Apparatus and method for making molded pulp articles having holes therethrough

Claim 1

THE METHOD OF FORMING A MOLDED PULP ARTICLE HAVING A HOLE THEREIN WHICH COMPRISES IMMERSING IN A PULP SLURRY A SURFACE IN THE SHAPE OF SAID ARTICLE AND HAVING AN APERTURE THEREIN OF THE APPROXIMATE SIZE OF SAID HOLE, APPLYING SUCTION THROUGH SAID SURFACE TO FORM A LAYER OF PULP ON SAID SURFACE EXTENDING, AT LEAST, PARTIALLY OVER SAID APERTURE, REMOVING SAID SURFACE FROM SAID SLURRY, FORMING A SOLID EXPANDING JET OF GAS AT A POSITION SPACED FROM SAID SURFACE ON THE OPPOSITE SIDE THEREOF FROM SAID LAYER BY PASSING A CONFINED STREAM OF GAS THROUGH A RESTRICTED ORIFICE SMALLER THAN SAID APERTURE, AND DIRECTING SAID JET THROUGH SAID APERTURE WHILE SAID SUCTION IS STILL BEING APPLIED AND IMMEDIATELY AFTER SAID REMOVAL OF SAID SURFACE FROM SAID SLURRY BEFORE THE PULP AROUND SAID APERTURE HAS PARTIALLY DRIED IN ORDER TO CAUSE SAID JET TO CLEAR THE PULP FROM SAID APERTURE AND TO FORM A SMOOTH HOLE IN SAID LAYER OF PULP WITH A THICKENED RIM OF PULP AROUND SAID HOLE.