Backflow prevention device
AssigneeKrauss-Maffei Kunststofftechnik GmbH
InventorMartin Würtele
Life of this patent
Estimating the term…
Abstract
A backflow prevention device for an injection molding machine includes a screw tip having a tip end, a central body member connected to the tip end, a thrust ring at a rear end of the body member, and a mounting end for attachment to a plasticizing screw. A locking ring is arranged at a distance to the body member to define an annular gap and is axially movable between an open position, in which a first sealing surface rests against a shoulder of the tip end, allowing passage of material, and a closed position, in which a second sealing surface rests against a shoulder of the thrust ring, prohibiting entry of material. Disposed in the annular gap coaxial to the locking ring is at least one mixing element in the form of a circular ring which has circumferential bores in spaced-apart disposition for axial material transport.
Claims20
A backflow prevention device for an injection molding machine, comprising:
- a screw tip defined by a longitudinal axle and having a tip end, a central body member connected to the tip end, a thrust ring positioned at a rear end of the body member, and a mounting end extending from the rear end of the body member for attachment to a plasticizing screw;
- a locking ring arranged in coaxial relationship to the longitudinal axis and having first and second sealing surfaces, said locking ring being movable in the direction of the longitudinal axis between an open position, in which the first sealing surface rests against a shoulder of the tip end, allowing passage of material, end a closed position, in which the second sealing surface rests against a shoulder of the thrust ring, prohibiting entry of material, wherein the locking ring and the body member define together an annular gap;
- and
- at least one mixing element disposed in the annular gap and constructed in the form of a circular ring in coaxial relationship to the looking ring, said mixing element having circumferential bares in spaced-apart disposition for transport of material in the direction of the longitudinal axis.
A backflow prevention device for an injection molding machine, comprising:
- a screw tip defined by a longitudinal axis and having a tip end, a central body member connected to the tip end, a thrust ring positioned at a rear end of the body member, and a mounting end extending from the rear end of the body member for attachment to a plasticizing screw;
- and
- a locking ring arranged in coaxial relationship to the longitudinal axis and having first and second sealing surfaces, said locking ring being movable in the direction of the longitudinal axis between an open position, in which the first sealing surface rests against a shoulder of the tip end, allowing passage of material, and a closed position, in which the second sealing surface rests against a shoulder of the thrust ring, prohibiting entry of material, wherein the locking ring and the body member define together an annular gap, wherein the locking ring has an end piece adjacent the tip end and constructed to serve as mixing element having circumferential spaced-apart mixing bores in offset relationship,
- wherein a first plurality of bores of the end piece directs a material flow in a substantially axial direction, and a second plurality of bores of the end piece directs a material flow in a substantially radial direction.
Dependencies are inferred from the claim text.