US2484418A - Oleopneumatic storage device - Google Patents

Description

Oct. 11, 1949. J. MERCI'ER 2,484,418

OLEOPNEUMATIC STORAGE DEVICE Original Filed March 17, 1942 2 Sheets-Sheet 1 Oct. 11, 1949. J, MERGER 2,484,418

OLEOPNEUMA TIC STORAGE DEVICE Original Filed March 17, 1942 2 Sheets-Sheet 2 Patented Oct. 11, 1949 UNITED STATES PATENT OFFICE OLEOPNEUMATIC STORAGE DEVICE Jean Mercier, New York, N. Y.

Original application March 17, 1942, Serial No. 435,111. Divided and this application September 13, 1945, Serial No. 615,957

This invention relates to an improvement in oleopneumatic storage devices consisting of a metallic container and a flexible and elastic bag inside said container. The bags are usually made of natural or synthetic rubber. Such devices are used on aircraft in order to provide a reservoir of oil or similar liquids under pressure. The container has one or more openings to admit and exhaust oil and the bag has an opening for the passage of a gas, in practice air. The bag is filled with air under pressure and closed or connected to a supplementary vessel also containing air under pressure. Oil is supplied under pressure to the container so as to compress the bag. It can then be withdrawn as required. Fresh oil is usually supplied as soon as the pressure falls below a desired value.

The operation of storage devices of this kind will produce frequent and alternating variations of the level of the liquid inside the casing and corresponding fluctuations of pressure.

My invention applies to devices of this kind in which the metallic container has a smooth inner surface and is of smoothly curved shape as, for instance, spherical or oval with or without a cylindrical portion extending between the spherical or oval ends. The bag is attached to one end portion of the container and the liquid is admitted and withdrawn at or near the opposite end of the container.

Q Such a storage device is described and illustrated in my pending application Serial No. 435,111, of which the present application is a division, now Patent No. 2,387,598.

For the use of such devices on aircraft the following requirements are important: the device must be. adapted to hold as much oil as possible. If used together with a supplementary container for compressed air, it should be possible to fill the container with oil until the air is almost completely expelled from the bag. In the absence of a supplementary container the device will usuallyhold, at maximum pressure a quantity of oil exceeding one half and sometimes three quarters of its volume.

On the other hand, when oil is withdrawn and the bag expands it is equally important that by progressive expansion of said bag as much oil as possible and, in the case of an extreme expansion, practically all oil be expelled from the container.

In order to expel the oil as required it is necessary to avoid oil-pockets between the outer side of the bag and the wall of the container. Such oil pockets are harmful not only on account of 3 Claims. (01. 138-44 the amount of oil lost for useful purposes but also because their presence may create a lack of uniformity in the stresses acting on the bag.

Storage devices of this kind, when used on aircraft, must usually work under high pressure. When the bag is used alone, i. e. without an auxiliary container for air under pressure, it may be filled with air up to a pressure of, for instance, -200 kg. per cm. operation and the bag is accordingly compressed, the pressure may rise to about 300-600 kg. per om. or even more.

On account of the high pressure prevailing in the bag, even if no oil is present in the container, for instance, in a case in which, due to an emergency, the oil in the storage device has been completely utilized, the bag is subject to therisk of beingforced into the oil-passage of the container and injured.

The present invention relates particularly to an inlet-outlet passage member for a storage device of the kind described, which member is adapted to substantially eliminate any turbulence in the oil or other pressure liquid passing therethrough, and thus insure maximum usefulness of the device, and also to prevent so far as possible and damage to the flexible bag of the container, due to causes outlined above.

Accordingly, it is the general object of the invention to provide, in combination with a storage device of the type described, a passage member having a plurality of relatively small passages therethrough, so shaped as to minimize turbulence, protect the bag member from contact with sharp edges, prevent the bag member from entry thereinto, due to the small size of the individual passagesryet provide adequate capacity for the passage in and out of the container of the fluid under pressure.

; Other and further objects, features and advantages will be noted from the description which follows, taken in connection with the accompanydrawings, in which- Figure 1 shows a section of a spherical storage device;

Figure 2 shows an enlarged section of the disclike member in the oil-passage member;

Figure 3 shows a section of an instrument adapted to pierce individual channels into said disc-like member;

Figure 4 is a view of an outer face of the disclike element in the oil-passage member;

Figure 5 is a partial view of a modified outer face of the disc-like element in the oil-passage member;

When the device is in Figure 6 is a view of another modification of the outer face of the disc-like element in the oilpassage member; and

Figure 7 is a diagrammatic perspective view illustrating the lines of intersection between conical outer portions of adjacent channels in the disc-like element.

