US2743510A - Inflatable fabric segment of curved configuration and the method of making the same - Google Patents

Description

May 1, 1956 P. MAUNEY ET AL 2,743,510 INFLATABLE FABRIC SEGMENT OF CURVED CONFIGURATION AND THE METHOD OF MAKING THE SAME Filed 061.. 19, 1955 FIG. I

IO l8 COATING 8 FABRIC OF UNTREATED 9 SYNTHETIC THREADS TIE THREADS FIG. 3

/7|5 UNTREATED 0R RAW lo SYNTHETI THREADS D 2?? coAnNG FABRIC OF TREATED c SYNTHETIC THREADS H TREATED SYNTHETIC THREADS BOTH DIRECTIONS FIG. 4

IN VEN TOR.

- 'ATTDRNEY FIG. 5

United States Patent" INFLATABLE FABRIC SEGMENT OF- CURVED- CONFIGURATIONv AND THE METHOD OF THE SAME Paul: Mauney, Kings Mountain, N. (3., and Charles. J.

ForrLLake Cable, Canton, Ohio, assignors, by mesneassignments, to The Goodyear Tire & Rubber Com-- pany, a corporation of Ohio Application October 19, 1953', Serial No, 386,830

' 3 Claims. (Cl. 2&44

The presentinvention pertains to an inflatable fabric segment or structural element and the process for making theisame. More particularly, the invention; is concerned with a-method' of fabrication as well as a form of infiat-" able; structure made in. accordance with. the method entirely from fabric which has been coated or treated to render'it impervious to gas and which is'capable ofi assuminga curved configuration upon inflation.

For certain specific uses of more or less temporary nature, structures fabricated from water-proofed canvas orrubbenzed fabrics and having the ability to be quickly. an'd'easilyv constructed and dismantled have proven' highly advantageous. Such conventional structures, however, usually require some means by. whichthe canvas on fabric is:suspended or supported in the form which it is tonssuni'e, depending upon the use to whichit is put. supports are usually rigid and often quite bulky, as a result of. which they are exceedingly diflicult to handle,

store, and transport. In addition, such supporting or sus problems encountered in the aforementioned conventional.

structures. Moreover, the product of the present invention possesses the features of rigidity and ease of storage and erection not found in the ordinary forms of structure.

There are many places where not only avoidance of rigid supporting means is desirable, but also curved or cylindrical surfaces can be employed to better advantage than flat or planar surfaces which must necessarily be angularly joined together to form most structures. The curved configuration of the fabric segment or structural element disclosed herein is highly advantageous in avoiding sharp or angular joints. The curved configuration of the fabric segment moreover affords a highly advantageous structural shape which possesses greater strength characteristics.

Thus, it is an object of the present invention to provide a form of inflatable fabric segment or structural element which possesses the aforementioned attributes by reason of its ability to assume a curved configuration upon inflation.

It is a further object of the present invention to provide a method of forming an inflatable fabric segment or structural element characterized by a curved configuration on inflation.

Other objects and advantages of the product of the invention will become apparent as a detailed description of one embodiment of the invention proceeds.

Fig. 1 of the drawings represents a vertical crosssection through an inflated flat fabric segment illustrating a form of conventional structural element.

Fig. 2 illustrates a vertical section through a typical These extent of curvature being readily controllable.

curved: fabric segment embodying the teachings: of the present: invention.

Fig: 3 is an enlarged fragmentary section corresponding generally tothat'shown in Fig.v 1.

Fig. 4 is a fragmentary plan view of the top: ply of" thefabri'c segment.

Fig;:5 corresponds to Fig. 4., but illustratesthebottom.

fabric.- plyof the fabric segment.

In: Fig. 1 of the drawings is shown one form of fabric segment,.indicated generally by the reference; numeralv 1,

constructedfrom. two spacedplies of fabric 2. and 3.whichz.

arejoined together in the weaving operation by means of a plurality of drop or tiegthreads 4; The fabric segment 1 is conveniently formed into an envelopeby joining-the.-

ends and' edges of the fabric plies 2 and 3 as by means ofathetapes 5 and 6 which are securely. cemented-'inplace about the entire periphery of the fabric segment'l.

The-outer or exposed surfaces of. the fabric plies 2 and 3' are customarily coated with some suitable gas imper vious coating'such, for example, as natural or synthetic.

rubber and the like. The tapes 5 and 6'which cooperate.

with thefabric plies 2 and 3 to form an envelope are made from. a fabric which has been previously coated:

with. rubber or impregnated witha material whichwill serve to retainygas under pressure in the chamber'7 of .the'fabric segment 1. 'Although many other coating and. impregnating materialsare known and couldbe' used.

for. the purpose of rendering the walls of the fabric seg:

ment imperviousto gasunder pressure, thercoatingwhich.

possesses: all the desired characteristics and. has been chiefly. employed is rubber or'synthetic origin.

