OA10345A

OA10345A - Cutting torch

Info

Publication number: OA10345A
Application number: OA59805A
Authority: OA
Inventors: Jon Bogue Beatty
Original assignee: Jon Bogue Beatty
Priority date: 1989-06-14
Filing date: 1990-06-14
Publication date: 2001-10-23
Also published as: AP138A; AP9000183A0; AU5710090A; EP0403246A2; EP0403246A3; ZA904383B; AU626689B2

Abstract

A petrol cutting torch has a fuel mixer (12) located in a complimentary shaped recess (24) of the cutting head (10) and includes a recessed land (36) which is scored and partially defines an annular petrol chamber; an oxygen passage (44) passes through the mixer from an oxygen chamber upstream of the petrol chamber in the head to the nozzle (14), and a petrol passage (46) is provided between the land and the oxygen passage (44).

Description

! 010345

FIELD 0Γ THE INVENTION ί i This invention relates ta a flame cutting torch and more ' 5 particularly to a such a cutting torch far use uith a petrol/oxygen fuel mixture.

ppg-'-nQ'jN? TP THE INVENTION 10

With conventional petrol/oxygen cutting torches the petrolis f ed under pressure from a source to a fabric uick uhichsurounds the mixing cône in the cutting head of the torch. '15 Pétrel vapour is draun from the uick by oxygen flou thrc_igh the cutting head, through passages in the cône, toa mi>,ing chamber betmeen the cône and torch nozzle in the j hear. A major irritation if not a problem to users of these torches is that uhen the supply of petrol or oxygen 20Î to the cutting head of the torch is interrupted or anything else happens to extinguish the flame, the petrolin the cutting head dounstream of the uick is caused bythe heated nozzle and cutting head to vapourise at a rapidrats making re-ignition of the torch a difficult and time 25 consuming process.

The petrol supply to the uick of these torches, through the handle tube to the cutting head, is controlled by a i ' needle and seat valve arrangement in the petrol supply 30 tube to the head. The needle of the valve arrangement is located at the end of a rod uhich extends axially through the supply tube from the torch haridle to the seat uhich is located in the tube adjacent the cutting torch head and is • adjustable in length to vary the needle and seat aperture 35 ; by a screu thread arrangement in the handle. The ignition prctlem ui'th these torches is further aggravated,

010345 particularly at or just after initial ignition of a cooltorcn, by expansion and contraction of the needle rodbetueen its adjustment arrangemnt at the handle and theneedle seat to cause variations in the set needle and seat

DB3EET QF THE INVENTION

It is the object of this invention to provide a petrolcutting torch uhich uill at least minimise the aboveignition problems uith knoun torches. sir:·'·-g y or the invention 20 i 25 30 A petrol cutting torch according to the invention includesa cutting head, petrol and oxyqen supply tubes to theheac, a fuel mixer in the head and a flame nozzle uhichextends from the head characterised in that the fuel mixeris located in a complementally shaped recess in thecutting head and includes a recessed land uhich is scoredand uhich defines betueen it and the mixer recess uall anann_lar petrol chamber in the head, at least one oxygenpassage uhich passes through the mixer from an oxygencha-iber upstream of the petrol chamber in the head to thenozzle and at least one petrol passage betueen the scoredmixer land and the oxygen passage.

Eurther according to the invention the oxygen chamber is! defined betueen a second land on the mixer and a wail of ί the head recess in uhich the mixer is located and the 35 . mixer includes a plurality of oxygen passages uhich are spaesd arbund an axis uhich includes the axes of the mixer

010345 and nozzle uith the petrol passage being an annular slotin the scored land uhich intersects each of the oxygenpassages.

Preferabiy the o/ygen passages are no greater than onemillimétré in diameter uith the uidth of the petrolpassage slot being less than one millimétré.

Still further according to the invention the nozzleincluras an inner elef’ient u"lch is fixed in axialalignaient to the mixer and a shroud uhich is engaged uithand surrounds the inner element of the nozzle to definebetueen it and the inner nozzle element an annular fuelpassage uhich is aligned uiith and open to the oxygenpassages in the mixer and extends betuieen the mixer andfuel discbarge flûtes, in the foruard end of the innernozzle element.

Still further according to the invention the cutting headincludes a second oxygen chanter which is located at therear of the mixer and a cutting oxygen passage ujhichpassez axially through the mixer and nozzle to emerge fromthe foruard end of the nozzle.

