Device for administering an injectable product

Abstract

The invention relates to a device for administering an injectable product, comprising: a) a casing ( 3 ); b) a container for said product accommodated by said casing ( 3 ) c) a delivering means ( 2 ) for delivering product out of said container ( 1 ); d) a drive means ( 8 ); and e) a transmission link via which said drive means ( 8 ) drives said delivering means ( 2 ). The device is characterised in that: f) a fluid space ( 21, 22 ) for an incompressible fluid and g) a pressure reducing means ( 3, 10, 23 ) are provided in said transmission link; h) wherein said fluid space ( 21, 22 ) can be impinged on a drive side by pressure from said drive means ( 8 ) and said pressure reducing means ( 3, 10, 23 ) reduces a fluid pressure generated by said drive means ( 8 ) toward a driven side of said fluid space ( 21, 22 ).

What is claimed is:  
     
         1 . A device for administering an injectable product, comprising: 
 a) a casing;    b) a container for said product accommodated by said casing;    c) a delivering means for delivering product out of said container;    d) a drive means; and    e) a transmission link via which said drive means drives said delivering means;    characterised in that:    f) a fluid space for an incompressible fluid and    g) a pressure reducing means are provided in said transmission link;    h) wherein said fluid space can be impinged on a drive side by pressure from said drive means and said pressure reducing means reduces a fluid pressure generated by said drive means toward a driven side of said fluid space.    
     
     
         2 . The device as set forth in  claim 1 , characterised in that a working stroke of said drive means is transmitted in said fluid space into a working stroke of said delivering means which is greater than the working stroke of said drive means.  
     
     
         3 . The device as set forth in the preceding claim, characterised in that a bias of said drive means is determined by a replaceably arranged distance ring.  
     
     
         4 . The device as set forth in  claim 1 , characterised in that said drive side of said fluid space is formed by a piston area of a drive piston which is larger than a piston area of a driven piston which forms the driven side of said fluid space.  
     
     
         5 . The device as set forth in  claim 1 , characterised in that said fluid space is sub-divided into a first partial space including said drive side and a second partial space including said driven side, and in that said two partial spaces are connected to each other by a fluid connection formed by said pressure reducing means.  
     
     
         6 . The device as set forth in the preceding claim, characterised in that said two partial spaces are connected to each other exclusively by a system of capillaries, if a higher pressure prevails in said first partial space than in said second partial space.  
     
     
         7 . The device as set forth in  claim 5 , characterised in that said fluid connection includes a spiral fluid channel or is formed by the same.  
     
     
         8 . The device as set forth in the preceding claim, characterised in that said pressure reducing means comprises a capillary body, and in that said spiral fluid channel is formed between a surface area of said capillary body and an opposite surface area.  
     
     
         9 . The device as set forth in  claim 5 , characterised in that said first partial space or said second partial space is formed as a toroidal chamber between an outer sleeve and an inner sleeve, and in that the other of said two partial fluid spaces is formed in said inner sleeve.  
     
     
         10 . The device as set forth in the preceding claim, characterised in that: 
 said toroidal chamber forms said first partial space; and    a drive piston guided fluid-proof by said outer sleeve and said inner sleeve forms said drive side.    
     
     
         11 . The device as set forth in  claim 9 , characterized in that: 
 said second partial space is formed in said inner sleeve; and in that    a driven piston guided fluid-proof by said inner sleeve forms said driven side.    
     
     
         12 . The device as set forth in  claim 9 , characterized in that: 
 said pressure reducing means comprises a separating body which forms a front face of said toroidal chamber and which separates said two partial fluid spaces from each other;    a valve is accommodated by said separating body, said valve only allows a flow of fluid from said driven side to said drive side of said fluid space; and in that    said separating body forms said fluid correction.