Abstract: A method of forming and removing thin walled plastic articles from a plurality of dies in a thermoforming apparatus is described. In the method, a plurality of articles are formed and trimmed in a plurality of dies of a thermoforming apparatus. The apparatus includes a flat movable extractor plate. After the articles are formed they are removed from the apparatus by opening the dies sufficient to permit entrance of the flat movable extractor plate between the dies. The extractor plate has a non-porous top plate and a bottom plate having a plurality of spaced holes. A suction chamber is formed by the top and bottom plates with that suction chamber connected to the outlet end of a vacuum source and the inlet end of the vacuum is connected to a pressure control valve with a vent valve between the inlet end of the vacuum source and the pressure control valve.

Abstract: A thermoforming apparatus having a plurality of dies for forming a plurality of thin walled plastic articles in combination with an improved movable extractor plate assembly for moving an extractor plate between the plurality of dies of the thermoforming apparatus to remove formed articles is described. The movable extractor plate assembly includes an extractor plate having a vacuum chamber connected to the outlet end of a vacuum source and having at the inlet end of the vacuum source a pressure control valve and a vent valve between the vacuum source and pressure control valve. The assembly permits the control of pressure to the vacuum chamber to provide holding contact of articles formed onto the extractor plate without deformation of the thin walled articles. Additionally, the assembly permits the injection of air pressure into the vacuum chamber upon closing of the vacuum source to facilitate release of the formed articles from the extractor plate.

Abstract: Method and apparatus for stacking a plurality of plastic cups disposed within individual plastic envelopes including a frame, a conveyor on the frame, a stuffer swingably movable on the frame to stuff a portion of the envelope into the cup and move it into nested relation with the next adjacent downstream one of the cups to form a stack.

Abstract: A tamper-proof closure for a container including an endwall and an annular, threaded sidewall. The sidewall includes an internal projection for mating with a part of the container to prevent turning of the closure when the closure is mounted on said container. A tear tab is provided on the sidewall radially outwardly of the projection. The sidewall includes tear facilitating portions on circumferentially opposite sides of the tear tab to enhance tearing of the sidewall on opposite sides of the tear tab to permit the tear tab and the projection to be swung outwardly to a removed position in which the closure can be turned. Another aspect of the invention includes a method of making the closure.