Apparatus for expanding thermoplastic food in a vacuum

Claim 1

Apparatus for expanding thermoplastic food in a vacuum comprising: a thermoplastic food mold, a cover therefor, said cover having a first sealing ring at the periphery thereof, a first hollow cylindrical cylinder which passes through said cover and communicates with said thermoplastic food mold, said first hollow cylindrical cylinder having a first cavity, a first spring and a first sphere disposed within said first cavity so as to bias said first sphere to close a first opening in said first cavity, said first sphere having a first projection thereon which extends beyond said first cavity when said first sphere is biased to close said first opening, a second hollow cylindrical cylinder which is adapted for connection to a vacuum source, said second hollow cylindrical cylinder having a second cavity, a second spring and a second sphere disposed within said second cavity so as to bias said second sphere to close a second opening in said second cavity, said second sphere having a second projection thereon which extends beyond said second cavity when said second sphere is biased to close said second opening, a guide ring, means rigidly connecting said guide ring to said second hollow cylindrical cylinder, a second sealing ring for slidably connecting said guide ring to said first hollow cylindrical cylinder, whereby movement of said guide ring with respect to said first hollow cylindrical cylinder causes said first projection of said first sphere to push against said second projection of said second sphere causing compression of said first and second springs and opening of said first and second cavities to permit the connection of a vacuum source to said thermoplastic food mold.