Abstract:
The present invention relates to a medicament delivery device comprising a generally elongated housing ( 10; 100, 102 ), a drive assembly disposed in said hosing and an actuation assembly operably connected to said drive assembly, wherein said drive assembly comprises a guard member ( 12; 104 ) and an actuator member ( 44; 180 ), characterized in that the actuation assembly further comprises a locking member ( 28; 32 ) disposed between the guard member and the actuator member, wherein said locking member is configured to be moved by the guard member when the guard member is pressed against a delivery site between a first locking position in which the locking member is blocking the actuator member and a released position in which the locking member allows the actuator member to be operated.

Description:
TECHNICAL AREA 
     The present invention relates to a medicament delivery device and in particular a medicament delivery device capable of handling medicament cartridges such as to facilitate the attachment of medicament delivery members for delivering a dose of medicament. 
     BACKGROUND OF THE INVENTION 
     Many drugs for use with medicament delivery devices are contained in so called cartridges that are generally shaped as glass tubes in which a stopper is positioned. The proximal end of the cartridge is arranged with a septum or a similar resilient membrane through which a distal end of a medicament delivery member can be pushed. 
     The devices are thus arranged with compartments in which these medicament containers may be placed and are further arranged with neck portions provided with attachment members intended to cooperate with corresponding attachment members on the medicament delivery members. 
     For a number of devices the medicament delivery members constitute injection needles. The injection needles could either be arranged to an attachment member that is designed to cooperate with corresponding attachment means on medicament cartridges in order to deliver a dose of medicament at the injection site of a patient. The injection needle could also be a part of a syringe, i.e. integrated with the medicament container. 
     Due to the risk of being unintentionally injured by the injection needle, but also for covering the needle before use for patients that are uncomfortable with seeing the needle during e.g. penetration, different covers, caps and/or shields and guards have been devised. These are often accompanied by spring members urging them in different directions in relation to the devices as well as locking members, releasable or non-releasable, for holding and locking the covers or shields in different positions. 
     Regarding the use of springs acting on the shields, they are often used to urge the shields in the proximal direction in a non-locked condition prior to drug delivery. One such device is disclosed in the document WO 2006/057604 having a needle shield that is released from a retracted position by a turning action of a dose setting member at a distal end of the device. The device of WO 2006/057604 comprises a number of functions such as mixing, priming, auto-penetration and auto-injection, making it complex with a plurality of components. Further, in order to release the needle shield, components need to extend through the whole device from the dose setting member. For some applications and uses, the device need not be so complex nor contain so many functions, but could yet be intuitive and easy to use. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The aim of the present invention is to provide a medicament delivery device that can contain a medicament cartridge to which a medicament delivery member can be attached and wherein a medicament delivery member guard can be easily activated. 
     This aim is obtained by a medicament delivery device according to the features of the independent patent claim. Preferable embodiments of the invention form the subject of the dependent patent claims. 
     According to a main aspect of the invention it is characterised by a medicament delivery device comprising a generally elongated housing having opposite distal and proximal ends, and adapted to store a medicament container assembly; a drive assembly disposed in said housing and configured to act on said medicament container assembly for expelling a dose of medicament; and an actuation assembly operably connected to said drive assembly for activating said drive assembly, wherein said drive assembly comprises a guard member being movable in relation to the housing and having a proximal part protruding from the proximal end of the housing, and an actuator member disposed in said housing and being operable through the housing; wherein the actuation assembly further comprises a locking member disposed between the guard member and the actuator member, wherein said locking member is configured to be moved by the guard member when the guard member is pressed against a delivery site between a first locking position in which the locking member is blocking the actuator member and a released position in which the locking member allows the actuator member to be operated and wherein said locking member is further configured to be moved by the actuator member between the released position and a second locking position in which the locking member is blocking the guard member after said guard member is removed from the delivery site. 
     According to another aspect of the invention the locking member is a rotator member configured to be rotated in relation to the housing by the guard member and by the actuator member. 
     According to a further aspect of the invention the actuation assembly further comprises a first resilient force member arranged between the rotator member and the guard member for urging said guard member towards the proximal end. 
     According to another aspect of the invention the container assembly comprises a syringe having a delivery member. 
