US2148936A - Flame machining nozzle - Google Patents

Description

FLAME MACHINING NOZZLE Feb. 28, 1939.

Filed Jan. l2. 1935 lNvENToR FRANK CGEIBIG BY wlsoi. JAcossoN ATTORNEY Patented Feb. 28, 1939 UNITED STATES PATENT OFFICE FLAME MACHINING NOZZLE Application January 12, 1935, Serial No. 1,493

Claims. .(Cl. 15S-27.4)

This invention relates to the art of ame machining in which surface metal at an ignition or kindling temperature is removed by applying an oxidizing gas stream on such metal and rela- 5 tively moving such gas stream and the surface and more particularly to a nozzle for flame machining a relatively deep groove.

. It has generally been the practice to employ substantially straight nozzles for applying an oxidizing gas stream or streams at an acute angle to the surface from which metal is to be removed, as shown and described in United States Letters Patent No. 1,957,351, granted May 1, 1934, to Samuel R. Oldham. This method of removing surface metal is not entirely satisfactory for cutting a deep groove, and particularly where it is desired to produce a cut or groove at a seam formed by two metallic bodies arranged adjacent to each other with a space therebetween. When a cut or groove is made along such a seam with the oxidizing gas stream applied at an acute angle to the surface of the adjacent metallic bodies, the. greater portion of the oxidizing gas passes through the space between the adjacent bodies without effecting any removal of metal. Moreover, the slight amount of cutting that is accomplished at the seam is very irregular and not uniform. Removing metal in this manner at a seam is further objectionable because, when the tip of the nozzle is below the surface of the body in a groove or cut it is producing, an insuflicient amount of metal is removed to provide clearance for the nozzle as it is moved relatively to the metallic body.

In accordance with the present invention the above objections are overcome by providing a nozzle comprising a straight body portion and a short outer portion at an angle thereto, the nozzle having an oxidizing gas passage extending therethrough which bends at the juncture of the straight body portion and the short outer portion.

When surface metal at a seam between adjacent metallic bodies is removed with such a nozzle, the short outer section is positioned substantially parallel to the surface and near the bottom of the cut that is produced. The oxidizing gas stream discharged from the tip of the nozzle is also substantially parallel to the surface, so that substantially all of the oxidizing gas is effectively utilized to remove metal with only a negligible amount passing through the space at the seam.

The objects of the present invention, therefore, are: to provide an improved nozzle particularly suitable for many applications of flame machining; to provide such a nozzle provided with an oxidizing gas passage having an angle to change the direction of flow of the oxidizing gas; to provide an abrupt bend in an oxidizing 5 gas passage near the discharge end of the nozzle to insure a rapid expansion of the gas as it is discharged from the passage; to provide such anozzle having an oxidizing gas passage with a larger outlet than an inlet so that a rela- 10 tively large volume of oxidizing gas is discharged from the nozzle; and to provide a nozzle having the outer portion thereof substantially rectangular-shaped in transverse section.

These and other objects and advantages of 15 this invention will become apparent from the following description and accompanying drawing, in which:

Fig. 1 is an end View, in elevation, of a nozzle embodying the principles of our invention; 20

Fig. 2 is a longitudinal view, in section, taken at line 2-2 of Fig. l;

-. Fig. 3 is a longitudinal view. in section, of a nozzle illustrating another embodiment of this invention; 25

Fig. 4 is a view, in section, taken at line ll-d of Fig. 3;

Fig. 5 diagrammatically illustrates the relation of the nozzle of Fig. 1 with respect to a metallic surface in order to produce a ame machining 30 cut;

Fig. 6 is a view, in section, taken at line 6 6 of Fig. 5; and y Fig. 7 is a view, in section, taken at line 'I-'l of Fig. 1. 5

Referring to Figs. l and 2 of the drawing, a 3 nozzle embodying the principles of our invention may comprise a body I0 having a shoulder II at its inner end. An externally threaded clamping nut I2 disposed about the body I0 and 40 bearing against the shoulder II is provided for securing the nozzle to a blowpipe head or adaptor (not shown), so that the tapered seating surfaces I3 and I4 will engage and form a gastight seal with similar seating surfaces in the 45 blowpipe head, which supplies the'oxidizing gas, such as oxygen or a mixture of oxygen and air, and a combustible gas, such as a mixture of oxygen and acetylene, yto the nozzle.

