Patent ID: 8715120
Filing Date: 2014-05-06
Classification: B62M

Abstract:
1. A chain guide of a front derailleur for shifting a chain between three chainrings, the chain having inner and outer links connected by link pins, the chain guide comprising: an inner guide plate; and an outer guide plate connected to the inner guide plate, the outer guide plate including an interior surface having a guide surface protruding toward the chain and a non-protruding surface offset from the guide surface, the guide surface having a length configured to extend along the outer guide plate to engage the chain during gear shifts between the chainrings, the guide surface having a width in a chain travel direction at least equal to a distance between consecutive outer links of the chain, the guide surface having a lower section and an upper section, the lower section extending to and along a lower edge of the outer guide plate to contact the chain when the chain is engaged on a largest one of the three chainrings and to contact the chain when the chain is engaged on a middle one of the three chainrings, the upper section extending upwardly from the lower section of the guide surface and the lower edge of the outer guide plate, the entire guide surface having a constant elevation in relation to the non-protruding surface and wherein the chain slides over the guide surface during a shift process to the adjacent, next smaller chainring; a portion of the non-protruding surface disposed forward of the guide surface along the chain travel direction from the non-protruding surface to the guide surface.