SCREW TIP AND MOULDING MACHINE INSTRUMENT Russian patent published in 2008 - IPC B29C45/52 

FIELD: technological processes; mechanics.

SUBSTANCE: technical outcome is achieved by screw tip, used in instruments for moulding machines, consisting of case, several inlet openings in the case; several guide holders, and a shut off valve chamber in the case. The chamber of the shut off valve is linked to the set of inlet openings for formation of a path for movement of a stream through the chamber of the shut off valve. The chamber of the shut off valve has a surface for contact with a transmission element in the operating position. The set of guide holders is located between the surface of the chamber of the shut off valve and the surface of the transmission element for keeping and directing the transmission element into the operation position. The chamber of the shut off valve at the end of the case can regulate the stream of material in the operating position. The chamber of the shut off valve is on the central axis of the case, and the set of inlet openings in the case are linked to the chamber of the shut off valve. The transmission element is on the axis in the chamber of the shut off valve. The set of guide holders work together with the case and the transmission element for positioning the transmission element on the axis of the chamber of the shut off valve and provision for movement of the transmission element between open and closed positions. The guide holders are in form of three pins, at equal distance from each other around the circumference of the chamber of the shut off valve. The pins touch the sides of the transmission element so as to hold and bring the transmission element into the operation position.

EFFECT: simple making and assembling of shut off valve; reduced wearing of space between shut off valve and bushing and improved resistance to jerking of tip of screw during injection process.

12 cl, 7 dwg