Thermoforming apparatus

Claim 1

In apparatus for continuous vacuum forming comparatively thin-walled articles from an intermittently moved sheet of thermoplastic material in a forming station comprising stamping means having stamping blades attached thereto and projecting therefrom in the direction of said sheet with their cutting edges spaced therefrom and means for heating said blades, said stamping means being disposed on one side of the sheet and being displaceable from a rest position away from said sheet to a working position adjacent said sheet, vacuum forming means on the opposite side of said sheet and comprising at least two vacuum forming dies, each displaceable alternately and successively from a molding location in substantial registry with said sheet in the forming station to a molded article discharge location out of registry with said sheet, each said forming die having a plurality of die molds with flat coplanar surfaces substantially parallel to said sheet having formed therein mold openings facing said sheet when at said molding location, each mold opening being bounded by a resilient counter-surface wider than a stamping blade and in substantial registry therewith when the mold in which it is formed is at said molding location, said stamping means being arranged so that, when displaced to the working position and during the stamping operation, the heated blades thereof engage the sheet and press it against said counter-surfaces for stamping and severing said articles from said sheet before the dies containing the articles are displaced from the molding location to the article discharge location, and means for displacing said stamping means to the working position and for carrying out the stamping operation with very little stamping force, whereby the molded articles can be completely severed from said sheet with said very little stamping force.