US 4,478,064 A · Modifications to a cooperative rolling system for increasing _maximum attainable reduction per pass

Abstract

A process for rolling a metal strip for reducing its thickness and for increasing the maximum reduction attainable per pass using a cooperative type rolling mill comprises applying differential separating forces to the metal strip without changing the magnitude of the compressive force applied to the rolls. By doing this, the maximum strip tension and the forward tension required to pull the strip through the mill may be reduced. The maximum strip tension and the required forward tension force may further be reduced by driving at least one work roll at a desired value of torque as well as applying differential separating forces. The cooperative type rolling mill uses a roll spacing arrangement to space at least some of the rolls for reducing the separating force applied to the metal strip at selected roll bites. In addition, individual drive motors to drive the work rolls at desired torque values may be utilized.

Claims19

Dependent claims

A process for rolling metal or metal alloy material and increasing the maximum reduction in material thickness obtainable per pass, said process comprising:

providing a rolling mill having a plurality of rolls forming a plurality of roll bites through which said material passes, at least one of said rolls forming two of said roll bites with at least two adjacent ones of said rolls;
passing said material through said mill in a serpentine arrangement;
applying a compressive force of predetermined magnitude to said rolls to create a separating force having a desired magnitude and obtain a reduction in said material thickness at each of said roll bites;
and
subjecting said material to increasing separating forces as said material passes from an entry one of said roll bites to an exit one of said roll bites while maintaining the magnitude of said compressive force substantially constant, said subjecting step comprising reducing the magnitude of said separating force applied to said material at at least one of said roll bites by creating a reducing force having a desired magnitude at said at least one roll bite.

2 more elements

A rolling mill apparatus for reducing the thickness of a strip material, said rolling mill comprising:

at least two back-up rolls and at least two work rolls forming a plurality of roll bites through which said material passes in a serpentine manner, said material being at least partially wrapped about each of said rolls;
at least one of said work rolls and two adjacent ones of said rolls forming two of said roll bites;
means for applying a compressive force of predetermined magnitude to said rolls for causing a reduction in said material thickness at each of said roll bites, said compressive force further creating a separating force of a given magnitude at each of said roll bites;
means for subjecting said material to increased separating force as said material passes from an entry one of said roll bites to an exit one of said roll bites while maintaining the magnitude of said applied compressive force substantially constant, said subjecting means including means for creating a reducing force at at least one of said roll bites to reduce the magnitude of said separating force applied to said material at said at least one roll bite;
means for driving said back-up rolls at a speed ratio substantially equal to a desired reduction in said material thickness;
and
means driving at least one work roll at a desired value of torque so that said at least one work roll moves substantially at the speed of said material wrapping said at least one work roll and assisting in pulling said material through said mill,
whereby said subjecting means and said driving means reduce the overall tension in said material as said material passes through said mill and increase the amount of reduction obtainable per pass.

5 more elements

Dependencies are inferred from the claim text.

Modifications to a cooperative rolling system for increasing _maximum attainable reduction per pass

Life of this patent

Modifications to a cooperative rolling system for increasing _maximum attainable reduction per pass

Life of this patent

Abstract

Claims19