CA2008892A1

CA2008892A1 - Pipe connection and a method of making same

Info

Publication number: CA2008892A1
Application number: CA002008892A
Authority: CA
Inventors: Ernst Wendorff
Original assignee: Ernst Wendorff; Hans-Peter Ruppert
Current assignee: HANS-PETER RUPPERT
Priority date: 1989-02-02
Filing date: 1990-01-30
Publication date: 1990-08-02
Also published as: KR900013240A; CN1046967A; AU4892490A; JPH02292595A; EP0380970A2; HU900632D0; EP0380970A3; HUT54787A; BR9000446A

Abstract

Abstract In a pipe connection the particularity lies in a support portion which is introduced into the interior of the pipe to be connected and which is provided with support surfaces, and a clamping means which is provided on the outside of the pipe and which has pressure surfaces co-operating with the support surfaces of the support portion. In the method of making that pipe connection, a support portion is introduced into the one end of the pipe to be connected and the pipe is thereby put into an outwardly bulged configuration, to which the clamping means is fitted.

(Figure 1)

Description

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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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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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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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~
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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 ~'~ ,"' ' . ' ' ' -: , ,.j", . . . .

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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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Claims

1. A pipe connection characterised by a support portion (4) which is introduced into the interior of the pipe (2) to be connected and which is provided with support surfaces (26, 27), and a clamping means (5) which is disposed on the outside of the pipe and which has pressure surfaces (28, 29) co-operating with the support surfaces (26, 27) of the support portion (4).

2. A pipe connection according to claim 1 characterised in that the support portion comprises a support ring (4) which has at least one bulge portion (25) extending outwardly from the periphery thereof, preferably in the form of a ring of bulged configuration extending over the periphery of the support ring, the bulge portion being pressed into the pipe (2).

3. A pipe connection according to claim 2 characterised in that the bulge portion (25) projects in a conical configuration with an angle of about 30°.

4. A pipe connection according to claim 2 or claim 3 characterised in that the support ring (4) has a tubular extension portion (31) which preferably terminates with a taper configeration and an angle of about 10°.

5. A pipe connection according to one of claims 1 to 4 characterised in that the clamping means (5) comprises a clamping portion (8) disposed behind the bulge portion (25) and a sealing portion (6) arranged in front of the bulge portion (25), the clamping portion and the sealing portion both being connected together.

6. A pipe connection according to claim 5 characterised in that the sealing portion (6) is provided with an external screwthread and the clamping portion (8) is screwed in the form of a cap nut on to the sealing portion (6) or that the sealing portion (6) and the clamping portion (8) arc connected by means of a screw connection (34).

7. A pipe connection according to claim 5 characterised in that the clamping means (5) comprises two clamping portions (8) which are connected together.

8. A pipe connection according to one of claims 1 to 7 characterised in that disposed in the region of the end of the pipe is an annular recess (9) of preferably substantially semicircular cross-section, into which the end (3) of the pipe can be inserted, and that the recess (9) is provided with a constriction or notching means (10) in the region of the opening through which the end of the pipe can be inserted.

9. A pipe connection according to one of claims 1 to 7 characterised in that the recess (9), of substantially slot-like configuration (12), corresponds to the thickness of the wall of the pipe (2) to be connected, and extends inclinedly outwardly.

10. A pipe connection according to one of claims 1 to 9 characterised is that the end of the pipe (3) extends inclinedly towards the end between the inwardly disposed support portion (4) and the outwardly disposed clamping means (5) and the recess (9), in the vicinity of the inner wall surface (14) of the clamping means (5), bends over the end (3) of the pipe in an outward direction.

11. A pipe connection according to one of claims 1 to 9 characterised in that the support portion (4) which is disposed in the pipe in the region of the end (3) of the pipe to be connected has an outwardly extending flange (15) and forms a recess (9, 16) for the end (3) of the pipe.

12. A pipe connection according to claim 11 characterised in that the flange (15) of the support portion (4) is provided with an annular projection (17) which engages into a complementary recess in a support portion (4a) of the other pipe end (2a) to be connected.

13. A method of making a pipe connection according to one of claims 1 to 12 characterised in that a support portion is introduced into the end of the pipe to be connected and thereby a bulge configuration is imparted to the pipe and that a clamping means is fitted to the bulge portion.

14. A method according to claim 13 characterised in that the pipe to be connected, comprising in particular a plastic material, is heated, and that the support portion is pressed into the pipe from the end thereof

15. A method according to claim 14 characterised in that the pipe to be connected is heated by heat radiation or by means of a medium comprising a gas or a liquid.