Note: Descriptions are shown in the official language in which they were submitted.
1~38~78
BACKGROUND OF THE INVENTION
The present invention relates to an apparatus and a method
for constructing cylindrical storage tanks from coiled strip steel.
Large diameter cylindrical storage tanks are constructed at
chemical plants, pulp mills, municipal water or oil related plants for
the storage of products. Conventionally these tanks are fabricated on
site from a large number of relatively small pre-formed curved heavy
gauge steel plates. The steel plates are slung and placed by a crane
or other lifting device and are then tediously hand fitted, tack-welded
and finally welded in place. Scaffolding must be erected around the
tank to allow the workers to work at the height of the tank under
construction. This method of tank construction is hazardous, due to the
heights involved, time consuming, due to the tedious hand-fitting in-
volved9 and expensive, due to the need for accurately pre-formed,
curved steel plates and a large work force.
Attempts have been made to construct these steel tanks
directly from coiled steel in order to eliminate the need for the
expensive pre-formed steel plates. In U.S. Patent No. 3,380,147
issued on April 30, 1968, to McDonald, a method of constructing steel
tanks from strip steel is disclosed. Strip steel is fed from a coil of
steel mounted on a stationary turntable, through a plurality of stationary
crimping rollers onto ~ helically arranged support structure. Thus
the steel is fed in a spiraling manner onto the lower tank walls, as
the upper, completed tank walls are progress;vely elevated. The
crimping rollers bend the lower edge of the strip steel in the tank
wall such that it overlaps the upper edge of the strip steel in
the wall therebelow.
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1~38'78
In U. S. Patent No. 4,121,747 issued on October 24, 1978, to
McFalter, and in U S. Patent No. 4,142,284 issued to Steuber, similar
methods are disclosed for constructing helically wound steel tanks from
coiled strip steel. Here ayain the strip steel is pulled from a coil
mounted on a stationary turntable, through stationary pinch rollers to
provide the proper curvature, through a stationary strip alignment
assembly to align the strip with the tank wall thereabove, and onto a
helically arranged support structure.
While the above methods may eliminate some of the problems
associated with the use of pre-formed steel plates, it appears that they
too have drawbacks. Firstly, the upper and lower finished edges of the
hel;cally wound tank are uneven. Thus to attach a roof or a floor,
these edges must usually be cut off. Secondly, the abovementioned
procedures require the rotation of the entire tank as it is assembled.
In addition to the energy required to do this, a very stable and complex
support system is needed. Further, the use of a stationary turntable
for the coil steel, the stationary pinching rollers and the stationary
strip alignment assembly, in my view, would require the use of accurately
cut and wound coiled steel. While such steel may be available, it would
be extremely expensive. In my experience, the coiled steel received
from the steel mills is often off specification having uneven strip
edges and curvature. Steel having such defects, when used in the prior
art devices described, would require constant adjustments of the distantly
spaced assemblies in order to feed the steel and fit the steel with the
tank wall existing thereabove.
Further, these helically wound systems are limited to handling
lightweight steelg for example in the construction of small storage bins
for grain and the like. Heavy plate steel cannot be bent by crimping or
corrugating operations described above. Also, in large cylindrical tanks
the tank wall thic~ness often needs to be increased in the lo~er portions
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1153~'~8
of the tank. Helically wound tanks cannot accommodate this change in
wall thickness.
SUMMARY OF THE INVENTI`ON
To overcome some of the above-mentioned problems, I have
provided an apparatus and a method for constructing cylindrical storage
tanks from coiled strip steel, wherein the coil of strip steel is carried
circularly around the tank under construction, preferably inside the tank,
and the strip of steel is aligned with the tank wall by fitting frame means
provided directly behind the coil. The tank is constructed substantially
at ground level and is supported by a circularly arranged support
structure. The support structure is progressively elevated to raise the
tank with its newly completed r;ng. The tank walls are not helically
wound, but rather are constructed from a plurality of adjoined hori-
zontal rings of the strip steel.
The apparatus includes a wheeled frame assembly comprising a
chassis frame attached to the wheels, a turntable assembly rotatably
mounted on the wheeled frame assembly, for vertically supporting the coiled
strip steel, and a fitting frame means mounted on the frame assembly
and positioned to receive the strip steel from the turntable assembly.
The fitting frame means vertically supports and guides the strip steel
into alignment with the tank wall supported thereabove.
In a more preferred aspect of the invention, the wheeled
frame assembly comprises both the chassis frame attached to the wheels,
and a pivoting frame mounted on the chassis frame for side-to-side
and forward-to-backward tilting movement relative to the chassis frame.
Means are provided for so pivoting the pivoting frame. The turntable
assembly and the fitting frame means are mounted on the pivoting frame
for tilting movement therewith. This movement is used to aid in align-
ing the strip steel with the overhead tank wall.
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1153~'~8
To further aid in aligning the strip steel, the fitting frame
means preferably comprises a fitting arm pivotally mounted to the wheeled
frame assembly, or more preferably to the pivoting frame, for generally
horizontal movement relative to the chassis frame. Means are provided
for so pivoting the fitting arm. The fitting frame means also preferably
includes a support means mounted on the fitting arm for supporting the
lower edge of the strip steel.
