| 摘要 |
A control assembly for extruders and the like in which stock is fed to the extruder at a substantially constant rate, passing through the outlet end into die members to form the plastic product defined by the mold members. The extruder head is provided with an additional outlet port for forming a skim along the interior surface of the product being formed which requires a cut-off of stock flow at periodic intervals. Rotatable means are provided for selectively diverting a portion of the main stock flow to be introduced into an opening within an extrusion die member so as to be diverted therethrough and passed through a central opening which communicates with an associated outlet opening provided in the extruder die head to form the skim layer. The control means comprises an axially rotatable plug member which, in a first angular position, provides for cut-off of the central stock flow while in a second position permits the main stock flow to be diverted therethrough and to enter into the extruder central opening. The control means, which is preferably a piston-driven structure, is loosely linked to the plug means so as to prevent any jarring or misalignment of the plug member while at the same time providing rapid and positive on/off action of the control means.
|
