US2404020A - Pressure-applying aviator's suit with helmet - Google Patents

Description

July 16,.1946. .JL D. AKERM AN' PRESSURE-APPLYING AVIATORS SUIT WITH HELMET Filed March 1Q, 1943 v3 Sheets-Sheet 2 il ii hven/iar j WW Aiior neys July 16, 1946. J. D- AKERMAN PRESSURE-APPLYING :AVIATORS SUIT WITH HELMET Filed March 10, 1943 5 Sheets-Shee s.

Patented July 16, 1946 OFFICE PRESSURE-APPLYING AVIATORS SUIT WITH HELMET John D. Akerman, Minneapolis, Minn.

Application March 10, 1943, Serial N 0. 478,640

6 Claims. (Cl. 128-144) This invention relates generally to apparatus and equipment for enabling an aviator to fly with safety and comparative comfort at high altitudes; and particularly to a complete aviators suit with helmet attached and with associated breathing and pressure-supply systems for supplying oxygen for breathing and for independently applying pressure to the entire body of the aviator above the atmospheric pressure at high altitudes.

In combat aviation, a marked advantage is obtained by the airplane which can attain the highest altitude, both from the standpoint of successfully attacking and destroying another plane and from the standpoint of avoiding attack when pursued. Consequently, efiorts are constantly made to increase the possible altitudes of airplane flight and such efforts have been reasonably successful in producing planes, motors, oxygen breathing systems, controls and other equipment which have from time to time increased the maximum altitudes for flight and combat work.

In high altitude flying it has been found necessary even at 15,000 feet to provide additional oxygen under pressure for breathing and when elevations in excess of 30,000 feet are attained, serious difiiculties are encountered in maintaining favorable life conditions. Not only must oxygen with suitable lung pressure be provided, but the body of the aviator must be subjected to a gaseous pressure considerably higher than the atmospheric pressure at such high elevations.

Various means have been attempted for subjecting the human body to greater than atmospheric pressures at high altitudes. Some developmental work has been carried out and some progress has been heretofore made in producing pressure-applying aviators suits based on such principles but such developmental Work has brought to light a number of diflicult problems which had to be solved before a completely successful suit and apparatus could be developed.

In the first place, suits in which the source of gaseous medium breathed was commingled with the pressure producing medium and air exhaled in the suit, were found dangerous, since the products of exhalation often increased within the suit beyond the proportion where the aviator could sustain life at high altitudes by breathing the mixture.

Secondly, with an inflated suit surrounding the head, limbs, arms and joints of the aviator, it was found exceedingly difficult to provide for tilting and turning of the head, clear vision and for flexing of the various body members to enable the aviator to operate his controls.

Another problem was the provision for adequate human comfort within such a suit to prevent fatigue, excessive perspiration at lower altitudes, and freezing of parts of the body at high.

altitudes.

Still another problem was the provision of a suit where all regulating mechanism for controlling the proper pressure within the suit, for regulating the supply and pressure of oxygen for breathing and the distribution and circulation of compressed air for pressure-applying purposes could be accessible for quick and convenient manipu'lation by the wearer.

The general object of my invention is the provision of a complete comparatively light, thoroughly practical and safe pressure-applying aviators suit adapted for high altitude flying and which successfully overcomes the many problems heretofore encountered in this art.

It is an object of my invention to provide a highly efficient pressure-applying aviators suit adapted to be conveniently slipped upon'the body of a wearer and having asfar as practical fitted relationship throughout the legs, trunk and arm portions of the suit with provision for a. high degree of flexibility and made up" essentially of 'a blouse portion, a trousers portion, with boots, glove portions and an enlarged substantially rigid helment portion for enclosing the head, all portions of the suit being readily united together with sealing effect at all of the joints.

It is a further object to provide an improved pressure-applying suit of the type described having a breathing system with a breathing mask disposed within a substantially rigid helmet and supported independently of the helmet upon the head of the wearer in combination with means for supplying an oxygen containing medium to the breathing mask and an independent connection for supplying a gaseous medium under pressure to the interior of the suit with associated means for maintaining the pressure against the body at higher than the atmospheric pressure outside of the suit.

A further and important object, is the provision of a two-ply, double-chamber suit of the class described so constructed and related with a system for supplying a gaseous medium under pressure and with valves and other mechanism that if either of the pressure-applying chambers becomes ruptured or otherwise develops a bad leak, the other chamber immediately functions to contain the pressure-producing gaseous medium and to apply the desired pressure above atmospheric, at the various altitudes against the body of the aviator.

