Patent ID: 7258256

Claim:
A surface pressure applying device for a slide valve that includes a housing fixed to a bottom surface of a molten metal vessel; a clamp supportedly provided to the housing in a manner that allows the clamp to open and close; and a slide case housed movably within the clamp and connected to plate driving means, the housing, the clamp, and the slide case forming a space in which at least two plate bricks are installed, the plate driving means causing one of the plate bricks to slide to change an opening of each of nozzle holes formed in the plate bricks, respectively, and control the outflow of molten metal, which comprises: a pair of spring holders; surface pressure releasing plates with projections; and a surface pressure releasing bar with a wedge portion, the spring holders each containing plural compression springs and flanking the housing in a direction parallel with a direction in which the slide case slides, the surface pressure releasing plates being placed under the spring holders in a manner that allows the surface pressure releasing plates to move up and down integrally with the spring holders, the surface pressure releasing bar being placed between the housing and the surface pressure releasing plates, the wedge portion being tapered on a slide contact surface on which the wedge portion is in slidable contact with the projections of the surface pressure releasing plates, the projections and the compression springs being arranged such that an arrangement center of peaks of the projections coincides with an arrangement center of the compression springs, and wherein the surface pressure releasing bar is slid while connected to the plate driving means by a connecting pin, to lift or depress the surface pressure releasing plates and thereby release or apply surface pressure, the spring holders being equipped with surface pressure applying hooks for engaging with the clamp when the surface pressure is applied and disengaging from the clamp when the surface pressure is released.