Injection syringe

Abstract

A syringe is provided with a body, a piston capable of sliding in the body, and an injection device comprising a needle oriented along a longitudinal axis and a casing removably secured to the body and carrying said needle, the casing comprising a plurality of flexible tabs each provided with a stop, the piston comprising a docking system provided with a housing that comprises a flange configured to hold the stops of the flexible tabs in the housing in an insertion position in which the tabs are inserted into the housing, the plurality of tabs comprising a first tab and a second tab situated in opposing areas around the longitudinal axis, the flange comprising a first bearing area and a second bearing area configured to be in contact respectively with the first tab and the second tab in the insertion position.

1 . A syringe provided with a body, a piston capable of sliding in the body, and an injection device comprising a needle oriented along a longitudinal axis and a casing removably secured to the body and carrying said needle, the casing comprising:
 a plurality of flexible tabs each provided with a stop, the piston comprising a docking system provided with a housing that comprises a flange configured to hold the stops of the flexible tabs in the housing in an insertion position in which the tabs are inserted into the housing, the plurality of tabs comprising a first tab, and   a second tab situated in opposing areas around the longitudinal axis, the flange comprising a first bearing area and a second bearing area configured to be in contact with the first tab and the second tab respectively in the insertion position, characterized in that the first tab and the second tab are configured to provide elastic support respectively on the first bearing area and the second bearing area in the insertion position, and in that the first bearing area and the second bearing area are dissymmetrical relative to the longitudinal axis.   
     
     
         2 . A syringe according to the previous claim, wherein the first bearing area is further from the longitudinal axis than the second bearing area. 
     
     
         3 . A syringe according to the previous claim, wherein the first bearing area is on an annular flange and the second bearing area is a portion protruding beyond this flange towards the longitudinal axis. 
     
     
         4 . A syringe according to one of the previous claims, wherein the second bearing area is an angular sector of a ring. 
     
     
         5 . A syringe according to the previous claim, wherein the angular sector forms an angle greater than 30°. 
     
     
         6 . A syringe according to one of the previous two claims, wherein the angular sector forms an angle of less than 90°. 
     
     
         7 . A syringe according to one of the previous claims, wherein the spacing between two adjacent tabs is smaller than the width dimension of the second bearing area. 
     
     
         8 . A syringe according to one of the previous claims, wherein the plurality of tabs includes at least one pair of additional flexible tabs, with the tabs of the pair of tabs being situated in opposite areas about the longitudinal axis. 
     
     
         9 . A syringe according to the preceding claim, wherein the first tab, the second tab and the additional tabs are uniformly distributed about the longitudinal axis. 
     
     
         10 . A syringe according to one of the previous two claims, wherein the plurality of tabs includes only one pair of additional tabs. 
     
     
         11 . A syringe according to one of the previous claims, wherein the tabs of the plurality of tabs are symmetrical two by two relative to the longitudinal axis. 
     
     
         12 . A syringe according to one of the previous claims, wherein the distal ends of the tabs are disjointed. 
     
     
         13 . A syringe according to one of the previous claims, wherein the two bearing areas are situated at the same height level along the longitudinal axis.