In another preferred aspect of the invention the apparatus
also includes stra;ghtening roller means, mounted on the wheeled frame
assembly and positioned to receive the strip steel from the turntable
assembly and to deliver the strip steel to the fitting frame means. The
roller means are included to remove a portion of the curvature from the
strip steel to fit the curvature of the tank walls. The roller means
is preferably attached to the pivoting frame for tilting movement
therewith. More preferably, the roller means are also pivotally at-
tached to the pivoting frame for general horizontal movement of the
roller means relative to the pivoting frame. This horizontal movement
is used to vary the angle of the strip steel delivered to the fitting
frame means.
The turntable assembly and the straightening roller means
are both preferably rotatably driven to deliver the strip steel to the
fitting frame means.
In another preferred aspect of the invention the apparatus
also includes a coil pick-up frame pivotally mounted to the frame
assembly for picking up a coil of steel laying horizontally on the
ground and pivoting the coil into a substantially vertically supported
position on the apparatus. The turntahle assembly is rotatably mounted
on the coil pick-up frame. Means are provided for pivoting the pick-up
frame between the vertical coil pick-up position and the horizontal
coil unwinding position.
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Broadly stated, the invention provides an apparatus for
constructing cylindrical tanks from coiled strip steel, wherein the
tank walls are constructed at substanti:ally ground level and are verti-
cally supported on a support structure, comprising: a frame assembly
comprising a chassis frame adapted for movement around the base of
the tank; a turntable assembly rotatably mounted on the frame assembly
for substantially vertically supporting the coiled strip steel; and
fitting frame means, mounted on the frame assembly and positioned to
receive the strip steel from the turntable assembly, for generally
vertically guiding the strip steel into alignmen$ with the tank wall
expected to be supported thereabove.
The invention also broadly provides a method of constructing
a cylindrical storage tank from coiled strip steel, comprising: ar-
ranging a support structure circularly around the base of the tank to
be supported for vertically supporting the tank walls; delivering a
first ring of strip steel around the base of the tank; severing the strip
steel and affixing together the abutting ends to complete the first ring
of the tank wall; supporting the first ring on the support structure
such that its lower edge is at a height greater than the width of the
strip steel; carrying the coiled strip steel around the base of the
tank while delivering a second ring of strip steel to the tank wall;
mechanically aligning, in vertical and horizontal directions, the upper
edge of the strip steel as it is de1ivered with the lower edge of the
ring of steel existing thereabove; affixing the upper edge of the strip
; 25 steel, once it is aligned, with the lower edge ~f the ring of steel
existing thereabove; severing the strip steel once a second ring of
steel has been delivered and affixing the abutting ends to complete a
second ring of the tank wal1; elevating the second ring on`the support
structure such that its lower edge is at a height greater than the width
of the strip steel; constructing additional rings of the tank wall in
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llS38'~8
the manner used to construct the siecond ring until the desired height
of the tank is reached; lowering the tank to ground level; and removing
the support structure.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a schematic drawing of the present apparatus and
method for constructing cylindrical storage tanks;
Figures 2a, 2b, and 2c are schematic top views of the chassis
frame alone, the pivoting frame mounted on the chassis frame, and the
turntable, straightening rollers and fitting arm mounted on the pivoting
frame;
Figures 3a, 3b and 3c are schematic illustrations of the
pivoting frame of the apparatus, showing the possible movements of the
pivoting frame relative to the chassis frame of the apparatus;
Figure 4 is a fragmentary front perspective view of the
apparatus showing the connections between the pivoting frame and the
chassis frame;
Figure 5 is a side schematic view of the apparatus showing
the movement of the front co;1 pick-up frame relative to the pivoting
frame from a coil pick-up position to a coil unwinding pGSitiOn;
Figure 6 is a fragmentary rear perspective view of the coil
pick-up frame in a coil pick-up position;
Figure 7 is a front v;ew of the coil pick up frame in a ::
coil pick-up position;
Figure 8 is a fragmentary side perspective view of the coil
pick-up frame in a coil unwinding position;
Figure 9 is a front perspective view of the apparatus showing ~.
the coil being unwound through the straightening rollers and along the
fitting arm frame;
Figure 10 is a side perspective view of the apparatus showing
the details of the straightening rollers and the fitting arm frame; and
11538~78
Figure 11 is a rear perspective view of the apparatus showing
the fitting arm frame and the rear dolly wheel~
DESCRIPTION OF THE PREFERRED EMBODIMENT
-
With reference to F;gure 1, the apparatus 1 is shown con-
structing a cyl;ndrical tank 2 substantially at ground level from a
coil of strip steel 3. The tank walls 4 are vertically supported by
a support structure 5 arranged circularly around the base of the tank 2.
As each ring of the tank wall 4 is completed, the ring is ele~ated
by the support structure 5, and the next ring constructed therebelow,
again at ground level.
The apparatus 1 is seen to comprise a wheeled frame assembly
10 which includes a chassis frame 11 attached to front and rear wheels 12
and 12a. A turntable assembly 13 is mounted on the frame assembly 10
; for substantially vertically supporting the coil 3 of strip steel thereon.
