Note: Descriptions are shown in the official language in which they were submitted.
The present invention relates to a pipe connection
in which facing pipe end portions are clamped together and
to a clamping collar for use therewith.
Pipe connections with clamping collars are known
in the prior art, in which the individual segments of the
clamping collar are locked together by tangential bolts. Such
constructions are expensive to manufacture and involve either
expensive wing nuts requiring much space for the tightening
operation or a special-purpose tool. Another type of const-
ruction which is neither equipped with a lever lock nor witha screw closure, is suitable only for very small internal
; pressures, if at all.
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The present invention seeks to avoid these
disadvantages and to provide a very inexpensive pipe
connection which can be established by the use of a very
simple tool and which also is able to withstand high pressures.
In one broad aspect, the invention consists of a
pipe connection between a first and a second part, the first
part being a cylindrical tube provided with an inclined wall ~ 1.
portion formed by a flared lip extending at a first angle to
the longitudinal axis of the tube, and the second part
including means providing a wall portion outwardly inclined
at an angle approximately similar to said first angle, and
~- including means for limiting movement of the two parts towards
each other, characterized by a clamping collar having an
annular portion operable to be tightened by contraction in
the radially inward direction and having an approximately
U-shaped lnternal cross-sectional profile providing internal
surfaces that are approximately complementary to the inclined
wall portions of said first and second parts, so that in the
contracted condition of the clamping collar the inclined wall
portions and therewith the first and second parts are urc~ed
- toward each other and into enyagement with said limiting means
to form a tight connection, wherein said clamping collar has
at least one plas-tically deformable, lug-shaped bulge means
in its annular portion, said bulge means being capable of .
belng contracted by plastic deformation for the purpose of
tightening the collar and the~eby establishing a permanent
pipe connection safe against unintentional opening and
. capable of withstanding relatively high pressures and
- ~0 vibrations, and which can be opened only by destruction of
the clamping collar or its bulge means, said U-shaped
internal profile extending over at least a substantial portion
. of the circumference of said clamping collar exclusive of
` said bulge means.
;~ In a more specific form, the invention consists of
a pipe connection comprising pipe end portions provided with
substantially axially symmetrical enlargement means and a
: clrcumferentlally extending clamping collar means hav.ing an
annular portion operable to be tightened by contraction in
20 ~ .the radially inward direction and providing an approximately
: : U-shaped profile at the internal surface thereof in a cross-
:sectional plane containing the axis of said clamping collar
means and parallel thereto, at least one of the two parts
consisting of the internaI surface of the clamping collar
means and end faces of the enlargement means faciny away
from the respective extreme ends o~ the pipe end portions
being inclined to the pipe axis in said cross-sectional plane,
80 that, in the c:ontracted condition oE the clamping collar
. means, the pipe end portions are urged toward each other, at
~30 least one sub~tantially plastically deformable lug-shaped
bulge means being provided in the annular portion of the
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clamping collar means, said bulge means being capable of
being contracted by plastic deformation for the purpose of
tightening the ring and thereby establishing a permanent pipe
connection safe against unintentional opening and capable of
withstanding relatively high pressures~ said U-shaped profile
e~tending over at least a substant:ial portion o~ the circum-
ference of said clamping collar means.
One obtains with rings, applied according to
specific embodiments of the present invention, a very
inexpensive yet at the same time very dependable pipe connect-
ion which can be realized and established with the simplest
possible tools.
In a specific embodiment of this invention, the ~ ,
clamping collar provided with a ring having a U-shaped profile
of the internal surface is unitary, i.e., in one-piece and is
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characterized by utmost ineXpensiveness. Added thereto is
~the fact that a larger de~ormation effort is required for the
contraction of the lug~shaped or ear-shaped bulge of a ring
having a U-shaped profile of the internal surface than for
20~ a ring having a cylindrical internal surface (as previously
provided), whereby also the resistance of the material to
; ~ expansion or reopening of the bulge is correspondingly
greater, whence this type of construction presses the joining
edges of the pipe ends together with extra reliability and
forcefullness.
