Note: Descriptions are shown in the official language in which they were submitted.
CA 02283111 1999-09-23
PORTABLE FOLDING SHELTER
Field of the Invention
The present invention relates to portable shelters, and particularly relates
to
portable shelters which may be compactly folded for transport on flatbed
trailers.
Background of the Invention
Temporary shelters have a number of uses, including industrial applications
such
as for sheltering construction materials or work operations, such as welding
operations, from
wind and weather. For these and other purposes, it is commonly desired to have
a reasonably
large temporary shelter which may be conveniently transported to the site
where it is needed.
Portable shelters are desirably collapsible or foldable to facilitate
transport and as light as
practically possible while still providing adequate structural strength. It is
further desirable that
such a shelter be relatively quick and easy to erect, without needing special
tools and equipment,
and without needing a large number of workers. In particular, it is desirable
that the shelter
may be erected without need for tools or power equipment, as it may be
commonly desired to
erect the shelter in relatively remote locations. Similarly, it is desirable
that the shelter be easy
to load or unload from a trailer or other transporting means, without
requiring extensive or
special equipment or manpower.
The prior art discloses a number of attempts to provide a portable temporary
shelter having the foregoing desirable features. For example, U.S. Patent No.
5,649,559 issued
to Scott, Jr. on July 22, 1997 discloses a roof frame supported by four
extensible leg members
and having a number of foldable transverse ribs for supporting a roof
covering. The legs may
be retracted and folded against the underside of the roof frame and the ribs
folded against the
top of the rib frame, whereupon the roof frame may be folded upon itself so
that the entire
assembly occupies a relatively compact volume for shipping purposes.
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Although it has some attractive characteristics, the Scott shelter also has a
number
of drawbacks. One drawback is that it has a large number of sliding or
pivoting components,
as well as numerous secondary struts, braces, and gussets; consequently, the
shelter is somewhat
complicated and expensive to fabricate. The large number of sliding and
pivoting components
also increases the probability that one or more of the sliding mechanisms or
pivot joints will
seize up and become inoperable due to corrosion or contamination with dirt. It
may be possible
to minimize the likelihood of this particular problem by ensuring that the
shelter is inspected,
cleaned, and serviced at regular intervals, but this entails an expense which
would be a further
drawback to the invention. Yet another drawback is that erecting and
dismantling the shelter,
as well as loading and unloading it from transportation means such as a
flatbed trailer, will
typically require the use of hoisting equipment such as a mobile crane, or
numerous workers,
or both.
Other pertinent examples of prior art include the following:
U.S. Patent No. 4,630,627 (Windows et al., 1986)
- U.S. Patent No. 5,485,863 (Carter, 1996)
- U.S. Patent No. 5,490,533 (Carter, 1996)
- U.S. Patent No. 5,632,292 (Carter, 1997)
- U.S. Patent No. 5,632,293 (Carter, 1997)
- U.S. Patent No. 5,813,425 (Carter, 1998)
- Japanese Patent No. 7,166,715 (Oni shi, 1995)
All of the inventions disclosed in these patents, however, share to a greater
or lesser degree the
same drawbacks as the Scott patent.
Accordingly, there is a need for a foldable or collapsible temporary shelter
which:
(a) may be conveniently transported, such as on a flatbed road trailer;
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(b) is as light as practically possible while still providing adequate
structural strength;
(c) has a minimal number of components, especially moving components, and
therefore is comparatively simple and economical to fabricate;
(d) is relatively quick and easy to load and unload from a transporting means,
and to
erect and dismantle, without need for special tools, equipment, or power
sources,
and without need for numerous workers; and
(e) does not require extensive or frequent inspection and maintenance to
ensure
reliable operability.
Summary of the Invention
The invention comprises a portable shelter apparatus which has a stable base,
a
central ridge support and folding wing supports which together with a flexible
membrane create
a portable canopy which may be conveniently transported and erected at a work
site.
In one aspect, the present invention is a portable shelter apparatus
comprising:
(a) a primary frame comprising:
(i) a substantially horizontal ridge girder having a first end and a second
end;
(ii) two substantially vertical primary masts, each having an upper end and a
lower end, each said upper end being rigidly connected to one of the ends
of the ridge girder, and each primary mast having near its lower end a
pair of leg-engaging brackets;
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(iii) two substantially horizontal base rails each having a first end and a
second
end, each said base rail being rigidly connected at a point along its length
to one of the primary masts such that the axis of each base rail is
substantially transverse to the axis of the ridge girder; and
(iv) four leg brackets each being rigidly connected to and projecting
substantially vertically from one of said ends of the base rails, each leg
bracket having a leg restraint member;
(b) two wing frames each comprising a substantially horizontal spandrel girder
having
a first end and a second end, each wing frame further comprising two wing
frame
masts, each wing frame mast having an upper end and a lower end, each said
upper end being rigidly connected to one of the ends of said spandrel girders,
and
each said lower end being hingedly mounted to the primary frame such that each
wing frame may pivot toward or away from the primary frame;
(c) four detachable outrigger legs each having an outboard, lower end, for
resting on
the ground, and an inboard, upper end for engaging one of said leg-engaging
brackets of the primary masts after the outrigger leg has been directed
inboard
and slopingly upward toward the primary mast, positioned under and bearing
against one of said leg restraint members; and
(d) a flexible membrane extending between the primary frame and the wing
frames
so as to substantially enclose the space defined by said primary frame and
wing
frames.
