Bicycle single-acted gear-shifting device and its unidirectional operator mechanism

摘要

Bicycle single-acted gear-shifting device (12), comprising one front or rear derailleur (10, 20) coupling a ratchet indexing mechanism (13) acted by only one single-acting slave-connector (110, 120) attached to said ratchet indexing mechanism (13), operated by a unidirectional operator mechanism (15) with optional multiple unidirectional handle operator units (30). Said ratchet indexing mechanism (13) removably defines and holds a plurality of predetermined working stable positions of the derailleur's cage-plate (102,202) for each gearshift, and it comprises a ratchet-gear (1) with a pawls' system. And said unidirectional operator mechanism (15) comprises optional multiple unidirectional operator units (30) connected in parallel with the only single-acting slave-connector (110, 120), in order to indistinctly operate it, by means of a branched single-acting drive circuit (115, 123) which can be arranged either using a hydraulic circuit (115, 115′, 115″) acting by pushing, or using flexible cables (123,123′) and housings (124) to act by pulling.

主权项

1. A bicycle single-acted gear shifting device (12) for a chain transmission system that incorporates a multiplicity of chainrings or sprockets in order to obtain different gear ratios, comprising:
a front (10) or rear (20) derailleur, which comprises, in turn, a floating cage-plate (102, 202) in order to allow for different working positions corresponding to the different gears, a movable member (303, 403) which carries said floating cage-plate (102, 202), and a derailleur body (101, 201) attachable to the bicycle frame and operatively coupled to said movable member (303, 403); a main spring (105, 205); a secondary spring (122); a single-acted ratchet-indexing mechanism (13), to removably define and hold a plurality of predetermined stable working positions of the movable member (303, 403) and consequently of the cage-plate (102, 202), which comprises: a base member (0) arranging a toothed ratchet-gear (1) mechanically connected to said movable member (303, 403), and biased by said main spring (105, 205) to a first direction named backward; a lock-element (2) coupled to said base member (0) in order to lock whichever of the ratchet-gear (1) teeth, blocking the ratchet-gear (1) movement in said first direction; an acting member (5) being able to move forward and backward relative to the ratchet-gear (1), being biased backward to its rest position by the abovementioned secondary spring (122); resting means (14) that limits the acting-member (5) displacement determining the mentioned rest position; a drive-element (3) coupled to the acting member (5) in order to engage the ratchet-gear (1) and move it integrally with the acting member (5); an ejector-element (6) driven by said acting member (5) in order to release the lock-element (2) from its locking position just only at the beginning of each shifting action, that is to say, along the first portion of the complete forward displacement range of the acting member (5), portion called ejecting action range; release-means (7) in order to disengage said drive-element (3) from the ratchet-gear (1) when said acting member (5) returns to its rest position; and a transmission assembly (8), mechanically connecting the movable member (303, 403) with the ratchet-gear (1), converting the input displacement of the ratchet-gear (1) into an output displacement of the movable member (303, 403) and consequently of the cage-plate (102,202); and one only single-acting slave connector (110) coupled to the acting member (5) in order to selectively operate it, and consequently to operate the single-acted ratchet-indexing mechanism (13),characterized in that said only one single-acting slave-connector (110) comprises a hydraulic slave-cylinder (111) and a hydraulic slave-piston (112) either mechanically coupled or integrally performed in a same element with the acting member (5) wherein said single-acting slave-connector (110), operated by hydraulic means, moves the acting member (5) in the abovementioned forward direction due to fluid pressure.