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Publication numberUS3919027 A
Publication typeGrant
Publication dateNov 11, 1975
Filing dateApr 25, 1974
Priority dateApr 25, 1974
Publication numberUS 3919027 A, US 3919027A, US-A-3919027, US3919027 A, US3919027A
InventorsWalter C Jones
Original AssigneeRubber Dynamics Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of making inflatable life raft
US 3919027 A
Abstract
A method of making an inflatable raft comprises forming an annular inflatable member of the raft from an elongate rectangular blank of gas impervious yieldable resilient material. The rectangular blank of material is measured and marked to locate a plurality of longitudinally spaced apart fold areas along one surface thereof, and the blank is then cut along its longitudinal center line to form two identical panels. The longitudinal edges of the panels are secured together in lapped sealing relation to form the panels into a tube with the marked fold areas thereof being disposed exteriorly. The ends of the tube are then secured together in telescoping sealed relation to form the tube into an annular hollow member, the fold areas being disposed along the inner external peripheral surface of the annular member. The fold areas are then folded inwardly and are secured in inward folded relation by an elongate fold engaging tape which is provided with a plurality of fold engaging elements that extend into the fold engaging areas. Narrow covering tapes encircle the annular member and cover the fold areas. The annular member when inflated, defines a polygon, each side of which extends between adjacent folds.
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United States Patent 1191 Jones METHOD OF MAKING INFLATABLE LIFE 73] Assignee: Rubber Dynamics Corporation,

Armstrong. Iowa 221 Filed: Apr. 25. 1974 211 Appl. No.: 464,204

[52] U.S. C1. 156/145; 9/2 A; 156/198; 156/203; 156/204; 156/218; 156/227 [51] Int. Cl. A63B 39/00 [58] Field of Search 156/198. 226. 227. 145. 156/147. 203. 218. 204. 205. 474; 9/2 A. 11 A. 330

[56] References Cited UNITED STATES PATENTS 1.392.533 10/1921 Smyth 9/2 A 2.456086 l2/l948 Schwall 1. 1 9/2 A 2.717.849 9/1955 Rempel et al 9/2 A X 1.839.440 6/1958 Pfeiffer et al [56/198 X 3.048.514 8/1962 Bentele et al 156/204 X 3.774.566 11/1973 Moore 9/2 A X Primary Emm/ner-Charles E. Van Horn Ass/5mm E.\(u11111erDavid A. Simmons Almraey. Agent. or F1r//1Williamson. Bains & Moore 14 1 Nov. 11, 1975 [57] ABSTRACT A method of making an inflatable raft comprises forming an annular inflatable member of the raft from an elongate rectangular blank of gas impervious yieldable resilient material. The rectangular blank of material is measured and marked to locate a plurality of longitudinally spaced apart fold areas along one surface thereof. and the blank is then cut along its longitudinal center line to form two identical panels. The longitudinal edges of the panels are secured together in lapped sealing relation to form the panels into a tube with the marked fold areas thereof being disposed exteriorly. The ends of the tube are then secured together in telescoping sealed relation to form the tube into an annu lar hollow member. the fold areas being disposed along the inner external peripheral surface of the annular member. The fold areas are then folded inwardly and are secured in inward folded relation by an clongate fold engaging tape which is provided with a plu rality of fold engaging elements that extend into the fold engaging areas. Narrow covering tapes encircle the annular member and cover the fold areas. The annular member when inflated. defines a polygon. each side of which extends between adjacent folds.

2 Claims. 6 Drawing Figures U.S. Patent Nov. 11, 1975 METHOD OF MAKING INFLATABLE LIFE RAFT SUMMARY OF THE INVENTION This invention relates to inflatable rafts, and more specifically to a method of making an inflatable raft.

