Patent Description:
Drug delivery devices which do comprise a cap with a plurality of parts are, for example, known from <CIT> or <CIT>.

It is an object of the present disclosure to provide solutions which facilitate the provision of an improved cap assembly or cap and/or improve the production of the cap. This object is achieved by the subject matter defined in the independent claims. Advantageous refinements and embodiments are subject matter of the dependent claims.

An aspect of the present disclosure is directed to a cap or a cap assembly for a drug delivery device. Another aspect of the present disclosure is directed to a kit, which is expediently a kit for assembling a cap or cap assembly for a drug delivery device. Another aspect is directed to a method for assembling a cap or cap assembly for a drug delivery device. Yet another aspect is directed to a drug delivery device comprising the cap or cap assembly.

Accordingly, features disclosed in connection with one of these aspects are also considered as being disclosed for the other aspects. Likewise, features disclosed in conjunction with different embodiments may be combined with one another. The difference between the kit and the cap assembly or cap is that, in the kit, the components or parts of the cap have not been assembled yet, whereas the cap assembly or cap refers to a situation where the components or parts have been assembled already.

The multi-part cap assembly according to the invention is defined in claim <NUM>.

In an embodiment, the cap or cap assembly comprises a first cap component and a second cap component. The first cap component may be adjusted to provide an inner or interior surface of the cap. Particularly, the first cap component may be formed in a sleeve-like shape. The first cap component may be adjusted to receive a cartridge of the drug delivery device via a, preferably proximal, opening of the cap assembly or the first cap component. The length of the cap assembly may be greater than or equal to the length of a cartridge of the drug delivery device. The second cap component may be designed to form an outer or exterior surface of the cap. Particularly, the second cap component may be formed in a sleeve-like shape. The first cap component may be made of or comprise a plastic material. The second cap component may be made of or comprise a metal or a metal based alloy. Consequently, the outer appearance of the cap can be governed by the second cap component, which suggests a durable and stable cap of high value, whereas the interior may be formed by the first cap component, which can be designed to suit several functions easily, for example by way of injection moulding a plastic cap component, which enables the provision of several functional features like snap features or other features in the first cap component.

In an embodiment useful for understanding the invention, the first cap component and the second cap component can be assembled to one another. The first cap component may, for example, be received in and/or secured relative to the second cap component. When assembling the cap assembly, the first cap component may be introduced into the second cap component, expediently via a proximal opening of the second cap component. When assembled, the first cap component and the second cap component may be secured to each other such that relative rotational and axial movement is prevented. The cap assembly comprising the two cap components may thus act as a single part.

In an embodiment, the first cap component and/or the second cap component comprises one or more openings, e.g. two openings. Preferably, the respective cap component has at least an opening at the proximal end, i.e. the proximal opening. If there are two openings, there is preferably one at the proximal end of the respective cap component and one at the distal end, i.e. the distal opening.

In the cap or cap assembly the first and second cap components are assembled to one another. The kit also comprises the first and second cap components as detailed above, but not yet assembled to one another, and, in the method, the first and second cap component as detailed above are provided for assembling the cap.

In an embodiment, one of the first cap component and the second cap component is provided with or comprises a guide track, preferably an axial guide track. The other one of the first cap component and the second cap component may be provided with or comprise a guide feature. The guide feature may be designed to cooperate with the guide track. The guide track and the guide feature may be arranged to cooperate to form a guiding interface, preferably an axial guiding interface, between the first cap component and the second cap component. Consequently, when the guide feature and the guide track cooperate, i.e. when the guiding interface is established, movement of the cap components relative to each other, expediently in the axial and/or the angular or rotational direction, is governed by the guiding interface. The axial guiding interface may be configured such that relative rotational movement between the first cap component and the second cap component is restricted or prevented. The axial guiding interface is expediently constructed such that relative axial movement, preferably only relative axial movement, between the first and second cap components is allowed. "Axial", "radial", "rotational", and "angular" as used herein may be understood as being with respect to a main longitudinal axis of the cap / cap assembly or one or more components thereof such as the first or second cap component.

In an embodiment, the guiding interface is configured such that it restricts relative rotational movement to angles of equal to or less than one of the following values: <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>° or <NUM>°, <NUM>°, <NUM>°, <NUM>°. Preferably, relative rotational movement is prevented entirely at least when the first and second cap components are fully assembled. By restricting or preventing the relative rotational movement between the cap components, it can be assured that, expediently already during the assembling process, a defined relative rotational orientation of the two cap components is achieved, which may have significant advantages. For example, features provided on one cap component do have a defined position relative to features on another cap component, which will simplify the assembling process and also increase the yield as cap components which have been assembled to each other in the wrong angular orientation might not be suitable for further use.

In an embodiment, the first cap component and/or the second cap component may be unitary. That is to say, the respective cap component may be formed as a single piece.

In an embodiment, the respective cap component may comprise a main body with the guide feature or the guide track being formed on the main body of the respective cap component.

In an embodiment, when assembling the multi-part cap assembly, the first cap component and the second cap component may be arranged with respect to each other such that the guiding interface is established. For doing so, the first cap component may be introduced into the second cap component. The guiding interface may be established, preferably only, after a first portion of relative movement, particularly relative axial movement, between the first cap component and the second cap component has been performed. In other words, before the guiding interface is established, there may be a situation where the guiding interface is not established, although the first cap component has already been received in the second cap component. After the guiding interface has been established, the first cap component and the second cap component may be moved relative to one another, particularly in the axial direction, towards an end position. This movement is expediently guided by the guiding interface, preferably from the onset of the guiding interface until the end position has been reached. In the end position, the first cap component and the second cap component may be secured to one another, expediently against relative axial and/or rotational movement.

In an embodiment, the cap, the first cap component and/or the second cap component do define a longitudinal axis, particularly a main longitudinal axis. The axes of the two cap components may coincide or be parallel.

In an embodiment, the guide track may extend in the axial direction. The guide track may be a straight track. The guide track may extend along the longitudinal axis, preferably parallel with respect to the axis. The guide track may coincide with the longitudinal axis when projected onto a plane comprising the axis. In other words, when seen in projection onto a plane which comprises the main longitudinal axis but does not comprise the guide track the guide track and the longitudinal axis may coincide.

In an embodiment, the first cap component and the second cap component are configured such that the relative angular orientations of the first cap component and the second cap component, in which the first cap component can be assembled to, e.g. arranged in the end position with respect to, the second cap component, are limited. This holds, preferably, even when disregarding the guiding interface mentioned above. Accordingly, aside from the guiding interface, the cap components may be designed such that they can be assembled to each other only in a limited number of relative angular orientations.

In an embodiment, the inner cross section of the second cap component and the outer cross section of the first cap component may be adjusted to one another at least in an adjusted region of the respective component. The adjustment may be performed by shaping the outer surface of the first cap component and the inner surface appropriately in the adjusted region of the respective cap component. When the cap components are misaligned, relative axial movement is not possible as the cross sectional shape does not permit this movement. When the cap components are aligned correctly, however, the adjusted sections of the cross section cooperate, e.g. they form a rotationally constrained interface or an interface of limited relative rotatability between the two components, and relative axial movement is possible.

Therefore, the first cap component and the second cap component can be pre-aligned, even if the guiding interface is not yet established. Consequently, the guide feature and the guide track may be pre-aligned such that they can be brought into mechanical cooperation for forming the guiding interface more easily and more reliably during the assembly of the cap assembly.

In an embodiment, the cap components are expediently designed such that a splined interface or pre-alignment interface is formed between the cap components while the two components are being assembled to one another and before the guiding interface is established by cooperation of the guide feature and the guide track.

In an embodiment, the relative angular orientations in which the first and second cap components can be assembled to one another are limited to a range of orientation angles, preferably a single and continuous range of orientation angles. Consequently, even when the axial guiding interface is not or not yet established, the cap components may be aligned in the range of orientation angles. The guiding interface is expediently configured to restrict the relative rotational movement which is permitted between the first cap component and the second cap component to a restricted range of angles. The restricted range of angles is expediently smaller, e.g. has a smaller extension, than the range of orientation angles. The restricted range of angles may be a subset of the range of orientation angles. The range of orientation angles is expediently such that the intended position in which the first and second cap components should be assembled is at <NUM>° with deviations possible in both rotational directions up to to - α1 and + α2, respectively. α1 and α2 may be different or equal. By means of the pre-alignment, α1 and/or α2 may be already restricted to values equal to or less than one of the following values: <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°, <NUM>°. The guiding interface may restrict the relative rotatability even more or prevent relative rotatability entirely. Consequently, by providing the guide track and the guide feature a very defined relative rotational position may be assumed by the first and second cap components during the assembly and/or in the end position once the assembling process has been completed.

In an embodiment, the guiding interface is established in the end position. The guide track may comprise an axial end stop which cooperates with the guide feature to indicate when the end position has been reached.

In an embodiment, the guide track is a slot or a groove.

In an embodiment, the guide feature has one or more curved surfaces. The respective curved surface may be designed to interact with the guide track. A reliable guiding interface may be realized in this way. The respective surface may extend in the radial direction.

In an embodiment, the cap assembly comprises a third cap component. The third cap component may comprise or be provided with a third cap component fixing feature, e.g. a snap feature. The third cap component may be a clip element for the cap assembly. The clip element may be designed such that the cap can be clipped to a pocket or the like.

In an embodiment, the first cap component is provided with or comprises a first cap component fixing feature, e.g. a snap feature. The third cap component may be fixed to the first cap component by means of the first cap component fixing feature. The first cap component fixing feature is expediently designed and arranged to cooperate with the third cap component fixing feature provided on the third cap component in order to fix the third cap component to the first cap component.

In an embodiment, the second cap component is provided with or comprises a fixing guide track, in particular an axial or axially extending fixing guide track. The fixing guide track may be arranged to guide movement of the third cap component and/or the third cap component fixing means to or towards the first cap component fixing means. In other words, the second cap component may interact with the third cap component in order to guide a fixing feature of the third cap component to the first cap component fixing feature. As the guiding interface ensures a defined relative angular position between the second cap component and the first cap component it is also ensured that the third cap component fixing feature is reliably guided to the first cap component fixing feature and may cooperate with the first cap component fixing feature.

In an embodiment, the axial fixing guide track and the axial guide track extend in, are arranged in and/or are restricted to a common plane when the axial guiding interface is established. This plane may be a plane which also comprises the main longitudinal axis of the cap assembly or of components thereof.

In an embodiment, the third cap component is used to secure the first cap component and the second cap component with respect to one another, in particular with respect to relative axial movement. Consequently, when the first cap component fixing feature and the third cap component fixing feature cooperate, relative axial movement between the first cap component and the second cap component is prevented. Relative rotational movement may also be prevented by the third cap component and/or by the guiding interface, which may be still operative in the end position.

