Controlled feed of stabilizing rod associated with controlled application of blowing gas
AssigneeThe Continental Group, Inc.
InventorWayne N. Collette
Life of this patent
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Abstract
This relates to a blow molding operation wherein centering rods are associated with preforms at least during the initial portion of the blowing cycle wherein the preforms are primarily axially elongated and wherein the freely suspended lower end of each preform must be guided against radial movement. In order to assure that the associated preform centering rods will remain in centering position with respect to the preforms at all times and will not engage the preforms so as axially to stretch the preforms, a control is provided for coordinating the advance of the preform centering rods with the introduction of blowing gas into the preforms, and thus with the axial elongation of the preforms due to internal blowing pressure.
Claims3
A blow molding apparatus of the type including a blow mold for receiving a preform and having a preform centering rod, feed means for advancing said centering rod from a retracted position to a position within and touching a preform positioned in said blow mold with said centering rod being in centering engagement with said preform, and control means for coordinating the application of blow gas with the movement of said centering rod wherein said centering rod is maintained in centering engagement with such preform while axial elongation of the preform is effected by blow gas pressure, said control means including a plurality of control switches for controlling the selective introduction of blowing gases into said preform, said control switches being spaced in the direction of centering rod movement, and switch actuating means connected to said centering rod for movement therewith and for sequentially actuating said control switches.
Dependencies are inferred from the claim text.