Note: Descriptions are shown in the official language in which they were submitted.
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MOBILE FOLDING STAGE
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to mobile
elevationally adjustable folding stages which fold between
a storage position and a use position.
2. Description of the Prior Art
Folding stages are used for a variety of
purposes to provide a temporary raised platform for use in
schools, hotels, convention centers and other institutions
wherein multiple use facilities require the capability of
setting up temporary stages. Such stages are made up of
individual stage structures which are positioned adjacent
each other to form extended stage surface. When not in
use, the individual stage structures may be folded to
compact dimensions and stored.
Stages which are used for forming an elevated
platform at lower heights, typically ranging between
stages having a minimum height of 16 inches and adjusting
in increments of 6 or 8 inches, up to stages having a
maximum height of 48 inches with lower height increments
of 6 or 8 inches, generally fold at their center with a
pair of stage decks having upper surfaces folding adjacent
each other in a nearly vertical storage position. The
folding linkage facilitates folding from a use position to
the storage position. Support legs may fold inward to be
substantially flush against the underside of the stage
decks. When folded, the stages are supported on rollers
or casters for moving between locations.
Although these stages have proven very useful at
providing folding lower level staging, further
improvements are possible. Such stages typically are only
able to adjust between two heights due to the complexity
of folding to a vertical position with the legs folding
proximate the underside of the stage decks as well as
unfolding with complicated bracing and maintaining the
support from the legs. The inner support legs may use a
short set and long set of legs for the two heights, with
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the short legs not foldable. In addition, the linkages
often do not maintain the decks so that they properly
align when in the use position. Furthermore, excessive
loads pressed at the hinge point in the center of the
two decks when in the unfolded position may cause the
outer ends of the stage to lift. Furthermore, when the
stage is folded in a substantially vertical position,
the tops of the decks may come into contact with one
another, having the potential to pinch users' hands or
fingers.
U.S. Patent No. 4,074,636 shows an .
elevationally adjustable folding stage. The folding
stage has legs which adapt to different floor
elevations. The folding stage includes stage panels
which fold from a horizontal planar position to a
vertical position wherein the panels face one another.
The inner support legs are folded under for one height
and are extended for a second height. The stage does
not provide for guidance of the legs and linkage during
folding and unfolding and for engagement of the floor to
ease folding.
U.S. Patent No. 4,779,542 shows fold and roll
staging. The staging includes panels which fold from a
use position wherein the panels are substantially
horizontal to a folded position wherein the stage panels
are substantially vertical and face one another. The
stage does not provide for elevational adjustment or
properly guiding adjustable legs during folding and
unfolding of the linkage.
It can be appreciated that a new and improved
folding s age is needed which folds from a use position
to a folded position with the tops of the decks
substantially facing one another. Furthermore, it can
be appreciated that a linkage is needed which controls
the motion of the decks and provides proper alignment.
Furthermore, the linkage should resist accidental
folding and provides sufficient support for the legs so
that greater loads may be applied. Moreover, the
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linkage should provide for legs which can extend to
three different heights rather than only two. The
present invention addresses these as well as other
problems related to folding stages.
c~m~.~.anav OF THE INVENTT_ON
The present invention is directed to a mobile
folding stage and in particular to a mobile folding
elevationally adjustable stage. According to the
present invention, a mobile folding stage has a pair of
stage decks which are joined along a center axis to form
a stage surface. The stage folds from a use position to
a folded position wherein the stage decks are at a
substantially vertical position with the upper surfaces
of the decks facing one another. The stage includes a
folding framework connected to a caster frame mounted on
rollers or casters for moving the stage from location to
location.
The stage includes a folding linkage which
folds a framework and the stage decks from their
horizontal use position to the nearly vertically folded
storage position.
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In addition, the linkage connects to outer support legs
which are folded between the use and non-use positions
with actuating of the linkage. Inner legs fold to an
extended position to provide additional support and to act
as a pivot for the stage when folding between the folded
position and the use position. Both the inner and outer
legs are elevationally adjustable for changing the height
of the stage. Each inner leg includes a foot having an
angled portion which supports and guides the inner leg and
the stage during the folding and unfolding operations.
