Medicament delivery device

Abstract

A medicament delivery device includes a housing having proximal and distal ends; a delivery member connected to the housing; a medicament container operably arranged within the housing; a drive mechanism configured to act on the medicament container for priming and for expelling a dose of medicament; and an activator mechanism configured to interact with the drive mechanism, such that a first interaction between the activator mechanism and the drive mechanism causes the container to move toward the delivery member, in which the container is primed, and such that a subsequent interaction between the activator mechanism and the drive mechanism causes a dose of medicament to be expelled through the delivery member.

Claims

1. A medicament delivery device, comprising: a housing having a proximal end and a distal end; a medicament container operably arranged within the housing; a delivery member holder fixedly attached to the housing, the delivery member holder comprising an injection needle having a proximal pointed end and a distal pointed end; a drive mechanism arranged within the housing and configured to act on the medicament container; a medicament container holder movably disposed inside the housing and configured to accommodate the medicament container; and an activator mechanism configured to interact with the drive mechanism; wherein the activator mechanism includes a safety member removably arranged to the distal end of the housing; and wherein the drive mechanism, activated by the activator mechanism, moves both the medicament container and the medicament container holder toward the distal pointed end of the injection needle, wherein removal of the safety member releases the drive mechanism to move the medicament container toward the distal pointed end of the injection needle for the distal pointed end to penetrate the medicament container.

2. The medicament delivery device of claim 1, wherein the activator mechanism includes a rotator arranged inside the housing and operably connected to the drive mechanism and the safety member such that removal of the safety member causes rotation of the rotator which then causes the drive mechanism to move the medicament container.

3. The medicament delivery device of claim 2, wherein a plunger rod is operably connected to the medicament container and a force member having a predetermined load force configured to act on the plunger rod; the plunger rod includes at least one first contact member; and the rotator includes at least one inner guiding member that interacts with the at least one first contact member to hold the plunger rod in either an initial state, an intermediate state, or a final state depending on a rotational angle of the rotator.

4. The medicament delivery device of claim 3, wherein the rotator includes at least one first outer guiding member; and the safety member includes at least one second contact member configured to interact with the first outer guiding member to turn the rotator, upon removal of the safety member, a first rotational angle such that the plunger rod is released from the initial state for the force member to move the plunger rod to the intermediate state and move the medicament container toward the distal pointed end of the injection needle.

5. The medicament delivery device of claim 4, wherein the at least one second contact member has at least one side edge in contact with the at least one first outer guiding member; and during removal of the safety member, the at least one side edge pushes the at least one first outer guiding member and rotates the rotator to release the plunger rod.

6. The medicament delivery device of claim 3, wherein the at least one inner guiding member includes a first inner transversal and circumferential section; and the plunger rod is held in the initial state by engagement of the at least one first contact member and the first inner transversal and circumferential section.

7. The medicament delivery device of claim 6, wherein the at least one inner guiding member further includes an inner inclined section; rotation of the rotator caused by removal of the safety member disengages the at least one first contact member and the first inner transversal and circumferential section in order for the force member to drive the plunger rod proximally to move the medicament container and also moves the at least one first contact member to act on the inner inclined section to rotate the rotator a second rotational angle.

8. The medicament delivery device of claim 7, wherein the at least one inner guiding member further includes a second inner longitudinal section and a second inner transversal and circumferential section; and the at least one first contact member moves along the second inner longitudinal section and reaches the intermediate state when contacting and engaging the second inner transversal and circumferential section.

9. The medicament delivery device of claim 3, wherein the medicament container includes a movable stopper in contact with the plunger rod; and during movement of the plunger rod from the initial state to the intermediate state, the plunger rod forces the stopper to move the medicament container toward the distal pointed end.

10. The medicament delivery device of claim 1, wherein the distal pointed end is covered by a protective sheath; and the distal pointed end penetrates the protective sheath and then the medicament container when the drive mechanism moves the medicament container.

