초록 ▼

In a wheel alignment system, the error caused by run-out of the axis of a fixture that is clamped to the wheel and mounts gravity stabilized inclination sensors is corrected by continuously providing fixture axis inclination signals during rotation of the wheel through at least 360°from any random s

In a wheel alignment system, the error caused by run-out of the axis of a fixture that is clamped to the wheel and mounts gravity stabilized inclination sensors is corrected by continuously providing fixture axis inclination signals during rotation of the wheel through at least 360°from any random starting position. Maximum and minimum comparator devices continuously receive these signals. A first adder adds the maximum and minimum signals and divides them by 2 to provide a preliminary alignment signal proportional to the actual angular inclination of the wheel axis in a selected alignment plane, and the preliminary alignment signal is subtracted from an intermediate inclination signal from the sensor that represents the inclination of the fixture axis at the wheel stopped position to provide a run-out error signal proportional to that portion of the total angular run-out of the fixture axis that is present in a selected alignment plane at the wheel stopped position. When the wheel is set down, a final inclination signal is received from the sensor means and the run-out error signal is subtracted therefrom to provide an inclination signal that represents the true wheel axis inclination in a selected alignment plane corrected for run-out error, and this signal is displayed for wheel alignment purposes. The sensors measure run-out errors in both the camber and toe planes and provide separate displays for the alignment in both planes.

대표청구항 ▼

The method of correcting for test instrument run-out error of vehicle wheels wherein a test instrument is installed on the wheel under test, said test instrument comprising a fixture that is detachably mounted on said wheel, sensor means on said fixture for detecting the angular inclination of said

The method of correcting for test instrument run-out error of vehicle wheels wherein a test instrument is installed on the wheel under test, said test instrument comprising a fixture that is detachably mounted on said wheel, sensor means on said fixture for detecting the angular inclination of said fixture during rotation of said wheel, signal means responsive to said sensor means for providing signals proportional to the angular inclination of said fixture in a selected alignment plane, and circuit means coupled to receive said signals and including maximum and minimum storage devices; the improvement comprising the steps of rotating said wheel at least 360°from any random starting position and thereafter stopping wheel rotation, continuously providing fixture inclination signals from said signal means during said wheel rotation, continuously comparing, during said wheel rotation, the present inclination signal with the previous inclination signals from said maximum and minimum signal storage devices, admitting the present inclination signal to said maximum signal storage device only when the present inclination signal is greater than that previously stored in said maximum signal storage device, and admitting the present inclination signal to said minimum signal storage device only when the present inclination signal is less than that previously stored in said minimum signal storage, thereby obtaining from said continuously provided inclination signals the maximum and minimum angular fixture inclination signals in said alignment plane relative to a selected reference plane, taking half the sum of said maximum and minimum angular fixture inclination signals to provide an inclination signal proportional to the actual angular inclination of said wheel in said selected alignment plane stopping the wheel at any random rotational position and sensing the stopped wheel fixture inclination, and combining the actual angular inclination signal with the stopped wheel fixture inclination to provide a run-out error signal indicative of the portion of maximum angular fixture run-out existing at the random stopped position.