Note: Descriptions are shown in the official language in which they were submitted.
o~
BACKGROUND Ol' TflE INVENTION
. .
This application is a division of Canadian Serial
No. 225,63Q, filed Apxil 28, 1975.
1. Field of the invention
The present invention relates gen~rally to the continu-
ous formation of t~bes and more specifically to the continuous ;
formation of helically welded pipes or tubes for~ed from strip
material.
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2. Description of the prior art
Helically wound pipes may generally be classified by
their method of formation as interlocking or welded. In the past,
hea~y gauge materials were welded to form the helically welded
pipe. Non-uniformity of the material strips of lighter gauge steel
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required that they be interlocked to compensate for the non- ;
... . . .
uniformity of the edges.
The devices of the prior art have included many compli-
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cated mechanisms to either interlock the material or to guide the
material into a butt weld. Difficulty has been experienced with
.. .. . .
~ the butt-welding of thin~gauge metal tgenerally between .020 and
~.030 inches thick) since it cannot be guided by t~e same mechanisms ~-
used for the heavl~r gauge. The number of parts used in the guiding ~ ;
mechanism~of the prior art increases the cost and the reliability
of~the devlce~
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~(~43'~30
To assure a perfectly mated edge for butt-welding,
prior art devices have overlapped the leading and trailing
edges of a piece o~ strip material-and cut the edges that
are overlapped prior to welding.
Also it has been considered impossible to continu-
ously weld a seam by ~lIG or TIG welding usi~g material thinner
than .030 inches and unthinkable when the material is from
.008 inches to .014 inches.
One solution provided by the prior art is to provide an
interlocking means or thin gauge material and then to subsequently
heat the interlocked edge so as to take advantage of the thick and
thin material technology. Though providing a sufficient interlock
and welded pipe, this device requires precision operation of a
group of sub-assemblies to provide the two mating interlocking
seams, as well as an alignment relative to the heating element.
Another problem faced by the devices used in welding is to provide
sufficient tension on the leading and trailing edge so as to guar-
antee their mating during the welding operation. Complicated belts
and rollers have been used to put a twist on the sheet material so -
as to increase tension and force the butted edges together on the
'~ .
spiral. These systems, as well as others, again increase the number
f necessary parts and decrease the reliability of the apparatus
of the prior art.
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SUMMARY OF TEIE INVENTION
.
This invention comprehends a perforated spirally wound metal
filter tube having welded ju~ta~osed external edges wi~hout the
addition of any ~elding material.
The invention also contemplatcs the~method for forming
metal tubing that has helical welding seams froiil sh~et material
and it comprises drawing the sheet material ~rom.a supply,
raising the two lateral edges of the sheet material to form
flanges extending at an an~le to the plane of the sheet material,
guiding the flange of a trailing edge of the sheet material
about a helical path to abut the flange of a-leading edge of the ;
sheet material, and welding the abutted flan~es.
Additionally, the invention contemplates a device for
helically welding sheet material with flanges on its lateral
edges ~to orm a tube. The device comprises means for enga~ing
the inside of the flanges of a leading and of a trailing edge ~ -
of the sheet material and for guiding the leading and trailing ,~ ;
edges into abutment, and a means fo~ welding sald abutted
edges to form the tube. ~-
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20 ~ ~ The invention also further contemplates a spirally wound
.
tube having a diameter and made ~ro~ sheet metàl, wi~h the sheet
metàl~having a~thickness. The tube compxises an outer surface,
and at~least one welded externally raised spiral seam. The seam
extends~above the outer~sur~ace~of~the tube in an amount greater
25 ~ than the thickness o~ the sheet metal.
This pe~-~orated~welded metal tubing is used as a core
for winding fiber rovi~gs thereover to form filters. One
~ethod~of forming such~a filter and apparatus therefor
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may be found in U.S. Patent No. 3,356,226, n~ owned
by the assignee of this invention, the Filterite Corpo-
ration. More par~icularly, metals such as stainless ~ :~
steel, low carbon ~nd medium car~on steels ~nd t in platcd
steels may be used ~o make perforate filter ~ube coresranging in diamet~r from 5/8" to 3-1/2" by using sheet
metal materials froln .005" thick to .030" thick. lt
should be noted, llowever, that it is not possible to
make 5/8" diameter tubing from the thicker ma~erials;
the generally accepted ranges contemplated for this
invention being tuLes having a diameter from S/8" to
about 1-1/4" made from sheet metals with thic~;nesses
.
ranging from .005" to .015"; from 1-1/4" to 1-3/4" : :
diameter tubes made from sheet metals having ~hicknesses
j 15 ranging from .005" to 015"; from 1-3/4" to approximately
,
~ 2-1/4" made from sheet metals having thicknesses ranging
:
from .008" to .020"; and, from 2-1/2i' to 3-1/2" and
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~0~3Z~30
greater, made from sheet metals having thic~nesses
ranging from .015'' to .030". The juxtaposed edges
that are welded as they are helically wound to~ether
to foxm the tubin~ can be provided with slig}ltly roughen-
ed edges in order to betLer hold the fiber roving material
applied during th~ filter formation.
