US1709886A - Cutting torch - Google Patents

Description

April 23, 1929. E. H. SMITH ET AL CUTTING TORCH 5 Sheets-Sheet Filed Sept. lO, 1927 In venors mm NW ELA/1ER H. SMITH HOME/L? E. 6A NNETT lllllllllllllll. 1/1111111 Aavorngs April 23, 1929 E. H. SMITH ET Al.

:CUTTING TORCH Filed Sept. l0, 1927 5 Sheets-Sheet In Ver: vors ELMER' H. 5M; TH HOME/'1 E. GANNETT E@ fm1 VWM April 23, 1929. E, H SMITH ET AL 1,709,886

CUTTING TORCH Filed Sept. lO, 1927 5 Sheets-Sheet 5 58 3,7 AcETyLE/vE l. l l B I l l l l l l l I i i l I i n a i u l I l l um) (n M OO Inventors T T 1 G, ELMTHSM/Tf/ HOMER E. 6ANNETT Patented Apr'. 23, 1.929.

UNITED STATES PATENT 1,109,886 orifice.

ELMER II. SMITH, or MINNEAPOLIS, MINNESOTA, ANI)- Hoi/ian E. GANNETT, F BERWYN, ILLINOIS.

CUTTING Tonen.

' Application led September 10, 1927. Serial No. 218,825.

This invention relates tonew and useful improvements in cutting torches, generally;v and more particularly relates to such a torch having means for heating the metal directly under the cutting orifice so that the initial cutting of the metal Will beexpedited.

Cutting torches, of ordinar construction, are usually provided With a p urality of preheating orifices Which surround the central or cutting orifice, through which the oxygen is projected against the metal for cutting. These outer orifices are connected With the fuel supply, and, when 'in operation, project a. plurality of heatlng' flames against the metal. The purpose of these flames 1s to heat the metal to a certain temperature before the cutting operation can be started. The outer or pre-heating orifices are usually arranged on an angle so that the flames converge toward a point directly in alinement With the cutting orifice and comparatively close thereto. If the preheating orifices converge too much, the flames projected therefrom have a tendency to interfere With the operation of the cutting jet in that they tend to break up the solid jet of pure oxygen, required for the cutting operation, and W'ulnch is projected from the central cutting orifice.

In order to obtain quick starting of the cutting operation, it is' necessary to bring the metal to a red heat very rapidly and in order to do this, the size of the preheating flames projected from the cutting ltip must necessarily be larger than is required to maintain the metal at the proper temperature during the cutting operation, after the' cutting is once started. It is, therefore, desirable that means be provided whereby the initial heating of the metal may be expedited and Without thenecessity of having to enlarge the preheating orifices, so that when the cutting operation has been started, the preheating flames projected from the torch will be only sufficiently large to maintain the metal at the proper temperature for rapid cutting. In the method now commonly employed for cutting metal, the flames are projected against the metal until the latter is brought to a red heat. A jetof oxygen, usually cold, is then directed upon the heated spot Which sometimes cools the metal to a point below the ignition point, after which it becomes necessary to reheat the metal before cutting can be started.

The novel cutting torch featured in this invention is provided with means for quickly heating the metal to the required temperaturein a comparatively short time. This is accomplished by using the center or' cutting orifice as a preheating orifice. in addition to` the usual preheating orifices arranged thereabout. To thus use the central or cutting orifice forprojecting a preheating flame against the Work, a valve mecha-- nism is provided upon the body of the torch for directing a portion of the fuel Agas and oxygen through this central orifice of the torch tip, simultaneously as the fuel gas and oxygen is projected from the preheating orifices arranged thereabout. Thus, all of theorifices in the torch tip may be used for projecting preheating flames against the Work, before the cutting operation is started, re-

sulting in very rapid heating of the Work.

