Patent ID: 6047455
Filing Date: 2000-04-11
Classification: B23P,B25B,G05D,Y10T

Abstract:
A method for simultaneously tightening two or more screw joints to a desired pretension condition by means of a nut running tool having two or more output spindles each having an adjustable output torque, said method comprising:individually operating each one of said output spindles according to at least one primary tightening parameter from among torque, angular position, time, clampload, and screw joint elongation;continuously detecting an instantaneous value of said at least one primary tightening parameter for each one of said output spindles;continuously comparing said instantaneous tightening parameter value for each one of said output spindles with a corresponding instantaneous tightening parameter value of each other one of said output spindles; andcontinuously adjusting a torque application speed by continuously adjusting a limit of the output torque of one of said output spindles on which the instantaneous tightening parameter value exceeds a predetermined boundary in relation to any other one of the spindles.