In conventional converter mechanisms with left-right door structures and slide-type slag-blocking tapping, to reduce the production cost of the inner slide bricks, the bottom plate of the slide brick slots in the fixed frame is typically made very thin, typically 10 mm, to ensure the correct height of the inner slide bricks, or the male opening, (i.e., the same height as the outer slide bricks). This can easily cause the fixed frame to warp and deform, resulting in poor contact between the inner slide bricks and the matching inner slide brick slots. This reduces the service life of the fixed frame, severely compromises system safety, and increases overall costs.

To address the serious safety issues of the system, two solutions were known prior to September 2013: Solution 1: Increase the height of the inner slide bricks, or the male height, typically by 20-30 mm, to increase the thickness of the fixed frame slide brick groove bottom plate. Solution 2: Thicken the inner slide bricks and give them a stepped edge. For example, in Patent 201210187741.6, the fixed frame slide brick groove bottom plate is designed as a ring structure with a width of 20-25 mm and a thickness equal to the inner slide brick step, typically 20-25 mm. These solutions have the following drawbacks: Solution 1 addresses the issues of easy deformation and insufficient safety of the fixed frame, but it also increases the height of the inner slide bricks, the production cost of the slide bricks, and the overall cost of the system. Solution 2: The supporting surface of the fixed frame slide brick groove bottom plate is too small, the central opening is too large, and the thickness increase is insufficient, failing to truly solve the problems of fixed frame deformation and reduced system safety. Furthermore, the stepped inner slide bricks increase thickness, increasing production costs.

As of September 2013, in the known left and right door structure and the converter mechanism for sliding plate to block slag for steel tapping, the spring clamping device usually adopts the surface pressure bolt pressure method. By tightening the surface pressure bolt, the spring pressure plate and the surface pressure spring are compressed to tighten the fixed frame and the opening and closing frame, completing the pressure process between the inner slide and the outer slide. It has the following defects: (1) The screwing depth of the surface pressure bolts on both sides of the spring clamping device (i.e. the pressing depth of the spring pressure plate) is completely controlled by manual operation based on the observation hole on the side of the spring chamber and personal experience. During the steel tapping process, the observation hole is easily adhered by steel slag, which is more likely to cause visual disturbance. Unclear inspection and inaccurate observation further aggravate manual operation errors, resulting in different depths of surface pressure bolts screwed in, causing uneven distribution of locking surface pressure between the inner and outer slide bricks, which is affected by human operation factors. (2) There are defects in the distribution of springs in the spring chamber. There are more springs on both sides of the bolt hole, which makes the outer sides of the bolt holes at both ends of the spring pressure plate longer. The two ends are prone to outward deformation, which reduces the compression of the springs at both ends and reduces the pressure, further aggravating the uneven distribution of surface pressure between the inner and outer slides, resulting in a significant reduction in the safety of the mechanism and easily causing steel leakage accidents between the slides.