Membrane-spring closure-nozzle processing thermoplastic - has spring-loaded bar accurately closing nozzle-bore with adjustable pressure

摘要

The nozzle has a cylindrical body, which is provided, from the outside, with a groove, running parallel to the central axis and directed towards the centre axis. The groove contains a membrane-spring, which is suspended in the groove in the back part of the nozzle, presses, in the first part of the nozzle, on a bar, which can be moved up to the nozzle-bore and accurately closes the nozzle-bore with its frong surface which is semi-spherical. The pressure of the spring on the bar is adjusted by means of a screw, which presses on the spring. The advantages are simple prodn.; robust construction; no external spring mechanism; can be easily heated; adjustable opening pressure; can be opened or closed in any position of the nozzle; no internal nozzle-parts and therefore unimpeded flow of matl.