Inventors:
Harold E. Patterson - Indiana PA
Paul I. Sleppy - Penn Run PA
Assignee:
FMC Corporation - Chicago IL
International Classification:
H02K 7065
Abstract:
A spring system for a vibration driver provides a non-linear stiffening reaction force as the deflection of the spring system increases. In a vibration driver, particularly an electromagnetic vibration driver, a reciprocating plate provides opposing bumpers which engage opposing elastomer blocks alternately during the stroke of the plate. Elastomer blocks include on three or four sides an elastomer impregnated fabric. The fabric controls the bulging of the elastomer block during impact by the bumper, substantially changing the spring rate of the elastomer block, to increase the resonant frequency of the spring system as the machine stroke increases. Increasing resonant frequency controls the stroke amplitude of the plate for a consistent feed rate of resonant tuned vibratory material handling equipment.