Note: Descriptions are shown in the official language in which they were submitted.
2()0~389
Pipe connectlon and a method of m~xing ~are
The ~nvention relate~ to a pipe connec~ion ~nd a method of
~aking same.
In particular the pipe connection i~ suitable for pl~stic piFee
and ho6e6.
It is known for plastic pipes which in particular consi~t of
hard polyamide to be joined together by screw connections, by virtue of
a cutting ring which iB dlsposed in the screw connectlon being pres~ed
into the pipe materiel, thereby providing the requirod adhesion to the
pipe end portion~
It has been found however that pipe connections of that kind no
longer operate satisfactorily ~en the pipes are subjected to hig~h
pressures. On the one hand it is nece~ary to ~pply a very high force to
the screw connection in order to urge the cutting ring deeply into the
material, so that expen6ive tools are required tor that purpose, and
often thQre is no~ enouyh space in order to operate therewith. On the
other hand, llmitetions are imposed by virtue of the fact that, at
hi~her pre6sure6, the cutting ring shearg off the material and thUB the
pipe connection cnr~s apart.
The objQct of ~he invention is ~herefore that of provlding a
20 pipe connection of ~he kind ~et forth in the opening part of this
~-~ 6pecification, which g~arantees a secure connection even at high
pres~ures and which can be m~de and assembled in a ~i~ple fashion. ~ -
~ he pipe ~onnection according to the in~ention is distinguished
by a support portion which is introduced into the interior of the pipe
to be connected and ~lic}l is provided with sup~ort ~urfaces, and a
clamping me~"s which is dispo6ed on the cutsidc of t~e pipe and which
has pressure ~urfaces co-operating with the support ~urfaces of the ;
support portion.
Advantageous feat~re~ and further develoFments of the invention
are characteri~ed in the sub~idiary claims,
The invention urther provides a method of nE~cing such pipe
connections, w~ich provide8 that a support portion is introd~ced into
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2~ 892
the end of the pipe to be connected and the pipe i8 thereby put into an
outwardly bulged con~iguration, and that a cla~ping meang 18 ~tted to
the bulge portion, in that a clamping portion i~ preferably fitted
behind the bulge portion o~ the pipe and a 4ealing portion i8 fitted in
front of the bulge yortion of ~he pipe and the cLamping portion and the
sealing portion are connected together.
Advantageous features of the method accoraing to the invention
are characterised in furthcr subsidiary claims. '~ ~ feature~ of the plpe
connection according to the invention g~arantee that a satisfactory
sealing action iB pr~duced, in particular even when large fluctuations
in temperature are involv~d, accompanied by resulting expansion and
~ontraction of the material.
l~)e invention will nvw be described in greater detail by means
of embod~ment~ with reference to the p~rtly sectional drawingg in which;
Fig~re 1 shows a pipe connection with an annular xece~ in the
clanping means, which is of approximately semicircular cross-section:
Figure 2 shows a modified embodlment oP the pipe con-nectlon
shown in Pigure l;
Figure 3 ~how~ a further modification of the embodi~ent of the
pipe connec~ion sh~wn m Fi.g~re ~:
Figure 4 show~ the ~peclf iG con~truction of a ~traight
- connection
Figure 5 BhOWS the specific conRtruction of a T-connection; and
Figure 6 shows an apparatus for making the pipe co~nection.
