Medicament delivery device and method of assembling the same

1. A device for injecting a medicament, comprising:

a housing having a distal end opening and a proximal end opening;

a needle guard extending from the proximal end opening and movable relative to the housing from an extended position to a retracted position, in which the needle guard is biased toward the extended position;

an activation member extending from the distal end opening and movable relative to the housing from an initial position to a final position;

a final position lock disposed on an inner surface of the housing and configured to restrict movement of the activation member relative to the housing when the activation member is in the final position; and

a needle guard lock configured to interact with the needle guard such that movement of the needle guard from the extended position to the retracted position is restricted when the activation member is in the final position.

2. The device of claim 1 , wherein the housing and the activation member have interacting locks that allow movement of the activation member in a direction from the initial position to the final position and restrict movement of the activation member in an opposite direction.

3. The device of claim 1 , wherein the activation member is a manual plunger rod.

4. A method of assembling the device for injecting a medicament according to claim 1 , comprising:

arranging the needle guard and a biasing member in the housing;

arranging a medicament cartridge in the housing; and

arranging, via the distal end opening of the housing, the activation member in the housing.

5. The method of claim 4 , further comprising arranging a container holder in the housing, wherein the medicament cartridge is arranged in the container holder.

6. The method of claim 4 , wherein the needle guard is arranged in the housing from the distal end opening of the housing or the proximal end opening of the housing.

7. The device of claim 1 , wherein the activation member has a cutout, and the final position lock engages the cutout when the activation member is in the final position.

8. The device of claim 7 , wherein the final position lock is a snap member.

9. The device of claim 1 , wherein the activation member has a blocking member configured to prevent movement of the needle guard from the extended position to the retracted position when the activation member is in the final position.

10. The device of claim 9 , wherein the needle guard has an activation member interaction leg that is aligned with and faces the blocking member when the activation member is in the final position and the needle guard is in the extended position.

11. The device of claim 1 , further comprising an initial position lock configured to interact with the needle guard and with the activation member such that movement of the activation member from the initial position to the final position is restricted when the needle guard is in the extended position.

12. The device of claim 11 , further comprising a container holder, wherein the initial position lock comprises a tab on the container holder, the activation member has a cutout, and the tab is configured to engage the cutout in the initial position.

13. The device of claim 12 , wherein the tab on the container holder is a resilient snap movable toward the container holder.

14. A device for injecting a medicament, comprising:

a housing having a distal end opening and a proximal end opening;

a needle guard extending from the proximal end opening and movable relative to the housing from an extended position to a retracted position, in which the needle guard is biased toward the extended position;

an activation member extending from the distal end opening and movable relative to the housing from an initial position to a final position;

a final position lock configured to restrict movement of the activation member relative to the housing when the activation member is in the final position; and

a needle guard lock configured to interact with the needle guard such that movement of the needle guard from the extended position to the retracted position is restricted when the activation member is in the final position;

wherein the activation member has a blocking member configured to prevent movement of the needle guard from the extended position to the retracted position when the activation member is in the final position; the needle guard has an activation member interaction leg that is aligned with and faces the blocking member when the activation member is in the final position and the needle guard is in the extended position; and the housing has an inner surface provided with a tab that is configured to push the blocking member away from the inner surface when the activation member is in the final position to align the blocking member with the activation member interaction leg when the needle guard is in the extended position.

15. A device for injecting a medicament, comprising:

a housing having a distal end opening and a proximal end opening;

a needle guard extending from the proximal end opening and movable relative to the housing from an extended position to a retracted position, in which the needle guard is biased toward the extended position;

an activation member extending from the distal end opening and movable relative to the housing from an initial position to a final position;

a final position lock configured to restrict movement of the activation member relative to the housing when the activation member is in the final position;

a needle guard lock configured to interact with the needle guard such that movement of the needle guard from the extended position to the retracted position is restricted when the activation member is in the final position;

an initial position lock configured to interact with the needle guard and with the activation member such that movement of the activation member from the initial position to the final position is restricted when the needle guard is in the extended position; and

a container holder;

wherein the initial position lock comprises a tab on the container holder, the activation member has a cutout, the tab is configured to engage the cutout in the initial position, and the needle guard has a container holder tab interaction leg configured to push the tab out from the cutout when the needle guard is in the retracted position.