US Patent 11878453 Leak protection bushing for hotrunner manifold assembly

A hotrunner assembly for an injection molding apparatus includes a hotrunner manifold, a nozzle for conveying liquid resin from an outlet of the hotrunner manifold, a valve pin linearly movable within and along a longitudinal axis of the nozzle to control flow of the liquid resin from the outlet of the hotrunner manifold, an actuator for driving the valve pin, a primary seal disposed radially between the valve pin and walls of a bore extending through the hotrunner manifold, and a secondary seal located axially between the hotrunner manifold and the actuator and circumscribing a section of the valve pin to prevent gases or liquid resin from contacting the actuator.