In the preferred embodiment, a jacking mechanism is provided in association
with
each base rail to controllably lift and lower each base rail.
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In the preferred embodiment, each outrigger leg has a wheel rotatably mounted
to its lower, outboard end, thereby allowing the assembled shelter to be
easily moved over the
ground .
Also in the preferred embodiment, the invention includes one or more wing
frame
braces, for fixing a desired angle of outboard rotation of the wing frames
relative to the primary
frame. Each wing frame brace could take the form of an elongate strut,
removably connected
to one of the wing frame masts, and removably connected at the other end to
the corresponding
outrigger leg. Alternatively, the wing frame brace could take the form of a
length of flexible
chain or cable extending between the primary frame and one of the wing frames.
The preferred embodiment also comprises one or more wing frame stops, for
limiting the maximum extent of inboard rotation of the wing frames relative to
the primary
frame. In a particular embodiment of the invention, each wing frame stop is a
saddle attached
to one of the primary masts.
In a preferred embodiment of the invention, one of the wing frames further
comprises an eave beam outboard of and substantially parallel to the spandrel
girder of the wing
frame, said eave beam being structurally supported by a plurality of eave
braces rigidly
connected to said spandrel girder. In this particular embodiment, the membrane
extends
outboard beyond said spandrel girder so as to pass over the eave beam.
The portable shelter apparatus of the present invention may also preferably
comprise a mechanical actuator for pivoting the wing frames inward or outward
relative to the
primary frame. In one particular variation, the mechanical actuator is a
manual winch-and-cable
assembly, mounted in association with the primary mast with cables connected
to the wing frame
masts .
In another aspect of the invention, the invention comprises a portable shelter
apparatus comprising:
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(a) two generally horizontal, substantially parallel and spaced apart beams;
(b) a central ridge support extending upwardly from and spanning between the
two
horizontal beams;
(c) two wing supports, each extending upwardly from and spanning between the
two
horizontal beams, each wing support pivotably attached to the horizontal beams
on opposite sides of the central ridge support;
(d) extendible support means associated with each horizontal beam, for
supporting the
apparatus with each horizontal beam raised above the ground; and
(e) a cover which extends over the central ridge support and the two wing
supports.
Brief Description of the Drawings
Embodiments of the invention will now be described with reference to the
accompanying drawings, in which numerical references denote like parts, and in
which:
FIGURE 1 is a cross-sectional view of an embodiment of the present invention
after assembly of same, with the wing frames folded outward.
FIGURE 2 is a side elevation of the invention after assembly.
FIGURE 3 is a cross-sectional view of the invention with the wing frames
folded
inward.
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Detailed Description of the Preferred Embodiment
Referring to Figures 1, 2 and 3, the present invention, generally denoted by
reference number (~, is a portable folding shelter having a primary frame (~
comprising a
substantially horizontal ridge girder (~ spanning between, and being rigidly
connected to, the
upper ends of two vertical primary masts (2~ . Each primary mast (22) is
rigidly connected to
a substantially horizontal base rail (~ at a point along the length of the
base rail (40), which
point is preferably mid-length of the base rail (40). The axis of each base
rail (40), when
viewed in plan, will be substantially perpendicular to the axis of the ridge
girder (24).
At each end of each base rail (40) there is a leg bracket (~ rigidly connected
to
and projecting upward from the base rail (40). Each leg bracket (50) defines a
leg restraint
member (~, which bears against the outrigger legs (~.
The invention (10) also comprises two wing frames (3~, each having a
substantially horizontal spandrel girder (~ spanning between, and being
rigidly connected to,
the upper ends of two wing frame masts (~. The lower end of each wing frame
mast (32) is
pivotably mounted to the upper end of a corresponding one of the leg brackets
(50), at pivot
point (~. Therefore, and as will be readily seen from the foregoing
description and the
Figures, each wing frame (30) may be pivoted inward toward or outward away
from the primary
frame (20), with spandrel beams (34) of the wing frames (30) being at all
times substantially
parallel to the ridge girder (24) of the primary frame (20).
The primary frame (20) and the wing frames (30) may preferably be fabricated
using hollow tubing such as pipe, as indicated in the Figures. However, it is
readily possible
to fabricate these components from different types of structural material
without departing from
the scope of the invention.
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In the preferred embodiment, the invention ( 10) further comprises four
outrigger
legs (70). As illustrated in Figure 1, the outrigger legs (70) may be
positioned so each of them
engages the leg restraint member (52) of one of the leg brackets (50) and then
is removably
connected at its inboard, upper end to the corresponding primary mast (22) at
connection point
(~. In the preferred embodiment, each outrigger leg (70) also has a wheel (~
rotatably
mounted to the lower, outboard end of the outrigger leg (70).
