Patent Description:
There are different types of medicaments that can be stored for a long time and that are filled in containers e.g. cartridges, syringes, ampoules, canisters or the like, containing a ready-to-use medicament in liquid state. However, there are also other types of medicaments that are a mixture of two substances, a medicament agent (e.g. lyophilized, powdered or concentrated liquid) and a diluent (e.g. water, dextrox solution or saline solution), wherein these types of medicaments cannot be pre-mixed and stored for a long time because the medicament agent is unstable and can be degraded and loses its effect over a period of time. As such, a user, e.g. a patient himself/herself, a physician, a nurse, hospital personnel or trained persons, has/have to perform the mixing within a certain time period prior to the delivery of a dose of medicament to a patient. Further, some medicament agents are subject to meet chemical changes while mixing. Such sensitive medicament agents require a particular treatment so that, when mixing the medicament agents with a diluent, unreasonable mixing force can degrade the medicament agents.

In order to facilitate the mixing, a number of containers for mixing have been developed comprising at least two chambers, known as multi-chamber containers. These multi-chambered containers comprise a first chamber containing the medicament agent and at least a second chamber containing the diluent. Typically, these chambers may be sealed off with stoppers so that the medicament agents do not become degraded. When the medicament agent is to be mixed shortly before administering, redirecting passages are opened between the chambers, usually by depressing a distal stopper and in turn a divider stopper of the container somewhat. The above mentioned requirements can be achieved by known medicament delivery devices, such as a common hypodermic syringe, but the procedure is rather awkward, in particular for users not used to handle such devices. In order to facilitate for the patients themselves to administer the medicament with a predetermined dose in an easy, safe and reliable way and also to facilitate the administration of medicaments for hospital personnel in the same facilitated way, an automatic or semi-automatic device is desired having a multiple-chamber solution for obtaining a mixing before delivery.

Documents <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> all disclose activators with locking members.

The aim of the present application is to provide an improved activator to be used with a medicament delivery device and according to a specific solution a medicament delivery device arranged to handle multi-chamber medicament containers in a safe and reliable way.

The aim is obtained by an activator and a medicament delivery device according to the independent patent claims. Preferable embodiments form the subject of the dependent patent claims.

According to a main aspect, disclosed is an activator for a medicament delivery device, comprising a manually operable activator element. An activator blocker is arranged to the activator element, where the activator blocker defines at least one locking member. A medicament delivery device housing comprises at least one flexible hook, wherein the at least one flexible hook of the medicament delivery device housing is operably arranged between a locked position where the flexible hook is releasably engaged with the at least one locking member of the activator blocker, thereby preventing operation of said activator element; and an unlocked position where the flexible hook is out of engagement with the at least one locking member of the activator blocker, thereby allowing operation of the activator element.

Thus a flexible hook that is stationary in a housing of a medicament delivery device is used for releasably locking an activator blocker such that the activator cannot be operated by a user until the flexible hook is moved out of engagement. This provides a robust solution with few components yet providing an enhanced security of the handling of a medicament delivery device provided with the activator.

According to one feasible solution, the flexible hook may be provided with engagement surfaces arranged to engage with stop surfaces of the activator blocker when in the locked position.

In that regard, the engagement surfaces of said hook may be directed in a proximal direction and wherein the stop surfaces of the movable activator element may be directed in a distal direction, preventing movement of the activator blocker in a distal direction in the locked position. Thus, when the activator is to be moved in a distal direction in order to release the activator, this solution is applicable.

One example is when the activator blocker may comprise a blocking element that may enclose the activator element and that the activator blocker and the activator may comprise engagement elements. The activator blocker may be movable in a distal direction in relation to the activator when in the unlocked position such that the engagement elements engage the activator blocker with the activator, enabling a manual movement in the proximal direction of the activator blocker and the activator.

In more detail, the engagement elements may comprise flexible tongues on the activator having ledges that are intended to engage with ledges of the activator blocker.

Another example is when the activator blocker may comprise a blocking element enclosing the activator element and that activator blocker may be movable in the distal direction in the unlocked position. Here the activator blocker is removed and the activator is exposed, enabling movement of the activator in the proximal direction.

As an alternative, the engagement surfaces of the hook may be directed in a distal direction and wherein the stop surfaces of the movable activator element are directed in a proximal direction, preventing movement of the activator blocker in a proximal direction in the locked position.

With this solution, the activator blocker may comprise a blocking element enclosing the activator element, wherein the activator blocker may be movable in the proximal direction in the unlocked position, also enabling movement of the activator in the proximal direction.

In a further alternative, the activator blocker may comprise a generally tubular member arranged turnable in relation to the housing between the initial position and the activated position. The activator may be arranged coaxial inside the activator blocker and protruding in the distal direction, that the activator blocker and the activator may be provided with engagement elements that in the locked position engage such to prevent movement of the activator in the proximal direction and in the unlocked position are moved out of engagement, allowing movement of the activator in the proximal direction.

In more detail, the engagement elements of the activator may comprise protrusions, and the engagement elements of the activator blocker may comprise a first transversally extending groove and a proximally extending groove.

