Patent ID: 7402035

Claim:
An apparatus for thermoshaping a thermoplastic foil, the apparatus comprising: a stationary frame; a lower tool carried on the frame and having an upper face formed with an array of upwardly open mold cavities; an upper beam vertically displaceable on the frame above the lower tool; a punch plate fixed on the upper beam and provided with an array of downwardly projecting punches fittable in the cavities; means for heating the punches; a hold-down plate below the punch plate and limitedly vertically shiftable relative thereto, the hold-down plate being formed with an array of holes through which pass the punches and in which the punches are loosely received; means for cooling the hold-down plate; actuator means for downwardly shifting the upper beam when the foil is extending horizontally between the lower tool and the hold-down plate for first pressing the foil with the hold-down plate against the upper face of the lower tool and then in an end position pushing the punches through the holes against the foil into the cavities to form pockets in the foil at the cavities, the punches fitting loosely in the respective cavities in the end position; a seal ring between the hold-down plate and the punch plate, extending around all of the punches, and defining when the punch elate is pressed by the actuator means down against the hold-down plate a pressurizable chamber; and means for pressurizing the chamber with a gas and thereby forcing the gas through the holes down against the foil and pressing the foil tightly into the cavities.