The present invention (10) also incorporates a jacking mechanism (~ mountable
in association with each base rail (40), and most conveniently in the vicinity
of the
corresponding primary mast (22). Each jacking mechanism (80) is mounted and
configured such
that, upon actuation, it can raise the associated base frame (40), as well as
the components
connected to that base frame (40) .
The operation of the preferred embodiment is best explained with reference to
Figures 1 and 3. With the invention (10) in the folded position illustrated in
Figure 3, the
invention (10) may be loaded and transported on a flatbed trailer (T), with
the outrigger legs
(70) disengaged from the primary masts (22) and the leg restraint members
(52), to a desired
location for erection of the portable shelter. By actuation of jacking
mechanism (80) at one of
the base rails (40), that base rail (40) and the corresponding end of the
primary frame (20) and
wing frame (30) assembly can be raised above the bed of the trailer (T) so
that two of the
outrigger legs (70) may be mounted so as to engage the primary mast (20) and
leg restraint
members (52) associated with the raised end of the assembly.
In the preferred embodiment, the various components of the portable shelter
(10)
are sized and configured such that when two of the outrigger legs (70) have
been installed at one
end of the assembly as just described, the base rail (40) at that end will be
elevated above the
bed of the trailer (T) after jacking mechanism (80) has been disengaged at
that end. It will be
readily seen, therefore, that upon repeating the jacking operation and
installing the remaining
outrigger legs (70) at the other end of the assembly, the entire assembly will
be elevated above
trailer (T), which may then be conveniently withdrawn without disturbing the
portable shelter
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CA 02283111 1999-09-23
(10). It will also be readily seen that the portable shelter (10) may be
easily loaded onto trailer
(T) for transport to another location, simply by backing trailer (T) under the
portable shelter (10)
and then disassembling the portable shelter (10) by reversing the steps for
assembling it.
Alternatively, the shelter (10) may simply be lifted off of the trailer (T)
and then
raised up off the ground working the jacking mechanism (80) in order to
install the outrigger
legs (70).
The outrigger legs (70) may be replaced by a jacking mechanism (not shown) at
each end of each base rail. This alternative embodiment however does not have
the stability of
the outrigger legs (70) which is very stable because of the width of the
stance taken by the legs
(70) .
As illustrated in Figure 1, the portable shelter ( 10) has a flexible membrane
(~
which may be draped across the spandrel girders (34) and the ridge girder
(24), thereby forming
an enclosure for protection against the elements such as rain and snow. In a
preferred
embodiment, the invention also has an eave beam (~ running parallel to and
outboard of each
spandrel girder (34), with a plurality of eave braces (~ rigidly connecting
each eave beam (60)
to its corresponding spandrel girder (34). The flexible membrane (90) may be
extended
outboard over the spandrel girders (34) thus increasing the size of the area
sheltered thereby.
Also in the preferred embodiment, the present invention (10) includes brace
means
for limiting the maximum degree of outboard rotation of the wing frames (30)
relative to the
primary frame (20). In one particular embodiment, as illustrated in Figure 1,
the wing frame
brace is an elongated strut (~ removably mounted between convenient points
along the length
of a given wing mast (32) and its corresponding outrigger leg (70). This strut
(38) serves the
additional beneficial function of adding structural bracing and rigidity to
the overall assembly.
Alternatively the brace means may comprise flexible strapping or chains (not
shown) connecting
the wing frames (30) to the primary frame (20).
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Because it is also desirable to limit the maximum degree of inboard rotation
of
the wing frames (30) relative to the primary frame (20), the preferred
embodiment also
comprises one or more wing frame stops. In the particular embodiment
illustrated in Figures
1 and 3, each wing frame stop is a saddle (2~ fixedly mounted to one of the
primary masts
(20). As is readily observable from Figure 3, saddles (26) will engage the
corresponding wing
masts (32) as the wing frames (30) are folded inward toward the primary frame
(20). Gravity
will assist in preventing the wing frames (30) from being unintentionally
pivoted outboard away
from saddles (26), however additional restraint is preferred, such as by
lashing the wing frames
(30) together or to the primary frame (20) after the wing frames (30) have
been positioned
against the saddles (26).
The wing frames (30) of the present invention may be manually pivoted, but it
is highly desirable to be able to carry out all pivoting of the wing frames
(30) using some form
of mechanical assist. Accordingly, the preferred embodiment also includes a
mechanical
actuator (not shown), such as a winch-and-cable assembly, for this purpose.
The mechanical
actuator may be manually operated, which is desirable when the portable
shelter (10) is being
erected at a remote location where sources of power such as electricity are
not available. Of
course, the mechanical actuator could also be of a power-operated type if an
appropriate external
power source is available.
It will be readily seen by those skilled in the art that various modifications
of the
present invention may be devised without departing from the essential concept
of the invention,
and all such modifications and adaptations are expressly intended to be
included in the scope of
the claims appended hereto.
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