According to a further aspect, the flexible hooks may be arranged to engage with a locking structure of the activator element for locking the activator element after manual operation. In this manner it is ensured that the activator element cannot be operated further, and also provides an indication to a user that the medicament delivery device is used and should be discarded.

According to a further main aspect of the application, a medicament delivery device is provided having a housing comprising a proximal housing part and a distal housing part, where the proximal housing part may be arranged to accommodate a multi chamber medicament container. The housing parts are preferably arranged movable in relation to each other from an initial position to a mixed position in which the content of the multi chamber medicament container is mixed. Further the medicament delivery device may comprise a drive unit arranged to act on the multi chamber medicament container for expelling a dose of medicament. Moreover, the medicament delivery device is provided with an activator operably connected to the drive unit and arranged with a manually operable activator element wherein the activator is manually operable in a proximal direction between an inactive position and an active position in which the drive unit is activated.

In line with previous aspects of the application, an activator blocker may be operably arranged to the activator element, where the activator blocker defines at least one locking member and the distal housing part comprising at least one flexible hook, wherein the at least one flexible hook of the distal housing part is operably arranged between a locked position where the flexible hook is releasably engaged with the at least one locking member of the activator blocker, thereby preventing operation of said activator element; and an unlocked position where the flexible hook is out of engagement with the at least one locking member of the activator blocker, thereby allowing operation of said activator element, wherein in the mixed position the proximal housing part acts on the flexible hook to move it to the unlocked position.

With this solution it is not possible to operate the activator until the multi chamber medicament container of the medicament delivery device has been mixed by moving the two housing parts together. Until the mixing is completed, the drive unit cannot be activated in any way, increasing the safety of the medicament delivery device.

Regarding the aspect of the drive unit, the medicament delivery device may further comprise an actuator sleeve operably connected to the proximal housing part so as to move in conjunction with the proximal housing part and to act on the flexible hook, which actuator sleeve cooperates with an actuator of the drive unit for holding a plunger rod in an energized state.

Moreover, the actuator may be generally tubular, accommodating the plunger rod, wherein the actuator may comprise arms that are flexible in a generally transversal direction, that the free ends of the arms are arranged with radially inwardly directed ledges that fit into recesses of the plunger rod. Also, the activator may be arranged with proximally directed fingers extending into the actuator and being in contact with a distal end of the plunger rod.

These and other aspects of, and advantages with, the present invention will become apparent from the following detailed description of the invention and from the accompanying drawings.

In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

An aim of the present disclosure is to provide an improved medicament delivery device capable of handling medicament delivery wherein the risk of accidental premature firing of the device is precluded or minimized. In the present disclosure, when the term "distal part/end" is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which is/are located the furthest away from the medicament delivery site of the patient. Correspondingly, when the term "proximal part/end" is used, this refers to the part/end of the delivery device, or the parts/ends of the members thereof, which, is/are located closest to the medicament delivery site of the patient.

<FIG> illustrates a side view of an exemplary drug delivery device <NUM>. As illustrated, the medicament delivery device <NUM> comprises a housing that extends from a proximal end <NUM> to a distal end <NUM>. More preferably, the medicament delivery device <NUM> comprises a generally elongated housing extending along a longitudinal axis L of the medicament delivery device, which housing comprises a proximal housing part <NUM> and a distal housing part <NUM>. In one preferred arrangement, the proximal housing part <NUM> and the distal housing part <NUM> are arranged and mounted to be movable relative each other along the longitudinal axis L of the medicament delivery device <NUM>. In one preferred arrangement, the distal housing part <NUM> comprises two housing component parts: a front distal housing part <NUM> and a rear distal housing part <NUM>. The front distal housing part <NUM> and the rear distal housing part <NUM> may be permanently or non-permanently coupled to one another. In the embodiment shown, <FIG>, the rear distal housing part <NUM> is arranged with outwardly directed protrusions <NUM> that are arranged to fit into recesses <NUM> in the front distal housing part <NUM>, creating a lock between the housing parts. The proximal end of the front distal housing part <NUM> is arranged with a central passage <NUM> through which the proximal housing part may extend. The inner edge surface of the passage <NUM> is arranged with thread segments <NUM> that are arranged and intended to cooperate with corresponding thread segments <NUM> or threads on an outer surface of the proximal housing part <NUM> as seen in <FIG>.

Moreover, the proximal housing part <NUM> is arranged with a generally circumferentially extending arm <NUM> being flexible in the generally radial direction. The free end of the arm <NUM> is arranged with an outwardly extending ledge <NUM>. The ledge <NUM> is arranged to fit into two cut-outs <NUM>, on the front distal housing part, one 40I near the proximal end and one 40II approximately midway along the housing <NUM>, the function of which will be explained below. The outer surface of the proximal housing part is further arranged with two insignia <NUM>, such as numeral <NUM> and <NUM>, which insignia are designed to be visible in a window <NUM> in the front distal housing part <NUM> as will be described. Moreover, the proximal housing part <NUM> is arranged with plate- or wing-shaped protrusions <NUM> at a proximal area thereof, providing a grip for a user as will be explained. Further, the proximal end of the proximal housing part <NUM> is arranged with a neck portion <NUM>, onto which a medicament delivery member (not shown) is arranged to be attached, either permanently or removably. In the embodiment shown, the neck portion <NUM> is provided with outer threads that are arranged to cooperate with corresponding threads on a medicament delivery member. It is of course possible to utilize other types of fastening elements such as bayonet couplings or luer connections.