As soon as the metal has been heated to the proper temperature, the valve mechanism is operated to gradually cut off the' supply of acetylene or fuel gas to the central or cutting orifice, after Which the supply of oxygen to the cutting orifice is increased. By thus gradually cutting off the fuel gas-and supplying additional oxygen to the cutting orifice, the central flame gradually changes neutral to lan oxidizing flame, and

from a thence to a jet of pure oxygen, and, finally as the oxygen predominates to such an extent that combustion Will barely continue, the cutting operation commences. By thus controlling, first, the fiow ofjacetylene or fuel gas to the central cutting orifice and then increasing the supply of oxygen therej to, the flame projected from the central orifice Will, as above stated, first, be a neutral or preheating fiame, will then change to an oxidizing flame, comprised mainly of oxygen heated to a high degree, and finally to a jet of pure oxy en for cutting, thereby greatly expediting the initial heating lof the metal preparatory to the cutting operation. l An object of the invention therefore is to provide an improved cutting torch comprising a valve mechanism forcontrolling the flow of'fuel gas and oxygen through the torch tip, and, whereby fuel gas and oxygen may be directed through the central or cutting orifice to assist ,in initially heating the metal before cutting is started, said valve mechanism being so constructed and arranged that a standard torch tip may be used'.

Other objects of the invention reside 'in the constructional details of the valve mechanism; the means provided for cutting off the supply of fuel gas to the central orifice and supplying additional oxygen thereto; in the provision of a mixing chamber in the head ofthe torch; and, in the simplicity of the torch and in the convenience with out the various objects of the invention, butwhich it may be operated.

Other objects of the invention will appear from the following description and accompanying drawings and will be .pointed out .in the annexed claims.

In the accompanying drawings, there has been disclosed a structure designed to `carry it isl to be understoody that the invention is not confined to the exact' features shown as various changes may be made within the scope of the claims which follow. c

In the accompanying drawings forming part of this specification;

Figure 1 is a sectional view on the line ,1--1 of Figure 2, showing the general conthe construction thereof;

Figure 7 is a view showing the tip removed from the torch head; 0

Figure 8 is a view showing the discharge end of the torch tip; and

Figure 9 is a diagrammatic view showing the connections between the various valves and the torch ti A In the selected embodiment of the invention here shown', for the purposes of disclosure, there is illustrated a cuttmg torchcomprising a head 2 having threaded vsockets 3 and 4 to which are secured respectively pipes 5, and 6. The opposite ends of the pipes 5 and 6 are secured to a valve body 7 having threaded extensions 8 and 9 for connecting the torch to a supply of' oxygen and acetylene, as indicated in Figures 1 and 9.

The torch head 2 has provided in the lower end thereof,ya threadedsocket 11 ladaptf ed to receive the threaded -portion 12 of a torch tip 13. The torch tip is secured to the head by means of a packing nut 14 received in threaded engagement. with the extension 15 of the head. A packing gland 16 cooperates'with the nut 14 to provide a j leak-proof joint between the' exterior of thetorch tipfand the'threaded extension 15 ofthe head.

The torch tip'13 is provided with the usual pre-heating orifices 17 and the central cutting or oxygen orifice 18, as shown in Figures 1 and 9. `The preheating orifices 17 are preferably arranged around the central cutting orifice 18 as shown' in Figure 8. A plurality of radial ducts 19 are provided in the upper portion of the tip 13, and connect the orifices 17 with an annular chamber 21, provided in the lower portion of the extension 15. duct 22 is provided in the lower portion of the ,head 2 and connects the annular chamber 21 with the interior of the pipe 6. Tubes 23 and 24 are mounted respectively within the pipes 5 and 6 as shown in Figure 1. These tubes each have on end secured in the torch head 2 and their opposite ends connected with the valve body 7. One end of the tube 24 is connected by a duct 25 to an annular chamber 26, provided around the reduced end portion 27 of the torch tip. This annular chamber 26 is in direct communication with'the upper ends of the preheating orifices 17, provided in the tip 13 as shown. The other end of the tube U24 is connected by a duct 28 to a small valve chamber 29, having a valve seat 31 in the lower portion thereof adapted to be engaged by a valve stem 32.. A port 33 connects the valve. chamber 29 with a supply conduit'34, terminating in the threaded extension 8 of the valve body. (See Figuresv (See Figures l and 9.) A

1 and 9.) The opposite end of the conduit 34 leads to a control valve 35, the operation of which will be subsequently described.

