| 摘要 |
The disclosure relates to a draw off control system for a roll of material in which a pivoted arm carries one end of a roller around which the material is passed to pull the arm in one direction, the arm being counter-balanced by a pneumatically operated thruster having a plunger acting on the arm. The force provided by the thruster varies with projection of the plunger so that as the material tension varies over a certain range the arm will move to establish a new equilibrium position. Movement of the arm in one direction with falling tension is arranged to apply a brake to the feed roller of the material when the arm moves beyond a certain position, the brake is applied to increase tension, the brake being released when the arm returns past said position.
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