The turntable assembly 13 is rotatably mounted on the frame assembly 10
for delivering the strip steel 14 from the coil 3 to the tank wall 4
under construction. In this manner the coil 3 is carried around the
base of the tank 2 by the wheeled frame assembly 10 as the tank walls 4
are constructed.
The apparatus 1 also comprises fitting frame means 15
mounted on the wheeled frame assembly 10, rearwardly of the turntable
assembly 13. The fitting frame means 15 is positioned to receive the
strip steel 14 from the turntable assembly 13 and to generally verti-
cally support and guide the strip steel 14 into alignment with the tank
wall 4 supported thereabove.
~ 3~37 8
The apparatus 1 also preferably includes straightening roller
means 16 mounted on the frame assembly 10 between the turntable assembly
13 and the fitting frame means 15~ The roller means 16 are positioned
to receive the strip steel 14 from the turntable assembly 13 and
deliver the strip steel 14 to the fitting frame means 15. The roller
means 16 are operative to remove at least a portion of the curvature
from the strip steel 14, to shape the str;p steel to the desired tank
curvature.
THE WHEELED FRAME ASSEMBLY
The frame assembly 10 is shown schematically in Figures 2a -
c. The chassis frame 11 and wheels 12 are shown alone in Figure 2a. The
chassis frame 11 includes front and rear axles 17, 18, interconnected
by a Y-shaped tubular member 19.
The turntable assembly 13, the straightening roller means
16, and the fitting frame means 15 are preferably each pivotally
mounted on the frame assembly 10 to aid in aligning the strip steel
13 with the tank walls 4. While it is possible to pivotally mount
each of these elements separately on the chassis frame 11, the frame
assembly 10 preferably includes a pivoting frame 20, onto which the
previously mentioned elements can be mounted, for pivotal movement
relative to the chassis frame 11. As shown in Figure 2b, the pivoting
frame 20 includes parallel spaced horizontal side beams 21, 22 joined
by a front cross member 23.
The front axle 17 includes a conventional walking beam
assembly 17a to allow the front axle 17 to have a side-to-side tilting
movement to follow rough ground conditions. This assembly is best
shown in Figure 4. The assembly 17a is common to off-road machinery
and therefore is not disclosed in detail herein. A cross beam 26
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is pivotally attached above the front axle 17 at pivot point 26a. One
end of the cross beam 26 is hinged, through hinge connection 26b, to
the side beam 21 o~ the pivot;ng frame 20~ The opposite end of the
cross beam 26 is not directly attached to the side beam 22 of the
pivoting frame 20, but rather extends below the side beam 22, ending
adjacent the wheel 12. An elevation cylinder 32 is provided between
the wheel 12 and the side beam 22. The elevation cylinder 32 is mounted
vertically, the piston end being attached to the cross beam 26 and the
cylinder end being attached to the side beam 22 as shown. As shown in
Figure 3c, expansion and contraction of the cylinder 32 will lift and
lower respectively the front portion of the pivoting frame 20 through
the hinge point 26b and the pivot point 26a.
The pivoting frame 20 is pivotally connected with and
above the chassis frame 11 by a universal joint 24, preferably located
slightly to the rear of the front axle 17. The joint 24 includes a
male universal connector 25 (Figures 2a and 6) on the chassis frame 11
and a female universal connector 25a (Figure 6) on the pivoting frame
20. The female universal connector 25a is attached to the vertical
rear facing surface 26c of the cross beam 26.
The universal joint connection 24 between the chassis
frame 11 and the pivoting frame 20 provides for some forward-to-back
and side-to-side tilting movement of the pivoting frame 20 relative to
the chassis frame 11. Similarly, any elements mounted on the pivoting
frame 20 have tilting side-to-side and forward-to-back movement relative
to the chassis frame 11. In Figures 2c and 3a and 3b, the turntable
assembly 13, the roller means 15 and the fitting frame means 15 are
shown to be mounted on the pivoting frame 20 for movement therewith.
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11538~
Figures 3a to 3c are included to show schematically the
relative movement of the pivoting frame 20 and the elements attached
thereto to the chassis frame 11. Movement of the pivoting frame 20
is effected by a pair of hydraulic cylinders 27 positioned at the rear
of the apparatus. The cylinders 27 are best shown in Figure 10. The
rod ends 28 of the cyl;nders 27 are pivotally connected to a pair of
upright supports 29 fixed to the pivoting frame 20. The cylinder ends
30 of the cylinders 27 are pivotally connected to a rear cross member
31 of the chassis frame 11. The cylinders 27 are controlled separately
to allow for both the side-to-side and forward-to-back tilting
movement. As shown in Figure 3a, simultaneous and even expansion and
contraction of the cylinders 27 will pivot the pivoting frame 20 for-
wardly and backwardly respectively about the universal joint 24. Uneven
movement of the cylinders 27, as shown in Figure 3b , will result in a
side-to-side movement of the pivoting frame 20, again about the universal
joint 24. If the cylinders 27 are expanded simultaneously with the
elevation cylinder 32 the entire pivoting frame 20 is elevated in
the manner shown in Figure 3c.
The elevational movement of the pivoting frame 20 and its
attached elements is useful both for aligning the strip steel 14,
and for lowering the apparatus 1 as it enters and leaves the tank 2
beneath the elevated tank walls 4.