An oxidizing gas passage I5, having an inlet 50 I6 communicating with an outlet in the head, extends longitudinally through the body I0. For a short distance at its inlet end the passage I5 is substantially constant in area and nonexpanding. From this non-expanding section the 55 passage I5 gradually expands toward its outlet I1, at which outlet is formed a short non-expanding section that is externally threaded. v

Disposed about the passage l5 and passing through the wall of the body IIJ is a group of combustible gas passages I8 which are substantially equally spaced and which extend longitudinally thereof from an inlet I9 adjacent the seating surface I3 and terminate adjacent the trated in Figs. 3 and 4, considerable drilling is which the combustible gas passes from the group of passages I8.

The inner end of a tip 23 is adapted to be connected to the outer end of the body I0 and the bushing 20. As shown, the straight body portion of the tip 23 is rectangular-shaped with flat side walls longer than the arcuate-shaped top and bottom walls. At its outer end the tip is provided with a short section 24 which is` also rectangular-shaped in cross section and forms an obtuse angle bend with the straight 'body portion,

A circular passage 25 of constant area extends longitudinally of the tip from its inlet to the discharge orifice at the end or discharge face 26, bending at the juncture of the short section 24 and the main portion of the tip. At its inlet the passage 25 is threaded for securing the tip 23 to the externally threaded outer section of the body I0. The extreme end ofl the threaded outer section of the body I0 is adapted to bear against a shoulder at the inlet of the passage 25, so that the cross sectional area of the passage 25 will be the same as that of the non-expanding outer section of the passage I5 with which it communicates. The inner end 21 of the tip is enlarged and circular and provided with a shoulder 28 adapted to bear against the outer end of the bushing 20v to which it may be secured. as by silver soldering, as indicated at 29.

Adjacent the short top and bottom sides of the tip 23 are two groups of passages 30 and 3I, respectively, which extend longitudinally of the tip from its inlet to the discharge face 26, these passages bending in the same manner as the passage 25 at the juncture of the short `section 24 and the main body portion of the tip. The combustible gas passes from the annular chamber 22 through the passages 30 and 3| to produce gaseous heating jets or heating flames to heat the metal to be removed to an ignition temperature. The passages 30 and 3| in the section 24 may be parallel to the oxidizing gas passage 25,I or the outer combustible gas passages may diverge toward the walls of a cut as it is being made, as shown in Fig. 7.

In the above-described embodiment the tip 23 maybe machined from a single metallic body, such as copper, for example, and the passages formed by drilling. In the embodiment illuseliminated by employing a number of parts which are assembled to provide a nozzle similar to that Yshown in Figs. 1 and 2. The particular nozzle construction in Fig. 3 may comprise a connector 40 having a shoulder 4I. A threaded clamping nut 42 iitted about the connector and bearing against the shoulder 4I is provided for securing the nozzle to a head or adaptor (not shown).

The connector 40 has a central oxidizing gas passage 43 and a plurality of combustible gas passages 44 disposed about its outer wall, the inlets of these passages communicating with an oxidizing gas passage and combustible gas passage in the head. To the outer end of the connector 40 .and at the opening of the passage 43 is secured, as

indicated at 45, the inner end of a sleeve 46 having a passage 41. The sleeve 46 forms the straight portion of the nozzle tip and its outer end is at an angle to its longitudinal axis. To increase the volume of oxidizing gas delivered by the nozzle and also reduce its velocity, the outer end of the passage 43 of the connector 40 is ared and the y inner end of the sleeve 46 is tapered to provide a.

section of oxidizing gas passage which will permit the oxidizing gas to expand during its ow through the nozzle.