Still another object is the provision in a pressure-applying flexible aviators suit, of an improved detachable helmet which is widely spaced from the head of the wearer and sealed at its lower edge with the torso portion of the flexible suit so that the head of the wearer may be freely turned and. tilted and his vision unimpaired in all directions and whereby the helmet may be quickly detached. from the suit with provision for air ventilation in the trunk, legs and arms of the suit when the helmet is removed.

Another object is the provision of an air distribution system built into the suit to provide for discharge and slow circulation of air or other gaseous medium in the helmet when the same is worn, and in the legs and arms of the suit and at one or more other points, if desired, with a control mechanism readily accessible to the wearer for selectively discharging air from any one of said points or any two of said points or other combination of air discharges included.

Another object is the provision of a complete piece of apparatus for applying gaseous pressure through a closely fittingsuit to an aviator and for supplying oxygen and proper control at Various altitudes for breathing as well as to provide all other. necessar equipment for an aviator with controls for the various parts of the apparatus including air distribution, oxygen supply, radio, all built into or mounted upon the suit itself for convenient control by the wearer.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same parts throughout the several views, and in which:

Fig. 1 is a front perspective view showing an aviator with an embodiment of my invention operatively worn;

Fig. 2 is a side perspective View of the same;

Fig. 3 is a rear perspective view showing the suit positioned as worn with the helmet detached;

Fig. 4 is a cross section of a suit distended, taken on a level just above the waist and belt;

Fig. 5 is a diagrammatic view diagramming the airdistribution system within the suit and illustrating a suitable type of selective control valve;

, Fig. 6 is a front elevation showing a suitable form of breathing control detached from the suit which may beutilized with my apparatus subjected to the pressure within the suit;

Fig. 7 is a vertical section showing my preferred type of double-walled transparent helmet and its connections with the envelopes of the suit as well as the valved connection with the air discharge system;

Fig. 8 is a detailed view showing the manner in which the lower edge of my helmet is sealed with a rigid collar and also illustrating connection of the air distribution system with the line extending to the top of the helmet;

Fig. 9 is a cross section taken approximately along the line 9-9 of Fig. '7 looking upwardly;

Fig. 10 (Sheet 1) is an enlarged detail section showing a suitable type of relief valve for maintaining the pressure within my suit above atmospheric pressure outside;

Fig. 11 is a view showing the double-chambered, double envelope flexible suit and one arrangement of valves which may be successfully utilized to maintain proper working pressure within the suit whether either the inner or outer envelope of the suit becomes ruptured; and

' Fig. 12 is a vertical elevation showing in detail a bellows type relief valve which may be substituted throughout my suit for the differential valves illustrated in Fig. 10.

Fig. 13 is a detail side elevation showing an alternate connection means for securing the rear part of the helmet.

My improved aviators suit as illustrated herein comprises double-walled or double envelope garment portions for covering the torso, the legs, feet, arms and hands of the aviator together with a rigid preferably double-walled helmet which extends downwardly at its forward lower edge to a point considerably below the neck of the wearer and which is rather widely spaced from the wearers head to provide for free tilting and turning movements of the head in all directions.

The suit includes a blouse portion B of flexible substantially air impervious material fitted to the wearer as far as practical while providing in conjunction with the body a surrounding air space. The blouse includes the arm portions A which terminate in sleeves reenforced and provided with suitable sealing means 28 which are engaged by cooperatingqsealing means 2| fixed to the wrist portions of the gloves G. The gloves G are constructed at points reenforced as will be disclosed in another patent application to afford flexibility of the fingers and to prevent bulging or formation of large air pockets. The blouse B is provided with upwardly extending lide fasteners 2'2 and 23 at front and back respectively and a wide, very thin flexible sealing flap 22a and 23a respectively is provided to completely seal the edges of the slide fastener when the garment is worn.

The lower edge of the blouse B and the upper circumferential edge of the trouser portions T are joined'together and sealed at the waist of the wearer by means of an elliptic shaped heavy rigid sealing ring upon which the said edge of the blouse and trousers are superimposed and a clamping belt 24 seals the garment members together against this clamping ring.

