US2829489A

US2829489A - Repeating cycle igniter control

Info

Publication number: US2829489A
Application number: US320653A
Authority: US
Inventors: Robert E Meyer
Original assignee: United Aircraft Corp
Current assignee: Raytheon Technologies Corp
Priority date: 1952-11-15
Filing date: 1952-11-15
Publication date: 1958-04-08
Anticipated expiration: 1975-04-08

Description

April 8, 1958 R. E. MEYER REPEATING CYCLE IGNITER CONTROL 2 Sheets-Sheet 1 Filed NOV. l5, 1952 INVENTOR ROBERT E. MEYER AGENT 2 Sheets-Sheet 2 Filed NOV. 15, 1952 INVENTOR noaa-Pr E. MEYER By 1 j C74 AGENT REPEA'HNG CYCLE IGNITER coNrnoL Robert E. Meyer, Glastonbury, Conn., assigner to United Aircraft Corporation, East Hartford, Conn., a corporation of Delaware `Application November 15, 1952, Serial No. 320,653

12 Claims. (Cl. 60---35.6)

This invention relates to an improvement in igniter controls for use with a turbojet engine having an afterburner for igniting said afterburner.

An object of this invention is to provide an igniter which will automatically repeat the injection of an afterburner igniting fuel charge to assure afterburner ignition during an afterburner starting cycle.

Another object of this invention is to sense an afterburner ameout and automatically inject, in repeating cycles, an afterburner igniting fuel charge until afterburner ignition occurs. l l

A further object of this invention is to time the frequency of repeating igniter cycles to prevent overheating of parts affected by the igniter charge combustion.

Other objects and advantages will become apparent from `the following specification and drawings.

In the accompanying rawings there is illustrated a suitable mechanical embodiment for the purpose of disclosing the invention. The drawings, however, are for the purpose of illustration only and are not to be taken as limiting or restricting the invention. t will be apparent to those skilled in the art that various changes in the illustrated construction may be made` without exceeding the scope of the invention. A portion of this igniter is shown and claimed in co-pending Application Serial No. 196,426 of Richard J. Coar, tiled November 18,` 1950, now Patent No. 2,819,587 issued January 14, 1958.

Fig, 1 is a schematic view of a turbojet engine including an afterburner showing the control system for said afterburner.

Fig. 2 is an enlarged view in section of the igniter control of the afterburner control system.

The turbojet engine 2 has a compressor 4, which, in the arrangement shown, is a centrifugal type, driven by a turbine 6. Combustion chambers 8 therebetween deliver air from the compressor to the turbine. An afterburner 10 is attached at the turbine outlet to provide a means of increasing the thrust.

The engine 2 has two axially-spaced annular intake openings 12 to direct the incoming air into the two oppositely facing annular compressor inlets. Compressed air discharging from the compressor 4 passes to the turbine through the combustion chambers 8 where it is mixed with fuel from fuel nozzles 14. These fuel nozzles 14 receive fuel from the governor 15 through Conduit 20. The fuel-air mixture is initially ignited within the combustion chambers 8 by a spark igniter 16. The governor '15 maintains the rotative speed of the turbine rotor assembly `in accordance with the value selected by the power lever 17 by controlling fuel ow supplied through conduit and nozzles 14 to the combustion chambers 8.

From the turbine, the gases pass around a cone 18 into the diffuser section 19 of the afterburner. When the afterburner is operating, fuel is discharged into these gases from a plurality of fuel nozzles 26 located in the diffuser 19.

Since the gases leaving the turbine 6 con-` tain considerable unburned oxygen, the additional fuel introduced by fuel nozzles 26 provides a combustible mixture which may be initially ignited within combustion chamber 27 by ignition means hereinafter described. The burning of this combustible mixture is stabilized in the afterburner combustion chamber 27 by

flameholders

30 and 32. The burned gases discharge from the engine through the variable area nozzle 44.

The variable nozzle 44 operates between a minimum opening for engine operation without afterburning and a maximum opening for operation of the engine with afterburning. A nozzle and actuating system, similar tothe one shown with this invention, is shown and claimed in co-pending application Serial No. 193,734 of Frederickv `car 140, and a track mechanism 142 for said car.

