Patent ID: 8832940

Claim:
A method for performing an operation on a workpiece, the method comprising: positioning a permanent magnet unit on a first surface of the workpiece, the permanent magnet unit attached to a housing via a spring configured to bias the permanent magnet unit towards the housing, the permanent magnet unit further including: a number of wheels, including a first wheel and a second wheel; a first lever having a first end and a second end, the first lever connecting to the housing at a first pivot point, and also connecting to the permanent magnet unit at about the first end, the second end of the first lever connecting to the first wheel: a second lever having a third end and a fourth end, the second lever connecting to the housing at a second pivot point and also connecting to the permanent magnet at about the third end and further connecting to the permanent magnet unit opposite the first lever, the fourth end of the second lever connecting to the second wheel; and an end effector, attaching to the housing between the first wheel and the second wheel; positioning an electromagnetic clamping device on a second surface of the workpiece, wherein the first surface opposes the second surface, the electromagnetic clamping device having an activated state and a deactivated state; placing the electromagnetic clamping device in an activated state such that a number of forces caused by a magnetic field clamps the workpiece between the electromagnetic clamping device and the permanent magnet unit; and performing an operation on the workpiece using the end effector.