As mentioned previously, the turntable assembly 13, the
roller means 16 and the fitting frame means 15 are each preferably
attached to the pivoting frame 20 for pivoting movement therewith. It
will be seen that the strip steel 14, supported by the turntable assembly
13, the roller means 16 and the fitting frame 15 (Figure 9), will thus
also follow this pivoting movement. By tying together the pivoting
movement of each of these elements 13, 15 and 16, the chance of the strip
steel 14 being bent out of shape is minimized.
llS387~3
The wheeled frame ass~embly 10 is preferably stabilized at
its front and rear ends to prevent the apparatus 1 from tipping
forwardly or rearwardly respectively. As will be discussed later,
the apparatus preferably includes a coil pick-up frame 35 at its forward
end, for picking up a coil of steel 3 from the ground and pivoting the
coil 3 onto the apparatus 1. During this pivoting movement the front
end of the apparatus 1 may tip under the weight of the coil 3. Thus,
to stabilize the front end, first stabilizing means 36 are attached to
the front end of the apparatus 1 for engaging the ground when the
coil pick-up frame 35 is being pivoted. These stabilizing means 36,
as shown in Figures 1 and 5, comprise a pair of outrigger cylinders 37
attached on either side of the front cross member 23 of the pivoting
frame 20. Expansion and contraction of these hydraulic cylinders 37
extend and retract respectively the shoes 38 in the manner shown in
Figure 5. The shoes 38 engage the ground in the extended position of
the cylinders 37, to thereby stabilize the apparatus 1. During construc-
tion of the tank 2 the cylinders 37 are retracted to allow the apparatus
1 to move around the base of the tank 2.
Second stabilizing means 40 is provided at the rear end
of the apparatus 1 adjacent the fitting frame means 15. As will be
explained later, the weight of the tank wall 4 above the fitting
frame means 15 is, at times, transferred to the fitting frame means 15.
The second stabilizing means 40 are provided to engage the ground to
stabilize the apparatus 1 when this we;ght is applied. As shown in
Figures 1, 10 and 11 the stabilizing means 40 comprises a dolly wheel 41
attached to a rearwardly extending member 42 and rear cross member 42a
of the chassis frame 11. The dolly wheel 41 is free to find its own
path behind the apparatus 1. Thus the wheel 41 is connected through a
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11538'7E~
pair of arms 43, to a pivoting shaft 44. The shaft 44 is pivotally
held by sleeve member 45 which in turn is rigidly fixed to the rearwardly
extending member 42~ A hydraulic cylinder 46 is pivotally connected
at its ends to the shaft 44 and the pair of arms 43 as shown. Expansion
and contraction of cylinder 46 varies the bracing effect of the
cylinder 46 applied to the dolly wheel 41 and therefore varies the
stabilizing effect of the second stabilizing means 40.
The wheeled frame assembly lO is preferably self-propelled
by conventional drive means (not shown) carried by the frame assembly
lO. Further, the wheeled frame assembly lO is preferably steered by
a conventional steering assembly (not shown). The steering assembly
preferably includes a power steering cylinder 49 between the cross beam
26 and one of the front wheels 12. The angle of the front wheels 12
can be set and locked by this cy1inder 49 to direct the wheeled frame
assembly lO on the proper circular course around the base of the tank 2.
Once set, of course, the steering cylinder 49 does not need further
attention by an operator.
THE TURNTABLE ASSEMBLY
The turntable assembly 13 is shown in Figures 5 - 9. As
previously stated, the turntable assembly 13 is rotatably and
pivotally mounted on the frame assembly lO. Preferably, it is
rotatably mounted to the pivoting frame 20 for pivotal movement with
said pivoting frame 20.
As shown in the drawings, the turntable assembly 13 is
preferably mounted on the coil pick-up frame 35. This pick-up frame
35, as shown in Figure 5, pivots between a vertical coil pick-up
position (dotted lines) and a horizontal coil unwinding position
(solid lines) to pick up a coil 3 of steel laying horizontally on the
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~ 8 7 E~
ground and pivot said coil to a vertically supported position on the
apparatus l. The pick-up frame 35 includes a pair of parallel, spaced
side members 50 having forward and rearward ends 51, 52 respectively.
The forward ends 51 are interconnected by front transverse member 56.
The forward ends 51 include sleeve members 53. The sleeve members 53
are free to rotate around the front cross member 23 of the pivoting
frame 20. The rearward ends 52 are connected together by rear transverse
member 54. The side members 50 of the pick-up frame 35 are nested
between the side beams 21, 22 of the pivoting frame 20 when the pick-up
frame 35 is in the horizontal position, as shown in Figure 8. In this
position the pick-up frame 35 is supported by the front cross member 23
and the cross beam 26 of the pivoting frame 20.
