A mold tool for injection molding
AssigneeLego A/S
InventorJozsef Gabor KOVACS
Life of this patent
Estimating the term…
Abstract
An injection-molding tool has at least two separate mold parts forming a set of mold cavities, and a set of runner channels extending between the mold inlet and leading melt flow to the mold cavities. The set of runner channels comprises a number of junctions, each junction dividing a downstream end of a primary runner channel extending upstream from the junction into two or more separate secondary runner channels extending downstream from the junction. A stretch of the downstream end of the primary runner has a cross section area being smaller than the cross section area of the primary runner further upstream from the junction.
Claims20
An injection-molding tool configured for being mounted in an injection-molding apparatus for automated molding of work pieces in plastics, the injection-moulding tool, in its closed position, comprising:
- at least two separate mold parts forming a set of mold cavities, the separate mold parts having:
- an inlet mold part having a mold inlet for injection of liquid plastics from the injection-moulding apparatus;
- and
- a second mold part, the inlet and second mold parts having abutting side faces facing a common mold separation plane, wherein:
- the abutting side faces form a set of runner channels extending between the mold inlet and leading melt flow to the mold cavities,
- the set of runner channels have a plurality of junctions, each junction dividing a downstream end of a primary runner channel extending upstream from the junction into two or more separate secondary runner channels extending downstream from the junction, and
- a stretch of the downstream end of the primary runner has a cross section area being smaller than the cross section area of the primary runner further upstream from the junction, and smaller than the largest cross section of the secondary runners.
(canceled)
An injection-molding cast comprising:
- a primary runner channel having:
- an upstream portion in communication with an inlet of the injection-molding cast;
- and
- a downstream portion having a cross-section that tapers to a narrow end;
- a first runner junction channel intersecting the downstream portion of the primary runner channel and receiving flow therefrom, the first runner junction channel having a cross-section that tapers to a narrow end toward a downstream portion;
- a second runner junction channel connected to the downstream portion of the first runner junction channel and receiving flow therefrom, the second runner junction channel having a cross-section that gradually increases toward a downstream portion;
- a secondary runner channel connected to the downstream portion of the second runner junction and receiving flow therefrom;
- and
- a molding cavity receiving flow from the secondary runner channel.
A mold for delivering molten material to mold cavities, the mold comprising:
- a sprue configured for receiving molten material at an inlet of the mold;
- a primary runner channel in fluid communication with the sprue, the primary runner channel for receiving the molten material;
- a secondary runner channel in fluid communication with and downstream of the primary runner channel;
- a tertiary runner channel in fluid communication with and downstream of the secondary runner channel;
- and
- a molding cavity receiving flow from the tertiary runner channel.
Dependencies are inferred from the claim text.