11. The medicament delivery device of claim 1, wherein the medicament container includes a septum; and the distal pointed end penetrates the septum to create a passage to release pressure and air inside the medicament container.

12. The medicament delivery device of claim 1, wherein the delivery member includes an injection needle assembly fixedly connected to the housing and including the injection needle and a hub accommodating the injection needle; and the distal pointed end is covered by a protective sheath and the proximal pointed end is covered by a protective sheath.

13. The medicament delivery device of claim 12, wherein the hub includes a proximally directed ledge and a distally directed ledge; the protective sheath covering the proximal pointed end is disposed on the proximally directed ledge; and the protective sheath covering the distal pointed end is disposed on the distally directed ledge.

14. The medicament delivery device of claim 12, further comprising: a medicament container holder movably disposed inside the housing and configured to accommodate the medicament container; and a delivery member holder arranged in the housing and including: a first section configured to accommodate the hub; and a second section configured to accommodate a neck portion of a proximal section of the medicament container holder; wherein activating the drive mechanism moves both the medicament container and the medicament container holder until the medicament container holder contacts the delivery member holder.

15. A medicament delivery device, comprising: a housing having a proximal end and a distal end; a medicament container operably arranged within the housing; a delivery member holder fixedly attached to the housing, the delivery member holder comprising an injection needle having a proximal pointed end and a distal pointed end; a drive mechanism arranged within the housing and configured to act on the medicament container; and an activator mechanism configured to interact with the drive mechanism, where the activator mechanism comprises a rotator that is sleeve shaped, axially fixed to the housing, rotatable relative to the housing and has an outer surface having an outer guiding member; wherein the activator mechanism includes a safety member removably arranged to the distal end of the housing; and removal of the safety member causes the drive mechanism to move the medicament container toward the distal pointed end of the injection needle for the distal pointed end to penetrate the medicament container.

16. A medicament delivery device, comprising: a housing having a proximal end and a distal end; a medicament container operably arranged within the housing; a delivery member holder fixedly attached to the housing, the delivery member holder comprising an injection needle having a proximal pointed end and a distal pointed end; a drive mechanism arranged within the housing and configured to act on the medicament container; a rotator; a contactor operatively engaged with an outer guiding member on the outside surface of the rotator; and an activator mechanism configured to interact with the drive mechanism; wherein the activator mechanism includes a safety member removably arranged to the distal end of the housing; and wherein removal of the safety member releases the drive mechanism to move the medicament container toward the distal pointed end of the injection needle for the distal pointed end to penetrate the medicament container.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) In the following detailed description of the invention, reference will be made to the accompanying drawings, of which

(2) FIG. 1 shows a perspective view of an exemplary embodiment of a medicament delivery device according to the invention,

(3) FIG. 2 is an exploded view of the device of FIG. 1,

(4) FIG. 3 is a cross-sectional view of the device of FIG. 1,

(5) FIGS. 4-10 are detailed views of different components comprised in the device of FIG. 1,

(6) FIGS. 11-12 are cross-sectional views of different functional positions of the device of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION

(7) The exemplary medicament delivery device shown in the drawings comprises a generally elongated housing having proximal and distal ends, a delivery member 40 connected to the housing; a medicament container 84 operably arranged within the housing; a drive mechanism capable of acting on the medicament container for priming and for expelling a dose of medicament; wherein the device further comprises an activator mechanism configured to interact with the drive mechanism, such that a first interaction between the activator mechanism and the drive mechanism causes the container to move towards the delivery member wherein the container is primed and such that a subsequent second interaction between the activator mechanism and the drive mechanism causes a dose of medicament to be expelled through the delivery member.

(8) Further, the activator mechanism is configured such that the second interaction is prevented to be achieved until the first interaction is achieved as it will be explained below.

(9) The housing comprises a tubular first housing part 10, FIG. 1, being open at both ends and a second housing part 114 attached to the distal end of the first housing part. These two housing parts may be considered as one component.

