Active center pivot device for controlling sheet tension and method of using same

Patent metadata

Field	Value
Publication number	US-9309081-B2
Application number	US-201314054216-A
Country	US
Kind code	B2
Filing date	Oct 15, 2013
Priority date	Oct 15, 2013
Publication date	Apr 12, 2016
Grant date	Apr 12, 2016

Abstract

A device for controlling web tension is disclosed. The device includes a carriage in which a first guide roller is spaced from a second guide roller by a frame. The carriage or frame pivots about a pivot location. A moving web is threaded through the carriage in a serpentine path. Rotation of the carriage or frame causes web displacement. When tension disturbances occur in the moving web, the device rotates for accumulating or releasing the web material and thereby dampening tension variations downstream. The pivot dancer device can be placed in a communication with a controller for open loop control or closed loop feedback control.

First claim

What is claimed:

1. A device for controlling tension in a sheet being fed to a process comprising:
a first guide roll spaced from a second guide roll, the first and second guide rolls being held in a coplanar relationship by a first frame, the first frame being pivotally attached to a second frame at a pivot location between the first and second guide rolls; and
a torque supplying device that supplies a controllable amount of torque to the first frame at the pivot location, the torque supplying device comprising a motor.

2. A device as defined in claim 1 , wherein the pivot location is midpoint between the first guide roll and the second guide roll on the first frame in the plane in which the first and second guide rolls reside.

3. A device as defined in claim 1 , wherein the motor of the torque supplying device is operatively attached to the first frame at the pivot location by a belt.

4. A device as defined in claim 1 , further comprising a torque controller that is configured to control the amount of torque applied to the first frame at the pivot location by the torque supplying device.

5. A device as defined in claim 1 , further comprising a first load cell that measures sheet tension of a sheet being fed to the device and a second load cell that measures sheet tension of a sheet exiting the device.

6. A device as defined in claim 5 , further comprising a torque controller that is configured to control the amount of torque applied to the first frame at the pivot location by the torque supplying device, wherein the torque controller is in communication with the first load cell and the second load cell.

7. A device as defined in claim 6 , wherein the torque controller is configured to compare sheet tension before the device to sheet tension after the device and, based on any differences in sheet tension, controlling the amount of torque applied to the pivot location.

8. A device as defined in claim 1 , wherein the torque supplying device rotates the first frame about the pivot location in an amount from about 0 degrees to about 180 degrees in adjusting the amount of torque applied to the first frame.

9. A device as defined in claim 1 , further comprising a first fixed roll positioned directly upstream from the first guide roll and a second fixed roll positioned directly downstream from the second guide roll.

Assignees

• Kimberly Clark Co

Inventors

• Duehring Douglas N
• Dollevoet Mark G
• Rudolph Jason M

Classifications

• B65H23/048 Primary

  by positively actuated movable bars or rollers · CPC title

• B65H23/188

  in connection with running-web · CPC title

• B65H2402/31

  Pivoting support means · CPC title

• B65H2515/32

  Torque e.g. braking torque · CPC title

• B65H2220/02

  indicating an entity which is controlled, adjusted or changed by a control process, i.e. output · CPC title