The turntable assembly 13 comprises a rotating platform 57,
pivotally mounted on a stationary platform 58 (Figure 6). A spindle member
59 is fixed to the centre of the rotating platform 57 to further support
the coil 3 of steel. The stationary platform 58 is preferably slidably
mounted on the pick-up frame 35. As shown in Figure 6, the platform 58
is rigidly fixed to a cross bar 60 positioned therebelow. The cross bar
60 has a pair of internally threaded sleeves 61 attached to its lower
surface. A pair of threaded rods 62, parallel with the side members 50,
extend through the threaded sleeves 61. Opposite ends of the threaded
rods 62 are rotatably received in journal bearings 63 on the front
and rear transverse member 56 and 54 respectively. The threaded rods
62 are rotatably driven by a hydraulic motor 64. The motor 64 turns
a chain and sprocket assembly 65 attached to the forward ends of the
threaded rods 62. Rotation of the threaded rods 62 moves the
turntable assembly 13 forward and backward i-n the horizontal coil
unwinding position and up and down in the vertical coil pick-up
position. This movement is shown in Figure 5. In the coil pick-up
position the up and down movement of the turntable assembly 13 is used
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11538'~8
to align the spindle member 59 w;th the centre of the coil 3. In the
coil unwind;ng position, forward and backward movement of the turntable
as~sembly 13 is used to vary the angle of the strip steel 14 delivered
to the straightening roller means 16 and the fitting frame means 15.
The coil pick-up frame 35 is pivoted between its vertical and
horizontal positions by a winch 70, shown schematically in Figure 5. The
winch 70 is attached to the upright supports 29 of the pivoting frame 20.
Winch cables 71 extend from the winch 70, over pulleys 72 on the rear
transverse member 54 of the coil pick-up frame 35 through the centre
of the coil 3 on the ground and down to the spindle member 59 of the
turntable assembly 13. An eye 73 is provided in the spindle member 59
for attachment of the winch cables 71.
The turntable assembly 13 ;s preferably rotatably driven to
deliver the strip steel 14. This feature has been found to be particu-
larly advantageous when using very large coils of steel. The means for
; driving the turntable assembly are best shown in Figures 6 - 8. A
first sprocket (not shown) is affixed to the underside of the rotatable
platform 57. A hydraulic motor 75 is mounted rearwardly of the turn-
table assembly 13 on the coil pick-up frame 35. The motor 75 rotatably
drives a second sprocket 76 mounted below the motor 75. A chain 77
interconnects the first and second sprockets to transfer rotational
movement to the rotating platform 57.
The spindle member 59 preferably includes a plurality of coil
centering cams 80 pivotally connected thereto. The cams 80 push outwardly
against the interior surface of the coil of steel 3 to keep the coil
centered on the turntable assembly. The cams 80 are triangularly shaped
as shown. The first apex 81 of each cam 80 is pivotally connected to
the spindle member 59. The second apex 82 includes a roller 83
pivotally connected thereto. The third apex 84 includes a roller 84a
~1538~
pivotally connected thereto, which roller bears against a plate member
85 of the spindle member 59. The plate member 85 is rigidly fixed to
a threaded pin rod 86. The pin rod 86 is held to the spindle member
59 by an internally threaded bolt (not shown) mounted within the spindle
member 59. Rotation of the pin rod 86 causes an up and down movement
of the plate member 85. Upward movement of the plate member 85 lifts
the rollers 84a and thus pivots the cams 80 outwardly such that the
rollers 83 bear against the interior surface of the steel coil 3.
THE STRAIGHTENING ROLLER MEANS
The straightening roller means 16, best shown in Figures 9
and lO, is vertically mounted to the horizontal side beam 21 of the
pivoting frame 20 intermediate the turntable assembly 13 and the fitting
frame means 15. The roller means 16 preferably comprises common pyramid
rollers, including an apex roller 90 and two base rollers 91, 92
arranged at the corners of a triangle. The rollers 90, 91, 92 are
each supported by a vertical support member 93, which is attached,
through horizontal arms 93a, to a vertical post 94 affixed to the side
beam 21 of the pivoting frame 20. As shown in Figure 9, the strip steel
14 is fed between the base rollers 91, 92 and the apex roller 90.
The apex roller 90 is mounted for inward and outward horizontal movement
relative to the base rollers 91, 92 to vary the squeezing force, and
therefore the straightening effect, of the roller means 16 on the strip
steel 14. To so move the apex roller 90, the upper and lower ends of
the roller 90 are mounted in slotted upper and lower guide plates (not
shown) and moved inwardly and outwardly therein by upper and lower
hydraulic cylinder (not shown) in a manner conventional with pyramid-
type rollers.
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The straightening roller means 16 are preferably rotatably
dr;ven to pull the strip steel 14 from the turntable assembly 13. The
means for driv;ng the roller means includes a hydraul;c motor 95, which
dr;ves a large sprocket 96 with a chain 97. The upper ends of the base
rollers 91, 92 are tied together by sprockets 98, 99 respectively and
a chain 100. The sprockets 98, 99 are attached to the large sprocket
96 for rotational movement therewith. Thus the rollers 91, 92 are
rotatably driven at the same speed to move the strip steel 14 through
the roller means 16.
The roller means 16 is preferably pivotally mounted on the
pivoting frame 20 to vary the angle of the strip steel 14 delivered to
the fitting frame means 15. To so pivot the roller means 16, the vertical
post 94 is pivotally mounted to the side arm 21 of the pivoting frame 20.