(10) The activator mechanism comprises a contactor 12 operably arranged to the housing at a proximal end thereof; a rotator 82 operably arranged inside the housing and operably connected to the contactor 12 and to the drive mechanism; and a safety member 128 operably arranged to the housing at a distal end thereof and operably connected to the rotator. Further, the contactor is axially movable in relation to the housing between an extended position in which the delivery member is hidden and protected by the contactor and a retracted position in which the delivery member is exposed. The contactor and the rotator are arranged to interact with each other such that the rotator prevents the contactor from being moved from the extended position to the retracted position, until the first interaction is completed.

(11) The first interaction is an interaction between the rotator and the drive mechanism caused by an interaction between the safety member and the rotator, whereby removal of the safety member 128 causes a rotation of the rotator 82 such that the drive mechanism may act on the container for priming the container. This interaction will be explained below in detail.

(12) The contactor 12 is in the embodiment shown as a delivery member cover. The contactor 12 comprises a generally tubular proximal part 14 having a transversal proximal end wall 16, FIG. 2. Two longitudinally extending arms 18, FIG. 4, extend towards the distal end from the tubular part 14. Each of the extending arms 18 has an outer surface with a curvature that generally corresponds to the inner surface of the first housing part 10, whereby the contactor is slidable in the longitudinal direction in relation to the first housing part. The outer surfaces of the arms 18 are arranged with guide ribs 20, FIG. 4, which guide ribs 20 are intended to fit into longitudinally extending grooves 22 on the inner surface of the first housing part 10, FIG. 4, whereby the contactor 12 is guided during longitudinal sliding of the contactor 12 in relation to the first housing part 10 and prevent a rotation of the contactor in relation to the housing. The contactor is arranged within the housing such that the tubular part 14 protrudes from the proximal end of the housing.

(13) The contactor 12 is further arranged with two generally radially flexing tongues 24, FIG. 4, one on each arm and with the free ends facing the proximal end of the contactor 12. The tongues 24 are arranged such that they have a certain inclination somewhat inwards in their free un-tensioned state. The transversal end wall 16 of the contactor is further provided with a centrally positioned passage 26, FIG. 2, through which a delivery member, such as an injection needle, may pass when the device is used, as will be described. Further, the contactor comprises a number of third contact members 30. Each of the arms 18 of the contactor 12 is arranged with a third contact member 30 which may be a protrusion, FIG. 4, on inner surfaces thereof at a distal end area of the arms.

(14) The delivery member 40 is an injection needle assembly comprising a hub 38 wherein an injection needle is arranged with a proximal pointed end 42 and a distal pointed end 44 and wherein the distal pointed end 44 and the proximal pointed end 42 are surrounded and covered with respective protective sheaths 48, 46, FIG. 5. The hub 38 has further a proximally directed ledge and a distally directed ledge and the sheaths 46, 48 are of a suitable flexible material such as rubber or silicone and press-fit on the ledges of the hub 38, for protecting the needle and for keeping the needle sterile before use. The injection needle assembly is fixedly connected to the housing.

(15) A contactor force member 31, which may be a compression spiral spring, is pre-tensioned arranged with a proximal end in contact with a distally directed surface of the transversal end wall 16 for urging the contactor 12 in the proximal direction. The distal end of the contactor force member 31 is in contact with a delivery member holder 32, FIG. 5, arranged in the first housing part 10. The delivery member holder 32 has a first section 34 with a generally tubular shape with distal and proximal openings. The proximal opening is arranged with a circumferential ledge 36. Inside the first section 34, the hub 38 may be positioned. The hub 38 is shaped to fit into the first section 34, preferably with some friction. The delivery member holder 32 is fixedly attached to the first housing part. Alternatively the first housing and the delivery member holder 32 are integral.

