Note: Descriptions are shown in the official language in which they were submitted.
~2~iS~27
This invention relates to a portable bleacher, and more
particularly to a portable bleacher having a foldable seating
system.
Portable bleachers and folding grandstands or seating
systems are known in the art, as illustrated in the following
patents:
2,05~,960 Adamson Sep. 22, 1936
2,611,422 Roney Sep. 23, 1952
~,6~3,914 Mackintosh Dec. 29, 1953
2,985,924 Burke May 30, 1961
3,752,531 Jones Aug. 14, 1973
3,914,909 McNeal Oct. 28, 1975
German 804,129 Jul. 8, 1949
The Roney and Burke patents disclose bleachers or grand-
stands in which the seat elements are disassembled.
The Adamson and Mac~intosh patents disclose folding seat
systems which are pivotally connected to a fixed wall
support.
~a The Jones and McNeal patents and the German patent
disclose portable type bleachers in which the upper stringer
member or seat assembly is fixed to the mobile frame and the
lower stringer member or seat assembly is connected by a
hinge to the frame so that the lower seat assembly can be
rotated upwardly and inverted on top of the upper seat
assembly for travel on a mobile frame.
None of the above patents disclose a portable bleacher
including a mobile frame upon which an upper seat assembly
and a lower seat assembly are pivotally mounted to each other
and to the mobile frame for swinging movement of both seat
assemblies between an extended operative position and a
J~
--1--
~6~
folded inoperative position for travel.
It is therefore an object of this invention to provide
a portable bleacher having a foldable and extensible seat system
mounted upon a mobile frame in which a single operator can con-
trol the folding and unfolding movement of the seat sections
with a minimum of effort and time.
The invention provides a portable bleacher comprising:
(a) an elongated mobile frame having opposed first
and second side edges,
lQ lb) an upper elongated stringer member carrying a
plurality of upper seat members spaced along said upper stringer
member, and having outer and inner end portions and an inter-
mediate portion,
(c) upper journal means mounting said intermediate
portion in an elevated position on said mobile frame for swing-
ing movement of said upper stringer member about a longitudinal
swing axis transverse of said upper stringer member,
(d) a lower elongated stringer member carrying a
plurality of lower seat members spaced along said lower stringer
member, and having an upper end portion and an intermediate
portion,
(e) hinge means connecting said inner end portion
and said upper end portlon for swinging movement about a hinge
axis parallel to said swing axis,
(f) an elongated link arm having first and second
end portions,
(g) lower journal means mounting said first end
'~ ~ portion of said link arm in a position on said mobile frame
below said swing axis and between sald swing axis and said
3~ second side of said mobile frame for swinging movement of said
link arm about a journal axis parallel to said swing axis,:
(h) pin means pivotally connecting said second end
--2--
~ Ei5~7
portion of said link arm to the intermediate portion of said
lower stringer member for pivotal movement of said lower
stringer member relative to said link arm about a pivotal axis
parallel to said swing axis,
(i) whereby said upper and lower stringer members
a--e adapted to swing between an operative position in which
said stringer members are in longitudinal alignment declining
toward said second edge, and an inoperative position in which
said hinge means is above both said journal means.
la Thus two seat sections are hinged together and pivot-
ally mounted upon a mobile frame in such a way that they can
be easily extended to an operative inclined position to provide
a strong and safe seat assembly for a multitude of spectators,
and when not in use, folded to a collapsed or stowed position
occupying a minimum of space upon the mobile frame so that the
portable bleacher, in stowed position, complies with the exist-
ing governmental requirements for over-the-road travel. Pre-
ferably the folding seat sections can be latched in the extended
operative position or the collapsed folded position with the
same latch mechanism. The structural members in the mobile
frame should not only safely support the seat assembly and the
seated spectators, but also adequately sustain the dead load
stresses encountered in over-the-road movement.
The lower seat section may swing between its extended
operative seating position and its contracted storage position
over the mobile frame with adequate clearance between the lower
seat section and the mobile frame. The foldable seat sections
may incorporate folding side rail sections linked to the seat
~ sections for movement therewith between extended and collapsed
3~ ~ positions, and without the requirements of any additional bolts,
pins or other coupling devices.
