Vacuum pump 1, powered by a belt drive, creates a vacuum in receiver 2. By means of directional valve 3, one of the ends of servomotor 4 is connected to the atmosphere and the other to receiver 2. Owing to the difference in pressure in the two ends of servomotor 4, its piston moves in the direction of lower pressure. This motion is transmitted by lever system 5, 6, 7 and 8 to engage one of the clutches 12 and disengage the other, thereby operating reversing gear 9. The reversing gear can be manually operated by turning lever 10, with its motion transmitted through lever system 11, 5, 6, 7 and 8.
$4293$CHP,GC$