CASTING HEAD WITH SPHERICAL TOP PORTION Russian patent published in 1997 - IPC

FIELD: foundry, namely constructions of central riser with spherical top portion for making castings such as impellers with cast boss and inner opening in ceramic molds for centrifugal pumps. SUBSTANCE: head has T-shaped ceramic bridge. Values of diameter of said bridge end in bottom part of head and impeller boss are connected by next relation: A=(0.156-0.196)C, where A- diameter of bridge end in bottom part of head; C - inner diameter of boss of impeller. Width and height of horizontally placed part of bridge are equal to A. Range of shrinkage porosity distribution in head is limited until 0.7-0.8. It allows to make boss if impeller from lower portion of head. EFFECT: improved design. 5 dwg, 1 tbl