US Patent 8480533 Multi-speed transmission

A multi-speed transmission may include an input member and an output member disposed in a housing. A first planetary gear set, a second planetary gear set, a third planetary gear set, and a fourth planetary gear set may also be disposed in the housing, each planetary gear set including a sun gear, a planet carrier, and a ring gear. Six control elements may be operably coupled to the planetary gear sets and selectively engageable to create a set of different gear ratios between the input member and the output member, the set of different gear ratios including at least nine forward gear ratios and at least two reverse gear ratios.