CA1195937A

CA1195937A - Soufflet de dilatation

Info

Publication number: CA1195937A
Application number: CA000418433A
Authority: CA
Inventors: Philippe Burnel; Claude Gerardot
Original assignee: Tuyaux Flexibles Rudolph
Current assignee: Tuyaux Flexibles Rudolph
Priority date: 1981-12-30
Filing date: 1982-12-23
Publication date: 1985-10-29
Also published as: EP0083889B1; FR2519110A1; DE3269915D1; EP0083889A1; FR2519110B1

Abstract

ABSTRACT OF THE DISCLOSURE

The present invention relates to expanding bellows which comprise corrugations forming an inner tubular part and an outer tubular part. An inner reinforcing ring slid in the corrugation comprises four annular portions joined along two parallel planes equidistant from the axis or the bellows. The reinforcing ring is held in place by a locking ring. The bellows are more particularly applicable to valve bodies in the petrochemical, iron and steel, and nuclear industries.

Description

I~ACl~G~20UND OF THE INVENTION
The pr0sent ln~rention relate~ to expandlng bello~
provided with annular exp~n~l~ n~ corrllgation:~ o i` dete~mined inner and outer dia~eter~3 wlth, inside each corrugatior anrlular reinforcin~ por tions adapted to b~ introclucedg each~ into the tubular part of i~ner diameter o:f the bel-low.e and b~ as~clDbled as a re~ nfo~cing rimg, a:3 well meanE~ for blocking th~ ar~ular portio~ p æach ~nrlular re:Lnf`orclng partion ha~rlng an i:llnE3r a;rc and an outer arc 10 of which the chords wh~ ch subtend them ha~e lengths at least e~ual to the in~er diameter of` the bellow3,.
Such expF~nc~ g bells>ws are alre~dy ]CllOW:n~9 particular-1~ by ~rench Pate~l; N~ 451 3279 Conventional axp~n~l~n~ b~llow~ can only with~tand a limited inner and/or outer pre~sllre of u~e.
To incr~a~ thi~ pr*~ure o~ u~e, it has al-ready b~cn propo~ed either to incre~se the thickness of the wall of the bellows~ or to incr~a~e the number of tha ~in.e wall~ constituting the bello~ In the ~ormer ca~e, it ~ the li~e duration o~ the bellows which limlts the thic~nes~ thereof~ in~er3e1~ proportional to thi~ life duration. I~ the latter case, it i~ the pheno~ena cf ~lld~
between wall~ which limit the numbar of the fi~9 ~Pll~ which may be a~soci~ted.
~ urth0rmore 1 a~ f~r as the inn~ li~iting press~re alone is concsrnad, it has already been proposed to rein-force the corr~gation~ o~ th~ bellows by outer reinforceme~ts~

.i, ~

5~

1~e latter may be oo~stit~ted by two annular piec~
di~po~d, aftsr manu:facture I b~twe~rl two corrugation~ ~nd mechanlcally s~onnected togatherO
~ Iowe~er, wh~n the bellow~ are manufas~tured by hydro~
forming7 it is pref`erably the ma~uf'acturing mould~ the~
re2s w~ich3 held in place a~ter m nuf~cture ~ serve aa monoblt)c ~uter rel:nf-orcl~g me n~sO
If` it i~ de~ired to rainf`orce eXp~n~ bellow so that they withstand higher out~3id~ pressur~ therefor~3 10 wit~ th~ aid. of` i~e:~ rein:~orce~ nt:3 ~ i t iL~ imperati~e to n~ount the latter after manu~acture of' the bellows ~ In :fact, the formation of the corrugation~s o:f the b~llows in t~he c~urse o:f manu~aoture; ln other words the ex~an:3ion cf the starting tube, make~; it imposslble to arr~nge in~ide it any reinrorcement which would be holl~;ed in one of the corrugations and would have an outer diameter forclbly greater than ths inn0r diameter o~ ~he corrugation~ i.e.
t~e diam~ter of the 3tarti~g tube.
A~ far a~ the eXpQn~;ne bellows of French Pate~t N 451 327 are concer~ed, they do i~dsed compri~e inner pieCeff which may be mounted arter manu~ac$ure of the bellows.
Howe~er~ there is a large numb~r o~ piece~ in the3e bellow~ and they are a~embled by ~crews a~d pin~ Thi~
re~ults in a mechanical weaknas~ o~ these piece~ which can therefore not per~orm a function o~ mechanical reinforce-~ent o~ the bellow~ 9 ~he~ the latter arc ~ub~ected to a considerabl~ out~lde pressure. The plece~ of the~e bellow$

