US 12,109,398 B2
Torsion spring driven injection device
Claus Urup Gjoedesen, Holte (DK); Niels Christian Egholm Soerensen, Hilleroed (DK); and Kim Roennow Sejtzer, Fredensborg (DK)
Assigned to Novo Nordisk A/S, Bagsvaerd (DK)
Appl. No. 17/286,845
Filed by Novo Nordisk A/S, Bagsvaerd (DK)
PCT Filed Oct. 28, 2019, PCT No. PCT/EP2019/079394
§ 371(c)(1), (2) Date Apr. 20, 2021,
PCT Pub. No. WO2020/089167, PCT Pub. Date May 7, 2020.
Claims priority of application No. 18203370 (EP), filed on Oct. 30, 2018.
Prior Publication US 2021/0386933 A1, Dec. 16, 2021
Int. Cl. A61M 5/20 (2006.01); A61M 5/315 (2006.01); A61M 5/31 (2006.01)
CPC A61M 5/2033 (2013.01) [A61M 5/31526 (2013.01); A61M 5/31543 (2013.01); A61M 5/3157 (2013.01); A61M 5/31585 (2013.01); A61M 5/31591 (2013.01); A61M 2005/2073 (2013.01); A61M 2005/3126 (2013.01)] 17 Claims
OG exemplary drawing
 
1. A torsion spring driven injection device for ejecting at least one dose of a liquid drug comprising:
a housing structure securing a container containing the liquid drug to be ejected,
a rotational dose setting element operable by a user for setting the size of a set dose to be ejected,
a rotatable dose setting structure transferring rotation from the dose setting element to a straining of a torsion spring such that a torque is stored in the torsion spring upon rotation of the dose setting element,
a rotatable display element arranged to follow rotation of the dose setting structure and helically movable relatively to the housing structure from an initial position to a dosing position, wherein the set dose is indicated by indicia carried by the rotatable display element,
a piston rod arranged in a longitudinal direction (X) and movable in a distal direction to expel the set dose from the container,
a rotatable drive element engaging the piston rod and adapted to move the piston rod in the distal direction upon rotation of the rotatable drive element,
an axially movable release element for releasing the torque stored in the torsion spring to rotate the rotatable drive element,
wherein,
the injection device further comprises a blocking structure which is operable between a first position and a second position, and wherein
the blocking structure in the first position prevents axial movement of the release element and in the second position allows axial movement of the release element,
and which blocking structure is operational by the rotatable display element,
such that whenever the rotatable display element is rotated to a specific axial position and/or rotational position it activates the blocking structure such that the release element becomes axially movable to thereby release the set dose.