~5 ~efe~ring to Figure l, shown therein i8 a pipe conne~tion which
i~ generally identified by reference numeral l and in which a pl æ tic
pipe 2 is pu~h~ over a 6upport portion 4, in the region of the pipe end
3 which i6 to be connected. m e support portion 4 is preferably in the
form of a support ring. A cLamping means 5 ;.~ pxvvided on the pipe on
the outside thereof. The cl~nping ~an~ 5 comprises a ~eallng portion 6
and a clamping portion 8. The sealing portion 6 is in the fonm of a
fitting and i~ provided with ~ qcrewthread 7 on to which the clamping
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892
por~ion 8 is ~crewed. The clamping portlon 8 is i n the forn of a cap
nut,
Thc support portion 4 has an outwardly extending bulge as
indic~ted at Z5, which can ~e of different configurations and which in
the present case project6 in the manner o~ a taper ring, whereby
pressure ~urfaces Z6 ~nd 27 ~re formed on the support portion 4, the
pressure surfaces 26 and ~7 r~xtending inclinedly relative to the axis of
the pipe 2. The se~ling por~ion 6 has a pre~r~ure surface 28 which co-
operates with the supporL surface 26 o~ the ~upport portion 4 while the
cl~mp~ng portion 8 has a pre6sure surface 29 w~lich co-oper~tes with the
~ Bupport surface 27. The support surfaces ~6 and Z7 can cx~ne together at
a polnt but it is also pos6ible for ~ sli~htly rounded conflguration to
be provided at the tip 30 thereof. Extending in the direction away from
the end of the pipc 2, the support portion 4 is prcvided with a taper
portion which, although thi~ i~ not shown, may ~l~o comprige a tubular
extension portion 31. Provided in thc sealing portion 6 in the region of
the inner wall ~urf~ce 14 o~ the pipe 2 is a recess 9 in which the end 3
of the pipe comes to l1e. If, a~ a re~ult of variations in temperature,
the material of the plastic pipe 2 contraets 50 that a cert~in ~pace i~
fonmed in the recess 9, a particular ~ealing effect is achieved by
virtue of the fact that the end 3 of the pipe comes to lie flnmly
ag~inst the/~ ~ ~ ~ Cgt ~ ansr 10. In order to enhance that a~tion, the
rece6s 9 may ha~e an outwardly extending front curved portion 11. The
- recess 9 i~ shown in the fonm of ~ circumf~rentially extending ring
portion o~ ~ubstantially semicirc~lar crOss-section, but it may also
comprise an inclined~y outwardly extendin~ slot into which the end 3 of
the pipe i~ inserted when th¢ pipe connectlon is made. The lot
approxirately corre~ponds to the gauge of the wall of the end 3 of the
pipo, ~nd here too a particularly good sealing effectOni8tr~lcc~leOvnedO~ ln
30 the case of a shrink~ge operation, at a corre ponding/notching mean~ 10.
In the ~nbodiments shown in Figures 2 and 3 the reces~ 9 is
provided on the inwardly dispose~ support portion 4. In other respect~
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the same components are identified ~I Pigures 2 and 3 by the ~ame
reference nu~eral~.
AS can be seen from Figure 2, the inwardly disposed cupport
portion 4 h~ an outwardly extendlllg flange 15 and thereby forms a
~odified, outwardly open recess 16 into which the end 3 of the pipe 2 to
be connected come~ to lie. The flange 15 of the support portion 4 is
provlded with a projection 17 which engage~ into a co~plementary reOeBB
in a support portion 4a of the other pipe 2a to be connected. A~ can
further be seen from Figures 2 ~nd 3, the outwa~dly di6posed sealing
~urfaces 18 may be provided with recesses in which 0-ring ~ea~e 19 are
di~po~ed.
Figure 3 show~ a recess ~ in the two inwardly disposed support
portions 4 in the form of a slot 12, altho~h the annular recess 9 may
al~o be of sub~tantially semicircular cross-section, corresponding to
the view shown in Figure 1. At any event the arrange~en~ ~as the
notchin~ means 10. It will b~ appreci~ted that it is al~o possible to
adopt combinations of di~ferent recesses ~ith 6uppor~ portion8 4 of
~itable configur~tions.
Figure 4 shows a straight screw-in connection 32, that iB to
say the two oppositely dispo~ed pipe ends pass into the rece~s 9 of a
common pipe screw fitting 6b which ~clongs to a cla ~ ing means 5, a~ is
r-~ s~wn in Figures 1 through 3, If the pipe contr~cts due to a poR~ible
shrinkage operation, then in this case also a particular sealing action
constriction or
i~ prcduced at the/notching means 1~.
25Figure 5 show6, in relation to T-connections 33, a screw
fitting 6a with a branch opening 13 which is provided with a scre~thread
and into which a pipc can be screwed. Moreover the pipe fitting 6a i5
illu~trated as having the rccesses 9 which can be of the above-described
different configurations as shown in Figures 1 through 37 in practlce,
generally either the one collfiguration or the other, na~ely either the
ann~lar recess 9 or a 610~-like ~ece66 12, ~ill be provided, rather than
different recesseR g, 12, as is ~hown in Figure 5 for the FLuqpo6es of
illustration.
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2~89~
When the clampiny means 5 is tightened, that is to say the
clamping por~ion ~ in the form of the cap nut shc~nl in Figure 1 i~
screwed fast on the sealing portion 6, the wall of the pipe 2 is cla~ped
fast between the pressure surface 28 of the sealing portion 6 and the
a6sociated ~upport surface Z6 of the support portion 4, and the preq~ure
sur~ace 29 of the clamping porti.on 8 and the associated support surPace
of the support portion 4, thus making a reliable pipe connection. The
sa~e applies even if the tWD clamping portions 8 of the clamping means
5, ag ~hcwn in Figu~es 2 and 3, are tightened together by ~eans of 8cr~w
bolts (not shown) which ~a~s through the bores 34 in the clamplng
portions 8. In ~hi~ case also the clamping surface~ 29 o~ the clanping
portions 8 co-operaLe wi~h the support 6urfsces 27 of the ~upport
portlons 4, with the sealing s~rfa~es al~o being provided in the support
portion 4.
