NO742990L

NO742990L -

Info

Publication number: NO742990L
Application number: NO742990A
Authority: NO
Inventors: E D Hauk
Original assignee: Spinnerhawk Co
Priority date: 1973-08-24
Filing date: 1974-08-20
Publication date: 1975-03-24
Also published as: DE2440501C2; GB1448757A; CA988844A; FR2241685A1; IT1019078B; DE2440501A1; FR2241685B3; NL7411151A

Description

Fremgangsmåte og anordning Method and device

til rotasjon av rør. for tube rotation.

Foreliggende oppfinnelse angår fremgangsmåter og anordninger til rotasjon av i det vesentlige sylindriske gjenstander, særlig borerør, borekraver, hylser etc, som anvendes ved oljeboring. Uttrykket "sylindrisk" er her anvendt på vanlig måte, nemlig for å definere gjenstander som har sirkulær eller så godt som sirkulær tverrsnittsform. The present invention relates to methods and devices for the rotation of essentially cylindrical objects, in particular drill pipes, drill collars, sleeves, etc., which are used in oil drilling. The term "cylindrical" is used here in the usual way, namely to define objects that have a circular or nearly circular cross-sectional shape.

På det felt det her er tale om har det vært gjort lang-varige anstrengelser for å erstatte den farlige og lite tilfreds-stillende rotasjonskjetting som anvendes for ved rotasjon å skru eller låse rørseksjoner i hverandre. In the field in question here, long-term efforts have been made to replace the dangerous and unsatisfactory rotary chain which is used to screw or lock pipe sections together by rotation.

Formålet med foreliggende oppfinnelse er å komme frem til en fremgangsmåte og en anordning som muliggjør rotasjon av rørene på en tryggere måte enn tidligere, og som gir større dreiemoment og forlenget levetid for kjettingen. The purpose of the present invention is to come up with a method and a device which enables the rotation of the pipes in a safer way than before, and which provides greater torque and an extended lifetime for the chain.

Det er tidligere kjent et stort antall rotasjonsanord-ninger for rør der røret trekkes av en kjetting (eller et annet fleksibelt drivelement) uten andre midler eller med ruller som har friksjonsdrift mot røret, uten kjetting. Ved anordningen i henhold til oppfinnelsen skal det imidlertid samtidig benyttes både kjetting og ruller med friksjonsdrift, idet man dermed oppnår en overraskende økning av dreiemomentet som virker på røret såvel som en sterk økning i kjettingens levetid. Økningen i dreiemomentet og økningen i kjettingens levetid får man uten å miste noen av fordelene med anordninger der det anvendes kjetting sammenliknet med anordninger som bare har ruller. A large number of rotation devices for pipes are previously known where the pipe is pulled by a chain (or another flexible drive element) without other means or with rollers that have friction drive against the pipe, without a chain. In the device according to the invention, however, both chain and rollers with friction drive must be used at the same time, thus achieving a surprising increase in the torque acting on the pipe as well as a strong increase in the lifetime of the chain. The increase in torque and the increase in the life of the chain is obtained without losing any of the advantages of devices where a chain is used compared to devices that only have rollers.

For å være praktisk i bruk og for å kunne benyttes hurtig skal en rotasjonsanordning kunne betjenes bare.fra en side av røret. Fra denne side skal rotasjonsanordningen kunne gripe røret, rotere dette og så slippe det. Anordningen som her beskrives skiller seg fra tidligere kjente anordninger der kjettingen måtte brytes når verktøyet var montert på røret og der låseanordninger måtte omslutte den side av røret som vender fra hoveddelen av rotasjonsanordningen, eller der man ikke hadde noen kraftdrevne kjever eller der røret ikke hadde direkte anlegg. Én rekke av de kjente verktøy av den sist-nevnte type er beskrevet i U.S. patent nr. 1.760.167, 1.805.007, 1.925.970, 2.460.671 og 2.573.212. To be practical in use and to be able to be used quickly, a rotation device must be operable only from one side of the pipe. From this side, the rotation device must be able to grasp the pipe, rotate it and then release it. The device described here differs from previously known devices where the chain had to be broken when the tool was mounted on the pipe and where locking devices had to enclose the side of the pipe facing away from the main part of the rotary device, or where there were no powered jaws or where the pipe did not have direct facility. A number of the known tools of the latter type are described in U.S. Pat. Patent Nos. 1,760,167, 1,805,007, 1,925,970, 2,460,671 and 2,573,212.

