May 16, 1950 s 2,507,939

PORTABLE COLLAPSIBLE WATER TANK Filed Aug. 5, 1947 2 Sheets-Sheet 1 y 1950 F. E. SMITH PORTABLE COLLAPSIBLE WATER TANK 2 Sheets-Sheet 2 Filed Aug. 5, 1947 ll'ld I '1.

Fatented May 16, 1950 UNITED STATES PATENT OFFICE PORTABLE COLLAPSIBLE WATER TANK Franklin E. Smith, South Dartmouth, Mass Application August 5, 1947, Serial No. 766,289

1 Claim.

The methods of fighting forest fires have been greatly improved in recent years, the modern technique depending, to a large extent, on the use of water in portable equipment. While some of this equipment is motor-driven, a very important part of it is carried on the backs of the fire fighters. Apparatus of this character necessarily requires an ample supply of water. If a natural supply is not conveniently available, then water must be transported. Because of the difficult terrain usually encountered in operations of this type and also because of the character of the fire fighting procedure itself, both the supply organization and the equipment used in it must be adaptable to rapidly shifting conditions, any of which may present an emergency.

The present invention is especially concerned with the problem of transporting water under these difficult circumstances, and it aims to devise tanks or containers which will greatly facilitate such transportation. Important requirements for such tanks are light weight, reasonable first cost, economy of space required by them, ease of handling, both when full and when empty, convenience in filling and discharging, and conservation of the water during transit. To meet these requirements is an important object of the present invention.

The nature of the invention will be readily understood from the following description when read in connection with the accompanying drawings, and the novel features will be particularly pointed out in the appended claim.

In the drawings:

Fig. 1 is a perspective view of a tank embodying the invention;

Figs. 2, 3 and 4 are sectional views taken approximately on the lines 2-2, 33 and 4-4, respectively of Fig. l; and

Fig. 5 is a perspective view, on a larger scale, showing details of construction at the lower corners of the tank.

Referring more particularly to Fig. 1, it will be observed that the tank comprises a bottom section, indicated in general at 2, a top 3, and four side sections or panels A, B, C and D stitched to each other at their longitudinal edges and also to the bottom and top sections.

All of these sections are made of some flexible sheet material which may be either substantially impervious to Water but will permit an extremely slow seepage, or which may be so treated as to be entirely waterproof, within the ordinary meaning of that term. A heavy canvas, either treated to waterproof it, or not, depending upon to 2 the requirements of individual uses, forms an excellent material.

According to the preferred method of manufacture, the side panels are completed individually, and the lateral edges of adjoining panels are then stitched together. As best shown in Fig. 2, the edges of the panels 13 and C are folded over, a folded piping or sealing strip 4 is inserted between them, and under the folded-over edges of these side panels, upwardly extending marginal panel strips 5--5 preferably are inserted. These parts then are stitched through and. through with several seams, thus producing a strong, watertight union of one panel to its next adjacent panel. Similar operations are repeated at the other corners, thus producing an open-ended tubular body, preferably tapered.

The assembly so far produced is next stitched either to the top or the bottom, as may be desired. Assuming that the bottom is first to be secured to the side panels at this stage, it should be observed that this bottom comprises two layers of canvas E and F, Fig. 3. While the edges of this bottom assembly may be secured to the side panels in any one of various ways, the construction which I have found most satisfactory is best illustrated in said figure where the margin b of the side panel B is shown overlapped upon a marginal part e of the bottom ply E. Another marginal part of the bottom ply E. is folded around the edge of the margin 1 of the bottom ply' F, and is then folded upon itself, under the part and is brought up around the edges of the parts b, c and f where it covers them, as shown at g, and it is then doubled over upon itself and overlapped upon the part b. These marginal portions b, e, i and g, superposed one upon the other, are then all stitched together, although some of these portions may previously be sewed together to facilitate handling.

The same procedure is followed in securing the other panels A, C and D to their respective marginal portions of the tank bottom 2. At the corners the sealing strip 4, above referred to, is spread out, as best shown in Fig. 5, and parts of the cover portion or of the upper bottom ply E are folded over these spread-out sections at the corners, before the marginal bottom parts are stitched together. Fig. 5 shows parts of this cover portion turned back. Thus a leak-proof joint is produced at the extreme lower corners of the tank.

Preferably, also, sheet metal reinforcing parts 6 are folded around the corners of the bottom flanges and secured in lace by rivets 1, Fig. 5.

In addition, a heavy fabric stay-strip 8, Fig. 5, may be secured diagonally across each corner, as also shown in Fig. 5, by rivets 9-9, where it serves both to strengthen the corner structures and also as a means for hanging up the tank while it drains and dries. The top 3 is secured to the side panels by seams essentially like the side seams except that they do not include the sealing strips 4. I I

Referring to Figs. 1 and 4, it will be seen that the top section 3 is provided with a central elongated tubular inlet opening I0, normally closed in some convenient manner, as by the wooden plug H. Preferably the inlet 10 is tapered slightly, being larger at the top than at the bottom, and a series of fabric strips 12 extendacr'os's its otherwise open mouth and are secured to its sides to prevent the plug from being forced down into the tank. Also, in order to secure it 'in'place, another series of straps l3, crossed over each other, as shown in Fig. l, are provided to prevent the plug from being forced out. Each of the latter straps is made in two sections normally held together by snap fasteners ['4 so that they "canfbe separated to release the plug when desired.

