About WGS grippers and cylinders
Grippers are normally used to pick sprues, but are often also used for parts picking, especially when the surfaces of the parts are not flat enough to use vacuum cups. Gripping pliers have the additional advantage that they can grip inside the part, pushing their jaws outwards.
The gripper can be activated via a compressed air circuit for closure (single-acting). In this case, the opening action is activated by a spring return. However, double-acting grippers are the most common solution. One compressed air circuit closes them, and another compressed air circuit opens them. This is the safest method, as the other compressed air circuit forces the grippers to open.