In the drawings which illustrate embodiments of the
-3-~
invention,
Figure 1 is an end elevational view of the portable
bleacher with the seat assembly in extended operative position;
Figure 2 is a view similar to Figure 1 in which the
seat assembly has been folded to an intermediate position;
Figure 3 is a view similar to Figure 1 in which the
seat assembly has been folded to its fully collapsed inoperative
position for travel;
Figure 4 is a reduced section taken along the line
4 of Figure l;
Figure 5 is an enlarged fragmentary rear perspective
view of a rear post mount for the rail assembly, taken generally
along the line 5-5 of Figure 1;
Figure 6 is an enlarged fragmentary perspective view
o the upper portion of the end rails in their position dis-
closed in Figure 2; and
Figure 7 is an enlarged fragmentary perspective view
o~ t~le locking mechanism.
Referring now to the drawings in more details, the
portable bleacher 2 made in accordance with this invention
includes an elongated mobile frame 1, which may be made up of
a plurality of longitudinal and transverse frame members, such
as the tubular frame members 3. The mobile frame 1 includes a
pair of longitudinal side frame members 4 and 6. The frame
member 1 is supported upon running gear, such as
-3a-
iS~2~
the ~heels W. The mobile frame 1 may be provided at one end
with a tongue T (Figure 4) to permit it to be connected to a
tractor vehicle, not shown, such as an automobile, truck, van
or tractor, so that the mobile frame 1 can be moved in a
direction parallel to its len~th or longitudinal axis.
Fixed rigidly to the middle portion of the mobile frame
l, and extending longitudinally thereof in an upright
position, is an elongated truss member 8 having elongated
upper bars or chords 35 and elongated lower bars or chords 36
la connected by crossed truss members or struts 37. The design
of the truss member 8 is such that both chords 35 an~ 36 will
resist either compression or tensile stresses imparted to the
~rame 1 by the bleacher 2 in either its operative seating
position or mode (Figure 1), or its inoperative stowed
position or mode (Figure 3).
The mobile frame 1 supports a plurality of upright
stringer standards 41 spaced longitudinally of the frame 1,
and a plurality of shorter support posts 17, also spaced
longitudinally of the frame 1 and in a vertical longitudinal
~a plane parallel to the vertical plane containing the stringer
standards 41. Each standard 41 is substantially transversely
aligned with a corresponding support post 17, and preferably
connected by a transverse cross bar 42, for stability. As
best illustrated in Figure 1, the elongated truss 8 is also
supported in fixed position against the support posts 17, the
cross bars 42 and the main frame 1~
Pivotally mounted to the upper portion of each upright
standard 41 by a journal bracket 43 lncluding a journal pin
13, is a corresponding elongated upper stringer member or
3~ beam 10. A plurality of the stringer members 10 are spaced
longitudinally of the frame 1.
Each of the upper stringer members 10 supports a
plurality of seat posts 44 and foot frame bars 45, which in
~2~ 7
turn support the respective elongated seat members 5 and foot
boards 46, which form -the upper or rear potion of -the seat
assembly 40.
Each journal pin 13 is connected to an intermediate
portion of a corresponding upper stringer member 10, such as
to one of the foot frame bars 45 fixed to the upper stringer
member 10, as illustrated in Figure 1. The upright standard
~1 is spaced from the rear side member 4, so that the upper
rear end portion of the upper stringer member 10 is elevated
l~ above the mobile frame 1 and projects slightly behind the
rear side member 4.
The lower or front end portion of each upper stringer
men~er 10 is connected by a hinge member 1~ to a corres-
ponding lower stringer member 11 of substantially the same
construction, size and shape as the upper stringer member 10.
The hinge member 12, permits the upper and lower stringer
members 10 and 11 to pivot or swing in a vertical plane
Lalative to each other, so that the hinge member 12 moves
upward from its operative position disclosed in Figure 1.