Most inflatable rafts are formed of an inflatable annular tube which forms the periphery or sides of the raft. A flexible bottom member is secured to the annular tube and forms the floor of the raft. In the manufacture of these prior art inflatable rafts, the annular tube is formed from a plurality of tubular sections which are secured together in sealing relation. Certain of the tubular sections, in these prior art devices, are of arcuate configuration, when inflated. Therefore, in order to make such an arcuate tubular section, the pieces of material from which each tubular section is made, must be cut so that when the pieces of material are secured together to form a tubular section, it will assume an arcuate shape. It has been found that inflatable rafts manufactured according to such a method results in a substantial loss of material since the pieces of material from which these arcuate tubular sections are formed must be cut into nonrectangular configuration. Furthermore, since the annular member of these prior art inflatable rafts are comprised of a plurality of sections which are sealingly joined together, each joined seam represents a potential area in which a leak may occur.

It is therefore a general object of this invention to provide a unique method of forming the inflatable annular member of an inflatable raft from a rectangular blank of material which has minimum of sealed seams. In carrying out this method, the blank is measured and marked to locate a number of fold areas along one surface of the blank and the blank is cut along its longitudinal center line to form two identical panels. The longitudinal edges of the panels are then secured together to fonn a tube and the ends of the tube are secured together to then form the tube into an annular member. The fold areas are disposed along the inner external surface of the annular member and the fold areas are folded inwardly and are secured in place by an elongate tape. When the annular member is inflated, the annular member defines a polygon, preferably an octagon, which is not only safer in construction than the prior art inflatable members, but which may be manufactured in a more economical manner than the manufacture of prior art rafts.

These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views.

DESCRIPTION OF THE FIGURES OF THE DRAWINGS FIG. 1 is a perspective view of the life raft made in accordance with the present invention;

FIG. 2 is a plan view of the blank used in the manufacture of the inflatable annular member of the raft; and with the fold areas marked thereon; and after the blank longitudinal cut;

1 FIG. 3 is a perspective view illustrating the formation Qof a tube from the panels;

FIG. 4 is a perspective view of the fold engaging tape;

FIG. 5 is a plan view of the inflatable annular member illustrating the manner in which the fold engaging ltape is applied;

FIG. 6 is an enlarged fragmentary cross-sectional view illustrating the manner in which the fold engaging portions or elements of the fold engaging tape engage the inward folds of the annular member.

DETAILED DESCRIPTION OF THE PREFERRRED EMBODIMENTS OF THE INVENTION Referring now to FIG. 1, it will be seen that one embodiment of an inflatable raft, designated generally by the numeral 10 is there shown. The raft I0 is comprised of an inflatable annular member 11 to which is secured a bottom sheet or floor 12. The raft is preferably formed of a yieldable resilient material, preferably neoprene rubber, although any suitable air impervious flexible resilient material may also be used. The inflatable annular member 11 is constructed from an elongate rectangular blank of material 13 of predetermined length and width. It will be appreciated that the length and width of the blank will be dependent upon the size of the inflatable annular member 11. The blank 13 includes opposed longitudinal edges 14 and opposed end edges 15.

After the blank I3 has been cut from a strip of material, a template (not shown) is applied to the blank to properly locate the plurality of longitudinally spaced apart fold areas 16. The fold areas 16 are marked on one surface of the blank by a suitable marking crayon or pencil, and it will be noted that the fold areas are defined by generally diamond shaped patterns which are truncated at their ends. It will also be noted that the annular member 11, illustrated in FIG. I, is of octagonal configuration, and accordingly, the blank 13 has eight substantially identical fold areas 16 marked thereon.

After the fold areas have been located and marked, the blank 13 is cut along its longitudinal center line to form the blank into two identical panels 130. The panels 13a are then formed into an elongate tube by overlapping each longitudinal edge of one panel with a longitudinal edge of the other panel. These lapped edges are secured together with an elongate inner tape or strip 17 and an elongate outer tape or strip 18. The inner and outer strips of tape each have one surface thereof coated with a suitable adhesive and the tapes are formed of a suitable air and water impervious material. When the tube 19 is formed by securing the longitudinal edges of the panels together in lapped relation, the patterns defining the fold areas 16 will be disposed on the exterior surface of the tube.

