Abstract A web-decurling device for use with a roll sheeter attachment includes a rotatable bar having a sharp edge projecting into engagement with the outer surface of the web as it is unwound from a supply roll. The decurling device is self-adjusting in operation and comprises means for sensing the periphery of the supply roll and, in response to reduction in its diameter, continuously rotating the bar so as to change the attitude of the sharp edge to present an ever increasing amount of uniform decurling pressure to the web as the supply roll is depleted. Also provided is a tension control for maintaining the web taut and in effective contact with the sharp edge during operation, and for preventing web breakage and lateral runout of the web as it is unwound from the supply roll.
A device for decurling a web as it is fed from a supply roll which comprises: means for rotatably supporting a supply roll of web material; feeding means for drawing the web from the supply roll; a decurling bar positioned so as to bear against the web as it passes between said roll and said feeding means, said bar having a sharp decurling edge, and being movable mounted in a manner to provide greater or less deflection of the web by the edge to effect greater or less decurling of the web; a movable sensing arm riding on the periphery of the supply roll; means Urging the arm towards the periphery of the supply roll; and means connecting the arm with the decurling bar to so move the bar as to increase web deflection by the sharp edge thereof in response to decrease in the diameter of the supply roll.
Claim 2
Independent Claim
150 words
A device for decurling a web as it is fed from a supply roll which comprises: means for rotatably supporting a supply roll of web material; feeding means for drawing the web from the supply roll; a decurling bar positioned so as to bear against the web as it passes between said roll and said feeding means, said bar having a sharp decurling edge, and being movable mounted in a manner to provide greater or less deflection of the web by the edge to effect greater or less decurling of the web; a movable sensing arm riding on the periphery of the supply roll; means Urging the arm towards the periphery of the supply roll; and means connecting the arm with the decurling bar to so move the bar as to increase web deflection by the sharp edge thereof in response to decrease in the diameter of the supply roll.
Claim 3
Dependent Claim
50 words
A device as set forth in claim 1 in which friction brake means is provided for resisting rotation of the supply roll in an unwinding direction, and which includes a tension roller urged against the web and tending to lengthen the run between said decurling bar and the feeding means.
Claim 4
Dependent Claim
28 words
A device as set forth in claim 2 in which check means is associated with the tension roller for damping its motion in a direction towards the web.
Claim 5
Dependent Claim
31 words
A device as set forth in claim 2 which also includes a means for applying a drag to the web at a location between the supply roll and the decurling bar.
Claim 6
Dependent Claim
27 words
A device as set forth in claim 1 including means for adjusting the ambit of decurling bar movement in relation to the travel of the sensing arm.