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Description  |
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FIELD OF THE INVENTION
The present invention pertains to the field of inflatable tents and similar
structures.
BACKGROUND OF THE INVENTION
A variety of inflatable structures have been described in the art. These
inflatable structures include devices in which the tent sheathing or
sheeting is itself inflatable, as in a cellular arrangement, or in which
the sheathing is unitary with spaced-apart inflatable frame cells.
Alternately, the structures comprise an inflatable frame covered by the
sheathing. Examples of such structures are discussed in U.S. Pat. No.
4,197,681 (Holcombe) and U.S. Pat. No. 4,959,901 (Parish).
The inflatable structures in the prior art often have inadequate load
bearing capacity and thus are prone to slouch or collapse when loaded with
a heavy snow, for example. In addition, all bends in these structures are
pre-formed, making them relatively complicated and expensive to
manufacture. The prior art inflatable structures also lack versatility as
they are designed to assume a single fixed configuration when inflated.
Therefore, a need exists for an improved inflatable frame and structure.
SUMMARY OF THE INVENTION
The present invention provides inflatable, air supported frame elements and
frames that may be employed in a variety of structures, including tents.
One embodiment of the present invention is an inflatable frame member for a
structure comprising an elongated inflatable air chamber; an air inlet in
communication with the air chamber through which the air chamber may be
inflated; and a restraint coupled to the air chamber so as to prevent full
extension of the chamber upon inflation such that the air chamber kinks
and forms an angle at the location of the restraint. The restraint, which
in one preferred form is an elongated strap, generally has a first portion
coupled to the chamber at a first location, a second portion coupled to
the chamber at a second location, and a spanning section extending between
the first and second locations, with the distance between the first and
the second locations being greater than the length of the spanning
section. The restraint is preferably located on the exterior of the air
chamber. The restraint is preferably adjustable, allowing one to adjust
the length of the spanning section, and thereby the angle formed in the
air chamber. As a result, the structure may be stabilized upon uneven
terrain or adjusted to cause the frame member to assume one of multiple
configurations.
The inflatable frame member may also include an optional pressure release
valve in communication with the air chamber for limiting air pressure
within the air chamber, allowing one to rapidly and safely inflate the air
chamber to its optimal pressure without the fear of overinflation and
possible damage to the inflatable frame.
The present invention also provides structures having an inflatable frame,
the inflatable frame comprising plural inflatable elongated frame sections
interconnected to form, when inflated, a framework. In a preferred
embodiment, the framework includes a ridge element, at least one top plate
element, at least one sole plate element, a plurality of rafter elements
extending between the top plate element and the ridge element; a plurality
of upright stud elements extending between the sole plate element and the
top plate element; and plural restraints coupled to the frame so as to
prevent full extension of the frame upon inflation, such that the frame
kinks and forms an angle at the location of each of the restraints.
In a preferred form of wall tent, the restraints are each positioned
adjacent to the top plate and extend generally from a lower end of a
respective rafter element and the upper end of a stud element. Preferably,
the structure further includes transversely extending cross pieces
interconnecting the rafter elements to add stability to the structure. The
top and sole plate elements are preferably generally horizontal, parallel,
and transversely spaced apart.
Although such a structure may be formed from inflatable frame members
having plural air inflation chambers, in the most preferred form of the
invention, the structure is a single air chamber. The structure further
comprises an optional pressure release valve in communication with the air
chamber for limiting the pressure of air within the air chamber. The
structure may further comprise a flexible covering.
When in the form of a frame for a walled tent, the structure preferably
comprises a pair of transversely spaced apart sole plate elements and a
pair of transversely spaced apart top plate elements. Preferably, the
space between the respective top plate elements in this structure is
bracing-free and the space between the respective sole plate elements is
likewise bracing-free.
In an alternative embodiment, the frame is in the form of a six-sided
structure for a pup tent or the like.
It is therefore an object of the present invention to provide a safer, more
reliable inflatable structure combining simplicity of design, ease of use,
and an improved load-bearing capability.
These and other objects, features and advantages of the invention will be
understood more clearly by reference to the following description and
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one form of an inflatable frame-supported
structure in accordance with the present invention configured as a tent.
FIG. 2 is an inflatable frame for the tent of FIG. 1.
FIG. 3 is an enlarged view of an interior corner of the tent of FIG. 1.
FIG. 4 is a view of one form of a restraint used to form an angle upon
inflation of the chamber.
