Patent ID: 8708598

Claim:
A speed control system for a self-propelled power trowel for finishing a concrete surface, said power trowel comprising: a rigid frame means adapted to be disposed over said concrete surface, said rigid frame means having a front and a rear and defining a centerline from front to rear; power means for powering said power trowel supported by the frame means; a pair of rotor assemblies for frictionally contacting said concrete surface and supporting said frame means on said concrete surface, connected to the frame means so as to allow tilting of said rotor assemblies and operably connected to the power means, with each of said rotor assemblies comprising a plurality of troweling blade assemblies with said speed control system comprising: a user input for generating a reference input signal for controlling rotation speed of said rotor assemblies; a speed feedback signal proportional to rotational speed of said rotor assemblies; computing means which comprises a follower logic pattern that compares the reference input signal and speed feedback signal of said rotor assemblies, and adjusts a control signal to minimize the difference between the feedback and reference input signal, with the control signal changing the speed of rotation of said rotor assemblies.