Pneumatic actuators fall into two classes: linear and rotary. Linear actuators move objects in straight lines, while rotary actuators turn objects, or rotate them in varying directions. Air cylinders (also called pneumatic cylinders), the most common type of linear actuators, use pressurized air to pull and push piston rods in and out of cylinder barrels. This motion moves mechanisms connected to the rods, or (for detached items) directs or blocks travel using rod-attached plates. Air cylinders execute pushing, pulling, lifting, lowering, pressing, and stopping functions, and they come in several different body types, including round, compact, tie-rod, guided, slide, and clamp. Pneumatic cylinders can be either single acting, with one compressed air port to push the rod in a single direction and a spring to return the rod, or double acting, with two compressed air ports on opposite ends of the cylinder to both extend and retract the rod. For quieter piston operation, air cylinders can come with cushioning in one or both ends of their barrels. Several mounting styles are available both for attaching the air cylinder ends to moving components in a pneumatic system and for mounting to rigid surfaces. Air cylinders are used in industrialized automation tasks in automotive, food processing, material handling, and robotics applications, among others.
Parker Hannifin manufactures electromechanical, hydraulic, and pneumatic motion technologies and systems for liquid handling, filtration, sealing and shielding, climate control, process control, and aerospace applications. The company, founded in 1918, is headquartered in Cleveland, OH.