I henhold til oppfinnelsen skal rotasjonsanordningen ha ruller som er i anlegg mot røret, ved endene av kraftdrevne kjever som lukker om røret med en stor kraft. Videre finnes det en kjetting med en innad buet del hvis ender ligger rundt kjettinghjul ved kjeveendene. Diametrene på rullene er tilstrekkelig stor til at de kommer i anlegg mot rørene og avlaster påkjenningen på de buede kjettingpartier som ligger rundt de angitte kjettinghjul. De buede partier blir derfor ikke trykket sammen mellom kjevehjulene og røret på tross av den store kraft kjevene utøver. På denne måte blir levetiden for kjettingen og kjettinghjulene vesentlig økt. According to the invention, the rotation device must have rollers that are in contact with the pipe, at the ends of power-driven jaws that close the pipe with a large force. Furthermore, there is a chain with an inwardly curved part whose ends lie around sprockets at the jaw ends. The diameters of the rollers are sufficiently large that they come into contact with the pipes and relieve the stress on the curved chain parts that are around the indicated sprockets. The curved parts are therefore not pressed together between the jaw wheels and the pipe despite the great force exerted by the jaws. In this way, the service life of the chain and sprockets is significantly increased.

Siden man ikke behøver bryte kjettingen når verktøyet monteres på røret eller å låse kjedene sammen kan anordningen og fremgangsmåten utøves fra bare en side av røret og den vil derfor være overordentlig praktisk og hurtigvirkende. Den beskrevne kombi-nasjon av kraftdrevne kjever, ruller og kjetting med et innad buet parti byr på mange fordeler. Disse fordeler innbefatter (som eksempler) høyt dreiemoment, lang levetid for kjettingen, god tilpasning til rør med forskjellige diametre, evne til godt grep på oljete og skitne rør, redusert skade på røret og evne til å arbeide på flater som ikke er perfekt sylindriske. Since there is no need to break the chain when the tool is mounted on the pipe or to lock the chains together, the device and the method can be carried out from only one side of the pipe and it will therefore be extremely practical and fast-acting. The described combination of power-driven jaws, rollers and chain with an inwardly curved part offers many advantages. These advantages include (as examples) high torque, long life of the chain, good adaptation to pipes of different diameters, ability to grip oiled and dirty pipes, reduced damage to the pipe and ability to work on surfaces that are not perfectly cylindrical.

Oppfinnelsen er kjennetegnet ved de i kravene gjengitte trekk, og et eksempel vil bli beskrevet i det følgende under hen-visning til tegningene der: Fig. 1 viser anordningen i henhold til oppfinnelsen sett i perspektiv, der man ser friksjonsruller montert i kjevene, The invention is characterized by the features reproduced in the claims, and an example will be described in the following with reference to the drawings where: Fig. 1 shows the device according to the invention seen in perspective, where friction rollers are seen mounted in the jaws,

fig. 2 viser anordningen sett nedenfra og i stilling for grep rundt et rør, fig. 2 shows the device seen from below and in position for gripping around a pipe,

fig. 3 viser et vertikalt snitt etter linjen 3-3 på fig. 2, fig. 3 shows a vertical section along the line 3-3 in fig. 2,

fig. 4 viser et horisontalt snitt"av kjevene i åpen stilling for innføring av røret, fig. 4 shows a horizontal section of the jaws in the open position for inserting the pipe,

fig. 5 viser et horisontalt snitt tatt etter linjen 5-5 på fig. 3, med kjevene lukket rundt røret og fig. 5 shows a horizontal section taken along line 5-5 in fig. 3, with the jaws closed around the pipe and

fig. 6 viser, i forstørret målestokk, et vertikalt snitt gjennom et bruddstykke, tatt etter linjen 6-6 på fig. 5, der man ser drivanordningen mellom kjettinghjulene og tilhørende friksjonsruller. fig. 6 shows, on an enlarged scale, a vertical section through a broken piece, taken along the line 6-6 in fig. 5, where you can see the drive device between the sprockets and associated friction rollers.

De forskjellige hoveddeler av anordningen i henhold til oppfinnelsen omfatter et langstrakt, endeløst , fleksibelt drivelement 33 som er slik ført at det får et utvendig parti 33a, et innad krummet.parti 33b og to tilbakeførte partier 33c som forbinder det ytre parti med det indre parti. The various main parts of the device according to the invention comprise an elongated, endless, flexible drive element 33 which is guided in such a way that it has an external part 33a, an inwardly curved part 33b and two returned parts 33c which connect the outer part with the inner part .

Det fleksible drivelement kan være et lydløst kjede. Slike kjeder er velkjent fra andre felt, og et eksempel som med for-del kan utnyttes som det fleksible drivelement 33 finnes i U.S. patent nr. 3.661.025, men andre utførelser kan også naturligvis komme på tale. The flexible drive element can be a silent chain. Such chains are well known from other fields, and an example that can be advantageously utilized as the flexible drive element 33 is found in the U.S. patent no. 3,661,025, but other designs can of course also be considered.