The proximal housing part <NUM> is arranged to accommodate a multi-chamber medicament container <NUM> and as disclosed herein, comprises e.g. a dual chamber container designed with a first compartment <NUM> and a second compartment <NUM>, <FIG>. In one arrangement, one compartment of the two compartments contains preferably the medicament in powder form and the other compartment contains preferably a diluent. The two compartments are separated by a resilient, movable stopper <NUM> (i.e., a proximal stopper), which stopper when moved, opens passages <NUM> between the compartments for mixing the medicament with the diluent. A distally arranged second stopper <NUM> (i.e., a distal stopper) closes a distal end of the medicament container <NUM>.

As illustrated in <FIG>, the rear distal housing part <NUM> comprises one or more generally radially flexible tongues <NUM> provided along an interior wall surface of a tubular proximal area, which tongues <NUM> are extending in the distal direction. The free ends of the tongues <NUM> are provided with generally wedge-shaped inwardly directed ledges <NUM>, where the tongues <NUM> and the ledges <NUM> form hooks <NUM> that are flexible in the generally radial direction. The ledges <NUM> of the hooks <NUM> are arranged with proximally directed engagement surfaces <NUM> as seen in Fig. 5b. The rear distal housing part <NUM> is further arranged with a transversal wall section <NUM> having a distally directed surface and a proximally directed surface. The distally directed surface is provided with distally directed protrusions <NUM>, which protrusions are arranged with wedge-shaped inwardly directed ledges <NUM>. The inner surface of a tubular distal area <NUM> of the rear distal housing part <NUM> is moreover arranged with longitudinally extending grooves <NUM> , which grooves are aligned in the longitudinal direction with the flexible tongues <NUM>, wherein the tongues <NUM> are positioned radially inwardly of the grooves <NUM> as seen in <FIG>. The tubular distal area <NUM> is arranged to accommodate a generally tubular activator sleeve <NUM>, <FIG>, wherein the activator sleeve <NUM> is provided with generally longitudinally extending ledges <NUM> on its outer surface at a distal end thereof. The ledges <NUM> are configured to fit into the grooves <NUM> of the rear distal housing part <NUM>, causing a rotational lock between the components while allowing relative movement in the longitudinal direction.

Further, generally rectangular cut-outs <NUM> are arranged proximal of and in line with the ledges <NUM>. At the distal end of the cut-outs <NUM>, generally rectangular, transversally extending and inwardly directed ledges <NUM> are arranged, forming connection elements. At the proximal end of the cut-outs <NUM> locking members in the form of generally transversal beams <NUM> are provided. The beams are arranged with distally directed stop surfaces <NUM>, Fig. 5b, arranged to interact with the engagement surfaces <NUM> of the ledges <NUM> of the hooks <NUM> as will be described. At the inner surface of the activator sleeve <NUM> a number of longitudinally extending ledges <NUM> are arranged. These ledges <NUM> are arranged to cooperate with side surfaces of generally arc-shaped arms <NUM> on an activator blocker <NUM> of an activator <NUM>, causing a rotational fixation between the activator blocker <NUM> and the activator sleeve <NUM>. Further the arc-shaped arms <NUM> are provided with cut-outs <NUM>, which cut-outs <NUM> are arranged to interact with inwardly directed protrusions <NUM> on the activator sleeve <NUM>, thereby locking the two components to each other. The distal end of the activator blocker <NUM> is provided with a generally tubular part <NUM> having grip elements <NUM> that in the embodiment shown are circumferentially extending grooves and protrusions. Further an end wall <NUM> is arranged at the distal end of the activator blocker <NUM>.

An activator element <NUM>, comprised in the activator <NUM>, is arranged coaxial with and inside the activator sleeve <NUM>, <FIG> and <FIG>. The activator element <NUM> has a distal generally tubular body <NUM>. The tubular body <NUM> is provided with distally directed arms <NUM>, which arms <NUM> are flexible in the generally radial direction. The outer surfaces of the arms <NUM> are provided with two transversal and generally parallel ledges <NUM> forming a transversal groove <NUM> between them, which transversal groove <NUM> is to cooperate with the transversal ledge <NUM> of the activator sleeve <NUM> as will be described. The most proximal ledge <NUM> has a wedge-shape, the function of which will be described below. Further, the side surface of the tubular body <NUM> is provided with two generally rectangular cut-outs <NUM>, forming a longitudinally extending bridge <NUM> there between. On the outer side of the bridge <NUM>, a locking structure in the form of a transversally extending groove <NUM> is arranged, which groove <NUM> is intended to cooperate with the wedge-shaped ledges <NUM> of the protrusions <NUM> of the distal housing part as will be described.