FIG. 5 is a top view of an optional air circulation vent for the tent of
FIG. 1.
FIG. 6 is a perspective view of an inflatable frame for a pup tent.
FIG. 7 is a perspective view of the frame of FIG. 6 with a covering.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The construction and operation of the present invention and the method of
its use can best be understood by reference to the drawings and the
following detailed description of several preferred embodiments.
The present invention provides an inflatable, air supported frame that may
be employed to support a variety of structures, including tents.
The inflatable frames of the present invention are composed of one or more
elongated inflatable air chambers, which are of a durable puncture
restraint material, such as 19-002 neoprene-coated nylon from Mann
Industries.
Restraints are coupled to the inflatable frame at selected locations where
the frame is to kink and form an angle in the frame. Although the
restraints may take a number of forms and may be internally positioned
within the frame structure, a specific form of restraint is indicated at
10, as shown in FIGS. 1-4, and most specifically in detail in FIG. 4.
With reference to FIG. 4, the restraint 10 is coupled to a portion of an
air chamber 12 so as to prevent full extension of the air chamber upon
inflation, thus causing the air chamber to bend or kink, as indicated at
13, and form an angle at the location of the restraint.
The illustrated restraint 10 has a first portion 14a which is coupled to
the air chamber 12 at a first location 15a. The restraint 10 also has a
second portion 14b coupled to the air chamber at a second location 15b.
The restraint may be coupled to the air chamber by a solvent weld or by
any other means known in the art, including, but not limited to, sewing or
gluing. The restraint is typically a flexible relatively inelastic element
such as a nylon strap 19. Reinforcement patches 17, preferably of the same
material as the air chamber, are secured to the air chamber at the
locations 15a, 15b, to reinforce the air chamber at the connection
locations for the restraint portions 14a, 14b.
The angle A at the location of the restraint is thus defined by length or
span of the restraint in comparison to the distance along the air chamber
between the first and the second coupling locations 15a, 15b. The shorter
the length of the restraint for a given distance, the greater the angle A
and vice versa.
Although not required, preferably the length of the restraint is
adjustable. In the case of a restraint comprised of a strap 19, a length
adjustment mechanism, such as a buckle 21, is used to permit the
adjustment of the length of the strap between connection points 15a, 15b.
Preferably, a lightweight material such as plastic is used for the buckle.
Other adjustable fastening approaches may be used, such as VELCRO fastener
material, to interconnect strap segments to form a strap of the desired
length. By adjusting the strap length, the angle A is changed. Similar
restraints are, in the illustrated embodiment, employed at selected
locations (for example, at the rafter element/stud element/top plate
element locations and at the rafter/ridge/rafter element locations). By
adjusting the lengths of the restraints, the angles between components at
the location of the restraints may be altered to, for example, stabilize
the frame even though the terrain may be uneven, such as on a hillside.
By adjusting the length of the restraint, one can thus change this angle A
or even eliminate the angle, if desired. Small adjustments can therefore
readily be made in order to stabilize the structure on uneven terrain.
Larger adjustments may also be made, such as, for example, to change the
number and position of the bends. As a result, a single frame can be
adjusted to assume more than one form. For example, by eliminating the
bends between the rafter elements and stud elements in the frame shown in
FIG. 2, the illustrated tent may readily be converted into an "A" frame.
Other configurations may also be assumed.
The use of restraints to form angles in the air chamber 12 reduces the
required number of pre-formed joints or bends required in the inflatable
frame. This makes the manufacture of an inflatable frame of the present
invention less complicated and reduces the manufacturing cost.
Referring again to the specific inflatable tent frame of FIG. 2, the
framework 16 is constructed from generally cylindrical flexible tubing
which is interconnected to form a single air chamber comprised of plural
inflatable elongated frame sections. When inflated, the illustrated frame
includes the following frame sections: a ridge element 18; a pair of
transversely spaced apart top plate elements 20a, 20b which are preferably
horizontal and parallel; a pair of transversely spaced apart sole plate
elements 22a, 22b which are preferably horizontal and parallel; a
plurality of rafter elements 24a, 24b extending between the respective top
plate elements 20a, 20b and ridge element 18; a plurality of generally
upright stud elements 26a, 26b extending between the respective sole plate
elements 22a, 22b and top plate elements 20a, 20b; and a plurality of
transversely extending cross pieces, in this case elements 28a, 28b,
interconnecting the respective rafter elements.