~5~7 ar~ in fact int¢nded only to limit th~ longitudinal co~-traction of the bello~. Strlctly speaki~gg they do not perform a role of reinforcement.
It i~ therefore an object of the pr¢sent invention to o~ercome the drawbacks of such bellow~.
SUMMARY OF THE INVENTION
To this end, the in~ention rel~*es *o bell3ws Or the type mentioned herelnabo~e~ characterized in that tha inner ch~r~ ~ a~ lea t one of th~ annular portion~ i~ at lea~t a~ large as the o~ter chord thereof.
The bellow~ o~ th~ inventlon therefore compri~e rei~-forcing portion~, of very li~ltsd numbar7 which buttres~
on one ~nother a~d remain assembled under the effect of tha outslde pres~ur~ 9 wlthout other means ~uch a~ the ~crew~ and pins of the prior art.
In a preferred embodiment of the b~llow~ of the inven-tion~ at least on~ of th~ annular reinforcin~ portions ha~ an i~er chord and an outer chord which are parallel a~d o~ the same length.
In this latter ca~ie~ it i~ advanta~eou~ to provide a rein:f`orcillg ring comprising two identical an3lular por-tions eac~ having an inn~r chord and an outer chord of which the ~agittae merge and o:f' whlch the di~tarlc:e~ to the ax~ ~ of th~ bellow~ are eqtlal9 the le~th o~ the inn~r e:hord being ~;lightly greate~ than one *h~ rd of tk~ length o:P the~ oute~
chDrd .

3S~37 BRIEF DESCRIPTION OF T~E DRAWIN&S
The in~0ntio~ will be ~ore readlly understood o~ rea~
ding the fO11DWing de~cription with reference to the acco~-pan~i~g dra~ings, in w~ich s Fig. 1 shDws a radial vlew of on~ of the corrugation~
of the bellows with a first a~nular reinfor2ing portion, be~or~ a~d afte~ introductlon.
Fig. 2 show~ an axial vlew o~ the cDrrugatlo~ of Pigo 1.
Fig. 3 6how~ a radial ~lew o~ the corrugation with a ~cond a~nular r~in~orci~g portion/` id~ntical to the flr3t~
be~ore a~d after introductio~
Fig. 4 sh~ws an axial ~i~w of th~ corrugatlon o~
~ig. 3-~ig. 5 show~ a radial vi~w of the corrugation, ~ith a third an~ular sein~orci~g portion~ before and a~ter introduction.
~ig. 6 show~ an axial view v~ the corrugation Or Fig. ~-Fig. 7 ~howY a radial view o~ the corrugatlo~, with a f`ourth a~d last a~nulas~ rein~orcing portion~ identical to th~ third, b~ore and after int~oductio~.
Fig. 8 show~ a~ axial vi~w of the corru~atio~ o~
igo 7 o Fig. 9 ~hows a ra~ial view o~ th~ corrug~tion~ with the inn~r rein~rcin~ ring and a blocking ring~ bsfor~
a~d aft0r introduction.

