US1408194A - Blowpipe - Google Patents

Description

J. HARRIS.

BLOWPIPE.

- APPLICATICN FILED MAR. 29. 1918.

Patented Feb. 28, 1922.

UNITED STATES PATENT OFFICE;

101m mars, or'mxnwoon, onto.

BLOWPIIEE.

useful. Improvement in Blowpipes, of whichthe following is a full, clear, and exact description, reference being had to the accompanying drawings. r

This invention relates to 'blowpipes such as are employed in the arts of cutting and welding with gases. It is the general object of my invention to provide .a blowpipe which is particularly efficient in operation. More limited objects of the invention are to provide a blowpip'e having a construction and arrangement of passageways whereby, by a mere variation in the cross-sectional areas'of such passageways, the same style of pipe may be used for all of the commercial gases and vapors; to provide a blowpipe which will not only burn all of such gases and vapors, but one wherein the flame will not blow out under such variations of pressure as are employed in cutting different thicknesses of metal; also to provide ablowpipe wherein back-firing in the high pressure oxygen passageway will be prevented; to provide a blowpipe wherein the preheating operation may be accomplished more quickly and with a smaller gas consumption than is possible withany other form of pipe with which I am familiar; to provide a blowpipe the tiporifices whereof are readilv and conveniently cleaned without the necessity for disassembling; to provide a blowpipe wherein a supply of cutting oxygen, ample in quantity and uniform in pressure, will be secured at all tin1es,'wit-h no restriction such as exists in the ordinary typeof drilled or bored-head pipes; to provide for such pipes a new and V efficient arrangement of the oxygen injector for the preheating jets or orifices; and toprovide a novel construction of'valve for the cutting oxygen. I secure these results and advantages in and through the embodiment of my invention illustrated in the drawings forming part -hereof,'wherein Fig. 1'represents a side elevation of such blowpipe; Fig. 2 anenlarged central vertical sectional 'view through the blowpipe head and'tip and the adjacent ends of the pipes conveying thevarious gases theretoyXFig. 3' a sectionalv view corresponding to the line 3-3 of Fig. 2; Fig. 4 a sectional "viewcorresponding to theline 4-4: of Fig; 1; Fig. 5

Specification of Letters Zfatent.

a sectional View corresponding to the line ways in a casting 5 to which the rear end ofthe sleeve 1 is, secured, as by means of a screw 6. Projecting from the rear end of w Patented Feb. 28, 1922.. Application filedill a'rch 29, 1918. Serial No. 225,431.

the casting 5 are the connections 7 and 8, i

the former connection receiving oxygen and the latter connection a combustible gas or vapor. The flow of oxygen through appropriate passageways in the casting 5 (not shown) to the tubes 2 and 3 is controlled by a valve 9' while the flow of combustible gas from the connection 8 and the casting passageway (not shown) to the tube at is controlled by'the valve 10. v

The pipe 2 conducts oxygen for cutting purposes to a blowpipe'head and is provided with a valve, which will now be described; This valve comprises" generally a casing 11 having a rearwardly extending connection 12 for oneof the branches of the tube 2 and a forwardly extending connection 13 for the other branch of said tube. The casing is preferably formed as a casting having a head provided with a central bore 14 in which. there is reciprocably mounted a valve-operating stem 15, the inner portion of said stem being reduced to provide an annular passageway therearourfd within said bore. The outer end of the stem passes through a suitable stufiing box'l6 and is adapted. to be engaged by a lever 17 pivoted between a pair of forks 18 (as indicated at 19) extending; forwardly .froin the head. 'Thejrear endj'of the lever'17 projects beyond the front end-' bf the handle 1, in convenient position to be grasped by the operator when it is desiredto open the valve controlling the supply of cutting oxygen. The inner end of the bore 14 communicates with a cylindrical chamber 20 withinthe casing 11, there being an outwardly projectingannular said bore. The valve is mounted within the chamber 20 and. comprisesa body 22, prefer abl of brass and hexagonal in shape, said chamber 37 in the blowpipehead and thepast5 -bo y having, at one end thereof an annular recess in which" there is pressed a rubber valve 23, thisv valve being held within the recess by pressing inwardly the outer wall surroundingthe same, as indicated at 21.

