US Patent 7914415 Automatic transmission

An automatic transmission is provided with three planetary gear units and five friction elements. The first planetary gear unit includes a first sun gear that is always fixed, a first carrier supporting a first pinion in meshed engagement with the first sun gear and a first ring gear in meshed engagement with the first pinion. The first to fifth friction elements are operatively arranged with respect to the first, second and third planetary gear units to selectively establish at least seven forward speeds and one reverse speed by combining simultaneous engagement of two out of five friction elements for transmitting torque from the input shaft to the output shaft.