Fig. 10 ~how~ an a~ial vi~w of the corrugation of Fig. 9-Fig. 11 ~how3 a radial view, with a~ial half section9of the bello~s of the i~rention9 and ~ ig. 12 shows a radial ~iew, with axial half~section, o~ the bellow~ ~r ~ig~ 11 9 with oute~ rein~orcing r.i~g~
DESCRIPTION OF A PRE~ER~ED EMBODIMENT O~ T~æ
lN v~ ON
Re~erring now to the drawin~s, th~ exp~n~7in~ bel~ow~
or ga~ket or equalizer~ ~ the in~ention, whish will be de~cribed~ i~ a body 1 o~ general tubular form, of a~ 59 compri~in~ identical an~lu~ar radial e~pa~ding CorrUgationB
29 four in th~ pre~ent case although the in~ntio~ i~ not limited to this number. The~ r~gularly spac~d-apart cor-rugation~ ~orm a tubular part 3 of determined lnner diameter~
and a part 4 Or d*ter~ined outer diameter, gr~ater tha~
that of the l~r part 3. Th~e c~rrugationo were ob~ained, for example r b~ hydroforming, which ls a process suf~i-ciently well known to the man skilled in the art ~or it to be unnQoessary to be de3crlbed h~re. 'rhe-~e corrugation have radial ~ides9 sub~tantially at right angle~ *o the a~is 5 o~ the bellows.
The compo ition~ i~troductio~ ~nd blockin~ o~ an in~er rein~orcin~ ring associated ~lth one o~ the corrugatlo~ 2 w~ 11 now be dgscribed, lt bei~g under~tood that each cor~
rugation 2 is pro~ided with 5uch a ring~
The iD~er rein~orc~ng ring 6~ once a3~smbled tFigs.8 -- 5 ~-5~33~

to 12), there~ore ha~ an annular ~orm o~ whlch the lnner part 7 i~ htly thicker tha~ the outer part 8~ a narro-wed cheek element 9~ o~ s~aller thlckne~s than the outer part, cDnnecting the two lnner ~nd outer parts. T~e out~r part 8 o~ the ring has sub~antially the same thickne3 as corrugation 2.
The rin~ 6 comprlse~ two pairs o~ identi~al annular portlon6 (10, 11) and (12~ 13).
Each ~n~ ~ portion (10013) has a~ inner arc and an outer arc. The chord~ ~hich ~ubtend these arc3 all ha~s a length le~ than th~ dlameter o~ the inner tubular part 3.
I~ fact, it i~ nece~sary t~ be able to lntroduc~ thes~
a~ular portion~ therein. ~ore~Yer9 lt ~u~fice~ that tha length o~ ~he~e chord~ b~ slightly le~ than thi~ inner diam~ter.
Th~ annular portlon~ 10, 11 have~n inner arc 14 and an outer arc 15 re~pecti~ely of the same radii a8 the tubular parts 3, 4. These arc3 are ubte~ded by chords which extend o~r the ~ame straight line. In other word3, the two chord~ which 3ubt~nd the~e two arc~ have ~erged s~gittae and their di~tances to the.axi3 5 of the bellows are equal. The Qhord of the ~ nner arc 14 ha~ a le~gth ~ htly greater tha~ one third o~ the le~gth of the chord Or the outer aro 15~ for a r~a~on whloh will appear herelw nafter~ In other word~ this i~ner chord 1~ ~lightly lo~ger than each Df the t~o adjacent port1on~ of the outer chordO
The annular portions 12, 13 have an inner arc 16 and 3~

an s~ter aro 17 respectlvel~ o~ the ~ame radii as the t~-bular parts 3, 4. T~le two chords which r~peotively ~ub-tend these two arc~ are parallel and of the same length.
The length of th~ outer arc 17 of the portions 12, 13 i~
equal to the differe~ce between half the ci~cumferenc~ of the outer tubular part 4 and the length of the outer aro 15 of thc portions 109 llc The length o~ the inner arc 16 of portions 12, 13 is equal to the dif~erence betwe~n half the circumfer~nce of the inn~r tubular part 3 and the le~gth Or the inner arc 14 of the portions 109 11.
The annular portion3 12, 1~ ha~e two plane~ o~ ~oin 18 19 perpendicular to their two chordR subten~l ng th~lr inn~r and outer arcs 16 and 17, re~pecti~ely, which are adapted to cooperate with the two portion~, co~pri~ed between the two arc~ 14 and 15 9 0~ the two outer chord~ of the annular portions 10, 11.
II1 the for~going de~cription, the thicknes~ of the annular portions, mentioned abova~ ha~ o~ cour3e, been disreg~rded.
Having described the annular por~io~ o~ the relnfor-cin~ ring 6, we shall now describe the introduction thereQ~
lnto ths corrugation 2 of the hellow~
With four annular portions 10-13 available, the ~lrst portion 10 is taken9 i~ltroduced a~ially (Fig. 1~ in-to the tubular part 3 and s~id radially ~Fig. 2~ i~to corrugation

