Submerged nozzle changing apparatus

A submerged nozzle changing apparatus comprising:

• a submerged nozzle holding cylinder actuator (42) fixedly provided below a slide valve device (32) provided at a bottom of a molten metal container (30) for controlling flow rate of a molten metal, said cylinder actuator (42) having a piston rod (43) movable vertically with respect to the slide valve device;
• a guide arm unit (44) fixedly mounted to said piston rod (43) for vertical movement with the piston rod and having a pair of a parallel horizontal guide rails (45) provided in oppositely facing inner surfaces thereof with horizontal guide grooves (46) having open opposite ends, said guide grooves (46) being adapted to receive, in slidable engagement therein, tongues (53) provided on a nozzle case (48) fitted on an upper portion of a submerged nozzle (47) respectively, said guide grooves (46) having a length for holding at least three nozzle cases;
• and
• a nozzle changing cylinder actuator (56) having a pressing member (60) movable horizontally into and out of said guide arm unit (44) for abutting and shifting the submerged nozzle with said tongues (53) in engagement in said guide grooves (46), along the guide grooves to a nozzle setting position immediately under a molten metal pouring opening of said slide valve device (32), said cylinder actuator (42) being operable to move said piston rod (43) and hence said guide rails (45) upwardly, to thereby move the submerged nozzle (47) in said nozzle setting position upwardly so as to press an upper end of said nozzle closely against a bottom of said slide valve device (32), said pressing member (60) being also movable to shift the submerged nozzle, after said piston rod (43) and hence said guide arm unit (44) are moved downward, from said nozzle setting position to a position away from the nozzle setting position.