Abstract: 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.

Abstract: The disclosure relates to a brake actuating mechanism in which a brake applying member is urged to apply a brake by a heavy coil spring. To release the brake a pivoted lever acts on the brake applying member and is moved in a brake releasing direction by an electric motor driven lead screw on which there is a ball-screw nut acting on the lever. The ball-screw nut causes the lead screw to spin under the load imposed by the spring through the lever so that when the motor is unlocked, the spring can apply the brake.

Abstract: A rotary fluid coupling which is particularly suitable for connecting a stationary source of fluid pressure to a fluid-pressure operated clutch comprises inner and outer, concentric, relatively rotatable members which have a space between them constituting a generally annular chamber for receiving pressurized fluid. The chamber is sealed to prevent the leakage of fluid by a releasable sealing mechanism which is itself fluid-pressure operated. Passages extend through the two members to connect the chamber to the stationary and rotary fluid lines. Preferably, the inner member rotates relative to the outer member which may be held relatively stationary against rotation.