摘要 |
PROBLEM TO BE SOLVED: To provide a method for regulating a web tension for a web offset rotary press for reducing a danger of tearing of a web in the case of starting the press. SOLUTION: In a method and apparatus for regulating a web tension for a web offset rotary press, when a rotational speed of the press 1 is accelerated via a set speed range, a tension of a web 6 is substantially linearly increased to the web speed by a tension regulator 10. The regulator 10 has a dancer roller 12, which is brought into contact with the traveling web 6 via a pneumatic cylinder 20. The cylinder 20 is connected to a compressed air source 24 via a proportional valve 22. An electronic controller 26 is coupled to a web speed measuring unit 32 via a connecting line 30 to control a position of the valve 22 and hence pressure in the cylinder 20 via a connecting line 28 according to present speed of the web 6. |