U.S. patent number 3,914,811 [Application Number 05/468,941] was granted by the patent office on 1975-10-28 for lightweight, compact air mattress with improved casing and inflatable members.
Invention is credited to Jonathan Francis.
United States Patent |
3,914,811 |
Francis |
October 28, 1975 |
Lightweight, compact air mattress with improved casing and
inflatable members
Abstract
A lightweight, compact air mattress particularly well suited for
use for backpacking is disclosed. The air mattress is comprised of
a lightweight, thin walled casing having a plurality of
side-by-side elongated pockets and a plurality of inflatable
tubular members removably mounted in the pockets. The casing is
formed with access openings at both ends thereof adapted for
insertion and removal of the tubular elements into the pockets from
either end of the casing. The tubular members are preferably thin
walled, thermal plastic extrusions which are sealed at each end to
provide an inflatable chamber and to provide a tab at each end
beyond the seals. Replacement of a punctured tubular member can be
accomplished by opening both access openings to the casing,
fastening the tab on a replacement member to the tab at one end of
the punctured element, and pulling the punctured element out of the
casing from the other end to pull the replacement tubular element
into the casing. A casing having a layer of foam material on one
side thereof to enhance thermal insulation is also disclosed.
Inventors: |
Francis; Jonathan (Berkeley,
CA) |
Family
ID: |
47002388 |
Appl.
No.: |
05/468,941 |
Filed: |
May 13, 1974 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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276425 |
Jul 31, 1972 |
3813716 |
Jun 4, 1974 |
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Current U.S.
Class: |
5/710; 297/DIG.3;
5/700 |
Current CPC
Class: |
A47C
27/10 (20130101); A47C 27/081 (20130101); Y10S
297/03 (20130101) |
Current International
Class: |
A47C
27/08 (20060101); A47C 027/08 () |
Field of
Search: |
;5/348-350,345R,344,355
;297/DIG.3 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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432,171 |
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Jul 1935 |
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GB |
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1,889,927 |
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Oct 1959 |
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FR |
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Primary Examiner: Gilliam; Paul R.
Assistant Examiner: Calvert; Andrew M.
Attorney, Agent or Firm: Warren, Chickering &
Grunewald
Parent Case Text
RELATED APPLICATION
This application is a continuation-in-part of copending application
Ser. No. 276,425, filed Jul. 31, 1972, now U.S. Pat. No. 3,813,716,
patented Jun. 4, 1974, and entitled "LIGHTWEIGHT, COMPACT AIR
MATTRESS AND METHOD."
Claims
What is claimed is:
1. In a lightweight, compact air mattress having a casing including
opposed sheet portions formed to define a plurality of side-by-side
elongated pockets, and a plurality of individual elongated
inflatable tubular members each being removably mounted in said
pockets, the improvement comprising:
said pockets and said tubular members having a diameter to length
ratio preventing manual insertion of replacement tubular members in
said pockets;
said casing being formed with an access opening proximate each end
of said casing, each said access opening being adapted to provide
access to each of said pockets for insertion and removal of said
tubular members to and from said pockets through said access
openings;
access opening closure means mounted to said casing proximate each
of said access openings and adapted for selective opening and
closing of said access openings; and
each said tubular member is formed with securement tabs adapted for
securement of a replacement tubular member to both ends
thereof.
2. A lightweight, compact air mattress as defined in claim 1,
and
at least one replacement inflatable tubular member dimensioned for
mounting in said pockets and formed with securement tabs proximate
both ends thereof and adapted for securement to securement tabs
provided on said tubular members mounted in said pockets.
3. A lightweight, compact air mattress as defined in claim 1
wherein,
said access opening closure means are provided by zippers, and said
tubular members have a diameter of no more than about 2-1/2
inches.
4. A lightweight, compact air mattress as defined in claim 1,
and
a thin layer of foam material secured to and substantially covering
at least one of said sheet portions.
