US 12,364,821 B2
Plunger rod for an auto-injector
Simon Francis Brereton, Cambridge (GB); Thomas Kemp, Ashwell (GB); Rosie Burnell, Cambridge (GB); and Matthew Ekman, Cheshire (GB)
Assigned to Sanofi-Aventis Deutschland GMBH, Frankfurt am Main (DE)
Filed by Sanofi-Aventis Deutschland GMBH, Frankfurt am Main (DE)
Filed on Jan. 13, 2025, as Appl. No. 19/017,947.
Application 19/017,947 is a continuation of application No. 18/755,787, filed on Jun. 27, 2024, granted, now 12,214,176.
Application 18/755,787 is a continuation of application No. 18/487,215, filed on Oct. 16, 2023.
Application 18/487,215 is a continuation of application No. 17/126,962, filed on Dec. 18, 2020, granted, now 11,819,670, issued on Nov. 21, 2023.
Application 17/126,962 is a continuation of application No. 15/897,872, filed on Feb. 15, 2018, granted, now 10,894,132, issued on Jan. 19, 2021.
Application 15/897,872 is a continuation of application No. 13/983,809, granted, now 9,925,344, issued on Mar. 27, 2018, previously published as PCT/EP2012/052647, filed on Feb. 16, 2012.
Claims priority of application No. 11155040 (EP), filed on Feb. 18, 2011.
Prior Publication US 2025/0144307 A1, May 8, 2025
Int. Cl. A61M 5/315 (2006.01); A61M 5/20 (2006.01); A61M 5/32 (2006.01); A61M 5/46 (2006.01)
CPC A61M 5/31501 (2013.01) [A61M 5/20 (2013.01); A61M 5/2033 (2013.01); A61M 5/3157 (2013.01); A61M 5/3158 (2013.01); A61M 5/322 (2013.01); A61M 5/326 (2013.01); A61M 5/46 (2013.01); A61M 2005/206 (2013.01); A61M 2005/208 (2013.01); A61M 2205/581 (2013.01); A61M 2205/582 (2013.01); A61M 2205/583 (2013.01)] 30 Claims
OG exemplary drawing
 
1. An assembly comprising:
a syringe; and
a plunger rod for an auto-injector, the plunger rod comprising:
an inner proximal portion located symmetrically about a first plane of the plunger rod, a proximal end of the inner proximal portion being configured to contact a stopper of the syringe for dispensing a medicament from the syringe when the plunger rod moves proximally relative to a member of the auto-injector;
an outer distal portion located symmetrically about the first plane, the outer distal portion configured to releasably latch to the member to limit proximal movement of the plunger rod relative to the member such that a radial inward deflection of at least two portions releases the plunger rod from the member, the at least two portions being spaced apart from (i) one another about the first plane and (ii) the first plane;
a flange located axially between the inner proximal portion and the outer distal portion and being substantially perpendicular to the first plane such that at least a portion of a proximal side of the flange extends along a second plane substantially perpendicular to the first plane and at least a portion of a distal side of the flange extends along a third plane parallel to the second plane, an outer portion of the flange extending outward from the outer distal portion and being configured to contact a compression spring for biasing the plunger rod in a proximal direction relative to the member to dispense the medicament from the syringe, and the inner proximal portion of the plunger rod extends from the proximal side of the flange; and
a rib configured to engage and deflect a clip as the plunger rod moves in the proximal direction relative to the member while dispensing the medicament from the syringe and prior to dispensing all medicament from the syringe;
wherein the distal side of the flange and the outer distal portion of the plunger rod define a first opening extending from the flange to a distal end of the outer distal portion.
 
11. An assembly comprising:
a syringe; and
a plunger rod for an auto-injector, the plunger rod comprising:
an inner proximal portion located symmetrically about a first plane, a proximal end of the inner proximal portion being configured to contact a stopper of the syringe;
an outer distal portion located symmetrically about the first plane, the outer distal portion configured to releasably latch to a member of the auto-injector to limit proximal movement of the plunger rod relative to the member of the auto-injector such that a radial inward deflection of at least two portions releases the plunger rod from the member, the at least two portions being located symmetrically about the first plane;
an outer flange located axially between the inner proximal portion and the outer distal portion and substantially perpendicular to the first plane, the outer flange configured to contact a compression spring for biasing the plunger rod in a proximal direction relative to the member; and
a rib configured to engage and deflect a clip as the plunger rod moves in the proximal direction relative to the member while dispensing a medicament from the syringe and prior to dispensing all medicament from the syringe,
wherein the outer distal portion of the plunger rod defines a first opening (i) extending from an axial location of the outer flange of the plunger rod to a distal end of the outer distal portion.
 
24. An assembly comprising:
a syringe; and
a plunger rod for an auto-injector, the plunger rod comprising:
an inner proximal portion located symmetrically about a first plane, a proximal end of the inner proximal portion being configured to contact a stopper of the syringe;
an outer distal portion located symmetrically about the first plane, the outer distal portion configured to releasably latch to a member of the auto-injector to limit proximal movement of the plunger rod relative to the member of the auto-injector such that a radial inward deflection of at least two portions releases the plunger rod from the member, the at least two portions being located symmetrically about the first plane;
an outer flange located axially between the inner proximal portion and the outer distal portion and substantially perpendicular to the first plane, the outer flange configured to contact a compression spring for biasing the plunger rod in a proximal direction relative to the member; and
a rib configured to engage and deflect a clip as the plunger rod moves in the proximal direction relative to the member while dispensing a medicament from the syringe and prior to dispensing all medicament from the syringe,
wherein the outer distal portion of the plunger rod defines a first opening extending from an axial location of the outer flange of the plunger rod to a distal end of the outer distal portion,
wherein the syringe and the plunger rod are configured such that when the plunger rod is fully inserted into the syringe with the proximal end of the inner proximal portion of the plunger rod in a proximal-most position within the syringe, (i) all portions of the plunger rod within the syringe are substantially symmetric about the first plane, and (ii) the outer flange of the plunger rod is axially spaced from a distal flange of the syringe.