Kjedet 33 løper rundt kjedehjulene 24 som er fast montert ved den forreste ende av hovedhuset for anordningen; og dette hus utgjør en bærer for anordningens forskjellige deler. Kjever 16a, 17a er svingbart lagret på huset rundt aksene for kjedehjulene 24. The chain 33 runs around the sprockets 24 which are fixedly mounted at the front end of the main housing of the device; and this housing constitutes a carrier for the device's various parts. Jaws 16a, 17a are pivotally mounted on the housing around the axes of the sprockets 24.

Kjevene har kjedehjul (som beskrevet nedenfor) ved sine ytre'ender og kjedet 33 løper rundt disse kjedehjul ved returpartiene 33c. The jaws have sprockets (as described below) at their outer ends and the chain 33 runs around these sprockets at the return portions 33c.

Når kjevene 16a, 17a er i åpen tilstand, som vist påWhen the jaws 16a, 17a are in the open state, as shown in

fig. 1 og 4, kan anordningen føres rundt et vertikalt rør 34 som skal settes i rotasjon. Med rotasjon menes her også bevegelser som er på mindre enn en omdreining. Deretter blir kjevene lukket med stor kraft, f.eks. til den stilling som er vist på fig. 2 og 5, og man skaper da en stor' strekkraft i det innad buede parti 33b som derved med friksjon griper utsiden av røret med et høyt anleggstrykk. fig. 1 and 4, the device can be guided around a vertical pipe 34 which is to be set in rotation. By rotation is meant here also movements that are less than one revolution. The jaws are then closed with great force, e.g. to the position shown in fig. 2 and 5, and a large tensile force is then created in the inwardly curved part 33b which thereby frictionally grips the outside of the pipe with a high contact pressure.

Åpning og lukning av kjevene 16a-17a foregår ved hjelpOpening and closing of the jaws 16a-17a takes place with help

av kraftutøvende innretninger som vist på fig. 2 og 3, nemlig med pneumatiske sylindre 61, hvis stempelstenger er forbundet med vekt-armer og leddmekanismer. Armene og leddmekanismene omfatter vekt-armer 56 som er fast forbundet med kjevene 16a-17a. of power-exerting devices as shown in fig. 2 and 3, namely with pneumatic cylinders 61, whose piston rods are connected by weight arms and joint mechanisms. The arms and joint mechanisms comprise weight arms 56 which are firmly connected to the jaws 16a-17a.

Når kjevene er lukket, vil deres ytre ender ikke berøre hverandre og i stedet vil kjedet 33 virke som begrensningsanordning for kjevenes lukkebevegelse, og resultatet av dette er at lukning av kjevene strammer kjedet til rundt røret. Kjevene er slik konstruert at om man ikke hadde noe kjede ville kjeveendene berøre hverandre når kjevene lukkes. When the jaws are closed, their outer ends will not touch each other and instead the chain 33 will act as a limiting device for the closing movement of the jaws, and the result of this is that closing the jaws tightens the chain around the pipe. The jaws are constructed in such a way that if you had no chain, the jaw ends would touch each other when the jaws are closed.

Etterat kjevene er lukket for at kjededelen 33b skalAfter the jaws are closed for the chain part 33b to

gripe rundt røret 34, settes kjedet i drift for å frembringe en hurtig rotasjon av røret. Denne drift foregår ved hjelp av en pneu-matisk motor 42 som arbeider gjennom en girkasse 47 for å rotere en aksel 51 (fig. 3 og 4), hvorpå det drivende kjedehjul 32 for kjedet 33 sitter montert. Når man således betjener.en styreventil for tilførsel av luft til motoren 42, drives akselen 51 og dermed også kjedehjulene 32 slik at kjedet 33 drives for ,å rotere røret 34. grip around the pipe 34, the chain is set into operation to produce a rapid rotation of the pipe. This operation takes place with the aid of a pneumatic motor 42 which works through a gearbox 47 to rotate a shaft 51 (fig. 3 and 4), on which the driving sprocket 32 for the chain 33 is mounted. When one thus operates a control valve for the supply of air to the engine 42, the shaft 51 is driven and thus also the sprockets 32 so that the chain 33 is driven to rotate the tube 34.

