Patent ID: 7320654

Claim:
A method for the controlling ratio-change occurrences of an automatic transmission in a motor vehicle, by at least first and second hydraulic pressure branches ( 3 , 9 ) having different pressures wherein, placing first and second pressure reducing valves ( 4 , 5 ) in the first hydraulic pressure branch ( 3 ) by which hydraulic users (S 1 , S 2 ) are supplied with hydraulic pressure, and installing a pressure regulation valve ( 6 ) in the first hydraulic pressure branch ( 3 ) having an output port of which is connected with a line of the second hydraulic pressure branch ( 9 ), and by the activation of the pressure regulation valve ( 6 ), the pressure in the first hydraulic pressure branch ( 3 ) the highest, necessary operational pressure of the hydraulic users (S 1 , S 2 , 11 ) plus an offset pressure; during certain operational conditions of the motor vehicle, one of the first and second pressure reducing valves ( 4 , 5 ) for one of positioning devices of the two hydraulic users (S 1 , S 2 ) of the transmission is fully open, and as well the offset-pressure is reduced to one of a value zero or nearly zero; and upon removal of the certain operational conditions, the offset-pressure is once again increased and the pressure reducing valve ( 5 ) renews a function as a pressure reducing element.