| 摘要 |
<p>* A follower roll or so-called spring roll system for use with a paper machine has a roll about which the paper web passes on its path through the machine, the web having a wrap angle about the roll of about 90.degree. , to exert a horizontal force component against the roll, due to web tension. The roll bearings are each supported on a low friction slide, to permit substantially friction free displacement of the roll horizontally. The position of each roll bearing housing is controlled by an air bag acting as a variable rate spring to oppose displacement of the roll under web tension, with a second air bag opposed thereto, acting as a constant rate displacer, to assist the displacing effects of web tension. The two bearing housings are synchronized in their displacement under web tension variations by a synchronizing shaft extending across the width of the machine and connected with each of the two bearing housings by a rack and pinion arrangement. Rotation of the synchronizing shaft in response to a displacement of the spring roll due to a change in web tension produces a change in a potentiometer or other control device connected with the synchronizing shaft, which potentiometer is connected in speed controlling relation with the paper machine drive, to correct the speed of the machine so as to maintain substantially constant the tension in the web. This invention is directed to a web tension control arrangement for use with a paper making machine, and in particular to a spring roll the position of which under the effects of web tension is controlled by a low friction positioning mechanism.</p> |
