A part of the compressed air delivered through pipeline 1 passes through flow-control valve 2 to nozzle 3 and to the space between bellows 4 and housing 6. The remainder of the air passes through tube 5 to the internal chamber of the amplifier from where it is partly discharged to the atmosphere through tube 8 and partly to the servomotor through tube 7. Valve plate 9, linked to the bellows by a rod, is located between the openings of tubes 5 and 8. When shutter 10 approaches nozzle 3, the pressure above bellows 4 increases, plate 9 is lowered, opening tube 5 somewhat and closing tube 8 to some extent. At this, the pressure of the air is increased in the internal chamber of the amplifier and, consequently, in the membrane servomotor (not shown).
$4122$EHP,Dr$