The hinge member 12 limits any swinging movement of the
s~ringer mambers 10 and 11 below their longitudinally aligned
operative position disclosed in Figure 1~
The front or lower end portion of the lower stringer
member 11 is provided with a foot pad or foot flange 18
adapted to engage the ground surface G supporting the wheels
W of the mobile frame 1, when the seat assembly 40 is in its
extended operative position, as disclosed in Figure 1. Pref-
erably, the load of the bleacher 2 upon the wheels W is re-
lieved by conventional leveling jacks J (Figure 4).
The lower stringer member 11 also supports a plurality
of seat posts 44, foot frame bars 45, seat members ~ and foot
boards 46, in the same manner as the upper stringer member
10, to define the lower seat structure of the seat assembly
~5~L27
~o .
Pivotally connected to the upper end of each support
post 17 by a pivot pin 16 is an elonga-ted link bar 14. The
lower end o~ the link bar 14 is pivotally connected by pin 15
to a bracket 47 depending from the upper intermediate portion
of the lo~er stringer member 11, as best disclosed in Figure
1.
Connected to the rear end of the upper stringer member 10
by connector 49 is an elongated cable 50 which is trained
about a lowe`r pulley 51 and an upper pulley 52 and wound at
its other end about a drum 53 of an electric winch 9. The
electric winch 9 may be energized by any appropriate control
means but preferably a remote control means, not shown.
Moreover, other types of winding mechanisms could be used,
such as a hand winch, not shown.
By driving the winch 9 to rotate the drum 53 in one
direction stringer members 10 and 11 may be swung through an
intermediate position, such as that disclosed in Figure 2, to
a compact inoperative stowed position as disclosed in Figure
3. Reversal of the winch 9 will reverse the swinging
movement to restore stringer members 10 and 11 to their
aligned operative position disclosed in Figure 1.
Preferably, the top of each support post 17 is provided
with a cap or seat Elange 80 which is vertically aligned
with, and at the proper elevation below, the upper stringer
member 10, to cause the upper stringer member to seat or rest
upon the seat flange 80, when the stringer member 10 is in
its extended operative position as discloséd in Figure 1.
The seat flange 80 is also preferably inclined at the same
angle as the extended upper stringer member 10. In this
manner, the support posts 17 bear a substantial portion of
the load sustained by the~bleacher 2 in its operative posi-
tion.
~2~5'~2~
The st.ringer standard 41 is sligh-tly offset from the
transverse align~ent o~ the upper stringer member 10 and the
seat flange 80 to permit free swinging movement of the
stringer member relative to the standard ~1.
The portable bleacher 2 may include an automatically
collapsible and e~tensible side rail assembly 48. The side
rail assembly 48 includes an upright rail standard 23 fixed
to the base frame 1 and projecting upwardly above the seats
5. Fixed to the rail standard 23 at vertically spaced inter-
l~ vals are a plurality of pivot brackets or ears 25 pivotally
connected by pins 26 to the front ends of upper side rails 21
and 22. The rear end of each oE the side rails 21 and 22 is
pivotally connected by a pin 54 to a corresponding end of a
back rail 74 fixed to the rear rail post 19.
Fixed to the lower end of each rail post 19 is a lockingsleeve 55 open in the front to receive a lower rail post 20
rigidly fixed to the rear end of the upper stringer member
19. The upper end of the lower post 20 is pivotally
~onnected to the sleeve 55 by means of the transverse hinge
pin 24. Thus, the lower post 20 is permitted to swing for-
wardly relative to the corresponding rear rail post 19, as
illustrated in Figure 2. However, rearward pivotal movement
of the lower post 20 relative to the rear rail post 19 is
limited by the sleeve 55 to a longitudinally aligned position
with the rail post 19, as best illustrated in Figure 5.