Motoren 42 og girkassen 47 er bevegelig mot og bort fra røret 37 slik at aksen for akselen 51 og for kjedehjulet 32 kan be-vege seg. Slik bevegelse foregår bare når det er ønskelig å tilpasse anordningen for rotasjon av rør 34 med diametere som avviker vesentlig fra tidligere innstilling av anordningen. For slik justering flyttes en kjedestyring og en låsedel 41 véd rotasjon av en jus-teringsskrue 52. Etterat justeringen er foretatt strammes låseskruer 48 The motor 42 and the gearbox 47 are movable towards and away from the tube 37 so that the axis for the axle 51 and for the sprocket 32 can move. Such movement only takes place when it is desired to adapt the device for rotation of pipes 34 with diameters that deviate significantly from previous settings of the device. For such adjustment, a chain guide and a locking part 41 are moved by rotation of an adjusting screw 52. After the adjustment has been made, locking screws 48 are tightened

(som stikker gjennom en flensdel på girkassen 47 og er skrudd inn i delen 41) for å låse delen 41 og dermed også delene 42, 47, 51 i stilling. For at den beskrevne justering skal kunne finne sted har den øvre del av anordningens hus spalter som vist, for opptagelse av låseskruene. (which protrudes through a flange part on the gearbox 47 and is screwed into part 41) to lock part 41 and thus also parts 42, 47, 51 in position. In order for the described adjustment to take place, the upper part of the device's housing has slits as shown, for receiving the locking screws.

Anordningen anbringes ved siden av et brønnhode for et oljeboringshull, ved hjelp av en V-formet bøyle 110 hvis nedre ender er forbundet med anordningens hus. Ved toppunktet av bøylen 110 finnes det en festeanordning 111 ved hjelp av hvilken bøylen kan for-bindes med det nedre ledd i en opphengningskjetting 112. Festeanordningen 111 er slik konstruert at kjettingen kan festes i forskjellige punkter aksialt langs festeanordningen for dermed å muliggjøre balansering av rotasjonsanordningen i stort sett horisontal tilstand. The device is placed next to a wellhead for an oil well, by means of a V-shaped hoop 110 whose lower ends are connected to the device's housing. At the top of the hoop 110, there is a fastening device 111 with the help of which the hoop can be connected to the lower link of a suspension chain 112. The fastening device 111 is constructed in such a way that the chain can be fixed at different points axially along the fastening device to thereby enable balancing of the rotation device in a mostly horizontal state.

For å kunne håndtere anordningen finnes det hensiktsmes-sige håndtak 113 under hver kjeve 16a-17a, som vist (ved kjeven 16a) på fig. 1. In order to be able to handle the device, there are suitable handles 113 under each jaw 16a-17a, as shown (at jaw 16a) in fig. 1.

Som det best fremgår av fig. 3 og 6 er hver kjeve 16a, 17a utvidet ved det ytre parti for å gi plass til to friksjonsruller 116 og et kjedehjul 117. Da delene ved de ytre ender av de to kjever 16a-17a er identiske, er bare delene i kjeven 16a vist og beskrevet i detalj. As can best be seen from fig. 3 and 6, each jaw 16a, 17a is expanded at the outer portion to accommodate two friction rollers 116 and a sprocket 117. Since the parts at the outer ends of the two jaws 16a-17a are identical, only the parts in the jaw 16a are shown and described in detail.

På fig. 6 ser man at de to ruller 116 er anbrakt på mot-stående sider (over og under) kjedehjulet 117 og alle delene 116 og 117 er montert koaksialt med hverandre på en vertikal aksel. Akselen er, som vist, en bolt 118 som stikker gjennom kraver 119. Disse kraver er sveiset fast til de øvre og nedre vegger av husdelen av kjeven 16a idet det finnes muttere 121 som holder bolten 118 fast i stilling. Rundt bolten 118, mellom de øvre og nedre husvegger av kjeven, finnes en hylse 122 som har en rekke friksjonsreduserende lagre (f.eks. nål-lagre) 123. Rullene 116 av kjedehjulene 117 er montert rundt disse lagre 123 for at delene 116 og 117 skal kunne rotere fritt i forhold til akselen eller bolten 118. In fig. 6 it can be seen that the two rollers 116 are placed on opposite sides (above and below) the sprocket 117 and all parts 116 and 117 are mounted coaxially with each other on a vertical shaft. The shaft is, as shown, a bolt 118 which sticks through collars 119. These collars are welded firmly to the upper and lower walls of the housing part of the jaw 16a as there are nuts 121 which hold the bolt 118 firmly in position. Around the bolt 118, between the upper and lower housing walls of the jaw, there is a sleeve 122 which has a number of friction-reducing bearings (e.g. needle bearings) 123. The rollers 116 of the sprockets 117 are mounted around these bearings 123 so that the parts 116 and 117 must be able to rotate freely in relation to the shaft or bolt 118.

Kjedehjulet 117 (og de andre kjedehjul) er av den type som normalt anvendes sammen med et lydløst kjede med vertikale tenner som er i inngrep med tannpartier på kjeven 33, som beskrevet i det nevnte U.S. patent nr. 3.661.025. Sprocket 117 (and the other sprockets) is of the type normally used in conjunction with a silent chain with vertical teeth which mesh with tooth portions on jaw 33, as described in the aforementioned U.S. Pat. patent No. 3,661,025.

