device (1) is defined as: - a distally facing surface (16) arranged axially fixedly relative to the housing (10), and - a shield removal mechanism comprising a cam interface (20) adapted to axially separate the needle shield (5) from the injection needle (4) when the cap body (15) is rotated relative to the housing (10), Characterized in that the cap assembly (3) also includes a lift member (12) that is rotationally and axially movable relative to the cap body (15), wherein the lift member (12) includes a proximally facing surface (17) configured to engage the distally facing surface (16), and wherein the lift member (12) includes a first anti-rotation geometry (18, 28, 31) configured to prevent the lift member (12) from rotating relative to the housing (10), The cam interface (20) includes engaging cam surfaces respectively arranged on the lifting member (12) and the cap body (15), and the cam surfaces are constructed to slidingly engage when the cap body (15) rotates relative to the housing (10) so that the proximal surface (17) of the lifting member (12) is axially pressed against the distal surface (16) while the cap body (15), the shield remover (9) and the needle shield (5) are moved distally relative to the housing (10).

2. An injection device according to claim 1, wherein the injection device (1) includes a second anti-rotation geometry (19, 29, 32, 33), the second anti-rotation geometry being configured to engage with the first anti-rotation geometry (18, 28, 31) of the lifting member (12), and being configured to prevent the lifting member (12) from rotating relative to the housing (10) when the cap body (15) is rotated relative to the housing (10).

3. An injection device according to claim 2, further comprising a needle shield (6) which is telescopically movable relative to the housing (10) but is prevented from rotationally moving relative to the housing, and wherein the needle shield (6) comprises the second anti-rotation geometry (19, 29).

4. Injection device according to claim 2, wherein the housing (10) or a component fixedly attached to the housing comprises the second anti-rotation geometry (19, 29).

5. An injection device according to any one of claims 3-4, wherein the first anti-rotation geometry of the lifting member (12) includes one or more axially extending shoulders (18, 31), each shoulder being rotationally locked relative to a corresponding axially extending shoulder of the second anti-rotation geometry (19, 32, 33).

6. The injection device according to any one of claims 2 to 4, wherein: - the second anti-rotation geometry (19, 33) is formed on a radially outwardly facing surface, cooperating with a first anti-rotation geometry (18) arranged on a radially inwardly facing surface of the elevation member (12), or - the second anti-rotation geometry (28) is formed on a radially inwardly facing surface, cooperating with a first anti-rotation geometry (18) arranged on a radially outwardly facing surface of the elevation member (12).

7. An injection device according to any one of claims 2-4, wherein the injection device includes a distally facing flange, the distally facing flange includes the second anti-rotational geometry provided by at least one recess (19, 29, 32) or protrusion arranged at the distally facing flange, and wherein the first anti-rotational geometry (18, 28, 31) of the lifting member (12) engages at least one recess or protrusion at the distally facing flange to provide a rotational lock between the lifting member (12) and the housing (10).

8. The injection device according to any one of claims 1 to 4, wherein the elevation member (12) is completely comprised within the cap body (15).

9. The injection device according to any one of claims 1 to 4, wherein a distal portion of the elevation member is included in the cap body (15), and wherein a proximal portion of the elevation member (12) extends proximally from the cap body (15).

10. The injection device according to any one of claims 1-4, wherein the cam interface (20) comprises a pair of cooperating rotation end stops (21) defining a rotation end stop position between the cap body (15) and the housing (10).

11. An injection device according to any one of claims 1 to 4, wherein the cam interface (20) comprises a pair of cooperating rotation start blocking members (22) defining a rotation start blocking position between the cap body (15) and the housing (10).

12. An injection device according to any one of claims 1 to 4, wherein the injection device comprises a first indicator (23) indicating a rotation of the cap body (15) relative to the housing (10) and a second indicator (24) indicating an axial pulling of the cap body (15) relative to the housing (10), wherein the injection device is configured to reveal the second indicator (24) in response to the rotation of the cap body (15).

13. An injection device according to any one of claims 1-4, wherein the cap assembly (3) further comprises a ratchet mechanism (25, 26) arranged between the cap body (15) and the lifting member (12), and wherein the ratchet mechanism is configured to provide tactile feedback regarding the distal movement of the cap body (15) relative to the lifting member (12) during rotation of the cap body (15) relative to the housing (10).

14. The injection device according to any one of claims 1 to 4, wherein: When the proximally facing surface (17) of the elevation member (12) axially engages the distally facing surface (16), the distally facing surface resists proximal movement of the elevation member (12).

15. The injection device according to any one of claims 1 to 4, wherein the shield remover (9) is mounted to be freely rotatable relative to the cap body (15).

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