The afterburner control system can be divided into three main parts, (l) the fuel system, (2) the ignition means and (3) the exhaust nozzle actuator control. These three parts are closely coordinated by fluid conduit connections and an electrical system.

The fuel system includes the fuel tank 46, the fuel booster pump 48, the fuel pump 50, the fuel meter 52 and the fuel nozzles 26. The fuel booster` pump 48 is mounted on the fuel tank 46 and is connected to the fuel pump 50 by conduits 54 and 56. The fuel pump 50 shown is of the type having a centrifugal impeller driven by a compressed air turbine. Compressed air supplied from the compressor outlet of the engine drives l rotor 58, the air being delivered to intake passage 60 in which the rotor is located by

conduits

230, 64 and 66 and discharged through passage 62.- A valve operated by electric motor 68 is located at the junction of

conduits

64 and 66 to control the operation of the fuel pump by regulating the flow of compressed `air to rotor 58. The rotor is connected to and drives centrifugal irnpeller 70 which pumps fuel to fuel meter 52 through conduit 72. The fuel meter 52 meters the fuel therein and injects it into the engine through conduit 74 and nozzles 26. The fuel meter represented herein may be any one of many types some of which are shown and claimed in copending applications Serial No. 196,423 of Richard I. Coar, led November 18, 1950, and Serial No. 196,414 of Robert N. Abild, tiled November 18, 1950, now

Patent No. 2,714,803 issued August 9, 1955.

The exhaust nozzle actuator control 76 is a device to divert a pressure to the exhaust nozzle actuating cylinders 130 either to open or to close the exhaust nozzle as required. Compressed air from the compressor 4 is delivered to the nozzle control 76 by conduit 230 to provide the operating pressure. Conduit 262 connects the nozzle control to the side of the cylinders nearest to the nozzle which causes the nozzle to open when the operating pressure is applied thereto and conduit 266 connects the nozzle control to the side of the cylinders 130 farthest from the nozzle which causes the nozzle 44 to close when the operating pressure is applied thereto. Turbine exhaust gas static pressure which is delivered to the control 76 by conduit 79 automatically controls this nozzle control 76 to connect conduit 230 to either

conduit

262 or 266. An exhaust nozzle actuator control of this type is shown and claimed in cro-pending application Serial No. 196,424 of Richard l. Coar, filed November 18, 1950, now Patent No. 2,715,311 issued August 16, 1955. v

The igniter control 28 injects an amount of fuel in addition to that normally supplied into a combustion chamber 8 where it is ignited resulting in flame propagation through the turbine into the afterburner for igniting Patented Apr. `8, 1958 a combustible mixture in the afterburner. Fuel is provided to the igniter control 28 from the afterburner fuel system by conduit 174.

Igniter control 28 has a housing 1134i (see Figure 2) with a cover 11i?, mounted on one end by bolts 15M. A bore 186 is provided in said housing having its end covered by cover 102 connected to passage 1143 which connects to a conduit 115, which is shown as carrying compressor discharge pressure.

The housing 18@ also has two bores 116 and. 113 of different diameters which are co-aXially aligned, one end of the smaller bore 118 extending into bore 116 through an inner cylindrical ilange 119. The other end of bore 11S is closed by housing 188. Cover 182, closes the opening presented by bore 116.

i A piston member .l2/i is mounted within bere 'l ing a skirt 126 slidably engaging said bore. Proiecticns 128 permit the end of piston member 124 to form a cham* ber 123 with cover 102 when piston 124 is in its extreme left position (see Fig. 2). A passage 131 connects chamber 123 to bore 106.

A piston member 125, with a bore 12'? therein, has a slidable l'lt in bore 118 and extends out of inner cylindrical flange 119 into a. chamber 136, v-.fhich is formed by said flange 119, piston member 124, and bore 116. Chamber 136 is connected to reference pressure through opening 137 and conduit 139. A spring seat 129 is formed on the end of piston member 125 in chamber 136. A spring 133 is seated at one end around cylindrical flange 119 against the end of bore 116 and at its other end against spring seat 129. This spring biases

piston mem bers

124 and 125 to the left, piston member 1135 against piston member 124 and the projections 128 of piston member 124l against cover 1112, thereby forming a cham-- ber 141 at the right end of bore 113 between housing ldd and the end of piston member 125. A bushing 1151i h ing an orifice 144 is threaded into an opening 126 n pi ha vi, ton member 124. This orifice connects chamber 123 with chamber 136 through holes 135 in piston 12S.

