is. ? S. Z7zvezzar; AA-7/w/ Zoza, ZvZAegea, 62/. y-p2 se Aug. 5, W. W. PAGET-- 2,425,000 & Filed March 27, Sheets-Sheet l

Transcription

1 Aug. 5, W. W. PAGET-- 2,425,000 APPARATUS FOR AUTOMATICALLY ROLLING PRESSURE AND TEMPERATURE WITHiiN AIRCRAFT CABINS m Filed March 27, Sheet-Sheet l S \ e o 2 y-p2 e R Ea i. V El N O HS S v? S. N Z7zvezzar; Zoza, ZvZAegea, 2g/ AA-7/w/ & /.

2 Aug. 5, ,425,000 APPARATUS FOR AUTOMATICAL W. W. PAGET CO NTROL ING PRESSURE AND TEMPERAT URE WITHIN AIRC RAFT CABINS Sheet-Sheet 2 Filed March 27 W M27 Z722/e72. 2Zaz. zea Aayee, 622/.

3 Aug. 5, W. W. PAGET 2,425,000 APPARATUS FOR AUTOMATICALLY CONTROLLING PRESSURE AND EPERATURE WITH IN AIRCRAFT CABINS Fied arch 27, Sheet-Sheet S

4 Aug. 5, W. W. PAGET 2,425,000 APPARATUS FOR AUTOMATICALLY CONTROLLING PRESSURE AND TEMPERATURE WITH IN AIRCRAFT CABINS Fied arch 27, Sheet-Sheet 4 N NNNNig NSGA SETI SNN: i ANS G SS WS N.N. NASANYANNYSKV ŠišSYS N N NASREZS WE, E N vš NS AAA' 2. i: N S S S. S. 2S ZS2 4. SS i 6 U23 if A NNS ) REE PAww. SAANSN S area <2 ZZ Na SSEE eee I/AN act teera E. Cl\\ 3 Sir II. III, 2EE Z7zzezza27. SI33 RN One 2XST?een over, Erret fifeylfur Zuzz, ZZ2Aatae, tee ell 1 AA-24/M4 E Ozzy.

5 Aug. 5, W. W. PAGE 2,425,000 FOR AUTOMATICALLY CONTROLLING PRESSURE AND APPARATUS TEMPERATURE WITH IN AIRCRAFT CABINS Filed arch 27, Sheet-Sheet 5 Zy azzn (l25.7% %.S.E wa ixw YK 2. Ali 160%. 3S Y'NS f49 %-3%tifiSš Eoin % N 33.7% a 2. %56S Z2 2SYS y 2 at: I AR HEN KS S.$3E2.W. 22%.S. eae et a /38-2, N SSS Né N 2N S& S. 3S323 %.S.% Zey. Y3 cal A37 7 W Zzazezza: Zvjazz, Aaayee,

6 Aug. 5, W. W. PAGET 2,425,000 APPARATUS FOR AUTOMATICALLY CONTROLLING PRESSURE AND TEMPERATURE WITH IN AIRCRAFT CABINS Filed arch 27, Sheet-Sheet 6 A. a L a vxy A. Z7azezaao Zezz Me 22/

7 Aug. 5, W. W. PAGET. 2,425,000 APPARATUS FOR AUTOMATICALLY CONTRONG PRESSURE AND TEPERATURE WITH IN AIRCRAFT CABINS Filed arch 27, Sheet-Sheet 7 Zzzaxezza7. 6 Z072 ZZ2.9ee, / a 4-76M4 (2éey.

8 Aug. 5, ,425,000 W. W. PAGET APPARATUS FOR AU TOMATICALLY CONTROL LING PRESSURE AND EPERA TURE WITH IN AIRCRAFT CABINS 8 Sheet-Sheet 8 Filed arch 27, 1943?. l?š Ø OESS Saawaaa. ay rava 222atea SYXA Z7zzvezza7. Zveza Z2Aayee. A., 4-war (2e2/.

9 Patented Aug. 5, ,425,000 UNITED STATES PATENT of FICE 2,425,000 My invention relate to cabin condition con trolling apparatu, and from one apect to cabin pressure and temperature controlling ytem, and from another apect to valve mechanim governed by preure and temperature condition for regulating the temperature of the air upplied to an aircraft cabin or imilar pace. In the field of high altitude flight, preurized cabin preent one of the bet mode-and at extremely high altitude the only practicable mode-of Operating aircraft. The maintenance of reaonably atifactory temperature condition in uch cabin, a well a adequate preure, i an important problem. In the preurizing oper ation, whether accomplihed by centrifugal u percharger or by other device for increaing the preure of the air upplied to the cabin, there i a ubtantial increae in the temperature of the air, and thi increae in the heat content of the air may be utilized in the heating of the cabin. The utilization of thi ytem of impoing an APPARATUS FOR AUTOMATICALLY CON TROLLING PRESSURE AND TEMPERA TURE WITN. ABCRAFT CABINS win W. Paget, Michigan City, Ind, aignor to Joy Manufacturing Company, a corporation of Pennylvania additional back preure on the cabin uper charger i ubject to a eriou diadvantage in that if the temperature elected were uitable for adequate heating at medium and high altitude, the Supercharger could be greatly overloaded at Sea level-a condition which could not be riked with the deign of upercharger for aircraft re quiring very cloe clearance and minimum weight. I have accordingly provided mean for automatically overriding the terhperature con trol of the back preure valve in uch a way that either the occurrence of a given differential be tween upercharger intake and dicharge at low Application March 27, 1943, Serial No. 480, Claim. (CL 98-15) altitude or a predetermined maximum compre ion ratio irrepective of altitude will prevent the impoition of a further back preure on the Supercharger. In a deirable form of preurizing device an arrangement i provided whereby coacting rotor are adapted to form pocket in which air i en cloed, and upon rotation of the rotor the pocket diminih in volume and the air i com preed, and after compreion through the de ired ratio the air i delivered through paage, into communication with which the pocket move, into the cabin. A, in the deign of uch a device, it i not deirable, for weight reaon, to provide the part of uch ize and trength a afely to enable maintained compreion through the deigned maximum range except when the plane i at Such a height that the total weight of air pumped will be much le than at ea level, there i included in the preferred type of pre urizing device mentioned an unloading mecha O nim which prevent ubtantial actual compre ion until a deired height i reached, uch a 20,000 feet; and the air taken in at the intake i freely dicharged until the rotor pocket move out of communication with a uitably valve-con trolled unloader port, and the air in the pocket, a thee move out of communication with the outlet port mentioned, i delivered by mere di placement to the cabin of the plane; although if the aircraft cabin preure exceed intake pre ure there may be a back preure on the pre urizing device which will neceitate the doing of work on the air and an increae in the ten perature of it. Of coure, with other type of upercharger, uch a Centrifugal upercharger, the ame principle applie a to the portion of the rotor beyond the outlet port mentioned. Now the maximum compreion range for de vice of the character mentioned above may not deirably exceed three to four compreion, and for centrifugal upercharger the maximum ratio hould not exceed three compreion, and thi compreion ratio hould not be utilized, at ea level, but only at high altitude, a previouly explained. Accordingly, when a cabin preure correponding to external preure of ay 8000 feet i to be maintained Over a wide range of higher flight level and proviion i to be made for a maximum ratio of Compreion to be reached only at a height of 35,000 to 40,000 feet, the upercharger, whatever it type, mut not be caued to operate againt a back preure in ex ce of even and one-half pound for any mate rial time at ea level. If a back preure of that value i impoed. On the dicharge, there will be an increae in the temperature of the dicharged air of 65. F., and thi i obviouly ufficient to aid greatly in cabin heating and to require under ome condition Cooling to prevent exceive Cabin temperature. My invention from one apect, in a preferred embodiment thereof, comprie mean for im poing a back preure on the dicharge of a Supercharger which deliver air to an aircraft cabin, and back preure impoing mean which i provided with mean for automatically lim iting the maximum differential in preure be tween intake and dicharge, and with mean for automatically limiting the maximum compre Sion ratio, and with mean for automatically con trolling, within the limit impoed by aid auto matic mean, the degree of back preure im poed on the Supercharger in accordance with cabin temperature variation. From another apect my invention include, in a preferred em W.... w