VELCRO fastener material patches 30, or other optional fasteners, on the
rafter elements, for example at a location adjacent to the top plate
elements, are used to secure a covering to the tent frame. Other means
known in the art for securing such a covering to the tent frame may be
employed.
Preferably the space in the plane between the respective top plate elements
20a, 20b and in a plane between the respective sole plate elements 22a,
22b is bracing-free, as shown in FIG. 2. This lack of bracing at these
locations is advantageous in a number of respects. For example, the lack
of bracing facilitates entry into and exit from the structure as one need
not stumble or step over such bracing; allows the frame, when deflated, to
lie flat for easy storage; and does not constrain the angles between the
side walls and rafters, allowing these angles to be easily adjusted, if
desired. Because of this relatively simple frame construction, the
inflatable frame constitutes a support for inexpensive, sturdy, stable,
and adaptable structures.
In order to use the inflatable frame as a tent, the frame is covered with a
covering 38, as shown in FIG. 3. Alternatively, the covering may be
present on the interior of the frame and suspended from the frame. The
covering is preferably flexible and separable, for example using a zipper
43, at the intersection between a floor 40 and side and end walls of the
tent. Consequently, the floor may readily be removed, for example for
cleaning purposes. In the case of a tent, the covering is preferably a
fabric that is light weight, heavy duty, fire retardant and waterproof.
Any of the flexible coverings known in the art for such purposes may be
employed. Specific examples include ANSOTEX urethane coated nylon in
weights ranging from 200 denier to 950 denier, preferably with heavier
weight fabric for the floor of the tent and CORDURA ripstop-type fabric.
As shown in FIG. 3, the tent in the illustrated configuration has two end
sections or walls 32, two side sections or walls 34, and roof sections 36
extending upward at an angle from the respective side sections to meet at
a ridge. The end wall sections are optionally made of two panel sections
selectively secured together, as by a zipper 48 (shown at one end wall in
FIG. 1) to define an opening for ingress and egress. The end walls may
also be selectively secured to the roof and side walls, for example, by a
zipper (not shown). Consequently, the end walls may be removed in the same
manner as the floor. This also permits replacement of an end wall of one
material with a different material (such as mesh fabric). This also
permits two tents to be joined together, utilizing the end wall zippers,
allowing the removal of the end walls, for example, to form a larger tent.
The seams of the tent sections are typically stitched together, although
any suitable seam sealing approach may be used. The side walls may be
parallel, as shown in FIG. 3, or sloping, depending upon the adjustment of
restraints 10. Also, only one side wall may be sloped, if desired, and the
structure may be configured as a lean-to.
Vents 41 may be incorporated into the flexible covering to facilitate air
circulation inside the tent. Preferably each vent comprises a screened or
mesh-covered opening overlayed by a flap. The flap is typically of the
same material as is used to form the roof of the tent. An air circulation
vent 41 is shown in greater detail in FIG. 5. In FIG. 5, the roof opening
is indicated at 45. The sides of the vent flap are of a generally
triangular shape and are reinforced to stand up from the tent roof to
facilitate air circulation to the vent opening. For example, triangular
pieces of open cell foam (not shown) may be same size as, and glued or
otherwise secured to, the sides of the vent flap for reinforcing purposes.
There are, in addition, a plurality of tie-downs 42 for use in securing the
tent to the ground. It is preferred that there be minimum of one tie-down
at or near each corner of the tent frame. In a preferred embodiment, each
tie down comprises a flexible strap which encircles the sole plate element
(see FIGS. 1 and 3) and passes through a slot in the covering of the tent.
The tent cover opening through which the tie-down passes is preferably a
button-hole type opening which may be closed, e.g., by stitching. The
exterior portion of the tie-down extends outward and away from the tent
and forms a loop, through which a tent stake can be driven into the
ground, thus anchoring the tent. By coupling the tie-down directly to the
frame, that is by encircling the frame with a strap, stresses arising
during use of the tent, for example as a result of wind loading, are
resisted by the frame and are not borne solely by the fabric covering.
Additional tie-downs, not shown, such as fabric loops at the corners and
center of the tent at the top plate level, are also typically used.
Preferably, in addition to the covering described above, an additional
layer of mesh fabric may be provided as a screen at the front of the tent,
which may be closed (e.g., zipped) while the outer covering is open to
provide ventilation and simultaneously exclude insects. For a day tent or
dining tent for warm weather use, the covering may comprise a first
portion covering the roof made from a fabric or the like with a second
portion covering the side and end walls made from a mesh material to allow
air circulation while excluding insects.