The method and apparatus of the present de~ice
reduces the number of parts and provides basically a
single guiding element which engages the insicle edge ~-
of a flange of a -trailing edge of a piece of sheet
material and guides it around a helical path illtO
abutment with the leading edge of a piece of sheet
material ~hich is guided for a short distance by
en~aging the inside of its flange to a point at which
the flanges are heated sufficiently to cause them to be
the filler of a weld.
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The guiding m~n~er, though engaging both interior
flange edges, does not contact the edges at the point
of welding. Prior~to engaging and abutting the flanged
edges of the sheet material, a pair of rollers are pro- ;
vided to produce the flanges on the lateral edge of the
, .
,` sheet material as w~ll as corrugate, if desired,~and
i ~drive the sheet material from a supply into the guiding
element.~ A cutter is provided which, upon sensing a
l 25 ~ predetermined lenqth of the contlnuously forn~ed tubing,
i ~ cuts the tubing on the fly. Positioned on each side
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of the cutter are two sets of drive rollers t~hich help
move the tubing to the cutter from the weldinq station
and from the cutter to a storage area, respectively.
The drive rollers are designed to also exert torque
on the freshly weld~d tube to prevent the ed~es frQm
: separating before the weld sets. Control c~rcuitry
is provided to interrelate the functions and drive
of various elements as just described. The metl~od
and apparatus of the preferred embodiment produces a
helically welded pipe or tubing having an outsicle
diameter from 5/8 o~ an inch on up from sheet material
between 5-30 thousandths of an inch thick, I~ the spiral
wrap angle is tightened, it is not necessary to have the
flanges contact the guide. - ~'
OBJ~CTS OF THE INVENTION
It is the object of the present invention to provide
a perorated, thin wall, spiral welded tubing which is
use~ul as a filter core material.
It is another object of this invention to provide
8uch a filter tube that has a thickness of from .005
inches to .015 inches when the tube has a diameter of
from 1 to l-l/2 inches. ;
It is another object of the present invention to
.
provide a method and apparatus for continuously p~oducing
, :
~ ~ such welded tubing.
; Another object is to provide an apparatus and method
2~ ~ for forming the continuously helical seamed welded pipe
from sheet material from 5-30 thousandths of an inch thick.
A further object of the present invention is the pro- ~
vision of a method and appaFatus of~high reli~bility and a -
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minimum number of parts to provide continuously welded
helical wound pipe.
Other objects, advantages and novel features of the present
invention will become apparent from the follo~ing detailed
S description of the preferred embodiment when considered in
conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING'; ~ :
Figure 1 is a perspective view of the apparatus of
the present inv~ntion;
Figure 2 is a view of the forming drive rollers;
Figure 3 is a view of the housing for tlle forming
drive rollers; : .
Figure 4 is an exploded view of the formi.ng guide box
assembly; - ~
I lS Figure 5 appearing with Fig. 1, is an enlarged partial view
of the guide liner and sheet material;
Figure 5a is an enlarged perspective view of a section
of the sheet material with side flanges; ;. .
Figure Sb is perspective view of a segment of the welded
1 20 tube 2;
I Figure 5c is a section perpendicular to the longltudinal
axis to the tube of Figure Sb; ;:
Figure Sd is a perspective view of the tube section of
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i~Figure 5b;
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~ Figure Se is a perspective longitudinal sectional view
of the welded seam;
Figure Sf is ~ perspective view of the welded tu~e of : ~.-
Pigure 5d with several roving overlaps;
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Figure 5g is a perspective view of the filter o~
this invention;
Figure 6 is a plane view of tubing drive rol].ers;
Figure 7 appearing with Fig. 4r is a plane view of one
of the rollers of Figure 6;
Figure 8 is a plane view of the control of one of
the tubing drive roller assemblies;
Fiyure 9 is a perspective view of the cu~ter assembly;
Figure 10 is an electrical schematic o~ the control
circuit of the present invention; and,
Pigure 11 apuearin~ with Fig. 9, is a pne~matic schematic
of the control circuit of the present inventi~n.
.
- DESCRIPTION OF TH~ PREFERRED EMBODI~IENTS
The helically welded perforate tubing lOX is depicted
in Figure 5b and illustrates a preferred embodiment of
the subject invention. The illustrated tubinq lOX is formed
by the apparatus wllich is depicted in Figure 1.
