John Brown Inc.

Brown Machine, LLC

Leesona Corporation

Roland Karklin

Albert W Arends

Victor L Chun

Robert C Whiteside

Edward J Russell

Terrance L Brokoff

James R Greiner

A thermoforming machine utilizes two clamping frames to advance cut sheets through heating and forming stations, with the clamping frames returned via an overhead path above the oven in the heating station. Pneumatic cylinders arranged about the inner perimeter of the frames are operated to grip the sheet and release the sheets, which are pressurized and released via fluid connections established when the frames are lifted from a transfer bar structure at the loading and forming stations. The clamping frames have pivoted end sections which are engaged by extendible gear posts at the forming station to bend the clamped sheet into greater conformity with the tooling shape prior to forming.

Thermoforming machine with linear recirculation of sheet holding frames

A differential pressure thermoforming machine has a female mold with a female mold cavity, and an opposing mold, with a mold closing portion cooperable therewith. A foam injection head is perimetrally separated from the mold closing portion and is provided on the opposing mold. When the molds are initially closed, a differential pressure is created in the molds to cause the heated plastic sheet to move into contact with the mold cavity and form a configured pocket in the sheet. Mechanism is provided for releasing the plastic sheet from the carriage in which it has been moved between the molds, after the molding operation, to the cavity in the female mold, after which the molds are restored to spread-apart position. Mechanism is then activated to move the opposing mold to a position in which the foam injection head is now aligned with the female mold, whereupon the molds are again closed to bring the injection head into the pocket, whereupon the foam injection head is operated to charge a settable foam material to the pocket formed.

Differential pressure thermoforming and foam injection process and

Thermoforming machines with a heating station and a downstream mold station have carrier clamp frames for gripping the edges of sheets of plastic at a load station and indexing them successively to a heating station and a mold station. The carrier frame members to which the plastic may be releasably clamped carry their own remotely operated clamps and are themselves expandable and contractible to a condition in which, prior to molding, they control the sag in the sheet formed during heating of the sheets to differential pressure forming temperature. The plastic sheet can be molded to only a portion of a product which functions as a mold member.

Thermoforming methods

Thermoforming methods and apparatus

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Beaverton, MI, United States of America

Roland Karklin