A piston member 148 is slidably mounted in here and biased by a spring 15@ to the right against the heus-- ing 100. A bore 152 extends into the left end ot i member 148 and is connected by passages 154i to an annular groove 156 around said piston member. "l'his annular groove 156 is also connected to passage 13"? said piston member is positioned to the left in Fig. 2. A second annular groove 158, and a third annular groove 160, are formed around piston member M8. A f.. 162 connects annular groove 168 to a passage 161i in piston member 148 which in turn is connected to a chamber 166 formed at the right end of piston 11th beni/ecn said piston and housing 10d. A bushing 16S with a restricting orice 170. is mounted in passage 16a.

Housing 10d has another bore 38h formed therein, one end of the bore being closed by said housing and the other end being closed by a cover 502. Cover 3G12 is held on by bolts 304. A passage 366 connects the lleft end ol' bore 300 to passage 131. Cover 3G12 has a circular portion 308 which extends into bore 38d and has a slidable fit therewith. A hole 310 in said circular portion 363 connects passage 306 to the interior of the circular portion.

A piston member 312 is slidably mounted in here and biased by a spring 314 to thc lett against the circular portion 308 of the cover 362 which forms a stop. annular' groove 316 extends around said piston. A ventwould not start to close until a two second passed from the time that an operatingl pr reached the oriiice. This time of delay is set to be some value over the time required for an actuating pressure to reach the right side of piston member 312.

A passage 1'72 in housing 10) connects annular groove 153 ot" piston member 148 with annular groove 316 of piston member 312 when piston member 312 is in its position against stop 308. ln this same position of piston member 312, a passage 318 connects annular groove 316 with conduit 174, which delivers fuel from the afterburner fuel system, When piston member 312 is positioned to the right against the end of bore 300 it closes conduit 172 and passage 318 Where they enter said bore. Conduit 326 connects the right end of bore 300 to conduit 262, which connects the nozzle control to the side of the cylinders 130 nearest to the nozzle which causes the nozzle to open when the operating pressure is applied thereto.

A passage 176 in housing 1th? connects annular groove 158 to chamber 1411 when piston member 143 is in its spring biased position, to the right in Fig. 2 and pistou 125 is in its spring biased position, to the left in Fig. 2. A passage 178 in housing 100 connects chamber 141 to annular groove 161) on piston member 168 in any posi tion of piston member 148 or piston member 125.

A passage 180 in housing 1d@ having a bushing 182 with a restricting orifice 18d therein connects annular groove 161i on piston member 148 with conduit 186 when piston member M8 is in its spring biased position, to the right in Fig. 2. Conduit 186 is a connection to drain. For convenience it is shown attached to the afterburner. An annular groove 188 in housing ititl around here 106 is connected to a conduit 19d to direct fuel to a cornbusu tion chamber 8 through a nozzle 191. This groove 188 is connected to annular groove 161') of piston member 148 when said piston member is positioned to the lett in Fig. 3.

Annuler grooves 192 and 194 in housing 1in! around bore 148, and annular groove 1% in housing lo@ around bore 118 are so positioned to prevent leakage along said bores between different pressures or" like lluids and between different liuids. These grooves are interconnected by passages 198 and 281B. A passage Ztl?v connects these grooves to conduit 264 which may go to drain. Annular groove 266 around piston 125 in bore '118 is connected by passage 268 to compressor discharge pressure conduit 115. Groove 2616 then having a higher pressure than the drain pressure in groove 1916 prevents llow from groove 196 into chamber 136.

The electrical system may include a temperature control amplifier 86 which during afterburner operation is sent a signal by thermocouples 88 which sense turbine discharge temperature. Therinocouplcs also sense turbine temperature but send their signal to temperature gage 92. This amplifier when energized sends a signal t the fuel meter 52 to attenuate fuel flow in accordance with turbine discharge temperature and controls the operation of a normally closed solenoid operated shut-Off valve in the fuel meter 52. The aftcrburner switch 94 controls the amplifier 86, sets the motor operated valve 68 and controls the fuel booster pump 48.

Operation Afterburner operation is initiated by placing switch 94 in its on position. This movement energizes the temperature control amplier which in turn opens a nermally closed solenoid operated shut-off valve in the fuel meter and sends a signal to the afterburner fuel meter for attenuating fuel' flow therethrough. This movement oi` the switch also places motor operated valve 68 in open position and starts the fuel booster pump 48.

The operation of the fuel booster pump.v forces fuel from the fuel tank 46 through conduits 54 and 56 to the impeller '70 of the fuel pump 50. The opening of the motor operated valve 68 allows compressed air to be directed' from the outlet of the engine compressor 4 through

conduits

230, 64 and 66 against turbine 58 to.` drive the imasesinan peller 70. The impeller 70 then delivers fuel to the afterburner fuel meter 52. This fuel meter 52 meters fuel under the influence of compressor pressure rise and the temperature control amplifier and this fuel passes by a normally closed solenoid shut-off valve, which is now open, through conduit 74 to the fuel nozzles 26.

The flow of fuel through conduit 74 is also directed to the igniter control 28 by conduit 174.` It passes from conduit 174 through passage 318, annular groove 316, passage 172, annular groove 158 and passage 176 into chamber 141. It also passes from annular groove 158 through passage 162 to passage 164 and through restricting orifice 170 to chamber 166. From chamber 141 the fuel passes through passage 178 into annular groove 160. This groove is connected to drain by a passage 180, which has a restricting orifice 184, to permit chamber 141 to become purged of air so that it may be filled with fuel.

When chamber 141 has become filled, the fuel owing into chamber 166 through orifice 170 begins to urge piston member 143 to the left against the spring 150. This action shuts ofi the supply 9f fuelto chamber 141, shuts off passage 180 from annular groove 160, ports compressor discharge pressure fromconduit 115 by way of passages 154 and 131 to chamber 123 and to the left end of piston member 312 by passage 306, orifice 307 and hole 310, and connects conduit 190 to annular groove 160 through annular groove 188. With restriction 307 in passage 306 the compressor discharge pressure does not reach the left end of piston member 312 immediately. However, since chamber 136 is connected to compressor inlet pressure the pressure differential across piston member 124 urges piston member 125 to the right. This action incidentally shuts olf passage 176 from chamber 141 and displaces the fuel in chamber 141 forcing it through passage 178,

annular grooves

160 and 188 and out conduit 190 to the nozzle 191. When piston 125 is at the left, the spring 133 is designed to be at its free length and exerts no force on the

pistons

125 and 124. Therefore, the initial rate of injection is determined by the balance existing between the differential of fuel pressure in chamber 141 and the compressor inlet pressure in chamber 136 exerted across piston member 125 and the differential of compressor discharge pressure in chamber 123 and compressor inlet pressure in chamber 136 exerted across piston 124. Since the compressor rise increases as a function of the increase in engine air flow, this increase in pressure difference across piston member 124 must be balanced by increased pressure in chamber 141 which results in a higher rate of fuel ow through the nozzle 191. By this means, a degree of altitude compensation is effected so that the excess fuel/air ratio in the combustion chamber provided for ignition is kept essentially constant. The amount of fuel injected during each operation of the igniter is determined by the compressor rise and spring 133. Ignition of the injected fuel results in ame propagation through the turbine to the tail pipe resulting in ignition in the afterburner of the fuel being introduced through nozzles 26.

The ignition of fuel Within the afterburner results in an increase in turbine exhaust gas pressure above that normally obtained without afterburning, This increase in pressure is transmitted to the exhaust nozzle actuator control through conduit 79. The control 76 in accordance with this pressure directs compressor discharge pressure from conduit 230 through conduit 262 to the side of the cylinders nearest the nozzle which causes the nozzle to open. This pressure is also directed from conduit 262 by conduit 320 to the right side of piston member 312. Since restriction 307 delayed the actuating pressure from reaching the left side of the piston member 312 before it reached the right side, the spring force of spring 314 keeps piston member 312 in an open position.

The above operation holds when the afterburner ignites. However, if the afterburner fails to ignite, the

.6 turbine exhaust gas pressure would not increase and thel control 76 would continue to direct compressor dis charge pressure from conduit 230 to conduit 266 to the side of the cylinders furthest from the nozzle which causes the nozzle to remain in a closed position. Since compressor discharge pressure is not directed into conduit 262 and therefore not directed into conduit 320` to the right side of piston 312, there will be no pressure acting to force piston 312 to the left. Now, when restriction 307 has performed its restricting function, the pressure on the left of piston member 312 will move said piston member to the right against the end of the bore thereby compressing spring 314. This action cuts off conduit 174 and passageway 318 from passage 172 and the rest of the igniter. Spring 150, by virtue of fuel leakage along piston member 148 from groove 158 to grooves 192 and 194, will move the piston member to the right cutting off passage 306 and passage 131 from annular groove 156 which contains compressor discharge pressure.

Now piston member 125 is returned to its positionrto the left of Fig. 2 by spring 133. The igniter is now in position to inject another charge of fuel through nozzle 191, as soon as fuel is permitted to enter the igniter.

y p Now piston member 312 which has been restricting the flow of fuel into the igniter from conduit 174 is moved to the left by spring 314,` the fluid to the left of said piston member being permitted to bleed through venting passage 317. As annular groove 316 connects conduit 174 and passage 318 to passage 172 and the rest of the igniter, the operation of the igniter is again set into action.

While the two paragraphs above describe the operation of the igniter when the afterburner fails to ignite, action of the igniter is similar when after the afterburner has ignited a fiameout occurs. In this event the turbine exhaust gas pressure decreases and the control 76 directs compressor discharge pressure from conduit 230 to conduit 266 to the side of the cylinders furthest from the nozzle to cause the nozzle to close. Since the compressor discharge pressure is not directed into conduit 262 and therefore not directed into conduit 320 to the right side of piston 312, there will be no pressure acting to force piston 312 to the left. Now, pressure on the left of piston member 312 moves said piston member to the right cutting off conduit 174 and passageway 318 from passage 172 and the rest of the igniter. The igniter now operates to reinject a charge of fuel as described above. p

Although a specific igniter control has been shown and described herein for the purpose of illustration, it will be evident to those skilled in the art that the -invention is capable of various modifications and adaptations within the scope of the appended claims. The control system for an after-burner as shown in this application is shown and claimed in copending application Serial No. 196,425 of Richard J. Coar et al., filed November 18, 1950, now Patent No. 2,780,054 issued February 5, 1957, and an igniter control of the type shown in this application is shown and claimed in copending application Serial No. 196,402 of Carlton W. Bristol, lr., filed November 18, 1950, now Patent No. 2,780,055 issued February 5, 1957.

I claim: y

1. A housing having a chamber for fuel and an inlet and outlet for the chamber, first valve means for controlling the admission of fuel to said chamber, second valve means for controlling the admission of fuel to said first Valve means, means responsive to fuel pressure in said chamber for closing said first valve means, and piston means to displace fuel from said chamber through said outlet, said first valve means having means for directing fluid under pressure to said piston means to actuate said piston means when said valve means is moved by said fuel pressure, said rst valve means having means for directing ud under pressure to said i lllrllllllllll second valve means to tend to close said second valve when said first valve means is moved by said fuel pressure.

2. A housing having a chamber for fuel and an inlet and outlet for the chamber, first valve means for controlling the admission of fuel to said chamber, means for permitting said chamber to be purged of air by said fuel so said chamber will become full of fuel, said last named means including a drain conduit connected to said chamber, second valve means for controlling the admission of fuel to said first valve means, means responsive to fuel pressure in said chamber for closing said first valve means, and piston means to displace fuel through said outlet, said first valve means having means for directing fluid under pressure to said piston means and to one side of said second valve means to close said second valve means and means for connecting said outlet to said chamber and disconnecting said drain conduit from said Ichamber when said valve is moved by said fuel pressure.

3. A housing having a chamber for fuel and an inlet and outlet for the chamber, first valve means for controlling the admission of fuel to said chamber, means for permitting said chamber to be purged of air by said fuel so said chamber will become full of fuel, said last named means including a drain conduit connected to said chamber, second valve means for' controlling the admission of fuel to said first valve means, said second valve means being biased to an open position, means responsive to fuel pressure in said chamber for closing said rst valve means, and piston means to displace fuel through said outlet, said first valve means having means for directing fluid under pressure to said piston means and to one side of said second valve means to close said second valve means and means for connecting said outlet to said chamber and disconnecting said drain conduit from said chamber when said valve is moved by said fuel pressure.

4. In combination, a jet engine, means for supplying air to said engine, means for supplying fuel to said engine, means for igniting the fuel-air mixture in the engine formed by said first vand second named means, an afterburner, means for supplying oxygen to said afterburner, means for supplying fuel to said afterburner, means for igniting the combustible mixture in the afterburner formed by said fourth and fifth named means, said last named means having piston means for displacing additional fuel into said engine thereby enriching the fuel-air ratio in the engine, second piston means responsive to the fuel supplied to said a'fterburner for controlling said first piston means, and third piston means responsive to a pressure under the control of said second piston means for controlling the fuel supplied to said second piston means.

5. In combination, a jet engine, means for supplying air to said engine, means for supplying fuel to said engine, means for igniting the fuel-air mixture in the engine formed by said first and second named means, an afterburner, means for supplying oxygen to said afterburner, means for supplying fuel to said after-burner, and means for igniting the combustible mixture in the afterburner formed by said .fourth and fifth named means, said last named means having piston means including two pistons for displacing additional fuel into said engine thereby enriching the fuel-air ratio in the engine, one piston being large and the other piston being small, second piston means responsive to the fuel supplied to said afterburner for controlling said large piston of the first piston means, said large piston moving said small piston to displace the additional fuel, and third piston means re- `sponsive to afterburner ignition for remaining in an open position if afterburner ignition occurs and for moving to a closed position if afterburner ignition does not occur.

6i. A jet engine having a combustion chamber, a turbine downstream of the combustion chamber, an afterburner downstream of the turbine, means for injecting lfuel into the afterburner, means for supplying oxygen to said afterburner, kmeans for igniting the fuel in the afterburner including an auxiliary nozzle in the combustion chamber and means for discharging a stream of fuel through said nozzle to be ignited and carried through the turbine into the afterburner, in combination with means responsive to pressure variations in the afterburner, and valve means responsive to said last means and operative in the absence of an increase in pressure `for cutting off the supply of fuel to said discharging means.

7. An igniter for the fuel in an afterburner including a nozzle for the discharge of igniter fuel, fuel supply means. plunger means for delivering fuel from said supply means to said nozzle, valve means controlling the admission of fuel to and the discharge of fuel from said plunger means, said valve means being movable in response to pressure in the fuel line for opening the connection from the plunger means to the nozzle, said valve means also operating by its movement to admit iiuid under pressure to said plunger means for moving it, a normally open valve between the fuel supply means and the valve means for cutting off the supply of fuel to said valve means, afterburner pressure responsive means for moving said valve into open position, and fuel pressure means acting in l opposition to said afterburner pressure responsive means for moving said valve into closed position during the operation of the igniter.

8. A housing having a chamber for fuel and an inlet and outlet passageway for the chamber, a third passageway entering said housing, a fourth passageway in said housing, first valve means being located between said third passageway and said fourth passageway, second valve means being located between said fourth passageway and said inlet passageway for said chamber, piston means to displace a fiuid in said chamber through said outlet passageway, a fifth passageway leaving said housing, third valve means located between said fifth passageway and said outlet passageway for said chamber, a sixth passageway connecting said piston means to said first valve means for controlling said means, a seventh passageway entering said housing, fourth valve means located in said sixth passageway and connected to said seventh passageway, said first valve means being biased to an open position, said second valve means being biased to an open position, said third valve means being biased to a closed position, said fourth valve means being biased to a closed position, means responsive to a pressure in said chamber for closing said second valve means and opening said third and fourth valve means, this action connects the seventh passageway to the sixth passageway and the second passageway to the fifth passageway and disconnects said first passageway from said fourth passageway, an eighth pa-ssageway entering said housing, said eighth passageway being connected to said first valve means for controlling said means.