Description
BACKGROUND OF THE INVENTION
Undoubtedly, one of the highest priorities of outdoorsmen and
campers is the enhancement of sleeping conditions at the camp site.
Accordingly, considerable efforts have been made in the development
of sleeping bags and cushioning devices, such as air mattresses and
foam pads on which the bags are placed. Foam pads, usually
polyurethane or the like, have been found to have the advantage of
lightweight and reasonably good cushioning. Such pads, however, are
undesirably bulky when sufficient thickness employed to give
adequate cushioning. Prior air mattresses have been undesirably
heavy, although affording superior cushioning. The above reference
application discloses a lightweight, compact air mattress having a
plurality of removable inflatable tubular members of relatively
small diameter which are mounted in a thin walled casing. This
improved air mattress provides the desirable cushioning, and it is
very lightweight and compact when stored.
It is highly desirable when any type of inflatable mattress is
employed to be able to easily and rapidly make repairs. Moreover,
the outdoorsman must be able to make repairs without special tools.
In the lightweight, compact air mattress of the above-referenced
application, it is contemplated that the puncturing of a tubular
member may occur. Moreover, one method of rapidly removing and
inserting a new replacement tubular member is set forth. When,
however, the air mattress is a full length air mattress and
particularly when the tubes are small in diameter, the difficulty
in connection with the replacement of such tubular members, even
with the method of the prior application, may be substantial.
It is a further known disadvantage of air mattresses that they tend
to conduct heat through the mattress at a substantially greater
rate than occurs for foam pads. Thus, under cold conditions, a foam
pad will provide significantly greater thermal insulation than will
an air mattress. The multiplicity of small cells in a foam pad
slows heat transfer over the relatively large air-filled chambers
of the air mattress.
Accordingly, it is an object of the present invention to provide a
lightweight, compact air mattress having inflatable tubular members
which can be more easily replaced and repaired.
It is another object of the present invention to provide a
lightweight, compact air mattress having improved thermal
insulation.
It is another object of the present invention to provide a method
for insertion and removal of inflatable tubular elements in a
lightweight, compact air mattress.
The lightweight, compact air mattress of the present invention has
other objects and features of advantage, which are set forth in
more detail hereinafter, and will become apparent from the
accompanying drawing and the following description.
SUMMARY OF INVENTION
The lightweight, compact air mattress of the present invention
includes a casing defining a plurality of side-by-side pockets, a
plurality of inflatable tubular members removably mounted in the
pockets, and the improvement comprising, briefly, the casing being
formed with an access opening proximate each end of the casing,
each access opening being adapted to provide access to the pockets
for insertion and removal of the tubular members through the access
openings. The access openings further preferably are formed with
closure means, such as zippers, and the tubular members are
preferably formed with securement means, or tabs, on the ends
thereof. Replacement of a tube is effected by fastening the tab on
one end of a punctured tube to the tab on a replacement tube and
pulling the punctured tube out of the casing by the other end to
simultaneously pull the replacement tube into the casing. The air
mattress further preferably includes extruded tubular members and a
layer of foam material secured to and substantially covering at
least one of the sheet portions of the casing to provide thermal
insulation.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a lightweight, compact air mattress
having an improved casing constructed in accordance with the
present invention, and showing a replacement tubular member.
FIG. 2 is an enlarged, fragmentary, side elevational view of the
left end of the air mattress of FIG. 1 with the casing in closed
position.
FIG. 3 is a schematic representation of a method of forming the
tubular elements employed in the air mattress of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIGS. 1 and 2, the lightweight, compact air
mattress of the present invention can be seen to include a casing,
generally designated 61, having opposed sheet portions 62 and 63
formed to define a plurality of side-by-side elongated pockets 64.
