General Electric Company

Lloyd W Garrett

Patrick J Bowles

John V Howard

Robert F Heil

A process and apparatus for molding a plurality of articles of hardenable material such as plastic which requires each article to be maintained under heat and pressure for a cure interval. A molding press is utilized wherein there is placed a first open mold assembly having spaced die halves between supporting mold platens. At least one of the die halves has a resilient pressure pad between the die and the mold platen supporting the die half. The press is closed to maintain the mold platens in a first force applying position having a slight gap between the die halves and locking the platens in the first position. The mold assembly is removed while in its first locked position from the press and gas from the curing material is evacuated through the gap between the die halves while heating the material. The mold assembly in its first locked position is again placed in the press and the press is closed to unlock the mold assembly and apply and maintain a second molding force greater than the first molding force and sufficient to completely close the die halves to a second position for curing the material and compress the resilient pressure pad. The mold platens are locked in the second position whereby the pressure pad will apply internal forces against the dies to maintain the correct curing pressure in the event of shrinkage of the cured material. The mold assembly is removed from the press in its second locked position and the material is cured under pressure and at elevated temperatures for the correct time interval to form the article. Finally, the mold assembly is unlocked and the article is removed therefrom.

Molding process

An apparatus for molding a plurality of articles of hardenable material such as plastic which requires each article to be maintained under heat and pressure for a cure interval. A molding press is utilized wherein there is placed a first open mold assembly having spaced die halves between supporting mold platens. At least one of the die halves has a resilient pressure pad between the die and the mold platen supporting the die half. The press is closed to maintain the mold platens in a first force applying position having a slight gap between the die halves and locking the platens in the first position. The mold assembly is removed while in its first locked position from the press and gas from the curing material is evacuated through the gap between the die halves while heating the material. The mold assembly in its first locked position is again placed in the press and the press is closed to unlock the mold assembly and apply and maintain a second molding force greater then the first molding force and sufficient to completely close the die halves to a second position for curing the material and compress the resilient pressure pad. The mold platens are locked in the second position whereby the pressure pad will apply internal forces against the dies to maintain the correct curing pressure in the event of shrinkage of the cured material. The mold assembly is removed from the press in its second locked position and the material is cured under pressure and at elevated temperatures for the correct time interval to form the article. Finally, the mold assembly is unlocked and the article is removed therefrom.

Molding apparatus

An article accumulator and transfer system and method is provided for combining the transfer of articles from a loading station to an unloading station and the accumulation of articles to avoid prolonged, interrupted operation of the unloading station in the event the loading station is inoperative. The method includes a first primary operation which intermittently moves and stops a continuous conveyor having a plurality of article stations between the loading and unloading stations, placing articles on the conveyor at the loading station when the conveyor is stopped and there is no article on the conveyor article station at the loading station at a rate greater than the rate at which the articles are removed at the unloading station and removing articles from non-sequential article stations of the conveyor when at the unloading station and the conveyor is stopped. A secondary operation is provided in the event the loading station is inoperative and includes intermittently moving and stopping the continuous conveyor between loading and unloading stations, sensing each time the conveyor stops the presence or absence of articles in the article station at the unloading station and at the first preceding article station before the unloading station and sending a corresponding signal to an electronic control device, and selecting, as a function of the signals, moving the conveyor to bring the next preceding article station to the unloading station when an article is absent at the unloading station, and selecting, when an article is in the article station at the unloading station, which one as between the article station at unloading station and first immediately preceding article station thereto the article to be unloaded at the unloading station based on the logic of selecting the article at the unloading station when there is an article at the unload station and no article at the first preceding article station and selecting the article of the first preceding article station when there is an article at the unload station and the first preceding article station then removing the selected article at the unloading station.

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Louisville, KY, United States of America

Lloyd W Garrett