The foot portion F of the garment may, as

shown, be constructed continuously from the legs of the trousers and, a shown, in Fig. 3 for convenience in donning, are provided with slide fasteners 25, these fasteners having incorporated therewith folded sealing flaps similar to flaps 22a and 23a. The trousers T, as indicated in the drawings, are reenforced and constructed to permit flexing at the kneesand hips, and to prevent bagging out of the garment at the abdominal, knee and other portions. The specific structure which provides for such flexing and reenforcement is disclosed in patent application entitled Pressure applying aviators suit with provision for reinforcement, adjustment and flexibility, Serial No. 495,258. Such reenforcing tructure and means for facilitating flexing is also provided beneath the arms and inwardly at the elbows to assure the necessary-movements of the wearer to enable him to operate his controls in the plane.

Straps 27 extend upwardly at the sides of the feet for adjustment for length and to provide reenforcement and prevent bagging. Heavier straps 28 extend from the reenforced portions at the sides of the suit near the upper portion of the trousers to the shoulders of the wearer. loops being formed for accommodation of the arms. These straps 28 provide reenforcement and adjustment for height and further facilitate bending of the body at the waist by supplying proper dead center relation between the torso and the hips. The two-ply or double-walled construction of my suit is illustrated in Figs. 4 and ll, inner and outer envelope being provided which fit practically the contour of the human body and which between the envelopes afford a continuous second pressure-retaining air chamber.

My helmet H is preferably constructed of general cylindrical peripheral shape, double-walled, as clearly shown in Fig. 7 to minimize frosting and having a dome 30 which is disposed some little distance above the wearers head. The lower edge of the helmet is reenforcecl by an annular channeled member 3| and this lower edge, it will be noted, slants materially from the rear portion of the helmet to the front thereof, therear portion being disposed at about the neck line of the wearer while the forward downwardly slanting portion is disposed below the neck of the wearer above the chest. This enables the wearer to have clear vision below the plane he is flying. The lower edge of the helmet is adapted to be attached and sealed in a rigid annular channel 32 which is connected to and sealed with the upper neck portion 33 of the blouse. Sealing with the-blouse is effected by a clamping band 34 which surrounds the open portion of the outer envelope or blouse, clamping and sealing the same against a shallow peripheral channel formed by the rigid ring 32. The slant or angulation of the ring 32 and. channel ring SI of the helmet is such that these rings will be comfortably supported by the natural contour of the shoulders and chest of the wearer. The helmet is readily attachable by means of a hook clamp 36 at the rear thereof and a toggle clamp 31 at the front thereof. The edge of the channel ring 3! is sealed against a suitable compressible member such as an annular rubber tube 38 seated in thechannel member 32.

As shown the inner envelope of the blouse has attached thereto a neck portion 39 which extends'about the neck of the wearer and is provided with a suitable slide fastener 43 to facilitate donning. The two envelopes of the blouse as shown are cemented Or otherwise bonded together at their upper edges about an annular zone 4! extending about the blouse for some distance below its connection with the helmet.

The helmet H is provided within with a vertical air tube 42 which may be flexible and, as shown, is connected at its upper end with an arcuate air discharge shower having a multiplicity of small orifices directed downwardly at the front of the helmet for preventing mist or frost from forming at the front. The flexible conduit 42 is attached to a nipple 44 which has attached to the base thereof a valve operating pin lea. Pin 44a, when the helmet is attached to its mounting ring or channel 32, strikes a spring pressed valve 45 and depresses the same, establishing communication between the air supply line 45 and conduit 4!. When the helmet is removed and valve 45 elevated by the spring, the passage through nipple Ml is closed and communication between the valve box 55a and conduit ll is established. Conduit 41 extends over and down the back of the garment for discharge of air for ventilation purposes at the back of the wearer when the helmet is removed.

The helmet H is also preferably provided with efiicient means in addition to the double walled construction for overcoming fogging or icing of the walls thereof. To this end, as shown in Figs. '7 and 9, I provide breather tubes 48 which communicate at their outer ends with the. space between the double walls of helmet H and which communicate within the helmet with cartridges 49 containing hygroscopic material, efficient to remove humidity from the air passing therethrough. The small cartridges 49 may be filled with such hygroscopic agent as silica gel, magnesium perchlorate or activated alumina or other equivalents. The cartridges 49 are supported preferably at the upper portion of the cylinder of the helmet by suitable means such as small frames 49a and are equipped-withsmah passages== ornipples 419D communicating with the space within the helmet.

