Extrusion press

Claim 1

THE METHOD OF MAKING A HOLLOW METAL EXTRUDED TUBE HAVING LONG THIN TUBULAR BODY AND EXTERNALLY THICKENED WALLS AT OPPOSITE ENDS THEREO, BY EXTRUDING A CONFINED METAL CHARGE THROUGH AN ANNULAR ORIFICE BETWEEN A DIE OF FIXED AND A SUBSTANTIALLY CYLINDRICAL MANDREL EXTENDING THROUGH THE BORE OF SAID DIE HAVING IN ALTERNATION, SMALL MANDREL PORTIONS, AND TERMINAL AND INNER LARGE MANDREL PORTIONS WHICH ARE OF EQUAL HEIGHT OR DIAMETER, TO VARY THE ORIFICE AND CONTROL THE WALL THICKNESS OF THE EXTRUDED PRODUCT, WHICH COMPRISES EXTRUDING THE CHARGE THROUGH THE ORIFICE WHILE ADVANCING THE MANDREL TO FORM UNIFORM SUCCESSIVE THICK AND THIN ADJOINING PARTS OF THE EXTRUDED PRODUCT BY VARYING THE INTERNAL CONFIGURATION OF THE EXTRUSION AT THE DIE, AND INCLUDES THE FOLLOWING STEPS: SUCCESSIVELY (A) ENLARGING THE EXTRUSION ORIFICE TO FORM A UNIFORMLY AND INTERNALLY THICKENED WALL, (B) GRADUALLY REDUCING THE ORIFICE TO FORM A TAPERED WALL OF DECREASING THICKNESS, (C) MAINTAINING THE REDUCED ORIFICE SUBSTANTIALLY CONSTANT TO FORM A LONG THIN TUBULAR BODY, (D) GRADUALLY ENLARGING THE EXTRUSION ORIFICE TO FORM A TAPERED WALL OF INCREASING THICKNESS, (E) MAINTAINING THE ENLARGED ORIFICE SUBSTANTIALLY CONSTANT TO FORM A SECOND UNIFORMLY AND INTERNALLY THICKENED WALL, AND PROGRESSIVELY FREEING THE EXTRUSION FROM CONFINEMENT BY THE DIE, WILE ADVANCING IT RELATIVE TO THE MANDREL OUTWARDLY OF THE DIE AND RADIALLY EXPANDING THE FIRST FORMED THICKENED WALL OVER THE TERMINAL LARGE MANDREL PORTION AND THE SUCCEEDING THICKENED WALL OVER AN INNER LARGE MANDREL PORTION TO FORM A COMPLETED HOLLOW EXTRUDED TUBE OF UNIFORM INTERNAL DIAMETER THROUGHOUT AND HAVING A LONG THIN TUBULAR BODY AND EXTERNALLY THICKENED WALLS OF SUBSTANTIALLY UNIFORM THICKNESS AT OPPOSITE ENDS THEREOF, AND HAVING AN EXTERNALLY THICKENED TAPERED WALL INTERMEDIATE EACH OF SAID UNIFORMLY THICKENED END WALL AND SAID TUBULAR BODY.

Claim 2

THE METHOD OF MAKING A HOLLOW METAL EXTRUDED TUBE HAVING LONG THIN TUBULAR BODY AND EXTERNALLY THICKENED WALLS AT OPPOSITE ENDS THEREO, BY EXTRUDING A CONFINED METAL CHARGE THROUGH AN ANNULAR ORIFICE BETWEEN A DIE OF FIXED AND A SUBSTANTIALLY CYLINDRICAL MANDREL EXTENDING THROUGH THE BORE OF SAID DIE HAVING IN ALTERNATION, SMALL MANDREL PORTIONS, AND TERMINAL AND INNER LARGE MANDREL PORTIONS WHICH ARE OF EQUAL HEIGHT OR DIAMETER, TO VARY THE ORIFICE AND CONTROL THE WALL THICKNESS OF THE EXTRUDED PRODUCT, WHICH COMPRISES EXTRUDING THE CHARGE THROUGH THE ORIFICE WHILE ADVANCING THE MANDREL TO FORM UNIFORM SUCCESSIVE THICK AND THIN ADJOINING PARTS OF THE EXTRUDED PRODUCT BY VARYING THE INTERNAL CONFIGURATION OF THE EXTRUSION AT THE DIE, AND INCLUDES THE FOLLOWING STEPS: SUCCESSIVELY (A) ENLARGING THE EXTRUSION ORIFICE TO FORM A UNIFORMLY AND INTERNALLY THICKENED WALL, (B) GRADUALLY REDUCING THE ORIFICE TO FORM A TAPERED WALL OF DECREASING THICKNESS, (C) MAINTAINING THE REDUCED ORIFICE SUBSTANTIALLY CONSTANT TO FORM A LONG THIN TUBULAR BODY, (D) GRADUALLY ENLARGING THE EXTRUSION ORIFICE TO FORM A TAPERED WALL OF INCREASING THICKNESS, (E) MAINTAINING THE ENLARGED ORIFICE SUBSTANTIALLY CONSTANT TO FORM A SECOND UNIFORMLY AND INTERNALLY THICKENED WALL, AND PROGRESSIVELY FREEING THE EXTRUSION FROM CONFINEMENT BY THE DIE, WILE ADVANCING IT RELATIVE TO THE MANDREL OUTWARDLY OF THE DIE AND RADIALLY EXPANDING THE FIRST FORMED THICKENED WALL OVER THE TERMINAL LARGE MANDREL PORTION AND THE SUCCEEDING THICKENED WALL OVER AN INNER LARGE MANDREL PORTION TO FORM A COMPLETED HOLLOW EXTRUDED TUBE OF UNIFORM INTERNAL DIAMETER THROUGHOUT AND HAVING A LONG THIN TUBULAR BODY AND EXTERNALLY THICKENED WALLS OF SUBSTANTIALLY UNIFORM THICKNESS AT OPPOSITE ENDS THEREOF, AND HAVING AN EXTERNALLY THICKENED TAPERED WALL INTERMEDIATE EACH OF SAID UNIFORMLY THICKENED END WALL AND SAID TUBULAR BODY.