Clutch 3 slides along square guide b of shaft 1; clutch 4 slides along square guide a of intermediate shaft 13. Gears 12 and 11 are keyed to shaft 2 and are in constant engagement with gears 8 and 7 which rotate freely about shaft 13. Gears 10 and 9 are keyed to shaft 13 and are in constant engagement with gears 6 and 5 which rotate freely about shaft 1. When driving shaft 1 rotates, driven shaft 2 can have any one of four speeds for which clutches 3 and 4 are engaged at the same time to gears 5 and 7, or gears 5 and 8, or gears 6 and 7, or gears 6 and 8. The corresponding transmission ratios are i₁₂=(z₉/z₅)(z₁₁/z₇), i₁₂=(z₉/z₅)(z₁₂/z₈), i₁₂=(z₁₀/z₆)(z₁₁/z₇) and i₁₂=(z₁₀/z₆)(z₁₂/z₈) where z₅, z₆, z₇, z₈, z₉, z₁₀, z₁₁ and z₁₂ are the numbers of teeth of gears 5, 6, 7, 8, 9, 10, 11 and 12.
$2850$CxG,SR$