A hydraulic cylinder 102 is pivotally connected between the base of the
rollers and the side beam 21 as shown. Expansion and contraction of the
cylinder 102 swings the rollers ;n an arc toward and away from the fitting
frame means 15.
Often during the tank construction it is necessary to
actually place counter camber into the steel strip in the roller means
16. This counter camber causes the strip steel to ride upwardly in the
roller means 16. To adjust for this action, there is some horizontal
play provided for in the vertical pivot point 103 of the vertical post 94.
This provision allows the roller means 16 to cant off their true vertical
plane when a change in the camber of the strip steel is made.
THE FITTING FRAME MEANS
The fitting frame means 15 is shown in Figures 9, 10 and 11
and comprises a fitting arm 105 connected to the upright support 29 of the
~538~f F~
pi~oting frame 20. Thus the frame means~ 15 is provided with side-to-side
and forward-to-back tilting move~ent with the p;voting frame 20. The
fitting arm lOS extends rearwardly from the upright support 29 generally
parallel with the s.ide beam 21 of the pivoting frame 20.
The fitting arm 105 ;s preferably pivotally mounted to the
upr;ght support 29 to provide for the generally horizontal movement
shown ;n Figure 2c. Th;s horizontal movement of the fitting arm 105,
together w;th the tilt;ng movement thereof aris;ng from the movement of
the p;vot;ng frame 20, aid ;n al;gn;ng the strip steel 14 with the tank
lo wall 4 supported thereabove.
The fitting arm lQ5 cons.ists of parallel spaced upper and
lower hor;zontal arms 106 and 107 respect;vely interconnected by front and
rear vertical members 108, 109 respectively. The front ends of the hor;zontal
arms 106 and lQ7 are p;votally connected through p;vot p;ns 110 and 111 to
a vert;cal post 112 r;g;dly connected w;th the upr;ght support 29. Th;s
connect;on provides for the above-descr;bed hor;zontal p;votal movement
of the fi`tting arm 105. To control this horizontal pivoting movement,
a hydraulic cylinder 114 is angled hori.zontally between the fitt;ng arm
105 and the upright support 29 of the pivoting frame 20. The ends of the
cylinder 114 are p;.votally connected to the fitting arm 105 and the
support 29. Expans;on and retract;on of this cylinder 114 sw;ngs the
fitt;ng arm 105 outwardly and inwardly respectively.
The lower end of vertical member 109 is provided with a
support means 115 for supporting the lower edge of the strip steel 14.
The support means 115 i.s bolted to the vertical member 109 as shown. The
support means consists of a pair of support pulley-type rollers 116
onto whi`ch the strip s.teel 14 is received, and four guide rollers 117 for
gui`ding the lower edge of the strip steel 14 through rollers 116. The
strip steel 14 is threaded through the guide rollers-117 as sho~n in
Fi.gure g.
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"
11538'~8
The fitting arm 105 preferably includes a platform 120
pivotally attached to the rear vertical member 109. The platform 120
supports an operator directly behind the fitting arm 105, to allow him
to weld the upper edge of the strip steel supported by the fitting arm
105 to the tank wall 4 thereabove. The platform 120 is pivotally
mounted to a horizontal arm 121, which in turn is pivotally mounted
to the vertical member 109. This provides desirable swinging movement
of the platform in a horizontal plane.
The fitting arm 105 preferably includes a push-out roller
means 124 connected above the vertical member 109 for pushing outwardly
against the tank wall 4 existing thereabove. The overhead tank wall 4
has a tendency to fall inwardly, especially when a section of the support
structure 5 is removed to allow the apparatus and the welding process
to move past. The push-out roller means 124 has been found to minimize
this problem.
The push-out roller means 124 includes a roller 125 rotatably
mounted on one end of a horizontal push-out arm 126. The opposite end of
the arm 126 is rigidly connected to the upper end of rotating vertical
post 127. The post 127 extends through a sleeve 128 mounted on the upper
; 20 arm 106 of the fitting arm 105. The sleeve 128 extends through the upper
arm 106. The post 127 is vertically rotatable with respect to the
sleeve 128. The lower end of the post 127 is pivotally connected to
the rod end of a hydraulic cylinder 129. The cylinder end of the cylinder
129 is pivotally connected to the vertical member 108 of the fitting arm
105. Extension and contractiGn of the cylinder 129 rotates the vertical
post 127 and thereby moves the arm 126 and roller 125 outwardly and
inwardly respectively relative to the overhead tank wall 4.
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The fitting arm 105 also preferably includes a push-down
roller means 131 connected above the upper arm 106 for pushing down-
wardly on the upper edge of the steel strip 14 delivered to the f;tting
arm 105. This action aids in maintaining a small gap between the upper
edge of the strip steel 14 and the tank wall 4 for welding purposes.
This resists the tendency of weld shrinkage to close the gap.
The push-down roller means 131 consists of a pulley-type
roller 132 rotatably mounted at one end of a horizontal push-down arm
133. The other end of the arm 133 is rigidly connected to a vertical
post 134. The post 134 is rotatably connected in a sleeve 135 on the
upper arm 106 of the fitting arm 105, to enable the roller 132 to
follow inward and outward swinging movement of the strip steel 14.
