Patent ID: 6015360
Filing Date: 2000-01-18
Classification: B62M

Abstract:
An automatic gearshifting device of a bicycle multi-stage fly wheel, said device comprising:a main body provided with a rotary shaft fastened pivotally therewith;a fastening arm fastened with said main body and a bicycle frame;a rotary member fastened with said rotary shaft and provided with a receiving cell;an urging member fastened with said rotary shaft such that said urging member is capable of sliding in the direction of a longitudinal axis of said rotary shaft, and that one end of said urging member is located in said receiving cell;a plurality of weights located in said receiving cell such that said weights are in contact with said rotary member;a drive chain guiding mechanism for shifting a drive chain from one tooth to another tooth of a fly wheel gear cluster;a connection member connecting said urging member with said drive chain guiding mechanism; anda transmission mechanism connecting said rotary shaft with said fly wheel gear cluster;said urging member capable of being actuated by a centrifugal force of said weights in motion to displace in the direction of the longitudinal axis of said rotary shaft so as to enable said drive chain guiding mechanism to shift said drive chain from one tooth to another tooth of the fly wheel gear cluster;wherein said receiving cell is provided with an inclined plane; and wherein said weights are driven by said rotary shaft to slide along said inclined plane.