US 3158149 A
Descripción (El texto procesado por OCR puede contener errores)
Nov. 24, 1964 F. GRAY ACCELERATION PROTECTIVE APPARATUS Filed June 29, 1959 AIR SOURCE ACCELERATION RESPONSIVE METERING MECHANISM ACCELERATION RESPONSIVE VALVE so as to prevent anemia of the retina, or blackout United States Patent 3,158,149 ACCELERATEON PROTECTIVE APPARATUS Reuben F. Gray, Levittown, Pa, assignor to the United States of America as represented by the Secretary of the Navy Filed June 29, 1959, Ser. No. 823,786 4 Claims. (Cl. 128-1) (Granted under Title 35, U.S. Code (1952), see. 266) The invention described herein may be manufactured by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.
The present invention relates to an acceleration protective apparatus and more particularly to an acceleration protective apparatus for use by an aviator subjected to accelerative forces of indefinite duration.
Various types of protective instrumentalities existing in the prior art are instrumental in mitigating with varying degrees of facility the depletion of blood flow to the head during periods in which the pilot is subjected to accelerative forces such as those experienced in the dive maneuvers of an aircraft. A known device applies to the chest bladder of a suit a pressure which is proportional to acceleration, such that the increased hydrostatic pressure of the vascular system of the body during periods of centrifugal acceleration is substantially offset by the internal pressure developed within the chest. During such periods it is a common practice for the pilot to hold his breath. For extended periods of acceleration, the pilot, of course, cannot hold his breath indefinitely, and the continued application of an accelerative responsive pressure to the chest results in extreme discomfort to the pilot, manifested as so-called skin divers squeeze. Such mani festation occurs because of the maintenance of a constant external pressure on the chest of the pilot during respiration.
Apropos of the restriction placed upon anti-blackout devices of the prior art, the instant invention includes the provision of a mechanism for metering a discrete quantity of pressurized air to the chest section of a protective suit. As will hereinafter be set forth in greater particularity, the chest section comprising a pneumatically infiatable jacket, is inflated to a pressure corresponding to the accelerative level, and is thereupon effectively isolated from the pressurized air source, so that the pressure within the jacket fluctuates as a direct function of the pilots chest expansion and contraction. Hence, the discomfort experienced by the pilot as skin divers squeeze is obviated, while the average pressure within the chest is sufiicient to combat the increased hydrostatic head in the vascular system during extended periods of acceleration to thus prevent blackout.
An object of the present invention is the provision of a protective suit in which an external air pressure is applied to the chest in order to develop a pressure within the chest for promoting blood flow to the head.
Another object is to provide a protective suit in which an acceleration responsive metering valve discretely controls the quantity of pressurized air supplied to the jacket section of the suit so that respiration can be accomplished without personal discomfort to the pilot.
A further object of the invention is the provision of a protective suit in which the pressure within the jacket section thereof varies as a function of the expansion and contraction of the pilot chest.
An additional object of the invention is the provision of a protective suit in which the initial pressure supplied to the jacket section thereof in discrete levels proportional to acceleration is varied as a function of the expansion and contraction of the pilots chest, and the pressure ice within the trousers section thereof is maintained directly proportional to the accelerative level.
The exact nature of this invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification relating to the annexed drawing in which:
FIG. 1 shows a schematic view in partial cross section of a preferred embodiment of the invention,
FIG. 2 illustrates a schematic side elevation view of the protective suit shown in partial cross section in FIG. 1, and
FIG. 3 is a diagrammatic view in partial cross section of the acceleration responsive metering mechanism of the invention.
Referring now to the drawings, wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a protective suit which comprises a jacket or chest section 11 and a trouser section 12. The inner portions 13 and 14 of the suit are made preferably from a pliable waterproof material such as rubber sheeting, rubber impregnated fabric, or the like, and readily conform to the contour of the subject in a contiguous relationship. The outer portions of the suit are made preferably from treated canvas, or other waterproof fabric, being characterized as flexible, but substantially inelastic. The sleeve member 17 illustrated in FIG. 2 is similarly constructed and is attached to the chest section 11 as an integral part thereof, forming the continuous closure 18. The inner and outer portions of the jacket including the sleeve member are joined by thermal bonding, adhesives, or the like. Not illustrated in the views of FIGS. 1 and 2 are the various conventional tightening appendages for maintaining the protective suit in a fixedly secured position relative to the pilot. Hoses 19 and 21 are attached in conventional manner to the jacket and trouser sections proper with the aid of couplers 22 and 23, respectively, as shown in FIG. 2.
