AS SEEN ON EACH "MOLD BASE MACHINING DIMENSION" SHEET IN THE D-M-E COLLAPSIBLE CORE TECHNICAL DATA BOOK, THE CROSS SECTION DEPICTS A TYPICAL COLLAPSIBLE CORE MOLD DESIGN. THE COLLAPSIBLE CORE IS MOUNTED IN THE EJECTOR RETAINER PLATE; THE CENTER PIN IS MOUNTED IN A BOTTOM CLAMP PLATE. AN EXTENDED STRIPPER PLATE HAS BEEN INCORPORATED FOR PROPER EJECTION AND CYLINDERS ARE SHOWN INSTALLED FOR THE LAST STAGE OF THE REQUIRED TWO STAGE EJECTION. ALSO, VITAL TO THE DESIGN IS THE USAGE OF GUIDED EJECTION.

THE MOLDING SEQUENCE CAN EASILY BE FOLLOWED BY STARTING WITH THE OPENING OF THE PRESS: THE PRESS OPENS AND THE MOLD PARTS AT THE MAIN PARTING LINE. WHEN SUFFICIENT MOLD OPEN IS ACHIEVED, THE EJECTOR PLATE ASSEMBLY IS MOVED FORWARD BY MECHANICAL OR HYDRAULIC KNOCKOUTS OF THE PRESS. THE EJECTOR PLATE ASSEMBLY WITH THE COLLAPSING CORE IS MOVING FORWARD THE NECESSARY STROKE REQUIRED TO MOVE THE CORE OFF OF THE CENTER PIN AND COLLAPSE THE CORE. (THIS IS THE FIRST STAGE OF EJECTION)

IF THE SEGMENTS OF THE CORE FAIL TO COLLAPSE FOR ANY REASON DURING THIS STAGE, THE POSITIVE COLLAPSE SLEEVE WILL COME INTO PLAY AND ENSURE THE START OF THE COLLAPSE. ALSO, THE STRIPPER PLATE AND EJECTOR PLATE ASSEMBLY MOVE TOGETHER BECAUSE OF THE RETURN PINS LOCATED DIRECTLY UNDER THE STRIPPER PLATE. THIS SIMULTANEOUS MOVEMENT CONTINUES UNTIL THE EJECTOR PLATE ASSEMBLY IS FULL FORWARD. AT THIS POINT, A LIMIT SWITCH IS ACTUATED. THIS IN TURN ACTUATES THE CYLINDERS TO TAKE OVER AND TO CONTINUE TO MOVE THE STRIPPER PLATE WITH THE STRIPPER INSERT, MOVING THE PART AWAY FROM THE COLLAPSED CORE. (SECOND STAGE)

WHEN AUTOMATIC PART STRIPPING IS REQUIRED, MEANS MUST BE PROVIDED FOR CARRYING THE MOLDED PART OFF OF THE COLLAPSED CORE AT THE COMPLETITION OF THE EJECTOR STROKE. THIS IS COMMONLY DONE BY PROVIDING A RING PROJECTION (.010 X .010 MIN.) ON THE FACE OF THE STRIPPER INSERT. SHOCK DISLODGES THE PART FROM THIS RING AND PERMITS IT TO DROP OUT OF THE MOLD AT THE END OF THE STRIPPER STROKE. THE PART MUST NOT

DRAG OVER THE CORE. WHEN REMOVING THE PART MANUALLY, THE STRIPPER RING AND THE CYLINDERS ARE NOT REQUIRED.

PLEASE NOTE THAT THE STRIPPER PLATE ACTUATION MUST BE SEQUENCED SO THAT THE CYLINDERS HAVE RETURNED THE STRIPPER PLATE BEFORE THE EJECTOR PLATES ARE RETURNED. THIS APPLIES TO ALL PARTS WHETHER THROUGH MOLDED OR NOT. THE STRIPPER PLATE MUST ALWAYS BE RETURNED TO ITS ORIGINAL POSITION BEFORE RE-EXPANDING THE CORE. THIS WILL AVOID INTERFERENCE OF THE STRIPPER INSERT WITH THE CORE AND POSSIBLE CORE DAMAGE.

WHEN THE TOP FACE OF THE COLLAPSIBLE CORE SHUTS OFF AGAINST THE CAVITY, ALL CORES MUST BE GROUND TO THE SAME OVERALL LENGTH. ALSO, WHENEVER THIS CONDITION EXISTS, AN EARLY EJECTOR RETURN MUST BE EMPLOYED. THE EARLY EJECTOR RETURN WILL ENSURE THAT THE CORE IS EXPANDED BEFORE THE MOLD CLOSES AT PARTING LINE.

Coreseq.doc

OCTOBER, 2004