When the tank is empty it collapses into a "smanspace. The filling of a collapsed tank with water can be a rather troublesome matter. The present invention, however, eliminates this 'diflimay by providing the tubular inlet l0, above referred -to, with its mouth located a substantial jdistance, say eight or ten inches, below the top 3. If the plug H is removed and the hose is inserted through the neck 10, even with the tank coir'ipletely collapsed, an'e water is delivered into it, the tank will begin to fill and when the water rises far enough to cover the mouth of the inlet it will trap 'air immediately under jthe"top"section '3. This air is confined between the level "of the water, the side walls, and that part of the top 3 surrounding the member 10. As the filling operation proceeds the tank 'will eex anded bothlaterallyandvertically-tonar ly its full capacity 'uritil finally the water 'Will 'r'un'out of the outlet 10, an annular body of "air,

however, still being trapped in the top -'-'of the tank. Usually the filling operation is stopped prior to this time and the plug H is inserted a'n'd secured in 'place.

Knother method of'filling the tank is to prim fthe filling tube lflout into the dotted line position shown in Fig. 4, insert ahose throughfthe tube, the tank then being collapsed, and start "the filling operation. The hydrostatic pressure fwill make the tank expand, the pressure "acting 'against the top 3 as well as against the sides, andjthis pressure can be increased by'filli'ngthe upstanding tube, pressure of the 'water in the tube being transmitted to the entire 'body'of "water in the tank in accordance with the laws of hydrostatics. When full the tank may be closedby the plug, as above described.

Preferably a flexible filling hose I5, Figs. land "4, is built into the tank. This hosemay'conveniently be made of canvas and it is stitched to the 4 of the tank and as the filling operation proceeds, the displaced air escapes through a hole [9 in the plug. When not in use the hose I5 is folded, as shown in Fig. 4, and its folded end is secured under the strap H.

In actual use numerous tanks so filled are loaded into a truck and transported to points near the scene of the fire where their water can be supplied to the portable equipment which the fire fighters them's'el'ves' carry, or utilized in any other convenient way. "The intake end of a pump can be inserted through the tube [0 and 'the water pumped out of the tank, or it can be poured out. The tube l0 can be pulled out through the top of the tank to facilitate this operation, but usually it will be found preferable to make use of the hose 15 for this purpose. For convenience in handling the tank at these times, several straps I8 are riveted to the edge flanges where the lateral margins of the side p'anelsare secured together. When pouringw'ater "out of the tank through the hose I 5, the vent 1'9 in the plug permits the inflow of air to take the place of the water so discharged. While the ta'r'iks are being transported, the fact that they are tightly closed at their tops is of "advantage in preventing the loss of water due to the mo- 'tion of the vehicle.

During transportation there is considerable 'r ubbing'of the tanks against each other, p'a'r'tly due to some lateral bulging of them under hydro static pressure. In order to protect them from undue wear caused in this manner, "the strips 5, above mentioned,-'have 'been provided. Buckles "or other fasteners 20'"'2'0 are secured at suitable intervals to these strips, and they are uti- "liz'ed in'sec'uring in place 'an abrasi'oh pa'iiel, such as thatshown at2| in'Fig. 'l. That is, this panel 'lias'suitably'spaced straps 7122to be secure'd-to th'e buckles 2-0 where they will hold the abrasion panel 21 in protective relationship' to the "side panel A. And the 'same'constr-u'ctidn may be used *to p'rotect each of the other panels. I

From the foregoing it will be evident'that' the invention provides a water tank or container of special value to the organizations that -fight forest fires, although its usefulness obviously -'l's not limited to this service. But the fact that the tanks are lightin'weight, occupy little'sp'a'ce, can be conveniently made in sizes suited to the Various requirements of this particular service, and are "eas'y'to fill, discharge and distribute, satisfies the requirements for fi'ghtin'g'forest'fires in a manner which has not' be'en t'riie "of any other form of container, so far as I have been able to learn.

While I have herein shown and described "the preferred "embodiment of "my invention, 'it "will be evident that the inveiition may be embodied in other forms without departing from 1 the spirit disclosed are of rectangular form iii-horizontal "crossse'ction "because they pack "better "in trans- :portation, 'but they could be of frusto corii'cal, or other shape,'while still utilizingma'ny'ofthe top "and bottom rectangular'sectio'ns andf'side sectionsfall of said sections beingma'de'of flexijb'le sheet material,'seams connecting "saidsections together at their edges, said botto'm isection"being much larg'er than "said top-section, said top section being provided "with 'a filling REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Number Name Date Hesser Feb. 17, 1891 Perelli-Minetti July 4, 1893 Wittmann Apr. 13, 1926 Seitz Apr. 30, 1935 Crawford July 2, 1935 Steiner Aug. 10, 1943 Royer June 12, 1945 Geraci Aug. 26, 1947 FOREIGN PATENTS Country Date Australia Nov. 12, 1943