Patent · US Expired

Method of injection molding employing multichannel wave screw

US4363768A · kind A · utility

6Cited by
17References
3Claims
0Family size

Assignee

Inventor

Key dates

Filing dateFeb 13, 1981
Grant dateDec 14, 1982
Priority date
Expiry dateFeb 13, 2001

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C48/03
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

An injection molding apparatus is disclosed which includes a screw having a multichannel wave screw section. In the wave screw section, a helical passage defined by a radially extending helical screw flight is divided into a pair of flow channels by a radially extending helical barrier. The helical barrier is radially shorter than the helical conveying flight and the effective outer width thereof is axially narrower than the helical conveying flight. Each flow channel is provided with an undulating base surface that defines a plurality of wave cycles. The base surface varies in a radial direction between a valley portion and a crest portion for the wave cycle and a wave cycle is defined as extending between consecutive crest portions. The crest portions of one flow channel are helically displaced from the crest portions of the adjacent flow channel.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.