     According to a further aspect of the invention the container assembly comprises a cartridge having a proximal end protruding in relation to the proximal part of the guard member for allowing a delivery member to be attached to the cartridge 
     According to yet another aspect of the invention the guard member is operably connected to the housing by guide means such that when said guard member is manually turned in relation to the housing, said guard member is forced towards the proximal end of the device by the first resilient force member and thereby covering the delivery member from sight. 
     According to yet a further aspect of the invention the guard member is arranged to be moved in relation to the housing when said guard member is pressed against the delivery site between an extended position in which the guard member is covering the delivery member from sight and a retracted position in which the guard member is arranged within the housing such that the resilient force member is compressed and such that the delivery member is exposed to sight. 
     According to another aspect of the invention the compressed resilient force member is adapted to force the guard member from the retracted position to the extended position when said guard member is removed from the delivery site. 
     According to a further aspect of the invention said medicament delivery device is an auto-injector. 
     There are a number of advantages with the present invention. By the use of a locking member arranged between the guard member and the actuator member several functions may be obtained by rather few components. Also there is created a functional link between the guard member at the proximal end of the device, where the medicament delivery member is placed, and the actuator member, such that the actuator member cannot be operated, and thereby the device actuated, until the device is pressed against a delivery site. 
     The locking member may be designed and arranged as a rotator member that is turnable around a longitudinal axis of the device and capable of preventing or allowing movement of the components. 
     Especially when the rotator is arranged with guide members cooperating with guides on the guard member as well as lock and release members, the guard member could be locked in different positions such as in a retracted position when a medicament delivery member is to be attached prior to a dose delivery, or in an extended position after dose delivery for covering the medicament delivery member in order to avoid accidental needle sticks if the medicament delivery member is an injection needle. 
     The rotator and other interacting components could thus comprise guides, protrusions, ledges and the like that are integrated in few components and that are moved in and out of contact, both linearly and by rotation, during different operations. 
     These and other aspects of and advantages with the present invention will become apparent from the following detailed description and from the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following detailed description of the invention, reference will be made to the accompanying drawings, of which 
         FIG. 1  is a perspective, partly exploded, view of a first embodiment of the present invention, 
         FIG. 2  is a detailed view a rotator barrel comprised in the device of  FIG. 1 , 
         FIG. 3  is a detailed view of the rotator barrel and a medicament delivery member guard, 
         FIG. 4  is a detailed view of the rotator barrel and an actuation member, 
         FIG. 5  is a perspective view of a second embodiment of the present invention, 
         FIG. 6  is a partly exploded view of the device of  FIG. 5 , 
         FIG. 7  is a further exploded view of the device of  FIG. 5 , 
         FIG. 8  is a cross-sectional view of the device of  FIG. 5 , 
         FIG. 9  is a detailed view of a rotator member comprised in the device of  FIG. 5 , 
         FIG. 10  is a detailed view of a medicament container holder comprised in the device of  FIG. 5 , 
         FIG. 11  is another partly exploded view of the device of  FIG. 5 , 
         FIG. 12  is a detailed view of a rotator member and an actuation mechanism comprised in the device of  FIG. 5 , 
         FIG. 13  is an exploded detailed view of an actuation mechanism, comprised in the device of  FIG. 5 , 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the present application, 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. 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. 