The end of the casing 11 which is'oppositethe lever 17 is provided with a cap 24 threaded thereupon, and between said cap and the valve body 22 a helical spring 25 is interposed, said spring normally holding the valve to its seat.

The rear branch of the oxygen pipe 2 communicates with the chamber 20 by means of an inclined passageway 26 while the front or forward branch of said pipe communicates with, the bore 14- by an inclined passageway 27.

At their front'ends, the pipes 2, 3 and 4 are connected to the rearv of the blowpipe head 28 and communicate respectively with a chamber 29. and assageways 30 and 31 in said head. The c amber 29 is cored and branched, the front ends of'the branches merging, as shown at 29, above the central head passageway 32 for the cutting oxygen. Between the branches of the chamber as the head is drilled, as indicated at 33 to provide a chambered passageway extending nearly in the same direction as the central oxygen passageway 32 and forming only a slight angle therewith. The upper portion of the passageway 33 is threaded for the accomodation of the injector by which the preheating oxygen is enabled to inject and form a preheating mixture with the combustible gas supplied through the pipe 4 and passageway 31. The injector is formed as part of the plug 34, the lower end whereof is enlarged and threaded to engage the thread within the chambered passageway 33,'as indicated at 34. The lower end of the plug is provided with a central bore or passageway 35 communicating by cross ports 35 with the annular space provided between the reduced portion of the plug and the interior of the chambered passageway 33 above said head and with which annular space or chamber the passageway 30 communicates. The upper end of the injector plug is provided with a head 34*, between which and the adjacent surface of the blowpipe there is inserted a suitable packing washer 34. The lower end of the head 34 is tapered, and this tapered end extends across the passageway 31. With this arrangement,,preheating oxygen is supplied to the bore 35 through the cross bores or passageways 35 and serves to inject the combustible gas supplied through pipe 4 and passageway 31 and to form an intimate mixture therewith during the flow of such gases through the passageway, 36 (forming an axial continuat on of the passageway 33) through the annular sageways provided between the tip members.

The chamber 37 extends upwardly from the lower end of the head 28 and merges with a reduced internally threaded chamber the upper end'of which in turn merges with the passageway 32. This internally threaded chamber receives the u per end of the inner tip member 38 whlch is threaded thereinto, as indicated at 38.

The tip as a whole comprises an' inner member 38 and an outer member, to be referred to hereinafter. he inner member comprises a plug having a central axial bore 39 of the same diameter (throughout the major portion of its extent) as and adapted to register with thepassageway 32.

'At 1ts lower end, the bore 39 is reduced to provide a restricted dischar e passagewa 39,, the wall of the bore 39 eing tapere as indicated at 39?, to facilitate the even flow of the gas from the larger to the re stricted portlon of the central bore. The tip plug 38 is provided with .a cylindrical upper enlargement 40 and below the lower on of such enlargement with a short cylindrical' enlargement 41 mergin at its lower end with a frusto-conical sur ace 42; The portions 40, 41 and 42 are adapted to fit snugly within the outer tip member, as will be explained hereinafter. These projections or enlargements provide means for centering the inner tip member within the outer tip member and also means wherebypassageways may be provided for the mixture of preheating gases conducted to the delivery end of the pipe.

40 denotes slots, preferably V-shaped or triangular in crosssection, which extend radially inwardly from the outer wall of the projection 40 and which serve to conduct the mixture of gases within the chamber 37 to a series of V-shaped or triangular slots 41 and 42 extending radially inwardly from the outer surfaces of the tip portions 41and 42 and providing passageways for the preheating gases. Three such slots 4O are shown, and their aggregate cross-sectional area is suchas to conduct the gases freely from the chamber 37 to the slots 41 and 42 The slots 42 are formed as continuations of the slots 41 and, as shown particularly in Fig. 8, extend inwardly as nearly as possible to the central bore of the inner tip member, the bottoms of the'slots 41 being parallel with the said bore while the bottoms of the slots 42 are inclined towards said bore at a slightly'less angle than the outer sides thereof. The bottoms of the slots 42 are not exactly, parallel with theoutersurface 41 but are inclined toward such outer l inner cylindrical and frusto-conical walls of the outer tip member are adapted to form a close fit with the portions 40, 41 and 412- of the inner member; and the outer a'ndinn'er tip members are usually fastened in operative relation to each other, as by means of a I pin (not shown) A leak-proof joint is provided between the outer tip member. and the bottom of the, head 28 by means of a packing washer 4+ witliin a gland nut 45 which is threaded onto the lower end of said head.