Upon-changes inair pressure interiorly and exteriorly of the helmet, passage of air from within the double walled space or the helmet is caused to take place through the cartridges;

discharge of air or other suitable gaseous medium, preferably at several spaced points within the suit in combination with a suitable valve system for maintaining the desired pressure.

As shown, see particularly Fig. -5, the-supply of air through air conduit 52 is connected with a nipple 53a of a selective Valve indicated as an entirety by the numeral 53A Connections from this valve communicate with conduits leading to the valve box a for supply of air to the helmet and selectively to the back, to .the two arms of the suit and to the two feet'of the suit; conduits 54 lead to the feet of the suit terminating in open dischargeends, such conduits being flexible and preferably stitched. and sealed in the inner envelope of the suit. Conduits 55 lead from the valve 53 to the two arms of the suit terminating in open discharge ends as shown within the gloves G. The conduit 46 a previously described leads to the valve box 45m The valve as shown has an inner rotatable shell provided with a multiplicity of ports for registra-- tion with the outlets indicated on the diagram. This shell member is conveniently manipulated by the' wearer by the medium of'a handle 53b which is disposed on the outside chest portion of the suit and which has engagement with aseries of notches indicating head off, "hands off, feet oil, hands and feet off," all off. Abutment limits the swinging movement of the handle 53b at the point where all discharge is shut ofi. Thus by opening the valve to the first. second, third or fourth position, the wearer can selectively control discharge of air in the various portions of the garment.

It will, of course, be understood that of air supply under pressure will be maintained with suitable means for both cooling and heating the air. Thus in cold temperatures and at high altitudes the air discharged within the suit may 1 be heated while at comparatively low altitudes ventilation and cooling is obtained by supplying cool air. The source of supply is conveniently located for immediate regulation by the wearer or may be provided with controls for automatically supplying cool or warm air as needed.

The suit, as shownin most of the views of the drawing, is equipped with a number of differential relief valves 51, although it will be understood that valves of the type shown in Fig. 12 for maintaining a suitable constant pressure, may be utilized successfully. As shown, two of the valves 51 are disposed at the front of the suit a short distance above the sealing belt and two or more of the said valve are mounted in the front leg portions of the garment, while, as shown, four of said valves are formed in the upper back portion of the garment below the neck. These valves are arranged in pairs, one valve controlling communication of the inner envelope, that is, the space between the inner Thus another application; but as shown herein maybe briefly described, as follows:

A valve body or disc 51a carries at its rear surface a somewhat compressible sealing annulus 51b which, as shown, has contact with an edged seat. The disc valve body 510. is spring pressed by a spiral spring 510 against its seat. The

spiral spring 510 is anchored by means of an adjustable anchor disc 51d which has a concentric boss threadedly engaged with an adjustment plug tile. The adjustment plug has a diminished end fitting the'bore of a surrounding cap member 51 which has threaded engagement with the boss of the base of the valve structure. A sheet of flexible fabric 51g preferably covers the base of the valve to filter off dust or lint.

A breathing system for supplying oxygen to the lungs of the wearer is provided and-this system has its oxygen supply line 58 independent of the air supply line 52 which discharges air or other gaseous medium into the suit for applying pressure therein. The apparatus shown) for supplying oxygen and the mask M for delivering the oxygen for breathing purposes might be of any successful conventional types, but the entire breathing system is preferably independent of my system for supplying air or other gaseous medium to the suit for producing pressure therein. Any suitable pressure-actuated oxygen control or regulator mechanism responsive to either atmospheric pressure or to air pressure within the suit may be utilized for controlling the pressure and flow of oxygen through the mask M, although I disclose a control mechanism C mounted within the suit and of course responsive to the pressure therein. The mask and breathing apparatus therein may be of the general type illustrated in Patent No. 2,228,502, granted January 14, 1941, to Dr. Walter M. Booth-by. It is important with my construction that the mask M be wholly supported from the head of the wearer and that its connection with the oxygen supply line and exhalation conduits be exremely flexible to permit the wearers head to be freely turned and tilted within the widely spaced helmet H. The mask M ha connected therewith as shown two very flexible depending exhaling conduits 60 which have their lower ends connected with tubular sockets Bl mounted as shown at the front neck portion 39 of the blouse of the suit. These sockets communicate with the interior or body portion of the double ply suit. Mask M as shown substantially seals against the nose, cheeks and face of the wearer and is attached to the head and supported therefrom in any suitable manner.