Thereafter, the respective ends of the tube are urged into telescoping lapped relation, as best seen in FIG. 5, and these lapped ends are glued together to form a sealed lapped joint 20 thereat. It is pointed out that when the tube 19 is formed into an annular member I l, as shown in FIG. 5, the patterns defining the fold areas 16 will be disposed on the inner, external surface of the annular member.

The fold areas are then tucked or folded inwardly so that each fold area forms an inward fold 21 which defines inwardly tucked or folded surfaces 21a. In this respect, the inwardly tucked or folded surfaces 21a will be folded or tucked inwardly so that only the periphery of the fold pattern will be disposed externally.

Means are then applied to the annular member to secure the inwardly folded surfaces 210 of each fold in inwardly folded relation, and this means includes an elongate fold-engaging tape 22. This fold-engaging tape 22 has an adhesive inner surface 23 and is of the length corresponding to the inner external periphery of the annular member 11, as best seen in H6. 5. The elongate strip of fold-engaging tape 22 has a plurality of longitudinally spaced apart reinforcing tabs secured to the nonadhesive surface thereof. each of these tabs 24 also being formed of the same material of which the fold-engaging tape 22 is formed. The reinforcing tabs 24 have the same width as the fold-engaging tape 22 and the spacing between the tabs corresponds generally to the spacing between adjacent inwardly extending folds 21. The fold-engaging tape is provided with a plurality of U-shaped fold-engaging elements or portions 25 each being secured to the fold-engaging tape at one of the reinforcing tabs 24 by suitable stitching 26. The U-shaped fold-engaging tape elements 25 each has an adhesive surface 27 and each tape element 25 is merely a short strip or piece of tape material of the type used to form the fold-engaging tape 22.

When the fold-engaging tape 22 is applied to the inner external peripheral surface of the annular member 11, each of the U-shaped fold-engaging elements 25 will be urged into a fold 21 and will adhere to the inwardly disposed fold surfaces 210 of each fold. Thus the inwardly folded surfaces 21a will be secured in inwardly folded relation and only the lines defining the fold areas will define the exterior fold lines of each fold 2i.

Thereafter, a plurality of elongate cover strips or tapes 28 will be applied to the annular member each encircling and covering one of the folds 21. Each tape 28 has an adhesive surface, and it is pointed out that each tape strip l7, I8, 22, 25 and 28 are preferably formed of the same material and each may be cut from an elongate roll of such tape material. Thus, all of the tape components used in the manufacture of the annular member will be of uniform width and will be formed of a gas and water impervious material.

After the cover tapes 28 are applied to the annular member to encircle and cover the fold areas, the floor l2 will be secured to the annular member by a suitable glue, tape or the like, the floor being formed of a flexible, yieldable water impervious material. The inflatable raft may also be provided with an inflatable tubular arch which is secured to the annular member 11, and when inflated, forms a support for a flexible cover or canopy. These cover supports are also formed in the identical manner except that the ends of the tubular arch are not secured together but are sealingly secured to the annular member.

When the inflatable raft is inflated, the annular member 11 will assume the configuration of a polygon. In the embodiment shown, the annular member comprises an octagon although other polygonal shapes may also be utilized. Each side of the polygon is defined by those portions of the annular member located between the fold lines. However, the annular member 11 has only three joints or seams, two of which are defined by the seals between the lapped longitudinal edges, and the other being fonned by the lapped sealed ends of the tube. Thus, applicant has provided an annular member in which the potential danger of leakage at seals has been substantially reduced because of the reduction in the number of sealed joints. lt is also noted that applicant, by utilizing the present method has constructed a geometrical annular member from a pair of panels formed from a single blank of material, thereby minimizing the loss of material normally experienced with typical prior art methods.

It will therefore be seen that applicants unique novel method of manufacturing inflatable rafts not only permits economic production of such inflatable rafts, but also provides a safer reliable raft than any heretofore known methods.

