# US 8,783,525 B2 · Drive mechanism for 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 8,783,525 B2 - Document ID: US8783525B2 - Status: Granted - Kind: B2 - Application number: 13/290,895 - Filed: 2011-11-07 - Published: 2012-06-14 - Granted: 2014-07-22 - Earliest claimed: 2010-11-19 - Assignees: Sanofi-Aventis Deutschland GmbH - Applicants: Faiza Mariami - Inventors: Faiza Mariami - Web page: https://patentgrep.com/patent/US8783525B2 ## CPC - A61M 5/31586: {the component being manually operated or triggered by a rotating or pivoting actuator operated by user, e.g. an injection lever or handle} - A61M 5/31571: {Means preventing accidental administration (for automatic syringes A61M5/20)} - 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 The present invention relates to a drive mechanism of a drug delivery device for dispensing of a dose of a medicament, comprising: a housing of substantially cylindrical geometry having a long axis extending in an axial direction, an at least axially displaceable piston rod adapted to become operably engaged with a piston of a cartridge containing the medicament for displacing the piston in a distal direction, at least one actuation means radially displaceable with respect to the housing by an externally applied depressing force for transferring a respective driving force to the piston rod, and a coupling means operably engaged with the actuation means and with the piston rod adapted to transfer the radially inwardly directed displacement of the at least one actuation means into a distally directed axial displacement of the piston rod. ## Claims ### Claim 1 A drive mechanism of a drug delivery device for dispensing of a dose of a medicament, comprising: a housing of substantially cylindrical geometry having a long axis extending in an axial direction, the housing having a distal portion and a proximal portion, a nut axially and rotationally fixed to an inner surface of the distal portion of the housing; an at least axially displaceable piston rod adapted to become operably engaged with a piston of a cartridge containing the medicament for displacing the piston in a distal direction, where the piston rod and the nut are configured such that the piston rod moves axially in the distal direction relative to the nut during dose delivery, two diametrically opposed dose buttons protruding from a lateral side wall of the housing at a location defining a transition between the distal and proximal housing portions when the buttons are in an activation position, where at least one dose button is radially displaceable with respect to the housing by an externally applied depressing force for transferring a respective driving force to the piston rod, an activation button is located at a proximal end of the proximal housing portion and is axially displaceable relative to both the housing and the two dose buttons, where the activation button is configured to cause the two dose buttons to move radially from an end position to the activation position when the activation button is moved distally, and a coupling located adjacent the nut operably engaged with the dose buttons and with the piston rod, where the coupling is configured to transfer the radially inwardly directed displacement of the at least one dose button into a distally directed axial displacement of the piston rod, characterized in that the coupling comprises a drive member threadedly engaged with the piston rod or with a drive sleeve. ### Claim 2 (depends on 1) The drive mechanism according to claim 1, wherein the at least one dose button comprises a toothed section engaged with an outer gearing of the drive member or of the piston rod. ### Claim 3 (depends on 1) The drive mechanism according to claim 1, wherein the drive sleeve and/or drive member is axially fixed and rotatably mounted in the housing. ### Claim 4 (depends on 1) The drive mechanism according to claim 1, wherein the drive sleeve is threadedly engaged with the piston rod being rotatably fixed and axially displaceable with respect to the nut. ### Claim 5 (depends on 1) The drive mechanism according to claim 1, wherein the dose buttons and the drive sleeve are unidirectionally coupled with respect to each other in such a way that only a radially inwardly directed displacement of the at least one of the dose buttons has a rotational effect on the drive sleeve. ### Claim 6 (depends on 1) The drive mechanism according to claim 1, wherein the at least one dose button is spring biased radially outwardly. ### Claim 7 (depends on 1) The drive mechanism according to claim 1, wherein the dose buttons comprise a radially inwardly facing, toothed protrusion meshing with diametrically opposite geared sections of the drive member. ### Claim 8 (depends on 1) The drive mechanism according to claim 1, wherein the at least one dose button is locked in position in a radial inward end position by means of at least one interlock member. ### Claim 9 (depends on 8) The drive mechanism according to claim 8, wherein the interlock member comprises a radially outwardly protruding tongue flexibly deformable in axial direction and being adapted to but against an inward facing side wall section of the housing in radial direction when the dose button is in its end position. ### Claim 10 (depends on 9) The drive mechanism according to claim 9, wherein an activation button is axially displaceably mounted in the proximal section of the housing for axially depressing the free end of the tongue into a release configuration. ### Claim 11 (depends on 1) A drug delivery device for dispensing a dose of a medicament comprising: a drive mechanism according to claim 1, and a cartridge comprising a movable piston to be engaged with a piston rod of the drive mechanism, the piston sealing an inner volume of the cartridge being at least partially filled with the medicament.