As mentioned above and shown in greater detail in FIG. 3, a first zipper
43, for example a #10 plastic zipper made by American Plastic, extends
horizontally around the perimeter of the tent and is used to selectively
attach the floor 40 to the flexible covering forming the side walls 34 and
end walls 32. FIG. 3 also shows the zipper 48 at the front end wall 32
extending vertically from the floor toward the ridge. When zipper 48 is
open, the tent is accessible.
As shown in FIG. 3, the inflatable frame has an air inlet 50, preferably a
standard inflate/deflate valve (for example, a series 690 valve made by
Halkey-Roberts). The frame also preferably includes a pressure relief
valve 52 (for example a series 780 valve from Halkey-Roberts) which limits
the maximum pressure in the inflated frame. Consequently, one can rapidly
and safely inflate the air chamber to its optimal pressure without
overinflation. The air inlet and pressure relief valves are preferably
located on an upright stud element 26 (for example, between sole and top
plate elements 20a, 22a) closest to an end wall to allow easy access for
inflating and deflating the tent. The inflate/deflate and pressure relief
valves are also preferably disposed on the air chamber 12 so as to face
the interior of the structure defined by the frame. Consequently, the
valves are easily accessible for inflation of the frame while preventing
friction between the valves and a fabric covering. If plural air chambers
are included in the frame, each air chamber is provided with an
inflate/deflate valve and optionally may be provided with a pressure
relief valve.
When deflated, the frame may be folded and/or rolled for storage,
preferably without removing the flexible covering. The tent may be
inflated using a conventional hand pump, such as a double action hand
pump. A tent as shown in FIG. 1, can be deflated and stored in a duffle
bag. To set up the tent, one simply removes the tent (the deflated frame
with surrounding covering), locates the inflate/deflate valve, and
inflates the frame until air begins to escape from the pressure relief
valve. The tent is thus fully inflated with the surrounding cover.
The inflatable frames of the present invention may also be used for tents
of other configurations, such as frames for small, lightweight pup tents,
as shown in FIG. 6. The pup tent frame is preferably constructed from
generally cylindrical flexible tubing (for example, neoprene-coated nylon)
which is interconnected to form a single air chamber comprising plural
inflatable elongated frame sections. The angles of the pup tent frame are
defined by restraints 10, such as described above. The inflatable frame
has an air inlet, typically a standard inflate/deflate valve, and,
preferably, a pressure relief valve (not shown).
When inflated, the illustrated pup tent frame includes the following frame
sections: a ridge element 58; a pair of base elements 60; and a plurality
of side wall elements 62 extending between the base elements and ridge
element. In the illustrated preferred embodiment, the frame has two ends,
each end having three side wall elements 62 that are joined together at
one end of the ridge element 58. The base 60 also joins the lower ends of
the side wall elements. The frame thus defines a pup tent frame having the
configuration of an elongated prism with generally pyramidal ends, as
shown in FIG. 6.
The pup tent frame with a flexible covering 66 is shown in FIG. 7. As
shown, the pup tent has two generally rectangular side walls 68, four
triangular end walls 70, two at each end of the tent, and a floor 74. A
first horizontal zipper 72 extends horizontally about the perimeter of the
tent and selectively attaches the floor 74 to the flexible covering
forming the side walls 68 and end walls 70. Another zipper 76 at one end
of the tent is opened to provide a doorway leading to the interior of the
tent.
Optional air circulation vents 84, like vent 41, are preferably located at
an upper region of each side wall of the pup tent. Tie downs 86, which may
be like tie downs 42 in FIG. 1, are typically used and may be located at
each of the six corners of the pup tent.
Preferably, the pup tent is inflated using a hand pump. A preferred hand
pump is a small, lightweight foot pump, such as a Sevylor U.S.A. 2041
pump. A lightweight pup tent as shown in FIG. 7, can be deflated and
stored, along with a lightweight foot pump, in a small carrying case,
which may take the form of a slightly oversized fanny pack.
Each of the zippers of the tents are preferably covered by an overlying
flap (not shown) to keep out the wind and rain.
Having illustrated and described the principles of the invention in several
preferred embodiments, it should be apparent to those skilled in the art
that the invention can be modified in arrangement and detail without
departing from such principles. We claim all modifications coming within
the spirit and scope of the following claims.
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