The pipe 6, in which the tube 24 is mount- A ed, has a port 36 connecting it .with a valve chamber 37, provided in a valve body 7. This valve chamber has a similar valve seat `38 adapted to be engaged by a valve stem 39, to control the fiow of fluid therethrough. The valve chamber 37 is connected by a port 41 to a supply conduit 42, having one end terminating in the threaded extension 9, as 'shown in Figures` 1 and 9. The opposite end of the conduit 42 terminates in a valve chamber. 43 having va valve stem 44 A provided therein for controlling the flow of fluid therethrough. This valve chamber is connected by a conduit 45, to 'a control valve 46 mounted adjacent to the control valve 35, as shown in Figures 2 and 9. The operation of this valve will subsequentlybe described.

A port 47 is centrally provided in the torch head 2 and has one end communicat- `'ing with the central orifice 18, in the torch tip,l and its other end communicating with a cone-shaped mixing chamber 48. This mixing chamber is defined by the cone-shaped bottomof a threaded socket 49 provided 'in the head, and by the tapered point of a p lug 51, received in threaded engagement with the socket 49 asshown' in Figure 1. The mixing chamber 48 is connected by a passage52 to one end of the pipe 5. An orifice 53 is provided in the plug 51 which is connected by a duct 54 to the adjacent end of the tube 23, as shown particularly in Figure 1.- The opposite end of the pipe 23 is connected with a valve chamber 55'by means of a duct 56, provided in the valve body 7. The valve chamber 55 is connected by a duct 57 t the supply conduit 34, and a. needle valve 58 is mounted within he chamber 55 toI control the flow of Huid therethrough. A by-pass 59 connects the valve 35 with the tube 23, as 'shown in Figure 9.

When the two oxygen valves 32 and 58 and also the two acetylene valves 39 and -44 are in the partially open positions shown in Figure 9, acetylene and oxygen will be supplied to the orifices 17 and 18 provided in the torch tip, with the result that a plurality of preheating flames will be projected therefrom to preheat the metal preparatory to cutting. The construction of these valves and their connections with the torch tip and fuel supplies, are such that they need not be regulated or adjusted after once having been set to supply the proper quantity of oxygen and acetylene to the torch tip for the preheating operation. Shut-off valves, not s own, are usually provided between the connections 8 and 9 and the source of supply vfor cutting off the fluid supply, when the cutting torch is inoperative.

When the needle valves have been adjusted to the positions shown in Figure' 9, wherein both oxygen and acetylene will be supplied to the orifices 17 and 18, in the torch tip, it will be seen that before the cutting operation can be started, the supply of acetylene to the central cutting orifice must be cut off and the supply of oxygen thereto must be increased. This is accom.- plished by means of the valves 35 and 46, hereinbefore mentioned. These valves are mounted respectively in bores 61 and 62, provided in cylindrical extensions 63 and 64, provided upon the valve body 7, as shown in Figure 2. The valve 35 is provided with `a stem 65 passing`thro1gh a stuffing b'ox 66,

and the valve 46 is similarly provided with a stem 67, having one end passing through a similar stuiiing boX 68. The valve stem 65 has a bracket 69 terminally secured thereto having a slot 71 adapted to receive an ex'- tension 72, provided upon a lever 73 having a finger grip 74 thereon, whereby it may be conveniently operated. The stem 67 Vof the valve 46 likewise has a bracket 75 terminally secured thereto which also has a slot 76 adapted to receive the end portion 77 of an off-set extension 78, also provided upon the lever 73. The lever 73 is supported upon a pivot 79 secured to a bracket 81 suitably clamped or secured to the pipe 6 by such means as al set screw 82, shown in Figures 1 and 2. The finger grip 74 is slidably secured to the lever 73 and has a notch 83 provided therein which isadapted to engage the end of a slot`84 provided in a casing 85 which surrounds the major portions of the pipes 5 and 6 and, through which the plate-like portion 86 of the finger grip projects. (See Figure 1.) A tension spring has one end attached lto the extension 77 and its other end to the end wall 80 of the casing 85 and functions to retain the lever 73 in its normal 1 and 9.

