Device for Controlled Delivery of an Injectable Liquid

Abstract

A device for the controlled delivery of an injectable liquid from a liquid container, wherein a flexible force transferor transfers the drive force of a drive wheel onto a piston which can be slid axially in the device, a permanently acting restoring force of a spiral spring is applied to the drive wheel to advance the piston and expel the liquid, and a lock locks the drive wheel against rotation and releases the drive wheel to expel the liquid. In one embodiment, the amount of liquid expelled can be indicated by audible clicks and, in one embodiment, the drive wheel moves only incrementally when the lock releases the drive wheel.

1 . A device for the controlled delivery of an injectable liquid from a liquid container sealed at a rear end by a piston which can be moved axially in the container to deliver the liquid from the container, the device comprising: 
 a flexible force transferor axially deviated behind the container away from a generally central longitudinal axis of the container;    a drive mechanism coupled to said transferor to axially move the piston for delivering the liquid;    a restorer applying a restoring force to said drive mechanism and resetting said drive mechanism for delivering liquid from the container, wherein the restorer permanently applies said restoring force to the drive mechanism to reset the drive mechanism from a starting position in which the piston is situated substantially at one end of the liquid container to an end position in which the piston is situated substantially at the other end of the liquid container; and    a lock enabling a controlled movement of the piston by a fraction of a maximum piston stroke pre-set by the starting and end positions of the piston in the liquid container.    
   
   
       2 . The device as set forth in  claim 1 , wherein the lock comprises a lever which comprises blocking projections on mutually opposite sides of a rotational point of said lever.  
   
   
       3 . The device as set forth in  claim 1 , wherein the lock comprises a lever which comprises blocking projections on mutually opposite sides of a rotational point of said lever, and wherein the drive mechanism comprises a drive wheel, said blocking projections cooperating with the drive wheel.  
   
   
       4 . The device as set forth in  claim 3 , wherein the drive wheel carries teeth, the blocking projections offset with respect to each other by a half a tooth of said teeth.  
   
   
       5 . The device of  claim 3 , wherein the drive wheel moves incrementally when the lock releases the drive wheel.  
   
   
       6 . The device as set forth in  claim 1 , wherein the flexible force transferor comprises a cylindrical coil spring coupled to a lateral facing area associated with the drive mechanism.  
   
   
       7 . A device for the controlled delivery of an injectable liquid from a liquid container sealed at a rear end by a piston which can be moved axially in the container to deliver the liquid from the container, the device comprising: 
 a coil spring axially deviated behind the container away from a generally central longitudinal axis of the container;    a drive mechanism coupled to said coil spring to axially move the piston for delivering the liquid;    a spiral spring applying a restoring force to said drive mechanism and resetting said drive mechanism for delivering liquid from the container, wherein the spiral spring permanently applies said restoring force to the drive mechanism to reset the drive mechanism from a starting position in which the piston is situated substantially at one end of the liquid container to an end position in which the piston is situated substantially at the other end of the liquid container; and    a lock enabling a controlled movement of the piston by a fraction of a maximum piston stroke pre-set by the starting and end positions of the piston in the liquid container.