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US 4,368,028 AGranted
Annular flow plastic extrusion nozzle or gate
OwnerAnthony J. Grish, Thomas A. Grishinventors
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OwnerAnthony J. Grish, Thomas A. Grishinventors
Estimating the term…
An annular flow plastic extrusion nozzle or gate is provided with a torpedo to heat the plastic to be extruded through the gate. A passage is provided around the torpedo and the torpedo has a flattened end in the parting line of the mold. An annular opening is provided around the base of the torpedo in the nozzle or gate housing. A conical recess is provided in the flat end of the torpedo to receive a correspondingly shaped male extension of a shaft or core pin removably mounted in a portion of the mold. A hub cavity in that portion of the mold may be provided around the end of the pin and mold cavities extend therefrom as desired to form propellers or impellers or rotors of the desired configuration. Discharge of the flowable plastic through the 360.degree. annular nozzle or gate into the mold cavities prevents any compacting of the plastic and provides an even distribution and flow thereof whereby the resulting propeller, impeller or rotor has no heavy spots affecting even and uniform rotation about the precisely centered core pin or shaft.
An annular flow plastic extrusion nozzle and mold for molding rotary members of uniform density and rotary balance, comprising first and second mold elements joining on a parting line, a nozzle housing in said first element, a bore in said housing opening on said parting line, a torpedo in said bore and annularly spaced therefrom, a taper in said bore adjacent said parting line, a corresponding taper on said torpedo, a flat end surface for said torpedo on said parting line, an annular nozzle between said taper of said bore and said taper of said torpedo opening on said parting line, mold cavities in said second mold element receiving plastic from said annular nozzle, a centered bore in said second mold element adapted to receive an axle pin, a male portion on an end of said pin, a female portion in said flat end of said torpedo receiving said male portion and centering said axle when said mold elements are joined.
Dependencies are inferred from the claim text.