The inner legs also have guide brackets which engage an
angled portion of the caster frame to direct the legs to
their fully extended use positions. When the stage is
folded, the inner and outer legs both lie substantially
flat against the bottom of the stage decks.
The actuating linkage for folding includes a
main mounting plate having raised end portions and a
raised center portion. A substantially U-shaped link
mounts from the raised center portion of the linkage
mounting plate to the frame while a shortened link mounts
from the end portion of the mounting plate to the frame.
An extended link mounts from the linkage mounting plate to
the outer leg to actuate folding the leg along with the
folding of the stage. The substantially U-shaped link has
a slight bevel at the top of the cross portion which
receives the edge of the deck when in the folded position
to angle the decks slightly toward one another. This
resists accidental unfolding, but keeps a space between
the upper edges of the decks so that users' hands and
fingers cannot get pinched between the decks. Alignment
pins on the edge of the decks also align with the
corresponding bores on the opposite deck to guide
alignment when in the use position.
The stage decks may be either permanently
mounted or may be interchangeable or reversible. A spring
engages a bore in one corner of the deck to slightly raise
the corner of the decks when they are being removed or
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reversed. This provides for gripping one corner of the
deck and easy reversal of the decks.
These and various other advantages and features
of novelty which characterize the invention are pointed
out with particularity in the claims annexed hereto and
forming a part hereof. However, for a better
understanding of the invention, its advantages, and the
objects obtained by its use, reference should be made to
the drawings which form a further part hereof, and to the
accompanying descriptive matter, in which there is
illustrated and described a preferred embodiment of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings, wherein like
reference numerals and letter indicate corresponding
elements throughout the several views:
Figure 1 shows a perspective view of a mobile
folding stage in the folded position, according to the
principles of the present invention;
Figure 2 shows a perspective view of the stage
shown in Figure 1 in the unfolded position with stairs
attached;
Figure 3 shows a perspective view of the stage
shown in Figure 1 partially unfolded;
Figure 4 shows a perspective view of the stage
shown in Figure 1 with the stage unfolded so that the
inner legs are engaging the ground;
Figure 5 shows a perspective view of the stage
shown in Figure 1 folded so that the stage is pivoting on
its inner legs;
Figure 6 shows a perspective view of the stage
shown in Figure 1 in a nearly unfolded position;
Figure 7 shows a perspective view of the stage
shown in Figure 1 with the stage unfolded;
Figure 8 shows a perspective view of the stage
shown in Figure 7 in a partially folded position;
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Figure 9 shows a perspective view of the stage
shown in Figure 7 in a nearly folded position;
Figure 10 shows a side elevational view of the
folding linkage for the stage shown in Figure 1 in the
5 folded position;
Figure 11 shows a side elevational view of the
folding linkage shown in Figure 10 in the unfolded
position;
Figure 12 shows an internal perspective view of
the inner support legs and linkage;
Figure 13 shows a perspective view of the inner
leg and guide bracket engaging the caster frame to direct
the leg to an unfolded position;
Figure 14 shows a side elevational view of the
outer leg and linkage for the stage shown in Figure 1;
Figure 15 shows a perspective view of a mounting
spring for the deck connectors for the stage shown in
Figure 1; and,
Figure 16 shows a perspective view of a deck
being raised at one corner by the spring shown in Figure
15.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings and in particular
to Figures 1 and 2, there is shown a mobile folding stage,
generally designated 20. The stage 20 includes a folding
frame 22 supporting a pair of decks 24. As shown in
Figure 1, in a folded storage position, the decks 24 are
positioned just past vertical with upper faces of the
decks 24 opposing one another. As shown in Figure 2, when
the stage 20 is unfolded, the decks 24 form an extended
planar stage surface. The stage 20 is supported on inner
legs 32 and outer legs 34 which extend to a support
position as shown in Figure 2. When the stage 20 is
folded, as shown in Figure 1, the inner legs 32 and outer
legs 34 fold to a position lying substantially flat
against the lower surfaces of the stage decks 24.
