Patent ID: 7063282
Filing Date: 2006-06-20
Classification: B02C,B27L,Y02P

Abstract:
1. A wood chipping apparatus the main parts thereof comprising a chipping disc and an electric short circuit motor journaled to a common axle for common rotation motion with a prominent speed of rotation at a nominal current frequency and a mass inertial moment, said electric short circuit motor having a nominal load value and means to ascertain the corresponding nominal current, the apparatus further comprising a frequency converter connected to the current circuit of said electric short circuit motor, wherein the apparatus includes electronic means for receiving the value of an actual rotational speed of said main parts, said electronic means being operationally connected to said frequency converter, said frequency converter being arranged to decrease the frequency of the current of the motor when detecting a decreasing rotational speed at said nominal current of the motor, for releasing thereby kinetic energy of the rotating main parts, and to reset the frequency at a decreasing current of the motor.