US 2689812 A
Description (OCR text may contain errors)
S p 1954 R. R. MoLLlcA ET AL METHOD OF MAKING INFLATABLE FABRIC LINED RUBBER ARTICLES Filed June 24, 1952 .ATIORNEY Patented Sept. 21, 1954 METHOD OF MAKING INFLATABLE FABRIC LINED RUBBER ARTICLES Russell R. Mollica, Cranston, and Helen T. Sweet,
Johnston, R. I., assignors to United States Rubber Company, New York, N. Y., a corporation of New Jersey Application June 24, 1952, Serial No. 295,372
This invention relates to a method of forming inflatable fabric lined rubber articles and in particular to articles of this type which have an internal tubular construction in which the tubes are freely intercommunicating.
Inflatable articles having a tough impervious outer surface of rubber or other suitable material are made in great quantities for a variety of purposes. Frequently these articles are made having an internal fabric lining of duck or other sturdy fabric to make the articles more durable in use, and when so constructed the articles have almost unlimited use in applications in which a sturdy construction is required, and which can be collapsed within a small compass so that it may be stored or transported easily when it is not in use. Articles made of this construction are suitable for such varied uses as water toys, collapsible boats, wading pools, portable tubs, etc.
It is an object of this invention to provide a method by which such articles may be made with a minimum number of operations that are extremely simple to perform, so that great savings in manufacturing costs may beachieved. More specifically this invention contemplates a method in which a sheet of fabric which is to form the lining for the inflatable article is doubled upon itself and sewed together along the unfolded edges of the fabric. A sheet of rubber or other suitable covering is applied to each exterior side of the folded fabric when flat, and the two covering sheets are joined to each other by overlapping joints beyond the boundaries of the folded fabric so that the fabric is entirely enclosed in the covering.
Although many of the advantages of this invention may be had when it is used to produce articles in which the folded fabric is sewed together at its edges only, the method has special advantages when used to make inflatable articles which are formed with a series of tubes extending through the article. Thus, for example, collapsible boats are made having a rubber bottom and inflatable sidewalls which are formed in a series of parallel tubes extending about the entire periphery of the boat. The side walls are given a tubular construction to provide rigidity when inflated, to economize on the material which is used to form the sides, and to provide the inflated boat with comparatively thin upstanding walls. Such walls may be made quite simply by the method of this invention, for a piece of fabric approximately equal in length to the desired periphery of the boat walls may 3 Claims. (Cl. 154-85) be folded transversely on itself and the folds sewed together lengthwise at spaced intervals so that seams are formed which will define the desired parallel tubes between adjacent seams. Before forming the tubes the ends of the fabric may be sewed together to form a closed loop, and after the tubes are formed the fabric is covered as described above. There will thus be formed an inflatable wall having a continuous parallel tubular construction in which the individual tubes intercommunicate freely along the entire length of the seams through the interstices between adjacent threads in the seam. Thus the walls may be inflated easily, for when air pressure is applied to any one of the tubes the entire wall will be inflated.
The method of this invention is very flexible, and the details of manufacture of articles by this method may be varied to produce articles having varied characteristics. Thus in inflatable boats and other articles it is frequently found desirable to have a somewhat different tubular construction at various points on a single article. For example, it may be desirable to have boat walls constructed so that at one portion thereof, for example the stern, they will have 3, 4, or more parallel tubes, yet at another portion of the wall such as the bow only 2 or 3 parallel tubes may be desired. When such a construction is desired it may be formed according to this invention by interrupting or resuming during the sewing operation one or more of the stitched seams at the required points about the periphcry of the walls, or the seam may be interrupted and resumed at a point which is shifted laterally from the interrupted seam to produce the construction desired in the finished article.
For a better understanding of the nature of this invention and of the means by which its many advantages are achieved, reference should be had to the following description in which a specific embodiment thereof is described as applied to the making of an inflatable wading pool, and to the illustration of the construction of such a pool shown in the accompanying drawing, wherein:
Fig. 1 is a plan view of a portion of the folded fabric after the folds have been stitched together to form the parallel tubes, and the ends have been stitched together to form a closed loop;
Fig. 2 is an enlarged sectional View along the line 22 of Fig. 1 of the fabric but having the sheets of impervious material applied to the outside of the fabric;
Fig. 3 is a perspective view of the completed Wading pool when it has been inflated; and
Fig. 4 is a sectional view of the inflated walls taken through the inflating valve along the line 4& and of a portion of the bottom of the wading pool.
Referring now to the drawing, to form a wading pool according to the method of this invention a piece of duck or other sturdy fabric It which is to form the lining for the rubber walls is cut to a shape required to produce the article desired. For the wading pool shown, this fabric Hi is cut to rectangular shape having a length approximately equal to the circumference desired in the wading pool and having a width large enough to produce the required height when the fabric is folded longitudinally upon itself and inflated as desired in the finished article.
To form the loop of the walls of the wading pool the ends I! and E2 of this fabric ID are overlapped and joined together by stitching a seam it across the entire fabric. The fabric loop is then folded upon itself lengthwise of the fabric at the middle 14 thereof to form a double ply fabric the plies at which have their longitudinal edges 25 adjacent each other.