Flgure 1, which i}lustrates the preferred embodiment
of the apparatus to'perform the method of the subject lnvention,
. .
~0 shows a strip of sheet material 10 being drawn from a supply (not
shown). The sheet material 10 is drawn from said supply and has !':~
~langes formed on the two outer edges of the sheet material at
flange forming and drive assembly 20. The flanged sheet material
10 is fed into a gui.ding and forming box 30 where~n the trailing
edge of the sheet material is guided into abutment with the lead- '
ing ~dge of the sheet material, ~t which point ît is welded by a
welding:device 40. The helically welded pipe or tubing 45 exits
, ~the forming and guiding box 30 and is torqued and driven by drive
.
roller assembly 50. The torque produced tightens -the helix and
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thus prevents the a~utted edges from separati~ efore the weld
cools. The drive roller assembl~ 50 drives tlle pipe or tubing past :
a flying cutter 60, which upon a proper elect~ical command, rotates
down and cuts the continuous welded pipe 45 without impeding move-
ment of the pipe or tubing. Past cutter 60 is a second drive
. roller assembly 70 which carries the cut pipe or tubing away from
the cutter 60. : .
Positioned in an appropriate place down the line from
cutter 60 is a sensor 80 which senses a prede!:ermined length of
tubing 45 so as to activate the cutter 60. As to be explained more
fully in later sections, a sensor 90 (for e~ample, an electric eye~
is positioned immediately before drive 70 to sense the presence of -
~the welded tubing 45. When the tubing 45 is absent, the sensor 90
provides a control signal to raise the upper roller of drive
roller assembly 70 to receive the end of the continuously welded
tubing 95. Once sensing extension of the tu}~e past the drive
xoller, sensor 90 allows the upper roller of drive roller assembly ;
; .. ..
. 70 to be lowered for driving the tubing. This relationship of sen-
sor 90 and drive assembly 70 will be explained more fully in later
2 O se c~ions.
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The continuously formed and welded tubing 45 extends
:~ ;generally on an I,-shaped support 95. After being cut, the tubing
: 45 ~is~driven by dr.ive roller 70 onto support 95. Once past the
drive roller 70, tlle tubing Is pushed off support 95 into an
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appropriate recep~acle (not sho~n) by an air cy].inder 96.
It should be noted ~hat the predetermined len~h sensing
device 80 is slidably mounted upon frame 95. The total assembly
is supported on a llorizontal surface 100, which may be any sort :,
of horizontal surface, for example, a table.
The present apparatus and method easily handlcs sheet
. material under twenty thousandths of an inch ~nd can continuously ..
weld helically wou~cl tubing at rates up to appro~imately 300
inches per minute.
FLANGE FOR'~lING AND DRIVE ASSE~IBI,Y 2()
The flange forming and drive assembly is shown as having ' .-
a drive motor 102 connected through transmi.ssi~n 104 to the ~.
'. roller drive housiny 106. Supported in appropri~te journalled
openings between roller drive housing 106 and support 108 are
` 15 a pair of rollers 110 and 112 on shafts 114.
,l As shown more e~plicitly in Figure 2, the drive rollers
110 and 112 may have a corrugated surface so as to produce a
, corrugation in the sheet material 10. It should be noted that
! . .
.l , these rollers may al50 be smoothed if corrugat.ion of the sheet
~' 20 material is not desired. The lower roller 112 is machined or has
,'l' attached thereto shoulders 116 and 118. 2he shoulders 118 are
separated by a distance approximately equal to the width of the
', sheet material 10 and guides the sheet,material between the rollers ~,
', 110 and 112. The s~oulders 116 lie between the roller 112 and '
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shoulders 118 and provides witl- roliers 112 tlle Eemale hal~ of
a die, about which the material 10 is bent so as to form the
flanges on the lateral edge thereof. As can hc see'n in Figure
~ 2, roller 110 is t~l~ male half of the die. ThUS, as the sheet
S material 10 is fed into the combination flan~e forming and drive
rollers 110,112, it is corrugated, if desired, and a flange is
formed extending u~ from the general horizontal. surface thereof
by the rollers 110 ~nd 112 in combination with shoulders 116, The .: ''
sheet material 10 i.s guided in between the ro.llers by a guiding . '
device 120 shown in detail in Figure 3. The guidin~ device 120 has
a vertical plate 122 with a recess 124 therein. A horizontal guide .:
frame 126 is generally perpendicular to the ~-ertical support 122 . ~
and lies in the plane of the bite between rollers 110 and 112. :.
As shown in phantom in Figure 3, the roller 112 lies '~
.~ ... . .
