Patent ID: 7086974

Claim:
Actuator device ( 10 , 100 ) for a bicycle gear-shift, comprising: an articulated quadrilateral ( 11 ) with four connecting rods ( 21 , 22 , 23 , 24 ) hinged together according to four pin axes ( 31 , 32 , 33 , 34 ) by four pin elements ( 41 , 42 , 43 , 44 ), in which the first connecting rod ( 21 ) is intended to be integrally fixed to the bicycle frame, the second connecting rod ( 22 ) is opposite to the first connecting rod ( 21 ) in the articulated quadrilateral ( 11 ) and is intended to be fixed to a support for a gear-shift derailleur; and a drive member ( 12 ), having a variable length according to a drive axis ( 13 ) and active between two opposite pin elements ( 41 , 42 ) to move them towards and away from each other deforming the articulated quadrilateral ( 11 ); wherein the drive axis ( 13 ) substantially intersects the pin axis ( 31 , 32 ) of both the two pin elements ( 41 , 42 ) between which the drive member ( 12 ) is active; wherein the drive axis ( 13 ) perfectly intersects at least one of the pin axes ( 31 , 32 ) of the two pin elements ( 41 , 42 ) between which the drive member ( 12 ) is active; wherein the drive member ( 12 ) comprises an electric motor ( 52 ) housed on a support ( 51 ) mounted on a first ( 41 ) of the pin elements, a screw ( 53 ) arranged axially along the drive axis ( 13 ) and put into rotation by the electric motor ( 52 ), a nut screw ( 54 ) engaged with the screw ( 53 ) and fixed to a second ( 42 ) of the pin elements opposite the first ( 41 ), wherein the drive axis ( 13 ) perfectly intersects the axis ( 32 ) of the second pin element ( 42 ); wherein the connecting rods ( 21 , 22 , 23 , 24 ) have a substantial width in the direction of the pin axes ( 31 , 32 , 33 , 34 ), with such a width defining an internal space in the articulated quadrilateral ( 11 ), wherein the drive member ( 12 ) is arranged inside such an internal space; and wherein the nut screw ( 54 ) comprises a tubular body ( 541 ) threaded internally, and two pin portions ( 542 , 543 ) opposite each other and perpendicular to the tubular body ( 541 ).