Patent ID: 7771189

Claim:
Injection molding apparatus comprising: a hot melt distribution block; a hot melt discharge nozzle secured to said block, said nozzle having a base end configured to permit the nozzle to swivel with respect to the block, said nozzle further having a discharge end comprising a nozzle tip; a mold having a pair of opposed mold halves that cooperatively define, when the mold is closed, a cavity and a gate passage leading to the cavity, at least one of said mold halves being movable away from the other mold half to open the mold along a split line that longitudinally bisects the gate passage and the cavity; and a tubular insert mounted on said other mold half and having an insert tip projecting into the gate passage in sealing engagement with sidewalls thereof, said insert having a chamber disposed to receive the nozzle for delivery of hot melt from the nozzle tip into the cavity through the insert tip, said chamber having an end wall surrounding an opening into said insert tip, said chamber further having an axially extending locating sidewall at the radially outer limit of said end wall, said nozzle tip having a radially outermost edge confined radially by said locating sidewall of the chamber for locating the nozzle tip in axial alignment with said opening and permitting the nozzle tip to swivel relative to the insert during swivelling of the nozzle relative to the block, said nozzle tip having an end face surrounding an outlet in the nozzle tip and disposed to be in opposed relationship to the end wall of the chamber of the insert when the nozzle tip is received within the insert, said end face sloping away from said outlet as said outermost edge is approached to render said end face generally convex, said end wall of the chamber sloping away from said opening as the locating sidewall is approached to render the end wall generally concave, said end face sloping away from said outlet at a faster rate than said end wall slopes away from said opening to provide a clearance void between the end face and the end wall that progressively increases in width as the locating sidewall is approached.