     One exemplary embodiment of a medicament delivery according to the present invention is shown in the drawings  1 - 4 .  FIG. 1  comprises a generally tubular, elongated housing  10 . At a proximal end of the housing a guard member in the form of a generally tubular needle guard  12  is arranged slidable in relation to the housing. The outer surface of the needle guard is arranged with first guide members  14 . Further the inner surface of the housing at the proximal end is arranged with second guide members  16 . The first and second guide members are arranged to guide the movement of the needle guard  12  as will be described below. According to the embodiment shown in  FIGS. 1-4  the first guide members are in the form of ridges  18  and the second guide member are protrusions  16  that are able to glide along the ridges  18 . The needle guard is further arranged with a locking member that in the embodiment shown is a protrusion  20  on an outer surface of a distally extending tongue  22 . The protrusion  20  is arranged to cooperate with a locking ledge  24 ,  FIG. 2 , which locking ledge  24  is arranged on the inner surface of a proximally directed tongue  26 , which tongue  26  is attached to a locking member in the form of a generally tubular rotator barrel  28 , where the rotator barrel  28  is arranged rotatable inside said housing  10 . The rotator barrel  28  is arranged with third guide members that in the embodiment shown are arranged as proximally directed inclined surfaces  30 . The surfaces of the third guide members are cooperating with fourth guide members that in the embodiment shown are distally directed inclined surfaces  32  arranged on the tongue  22  of the needle guard. A spring member  34  is arranged between the rotator barrel  28  and the needle guard  12  for urging the latter in the proximal direction of the device. Further the rotator barrel  28  comprises a proximally directed lock tab  35 . On an area  37  of the inner surface of the lock tab  35 ,  FIG. 2 , adjacent the rotator barrel  28 , material has been removed. Further a sloping transition  37   I  is provided between the surfaces of the area  37  and the rest of the inner surface of the lock tab  35 , the function of which will be described below. 
     The distal end of the rotator barrel  28  is arranged with second locking and release member that in the embodiment shown comprises a distally directed end surface  36  of the rotator barrel and a cut-out  38 ,  FIG. 4 , which cut-out  38  is provided with an inclined side surface  40 . Further an actuation member  42  is arranged in the distal end of the device that in the embodiment shown comprises an actuation member in the form of an actuation button  44  protruding through the distal end. The actuation button  44  is arranged with a proximally directed tongue  46  having an inclined proximally directed surface  48 . 
     The device according to the first embodiment is intended to function as follows. When the device is delivered to the user, the needle guard  12  is in a retracted position inside the housing, exposing a proximal end part of a medicament cartridge (not shown). The needle guard  12  is held in the retracted position by the protrusion  20  of the needle guard  12  abutting the ledge  24  of the rotator barrel  28 . Thus it is easy for a user to attach a medicament delivery member such as e.g. an injection needle, to the medicament cartridge. 
     In order to activate the device for delivering a dose of medicament, the user turns the needle guard  12  whereby the protrusion  20  is moved out of contact with the ledge  24 . The needle guard  12  is thus free to move in the proximal direction by the force of the spring  34 , thereby covering the medicament delivery member. The movement of the needle guard  12  causes the protrusion  16  on the housing  10  to move along the ridges  18  of the needle guard  12 . Certain ridges  18 a are somewhat inclined in relation to the longitudinal direction of the device, whereby the needle guard  12  is rotated somewhat such that the inclined surface  32  of the tongue  22  of the needle guard  12  is moved in line with the proximally directed inclined surface  30  of the rotator barrel  28 . During the above operations, the actuation member  42  is locked from actuation because the proximal end of the tongue  46  is in contact with the distal end surface  36  of the rotator barrel  28 . 
     The next step is to perform a dose delivery at a dose delivery site. The user then presses the proximal end of the needle guard  12  against the dose delivery site, causing a penetration when the medicament delivery member is an injection needle, whereby the needle guard  12  is moved in the distal direction against the force of the spring  34 . This movement of the needle guard  12  causes the inclined surface  32  of the tongue  22  to move in contact and act on the inclined surface  30  of the rotator barrel  28 . This action causes the rotator barrel  28  to rotate a certain distance such that the inclined side surface  40  of the cut-out  38  of the rotator barrel  28  is moved in line with the inclined end surface  48  of the tongue of the actuation member  42 . 
     The next step is to perform a dose delivery. The user then presses the actuation button  44  in the proximal direction. This forces the plunger rod to move in the proximal direction, whereby the stopper of the medicament cartridge is also moved in the proximal direction, causing a dose of medicament to be expelled through the medicament delivery member. The movement of the actuation button  44  in the proximal direction causes the inclined surfaces  40 ,  48  to cooperate such that the rotator barrel  28  is rotated a certain distance. The rotation of the rotator barrel causes the protrusion  20  to come in contact with, and move onto, the area  37 . 