In an embodiment, the third cap component fixing feature and the first cap component fixing feature are arranged to cooperate, particularly only, when they are arranged in a fixing range of relative angular positions or orientations with respect to one another. Thus, even if they were at the correct relative axial position, i.e. corresponding axial locations, the fixing features could not cooperate if their relative angular position or orientation is arranged outside of the fixing range. Similar as above, <NUM>° is the ideal relative angular position or orientation in which the fixing features should be arranged to allow cooperation. The tolerance which has to be met for still allowing proper cooperation of the fixing features may be as low as <NUM>° or even less from the ideal position. Thus, the fixing range is very small. The fixing range may fully cover the relative angular positions or orientations in the restricted range of angles, when the guiding interface is established. The fixing range may not fully cover the relative angular positions orientations in the range of orientation angles. That is to say, the range of relative angular orientations which is possible when disregarding the guiding interface may comprise orientation angles where the fixing features of the first and third cap components could not cooperate. The guiding interface, however, restricts the range of possible relative angular positions or orientations to the restricted range of angles, where it is ensured that the fixing features can cooperate. In other words, a fixing range of angles may fully cover the restricted range of angles but not the range of orientation angles.

In an embodiment, the second cap component forms an outer surface of the cap assembly. The second cap component may be made of metal or of a metal alloy.

In an embodiment, the second cap component is a deep drawn component. Deep drawing facilitates the manufacturing of a metal or metal alloy second cap component. Deep drawing is a production method for metal components which is very cost effective, is suitable for high volumes, and/or ensures a high yield.

In an embodiment, the guide track is provided on the first cap component and the guide feature is provided on the second cap component or vice versa. Expediently, the guide feature is arranged on an inner surface of the second cap component and the guide track is arranged on an outer surface of the first cap component.

In an embodiment, the guide feature is formed by a protrusion. The protrusion may extend in the radial direction. The protrusion may be provided on an inner surface of the second cap component. The protrusion may be realised by deep drawing. The protrusion may protrude from a main body of the respective cap component. The protrusion may have a hemispherical shape.

In an embodiment, the second cap component, particularly an outer surface thereof, comprises a depression. The depression may have a hemispherical shape. The depression may be formed by a pressing operation that occurs as part of a multi-stage deep-drawing process. The protrusion may be defined by the depression. This facilitates manufacturing the protrusion in a deep drawing process as protrusion and depression can be formed simultaneously.

In an embodiment, the guide feature, particularly the protrusion, is defined by a depression. The guide feature may be arranged on the opposite surface of the same cap component which comprises the depression. The depression may be the same depression as discussed further above.

In an embodiment, a section of the third cap component, particularly a radially extending section of the third cap component, which protrudes radially from the remainder of the third cap component, may be arranged in the depression. Consequently, the depression may provide for a bearing surface of a clip element of the cap assembly.

In an embodiment, the third cap component or clip element is a multi-part component. The third cap component may comprise a first or inner part, preferably a plastic part, which is connected with a second or outer part, e.g. an outer shell, preferably of metal or a metal alloy.

In an embodiment, the guide track comprises a lead-in region, preferably at the start of the guide track. Via a transition region of the guide track, the lead-in region may pass into a guiding region. In the lead-in region, the relative orientation angles, in which the guide feature can cooperate with the guide track may be wider than in the guiding region. In other words, the lead-in region may be arranged to accept the guide feature and guide the guide feature to a guiding region of the guide track, in which the guide feature is guided more tightly than in the lead-in region. This ensures a tight guiding when the guiding interface is established, which is expediently the case when the guide feature and the guiding region cooperate. Consequently, even if the first and second cap components are misorientated or misaligned with respect to one another in the angular direction such that the guide feature could, without the lead-in region, not cooperate with the guide track, the lead-in region can capture the guide feature during relative axial movement of the cap components during the assembling process and orient the first and second cap components appropriately in the angular direction such that the guide feature and the guiding region of the guide track can cooperate.

In an embodiment, the drug delivery device, which comprises the cap assembly, comprises a cartridge containing a drug, preferably a plurality of doses of the drug, which is preferably a fluid drug. The drug delivery device is expediently configured such that the cartridge is replaceable.

In other words, the drug delivery device is preferably reusable. The device may be a pen-type device.

In a preferred embodiment, a multi-part cap assembly for a drug delivery device comprises a first cap component and a second cap component, wherein the first cap component is assembled to, in particular received in and/or secured relative to, the second cap component, wherein one of the first cap component and the second cap component is provided with a guide track and the other one of the first cap component and the second cap component is provided with a guide feature, wherein the guide track and the guide feature are arranged to cooperate to form an axial guiding interface between the first cap component and the second cap component, and wherein the axial guiding interface is configured such that relative rotational movement between the first cap component and the second cap component is restricted or prevented.

According to the invention as defined in claim <NUM>, a kit for assembling a multi-part cap for a drug delivery device comprises a first cap component and a second cap component which can be assembled for the cap assembly, wherein the first cap component can be received in and secured relative to the second cap component, and wherein one of the first cap component and the second cap component is provided with a guide track and the other one of the first cap component and the second cap component is provided with a guide feature, wherein the guide track and the guide feature are arranged to cooperate to form an axial guiding interface between the first cap component and the second cap component, and wherein the axial guiding interface is configured such that relative rotational movement between the first cap component and the second cap component is restricted or prevented.

According to the invention as defined in claim <NUM>, a method for assembling a multi-part cap for a drug delivery device comprises the steps of:.

The preferred embodiments discussed above do have particular advantages which become apparent from the description further above and the following description.

Features which are described herein above and below in conjunction with different aspects or embodiments, may also apply for other aspects and embodiments. Further features and advantageous embodiments of the present disclosure will become apparent from the following description of the exemplary embodiments in conjunction with the figures, in which:.

Like elements, elements of the same kind and identically acting elements may be provided with the same reference numerals in the figures. Additionally, the figures may be not true to scale. Rather, certain features may be depicted in an exaggerated fashion for better illustration of important principles.

<FIG> show a drug delivery device <NUM> in the form of an injection pen. Consequently, references herein using the wording "an injection pen" or similar wordings should also be understood as relating to a drug delivery device, preferably a pen-type drug delivery device. The device <NUM> has a distal end (lower end in <FIG>) and a proximal end (upper end in <FIG>). The components of the drug delivery device <NUM> are shown in <FIG> in more detail. The drug delivery device <NUM> comprises an outer housing part <NUM>, an inner body <NUM>, a piston rod <NUM>, a driver <NUM>, a nut <NUM>, a display member <NUM>, a button <NUM>, a cartridge holder <NUM> for receiving a cartridge <NUM>, a clutch <NUM>, a clicker <NUM>, a spring <NUM>, a cap <NUM> and a window insert <NUM>. A needle arrangement (not shown) comprising a needle hub and a needle cover may be provided as additional components, which can be exchanged. The piston rod <NUM> comprises a bearing <NUM>. The driver <NUM> comprises a distal driver part <NUM>, a proximal driver part <NUM> and a coupler <NUM>. The display member <NUM> comprises a number sleeve <NUM> and a dial sleeve <NUM>. The clicker <NUM> comprises a distal clicker part <NUM>, a proximal clicker part <NUM> and a spring <NUM>.

The outer housing part <NUM>, which is shown in <FIG>, is a generally tubular element having a distal part <NUM> for attaching the inner body <NUM> and a proximal part, which is provided with a rotational hard stop <NUM> on its inner surface (not shown) which contact mating faces of the display member <NUM> when the maximum units (in this example 80U) stop is engaged. The end face also serves as the end of dose dispense stop for the button <NUM>, and the bore in the end face centers the display member <NUM> during both dialing and dispense. An aperture <NUM> is provided for receiving window insert <NUM>. The outer body <NUM> provides the user with a surface to grip and react against during dispense.

The inner body <NUM> is a generally tubular element having different diameter regions. As can be seen in <FIG>, the inner body <NUM> is received in the outer body <NUM> and permanently fixed therein to prevent any relative movement of the inner body <NUM> with respect to the outer body <NUM>. The inner body has the functions to house the drive mechanism within, guiding the clickers and the last dose nut <NUM> via internal splines, to provide an internal thread through which the piston rod <NUM> (lead screw) is driven, to support and guide the number sleeve <NUM> and the dial sleeve <NUM> on an external thread form, to secure the cartridge holder <NUM> and to secure the outer body <NUM> and the window insert <NUM>.

The outermost diameter of the inner body <NUM> also forms part of the visual design and remains visible when the cap <NUM> is secured to the cartridge holder <NUM> as a ring separating the cap <NUM> from the outer body <NUM>. This visible ring also has depressions which align with the cap snap features on the cartridge holder <NUM> to indicate that the cartridge holder has been correctly fitted.

An external thread <NUM> is provided on the outer surface of the inner body <NUM>. Further, splines <NUM> (<FIG>) are provided on the inner surface of the inner body <NUM>. These internal splines <NUM> guide the clicker <NUM> axially during both dialing and dispense and also prevent the last dose nut <NUM> from rotating. Some of the splines may be wider to ensure correct rotational assembly of the internal components, and these wider splines may have a stepped entry and angled surface to encourage the last dose nut <NUM> to rotate up against the stop face on the distal drive sleeve <NUM> during assembly. At the open end shown in <FIG> there are additional short splines which together with the alternating long splines <NUM> are used to rotationally lock the button <NUM> (dose dial grip) at the end of dispense and serve to increase the strength of the 0U dial stop when the button <NUM> is depressed. This is achieved by engagement with male spline features on the clutch component <NUM>.

Bayonet features <NUM> guide the cartridge holder <NUM> into the mechanism during cartridge replacement, compressing the cartridge bias spring <NUM>, and then back off the cartridge holder <NUM> a small distance in order to reduce axial play in the mechanism. Snap features inside the inner body <NUM> lock the cartridge holder <NUM> rotationally when it has been correctly fitted. The profile of these snaps aims to prevent the user from partially fitting the cartridge holder <NUM>, the cartridge bias spring <NUM> ejecting the cartridge holder <NUM> if the snaps have not at least started to engage. A window retention nose <NUM> retains the window insert <NUM> when the outer body <NUM> and window insert <NUM> assembly is axially inserted onto the inner body <NUM>. Two diametrically opposite stop faces <NUM> define the rotational end position for the number sleeve <NUM>. This end position is the end of dose detent position for the minimum dose (0U).

The piston rod <NUM> is an elongate element having two external threads <NUM>, <NUM> with opposite hand which overlap each other. One of these threads <NUM> engages the inner thread of the inner body <NUM>. A disk-like bearing <NUM> is provided at the distal end of the piston rod <NUM>. The bearing <NUM> may be a separate component as shown in <FIG> or may be attached to the piston rod <NUM> as a one-piece component via a predetermined breaking point.

