US 12,214,170 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 Jun. 26, 2024, as Appl. No. 18/754,728.
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 2024/0342385 A1, Oct. 17, 2024
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 5/326 (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:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein an inner surface of the sidewall and an inner portion of the distal side of the flange portion define a central opening of the plunger rod that extends through the distal portion,
wherein a diameter of an outer surface of the sidewall is largest in the proximal region compared to the central and distal regions, and is substantially constant throughout the central region, wherein at least a portion of the outer surface in the distal region has a reduced diameter compared to the diameter throughout the central region,
wherein the outer surface, in the distal region, defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from the outer surface,
wherein the distal end of the plunger rod comprises a second opening that extends proximally from the distal end of the plunger rod and has a proximal end that is distal to the first opening, wherein the portion of the outer surface in the distal region having the reduced diameter at least partially defines the second opening,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein the inner surface of the sidewall defines a third opening that extends radially outward from the inner surface, the third opening being located proximal to the first and second openings,
wherein the central opening intersects the second and third openings,
wherein the proximal portion has a proximal region and a distal region, an outer dimension of the proximal region of the proximal portion being larger than an outer dimension of the distal region of the proximal portion, and the proximal and distal regions of the proximal portion being substantially centered about a longitudinal axis of the housing,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing;
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring,
a first collar disposed within the housing;
a second collar disposed within the housing and distal to the first collar, wherein the auto-injector is configured such that a predetermined relative movement between the second collar and the sleeve allows the sleeve to be released from being held in an initial position and move distally for needle retraction; and
a cap removably attached to a proximal end of the housing, the cap comprising an inner sleeve comprising a barb configured to engage a needle shield removably attached to the syringe, the auto-injector being configured such that removal of the cap from the housing removes the needle shield from the syringe when the syringe is disposed within the housing without proximally moving the syringe relative to the housing.
 
6. An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein an inner surface of the sidewall and an inner portion of the distal side of the flange portion define a central opening of the plunger rod that extends through the distal portion,
wherein a diameter of an outer surface of the sidewall is largest in the proximal region compared to the central and distal regions, and is substantially constant throughout the central region,
wherein the outer surface, in the distal region, defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from the outer surface,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing; and
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring.
 
17. An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein an inner surface of the sidewall and an inner portion of the distal side of the flange portion define a central opening of the plunger rod that extends through the distal portion,
wherein the distal region defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from an outer surface of the distal portion,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein the inner surface of the sidewall defines a third opening that extends radially outward from the inner surface, the third opening being located proximal to the first opening,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing; and
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring.
 
26. An auto-injector comprising:
a housing;
a sleeve disposed within the housing, the sleeve comprising a retaining surface located on a distal end of the sleeve;
a compression spring disposed within a distal section of the sleeve and having a distal end engaged to the distal end of the sleeve;
a plunger rod disposed within the housing, the plunger rod comprising
a flange portion engaged to a proximal end of the compression spring;
a proximal portion extending from a proximal side of the flange portion and having a proximal end configured to engage a stopper of a syringe,
a distal portion extending distally from a distal side of the flange portion to a distal end of the plunger rod, the distal portion having a sidewall extending from a proximal region of the distal portion, through a central region of the distal portion, and to a distal region of the distal portion,
wherein the distal region defines a first opening for axially coupling the plunger rod to the retaining surface of the sleeve, the first opening extending radially inward from an outer surface of the distal portion,
wherein the proximal portion has a proximal region and a distal region, an outer dimension of the proximal region of the proximal portion being larger than an outer dimension of the distal region of the proximal portion, and the proximal and distal regions of the proximal portion are substantially centered about a longitudinal axis of the housing,
wherein the auto-injector has (i) a first state in which the first opening and the retaining surface are engaged to one another to hold the plunger rod in a distal position within the housing and (ii) a second state in which the retaining surface has disengaged from the first opening by a radially inward deflection to release the plunger rod from being held in the distal position within the housing,
wherein an axial length of the proximal portion of the plunger rod is longer than an axial length of the distal portion of the plunger rod, and
wherein the compression spring is disposed around at least the proximal and central regions of the distal portion of the plunger rod,
a button disposed at a distal end of the housing, the button comprising a proximally-extending protrusion, the auto-injector configured such that a relative axial movement between the proximally-extending protrusion and the plunger rod allows the auto-injector to change from the first state to the second state by allowing the radially inward deflection to release the plunger rod from being held in the distal position within the housing; and
a second spring biasing the sleeve in a distal direction relative to the housing such that the sleeve distally moves relative to the housing during needle retraction, a diameter of the second spring being larger than a diameter of the compression spring.