Patent ID: 8069744

Claim:
A device ( 1 ) for synchronization and engagement of a gear transmission of a motor vehicle comprising a shaft ( 3 ) and at least one idle gear ( 9 ) coaxial with respect to said shaft; the device comprising: a cylindrical hollow portion ( 18 ) designed to be coaxial and in a fixed position with respect to said shaft; a driving ring ( 44 ), designed to be fixed to said gear and comprising a first toothing ( 46 ); a first conical friction surface ( 47 ), carried by one between said driving ring ( 44 ) and said gear ( 9 ); a floating synchronizing ring ( 39 ), set between said cylindrical hollow portion ( 18 ) and said driving ring ( 44 ) and comprising: a) a second conical friction surface ( 40 ) mating with said first conical friction surface ( 47 ); and b) a second toothing ( 41 ); and at least one engagement member ( 54 ), which is angularly fixed with respect to said cylindrical hollow portion ( 18 ), is able to slide axially under the action of a control device ( 16 , 16 a ), and has a cylindrical toothing ( 55 ) designed to mesh progressively with said second toothing ( 41 ) and with said first toothing ( 46 ) to render said cylindrical hollow portion ( 18 ) angularly fixed ( 17 ) with said driving ring ( 44 ); an inner portion of said engagement member ( 54 ) being actuated by said control device ( 16 , 16 a ) and being located in a radial position that is more internal with respect to that of said toothings ( 41 , 46 , 55 ); said device being characterized in that said toothings ( 41 , 46 , 55 ) are located in a radial position that is more internal with respect to that of said conical friction surfaces ( 40 , 47 ).