A hydraulic cylinder 136 is vertically mounted between the lower arm
107 of the fitting arm 105 and the lower end of the vertical post 134.
Expansion and contraction of the cylinder 136 moves the roller 132 and
push-down arm 133 upwardly and downwardly respectively.
Controls 140 are preferably provided on the fitting arm 105,
most preferably adjacent the platform 120, to permit the operator to
adjust those elements of the apparatus 1 instrumental to fitting and
welding of the strip steel 14 to the tank walls 4. Most preferably the
controls 140 include six control levers 141 - 146 to independently
control movement of the hydraulic cylinders 27, 32, 114, 129 and 136,
and a forward speed control valve 147 to vary the forward speed of the
apparatus 1. The speed of rotation of the turntable assembly 13
through the hydraulic motor 75 and the speed of the rotation of base
rollers gl, 92 through the hydraulic motor 95 are co-ordinated to the
forward speed of the apparatus 1 to provide smooth delivery of the
strip steel 14. Thus the forward speed control valve 147 adjusts the
speed of the hydraulic motors 75 and 95 in accordance with the forward
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speed of the apparatus . The control levers 141 - 146 permit the operator,
standing on the platforrn, to adjust each oF the pivotal movements of
the pivoting frame 20, the horizontal swinging movement of the fitting
arm 105, the outward force applied to the overhead tank wall 4, and the
downward force applied to the upper edge of the strip steel 14.
The fitting arm 105 also preferably includes a roller 148
rotatably mounted on the outwardly facing side of the vertical member
109. The roller 148 keeps the strip steel 14 spaced a small distance
from the fitting arm 105.
OPERATION
With reference to Figure 1, the tank 2 can be constructed
with the apparatus 1 of the present invention by a work force of two
operators. A first operator 150 stands on the platform 120 to align
and weld the strip steel 14 to the tank walls 4. The aligning operation,
as previously explained, includes adjustment of the forward speed of
the apparatus, the various pivoting movements of the pivoting frame 20,
and the movements of the fitting arm 105 and its associated elements.
A second operator (not shown) might be included to raise and lower the
support structure 5 as the apparatus 1 moves by, or to assist in the
welding operation.
The support structure 5 shown in Figure 1 consists of a
plurality of individually or synchronously powered hydraulic jacks 151
cylindrically arranged around the base of the tank 2 at about 20 foot
intervals. Each jack 151 includes a lifting hook 152 on which to
vertically support the lower edge of the tank walls 4.
In the majority of cases, the cylindrical tank 2 includes a
roof 153 and a floor 154 welded to the upper and lower edges of the
tank walls 4. The following description includes the details of attach-
ing the roof 153 and the floor 154.
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A circular floor 154 and roof 153 are constructed on the ground
from sheet metal in a known manner. The support structure 5 is arranged
circularly around the base of the tank to be constructed. The roof 153
is elevated and supported horizontally on the hooks 152 of the jacks
151. A first ring of steel is then delivered around the base of the
tank 2. This first ring is preferably delivered from the apparatus 1.
The coil pick-up frame 35 is pivoted to the vertical coil
pick-up position adjacent a coil 3 of steel lying horizontally on the
ground. The turntable assembly 13 is adjusted upwardly or downwardly
to al;gn the spindle member 59 with the centre of the coil.
The apparatus is moved forwardly to slide the coil 3 onto
the spindle member 59. The winch cable 71 is attached to the spindle
member 59 and the outrigger cylinders 37 are extended to engage the
ground and stabilize the apparatus 1. The coil 3 is lifted onto the
apparatus 1 by pivoting the coil pick-up frame 35 to its horizontal
position and moved rearwardly by threaded rods 62 to the coil unwinding
position. The outrigger cylinders 37 are retracted and the apparatus 1
is driven onto the floor 154 of the tank 2.
To enter and leave the interior of the tank 2, the pivoting
- 20 frame of the apparatus 1 is preferably lowered, by adjusting hydraulic
cylinders 27 and elevation cylinder 32 to their lowest positions, to
clear the roof 153 or the tank walls 4 supported on the support structure
The strip steel 14 is fed through the straightening roller
means 16 and along the fitting arm 105. The degree of straightening
by the roller means 16 is adjusted by varying the spacing of the base
and apex rollers 91, 92 and 90. The degree of straightening desired
varies with the tank diameter and is set by trial at the beginning
of each coil or cours-e. For the first ring of strip steel, the
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pivoting frame 20 is preferably angled rearwardly downwardly, by adjust-
ment of cylinders 27 and 32, to direct the strip steel toward the ground.
Once the first ring of strip steel is delivered, the strip steel is
severed from the coil slightly over length for the desired diameter~
The supported roof 153 is then lowered on the support structure 5
and the upper edge of the first ring is welded to the roof 153. The
abutting ends of the first ring of steel are then welded together to
complete a first ring of the tank wall. The apparatus 1 is driven
from the tank 2 for this operation. The first ring is then elevated
on the support structure 5 such that its lower edge is higher than the
combined width of the next ring of strip steel to be delivered and the ~ -
height of the turntable assembly 13 from the floor.
