planetary gear set is permanently coupled to a first component or element of a third planetary gear set referring now to fig1 an embodiment of a six speed transmission 10 is illustrated in a lever diagram format a lever diagram is a schematic representation of the components of a mechanical device such as an automatic transmission each individual lever represents a planetary gear set wherein the three basic mechanical components of the planetary gear are each represented by a node therefore a single lever contains three nodes one for the sun gear one for the planet gear carrier and one for the ring gear the relative length between the nodes of each lever can be used to represent the ring to sun ratio of each respective gear set these lever ratios in turn are used to vary the gear ratios of the transmission in order to achieve an appropriate ratios and ratio progression mechanical couplings or interconnections between the nodes of the various planetary gear sets are illustrated by thin horizontal lines and torque transmitting devices such as clutches and brakes are presented as interleaved fingers further explanation of the format purpose and use of lever diagrams can be found in sae paper 810102 u201c the lever analogy a new tool in transmission analysis u201d by benford and leising which is hereby fully incorporated by reference the transmission 10 includes an input shaft or member 12 a first planetary gear set 14 a second planetary gear set 16 a third planetary gear set 18 and an output shaft or member 22 the first planetary gear set 14 has three nodes a first node 14 a a second node 14 b and a third node.