Patent ID: 8900201

Claim:
An automatic medicament injection device comprising: an outer body extending along a longitudinal axis; a syringe unit arranged in said outer body and fixed therewith, comprising a syringe containing a medicament to be injected, a needle and piston means slidable axially; means for arming the device from a rest position to a first armed position for delivering a first dose and to a second armed position for delivering a second dose, said means for arming being arranged at one end of said outer body and comprising a dose selection sleeve extending within said outer body; first elastic means arranged between said means for arming and said piston means, said first elastic means being in a compressed state when the device is in its rest position and decompressing to push forward said piston means and deliver said first and said second dose one after the other; an inner body secured to said outer body and coaxial thereto, said piston means being slidably arranged therein, guide means between said inner body and said piston means for controlling the axial sliding motion of said piston means relative to said inner body, said guide means comprising first guide members formed on said inner body and second guide members extending from said piston means and slidingly engaging within said first guide members; a slide arranged at the other end of said outer body and constrained to slide axially therewith as a result of a pressure exerted on its free end against a second elastic means arranged between said slide and said outer body between a first position, wherein the sliding motion of the slide is prevented and the slide extends from said outer body over the syringe needle, and a second position, wherein said slide is retracted in said outer body exposing the syringe needle; cam transmission means between said slide and said inner body to transform the axial sliding of the slide into a triggering command for the device, comprising a transfer sleeve sliding as a result of the sliding of the slide and being formed with first cam means of the transfer sleeve for interacting with said second guide members of piston means, said transfer sleeve being axially pivotable as a result of interaction of second cam means of the transfer sleeve with said inner body and said selection sleeve, whereby said transfer sleeve is subjected to a first and a second angular displacement which, through said first cam means, displaces said second guide members pushing them to a first dose triggering condition and afterwards, to a second dose triggering condition; and third cam means being provided arranged within said outer body and pivotable in only one direction as a result of the axial sliding of said slide, said third cam means defining a cam track configured for controlling the motion of the slide from said first position to said second position and back to said first position controlled by said second elastic means once said pressure exerted on the free end of said slide ceases.