GB1428571A - Pneumatic logical cell with not-function - Google Patents

Abstract

1428571 Valves SOC MINERVE SA 4 May 1973 [5 May 1972] 21286/73 Heading F2V [Also in Division A5] A valve for use in a respirator system comprises ball closure members 3, 4, in a chamber 2 which control communication between an inlet E and an outlet S and between the outlet S and exhaust P and a diaphragm defining a control chamber 12 with a control port C, which diaphragm is integral with a rod for actuating the closure members. The ball 4 is normally held against the exhaust seat by inlet pressures but it is moved towards the inlet seat by the rod for a given pressure in chamber 12. The inlet seat is smaller than the exhaust seat so that, for a given inlet pressure, the pressure in chamber 12 which moves the ball 4 is greater than that pressure in chamber 12 which is overcome by the inlet pressure to move the ball 4 back on to the exhaust seat. Two such valves 13, 14 and a "trigger" valve 31 (Fig. 3) are included in a pneumatic respiratory system (Fig. 2). The trigger valve is a spring-biased diaphragm valve which connects an inlet 45 with an outlet 46 or an exhaust 40 to outlet 46. A pressure source is connected to the inlets of valves 13, 14 and the outlet of 13 is connected to the control of 14 so that they are always in opposite states. The switching and timing is controlled by the build-up of pressure in chamber 25 via a throttle 27. When the pressure in 25 reaches said given pressure the valve 13 will switch over as with valve 14 and air will be supplied via conduit 22 and a remotelycontrolled valve 19 to a mask 18. Throttle 28 and valve 29, during this phase, exhaust the chamber 25 until the lower pressure is reached when the valve 13 switches back again. The trigger valve is included to give air on patientdemand. Inhalation by the patient connects inlet and outlet of the trigger valve to supply pressure direct to chamber 25 so that switching takes place immediately to give the patient air. A valve similar to valve 29 may be placed in series with throttle 27 and, in another variation, the valving functions of valve 29 and its counterpart may be performed by a single valve (62, Fig. 5, not shown).