Field of the Invention
[0001] This invention relates to an inflatable raft made of rubberized cloth or the like,
and which may be stored on ships or airplanes for rescue use in an emergency, or which
may be used for recreational purposes.
Description of the Prior Art
[0002] Conventional inflatable rafts are polygonal, circular and elliptical in shape. An
example of a polygonal raft is illus- 'trated in Figs. 1 through 3, wherein Fig. 1
shows a perspective view of a continuous gas cell of the raft Fig. 2 shows a horizontal
section taken on line A-A of Fig. 1, and Fig. 3 shows a flat blank from which a single-gas
cell is made. The polygonal gas cell 1 is made of impermeable sheets of rubberized
cloth which are formed into tubular units and adhesively connected to each other.
[0003] In manufacturing the gas cell, sheets la, lb, lc, etc. with S-curved edges at both
ends are cut out on a floor surface such that each sheet is offset by a certain length
from an adjacent sheet, and has an overlapping edge margin for adhesion. The sheets
are then coated with adhesive at the margins, and formed into tubular units. A predetermined
number of such units, two for example, are connected together at their ends as shown
in Fig. 2, and the connected units are then similarly joined with other connected
units to eventually arrive at the.final gas cell configuration shown in Fig. 1.
[0004] The manufacture of this conventional raft thus necessitates connecting a plurality
of gas cell units together, an operation which inevitably requires specialized manual
skills; the sequence is very difficult and the reliability of the completed is generally
poor. The complex shapes of the various gas cell blanks make the work very tedious,
and since it is carried out on the floor level the workers must be constantly bent
over. Finally, the large quantity of adhesives involved contain dangerous and harmful
substances, which have harmful effects on the operators' health.
SUMMARY OF THE INVENTION
[0005] This invention provides an inflatable raft which can be constructed in a short time
and which eliminates the troublesome operation of adhering together a plurality of
separate sections. A single, elongated continuous tubular gas cell is formed from
a rectangular sheet, and is then bent into a polygonal shape and secured by simple
angulation members at the corners.
[0006] The efficiency of the angulation assembly operation is increased in one embodiment
by using a pair of patches fixed to the walls of the gas cell and a joining member
connected at its ends between the patches; the joining member can also be used as
a handle.
[0007] The rafts can be made easily without requiring special assembly skills by simply
connecting one end of the tubular gas cell to the other end to form a continuous circular
cell, and then, in another embodiment, inserting angulation members with projecting
tabs into predetermined corner portions of the cell to bend it into a polygonal shape.
[0008] In another embodiment a projection on the angulation members supports a grab or safety
rope extending around the inside of the raft.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009]
Fig. 1 is a perspective view of a continuous gas cell of a conventional raft;
Fig. 2 is a horizontal sectional view taken on line A-A of Fig. 1;
Fig. 3 is an unfolded view of a single gas cell sheet of a conventional raft;
Fig. 4 is a perspective view of a continuous gas cell of a raft according to this
invention;
Fig. 5 is a horizontal sectional view taken on line B-B of Fig. 4;.
Fig. 6A is a perspective view of an angulation member with a connected joining member;
Fig. 6B is a perspective view of an angulation member with a cord joining member;
Fig. 7A is a fragmentary sectional view of an angulated corner having a patch type
angulation member;
Fig. 7B is an enlarged fragmentary perspective view of the embodiment of Fig. 7A;
Fig: 8 is a fragmentary sectional view of an embadiment having a T-shaped angulation
member;
Figs. 9 through 11B are enlarged perspective views of various T-shaped angulation
members;
Fig. 12 is a perspective view of a raft according to another embodiment of this invention;
and
Fig. 13 is an enlarged- horizontal-sectional view taken on line C-C of Fig. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0010] 'In Figs.
:4 and 5 a continuous gas cell 1 is in the form of a hollow polygonal tube made of
a nonpermeable sheet material; Flexible patches 2 are fixed to the outer wall of the
gas cell on the inner side of the tube. A joining member 3 is connected between adjacent
patches 2 to draw them towards each other to thereby angulate the gas cell 1. A pair
of patches 2 and a joining member 3 constitute an angulation member.