The piston rod <NUM> transfers the dispense load from the driver <NUM> to the bearing <NUM>, creating a mechanical advantage greater than <NUM>:<NUM> by converting the torque generated on the piston rod <NUM> by the driver <NUM> thread interface into additional axial load as the piston rod passes through the thread in the inner body <NUM>. The piston rod <NUM> is reset by pressing on the bearing <NUM> and this in turn rotates the piston rod back into the inner body <NUM>. This disengages and then rotates the distal drive sleeve <NUM>, resetting the last dose nut <NUM> back to its starting position on the distal drive sleeve <NUM>.

The driver <NUM> is a generally tubular element having in the embodiment shown in the Figures three components which are depicted in <FIG> in more detail.

The distal drive sleeve <NUM> engages with the piston rod thread <NUM> to drive the piston rod <NUM> through the inner body <NUM> during dose delivery. The distal drive sleeve <NUM> is also permanently connected to the coupler <NUM> which in turn is releasably engaged through reset clutch features to the proximal drive sleeve <NUM>. The two halves of the drive sleeve are rotationally and axially connected during dialing and dispense, but are de-coupled rotationally during device reset so that they can rotate relative to each other.

The external thread <NUM> engages with the last dose nut <NUM>. The thread form has three stages, a shallow first stage (left hand side in <FIG>) over which the nut <NUM> travels to count the majority of the units dialed, a fast stage over which the last dose nut moves rapidly axially prior to engaging the stop faces, and a final shallow section which ensures that when the stop faces have engaged, the axial restraint on the nut <NUM> extends over a reasonable length of thread form. Four equi-spaced stop faces <NUM> engage with mating stop faces <NUM> on the last dose nut <NUM> to limit the number of units that can be dialed. Splines <NUM> are provided at the proximal end of distal drive sleeve <NUM> to transfer torque from or to the coupler <NUM>, which may be snapped on the distal drive sleeve <NUM>.

The proximal drive sleeve <NUM> shown in <FIG> supports the clicker components <NUM> and the clutch <NUM> and transfers rotational movement from the dose button <NUM> to the coupler <NUM> and distal drive sleeve <NUM>.

Teeth features <NUM> located at the distal end of proximal drive sleeve <NUM> engage with the reset clutch features on the coupler <NUM> to connect both halves of the drive sleeve during dialing and dispense. During reset these teeth <NUM> disengage.

Several splines are provided on the outer surface of proximal drive sleeve <NUM> engaging with the distal and/or proximal clicker part <NUM>,<NUM>, preventing relative rotation during dialing and dispense. Further splines, which are located in the middle region of proximal drive sleeve <NUM>, engage with the clutch <NUM> component. They may be arranged to be rotationally non-symmetric so that the various clicker components cannot be assembled accidentally upside down.

The proximal portion of proximal drive sleeve <NUM> has four arms or fingers <NUM>. A hook-like bearing surface <NUM> exists on the underside (as seen in <FIG>) of flange segments on the end of the flexible fingers <NUM>. The flexible fingers <NUM> are separated with gaps or slots that make space for the button <NUM> to snap to the clutch <NUM> and also enable these fingers to flex inwards during assembly of the proximal drive sleeve <NUM> to the dial sleeve <NUM>. After assembly the hooks <NUM> retain the proximal drive sleeve <NUM> relative to the dial sleeve <NUM> under the reaction force from the spring <NUM>. During dispense the button <NUM> depresses the spring <NUM> via the clutch <NUM> and the clicker components and this spring <NUM> is reacted through the coupler <NUM> to the proximal drive sleeve <NUM> which then through these bearing surfaces applies axial load to the dial sleeve <NUM>. This axial load drives the dial sleeve <NUM> and hence number sleeve <NUM> along the helical thread of the inner body <NUM>, back into the body of the device, until the 0U stop faces on the number sleeve <NUM> contact the inner body <NUM>.

The coupler <NUM> shown in <FIG> rotationally couples the two halves of the drive sleeve together during dialing and dispense, whilst allowing them to de-couple during reset. The coupler <NUM> has to also transfer the last dose protection stop load from the proximal drive sleeve <NUM> to the distal drive sleeve <NUM>. Two sets of teeth are provided in the coupler <NUM> for engaging teeth <NUM> and teeth <NUM>, respectively. The coupler <NUM> is snapped onto distal drive sleeve <NUM> allowing limited relative axial movement with respect to the proximal drive sleeve <NUM>.

The nut <NUM> is provided between the inner body <NUM> and the distal drive sleeve <NUM> of driver <NUM>. Stop faces <NUM> are located on the proximal face of last dose nut <NUM> to limit the number of units that can be dialed if the stop faces <NUM> contact stops <NUM> of distal drive sleeve <NUM>. The function of the last dose nut <NUM> is to prevent the user from dialing beyond a finite amount. This limit is based on the dispensable volume of the cartridge <NUM> and when reached, the user must replace the cartridge <NUM> and reset the device.

External ribs <NUM> of the nut <NUM> engage splines <NUM> of inner body <NUM>. An internal thread <NUM> of the nut engages the external thread <NUM> of distal drive sleeve <NUM>. As an alternative, splines and ribs could be provided on the interface between the nut <NUM> and the driver <NUM> and threads could be provided on the interface between the nut <NUM> and the inner body <NUM>. As a further alternative, the nut <NUM> may be designed as e.g. a half nut.

The display member <NUM> is a generally tubular element which is composed of number sleeve <NUM> and dial sleeve <NUM> which are snapped together during assembly to axially and rotationally constrain these two components, which thus act as a single part.

The main functions of the number sleeve <NUM> depicted in <FIG> are to provide a surface onto which dose numbers can be printed to display the dialed dose, to guide the helical path of the internal mechanism during dialing to follow the helical thread form on the piston rod <NUM> when threaded to the inner body <NUM> and to attach to the dial sleeve <NUM>.

The number sleeve <NUM> is designed to be fully enclosed in the outer body <NUM> during dialing and dispense and therefore only the dialed dose is visible to the user through the window aperture. The number sleeve has a 0U (minimum dose) stop face <NUM> to limit its travel when dialed in but the 80U (maximum dose) stop faces that limit the dialed out condition are located on the dial sleeve <NUM>. At the end of each dispense stroke, this stop face <NUM> engages with mating surface <NUM> on the inner body <NUM> to limit the rotational position of the number sleeve <NUM>.

A helical drive face <NUM> forms a thread that guides the number sleeve <NUM> during dialing and dispense to follow the helical path <NUM> on the inner body.

The dial sleeve <NUM> is assembled to the number sleeve <NUM> such that once assembled, no relative movement is allowed. The parts are made as separate components to enable both molding and assembly. Also, whereas the number sleeve <NUM> is preferably white to give contrast for the e.g. black dose numbers, the dial sleeve <NUM> color can be chosen to suit the aesthetics or perhaps to distinguish the drug type.

At the proximal end, the dial sleeve <NUM> has internal clutch features <NUM> that engage with the clutch component <NUM> during dialing and disengage from the clutch during dispense. These clutch features <NUM> rotationally lock the dial sleeve <NUM> to the clutch <NUM> during dialing and when the 0U and 80U stops are engaged. When the button <NUM> is depressed these clutch features disengage to allow the clutch <NUM> and drive mechanism to move axially whilst the dial sleeve <NUM> and number sleeve <NUM> spin back to the 0U start position.

The dial sleeve <NUM> rotates out during dialing through its engagement with the clutch <NUM> and number sleeve <NUM>, and rotates back in during dispense under the axial force applied by the proximal drive sleeve <NUM> to a flange-like bearing face <NUM> on the end of the dial sleeve. This bearing face <NUM> engages with the flexible arms <NUM> of the proximal drive sleeve <NUM> during dispense. Two diametrically opposite faces <NUM> engage with the outer body <NUM> when the maximum dose (e.g. 80U) has been dialed, forming the maximum dose stop faces.

A ratchet arm <NUM> engages with ratchet features on the button <NUM> (dose dial grip) to provide audible feedback during dispense, giving one click per unit delivered. Further, this prevents the user from gripping and rotating the number sleeve <NUM> outwards from a partially dialed out position whilst holding the button <NUM> pressed in. This would back wind the piston rod <NUM> which would result in an under dose on the subsequent dialed dose. It may further strengthen the 0U stop.

The button <NUM> which is shown in <FIG> serves as a dose dial grip and is retained by the clutch <NUM> to transfer the actions of the user to the clutch. It also carries ratchet teeth <NUM> that engage the ratchet arm <NUM> on the dial sleeve <NUM>, which serves as the dispensing clicker giving audible feedback (ratchet clicks), and an end face <NUM> which serves as the dose completion stop face with the outer body <NUM>. This end face <NUM> thus serves to define the end position during dispense when it contacts the outer body <NUM> to provide a very positive stop improving dose accuracy.

A central sleeve-like portion of button <NUM> is provided with four arms <NUM> having hook-like snap features <NUM> at their respective distal ends. The arms <NUM> form splined surfaces engaging with the clutch <NUM> to transfer torque from the button <NUM> through the clutch to the dial sleeve <NUM> and proximal drive sleeve <NUM>. The snap features <NUM> engage apertures in the clutch <NUM> and are designed with angled undercut faces to maintain engagement when an axial load is applied to pull the button <NUM> out of the pen body <NUM>. The space between arms <NUM> defines pockets giving clearance for the flexible arms <NUM> of proximal drive sleeve <NUM> to slide freely relative to the button <NUM> and clutch <NUM> when the button <NUM> is depressed and released during dose dispense.

The cartridge holder <NUM> attaches to the inner body <NUM> with a bayonet connection <NUM> and houses the glass ampoule or cartridge <NUM> containing the medication to be dispensed. The cartridge holder <NUM> includes an aperture <NUM> in the rear face (as seen in <FIG>) which if gripped by the user prevents the ampoule from falling out when the cartridge holder is removed from the inner body <NUM>. The front face is printed with a dose number scale. The threaded distal end <NUM> is used to attach disposable pen needles.

The term "drug" or "medication", as used herein, preferably means a pharmaceutical formulation containing at least one pharmaceutically active compound,.

Hormones are for example hypophysis hormones or hypothalamus hormones or regulatory active peptides and their antagonists as listed in <NPL>, such as Gonadotropine (Follitropin, Lutropin, Choriongonadotropin, Menotropin), Somatropine (Somatropin), Desmopressin, Terlipressin, Gonadorelin, Triptorelin, Leuprorelin, Buserelin, Nafarelin, Goserelin.

