Patent ID: 6167943
Filing Date: 2001-01-02
Classification: B22D

Abstract:
Apparatus for continuously casting metal strip comprising a pair of parallel casting rolls forming a nip between them; metal delivery means to deliver molten metal into the nip between the rolls to form a casting pool of molten metal supported on casting roll surfaces immediately above the nip; pool confining means to confine the molten metal in the casting pool against the outflow from the ends of the nip; and roll drive means to drive the casting rolls in counter-rotational directions to produce a solidified strip of metal delivered downwardly from the nip; wherein at least one of the casting rolls is mounted on a pair of moveable roll carriers which allow that one roll to move bodily toward and away from the other roll, wherein there is a pair of roll biasing units acting one on each of the pair of moveable roll carriers to bias said one roll bodily inwardly toward the other roll, and wherein each roll biasing unit comprises: a spring housing barrel, a fixed barrel mounting adjacent the respective roll carrier, barrel positioning means to move the barrel on the fixed barrel mounting between a retracted position and an extended position adjacent the respective roll carrier, compression spring means housed within the barrel, a thrust transmission structure slidably mounted in one end of the barrel so as to be abutted by the spring means, a thrust reaction structure slidably mounted in the other end of the barrel so as to be abutted by the spring means, bias adjustment means mounted on the barrel so as to be movable with it and operable to move the thrust reaction structure along the barrel to alter the effective gap between the thrust transmission structure and the thrust reaction structure within the barrel thereby to adjust the thrust exerted by the spring means, releasable clamping means operable to clamp the thrust structure to the roll carrier when the barrel is in its extended position, and the barrel positioning means being operable to set the barrel in the extended position with the clamping means conditioned to clamp the thrust transmission structure to the roll carrier whereby thrust is transmitted from the spring means to that roll carrier with the barrel serving as a fixed structure to absorb the reaction to the thrust and wherein the barrel positioning means is operable on release of the clamping means to move the barrel to its retracted position causing the thrust transmission structure to be drawn away from the roll carrier.