Tech Tips - Compact Air Cylinders Are Still A Big Deal

3 sponsored by: compact air cylinders: 101 continued figure 3. two extruded body designs Compact air cylinders have a piston rod configuration (as opposed to a rodless cylinder). Piston rod cylinders function in two ways: double-acting and single-acting. Double-acting cylinders (of which Figure 1 is an example) use compressed air to power both the extend and the retract stroke (moving the rod back and forth). This arrangement makes double-acting cylinders ideal for pushing and pulling loads. Here are some common double-acting, compact air cylinder application functions: • Assembling • Bending • Clamping • Feeding • Forming • Lifting • Lowering • Positioning • Pressing • Processing • Punching • Shaking • Sorting Single-acting cylinders have compressed air supplied to only one side of the piston; the other side vents to atmosphere. Depending on whether air is routed to the cap or rod end determines whether the rod extends or retracts. The most common type is pressure-extended with an internal spring returning the piston to its original position when air exhausts. This is typically called spring return. ( Figure 4 ) figure 4. spring return figure 5. spring extend Spring extend is when air pressure retracts the rod and the spring force causes the rod to extend when pressure is removed. This makes single-acting cylinders ideal when a force is needed in one direction only and where the return stroke is unimpeded and unloaded. These are also popular in areas where, for safety reasons, a defined position must be taken in the event of a power failure. Here are some typical single-acting, compact air cylinder application functions: