Inflation aspirator

Dec. 4, 1956 j. v. crawford et al 2,772,829

INFLATION ASPIRATOR

Filed May 2, 1955

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2,772,829

Patented Dec. 4, 1956

United States Patent Office valves having large area may be used to admit air from the atmosphere, the check valves being supported for swinging movement adjacent the periphery of the inlet end of the body in order to assist in directing the induced 5 atmospheric air toward the swiftly flowing jet, thus prolonging the aspirating cycle during final· stages of flow from the compressed air source.

A further object of the invention is to provide the aspirator referred to in the previous paragraphs with 10 a safety, pressure relief or limiting valve which prevents the pressure in the receptacle from exceeding a predetermined maximum in the event the receptacle should be exposed to sunlight or other source of heat which might cause the air therein to expand, or in the event 15 flow of air from the compressed source through the nozzle continues after the closing of the check valves and the pressure in the receptacle tends to increase beyond the predetermined maximum; the relief valve thus serves to determine the final pressure in the receptacle.

Other objects and advantages will be apparent from the following description taken in connection with the accompanying drawing in which one form of the invention has been illustrated.

In the drawings:

Figure 1 is a diagrammatic view of apparatus for inflating collapsible containers, such apparatus having a jet pump or aspirator formed in accordance with the invention.

Figure 2 is a detail horizontal sectional view taken 30 through the aspirator on the plane indicated by the line 2—2 of Figure 1.

Figure 3 is a vertical· transverse sectional view taken on the plane indicated by the line 3—3 of Figure 2.

Figure 4 is a detail horizontal sectional view taken on 35 the plane indicated by the line 4—4 of Figure 3.

Figure 5 is a perspective view of a modified type of jet nozzle which may be used in the aspirator forming the subject matter of the invention.

Figure 6 is a vertical sectional view through a further 40 modified type of jet nozzle.

Referring more particularly to the drawings, the numeral 10 designates the inflating apparatus in its entirety. This apparatus includes a tank or bottle 11 containing air under relatively high pressure. A conduit 12 45 is connected with the outlet portion of the container, this conduit containing a shut-off valve 13 of any suitable type. The conduit leads from the shut-off valve to a regulator 14 employed to reduce the pressure of the air or other fluid issuing from the tank 11 to a desired value 50 and to maintain the air flowing from the regulator at the predetermined pressure. A conduit 15 leads from the regulator 14, which may be of any suitable type, such as shown in our co-pending application Serial No. 507,356, filed on even date herewith, to a jet pump or as55 pirator 16 which forms the subject matter of this invention. The member 16, as pointed out in the objects, is secured in the inlet of a collapsible container, such as a fabric or plastic bag 17, a portion only of which has been illustrated in the drawing. The bag 17 may 60 be a life raft, an escape slide, or other type of lifesaving device provided for use in airplanes and other personneltransporting equipment. In most instances the bag is formed from suitably treated fabric which may be collapsed to reduce the space required for stowage.

The aspirator 16 has been provided to effect a rapid inflation of the bag 17. This aspirator includes a tubular body 18 which, in the present instance, has an inlet end 20 of rectangular or square cross-section which converges into an outlet portion 21 having a circular cross70 section. The inlet section 20 is provided with an external flange 22 to which is secured a frame 23. This frame is also rectangular, to conform to the inlet section 20, and

2,772,829

INFLATION ASPIRATOR

James V. Crawford and Richard A. Fischer, Los Angeles, and Dan B. Le May, Palos Verdes Estates, Calif., assignors to The Garrett Corporation, Los Angeles, Calif., a corporation of California

Application May 2,1955, Serial No. 507,355 (Filed under Rule 47(a) and 35 U. S. C. 116) 8 Claims. (Cl. 230—95)

This invention relates generally to apparatus for inflating devices of any type, such as, lifesaving devices, air mattresses, shelters, construction forms and other structures, which are designed to be filled with air or gases under relatively low pressure. Some articles of such type, particularly lifesaving devices, may be formed of fabric, plastic and/or other suitable materials and are usually stowed in a collapsed condition, and when the occasion for use arises they must be inflated. Since these devices are used in emergencies, the inflation thereof must be comparatively rapid. This invention is more specifically directed to container-inflating apparatus of the type utilizing, as its power source, compressed air or other suitable gases.

