Apparatus for injecting resin into a mold

An injection apparatus for injecting thermosetting resin having fibers into a mold, comprising:

• a double barrel arrangement including an outer cylindrical barrel having an injection nozzle at a free front end thereof, said double barrel arrangement also including an inner cylindrical barrel slidably disposed within said outer barrel, and said inner barrel being engaged with an inner surface of said outer barrel;
• a stuffer of a jack for feeding the fibrous resin to said injection nozzle, said inner barrel communicating with said outer barrel at said free front end, said inner barrel also communicating with a feed outlet of said jack stuffer;
• a plunger disposed in said double barrel arrangement for axial, reciprocating and rotation, said plunger including a peripheral portion having a cross-section narrower than the diameter of said inner barrel, said peripheral portion and said inner barrel defining a continuous annular gap along a substantial length of said inner barrel to channel the thermosetting resin containing the fibers;
• check valve means for preventing a back flow of the fibrous resin and including a piston-cylinder arrangement for actuating said movable inner barrel relative to said outer barrel;
• a jack for activating said plunger relative to said inner barrel;
• motor means for rotating said plunger, said plunger and said inner barrel in combination being activated by cooperation of said piston-cylinder arrangement and said jack to move axially toward said injection nozzle;
• a metering or volume chamber having a variable volume for the fibrous resin being defined by the inner surface of said outer barrel, the free front end thereof, said check valve means and said inner barrel, wherein the fibrous resin is forced to enter from said jack stuffer into said inner barrel, and said plunger being forced to rotate with the fibrous resin and having freedom to move axially, together with said inner barrel, away from said injection nozzle against a back pressure applied thereto, the fibrous resin passing through said check valve means to fill said metering chamber, whereby said check valve means is closed to prevent a back flow of the metered resin from said metering chamber, said plunger and said inner barrel urged axially toward said injection nozzle to thereby inject the fibrous resin out of said nozzle.