Journaled to the front ends of the pivot brackets 25 by
pins 56 are a plurality of vertically spaced front or lower
side rails 57. The front ends of the side rails 57 are
respectively connected by pivot pins 58 to pivot brackets 59
fixed on the front rail post 60. The lower end of the front
rail post 60 is adapted to fit within a sleeve member 61
forming the upper portion of a post 62 fixed to project
upwardly from the lower stringsr member 11. The lower end of
~i;5~:7
the front rail post 60 is also provided with a latch tongue
63 havin~ a hole therethrough adapted to be aligned ~7ith a
corresponding hole in a fixed latch tongue 6~ mounted on the
front portion of the mobile frame 1. I~hus, when the front
rail post 60 is removed from the sleeve 61, the latch tongues
63 and 64 may be connected by a pin 65, as illustrated in
Figure 3 to secure the rails 57 and Front posts 60 in a fixed
position relative to the mobile frame 1, particularly when
the seat assembly 40 is in its stowed or compact position.
ld To permit the rails 22 to swing relative to the rail
standard 23, each rail 22 is provided with a telescoping
section ~7, as best shown in Figure 6. Thus, even though the
top rail 21 is rigid and of fixed length, the telescoping
section 27 within the lower rails 22 permit each successive
lower rail 2~ to extend in increasing lengths, as the rails
~1 and 22 swing downwardly about their pivot pins 26, as best
illustrated in Figures 2 and 3.
As shown in Figure 1, each rear rail post 19 is
initially in a substantially vertical alignment with the
lower post 20. As the rails Z1 and 22 swing downward, the
hin~e joint 24 swings outwardly, and then inwardly. In
Figure 3, the upper post 19 is again restored to its substan-
tially vertical position, while the lower post 20 extends
inwardly and even upwardly to follow the movement of the
upper stringer member 10.
Thus, the side rail assembly 48 is designed to move in
response to the movement of the upper stringer member 10, as
this member is moved by the operation of the winch 9. Thus,
the entire seat assembly 40 and the rear portion o~ the side
rail assembly 48 may be expanded and collapsed simultaneous-
ly.
The front or Iower rails 57 of the side rail assembly 48
are extended and contracted manually by assembling and sepa-
--8--
~i5~
rating the front rail post 60 from the lower post 62l as pre-
viously described.
A locking mechanism 66 is provided for locking the seat
assembly ~0 in its extended position as illustrated in Figure
1, and also in its stowed or contracted position as disclosed
in Figure 3. The locking mechanism 66 inclwdes an elongated,
longitudinally extending, rotary shaft 29, which may extend
the length of the mobile frame 1. The rotary shaft 29 is
rotatably mounted in a plurality of longitudina].ly spaced
la journal plates 32 fixed to the mobile frame 1. Longitudi
nally spaced and fixed along the rotary shaft 29 are a
plurality of double-acting hold-down lugs 30.
Depending from the lower end portion of the link bar 14
is a latch flange 33 adapted to be engaged by the hold-down
lug 30 when the lower stringer member 11 is in its operative
extended position, and when the hold-down lug 30 has been
rotated clockwise to its extreme forward position in Figure
1.
Mounted on the frame 1 behind and in the rotary path of
the lug 30 is a foot stop 28. The foot stop 28 has a forward
face or flange inclined rearwardly and adapted to receive in
flush engagement the foot pad 18, when the lower stringer
member 11 is in its contracted stowed position, as disclosed
in Figure 3. When the hold-down lug 30 is rotated counter-
clockwise in Figure 3 to its extreme rearward position, the
lug 30 engages the foot pad and holds it against the foot
stop 28, as illustrated in phantom in Figure 7, to prevent
the lower stringer member 11 from moving, and thereby secure
the seat assemhly 40 in its stowed position.
A lever handle 31 is fixed to each end of the rotary
shaft 29 to permit rotation of the hold-down lug 30 to either
its forward or rearward locking positions, previously
describedO The handle 31 may be provided with a pin hole for
~2~
registry with corresponding pin holes in upstanding fixed
posts 68 and 69 by a registering pin 70, to secure the handle
31 and consequen~ly the shaft 29 and the hold-down lug 30 in
their respective locked positions, as disclosed in Figures 1
and 3. The pin 70 might be replaced by a hasp of a padlock,
.if desired to prevent unauthorized tampering with the locking
mechanism 66.
