TWO-SPEED GEARBOX MECHANISM

Clutch 3 slides along square guide a of shaft 2. Gears 4 and 5 are keyed to shaft 1; gears 6 and 7 rotate freely on shaft 2. When driving shaft 1 rotates, driven shaft 2 can have either of two speeds depending upon whether clutch 3 is engaged to the clutch member of gear 6 or 7. The corresponding transmission ratios are i₁₂=-z₆/z₄ and i₁₂=-z₇/z₅ where z₄, z₅, z₆ and z₇ are the numbers of teeth of gears 4, 5, 6 and 7.
$2846$CxG,SR$