Conueniently, the torch includes a handle having petroland oxygen supply connections, an oxygen supply tubeextending from the handle to a valve betueen the handleand cutting head, tuo tubes from the valve to the cuttinghead uiith one tube connected to an oxygen supply passagein the head to the first oxygen chamber and the second toa supply passage in the head to the second oxygen chamber,a trigger mechanism for supplyirig oxygen from the valve tothe tube to the second oxygen chamber, a petrol supplytube extending betueen the handle and a passage in thehead to the pet.rol chamber and a needle and seat valve inthe petrol tube uith the seat fixed in the tube in or lizxji' Γ-·.. àü?,\t*i2 i 010345 “ [--------- j j adjacent the cutting head and the needle on the end of aJ rod uhich is rotatable from the handle and screu engaged 1 in a sleeve uhich is fixed to the tube adjacent the valueseat. 5: ! BRIEF DESCRIPTION 0Γ THE DRAWING5 i 1θ; An e~boriimenf of tKe invention is nou deccribed by uav ofi ! example only uith reference to the drauings in uhich: FIGURE 1 is a sectioned side élévation of the cutting head J of the cutting torch of the invention, i5i FIGURE 2 is an enlarced half sectioned side élévation of the mixer and inner nczzle élément of the Figure 1 torch, i I and FIGURE 3 is an end élévation of the Figure 2 component asseen from the right in the drauing. i DETAILED DESCRIPTION OF THE PREFERRED ENBODIFQT25:

I

The cutting torch of the invention is shcun in thedrauings to include a cutting head 1U, a fuel mixer 12, aflame nozzle 14, a gland nut 16, tuo oxygen supply tubes

I 3θ: 1B and 20 and a petrol supply tube 22.

I

The cutting head 10 is recessed to receive the fuel supplyi tubes IB, 20 and 22 and includes a frusto conical recess 24 in uhich the mixer 12 is located, an oxygen cutting5 i chamber 26 at the rear of the recess 24, oxygen passages 2B and 30, a petrol passage 32 and a screu threaded bore 010345 *

} 1 5

I 1' 10

I i 15; f 20 25 ho for the nut 16 uhich is co-axial uith the recess 24.

The fuel mixer 12, as is more clearly seen in Figure 2, ismade intégral uith an inner élément 34 of the nozzle 14uith the outer surface of the mixer being complementallyshaped to the shape of the cutting head recess 24. Themixer includes a first recess 36 the base surface 3S ofuhich has a scored or roughened surface uhich couldconveniently tie provided by fnurlling, a second recess 40,four bores uu uhi;- e>tend betueen a side uall of therecess 40 and the front face of the mixer 12 and anannular slot 46 uhich is centrally located on the base ofthe recess 36 and intersects each af the bores 44. Acentral bore 48 passes through the mixer and inner nozzleélément 34 to the foruard end of the nozzle.

The foruard portion of the nozzle element 34 carries, asis conventional, fuel directing flûtes 50. The nozzle 14additionally includes, as is also conventional, a shroud52 the foruard end of uhich is frictionally engaged uiththe outer surface of the inner nozzle element 34, as shounin Figure 1, uith its rear end carrying a step formationuhich is sanduiched betueen the foruard face of the mixer12 and the nut 16. The rear portion of the shroud isspaced from the inner nozzle element to provide an annularfuel flou passage 54 uhich extends betueen the bores 44 inthe mixer and the flûtes 50 on the inner nozzle element34.

The oxygen supply tubes 18 and 20 hâve their ends locatedin the recesses in the cutting head and are fixed inposition by braising. Although the petrol supply tube 22is also shoun braised to the cutting head it is, inpractise, preferably threadedly engaged uith the cuttinghead so that it may he easily removable from the head. 35 * ·Γ-4 ••fil· : t·-'*'·· k*''· ^«iSaFirii 10 15 20 25 30 010345

The cutting torch includes the conuentional handle andoxygen and pétrel connections uith the oxygen supply tubes1Θ and 20 being connected to a trigger operated value forsupplying cutting oxygen to the tube IB on demand. Thepétrel tube 22 has fixed in its bore in the head a valueseat 56 and directly adjacent it a threaded sleeve 5Bu/hich is also fixed to the inner u/all of the bore of thetube 22. The sleeve 58 has a plurality of grooves spacedaround its ci Γου·~Γο ronce fer the passage of petrol throughfn.? sien··?. 4 vai\,r needle i: formt-d on thr- free end of arod 50 u/hich is co-axially held in the tube 22 by thethreaded sleeve 50. The remote end of the rod 65 isconnected to a rotatable nob on the handle for rotatingthe rod ana y) varying the oap betueen the needle and seat