According to another specific embodiment of this
invention a short seation of a pipe piece which abuts flush
against the inner surfaces of the pipe ends and which axially , ~
overlaps the jOiIlt area may be provided on the inside of the ~`
pipe ends, whereby an annular seal arranged between the
,.
joining edges and surrounding the short Piece of pipe is
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prOvided~ whereby the bulge of the ring of such embodiment is
preferably provided with a notch or groove within the area of
; its apex. On the one hand, a reliable axial alignment of the
pipe ends is assured in this manner and, on the other, the
seal is reliably held in its radial position between the
joining edges of the pipe ends ancl thereby ensures that the
bulge does not fold up when being contracted so that only the
material in the area of the leg portion of the bulge is being
deformed during contraction. This ensures a secure and
reliable contracted condition of the ring, capable of
elastically absorbing also a diameter change of the pipe ends,
as under temperature effects.
The notch or groove thereby presents an approx-
imately elliptical or circular form extending in the direct-
ion of the ring circumference. This type of construction
results in an especially stable apex of the bulge.
The invention also consists of a one-piece clamping
collar for use in making a pipe connection between a first
and a second part, the first part being a cylindricaI tube
provided with an inclined wall portion formed by a flared lip
extending at a first angle to the longitudinal axis of the
tube, and the second part i.ncluding means providing a wall
portion outwardly inc].ined at an angle approximately similar
to said flrst angle, and including means for limiking move-
ment of the two parts towards each other, sald collar
comprising (a) an annular portion operable to be tightened
by contraction in the radially inward direction and having
an approximately U shaped internal cross-sectional profile
for provi.ding internal surfaces approximately complementary
; 30 to the inclined wall portions of said first and second
parts, and (b) at least one plastically deformable, lug-
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shaped bulge means in said annular portion, said bulge meansbeing capable of being contracted by plastic deformation for
the purpose of tightening the coll.ar, (c) said U-shaped
internal profile extending over at least a substantial portion
of the circumference of said clampihg collar exclusive of
: said bulge means.
These and further features and advantages of ~ !
embodiments of the present invention will become more appar-
ent from the following description when taken in connection
with the accompanying drawing which shows, ~or purposes of
~ illustration only, various embodiments in accordance with
; the present invention, and wherein:
Figure 1 is an axial cross-sectional view through .
a pipe connection according to an embodiment of the present
invention; ~.
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Figure 2 is a cross-sectional view taken along line I-I of
Figure l;
Figure 3 is an axial cross-sectional view through another em-
bodiment of a pipe connection in accordance with the present invention,
and
Figure 4 is a cross-sectional view taken along line III-III in
Figure 3.
Referring now to~the drawing wherein corresponding parts are
designated hy the same reference numerals throughout the various views,
and more particularly to Figure 1, this figure illustrates the pipe ends
1 and 2, which are provided with axially symmetrical Lips or flarings
..
5, 6 within the area OI their joining edges 3, 4. In the illustrated
embodiment, the lips or flarings 5, 6 are constructed as trumpet-
shaped enlargements of the pipe ends which are formed by flaring
the pipe ends. The surEaces 7, 8 of the lips 5, 6 opposite the joining
edges 3, 4 are bevelled off in the direction toward the pipe axis, i. e.,
are inclined toward the pipe axis. A clamping collar 9 having a U-
shaped profile of the internal surface (Figure lj is adapted to be
tightened radial~ly inwardly. Its internal flanks 10, 11 are also bevelled
off, i. e., inclined toward the pipe axis, so that, in the tightened con-
ditiorl of the clamping collar 9, the joining edges 3, 4 of the pipe end~
1, 2 are pressed again~t each other. It wouLd be sufficient as such, if
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only the lip faces facing awa~ frorn the joining edges or if' only the internal
:faces of the clamping collar were bevelled off, i. e., inclined toward the
pipe axis; however, the establi~hing of the pipe connection is considerably
Eacilital;ed if both the mentioned faces are constructed so as to
10tj454~
be inclined toward the pipe axis.
