# US 8,771,239 B2 · Drive mechanisms suitable for use in drug delivery devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,771,239 B2 - Document ID: US8771239B2 - Status: Granted - Kind: B2 - Application number: 13/173,445 - Filed: 2011-06-30 - Published: 2012-07-05 - Granted: 2014-07-08 - Earliest claimed: 2006-11-17 - Assignees: Sanofi-Aventis Deutschland GmbH - Applicants: Malcolm Boyd; Richard Letham; David Plumptre; Robert Veasey; James May - Inventors: Malcolm Boyd; Richard Letham; David Plumptre; Robert Veasey; James May - Web page: https://patentgrep.com/patent/US8771239B2 ## CPC - A61M 5/31578: {the piston rod being moved by the axial movement of a component directly in contact with it} - A61M 5/31555: {by purely axial movement of dose setting member, e.g. during setting or filling of a syringe} - A61M 5/24: Ampoule syringes, i.e. syringes with needle for use in combination with replaceable ampoules or cartridges, e.g. automatic - A61M 5/30: Syringes for injection by jet action, without needle, e.g. for use with replaceable ampoules or carpules - A61M 5/31541: {Means preventing setting of a dose beyond the amount remaining in the cartridge} - A61M 5/3156: {using volume steps only adjustable in discrete intervals, i.e. individually distinct intervals} - A61M 5/31585: {the component being manually operated or triggered by an axially moving actuator operated by user, e.g. an axially movable injection button} - A61M 5/31593: {Multi-dose, i.e. individually set dose repeatedly administered from the same medicament reservoir} - A61M 2005/2407: {from the rear} - A61M 2005/3104: {Caps for syringes without needle} - A61M 2005/3152: {including gearings to multiply or attenuate the piston displacing force} - A61M 2205/581: by audible feedback - A61M 2205/582: by tactile feedback - Y10T 29/49826: Assembling or joining - 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)} - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract The present invention relates to drive mechanisms suitable for use in drug delivery devices, in particular pen-type injectors, wherein a number of pre-set doses of medicinal product can be administered. In particular, the present invention relates to such drug delivery devices where a user may activate the drug delivery device. ## Claims ### Claim 1 A drive mechanism for use with a delivery device, the drive mechanism comprising: a rack that is moveable in a proximal direction and in a distal direction; a piston rod coupled with said moveable rack, said piston rod comprising a first plurality of indentations along at least a portion of said piston rod; and a rotating component engaged with said movable rack such that it transfers movement between said movable rack and said piston rod, said rotating component releasably engaged with said first plurality of indentations of said piston rod, and a carrier releasable engaged with said piston rod, said carrier allowing relative movement between said rotating component and said piston rod. ### Claim 2 (depends on 1) The drive mechanism of claim 1 wherein when said drive mechanism is used to set a dose of a medicament contained within a drug delivery device, said rack is moved proximally with respect to said piston rod. ### Claim 3 (depends on 2) The drive mechanism of claim 2 wherein when said drive mechanism is used to set of dose of a medicament contained within a drug delivery device, said rotating component moves proximally with respect to said piston rod. ### Claim 4 (depends on 3) The drive mechanism of claim 3 further comprising a drive member operatively coupled to said movable rack such that when said drive member is moved in the proximal direction with respect to said piston rod, said moveable rack is also moved in proximally with respect to said piston rod. ### Claim 5 (depends on 1) The drive mechanism of claim 1 wherein said piston rod further comprises a second plurality of indentations, said second plurality of indentations residing along an external surface of said piston rod. ### Claim 6 (depends on 5) The drive mechanism of claim 5 wherein said second plurality of indentations are configured to releasably engage a housing of a drug delivery device so as to prevent said piston rod from moving in a proximal direction. ### Claim 7 (depends on 1) The drive mechanism of claim 1 wherein said drive mechanism is configured to be coupled to a cartridge retaining part. ### Claim 8 (depends on 7) The drive mechanism of claim 7 wherein said drive mechanism is configured to be releasably coupled to the cartridge retaining part. ### Claim 9 (depends on 1) The drive mechanism of claim 1 wherein said drive mechanism can be used to administer one or more pre-set doses of a medicament contained within a drug delivery device. ### Claim 10 (depends on 1) The drive mechanism of claim 1 wherein said rotating component comprises a gear, said gear comprising said carrier and a gear wheel. ### Claim 11 (depends on 1) The drive mechanism of claim 1 wherein said carrier is operatively coupled to said piston rod.