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As shown in Figure 1, the stage 20 is rolled on
casters or rollers 26 which are mounted on a caster frame
38. The caster frame 38 has a center cross member running
substantially along the folding axis of the stage 20 and
end members extending substantially perpendicular to the
center axial member. End portions 40 of the perpendicular
members are angled slightly inward from the edge of the
stage to aid in alignment of the inner legs 32 during
unfolding, as explained hereinafter.
The decks 24 may be permanently attached to the
folding frame 22 or may be reversible or removable to
provide a variety of deck surfaces for different uses. In
addition, the decks 24 and frame 22 are configured with
attachment members 90, as shown most clearly in Figures 14
and 15, which provide for attaching to other similar
stages or for decks 24 being supported between stages 20
for forming an expanded extended stage surface with fewer
stages. Curtains or other decorative accessories may be
hung from a mounting strip 92 along the edge of the decks
24. In addition, as shown in Figure 2, removable stairs
36 may be mounted to an edge of the stage 20 to provide
easier access to the stage. In addition, guard rails and
other safety equipment may also be mounted to provide
greater flexibility for configuring the stage 20.
As shown most clearly in Figures 1, 3 and 14;
the outer legs 34 include a telescoping leg portion 56 and
outer leg member 58. The telescoping member 56 includes
height adjustment holes 62 which engage a spring loaded
pin 68 having a handle attached thereto. A pin 68 inserts
into the hole 62 to maintain the leg 34 at a desired
height. In the preferred embodiment, each of the outer
support legs 34 has three different adjustment holes 62
for maintaining the stage 20 at one of three different
heights. As shown in Figure 14, the legs 34 include
spacers 60 having a substantially rectangular
configuration extending between the outer leg member 58
and the telescoping member 56 to provide easy sliding
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between the members 56 and 58 and to provide solid support
with little relative movement between the outer member 58
and telescoping inner member 56. As shown more clearly in
Figures 1 and 3, each of the outer legs 34 includes a
strut 64 which connects to the folding linkage 30, as
explained hereinafter. A cross member 42 extends between
the pair of the outer legs 34 on the underside of each
deck 24. In addition, as shown in Figure 14, the legs
pivot on a mounting plate 126 which provides for direct
support to the frame 22 by the framework on the outer legs
34 when in the use position.
Referring to Figure 14, the inner support legs
32 include an outer member 46 and an inner telescoping
member 44 for varying the height of the inner legs 32.
The telescoping member 44 includes height adjustment holes
50 which receive a spring loaded pin 66 which inserts into
the height adjustment holes 50 to maintain the telescoping
member 44 at a desired height. Rectangular spacers 48
insert between the outer member 46 and the telescoping
member 44 for providing easy sliding between the members
while also providing increased support and stability to
the inner legs 32. The inner legs 32 pivot about a
bracket 124 mounting to the frame 22. When in the
extended position, the inner legs 32 carry the load
directly from the frame 22 through the legs 32.
Since the inner legs 32 support the decks 24 and
the entire stage 20 during folding and unfolding, the
inner legs 32 include feet 70 which are configured for
aiding and supporting the legs 32 and stage 20 during
folding and unfolding, as explained hereinafter. Each of
the feet 70 includes a flat bottom portion 72 and an inner
angled portion 74 which extends at a substantially 45°
angle upward from the bottom portion 72 in the preferred
embodiment and then extends upward at a second 45° bend.
In addition, the feet 70 include an angled outer portion
76 extending away from the folding axis of the stage 20.
In the preferred embodiment, the outer portion 76 is
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angled at a 45° angle from the bottom portion 72. The
configuration of the feet 70 provides for pivoting while
also maintaining an increased contact area between the
feet 70 and the ground. In addition, the feet 70 act as
skids allowing for some sliding to take place during
folding and unfolding the stage 20.