(16) A second section 50 of the delivery member holder 32 is also generally tubular and designed such that the distal pointed end 44 of the injection needle 40 protrudes into the interior of the second section 50. The diameter of the second section 50 is chosen such that a neck portion 52 of a proximal section 54 of a medicament container holder 56, FIG. 6, may fit therein. The proximal section 54 of the medicament container holder comprises a circular end wall 58 with two distally extending tongues 60, where the tongues 60 are arranged to be flexible in the radial direction. The free ends of the tongues are arranged with radially outwardly extending ledges 62, which ledges 62 have a wedge-shape as seen in FIG. 7.

(17) The ledges 62 of the tongues 60 are designed to fit into recesses 64, FIG. 6, arranged in a proximal area of an elongated second section 66 of the medicament container holder 56 such as to connect the two sections with each other. The second section 66 is arranged with two diametrically positioned first wall sections 68 extending from the neck portion and having dimensions and curvature generally corresponding to the inner surface of the first housing part 10. The first wall sections 68 are attached to diametrically positioned second wall sections 70 having dimension such that the arms 18 of the contactor 12 can be accommodated. The distal ends of the first and second wall sections are attached to an end wall 72, which end wall 72 is arranged with a central passage 74. The end wall 72 is arranged with generally inwardly directed protrusions 76 positioned diametrically with respect to each other. The medicament container holder is designed to accommodate the medicament container 84, FIG. 6, provided with a neck portion 86, which neck portion fits into the neck portion 52 of the medicament container holder 56, and is sealed off by a flexible membrane, a septum. The distal end of the medicament container is sealed off by a movable stopper 88.

(18) Further, at the end wall 72 of the second section 66 of the medicament container holder, two distally directed loops 78 are arranged. Each loop comprises a radial inwardly extending protrusion or ledge. Each of the radial inwardly extending protrusion or ledge is arranged such that it may be inter-connected with radial outwardly extending protrusions 80 on an outer surface of the rotator 82, FIG. 7, such that the medicament container holder 56 is held in an initial position in which the medicament container holder 56 with its container is placed such that there is a distance between the distal pointed end 44 of the injection needle 40 and the neck portion of the medicament container, FIG. 3.

(19) In order for the contactor 12 not to be pushed out from the housing in the proximal direction by the contactor force member 31, it is held in position by the tongues 24 of the arms of the contactor being in contact with a distal annular surface of the delivery member holder 32, as seen in FIG. 3.

(20) The second interaction is a further interaction between the contactor and the rotator causing a further interaction between the rotator and the drive mechanism, whereby movement of the contactor from the extended to the retracted position causes a further rotation of the rotator 82 such that the drive mechanism may further act on the container for expelling a dose of medicament through the delivery member. This second interaction will be explained below in detail.

(21) The rotator 82 is a sleeve-shaped member having an outer and an inner surface. The outer surface of the rotator 82 is arranged with a number of outer guiding members of different functions. The outer surface of the rotator 82 is arranged with first outer guiding members 94, FIG. 7, which are transversal circumferential ledges located at a distal end of the rotator 82, and are arranged with cut-outs 96 at two diametrical positions, which cut-outs 96 have a certain width. The functions of the first outer guiding members 94 and cut-outs 96 will be explained below.

(22) The rotator is operably connected to the housing. Preferably, the rotator is rotatably and slidably locked to the housing, more preferably to the second housing part. Thus, the rotator further comprises on it outer surface holding members 93 which are preferably radial outwardly protrusions or ledges configured to interact with corresponding holding members which are preferably radial inwardly protrusions or ledges 115 on the inner surface of the second housing part such that the rotator may rotate in relation to said housing but is prevented to be longitudinally movable.