10 3 bodiment, an improved upercharger having mean for delivering a ubtantial volume of air without material compreion to a heat ex changer or returning the ame to the outide of the aircraft, and mean controlling the di tribution of the air o pumped automatically in accordance with the cabin temperature varia tion, aid upercharger having, further, mean for delivering an additional quantity of air, againt an automatically controlled and limited back preure, through the heat exchanger and pat a back preure impoing valve whoe poi tion i automatically controlled by cabin tempera ture, ubject to an overriding, automatic control if either a predetermined maximum deired dif ferential between back preure and external preure i attained or if a predetermined maxi mum deired ratio between back preure and intake preure i reached. From till another apect my invention comprie an improved auto matic valve having improved controlling mean reponive to temperature and preure condi tion. It i an object of my invention to provide an improved aircraft cabin preurizing ytem. It i another object of my invention to provide an improved aircraft cabin preurizing ytem hav ing improved mean incorporated therein for con trolling cabin temperature. It i till another object of my invention to provide an improved aircraft cabin preurizing ytem having incor porated therein inproved mean electively effec tive to heat or to cool air in tranit to the Cabin. Still another object of my invention i to pro wide an improved controlling valve. Yet a fur ther object of my invention i to provide an im proved controlling valve having incorporated therein improved temperature and preure re ponive controlling mean. In the accompanying drawing in which for purpoe of illutration a preferred embodiment of my invention from it everal apect i hown for purpoe of illutration: Fig. 1 i a generally diagrammatic view with part in ection howing a cabin preure and temperature controlling ytem. Fig. 2 i a view partially in ection howing a control device for a flow ditributing valve which form a part of the ytem of Fig. 1. Fig. 3 i a view in central vertical ection through a back preure valve forming a portion of the Sytem hown in Fig. 1, and itelf embody ing one apect of my invention. Fig. 4 i a ection on the plane of the line 4-4 of Fig. 3. Fig. 5 i a ection on the plane of the line 5-5 of Fig. 3. Fig. 6 i a fragmentary perpective view how 2,425,000 ing a portion of a manual controlling device for optionally locking the back preure controlling valve Out of Operation, Fig. 7 i a view in central longitudinal ection on the plane of the line 7-7 of Fig. 14, through the Supercharger, with part hown in elevation. Fig. 8 i a view on the ame plane, but on an enlarged cale, howing, with additional part in ection, the controlling mechanim hown in elevation in Fig. 7. Fig. 9 i a detail ectional view on the plane of the line 9-9 of Fig. 8. Fig. 10 i a ectional view of an oil pump. Fig, 11 i a tranvere ection on the plane of the line ff-ff of Fig. 10. Fig. 12 i a ection on the plane of the line 12 2 of Fig. 11. O Fig. 13 i a ection on the plane of the line 3 3 of Fig. 3. Fig. 14 i a central vrrtical ection on the plane of the line 4-4 of Fig. 7. Fig. 15 i a vertical ectional view on the plane of the line 5-5 of Fig. 7, howing the paag ing at the intake end of the upercharger. Fig. 16 i a vertical ection on the plane of the line 6-6 of Fig. 7, howing the paaging at the dicharge end of the upercharger. Fig. 17 i a central longitudinal ection through a cabin vent valve whoe function it i to main tain automatically the cabin preure. Fig. 18 i an enlarged ectional view on the Sane plane a Fig. 3, illutrating on a larger cale detail of contruction. Referring to the drawing, it will be noted that there i indicated at 2 the bounding wall of a Space 22 intended for pilot or paenger occu pancy a the cae may be. Suitably upported alo by the aircraft of which the compartment 22 form a part i a rammed inlet connection 23 Opening, for example, through the front Surface of a wing (not hown); and thi rammed inlet ha in communication with it a conduit 24 which i connected through an elbow 25 with the intake pace 26 of a upercharger 27 whoe contruction will hortly be decribed in greater detail. Thi Supercharger may be driven in any uitable man ner and preferably at different peed, a ex plained in my copending application Serial No ,641, filed September 17, 1942, from an air 3raft engine, not hown; and it comprie inter mehing rotor 30, 3 dipoed in interecting bore 32 and 33 in a caing 34. The caing 34 ha a dicharge opening 35 controlled by a valve 36 whoe contruction and method of control will be more fully decribed hereinafter, and thi Opening 35 i deigned to permit free paage of air received in the pocket formed between the houing and the peripheral convolution of the rotor into a chamber 37 until uch time a uch pocket Inlove out of communication with the opening 35. A econd paage 38 i arranged at the dicharge end of the upercharger 27, and to thi pace air i delivered either by mere diplace ment, when the valve 36 i open, or after an ac tual compreion through a given range when the valve 36 i cloed. The paage 38 communi cate with a conduit 39 which conduct the main dicharge from the upercharger 27, and thi con duit 39 in turn communicate through an elbow 40 with an end chamber 4 of a heat exchanger 42, the inner pa of which i formed by a erie of tube 43, the one end of which are in free S communication with the chamber 4 and the other end of which are in free communication With a chamber 44. The outer pa of thi heat exchanger i formed by a erie of oppoitely ex tending baffle 45, 45 which provide a tortuou paage back and forth around the tube, progre ively lengthwie of the heat exchanger. The chamber 37 i connected herein by an elbow 47 with a conduit 48 which open into a valve caing 49 in which a valve element i rotatably up ported for control by mean hereinafter decribed. In line with the conduit 48 i a further conduit 5 opening into the upply end of the outer coure of the heat exchanger 42, and at right angle to the opening 5f there i another opening 53 which i connected by a conduit 54 with a conduit 55 one end of which communicate, a at 56, with the dicharge end of the outer coure of the heat exchanger and the other end of which i con nected in any uitable manner (not hown) with

11 5 the atmophere, a indicated by the legend. The valve i provided with an operating haft 58 having a lever 59 thereon by which the valve i moved through the action of a rod-60 having an eye 6f cooperating with a pin 62 on the arm 59. The rod 60 ha a head 63 on which a pring act normally to move the valve toward a poition in which fluid paing into the valve cae ing 49, through the conduit 48, may be delivered through the conduit 54 and to the atmophere, whereby only a part or even none of uch fluid may be permitted to pa through the Outer coure of the heat exchanger. An expanible bellow device 65 i provided with whoe interior a tube 66 communicate, the tube 66 having formed on the end thereof a thermotat bulb 6 which i arranged within the pace 22 and adapted, upon an increae in the temperature in the cabin Space 22, to provide fluid preure to move the valve in a direction to diminih the free flow from the conduit 48 to the atmophere and to require in creaing amount of thi air to pa through the outer coure of the heat exchanger. From the dicharge chamber 44 of the inner coure of the heat exchanger a conduit O lead to a valve ca ing in which there i arranged a back preure valve 72 (Fig. 3) whoe poition i both manually controllable and automatically controllable by mean which will hortly be decribed. The function of thi valve i to provide a back pre ure againt which the upercharger mut deliver air through the conduit 39, and aid valve ha controlling mean generally deignated for effecting a control thereof in accordance with cabin temperature variation but ubject to an overriding, automatic control if either a prede termined maximum deired differential between back preure and external preure i attained or if a predetermined maximum deired ratio be tween back preure and intake preure i reached. The tructure of thi back preure controlling valve mechanim will hortly be more fully decribed. The back preure controlling valve mechanim ha a delivery paage which communicate with ducting 75 of any uitable type, and herein diagrammatically hown, open ing into the cabin through vent 76. For the purpoe of controlling the preure in the cabin an automatic cabin vent valve 78, which may be of a contruction uch a i illutrated in my copending application Serial No. 468,938, i pro vided, and thi vent valve function to permit cabin preure to vary ubtantially directly with external preure up to a predetermined altitude uch a 8000 or 10,000 feet, and then during Cer tain further increae in altitude to maintain cabin preure ubtantially contant, and when a till higher altitude i reached, ay 30,000 feet, to provide for the maintenance of a relatively contant differential in preure between cabin preure and external preure, and when a till higher altitude i reached, ay 40,000 feet, to provide for the maintenance of a cabin preure which hall bear a relatively contant ratio to the external preure. The Supercharger di cloed and it unloading mean, the back preure valve and it controlling, mean, and ome at leat of the detail of the cabin preure Went valve may now be ucceively decribed, before the operation of the improved ytem a a whole i taken up. The upercharger and it unloading mean A previouly explained, the upercharger 2 comprie intermehing rotor 30 and 3 dipoed in interecting bore 32 and 33 in the caing 34. 2,425,000 O While it will be undertood that it would be po ible to ue rotor having generated curve and generated lobe, in the contruction hown I have illutrated the rotor 30 a a male rotor con priing four helically arranged lobe 84, the rear ward ide 85 of which are hown a generated curve in profile, while the leading or preure ide 86 of each of thee lobe i in profile ib tantially in the form of a circular arc. The female rotor 3 i provided in the form hown with ix helically arranged groove 87, adapted to "cooperate with the lobe of the rotor 30 and the leading concave urface 88 of the groove 87 are in profile ubtantially in the hape of in arc, to coact with the arcuate preure urface 86 of the lobe of the rotor 30, while the follow ing concave urface 89 of the groove 8 are generated groove. in profile. The rotor are adapted to operate with pace packing, that i to ay, they are maintained in Such relation to each other through gearing that there i no actual contact between the rotor with each other, al though their coacting urface are very cloe to gether. Herein a gear 90 i operatively connected with the rotor 30 and a gear 9 with the rotor 3, o that the rotor are maintained in the de ired out of contact relation. Any uitable mean Such, for example, a i hown in my Copending application Serial No. 458,641, and including the gear 90, 9 and additional gear 92 and 93, may be ued for the drive of the rotor. The intake pace 26 of the upercharger communicate with the right hand, low preure end of the rotor and alo for a ubtantial part of the length of the rotor communicate with the back portion thereof, o to peak, the portion at the oppoite ide of the plane which include the rotor axe, from the dicharge. The caing 34. i provided, a previouly noted, with the dicharge paage 38, and alo with the dicharge paage or cham ber 3 which i connectible, under the control of the valve 36, with the rotor chamber. If deired, the compreor may have the peed of drive thereof automatically governed a by the mechanim more fully decribed in my copending application above identified. Referring now more particularly to Fig. 7, 14 and 15, it will be oberved that the caing at the intakeide doe not fit at all cloely to the periph erie of the rotor, and that the arcuate intake groove 94 extend at the intake end of the uper charger omewhat more than 90 in one cae and omewhat le than 90 in the other pat the plane which include the axe of rotation of the rotor, and that there are Wall portion repec tively marked 02 and 03 which, except for clearance adequate to contitute pace packing, do conform or fit quite cloely to the cylinder 55 traced by the Outermot portion of the rotor, 60 and that thee portion O2 and 03 interect 65 O along a line 04 parallel to the rotor axe. Now the fluid which i 'ealed' in the ucceive progreively diminihing chamber between the rotor and the caing Wall would be ubtan tially compreed if no ecape or dicharge Were provided between the time pair of tooth pace or groove move out of communication with the groove 94 and the intant that the leading edge of the tooth pace come into communication with the dicharge 38; and under certain condi tion uch compreion i very deirable, but un der other circumtance, a ha been hown, and a will be further hown, it i deirable to avoid material compreion, and accordingly I have provided an opening at 35 o related to the length 1.

