Mold for plastics, particularly multi-component plastics injection mold having blind channel

Claim 1

In a mold for multi-component plastics wherein cooperating mold sections confront each other at plane surfaces and cooperate with each other to define a plastics-receiving portion and a mold cavity communicating with the plastics-receiving portion to receive plastics therefrom, th plastics-receiving portion including a sprue runner, a blind channel with an inlet end in unobstructed open communication and longitudinal alignment with the sprue runner and having substantially the same cross-sectional flow area as the sprue runner, the inlet end being the only plastics flow access to the blind channel, and a sprue runner branch in communication with the sprue runner and intersecting the sprue runner in a direction transversely of the sprue runner, the sprue runner branch delivering plastics to the mold cavity, the sprue runner branch having a significant restriction to flow of plastics from the sprue runner as compared to the free flow of plastics through the unobstructed open communicaton into the blind channel from the sprue runner, the restriction being located adjacent the intersection of the sprue runner branch with the sprue runner.