Wheel 1 rotates about fixed axis A and has holes a which engage pins d of pin wheel 2. Wheel 2 rotates about fixed axis B. Pins d are located on the end face of wheel 2 in three concentric circles. By shifting hub b of wheel 1 along axis A, the wheel can be brought into mesh with the pins of any of the three circles. In this way, when wheel 1 rotates at constant speed, wheel 2 can have either of three different speeds. When wheel 1 is shifted beyond point B to the right, rotation of wheel 2 is reversed.The transmission ratio from wheel 1 to wheel 2 is i₁₂=ω₁/ω₂=z₂/k₁ where k₁ is the number of holes in wheel 1 and z₂ is the number of pins on the circle with which wheel 1 meshes.
$2587$PG,3L$