Pockets 64 are preferably formed by stitching the upper and lower
sheet portions 62 and 63 together along longitudinally extending
lines 66. Removably mounted in pockets 64 are a plurality of
individual elongated inflatable tubular members 71, with each
individual and inflatable member being provided with its own valve
means 72. Valve means 72 is preferably constructed in a manner
enabling the maintenance of a positive pressure on the air in
tubular member 71 while the valve is being moved from the open to
the closed position so as to insure full inflation of the tubular
members. This is particularly desirable when small diameter tubular
members, for example, about 2 to 2-1/2 inches in diameter, are
employed. My abovereferenced application sets forth a suitable
valve structure in more detail.
In order to enable mounting of tubular members 71 in pockets 64,
casing 61 must be provided with at least one access opening to the
pockets. In my above-referenced application, such an access opening
is provided at the end of the casing, and a zipper is employed to
effect selective opening and closing of the access opening. The
inflatable tubular members are inserted into the casing of my prior
application by means of a tab on the end of the tubular members
having an opening into which a willow stick or the like could be
engaged and used as a rod to provide the necessary stiffness for
insertion of a replacement tube into the casing pocket. It has been
found, however, that this structure and method of inserting tubes
into the air mattress casing is undesirably tedious, particularly
when the air mattress is a full length air mattress. It is
difficult, for example, to obtain a 6 foot long, reasonably
straight and smooth small diameter willow stick or the like in some
locations.
Accordingly, in order to overcome the disadvantages noted in
connection with the insertion of the inflatable tubes into the air
mattress casing pockets, an improved air mattress casing is
provided. The improved casing includes an access opening 81 formed
proximate a first end 82 of the casing, and a second access opening
83 formed proximate second end 84 of the casing. Each of access
openings 81 and 83 are adapted to provide access to each of pockets
64 across the width of the casing for insertion and removal of
tubular members 71 through the access openings.
As shown in FIG. 1, the access openings are provided by flap
portions 86 and 87 of the upper sheet portion 62 of the casing.
Flaps 86 and 87 may be laid back as shown in FIG. 1 to expose
tubular members 71 as they are mounted in the pockets. As will be
understood, flaps 86 and 87 may be constructed so that they can be
laid back from either or both sides of the mattress so that all of
the pockets are readily exposed for access to the inflatable
tubes.
It is preferable in order to prevent the entry of dirt, twigs and
foreign objects into the casing pockets that access openings 81 and
83 further be provided with access opening closure means proximate
each of the access openings and adapted for selective opening and
closing of the access openings. Such closure means may be
advantageously provided by zippers 88 and 89, which can be readily
secured to the fabric sheet portions of the casing.
In order to further facilitate the replacement of tubes, the
tubular members 71 should be formed with securement means proximate
at least one end thereof, which securement means is adapted for
securement of a replacement tubular member thereto. The tubular
members of my above-referenced prior application are suitable for
use with the improved casing of the present invention. It is
preferable, however, to form tubular member 71 with securement
means in the form of tabs 73 and 74 at both ends of the tubular
members.
The method of replacing the inflatable tubes disposed in the
improved casing of the present invention can now be described. If
the access openings to the casing are provided with closure means,
the closure means are first opened. Thus, zippers 88 and 89 are
both zipped to the open position to expose tubes 71. A replacement
tubular member 71a having tabs 73a and 74a on the ends thereof, is
positioned adjacent the tubular member to be replaced. Tab 74a on
replacement tubular member 71a may now be secured to tab 73 on a
first end of the tubular member to be replaced. Such a securement
can be advantageously effected by means of a safety pin 76 which
can be pinned through each of the tabs without puncturing the
inflatable portion of the tubes. With the end of replacement tube
71a secured through access opening 81 to the end of the tube to be
replaced, the camper may then grasp the second or opposite end of
the tube to be replaced through access opening 83. The camper can
then pull the tube to be replaced outwardly to second access
opening 83, as indicated by arrow 77 and the phantom lines at the
right of end 84 of the casing. Since the replacement tube is
secured to the tube to be replaced, the replacement tube will be
simultaneously pulled into the pocket vacated by the tube to be
replaced through the first access opening. When tab 74a of
replacement tube 71a reaches second end 84 of the casing, the
tubular member to be replaced may be released from the replacement
tubular member by releasing safety pin 76. Thus, the removal of the
punctured tube is used to effect a simultaneous insertion of the
new replacement tube. The camper can, therefore, carry a small
repair kit with the air mattress of the present invention. The kit
would include one replacement tube, a safety pin, a small piece of
tubing material, and a small tube of adhesive. This kit would allow
a rapid insertion of a new tube and repair of a punctured tube.