[0011] In the production of the raft a flexible and impermeable sheet, such as rubber or
resin coated cloth, is cut into an elongated belt-like strip of sufficient length
to form the polygonal gas cell 1 and sufficient width to allow an overlapping margin
for an adhesive tube joint at the edge of the rectangular strip. One longitudinal
edge of the strip is joined to the other longitudinal edge to form an elongated linear
tube, and subsequently one end of the tube is joined to the other end to form a continuous
circular tube.
[0012] A joining member 3 made of a synthetic cloth, a belt or the like is connected to
a pair of adjacent patches 2 by sewing · . at both ends to form an angulation member.
The patches are made of rubber cloth or the like, and may be round, elliptical or
quadrilateral in'shape.
[0013] The angulation members are adhered to the inside wall 1A of the raft such that they
traverse the angles of the bent portions of the-gas cell 1, and thus tension the cell
to form corners and thereby define a polygonal gas cell. A bottom sheet 4 and other
additional devices may be attached to the cell to make up a complete raft. The raft
is usually folded for storage in a suitable place, and is inflated by gas in cases
of emergency or as desired when the raft is to be used recreationally.
[0014] The angulation members are not restricted to those described above, with various
other.configurations being adoptable. In Fig. 6A a joining member 31 made of a synthetic
cloth, a belt or the like, has one end sewn to a patch 21. The complete angulation
member is thus composed of two sets of joining members 31 and patches 21, and is applied
by adhering each half at a predetermined position on the gas cell 11 and then drawing
together and connecting the free ends of the joining members by sewing, gluing or
tying to form a suitable angle in the gas cell 11.
[0015] In Fig. 6B the patches 22, 22 are each provided with a plurality of holes with eyelets.
A cord or cords 32 are stretched across the gap between the patches 22 and drawn tight
to give the gas cell a suitable angle.
[0016] The patches may be fixed to the gas cell either manually or automatically, using
a pressure fixing machine, in accordance with the wishes and requirements of the manufacturer.
[0017] In the embodiments shown in Figs. 4 through 6B the joining members of the angulation
members are spaced from the wall of the gas cell. This is very convenient as, accordingly,
they can be utilized as handles for carrying the raft, or when actually riding in
it.
[0018] In Figs. 7A and 7B the gas cell 12 is tucked inwardly at the angled corner portions
12a. The patch-like angulation member 23 shown in Fig. 7A is adhered to the bent corner
portion with its interior surface directly affixed to and covering the portion 12a
to angulate the gas cell 12 at a number of positions 12b to form a polygonal shape.
[0019] The gas cell 12 in Fig.7B has two vertically arranged chambers..There is no substantial
difference in the angulation. members of the two independent chambers, although obviously
the corner bends must be vertically aligned to prevent distortions in the inflated
raft.
[0020] It is preferable that the tucked portions 12a be smeared with adhesive to stick the
folded layers together in order to reliably maintain the connection and angulation.
[0021] The tucks shown in Figs. 7A and 7B prevent the outside wall of the gas cell from
being excessively stretched when inflated. Accordingly, the tensions in the inside
and outside wall of the gas cell when,inflated are substantially uniform, enabling
the raft to withstand long-term use.
[0022] In the embodiment shown in Fig. 8 the angulation member 24 has a projecting portion
24a which is inserted into the folded tuck portion 13a and adhesively adhered thereto
to provide a rigid and inseparable connection.
[0023] In Figs. 9 through 11B, various other modifications of the angulation member are
shown, each of them being.employed in the insertion manner shown in Fig. 8.
[0024] In Fig. 9 the angulation member is made of a flexible material which is folded into
a T-shape having a planar portion 24la and a projecting insertion tab 241. The contacting
surfaces proximate the central fold line are sewn together at 242.
[0025] .In Fig. 10 the flexible angulation member is folded into a T-shape in the same manner
as shown in Fig. 9 to define an insertion tab 243, and a flexible patch 244 is adhered
to the planar portion thereof.
[0026] In Fig. 11A the angulation member 245 is molded of plastic as a single, integral,
flexible unit, which is'ideally suited for mass production.
[0027] In Fig. 11B the planar portion 25 is given a curvature to provide an untensioned,
snug fit against the wall of the inflated gas cell, and to enable its easy adhesive
attachment.