I have found that, by inclining the surface42at .an angle of about 4-1/2" to the axis or bore of said inner member and by forming the passageways 42 in the manner .shown and described, I am enabled to obtain very important, advantages in operation. For instance, I am enabled to impinge the ignited preheating gases more" nearly upon a single spot of 'metal (in the line of the 3Qaxis of the tip) than 'is possible with any other form of blowpipe with which I am familiar; this results in a ,more nearly instantaneous preheating of the metal with a minimum consumption of gas. The particular shape of the slot-s contributes to this result. Moreover this particular shape of 40 weakening th tipso! as to render it incapable of withstanding the incidents of use.

In what is known to the trade as a No. 1

tip, thev diameter of the central bore 39 is the same as that of a No. 56 drill.

42 are shown. and the area of the discharge end'of each of said slots varies as follows, with the same diameter of'central bore, with the use of different gases i v with acetylene, 25/1000 square inch;

with carbo-hydrogen, 35/1000 square inch; with hydrogen, 41/10 00 square inch; with artificial gas, 42/1000 square inch with natural gas, 45/1000 square inch;

with thermalene, 45/1000 square inch.

These dimensions will insure the productionof a maximum size preheating flame for the particular size of cutting jet or O I'1fiC B specified. In tips of greater capac1ty,,1t

will be necessary only to preserve the same burn all of the above mentioned gases and Six slots cleaned by means of wires inserted through the lowerends thereof.

' So far as I am advised, the tip shown and described herein is the only style of tip. or blowpipe that will burnall of the gases above specified and such gases ,as'casing gas, rock gas, gasolene vapor, alcohol vapor, and, generally. all of the commercial gases by a mere variation in the cross-sectional area of the slots 41*, 42*. 'Because ofthe particular taper, of the lower end of the inner member or plug and the consequent taper or inclination given to the slots 42, the tip will will do so without the blowing out of the flame under the range of pressures ordinarily employed in cutting diiferent thicknesses of metal.

By the particular arrangement of injector (extending as nearly as practicable in the same direction as the preheati g passageavays and the central duct for high pressure oxygen) a maximum efliciency is secured 1n the mixing of the preheating gases and in their delivery to the slotted passageways. of the tip.

The manner of forming the chambered oxygen passageway 29 in the head provides therein a large high pressure. oxygen chamber which secures an ample supply of suchoxygen to the central bore. of thetip and an even pressure within such bore; there is no restriction of the oxygen supply such as exists in blowpipes wherein this gas is supplied through a drilled or bored passageway. I100 The high pressure oxygen valve described herein is particularly eflioient in operation. The hexagonal or angular shape of the body 22 enables the oxygen freely to enter the chamber 20; the-rubber valve body 23 can not mar or injure the narrow annular seat 21, The oxygen, being supplied to the chamber 20, assists normally in holding the valve body .22 to its seat, enabling me to use a light tension spring 25, which makes it extremely easy! to unseat the valve by the, operation of the handle of the lever 17. Furthermore,

the valve body 22 is extremely cheap of production and, when the rubber=-valve portion thereof becomes worn, it may be conveniently removed and replaced with a new one at the place of use and at a trifling expense.

The great majority of all back fires which occi1 r within blowpipes is due to the leak-- age between the tip and the head into the high-pressure connection. As blowpipes are usually constructed, the duct for high pressure oxygen therein is formed jointly of passageways or bores in the head and in the tip. After the pipe becomes heated through operation,"- there is an unequal expansion ofthe metal in the head and that in the tip, resulting in a separation or breaking of the joint between the hea and the tip which allows the preheating gases' and the high l,30

pressure oxygen to form an explosive mixture 1n the high pressure oxygenpassageway. I have been able to obviate this leak tering with and forming with the passageproximatel 1/100 high way 32 and bore 39 a duct for the high pressure oxygen. This washer, by its capability of expansion after compression by the upper end of the plug 38, effectually takes care of the unequal expansion between the head and the tip after the blowpipe becomes heated, malntains a closed joint between the head an'dthe tip, and thus prevents the leakage of preheating gases into the high pressure oxygen duct.