12 7 of the caing and the helix angle of the rotor that when the opening 35 i unobtructed no compreion of the fluid encloed between the rotor 30, 3 will take place before communica tion with the opening 35 i had; and the relation hip of the opening 35 to the dicharge paage 38 i uch that the air remaining in the pocket in the rotor, a thee pocket move out of con munication with the opening 35, will not be compreed before thee ame pocket communi cate with the dicharge-38. It may thu be noted that the poition of the end of the intake groove 94 and the poition and dimenion of the open ing 35 are uch that with the helix angle of the rotor ued, tooth pocket whoe "trailing' edge are jut ceaing to communicate with the intake are jut about to commence to have their forward edge pa over the opening 35, and that a the "trailing" edge of tooth pocket approach their point of final communication with the opening 35 when the latter i open they have their leading edge pa beyond the edge of the final dicharge opening, whereby there i diplacement but not compreion in ealed pocket, of fluid when the opening 35 i not cloed by the valve 36. However, when the valve 36 i cloed, there i a ubtantial compreion of the fluid between the time the tooth pace ceae to communicate with the groove 94, 94 and move into communication with the dicharge 38. In Fig. 16 the pecial conformation of the dicharge end plate i hown, whereby the needed extent of the dicharge open ing 38 i obtained. The valve 36 i of uch hape that when it i 2,425,000 cloed it conform very cloely to the wall of the bore 32, 33. Thi valve ha ear to through which pin 08 pa, and thee pin are ecured in the arm or flange O9 carried upon a pivotal upport member to which i ecured by a pivot pin to the wall of the caing 34. A houlder 2 on the valve and a houlder 3 on the caing limit the cloing movement of the valve 36 to a poition in which the wall of the valve conform exactly to the urface of the rotor chamber. Thi valve i adapted normally to be maintained open by a pring 5 engaging at one end the wall of a member 6 which form a portion of the cloure of the dicharge chamber 37 and which i ecured in any uitable manner to the caing. The other end of the Spring act againt a piton T movable in a cylindrical chamber 9 which i formed in a cylinder-providing member 20, which i alo ecured in any uitable manner to the caing, being herein hown a held thereto by machine crew. The piton rod or operating tem 22 with an elongated eye 23 i connected at it outer end to the piton f7, and by mean of the eye and a pin 24 i connected to the valve 3S. The piton T and the member 20 coop erate to form a ervo-motor 25 to which fluid may be admitted through a connection or paage 26 under a control hortly to be decribed; and a leakage port, not hown, and illutrated in my copending application mentioned, i provided to conduct away any liquid which may ecape pat the piton to an oil ump 30 (Fig. 10) in the lower part of the caing 34. The pring 5 tend normally to maintain the valve 36 open, but when preure i upplied under certain predetermined condition to the ervo-motor mentioned the pi ton if T will be caued, through the operating tem 22 and the pin 24, to cloe the valve 36, and the upercharger will thu operate ubtantially pre ciely a though there were no opening 35 avail able. Thu, depending upon the poition of the O S valve 38, there i provided in a ingle unit, in effect, a mere diplacement device, and a con 45 preor capable of ubtantial compreion of air taken in, between the moment of intake and di charge. The upercharger caing ha, a above tated, in the bae thereof a Sump 30. A pump of the intermehing gear type 32 i normally partially ubmerged, and ha it intake alway ubmerged, in the horizontal poition of the ca ing, in the oil in the ump. Thi pump include a caing 33 having interecting rotor" chamber 34 therein in which there are rotor 35 whoe intermehing teeth 36 are adapted to tranport oil from an intake paage 3 to a dicharge pace 38 above the plane of the meh line of the rotor. One of the rotor drive the other and the firt mentioned rotor i provided with a haft 39 which extend through a cover 40 and carrie a gear 4f which i in turn driven by a pinion 42 rotatably upported on a leeve men ber 43. A larger gear 44, herein hown a formed integrally with the gear 42, i driven by a pinion 45 which i rotatable with the rotor 3. The dicharge paage 38 communicate through a manually controlled hollow valve 47 which need not be herein decribed, but which i decribed in my above mentioned copending ap plication, and through a trainer 48 with a pa age 49 which i connected, a more fully hown in my copending application hereinabove iden SS tified, with a tranvere paage or chamber. The chamber i adapted to be connected, un der the control of a pring-loaded valve 5, with a paage f$2 which i connected by an annular paage 53 with a further paage 54. The pa age 54 ha a bore 55 communicating with it, and a uitable pring loaded valve 56 recipro cate in the bore. A ide vent 57 open out of the bore and lead into a Space S which i in communication with the ump 30 and which i O under external preure-preure outide the cabin. The valve 56 i adapted to control the preure in the paage 54 by controlling the e cape of fluid through the ide vent. The paage 54 further communicate through a port 58 with a bore 59 of a valve eat member 60 mounted in the paage 6, which i connected by another paage 62 to a paage 63 leading to the ervo-motor which control the poition of the valve 36. It will be evident that if ecape through the bore 59 i prevented, fluid will be upplied to the ervo-motor at a preure deter mined by the valve 56. Mean i provided whereby the preure may be freely vented from the bore 59 back to the ump 30 at all time when the airplane i operating at level where the external preure i below a predetermined amount, and the valve eat member 60 i pro vided with a plurality of port f 64 opening through a urface urrounded by an annular valve eat 65, and there i further provided a central guide extenion f 66. Reciprocably mounted on thi guide extenion i a valve ele ment 67. Movement of thi valve element in an 5 opening direction i limited by a leeveportion f68 formed on a threaded leeve member 69 which i upported by a further leeve mounting element TO carried by a wall of the caing 34. An ad jutable cloure element and pring tenion regul lator 7 engage a pring f2 which act upon the valve 67 and normally tend to eat it. Con nected to the valve 6 and to the leeve member 69 at oppoite ide of the leeve portion 68 are bellow device f3 and 74 bounding a chamber 5 in which the leeve 68 i encloed, and thi