Figures 1, 2, and 9 illustrate the position of the lever 73 and the valves 35 and 46, when the torch is used in the initial operation of preheating the work, prior to starting the cutting operation. This therefore,

1s the normal position of the parts. A -spring 87 is coiled labout the valve stem 65 and normally holds the valve 35 in its closed position, as shown in Figure 2. A lrelatively smaller spring 88 is also coiled yabout the valve stemA 67 and constantly tends to urge the valve 46 into closing position against the tension of the relatively strongerv spring 87. The slots 71 and 76 provided respectively in the brackets 69 and 75 are relatively longer than the widths, of the extensions 72 and 77 so that when the linger grip 74 is depressed, the valve 46 will be moved into closing position before the valve 35 begins to open. Conversely, when the valve 35 is moved into closing position, the valve 46 will not be lifted from its seat until the valve 35 has been moved into closing position'.

In Figure 9, the lever73 and the valves 35 and 46A are shown in their normal posiposition, shown in Figures tions such as when the torch is used for preheating the Work. By reference to this figure, it will be noted that the valve 35 is in closed position and that the extension 72 of the lever 73 does not engage either end of the slot 71. The valve '46, however, is open, caused by the extension 77 engaging one end of the slot 76, as a result of the spring 70 holding the lever 73 in its normal position. The strength of the spring 70, therefore, is greater than -that of the spring 88, so that it will hold the parts in the position shown in Figure 9, against the tension of the spring 88. By thus arranging the valves with their complementary springs, it will be seen that when the lever 73 is depressed'to the position shown in Figure 6, the spring 88 will cause the valve 46 to be moved into closing position, before the extension 72 engages the outer end of the slot 71 and opens the valves 35. Such actuation of the valves. 35 and 46 after which,when oxygen and acetylene is Cil V 74'is depressed or moved into the position` supplied respectively to the conduits 34 and 42, a combustible fuel mixture will be discharged from the orifices 17 and 18provided in the torch tip. This fuel mixture, when ignited, provides an intense heating flame which, `when directed against the work, will quickly heat it to the desired temperature for cutting,` As soon as the metal has been heated to such temperature, the finger grip shown in Figure 6, thereby closing the valve 46 and cutting off the supply of fuel gas tothe central orf cutting orifice 18 and, subsequently opening the valve to allow additional oxygen to flow through the by-pass 59 and into the tube 23, to increase the supply of oxygen to the cutting orifice18, thereby starting the cutting operation. vBy thus controlling the flow of'acetylene and oxygen through the central orifice 18 of thetorch tip, the flame projected from the central or cutting orifice 18 can be gradually changed from a neutral or heating flame to a highly oxidizing-flame, and the-n to a'jet of-pure oxygen, which will be projected or impinged against the highly heated metal surface, with the result that cutting immediately starts. This is accomplished as a result of using the central cutting orifice 18 in addition to the preheating orifices 17 arranged thereabout,

` for initially heating the work. It has also been found that by using the central or oxygen orifice 18 as a preheating orifice, before the cutting operation is started, that the supply of fuel gas or mixture discharged from the'preheating orifices 17 may be materially decreased because of the fact that after actual cutting is started, less heat is required than4 in starting.

