Method and apparatus for molding

Claim 1

A MOLDING APPARATUS FOR MOLDING THERMOSETTING MATERIALS WITH EXTREME DIMENSIONAL ACCURACY AND LIMITED FLOW OF SAID MATERIALS INTO THE MOLD, SAID APPARATUS CONSISTING OF A FIXED BASE HAVING VERTICALLY EXTENDING WALL PORTIONS SAID BASE AND SAID WALL PORTIONS DEFINING A MOLDING CAVITY ADAPTED TO RECEIVE A MATERIAL TO BE MOLDED AND AN UPPER SHOULDER AREA; AN INTERMEDIATE MEMBER SLIDABLY RECEIVED IN SAID VERTICALLY EXTENDING WALLS, A CENTRAL BORE EXTENDING THROUGH SAID MEMBER, SAID BORE TERMINATING IN AN ENLARGED SHALLOW CUP-SHAPED RECESS AT THE UPPER END OF THE BORE, SAID INTERMEDIATE MEMBER HAVING A STEPPED SHAPE COMPLEMENTARY TO THE MOLDING CAVITY DEFINED BY THE FIXED BASE AND VERTICALLY EXTENDING WALLS, SAID INTERMEDIATE MEMBER BEING POSITIONED SO AS TO BE SPACED FROM THE UPPER SHOULDER AREA OF THE BASE PRIOR TO THE APPLICATION OF PRESSURE TO SAID MOVABLE INTERMEDIATE MEMBER AND THEREFORE BEING SLIDABLE INTO AND OUT OF ONE PORTION OF SAID MOLDING CAVITY, AND A PISTON ADAPTED TO SLIDE WITHIN THE VERTICALLY EXTENDING WALLS OF SAID CUP-SHAPED RECESS AND TO APPLY PRESSURE TO MATERIAL TO BE MOLDED LOCATED IN SAID RECESS AND THEREBY TO CAUSE SAID SLIDABLE MEMBER TO MOVE RELATIVE TO SAID FIXED BASE AND INTO ENGAGEMENT WITH THE SHOULDER CONSTITUTING AN UPPER SURFACE OF SAID BASE, THE CROSS SECTIONAL AREA OF THE FACE OF SAID PISTON BEING GREATER THAN THE CROSS SECTIONAL AREA IN THE MOLDING CAVITY FORMED BY SAID VERTICALLY EXTENDING WALLS, MEASURED IN A PLANE PERPENDICULAR TO THE DIRECTION OF MOTION OF THE PRESS PLATENS.