The two plies which are thus formed by the folding of the fabric are then made into a flat sleeve by joining the plies together near the edges iii of the fabric by stitching a seam l5 about the looped fabric. To form the tubular construction in this sleeve the folds of the fabric are joined together at spaced points by stitching additional parallel spaced apart seams ll about the looped folded fabric Hi. The fabric H3 may then be coated with a suitable cement, or it may have been so coated previously, and a sheet of impervious material l8 of rubber or other suitable material is applied to one side of the flat folded fabric. The cement serves to bond the impervious sheet l8 firmly to the fabric it throughout the contacting areas of the fabric and coating. This impervious material has a length suflicient to extend entirely around the loop of the fabric and a width such that it will completely cover the fabric and extend over the edges thereof to form flanges it, for a purpose to be described. A second sheet of impervious mtaerial I8 is applied to the other side of the flat folded fabric. This. second sheet of impervious material has a length and width similar to the first sheet so that after the application of both sheets to the folded fabric It, it is entirely enclosed in the impervious material. Thus the fabric Ill will line the entire rubber article when it is inflated. The flanges E9 of the first sheet it of impervious material which extend beyond the edges of the fabric are bonded to the similar flanges of the second sheet to form flange seams to close the walls so that only that portion of the wall which is lined with the fabric is may be inflated. A bottom 20 for the wading pool of rubber or other suitable material is then applied over one of the ends of the loop of covered fabric to form the completed wading pool. An inflating air valve 2| is applied in the usual manher to the walls of the wading pool at any desired point. Since in making the article the impervious coatings !8 have been applied after the sewed seams it and ii are formed, external leakage of air through the seams will not occur.
Other articles may be made by the above described process by suitably varying the manufacturing procedure to produce an article having the characteristics desired. Thus an inflatable boat would be made by substantially the above described process, but the fabric if] and sheets of impervious material [8 would be selected having such a length as would be required for the periphery of the boat walls. Similarly the bottom of the boat would be out to the desired boat outline. To form a surfboard water toy, the procedure would be varied by omitting the step of joining the ends of the fabric before it is folded. These ends would be cut to a suitable shape for the surfboard and, when folded, the fabric would be stitched about its edges, and the parallel seams would be stitched therein to form the tubes. An inflatable mattress could be similarly formed.
Although many specific procedures may be used for making inflatable fabric lined articles according to this invention the following is a satisfactory procedure for making the wading pool illustrated in the drawing. A duck fabric is coated on one side with a suitable adhesive, and then cut to correct width and length. The ends of the fabric are then stitched together to form a closed loop, and the looped fabric is folded to form a circular sleeve having the coated side exposed. Then equally spaced compartments which are to form the tubes are made by stitching the folds together with nylon thread in substantially parallel seams running about the looped fabric. The use of nylon thread for the stitching is desirable because it is a stronger.
thread, so that when'the nylon thread is used with a duck fabric the inflated article may be capable of withstanding greater inflating pressures; and also because nylon thread stretches, so that when inflating pressures are applied to the article these threads will elongate somewhat to permit the walls of the article to part slightly at the stitching to facilitate further the inflaion of the article from a single air valve. The sewn sleeve is then placed on a building form, which when the article to be made is a wading pool would be a drum type form having a flat end and cylindrical sides. A sheet of neoprene gum is applied to one side of the sleeve, and the sleeve is then reversed on the building form and a second sheet of neoprene gum is applied to the opposite side of the sleeve making the flange seams described above with the first sheet of gum. The bottom 29 is then laid over the end of the drum and aproximately one inch of the inflatable side wall is turned down over the base of the drum and adhered to this bottom 20. The article is then removed from the building form, turned inside out and placed on a similar curing form and cured in the usual manner. After the article has been cured an air valve is applied to the inflatable walls in the usual manner to produce the completed wading pool shown in Figs. 3 and 4 of the drawing.
Having thus described our invention, what we claim and desire to protect by Letters Patent 1s:
1. The method of forming a fabric-lined rubber pool having inflatable walls with a parallel tubular construction which comprises, applying an adhesive to one face of a rectangular sheet of a woven fabric, stitching the ends of the fabric together to form a closed loop, folding the fabric upon itself to form a sleeve having the adhesive exposed, stitching the edges of the fabric together, sewing additional substantially parallel seams of strong and stretchable threads through the folded fabric to form a plurality of tubes in the sleeve which intercommunicate through the interstices of the seams, applying a rubber coating to both sides of the flat stitched fabric to completely enclose the fabric in rubber, and applying a liquid impervious bottom over one end. of the fabric to close the loop and form a pool.
2. The method of forming an inflatable fabriclined article which comprises folding a piece of fabric upon itself, stitching the folded fabric to itself along a seam to form a pocket Within the fabric bonded. by the fold line and the seam, applying a sheet of air and liquid impervious material to each exterior side of the fiat folded fabric to enclose the fabric and to form flange joints with each other beyond the edges of the fabric, and applying an adhesive to the exterior face of the fabric which is to receive the sheets of impervious material before applying the impervious material.
3. The method of making an inflatable fabriclined rubber article formed of a plurality of distinct intercommunicating tubes, which comprises folding a piece of duck fabric upon itself, sewing parallel spaced apart seams in the folded fabric to join the fabric to itself along spaced apart seams, applying a sheet of neoprene gum to each exterior side of the flat seamed fabric to enclose the fabric and to form flange joints with each other beyond the edges of the fabric, and applying a cement to the exposed face of the fabric at any time before applying the sheets 10 of neoprene gum to the fabric.
References Cited in the file of this patent UNITED STATES PATENTS 2,408,789 Luisada Oct. 8, 1946