Patent ID: 8308687

Claim:
Injection assistance device ( 1 ) for an injection device ( 3 ) for injecting a product ( 25 ) into an injection site ( 27 ), this injection device ( 3 ) comprising at least one hollow body ( 2 ) intended to receive a product ( 25 ) that is to be injected, at least one hollow injection needle ( 7 ) intended to penetrate the injection site ( 27 ), and at least one piston plunger ( 26 ) housed in the said body ( 2 ), the said body ( 2 ) and the said piston plunger ( 26 ) being able to be moved in axial translation one with respect to the other, characterized in that the said injection assistance device ( 1 ) comprises at least: a hollow sleeve ( 4 ) provided with at least one bearing surface ( 5 ) intended to come into contact with the surface of the said injection site ( 27 ), the said sleeve ( 4 ) being intended to receive, at least in part, the said body ( 2 ) and being arranged in such a way as to allow the said body ( 2 ) axial mobility between at least a first position known as the initial position in which the said needle ( 7 ) is covered by the said hollow sleeve ( 4 ) so as to be not exposed over its insertion length, and a second position known as the insertion position in which the said needle ( 7 ) extends beyond the said hollow sleeve ( 4 ) so as to be exposed by a predetermined insertion length L, a coupling ( 10 , 76 ) arranged in such a way as to be coupled to said piston plunger ( 26 ) at least during an injection step so as to move said piston plunger ( 26 ) from an end-of-insertion position to an end of injection position and to administer the injection when submitted to a distal pressure exerted thereon, a spacer ( 8 ; 30 ; 59 ; 69 ; 81 , 80 ) arranged in such a way as to maintain at least said piston plunger ( 26 ) and said body ( 2 ) in said initial position, a disengager ( 22 , 14 , 15 , 16 ; 25 , 31 ; 61 ; 70 , 71 ; 4 ) linked with said spacer ( 8 ; 30 ; 59 ; 69 ; 81 , 80 ), said spacer ( 8 ; 30 ; 59 ; 69 ; 81 , 80 ) and disengager ( 22 , 14 , 15 , 16 ; 25 , 31 ; 61 ; 70 , 71 ; 4 ) being arranged in order to free distal displacement of said piston plunger ( 26 ) only after distal displacement of said body ( 2 ), with the said body ( 2 ) comprising a flange ( 6 ) at its proximal end, the said spacer comprises at least one deflecting tab ( 59 ) engaging the said flange ( 6 ) and the said coupling ( 10 ) in the insertion position so as to inhibit distal movement of the said coupling ( 10 ) relative to the said body ( 2 ), the said tab ( 59 ) deflecting to disengage from the said flange ( 6 ) at the end of the insertion position with the said needle ( 7 ) being exposed by the predetermined insertion length L so as to allow the said coupling ( 10 ) to move distally relative to the said body ( 2 ).