PINCH ROLL SYSTEM FOR VERTICAL LAYING HEADS

摘要

In a rolling mill wherein hot rolled rod is directed along a downwardly curved path into a vertical laying head which forms the rod into a series of rings, a method of and apparatus for propelling the rod through the laying head. The rod is passed between a pair of adjustable driven pinch rolls located in advance of the downwardly curved path. An initial closing force is exerted on the pinch rolls to establish an initial parting prior to entry of a rod front end therebetween. The initial parting is sized to produce at least some rod deformation while providing a driving relationship between the pinch rolls and the rod. The initial closing force is greater than the momentary surge in separating force accompanying impact of a rod front end with the pinch rolls. The initial parting is maintained until the rod front end has negotiated the downwardly curved path and has passed through the laying head, at which time the initial closing force is released. The pinch rolls can then either be opened completely to allow the rod to continue running freely therebetween, or the initial closing force can be replaced by a lower secondary closing force which allows the rod to push the pinch rolls apart to a secondary parting. The secondary parting continues the driving relationship between the pinch rolls arid the rod, without any accompanying rod deformation.