2, so that the two chords o~ its ~w~ arc~ 14 9 15 are var~
tical, in the Figure~. ~he second portion 11 i5 then takeng ~ 7 ~9~;~3~

int~oduced axially (~:lg~ 3~ ~nto part 3 and ~ilid radially (~ig. 4) in the directlon opposite that o~ portion 109 into corrugation 2; so that the four in~e~ and outer chord~ of the two por*ions 109 11 are parallelO Then th~
third portion 12 i~ taken, l~troduced ~xially (Fig. 5) into part 3, and slid radially (~ig. 6~, in ~ direction at right angles to th~t of portion~ 10, llt into co~rugatlo~
2, so that its plane~ of Join 18 9 ~9 ~lide alon~ the cor responding portion~ of the outer chJrd~ of portlonq 10, 11, likewise constitutl~g plane~ o~ ~oin. Finally~ th~ ~ourth portion 13 1~ taken, lntroduced a~ially (Fig. 7) lnto part

3 and ~lid radially (Fig~ 8) in the dire¢tion op;oo~ite that of portion 12 D into corrugation 2 9 ~0 that it~ plane~ o~
join 18, 19 slide alo~g the otha~ cor~espo~ding portion~
of the outer chords o~ portio~s 10, 11~ llk~wl~ constitu-ting planes of join~
It wlll be noted that the a~ial intrDdUCtio~ into part 3 of por-tions 12, 13 i~ allowed, due to the fact that the length of their edge~ 18, 199 equal to that o~ the 2V corresponding portions o~ the out~r chord~ of portions 10, i9 sub3tantially le88 tha~ the length o~ the inner chord3 o~ portions 10 9 11 ~
The inner rel~forci~g rln~ 6 1~ th~ as~embled in ths corrugation 2 9 wlth ~our annular portion~ joined alorlg two parallel planes equidistaIlt fro~n a~is 5 o~ b011OWS 1~ the amlular portio~ buttressl~g on vne ~nother~
A ring O, of outer di~meter substantiallr equal to ;37 the ln~er diameter of the tubula~ part 3, i8 then introdu-ced ~ially, ln ord~r to block the four a~aular portions in the corrugation 2 a~d hold r~ng 6 in positio~ of ~ei~
forcement, which is then fixed for e~ample by welding or crimping ..
These operations are repeated for each corrugation Z.
An inner reinforcing ri~g comprising four annular portions has been described. This i~ the simplest solution, which is characterized by the presence of ~o~r pieces only, of which two each haYe an inner chord and an outer chord which are parallel, ~f the same length, and definin~ two lateral edges perpendlcular to the~e chord~. L~t u~ recall here that it suffice3 for one Or the annular portions cons-tituting the rein~orcing ring to haYe two parallel or in-wardly diverging edges in order to be able tD lntrcduce this portion into the corrugation after the precsding ones have been positloned.
In other words, th~ inner chord Or thi~ latter annular portion must haYe a length equal to or greater than that of the outer chord.
The apice~ o~ the rein~oroing ring~ 6, like those of tha expanding corrugatlon~ 2, shown in the drawing~9 are rou~ded. Stiffening reinforcement~ ~ay furth~r be arrang~d around the corrugation~ 2~ ~hich comprisa at least two p~ece~ whose inner part ~ollow~ khe shape of the corr~ga~
tions 29 and presentin~ a flat, out~r an~ular edge parallel to the a~is 5 of the bellows 1, the piece3 of each of the g _ outer relnforce~ents being blocked by a~ outer lockin~
ring. The stiffe~er reinforcem~nts contrlbut~ to pre~e~ti~g the corrugations from "rising'?. The apex o~ the expandi~g corrugations may9 moreover, also be flat.
~ inally~ outer rein~or~ing rings 7 well k~lown to the ~an skilled in the art~ may be proYided between the corru-gations, in order al~o to withstand a hlgh in~ide pressure9 suoh outer reinforoement~ being co~po~ed Or a plurallty of pieces ~r, preferably, being monobloc and constltuted by the mould~ 21 the~lves u ~d in the process ~or obtai-ning the cosrug~tivn~ by hydro~orming (~ig, 12).
The lnner r~inforcing rl~gs of th~ bellows according to the invention en~ble the latter to with~ta~d ~ery high outside pressures of use. By way o~ example 7 con~entional ex~n~ n~ bellows, withst~n~ n~ only an out~ide pre~s~tre of a few bar6, may, due to th~se inner reinforcing ringR9 , with~tand an out~ide pre~sure of ~everal hundred~ of bar~.
: It goe~ wlthout saying, a~ has already been ~mpha~iæ~d hereinabo~e 9 that the in~ention is also applicable to a ~0 connecting sleeve provided with at least o.na a~ular groove adaptsd to recaive an annular ga~ket, o~ d~*er~lned inner and out~r diameter~, characte~iz~d 1~ that the gaske* com-pri3e~ annular portion~ adapted to be introduced into th~
part of inner diameter o~ the ~leeve and ba a~mbled to form the ga~ketg a~ well a~ mean~ ~or blocking th~ a~7ar portion~ Df the ga~ket9 each annular porti~n having an inner arc and an outer arc of which the ohord~ whl~h 5~3~7 subtend th~m ha~e le~gthEj ~t ~h~ most equal to the ir~er diameter of' th~ slee~e, Emd the i2~e~ chord o~ at l~a~t on~ of the annular portio~s of th~ gaskç~t i5 a~ leas-t a~
large a~3 the outer chord thereof.

