GB868164A - Improvements in the combination with a compressor of a motor for driving said compressor and a control device for the delivery of said compressor - Google Patents

Abstract

868,164. Fluid-pressure servomotor control systems; valves. ATLAS COPCO A.B. April 14. 1959 [Jan. 27, 1959], No. 12679/59. Class 135. [Also in Group XXVII] A mobile frame 1, Fig. 2, such as a motor vehicle, supports two compressors 4, e.g. of the screw, reciprocating, sliding vane or centrifugal type, each driven by an I.C. engine 2 through a step-up gear transmission 3 and e.g. a centrifugal coupling; the engines 2 are provided with centrifugal governors 68. Each compressor 4, which has an air inlet filter and silencer 8, delivers to a conduit 12, Fig. 3, via a pipe 9, a check valve 10 and a pressure equalizer 11. the latter having plates 35 of different length which form chambers 36 that effect silencing as well as pressure equalization. Each pipe 9 has one branch leading to an adjustable safety valve 13 and another branch connected via solenoidactuated unloading valve 19 to a pipe 22 having a silencer 23, Fig. 2, therein common to both compressors. The conduit 12 is connected through a hose 39 and a snap-coupling to the air intake of an aircraft 42; the conduit 12 is also connected to a double-beat blow-off valve 43, Fig. 4, common to both compressors and which leads to the silencer 23. The valve 43 is actuated by a diaphragm 48 the lower side of which is open to atmosphere and upper side of which is open to the pipe 12 through a restriction 65, the pipe 12 also being connected to a bellows 55 that control a spring-loaded hinged closure 57 co-operating with a nozzle 62 having a flow passage of larger area than the restriction 55 and connected to the chamber above the diaphragm 48, which chamber may be supplied with fluid from a source other than pipe 12. Upon closing a switch 24, Fig. 3, an electric motor 26 starts the engines 2 and the air delivered by the compressors 4 escapes through valve 19 and silencer 23 to atmosphere; after a given period a time-delay switch is opened and the solenoid of valve 19 is de-energized whereby the latter closes and the compressors build up pressure in the pipe 12; this pressure acts both on the diaphragm 48 to open the valve 43, and in the bellows 55 to cause the closure 57 to firstly throttle and then close off the nozzle 62 so that the valve 43 opens fully and the output of the compressor is directed to atmosphere. When air is being delivered to the aircraft the valve 43 is kept partly open and the pressure in the pipe 12 is kept at a constant value depending upon the spring-loading of the closure 57. The valve 19 may be dispensed with and the apparatus may be used for air conditioning or heating of aircraft cabins. The unit may comprise one engine and compressor only.