In order to facilitate an understanding of the invention, reference is made to the embodiments thereof shown in accompanying drawings, and detailed descriptive language is employed. It will, nevertheless, be understood that no limitation of the invention is thereby intended and that various changes and alterations are contemplated such as would ordinarily occur to one skilled in the art to which the invention relates.

Referring now to the drawings, the storage device of Figure 1 comprises a metallic container I, a flexible and elastic bag 2, an air or gas valve 3 and a passage member 4, for oil or other fluid. 4

The features. of construction of'the storage device are fully described in my above-mentioned co-pending application and, apart from the passage member 4, will not be further described herein.

The passage member 4 comprises a plug-like member 5, the inner end of which is fitted with a disc shaped member 6, pierced by a plurality of smalllchannels. l of" special shape to be described. As the bag is required to expel the oil completely from ,the container, if needed, and as the bag will, in such a case, contact the oil-passage member under a pressure whichmay attain for example 150 kg./cm. special precautions are necessary to prevent the bag from descending into the channelsof the oilpassage and from undergoin elastic. stresses which it could not resist. It is not feasible to make the channels narrow enough to prevent the contemplated disturbance because this would impair the usefulness of the storage device.

It would not. be possible either to reinforce the lower end portion of the bag to such an extent that channels of suflicient size could be used because the reinforcement would impair the required: elasticity and flexibility of the bag.

The structure of the channels according to my invention hasbeen devised with the purpose of avoiding or at least reducing to a minimum any turbulence. in the flowing liquid.

Channels 1 have three portions of different shape, to wit: A central cylindrical portion, an innerand an outer end portion. I call "inner the PQI'tiOIlrdilBCtBd towards the inside of the container and outer the opposite portion.

In order to. facilitate the clear understanding of the-structure of the outer end portion of these channels, it willbe helpful to assume that the channels are pierced into the disc-like element 6 by an instrument 8, a section of which is shown inFig ure 3. Portion 9 of that instrument is to be cylindrical and portion It] may be conical or pyramidal. This assumption is made merely to per-mita clearer understanding of the structure of these channels, and the present application is net concerned with the actual process of making these channels. It is also clear that the inner end portion of these channels will be made in some other way.

By applying an instrument according to Figure 3 to the disc-like member, we will obtain holes the structure and arrangement of which will be explained in connection with Figure 2. Figure 2 shows an enlarged section of thedisc-like element 6. The holes include the central cylindrical por-.

tion H and the outer end portion I2. The outer end portion l2 will be conical or pyramidal according to the shape of portion ll) of instrument 8. The walls l3 defining the outer end portion l2 taper off toward the outer end face [4 of disclike member 6. The angle included between the tapered surfaces, as shown at I 5 in Figure 2, should not be over degrees. It is preferably smaller. The tapered portions of walls I3 of adjacent channels should meet along sharp edges. The angle above referred to must be big enough to make the formation of said sharp edges possible within the practical limits for the length of the tapered portions.

If portion It of instrument 8 is pyramidal, we may apply it in such manner that adjacent pyramidal holes end in a common base line of the respective pyramids. Figure 2 shows in solid lines two adjacent channels made in this way. The common base line It of the two holes lies inthe plane of end face I4. A view of this outer face it, in the case of an embodiment with four channels, is shown in Figure 4. The numeral I6 indicates the common base lines lying in the plane of the figure. Lines i'l indicate the edgesof the pyramid and the small circles ll indicate the central cylindrical portion of the channel. If more holes are required than can be arranged in the aforesaid manner within the periphery of the disc-like element, then we would have to apply the instrument 8 so as to produce a hole in the manner shown in dash lines in Figure 2. In that case, the common base line of the two holes will be at I? and the wall portion defining the first hole between I! and i? Figure 5 illustrates a partial view of the outer end face 54 in an embodiment with a plurality of triangular pyramidal holes, of which some extend down to the plane of the figure while others end in common base lines which lie in a plane parallel to that of the figure but located farther inside the disc-like element. Lines [8 indicate common. base lines lying in the plane of outer face l4; Lines [9. indicate common base lines lying in a plane inside the disc-like member. Lines. 20 indicate the edges of the triangular pyramids. The small circles l I indicate the beginning of the central cylindrical portion.