The acceleration responsive metering valve 24 shown in block diagram form in FIG. 1 will be discussed with greater particularity in connection with FIG. 3. This mechanism is coupled at the inlet side to a hose or conduit 27 and at the outlet side to hose id, supplying to the jacket section 11 of the protective suit a metered quantity of pressurized air, which is proportional to acceleration. The acceleration responsive valve 26 is conventional and may be of the type disclosed in the patent issued to- T. Ferwerda, No. 2,760,484, for an Anti-Blackout Device, and through conduits 2i and 27 supplies to the trouser section 12 of the protective suit a pressure which is directly proportional to the accelerative level.
Referring next to FIG. 3, there is schematically illustrated in partial cross section the acceleration responsive metering mechanism of the invention. An acceleration responsive valve 313 comprising member 311 of general cylindrical configuration having ports 34 and 4 8 is disposed for movement within cylinder 32. A calibrated weight 33 is attached to the acceleration responsive member 31 to impart to valve 30 proper displacement characteristics. Annular lips 35 and 36 forming a part of the cylinder, fix the permissible limits of travel of the acceleration responsive member 31. A compression spring 37 is interposed between the lower end of the member 31 and the bellows 39 over the stem 38, the latter being attached to member 31 and slidably disposed within the collar 60. The bellows is actuated by the air pressure of tube 41. In response to an acceleration force directed vertically as in normal gravity, the member 31 is operably actuated so that the ports 34 and 40 approach alignment with tubes 28 and 29, respectively.
Valve 42 deviates in its construction from valve 30 in that a single port 43 is provided. A compression spring 44, the lower end of which is immobilized, operably coacts with member 45 within cylinder 46 in opposition to the calibrated weight 47. The acceleration responsive member 45, as in the previous instance, is operable to open or reduce the constriction in tube 28 with an increase in acceleration force. The purpose of valve 42 is to provide a linear relationship between the quantity of air supplied to the chest section of the suit and the applied acceleration force.
The acceleration responsive valve 49 with bellows 51 functions to exhaust tubes M, 52, 53, 5d and 19 when the pilot is no longer subjected to centrifugal acceleration forces. Displaceable member 54 having ports 61 and 62 is connected at its upper end to a stem or rod 65, the latter being fixedly secured to a collar 66 which in turn is secured to bellows 51. At its opposite end, member 54 is connected by a suitable projection and retaining pin to lever 56, which is rotatable about a fixed pivot 57. For purposes of adjustment, a Weighted member 58, which is slidable along lever 56 and includes a set screw 59, is provided so that with gravity only, member 54 is operably resting against the annular lip 67 of the cylinder 55. The exhaust outlets 63 and 6d are provided with suitable constrictions, as illustrated, to introduce a suitable resistance to airflow for purpose of precluding abrupt exhausting.
The operation of the protective suit of the instant invention is best described in connection with the acceleration responsive metering mechanism illustrated in FIG. 3. The regulated and pressurized air of air source 25 is present in tube 27 and at the entrance to the valve 36 by way of the bifurcated passage consisting of tubes 28 and 29.
During aircraft maneuver-s involving centrifugal accelerations operable to actuate valves 30 and 42, each of the slidable members 31 and 45 is displaced from the position illustrated in FIG. 3, according to the magnitude of the acceleration. Air pressure is admitted to tubes and 20, the former supplying air pressure to the jacket section 11 through the hose 19. The air pressure in tube .41 is modified by the acceleration responsive valve 4-2,
the modified pressure causing bellows 39 to expand, compressing the spring 37 so that valve 36 closes. Thus, a metered quantity of air is supplied to the jacket section of the suit. A pressure proportional to the acceleration is also present at this time in. tubes 52 and 53, but since weight 58 is being subjected to the vertically directed acceleration, bellows 51 do not expand and valve 49 remains stationary in the position illustrated. Thus, a metered quantity of pressurized air is supplied to the jacket section of the protective suit, the jacket efiectively being a closed system isolated from the air source 25. The pressure within the jacket, therefore, will vary concomitantly with expansion and contraction of the pilots chest. The average pressure within the jacket is suflicient at all times to offset the increased hydrostatic pressure in the vascular system at the base of the lungs during acceleration so that circulation is effectively maintained to the head. For still higher accelerations the valve 3% admits more air to the chest section, and the bellows 39 respond to shut off valve 30, as before. Thus, the mechanism depicted in FIG. 3 is operable to supply to the chest section a discrete quantity of air, such that during acceleration intervals of indefinite duration, respiration of the pilot is accomplished without any manifestation of so-called skin divers squeeze.
When the accelerative forces cease, valve 42 closes to the upward position, while valve 39, already closed, remains in the position, as shown. In addition, the pressure in bellows 51 is now sufiicient to overcome the force of weight 58 in the absence of acceleration, causing expension of the bellows, which effects downward displacement of valve member 54 so that the ports 61 and 62 align with the exhaust outlets c4 and 63, respectively. The chest section is now effectively evacuated along with the line 41, relieving the bellows 39. When thepressure between exhaust outlet 63 and the line 53 is approximately equal, the valve 49 assumes the position illustrated in FIG. 3. It should be understood that in the event the acceleration decreases from a higher level to a lower level, the acceleration responsive metering mechanism depicted in FIG. 3 operates to release a discrete portion of air from the jacket through its associated exhaust outlet, and thereupon, the mechanism is operably maintained in dynamic equilibrium at the lower accelerative level.
