| CPC A61M 5/2033 (2013.01) [A61M 5/3202 (2013.01); A61M 5/3232 (2013.01); A61M 2005/206 (2013.01); A61M 2005/2073 (2013.01); A61M 5/3204 (2013.01); A61M 5/326 (2013.01)] | 30 Claims |
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1. An auto-injector comprising:
a housing;
a syringe carrier defining an opening for a syringe, the syringe carrier configured to slide within the housing from (i) a distal position in which a needle of the syringe is not exposed from a proximal end of the housing to (ii) a proximal position in which the needle of the syringe is exposed from the proximal end of the housing when the syringe is in the syringe carrier, the syringe carrier comprising an inwardly angled protrusion located at a proximal end of the syringe carrier for engaging with a proximal portion of the syringe to limit proximal movement of the syringe relative to the syringe carrier, a length of the syringe carrier sized such that a proximal side of a distal flange of the syringe is axially spaced apart from a sidewall of the syringe carrier when the syringe is in the syringe carrier;
a plunger rod slidably disposed in the housing, a proximal end of the plunger rod configured to displace a stopper in slidable contact with the syringe to dispense a medicament from the syringe, the plunger rod and the syringe carrier being configured such that the syringe carrier moves from the distal position to the proximal position as the plunger rod proximally moves relative to the housing, the plunger rod comprising an outer protrusion having an outer diameter that is greater than an inner diameter of a sidewall of the syringe;
a compression drive spring surrounding a portion of the plunger rod, the compression drive spring configured to apply a proximally-directed force to the outer protrusion of the plunger rod for causing the plunger rod to proximally move relative to the housing;
a first member disposed within the housing, the first member comprising a distally-extending resilient arm releasably coupled to the plunger rod, the first member having (i) a first state in which the distally-extending resilient arm is held in engagement with the plunger rod to limit proximal movement of the plunger rod relative to the first member under the proximally-directed force of the compression drive spring, and (ii) a second state in which the distally-extending resilient arm has outwardly deflected out of engagement with the plunger rod to allow the plunger rod to move proximally relative to the first member under the proximally-directed force of the compression drive spring to dispense the medicament; and
a second member configured to slide axially relative to the housing from a first position in which the second member extends from an end of the housing by a first distance to a second position in which the second member extends from the end of the housing by a second distance, the first distance being greater than the second distance, wherein when the second member is in the second position the first member can change from the first state to the second state; and
a third member configured to move relative to the housing between (i) an inward position in which a first portion of the third member is disposed in an opening of a sidewall of the housing and limits axial movement of the second member relative to the housing and (ii) an outward position in which the first portion has moved outward relative to the housing and allows axial movement of the second member relative to the housing, wherein a second portion of the third member is outward of the housing when the third member is in the inward position and the outward position,
wherein the compression drive spring is disposed between the first member and the plunger rod.
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