13 leeve i perforated o that free communication may at all time exit throughout the interior of thi chamber. The chamber 75 i evacuated and the compreion of the pring T2 i o deter mined that until the preure acting upon the exterior of the bellow arrangement fall to a predetermined low value, the valve 67 will be held firmly open againt the top leeve 68. However, whien the preure in the pace S fall below a predetermined value the valve 8 will firmly eat and interrupt the dicharge of fluid back to the ump, and caue the building up of uch a preure in the chamber 59 a to cloe the valve 36 and caue the upercharger to op erate a a compreor intead of diplacement mean. The wall of the element?o are per forated a at 79, 80 to permit the fluid paing through the paage 64 to flow freely to the ump through the pace S. Thi pace i con nected to external preure-preure outide the cabin- in any uitable manner, a earlier noted. The etting of the pring ft 2 i uch that the valve 67 i normally open at height of the air plane below ay 25,000 feet. The valve 67 i of the overbalanced type, being of the harp opening variety o that when the valve 36 i to open it may be permitted to open harply and cleanly. Extending axially through the guide extenion f 66 i a paage 82 through which fluid pae from the bore 59 to the interior of the leeve member 69 and the bellow device (14. When the valve device 67 i uneated fluid upplied un der preure through the paage 82 act againt the outer end of the valve and counteract the in creae in preure on the inner end of the valve produced by the fluid acting through the port f64. The tariable back preure value The variable back-preure valve mechanim a previouly noted include a caing in which there i arranged a retricting or back-preure impoing valve 72 whoe poition i both man ually controllable and autornatically controllable. The valve. T2 (Fig. 3) i of the approximately balanced type and include a generally conical portion 90 and an outer, peripheral, generally cy lindrical portion 9 f. The portion 90 i travered by port 92 to balance the preure at oppo ite ide of the valve. The cylindrical portion 9 ha an annular inner fange portion 94 formed thereon carrying pin 95 which are adapted to lide in traight lot f$6 formed in a portion 97 of the valve caing. A leeve portion 98 (ee Fig. 3 and 6) ha a plurality of elongated gen erally triangular opening 99 formed therein in to which the pin 95 project. The leeveportion 98 i rotatably mounted within the portion 9 of the caing and may be turned relative to the latter by mean of a handle 200. In view of the fact that the hypothen ue of the triangular Open ing 99 face downward, it will be evident that rotation of the leeve 98 may manually caue opening of the valve 72, but it i not poible to cloe the valve 72 by thi control. Thu thi manual control can lock the valve 72 out of op eration when deired. The valve 2 i carried by a tubular tem por tion 202 and i connected to that tem portion and to a paced plate 204 by nut and bolt mean 205. The tem i guided for reciprocatory no tion in a guide tructure 206 carried by an inner wall portion. 207 forming a part of the valve ca ing. To thi latter portion there i attached a houing element 208 which encloe a bellow de 490, O vice 209 attached in ealing relation at it upper end to the plate device 204, while it lower end i attached in ealed relation to an annular men ber 20 between which and a hollow inner men ber 2 a flange upon the houing 208 i clamped. The bellow 209 i continuouly ubjected through conduit mean 2t2 and a paage 22' to the pre ure in the throat of the valve caing f at the upper ide of a valve eat 23 with which the valve T2 i adapted to cooperate. In other word, the Outide of the below 209 i ubjected to the pre ure in the conduit T0. It interior i ubjected to a variable preure. Thi variable preure i determined by the relative rate of admiion of preure to the below from the conduit 70 and of dicharge of preure from the bellow. The member 2ff upport a domelike encloure mem ber 24 which houe bellow device hortly to be decribed which control the poition of a pilot valve 25. Another pilot valve 26 ha it poi tion regulated by a pring 27 and a thermotati cally expanible operating device 28. Each of the pilot valve 25 and 26 ha aociated with it a valve eat forming element 29. Each of thee element ha an axial paage 29' for which the aociated pilot valve i not a Snug fit, whereby preure from the conduit 70 may retrictedly pa along between the pilot valve and the wall of the opening 29'. Each of the valve eat mem ber ha a central chamber 220 into which the aociated paage 29' open and which com municate through a paage 22 with paage mean 222 which i connected with external pre Sure through a conduit 223. It will be noted that thi ame external preure connection communi cate with the interior of the domelike houing member 24. Each of the chamber 220 com municate through a paage 224 with the pace inide the bellow 209. The pilot valve 26 ha a head 226 againt which the pring 2 act; and a bell crank lever device 22T ha one arm thereof 228 poitioned to act on the head 226. The other arm. 229 of the bell crank i engaged by a pring preed plunger 230 actuated by a pring 23 whoe compreion i variable by mean of a foll lower 232. Were there nothing ele to oppoe the force exerted on the arm. 229 by the pring preed plunger 230 the pilot valve 26 would nor mally be cloed; and thi would mean that the preure within the bellow 209 would build up, by reaon of the flow of preure along the tem of the valve 26 and through the chamber 220 and lower paage 224 in Fig. 3 into the bellow. Thi would mean that the valve 72 would cloe, and accordingly the back preure impoed on the upercharger would build up, which would mean that the air would be increaed ubtan tially in temperature before it admiion to the cabin. The temperature reponive bellow 28 ha an end portion 234 which act on the oppoite ide of the bell Crank lever arm 229 and tend to move it in oppoition to the pring 23 and the bellow 28 i connected by a tube 235 to a ga filled, bulb type thermotatic device 236 in the cabin, o that when the cabin temperature in creae the bellow 28 will be expanded and the bell crank 22 moved in oppoition to the action of the pring 23 to permit the pring 27 to open the pilot valve 26 and thu permit an opening movement of the back preure impoing valve 2. The mounting for the pring preed plunger 230 and for the operating device 28 are upported by an end cloure element 237 which complete the encloure of the pace 238 with which the conduit 22 communicate.

14 11 From what ha been aid, it will be apparent that whenever the cabin temperature tend to be come undeirably low the pilot valve 26 will be moved in a direction to effect cloing of the back preure valve 72, with a reulting additional heating of the air entering the cabin. When the cabin tend to get undeirably warm the back preure on the upercharger will be reduced, o that the air entering the cabin will not be heated o much, thereby giving the cabin a chance to cool. A it i deirable that there hall, under no cir cumtance, be exceeded a predetermined mad mum differential between upercharger back preure and external preure, and that alo there hall be no exceeding of a predetermined maximum deired ratio between upercharger di charge and intake preure, I have provided ap propriate controlling mean for the pilot valve 2 to attain thee end. The pilot valve 25 i here in governed by the following device. An annular member 240, omewhat T-haped in radial cro ection, i mounted upon the member 2 at the upper end of the latter. The member 240 include a cylindrical top portion 24, an outer fange portion 242 and an inner flange portion 243. Suit able bellow device 244 and 25 are brazed, or otherwie held, at their lower end, to the flange 242 and 243, and at their upper end thee de vice are ecured to an annular member 246. The pace between thee bellow i evacuated, and the member 246 include an end flange 24 to a425,000 which the end of the bellow 244 i ecured, a cylindrical portion 248 and a econd radially but inwardly extending flange portion 249. To thi latter portion i ecured the bellow device 245. The radial flange 247 i adapted, in the relatively collaped condition of the bellow, to engage the end of the top portion 24. The upper end of the leeve portion 248 carrie an annular up port member 25 within which there i mounted a circular plate 252 carrying a guide leeve por tion 253. Slidably mounted within the guide leeve 253 i a tem 254 having at it lower end a ocket 255 in which the pilot valve element 25, i mounted with a limited freedom of movement laterally. The holding arrangement for thi pilot valve i illutrated in detail in my copending ap plication, Serial No. 472,567, filed January 16, The tem 254 ha between it end, and in the roatruction hown, approximately midway between it end, a radial flange 257. Thi flange ha a eating urface 258 which i adapted to en gage a urface 259 on the upper ide of the flange portion 249 of the member 246. A hallow radial groove 260 in the peripheral portion of the fiange 257 maintain communication between the pace between the bellow 245 and the lower end of the tem 254 and the pace encloed by the leevelike portion 248 of the member 246, even when the urface 258 and 259 are in contact. Between the member 25 and the flange 257 there extend a uitable bellow device 26 uitably connected in ealed relation to the flange and to the member, and a pring 262 of appropriate trength act upon the flange and upon the plate 252 and tend to move the tem 254 in a direction to caue the pilot valve 25 to eat. It will be oberved that the plate 252 i travered by one or more opening 263 o that the interior of the bellow device 26 i in contant communication with external pre ure through the interior of the caing 24 and the paage 223. A previouly noted, the pace within the bel O O 12 external preure; and the pace below the flange 257 and alo that urrounding the bellow device 26 f i ubjected to the preure from within the conduit 70 at all time. The pring 262 i o proportioned that it preure on the flange 23 i jut equal to the difference between uper charger dicharge preure and external pre ure applied to the effective area of the bellow device 26 when the maximum deired preure differential between Supercharger intake and di charge preure i reached. The maximum deired preure differentia be tween upercharger intake and dicharge pre ure may well be the ame a the maximum de ired preure differential between external pre. ure &nd cabin preure, and a the maximurn de ired preure differentia between cabin preure and external preure may be 9.SSuriled to be that of the difference in abolute preure at a height of 10,000 feet and the aboiute preure at 30,000 feet, repectively inche of mercury and 8.87 inche of mercury, the control device lat de cribed may advantageouly be o contructed that when a difference in preure equal to ap proximately 11.7 inche of mercury develop, the pilot valve 25 will open and by wenting preure from within the bellow 209 will reduce the back preure on the Supercharger. The deirability of having the ame maximum preure differen tial etablihed for the control of the pilot valve 25 which exit in connection with the cabin went valve which will hortly be decribed in detail, will be apparent when it i conidered that whe the aircraft i operating with the control for the vetive 2 rendered inoperative and with thi valve held wide open, the maximum pre ure differential which will be impoed on the upercharger under the control of the cabin vent valve will then be the ame a can be impoed by the automatic control for the back preure valve. Of coure, it will be undertood that the maxi mum preure differential between upercharger intake and dicharge may be attained at much lower altitude, by reaon of the operation of the thermotatic control for the valve 2, than would occur were thi back preure impoing ar rangement not preent. It i alo deirable that the ame maximum preure ratio imitation be impoed on the valve 2. that i impoed by the cabin preure went valve later decribed. For, jut a it i important that the cabin vent valve hall be operative at height, for example above 40,000 feet, to limit the maximum preure ratio between cabin pre Sure and external preure (Supercharger di charge preure and upercharger intake pre Sure when the valve 2 i wide open), o it i im portant that the upercharger hall not be over loaded by permitting the impoition of back preure in exce of cabig preure on the uper charger great enough to etablih compreion ratio in exce of the deired limit, when the plane i flying at lower altitude. When the air craft i at a height of 40,000 feet, the external preure will have fallen to a value of approxi mately 5.54 inche of mercury while the cabin preure will till be equal to approximately , or about it.25 inche of mercury. There will therefore be approximately a com preion ratio of omething more than three to One neceary to raie outide air at 40,000 feet to cabin preure. If it i deired to prevent thi Compreion ratio being exceeded when the plane goe above 40,000 feet, it i alo deirable low device 26 i continuouly connected with 5 to prevent that compreion ratio being exceeded

