Abstract: An automatic device for supplying an elastomer or like material for an intion machine comprising an injection cylinder and a piston, wherein the piston is controlled by a hydraulic multiplier device formed by two stages, the first stage being called the downstream stage and the second stage being called the upstream multiplier stage, and wherein the device comprises a sensor for controlling the supplying of the cylinder with material so as to stock said cylinder by an electrically driven tape advance unit, the sensor being brought into play when the piston is moved in the forward direction, a pressure controller for tripping the upstream multiplier stage to multiply the pressure in the injection cylinder, the pressure controller being controlled from a pressure threshold of the fluid supply of the first downstream stage and an end of travel sensor for tripping the return of the first and second stages to make the piston return at the end of the injection.