As shown most clearly in Figures 10 and 11,
the folding linkage 30 provides for folding of the stage
decks 24 from a flat use position to a folded storage
position. The linkage 30 includes a main linkage
mounting plate 100 at each end of the decks which
attaches to end members of the cater frame 38. The
linkage mounting plate 100 includes raised end portions
102 which extend vertically upward at each end of the
mounting plate 100. A raised center portion 104 is
positioned intermediate the end portions 102. Therefor,
each end portion 102 forms a channel with the center
portion 104 which supports ends of the decks 24 when in
the folded position. The linkage 30 further includes a
substantially horseshoe shaped link 108 which mounts
from a pivot point 128 at the center portion 104 of the
main plate 100. The U-shaped link 108 includes a first
side portion 110 and a second side portion 112 connected
by an angled bottom portion 114. The bottom portion 114
includes a beveled upper surface which receives and
supports she edge of the deck 24 when the stage 20 is
folded. The bevel of the bottom portion 114 tilts the
stage deck 24 slightly past vertical toward the center
axis to aid in resisting accidental unfolding of the
stage 20 when in the folded position. The second side
portion lit mounts to the mounting bracket 124 on the
frame 22 at a pivot point. In addition, a short link
106 mounts to the mounting bracket 124 at pivot point
122 and also to the end portion 102 of the main plate at
a pivot point 118. An extended link 116 which jogs
toward the frame to lie. substantially flat against the
bottom of the deck 124 in the folded position extends to
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the strut 64 on the outer leg 34 as shown in Figure 14.
The
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extended link 116 mounts at a pivot point 120 at an outer
position of the end portion 102.
The decks 24 include pins 140 engaging
corresponding bores along the inner edges of the decks 24
to guide and align the decks along the center axis.
It can be appreciated that with this
arrangement, the linkage 30 folds the stage deck 24 and
outer legs 34 from a folded position as shown in Figure 1
to a use position, as shown in Figure 2, and then back to
a folded position. The linkage 30 provides for greater
stability so that when in the use position, a load placed
at the direct center of the stage 20 cannot cause the
decks 24 to fold up. In addition, the linkage provides
for slightly raising the inner edges of the decks 24 when
folding the stage 20 so that the decks 24 have room to
fold and unfold without binding upon one another or the
linkage 30. Furthermore, the linkage 30 is designed so
that the stage decks 24 are in a just past vertical
position when folded, so that they resist accidental
unfolding, yet are spaced slightly apart at their top edge
so that operators' and users' hands will not be pinched
between the tops of the decks 24. Furthermore, the
linkage 30 also folds the outer legs 34 from a folded
position to an extended position wherein they are directly
supporting the stage frame 22. The linkage 30 actuates
the outer legs 34 so that the outer legs 34 are
substantially flat against the bottom of the decks 24 when
folded and so that the extended link 116 is also
substantially flat against the deck 24 when folded with
only end portions extending to engage the linkage 30.
The operation of unfolding the stage is shown in
Figures 1 and 3-7. Referring to Figure 1, when the stage
20 is folded, the decks 24 are substantially vertical and
extending slightly towards one another. The legs 32 and
34 are typically in a folded position stored flat against
the bottom of the decks 24. The stage 20 is supported on
the casters 26 and may be easily rolled to a desired
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location. To begin unfolding, the outer legs 34 are
pulled outward away from the bottoms of the decks 24, as
shown in Figure 3. The linkage 30 passes through a toggle
point, so that the legs 34 slightly 'snap" outward with
5 the linkage 30 and the extended links 116 also move
slightly outward from the bottoms of the decks 24. In
addition, the inner legs 32 are folded outward to their
fully extended position, as also shown in Figure 3. As
the stage continues to unfold, with the decks 24 lowering,
10 the feet 70 of the inner legs 32 engage the floor. At the
position shown in Figure 4, the inner portion 74 has its
angled surface substantially flat against the floor. At
the point wherein the stages are supported on the inner
portion 74 of the foot 70 the outer legs 34 become
slightly more extended. As the unfolding continues and
the decks 24 are lowered further, the stage 20 pivots
about the bend between the bottom portion 72 and the
angled inner portion 74 of the feet 70. At this point,
the caster frame 38 and the casters 26 are lifted upward
so that the casters 26 are no longer engaging the floor
and the stage 20 is supported entirely on the inner legs
32. The linkage 30 also extends the outer legs 34
slightly more, as shown in Figure 5. The inner edges of
the decks 24 are also moved slightly closer to facing one
another.