Antibodies are globular plasma proteins (~<NUM> kDa) that are also known as immunoglobulins which share a basic structure. As they have sugar chains added to amino acid residues, they are glycoproteins. The basic functional unit of each antibody is an immunoglobulin (Ig) monomer (containing only one Ig unit); secreted antibodies can also be dimeric with two Ig units as with IgA, tetrameric with four Ig units like teleost fish IgM, or pentameric with five Ig units, like mammalian IgM.

Further examples of pharmaceutically acceptable salts are described in "<NPL>and in <NPL>.

A tubular clutch <NUM> is provided between the display member <NUM> and the button <NUM>. The clutch is fixed relative to and retains the button <NUM> and together they travel axially relative to the proximal drive sleeve <NUM> when the button <NUM> is depressed during dispense, disengaging the clutch teeth from the dial sleeve <NUM>. It also transfers torque from the button to the proximal drive sleeve <NUM>, and the dialing and 0U/80U stop loads from the button via the clutch teeth to the dial sleeve and number sleeve.

Drive sleeve splines <NUM> provided on an inner surface of the clutch engage with the proximal drive sleeve <NUM>. At the distal end face, clutch biasing teeth <NUM> are provided which mate with similar teeth on the proximal clicker part <NUM> to ensure that in the button out position (dialed dose) the clutch is locked in rotation to the proximal clicker part <NUM> under the biasing action of the clutch spring <NUM>. The teeth <NUM> are shallow in height to prevent the proximal clicker part <NUM> from engaging with splines on the proximal drive sleeve <NUM> during dialing. Four snap apertures <NUM> serve to retain the snap features <NUM> of button <NUM>. Near its proximal end, the clutch has splines <NUM> which at the end of dispense with the button <NUM> depressed lock to the inner body <NUM> to prevent the user from rotating the button <NUM> below the 0U position.

Clutch teeth <NUM> engage with clutch teeth <NUM> of the dial sleeve to rotationally couple the button <NUM> via the clutch to the number sleeve <NUM>. During dispense the clutch is moved axially so as to disengage these clutch teeth <NUM> releasing the dial sleeve <NUM> to rotate back into the device whilst the clutch <NUM> and hence driver <NUM> move axially to dispense the dose.

The clicker <NUM> comprises a distal clicker part <NUM>, a proximal clicker part <NUM> and a spring <NUM>. The clutch spring <NUM> serves to bias the button <NUM> out so that at the end of a dose the button <NUM> pops out, re-engaging the clutch <NUM> with the dial sleeve <NUM> ready for dialing. Further, it provides the spring force for the clicker components to act as clickers and also as detent positions for the number sleeve <NUM>. In addition, it holds the two halves of the drive sleeves <NUM>, <NUM> in rotational engagement during dialing and dispense, whilst allowing them to disengage during device reset.

The distal clicker part <NUM> is permanently splined to the proximal drive sleeve <NUM> and engages with the proximal clicker part <NUM> which in turn is splined to the inner body <NUM>. During dialing when the drive sleeve is rotated relative to the inner body, the two clickers <NUM>, <NUM>, rotate relative to each other under the compression force of the clutch spring <NUM>. This force combined with the clicker teeth formed on the end face of each clicker provides the clicks and also the detent dialing positions.

During dispense the two clickers <NUM>, <NUM> are pressed together under the dispense load and therefore prevent relative rotation between the proximal drive sleeve <NUM> and inner body <NUM>, driving the piston rod forwards to deliver the dose. The splines <NUM> on the inner bore rotationally couple the distal clicker part <NUM> to the proximal drive sleeve <NUM> at all times, but allow free axial movement when the button <NUM> is depressed during dispense and when the two clickers ride over each other during dialing. The profile of the clicker teeth <NUM>, <NUM> on both distal clicker part <NUM> and proximal clicker part <NUM> are identical and ride over each other under the compressive load from the spring <NUM> during dialing.

The proximal clicker part <NUM> is permanently splined to the inner body <NUM> by external splines <NUM> which prevent relative rotation with the inner body during both dialing and dispense, providing clicks during dialing and locking the proximal drive sleeve <NUM> in rotation during dispense. Additional cylindrically shaped splines <NUM> also couple the proximal clicker part <NUM> rotationally to the proximal drive sleeve <NUM> when the button <NUM> is depressed, this preventing the user from dialing past <NUM> units with the button depressed. Proximal clicker part <NUM>, in addition to the primary clicker teeth <NUM>, has clutch biasing teeth <NUM> on the opposite end face. These teeth mate with similar teeth <NUM> on the clutch to ensure that in the button out position (dialed dose) the clutch is locked in rotation to the proximal clicker part <NUM> under the biasing action of clutch spring <NUM>.

The cartridge bias spring <NUM> is assembled as two components one after the other, the lower first and the upper second. The spring combination serves to apply an end load to the cartridge <NUM> at extremes of tolerance so as to bias it forwards onto the end face of the ferrule in the cartridge holder <NUM>. This ensures that when the user removes and attaches a needle, the friction between the needle cannula and septum of the cartridge does not move the cartridge <NUM> axially relative to the cartridge holder <NUM>. The bias spring <NUM> also acts to provide a force against which the user has to connect the cartridge holder <NUM> and this may add to the tactile feedback of this bayonet joint. The spring <NUM> also serves to eject the cartridge holder <NUM> if the cartridge holder is not rotated into a secure position, highlighting this error to the user.

The cap <NUM> serves to protect the cartridge holder <NUM> from damage and the cartridge <NUM> itself from dust dirt ingress on to the area around the septum. The cap <NUM> is designed to accommodate a standard pen injector needle. The cap <NUM> comprises a clip element <NUM> or fixing element for attaching the cap <NUM> and, hence, the drug delivery device <NUM> to a further element, e.g. a jacket pocket of the user. Preferably, the clip element <NUM> is snap-fitted to the cap <NUM>. Details concerning the structure of the cap <NUM> and the clip element <NUM> as well as their connection are described later on.

The window insert <NUM> may include a lens to magnify the dose numbers e.g. by approximately <NUM>% from their printed size. The window insert <NUM> may be back printed to protect the printed surface from abrasion and also to maximize the light entering through the window aperture, giving uniform illumination of the dose numbers and white area around these numbers. Arrows may be printed adjacent to the window aperture that indicate the dose dialed.

In the following, the function of the drug delivery device and its components will be explained in more detail with reference to <FIG>.

To use the device, a user has to select a dose. In the start (at rest) condition as shown in <FIG> the display member <NUM> indicates the number of doses dialed to the user. The number of dialed units can be viewed through the dose window <NUM> in the outer body <NUM>. Due to the threaded engagement between the display member <NUM> and the inner body <NUM> rotation of the button <NUM> in a clockwise fashion causes the display member <NUM> to wind out of the device and incrementally count the number of units to be delivered. <FIG> shows an intermediate stage of dialing (e.g. <NUM> of <NUM> units).

During dose setting button <NUM>, driver <NUM> and display member <NUM> are rotationally locked together via clutch <NUM>. Further, button <NUM>, driver <NUM> and display member <NUM> are axially coupled. Thus, these three components wind out of the outer housing <NUM> during dose setting. Clockwise rotation of the button <NUM> causes the driver <NUM> to rotate and in doing so it advances along the piston rod <NUM> which remains fixed throughout dialing. The clicker arrangement <NUM> provides tactile and audible feedback to the user when dialing doses. At the maximum settable dose of <NUM> units, the stop features <NUM> and <NUM> engage to prevent further dialing.

The last dose nut <NUM> provides the function of counting the number of dispensed units. The nut <NUM> locks the device at the end of cartridge life and as such no more drug can be dialed by the user. The last dose nut <NUM> and the driver <NUM> are connected via a threaded interface as explained above. Further, the last dose nut <NUM> is assembled into splines <NUM> such that the nut <NUM> and the inner body <NUM> are rotationally locked together (at all times). Rotation of the driver <NUM> during dialing causes the nut <NUM> to advance along the thread <NUM>. The nut <NUM> is free to slide axially within the inner body <NUM> at all times which allows advancement of the nut. The change in pitch of thread <NUM> shown in <FIG> towards the final doses axially accelerates the advancement of the nut <NUM> towards the end of cartridge life lockout condition. At the end of life condition, the stop features <NUM> of the last dose nut <NUM> contact the corresponding features <NUM> on the driver <NUM>. The splined contact with inner body <NUM> reacts any torque transmitted by these stop features <NUM>.

With the desired dose dialed, the device <NUM> is ready for dose dispensing. This basically requires pushing button <NUM> which will result in a disengagement of the clutch <NUM> from dial sleeve <NUM> thus allowing relative rotation between the display member <NUM> and the button <NUM>. In all conditions the driver <NUM> and the button <NUM> are rotationally locked together by engagement of arms <NUM> and fingers <NUM> and by splines <NUM> engaging corresponding splines on proximal drive sleeve <NUM>. Thus, with the clutch <NUM> disengaged (button <NUM> pushed in) button <NUM> and driver <NUM> are rotationally locked together with the button <NUM>, the driver <NUM> and the display member <NUM> still being axially coupled.

When dispensing a dose, the dose button <NUM> and clutch <NUM> are moved axially relative to the mechanism compressing the clutch spring <NUM>. Because the proximal clicker part <NUM> is splined to the inner body <NUM> and the axial load passing through the clicker teeth <NUM>, <NUM> locks the distal clicker part <NUM> in rotation to the proximal clicker part <NUM>, the mechanism is forced to move axially whilst the dial sleeve <NUM> and number sleeve <NUM> are free to spin back into the outer housing <NUM>. The interaction of mating threads between the piston rod <NUM>, driver <NUM> and inner body <NUM> delivers a mechanical advantage of <NUM>:<NUM>. In other words, axially advancing driver <NUM> causes the piston rod <NUM> to rotate which due to the threaded engagement of piston rod <NUM> with the inner body <NUM> advances the piston rod. During dose dispensing dispense clicker <NUM>, <NUM> is active which involves button <NUM> and display member <NUM>. The dispense clicker provides primarily audible feedback to the user that drug is being dispensed.

The end of this step is shown in <FIG>. At this point the dose is complete and when the user removes the force from the end of the dose button <NUM>, the clutch spring <NUM> pushes this dose button <NUM> rearwards, re-engaging the teeth <NUM> and <NUM> between the clutch and the dial sleeve.