15 13 when the plane i below 40,000 feet, and it will be obviou that it would be eaily poible to exceed uch a ratio at much lower height by placing back preure on the upercharger dicharge. In view of the preence of the groove 260, the preure in the conduit To act upon a contant area, regardle of whether the urface 258 and 259 are in contact with each other, in a direc tion to move the member 246, 25 etc. in a direction to open the valve 25, and external 10 preure act on a larger but contant area tend-. ing to move the member 246, 25 etc. in a direc tion to cloe the valve 25. The two area men tioned repectively expoed to upercharger back preure and to external preure are deirably o determined that their ratio to each other will be the ame a the ratio of external preure to cabin preure at the choen height of 40,000 feet, namely 5.54 to Accordingly, a oon a thi ratio between the preure in the conduit 70 and external preure i attained, at what ever height it be attained, the valve 25 will be uneated and the impoition of additional back preure on the upercharger will be prevented. It will be noted that except a the ame may be open to prevent the impoition of an undeired maximum differential in preure between intake and dicharge preure on the Supercharger, or the exceeding of a maximum compreion ratio between upercharger intake and dicharge pre ure, the valve 25 will remain cloed and thu the cabin temperature, through the governing of the poition of the pilot valve 26, will maintain the primary control on the upercharger di charge, but the amount of air that can be bled pat thi valve when it i Open, through it re pective paage 224 into the bellow 209, will not be ufficient to prevent the opening of the valve 72 when the pilot valve 25 etablihe a connection between it aociated paage 224 and the atmopheric connection 223. The cabin preure vent valve While any uitable device may be provided for regulating the cabin preure, I have choen, for purpoe of illutration, a device which i fully dicloed in my copending application Ser. No. 468,938, filed December 14, 1942, and which i claimed therein. Thi device i adapted to permit the cabin preure to fall off at ubtantially the ame rate that external preure fall until the aircraft reache a deired elevation, uch a 8000 or 10,000 feet. Thereafter, thi device i adapted, until a coniderably greater height i reached, ay 30,000 feet, to maintain the cabin preure relatively contant at whatever preure prevail at the height at which the following of external preure by cabin preure ceae to be deired. When the aircraft goe above the height of 30,000 feet, thi device will operate, over perhap an other 10,000 feet of increae in elevation, to re duce the cabin preure a elevation increae in uch a manner that there will be maintained a contant preure differential between cabin preure and outide preure. And if the air craft i to operate above 40,000 feet, for example, then the nature of the control will be changed o that there will be maintained a contant ratio between cabin preure and Outide preure from 40,000 feet on up. Thi device will not be decribed in complete detail here in view of it full dicloure in the copending application, but it will uffice to point out that it include a valve 263 (Fig. 17) of the approximately balanced type whoe poition i 2,425, adjuted and determined by a bellow device 264, one end of which i fixed, a at 265, and whoe other end i connected through an inner cloure plate 266 and a tem 287, to the valve 263. The valve 263 i movable relative to a tationary eat and control the flow from the interior of the cabin through a creen 269 and paage 270 to a conduit 27 which i connected through any uitable connection 272, preferably terminating, Say, at the rear of a wing of the aircraft, with external preure. The preure within the bel low 264 i controlled by a pair of pilot valve 278 and 274. Each of thee i deigned to cone trol the connection of the interior of the bellow 264, through uitable paage 25 opening into 40 the interior of the bellow, chamber 27 into which the pilot valve extend, port 277 con trolled by the pilot valve, a chamber 278 and conduit mean 279 which lead into the paage 27 f, with external preure. Each of the valve ha clearance about it o that cabin preure may pa along the tem portion of the valve and pa either into the interior of the bellow or to the exterior of the cabin, depending upon the poition of the valve. The valve 273 i con trolled by an evacuated bellow 280 with which 45 a Spring 28 coact. Appropriate mean, gen erally deignated 282, and including an internal thread 283 on a manually adjutable element 284 and pin 285 carried by a pring follower 286, i arranged to vary the degree of compreion of the pring 28 and thereby to raie or lower the point at which cabin preure will become inufficient to maintain the evacuated bellow 280 collaped againt the expanding force exerted thereon by the pring 28. A long a the cabin preure i great enough to maintain the evac luated bellow 280 collaped, the valve 263 will be maintained open in uch a manner that cabin preure will fall off ubtantially at the ame rate that external preure fall off. When, how ever, the predetermined height of 8000 or 10,000 feet, or whatever may be elected, i attained, the cabin preure will have diminihed ufi ciently o that the pring 28 will be able to ex pand the bellow and move the valve 273 to it Seat. Thi will reult in a partial cloure of the cabin vent valve 263, and cabin preure will thereupon tend to rie, with a reultant action On the evacuated bellow which will bring about Such a control of the valve 263 that, until a pre determined higher elevation, uch a 30,000 feet i reached, the valve 263 will have it poition 70 adjuted to keep the cabin preure ubtantially contant. When thi deired higher altitude i attained, the pilot valve 274 take over control, and thi pilot valve i governed, a more fully explained in my copending application Ser. No. 468,938, by a pair of control. From 30,000 to 40,000 feet, the control i by a bellow device 290 whoe outer end i mounted on a plate 29 which i carried by other bellow device which I hall hortly decribe. A pring 292 contantly tend to maintain the bellow 290 expanded and to eat the pilot valve 274. The exterior of thi bellow device, and it upper end formed by a flange 293 on the tem 294 carrrying the pilot valve 274, are contantly ubjected to cabin preure, while the interior of the bellow i in communication through. One or more port 295 and the pace within a bellow caing 296 and the conduit mean 279 with external preure. The plate 293 ha a groove in it face at 29, o that even when the plate 293 i engaging a urface 298 which i mov able with the other bellow device hortly to he

16 15 decribed, there i communication between the interior of the cabin and the pace Surrounding the bellow 290. It will therefore be evident that when the aircraft attain to the predetermined deired height, ay 30,000 feet, the reduction of the preure within the bellow 290, by reaon of the venting of preure therefrom via the port 295, will enable cabin preure acting on the outide of the below to overcome the pring 292 and caue the pilot valve 274 to open, thu vent ing preure from within the bellow 264 and permitting a partial opening of the valve 263 o that the cabin preure will again commence to fall. The part jut decribed will then function to maintain a contant preure differential be tween cabin preure and external preure until a higher elevation till i reached, at which time the other control of the valve 274 will take over, Thi other control include a pair of bellow device 300 and 30 whoe upper end in Fig. 17 are connected to a tationary annular member 302 and whoe lower end are connected to the upport for the plate 29 and to an integrally connected upport 304 connected with the firt mentioned upport by a leeve portion 305. The pace between thee bellow i evacuated, and, a will be oberved, a larger exterior area i ex poed to external preure, while a maller inte rior area i expoed to cabin preure, and the ratio of thee two area may be the ame a the deired ratio between external preure and cabin preure at the choen height of 40,000 feet. Accordingly, a oon a thi height i exceeded, the valve 274 will be uneated, and a long a the aircraft operate at height above 40,000 feet, the control of cabin preure will be regulated by thi valve under the control of the evacuated bellow 300, 30; and a contant ratio between cabin and external preure will be maintained; and the actual differential between cabin and external preure will become le than exited at the elevation of 40,000 feet; wherefore, the urface 298 will continuouly engage the flange 2.93 and the whole control will be by the com poite bellow 300, 30, until the aircraft again move below 40,000 feet. From the foregoing decription, the mode of operation of the illutrative embodiment of the different apect of the invention will be readily followed. The aircraft may be aumed to be on the 2,435,000 ground awaiting takeoff. The upercharger i Operating with it unloading valve open and the air will be diplaced from the rotor pocket ub tantially without compreion through the un loader port until the pocket move out of com munication with the latter. Thi air will be de livered through the conduit 48 to the valve caing 49, and then pa through the conduit 54 back to the outide air or pa through the conduit 5 into the outer coure of the heat exchanger 42 and then to the outide air, the ditribution between thee two poible travel being deter mined by the poition of the valve which i governed by cabin temperature. When the cabin i relatively warm thi air will pa largely through the heat exchanger; when the cabin i cool and cooling of the cabin preurizing air i not deired, the valve will direct the fiow o that relatively little or no air will pa through the outer coure of the heat exchanger. Below preurizing level little heat exchange will occur a there will be a preure in conduit 39 only a few inche of water higher than in the conduit commence to operate and the height at which valve 38 cloe, coniderable heat exchange will be poible. Air will be delivered from the main dicharge of the upercharger through the conduit 39, 40 to the inner pa of the heat exchanger 42 and thence to the conduit 70 whoe communication with the cabin i controlled by the back preure impoing valve T2. When the cabin i relatively warm, the valve element 72 will tand nearly full Open, whereby there will be little or no back pre ure placed upon the flow through the conduit 10, while, if the cabin i relatively cool the valve 72 will be relatively cloe to it eat and there will be impoed on the dicharge of the uper charger a back preure uch a to increae the temperature of the air entering the heat ex changer and paing through the latter to the cabin. A will be apparent, the poition of the valve 72 will be controlled by the ga-filled bulb-type thermotatic device 236, the valve 72 being caued to cloe a cabin temperature drop and to open more a cabin temperature rie. However, the automatic control previouly decribed preclude the exitence of a preure differential between external and Supercharger dicharge preure which would overload the upercharger-thi control of primary importance at ground level, or the exitence of a ratio between intake and dicharge (or back) preure in exce of the value which the deign of the upercharger i adapted for-thi control more particularly ef fective at higher level of flight. The manner in which the control operate will be readily followed, ince it will be recalled that the back preure control valve operating bellow 209 i ubjected externally to upercharger di charge preure while it interior i ubjected 70 under control of the pilot device decribed, to dicharge preure leaking pat, the pilot valve or to a lower preure produced when the interior of the bellow i connected to the outide of the cabin upon opening of the pilot valve. If the cabin i not warm enough a the air craft tand awaiting takeoff, the ga in the cabin thermotat bulb 236 will exert a reduced preure On the expanible device 28 and the bell crank lever 22 will be wung in a direction to eat the pilot valve 26, interrupting communication be tween the interior of the operating bellow for the valve 2 and the outide of the cabin, and permit. ting upercharger dicharge preure entering the bellow 209 to move the back preure control valve 2 in a cloing direction. The reult of thi cloing movement of thi control valve i to im poe a back preure on the upercharger di charge, with the reult that the upercharger i forced to work through a compreion ratio greater than unity, and the dicharge tempera ture i therefore higher. A previouly explained thi increae in dicharge temperature may be as nuch a 65 F. if the back preure i increaed to the limit for which the particular device de Scribed i deigned, even at ea level. When the air o increaed in temperature pae the re tricting or back preure valve 72 it expand back down to cabin preure, and thi expanion of the air reduce it temperature and increae it velocity, and, neglecting the practically peak ing negligible factor of the Joule-Thompon effect, the mechanical equivalent of the heat lot due to expanion i equal to the increae in kinetic energy. A the velocity of the air i 48, but between the height at which the valve 78 i reduced by turbulence, the kinetic energy i Y