In the case of pyramidal holes, it is generally not necessary to resort to the complicated structure explained above. reduce the angle at the summit of the pyramidto obtain any necessary increase in the number of channels. However, if conical holes are desired,

then the simplified structure, as illustrated, for

instance in Figure 4, becomes impossible because,

if the cones are to end in the plane of end face is, islands will necessarily be left between the outer ends of adjacent cones. This would defeat the requirement that the walls of adjacent outer end portions shall meet along sharp edges, and the absence of these sharp edges may lead to turbulent flow of liquid passing through said channels. Therefore, in the case of conical holes, the latter must be made in the manner illustrated in dash lines in Figure 2 except, of course, for the wall portions 93 nearest the periphery of element 6. Figure 6 illustrates a View of the end face M in the case of an embodiment having three channels with conical outer end portions. Lines 2| are the lines of intersection between the three cones and lie in a plane perpendicular to that figure. Circles ll indicate the beginning or the central cylindrical portion of the channels.

will be cut away;

It is generally simpler to.

Figure '7 is a diagrammatic perspective view illustrating the lines of intersection 2|.

In the preceding description of outer end portions of channels 1, I have explained the structure of regular conical or pyramidal holes. In similar manner, these holes could also be made so as to have irregular pyramidal or conical shape. This would lead to a more complicated structure of the outer end of the disc-like member 6, but without necessarily affecting the usefulness of channels 1.

The inner opening of the channels toward the bag must be completely rounded off. In practice, I have found it useful to join the cylindrical portion of the channels to the flat inner wall of the oil-passage member by a circularly curved flaring portion, the radius of the curvature (shown in Figure 2 at 22) being approximately equal to the radius of the cylindrical part of the channel.

The central cylindrical portion 1 l of channels 1 should be as short as possible. Its diameter depends on the strength of the bag portion likely to come into contact with the oil-passage member, the properties of the rubber compound employed and the pressure inside the bag when'it is fully expanded. Under the usual conditions, I have obtained satisfactory results with diameters from four to ten hundredths of an inch.

The outer portion '23 (Fig. 1) of the plug-like member 5 will receive a pipe 24 or the like for supply and discharge of liquid to and from the storage device. The inner end-face of the pluglike member has preferably somewhat larger dimensions than the pipe. This will permit piercing of a sufficient number of individual channels into the disc member 6. The number of channels depends on the cross sectional area of the narrowest portion of each channel and the cross sectional area of pipe 24. The sum of the cross sectional areas of all individual channels-taken at the narrowest point of each channel--should not be less and preferably more than 50% of the cross sectional area of pipe 24. Otherwise the usefulness of the storage device will be impaired.

Having thus described my invention, what I' claim as new and desire to secure by Letters Patent is:

1. An inlet-outlet passage for a storage container, comprising a plug-like device having a flat surface at the end toward the container and a port at the opposite end, said flat surface being pierced by a plurality of channels each having a cylindrical portion, said portion merging with said flat surface by smoothly curved flaring surfaces, and each said channel having an outwardly tapering portion toward the exterior of the container, and a common passage connecting said channels and said port.

2. A device according to claim 1, said flaring surfaces being circularly curved, the radius of curvature being substantially equal to the radius of the cylindrical portions of said channels.

3. An inlet-outlet passage for a storage container, comprising a plug-like member having a passage therethrough and having a disc-like member secured in and extending across the inner end of said passage, said disc-like member being pierced by a plurality of channels each comprising an inner end portion, an outer end portion, and a central cylindrical portion, said inner end portions joining said cylindrical portions to the flat inner face of said disc-like member by smoothly curved flaring surfaces, said outer end portions being tapered outwardly and meeting in sharp edges at the outer face of said disc-like member.

JEAN MERCIER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,938,475 Alexander Dec. 5, 1933 1,971,159 Laurent Aug. 21, 1934 2,096,807 r Hulbert Oct. 26, 1937 2,399,444 Mercier Apr. 30, 1946 2,401,791 Overbeke June 11, 1946

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