The clamping collar 9 is constituted by a ring which is provided
with two plastically deformable lug-shaped bulges 12, 13 capable of being
contracted for the purpose of tightening the ring. In the illustrated embodimen
only the bwlge 12 is contracted, so that the clamping collar 9 is not yet
fully tightened. Only after also the bulge 13 is contracted, either with an
ordinary pair of pincers or, in an assembly line production, with pneumatic
pliers, will the clamping collar 9 be completely tightened. It can ibe seen
from Figure 1 that the ring 9 has a comrex external surface. For this ~1'
reason, the pair of pincers, by means of which the ring is tightened, is
preferably provided with corresponding recesses in its jaws.
Arrangedl on the inside the pipe ends 1J 2 is a short pipe section
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14 which axially_overlaps the joinin~_edges 3" 4 and rests snugly against
the internal surfaces OI the pipe ends. A ring ~ is arranged between
5 ~ : t~e joining edges 3, 4 which surrounds the pipe section 14. -
In the pipe connection according to Figure 3, the pipe ends l, 2
, .
are provided wi~hin the area o~ their joining edges 33, 44 with lips 55, 66
in the form of ring flanges which are integral with the pipe ends. The !.
îaces 77, 88 opposite, i. e., facing away Erom the joining edges are also
~20 ~ ~ ~bevelled of, l.e. ~ inclined toward the pipe axis.
The interrlal radial portion of the clamping collar 99 is formed
r tWQ ring segtnents 100 having a U-shaped profile at the internal surfaces
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t hereof and c~rlindrical-conical external sur~aces, while the external radial
portion of the clamping collar 9~ is formed by a ring 101 which is provided
~; 25 ~ With two plastically deormable lug-shaped bulges 12, 13. The internal end
face~s 110, 111 o~ the ring segments 100 are bevelled off, i. e., inclined toward
the pipe axisJ corre8ponding to the end faces 77J 88 of the lips 55, 66 facing
away rom the joining edges 33, 44. Instead OI having a single ring 101, ~ ,;
it is aIso possible to use several rings, which are then arrangecl symmetricall,
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with respect to the joining edges 33, 44 in the axial direction of the pipe.
It is expedient at any rate to provide -the edges or end faces of the ring
segments 100 with flanges to prevent a slipping-o~ of the rings 101 having
cylindrical internal surfaces.
The lug-shaped bulges 12~, 13 are each provided within the area
of their apices with an indentation or groove 16 having an elliptical or
circular form extending in the direction of the circumference of the ring
which serve to stiffen and reinforce the apex portion of the bulges 12, 13.
The insertion of the short pipe section 14 is not absolutely
necessary, depending on the prevailing conditions. ~,
While I have shown and described only two embodlments
in accordance with the present invention, it is understood that the same
~: ~ is not limited there~o but Is susceptible of numerous changes and
modifications as known to those skilled in the art and I therefore do not
'~ 15~ wiBh to be limited to the detalls shown and described herein but intend
to cover all such changes and modifications as are encompassed by the
scope ~of the appended claims.
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SUPPLEMENrARY DISCLOSURE
Further emhodiments of the invention are illustrated
in Figures 5 to lSb.
Figure 5 i5 a cross-sectional view through a pipe
connection according to an embodiment of the present invention
for applications under extreme temperatures with a beaded pipe
insert section and with two flat high heat resistant seals; ~-.
