This invention relates to a cutting tool guiding system for metal cutting machines.
In the manufacture of steel plates and sheets, it is desirable to start with metal slabs which are an optimum width for the particular end product desired. Many such slabs are formed on continuous casting machines and are often wider than necessary. It is usually the practice to slit such slabs longitudinally into two or more strips.
The original slabs are often separated from the continuous cast strand by a flame cut-off device which utilizes a cutting torch which is moved transversely across the strand. The separated slab has often been found to have corners which are deformed in that they contain slag, or are rounded. These deformities have caused problems with prior guidance systems for slitting the slab when such systems followed the slab edge. Furthermore, at least some prior edge following devices have also had to contend with warped or misplaced slabs.
The present invention overcomes the aforementioned problems and provides a longitudinal cutting device which is edge-guided by a system which is not affected by corner deformities or warpage or misplacement of the slab.
In accordance with the various aspects of the invention, a cantilevered transverse arm is mounted for movement along both a longitudinal and transverse axis. The outer end of the arm is adapted to be disposed over a metal slab to be cut and carries a tool assembly which is adjustable thereon. A guiding assembly is fixedly mounted to the arm and includes a pair of longitudinally spaced guide rollers positioned so that the cutting tool is disposed in a transverse plane extending between the rollers. Each roller is individually shiftable into and out of engagement with the slab edge.
Initially, the leading roller is advanced toward the slab edge, while the trailing roller is retracted. The rollers are then moved toward the slab edge until the leading roller engages the said edge ahead of the slab corner. As the entire device moves longitudinally along the slab, the leading roller is retracted while the trailing roller moves into engagement with the slab edge. Deformed slab corners are thereby bypassed by the tool guidance system.