Abstract: A differential pressure actuator includes two fluid containing bags mounted on opposite sides of a support bar, and one of the bags is coupled to a load by a plate at the side of the bag opposite the bar. The other bag is also coupled to the load by a second plate mounted at the opposite end of the other bag, and the second plate is mechanically connected to the first plate by a rod extending along the central axis of the first and second bags. Both of the bags contained a pressurized fluid in excess of atmospheric pressure, and the difference in the forces generated by the two bags is impressed upon the load. In one embodiment, the first and second bags are provided with a bellows surrounding the rod to seal the interior of the bag from ambient atmosphere. In another embodiment, the seal is provided by two sleeves coupled by a sealing ring. The load is a movable roller in a ringer for coating steel, and the movable roller is provided with separate actuators at opposite ends of the roller.

Abstract: A differential pressure actuator includes two fluid containing bags mounted on opposite sides of a support bar, and one of the bags is coupled to a load by means of a plate at the side of the bag opposite the bar. The other bag is also coupled to the load by means of a second plate mounted at the opposite end of the other bag, and the second plate is mechanically connected to the first plate by rods. Both of the bags contained a pressurized fluid in excess of atmospheric pressure, and the difference in the forces generated by the two bags is impressed upon the load. The load is a movable roller in a ringer for coating steel, and the movable roller is provided with separate actuators at opposite ends of the roller.