Gears 2 and 4 and ratchet wheels 6 and 7 are keyed on shafts 11 and 12 which rotate about fixed axes B and C. Pawls 9 and 10 are pivoted to gears 3 and 5 which rotate freely on shafts 11 and 12. Rack 1 has teeth on opposite sides which mesh with gears 2 and 4, rotating them alternately in each direction as rack 1 reciprocates. These rotating motions are transmitted to ratchet wheels 6 and 7 and alternately through pawls 9 and 10 to gears 3 and 5. When rack 1 travels to the left, gear 2 and ratchet wheel 6 rotate clockwise, engaging pawl 9 which rotates gear 3 clockwise and gear 8, with which it meshes, counterclockwise. At the same time, gear 4 and ratchet wheel 7 rotate counterclockwise and pawl 10 rides over the ratchet teeth without transmitting rotation to gear 5. When rack 1 travels to the right, clockwise rotation is transmitted to gear 5 and no rotation is transmitted to gear 3. In either case, gear 8, which meshes with gears 3 and 5, rotates counterclockwise, but intermittently with short dwells at the ends of the rack strokes.
$2733$RG,ML$