Patent ID: 6228303
Filing Date: 2001-05-08
Classification: B29C

Abstract:
A method of injection molding, which comprises the steps of:a) supplying mold medium to a passageway;b) passing the mold medium through the passageway;c) directing the flow of fluid from the passageway through a cold runner and transversely to a mold cavity opening and through the mold cavity into a mold cavity opening into the mold cavity and said cold runner having an outwardly flared portion adjacent said mold cavity opening;d) allowing the mold medium to partially harden;e) moving a gate having an end surface with outermost dimensions substantially equivalent to the innermost dimension of the mold cavity opening from a first retracted position even with a side of the cold runner opposite the mold cavity opening, across an end of the cold runner, and into the mold cavity opening to a second position flush with a wall of the mold cavity forming a flush boundary wall of the mold cavity, whereby the gate, while moving from said first position to said second position transversely cuts off the portion of the mold medium in the cold runner downstream of said gate, drives and embeds said cut off end into the mold cavity so as to produce a flush finish on the molded part adjacent to and in the region of the opening.