Abstract: The disclosure relates to apparatus for center punching a hot metal billet preparatory to a piercing operation, in the production of seamless tubing. The apparatus provides a simple, reliable, mechanical arrangement effective to automatically compensate for normal variations in the diameter of successive hot metal billets, such that the center punching operation is carried out with greater accuracy than has heretofore been attained in regular production operations. The apparatus includes means for mechanically clamping a hot metal billet preparatory to center punching, and means for axially advancing a center punching tool into the end of the clamped billet. The center punching tool itself is mounted for limited transverse movement in relation to its advancing means, and is mechanically coupled to the clamping means by a compensating mechanism.

Abstract: The disclosure relates to method and apparatus for the operation of a plug mill, in the production of seamless tubes. Provisions are made for maintaining a circulating supply of plug and mandrel assemblies such that, after a tubular shell from a piercing mill has been given a first pass through the plug mill, the entire combination of the plug and mandrel assembly, and the just-processed shell, are transferred bodily into alignment with the axis of a second stage mill. The shell is then advanced in the same direction through a second mill stand, over a second plug, while simultaneously being stripped from the first mandrel. By enabling the shell to be passed through the second plug mill pass, without the requirement of an intermediate operation of stripping the shell from the first stage mandrel, significant time economies are realized. With conventional plug mill equipment and techniques, the plug mill represents a bottleneck in the sequence of operations involved in the production of seamless tubing.

Abstract: The disclosure is directed to structural features of piercing and reeling mills to facilitate and expedite the changing of mill rolls, as is necessary from time to time for accommodation of new work sizes and/or for refurbishing of the rolls. The new mill construction includes a cap member which is removably secured to the upright members of the mill frame structure and forms, in effect, an integral part of the mill structure during normal operation. To effect changing of the mill rolls, provision is made for moving the cap to a laterally offset position, while still supported on the basic mill structure, to permit access to the mill rolls by means of an overhead crane. In the new mill structure, provision for releasing and lateral offset movement of the mill cap is self-contained within the mill structure, so that the plant crane is not required to be utilized in removing the mill cap, as heretofore.

Abstract: The disclosure is directed to improvement in piercing and reeling mills, to facilitate the changing of mandrel plugs and mill shoes. In piercing and reeling operations, mandrel plugs are supported at the ends of elongated mandrel bars, and workpieces are driven over the mandrel plugs while being rotated, to effect piercing and enlarging, in the case of piercing mills, and to achieve roundness, in the case of reeling mills. In each case, after processing a finite length of tubing, and while the workpiece remains on the mandrel, the mandrel is retracted, first stripping off the just-used mandrel plug, and then withdrawing the mandrel from the processed workpiece. A multi-position magazine is provided for retaining a circulating supply of mandrel plugs such that, after each operation, the used mandrel plug may be returned to the magazine for cooling, and a new plug may be brought quickly into working position ready for the next operation.

Abstract: The disclosure is directed to improvements in flying cutters, particularly shears for severing light gage sheet or strip metal. Conventional flying shear mechanisms include a severing mechanism which is accelerated up to the speed of a moving strip or sheet material and then operated to sever the strip while moving synchronously therewith. The cutter mechanism is then returned to its starting position in readiness for a further operation. The present invention is directed to a novel and unique form of conveyor support, which is arranged in a novel manner to automatically extend or contract in accordance with movements of the shear, so that the sheet or strip material remains effectively continuously supported on both sides of the shear.