Resetting the device starts with removal of the cartridge holder <NUM> and replacing an empty cartridge with a full cartridge <NUM>. As the cartridge holder is re-attached, the bung of the new cartridge contacts bearing <NUM>, thus pushing piston rod <NUM> back into the housing. Initially, the piston rod <NUM> screws into the inner body <NUM>, thereby axially disengaging the coupler <NUM> from the proximal drive sleeve <NUM> against the biasing force of spring <NUM>. Once disengaged the coupler <NUM> is free to start rotating together with distal drive sleeve <NUM> and continues to do so as the cartridge holder <NUM> is moved axially into engagement with the inner body <NUM>. Thus, the distal drive sleeve <NUM> rotates with respect to the proximal drive sleeve <NUM> which is still rotationally constrained in inner body <NUM> as clicker parts <NUM> and <NUM> are pressed together by compressed spring <NUM>. As the distal drive sleeve <NUM> rotates, last dose nut <NUM> is reset to its (distal) start position. Coupling the cartridge holder <NUM> to inner body <NUM> backs off the mechanism due to the bayonet structure <NUM> allowing re-engagement of the proximal drive sleeve <NUM> with coupler <NUM> and thus the distal drive sleeve <NUM>.

In the following the cap or cap assembly <NUM> is described in more detail. An embodiment of the cap is shown in <FIG>.

The cap <NUM> has a distal end <NUM> and a proximal end <NUM>. It serves to cover and protect the cartridge holder <NUM> from damage and the cartridge <NUM> itself from dust and dirt ingress on to the area around the septum. The cap <NUM> is designed to accommodate a distal part of the pen injector which is moved into the cap <NUM> through a proximal opening of the cap <NUM>. The cap <NUM> may be attached to the remainder of the drug delivery device <NUM> in such a manner that the needle arrangement <NUM> attached to the cartridge or to the cartridge holder and the cartridge holder <NUM> are located inside the cap <NUM>, in particular, when the cap is fixed to the remainder of the device. The cap <NUM> is detached before use of the drug delivery device <NUM>, such as to set and/or dispense a dose of drug. The interior of the cap <NUM> is formed such that there is enough space for the needle arrangement <NUM> attached to the cartridge and the cartridge holder <NUM>. The cap may be configured such that it covers the remainder of the device on all sides, when it is attached. The proximal opening of the cap may be the only opening of the cap. Means (not shown) for guiding and holding the cartridge holder <NUM> and the needle arrangement <NUM> may be provided on the inner surface of the cap <NUM>.

<FIG> shows an exploded view of the cap <NUM> comprising an outer cap element <NUM> and an inner cap element <NUM>. Furthermore, the clip element <NUM> is shown. The inner and outer cap elements and, preferably the clip element, form together a cap assembly <NUM>, which is described later on in detail. The outer and inner cap elements <NUM>, <NUM> are formed by or made by a metal sleeve and a plastic sleeve, respectively. The sleeves can be assembled together to form the removable cap <NUM>. The outer and inner cap elements <NUM>, <NUM> are connected by suitable means, e.g. adhesive means, positive locking, friction locking and/or a snap interaction. The clip element <NUM> allows connection of the injector pen <NUM> by means of the cap <NUM> to a shirt or jacket pocket and is always handy for that reason. An aperture <NUM> in the outer cap element <NUM> enables the clip element <NUM> to cooperate with, such as to snap to, the inner cap element <NUM>.

The outer cap element <NUM> is preferably made of metal or of a metal alloy; the inner cap element <NUM> is preferably made of plastic. The combination of the metal outer cap element <NUM> and the plastic inner cap element <NUM> provides a high-quality look and pleasant touch. Also, the metal outer cap element <NUM> provides a hard wearing exterior surface of the device. The cap <NUM> is not too heavy and allows comfortable handling. The design of the inner component of the cap <NUM> allows retaining the clip element <NUM> and provides sufficient space to accommodate a standard needle and needle cover fitted to cartridge holder <NUM> inside the cap <NUM>, in particular, when the cap is attached to the cartridge holder or another part of the device.

The outer cap element <NUM> may be a <NUM> to <NUM> thick aluminium element that provides a metal skin over the polymer inner cap element <NUM>. The form of the cap <NUM> may be similar to that of a cap completely made of plastic. Such a cap <NUM> may substitute a cap completely made of plastic with no change in the tactile feel during attachment. Similar plastic features of the inner cap element <NUM> will not increase the risk of wear that may otherwise occur if attaching a plain metal sleeve to the existing plastic cartridge holder retention features.

The inner and outer cap elements <NUM>, <NUM> are sleeve-shaped. The metal sleeve can be deep drawn from a metal sheet and then anodised over at least the outer surface. The anodising provides a high quality and hard wearing exterior surface to the cap <NUM> and enables the cap <NUM> to be given a variety of metallic colours. The removable cap <NUM> comprising the metal outer cap element <NUM> and the plastic inner cap element <NUM> can then be attached to a pen housing/mechanism which may be also made with a similar metal sleeve, to provide a reusable injection device that has a high quality visual appearance and a robust surface.

This design minimises cost and provides robust hard-wearing features. Hence the use of a combination of metal and plastic sleeve-shaped components enables the plastic sleeve to be moulded with features that attach to the plastic cartridge holder cap retention means. The cap retention means of the cartridge holder and/or of the cap assembly may be provided in the proximal section of the respective component.

<FIG> shows a sectional view of a proximal region of the outer cap element <NUM>. <FIG> shows a three-dimensional cut-out view of this component. The outer cap element <NUM> is formed by a metal sleeve deep drawn with reduced thickness at the open end section. The very proximal region is rolled over to form a rounded or folded end <NUM>. Such rolling back of the material may form a beading. In this embodiment the material of the outer cap element <NUM> has been bent once. Nevertheless, the material may be bent more than once. Such bending means that sharp edge <NUM> is on the inner surface of the outer cap element <NUM> and therefore is not accessible by the user.

Due to the thinner material of the open end, which is created during the deep drawn process, and then forming the beading, a circumferential recess <NUM> is formed on the inner surface of the outer cap element <NUM>. This recess <NUM> serves as space into which the inner cap element <NUM> can deform when attaching the cap <NUM> to the cartridge holder <NUM>. The sharp edge <NUM> is the proximal edge of the recess <NUM>, the edge <NUM> serving to retain the plastic inner cap element <NUM> after assembly.

<FIG> shows a sectional view of a proximal section <NUM> of the cap <NUM> during attachment to the drug delivery device <NUM>. During attachment the cap <NUM> including the inner and outer cap elements <NUM>, <NUM> moves proximally with respect to the cartridge holder <NUM> in such a manner that the cartridge holder <NUM> moves into the cap <NUM>.

The outer cap element <NUM> has a proximal section <NUM> comprising a cavity <NUM> on the inner surface of the outer cap element <NUM>. The cavity <NUM> is formed as a circumferentially running recess in this embodiment. Alternatively the cavity <NUM> may have another form which may correspond with the form and size of the deformable region <NUM> of the inner cap element <NUM>.

The thickness of the outer cap element <NUM> in the region of the cavity <NUM> is smaller than the thickness of a distal section or a middle section of the outer cap element <NUM>. The distal edge <NUM> of the cavity <NUM> is formed in the shape of a ramp which allows a gentle transition between the middle section of the outer cap element <NUM> and the cavity <NUM> located in the proximal section <NUM>. The proximal edge <NUM> of the cavity <NUM> is steeper than the distal edge <NUM> and may be formed as a sharp edge.

The inner cap element <NUM> comprises cap snap means <NUM> located on the inside of a proximal section of the inner cap element <NUM> and suitable for engaging with a cap retention means <NUM> located on the cartridge holder <NUM> of the drug delivery device <NUM>. The cap snap means <NUM> is formed by at least a proximal part of the deformable region <NUM> that may be deformed during attachment and detachment in order to lock the cap snap means <NUM> to the cap retention means <NUM> of the drug delivery device <NUM> and to release the cap snap means <NUM> from the cap retention means <NUM>. The cap snap feature <NUM> comprises a raised internal bump feature <NUM> or finger and a cavity <NUM> where the inner cap element <NUM> in the region of the cavity <NUM> is thinner than in other regions; the cavity <NUM> may be formed by the deformable region <NUM>. The internal bump feature <NUM> has a proximal slope being less steep than a distal slope.

The reduced thickness of the inner cap element's cavity <NUM> enables the deformation of the cap snap means <NUM>, thereby allowing engaging to the cap retention feature <NUM>. Due to the cavity <NUM> of the outer cap element <NUM> there is a gap between the outer and inner cap elements <NUM>, <NUM>. The deformable region <NUM> is deformable into the cavity <NUM> of the outer cap element <NUM>. In other words, the deformable region <NUM> is deformable into the gap between the outer and inner cap elements <NUM>, <NUM>.

According to one embodiment, the proximal end <NUM> of the cap snap means <NUM> extends proximally over the proximal edge <NUM> of the cavity <NUM>; the proximal edge <NUM> preventing outwards movement of the proximal end <NUM> of the cap snap means <NUM> and to hold this end circular. According to a further embodiment, the proximal end <NUM> of the cap snap means <NUM> does not protrude over the edge <NUM>. In particular, there may be no need for the proximal end <NUM> to protrude over the edge <NUM> as the clip holds both cap parts together axially.

The cap retention means <NUM> is located on the outer surface of the plastic cartridge holder <NUM>. The cap retention means <NUM> comprises an elevation <NUM> which may have a base area formed as trapezium, circle, triangle or any other shape. In one embodiment two elevations <NUM> may be arranged on opposite sides of the cartridge holder <NUM>, as shown in <FIG> and <FIG>. In one embodiment there are two or more than two elevations that are arranged equally or non-equally spaced on the drug delivery device <NUM>.

The elevation <NUM> has proximal and distal slopes; the latter being less steep than the proximal slope of the elevation <NUM>. The distal slope enables easy sliding of the proximal slope of the internal bump feature <NUM> over the top of the elevation <NUM> during attachment. The steeper slopes of both the elevation <NUM> and the internal bump feature <NUM> hinder distal movement of the internal bump feature <NUM> once it has moved over the top of the elevation <NUM>, thereby preventing backward movement of the internal bump feature <NUM> after attachment. However, the application of a sufficient force by the user pulling the cap <NUM> distally pulls the internal bump feature <NUM> over the elevation <NUM> again, thereby allowing detachment of the cap <NUM>. Since the distal slope of the internal bump feature <NUM> and the proximal slope of the elevation <NUM> are steeper, the force required for detachment is higher than for attachment, which prevents accidental detachment of the cap <NUM>. Nevertheless, alternative internal bump feature <NUM> and elevation <NUM> embodiments may have other slope designs, which may be symmetrical.

When the internal bump feature <NUM> slides over the elevation <NUM>, the internal bump feature <NUM> is pushed towards the outer cap element <NUM>. Since the proximal end <NUM> of the cap snap means <NUM> is held in its position by the proximal edge <NUM> of the outer cap element <NUM>, the resulting torque deforms the deformable region <NUM> outwardly and allows the nose tip to slide over the elevation <NUM>. The cavity <NUM> of the outer cap element <NUM> allows space to accommodate at least some of the deformation of the plastic inner cap element <NUM> when the internal bump feature <NUM> slides over the elevation <NUM> during attachment of the cap <NUM>.

