Bicycle Single-Acted Gear-Shifting Device and Its Unidirectional Operator Mechanism

A unidirectional operator mechanism (15), to operate a bicycle single-acted gear shifting device (12), this latter comprising a front (10) or rear (20) derailleur that comprises, in turn, a floating cage-plate (102, 202), 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 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 only one single-acting slave connector (110) coupled to the single-acted ratchet indexing mechanism (13) in order to selectively operate it;
• comprising multiple unidirectional handle operator units (30) and a single-acting drive circuit (115, 123) linking the unidirectional handle operator units (30) with the one only single-acting slave connector (110, 120),
• characterized in that each unidirectional handle operator unit (30) comprises only one unidirectional single shifting-lever (116, 126) or button coupling a single-acting master connector (32), and said single-acting drive circuit (115, 123) is branched in order to mechanically connect in parallel each one of the single-acting master connectors (32) with the above mentioned single-acting slave connector (110, 120) to indistinctly and selectively operate it;
• said unidirectional single shifting-lever (116, 126) can be manually operated only in one direction, in order to transmit the action to the single-acting drive circuit (115, 123), so that a short stroke of the single shifting-lever (116, 126) causes a downshifting movement in the single-acted gear shifting device (12), while a longer stroke of said single shifting-lever (116, 126) causes an up-shifting movement in the single-acted gear shifting device (12).