Clutch 3 with rigidly attached (or integral) gear 6 slides along square guide a of shaft 2. In the neutral position clutch 3 is stationary when shaft 1 rotates. When clutch 3 is engaged to the clutch member of gear 4 (keyed to shaft 1), shafts 1 and 2 rotate at the same speed in the same direction. Gears 8, 7 and 9 are keyed to shaft 10. Gears 8 and 9 are in constant engagement with gears 4 and 5. When clutch 3 is engaged to the clutch member of gear 5 (freely mounted on shaft 2), shafts 1 and 2 rotate in the same direction with the transmission ratio i₁₂=(z₈/z₄)(z₅/z₉) where z₄, z₅, z₈ and z₉ are the numbers of teeth of gears 4, 5, 8 and 9. If gear 6 is shifted into mesh with gear 7, shafts 1 and 2 rotate in the same direction with the transmission ratio i₁₂=(z₈/z₄)(z₆/z₇) where z₆ and z₇ are the numbers of teeth of gears 6 and 7.
$2845$CxG,SR$