The activator element <NUM> is further arranged with longitudinally extending, elongated and inwardly directed, ledges <NUM> placed on inner surfaces of the bridges <NUM> as seen in <FIG>. Two proximally directed, generally arc-shaped, elongated fingers <NUM> are attached to or made integral with the elongated ledges <NUM>. These fingers <NUM> are designed to fit into generally arc-shaped passages <NUM> in a distal end wall <NUM> of an actuator <NUM>, <FIG>. The actuator <NUM> is arranged with a distal generally tubular part <NUM> into which the fingers <NUM> extend. The tubular part <NUM> is arranged with oppositely positioned outwardly extending ledges <NUM>, which ledges <NUM> are provided with distally directed support surfaces <NUM>. On the outer surface of the tubular part <NUM>, a number of outwardly directed protrusions <NUM> are arranged, which protrusions <NUM> are intended to fit into the rectangular cut-outs <NUM> of the activator element <NUM>, creating a rotational lock between the components but allowing relative movement in the longitudinal direction.

The actuator <NUM> is further arranged with a proximal part <NUM> which is provided with a number of proximally extending arms <NUM>, in the embodiment shown four arms having free ends that are flexible in the generally radial direction. As illustrated in <FIG>, each proximally extending arm <NUM> has both an inwardly directed ledge <NUM> as well as an outwardly directed ledge <NUM>.

An elongated plunger rod <NUM> is further arranged coaxial with and inside the actuator <NUM>. The plunger rod <NUM> is provided with a circumferential groove <NUM>, <FIG>, in which the inwardly directed ledges <NUM> of the arms <NUM> of the actuator <NUM> may fit.

The plunger rod <NUM> is hollow an inside the plunger rod <NUM> a drive spring <NUM> is arranged between a proximal end wall <NUM> of the plunger rod <NUM>, <FIG>, and the end wall <NUM> of the actuator. A guide rod <NUM> is further arranged inside the drive spring <NUM> for preventing buckling of the drive spring <NUM>. The proximal end of the plunger rod <NUM> is designed to act on the distal stopper <NUM> of the medicament container <NUM> as will be described.

Outside of and coaxial with the actuator <NUM> is a generally tubular actuator sleeve <NUM>, <FIG> and <FIG>. The proximal area of the actuator sleeve <NUM> has a diameter generally corresponding to the outer diameter defined by the outwardly directed ledges <NUM> of the actuator <NUM> when the inwardly directed ledges <NUM> are positioned in the circumferential groove <NUM> of the plunger rod <NUM>, thereby providing a locking function of the plunger rod <NUM> as will be described. Further the inner surface of the proximal area is arranged with inwardly directed ledges <NUM> that form proximal blocking surfaces <NUM> for distally directed surfaces of the outwardly ledges <NUM> of the actuator <NUM>, preventing movement of the actuator <NUM> in the distal direction when the inwardly directed ledges <NUM> of the actuator are positioned in the groove <NUM> of the plunger rod <NUM>. The actuator sleeve <NUM> is further arranged with a proximally directed circumferential ledge <NUM>, <FIG>, which is to cooperate with a distally directed circumferential surface of the proximal housing part <NUM> as will be described. Moreover, the distal area of the actuator sleeve is arranged with cut-outs <NUM>, <FIG>, intended to accommodate the ledges <NUM> of the actuator <NUM>. The combination of the actuator <NUM>, the plunger rod <NUM>, the drive spring <NUM>, the guide rod <NUM> and the actuator sleeve <NUM> forms a drive unit <NUM> of the medicament delivery device, <FIG>.

The device is intended to function as follows. When the device is delivered to a user, a multi-chamber medicament container <NUM> is positioned in the proximal housing part <NUM>. Further, the proximal housing part <NUM> is in an extended position in relation to the distal housing part as seen in <FIG> and <FIG>. The drive spring <NUM> is in a tensioned state inside the plunger rod <NUM> with the inwardly directed ledges <NUM> of the actuator <NUM> positioned in the circumferential groove <NUM> of the plunger rod <NUM> as seen in <FIG>. The inwardly directed ledges <NUM> are prevented from leaving the groove <NUM> due to the actuator sleeve <NUM> positioned radially outside the arms <NUM> of the actuator <NUM> whereby the outwardly directed ledges <NUM> of the arms <NUM> of the actuator <NUM> are in contact with the inner surface of the actuator sleeve <NUM>, <FIG>. The actuator sleeve <NUM> is locked in the longitudinal direction in that its distal end surface is in contact with an inclined part of the tongues <NUM>, and in that the surfaces <NUM> of the ledges <NUM> of the actuator sleeve are in contact with distally directed surfaces of the outwardly directed ledges <NUM> of the actuator <NUM>, <FIG>.

The activator sleeve <NUM> with the activator blocker <NUM> is in an initial position where a proximal edge of the activator blocker <NUM> is in contact with a distal end surface of the distal housing part <NUM>, <FIG>. The activator sleeve <NUM> is further locked in this position in that the engagement surfaces <NUM> of the ledges <NUM> of the distally directed tongues <NUM> of the rear distal housing part <NUM> engage the stop surfaces <NUM> of the beams <NUM> of the activator sleeve <NUM> as seen in <FIG>, thereby preventing any pulling of the activator blocker <NUM> in the distal direction. Further, the activator element <NUM> is held in position longitudinally in that the ledge <NUM> is in contact with the transversal ledge <NUM> of the activator sleeve <NUM>, preventing movement in the proximal direction of the activator, and in that the protrusions <NUM> engages the proximal edge of the cut-outs <NUM>, as seen in <FIG>, preventing movement in the distal direction of the activator element <NUM>. Further, the actuator <NUM> with its tensioned plunger rod <NUM> is also locked in the longitudinal direction by the protrusions <NUM> as described and also the ledges <NUM> abutting the transversal wall section <NUM>, <FIG>. The ledge <NUM> of the arm <NUM> of the proximal housing part <NUM> is positioned in the first cut-out 40I in the distal housing part, <FIG>.