17 2,425, tranformed back into heat, o that the final temperature of the air entering the cabin i almot the ame a it wa when it reached the retricting valve 2. If the pilot valve 26 remain in it cloed poi tion o long that the valve 2 tend to build up a back preure o great that the differential be tween intake and dicharge preure reache the value beyond which it i conidered undeirable to load the upercharger ytem, the Spring loaded bellow device 26, which i ubjected in ternally to external preure and on it exterior to upercharger dicharge preure will move the pilot valve 25 to a poition to vent preure from within the actuating bellow 209 for the valve T2 and caue the latter to ceae it cloing move ment and tend to move in the oppoite direction, thereby preventing further loading of the uper Charger. When the aircraft reache ay 20,000 feet, the unloading valve cloe and the upercharger then operate a a poitive compreor, but the reduced volume of air taken in preclude overloading of the mechanim. A the cabin vent valve i hold ing cabin preure at a value of ay 8,000 feet at thi time, there i no danger of the permiible maximum ratio of compreion being exceeded. When the aircraft reache an elevation of 40,000 feet, in the cae of certain deign of the pre ferred type of upercharger herein illutrated, it i deirable, and at coniderably lower height in the cae of preent centrifugal upercharger, it i imperative, to prevent the range of compre ion increaing further, and the evacuated bel low control. 244, 245, reponive on different area to upercharger dicharge and to intake preure i of coure deigned for the particular equipment with which it i to be ued. Accord ingly, when the ratio of dicharge preure get, with repect to the falling (with height) intake preure to the deired maximum, the pilot valve 25 will be moved to open the valve 72 and pre vent an exceive range of compreion being impoed on the upercharger. Of coure, it will be undertood that the automatic cabin vent valve 263 will function to prevent cabin preure exceeding the ame ratio, and the Supercharger dicharge will be at the ame preure a cabin preure at height above the level at which the contant ratio control of valve 72 become effec tive. Of coure at thi time the upercharger i delivering the dicharge air at a high a temper ature a poible, o that the inaction of the valve T2 i immaterial. It will be undertood that at tarting the op erator can render the back preure impoing valve 72 ineffective by uitably turning the ring 98 by mean of the handle 200. While I have in thi application pecifically decribed certain embodiment which my inven tion may aume in practice from it ytem and valve mechanim apect, it will be undertood that thee embodiment have been hown for purpoe of illutration only and that the inven tion in it different apect may be modified and embodied in variou other form without depart ing from it pirit or the cope of the appended claim. What I claim a new and deire to ecure by Letter Patent i: 1. In combination, mean forming a chamber, a upercharger having a terminal dicharge port and an intermediate dicharge port and having mean governed by intake preure for cloing Said intermediate dicharge port and cauing an y increae in terminal dicharge preure, a heat exchanger having plural paage, mean for Con necting the terminal dicharge port to one end of one of aid paage, mean for connecting aid paage at it other end to aid chamber forming mean, a variable back preure valve controlling the delivery through aid paage to 60 aid chamber, mean for connecting one end of another paage of aid heat exchanger to at mophere, mean for connecting aid intermedi ate dicharge port to the Other end of aid econd paage including a valve caing having alo a connection with atmophere, and a valve ad jutable to vary inverely the connection be tween aid intermediate dicharge port and aid econd paage and the atmophere repectively. 2. In a variable back preure valve, a caing having a throat through which preure i ad mitted to the caing and a volute leading to a dicharge connection and a valve eat between aid throat and aid volute, a valve movable rel (55 ative to aid valve eat, valve moving mean in cluding a preure actuated Wall Operatively con nected to aid valve, mean for ubjecting one ide of aid wall continuouly to the preure condition in aid throat, a plurality of continu ouly open, retricted connection between the throat of aid valve caing and the other ide of aid wall, temperature reponive mean, and mean controlled thereby for effecting a con trolled connection between the lat mentioned ide of aid wall and a point under external pre ure, and differential preure reponive mean and mean controlled thereby for effecting an other controlled connection of the lat mentioned ide of aid wall with a point under external pre ure, aid controlled connection being independ ent of each other. 3. In a valve mechanim for controlling condi tion in an aircraft cabin, in combination, an in let opening, a valve for controlling the flow of fluid through aid inlet opening, preure repon ive mean including a member having oppoitely directed preure area for controlling the poi tion of aid valve relative to aid inlet opening, mean for ubjecting one of aid preure area continuouly to the preure Condition at the Supply ide of aid inlet opening, mean for con necting an oppoite preure area in retricted communication with the pace at the upply ide of aid inlet opening irrepective of the poition of Said valve, eparate paage mean for con necting aid lat mentioned preure area in com munication with ambient preure, a plurality of 5 valve, one for each of aid paage mean, for controlling the flow of fluid through aid pa age mean, temperature reponive mean for controlling one of aid lat mentioned valve, and preure reponive mean for controlling another of aid lat mentioned valve including mean for preventing the exceeding of a deired maximum ratio between the preure at the up ply ide of aid inlet opening and ambient pre Sle. 4. In a valve mechanim, in combination, an inlet opening, a valve for controlling the flow of fluid through aid inlet opening, preure repon ive mean having oppoitely directed preure area for controlling the poition of aid valve relative to aid inlet opening, mean for ub jecting one of aid preure area continuouly to the preure condition at the upply ide of aid inlet opening, mean for connecting an op poite preure area in retricted communication with the pace at the upply ide of aid inlet