~ithin the recess 1~4 of vertical plate 122. ~hereas the input ~"
guide f.rame 126 is yeneral.l.y hori.zontal to recei.ve the ~ nar '''.
sheet material 10, t:he output guide frame 128 is shaped so as to .,
' accommodate the corrugated horizontal portion and the two flange ,'.
portions,of the res~aped.material 10. The output edge of the out~
put guide frame 128 is slanted in the horizontal plane to accomo-,
date the guLde and forming box 30 through which the flange forming
and drive assembly 20 delivers the flanged sheet material 10 at
an angle, (preferrably 45).: .
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GUIDE ~ND FORMING ~oX 30
Explosive view of the guide and forming box 30 is shown
in Figure 4. The guide and forming box 30 has a housing 130 in
which are assembled an arbor 132 carrying sleeves 134 and 136.
Encompassing the sleeves 13q an.d 136 is the gui.de sleeve or liner
138. End-cap 140 mai.ntains guide liner 138 stationary and in place
. within housing 130. A thrust bearing 142 and fastener 144 maintain
the sleeves 134 and 136 on arbor 132. An arbor bushing 146 is
received within borc 147 of housing 130 and includes apertures
148 in the top and bottom thereof. ~lousing 133 llas apertures 150
in the top and bottom thereof to receive a locking screw 152 and
a locking pin 154. The locking screw 152 is received through the
aperture 150 in housing 130, aperture 148.in arbor bearing 146 and
rests against a flat surface 156 of the arbor~ Similarly, the
locki.ng pin 154 is received within apertures 150 of housing 130
and apertures 148 of arbor bearing 146 and aligns with slot 158 of
the arbor 132. Thus, once the arbor 132 is inserted throuyh bore
147 of housing 130, it is aligned by locking pin 154 to prevent
rotation thereof and is secured from lateral movement by locking
screw 152.
Sleeve 134 and 136 may be made of any material, though
; sleeve 136 is made of a heat resistant material ~uch as copper, ~.
since it:~will underlle the weldLng statlon. ~s will be éxplained .:.
more:fully~hereafter, sleeves 134 and 136 rotate around arbor 132
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~0~3Z~30
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as the sheet material 10 is introduced within housing 130. The
end cap 140 is s~cured to the housing 130 by fasteners 160
through aperture~ 162 in the end cap 140 and 164 in the housing
130, respectively.
The housing 130 has a slot 166 ther~in through which
the sheet materi~l with ~langes thereon is introduced. A
cuxved edge 168 of the housing 130 acts as a guide and is
generally at an an~le to the longitudinal axis o~ the bore 147
of the housing 130. A generally circular opening 170 is pro- -
vided in housing 130 for maximum exposure o the helically
wound sheet material 10 so that it may be w~Lded. The opening
170 is shown as being circular and may be o~-any other shape, as
long as it provides sufficient space to expose the seam ~f the ;
sheet material so ~hat it mav be welded.
The guide liner 138 is generally a cylindrical member
having a forward edge 172 cut so as to form a helical path. The
longitudinal edge 174 is formed, thereby ancl has a length such
that edges 176 and 178 engage the inside of a leading and trail-
ing edges' flanges of~sheet material lO, res~?ectively. A channel
~ 180 continues around the perlphery of the liner 138 beginnlng
at~edge 176 of l~ngitudinal edge 174 and being offset from the
t
~ termination point 182 of helical edge 172. ~ -
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I ~ - As can be seen in Figure 5, the trailing flange lOB
3Z80
- follows the helical edge 172 and enters chclnnel 180 leaving
edge 172 a~ poin~ 1~2. The leading edge 10~ is momentarily
engaged by edge 176 of longitudinal edge 17~ and extends into
channel 180. Tile relationship of points 182 and 176 are such
that leading edg~ lOA and 10B are guided into an abutting
engagement in chclnnel 180 in approximately the center a~lay from
the walls thereof. It is in channel 180 that the flanged ends
lOA and lOB are heated sufficiently to cause thcm to melt and
to become the filler of the welded helical seam of the tubing.
Thus, as can be seen from Figures 4 and 5, ~ simple guide liner
138 has been provided which engages the interior side of flanges
lOA and 10B and ~uides these flanges 1nto abutting engagement
where they are welded together without the use of a multitude
oE mechanical suhassemblies.
The liner 138 terminates in a shoulcler 184 whLch is
secured between the end cap 140 and the housing 130 and received
in an aperture 1~6 o~ end cap 140. It should be noted that ~ - -
liner 138 is rot~ted about the axis of tbe llousing 130 until
points~182 and 176 are properly aligned rela~ive to the ~eed
; 20 o~ the sheet material lO to produce the desired abutment in --
.
channel 180. Once this adjustment has been made, the end cap
.
O is~secured in place to lock the guide sleeve 138 relative
~` to the`housing 130 and the arbor 132.
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The formin~ box 30 and the liner 138 must be made so that
the entering stri~ main~ains an anyle of 4$ I 2 to the center~
line of the formil~g box and arbor 132. An angle of less than
45 results in a longer welded seam in relation to the lenyth
of finished tubinc~ than is required. One vi~tue of this inven-
tion is its simplicity and lack of complicated parts or adjust- -
ment. A forming ~ox, liner and drive rolls must be provided
for each different size of tubing made. With the 45 angle held
constant, a change in the diameter necessitates a change in the
width of the strip. The proper width is ascertained by tri-
gonometrical calculation well known to prior art, -- diameter
desired, X 1~ X sine o angle = width of srip required. This
will be the width of drive roller 110. The material must be
wider to allow for the flanges turned up on each side. For opti-
mum weldinq these flanges must be at least 3 times the thicknessof the metal. Also liner 138 must be made with a helix angle
of 45 and the lead of helical edge 172 and tlle length of edge
174 must be determined from this.
If the anqle M, between the material 10 feed and the
centerline of forming box 30 is increased from 45 to aproxi-
mately 46 to a8 and more preferably from 47 to 47 3/~ , then
natural flexing of the material will assist in holding the edges
or flanges 10A and 10B together without usin~ the gulde edges
17~ and 178.
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1 ~ TUBING DRIVE ROLI.~R ASSEMBLIES 50 AND 70
;, 20 Tubing~drive roller assemblies 50 and 70 as shown in
Figure 1 are drivell by motors 188 connected to a sprocket 190
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by chain 192. The sprocket 190 is secured to shaft 193 shown
'~ in Figure 7 upon ~/hich the lower roller 19~ is formed by machining,
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432~30
As may be seen in ~igure 7, the lower roller 194 has a slot 196
in the center thereof to receive the welded seam of the tubing
45 and allow it to pass through the drive rollers. It should
be noted that slot 196 may be provided in the top or bottom
roller depending u~on the orientation of th~ ~ubing drive roller
assembly relative to the axis of the tubing '15. The top and
bo-ttom rollers ar~ l-nachined to have hyperbolic surfaces which
produce the required torque on the tubing 45 The shaft 193 is
journalled between a pair of brackets 198 which are secured to
a base 200. Also secured to the base 200 is vertical support
202 to which are secured horizontal support 204 and 206. The
other end of horiæontal support 204 is secured to the pair of
brackets 198. , ~ -~
Journalled between the horizontal support 206 and a cap 20
is top roller 210. The cap 208 is secured to the horizontal support
206 by bar 212. I'he drive rollers 194 and 210 have axes which are
90 to each other and receive the tublng 45 at 45 angles relative
to their individua3 axls. m is angular relatlonship and the hyper-
~olic surfaces provide maximum surface contact with the tubing 45.
~The motor~188 keeps the rollers overdriven in speed and slip on ~ -
the welded tubing 45 so as to draw the tubing 45 from the forming
box and to~maintain a torque thereon besides merely driving them
into the~cutter 60. The torque twists the tubing in the direction
to-tighten~the helix. This prevents the edges from separating
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lQ~3~280
before the weld s~s and cools. It should be noted that horizon-
tal support 206 is pinned at 214 to vertic~l support 202 so that
horizontal suppor~ 206 and top roller 210 may be raised relative
to the bottom roll~r 194 so as to admit the ~ubing 45. -
S As shown in Figure 8, roller drive ~ssembly 70 is essen-
tially like drive roller assen~ly 50 having modifications indicate~
thereafter. Secured to base 200 is a pneumatic cylinder 216
having a rod 218 e~:tending therefrom and pinl-ed at 220 to the
upper horizontal support 206. Support 206 ls modified so as to
receive the end of rod 218 and the pin 220. ~n opening also is ~;
provided in the lo~^~er horizontal support 20:~ to accommodate the
cylinder 216 and i-ts rod 218. A stop 222 i5 secured to horizontal
support 204 by a ]ock 223. As expIained briefly in the intro-
duction and the dlscussion of ~igure ~, when electric eye 90 s
not actLvated by tubing, port A of cylinder 216 Figure 8 is
pressurized thus raising top roller so that space between rollers -
is greater than t~ing diameter and tubing can freely enter.