What is claimed is:

l. A method of making an inflatable life raft comprised of an inflatable tubular annular member and a bottom member, said method including:

forming the inflatable annular member from a single elongate rectangular blank of gas-impervious flexible, yieldable resilient material, measuring, locating and marking a plurality of longitudinally spaced apart generally diamond-shaped fold areas on said blank, said fold areas being of identical size and shape and being equally spaced apart, cutting said blank along its longitudinal center line to form the blank into a pair of identical panels,

securing each longitudinal edge of one panel to a longitudinal edge of the other panel in sealing relation to form the panels into a tube, the marked fold areas of the tube being disposed exteriorly,

securing the ends of the tube together in lapped sealed relation to form the tube into an annular hollow member, said fold areas being disposed along the inner external peripheral surface of the annular member,

folding the fold areas inwardly, each fold area including inwardly extending fold surfaces,

securing an elongate narrow fold-engaging tape to the inner external peripheral surface of the annular member, said fold-engaging tape having a plurality of longitudinally spaced apart U-shaped fold engaging elements secured thereto, the spacing between the fold engaging elements corresponding to the spacing between said fold areas, said foldengaging elements having the same width dimension as the fold-engaging tape, each fold-engaging element extending into each fold area and being secured to the fold surfaces thereof to retain each fold in inwardly folded relation, said fold-engaging tape extending throughout the entire peripheral surface of said annular member,

applying a plurality of spaced apart narrow cover tapes to the annular member, each cover tape having a width dimension corresponding to the width dimension of the fold-engaging tape, each tape encircling said annular member at one of said folds to cover the transverse inward fold line defined by the fold whereby said annular member when inflated defines a polygon, each side of which extends between adjacent folds,

securing a flexible water impervious bottom member to said annular member in sealed relation there with.

2. The method as defined in claim 1 wherein said annular member has eight inward folds and thereby defines an octagon.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1392533 *Jul 16, 1920Oct 4, 1921 Necticut
US2456086 *May 17, 1945Dec 14, 1948Gen Tire & Rubber CoCollapsible boat and method of making the same
US2717849 *Apr 30, 1953Sep 13, 1955Rempel Manufactruing IncMethod and apparatus for making compartmented tubular devices
US2839440 *Jul 23, 1956Jun 17, 1958Gen Tire & Rubber CoMethod of making an air cushion assembly
US3048514 *Sep 17, 1958Aug 7, 1962Us Rubber CoMethods and apparatus for making inflatable cushions
US3774566 *Feb 16, 1973Nov 27, 1973Moore ALight-weight, crash-resistant, vehicular structure
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4472225 *Nov 7, 1980Sep 18, 1984Dunlop LimitedBuoyancy tubes with bends for liferafts
US5032212 *Apr 21, 1989Jul 16, 1991Campbell Colin GPetroleum containment barrier, apparatus for the manufacture thereof and method and apparatus for recovering floating petroleum
US5056958 *Jul 25, 1990Oct 15, 1991Campbell Colin GMethod and apparatus for recovering floating petroleum
US5085538 *Jul 17, 1990Feb 4, 1992Campbell Colin GPetroleum containment barrier for recovering floating petroleum
US5419726 *Dec 17, 1993May 30, 1995Switlik Parachute Company, Inc.Inflatable flotation raft apparatus having heated seal areas and method of assembly thereof
US5922156 *Jan 23, 1997Jul 13, 1999Dunlop Beaufort LimitedMethod of making a bent inflation tube
EP0787575A1 *Jan 20, 1997Aug 6, 1997Dunlop Beaufort LimitedInflatable tube
Classifications
U.S. Classification156/145, 441/67, 156/227, 156/203, 441/40, 156/204, 428/12, 156/218, 156/198
International ClassificationB29C53/36, B29D22/02
Cooperative ClassificationB29C53/36, B29K2021/00, B29D22/02
European ClassificationB29D22/02, B29C53/36