Patent ID: 8496562

Claim:
A method of operation of a transmission device ( 1 ) comprising a plurality of shiftable elements comprised of a plurality of frictional shift elements (A, D, E, F) and at least one interlocking shift element (B, C) for obtaining various gear ratios (“ 1 ” to “ 9 ”, “R”) such that, when a shift to a selected target gear ratio is called for, during which the at least one interlocking shift element (C) is changed from a disengaged to an engaged operating condition, the at least one interlocking shift element (C) is at least approximately synchronized by increasing a transmission capacity of at least a first frictional shift element (A), which is disengaged in force flow of the transmission device ( 1 ) in both of a current gear ratio and the selected target ratio, and in an approximately synchronized condition the interlocking shift element (C) is changed to an engaged operating condition, only three of the shiftable elements are engaged in each of the various gear ratios, the method comprising the steps of: initiating the shift to the selected target gear ratio; maintaining engagement, during the shift to the selected target gear, of one of the plurality of shiftable elements which is engaged in the current gear ratio in the force flow in the transmission device; increasing the transmission capacity of the first frictional shift element so as to at least approximately synchronize the at least one interlocking shift element; engaging the at least one interlocking shift element in the force flow of the transmission device when the at least one interlocking shift element is at least approximately synchronized; engaging a further frictional shift element (D), which produces the force flow in the transmission device ( 1 ), such that only three of the shiftable elements are engaged in the selected target gear ratio, the further frictional shift element being disengaged in the current gear ratio and engaged in the selected target gear ratio.