[0028] In Figs. 12 and 13 the gas cell 14 has angulation members 26 each having a first
projection 26a which is inserted into a corner tuck and an apertured, outwardly extending
projection 26b through which a grab rope'40 is threaded. A plug 41 prevents the inflation
gas, such as C0
2, from leaking out of the gas chamber, and a bottom sheet 42 is adhesively attached
to the bottom of the gas cell 14. Since the angulation members are also used to support
the grab rope, separate attachments therefor are not needed. This reduces the number
of parts needed to assemble a complete raft, and thereby lowers the production time
and cost.
[0029] The rafts of this invention are usually folded for storage when not in use, and it
is therefore important that the angulation members be flexible. If they are rigid
they will obstruct the folding of the rafts, and cause unwanted frictional wear and
rubbing of the raft tube material.
[0030] A synthetic rubber adhesive which hardens at normal room. temperatures may be used
to form the gas cells, and to fix the angulation and other members thereto. Alternatively,
an epoxy or a phenolic adhesive which is hardened by heating may be used, as well
as a hot-melt type adhesive such as an ethylenevinyl acetate copolymer.
1. An inflatable, polygonal shaped raft, characterized by a continuous tubular gas
cell (12; 13; 14) having at least one chamber and made of a single sheet of flexible
impermeable material,
a plurality of flexible angulation members(23; 24; 26) individually attached at a
plurality of predetermined positions to said gas cell to form and retain a plurality
of angled corners (12a; 12b) upon inflation and thereby establish said polygonal shape,
and
a bottom sheet (42) attached to a bottom surface of said gas cell to form a bottom
of said raft.
2. A raft as claimed in claim 1, characterized in that said angulation members (23;
24; 26) are attached to an interior wall of said gas cell and span the angled corners
(12a; 12b) thereof.
3. A raft as claimed in claim 2, characterized in that said gas cell is formed by
sealingly connecting one end of a continuous, linear, tubular body to the other end
to form a closed circular tube.
4. A raft as claimed in claim 3, characterized in that said tubular body is formed
by joining an elongated longitudinal edge of said single sheet to an opposite longitudinal
edge thereof, and wherein said sheet is rectangular.
5. A raft as claimed in claim 2, characterized in that each angulation member comprises
a pair of flexible patches (21; 22) attached to spaced opposite sides of said gas
cell wall at an angled corner, and a joining member (31; 32) connected to said patches
at its two opposite ends to draw said patches towards each other and maintain a bend
at said corner.
6. A raft as claimed in claim 5, characterized in that said joining member (31;-.32)
is spaced from the wall of said gas cell, and may also serve as a handle.
7. A raft as claimed in claim 6, characterized in that said joining member comprises
a pair of belt members (31), one being connected to each patch (21) at one end, and
the other, free ends of said belts (31) being mutually joined midway between said
patches.
8. A raft as claimed in claim 6, characterized in that said joining member comprises
a cord (32) drawn between a pair of said patches (22).
9. A raft as claimed in claim 2, characterized in that each angled corner is formed
by an inward fold (12a) of said gas cell wall.
10. A raft as claimed in claim 9, characterized in that each angulation member comprises
a patch (23; 24) attached to said gas cell wall to cover a central portion of an inward
fold (12a, 13a).
11. A raft as claimed in claim 10, characterized in that each fold is internally coated
with adhesive.
12. A raft as claimed in claim 11, characterized in that said gas cell comprises a
plurality of vertically arranged chambers.
13. A raft as claimed in claim 10, characterized in that each patch (24) has a Y-shape
defined by a first projecting tab portion (24a) inserted into and adhesively attached
to said inward fold (13a).
14. A raft as claimed in claim 13, characterized in that each angulation member (24)
is made of a flexible material centrally folded to form said Y-shape.
15. A raft as claimed in claim 14, characterized in that said flexible material is
sewn together at mutually contacting surfaces thereof proximate the central fold (Fig.
9).
16. A raft as claimed in claim 13, characterized in that each angulation member (24)
is made of flexible plastic (Fig. 11A).
17. A raft as claimed in claim 13, characterized in that an adhesion portion (25)
of each angulation member (24) has a curvature which conforms to the curvature of
the inflated gas cell wall.
18. A raft as claimed in claim 13, characterized in that each patch (26) has a second
projecting tab portion (26b) extending oppositely from said first tab portion (26a),
and a grab rope (40) supported by and drawn between said sencond tab portions.
19. A raft as claimed in claim 18, characterized in that each angulation member (26)
is made of a flexible plastic with said first and second projecting tab portions (26b)
integrally formed.