US 11,872,381 B2
Drive train for dial of a torsion-spring assisted wind-up injection device
Michael Jugl, Frankfurt am Main (DE); Stefan Blancke, Frankfurt am Main (DE); Axel Teucher, Frankfurt am Main (DE); Ralph Donald Quentin Collings, Bristol Bristol (GB); James Robert Coop, Bristol Bristol (GB); James Anthony West, Bristol Bristol (GB); Stephen Francis Gilmore, Bristol Bristol (GB); Daniel David Higgins, Bristol Bristol (GB); Mark Digby Teucher, Bristol Bristol (GB); Anthony Paul Morris, Warwick (GB); Matthew Meredith Jones, Warwick (GB); William Geoffrey Arthur Marsh, Warwick (GB); and Samuel Keir Steel, Warwick (GB)
Assigned to Sanofi, Paris (FR)
Appl. No. 16/479,790
Filed by SANOFI, Paris (FR)
PCT Filed Jan. 22, 2018, PCT No. PCT/EP2018/051374
§ 371(c)(1), (2) Date Jul. 22, 2019,
PCT Pub. No. WO2018/134385, PCT Pub. Date Jul. 26, 2018.
Claims priority of application No. 17305065 (EP), filed on Jan. 23, 2017; and application No. 17306212 (EP), filed on Sep. 19, 2017.
Prior Publication US 2020/0345945 A1, Nov. 5, 2020
Int. Cl. A61M 5/315 (2006.01); A61M 5/31 (2006.01)
CPC A61M 5/31585 (2013.01) [A61M 5/31526 (2013.01); A61M 5/31553 (2013.01); A61M 2005/3143 (2013.01); A61M 2205/0216 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A drive train for a wind-up injection device for injecting a liquid drug, the drive train comprising:
a torsional energy storage adapted to be loaded or unloaded by a rotatable element;
a rotatable user handle;
a rotationally driveable expelling mechanism adapted to expel the liquid drug;
a clutch element coupled with the torsional energy storage via the rotatable element and comprising a ratchet for maintaining the rotatable element at one of a number of discrete angular positions against a torque of the torsional energy storage,
wherein the clutch element is adapted to transmit a torque from the user handle via the rotatable element to the torsional energy storage or alternatively from the torsional energy storage via the rotatable element to the expelling mechanism,
wherein the ratchet is switchable from one position to an adjacent position by the torque transmitted from the user handle to the torsional energy storage; and
a dampening element adapted to dampen torque peaks, and comprising a visco-elastic dampening element adapted to elastically transmit a torque, and/or a visco-frictional dampening element adapted to frictionally resist a rotation; and
wherein the dampening element comprises the visco-elastic dampening element, and the visco-elastic dampening element is arranged in a radial direction between the user handle and the ratchet, wherein the user handle surrounds the visco-elastic dampening element and the ratchet, or
wherein the torsional energy storage comprises a housing, wherein the dampening element comprises the visco-frictional dampening element, and the visco-frictional dampening element is formed as a bushing that is torque proof coupled with the user handle and that is longitudinally coupled with the user handle and with the housing and that at least partially visco-frictionally directly engages an outer surface of the housing, wherein the bushing is formed as a radially inwardly protruding collar for the user handle in the direction of the housing, the collar being received in an annular recess along an outer circumference of the housing.