The apparatus 1 is driven back into the tank and directed on
~; a circular course beneath the first ring on the inside of the tank. The
power steering cylinder 49 is locked onto the proper course. A chain
(not shown) is attached between a point on the front of the apparatus 1
and a swivel point (not shown) in the centre of the tank 2. This
prevents the apparatus 1 from accidentally going off course and colliding
w;th the lifting jacks 151.
The apparatus 1 is slowly moved forwardly around the base of
the tank 2, carrying the coil 3 of strip steel therearound while
simultaneously delivering the strip steel along the fitting frame means
15 to the tank wall. The lower edge of the delivered strip steel is
supported by the support means 115 on the fitting arm 105. The speed
of delivering the strip steel from the coil 3 should be synchronized
with the forward speed of the apparatus 1. Thus the rotating speeds
of the turntable assembly 13 and the straightening roller means 16 are
synchronized with the forward movement. This speed coordination is
accomplished by setting a needle valve means (not shown) to divide the
flow of oil to the respective hydraulic motors controlling forward speed,
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3.~..1~3~`78
turntable rotation and roller drive. After setting this needle valve
means the volume flow control can be adjusted by the operator l50,
through the forward SPeed control valve l47, to feed strip steel as
fast as he can use it.
The upper edge of the supported strip steel is mechanically
aligned along the fitting arm 105 with the lower edge of the overhead
tank wall 4. A gap of controlled size is also provided between the
lower edge of the tank wall 4 and the upper edge of the steel strip l4
to accommodate the weld. These aligning and weld gap control operations
are achieved by the separate or simultaneous movement of the fitting arm
lO5 itself, the push-down roller means l3l, the push-out roller means
l24, and the straightening roller means 16.
In the most preferred embodiment of the apparatus 1, the
turntable assembly l3, the straightening roller means l6 and the
fitting arm lO5 are fixed to the pivoting frame 20 and thus can be
adjusted simultaneously for forward-to-back and side-to-side tilting
movement, for alignment purposes, through the pivoting movement of the
pivoting frame 20. This movement, as previously explained, is accomplished
through even or uneven movement of the hydraulic cylinders 27 through
the controls l40 by the operator lS0. The pivoting frame 20, and there-
fore the strip steel supported thereon, can be raised and lowered to
align the strip steel, through movement of the elevation hydraulic
cylinder 32.
The straightening roller means l6 can be moved generally
horizontally relative to the tank walls, to vary the angle of the
strip steel delivered to the fitting arm lO5, and to therefore aid in
aligning the strip steel. This angle is usually set at the beginning
of the tank construction, in accordance with the tank size.
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il~i38'78
The first operator, a ~relder, standing on the fitting arm
platform 120, can further align the strip steel through horizontal
swinging movement of the fitting arm 105 relative to the tank wall 4,
through adjustment of the push-down roller means 131 and the push-out
roller means 124 and through adjustment of the pivotal movement of the
pivoting frame 20. These several adjustments are made through the
control levers 141 - 146 on the fitting arm 105 close to the operator
150. These controls adjust fluid flow to the hydraulic cylinders 114,
136, 129, 27 and 32, as previously disclosed.
Once aligned, the upper edge of the strip steel is affixed by
welding to the lower edge of the overhead tank wall 4. These supporting,
aligning and affixing operations are continued around the tank perimeter
while simultaneously delivering the str;p steel.
As the apparatus 1 approaches a lifting jack 151 of the
support structure, the lift;ng jack ;s temporarily removed, by a second
operator (not shown), to allow the apparatus to pass, and to allow the
strip steel 14 to be affixed. The lifting jack 151 is removed as the
support means 115 at the rear of the fitting arm 105 approaches the
jack 151. Once the jack is removed, the weight of the tank wall 4 above
the fitting arm 105 is transferred to the support means 115 on the fitting
arm 105. The dolly wheel 41 stabilizes the rear end of the apparatus
under this weight. The push-out roller means 124 pushes outwardly
against the overhead tank wall 4 to resist the tendency of the wall to
move inwardly. The force exerted by the push-out roller means 124
against the wall 4 is usually adjusted through the hydraulic cylinder 129.
The lifting hook 152 of the jack 151 is lowered to the height of the
lower edge of the strip steel in the second ring. As soon as the ap-
paratus moves past this point, the lifting jack 151 is replaced, this
time supporting the lower edge of the section of the second ring of
strip steel, now affixed to the overhead tank wall 4.
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Once the second ring is affixed, the strip steel is severed
and the abutting ends welded together to complete a second ring of the
tank wall 4. The second ring is then elevated on the support structure
to a height greater than the w;dth of the next ring of strip steel to
be constructed plus the height of the turntable assembly 13 above the
floor.
Additional rings of the tank walls 4 are constructed in the
same manner as used for the second ring until the desired height of the
tank is reached. The apparatus is then removed from the tank interior.
The tank 2 is lowered on the support system 5 to ground level or a few
inches thereabove. The tank floor 154 is then welded to the lower edge
of the tank walls 4. Each jack 151 of the support system 5 is removed
as it is approached by the welder.
While the present invention has been disclosed in connection
with the preferred embodiment thereof, it should be understood that
there may be other embodiments which fall within the spirit and scope
of the invention as defined by the following claims.
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