Patent ID: 7287571
Filing Date: 2007-10-30
Classification: B22C

Abstract:
1. A fugitive, polymeric, lost foam pattern for embedding in a bed of compacted, unbonded sand to form a mold comprising: a sprue-forming portion for forming a sprue that receives a metal melt from a melt source; a casting-cavity-forming portion for forming a cavity in said mold for making a casting from melt received from said sprue; at least one runner-forming portion forming a runner extending between said sprue and said cavity for delivering melt from said sprue to said cavity during pouring of said melt; a gate-forming portion forming a gate communicating said runner and said cavity, wherein said gate-forming portion forms a gate having a mouth that receives melt from said riser, and said pattern includes a moat that surrounds said mouth for forming a dam of sand around said mouth when said pattern is embedded in said sand, which dam is arranged and configured to trap particulates carried by liquefied said foam that is pushed ahead of said melt during pouring; and a riser-forming portion for forming an inline riser in said runner through which said melt flows to supply melt to said gate during said pouring, and in which melt is stored for outflow into said cavity after the melt in the remainder of the runner has solidified and as the melt in said cavity solidifies and shrinks.