<FIG> shows a sectional view of the proximal section of the cap <NUM> after attachment to the drug delivery device <NUM>.

The internal bump feature <NUM> is engaged behind the proximal edge of the elevation <NUM>. The elevation <NUM> engages to the cavity <NUM> of the inner cap element <NUM>. Though the internal bump feature <NUM> has slid over the elevation <NUM>, the cap snap feature <NUM> is still deformed into the cavity <NUM> of the outer cap element <NUM>. The combination of the proximal edge <NUM> of the outer cap element <NUM> holding the proximal end <NUM> of the cap snap means <NUM> in its position and the elevation <NUM> pushing the deformable region <NUM> into the cavity <NUM> of the outer cap element <NUM> cause a close or interference fit of the cap snap feature <NUM> over the elevation <NUM>, thereby holding the cap <NUM> in the attached position.

<FIG> shows a sectional view of the proximal section of another embodiment of cap <NUM> after attachment to the drug delivery device <NUM>.

This embodiment differs from the one described above by the design of the inner cap element <NUM>. The proximal end <NUM> of the cap snap means <NUM> does not extend over the proximal edge of the cavity <NUM>, which allows a deformation in such a manner that the proximal edge <NUM> also moves into to the cavity <NUM> during attachment. In this embodiment the cap snap means <NUM> are able to deform more readily with less force input required from the elevation <NUM>.

The features of the embodiments mentioned above may be combined. The layout, function, and number of components may be changed in other embodiments.

In the following, the clip element <NUM> is described in more detail with reference to <FIG>.

<FIG> and <FIG> show the clip element <NUM> or fixing element of the drug delivery device <NUM>. By means of the clip element <NUM>, a fixation or attachment of a cap, e.g. the previously described cap <NUM> or a cap assembly <NUM> (see also below) of the drug delivery device <NUM> or the drug delivery device <NUM> may be fixed to a further component. The clip element <NUM> comprises a fixing portion <NUM> or main body with an elongate shape (see <FIG>). Moreover, the clip element <NUM> comprises a slight curvature at a distal end (on the left in <FIG>) of the clip element <NUM>.

The clip element <NUM> comprises two components, i.e. a first component <NUM> and a second component <NUM> (see <FIG>, for example). Each one of the first and the second component <NUM>, <NUM> is integrally formed. This may mean that the first and the second component <NUM>, <NUM> are single-piece components. The first and the second component <NUM>, <NUM> are attached, preferably non-releasably attached, to one another. The second component <NUM> is adapted and arranged to at least partly receive the first component <NUM>. In particular, the first component <NUM> is at least partly introduced into the second component <NUM>. Thus, the second component <NUM> may provide an outer shell of the clip element <NUM>.

The first component <NUM> is at least in parts flexible and/or elastically deformable. In particular, the first component <NUM> comprises a flexible section. The flexible section provides a local radial flexibility of the first component <NUM> enabling the attachment of the clip element <NUM> to a further component, e.g. a jacket pocket. The first component <NUM> comprises plastic. In particular, the first component <NUM> is a plastic component. This may provide a certain degree of elastic deformability of the first component <NUM> per se. The first component <NUM> is injection moulded, for example.

In section, the first component <NUM> has an I-like shaped region (see, for example, <FIG>). One horizontal stroke or bar of the "I" may, thereby, at least in parts be received by the second component <NUM> (upper horizontal stroke in <FIG>). In the following, this stroke is referred to as "the upper horizontal stroke". The upper horizontal stroke may constitute the previously mentioned main body or elongated body <NUM>. A further horizontal stroke or bar of the "I" may be received by the previously mentioned cap <NUM>, which is described later on in more detail. A vertical stroke or bar of the "I" may connect the two horizontal strokes.

The first component <NUM> comprises a tip <NUM> (see <FIG>, for example). The tip <NUM> is arranged in a proximal end section of the clip element <NUM>. The tip <NUM> may constitute the very proximal region of the first component <NUM>. In particular, the tip <NUM> may constitute the proximal end of the upper stroke of the "I".

In the proximal end section, a thickness or radial extension of the first component <NUM> reduces towards its very proximal end. Accordingly, the tip <NUM> comprises a reduced thickness as compared to further sections of the first component <NUM>, e.g. a distal section or a middle section. In other words, the tip <NUM> is thinner or has a reduced radial extension as compared to the remainder of the first component <NUM>. On an upper side of the tip <NUM>, i.e. that side, which faces the second component <NUM>, the tip <NUM> may be slightly sloped. The thin tip <NUM> enables the first component <NUM> to flex locally in this region, as mentioned above.

The second component <NUM> may be made of a rigid material. In particular, the second component <NUM> may comprise a material which is more rigid than the material of the first component <NUM>. The second component <NUM> may comprise or be made of metal or a metal alloy, e.g. steel or aluminium. The second component <NUM> may completely consist of metal. In this embodiment, the second component <NUM> may be stamped from a sheet of metal and then plated. In an alternative embodiment, the second component <NUM> may comprise fibreglass. The second component <NUM> may completely consist of fibreglass.

The second component <NUM> comprises an elongate shape having rounded edges. The second component <NUM> comprises a shape which is adjusted to the shape of an upper side of the first component <NUM> such that the second component can at least partly receive and/or cover the first component <NUM>. The second component <NUM> comprises folded over edges or side walls. The folded over side walls may comprise a radial extension or height similar or equal to a thickness of one of the horizontal strokes of the previously described "I" (see <FIG>). The second component <NUM> further comprises a curvature in a distal end section. By means of the rigid and hard material of the second component <NUM>, a high quality and hard-wearing exterior surface of the clip element <NUM> is provided. In the embodiment where the second component <NUM> comprises metal, the second component <NUM> can further be given a variety of metallic colours.

The second component <NUM> further comprises a cavity or clearance region <NUM> (see <FIG>). The cavity <NUM> is arranged on the underside of the second component <NUM>, i.e. that side of the second component <NUM> which faces the first component <NUM> when the components <NUM>, <NUM> are attached to one another. The cavity <NUM> is delimited by the folded over side walls. The design of the tip <NUM> allows it to flex into the cavity <NUM> of the second component <NUM>, thus replicating a pinching effect of a standard pocket clip. In this way, a measure of retention is provided when the cap <NUM> and, hence, the device <NUM> is placed into a pocket or similar.

The first and second component <NUM>, <NUM> are firmly connected to one another. Preferably, the first and the second component <NUM>, <NUM> are non-releasably connected to one another. The second component <NUM> is press fitted to or clipped onto the first component <NUM>. In particular, the second component <NUM> is press-fitted over the first component <NUM>, thus providing a robust and hard-wearing shell for the first component <NUM>.

The second component <NUM> comprises a retaining feature <NUM>, which is shown in <FIG>, <FIG>, for example. The retaining feature <NUM> may extend along the whole length of the second component <NUM>. The retaining feature <NUM> may comprise the previously mentioned side walls of the second component <NUM>. The fold over of the respective side wall is greater than <NUM> degrees with respect to a lateral axis of the clip element <NUM>. The fold over may be <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or <NUM> degrees, for example. The folded over side walls do not contact an underside of the second component <NUM>, wherein the underside may be that side of the second component <NUM> facing and/or receiving the first component <NUM> when the clip element <NUM> is assembled.

The folded over side walls of the second component <NUM> delimit an inner space of the second component in which the first component <NUM> is partly received when assembling the clip element <NUM>. For coupling the first component <NUM> and the second component <NUM> to one another, in particular for clipping the second component <NUM> onto the first component <NUM>, the first component <NUM> is partly or wholly introduced into the second component <NUM>. An upper side of the first component <NUM> is received between the folded over side walls of the second component <NUM>. In particular, the upper horizontal stroke of the "I"-shaped first component <NUM> is introduced over its whole length between the folded over side walls <NUM> of the second component <NUM>. The folded over side walls of the second component <NUM> thereby keep the first component <NUM> in a predefined position with respect to the second component <NUM>. The design of the components <NUM>, <NUM> allows for an elastic deformation especially of the second component <NUM> when the first component <NUM> is inserted past the folded over side walls. The second component <NUM> forms a C-section when viewed in cross section (see <FIG>). This allows a relatively large amount of flexibility of the tips of the ,C', when the second component <NUM> is clipped onto the first component <NUM>. The first component <NUM> acts as a solid block in compression. Once inserted, the second component <NUM> may spring back for retention. Due to the fold over of the side walls being just greater than <NUM> degrees, the second component <NUM> is firmly retained once press-fitted over the first component <NUM>.

However, before the second component <NUM> and the first component <NUM> are connected to one another as described above, the first component <NUM> of the clip element <NUM> is secured to the cap <NUM>. For securing the clip element <NUM> and, in particular the first component <NUM>, to the cap <NUM>, the first component <NUM>, comprises a guiding element <NUM>, which can be seen from <FIG> and <FIG>, for example. The guiding element <NUM> is disposed in a distal end section of the first component <NUM> at an inside of the above mentioned curvature. The guiding element <NUM> is arranged on an underside of the first component <NUM> facing away from the second component <NUM>. The guiding element <NUM> may constitute or comprise a rail such that the clip element <NUM> may be guided by an element receiving the guiding element <NUM>, preferably, along a longitudinal axis of the clip element <NUM> or the device <NUM>.

The guiding element <NUM> extends over less than half of the axial extension of the first component <NUM> of the clip element <NUM>. The guiding element <NUM> comprises a T-shaped cross-section for facilitating the mentioned guiding functionality (see also <FIG>). In order to form the T-shaped section, the guiding element <NUM> comprises a receiving portion <NUM> (see <FIG>). The receiving portion <NUM> may constitute the horizontal stroke or bar of the "T" of the T-shaped section. Preferably, the receiving portion <NUM> is configured to be received by one or more openings or apertures of the components to which the clip element <NUM> is to be mounted, e.g. in a cap assembly <NUM> (see <FIG> and <FIG>).

Furthermore, the guiding element <NUM> comprises a guiding portion <NUM> (see <FIG>). The guiding portion <NUM> constitutes the vertical stroke or bar of the "T" of the T-shaped section of the guiding element <NUM>. The guiding portion <NUM> may be a web connecting the elongated main body (upper horizontal stroke of the "I") of the first component <NUM> with the receiving portion <NUM>. The guiding portion <NUM> may further be received by or arranged in one or more openings of the components to which the clip element <NUM> is to be mounted, e.g. in the mentioned cap assembly <NUM>.

