Patent ID: 7014583

Claim:
A continuously variable belt-drive transmission for a motor vehicle, in which a belt-drive ( 4 ) runs between primary and secondary pairs of cone pulleys ( 2 , 3 , 6 , 7 ) with the primary pair of cone pulleys ( 2 , 3 ) mounted on an input shaft ( 1 ) and the secondary pair of cone pulleys ( 6 , 7 ) mount on an output shaft ( 5 ), and one pulley of each of the primary and secondary pairs of cone pulleys ( 2 , 3 , 6 , 7 ) being a fixed pulley ( 2 , 6 ) and the other pulley being an axially displaceable adjusting pulley ( 3 , 7 ), each pulley having tapered friction surfaces ( 25 to 28 ), and a first contact pressure device ( 9 ) being provided for axial displacement of the primary adjusting pulley ( 3 ), and a second contact pressure device ( 10 ) being provided for axial displacement of the secondary adjusting pulley ( 7 ); wherein a first pressure chamber ( 19 ) is defined between the primary adjusting pulley ( 3 ) and a first load piston ( 14 ), and during a pressureless state of the transmission, the primary contact pressure device ( 9 ) ensures, via a plate spring ( 13 ) located outside of the first pressure chamber ( 19 ), a contact pressure upon the primary adjusting pulley ( 3 ) of the input shaft ( 1 ), and the plate spring ( 13 ), during an engaged state thereof, braces the first load piston ( 14 ) with a shaft-tied cylinder ( 11 ).