As shown in the drawings an automatic pressure-operated control for supplying oxygen or oxygen-containing gas to the breathing mask is provided and disposed within the two-ply suit, having a manually operated handle extending on the outside of the suit. This control indicated as an entirety by the letter C, see Fig. 6, may be of conventional type having within the casing a diaphragm or bellows controlling a valve responsive to pressure for decreasing the mixture of air with the oxygen supplied to the mask. .The oxygen supply line communicates with the nipple n in the front part of the control casing and the (not oxygen exhausting from the control casing passes through a tube t into the short flexible conduit 62 which connects with the breathing mask M. The control as shown, at low altitude within the suit permits some amount of air from the suit to be mixed with the independent oxygen suply for breathing while at higher altitude only oxygen is delivered.

It will, of course, be understood that this control is optional and that the oxygen supply line may be directly connected with the mask without any control in the suit or means for mixing any air with the oxygen supplied under any conditions. In such case, an automatic control of conventional type may be provided at the discharge of the source of oxygen supply.

For parachute jumping from a plane a small independent source of oxygen is provided as shown in the form of a small tank 53 strapped to the lower portion of the right leg of the wearer and having a valve 63a and a supply conduit 631) which as shown has branch connection withthe upper portion of the main oxygen supply conduit 58. A nipple 58a equipped with a check valve is provided just below the branch connection with conduit 63b and the main oxygen supply line or hose 58 may be readily disconnected by pulling the upper end from the nipple when the aviator desires to bail out. Thereafter the valve 63a in the small oxygen tank may be opened to supply oxygen for breathing in the parachute jump.

As shown in the drawing I provide externally of one arm of the suit a pressure gauge 54 which will readily indicate to the aviator the pressure within the suit. A quick action release valve 61 may also be provided for enabling the pressure to be very quickly exhausted in the suit. The structure may resemble the release and locking structure of the pressure valve illustrated in Fig. 12. 7

Instead of providing differential relief valves, as illustrated in Figs. 10, 11 and 4, wherein a differential pressure above atmospheric outside of the suit is always maintained, I may provide a valve system employing relief valves for maintaining in conjunction with said air discharge system in the suit, a constant pressure against the body of the wearer. With my two-ply double walled pressure applying suit one or more of such valves would have to control communication with the space between the inner envelope of the suit and the body, whil one or more of said valves would control communication between the outer air chamber and the atmosphere outside the suit. In the form of valve show: in Fig. 12 I provide a flexible pressure containing bellows 65 mounted within a suitable cage or apertured shell 65a and carrying concentrically thereof at its inner face a valve body or disc 65b of poppet construction which is adapted to seal against an annular bevelled valve seat formed in a rigid base member. The outer face of the bellows 65 is anchored at its central portion to the outer face of cage 65a with provision preferably for adjustment and communication of the interior of the bellows with the atmosphere outside is made possible through a tubular fitting 650 having mounted therein a quick acting lock valve 66 which is closed when pressure within the bellows exceeds the atmospheric. Valve 66 carries an axial stem 66a projecting outwardly for engagement with the eccentric 66b of a camming member 660 mounted across the outer end of the tubular fitting 650. Thus the valve 66. may be quickly opened and held in open position and "locking the pressure therein.

9.. when it is desired to lock atmospheric pressure within the" bellows "at .a predetermined altitude, a cam lever 660 may be released and as the aviator ascends the pressure within the bellows being greater than atmospheric holds valve 66 closed Thus pressure within the suit is determined by the pressure locked within bellows and when it exceeds that pressure valve65b is opened and the constant pressure is maintained until the plane descends to an altitude where atmospheric pressure is sufficient to open Valve 66 and equalize the pressure.

In utilizing my apparatus the trousers section ofthe suit may be readily slipped upon the wearer' by openin the slide fasteners provided. Whereafter the blouse, with the slide fasteners opened at the rear and inthe front neck portion, may be slipped over the head. Adjustments are then made in the straps 27 for the boot portion of the troubers and the straps 2.8 for connection with the shoulders to conform to the height of the wearer. The blouse and trousers have their edgessuperimposed upon the sealing annulus and the clamping belt 24 is tightened to i join the blouse and trousers with sealing effect at the waist.

Connections are then made with the air supply line 52 and the oxygen supply line 58, the ends of such conduits or tubes being connected with theappropriate nipples on the controls externally of the suit. The gloves are readily attached by connecting the rigid annular members 2! at the wrist portions thereof with the receiving ring 20 secured to the outer ends of the arm portions of the blouse.

