Patent ID: 6464116
Filing Date: 2002-10-15
Classification: B22D

Abstract:
A stopper rod for use in the casting of molten metal comprising:a) an elongated body of refractory material having a lower end, an upper end, a longitudinal axis extending between the lower and upper ends, an inner surface open to the upper end and defining a borehole along the longitudinal axis, the borehole having an enlarged portion comprising an annular sealing surface spaced away from upper end, and a fastener within the borehole spaced further from the upper end than the annular sealing surface; b) a metal rod comprising a first material having a first coefficient of thermal expansion, a first end, and a second end, the first end fixedly secured to the fastener, and the second end adapted to be attached to a lifting mechanism capable of vertically displacing the stopper rod inside of a casting vessel; c) a blocking device attached to the metal rod and contacting the upper end of the body; and d) a sleeve comprising a second material having a second coefficient of thermal expansion greater than the first coefficient of thermal expansion, the sleeve having a second sealing surface cooperating with the annular sealing surface, the sleeve secured against the annular sealing surface by the blocking device, and having a length at least sufficient to compensate for thermal expansion of the metal rod during casting.