(23) The outer surface of the rotator 82 is further arranged with second outer guiding members 90. Each second outer guiding member 90 comprises a first outer longitudinal section 90.sup.I, a first outer transversal and circumferential section 90.sup.II, a second outer longitudinal section 90.sup.III, an outer inclined section 90.sup.IV, a third outer longitudinal section 90.sup.V, and a fourth outer longitudinal section 90.sup.VI which is parallel with the first, second and third outer longitudinal sections. The first outer longitudinal section 90.sup.I is connected to the first outer transversal and circumferential section 90.sup.II. This section is then connected to the second outer longitudinal section 90.sup.VI, which in turn emerges into the outer inclined section 90.sup.IV continuing in the third outer longitudinal section 90.sup.V. The fourth outer longitudinal section 90.sup.VI is parallel with the first, second and third outer longitudinal sections. Adjacent this fourth outer longitudinal section is a first lock member 92 which is a generally radially flexing tongue having a free end pointing in the proximal direction. The shape of the tongue 92 as seen in a side view of FIG. 7 is generally a wedge.

(24) The inner surface of the rotator 82 is arranged with a number of inner guiding members 100 which may be two sets of ledge sections, FIG. 8. Each inner guiding member 100 comprises a first inner longitudinal section 100.sup.I, a first inner transversal and circumferential section 100.sup.II, an inner inclined section 100.sup.III, second inner longitudinal section 100.sup.IV, a second inner transversal and circumferential section 100.sup.V, third inner longitudinal section 100.sup.VI, and a third inner transversal and circumferential section 100.sup.VII. The first inner longitudinal section 100.sup.I is connected to the first inner transversal and circumferential section 100.sup.II. This section is in turn connected to the inner inclined section 100.sup.III which is inclined with respect to the longitudinal direction. The inner inclined section 100.sup.III is connected to the second inner longitudinal section 100.sup.IV, which in turn is connected to the second inner transversal and circumferential section 100.sup.V. This section is in turn connected to the third inner longitudinal section 100.sup.VI, which terminates with the third inner transversal and circumferential section 100.sup.VII. A long inner longitudinal section 100.sup.VIII, extending in the proximal direction is connected to the third inner transversal and circumferential section 100.sup.VII. The two ledge sections are placed diametrically opposed on the inner surface of the rotator.

(25) A generally elongated tubular plunger rod 102 comprised in a drive mechanism, FIG. 9, is coaxially arranged through the rotator 82. The plunger rod 102 is initially positioned such that a proximal end thereof is in contact with the stopper 88 of the medicament container 84. The plunger rod 102 comprises a number of first contact members 104 which may be two generally radially outwardly extending protrusions. These first contact members 104 are intended to interact with the inner guiding members 100 on the inner surface of the rotator 82. The plunger rod 102 is further arranged with two longitudinally extending grooves 106. These grooves 106 are intended to interact with the protrusions 76 of the central passage 74 of the second section 66 of the medicament container holder 56, such that a rotational lock is obtained between the two while allowing relative longitudinal movement. The plunger rod is a hollow rod and inside the plunger rod 102 a force member 108 is positioned, also comprised in the drive mechanism, FIGS. 2 and 3. The force member 108 is in the embodiment shown as a compression spiral spring having a proximal end in contact with an end wall 110 at the proximal end of the plunger rod. A distal end of the force member 108 is in contact with a wall section 112 of the second housing part 114, FIG. 4. The force member 108 is pre-tensioned and has a predetermined load force configured to act on the plunger rod. Thus, the first contact members 104 of the plunger rod 102 are configured to interact with the inner guiding members 100 of the rotator 82 for holding the plunger rod in an initial state, an intermediate state and in a final state depending on the rotational position of the rotator 82.

(26) In the shown embodiment, the second housing part 114 is intended to be connected to the distal end of the first housing part and is arranged with two proximally directed arms 116, where each arm is arranged with a generally radially flexible tongue 118, having a free end in the distal direction. The tongues 118 are arranged with outwardly directed ledges, which ledges are intended to fit into cut-outs 120 on a distal area of the first housing part 10, for locking the two housing parts together. The end wall 112 of the second housing part 114 is arranged with a proximally directed spring guide rod 122, intended to guide and support the force member 108. The end wall 112 of the second housing part 114 is further arranged with a number of passages 124, in the embodiment shown two passages arranged diametrically. The outer surface of the second housing part is further arranged with two diametrically opposed recesses 126.