Figure 6 is a cross-sect:ional view through a modified
embodiment, similar to Figure 5, in which the ends of the
10 pipes are flared over predetermined axial lengths to receive ~ ~
within the widened portions a short pipe insert section with ~ `
an inner diameter corresponding to the full normal inside
diameter of.the selected tubing; ::
Figure 7 is a cross-sectional view through still
another embodiment for high temperature applications, in
which the short pipe insert section is obviated by providing ~ :
a bead near one end of a pipe itself;
Figure 8 is a cross-sectional view through a
further modified embodiment, similar to Figurel, in which the
20; :pipe ends are flared over predetermined axial lengths to
receive within the widened portions a short pipe insert section
with an inside dia~eter corresponding to the full inside
diameter of the selected tubing;
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Fl.gure 9 i9 a cross sectional view of a pipe
:connection in accordance with a further embodiment, similar
to Figure 8, in which instead of widening both pipe ends, a
small prefabricated ~iece of flared tubing is slipped over the .:
unflared tubing;
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Figure 10 is a cross-sectional view through a pipe :~:
30: ~ connection, in accordance with another embodiment, in which
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pipe~ends are deformed so as to eliminate the need for a
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separ~te pipe insert section;
Figure 11 is a cross-sectional view illustrating
the use of a special plug possibly with a valve to close the
pipe end by the use of a pipe connection in accordance with
yet another embodiment;
Figure 12 is a cross~sectional view through a
threaded adapter member for use with a pipe ConnectiOD. in
accordance with a still further embodiment, utilizing a
threaded connecting member;
Figure 13 is a cross-sectional view through a pipe
connection in accordance with another embodiment utilizing an
adapter member provided with a female threaded end;
Figure 14 is a somewhat schematic elevational view
illustrating typical applications of tube connections in
accordance with embodiments of the present invention in a
system of interconnected tubes; and
Pigure 15a is an exploded view illustrating an
;angle fitting in a tube-connecting system and illustrating
the advantages realizable thereby over a corresponding prior
20 ~ art angle fitting illustrated in Figure 15b.
Figure 5 lllustrates an embodiment of a pipe . ~
connection according to the present invention which can be : i:
used for special appl:lcations under e~treme heat or temperatures.
This~:embodiment dif:Eers from Figure 1 in that the short pipe
insert section 114 :Ls prov.lded by a more or less centrally
: ~ arranged bFad gencrally designated by reference numberal 115
which is defined by inclined wall portions 116 and 117 formed
by conventional means in the tube section 114. The wall portions
a~re thereby~incllned to the tubing axis at an angle substantially
~30 ~similar to the angle of inclination of the flared lips 5 and 6.
Plat gasket-like seals 118 and ll9 made of high heat-resistant .:
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material such as asbestos are placed between the external
surfaces of wall portions 116 and 117 and the internal
surfaces of the flared lips 5 and 6. As to the rest, the
arrangement of Figure S is similar to that of Figure 1, but
provides a stronger mechanical COrlneCtiOn than the construction
of Figure 1. Moreover, this arranglement can also be used for
relatively high temperature applica~ions without any seals;
- For lower temperature applications, either rubber or Teflon
gaskets may also be used or Teflon tape may be wrapped around
the bead 115.
The embodiment of Figure 6 differs from that of
Figure 5 merely in that the pipes 1 and 2 are flared over
predetermined axial lengths to form widened portions 1' and 2'
to receive a short pipe insert section 114 which has the same
ineernal diametric~dimension as the normal inside diametric
dimension of the used pipes or tubes 1 and 2. Flow losses or
restrictions are avoided in this manner in the pipe connection
according to the present invention.
Figure 7 differs from Figure 6 in that the bead 115
20~ with wall portions 116 and 117 is formed in the pipe or tube 2
itsel~ near the free end thereof. The flat gasket-like seal
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118 is thereby accommodated between inclined wall portion 116
and flared lip 5 while the clamping collar cooperates wlth the
~sxternal surEace of flared lip 5 and wall portion 117. This
arrangement obviates the need Eor a separate short tubing insert
114~while the use of the widened portion 1' of pipe or tube 1
again ellminaees flow restrictions in the pipe connection of
the present invention.
