Patent ID: 7555833

Claim:
A self-piercing riveting system for piercing and riveting a plurality of workpieces defining first and second opposite surfaces, and promoting proper alignment between a rivet gun and back-up, said system comprising: a rivet gun for driving a self-piercing rivet at a first point along one of said surfaces; a first emitter coupled with the rivet gun and operable to emit a first emission towards said one of the surfaces; a back-up including a die for shaping a projecting end of the driven self-piercing rivet at a second point along the other of said surfaces, and substantially directly opposite the first point; a second emitter coupled with the back-up and operable to emit a second emission towards said other of said surfaces; and at least one sensor for receiving the first and second emissions and configured to determine the relative positions of the rivet gun and the back-up and whether the second point is substantially directly opposite the first point.