Patent ID: 7942663
Filing Date: 2011-05-17
Classification: B29C

Abstract:
1. A valve gate system for an injection molding machine, comprising: a valve gate unit configured to be in contact with a manifold of an injection molding machine for delivering a molten plastic flow from a hot runner system to an injection chamber, said valve gate unit having a valve pin for controlling the flow of the molten plastic from a hot runner system to an injection chamber, said valve pin connected substantially rigidly in the axial direction with a sliding unit; and an activating unit coupled with said valve gate unit, configured to be mounted external to a mold unit that houses the injection chamber, said activating unit having an element that extends through the mold unit to engage said sliding unit, so as to control valve pin, thus controlling the molten plastic flow from a runner system to an injection chamber, wherein said activating unit comprises one of a pneumatic and a hydraulic cylinder, wherein the piston of said cylinder is configured to engage a pair of substantially parallel activating bars of said element, said activating bars connected substantially rigidly and moving together, said activating bars each having an inclined slot configured to engage with a transversal pin, said transversal pin extending from said sliding unit, passing through vertical slots on the valve gate unit, and engaging with the inclined slots on the activating bars, such that a push-pull movement of the piston causes said transversal pin to slide in the inclined slots in the activating bars which in turn causes an up and down movement of said transversal pin inside the vertical slots, which in turn causes up and down movement of said sliding unit, which in turn causes an up and down movement of said valve pin.