The clip element <NUM>, particularly the guiding element <NUM>, comprises a connection feature <NUM>. The connection feature <NUM> comprises or constitutes a protrusion protruding radially at the underside of the first component <NUM>. Preferably, the connection feature <NUM> is configured to interact with a corresponding connection feature <NUM>, e.g. of an inner part or cap element <NUM> (see <FIG>) for connecting the first component <NUM> and the cap <NUM>. The connection feature <NUM> is disposed in a proximal end section of the guiding element <NUM>. The connection feature <NUM> may further comprise or constitute a distal face of the guiding element <NUM>. The connection feature may be designed to establish a snap fit connection to the inner cap element <NUM>.

The first component <NUM> further comprises a feature <NUM>. The feature <NUM> comprises a radial face with a normal perpendicular to the longitudinal axis (not explicitly indicated) of the first component <NUM> and a longitudinal face which is designed to hide or cover over any gaps between the first component <NUM> of the clip element <NUM> and the outer part <NUM> resulting from tolerances in manufacture and assembly. The feature <NUM> is designed to be in small amount of clearance rather than abutting in nominal tolerance conditions. In particular, the feature <NUM> may be configured to be in small amount of clearance to one or more corresponding components to which the clip element <NUM> is to be mounted, e.g. in the cap assembly <NUM> (see <FIG>).

Moreover, the clip element <NUM>, in particular the first component <NUM>, comprises an attachment feature <NUM>. The attachment feature <NUM> may be configured to interact with a further component (see depression <NUM> in <FIG>). The attachment feature <NUM> comprises a bump or pip. The attachment feature <NUM> is axially spaced from the guiding element <NUM> and arranged near a proximal end of the first component <NUM> and/or the clip element. The attachment feature is arranged on the underside of the first component <NUM> facing away from the second component <NUM>. The attachment feature <NUM> is, preferably, configured to interact with the outer part <NUM> by means of mechanical contact, or close proximity to create a 'pinch point'. Thereby, fixation or attachment of the cap assembly <NUM> or drug delivery device <NUM> to the further element, such as a shirt pocket of a user of the assembly <NUM> or the device <NUM> may be facilitated or aided. Particularly, said mechanical contact may increase the friction or the grip force and, therewith, the reliability of the attachment of the cap assembly <NUM> to the further element.

<FIG> shows a perspective view of an outer part or outer cap element <NUM> which may be or relate to the above-mentioned outer cap element. The outer part <NUM> comprises an elongate shape. The outer part <NUM> further comprises a sleeve-like shape. Preferably, the outer part <NUM> is made of a metal, e.g. from aluminium. To this effect, the outer part <NUM> is, preferably, formed or fabricated by deep drawing (as mentioned above). The outer part <NUM> further comprises the previously mentioned opening <NUM>. The opening <NUM> is arranged at a distal end of the outer part <NUM>. The opening <NUM> is, preferably, formed from the outer part <NUM> by punching. The outer part <NUM> may further comprise a proximal opening which is not explicitly indicated in <FIG>. Formed within the opening <NUM> is a corresponding guiding feature <NUM> corresponding to the guiding element <NUM> described by means of <FIG>. The corresponding guiding feature <NUM> extends - originating from the opening <NUM> - in a proximal direction of the outer part <NUM>. The corresponding guiding feature <NUM> may be a guide slot. The corresponding guiding feature <NUM> may be configured to receive the guiding portion <NUM> of the guiding element <NUM> such that the guiding portion <NUM> is arranged inside the corresponding guiding feature <NUM>. Preferably, the opening <NUM>, the corresponding guiding feature <NUM> and the clip element <NUM> are configured such that the guiding element <NUM> can be introduced in or received by the opening <NUM>. When, in particular after introduction of the guiding element <NUM> into the opening <NUM>, - e.g. during an assembly of the cap assembly <NUM> - the first component <NUM> is pushed proximally, the guiding portion <NUM> may be received by or arranged in the corresponding guiding feature <NUM>, wherein the receiving portion <NUM> is, preferably, only received by the remainder of the opening <NUM> and arranged inside the outer part <NUM> and/or the inner part <NUM> (see <FIG> and <FIG>).

The outer part <NUM> further comprises the previously mentioned depression <NUM>. The depression <NUM> receives or interacts with the above-mentioned attachment feature <NUM> of the clip element <NUM> when, e.g., the first component <NUM> and the outer part <NUM> are assembled (see <FIG> and <FIG> below). Preferably, the attachment feature <NUM> extends into the depression <NUM> and/or contacts the outer part <NUM> in the depression <NUM>. The depression <NUM> is axially, particularly proximally, spaced from the opening <NUM> along a longitudinal axis of the outer part <NUM>. Preferably, the depression <NUM> is shaped according to the attachment feature <NUM>, i.e. with similar curvature as the mentioned bump of the attachment feature <NUM> (see <FIG>).

<FIG> shows a perspective top view of an inner part <NUM>. The inner part <NUM> may be a sleeve and configured to be introduced in the outer part <NUM>. The inner part <NUM> comprises a corresponding connection feature <NUM>. The corresponding connection feature <NUM> corresponds to the connection feature <NUM> of the first component <NUM> such that the first component <NUM> can be connected to the inner part <NUM> by an interaction of the connection feature <NUM> and the corresponding connection feature <NUM> (see <FIG>). The corresponding connection feature <NUM> may constitute or comprise a proximal face of the inner part <NUM>. The inner part <NUM> further comprises an opening <NUM>. The opening <NUM> is arranged at or near the distal end of the inner part <NUM>. The opening <NUM> may further be shaped similar to the opening <NUM> of the outer part (see <FIG>). Formed within the opening <NUM> is a corresponding guiding feature 172a corresponding to the guiding element <NUM>.

<FIG> shows a schematic section of parts of a cap assembly <NUM> (see also <FIG>). The assembly <NUM> comprises the previously described clip element <NUM> and the outer part <NUM> and the inner part <NUM>. <FIG> shows the mentioned components in an assembled state. An inner side of the cap assembly <NUM> is shown at the bottom and an outer part is shown at the top of the section shown in <FIG>. In the depicted situation, the inner part <NUM> is arranged in the outer part <NUM> and at least a section of the clip element <NUM> and/or the guiding element <NUM> extends through the opening <NUM> of the outer part <NUM> and, preferably, also through the opening <NUM> of the inner part <NUM>. To this effect, the openings <NUM> and <NUM> may overlap in the cap assembly <NUM>. It is further shown in <FIG> that the guiding element <NUM> comprises the T-shaped section (said "T" is depicted upside down), as described above. The section of the whole first component <NUM> may, thereby, be shaped I-like, as described above. The guiding portion <NUM> is arranged in the corresponding guiding feature <NUM> (see also <FIG>). The guiding element <NUM>, particularly the receiving portion <NUM> may prevent an (outward) radial movement of the clip element <NUM> with respect to the outer part <NUM> and/or the inner part <NUM>, for example. This is because the corresponding guiding feature <NUM> is too narrow, as to allow for the receiving portion <NUM> to radially pass or move through the corresponding guiding feature <NUM>.

<FIG> shows a longitudinal section of parts of the cap assembly <NUM>. The cap assembly <NUM> comprises a longitudinal axis X. The longitudinal axis X may coincide or be collinear with the longitudinal axis of the clip element <NUM>, the outer part <NUM> and/or the inner part <NUM>. Also, a drug delivery device in which the cap assembly <NUM> is attached is shown in <FIG> which shows, e.g. the cartridge holder <NUM>.

The clip element <NUM> closes the opening <NUM> of the inner part <NUM> and the opening <NUM> of the outer part <NUM> such that a rounded shape of the cap assembly <NUM> results. The connection feature <NUM> is arranged at least partly in the opening <NUM> of the outer part <NUM>, as well as in the opening <NUM> of the inner part <NUM> (openings are not explicitly indicated in <FIG>). Particularly, the corresponding guiding feature <NUM> is configured to receive the receiving portion <NUM> of the guiding element <NUM> such that the receiving portion <NUM> is arranged inside of the outer part <NUM> and also inside the inner part <NUM>.

The clip element <NUM>, in particular its first component <NUM>, and the inner part <NUM> are connected with one another. Particularly, the connection feature <NUM> interacts with, preferably abuts, the corresponding connection feature <NUM> via a snap interaction such that the clip element <NUM>, in particular the first component <NUM>, and the inner part <NUM> are connected with respect to one another. The clip element <NUM> and the inner part <NUM> are, preferably, reliably connected to one another, as the distal face of the connection feature <NUM> and the proximal face of the corresponding connection feature <NUM> abut. In order to connect the mentioned components or during the connection, at least one of the first component <NUM> and the inner part <NUM>, may at least slightly be deformed. The connection feature <NUM> blocks proximal movement (i.e. to the right in <FIG>) of the inner part <NUM> with respect to the outer part <NUM> such that the inner part <NUM> is retained within the outer part <NUM>.

The previously mentioned feature <NUM> is - under nominal tolerance conditions - arranged in a small amount of clearance to a distal face of the inner part <NUM> and a distal face and a radial face of the outer part <NUM> (faces are not explicitly indicated). Although this is not explicitly indicated in <FIG>, the attachment feature <NUM> of the clip element <NUM>, preferably, mechanically contacts or lies in close proximity to the depression <NUM> of the outer part <NUM> (see description above).

Also further components e.g. of a drug delivery device, wherein the cap assembly <NUM> may be applied to, are shown. Such components relate to a cartridge or cartridge holder <NUM> which may retain a drug (not explicitly indicated). Furthermore, an injection needle <NUM> is shown which is in fluid communication with the drug from the cartridge or cartridge holder <NUM>. It is shown that the inner part <NUM> accommodates the needle <NUM>, an inner needle cover and furthermore at least a section of the cartridge or cartridge holder <NUM>.

The inner part may, advantageously, be designed to be mouldable by an injection moulding process with simple open-shut injection mould tooling. Thereby, it can be manufactured by a low-cost moulding process.

It should be acknowledged that all of the concepts disclosed above and below can be combined especially as far as they concern concepts relating to a cap or cap assembly. Further, the present disclosure may sometimes address the same elements with different expressions which, of course, should not be understood as forming different elements merely because of the fact that they are addressed slightly differently herein. Specifically: The cap <NUM> (see <FIG>) may be or relate to the cap assembly <NUM>. The cartridge or cartridge holder <NUM> may be or relate to the cartridge <NUM> and/or to the cartridge holder <NUM>. The metal element of the cap may be or relate to the outer part <NUM>. The plastic element of the cap may be or relate to the inner part <NUM>. The outer cap element may be or relate to the outer part <NUM>. The inner cap element may be or relate to the outer part <NUM>. The aperture <NUM> may be or relate to the opening <NUM>. Also, elements not explicitly mentioned in the enumeration above may be addressed with different expressions.

It was discovered that, when assembling the cap assembly or cap as disclosed in the previous embodiments, it is difficult to secure components of the cap, for example the inner and the outer cap element <NUM>, <NUM>, with respect to each other reproducibly in a defined relative angular orientation.

