11.1.2 Gripper Mechanisms

•A gripper is specifically EOAT that uses a mechanical mechanism and actuator to grasp a part with gripping surfaces (aka fingers)

•Quite often gripper mechanisms can be purchases, and customized fingers attached.

•Fingers are designed to,

1.Physically mate with the part for a good grip

2.Apply enough force to the part to prevent slipping

g = gravity

S = factor of safety

(for basic applications 2 to 3 should be the absolute minimum, but high speed applications will require more force to resist inertial forces)

•Movements of the fingers

-pivoting (often uses pivotal linkages)

-linear or translational movement (often uses linear bearings and actuators)

•Typical mechanisms

-linkage actuation

-gear and rack

-cam