Patent ID: 6212445
Filing Date: 2001-04-03
Classification: B06B,F16F,G05D,Y10T

Abstract:
A method for varying the amplitude of a substantially linear vibratory output force, said output force being generated by a device having a first Pair of counter-rotating eccentric masses which are mechanically linked so that they generate a first periodic force which always acts along a line which is fixed in a plane perpendicular to an axis of rotation of said first pair, wherein said first pair has an associated frequency of rotation and having a second pair of counter-rotating eccentric masses which are mechanically linked so that they generate a second periodic force which always acts along said line, wherein said second pair has an associated frequency of rotation, said first periodic force and said second periodic force algebraically combining to produce said vibratory output force acting along said line and, said method comprising the steps of:controlling the phase of rotation of said first pair of counter-rotating eccentric masses relative to the phase of said vibratory output force to advance said phase of said first pair relative to said phase of said vibratory output force by a specific amount while said first pair of counter-rotating eccentric masses are rotating, wherein said step of controlling the phase of rotation of said first pair comprises the step of adjusting said associated frequency of rotation of said first pair; andsimultaneously controlling the phase of rotation of said second pair of counter-rotating eccentric masses relative to said phase of said vibratory output force to retard said phase of said second pair relative to said phase of said vibratory output force by said specific amount while said second pair of counter-rotating eccentric masses are rotating wherein said step of controlling the phase of rotation of said second pair comprises the step of adjusting said associated frequency of rotation of said second pair.