Gloucester Engineering Co., Inc.

United Industrial Syndicate, Inc.

Karl H Keim

A dual flow air ring is used to cool the exterior surface of thermoplastic tube after the plastic is extruded from an annular die. The surface of the wall forming the divider between the upstream and downstream flow paths which confronts the extruded tube is shaped to include a region of decreasing diameter in the direction of tube travel so that the flow path for air issuing from the lower discharge formed between the extruded tube and the surface is caused to converge. This converging flow stabilizes the tube thereby permitting more vigorous cooling and consequently higher production rates.

Air cooling ring for plastic film

For use with a thermoforming press adapted to form individual articles in the body of a thermoplastic web which has a degree of inherent stiffness, a trimming station for trimming the formed articles from the web subsequent to their formation characterized by a web transport that comprises at least a pair of rotary advancing devices directly engaged with the web at spaced apart locations across the width of the web, a drive for periodically rotating the advancing devices to produce indexing movement to the trimming press and means to periodically release the drive engagement of the rotary advancing devices with the web to enable relaxation of stress developed in the thermoplastic web and to allow the interaction of the web with the guides to realign the web in the absence of constraint by the rotary advancing devices, and the method of operation thereof. In the embodiment shown the rotary advancing devices positively engage the web, the drive is accurately controlled to move the web a predetermined distance after sensing of the approach of the formed article toward the trimming position, and the release of the advancing means occurs after the trim die has engaged the web, during selected trim cycles.

Rotary apparatus for advancing a web

Apparatus for forming and trimming articles from a web, featuring two conveyors, the first conveyor moving the web through the forming press and into a trimming station, the second conveyor moving the web within the trimming station. The two conveyors move in unison to transport a newly-formed section of web into the trimming station; a shear located between the conveyors severs the web; and, without loss of registration, the second conveyor moves the severed section of web past a trimming die, which cuts articles from a fraction of the severed section during each cycle.

Apparatus for forming and trimming articles from a web

In the application of working pressures, devices are used of the type having at least two members by which the working pressure is applied and a connection between them operable to vary the relationship of one of them relative to the work. Each connection includes first parts with the first part rotatably carried by the one member. Each part has an eccentric portion of a circular section with that of the first part rotatable within the eccentric portion of the second part and the second part is rotatably carried by the other pressure-applying member. Adjusting means are provided to turn the parts equally but oppositely with the members operatively connected and with the axis of the eccentric portion of the second part always in the plane of a predetermined line of force inclusive of the axis of the first part. The devices are shown as the toggle joints operable by means responsive to fluid under pressure to move one of the platens of the forming station of a thermoformer in opening and closing the molds, said station also desirably having means to assist in the reciprocation of the platens with the toggle joints desirably having an acute angular relationship when the molds are open. The adjusting means desirably but not necessarily includes a servo motor controlled by a gauge continuously monitoring the thickness of the sheet material being advanced through the thermoformer.

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South Portland, ME, United States of America

Karl H Keim