US 12,434,003 B2
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. 6, 2025, as Appl. No. 19/010,652.
Application 19/010,652 is a continuation of application No. 18/754,728, filed on Jun. 26, 2024, granted, now 12,214,170.
Application 18/754,728 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 2025/0135117 A1, May 1, 2025
Int. Cl. A61M 5/32 (2006.01); A61M 5/20 (2006.01); A61M 5/315 (2006.01); A61M 5/46 (2006.01)
CPC A61M 5/322 (2013.01) [A61M 5/20 (2013.01); A61M 5/2033 (2013.01); A61M 5/31501 (2013.01); A61M 5/3157 (2013.01); A61M 5/3158 (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 auto-injector comprising:
an elongate housing;
a sleeve disposed in the elongate housing, the sleeve being configured such that a distal flange of a syringe is disposed axially and radially within the sleeve when the syringe is disposed in the auto-injector during use of the auto-injector, wherein a proximal end of the sleeve has an inner dimension that is smaller than an outer dimension of the distal flange of the syringe;
a plunger rod configured to be releasably held by a distal end of the sleeve prior to injection such that (i) when the auto-injector is in a first state one or more axially-extending resilient arms hold the plunger rod in a first position relative to the sleeve, and (ii) when the auto-injector is in a second state the one or more axially-extending resilient arms have deflected radially inward to release the plunger rod from the sleeve to allow proximal movement of the plunger rod relative to the sleeve;
a drive spring at least partially surrounding the plunger rod and biasing the plunger rod in a proximal direction relative to the sleeve for driving an axially-extending portion of the plunger rod into the syringe to displace a stopper and dispense a medicament from the syringe when the auto-injector is in the second state and the syringe is in the auto-injector, wherein the axially-extending portion of the plunger rod is substantially centered about a first central axis of the elongate housing of the auto-injector and a second central axis of the syringe; and
a trigger button configured to be depressed relative to the elongate housing to slidably engage the one or more axially-extending resilient arms to change the auto-injector from the first state to the second state to dispense the medicament from the auto-injector.
 
8. An auto-injector comprising:
an elongate housing;
a sleeve disposed in the elongate housing, the sleeve sized to surround a distal flange of a syringe containing a medicament when the syringe is disposed in the auto-injector;
a plunger rod configured to be releasably held by the sleeve prior to injection of the medicament such that (i) when the auto-injector is in a first state one or more axially-extending resilient arms hold the plunger rod in a first position relative to the sleeve and (ii) when the auto- injector is in a second state the one or more axially-extending resilient arms have deflected radially inward to release the plunger rod from the sleeve;
a drive spring at least partially surrounding the plunger rod and disposed within the sleeve, the drive spring biasing the plunger rod in a proximal direction relative to the sleeve for driving an axially-extending portion of the plunger rod into the syringe to displace a stopper and inject the medicament into an injection site when the auto-injector is in the second state, wherein the axially-extending portion of the plunger rod is substantially centered about a central axis of the elongate housing of the auto-injector; and
a button configured to be depressed relative to the elongate housing to slidably engage the one or more axially-extending resilient arms to change the auto-injector from the first state to the second state to inject the medicament into the injection site.
 
19. An auto-injector comprising:
a housing;
a cylindrical sleeve disposed in the housing, the cylindrical sleeve configured to move distally relative to the housing of the auto-injector during needle retraction;
a plunger rod configured to be releasably held by the cylindrical sleeve prior to injection of a medicament from a syringe such that (i) when the auto-injector is in a first state at least two axially-extending resilient arms hold the plunger rod in a first position relative to the cylindrical sleeve to prevent the medicament from being dispensed from the syringe and (ii) when the auto-injector is in a second state the at least two axially-extending resilient arms have deflected radially inward to release the plunger rod from the cylindrical sleeve to allow the medicament to be dispensed from the syringe; and
a drive spring at least partially surrounding the plunger rod and biasing the plunger rod in a proximal direction relative to the cylindrical sleeve for driving an axially-extending portion of the plunger rod into the syringe to displace a stopper and dispense the medicament from the syringe when the auto-injector is in the second state, wherein the axially-extending portion of the plunger rod is substantially symmetric about at least two planes, the at least two planes being perpendicular to one another.
 
25. An auto-injector comprising:
a housing;
a sleeve disposed in the housing, the sleeve sized to receive at least a distal portion of a syringe, the syringe being substantially symmetric about at least two planes that are perpendicular to one another;
a plunger rod having an axially-extending portion that is substantially symmetric about the at least two planes, the plunger rod comprising a flange located axially between a proximal end of the plunger rod and a distal end of the plunger rod;
a drive spring at least partially surrounding the plunger rod and disposed in the sleeve;
a button configured to slidably engage at least two axially-extending resilient arms for changing the auto-injector from a first state to a second state,
wherein (i) when the auto-injector is in the first state the at least two axially-extending resilient arms hold the plunger rod in a first position relative to the sleeve to prevent a medicament from being dispensed from the syringe and (ii) when the auto-injector is in the second state the at least two axially-extending resilient arms are allowed to deflect radially inward to release the plunger rod from the sleeve to allow the medicament to be dispensed from the syringe,
wherein a proximal end of the drive spring is configured to contact the flange of the plunger rod for providing a driving force to advance the axially-extending portion of the plunger rod into the syringe to dispense the medicament from the syringe when the auto-injector is in the second state.
 
30. An auto-injector comprising:
a housing;
a cylindrical sleeve disposed in the housing, the cylindrical sleeve sized to receive at least a distal portion of a syringe and configured to move distally relative to the housing of the auto-injector during needle retraction, the syringe being substantially symmetric about at least two planes that are perpendicular to one another;
a plunger rod having an axially-extending portion that is substantially symmetric about the at least two planes, the plunger rod comprising a flange located axially between a proximal end of the plunger rod and a distal end of the plunger rod;
a drive spring at least partially surrounding the plunger rod and disposed in the cylindrical sleeve, wherein the auto-injector has (i) a first state in which at least two axially-extending resilient arms hold the plunger rod in a first position relative to the cylindrical sleeve to prevent a medicament from being dispensed from the syringe and (ii) a second state in which the at least two axially-extending resilient arms are allowed to deflect radially inward to release the plunger rod from the cylindrical sleeve to allow the medicament to be dispensed from the syringe,
wherein a proximal end of the drive spring is configured to contact the flange of the plunger rod for providing a driving force to advance the axially-extending portion of the plunger rod into the syringe to dispense the medicament from the syringe when the auto-injector is in the second state.