18 19 opening, eparate paage mean for connecting aid lat mentioned preure area in communi cation with a pace containing fluid at a pre ure below that at the upply ide of aid inlet opening, a plurality of valve, one for each of aid paage mean, for controlling the flow of fluid through aid paage mean, temperature reponive mean operative on an increae in temperature above a predetermined maximum value in a pace at the dicharge ide of aid inlet opening for effecting an opening of one of aid valve, and preure reponive, mean operative on a predetermined maximum preure differen tial between the preure at the upply ide of aid inlet opening and in aid Space containing fluid at a preure below that at aid inlet open ing for effecting an opening of another of aid lat mentioned valve. 5. In a valve mechanim, in combination, an inlet opening, a valve for controlling the flow of fluid through aid inlet opening, preure repon ive mean having oppoitely directed preure area for controlling the poition of aid valve relative to aid inlet opening, mean for ubject ing one of aid preure area continuouly to the preure condition at the upply ide of aid inlet opening, mean for connecting an oppoite preure area in retricted communication with the pace at the upply ide of aid inlet opening, 8,425,000 paage mean arranged in parallel for. connect ing aid lat mentioned preure area in com munication with a pace containing fluid at a preure below that at the upply ide of aid inlet opening, a plurality of valve, one for each of aid paage mean, for controlling the flow of fluid through aid paage mean, mean repon ive to temperature at the dicharge ide of Said opening for controlling one of aid lat men tioned valve, and mean reponive to preure differential between the preure at the upply ide of aid inlet opening and in Said pace con taining fluid at a preure below that at aid inlet opening for controlling another of aid lat men tioned valve. 6. In combination, in a cabin temperature con trolling ytem, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure in aid upercharger dicharge Connec tion, preure reponive mean having oppoitely directed preure area for controlling the poi tion of aid valve, mean for ubjecting one of aid preure area continuouly to the preure condition in aid dicharge connection, mean for connecting an oppoite preure area in re tricted communication with aid dicharge con nection, paage mean for connecting aid lat mentioned preure area in communication with the exterior of aid cabin, valve mean for con trolling the flow of fluid through aid paage mean, and mean reponive to the temperature in aid cabin for controlling aid valve mean. 7. In combination, in a cabin temperature Con trolling ytem, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure in aid upercharger dicharge connec tion, preure reponive mean having oppoitely directed preure area for controlling the poi tion of aid waive, mean for ubjecting one of Said preure area continuouly to the preure condition in aid dicharge connection, mean for connecting an Oppoite preure area in re tricted communication with aid dicharge con nection, paage mean for connecting aid lat O o 20 mentioned preure area in communication with the exterior of aid cabin, waive mean for con trolling the flow of fluid through aid paage 40 mean, and mean reponive to the temperature in aid cabin for controlling aid valve mean, Said temperature reponive mean operating on an increae in cabin temperature above a prede termined maximum for effecting an opening of aid valve mean. 8. In combination, in a cabin temperature con trolling ytem, a cabin, a upercharger, mean 45 for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure in aid upercharger dicharge connec tion, preure reponive mean having oppo itely directed preure area for controlling the poition of aid valve, mean for ubjecting one of Said preure area continuouly to the pre ure condition in aid dicharge connection, mean for connecting an Oppoite preure area in retricted communication with aid dicharge Connection, paage mean for connecting aid lat mentioned preure area in Communication with the exterior of aid cabin, a valve for con trolling the flow of fluid through aid paage mean, mean for yieldably urging aid lat men tioned valve toward an open poition, and mean including a device reponive to the temperature in aid cabin and Operative on a decreae in cabin temperature below a predetermined value for effecting a cloure of aid lat mentioned valve. 9. In combination, in a cabin temperature con trolling Sytem, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure in aid upercharger dicharge connec tion, preure reponive mean having oppoitely directed preure area for controlling the pot tion of aid valve, mean for ubjecting one of aiad preure area continuouly to the preure condition in aid dicharge connection, mean for connecting an Oppoite preure area in re tricted communication with aid dicharge Con nection, paage mean for connecting aid lat mentioned preure area in communication with the exterior of aid cabin, a plurality of valve for controlling the flow of fluid through aid paage mean, mean reponive to the temper ature in aid cabin for controlling one of aid lat mentioned valve, and mean reponive to the preure differential between aid dicharge connection and the exterior of aid cabin for con trolling another of aid lat mentioned valve. 10. In combination, in a cabin temperature controlling ytem, a Cabin, a upercharger, mean for Connecting the upercharger dicharge to aid cabin, a valve movable to impoe a vari able back preure in aid upercharger di charge connection, preure reponive mean having oppoitely directed preure area for Controlling the poition of aid valve, mean for Subjecting one of aid preure area continu Ouly to the preure condition in aid dicharge connection, mean for connecting an oppoite preure area in retricted communication with aid dicharge connection, paage mean for Connecting aid lat mentioned preure area in 5 Communication with the exterior of aid cabin, a plurality of valve arranged in paralle for con trolling the flow of fluid through aid paage mean, mean reponive to temperature in aid cabin for effecting an opening of one of aid lat mentioned valve when the cabin temperature goe above a predetermined value, and preure reponive mean Operative on an increae in the

19 21 preure differential between aid dicharge con nection and the exterior of aid cabin for effect ing an opening of another of aid lat mentioned valve. 11. In combination, in a cabin temperature controlling ytem, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a vari able back preure in aid upercharger dicharge connection, preure reponive mean having a preure area againt which preure act to urge aid valve in an opening direction, mean for ub jecting aid preure area continuouly to the preure condition in aid dicharge connec tion, aid preure reponive mean having an other preure area againt which preure act to urge aid valve in a cloing direction, mean for connecting aid lat mentioned preure area in retricted communication with aid dicharge connection, paage mean for connecting aid lat mentioned preure area in Communication with the exterior of aid cabin, valve mean for controlling the flow of fluid through aid pa age mean, and mean reponive to the tem perature in aid cabin for controlling aid valve e8s. 12. In combination, in a cabin temperature controlling ytem, a cabin, a upercharger, mean for connecting the upercharger dicharge 2,425,000. to aid cabin, a valve movable to impoe a vari able back preure in aid upercharger dicharge connection, preure reponive mean having a preure area againt which preure act to urge aid valve in an opening direction, mean for ubjecting aid preure area continuouly to the preure condition in aid dicharge connection, aid preure reponive mean having another preure area againt which preure act to urge aid valve in a cloing direction, mean for Con necting aid lat mentioned preure area in re tricted communication with aid dicharge Con nection, paage mean for connecting aid lat mentioned preure area in communication with the exterior of aid cabin, valve mean for con trolling the flow of fluid through aid paage mean, and mean reponive to the temperature in aid cabin for controlling aid valve mean, Said temperature reponive mean operating on an increae in cabin temperature above a pre determined maximum for effecting an opening of Said valve mean. 13. In combination, in a cabin temperature controlling ytem, a cabin, 8 upercharger, mean for Connecting the upercharger dicharge to aid cabin, a valve movable to impoe a vari able back preure in aid upercharger dicharge Connection, preure reponive mean having a preure area againt which preure act to urge aid valve in an opening direction, mean for ub jecting aid preure area continuouly to the preure condition in aid dicharge connection, Said preure reponive mean having another preure area againt which preure act to urge aid valve in a cloing direction, mean for con necting aid lat mentioned preure area in re tricted communication with aid dicharge con nection, paage mean for connecting aid lat mentioned preure area in communication with the exterior of aid cabin, a plurality of valve arranged in parallel for controlling the flow of fluid through aid paage mean, mean repon ive to temperature in aid cabin for effecting an Opening of one of aid lat mentioned valve when the cabin temperature goe above a pre determined value, and preure reponive mean 90 SO 22 operative on predetermined increae in the pre Sure differential between aid dicharge Connec tion and the exterior of aid cabin for electing an opening of another of aid lat mentioned valve. 14. In combination, in a cabin temperature Controlling Sytem, a cabin, a Supercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a vari able back preure on aid upercharger, an ex panible chamber device for controlling the poi tion of aid valve including a movable wall, mean for Subjecting aid wall Continuouly on one ide to aid upercharger dicharge pre Sure, and mean including a control device gov erned by cabin temperature for ubjecting aid wall on it other ide intermittently to aid uper charger dicharge preure and to the preure at the exterior of aid cabin, 15. In combination, in a cabin temperature controlling ytem, a cabin, a Supercharger having a terminal dicharge port and in inter- : mediate dicharge port, a heat exchanger having two fluid conducting pae, mean for connect ing the terminal dicharge port to one end of one of aid pae, mean for connecting aid pa at it other end to aid cabin, a variable back preure valve for controlling fluid flow through aid pa to aid cabin, mean reponive to cabin temperature for controlling aid back preure valve, paage mean for connecting aid intermediate dicharge port to One end of the other of aid pae and to the exterior of aid cabin, valve mean reponive to cabin tem perature for controlling communication through Said paage mean, and mean for connecting the other end of aid lat mentioned pa in com munication with the exterior of aid cabin. 16. In combination, in a cabin temperature controlling Sytem, a cabin, a upercharger having a terminal dicharge port and an interme diate dicharge port, a heat exchanger having two fluid conducting pae, mean for connect ing the terminal dicharge port to one end of one of Said pae, mean for connecting aid pa at it other end to aid cabin, a variable back pre ure valve for controlling fluid flow through aid pa to aid cabin, mean reponive to cabin temperature for controlling aid back preure valve, paage mean for connecting aid inter mediate dicharge port to one end of the other of Said pae and to the exterior of aid cabin, valve mean reponive to cabin temperature for controlling communication through aid paage mean, aid lat mentioned valve mean operative 75 to cut off communication between aid interme diate dicharge and the exterior of aid cabin when the cabin temperature are above a prede termined value, and mean for connecting the Other end of aid lat mentioned pa in com munication with the exterior of aid cabin. 17. In combination, in a cabin temperature controlling ytem, a cabin, a upercharger having a terminal dicharge port and an inter mediate dicharge port, a heat exchanger having two fluid conducting pae, mean for connect ing the terminal dicharge port to one end of one of aid pae, mean for connecting aid pa at it other end to aid cabin, a variable back preure valve for controlling fluid flow through aid pa to aid cabin, mean reponive to cabin temperature for controlling aid back preure Valve, paage mean for connecting aid inter mediate dicharge port to one end of the other of aid pae and to the exterior of aid cabin,