To secure the best results the walls of each of the slots 42 form an angle of about with each other. The opposite walls of each web (intermediate adjacent slots) are substantially parallel; and the bottom or inner walls of the slots can be brought into extremely close proximity to the central bore by this arrangement.

' Having thus described my invention, what I claim 1s:

1 In a blowpipe, the combination of a head, and a tip connected thereto, said tip havmga central bore for cutting oxygen and having a plurality of V-shaped passage waysfor preheating ases rouped about and converging toward the elivery end of said bore at an angle of approximately four and one-half degrees;

2. Ina blowpipe, the combination of a head, and-a tip connected thereto, said tip having a central bore therethrough and having a plurality of V-shaped passageways for preheating gases grouped about said bore and converging toward the'delivery end of said bore at an an le of approximately 4-1/2", the upper en s of said passageways being deeper than the lower ends thereof and the lower ends of said passageways being apfrom said bore. 3. In a lowpipe the combination, of a head, and a tip detachably connected thereto,'-said'tip. comprlsing van inner memberhavin a central bore, the lower or discharge end 0 said inner member being-tapered wards said central bore at an angle of approximately four and one-half degrees and provided in such tapered portion with inwardly; extending V-sha'ped slots and an 7 outer member surrounding the inner memher and havingits lower end tapered to conform to the tapered end of the inner mem her and to provide therewith an outer wall for each of,- said slots, the delivery ends of said slots being approximately 1/100 inch from the delivery end of said bore.

4. In a blow ipe,-thecomb1nat1on of a.

head, and a tip etachably connected thereto,

bore at an angle of approximately four and,

one-half degrees, such tapered lower end being provided with V-shaped slots extending inwardly from the outer surface toward said bore, the upper ends of said slots being deeper than the lower end sthereof and the lower ends of said slots being approximately 1/100 inch from said bore, and an outer 5. In a blowpipe, the combination, with a the preheating gases conducted through the first mentioned passageway.

6. In a blowpipe, the combination, with a head having a chamber for preheating gases and provided with a longitudinally extending passageway communicating therewith, of an injector in said passageway, said injector having a central bore at the lower portion thereof for oxygen, there being at passageway for conducting a combustible gas to the first mentioned passageway adjacent the delivery end of said injector, said head having a duct for cutting oxygen, and

:a tip having a centralbore arranged to" receive cutting oxygen from said .ductand provided with passageways for theprehea'ting gases conducted through the first mentloned passa eway.

7. n a blowpipe, the combination of a head having a branched chamber, for cutting oxygen, and a, tip having a central borefor such cutting oxygen and passageways for preheating gases surrounding said bore, said head having a passageway 'QXtGildlIlg through said chamber and approxlmately in the' direction of said preheating passage- 'ways and said bore and also having passageways f r preheating'oxylgen and combustible the first mentioned gas communicating wit passageway, and an injector in said first mentioned passageway arranged to conduct preheating oxygen in operative relation to the delivery end of the passageway for com bustible gas.

8. A valve for cutting-blowpi es comprising a cylindrical chamber an means for conducting fluid thereto, an angular valve body in said chamber and having at one end thereof a valve of compressible material, an outlet passageway extending from said chamber, an annular valve seat surrounding said passageway and adapted to engage said valve, an inlet passageway communicating with said chamber, a stem in said outlet passageway for unseating said valve, and a spring in said chamber tending to hold the valve on its seat.

9. A valve for blowpipes comprising an angular metal body having an annular recess in one end thereof, and rubber in said recess, the metal wall surrounding said recess being pressed inwardly to retain the rubber within said recess.

10., In a blowpipe, the combination of a an angle of substantially 60, and an outer tip member surrounding the delivery portion of the inner tip member and closing the outer sides of said slots.

In testimony whereof, I hereunto aiiix my signature.

JOHN HARRIS.

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