Patent GB-920640-A (GB)
Title: Improvements in feed devices feeding pressurized garments for life at high altitude
IPC: B64D10/00
Filed: 1959-07-01
Abstract: 920,640. Flying suit pressure regulators. BRONZAVIA S.A. July 1, 1959 [July 4, 1958], No. 22535/59. Class 68 (2). A regulator for an inflatable flying suit controls the gas pressure in the suit relative to the ambient pressure and maintains the breathing mask supply at a pressure related to the suit pressure. Fig. 1 shows the system diagrammatically. Oxygen from a supply cylinder 1 passes through a reducing valve, then to a demand valve 3, actuated by a diaphragm 4, and hence through a pipe 6 to a breathing mask. Oxygen also passes to a second reducing valve 7, the outlet pressure of which varies with altitude, through the regulator 8 and so to the suit through a pipe 9. There is an emergency oxygen supply 12. The regulator 8 is shown in Figs. 2, 3, 4 and 5 which together form a single drawing. Oxygen reaches the compartment 23 by way of a main control tap 14, a pressure gauge 15, reducing valve 2, safety valve 17 and altitude sensitive reducing valve 7. This compartment has a very small orifice 24 open to atmosphere and a second opening closed by a valve 25 which leads into a chamber 26. From this chamber a pipe 9 leads to the suit, there is also a spring-loaded inlet valve 28, a safety valve 29 and a compensated valve 30, which is mounted on a diaphragm 32 and is subject on one side to the pressure in the compartment 23. At altitudes up to 12,000 metres, the outlet pressure from the valve 7 does not exceed the ambient pressure, and as this pressure falls, gas escapes from the suit through the valve 30. Alternatively, as the ambient pressure increases air enters the chamber 26 through the valve 28 which is very lightly loaded. Above a height of 12,000 metres the outlet pressure of the valve 7 increases and results in increased pressure in the suit (only a small part of the flow from the valve 7 escapes from the orifice 24). The pressure drop across the valve 25 ensures that the valve 30 remains closed. A pipe 27 leads from the chamber 26 to a capsule 10 and increases the opening of the demand valve 3 so that the breathing supply pressure also increases. An emergency valve 12 fed through a pipe 35 has an " OFF " position and two operating positions. In the first operating position which is used if an emergency arises at an altitude of less than 12,000 metres, oxygen is fed directly to the jet 13 and hence to the breathing mask, but in the second position, used at altitudes above 12,000 metres, the suit is also pressurized to the greatest pressure allowed by the valve 29. A safety device 11 comprises a valve 48 closing a vent to atmosphere in the chamber 5 and attached to the piston 47, which is subjected to the pressure existing in the distribution chamber 26. If a fault develops at an altitude less than 12,000 metres and the pressure in the chamber 5 increases, the valve 48 opens and permits excess oxygen to escape. Above 12,000 metres the piston 47 is biased by the pressure which exists in the distribution chamber 26 and this allows a corresponding increase in the pressure in the chamber 5 before the valve 48 opens.