Auto-Injector Apparatus

Abstract

An auto-injector apparatus includes a flexible container containing a liquid medicant, a needle communicated with a container, a housing with a container being received in the housing, a pump disposed in the housing and positioned to engage the flexible container and expel the medicant from the container through the needle upon relative movement between the pump and the container, and a main drive spring operably associated with the needle to extend the needle from a first needle position wherein the needle is completely received in the housing to a second needle position wherein the needle protrudes from the housing. The pump may be a roller.

What is claimed is: 
     
         1 . An auto-injector apparatus, comprising: a flexible container containing a liquid medicant; a needle communicated with the container; a housing, the container being received in the housing; a pump disposed in the housing and positioned to engage the flexible container and expel the medicant from the container through the needle upon relative movement between the pump and the container; and a main drive spring operably associated with the needle to extend the needle from a first needle position wherein the needle is completely received in the housing to a second needle position wherein the needle protrudes from the housing. 
     
     
         2 . The apparatus of  claim 1 , wherein: the main drive spring is operably associated with the pump to create the relative movement between the pump and the flexible container. 
     
     
         3 . The apparatus of  claim 2 , further comprising: a retraction spring operably associated with the needle to retract the needle back into the housing after the medicant is expelled from the container. 
     
     
         4 . The apparatus of  claim 1 , further comprising: a container carriage reciprocably disposed in the housing, the container being received in the carriage so that the carriage, the container and the needle are movable together within the housing between first and second carriage positions corresponding to the first and second needle positions. 
     
     
         5 . The apparatus of  claim 4 , further comprising: a needle return chassis; a retraction spring connected between the housing and the needle return chassis; an interlock operably associated with the needle return chassis and the container carriage, the interlock releasing the needle return chassis after the pump expels the medicant from the container so that the retraction spring can withdraw the needle return chassis, the container carriage, the container and the needle to a safety position wherein the needle is fully received back in the housing. 
     
     
         6 . The apparatus of  claim 4 , wherein: the pump includes a roller; the container carriage includes a roller track; and the roller is received in the roller track so that the roller is guided by the roller track as the roller rolls over the flexible container. 
     
     
         7 . The apparatus of  claim 6 , further comprising: a roller interlock between the roller and the container carriage to prevent the roller from rolling over the flexible container until after the main drive spring moves the needle to its second needle position. 
     
     
         8 . The apparatus of  claim 1 , further comprising: a needle hub connected to the flexible container, the needle being attached to the needle hub and including a needle proximal end extending proximally from the needle hub; and a needle protection frame slidably connected to the needle hub, the needle hub being slidable relative to the frame from a first hub position wherein the frame extends proximally beyond the needle proximal end, to a second hub position wherein the needle proximal end extends proximally beyond the frame. 
     
     
         9 . The apparatus of  claim 8 , further comprising: a collapsible needle sheath supported by the frame and covering the needle to aid in maintaining sterility of the needle when the needle hub is in its first hub position relative to the frame. 
     
     
         10 . The apparatus of  claim 1 , wherein: the main drive spring comprises a coiled spring strip. 
     
     
         11 . The apparatus of  claim 1 , wherein: the housing comprises a closed single use housing having an interior inaccessible by a user without damage to the housing. 
     
     
         12 . The apparatus of  claim 11 , further comprising: the housing having a transparent window therein through which the flexible container is visible; and an opaque secondary container in which the housing is sealed. 
     
     
         13 . The apparatus of  claim 11 , further comprising: the housing having a transparent window therein through which the flexible container can be viewed; and a pull strip movable between a first position blocking the transparent window and a second position wherein the transparent window is unblocked so that the flexible container can be viewed prior to use. 
     
     
         14 . The apparatus of  claim 1 , wherein the pump comprises a roller. 
     
     
         15 . The apparatus of  claim 14 , wherein: the roller has a rotational axis, and the relative movement between the roller and the container is a relative longitudinal movement in a longitudinal direction transverse to the rotational axis, and the container is longitudinally fixed relative to the housing during at least part of the relative longitudinal movement between the roller and the container. 
     
     
         16 . The apparatus of  claim 14 , wherein: the roller has a rotational axis, and the relative movement between the roller and the container is a relative longitudinal movement in a longitudinal direction transverse to the rotational axis, and the roller is longitudinally fixed relative to the housing during at least part of the relative longitudinal movement between the roller and the container. 
     
     
         17 . The apparatus of  claim 16 , wherein: the roller includes two spaced co-axial roller portions; and the needle extends between the roller portions. 
     
     
         18 . The apparatus of  claim 1 , wherein the pump comprises an inflatable balloon. 
     
     
         19 . The apparatus of  claim 1 , wherein the pump comprises a pair of magnets on opposite sides of the flexible container. 
     
     
         20 . The apparatus of  claim 1 , wherein the pump comprises an electro-magnet and a magnetically attracted mass on opposite sides of the flexible container. 
     
     
         21 . The apparatus of  claim 1 , wherein the pump comprises a source of fluid pressure communicated with the interior of the flexible container.