BICYCLE WITH AUTOMATIC GEAR SHIFT Russian patent published in 2010 - IPC B62M9/122 B62M25/02 F16D43/284 F16H61/28 F16H13/08 

FIELD: transport.

SUBSTANCE: spring-loaded control link (9) is revolved by front wheel hub (8) and linked with control link displacement drive to respond to bicycle speed increase or decrease. Control link displacement drive (9) comprises a set of bundles (15), Newton fluid (16) and journal of fixed shaft (7). Bundles (15) are regularly arranged around the ring of control link (9), one end of every bundle being fitted in said control link while another end can stays in permanent contact with aforesaid journal of fixed shaft (7) via Newton fluid (16). Balanced state of link (9) between faces of half-couplings (10, 11) is provided by spring and viscous friction between bundles (15) of revolving link (9) and journal of fixed shaft (7). Increasing speed causes an increase in viscous friction, makes ends of bundles (15) sitting on main part of journal sector and link (9) engaging with threaded half-coupling (11) that moves on threaded part of fixed shaft (7). Further displacement of threaded half-coupling (11) on shaft (7) controls via cord (6) the rear gear shift lever to shift drive chain from larger sprocket to smaller one. Decrease in speed causes the decrease in viscous friction and makes link (9) coupled with reversing half-coupling (10) which drives, via balls (13), threaded half-coupling (11) in opposite direction. Further displacement of threaded half-coupling (11) on shaft (7) controls via cord (6) the rear gear shift lever to shift drive chain from smaller sprocket to larger one.

EFFECT: simplified design, smaller sizes and weight.

2 dwg