When the medicament delivery device is to be used, a user turns the proximal housing part <NUM> in relation to the distal housing part, preferably with the aid of the grip enhancing protrusions <NUM>, whereby the proximal housing part <NUM> is moved distally in relation to the distal housing part. The design of the arm <NUM> and its ledge <NUM> enables only rotation in the correct direction. The relative movement of the housing parts will cause the plunger rod <NUM> to move the distal stopper <NUM> in the proximal direction which in turn will cause a movement of the proximal stopper <NUM> such that the by-pass passage <NUM> is opened between the compartments <NUM> and <NUM>, wherein the diluent may be mixed with the medicament in powder form.

The relative movement of the housing parts will further cause the distal end surface of the proximal housing part <NUM> to come in contact with the proximally directed ledge <NUM> of the actuator sleeve <NUM>, wherein the latter is also moved in the distal direction. The movement of the actuator sleeve <NUM> will in turn cause a distal end of the actuator sleeve <NUM> to come in contact with the tongues <NUM> of the rear distal housing part <NUM> and bias the hooks <NUM> outwards in the generally radial direction, <FIG>. The engagement surfaces <NUM> of the ledges <NUM> will then move out of contact with the stop surfaces <NUM> of the beams <NUM> of the activator sleeve <NUM>. Further, the proximal end surface of the actuator sleeve <NUM> has now moved in relation to the outwardly directed ledges <NUM> of the arms <NUM> of the actuator <NUM>, as seen in <FIG>, such that the end surface of the actuator sleeve <NUM> is generally in line with the proximal end surface of the actuator <NUM>. When the proximal housing part <NUM> is in the most retracted position inside the distal housing part, the ledge <NUM> has entered the second cut-out 40II of the distal housing part, which locks the proximal housing part from being rotated back.

The medicament delivery device is now ready for delivering a dose of medicament. A medicament delivery member is attached to the proximal end of the proximal housing part <NUM>, wherein a priming of the medicament container <NUM> may be performed. In order to activate the medicament delivery device, the activator blocker <NUM> of the activator <NUM> is pulled in the distal direction, which may be facilitated by the grip elements <NUM> on the side surface thereof. Due to the connection with the activator sleeve <NUM>, the latter will also be moved distally, wherein the distally directed arms <NUM> of the activator element <NUM> will flex radially inwards due to the wedge-shaped ledges <NUM> coming in contact with the inwardly directed ledges <NUM> of the activator sleeve <NUM> until the ledges <NUM> of the activator sleeve <NUM> are positioned between the ledges <NUM> of the arms <NUM> of the activator element <NUM>, <FIG>. The activator sleeve <NUM>, and thus the activator blocker <NUM>, is now operably connected in the longitudinal direction with the activator element <NUM>.

The next step is now to perform a penetration whereby the proximal end with the medicament delivery member is pressed against a dose delivery site. After that the user presses on the distal end wall <NUM> of the activator blocker <NUM> whereby the activator <NUM>, i.e. the activator blocker <NUM>, the activator sleeve <NUM> and the activator element <NUM> are moved in the proximal direction in relation to the rest of the medicament delivery device. This movement of the activator element <NUM> will cause its proximally directed fingers <NUM> to move inside the actuator <NUM> such that the proximal end surfaces of the fingers come in contact with a distal end surface of the plunger rod <NUM>, <FIG>. This in turn will cause the plunger rod <NUM> also to move in the proximal direction together with the actuator <NUM> due to the connection of the inwardly directed ledges <NUM> in engagement with the circumferential groove <NUM> of the plunger rod <NUM>. Now the movement of the actuator <NUM> will cause the outwardly directed ledges <NUM> of the arms <NUM> to move out of engagement with the actuator sleeve <NUM>, <FIG>, whereby the arms <NUM> are free to flex in the radial direction, releasing the plunger rod <NUM>. In this position, the activator blocker <NUM> is again in contact with the distal housing part, Fig. 11b, stopping further movement of the activator <NUM>. In this position of the activator <NUM> and thus the activator element <NUM>, the inwardly directed ledges <NUM> of the protrusions <NUM> on the transversal wall section <NUM> of the rear distal housing part <NUM> to engage the transversal grooves <NUM> of the activator, thereby locking the activator element <NUM> in the longitudinal direction, and thereby also the activator sleeve <NUM> and the activator blocker, <FIG>.

