Patent · US Expired

Apparatus for injection-molding a liner onto a metal spool

US4403933A · kind A · utility

28Cited by
7References
7Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 14, 1982
Grant dateSep 13, 1983
Priority date
Expiry dateApr 14, 2002

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB29C45/2708
  • WIPO fieldOther special machines
  • WIPO sectorMechanical engineering

Abstract

An apparatus for injection-molding an insulating liner onto the surface of a metal spool to be included in an electromagnetic flowmeter in which the fluid to be metered is conducted through the lined spool. The spool is composed of a cylindrical body having end flanges and a pair of diametrically-opposed circular bosses disposed midway between the flanges to receive the meter electrodes. To carry out injection molding, the spool is supported within a mold which defines a liner cavity conforming to the inner surface of the cylindrical body and to the faces of the end flanges, the liner cavity communicating with cavities conforming to the inner surface of the electrode bosses. The molding material is injected into a sprue in the mold which runs along the longitudinal axis of the spool toward the hub of a runner extending radially toward an axisymmetric ring gate opening into the liner cavity at a point adjacent the boss cavities. The molding material passing through the ring gate then flows in opposite directions in the liner cavity to evenly fill this cavity as well as the boss cavities without creating weld lines therein.

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