When eye 90 detects tubing it acts through a 3 second (approxi-
mately) delay mechanism to exhaust port A and pressurize port B
thus lowering arm 206 and holding it~against stop 222. Stop 222
is set~so~the space between rollers 194 and 210 is .OlO to .015
~less than~the tubing diameter, thus giving a firm drive to the
~tube but not cru~hing it. When the flying cut o~f cuts the tubing~
15 -
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the cut section is drive ~ away from the cut o~ by drive at a
faster speed than it is coming to the cut o~f. As the cut end
passes under the electric eye, port B is exh~usted and port A lS
pressurized thus releasing the tubing, at the same time air
cylinder 96 (Fig. L) pushes the tube off t~e ci~rrier 95 (Fig. l).
As new tubing passes under the electric eye ~he cycle is repeated. : :
- While drive assembly 50 drew the tubin~ 45 from the
welding station 40 into cutter 60, the drive assen~ly 70 drives
the tubing from cutting station 60 onto the support 95. As
explained for drive roller assembly 50, drive roller assembly 70
is overdriven so that when the tubing is cut, the cut portion is
accelerated and wis];ed away from the cutter ~0 through the top
and bottom rollers 210 and 194 of the drive roller assembly 70
once the cut edge leaves the drive roller assembly 70 and passes ~ .
i lS electric eye 90, cylinder 216 is reactivated to lift top roller
2lO to receive the cut end of the next section. :
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FLYING CUTTER 60
The flying cutter 60 is shown in detail in Figure 9 and
has a support bracket 224 with a pair of vertical members 226. . .
``~ 20 Pivota11y secured~to support members 226 is a pi~otal carrier 228.
Journalled into the carriage~228 is a fluted shaft 230 having a
Gtop bar 232 thereot~.- Also on shaft 230 is the circular cutter
234. The shaft 230 is driven~by a motor 236 connected thereto by
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a belt 238. At ~he rear of carriage 228 is a combination air
and oil cylinder 240 having a piston rod 2~2 pinned to the
carriage 228 at 2~4 and secured at the other end thereof to the
horizontal support 100 at 246. Cylinder 240 causes the carriage
228 to rotate around the horizontal supports 226 so as to raise
and lower the circular cutter 234. The interior of cutter 234
....
is grooved so as to fit within the fluting on rod 230 so as to . ; .
be driven thereby. As the cutter 234 enga~es the tubing 45, it
rotates so as to cut through the width and ~ides along the fluting
on rod 230 so as ~o cut the tubing 45 on the fly and not impede I .
the continuous formation of the helical wound tubing in the .. :
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forming and guide box 30. Once the clrcula.r blade 234 cuts
through the tubing 45, the control circuit rotates the carriage
228 by deactivating cylinder 240 out of the plane of the tubing
45 to allow it to proceed further down the line.
To return the blade.234 to the initial position against
` stop 232, a blast of air is provided by no~zle 248 secured to ~ :
the carriage 228. The hlast of air intersects the blade 234 and
~sends it back along the fluting 230 to the stop 232~ As will
be explained more fully hereinafter in the control section, two
limit~switches are provided in the cutting assembly 60 so as to
~: sense the up and down final position of the carriage 228
.
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~343~80
THE TUBING, T~IE FIL'I'E`R CORE AND T~IE FILTER
As indicated previously, an important f~ture of this
invention, as seen in Figure 5a, is that the lleight of the
flange B is at least three times the thickness of the sheet
lOA's thickness a. The overall flange height c obviously must
be at least four tin~es the thicknes~ a as the dimension c
includes the initial thickness of the sheet. When the tube
lOX is formed with the weld lOD, it should be noted that the
height of the weld h is greater than the thlckness a. In
adjusting the weld;ng head, it has been founcl desirable in
some instances to cause a slight bit of irregularity in the
weld, thereby makin~ the weld appear as in lODj where it is
slightly jagged or serrated. The jaggedness of the weld
assists when fiber roving lO00 is wound over ~he tube when
it is cut to length and used as a filter core, as shown in
Figures 5E and F.
Since no weld material can be added to these thin flanges
in order to secure them together, the form of welding used
,
I requires heating the edge material to form the welded seam.
,
In order to have a sufficient amount of material available,
it has been found that the height of the flange must exceed a~
least three times the thickness of the material or a satis- ~
factory weld cannot be produced. Previous attempts-at trying ;
~ to form spirally wound welded perforate tubes hav~ing a size
!
~ range 'of ~ 5/8" diameter to approximately 3-1/2" diameter have
~ailed when uslng t~lin walled material ranging from 5 mils
;to 30 mlls while~the invention hereof achieves such a tube.
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1~432~
In addition, it has been found, quite surprisingly, that ;
in order to provi(~e perforate tubes having these small
diameters it is necessary to go to resort thin walled
tubing. It has been found that the followin~ range of
:
tube diameters can be successfully made from the indicated
thicknesses of sheet metal materials~
,' , ' '
TUBE DIAMETER RANGE OF SI~EET METAL T~ICKNESS
' . ' ~' '
5/8" - 1-1/4" .005" - .015"
,
1-1j4" - 1-3/4" O005" - .015"
~, .
