The working fluid is admitted into the system through flow-control valve 6 and is delivered to nozzle 3. When the temperature of the item being controlled increases, thermoelement 1 moves shutter 2 toward nozzle 3, thereby increasing the pressure acting on membrane 5. This moves rod 4, rigidly attached to the membrane, downward, reducing the supply of heat-carrying agent to the system and, consequently, the temperature of the item being controlled. As rod 4 moves downward, lever 7 raises needle 8, partially closing the orifice in flow-control valve 6. This reduces the delivery of working fluid to the system and the pressure on membrane 5. When the temperature drops, the elements of the regulator operate in the reverse direction. Rod 4 has pins A sliding in forks d and f of levers 7 and 9, which turn about fixed axes B and C. Weight 10 can be adjusted along the axis of lever 9 to regulate the pressure on membrane 5.
$3901$LHP,Rg$