The helmet can be attached at any time either prior to taking oil or after some altitude has been reached. shown in the drawings, the helmet is readily attached by engaging the rear books at the attachment portion 3a or 3th whichever construction is utilized, fitting the depending edge 01" the helmet against sealing channel 32 and then clamping the toggle clamps Bl at the front and side lower edges.

Pressure is then supplied within the suit and the air is selectively distributed by means of the valve 53, through manual operation of the valve handle 53b on the exterior of the suit. Similarly the wearer may turn on supply of oxygen by manipulating the exterior handle of the control mechanism C.

Assuming that the suit is equipped with a valve system employing the control or relief type valves shown in Figs. 10 and 11, the pressure within the suit will at all times during air flight and at all altitudes be maintained at a predetermined differential above the atmospheric pressure outside; I have found that differential pressures varying from 1 to 3 pounds per square inch are most satisfactory and are practical with materials now available although diiierential pressures above l Q pounds per square inch may be utilized under some conditions.

i In the operation of the valve system with my double chambered suit, the valves of course, are caused to open by interior pressure when pressure W him the suit exceeds the predetermined ential pressure above atmospheric. By reference to Figs. 4 and 11', it will be noted that with my double ply suit one or more of the valves extend from the outer air space defined between the inner and outer envelopes to the exterior of the suit while one or more of the differential valves 57 extend between the interior of iii) the suit communicating with the pressure-applying space around the wearers body and communieating exteriorly with the air outside of the suit. Thus, there can never be a situation where a greater pressure can accumulate in the outer air chamber, but the pressures of the inner and outer air chambers of the suit will at all times be equalized.

If the inner wall or envelope of the suit becomes ruptured or develops a bad leakage, the outer wall of the suit, of course, contains the air and the valves 57 in both layers or walls of-the suit serve to function in conjunctionwith the injection of air into the suit to maintain the predetermined differential pressure. Likewise, if the outer layer or wall of the suit becomes ruptured the inner wall serves with its valve system to regulate and maintain the predetermined differential pressure above atmospheric within the inner layer of the suit.

If my suit is equipped with the predetermined fixed pressure valves of the type illustrated in Fig. 12, then the air within the confines of the bellows is opened to atmospheric pressure by opening the valve 66 by means of the camming lever 660 until the desired predetermined altitude is reached. whereupon, the bellows valves or valves 66 are locked by merely releasing thecam levers 6-60, springs 66a retaining the valves in closed position. Thereafter pressure withinth'e suit is controlled by the large valve 65 and only when pressure within the suit acting against the inner area of the valve 651) is greater the" pressure due to the air locked within the bellows is air released from the suit. Thus, a predetermined fixed pressure is maintained within the suit until such time as the wearer desires to open valves '65 for the bellows.

Another important alternative valve system may constitute the combination in my suit of one or more differential valves of the type illustrated in Figs. 10 and 11 with one or more fixed pressure valves of the type shown in Fig. 12. With such a valve system the differential valves 51 employed may be set for a predetermined maximum differential above atmospheric, say for example, two pounds per square inch, while the fixed pressure valve would be locked at an altitude of for example 30,000 feet. Thus, the pressure within the suit would be maintained at a fixed level by the diaphragm actuated valve 651) until the elevation is attained where atmospheric pressure about the suit is less than two pounds per square inch below pressure within the suit, at winch time the differential relief valves 5i will function, thereby preventing the pressure in the suit at a predetermined altitude and at altitudes thereabove from exceeding a differential greater than the predetermined said amount, in the example taken, two pounds per square inch.

The operation of the air distribution system and its selective control has been previously described and proper distribution of air as desired to the different parts of the suit may be readily controlled by the valve 53, through. the manipulation by the wearer of the external handle.

With the construction of my improved apparatus including the independent breathing system with the mask supported wholly upon the head of the wearer, clear vision can be obtained in all necessary directions including upwardly and 11 supply of oxygen is provided independently of the supply of air for producing pressure against the body.

My entire suit as constructed in accordance with the disclosure herein, affords comfort to the wearer in the selective means for supplying cool or warm air as desired and circulation of air within the suit. At low altitudes when it is not necessary to wear the helmet, the air discharge through line t! to the back is automatically connected when the helmet is removed and the wearer can then cause a circulation of air to the back in addition to the discharge of air at the various other points in the arms and feet.