20 23 valve mean reponive to cabin temperature for controlling communication through aid paage mean, aid lat merationed valve mean operative to cut off communication between aid inter mediate dicharge port and aid heat exchanger when the cabin temperature drop below a pre determined value, and mean for connecting the other end of aid lat mentioned pa in come munication with the exterior of aid cabin. 18. In combination, in a cabin temperature controlling ytem, a cabin, a upercharger having a terminal dicharge port and an inter mediate dicharge port, a heat exchanger having two fluid conducting pae, mean for connect ing the terminal dicharge port to One end of one of aid pae, mean for connecting aid pa at it other end to aid cabin, a variable back preure valve for controlling fluid flow through aid pa to aid cabin, mean reponive to cabin temperature for controlling aid back preure valve, paage mean for connecting aid intermediate dicharge port to one end of the other of aid pae and to the exterior of aid cabin, valve mean reponive to cabin tempera 495,000 ture for controlling communication through aid paage mean, aid lat mentioned valve mean operative to vary the cornmunication between aid intermediate dicharge port and aid lat mentioned pa directly with increae in cabin. temperature and to vary the communication between aid intermediate dicharge port and the cabin exterior inverely with increae in cabin temperature, and mean for COEnnecting the other end of aid lat mentioned pa incom-. munication with the exterior of aid cabin. 19. In combination, a cabin, a upercharger having intermediate and terminal dicharge port, a heat exchanger having paage out of communication with each other, mean for con necting aid terminal dicharge port with the cabin through one of aid paage, mean for connecting aid intermediate. dicharge port either directly or through another of aid pa age, with the atmophere, thernotatic con trol mean governed by cabin temperature for controlling aid lat mentioned mean, and mean for maintaining cabin preure higher than external preure when aid cabin i above a predetermined altitude. 20. In combination, a cabin, a upercharger having intermediate and terminal dicharge port, a heat exchanger having paage out of communication with each other, mean for con necting aid terminal dicharge port with the cabin through one of aid paage, mean for connecting aid intermediate dicharge port either directly or through another of aid pa age with the atmophere, thermotatic control mean governed by cabin temperature for aid lat mentioned mean, altitude reponive mean for cloing aid intermediate dichare port when aid cabin reache a predetermined alti tude, and mean for maintaining cabin preure higher than external preure when aid cabin i above a predetermined altitude. 21. In combination, a cabin, a upercharger having intermediate and terminal dicharge port, a heat exchanger having paage out of communication with each other, mean for con necting aid terminal dicharge port with the cabin through one of aid paage, mean for connecting aid intermediate dicharge port either directly or through another of aid pa age with the atmophere, thermotatic control mean governed by cabin temperature for aid O, SO lat mentioned mean, altitude reponive meani for cloing aid intermediate dichargeport when aid cabin reache, a predetermined altitude, mean for maintaining cabin preure higher than external preure when aid cabin i above a predetermined altitude, and mean for ubject ing the flow from aid terminal port to a back 45 preure, aid lat mentioned mean including Control mean reponive to cabin temperature. 22. In combination, a cabin, a upercharger having intermediate and terminal dicharge port, a heat exchanger having paage out of communication with each other, mean for coin necting aid terminal dicharge port with the cabin through one of aid paage, mean for CO g aid intermediate dicharge port either directly or through another of aid pa age with the atmophere, thermotatic control mean governed by cabin temperature for con trolling aid lat mentioned mean, altitude re ponive mean for cloing aid intermediate di charge port when aid cabin reache a predeter mined altitude, mean for maintaining cabin preure higher than external preure when aid cabin i above a predetermined altitude, and mean including both cabin temperature and preure reponive control mean for ubjecting the flow from aid terminal port to a back pre tre In a cabin temperature controlling ytem, in combination, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back 65 preure on aid upercharger, and controlling mean for aid waive including device repec tively reponive to cabin temperature and uc ceively to the differential between upercharger dicharge preure and the preure at the exte 70 rior of the cabin and to the ratio between uper charger dicharge preure and the preure at the exterior of the cabin. 24. In a cabin temperature controlling ytem, in combination, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure on aid upercharger, preure re ponive mean having oppoitely directed pre ure area for controlling the poition of aid valve and operative when the preure on aid area are equal to cloe aid valve, mean for ub jecting one of aid preure area continuouly to the preure condition in aid dicharge con nection, mean for connecting an oppoite pre ure area in retricted communication with aid: dicharge connection, paage mean for con necting aid lat mentioned preure area in com munication with the exterior of Sald cabin, a plu rality of valve for controlling the flow or fluid through aid paage mean, mean reponive 5 to the temperature in aid cabin for controlling one of aid lat mentioned valve, and mean re ponive to the preure in aid dicharge con nection and at the exterior of aid cabin for Con trolling another of aid lat mentioned valve. 25. In a cabin temperature controlling ytem, in combination, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure on aid upercharger, preure re ponive mean operating normally to cloe aid valve and having a preure area againt which preure act to urge aid valve in an opening di rection, mean for ubjecting aid area continue ouly to the preure condition in aid dicharge connection, aid preure reponive mean have

21 25 ing another preure area againt which pre ure act to urge aid valve in a cloing direction, mean for connecting aid latmentioned preure area in retricted communication with aid di charge connection, paage mean for connect ing aid lat mentioned preure area in COmn munication with the exterior of aid cabin, a plu rality of valve arranged in parallel for control ling the flow of fluid through aid paage mean, mean reponive to cabin temperature for con trolling one of aid lat mentioned valve, and mean reponive to the preure in aid di charge connection and at the exterior of aid cabin for controlling another of aid lat men tioned valve. 26. In a cabin temperature controlling ytem, in combination, a cabin, a upercharger, mean for connecting the upercharger dicharge to aid cabin, a valve movable to impoe a variable back preure on aid Supercharger, preure re ponive mean operating normally to cloe aid valve and having a preure area againt which preure act to urge aid valve in an opening direction, mean for ubjecting aid Srea, Con tinuouly to the preure condition in aid di charge connection, aid preure reponive mean having another preure area againt which preure act to urge aid valve in a clo ing direction, mean for connecting aid lat mentioned preure area in retricted communi cation with aid dicharge connection, paage mean for connecting aid lat mentioned pre ure area in communication with the exterior of aid cabin, a pair of valve arranged in parallel for controlling the flow of fluid through aid pa age mean, mean reponive to cabin tempera ture for controlling one of aid lat mentioned valve, and a plurality of preure reponive mean for controlling the other of aid lat men tioned valve, one of aid plurality of preure reponive mean reponding to the differential between the preure in aid dicharge connec tion and at the exterior of aid cabin and oper ating to prevent the exceeding of a predeter mined differential between aid preure and another of aid preure reponive mean re ponding to the differential between the pre ure in aid dicharge connection and at the exterior of aid cabin and operating to prevent the exceeding of a predetermined ratio between aid preure. 27. In a valve mechanim, in combination, an inlet-opening, a valve for controlling the flow of fluid through aid inlet opening, preure re 2,425,000 O ponive mean for controlling aid valve and operating when the preure acting thereon are balanced for moving aid valve to a poition cloe ing aid inlet opening, aid preure reponive mean including a member having a preure area againt which preure fluid act to urge aid valve in an opening direction, mean for ub jecting aid preure area continuouly to the preure condition at the upply ide of aid in let opening, aid preure reponive mean hav. ing another preure area againt which pre ure act to urge aid valve in a cloing direc tion, mean for connecting aid lat mentioned preure area in retricted communication with the pace at the upply ide of aid inlet open-. ing irrepective of the poition of aid valve, ep arate paage mean for connecting aid lat mentioned preure area in communication with a Space containing fiudd at a preure below that at the upply ide of aid inlet opening, a plu rality of valve, one for each of aid paage mean, for controlling the flow of fluid through aid paage mean, temperature reponive mean for controlling one of aid lat mentioned valve, and preure reponive mean for con trolling another of aid lat mentioned valve in cluding mean for precluding the exceeding of a predetermined maximum ratio between the preure at the upply ide of aid inlet opening and the preure in the econd mentioned pace irrepective of variation in the lat mentioned preure. WIN. W. PAGE. REFERENCES CTED The following reference are of record in the file of thi patent: UNITED STATES PATENTS Number Name Date 2,316,237 Grunert et al Apr. 13, ,327,737 Pendergat Aug. 24, 1943 Re. 22,272 Price Feb. 16, ,176,535 Fulton Mar. 21, ,017 Gaett Dec. 5, ,813,401 Helmtaedter July 7, ,848,031 Spencer Mar. 1, ,200,318 Yonker May 14, ,280,128 Price "Apr. 21, ,853,194 Bogle Apr. 12, ,265,461 Wagner Dec. 9, ,353,201 Talbot July 11, ,391,197 Schwien Dec. 18, ,575,725 Stewart Mar. 9, 1926