1-3/4" - approx. 2-1/4" .008" - .020"
- ,
j 2-1/2" - approx. 3-1/2" .015" - .030"
(and greater~ ~
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In one specific embodiment of the invention, stain-
I less steel and lo~ carbon steel sheets havin~ a thickness
I of approximately .011" are formed into tubes having a
j 15 diameter of approxilnately 1-1/8" and rough serrated weld
seam having a height h of approximately 1/32" to 1/16".
~This seam~corresponds in appearance to the cross SeCtlOn
and the`serrated edge seam lODj of Figures Sc ~nd~5e. ~ ~;
When the tubillg lOX;is cut to precise lenqths, the
20;~ tubes~lOX~can be~pl~ced on a machine such as that taught
in U.S.~Patent No. 3,356,227, where a diamond fiber roving
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wind will be applied to the tubing. Quite surprisingly -
t and ~uite advantac3eously, it has been found that the
raised serrated welded seam 10D and lODj su~stantially
aid the roving 1000 to grip and maintain its position
while .being wound over the tube lOX. In act, it has
been found that filters which are roving wollnd over filter
coxes lOX make superior filters due to the f~ct there is
no relative movement between the body of rovings 1000
and the filter core lOX.
As long as the metal forming the tubin~ is capable ..
of being welded without the addition of weld material,
the tubing may be made from any meta~ includ.ing stainless
steels, medium carbon steels, tin steel and the like, but
not limited thereto. ~ecause the method and apparatus of
this invention are capable of producing the thin welded
tubing, it has been found quite advantageous to have special
. tubing made from stainless steels, such as type 304, type
316 and type 347; and,in another specific embodiment of .
the invention the thickness of the metal ranges between .
- .
.009" and about .013" and having a diameter of approximately . ..
1" to 1-1/4". Filter cores of this particular size and ::~
diameter when overwrap wlth roving 1000 provi.de exceptionally
good filters and in certain instances the amount of roving ..
; . may be ~ reduced when ~ompared to a standard filter due to the ...
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25 ~ ~ ~act that during the winding operation the fiber roving does .
not move~relative~to~the core. The roving materials may be .
. ., ~ .: . .
made of~ staple fibers; selected from cotton, gla.ss, nylon, : -:
rayon, polyester and other synthetic materials, but not
limited thereto. ~ .
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ELECTRIC~L SC~ ~TI(' ~43~
The electrical schematic, as shown in Fiyure 10, has the
AC input power connected across a main power up switch 248 ~ -
through two fuses 250. Out of fuses 250 are lines 252 and 254,
respeetively, whicll complete a general circuit. Connected between
lines 252 and 254 i.s an electrie eye 90 located just ahead of . ~.
drive roll assemb]y 70 shown in Fiyure 1. ~pon detecting the
presenee of tubilly ~5 the electric eye 90 activates switeh 256 ~:
thru a short tlme c~lay ~built in eye meeh~nism) which completes
the eireuit to activate solenoid 258 whieh oFerates valve V3 to
elose rollers o~ drive roller 70 and drive tu~ing onto and along
support 95.
When tubiny travels along support 95 to the desired
random length for ~landling, lt is touehed by finger 80 whieh is
connected to low voltage thru transformer 278, this aetivates
solenoid 276 whieh eloses eontaets 274 conneeting line 252 to
solenoid 270 and OIl ~through eontaets 264 thru eontrol system
thermal relays in motor 236 ~not shown) to line 254 thus aetivating
. solenoid 270. Motor switeh 260 must be elosed, activating
solenoid 262 thus elosing eontaets 264 and 268 bPfore this ean :~
j occur, thus insuring that eut off wheel 234 cannot eontaet tubing :;45 unless motor 236 is runnin~. When solenoid 270 is aetivated
`:' ' .
contacts 282, 284 and 286 elose. Contaet 282 aetivates solenoid -
288 which feeds cut off wheel 234 into tubing and solenoid 290
25~ which cuts off air ~last holding cut o~E wheel 234 against its
... .
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~0~ 8(1
stop, leaving it free to travel with the tubiny 45. Contact 284
- activates solenoic1 292 which opens contacts 293 and holds them
open thru a secol~d time delay, thus preventing any chatter feed
b~ck thru contact 80 until after tube 45 has been pushed off of
support 95 and c~n no longer contact finger ~0.
Contacts 2~6 are an interlock thru colltacts 294 back to
solenoid 270 and hold 270 activated after colltacts 274 are open.