An object of this invention is to provide apparatus for inflating a container, such apparatus including a source of compressed gas and a jet pump or aspirator of a novel design which functions to induce a flow of air from the atmosphere into the bag to effect a quicker, more efficient inflation of the container than has been possible with prior apparatus.

Another object of this invention is to provide a container-inflating apparatus having an improved jet pump or aspirator which has a body of tubular configuration, a nozzle for directing a jet-like stream of air or gas from a suitable source into or through the body, and check valve elements for admitting ambient air into the body under the inducement of the flow through the body created by the jet stream, the check valve elements serving to prevent the escape of air from the container.

Still another object of the invention is to provide a receptacle-inflating apparatus with an improved aspirator having a tubular body with check valves at the entrance end and a nozzle terminating, in inwardly spaced relation from the entrance end, in a restricted orifice which directs a jet stream of air from a suitable source, axially through the body to cause a flow of air from the atmosphere past the check valves into the receptacle; the location of the check valves relative to the nozzle provide improved air induction and prevent the loss of air from the receptacle during the last stages of inflation when the source pressure falls below a predetermined value.

Another object of the invention is to provide an aspirator having a tubular body with a nozzle for directing a jet stream of air therethrough to induce a flow of atmospheric air into the body, the latter being provided with one or more check valves arranged between the nozzle and the atmospheric air inlet so that although the check valves will readily open to admit atmospheric air, the jet stream from the nozzle will not strike the check valve and tend to hold it open, which would permit escape of air when the jet stream becomes too weak to induce an inflow of atmospheric air.

Another object of the invention is to provide an aspirator having a tubular body with a rectangular crosssection at the inlet end, so that one or more check

2,772, ³ has a peripheral flange 24 in which openings are provided for the reception of screws or other fastening devices employed to secure the frame to the body 18. Flanges 22 and 24 are also provided with openings, certain of which are threaded to receive fastening elements 25 which se- 5 cure a channel-sectioned clamp 26 to the aspirator and serve to unite the latter and the bag 17, the connection between the aspirator and bag being made airtight by squeezing the latter between the clamp and the frame. The frame 23 has the surface 27 thereof, which engages 10 body 18, provided with a groove 28 for the reception of a peripheral bead 29 formed on a rubber or other flexible plate-like member 30, this member being inserted between the frame 23 and the body 18 when the former is being assembled with the latter. The screws employed 15 to fasten the frame to the body cause, the frame to clamp the edge, of the rubber member 30- in airtight relationship with the body. The member 30 provides check valves for permitting atmospheric air to flow into the bag and prevents the escape of such air therefrom. 20

The frame 23, -in the present illustration, has ribs 31 extending from the central portions of -each side toward the opposite side, these ribs being joined with a boss 32 disposed centrally of the frame, the frame providing a rectangular opening constituting a continuation of the 25 inlet portion of the body 18. Boss 32 has a central opening 33 formed therein, the outer portion of which is threaded to receive the conduit 15. The inner portion of this opening is formed -to receive a nozzle 34 formed ' of metal or other -suitable material, -the nozzle being of 30 thimble-like shape and being flared, as at 35, to engage and -seal against a shoulder 36 in the boss 32. Nozzle 34 may be suitably secured in place -in the boss, as by clamping or otherwise, to provide an airtight joint; it terminates at its inner -end, in spaced relation from the 35 frame, in a restricted orifice, the first form -of the invention showing an elongated -slot 37 of substantially rectangular configuration having a length many times greater -than its width to cause a jet stream having extended surface. One specimen of the device was found 40 to perform satisfactorily with a jet orifice having a length and width of .600 and .006 inches, respectively. This slit-like orifice causes a fan-shaped jet of air to issue from the nozzle and results in an intimate mixing of the primary and secondary or atmospheric air in the shortest ₄possible length of body 18.