The now released plunger rod <NUM> is urged in the proximal direction by the force of the drive spring <NUM>, in turn driving the stoppers <NUM>, <NUM> in the medicament delivery container <NUM> in the proximal direction, causing the expelling of a dose of medicament through the medicament delivery member at the dose delivery site, <FIG>. Further, the release of the arms <NUM> of the actuator <NUM> will cause them to be forced suddenly outwards hitting the proximal end surface of the actuator sleeve <NUM>, <FIG>, causing an audible and tactile signal to the user, informing the user that the dose delivery sequence has started. The actuator <NUM> is however prevented from being moved in the distal direction by the counter force of the drive spring <NUM> acting on the end wall <NUM> of the actuator <NUM>, due to the outwardly directed ledges <NUM> of the arms <NUM> engaging the proximal end surface of the actuator sleeve <NUM> and by the inwardly directed ledges <NUM> engaging the side surface of the plunger rod <NUM> as seen in <FIG>.

When the plunger rod <NUM> has almost come to its most proximal position after dose delivery, its distal end will move out of contact with the inwardly directed ledges <NUM> of the arms <NUM> of the actuator <NUM>, <FIG>. This will cause the actuator <NUM> to be moved suddenly in the distal direction due to the residual force of the drive spring <NUM>, until the transversal ledges <NUM> of the actuator <NUM> hit the proximally directed surfaces of the transversal wall <NUM> of the distal housing part, <FIG>, creating a tactile and audible signal, informing the user that the dose delivery sequence has ended. The medicament delivery device can now be safely removed from the dose delivery site and discarded in a safety container for example.

<FIG> disclose another embodiment of a medicament delivery device provided with locking features. In this embodiment, only two components are different from the previous embodiment, and thus, the components that are the same have retained their reference numerals. One of the components or elements that is different is an activator <NUM>, where the difference is that there are generally rectangular protrusions <NUM> on the side surface forming the bridge <NUM> and distal of the transversal groove <NUM> of an activator element <NUM>. The activator element <NUM> of the activator <NUM> of the second embodiment comprises a distal tubular section <NUM> and a distal end wall <NUM>, which will function as a contact surface as will be described. For the rest, the activator is arranged with proximally directed fingers <NUM> as the previous embodiment. The distal section <NUM> of the activator element <NUM> is intended to fit into an activator blocker <NUM> having a generally tubular body <NUM> with an inner diameter somewhat larger than the distal section of the activator element <NUM>. The activator blocker <NUM> is arranged with a distal passage <NUM> through which the distal end wall <NUM> of the activator element <NUM> is visible.

The activator blocker <NUM> is further arranged with longitudinally extending grooves <NUM> running from the distal end surface, in which grooves <NUM> the rectangular protrusions <NUM> of the activator element <NUM> are designed to fit. The design of the activator blocker <NUM> and the activator element <NUM> are formed such that the distal end wall <NUM> of the activator element <NUM> is generally in level with the distal end surface of the activator blocker <NUM> as seen in <FIG>. The activator blocker <NUM> is further arranged with longitudinally extending ledges <NUM> that are intended to fit into the grooves <NUM> of the distal housing part. Moreover, proximally of the ledges <NUM>, grooves <NUM> are arranged, which grooves <NUM> are provided with transversal ledges <NUM>. These ledges <NUM> are designed to interact with the ledges <NUM> of the hooks <NUM> of the rear distal housing part <NUM>. Further, a proximally directed end surface <NUM> of the activator blocker <NUM> functions as stop surface as will be described.

The medicament delivery device according to the second embodiment is intended to function as follows. As with the previous embodiment the proximal housing part <NUM> is in an extended position in relation to the rear distal housing part <NUM> when delivered to a user. The plunger rod <NUM> is held in a tensioned state by the inwardly ledges <NUM> of the arms <NUM> of the actuator <NUM>, wherein the arms <NUM> are held in position by the actuator sleeve <NUM>. The activator element <NUM> cannot be operated since the surrounding activator blocker <NUM> is locked from movement in the longitudinal direction because the proximally directed stop surface <NUM> of the activator blocker <NUM> is in engagement with distally directed engagement surfaces <NUM>, <FIG>, of the ledges <NUM> of the hooks <NUM> as seen in <FIG>. The user now performs a mixing action by rotating the proximal housing part in relation to the distal housing part, whereby the plunger rod will act on the stoppers <NUM>, <NUM> of the medicament container <NUM> as described above. The proximal housing part <NUM> will as described come in contact with the proximally directed end surface of the actuator sleeve <NUM>, which will then move the actuator sleeve <NUM> in the distal direction in relation to the actuator <NUM>. Also the distal end surface of the actuator sleeve will come in contact with and bias the tongues <NUM> of the hooks <NUM> outwardly in the radial direction as seen in <FIG>.

When now the mixing has been performed and the medicament delivery device is placed at the dose delivery site, the user can press on the distal end wall <NUM> of the activator element <NUM> whereby it will move in the proximal direction together with the activator blocker <NUM>. Since the hooks <NUM> have been moved radially outwardly, the proximal edge surface of the activator blocker <NUM>, which may be somewhat bevelled, comes in contact with the inclined surface of the ledge <NUM>, forcing the hook <NUM> to be biased further outwardly in the radial direction. The hooks <NUM> will then slide along the outer side surface of the activator blocker <NUM>. As with the previous embodiment, the movement in the proximal direction of the activator element <NUM> will cause its fingers <NUM> to contact and move the plunger rod <NUM> and the actuator <NUM> in the proximal direction until the outwardly ledges <NUM> of the arms <NUM> of the actuator <NUM> are moved out of contact with the actuator sleeve <NUM>, <FIG>, whereby the plunger rod <NUM> is released and performs a dose delivery operation as described above.