Contacts 294 are held closed by solenoid 236 ~ ich receives its
current from motOr 236. When cutter 234 lowers enough to cu-t
tubing 45, contac-ts 298 are opened by a cam thus deactivating
solenoid 296. However, contacts 294 are held closed by a time
delay mechanism lony enou~h for cutter 234 to travel more than
the length of one helix of the tube thus givI;lg a clean cut. As ~
soon as tubing 45 is cut thru, the severed length is driven by ;~ -
drive rollers 7~ along support 9~ and since ~ubing 4~ is now free,
::
drive rollers 70 no longer slip and tubing 45 is driven at an
. : .
accelerated rate. When the severed end passes the electric eye
90 it deactivates s~itch 256 and solenoid 258 which opens the
drive rollers, thus releasing tubing 45 and at the same time ;~
operating air cylinder 217 which pushes tubing off to support 95
:
onto storage area.
While this is happening fresh tubing ~5 is moving forward ~'
~ ~ ~rom t~he ~orming hox and as the end of it reaches ~he electric ~ ~ -
j ~ eye 90,~the eye reactivates switch 256 as described before and ~- ~
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'~ the entire cycle repeats.
It is important that solenoid 270 nll~st not be activated
unless motor 236 alld cutter 234 are runnlng. Thus, motor switch
260 operates solenoid 262 which closes cont~cts 264 and 268
making solenoid 270 live and completing the control circuit ~not
shown) of motor 236. In addition if overloz~ds interrupt the
control circuit of motor 236, solenoid 296 ~ ill not operate as
it draws its current from the motor leads. Switch 272 is a
manual switch used to cut a short length or for test purposes.
It is readily seen, and within the scope of this inven-
tion that this electrical control circuit can be easily replaced
with an air logic system.
'.
THE PNEUM~TIC COI~TROL CIRCUIT
The pnewllatic control circuit as depicted in Figure 11
has an input 300 connected to a filter 302 and a T connection
304. Out of~ T connection 304 is a regulator 306 into a lubricator
308. Out of lubricator 308 is a T connectiqn 310 having one side
connected to a four-way solenoid controlled valve V3~ The out- ~ -
put of solenoid control valve V3 is connected to pneumatic
cylinder 216 of tlle second tube drive roller assembly 70, and
' pne~unatic cylinder (with spring return) 96 ~or pushing the cut
tubing of of support ~5. The other side o~ T valve 310 is
~connected to a four-way solenoid control va]ve Vl, which is ,~
i: . : -
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.
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~L09132~0
connected to the lower half of the cylinder 240 wllich lowers the
''1 cutter assembly G0. ~lso connected to valve Vl is a muffler 312.
Connected to the other side of T 304 is a solenoid control valve
V2 which controls through needle valve 314 tlle air blas~ 248
which blows back ~he cutting blade to its ini~ial position. The
valves Vl, V2 and V3 are controlled, respeclivcly, by solenoids
2~8, 290 and 258 ~s illustrated in'Figure l0.
OPERATION
The opera~ion of the present invention begins with the
material l0 being pulled from a supply and having flanges 10A
, ' and 10B formed therein by the flange forming and drive assembl~
' 20. The ~langed m~terial 10 is then introdu-~ed into a guiding
,~ and forming box 30 wherein the trailing edge flange is guided
along a helical ~ath to come into abutting engayement wlth the ,~
~, 15 leading edge flange wherein it is heated sufficiently so that
, said flanges melt -to provide a filler material for the weld.
~ 'li 4' " ' ' ' "'', The'welded tubing 45 is driven by drive,rollers 50 past a cutter
,.
'1 assembly 60 which is pivotally controlled so as to rotate down
., :... .
into the axis of the tubing 45 and to cut it on the fly. The ';
~ : . : . .:
j 20 tubing is driven past and away from the cutter by drive roller ;--"
70 whose~drive is controlled by a sensor 90. The cutt~r 60 is '~ '-
activated by an adjustable~fee1er 80 which senses a predetermined '~,
,J : : - . :
` lenyth oe tub~og 45,
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~0~3Z~30
The presetlt apparatus and method is capable of effectively
and efficiently halldling sheet material of from 5 to 30 thousandths
of an inch to form a tube having an outside diameter from 5/8
inch on up. ~y using a single guide liner, the number of parts
required ~o shape the helically wound tubin~J is reduced to a
minimum. Produc~ion of tubing at a rate of ~80 inches per minute
is possible with the present apparatus.
Although the invention has been desclibed and illustrated
in detail, it is to be clearly understood t~lat the same is by way
of illustration ~nd example only and is not to be taken by way of
limitation, the spirit and scope of this in~ention being limited
only by the terms of the appended claims.
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