Patent ID: 6095789
Filing Date: 2000-08-01
Classification: B29C

Abstract:
A hot sprue bushing for transporting plasticized material from an injection nozzle to a mold cavity while controlling the temperature of the plasticized material, the hot sprue bushing comprising:an elongate body having a head, a stem and a distal end portion, the body having a through passage extending therethrough from end to end through the head, stem and distal end portion of the body for transporting said plasticized material through the hot sprue bushing from the head to the distal end portion thereof, the distal end portion of the body bearing first engaging means, and the head of the body being of greater cross-section than the stem so that the head provides a first abutment surface extending outwardly of the stem;an electrically powered heater wrapped around the stem of the head in heating conducting relationship with respect thereto;a sleeve surrounding the electrically powered heater; anda tip member having second engaging means engaged with the first engaging means on the distal end portion of the body, the tip member having a second abutment surface engaged with one end of the sleeve so as to urge the opposed end of the sleeve into engagement with the first abutment surface on the head, the tip member permitting egress of plasticized material from the through passage in the body,the head being provided with a recess for receiving an injection nozzle, and a bore communicating with the recess and extending through the head and into the stem of the body, the bushing further comprising an insert having high thermal conductivity and secured within the bore, the insert having a substantially central aperture extending therethrough, which central aperture forms part of the through passage extending through the body.