15Figure 6 shows an apparatus ~or makiny the pip~ connection. The
sup~port portion ~ is intl~xduced in~o the el~, which has the end edge
124, of the pipe 2 to be connected, thereby producing the outwsrdly
bulged configuration on the pipe Z, at which the Glamping ~e~ns 5 is
~ount~d. In order to m2ke it easier to introduce the support ring 4, ~he
Z0 pipe 2 to be connec~ed i~ heated, which can be achieved by ~Rsn6 of a
hoL medlwm su~h as gases or oils, or radiant he~t. A pi~ton 133 is
~Lvably arranged on a fixedly dispo~ed bar 131, by way of a carriage or
slider 132, while the pipe 2 to be connected i~ fixed in relation to the
bar L31 by means of a holdin~ deviee 134. The piston 133 is of an inside
diaTeter which approxim~tely corre~ponds to that of the pipe 2 to be
connected, and on which the ~upport portion 4 c~n be fitted. In the
rogion of the f~ont cnd 135 the pi~ton 133 is tapered or has rece~e~
13~ (sh w n in broken lines) which are of considerable ~ize and which
produce a tapered configu~ation on Lhe piston. ~uct~ 137 which are
comm~nicated with a cenLral feed bore 138 open in the front region 135
of the pi~ton. The piston 133 is f~rther connected ~o an annular body
1~9 which is disposed a~ a 3pacing around the piston and in whi~h there
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2~;389~
are provided ducts 140 having ~utlets 141 which are disposed cppo9ite
the front region 135 of t~e piston 133 ~d which are directed tcw~rds
the pi~ton 133. Dispo~ed behind the pi8~0n 133 is ~ heating chamber 142
provided with a heating means 143 and a pressure fluid fe~d 144. A
te~perature sensor 145 serves to regulate or adjust the desired heating
effect in respect of the medium which flows out into the ducts 137 and
140, 1~1 by way of the feed bore 138. It is also possible to provide a
heating means (not shown) which heats the pipe 2 for example by heat
radiation. Thc rearward end of the piston 133 has a laterally extending
mounting surface 146 agaill~t whih the end edge 147 of the support
portion 4 comes Lo bear in ~he ~orward fc~d n~v~nent of the piston 133,
when the latter move6 forwardly into the interior of the pipe 2. In that
situation the heated pipe 2 is moved outwardly by the support portlon 4
which is carried on the piston 133 and the wall o~ ~he pipe 2 is pushed
over the outwardly bulged configuration of the ~upport ring 4. In that
way the 8upport ring 4 i~ m troduced into the interior of the pipe and
then the clamping meanæ 5 i~ fixed on the outside of the pipe 2, a8 ig
shown in particular in Figure~ 1 th~ough 3.
The piston 133 ~y be in the fonm of a replaceable head nember
~~~ 20 for sup~port portions 42 of dif~erent sizes, co~responding to different
inside dianeters in respect o~ the pipes 2 to be connected.
The inven~ion thus provides a relisble pipe connectlon which
can withstand high pressures and which can also be used without
involving difficulties in pipe line 6ystems which have already been
laid. Besides incxpensive production, the inv~ntion also ens~res eaoy
z3~oe~bly.
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List of reference num~ral~
~ .
1 pipe connection
2, 2a plaYtic pip~
3 plpe end
4, 4a ~upport porton
cl~mping means
6 sealing portion ~ :
~a, 6b pipe ~crew fitting
- 7 screwthre~d
8 clamping port.lon
9 annular rcoess
no'cchmg means
11 curved portion
12 slot-like recess
13 branch opening
14 boundary wall : :
flange
16 reces~
17 projection
lB 6ealing ~urface
19 C-ring xeal
bul~e porton
26, 27 support ~urface
2B, 29 pre~ure surfacc
tlp
3~ tubular exten~ion portion
3Z screw-in connection
33 T-connectionS
34 bores
124 end edge
131 bar
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132 carriage
133 pi~ton
137 ductg
138 feed ~ore
139 annular body
140 duct~
141 outlets
142 heating chamber
143 heat~ng me~ns
144 pre~re fluid feed
145 tenperature sensor
146 m~unting ~urf~cc
147 end edg~
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