(27) In the shown embodiment, the safety member 128 is releasibly attached to the second housing part. It comprises an end wall 130. On the end wall 130, two proximally directed grip panels 132 are arranged, which grip panels 132 are intended to fit into the recesses 126 of the second housing part 114. The safety member 128 further comprises second contact members 134, which are two arms attached to the end wall 130, also being directed in the proximal direction. These second contact members 134 are intended to fit into the passages 124 of the second housing part 114 and in the cut-outs 96 of first outer guiding members 94 of the rotator 82. The second contact members 134 are arranged with side edges 136 having a curved shape as seen in FIG. 4, providing a side-directed protrusion. The function of the shape of the second contact members will be explained below.

(28) The device is intended to function as follows. When delivered to the user, the device is preferably assembled and ready to use. This means that the delivery member 40, here an injection needle is fitted into the holder 32 of the first housing part 10 and a medicament container 84 has been placed in the medicament container holder 56. In the initial position, the medicament container holder 56 with its container is placed such that there is a distance between the distal pointed end 44 of the injection needle 40 and the neck portion of the medicament container, FIG. 3.

(29) Further, the safety member 128 is attached to the second housing part 114. The contactor 12 is in the extended position urged by the contactor force member 31. Also, the contactor 12 is locked from being moved from the extended to the retracted position in relation to the first housing part due to the interaction between the third contact members 30 of the contactor 12 and the first outer transversal and circumferential section 90.sup.II of the second outer guiding members 90 on the outer surface of the rotator 82, as seen in FIG. 10, wherein the first outer transversal and circumferential section 90.sup.II will function as a blocking member. The plunger rod 102 is held in the initial state due to the interaction between each of the first contact members 104 of the plunger rod 102 and each of the first inner transversal and circumferential sections 100.sup.II of the inner guiding members 100 on the inner surface of the rotator 82 as seen in FIG. 8, pos. I. until the rotator 82 is turned when the safety member 128 is removed.

(30) When the device is to be used, the safety member 128 is removed from the device by a user gripping the grip panels 132 and longitudinally pulling the safety member 128 in the distal direction. Thereby the second contact members 134 are also longitudinally moved in the distal direction and the curved side surfaces 136 which are in contact with an end surface of the first outer guiding members 94 as seen in FIG. 10, forces the rotator 82 to rotate a certain rotational angle. At the same time, the rotation of the rotator 82 when removing the safety member 128 causes the first contact members 104 of the plunger rod 102 to be released or to be moved from the initial state where they leave the contact with the first inner transversal and circumferential section 100.sup.II of the inner guiding member 100 on the inner surface of the rotator 82 and come in contact with the inner inclined section 100.sup.III as seen in FIG. 8, pos. II. The plunger rod 102 is then forced to move proximally by the force member 108, and the contact with the inner inclined surface 100.sup.III will cause the rotator 82 to rotate a further angle such that the radial inwardly extending protrusions or ledges of the loops 78 are released from the radial outwardly extending protrusions 80 on the outer surface of the rotator 82.

(31) During the movement of the plunger rod 102 from the initial state to the intermediate state, the plunger rod act with a force on the stopper 88 of the medicament container 84 such that the medicament container 84 and the medicament container holder 56 move as a unit in the proximal direction. In the embodiment shown, this movement now causes the distal pointed end 44 of the injection needle 40 to first penetrate the protective sheath 48 and then a septum at the neck portion of the medicament container 84, while compressing the protective sheath 48 surrounding the distal end of the needle, FIG. 11.

(32) When the septum is penetrated by the distal end 44 of the needle, a passage from the container is opened by the injection needle 40 and the pressure is released, causing a priming of the medicament container 84. Air, and possibly a small amount of medicament, will then be expelled into the interior of the protective sheath 46 surrounding the proximal end of the injection needle 40.

(33) The movement of the plunger rod 102 is stopped when the first contact members 104 hit the second inner transversal and circumferential section 100, FIG. 8, pos. III. The plunger rod 102 has moved from the initial state to the intermediate state. The plunger rod 102 is held in the intermediate state due to the interaction between each of the first contact members 104 of the plunger rod 102 and each of the second inner transversal and circumferential sections 100.sup.V of the inner guiding members 100 on the inner surface of the rotator 82.

(34) Further, the rotation of the rotator 82 causes the first outer guiding members 94 to move to a position in front of the passages 124 of the second housing part. Any attempts to reintroduce the second contact members 134 of the safety member 128 into the passages 124 of the second housing part 114 are thereby prevented. Thus, the first outer guiding members 94 on the rotator prevent re-connection of the safety member 128 after removal of the safety member and turning of the rotator.

(35) Also, the above described rotation of the rotator 82 has now moved the first outer transversal and circumferential sections 90.sup.II out of contact with the third contact members 30 of the contactor 12, as seen in FIG. 7, pos. II, whereby the latter is free to move in the distal direction from the extended position to the retracted position.

(36) The next step is then to perform a manual penetration or semi-penetration such that the contactor moves in relation to the delivery member to expose the proximal pointed end 42 of the injection needle. The transversal end wall 16 of the contactor is positioned on a delivery site i.e. an injection site and the contactor 12 is thereby pressed against the delivery site, whereby the contactor 12 will be moved, relative to the housing, in the distal direction from the extended position to the retracted position whereby the contactor force member 31 is compressed. In the embodiment shown, the proximal end of the injection needle will then penetrate the proximal protective sheath 46 and pass through the passage 26 on the transversal end wall 16 of the contactor and into the tissue of a user, FIG. 12. When the contactor is moved from the extended position to the retracted position, each of the third contact members 30 of the contactor 12 will first pass along each of the second outer longitudinal sections 90.sup.III and then come in contact with each of the outer inclined sections 90.sup.IV, FIG. 7, pos. III.

(37) The interaction between the third contact members 30 of the contactor 12 and the outer inclined sections 90.sup.IV forces the rotator 82 to be further turned/rotated a certain angle. This further rotation allows the plunger rod to move from the intermediate state in which the plunger rod is held due to the interaction between each of the first contact members 104 of the plunger rod 102 and each of the second inner transversal and circumferential sections 100.sup.V of the inner guiding members 100 on the inner surface of the rotator 82, to a final state in which the plunger rod is prevented from moving further due to the interaction between each of the first contact members 104 of the plunger rod 102 and each of third inner transversal and circumferential section 100.sup.VII of the inner guiding members 100 on the inner surface of the rotator 82. This movement causes the stopper 88 of the medicament container 84 to be moved in the proximal direction, from pos. IV to pos. V, whereby a dose of medicament is expelled through the delivery member 40 at the delivery site. As described above, the delivery is stopped when the first contact members 104 of the plunger rod 102 are moved in contact with the third inner transversal and circumferential section 100 v.sup.VII, FIG. 8, pos. V.

(38) The device may then be removed from the delivery site whereby the contactor force member 31 will urge the contactor 12 in the proximal direction, relative to the housing, from the retracted position to the extended position. At the same time, the third contact members 30 of the contactor will move axially along the rotator, FIG. 7, until they pass the first lock members 92 of the rotator, pos. V, FIG. 7. The lock members 92 will flex radially inwards as the third contact members pass from pos. IV to pos. V. Afterwards they will flex back and their wedge shape prevents the contactor 12 from being moved again in the distal direction from the extended to the retracted position.

(39) Thus, the delivery member 40, i.e. an injection needle, is hidden and protected inside the contactor, preventing any accidental needle sticks. The device may now be discarded.

(40) It is to be understood that the embodiment described above and shown in the drawings is to be regarded only as a non-limiting example of the invention and that it may be modified in many ways within the scope of the patent claims.