Patent ID: 7346971

Claim:
A system for setting a blind rivet and evaluating the acceptability of the set, said rivet being of the type having a frangible tubular body and an elongated mandrel that includes an enlarged head and a stem extending rearwardly of the head and through said frangible tubular body, said system comprising: a hydraulically operated blind rivet setting tool, said tool including a rivet engaging assembly for engaging said stem of said mandrel, an axially movable piston assembly operatively coupled to said rivet engaging assembly for driving said mandrel in response to the application of pressurized hydraulic fluid to said piston assembly, a housing annularly disposed about said piston; a first transducer for monitoring strains induced in the housing during a rivet setting process and producing strain output signal related thereto; a second transducer configured to measure a supply pressure of a working fluid to the hydraulically operated blind rivet setting tool; a control circuit, said control circuit having circuitry to: (a) receive a series of said strain output signals during the rivet setting process; (b) receive a signal indicative of the supply pressure; (c) align the series of strain output signals with a predetermined set of output signals to form a series of strain output/predetermined value pairs; (d) apply a scaling factor which is a function of the output of pressure sensor to the value pairs; and (e) compare the values of the strain output/predetermined value pairs to the predetermined if any of the strain output signals are more than a predetermined amount away from the predetermined values.