It has been found in the design of the seat assembly 40
that the pivot pin 16 must be located closer to an imaginary
l~ line L extending through the pivot axis of hinge member 12,
and parallel to the upper stringer member 10, than the
distance between the pivot pin 15 and the imaginary line L.
~uch construction permits the foot pad 18 to be immediately
~levated, rather than being depressed into the ground G, when
winch 9 commences its operation to swing the stringer members
10 and 11 from~their extended position of Figure 1 upward to
their contracted position of Figure 3. Experiments with the
stringer members 10 and 11 when the distance between the
upper pivot pin 16 and the line L is greater than the
distance between the lower pivot pin 15 and the line L,
resulted in the foot pad 18 digging into the ground G before
its elevational movement commenced.
As the winch 9 is operated to wind in the cable 50, the
upper stringer member 10 rotates in a counter-clockwise
direction about the upper pivot pin 13, as illustrated in
Figure 2, while the lower stringer membe.r 11 is move upward
with only slight rotation. Of course, the lower stringer
member 11 is rotating downward about the hinge member 12, so
that the two stringer members 10 and 11 continue to swing
3~ toward each other until they arrive at their contracted
stowed position, illustrated in Figure 3, in substantially an
inverted V-shaped configuration directly above the mobile
frame 1 and completely contained between the side edges of
--10--
~S~7
the ~rame 1.
As the stringer members 10 and 11 move upward, the lin~
bar 14 pivots upward about its fixed rear pivot pin 16, and
tends to thrust the lower stringer member 11 forward away
~rom the frame member 1, so that the lower stringer member 11
will always clear the mobile frame 1 until the foot pad 18 is
pulled inwardly over the mobile frame 1 and against the foot
s~op 28, as illustrated in Figure 3.
~ s previously described, as the stringer members 10 and
l~ 11 are swinging from their extended to their contracted
position, the lower rear post 20 fixed to the rear of the
upper stringer member 10 is rotating with the upper stringer
member 10 and pulling downward the rear rail post 19 with the
rear side rails 12 and 22 and the back rails 74, which in
turn swing about their pivot pins 25 and the rail standard
~3, to move through the positions disclosed in Figures l, 2
and 3.
As illustrated in Figure 3, the rear rail post 19, in
its stowed position is not only lowered but pulled inward to
a position adjacent the wheels W, or against the outer margin
o~ the wheel fenders 72.
It will be understood that a side rail assembly 48 is
also provided at the opposite end of the seat assembly 40,
and the rear rail posts 19 are connected by the longitudi-
nally extending, vertically spaced, horizontal back rails 74.
It will also be understood that the stringer members 10
and 11, as well as their supporting membexs are duplicated
and spaced longitudinally along and above the mobile frame 1,
as illustrated by the longitudinally spaced support posts 17
in Figure 4.
Thus, in order to convert the portable bleacher 2 from a
stationary extended position to a stowed position, and vice
versaj it is only necessary for a single operator to manipu-
j;5~7
late the latch handle 31 to remove the lug 30 from a latchedposition, to disconnect the front rail post 60 from its
sleeve 61 and lock the tongues 63 and 64 by means of the pin
65, (Figure 3), and to op~rate the electrical winch 53, in
order to swing the various pivotal elements of the seat
assembly 40 and the side rail assembly 4~ from one extreme
position to another, that is from the extended to the
contracted position, or vice versa.
The design of the portable bleacher 2 is such that all
o~ the elements are in their stowed position as illustrated
in Figure 3, the height, width and length of the seat
assembly 40 is entirely within the federal highway limita-
tions to permit portage of the bleacher over the roads and
highways without special permit.
As best seen in Figure 1, the design of the portable
blaacher 2 permits at least 9 rows of seàts 5, and the length
of the seats is limited only by the allowed length of a
trailer vehicle.
The rate of incline of the stringer members 10 and 11 in
~a their aligned extended position is approximately 35 degrees
to the ground G.