     When now the device is removed from the injection site, the needle guard  12  is again free to move in the proximal direction by the spring  34 , whereby the protrusion  20  of the needle guard  12  is moved from the area  37 , over the transition  37   I  and then past a proximal end surface of the lock tab  35 ,  FIG. 1 . In this position, the needle guard  12  is locked in the extended position, protecting the medicament delivery member, thereby avoiding unintentional needle sticks if the medicament delivery member is an injection needle. 
       FIGS. 5-13  show a second exemplary embodiment of the present invention. It comprises a generally elongated tubular distal housing part  100 . The distal housing part is connected to a generally tubular proximal housing part  102 . At the proximal end of the proximal housing part  102  a guard member in the form of a medicament delivery member guard  104  is arranged. The medicament delivery member guard  104  is arranged with outwardly directed protrusions  106 , which protrusions  106  fit into elongated grooves  108  in the proximal housing part  102  such as to enable sliding in the longitudinal direction of the medicament delivery member guard but a rotational lock. The proximal end of the medicament delivery member guard is arranged with a helical groove  110  on its outer surface, which groove  110  is arranged to cooperate with a helically extending ridge  112  on an inner surface of a protection cap  114 . The distal end of the medicament delivery member guard is arranged with two distally directed tongues  116 , where each tongue is arranged with an inclined distally directed surface  118 . 
     The proximal housing part  102  is further arranged with a medicament container holder  120 , in the embodiment shown integrated with the proximal housing part  102 . The medicament container holder is adapted to receive a medicament container  122 , in the embodiment shown a syringe provided with a medicament delivery member  124  in the form of an injection needle. It is however to be understood that other types of medicament delivery members such as mouth or nose pieces, nozzles, nebulisers and the like can be utilized. A compression spring  126  is arranged between a proximal end surface  128 ,  FIG. 8 , of the medicament container holder  120  and a distally directed surface inside the medicament delivery member guard  104 . Further both the medicament container holder and the proximal housing part are arranged with openings or windows  130  such that the medicament container  122  is visible, and since preferably the medicament container  122  is made of a transparent material, the content of the medicament container  122  is visible to a user. 
     Surrounding the medicament container holder  120  is a locking member in the form of a rotator barrel  132  arranged rotatably but locked against linear movement due to circumferentially extending grooves  134  on the outer surface of the rotator barrel cooperating with inwardly extending protrusions on flexible arms  136  arranged to the proximal housing part,  FIG. 11 . The rotator barrel is further arranged with proximally directed tongues  138 ,  FIG. 11 , which tongues  138  are arranged with inclined surfaces  140  intended to cooperate with the inclined surfaces  118  of the tongues of the needle guard. A flexible proximally extending arm  142  is further attached to the proximal end surface of the rotator barrel, having an inclined direction generally corresponding to the inclined surface  140  of the tongue  138 . At the proximal end of the flexible arm  142  a circumferentially extending arm portion  144  is attached. At the end of the arm portion  144  a distally directed ledge  146  is attached or made integral, which distal ledge  146  is positioned in a cut out of the rotator barrel  132 ,  FIG. 11 . The distal end of the rotator barrel  132  is provided with cut-outs  148 , where each cut-out  148  is arranged with an inclined side surface  150 . Further the distally directed end surface of the rotator barrel is arranged with circumferentially extending flexible arms  152 ,  FIG. 12 , which arms  152  are arranged with distally directed wedge-shaped protrusions  154 . The protrusions  154  are intended to cooperate with a corresponding wedge-shaped ratchet  156 ,  FIG. 10 , on a proximal wall surface inside the proximal housing part  102 . 
     Further an elongated plunger rod  158 ,  FIG. 8 , is arranged inside the housing of the device, having a proximal end in contact with a movable stopper  160  arranged inside the medicament container  122 . The plunger rod extends inside a tubular compartment of a guide member  162  positioned in the distal housing part  100 . A drive spring  164  in the form of a coiled compression spring is arranged surrounding the plunger rod with its proximal end in contact with a circumferential ledge  166  attached to the proximal end of the plunger rod and with its distal end in contact with an end wall  168  of the guide member  162 ,  FIG. 8 . The distal end is further extending through a central passage of the end wall  168  of the guide member  162 . The distal end of the plunger rod is further provided with a circumferential ledge  170 . A locking means  172  is surrounding the distal end of the plunger rod. The locking means comprises a generally tubular shape having a number of slits  174 , thereby forming flexible arms  176 . The ends of the arms are provided with inwardly directed protrusions  178 , which cooperate with the circumferential ledge  170  of the plunger rod  158  for locking it in place. A proximal end surface of the locking means  172  is abutting a distal end surface of the guide member  162 . 
