# US 10,478,562 B2 · Drive mechanism of a drug delivery device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,478,562 B2 - Document ID: US10478562B2 - Status: Granted - Kind: B2 - Application number: 14/782,622 - Filed: 2014-04-08 - Published: 2016-02-18 - Granted: 2019-11-19 - Earliest claimed: 2013-04-10 - Assignees: Sanofi - Applicants: Sanofi - Inventors: Stefan Bayer; Daniel Berning; Philippe Blank; Wolfgang Pelzer; Björn Wilden - Web page: https://patentgrep.com/patent/US10478562B2 ## CPC - A61M 5/315: Pistons; Piston-rods; Guiding, blocking or restricting the movement of the rod {or piston}; Appliances on the rod for facilitating dosing {; Dosing mechanisms} - A61M 5/20: Automatic syringes, e.g. with automatically actuated piston rod, with automatic needle injection, filling automatically (A61M5/142 takes precedence) - A61M 5/31511: {Piston or piston-rod constructions, e.g. connection of piston with piston-rod (A61M5/5066 takes precedence)} - A61M 5/31533: {Dosing mechanisms, i.e. setting a dose (administrating mechanisms A61M5/31565)} - A61M 5/31541: {Means preventing setting of a dose beyond the amount remaining in the cartridge} - A61M 5/31553: {without axial movement of dose setting member} - A61M 5/31583: {the piston rod being moved by the rotational movement of a component directly in contact with it} - A61M 5/24: Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or cartridges, e.g. automatic - A61M 5/31593: {Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir} - A61M 2005/3126: {related to dosing} - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} ## Abstract A drive mechanism of a drug delivery device for setting and dispensing of a dose of a medicament includes a housing, a piston rod, a dose indicating member with a dose size information thereon, and a drive wheel. The piston rod engages with a piston of a cartridge for displacing the piston in a distal direction. The dose indicating member is connected to a spring element and is rotatable in a dose incrementing direction against the action of the spring element for setting a dose. The drive wheel is operably engaged with the piston rod for displacing the piston rod in the distal direction for dose dispensing. The dose indicating member is engageable with the drive wheel during dose dispensing to transfer a force to the drive wheel when driven by the relaxing spring element in a dose decrementing direction. ## Claims ### Claim 1 A drive mechanism of a drug delivery device for setting and dispensing of a dose of a medicament, the drive mechanism comprising: a housing; a piston rod to operably engage with a piston of a cartridge for displacing the piston in a distal direction; a dose indicating member with dose size indicating numbers or symbols thereon, wherein the dose indicating member is connected to a spring element and is rotatable in a dose incrementing direction against an action of the spring element for setting of the dose, and wherein the dose indicating member is rotatable in a dose decrementing direction under an action of the spring element for dispensing of the dose, the dose decrementing direction being opposite to the dose incrementing direction; and a drive wheel operably engaged with the piston rod for displacing the piston rod in the distal direction for dose dispensing, wherein the dose indicating member is engageable with the drive wheel during dose dispensing to transfer a driving force to the drive wheel when driven by the relaxing spring element in a dose decrementing direction. ### Claim 2 (depends on 1) The drive mechanism according to claim 1, wherein the dose indicating member comprises a flat-shaped dose indicating disc. ### Claim 3 (depends on 1) The drive mechanism according to claim 1, wherein the spring element comprises a spiral spring having a first end section connected to the housing and having a second end section connected to the dose indicating member. ### Claim 4 (depends on 1) The drive mechanism according to claim 1, further comprising a ring-shaped dose setting member rotatably supported by the housing and being selectively engageable with the dose indicating member for setting of the dose. ### Claim 5 (depends on 4) The drive mechanism according to claim 4, wherein the ring-shaped dose setting member comprises a circumferential side wall portion extending into the housing. ### Claim 6 (depends on 5) The drive mechanism according to claim 5, wherein a last dose limiting member radially sandwiched between the side wall portion and the housing is threadedly engaged with the side wall portion and rotatably locked to the housing. ### Claim 7 (depends on 1) The drive mechanism according to claim 1, further comprising a dose dispensing member rotatably fixed to the housing and being depressible in an axial direction against an action of a dispensing spring element. ### Claim 8 (depends on 7) The drive mechanism according to claim 7, wherein the dose indicating member axially abuts with the dose dispensing member. ### Claim 9 (depends on 7) The drive mechanism according to claim 7, wherein the dose dispensing member comprises a through opening serving as a dose indicating window through which a portion of the dose size indicating numbers of symbols of the dose indicating member is visibly displayed. ### Claim 10 (depends on 7) The drive mechanism according to claim 7, wherein a dose dispensing member is radially enclosed by a dose setting member. ### Claim 11 (depends on 1) The drive mechanism according to claim 1, wherein the dose indicating member comprises a spiraled groove to engage with a single dose limiting member. ### Claim 12 (depends on 11) The drive mechanism according to claim 11, wherein the single dose limiting member is radially displaceable relative to a dose dispensing member along the spiraled groove and is rotatably fixed to the dose dispensing member. ### Claim 13 (depends on 12) The drive mechanism according to claim 12, wherein the dose dispensing member comprises a radially outwardly extending appendix engaged with a notch of the single dose limiting member. ### Claim 14 (depends on 1) The drive mechanism according to claim 1, wherein the dose indicating member comprises a centrally located toothed through opening engaged with at least one resilient ratchet element in a dose setting configuration. ### Claim 15 A drug delivery device for setting and dispensing of a dose of a medicament, the drug delivery device comprises: a drive mechanism comprising: a housing; a piston rod to operably engage with a piston of a cartridge for displacing the piston in a distal direction; a dose indicating member with dose size indicating numbers or symbols thereon, wherein the dose indicating member is connected to a spring element and is rotatable in a dose incrementing direction against an action of the spring element for setting of the dose, and wherein the dose indicating member is rotatable in a dose decrementing direction under an action of the spring element for dispensing of the dose, the dose decrementing direction being opposite to the dose incrementing direction; and a drive wheel operably engaged with the piston rod for displacing the piston rod in the distal direction for dose dispensing, wherein the dose indicating member is engageable with the drive wheel during dose dispensing to transfer a driving force to the drive wheel when the dose indicating member is driven by the relaxing spring element in the dose decrementing direction; and the cartridge containing the medicament and being arranged in the housing of the drive mechanism. ### Claim 16 (depends on 15) The drug delivery device according to claim 15, wherein the dose indicating member comprises a flat shaped dose indicating disc. ### Claim 17 (depends on 15) The drug delivery device according to claim 15, wherein the spring element comprises a spiral spring having a first end section connected to the housing and having a second end section connected to the dose indicating member. ### Claim 18 (depends on 15) The drug delivery device according to claim 15, further comprising a ring-shaped dose setting member rotatably supported by the housing and being selectively engageable with the dose indicating member for setting of the dose. ### Claim 19 (depends on 18) The drug delivery device according to claim 18, wherein the ring-shaped dose setting member comprises a circumferential side wall portion extending into the housing. ### Claim 20 (depends on 19) The drug delivery device according to claim 19, wherein a last dose limiting member radially sandwiched between the side wall portion and the housing is threadedly engaged with the side wall portion and rotatably locked to the housing.