' For. many purposes, the flat'form of fabric segment" hascertainz disadvantages as we have already seen. To

overcome these disadvantages, the fabric segment 8 of Fig. 2, comprising a top fabricply 9 and a bottom fabric ply 10; has been devised. The fabric segment8 allows for extensibilityv of thetop ply 9 along the largerzradius ofithecurved sectionand is characterizedby a smoothly. curved: configuration. upon inflation with the degree or Heretofore, in order to produce a curvature in a flat fabric segment such as the segment 1, it has been the practice to take a series of folds or tucks in the fabric ply 3 along the smaller radius of the desired curved section. Such folding or tucking creates a break line in the fabric segment 1, tending to weaken it and frequently interferes with the freedom of the tie threads 4 and, as a result, does not produce a satisfactorily smooth curved section.

Referring to the fabric segment 8 of Fig. 2, the fabric top ply 9 is woven from warp and weft threads 11 and 12, respectively, which are of untreated synthetic origin such, for example, as raw nylon which has not been tensilized, so that'when subjected to heat and tension, will extend or stretch. The fabric bottom ply 10 is woven from threads 13 and 14 which are of tensilized nylon and have been rendered substantially inextensible before being converted into the fabric. The bottom ply 10 which is joined to the top ply 9 in the weaving operation by a large number of drop or tie threads 15 which are also substantially inextensible.

After the fabric top and bottom plies 9 and 10 joined by the tie threads 15 have been fabricated, the outer surfaces of the plies are coated with some suitable gasimpervious coating 16, 17 such, for example, as natural or synthetic rubber and the like. Next, the edges and ends of the fabric segment 8 are joined together by the tapes 18 and 19 of coated or rubber impregnated fabric to form a gas-impervious envelope enclosing the chamber 20 as shown in Fig. 2. Many different forms of coating and impregnating material maybe used for the purpose of rendering the walls of the completed fabric segment 8 substantially completely impervious to gas under pressure.

Patented May 1,. 1956 and 'may be of either-natural."

3 Rubber of either natural or synthetic origin has proven most satisfactory as a coating material.

The completed fabric segment 3 is then inflated and subjected to heat in the range of approximately 275 to 300 degrees Fahrenheit, at which the coating material, in this instance, rubber, is set or vulcanized. This temperature range corresponds generally to the softening point for the untreated synthetic threads 11 and 12 from which the top ply 9 of the fabric segment is fabricated. Thus, the temperature and pressure coact to soften the untreated threads 11 and 12 and cause them to extend or stretch while the treated threads 13 and 14 in the bottom ply of the fabric segment}; remain unaffected.

With the anchoring effect produced by the fabric construction embodying the substantially inextensible threads 13 and 14 of the bottom ply 10 and tie threads 15, the extension of the top ply 9 will cause the fabric segment 8 to assume the smooth curved configuration illustrated in Fig. 2. The fabric segment 8 is capable of assuming the predetermined degree of curvature originally imparted to it. it may be originally formed into a cylinder or any intermediate arcuate form of structure, if desired. These forms of fabric segments afford greater rigidity and strength characteristics without sacrificing the adaptabil ity of the material.

Whenever the gas is released from chamber 20 of the fabric segment 8 through a tube or conventional valve unit (not shown) which may take the form of a tire inflating valve, the entire element will collapse into a conveniently small and compact bundle. This structure with its curved configuration is capable of extensive use in all types of temporary buildings, shelters, forms, flotation elements, supporting structures, and the like.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modificationsmay be made therein without departing from the spirit or scope of the invention.

We claim:

l. An inflatable fabric segment capable of assuming a curved configuration upon inflation, said fabric segment comprising a double ply construction in which the plies are substantially superposed and joined together by a plurality of substantially inextensible tie threads woven partially into each of the plies for restricting the extent of separability of the plies, one of said plies being woven from untreated raw nylon threads and the other being woven from treated and pre-stressed nylon such that on being subjected to heat and pressure, the first ply will be stretched and the other will remain unaffected; and a vulcanized rubber coating applied to the outermost surfaces of each ply.

2. The method of making an inflatable fabric segment capable of assuming a curved configuration upon inflation comprising the step of weaving a double ply fabric in which the plies are disposed in substantially superposed relation, being joined together by a plurality of substantially inextensible tie threads woven partially into each of the plies, one of said plies being formed of threads which, when subjected to heat and tension, will stretch to a predetermined extent and the other being formed from prestretched threads incapable of further extension; coating the outermost surfaces of each ply with a gas impervious coating; and inflating the double ply fabric segment and subjecting to heat while inflated to set the coating and simultaneously stretch the previously unstressed ply of fabric, whereby a segment of curved configuration is formed.

3. The method of making an inflatable fabric segment capable of assuming a curved configuration upon inflation comprising the step of weaving a double ply fabric in which the plies are disposed in substantially superposed relation, being joined together by a plurality of substantially inextensible tie threads woven partially into each of the plies, one of said plies being formed of untreated and unstretched nylon threads and the other being formed of prestretched nylon; coating the outermost surfaces of each ply with a vulcanizable rubber; and vulcanizing the coating and simultaneously subjecting the nylon to heat and tension, whereby a segment of curved configuration is formed.

References Cited in the file of this patent UNITED STATES PATENTS 2,197,896 Miles Apr. 23, 1940 2,459,545 Schultz Jan. 18, 1949 2,474,124 Schultz June 21, 1949 2,657,716 Ford Nov. 3, 1953

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