9. A housing having a chamber for fuel `and an inlet and outlet passageway for the chamber, a third passageway entering said housing, a fourth passageway in said housing, first valve means being located between said third passageway and said fourth passageway, second valve means being located between said fourth passageway and said inlet passageway for said chamber, piston means to displace a iiuid iu said chamber through said outlet passageway, a fifth passageway leaving said housing, third Valve means located` between said fifth passageway and said outlet passageway for said chamber, a sixth passageway connecting said piston means to said first valve means for controlling said means, a Iseventh passageway entering sa-id housing, fourth valve means located in said sixth passageway and connected to said seventh passageway, said first valve means being biased to an open position, said second valve means being biased to an open position, said third valve means being biased to a closed position, said fourth valve means being biased to a closed position, means responsive to a pressure in said chamber for closing said second valve means and opening said third and fourth valve means, this action connects the seventh passageway to the sixth passageway and the second passageway to the fifth passageway and disconnects said first passageway from said fourth passageway, an eighth passageway entering said housing, said eighth passageway being connected to said first valve means for controlling said means, said second, third and fourth valve means being interconnected so as to operate simultaneously.

10. A jet engine including a compressor, a turbine driving the compressor, a combustion chamber into which air from the compressor is discharged and from which the products of combustion are delivered to the turbine, means for supplying fuel to the combustion chamber to be burned with the air therein, and an afterburner connected to the exhaust side of the turbine and into which gas containing oxygen from the turbine is delivered, in combination with means for admitting fuel to the afterburner to mix with the gas therein, and means for igniting the mixture of fuel and gas therein, said last named means including a chamber for fuel and an outlet for the chamber, rst valve means for controlling the admission of fuel to said chamber, second valve means for controlling the admission of fuel to said first valve means, means responsive to fuel pressure in said chamber for closing said first valve means, and piston means to displace fuel from said chamber through said outlet into said combustion chamber, -said first valve means having means for directing fluid under pressure to said piston means when said valve means is moved by said fuel pressure, said first valve means having means for directing fluid under pressure to 'said second valve means when said first valve means is moved by said fuel pressure.

11. A jet engine including a compressor, a turbine driving the compressor, a combustion chamber into which air from the compressor is discharged and from which the products of combustion Eare delivered to the turbine, means for supplying fuel to the combustion chamber to be burned with the air therein, and an afterburner connected to the exhaust side of the turbine and into which gas containing oxygen from the turbine is delivered, in combination with means for admitting fuel to the afterburner to mix with the gas therein, and means for igniting the mixture of fuel and gas therein, said last named means including a chamber for fuel and an outlet for the chamber, .first valve means for controlling the admission of fuel to said chamber, second valve means for controlling the admission of fuel tosaid first valve means, means responsive to fuel pressure in said chamber for closing said irst valve means, and piston means to displace fuel from said chamber through said outlet into said combustion chamber, said first valve means having means for directing air from said compressor to said piston means when lsaid valve means is moved by said fuel pressure, said first valve means having means for directing air from said compressor to said second valve means when said first valve means is moved by said fuel pressure.

l2. A jet engine including a compressor, a turbine driving the compressor, a combustion chamber into which air from the compressor is discharged and from which the products of combustion are delivered to the turbine, means for supplying fuel to the combustion chamber to be burned with the air therein, and an afterburner con-v nected to the exhaust side of the turbine and into which gas containing oxygen from the turbine is delivered, in combination with means for admitting fuel to the afterburner to mix with the gas therein, and means for ignitin g the mixture of fuel and gas therein, said last named means including a chamber for fuel with an inlet and outlet, rst valve means responsive to fuel pressure in said chamber for 'controlling the admission of fuel to said chamber, second valve means responsive to afterburner ignition for controlling the admission of fuel to said first valve means, and piston means to displace fuel from said chamber through said outlet into said cornbustion chamber.

References Cited in the file of this patent UNITED STATES PATENTS 694,187 Pirie et al. Feb. 25, 1902 1,482,467 Harrington Feb. 5, 1924 1,994,747 Bishop et al. Mar. 19, 1935 2,279,546 Ziegler Apr. 14, 1942 2,520,967 Schmitt Sept. 5, 1950 2,552,231 Streid et al. May 8, 1951 2,640,316 Neal June 2, 1953 2,670,033 Ray Feb. 23, 1954 FOREIGN PATENTS 211,134 Switzerland Nov. 1, 1940