It will be noted from Figure 3 that the member 30 has slots 38 and 39 formed therein to provide substantially· rectangular check valve flaps 40 and 41, these -flaps being joined -with the member 30 -along regions located ₅₀at opposed sides of the inlet section of the body 1'8. This arrangement permits the valve flaps 40 and 41 to swing into the body without undue interference. The frame 23 is provided, along the sides of the openings formed therein, with flanges 42 for engagement by the valve flaps _gg40 and 41 to prevent -these elements from swinging outwardly under the influence of pressure within the body 18 or the bag 17. When the flap valves engage the flanges, an airtight joint will be formed. The flaps may, if desired, -be reinforced by incoiporating fabric or metal- ₆₀lie sheeting 43 -therein during the formation of the member 30. -This reinforcement will prevent the flaps from flexing when pressure -urges them against the flanges.

It will be noted from Figure 2 that the inner end of the nozzle 34 terminates at a point spaced inwardly from _ggthe flap valves. This -arrangement is advantageous since it prevents the high velocity air issuing from the nozzle from engaging the flaps and tending to swing the same toward open position. In prior devices of this character, high velocity jets impinged on the check valves and tended 70 to hold them in open position, particularly during the final stages of bag filling. When the check valves were so engaged -and held, air escaped -from, the bag. -and a complete- filling was prevented-. With th? construction shown, this objection is eliminated, 75

829

In the operation of the device, a jet stream of air at high velocity issues from the orifice 37 in the nozzle, mixes with the -air in the body 18 and flows through the outlet portion 21 of the body into the bag 17. This flow of -air reduces the pressure at the inlet end below the atmospheric pressure existing exteriorly of the bag. The pressure of -atmospheric air on . the outer surfaces of the flap valves 40 and 41 swings them inwardly toward an open position, permitting the atmospheric -air to enter the bag and-mix. with the jet stream issuing from the nozzle. Since the flap valves 40. and -41 possess relatively large areas, large quantities of air may enter the -bag; a rapid filling operation will thus result.

In some instances, improved results may be secured by forming -the orifice in the jet nozzle with different configurations, such as illustrated in Figures 5 and 6. In the former figure, the nozzle is provided with a crossshaped orifice 44, while in Figure 6, the orifice 45 is formed in -a hollow ring-like element 45α and has an annular configuration. Other forms may be employed if. found desirable, the essential feature of the orifice being a large ratio of jet periphery to cross-sectiona! area with all of the periphery exposed to induce a flow of ambient air.

. During the major portion of the container filling operation or when the pressure of the supply is above a predetermined minimum, the jet stream flowing from the nozzle will have a velocity sufficient to induce a flow of atmospheric air past the check valves 40 and 41. When, however, the. pressure at the source is reduced, and the velocity of the jet falls, the tendency of the air within the container to flow outwardly through the body will cause the check valves to close. Since the pressure of the air from the source will still be above that of the container, air will continue to flow from the nozzle and tend to increase the pressure in the container. The final pressure of the inflated container may be determined or limited by providing another check valve 46. This valve, however, is disposed on the outside of the device, on the check valve 40 in the illustration, and is responsive to pressure from within the container to open and permit some air to escape. Check valve 46 constitutes a flat plate riveted, or otherwise secured, as at 47, to the valve 48-, a portion of the valve covering opening 48. Should the pressure within the container tend to exceed a predetermined value, valve 46 will open and permit some air to escape until the predetermined pressure exists in the container; valve 46 will then close to prevent further escape of air. Normally, valve 46 will then remain in a closed position.

In some instances, the bag may be inflated when the atmospheric air is at a relatively low temperature, then, after being filled, the bag may be exposed to sunlight or other conditions which will cause the air in the bag to heat and expand. Valve 46 will again permit the escape of air to prevent undue pressures from building up in the bag.

The frame 23 may have a suitable screen 49 secured over the openings therein to prevent the entrance of foreign matter. This screen, in the form of the invention illustrated, is held in engagement with the outer surfaces of the ribs 31 and flanges 42 by a snap ring 50 secured in a groove formed in boss 32.

While the invention has been illustrated in one embodiment only, many minor changes may be made in the formation and arrangement of parts without departing from the spirit and scope of the invention as set forth in the following claims.