Two stage injection molding apparatus for encapsulating deformable articles

Claim 1

AN INJECTION MOLDING APPARATUS, COMPRISING: A MOLD HAVING A CAVITY FOR A DEFORMABLE ARTICLE TO WHICH A THERMOPLASTIC MATERIAL IS TO BE MOLDED; A SOURCE OF LIQUID THERMOPLASTIC MATERIAL; A MOVABLE RAM; A PNEUMATIC PISTION AND CYLINDER DEVICE CONNECTED WITH SAID RAM, MOVING THE SAME WITH RELATION TO SAID MATERIAL SOURCE AND SAID MOLD TO FORCE PLASTIC MATERIAL FROM THE SOURCE INTO SAID MOLD, THE QUANTITY OF MATERIAL FORCED INTO THE MOLD BEING A FUNCTION OF THE POSITION OF SAID RAM; A SOURCE OF AIR UNDER PRESSURE FOR OPERATING SAID PISTON AND CYLINDER DEVICE; VALVE MEANS CONTROLLING THE AIR FROM SAID SOURCE TO SAID PISTON AND CYLINDER AND HAVING AN OPEN CONDITION IN WHICH SAID PISTON AND CYLINDER DEVICE IS ACTUATED BY SAID AIR AT A FIRST AIR PRESSURE; AND CONTROL MEANS, CONNECTED WITH SAID VALVE MEANS, AND RESPONSIVE TO THE POSITION OF SAID RAM, ACTUATED WHEN THE QUANTITY OF MATERIAL IN SAID MOLD IS LESS THAN SUFFICIENT TO FILL THE MOLD, TO CLOSE SAID VALVE, TGHE AIR UNDER PRESSURE IN SAID CYLINDER EXPANDING TO FORCE ADDITIONAL MATERIAL INTO THE MOLD AT A PRESSURE LESS THAN SAID FIRST PRESSURE.