In use, oxyaen under pressure is f(?d through the tube 20,oxyaen passage· 50 and into a chanber 62 defined betu/eenthe recess 40 in the mixer and the u/all of the recess 24to flou/ f rom t.he chanber 62 through the bores 44, throughthe fuel flou/ passage 54 in the nozzle 14, and f rom theflûtes 50 at (die foru/ard end of the nozzle 14. Petrolunder pressure is thon fed through the tube 22, the slotsin the sleeve 58, through the needle and seat valve into apetrol chamber 6ώ in the head. The surface tension of thepetrol in the chamber 64 is reduced mechanically by thescored surface 38 in the chamber to cause the petrol toflou/ evenly over the surface 30 and into the slot 45uniformly to enter and be entrained by the oxygen flou/ingunder pressure thrr/uah the bores 44 in the mixer. Thiseuen petrol distribution in the rnixed fuel leaving thebores 44 is further rnixed in the nozzle fuel passage 54and is evenly ".prend by the flûtes around the nozzle toprovide a circumferentially consistent flame around thecentral outlet f rom thr? nozzle bore 48 u/hich ujouldotheru/ise not ho the case if the surface of the recess 32 35 01 0345 had been smooth to cause the petrol in the chamber 64 topuddie under gravit y in the changer en en? side or anotherin the chamber 54 in dependence on the direction in uhichthe cutting head uas beino held by the ocerator during thecutting operation.

With the flame burning to the satisfaction of the cuttingtorch operator there is little possibility of the needleand seat oan varving du? to expansion or contraction ofthe ccd Cû ac the needle is firnl·. held i~> ito axialdirection relatiuely to the seat by the threaded sleeve5Θ. To commence cutting with the torch the operator, asis conventional, opérâtes the handle trigger to causeoxygen to flou under pressure through the tube 1Θ, thehead passaoe 25, chamber 25 and the bore 45 in the mixerand nazzle t.n pruvide a cuttinc, flame cr high intensity.

Shouid the flame nou accidentai 1 y or otneruise beextinguished, the torch may immediately be re-ignited asliquid petrol is immediately available to the ignitionoxygen from the chamber 54 uith no possibility of theheated cutting head causino the fuel mixture to be overleaned due t.p petrol évaporation in the cutting head of the torch.

Claims

010345 CLflIPIS 10 10

1 . A petrol cutting torch including a cutting head,petrol and oxygen supply tubes to the head, a fuel mixerin the head and a flame nozzle mhich extends from the headcharacterised in that the fuel mixer is located in acomplementally shaped recess in the cutting head andincludes a recessed land mhich is scored and mhich definesbetmeen it and the mixer recess mall an annular petrolchamber in the head, at least one oxygen passage mhichpasses through the mixer from an oxygen chamber upstreamof the petrol chamber in the head to the nozzle and atleast one petrol passage betmeen the scored mixer land andthe oxygen passage.
2. A cutting torch as claimed in claim 1 in mhich theoxygen chamber is defined betmeen a second land on themixer and a mall of the head recess in mhich the mixer islocated mith the mixer including a plurality of oxygenpassages mhich are spaced around an axis mhich includesthe axes of the mixer and nozzle mith the petrol passagebeing an annular slot in the scored land mhich intersectseach of the oxygen passages.
3. A cutting torch as claimed in claim 2 in mhich themixer includes four oxygen passages mhich are onemillimétré in diameter mith the m.idth of the petrolpassage slot being less than one millimétré. 010345 A. A cutting torch as claimed in ciaim 3 in uhich thenozzle includes an inner element uhich is fixed in axialaligmment to the mixer and a shroud u/hich is engaaed u/ithand sjrrounds the inner element of the nozzle to define 5 betu/een it and the inner nozzle element an annular fuelpassage u/hich is aligned u/ith and open to the oxygenpassages in the mixer and extends betu/een the mixer andfuel disoharoe flûtes in the foru/ard end of the innerΠ Ί? ~ 5 _ r? 1 ΠιΓ1 π L « 10
5. A cutting torch as claimed in ciaim A in u/hich thecutting head includes a second oxygen chamber uhich islocated at the rear of the mixer and a cutting oxygenpassage uhich passes- axially thrcugh the mixer and nozzle 15 to e~erge f'rom the formard end of the nozzle.

5. A cutting torch as claimed in ciaim 5 including ahandle having petrol and oxygen supply connections, anoxygen supply tube extending from the handle to a valve θ betuzeen the handle and cutting head, tuo tubes from the valve to the cutting head u/ith one tube connected to anoxygen supply passage in the head to the first oxygenchamber and the second to a supply passage in the head tothe second oxygen chamber, a trioger mechanism for 5 supplying oxygen from the valve through the second tube to the second oxygen chamber, a petrol supply tube extendingbetueen the handle and a passage in the head to the petrolchanter and a needle and seat valve in the petrol tubeu/ith. *:he seat fixed in the tube in or adjacent the cuttinghead and the needle on the ena ui c rnd uhich is rotatablefrom the handle and screu enoaged in a sleeve u/hich isfixed to the tube adjacent the valve seat.

0ÎÛ345 i
7. A petrol cutting torch as herein described uiith i reference to and as illustrated in the drauings. Θ. A fuel mixer for use in a cutting torch as herein 5i described uiith reference to and as illustrated in the i drauings. i