The acceleration responsive valve 26 operates in a conventional manner and supplies to the trousers section a pressure which is maintained at a constant value proportional to t e accelerative level.
Hence, in the manner described, the protective suit of the instant invention enables the pilot of an aircraft to breathe comfortably without any manifestation of skin divers squeeze during periods of acceleration of indefinite duration. In addition, the application or" a discrete quantity of air to the jacket section along with a constant pneumatic pressure to the trousers section of the protective suit as a function of acceleration provides for an increase of pressure within the chest of the pilot so as to oflset the hydrostatic pressure in the vascular system. In this manner, the depletion of blood flow to the head is minimized.
While the acceleration responsive metering mechanism embodies a valve 39 having two ports, it should be understood that a valve having a single port may be used. In such modification, tube 28 is unnecessary, while tube 20 would then be connected to tube 10. Furthermore, since valve 42 pertorms a linearizing function, its incorportion is desirable but not mandatory.
It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment of the invention and that numerous modifications or alterations may be made therein without departing from the spirit and the scope of the invention as set forth in the appended claims.
What is claimed is:
1. In an acceleration protective apparatus including a source of pressurized fluid and an inflatable jacket for providing an external pressure to the chest of a subject, an acceleration responsive metering mechanism comprising, valve means connected between the source of pressurized fluid and the jacket, said valve means including a displacement member operable in response to an accelerative level to admit the flow of said fluid to the jacket, bellows means operably coupled to said valve means for receiving said fluid and connected to the displacement member so that actuation of the valve means in response to the bellows means causes a quantity of fiuid to be timemetered to the jacket proportional to the accelerative level isolating thereupon the jacket from the pressurized source, and means including a bellows coupled to the jacket and operable in response to the removal of acceleration to exhaust the jacket.
2. Apparatus for protecting a subject against the adverse eftects of acceleration comprising, a pneumatically inflatable jacket section, a pneumatically inflatable trousers section, said jacket and trousers sections each being constructed of an inner substantially pliable member adapted to conform in contiguous relation with the body contour of said subject and joined to an outer relatively flexible member having a substantially unyielding characteristic, a pressurized source of pneumatic fluid, means coupled with said pressurized source of'pneumatic fluid and said trousers section operable to supply a constant fluid pressure to the trousers section proportional to an accelerative level, and means coupled with said pressurized source of pneumatic fluid and said jacket section for operably admitting to the jacket section a quantity of said pneumatic fluid for a time interval solely proportional to the acceleration and thereupon operable to close said jacket section to the entrance of additional fluid, whereby the fluid pressure Within the jacket section varies in accordance with the respiration of the subject.
3. Apparatus for protecting a subject against the adverse eflects of acceleration comprising, an inflatable jacket section including integrally formed inflatable sleeves, an inflatable trousers section, said trousers and said jacket sections including sleeves being constructed or" an inner substantially pliable member adapted to conform in contiguous relation with the body contour of said subject and an outer relatively flexible member having a substantially unyielding characteristic, a pressurized source of fluid, means coupled With said pressurized source of fluid and said trousers section operable to supply a constant fluid pressure to the trousers section proportional to an accelerative level, and means coupled with said pressurized source of fluid and said jacket section for operably admitting to the jacket section including said sleeves a quantity of fluid for a time solely proportional to the acceleration and thereupon operable to close the jacket to the entrance of additional fluid, Whereby the fluid pressure within the jacket section including said sleeves varies in accordance with the respiration of the subject.
4. Apparatus for protecting a subject against adverse effects of acceleration comprising, an inflatable jacket means adapted to provide an external pressure to the chest of said subject, a pressurized source of fluid, acceleration responsive metering means coupled with said pressurized source of fluid and the jacket means for operably metering to the jacket means a quantity of fluid for a time interval proportional to the acceleration, bel lows means coupled with said acceleration responsive metering means to close the jacket means to the entrance of additional fluid, and bellows-actuated exhausting means coupled with the jacket means and operable in response to the removal of acceleration to exhaust the jacket means, whereby the fluid pressure within the jacket means varies in accordance with the respiration of the subject.
References Cited in the file of this patent UNITED STATES PATENTS 2,228,115 Holste Ian. 7, 1941 2,335,474 Beall Nov. 1943 2,676,586 Coakwell Apr. 27, 1954 2,760,484 Ferwerda Aug. 28, 1956 2,871,849 Chatham Feb. 3, 1959 2,952,264 Burns Sept. 13, 1960
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