There are many kinds of steel cable cylinders that rely on metal belts instead of steel cables to bypass pulleys. Both ends of the upper part of the frame are supported on the cylinder to provide better load stability and greater load capacity, so there is no need for additional supports in many applications. After the brakes are installed on these cylinders, they can stop and pull the load at any time during the stroke.
The flexible wall cylinder evolved from the original vibration and insulation device design. They consist of many metal mounting plates fixed in reinforced rubber cavities. When pressurized and deflated, the metal plate straightens and relaxes respectively. The allowable tolerance of their lateral alignment is large, and they can be started only by arc without U-clamp.
There are some precautions when applying these cylinders. First, mechanical stops should be provided to limit the protruding length. Otherwise, when the load runs over speed, the metal sheet at the end will be separated from the cylinder. The mechanical stopper can also limit the contraction range, thus preventing the elastic material of the cylinder between the metal sheets from being damaged. This kind of cylinder requires far less arrangement than the traditional cylinder. However, relative torsion between the cylinder heads at both ends should be prevented to prevent excessive shear stress from damaging the elastic material.
Another design is very similar to a hose sealed at both ends. When there is no pressure, the hose is flat; When air is forced in, the hose will expand into a tube. The maximum stroke is about the inner diameter of the hose after air flushing. If a long hose is used, a large force can be generated at a relatively low pressure. However, the longer the stroke, the smaller the starting force. This is because as the hose inflates, it will become round, so that the contact surface with the load becomes smaller and the force application surface becomes smaller.