Compressed Air Grippers

Grippers; you can, and many companies do, make their own compressed air grippers, using a collection of air actuators to provide the gripping motion.

Custom built grippers can work well enough, but their use has penalties. They are usually large and weigh a lot. For large pick and place applications, a large gripper is fine. For smaller, high speed pick and place, you need a gripper built for that use, low in weight and high in speed.

Heavy Tooling - Less Payload

Of course, the heavier the end tooling is, the less load capability of the pick and place apparatus, and the slower the cycle of the system. If high speed is what you need you will do better buying a gripper that is ready to use and the right size and weight for the application, if one can be found.

Compressed air equipment manufacturers have risen to the occasion, churning out standard air grippers to suit many applications, grippers that are compact in size, light in weight, lightning fast, and able to handle extraordinary loads when you consider their size.

How They Work

Almost all air gripper contain a double acting air cylinder to impart linear motion to the gripper gearing.

The gripper has gearing produces movement in the gripper fingers when the piston on the internal cylinder cycles. Air in one in port and the fingers open; air in the other, fingers close.

Gripper fingers are designed for tooling attachment. Tooling might be a simple as rubber nubs or some such, to enable the gripper fingers to better clamp and hold a part.

Gripper Use

The obvious first thing to be concerned about is if the gripper has the load carrying capacity for what is to be gripped and lifted. If the gripper is to be used to position something, it must be strong enough to hold the part.

The strength of the gripper fingers is predicated on how big the piston is inside it, and the available air pressure. Force equals pressure times area, after all, and the force on the internal cylinder piston is transferred to the available gripping force of the gripper fingers.

Self-Centering

Grippers will normally self-center the part to be held. All the commercially available grippers move their fingers together or apart at the same time. If moving together, the fingers will tend to move a part to the center point, at which the fingers grip the item.

Gripper Tooling

Gripper fingers are made to have tooling attached. That tooling may be nothing more than rubber bumpers to add better gripping as the fingers close on an item.

Grippers do work by opening as well as closing, and putting rubber tips on the outside of the tooling can improve gripping. In this type of use, the gripper fingers are inserted into an opening on a part, and by having the gripper fingers open, that part is effectively gripped.

The types of gripper tooling are unlimited, and predicated on what it is that is to be done by the part that is being gripped.