Medicament delivery device
The invention relates to a medicament delivery device comprising a locking mechanism ( 5 ) for locking a plunger rod ( 4 ). The locking mechanism ( 5 ) comprises a locking wheel ( 6 ) and locking means ( 7 ), said locking means ( 7 ) being moveable between an active position where the locking means ( 7 ) prevent the locking wheel ( 6 ) from rotation and an inactive position where the locking means ( 7 ) allow the locking wheel ( 6 ) to rotate, wherein said plunger rod ( 4 ) extends through an opening in the locking wheel ( 6 ); and a resilient member ( 8 ) arranged at the moveable locking means ( 7 ) and being arranged to act on the moveable locking means ( 7 ) to displace said movable looking means ( 7 ) towards the inactive position where the locking means ( 7 ) allow the locking wheel ( 6 ) to rotate.
1. A medicament delivery device, comprising:
a container housing arranged to receive and hold a medicament container having a plunger; and
a rear housing releasably connected to the container housing and comprising:
a plunger rod arranged to act on the plunger when the medicament container is received in the container housing;
a drive mechanism arranged to drive the plunger rod; and
a locking mechanism for locking the plunger rod, comprising:
a locking wheel;
a locking device movable between an active position, in which the locking device prevents rotation of the locking wheel, and an inactive position, in which the locking device allows rotation of the locking wheel, wherein the plunger rod extends through an opening in the locking wheel, and the plunger rod and the opening in the locking wheel are arranged to mate with each other such that axial movement of the plunger rod relative to the locking wheel is allowed while rotation of the plunger rod relative to the locking wheel is prevented; and
a resilient member arranged at the movable locking device and to act on the movable locking device to displace the movable locking device toward the inactive position;
wherein the locking device comprises at least one flexible arm having a cogged segment which in the active position engages with a cogged surface of the locking wheel.
2. The medicament delivery device of claim 1 , wherein the locking mechanism further comprises a hollow casing arranged at the rear housing, and the at least one flexible arm is formed in at least one recess provided in an outer wall of the casing, the locking wheel is arranged within the hollow casing such that the cogged segment of the at least one flexible arm and the locking wheel interact when the locking device is in the active position.
3. The medicament delivery device of claim 1 , wherein the container housing, when connected to the rear housing, engages with the locking device and forces the locking device into the active position.
4. The medicament delivery device of claim 1 , wherein the container housing is releasably mounted in a locking ring releasably connected to the rear housing; and the locking ring, when connected to the rear housing, engages with the locking device and forces the locking device into the active position.
5. The medicament delivery device of claim 1 , wherein the locking device comprises protrusions extending outwardly.
6. The medicament delivery device of claim 2 , wherein the resilient member comprises a sheet metal spring mounted along an inner surface of the casing.
7. The medicament delivery device of claim 1 , wherein the flexible arms extend in a direction perpendicular to a longitudinal direction of the plunger rod.
8. The medicament delivery device of claim 1 , wherein the flexible arms extend in a direction parallel to a longitudinal direction of the plunger rod.
9. The medicament delivery device of claim 1 , wherein the medicament delivery device is a reusable injector.
10. The medicament delivery device of claim 1 , wherein the medicament delivery device is a reusable inhaler.
11. A medicament delivery device, comprising:
a container housing arranged to receive and hold a medicament container having a plunger; and
a rear housing releasably connected to the container housing and comprising:
a plunger rod arranged to act on the plunger when the medicament container is received in the container housing;
a drive mechanism arranged to drive the plunger rod; and
a locking mechanism for locking the plunger rod, comprising:
a locking wheel;
a locking device movable between an active position, in which the locking device prevents rotation of the locking wheel, and an inactive position, in which the locking device allows rotation of the locking wheel, wherein the plunger rod extends through an opening in the locking wheel, and the plunger rod and the opening in the locking wheel are arranged to mate with each other such that axial movement of the plunger rod relative to the locking wheel is allowed while rotation of the plunger rod relative to the locking wheel is prevented; and
a resilient member arranged at the movable locking device and to act on the movable locking device to displace the movable locking device toward the inactive position, wherein the resilient member comprises a wire spring.
12. The medicament delivery device of claim 11 , wherein the locking device comprises two flexible arms, each having a cogged segment which in the active position engages with a cogged surface of the locking wheel; and the wire spring has two opposed ends, each arranged at a different flexible arm.
13. The medicament delivery device of claim 12 , wherein the locking mechanism further comprises a hollow casing arranged at the rear housing; the flexible arms are formed in recesses provided in an outer wall of the casing; the locking wheel is arranged within the hollow casing such that cogged segments of the flexible arms and the locking wheel interact when the locking device is in the active position; the hollow casing has a cylindrical cross-section; the flexible arms are arranged diametrically opposite each other; and the wire spring is arranged to follow a contour of an outer wall of the hollow casing.
14. A medicament delivery device, comprising:
a container housing arranged to receive and hold a medicament container having a plunger; and
a rear housing releasably connected to the container housing and comprising:
a plunger rod arranged to act on the plunger when the medicament container is received in the container housing;
a drive mechanism arranged to drive the plunger rod; and
a locking mechanism for locking the plunger rod, comprising:
a locking wheel;
a locking device movable between an active position, in which the locking device prevents rotation of the locking wheel, and an inactive position, in which the locking device allows rotation of the locking wheel, wherein the plunger rod extends through an opening in the locking wheel, and the plunger rod and the opening in the locking wheel are arranged to mate with each other such that axial movement of the plunger rod relative to the locking wheel is allowed while rotation of the plunger rod relative to the locking wheel is prevented; and
a resilient member arranged at the movable locking device and to act on the movable locking device to displace the movable locking device toward the inactive position, wherein the resilient member comprises a sheet metal spring.