As shown in Figure 6, as the unfolding
continues, the inner legs 32 are substantially supported
on the bottom portion 72 of the feet 70. The outer legs
34 are almost entirely perpendicular to the stage decks 24
and the inner edges of the decks 24 substantially face one
another. With further folding, the edges of the decks 24
entirely face one another and engage with alignment pins
140 engaging opposed complimentary bores 142 along the
inner edges of the decks 24, as shown in Figure 11. When
the stage is entirely unfolded, as shown in Figure 7, the
load is supported directly through the inner and outer
legs 32 and 34 for increased stability and support.
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To fold the stage 20, the steps are
substantially reversed with some slight variations. As
shown in Figure 8, as the stage decks 24 are lifted
towards one another, the stage 20 will be supported on the
feet 70 and substantially on the inner portions of the
feet 74. One deck 24 will typically be lowered before the
other so that at least one set of the casters 26 engages
the ground. At this point, the second deck 24 will be
folded so that both sets of casters 26 will engage the
ground. One deck 24 is lifted upward, as shown in Figure
9, to the substantially folded position. Then the second
deck 24 can be folded upwards so that both decks are
substantially folded, as shown in Figure 3. The legs 32
and 34 are then refolded to the original storage position,
shown in Figure 1.
Referring to Figure 12, when the stage is
unfolded, the inner leg 32 includes a support member 54
which substantially rests against the perpendicular end
portion of the caster frame 38. This provides increased
stability and directs the load substantially through the
leg 32. In addition, on an inner portion of the inner
legs 32 there is mounted a guide bracket 52. As shown in
Figure 13, the guide bracket has a curved profile which
may engage the bent end portions 40 of the caster frame 38
if the inner leg 32 is not fully unfolded or is misaligned
while unfolding the stage 20. If the inner leg 32 is not
entirely moved from its folded storage position and is
still slightly folded,,as the stage 20 is unfolded, the
guide bracket 52 will engage the angled end portions of
the caster frame 40 and move the leg 32 outward toward its
proper support position for supporting the stage 20. It
can be appreciated that as the stage 20 is unfolded more,
the guide bracket 52 pushes the leg 32 outward along the
angled portion 40 so that it is forced into its extended
support position perpendicular to the deck 24. In this
manner, the guide bracket 52 and the angled end portion 40
of the caster frame 38 guide and align the inner legs 32.
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The attachment system for supporting the decks
24 to the frame 22 is shown in Figures 15 and 16. The
decks 24 include orifices along their lower portion which
are hidden beneath a captive nut 82, as shown most clearly
in Figure 14. The captive nut 82 connects to a bolt 86
attaching through the orifices in the bottom of the deck
24. However, at one of the corners, a spring 80 will be
placed to help raise the decks when removing or flipping
the deck members 24. The spring 80 helps to raise one
corner of the decks 24, as shown in Figure 16. When the
bolt 86 is loosened, the spring 80 forces the one corner
of the deck 24 upward so that it may be grabbed by the
fingers, allowing easier lifting of the remaining corners
of the deck 24. In this manner, the decks 24 may be more
easily removed and with less chance of fingers being
pinched while trying to lift the decks 24.
It is to be understood, however, that even
though numerous characteristics and advantages of the
present invention have been set forth in the foregoing
description, together with details of the structure and
function of the invention, the disclosure is illustrative
only, and changes may be made in detail, especially in
matters of shape, size and arrangement of parts within the
principles of the invention to the full extent indicated
by the broad general meaning of the terms in which the
appended claims are expressed.
