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US 4,666,396 AGranted
Thermally insulated heated sprue bushing in plastic molding apparatus
OwnerRichard J. Shawinventor
Life of this patent
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Abstract
This invention is to disclose an insulated heated sprue bushing in plastic molding apparatus, and comprises a plastic molded segment as a thermal barrier to insulate or break the heat flow between the sprue bushing shoulder and neck section of the stem of the sprue bushing, and a heater band placed on the head of the sprue bushing.
Claims3
In plastic molding apparatus comprising a sprue bushing and a heater band positioned around a radially extending head section of said sprue bushing, wherein the improvement comprises:
- (a) Molded plastic insulation on a stem section and adjoining radially extending surface of said head section of said sprue bushing and an intermediate surfaces therebetween,
- (b) said molded plastic thermal insulating section in said stem section having the same outer diameter as the sprue bushing stem, and
- (c) said molded plastic thermal insulating section molded of polyphenylene sulide compound.
Dependencies are inferred from the claim text.