Speed control means

Claim 1

APPARATUS FOR ELECTRICALLY CONTROLLING THE R.P.M. OF A LOAD, SAID APPARATUS COMPRISING: AN EPICYCLIC TRANSMISSION GEAR, SAID TRANSMISSION GEAR INCLUDING A DRIVEN SHAFT COUPLED WITH THE LOAD, AND A SECOND DRIVEN TRANSMISSION SHAFT; AN EPICYCLIC CONTROL GEAR COUPLED TO SAID TRANSMISSION GEAR, SAID CONTROL GEAR INCLUDING AN INNER DRIVEN SHAFT; A FIRST ELECTRICALLY CONTROLLED BRAKE ACTING UPON SAID INNER DRIVEN SHAFT, SAID CONTROL GEAR INCLUDING AN OUTER DRIVEN SHAFT; A SECOND ELECTRICALLY CONTROLLED BRAKE ACTING UPON SAID OUTER DRIVEN SHAFT; AN INTERMEDIATE GEAR COUPLING SAID TRANSMISSION GEAR AND SAID CONTROL GEAR AND TRANSMITTING THE R.P.M. OF SAID CONTROL GEAR INNER DRIVEN SHAFT TO SAID TRANSMISSION GEAR SECOND DRIVEN SHAFT; A DIFFERENTIATING AMPLIFIER CONTROLLING THE ENERGY IMPULSE SUPPLIED TO THE BRAKE; A TACHO GENERATOR DRIVEN BY SAID TRANSMISSION GEAR LOAD DRIVING SHAFT TO PROVIDE A SIGNAL TO SAID AMPLIFIER REPRESENTATIVE OF THE ACTUAL VALUE OF THE R.P.M. OF SAID LOAD SHAFT; AND A CONTROL SIGNAL SOURCE PROVIDING A SIGNAL TO SAID AMPLIFIER REPRESENTATIVE OF THE DESIRED LOAD R.P.M., WHEREBY THE AMPLIFIER OUTPUT WILL BE THE DIFFERENCE BETWEEN SAID SIGNALS.