When the tubes are formed with a tab at each end, all the valves 72
can readily be maintained oriented proximate a single access
opening, in this case opening 81. If the tubes of my prior
application having a single tab are employed with the improved
casing, replacement will be effected readily, but the valves will
be disposed at alternate ends of the casing.
In another aspect of the lightweight, compact air mattress of the
present invention, improved thermal insulation is provided without
substantially increasing the overall bulk and weight of the air
mattress. As best as may be seen in FIG. 2, casing 61, having
inflatable means or tubes 71 disposed therein, is provided with a
layer of foam material 91 substantially covering at least one of
sheet portions 62 or 63 which form the casing. As shown in FIG. 2,
layer 91 of foam material is laminated to lower sheet portion 63 of
the casing, either by means of an adhesive or foaming layer 91 in
situ on sheet 63. As will be seen, the layer of foam material 91
has a substantially smaller thickness dimension than the diameter
of tubes 71. For example, it is preferred that layer 91 have a
thickness of about 1/4 to 1/2 inch, whereas tubes 71 are preferably
about 2 to 2-1/2 inches in diameter.
Foam material 91 can advantageously be formed of an open cell
polyurethane foam. The primary purpose of this layer is to reduce
heat transfer through the air mattress, not increase cushioning. To
some degree, of course, the layer of foam will supplement the
cushioning effect of tubular members 71, but this supplementation
is minor in nature. Thus, the thin layer of foam enables the
outdoorsman to have the advantage of thermal insulation found in
foam pads, together with the advantages of an air mattress which is
compact and light in weight. It is possible to provide a foam layer
on both sheets 62 and 63, although there is an attendant increase
in bulk of the air mattress, which may become undesirable.
Referring now to FIG. 3, a schematic representation of the
formation of tubular members 71 is shown. While it is possible to
heat seal two opposed sheets to form a tube suitable for use in the
mattress of the present invention, it has been found to be
preferable to form tubular members 71 by an extrusion process.
Thus, extruder 92 may be used to extrude a continuous plastic tube
93, which can be rolled up on a reel or the like for storage. Tube
93 is preferably extruded at a diameter smaller than the desired
end diameter of the tubing and with a greater wall thickness. The
tube 93 can then be enlarged with its wall thinned by a blowing-out
process, well known in the extrusion art. The blowing-out process
produces a tube of the proper diameter and uniform wall thickness.
If an extruded polyurethane film is employed, the wall thickness
may be as low as 0.002 inches.
After the blowing-out process, tube 93 can be run through a bagging
machine to cut the tube to the desired length and effect a heat
sealing of one end of the tube along line or seal 94. As will be
seen, seal 94 is inwardly of the cut end 96 of the tube to define
tab 74 between the seal and the cut end. The next step is to cut a
valve opening 97 approximate to the end of the tube opposite seal
94. Valve 72 can be inserted in opening 97 and heat sealed or
adhesively sealed in place. In the final step, a second seal 98 is
formed adjacent valve 72 to define a chamber between seals 94 and
98. Seal 98 is formed inwardly of the end of the tubular members so
that the wall portions extending past seal 98 provide tab 73. The
process for formation of seals 94 and 98 can be employed to
laminate the wall portions forming tabs 73 and 74 together so that
they act as a single member.
* * * * *