Vacuum-forming apparatus

Claim 1

VACUUM-FORMING APPARATUS FOR VACUUM-MOLDING PRECISION ARTICLES FROM THERMOPLASTIC SHEET MATERIALS COMPRISING: (A) AN OVEN LOCATED IN THE BACK PORTION OF SAID APPARATUS HAVING SEPARABLE TOP AND BOTTOM SECTIONS WITH HEATING ELEMENTS MOUNTED THEREON IN PARALLEL SPACED RELATIONSHIP AND DEFINING A SPACE THEREBETWEEN IN THE CLOSED POSITION INTO WHICH A SHEET OF SAID MATERIAL CAN BE LOCATED FOR SOFTENING, (B) A MOLDING PLATFORM MOUNTED ADJACENT SAID OVEN IN THE FRONT PORTION OF THE APPARATUS AND DEFINING A MOLDING SURFACE WITH A RAISED MARGINAL RIDGE EXTENDING THEREFROM, SAID SURFACE WITHIN SAID RIDGE BEING GRADUATED IN DEPTH, SAID MOLDING PLATFORM SURFACE AND SAID SPACE BETWEEN THE HEATING ELEMENT BEING SUBSTANTIALLY UNIPLANAR, (C) VACUUM PUMP MEANS CONNECTED TO SAID PLATFORM WITH A VACUUM EXHAUST OUTLET OPENING INTO SAID MOLDING SURFACE AT THE DEEPEST PORTION THEREOF, (D) A CLAMPING FRAME ASSEMBLY HAVING PARALLEL SPACED SUPPORT ARMS PIVOTALLY MOUNTED ABOUT A HORIZONTAL AXIS EXTENDING LATERALLY ACROSS SAID APPARATUS BETWEEN SAID OVEN AND SAID PLATFORM TO PIVOT BACKWARD TO A FIRST HEATING POSITION BETWEEN SAID HEATING ELEMENTS AND FRONTWARD TO A SECOND MOLDING POSITION ADJACENT SAID MOLDING PLATFORM, A SHEET FRAME FOR HOLDING THE THERMOPLASTIC SHEET MOUNTED BETWEEN SAID ARMS, A PRESSURE FRAME MOUNTED ON SAID ARMS WITH THE SHEET THEREBETWEEN, SAID PRESSURE FRAME HAVING A RAISED PERIPHERAL RIDGE PROJECTING FROM SAID FRAME FOR HOLDING A PERIPHERAL PORTION OF SAID SHEET MATERIAL BETWEEN IT AND ONE OF SAID RIDGE AND SAID GRADUATED SURFACES OF THE MOLDING PLATFORM IN ITS MOLDING POSITION TO EFFECT A SEAL THEREBETWEEN UPON APPLICATION OF PRESSURE ON SAID PRESSURE FRAME DOWNWARD AGAINST SAID PLATFORM, (E) A HANDLE ON SAID ARMS AGAINST WHICH HAND PRESSURE CAN BE APPLIED TO THE FRAME IN THE MOLDING POSITION TO SEAL SAID PERIPHERAL PORTION OF THE SHEET MATERIAL BETWEEN THE PRESSURE FRAME AND THE MOLDING PLATFORM, (F) MEANS FOR SWINGING SAID TOP SECTION OF THE OVEN AND ONE OF SAID HEATING ELEMENTS LATERALLY AWAY FROM SAID BOTTOM SECTION SO THAT SAID FRAME CAN BE PIVOTED TO POSITION SAID SHEET MATERIAL IN AND OUT OF SAID FIRST POSITION, AND (G) LEVER MEANS CONNECTED TO SAID FRAME AND EXTENDING FRONTWARD THEREFROM TOWARD SAID MOLDING PLATFORM WHEN SAID FRAME IS IN SAID FIRST POSITION FOR INITIALLY PIVOTING SAID FRAME TOWARD SAID SECOND POSITION OUT OF THE OVEN AND BRINGING SAID HANDLE WITHIN REACH AT THE FRONT OF THE APPARATUS.