Abstract: Control method for effecting a gear shift in a stepped automatic transmission with an input shaft and an output shaft for transmitting power between two inertia components at distinct speed ratios with a first power transmission path and a second power transmission path being provided with a high clutch having an adjustable torque transmitting capacity TH and a low clutch having an adjustable torque transmitting capacity TL respectively. The method includes the steps of determining a gear set input torque Tin to be transmitted by the transmission in the direction from the input shaft to the output shaft and controlling the torque transmitting capacities TH and TL in dependency on the gear set input torque Tin to be transmitted such that: a) if Tin>=0 then TH=Tin and TL=0 b) if Tin<0 then TH=0 and TL=Ti.

Abstract: A control system for a continuously variable transmission provided with a first pulley (1) having two pulley discs (5, 7), with a second pulley (2) having two pulley discs (6, 8) and with a drive belt (10) wound around said pulleys (1, 2) for transmitting torque there between, at least one disc (7) of the first pulley (1) being axially movable with respect to the other disc (5) of the pulley (1) under the influence of an axial force provided on the movable disc (7) by a line pressure (PLP) in a cylinder (11) of a piston/cylinder assembly (11, 13) associated with the the first pulley (1) and at least one disc (6) of the second pulley (2) being axially movable with respect to the other disc (8) of the pulley (2) under the influence of an axial force provided on the movable disc (8) by a second cylinder pressure (P2CP) in a cylinder (12) of a piston/cylinder assembly (12, 14) associated with the the second pulley (2).

Abstract: A control system for a continuously variable transmission provided with a first pulley (1) having two pulley discs (5, 7), with a second pulley (2) having two pulley discs (6, 8) and with a drive belt (10) wound around said pulleys (1, 2) for transmitting torque there between, at least one disc (7) of the first pulley (1) being axially movable with respect to the other disc (5) of the pulley (1) under the influence of an axial force provided on the movable disc (7) by a line pressure (PLP) in a cylinder (11) of a piston/cylinder assembly (11, 13) associated with the the first pulley (1) and at least one disc (6) of the second pulley (2) being axially movable with respect to the other disc (8) of the pulley (2) under the influence of an axial force provided on the movable disc (8) by a second cylinder pressure (P2CP) in a cylinder (12) of a piston/cylinder assembly (12, 14) associated with the the second pulley (2).