US 12,226,618 B2
Drive train for dial of a torsion-spring assisted wind-up injection device
Michael Jugl, Frankfurt am Main (DE); Matthew Meredith Jones, Warwick (GB); Axel Teucher, Frankfurt am Main (DE); Stefan Blancke, Frankfurt am Main (DE); Ralph Donald Quentin Collings, Bristol (GB); James Robert Coop, Bristol (GB); James Anthony West, Bristol (GB); Stephen Francis Gilmore, Bristol (GB); Daniel David Higgins, Bristol (GB); and Mark Digby Teucher, Bristol (GB)
Assigned to SANOFI, Paris (FR)
Appl. No. 16/979,629
Filed by SANOFI, Paris (FR)
PCT Filed Mar. 11, 2019, PCT No. PCT/EP2019/055948
§ 371(c)(1), (2) Date Sep. 10, 2020,
PCT Pub. No. WO2019/175072, PCT Pub. Date Sep. 19, 2019.
Claims priority of application No. 18305261 (EP), filed on Mar. 13, 2018.
Prior Publication US 2021/0038824 A1, Feb. 11, 2021
Int. Cl. A61M 5/31 (2006.01); A61M 5/20 (2006.01); A61M 5/315 (2006.01)
CPC A61M 5/31551 (2013.01) [A61M 5/2033 (2013.01); A61M 5/31536 (2013.01); A61M 5/31541 (2013.01); A61M 5/31586 (2013.01); A61M 2205/42 (2013.01); A61M 2205/581 (2013.01); A61M 2205/582 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A drive train for a wind-up injection device for injecting a liquid drug, comprising:
a rotatable element,
a torsional spring adapted to be loaded or unloaded by the rotatable element,
a rotatable user handle coupled with a button,
a rotationally drivable expelling mechanism adapted to expel the liquid drug, and
a clutch element configured to couple to the rotatable element and comprising a ratchet for maintaining the rotatable element at one of a number of discrete angular positions against the torque of the torsional spring,
wherein the clutch element is adapted to transmit a torque from the user handle via the rotatable element to the torsional spring or from the torsional spring via the rotatable element to the expelling mechanism, and
wherein the ratchet is switchable from one position to an adjacent position by a torque transmitted from the user handle to the torsional spring, and
wherein the drive train is adapted to dampen torque peaks by a flexible impact portion associated with the clutch element, thereby allowing softening of a possible impact between the clutch element and the expelling mechanism.