Det skal påpekes at tennene på det lydløse kjede ikke ligger an mot røret 34 idet grepet mellom røret og kjedet foregår med en flerhet av ikke-fortannede anleggskanter på kjedet. It should be pointed out that the teeth of the silent chain do not rest against the pipe 34, as the grip between the pipe and the chain takes place with a plurality of non-toothed contact edges on the chain.

Som kjent fra og vanlig for mange lydløse kjeder kan styring av kjedet foregå ved hjelp av styreledd som løper i et peri-ferielt omløpende spor i midtpartiet av kjedehjulet 117. Slike styreledd er antydet ved 124 på fig. 6, og løper hele veien rundt hjulet 117 som sporet 126. De andre kjedehjul i anordningen har liknende omløpende spor for styreleddene 124. As is known from and is common for many silent chains, control of the chain can take place by means of guide links which run in a peripheral circumferential groove in the middle part of the sprocket 117. Such guide links are indicated at 124 in fig. 6, and runs all the way around the wheel 117 as the groove 126. The other sprockets in the device have similar circumferential grooves for the steering links 124.

Som vist på fig. 6 er de sylindriske omkretsflater av rullene 116 i direkte anlegg mot utsiden av røret 34. Rullene 116 har diametere som er tilstrekkelig store til å sikre at hverken kjedet eller kjedehjulene tar skade på grunn av anleggstrykket mot røret 34. Mer bestemt er rullenes diametere tilstrekkelige til at de tilbakeløpende partier 33c av kjedet 33 ikke knuses eller trykkes sammen mellom kjedehjulene 117 og utsiden av røret. As shown in fig. 6, the cylindrical circumferential surfaces of the rollers 116 are in direct contact with the outside of the tube 34. The rollers 116 have diameters that are sufficiently large to ensure that neither the chain nor the sprockets are damaged due to the contact pressure against the tube 34. More specifically, the diameters of the rollers are sufficient to that the returning parts 33c of the chain 33 are not crushed or pressed together between the sprockets 117 and the outside of the pipe.

Det har vist seg at hvis slik knusing eller komprimering tillates å oppstå fører dette til at "brinellering" av kjedeleddene og/eller kjedehjulene med dermed følgende stivhet i kjedene og ned-settelse av kjedets levetid. It has been shown that if such crushing or compression is allowed to occur, this leads to "brinelling" of the chain links and/or sprockets, with consequent stiffness in the chains and reduction of the chain's service life.

Som et eksempel har man i den viste utførelsesform et lite gap (f.eks. på 0,75 mm) ved 127 (fig. 6) mellom hvert returnerende kjedeparti 33c og utsiden av røret. Dette gap sikrer at selv etter vesentlig nedslitning av rullene slik at deres diametere blir mindre, vil kjedet 33 ikke bli klemt mellom kjedehjulene 117 og røret, og man unngår derved slitasje og at kjedet blir stivere. As an example, in the embodiment shown, there is a small gap (e.g. of 0.75 mm) at 127 (Fig. 6) between each returning chain portion 33c and the outside of the tube. This gap ensures that even after considerable wear of the rollers so that their diameters become smaller, the chain 33 will not be pinched between the sprockets 117 and the tube, thereby avoiding wear and the chain becoming stiffer.

Det skål her fremheves at hvert gap 127 bare befinner seg over et forholdsvis smalt område akkurat mellom kjedehjulet 117 og røret og at kjedepartiet 33b er i direkte anlegg mot en vesentlig del av rørets omkrets. Man har således to viktige friksjonsområder mellom de drivende deler og røret 34. Det ene av områdene skapes av rullene 116 og det andre av områdene (som er meget større enn det førstnevnte) ligger over en vesentlig del av rørets omkrets, der det lydløse kjede med høy friksjon griper rundt røret. It should be emphasized here that each gap 127 is only located over a relatively narrow area exactly between the sprocket 117 and the pipe and that the chain part 33b is in direct contact with a significant part of the pipe's circumference. There are thus two important areas of friction between the driving parts and the pipe 34. One of the areas is created by the rollers 116 and the other of the areas (which is much larger than the former) lies over a significant part of the pipe's circumference, where the silent chain with high friction grips around the pipe.

Sagt på en annen måte vil kjedet med friksjon gripe rundt røret over en lang bue av defcs omkrets mens friksjonsdriv-rullene med friksjon ligger an mot røret ved (eller mellom) endene av den lange bue. Uttrykket "omkrets" anvendes her for å angi bare Put another way, the chain will frictionally grip the pipe over a long arc of defc's circumference while the friction drive rollers frictionally abut the pipe at (or between) the ends of the long arc. The term "circumference" is used here to indicate only

ett omkretsparti over rørets lengde.one circumferential section over the length of the pipe.

