Manufactured by Schunk Inc., the PGN-plus series includes eight gripper sizes with six versions each. These units offer gripping forces ranging from 140-12,500N.
PGN-plus grippers include a redesigned jaw guide featuring a serrated inner surface. With a new set of teeth to interact with the jaw, the guide spreads gripping forces and moments over more surfaces, explains Jesse Hayes, PGN-plus product manager. As a result, the redesigned guide more than doubles the gripper's maximum payload and allows up to a 30% increase in finger length, according to Schunk.
The firm also changed the piston that actuates the gripper fingers. Inside the new oval piston, Hayes notes, air pressure acts on a larger surface, which can boost grip force by up to 36%. To allow this higher capacity, Schunk strengthened the gripper's wedge-hook actuation system with additional steel.
All of the gripper's functional parts are made of hardened steel. The actuation system is encased in a housing made of hard-anodized aluminum alloy, which provides wear resistance without adding excessive weight to the unit.
The PGN-plus "is a very reliable gripper. We don't have any gripper failures at all," reports Jim Beahm, a project engineer for Lanco Assembly Systems Inc., a manufacturer of automated assembly equipment based in Westbrook, ME.
Lanco chose the PGN-plus as its standard gripper because the unit's load capacity makes it suitable for almost any application. Still, some plant-floor situations pose a threat to the gripper. But precautionary steps can be taken to minimize the threat, Hayes notes. In machine-loading applications, for example, metallic dust covers can shield the unit from harmful exposure to coolant. In other cases, the gripper's seals can be made of Viton to prevent damage in high-temperature settings.
In a variety of settings, project manager Hayes thinks people with part-handling machinery should be attracted by the gripper's high load-carrying capacity and compact design. "The heavier your tooling, the bigger everything behind it has to be," he explains. "But if you have a gripper that's half the weight [of a typical unit] to handle the part, all of your components [going] back into the machine can be smaller. That makes the whole job cheaper." Schunk Inc., www.schunk.com Enter 585