Figure 8 illustrates the use of widened pipe portions
~30~ snd 2' provided by additionally flaring the pipe end portions
m~inimize flow lossei~3 in a pipe connection according to Figure 1. ';
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5~4
As mentioned above in connection with Figure 6, this arrange-
ment is of advantage where the full inside diameter of the
tubing is required without flow restriction. Moreover, this
arrangement also assures the proper location of the tube
section 14 (Figure 8) or of the tube section 114 (Figure 6)
within the pipe ends. Hence, the additional costs of flarlng
the pipe or tube ends to provide the widened portions 1' and
2' can be accepted where this or these features are of
sufficient importance.
In the embodiment of Figure 9, a small prefabric-
ated piece of flared tubing 202 with a flared lip 206 is
slipped over and fixed to the unflared tubing 222. This
arrangement obviates the need for widening both tube ends ~-
by flaring the same, yet again eliminates flow restriction
and obvistes the need for a separate pipe insert.
With the use of a rubber-like ring ~seal 15, it
may even be unnecessary to fix the flared tubing 202 onto the
unflared tubing 222 since the sealing ring 15, when compressed
by the contraction of the clamping collar 9, will exert
20~ sufficient frictional force on the tubing 222 to prevent any
axi~al novement thereof relative to tubing 202. While the
frictional retention ls able to withstand substantlal forces,
relative axial movement between the parts 202 and 222 can be
further prevented, if necessary, for example, by the use of
a center punch or pricking tool whlch may be applied at one
or more circumferentially located areas on the tubing 202,
thereby indenting the same and also correspondingly indentlng
the inwardly disposed tubing 222 ~o provide a detent type
connection. In the alternative, if a ~still stronger
30~ connection ls to be established between ~he two parts 202 and
Z22, a conventional tub-cutting tool wi~h a rounded-off roller
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may be used in a conventional manner to produce a
circumferential groove simultaneously in both parts 202 and
222.
The arrangement of Figure 9 is particularly
useful, for example, when the tubing 222 is of conventional
; stock and is to be connected with a flared fitting, for
example, a T-shaped fitting with a diameter corresponding
to portion 1' and specially made for use with the pipe
connection of the present invention.
Figure 10 illustrates a pipe connection of the
present invention for applications requiring larger quantities.
In that case, the pipes or tubes 2 are automatically deformed
near their ends by conventional means to provide a bead-like
projection generally designated by reference numeral 315 which ~-
i8 formed by an inclined wall portion 316, corresponding in
its inclination to lip 6 of Figure 1, and by a generally
outwardly extending portion 317 against whlch the seal 15 abuts
reinforci~ngly. The clamping collar 9 cooperates with the
outer surfaces of the flared lip 5 and of the wall portion 316.
In the alt~ernative, as shown in the lower half of Figure 10,
a flat~gasket-like seal 318 may be interposed betwee~ flared
p 5 a~nd wall portion 317' of bead-like pro~ection 315,
whereby a wire ring 319 or the like will reinforcingly support
the wall portion 316' , if required. The clamping collar 9
then cooperates with the outer surface of flared llp 5 and the
supporting wire 319.
Figure 11 illustrates how a pipe connection can be
used to close off the open end of a pipe or tube by the use
oE~a special plug generally designated by reference n~eral
~30~ ~430 which i9 provided with mutually inclined surfaces 431
and 432, whereby the lnner surface of lip 5 cooperates with
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the outer inclined surface 431 while the clamping collar 9
acts on the outer surface of lip 5 and on the inclined surface
432 of plug member 430. An 0-ring 435 is provided in annular
~roove 436 to provide proper fluid-tightness. Moreover, instead
of being solid throughout, the plug member 430 may be.provided
with a threaded bore 437 to threadably receive a valve of any
conventional collstruction (shown in dash and dotted lines)~ -
Figure 12 shows a threaded adapter member generally
10 designated by reference numeral 530 to enable a tube or pipe
connection in accordance with the present invention with a
structural part (not shown) such as a carburetor, provided
with a bore having a female threadS into which a threaded -~
nipple is screwed in the prior art for purposes of connecting
thereto a pipe or tube. The adapter member 530 includes a
threaded section 531 on one side thereof, intended to be :
screwed into the structural part, an unthreaded section 532
adapted:to receive over the same the flared end 6 of a tube 2
(shown in dash and dotted lines~ and a bead-like pro~ection
20~ ;~generally designated by reference numeral 535 and formed in
the~adspt~er member itself by wall portions 536 and 537. The
clamping collar 9 thereby cooperates with the outer surface
of~f:lared lip 6 and with the outer surface of wall portlon 536.