Det har vist seg at hvis rullene 116 ikke drives, men tillates å rotere fritt med friksjonsreduserende lagre, drevet av røret 34, vil størrelsen av det drivende dreiemoment som rotasjonsanordningen kan frembringe bli drastisk nedsatt. Hvis på den annen side, rullene drives direkte med eller av kjedehjulene 117 vil det drivende dreiemoment som frembringes av rotasjonsanordningen øke sammenliknet med det dreiemoment man får om ruller ikke ble benyttet. En slik økning var uventet, særlig fordi rullene bare har linje-kontakt med røret, mens kjededelen (som jo blir løftet fra røret av rullene) var i overflatekontakt med røret. It has been found that if the rollers 116 are not driven, but are allowed to rotate freely with friction reducing bearings, driven by the tube 34, the magnitude of the driving torque which the rotary device can produce will be drastically reduced. If, on the other hand, the rollers are driven directly with or by the sprockets 117, the driving torque produced by the rotation device will increase compared to the torque obtained if rollers were not used. Such an increase was unexpected, especially because the rollers only have line contact with the pipe, while the chain part (which is lifted from the pipe by the rollers) was in surface contact with the pipe.

Som en oppsummering kan man derfor slå fast at de drevne ruller 116 byr på to vesentlige fordeler sammenliknet med den kon-struksjon som er beskrevet i det nevnte amerikanske patent, der det ikke anvendes ruller. Disse fordeler er øket dreiemoment og vesentlig økning i kjedets levetid. As a summary, it can therefore be stated that the driven rollers 116 offer two significant advantages compared to the construction described in the aforementioned American patent, where no rollers are used. These advantages are increased torque and a significant increase in the lifetime of the chain.

Driften av rullene 116 på hver kjede 16a-17a kommer i stand ved hjelp av drivpinner 128 som stikker inn i åpninger i endene :på kjedehjulet og rullene. Da hvert kjedehjul 117 drives av kjedet 33 (som på sin side drives av kjedehjulet 32 når motoren 42 The operation of the rollers 116 on each chain 16a-17a is accomplished by means of drive pins 128 which insert into openings in the ends of the sprocket and rollers. As each sprocket 117 is driven by the chain 33 (which in turn is driven by the sprocket 32 when the motor 42

er igang og driver girkassen 47), og siden rullene 116 er forbundet med kjedehjulene 117 ved hjelp av drivpinnene 128, følger det av dette at rullene 116 drives direkte og arbeider som friksjonsruller for røret 34. is running and drives the gearbox 47), and since the rollers 116 are connected to the sprockets 117 by means of the drive pins 128, it follows from this that the rollers 116 are driven directly and work as friction rollers for the pipe 34.

Fremgangsmåten går i store trekk ut på at kjevene 16a og 17a først åpnes ved betjening av de pneumatiske sylindre 61, f.eks. til den stilling som er vist på fig. 1 og 4. Størrelsen på åpningen er tilstrekkelig til at anordningen kan svinges mot røret 34,slik at røret bringes inn i rommet mellom de returnerende partier 33c av kjedene og stort sett blir omsluttet av kjedets innadrettede parti 33b. The procedure broadly involves the jaws 16a and 17a first being opened by operating the pneumatic cylinders 61, e.g. to the position shown in fig. 1 and 4. The size of the opening is sufficient so that the device can be swung towards the pipe 34, so that the pipe is brought into the space between the returning parts 33c of the chains and is largely enclosed by the chain's inwardly directed part 33b.

Sylindrene 61 blir så betjening for å lukke kjevene 16a, 17a med stor kraft, f.eks. til de stillinger som er vist på fig. 2 og 5. Kjevene beveges ikke så langt sammen at de kommer i anlegg mot hverandre og hindrer hverandres bevegelse, og størrelsen på lukke-bevegelsen bestemmes av kjedets lengde. Kjevene lukker således inntil kjedestrekket er så stort at det balanserer lukkekraften- som virker på kjevene. Den nevnte lukkekraft for kjevene og strekket i kjedet The cylinders 61 are then operated to close the jaws 16a, 17a with great force, e.g. to the positions shown in fig. 2 and 5. The jaws are not moved so far together that they come into contact with each other and prevent each other's movement, and the size of the closing movement is determined by the length of the chain. The jaws thus close until the chain tension is so great that it balances the closing force acting on the jaws. The aforementioned closing force for the jaws and the tension in the chain

Claims

leads to a strong pressure system between the rollers 116 and the pipe and between the inwardly directed chain portion 33b and the pipe. Such pressure systems create great friction without damaging the pipe, and the friction is used to rotate the pipe after the engine 42 starts to pull the shaft 51 and thus the sprocket 32 and the chain 33 with the help of the gearbox 47.

