US 12,311,148 B2
Auto-injector
Matthew Ekman, Cheshire (GB); Yannick Hourmand, Haslingfield Cambridge (GB); and Timothy Donald Barrow-Williams, St. Albans Herts (GB)
Assigned to Sanofi-Aventis Deutschland GMBH, Frankfurt am Main (DE)
Filed by Sanofi-Aventis Deutschland GMBH, Frankfurt am Main (DE)
Filed on Dec. 16, 2024, as Appl. No. 18/982,446.
Application 18/982,446 is a continuation of application No. 17/719,441, filed on Apr. 13, 2022.
Application 17/719,441 is a continuation of application No. 16/809,669, filed on Mar. 5, 2020, granted, now 11,311,671, issued on Apr. 26, 2022.
Application 16/809,669 is a continuation of application No. 15/880,251, filed on Jan. 25, 2018, granted, now 10,603,436, issued on Mar. 31, 2020.
Application 15/880,251 is a continuation of application No. 15/165,720, filed on May 26, 2016, granted, now 9,931,471, issued on Apr. 3, 2018.
Application 15/165,720 is a continuation of application No. 13/806,324, granted, now 9,352,088, issued on May 31, 2016, previously published as PCT/EP2011/060726, filed on Jun. 27, 2011.
Claims priority of application No. 10167506 (EP), filed on Jun. 28, 2010.
Prior Publication US 2025/0114526 A1, Apr. 10, 2025
Int. Cl. A61M 5/20 (2006.01); A61M 5/32 (2006.01)
CPC A61M 5/2033 (2013.01) [A61M 5/3202 (2013.01); A61M 5/3257 (2013.01); A61M 2005/206 (2013.01); A61M 2005/208 (2013.01)] 30 Claims
OG exemplary drawing
 
1. An auto-injector comprising:
a housing defining a longitudinal axis;
a plunger disposed within the housing, the plunger comprising
a proximal portion having a first width and a proximal end configured to engage a stopper within a syringe, the first width being measured in a first cross-sectional plane along a direction perpendicular to the longitudinal axis of the housing;
a central portion directly distal to the proximal portion of the plunger and having a second width that is less than the first width of the proximal portion, the second width being measured in the first cross-sectional plane along the direction perpendicular to the longitudinal axis of the housing;
a shoulder located distal to the proximal portion of the plunger and the central portion of the plunger, and proximal to a distal end of the plunger, the shoulder having a third width that is greater than the first and second widths of the plunger, the third width being measured in the first cross-sectional plane along the direction perpendicular to the longitudinal axis of the housing; and
a distal portion distal to the proximal portion of the plunger and the central portion of the plunger, and distal to the shoulder of the plunger, the distal portion of the plunger having a fourth width that is less than the third width, the fourth width being measured in the first cross-sectional plane along the direction perpendicular to the longitudinal axis of the housing;
a syringe holder disposed within the housing, the syringe holder comprising
a first portion sized to receive a distal flange of the syringe such that the distal flange of the syringe is radially and axially within the first portion of the syringe holder while an axial length of the proximal portion of the plunger is within a barrel of the syringe before needle insertion, and the axial length of the proximal portion of the plunger within the barrel of the syringe is greater than an axial length of the stopper within the syringe;
a distal portion extending radially inward from a distal end of the first portion of the syringe holder, the distal portion of the syringe holder configured to (i) engage a distal wall of the proximal portion of the plunger while surrounding opposite sides of the plunger in the first cross-sectional plane before needle insertion to limit relative axial movement between the plunger and the syringe holder, and (ii) slide along the central portion of the plunger while surrounding the opposite sides of the plunger in the first cross-sectional plane as the plunger proximally advances relative to the housing during medicament delivery and the proximal portion of the plunger proximally displaces the stopper within the syringe to dispense a medicament from the syringe; and
a proximal portion extending radially inward from a proximal end of the first portion of the syringe holder, an inner diameter of the proximal portion of the syringe holder being greater than an inner diameter of the distal portion of the syringe holder; and
a trigger button configured to rotate relative to the housing from (i) a first button position in which the trigger button cannot be depressed to (ii) a second button position in which the trigger button can be depressed, wherein the auto-injector is configured such that when the trigger button is in the second button position depression of the trigger button deflects a resilient arm in a radially inward direction in the first cross-sectional plane by a ramped engagement between the trigger button and the resilient arm to allow the plunger to be released from being held in a distal position within the housing such that the plunger moves proximally by a proximally-directed biasing force of a compression drive spring for needle insertion and medicament delivery.