To facilitate installation of the adapter member 530 into the
structural part, the unthreaded section 532 may be provided
wlth:a d~ametral sl.ot 539 for the lnsertion of a tool, such
as;a socket ~rench. In practice, the connection of Figure 12
~:entailed æignificant savings in cost and weight as well as
cost:of~installation over the prior art connection which
~30~ involved dooble flared tube ends, together with connecting
nuts~and requiring a housing with an internal thread and a
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special sealing cone on the inside. If the adapter member , ,
; of the present invention can be brazed onto the structural
part or formed integral therewith, e.g., by casting, the
connection will be still further siimplified. , ',
Figure 13 illustrates an adapter member generally
, designated by reference numeral 63() which is provided with
a flared lip 605 at one end thereof and with an internally ~,
threaded bore portion 631 at the other end thereof. As to
the rest, the arrangement i9 similar to that of Figure 1. " ~,
Figure 14 illustrates schematically the multiple
u.ses and possibilities which are feasible with pipe couplings
of the present invention, especially with tubing assemblies
that are now made available by applicant as standard parts. '~
Figure 15a shows, in exploded view, a pressed '
angle fitting combined with the connecting system of the
present invention. The pressed angle fitting generally
- designated by reference numeral 700 forms an elbow which
subt;ends an angle of 90 and is provided with flared ends
701~and 702. The flared end 702 is connected with the
20~ flared~end 5 of tube~l by the use of a short pipe insert 714
with a seal 715 and by means of the clamping collar 9. The
flared~end 701 is connected with the adapter member generally
de~s~ignated by reference numberal 730, which is similar to
adàpter member 530 of Figure 12, by use oP clamping collar 9
cooperating with the outer surface oE flared lip 701 and
: : :
uith the ~uter surface 736 of bead-like proJection 735,
whereby a flat gaæket 718 is interposed betwean the inner ','
surface o f Elared end 701 and the outer surface 737.
Figure 15b shows a prior art angle fittin~ made of
~ machined parts in which the elbow 800 is provided with machined
ext~e~rnal threads 801 and ao2 as well as with bores 803 and
13-- ~,
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804 intersecting at right angles, for connection with the
other parts such as pipe ~11 by conventional means such as
nut 820. Apart from the much greater weight involved witn
the arrangement of Figure 15b, the present angle fitting 700
of Figure 15a is considerably less expensive and sub.stantially
does not interfere with the flow pattern, as corltrasted to
the angular arrangement of Figure 15b.
From the foregoing, it is apparent that the clamp-
ing collar 9 in the various figures of the drzwing is effective
to tightly pull together the two parts 1, 2 or 1, 202 or 6,
430 or 6, 530 or 6,630. The movement of these two parts
toward each other is limited in effect in each of the
embodiments, for example, in Figure 1 by the end faces of the
flared lips with or without the interposition of a seal 4,
in Figure 3 by the lips 55 and 66, in Figure 5 by the flared
lips 5 and 6 in conjunction with the bead 115, etc.
The inner tubular member or section, e.g. section
14 or 114 or the equivalent in any of the other embodiments,
may be made of brass or copper, cr alternatively can either
be~made of a plastic material or coated with a plastic
material, whereby to avoid or minimise electrolytic action.
Thls inner tubular section can also be so shaped that it
eliminates the need for a sealing 0-ring or other gasket.
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