Machine for balancing vehicle wheels

A machine for balancing vehicle wheels comprising a rotary shaft defining an axis of rotation and adapted to receive the wheel to be balanced, a motor connected to the shaft to drive the shaft and wheel to a predetermined speed, at least one measuring device responsive to imbalance of the wheel and furnishing a measurement signal as a function of the value of the imbalance, and means for determining the angular position of the imbalance, after stoppage of the wheel, by a new rotation of the wheel, said means for determining the angular position of the imbalance comprising an angular coding device comprising a rotary member coupled to said shaft for rotation therewith, said rotary member having inscribed thereon a series of code numbes, each of which is inscribed respectively in a given radial position with respect to said axis of rotation so as to be representative of a corresponding angular position of the wheel, a stationary reader associated with said rotary member and so arranged as to be capable of reading successively each of said individual code numbers inscribed on said rotary member upon rotation of said wheel, at least one store connected to the reader, a measuring device for storing, in said store for a predetermined position of the imbalance, the value of the individual number which is presented in front of the reader at the moment when the imbalance passes through said predetermined position, and a storage authorizing circuit for authorizing said storage while said motor rotates at the desired measuring speed, there being also provided a calculating device for calculating the difference (.gamma.) between the valve (.beta.) furnished by the reader and corresponding to the instantaneous individual number read thereby, and the value (.alpha.) stored in the store, after stoppage of the wheel, and a circuit for utilizing said difference for indicating, after said new rotation, the position that the imbalance had at the moment of the storage.