Careful and accurate service tests have been made of the embodiments of my invention disclosed herein in high altitude chambers wherein pressures have been equivalent to those at altitudes exceeding 50,000 feet.

From the foregoing description it will be seen that I have provided a complete pressure-applying aviators suit and apparatus thoroughly practical and safe in every respect and overcoming the many problems heretofore encountered in this art.

It will, of course, be understood that various changes maybe made in the form, details, proportions and arrangements of the several parts without departing from the scope of my invention.

What is claimed is:

. 1. A pressure-applying aviators suit for use at high elevations having in combination a. highly flexible envelope covering the torso, limbs and arms of the wearer in practical fitting relationship, a substantially rigid helmet surrounding the head of the wearer and proportioned to be spaced throughout its periphery from the head to permit of free tilting and turning movements of the head in all directions therein, said helmet having the entire front portion thereof extending from a DOSition above the head of the wearer to a point below the neck of the wearer constructed of transparent material, the lower peripheral edge of said helmet having its forward portion slanting downwardly below the neck of the wearer to permit free downward vision, means for forming a, sealed joint between the lower edge of said helmet and the upper portion of said envelope, mean for discharging a gaseous medium under pressure into said suit and means associated with said suit for controlling the pressure therein.

2. A pressure-applying aviators suit for use at high elevations having in combination a highly flexible envelope covering the. torso, limbs and arms of the wearer in practical fitting relationship, a substantially rigid helmet surrounding the head of the wearer and proportioned to be spaced throughout its periphery from the head to permit of free tilting and turning movements of the head in all directions therein, said helmet having sealed connection at its lower edge with the upper portion of said envelope, a supply connection for injecting a gaseous medium under pressure within said suit, said helmet having a discharge means extending to the upper portion thereof and connectable with said supply QOnnection and a valve operated by said helmet when said helmet is attached, to connect said discharge means and adapted to disconnect said discharge means when said helmet is detached from said suit.

3..A double chamber, pressure-applying aviators suit for use at high elevations having in combination a helmet for enclosing the head of the wearer and leaving a pressure-applying air space surrounding said head, a flexible envelope surrounding and enclosing the torso, limbs and arms'of the wearer in practical fitting relationship, a second flexible envelope superimposed over said first mentioned envelope and connected therewith in practical fitting relationship, said envelopes both having openings at their upper portions for accommodation of the neck of the wearer, the edges defining said openings being connected with sealed effect to said helmet, means for injecting a gaseous medium under pressure within the space defined between said inner envelope and the wearers body and a valve system built into the envelopes of said suit for controlling and maintaining pressure within said suit regardless of whether either the inner or outer envelope becomes ruptured, said valve system including at least one relief valve extending through both envelopes of said suit.

4. The structure set forth in claim 3, and said valve system including at least one relief valve extending through both envelopes of said unit for communication with the space between said inner envelope and the body of the wearer and at least one relief valve extending through the outer envelope only.

5. A double chamber, pressure-applying aviators suit for use at high elevation having in combination a helmet for enclosing the head of the wearer and leaving a pressure-applying air space surrounding said head, a flexible envelope surrounding and enclosing the torso, limbs and arms of the wearer in practical fitting relationship, a second flexible envelope superimposed over said first mentioned envelope and connected therewith in practical fitting relationship, said envelopes both having openings at their upper portions for accommodation of the neck of the wearer, the edges defining said openings being connected with sealed effect to said helmet,

mean for injecting a gaseous medium under pressure within the space defined between said inner envelope and the wearers body, a valve system in said suit for controlling and maintaining pressure within said suit regardless of whether either the inner or outer envelope becomes ruptured and an independent breathing system for supplying oxygen to the wearer said valve system including at least one relief valve extending through both envelopes of said suit.

6. A pressure-applying aviators suit for use at high elevations constructed and proportioned to envelop the entirebody including the head of the wearer and constructed throughout of substantially air impervious material, means for discharging a gaseous medium under pressure within said suit and a valve system associated with said suit for controlling the pressure therewithin, said valve system comprising at least one differential relief valve in said suit adapted to release pressure from within when the same exceeds a predetermined difierential above atmospheric pressure outside of said suit and at least one fixed pressure relief valve having means for setting the same to open only in response to a predetermined pressure from within said suit.

JOHN D. AKERMAN.

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