Screw mixer, particulary for foundry molds

Mixer comprising an axle (2) mounted rotatably within a trough (1) and said axle having at a periphery at least one opening constituting an injection point (21) of at least one of several constituents of a mixture, said at least one constituent being supplied to said injection point (21) by means of a distributor (6) disposed within the axle (2), said distributor (6) comprising at least one injection nozzle (3) disposed at the injection point (21) in a wall of the axle (2) delimiting an injection channel (23) directly connected to a pressurized supply conduit (8) having an inlet for supplying said at least one constituent, and at least one jack (7) driven in axial reciprocatory movement within said axle to pass from an extended position in which said jack closes the inlet of the constituent supply conduit (8) opening into the injection channel (23) and a retracted position in which said jack exposes the inlet of said constituent supply conduit thereby permitting communication of the constituent supply conduit with the injection channel of the injection nozzle (3) and thus the injection into the trough (1) of said at least one constituent contained in the constituent supply conduit (8).