Apparatus for making plastic covers

Claim 1

IN AN APPARATUS FOR MAKING MULTILAYER PLASTIC COVERS BY ALINING STACKED WORK PIECES INCLUDING TWO OPPOSED THERMOPLASTIC SHEETS HAVING OPPOSED PORTIONS EXTENDING BEYOND AN INTERMEDIATE MEMBER FOR BEING SUBJECTED TO HIGH FREQUENCY ELECTRICAL ENERGY AS WELL AS PRESSURE CLOSELY ADJACENT THE PERIPHERY OF SAID INTERMEDIATE MEMBER, THE COMBINATION OF A JIG ADAPTED TO BE MOUNTED ON A PRESS BED IN OPERATIVE RELATION WITH A MOVABLE PRESS HEAD SAID JIG ADAPTED TO BE CONNECTED TO ONE SIDE OF A SOURCE OF SAID HIGH FREQUENCY ELECTRICAL ENERGY, SAID JIG COMPRISING A FIRST ALINING MEANS AND A SECOND ALINING MEANS, SAID FIRST ALINING MEANS INCLUDING A NONCONDUCTIVE FRAME MEMBER FOR RECEIVING AND ALINING SAID THERMOPLASTIC SHEETS, SAID SECOND ALINING MEANS BEING MOVABLE RELATIVE TO SAID FRAME MEMBER A PREDETERMINED DISTANCE TO A POSITION FOR OVERLYING A PORTION OF A FIRST ONE OF SAID SHEETS AND FOR DEFINING THE POSITION OF SAID INTERMEDIATE MEMBER ON SAID ONE SHEET, RELEASABLE LOCKING MEANS ON SAID JIG FOR HOLDING SAID SECOND ALINING MEANS IN SAID POSITION, MEANS FOR MOVING SAID SECOND MOVALBE MEANS OUT OF SAID POSITION ON RELEASE OF SAID LOCKING MEANS, WHEREBY THE SECOND ONE OF SAID SHEETS MAY BE PLACED OVER SAID INTERMEDIATE MEMBER AND SAID SECOND ALINING MEANS WHILE THE INTERMEDIATER MEMBER IS ENGAGED BY SAID DSECOND ALINING MEANS, AND MEANS FOR RELEASING SAID LOCKING MEANS WHEN SAID PRESS HEAD IS MOVED TOWARDS IT, SAID RELEASING MEANS BEING CONNECTED TO SAID PRESS HEAD, SAID HEAD FORMING THE OTHER SIDE OF THE CONNECTION TO SAID SOURCE OF ELECTRICAL ENERGY.