_ 11 ~

Claims

The embodiments of the invention in which an exclu-sive property or privilege is claimed are defined as fol-lows:

1. Expanding bellows provided with annular expanding corrugations of determined inner and outer diameters, with, inside each corrugation, annular reinforcing por-tions arranged to be introduced, each, into the tubular part of inner diameter of the bellows and be assembled as a reinforcing ring, a well as means for blocking the an-nular portions, each annular reinforcing portion having an inner arc and an outer arc of which the chords which subtend them have lengths at the most equal to the inner diameter of the bellows, characterized in that the inner chord of at least one of the annular portions is at least as large as the outer chord thereof.

2. The bellows of Claim 1, characterized in that at least one of the annular reinforcing portions has an inner chord and an outer chord which are parallel and of the same length.

3. The bellows of Claim 2; characterized in that the reinforcing ring comprises two identical annular portions each having an inner chord and an outer chord of which the sagittae merge and of which the distances to the axis of the bellows are equal, the length of the inner chord being slightly greater than one third of the length of the outer chord.

4. The bellows of Claim 3, characterized in that the reinforcing ring comprises four annular portions joined along two parallel planes equidistant from the axis of the bellows.

5. The bellows according to Claims 1, 2 or 3, cha-racterized in that the means for blocking the reinforc-ing ring comprise a blocking ring whose outer diameter is substantially equal to the diameter of the inner part of the bellows.

6. The bellows according to Claims 1, 2 or 3, charac-terized in that stiffening reinforcements having a flat outer annular edge, each locked by a ring, are provided around the corrugations.

7. The bellows according to Claims 1, 2 or 3, charac-terized in that outer reinforcing rings are provided.

8. Connecting sleeve provided with at least one annu-lar groove adapted to receive an annular gasket, of determined inner and outer diameters, in which the gasket comprises annular portions adapted to be introduced into the part of inner diameter of the sleeve and be assembled to form the gasket, as well as means for blocking the annular portions of the gasket, each annular portion having an inner arc and an outer arc of which the chords which subtend them have lengths at the most equal to the inner diameter of the sleeve, said sleeve being characterized in that the inner chord of at least one of the annular portions of the gasket is at least as large as the outer chord thereof.

9. Tubular body provided with at least one annular groove adapted to receive an annular body, of determined inner and outer diameters, in which the annular body com-prises annular portions adapted to be introduced into the part of inner diameter of the tubular body and be assembled to form the annular body, as well as means for blocking the annular portions of the annular body, each annular portion having an inner arc and an outer arc of which the chords which subtend them have lengths at least equal to the inner diameter of the tubular body, characterized in that the inner chord of at least one of the annular portions of the annular body is at least as large as the outer chord thereof.