What Are Pneumatic Grippers?

Post By: Ryan King On: 27-07-2023 Read Time: 5 minutes - Guides - Pneumatics

A pneumatic gripper is a simple pneumatic actuator that can be easily implemented. They’re immensely versatile, as their jaws can be customised to deal with a wide range of different objects. You’ll find pneumatic grippers grasping or holding parts in many industrial settings. Their versatility allows a range of actions, such as moving, stacking, orienting or inserting parts in a wide range of manufacturing processes.

How Do Pneumatic Grippers Work?

A pneumatic gripper is a self-explanatory industrial tool – it grips, by means of compressed air and a range of supporting components like valves and pressure switches. It has tooling jaws or fingers that do the gripping and is used to grasp all sorts of objects in an automated manufacturing environment. Pneumatic grippers are similar to human fingers: grasping workpieces, holding them in place and releasing them.

Workpieces that can be managed using pneumatic grippers range from small objects like microchips or circuit boards to large pieces such as an engine block. Typical applications are in laboratory processing, pharmaceuticals, biotech, medical device manufacturing, electronics, robotics, automation and plastics.

What Types Of Pneumatic Grippers are There?

Pneumatic grippers are available in many variations, which include opening widths, force applied and what type of gripping surfaces they use. With the advance of technology, pneumatic grippers are being used more frequently in interaction with other objects and devices.

What Are Pneumatic Grippers

Pneumatic Two and Three-Finger Grippers

Pneumatic grippers are normally provided with two or three fingers, though more fingers are used in some applications. In both two and three-finger pneumatic grippers the fingers move simultaneously, opening and closing from the gripper’s outer perimeter towards its central axis.

Two-finger grippers are the most common, with the fingers mounted opposite each other.

Three-finger grippers come in two types: either self-centring or adaptive. The self-centring type has three fingers evenly spaced around a machine chuck. Adaptive three-finger grippers have two fingers set close together, with the third finger placed opposite them, like an opposable thumb.

Parallel Grippers

The fingers of parallel grippers move in parallel to the gripper body. They’re the most common type, and can be easily custom-designed. Parallel grippers are straightforward to install, as they only use one axis of motion. They’re adaptable to workpieces in all sorts of shapes and sizes.

Angular Grippers

Angular grippers can move their fingers radially, from the perimeter towards the centre. The fingers open and close around a central point where the workpiece will be. Angular grippers are a better choice for large workpieces and irregular shapes. They’re also often used in tight-space applications, as the fingers can be moved out of the way.

External and Internal Grippers

Pneumatic grippers are also defined by the type of gripping mechanism they use.

External grippers use the closing force of the fingers to hold the workpiece in place, grasping the object on its outer surface.

Internal grippers hold the part using opening force, grasping objects on their internal surface. This action can be combined with the more common external gripping.

Single-Acting and Double-Acting Grippers

Pneumatic grippers can also be configured as single or double-acting.

Single-acting pneumatic grippers use pneumatic power to drive the fingers, either to open or to close. The return action is achieved by means of a spring.

Most pneumatic grippers are double-acting, using compressed air to drive the fingers open and closed. This allows the grippers to use both internal and external clamping. Double-acting grippers can also have a backup spring to hold a workpiece if air pressure is lost.

Magnetic Grippers

Magnetic grippers have permanent magnets at their core and are used for handling ferromagnetic objects. The grippers can handle a range of object sizes, depending on the magnet’s strength. Their drawback is that permanent magnets don’t function at temperatures over 150°C.

Why Would You Use a Pneumatic Gripper?

Where working space is limited, pneumatic grippers are a cheap and ergonomic option. They’re fairly easy to maintain and will run for millions of cycles without requiring service. Pneumatic grippers are the ideal solution in high-mix production processes. They can be combined with quick-change finger options or simple tool changers to handle complex geometry and a variety of parts.

Since most manufacturing facilities are already using compressed air for other applications, deploying pneumatic grippers is cost-effective and easy. One of their main benefits is their powerful gripping force, in a compact, light and low-cost unit.

When Would You Use a Pneumatic Gripper?

Pneumatic grippers are used in any industrial application that requires putting objects in set positions and places. The most common actions are grasping and lifting, rotating and holding. Modern pneumatic grippers are most often installed on the outermost reaches of major processing equipment. This might be some kind of workpiece processing machine or a robotic arm.

The grippers are designed to carry out various material handling tasks such as:

  • Picking and placing
  • Material transfer
  • Parts handling
  • Parts ejection
  • Parts seating
  • Camming and indexing
  • Clamping and fixturing
  • Heavy loads
  • Oversize loads

Pneumatic grippers are now very common in industrial settings. They’re used for assembly and production lines, automated work cells and machine-tending tasks in advanced manufacturing processes. They’re also used in automated warehousing operations, logistics and hazardous plant areas, as well as in precision automation tasks requiring exceptional repeatability.

The actions of which pneumatic grippers are capable (primarily grasping and releasing) have been refined in line with the technological advancements of Industry 4.0. This means that the grippers’ sensors, feedback connectivity and control capabilities now typically coordinate with those of the robotic arm or machine axis on which they’re mounted.

Cost-Effective Choice

Pneumatic grippers are often the fastest, cleanest and most cost-effective choice for parts handling. They offer the best grip force while still being lightweight and easily installed. They can cope with a wide variety of workpiece configurations and offer adjustable dimensions and gripping force. Pneumatic grippers are essential to material handling on production lines as robotic end effectors. They’re increasingly versatile and are being integrated with new technologies to provide even more robust and diverse processes.