In the following, an embodiment of a cap or a cap assembly is disclosed which addresses this issue in conjunction with <FIG>. Therein, the cap assembly as well as a method of assembling the cap assembly are described. The components of the cap assembly disclosed below can be the ones as disclosed further above. Accordingly, features disclosed herein below with respect to the cap assembly can also apply to the further caps or cap assemblies disclosed herein.

<FIG> shows components of the cap assembly in an unassembled state. As is apparent from <FIG>, the components for the cap assembly comprise a first cap component, which is herein above and below also designated as inner cap element <NUM>, and a second cap component, which is herein above and below also addressed as outer cap element <NUM>. Further, the cap components for the cap assembly comprise a third cap component, which is herein above and below also referenced as clip element <NUM>. The first and second cap components are formed sleeve-like, where the first cap component is adjusted to be received in and secured to the second cap component.

For the assembling of the cap assembly as illustrated in <FIG>, for example the first cap component <NUM> can be arranged on a fixture and the second cap component <NUM>, e.g. a deep-drawn metal component, is guided over the first cap component until a defined end position is reached.

As can be seen in <FIG>, the first cap component <NUM>, which is preferably an injection moulded plastic part, comprises a guide track <NUM>, e.g. a groove. The guide track is axially oriented. The guide track is, preferably, arranged in a section of the first cap component <NUM>, which is oriented axially. The guide track may run parallel or essentially parallel to the longitudinal axis X of the first cap component <NUM>. Preferably, in the region with the axial guide track the cap component <NUM> does not or not significantly widen in the radial direction along the axis X. In a different region of the cap component, e.g. a region <NUM> which axially overlaps with the region comprising the guide track and/or a non-overlapping region, the cap component, particular the exterior surface, may widen more in the radial direction as seen along the axis X than in the region with the guide track <NUM>.

The guide track <NUM> is preferably provided in a region which is spaced from a distal end and/or from a proximal end of the first cap component <NUM>. That is to say the start and/or the end of the track may be arranged at a distance from the proximal end and/or from the distal end of the cap.

The guide track <NUM> may be offset in the proximal direction with respect to the opening <NUM> and/or the guiding feature 172a which is provided at or near the distal end of the cap component. The guiding feature 172a is intended for interaction with the third cap component, that is to say the clip element <NUM>, as disclosed further above. The guide track <NUM> may also be distally offset from a proximal opening of the first cap component <NUM>. The guide track and the guiding feature 172a may be aligned with respect to each other. They may extend in a common plane. Preferably, the guide track <NUM> extends in the, preferably axial, direction predetermined by the guiding feature 172a. As also disclosed further above, the third cap component <NUM> may be designed to be fixed to the first cap component by means of a snap-fit interaction provided between the third cap component and the first cap component <NUM>, for example.

The second cap component comprises a guide feature <NUM> (best seen in <FIG>. The guide feature <NUM> is formed by a protrusion protruding from an inner surface of the second cap component. The guide feature is arranged to interact with the guide track to form a guiding interface. The second cap component <NUM> further comprises the guiding feature <NUM> which has already been discussed further above. The guiding feature continues opening <NUM> in the proximal direction. The guiding feature <NUM> is axially oriented. It is expediently oriented in the same direction and or arranged at a corresponding angular position as the guide track <NUM> and/or the guiding feature 172a, when the two cap components <NUM> and <NUM> have been assembled to each other.

The second cap component further comprises the depression <NUM> as disclosed further above. The second cap component is preferably manufactured by deep drawing. By means of a pressing operation that occurs as part of a multi-stage deep drawing process, the depression <NUM> may be formed and in the region of the depression <NUM>, on the interior surface of the second cap component, the protrusion forming the guide feature <NUM> may be formed. The protrusion expediently has the complimentary shape of the depression, e.g. both may be of hemispherical shape. Thus, guide feature <NUM> may have a curved surface which is designed to interact with a bearing surface or bearing surfaces of the guide track <NUM>, e.g. side walls of a groove. When the third cap component <NUM> has been connected to the first cap component <NUM>, a bump or a pip <NUM> of the third cap component may be arranged within the depression <NUM> (see <FIG>).

The guiding feature 172a may form the fixing guide track, which guides the fixing feature of the third cap component <NUM>, for example the connection feature <NUM> shown in <FIG>, to the appropriate fixing feature provided in the interior of the first cap component <NUM>. When the third cap component <NUM> has been fixed to the first cap component <NUM>, the second cap component <NUM> may be secured relative to the remaining two components of the cap.

The first and second cap components <NUM>, <NUM> are expediently adjusted with respect to one another such that their cross sections ensure that they can only be assembled to one another when they have a certain relative angular position or orientation. Accordingly, by way of the cross sections at least a certain kind of pre-alignment may be provided. The pre-alignment expediently ensures at least that the guide feature <NUM> and the guide track <NUM> can be brought into cooperation. For example, the outer cross section of the first cap component and the inner cross section of the second cap component may be adjusted in their shapes to suit or match one another such that they can only be assembled or moved axially relative to one another when they have the correct orientation. The cross sections are, for this purpose, expediently not circular but rather designed to form a rotationally constrained interface between the two cap components. Therefore, it is expedient, to match the outer surface of a cross section of a region <NUM> of the first cap component to the inner surface of a cross section of a region <NUM> of the second cap component. The regions <NUM> and <NUM> may be arranged such that the surfaces do cooperate, e.g. to form the rotationally constrained interface, during the assembling process, before the guiding interface is established. For example, the region <NUM> may be arranged proximally offset from the guide feature <NUM> and the region <NUM> may be arranged distally offset from the distal end of the guide track <NUM>.

The guide track <NUM> may, for example in its distal end region <NUM>, comprise a lead-in region, where it accepts the guide feature <NUM> even if it is slightly misoriented. In the further course of the guide track, the guide feature <NUM> may be guided more tightly as compared to the lead-in region. The guide track may comprise an end stop <NUM>, which is designed to abut the guide feature <NUM>. The end stop may define an axial end position during the assembling process. In the region of the end stop <NUM>, the guide track may comprise a curved surface, where the curvature, preferably, matches the one of the guide feature. This facilitates provision of a large area bearing surface between the two cap components in the end position.

The guide track <NUM> may extend in the axial direction over a length which is greater than or equal to one of the following values: <NUM>*L, <NUM>*L, <NUM>*L, <NUM>*L, <NUM>*L, <NUM>*L. Alternatively or additionally, the guide track <NUM> may extend in the axial direction over a length which is less than or equal to one of the following values: <NUM>*L, <NUM>*L, <NUM>*L. "L" is the length of the first cap component, the second cap component or of the cap or cap assembly. The guide feature <NUM> may extend in the axial direction over a length which is less than the axial extension of the guide track, particularly less than a quarter of the axial extension of the guide track <NUM>.

The guide feature <NUM> may protrude from a main body of the respective cap component by <NUM> or more, preferably by <NUM> or more.

The guide feature may be arranged at a distance from the proximal opening of the cap or the second cap component. This distance is preferably greater than the distance of the proximal end of the guiding feature 172a or <NUM> from the distal end of the first or second cap component, respectively.

In order to assemble the cap assembly, the first cap component <NUM> and the second cap component <NUM> are arranged such that the guide feature <NUM> and the guide track <NUM> are brought into a mechanical cooperation. Preferably, for doing so, at first the surfaces of the cap components in regions <NUM> and <NUM> interact to ensure pre-alignment of the guide feature <NUM> and the guide track <NUM>. This ensures preferably at least that the guide feature <NUM> can cooperate with the lead-in region of the guide track <NUM>. Alternatively, a lead-in region might not be required if the pre-alignment is accurate enough to ensure that the guide feature <NUM> always engages the guide tack <NUM>. Once the lead-in region has been passed, the axial movement between the first and the second cap component is tightly guided axially by the axial guiding interface which is then formed by the guide feature and the guide track such that relative rotation between the two cap components is prevented. Accordingly, it can be assured that the guiding feature <NUM> does guide the connection feature <NUM> of the third cap component appropriately to the corresponding fixing feature provided on an interior of the first cap component <NUM>, such that the features can interact to connect the first and third cap components. This ensures that the cap is reliably assembled. Without this interface a significant relative rotation would still be possible, such that the fixing features of the first and third cap components could not interact reliably as explained in the introductory section. The tighter axial guiding via the guiding interface ensures that the cap components do have a defined relative position. A situation which is just before the assembling process has been finished is shown in <FIG> on account of a partial sectional view and in <FIG> based on a side view. The second cap component has almost reached its end position with respect to the first cap component. In the end position, the guiding interface is preferably still active. Expediently, the guide feature <NUM> may interact with the end stop <NUM> in order to indicate that the end position has been reached.

In <FIG> it is immediately apparent how the bump or pip <NUM> of the clip element rests in the depression <NUM>, which simultaneously defines the guide feature <NUM> in the interior. The curved surface(s) of the guide feature have the advantage that the guide feature can, on its curved surface, take up some manufacturing tolerances, as along the radial extension of the curved surface there are different points where the guide feature could interact with a guide track.

It should be readily acknowledged that the guide track could also be provided on the second cap component and the guide feature could be provided on the first cap component. However, it is preferred that the guide track is provided on the first cap component and the guide feature on the second cap component, because by using the hemispherical depression as defining the hemispherical guide feature, the aesthetic appearance of the cap is not negatively affected as it might be, if a ridge were formed on the exterior surface to define a groove as guide track on the interior surface of the cap component.

The proposed design of the second cap component (which later forms the outer shell of the cap or cap assembly) enables the second cap component to be made of metal or a metal based alloy on a single press designed for deep drawing, without the requirement for any secondary forming operations to be added to the component after deep drawing. This minimizes cost and maximizes the output from the process, enabling a low cost drug delivery device to be assembled without sacrificing the aesthetic and perceived quality. Further, on account of the guiding interface which is formed a defined angular orientation of the cap components can be ensured.

Claim 1:
A multi-part cap assembly (<NUM>, <NUM>) for a drug delivery device (<NUM>), comprising:
- a first cap component (<NUM>), and
- a second cap component (<NUM>), wherein
the first cap component is assembled to the second cap component, wherein one of the first cap component and the second cap component is provided with a guide track (<NUM>) and the other one of the first cap component and the second cap component is provided with a guide feature (<NUM>), wherein the guide track and the guide feature are arranged to cooperate to form an axial guiding interface between the first cap component and the second cap component, wherein the axial guiding interface is configured such that relative rotational movement between the first cap component and the second cap component is restricted or prevented, characterized in that the first cap component (<NUM>) and the second cap component (<NUM>) are secured to each other such that relative rotational and axial movement is prevented, and in that the first cap component can be introduced into the second cap component via a proximal opening of the second cap component, when assembling the cap assembly.