When the activator element <NUM> and the activator blocker <NUM> have been pressed in the proximal direction until the activator blocker <NUM> abuts the transversal wall section <NUM> of the rear distal housing part <NUM>, the activator blocker <NUM> is locked in that the ledges <NUM> of the hooks <NUM> engage with the transversal ledges <NUM> of the activator blocker <NUM>. Further the ledges <NUM> of the protrusions <NUM> of the rear distal housing part <NUM> enter the transversal grooves <NUM> of the activator <NUM>, <FIG>. The activation mechanism is thus locked in the depressed position, indicating that the medicament delivery device has been used. The signalling functions described in the previous embodiment are also present in the second embodiment.

<FIG> disclose a third embodiment. It comprises an activator <NUM> comprising an activator blocker <NUM> provided with a generally tubular body <NUM> having an inner diameter generally corresponding to the outer diameter of an activator element <NUM>, which activator element <NUM> generally has the same shape as the activator element of the second embodiment, having a body <NUM> and being provided with rectangular protrusions <NUM>. The body <NUM> of the activator blocker <NUM> is arranged with longitudinally extending grooves <NUM>, in which the rectangular protrusions <NUM> of the activator element <NUM> fit. The activator blocker <NUM> is further arranged with generally rectangular protrusions <NUM> on its outer surface, which protrusions fit into the longitudinal grooves <NUM> of the inner surface of the rear distal housing part <NUM>. Proximal of the rectangular protrusions <NUM> are generally rectangular cut-outs <NUM>, wherein the proximal area of the cut-outs are provided with transversal beams <NUM>. The transversal beams <NUM> are arranged with distally directed stop surfaces <NUM> that are arrange to interact with the proximally directed engagement surfaces <NUM> of the hooks <NUM>. The distal end of the activator blocker <NUM> is provided with a grip part <NUM> having a diameter generally as large as the diameter of the distal housing part. The grip part <NUM> may be arranged with grip enhancing elements such as circumferential grooves and protrusions <NUM>. The grip part <NUM> is further arranged with an end wall <NUM>.

When the medicament delivery device is delivered to a user, the activator blocker <NUM> is inserted into the distal end of the medicament delivery device. The engagement surfaces <NUM> of the ledges <NUM> of the hooks <NUM> of the rear distal housing part <NUM> are engaging the stop surfaces <NUM> of the transversal beams <NUM> of the activator blocker <NUM> as seen in <FIG>, preventing any removal of the activator blocker <NUM>. When the mixing of the medicament delivery device is performed as described earlier, the distal end of the moving actuator sleeve <NUM> will contact the tongues <NUM> of the hooks <NUM> and bias them in the radial direction, whereby the ledges <NUM> of the hooks <NUM> are moved out of engagement with the transversal beams <NUM>, <FIG>. The activator blocker <NUM> is thus released and can be pulled in the distal direction away from the medicament delivery device. The distal part of the activator element <NUM> is now exposed, <FIG>, and can be pushed in the proximal direction for delivering a dose of medicament in the same manner as described above.

<FIG> shows a fourth embodiment. An activator <NUM> is arranged at the distal end of the medicament delivery device. The activator <NUM> is arranged with an activator blocker <NUM> provided rotatable in relation to the distal housing part. The activator blocker <NUM> is provided with a generally tubular body <NUM> having an outer diameter generally corresponding to the inner diameter of the distal housing part. At the distal end of the body <NUM> a generally ring-shaped grip part <NUM> is provided having a diameter generally corresponding to the outer diameter of the distal housing part. An indicator <NUM> is attached to or made integral with the grip part <NUM>, extending in the longitudinal direction proximally. The indicator <NUM> is arranged to point at different indicia <NUM> on the outer surface of the housing, wherein the indicia <NUM> may be numbers like "<NUM>" and "<NUM>" or symbols like a locked padlock or unlocked padlock.

The body <NUM> of the activator blocker <NUM> is further arranged with circumferentially extending groove sections <NUM>, <FIG>. These groove sections <NUM> connect with longitudinally extending groove sections <NUM> that end at the proximal end surface of the body <NUM>. These groove sections <NUM>, <NUM> are arranged to interact with rectangular protrusions <NUM> on the outer surface of an activator element <NUM>. The activator element <NUM> of the fourth embodiment is similar to the activator element of the second embodiment. However, the rectangular protrusions <NUM> of the fourth embodiment are placed on the side of rectangular cut-outs <NUM> instead of on a bridge <NUM>.

At the proximal end surface of the body <NUM> of the activator blocker <NUM>, generally rectangular, arc-shaped sections <NUM> are attached or made integral. The transversal part <NUM> of each arc-shaped section <NUM> is provided with an outwardly directed cut-out <NUM> provided with side surfaces <NUM> that will function as stop surfaces as will be described.

When the medicament delivery device is delivered to a user, the proximal housing part is extended in relation to the distal housing part as described above. The activator blocker <NUM> is positioned with its indicator <NUM> towards the initial indicia, such as zero, as shown in <FIG>. The activator blocker <NUM> is locked in this rotational position by the tongues <NUM> of the hooks <NUM> fitting into the outwardly directed cut-outs <NUM> of the arches, whereby side surfaces <NUM> of the tongues <NUM> of the hooks <NUM> are engagement surfaces that are in blocking contact with the stop surfaces <NUM> of the cut-outs <NUM>, <FIG>. The activator blocker <NUM> is further locked in the distal direction by the ledges <NUM> of the hooks <NUM> of the rear distal housing part <NUM> engaging distally directed surfaces of the transversal parts <NUM> of the arc-shaped sections <NUM>. Further, in the initial position the protrusions <NUM> of the activator <NUM> are positioned at one end of the circumferential groove section <NUM> of the body <NUM> of the activator blocker <NUM>, <FIG>. The distal end of the activator element <NUM> protrudes out of the activator blocker <NUM> but is prevented from being depressed by the protrusions <NUM> positioned in the transversal groove sections <NUM>.

When now a mixing operation is performed, the distal end of the proximal housing part <NUM> engages the actuator sleeve <NUM> and pushes it in the distal direction. The distal end of the actuator sleeve <NUM> is then moved in contact with the tongues <NUM> of the hooks <NUM>, biasing the hooks <NUM> outwards in the radial direction, <FIG>. This will cause the engagement surfaces <NUM> of the hooks <NUM> to be moved out of contact with the stop surfaces <NUM> of the cut-outs <NUM> of the arc-shaped sections <NUM>, <FIG>. However, the hooks <NUM> are biased such that the ledges <NUM> still engage the arc-shaped sections <NUM>, <FIG>, still locking the activator blocker <NUM> in the longitudinal direction. Since the activator blocker <NUM> now is free to rotate, a user may turn the activator blocker <NUM> so that the indicator <NUM> is pointing to the unlocked indicia such as "<NUM>" as seen in <FIG>. This has caused the protrusions <NUM> to move in the transversal groove sections <NUM> to the point where these grooves meet the longitudinal groove sections <NUM>, <FIG>. This enables the activator element <NUM> to be pushed or pressed in the proximal direction and when the medicament delivery device has been placed at a dose delivery site, the activator element <NUM> is pushed in the proximal direction, <FIG>. This causes a release of the tensioned plunger rod <NUM> and a dose delivery sequence is performed as described earlier.

It is to be understood that the embodiments described above and shown in the drawings are to be regarded only as a non-limiting example of the invention and that they may be modified in many ways within the scope of the patent claims. It should be understood that arrangements described herein are for purposes of example only. As such, those skilled in the art will appreciate that other arrangements and other elements (e.g. machines, interfaces, functions, orders, and groupings of functions, etc.) can be used instead, and some elements may be omitted altogether according to the desired results. Further, many of the elements that are described are functional entities that may be implemented as discrete or distributed components or in conjunction with other components, in any suitable combination and location.

Claim 1:
Medicament delivery device having a housing comprising a proximal housing part (<NUM>) and a distal housing part (<NUM>), said proximal housing part (<NUM>) being arranged to accommodate a multi chamber medicament container (<NUM>), wherein the housing parts are arranged movable in relation to each other from an initial position to a mixed position in which the content of the multi chamber medicament container (<NUM>) is mixed,
- a drive unit arranged to act on said multi chamber medicament container for expelling a dose of medicament;
- an activator (<NUM>; <NUM>; <NUM>; <NUM>) operably connected to said drive unit and arranged with a manually operable activator element (<NUM>, <NUM>, <NUM>; <NUM>) wherein the activator (<NUM>; <NUM>; <NUM>; <NUM>) is manually operable in a proximal direction between an inactive position and an active position in which said drive unit is activated;
- an activator blocker (<NUM>; <NUM>; <NUM>; <NUM>) operably arranged to said activator element (<NUM>, <NUM>, <NUM>; <NUM>), said activator blocker (<NUM>; <NUM>; <NUM>; <NUM>) defining at least one locking member (<NUM>; <NUM>; <NUM>; <NUM>);
said distal housing part comprising at least one flexible hook (<NUM>), wherein the at least one flexible hook (<NUM>) of the distal housing part is operably arranged between a locked position where the flexible hook (<NUM>) is releasably engaged with the at least one locking member (<NUM>; <NUM>; <NUM>; <NUM>) of the activator blocker (<NUM>; <NUM>; <NUM>; <NUM>), thereby preventing operation of said activator element (<NUM>, <NUM>, <NUM>; <NUM>); and an unlocked position where the flexible hook (<NUM>) is out of engagement with the at least one locking member (<NUM>, <NUM>, <NUM>; <NUM>) of the activator blocker (<NUM>; <NUM>; <NUM>; <NUM>), thereby allowing operation of said activator element (<NUM>, <NUM>, <NUM>; <NUM>), wherein in said mixed position said proximal housing part acts on said flexible hook (<NUM>) to move it to said unlocked position.