. We claim as our invention:

1. A cutting torch comprising a head having an orifice therein, means for supplying a cutting gas to said orifice, a conduit for supplying ra fuel gas thereto, valves for controlling said gases, anda control lever operatively' connecting said valves and adapted to simultaneously operate said valves to cut off the supply of fuel gas from s'aid orifice and increasing the iiow of cutting gas thereto, whereby the flame is converted from a heating to a cutting' flame.

2. A cutting torch comprising a head having a duct therein, a mixing chamber also in said head, a conduit for supplying fuel gas to said chamber, a valve in said conduit, a second conduit for supplying oxygen to said chamber and also having a valve therein,

' and means for simultaneously operating said valves to cut off the supply of fuel gas to said chamber and to increase the'supply of oxygen thereto, whereby the cutting operation is started.

jected therefrom to assist in initially heating'- d the work and to expedite the heating operation, and means operable to cut off the fuel supply to said duct and deliver a cutting fluid thereto to start the cutting operation.

4. A cutting torch comprising a head having a preheating orifice therein connected with a fuel supply and from which a flame may be projected to preheat the work prior to'cutting, a duct also in saidfhead adjacent to said orifice and having means for connecting it with said fuel Supply and also with a source of oxygen, whereby a preheating fiame may also be projected therefrom to assist in initially heatinglithe work and to .expedite the heating operation, andv a valve mechanism operable to gradually cut off the fuel supply from said duct andto increase the supply of oxygen thereto, whereby the cutting operation is accelerated.

' 5. A. cutting torch comprising a head having a plurality of preheating orifices therein Vconnected with the source of fuel supply and from which fiames may be projectedto pre heat the work prior to cutting, a duct also in said head having means for connecting it with said fuel supply, whereby a preheating flame may also be projected therefromv to assist 1n initially heatingthe work and i to expedite the heating operation, a valve connected with said duct and having a connection with a source of cutting fluid, a second valvefor controlling the supply of fuel to said duct, and means for simultaneously operating said valves to out off the supply of fuel to said duct and to deliver a cutting fluid thereto whereby the cutting operation is started.

6. A cutting torch comprising a head having a plurality of preheating orifices therein connected with a fuel supply, a cutting jet duct also in said heada conduit connecting said duct with a source of fuel gas, a tubular' member connecting said duct with a source of oxygen, valves for controlling the normal supply of fuel gas and oxygen to said conduit and said tubular member, a' pair of plunger valves associated with said conduit and said tubular member, and means for operating said plunger valves to cut off the supply offuel gas to said cutting jet duct and to increase the flow o f oxygen thereto to provide a cuttin jet.

Y 7. A cutting torc comprising a head having a plurality of preheating orifices therein connected with a source of fuel supply, a

cutting jet duct also in said head, means for supplying fuel gas and oxygen to said duct whereby a preheating flame may be projectedtherefrom to assist in preheating the Work, a by-pass associated with said duct and With a supply of oxygen, and a valve mechanism operable to cut off the supply of fuel gas to said duet and to open sa1d by-pass to increase the supply of oxygen to said duct, whereby a cutting jet may be projected therefrom.

8. A cutting torch comprising a head having a cutting jet duct therein, a mixing ihamber at one end of said duct, a pipe hav- ,ing one end connected With said mixing chamber and its other end connected With a source of fuel gas, a tubular member mounted within said pipe and having one end connected With said ymixing chamber and having its other end connected with a source of oxygen, valves for controlling the normal supply of fuel gas and oxygen respectively to said pipe and said tubular member, a normally closed plunger valve connected with said oxygen supply,l a by-pass connecting said valve With said tubular member, a second Valve interposed in the connection between said pipe and the source of fuel gas and normally open, a lever for operating said valves, said lever being adapted to close said `second valve to cut off the supply of fuel gas to said mixing chamber, and thereafter to open said plunger valve to permit the flow of oxygen through said by-pass, whereby an increased flow of pure oxygen is delivered to said cutting duct to provide a cutting jet. In Witness whereof, We have hereunto set our hands thisfth day of September 1927.

ELMER H. SMITH. HOMER E. GANN ETT.

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