The rotation continues until the desired pipe joint is turned together or opened at one end of the pipe 34, after which the cylinders 61 are operated to open the jaws and to perform the same operation again on another length of pipe.

As described above, the operation of the chain leads to operation of the rollers 116 so that they work as friction rollers and cooperate with the inwardly curved part 33b of the chain when it comes to driving and rotating the pipe without it being damaged.

The device can process pipes with somewhat varying diameters without adjusting the position of the driving sprocket 32.

When a pipe with a significantly different diameter is to be pulled around,

the position of the axis of the wheel 32 is adjusted as described above and in the aforementioned patent. Briefly, this adjustment takes place by loosening the locking screw 48, turning the adjusting screw 52 until the position of the shaft 51 is such that the chain gets the desired length and then the screws 48 are tightened again. This is repeated in the manner described each time you switch to pipes with a significantly different diameter.

What has been described so far is only to be considered as examples, and the protection this patent provides is not limited to this.

Patent claims.

1. Device for rotating pipes, characterized in that it includes:

a) an allowance,

b) two jaws which are movably placed in the support,

c) power-operated devices for closing the jaws with great force,

d) an elongate endless, flexible drive element having an external part and an inwardly extending part lying in the external part, where the inwardly extending part is arranged to enclose the pipe to be pulled around,

e) first and second wheels which are stored on each of the jaws, which wheels lead return running parts by which the said external part of the flexible drive element is connected to the said inward running part,

f) rolling devices mounted on the jaws to bear against the pipe after force-driven closing of the jaws by said power-exerting devices and to prevent the flexible drive member or the wheels from being damaged or worn due to force against the pipe in the vicinity of the wheels and

g) devices for operating the flexible drive element for rotation of the pipe after the jaws are closed by the power-driven devices.

2. Device as stated in claim 1, characterized in that the power-driven devices comprise cylinders with pistons as well as devices for introducing pressure medium to the cylinders.

3. Device as specified in claim 1, characterized in that the flexible drive element is a chain and that the wheels are sprockets in engagement with the chain.

4. Device as stated in claim 3, characterized in that the chain is a silent chain, where the sprockets are shaped to engage with the teeth of the silent chain and where non-toothed guide edges of the chain lie on the inside of the said inward running part, so that the guide edges will rest against the cylindrical outside of the tube when the jaws are closed, and where the rollers prevent the chain from being pressed together between the tube and the wheels.

5. Device as specified in claim 1, characterized in that the flexible drive element has such a length that it prevents the jaws from closing so far together that they touch each other, which flexible drive element, when the pipe is in the running-in internal part, forms the only device for balancing the force exerted by the power device, whereby the inflowing part is strongly tightened and therefore rests against the pipe with great force.

6. Device as stated in claim 1, characterized in that the jaws are pivotably arranged on the support and in that they do not have locking devices for mutual connection between the jaws on the side of the pipe facing away from the support.

7. Device as specified in claim 1, characterized in that the rolling devices comprise rollers that are mounted on the first jaw coaxially with the first wheel, and rollers that are mounted on the second jaw coaxially with the second wheel, and in that the diameters of the rollers are sufficiently large so that the rollers come into contact with the pipe when the jaws are closed and thereby ■relieve pressure that seeks to squeeze the flexible drive element and the wheels against the pipe.

8. Device as specified in claim 7, characterized in that the diameters of the rollers are sufficiently large to keep the flexible drive element in the area near the wheels at a distance from the pipe.

9. Device as stated in claim 7, characterized in that the rollers are connected to the wheels and therefore rotate together with them, so that the rollers serve as drive rollers for supporting the flexible drive element with rotation of the tube.

10. Device as stated in claim 1, characterized by devices for operating the roller devices so that the roller devices serve as drive elements to assist the flexible drive element during rotation of the pipe.

11. Device as stated in claim 1, characterized in that the devices for operating the chain comprise a power-driven wheel in drive connection with the flexible drive element, and devices for storing the power-driven wheel in such a way that its axis is in a fixed position at all times when the device is used to rotate pipes with a predetermined diameter.

12. Device for rotating pipes about their longitudinal axis, characterized by the fact that it includes:

a) an elongate flexible drive element which must rest against the pipe along a significant arc of the outside of the pipe in order to rotate the pipe about its longitudinal axis,

b) drive rollers which are designed to come into contact with the pipe for rotation thereof, the flexible drive element and the drive rollers being in contact with the pipe at the same time, and

c) means for forcefully driving the flexible drive member and the rolling means for rotation of the tube due to the combined action of the flexible driving member and the rolling means.