     Further an actuator member  180  is arranged at the distal end of the device. It comprises an actuation button  182  protruding through the distal end of the device. The proximal end of the actuation button  182  is designed generally tubular. The actuation button of the actuation member is attached to a lock/release member  184 , having a generally tubular shape. The lock/release member  184  is surrounding, and in contact with, the locking member  172 , preventing its flexible arms  176  from flexing radially outwardly. The lock/release member  184  is further arranged with proximally extending arms  186 , having proximal end surfaces  188  adjacent the distal end surface of the rotator barrel,  FIG. 13 . 
     The device is intended to function as follows. The device preferably is delivered with a medicament container  122  mounted inside. When a dose is to be delivered the protective cap  114  is removed. The medicament delivery member guard  104  is urged in the proximal direction by the spring  126 , thereby covering the medicament delivery member. The actuation button  182  can not be pressed because the proximal end surfaces  188  of the arms  186  come in contact with the distal end surfaces of the rotator barrel  132 , preventing any movement of the actuation member  180 . 
     The patient then places the proximal end of the device against a dose delivery site, such as e.g. an injection site. The medicament delivery member guard  104  is then pushed in the distal direction, exposing the medicament delivery member  124 . The medicament delivery member guard  104  can only move linearly due to the protrusions  106  sliding in the grooves  108 . The distal movement of the medicament delivery member guard  104  causes its inclined surfaces  118  to come in contact with the inclined surfaces  140  of the rotator barrel  132 , causing a rotation of the rotator barrel  132 . When the medicament delivery member guard  104  has been pushed a certain distance distally, for example corresponding to a penetration depth if the medicament delivery member  124  is an injection needle, the rotator barrel  132  has rotated such that the cut-outs  148  of the distal end of the rotator barrel  132  are in line with the arms  186  of the lock/release member  184 . 
     When now the patient pushes the actuation button  182  in the proximal direction the lock/release member  184  is also moved in the proximal direction and in relation to the stationary locking member  172  until the distal end surface of the lock/release member  184  passes a proximal end surface of the locking means  172 . Then the arms  176  of the locking means  172  are free to flex outwardly in the radial direction, thereby releasing the plunger rod  158 . The plunger rod  158  is now forced in the proximal direction by the drive spring  164 , whereby the plunger rod  158  pushes the stopper  160  in the proximal direction and a dose of medicament is delivered through the medicament delivery member  124 . 
     The pushing of the actuation button  182  also causes the arms  186  to act on the inclined side surfaces  150  of the cut-outs  148  of the rotator barrel  132  so that the latter is rotated a further distance. The rotation of the rotator barrel  132  causes the flexible arms  142  to move in contact with a side surface of the distally directed tongues  116  of the needle guard  104  and to flex in the circumferential direction. The flexible arms  152  on the distal end of the rotator barrel  132  cooperate with the ratchet  156  of the housing to prevent any return movement of the rotator barrel  132 . 
     After the dose delivery the device is removed from the dose delivery site whereby the medicament delivery member guard  104  is pushed in the proximal direction by the action of the spring  126 . The proximal movement of the medicament delivery member guard  104  causes its distally directed tongues  116  to move out of contact with the flexible arms  142 , whereby the latter are free to move in the circumferential direction such that their proximal end surfaces are in line with the distal end surfaces of the tongues  116  of the needle guard  104 . Thereby the needle guard  104  is prevented from being pushed in the distal direction, whereby the needle guard surrounds and protects the medicament delivery member, which, in the case of an injection needle, prevents any unintentional needle sticks on a used and contaminated injection needle. The device can now be discarded. 
     It is to be understood that the embodiments described above and shown in the drawings are to be regarded as only exemplary embodiments of the invention and that it may be modified in many ways within the scope of the patent claims.