What is a Gripper?

A gripper is a type of end effector which enables the holding of an object to be manipulated. The gripper is a lot like a human hand because, similar to the human hand, the gripper allows holding, tightening, handling and releasing of an object. A gripper can be attached to a robot or it can be part of a fixed automation system. Many styles and sizes of grippers exist so that the correct model can be selected for the application.

How Does A Gripper Work?

Compressed air or hydraulic liquid is supplied to the cylinder of the gripper body forcing the piston up and down, which then forces the gripper jaws to open or close. There are 3 basic motions of gripper jaws; parallel, angular and toggle. These terms refer to the motion of the gripper jaws in relation to the gripper body.

Parallel Gripper

The gripper jaws move in a parallel motion in relation to the gripper body.  Used in a majority of applications, parallel grippers are typically more accurate than other style grippers.

Angular Gripper

The gripper jaws are opened and closed around a central pivot moving in an arcing motion. Angular grippers are often used when limited space is available or when the jaws need to move out of the way.

Toggle Gripper

The toggle gripper is used to lock parts. It provides a very high grip force and will remain locked even if air pressure is lost.

2 Jaw Grippers Vs 3 Jaw Grippers

2-Jaw Gripper

The most popular style of gripper (angular, parallel and toggle)

3-Jaw Gripper:

A more specialized style of gripper (parallel and toggle) 3 Jaws provide more contact with the part to be grasped and  more accurate centering than 2 jaw models.

 

Internal Vs External Gripping

Grippers are used in two different holding positions, External and Internal. The choice is determined by the geometry of the part to be held, the process to be carried out, orientation of the parts to be gripped and the space available.

External:

External gripping is the most common way to hold parts.

Internal:

Internal gripping is used when the process to be performed requires access to the outside surface of the part grasped.

Custom Gripping Fingers

Every application requires different fingers/ tooling requirement as such customisation is necessary for each job. careful design is necessary so that the size and grip force is appropriate to the job.