13. Device as specified in claim 12, characterized in that the flexible drive element rests against the pipe over a relatively long arc of the circumference, but not around the entire circumference, and in that the roller devices rest against the pipe over part of the circumference close to or between the end parts of the arch.

14. Device as set forth in claim 12, characterized in that the flexible drive element is endless with an outer part and a running-in inner part, where the inside of the running-in part is intended to rest against the outside of the pipe around a significant part of the pipe's circumference , and in that the rolling devices rest against the pipe close to the recirculating parts where the said outer part of the flexible drive element transitions into the said inward running part thereof.

15. Device as specified in claim 14, characterized in that the recirculating parts are placed around wheels and in that the rolling devices have rollers that are in drive connection with the wheels to be driven by them.

16. Device as stated in claim 15, characterized in that the rollers are coaxial with the wheels and are rigidly connected to them for rotation together with them.

17. Device as specified in claim 16, characterized in that the diameters of the rollers are sufficiently large to prevent damage to the flexible drive element and the wheels due to strong contact with the pipe.

18. Device as stated in claim 12, characterized in that the flexible drive element is a chain.

19. Device as stated in claim 18, characterized in that the chain is a silent chain.

20. Pipe rotation device for the rotation of pipes at wellheads on oil wells, characterized in that it includes:

a) a movable support,

b) two jaws which are pivotably placed on the support for swinging movement in such a way that the free ends of the jaws move towards and apart when the jaws open and close, where the free ends of the jaws are in relation to each other in such a way that if they are not prevented from doing so , would collide with each other by the closing movement of the jaws,

c) piston and cylinder devices connected to the jaws to forcibly close and open them;

d) two sprockets for silent chain rotatably stored at the ends of each chain,

e) a silent chain with an outer part and an inwardly curved inner part, where the inner and outer parts merge into each other by return running parts which lie around and engage with the sprockets, and where the inner part is arranged to receive it tube to be rotated,

f) a drive sprocket placed on the movable support and in engagement with the chain, the length of the chain being such that when the running-in part of the chain encloses a pipe of a predetermined diameter the jaws will not close together sufficiently for their free ends to touch each other,

g) devices on the support for operation of the driving sprocket and

h) two roller devices which are mounted at the end part of each chain, which roller devices are coaxial with the sprockets and have diameters that are sufficiently large to prevent the return running chain parts from being pressed together between the tube and the sprockets.

21. Device as stated in claim 20, characterized by devices for direct drive connection between the roller devices and the sprockets so that the rollers form friction rollers that interact with the aforementioned inner part of the chain to rotate the pipe.

22. Device as stated in claim 20, characterized by devices for adjusting the position of the axis of the driving sprocket and for locking the axis in the set position for adapting the device to different diameters of the pipes to be set in rotation.

23. Device as stated in claim 20, characterized by further sprockets for the silent chain, arranged at the pivot axis for the two jaws, which further sprockets are also in engagement with the chain.

24. Method of rotation of pipe at the wellhead for an oil well to screw together or screw up threaded joints between coaxial pipe sections, characterized in that it comprises:

a) laying part of a flexible drive element around a significant part of the circumference of the pipe to be rotated and in contact with the outside of the pipe,

b) guiding roller devices in contact with the outside of the pipe in the area of the flexible drive element,

c) producing a strong stretch in the flexible drive element to force it with high pressure into contact with the outside of the pipe,

d) producing a high contact pressure between the roller devices and the outside and

e) simultaneous operation of both the flexible drive element and the rolling device to thereby rotate the pipe, the operation of the flexible drive element exerting a

driving torque on the pipe in the installation area between the flexible drive element and the outside of the pipe, and as the operation of the roller devices communicates a driving torque to the pipe in the installation area between the roller

• the device and the outside of the pipe.

25. Method as set forth in claim 24, characterized in that it comprises that the ends of the aforementioned section of the flexible drive element are placed around wheels and that the rolling devices are coaxial with the wheels, as well as in that the rolling devices relieve the pressure between the ends and the outside of the tube thereby to prevent damage to the flexible drive element, as the roller devices not only help to drive the pipe, but also to prevent damage to the flexible drive element.

26. Method as stated in claim 24, characterized in that it includes operation of the roller devices by producing a direct drive relationship between the roller device and the flexible drive element, after which the flexible drive element is driven.

27. Method as stated in claim 24, characterized in that the flexible drive element is a chain.

28. Method as stated in claim 27, characterized in that the chain is a silent chain.

29. Method as set forth in claim 24, characterized in that it comprises placing roller devices at the part of the circumference where the flexible drive element is not in contact with the pipe.