| 摘要 |
This invention relates to an improved connector assembly for an electrically heated injection molding sprue bushing and a method of making the same. The sprue bushing has a helical portion of the heating element extending around a central core portion which conveys pressurized melt from a molding machine to a cavity in the mold. It is formed by filling the space between the stainless steel core portion and a stainless steel outer sleeve by a highly conductive copper alloy. The heating element has a lead portion which extends out through an aperture. The aperture provides a seat which receives two split washers with central openings therethrough for the lead portion. The washers are each formed of two half washers which are oriented so that the divisions therebetween are not aligned. A connector sleeve is inserted over the projecting lead portion with a flared end which is received in the aperture against the washers. The washers and connector sleeve are brazed in position in a vacuum furnace. This provides an integral connector assembly with sufficient structural strength which is sealed at the aperture against the copper alloy. This prevents the transfer of excessive heat out to the area of the connection with the external lead wires. |