The outer end of the tip comprises a short annular member 48 secured to the outer end of the sleeve 45, as indicated at 49. The member 48 has a main passage 50 communicating with the passage 41 and a plurality of passages 5I disposed about its wall. The member 48 forms a short outer section of the tip which is at an angle to the straight sleeve portion 46 to provide .an abrupt angular bend in the oxidizing gas passage of the nozzle.

The combustible gas is conducted from the passages 44 in the connector 40 to the passages 5I in the annular member 48 through sections of tubing 52. The inner ends of the tubes 52 lt into recesses at the outlets of the passages 44 and are secured to the connector, as indicated at 53. The outer end of each tube 52 receives one end of a short tubular insert 54 which is bent intermediate its ends, the opposite end of which insert fits into a recess formed at the inner end of one of the passages 5I.

In order to protect the sections of tubing 52, the spaces therebetween are lled with suitable material 55, such as copper or bronze, as shown'in Fig. 4. If desired, the annular member 4B may also be rectangular-shaped to provide a nozzle similar to the embodiment shown in Figs. 1 and 2.

In Figs. 5 and 6 is shown the nozzle of Figs. 1 and 2 during a metal removing operation to produce a relatively deep groove at a seam formed by two plates 51 and 58 arranged adjacent to each other with a space 59 therebetween. The oxidizing gas stream discharging from the tip of the nozzle is applied in the direction .of the successive portions from which metal is to be removed and is substantially parallel to the surface and near the bottom of the cut.

The combustible gas issuing from the passages 30 and 3| heats the metal directly ahead of the nozzle to an ignition temperature, such metal being indicated at B0. The oxidizing gas contacting the heated metal causes the same to ignite and burn. This burning or oxidation of the metal takes place in a denite manner to produce a smooth and even cut.

The oxidizing gas sweeps over the heated metal and is deflected upwardly to the surface of the plates 51 and 5 8. This deflection of the oxidizing gas is caused by the metal underneath the metal at an ignition temperature, such iirstmentioned metal being in a solid state so that it acts as a baiiie for the molten and burning or oxidized metal which is swept out of the cut and over the surfaces of the plates 51 and 58 by the force of the oxidizing gas stream. The foregoing action takes place about the entire end surface of the cut. In the particular shaped cut shown in Fig. 6, for example, the heating flames and oxidizing gas stream are applied on the .sidewalls as Well as to the metal directly ahead of the nozzle.

'Ihis burning or oxidation of surface metal takes place progressively as each successive portion of heated surface metal comes in contact with the oxidizing gas stream. When a cut is made in this manner at a seam,substantially all of -the oxidizing gas is effectively utilized to remove metal with only a negligible amount pass` ing through the space at the seam. A

By employing either embodiment of the noz- K zles illustrated and described above, the passage of a relatively large volume of oxidizing gas is insured. This is effected by providing the expanding portions of the oxidizing gas passages to allow the oxidizing gas to expand as it flows through the nozzle. Such expansion of the oxidizing gas is at such a rate that it is accompanied by a reduction in its velocity which is desirable. The arrangement of the short outer section of the tip at an angle to the main straight portion thereof changes'the direction of flow of oxidizing gas so that the oxidizing gas stream produced is applied substantially parallel to the surface with only a portion of the tip extending below the surface.

It has been found that the short outer section of the tip, which abruptly changes the direction of the stream, yacts as a rapid expansion outlet for the oxidizing gas as it issues from the discharge orice. the oxidizing gas stream to produce a cut which will provide adequate clearance for the outer portion of the tip as it is moved relatively to the surface. By providing a tip having straight.

side walls instead of the usual circular nozzle tip (such side walls being formed by removing metal from diametrically opposite sides of a circular nozzle) sufficient clearance is insured for any cutting or flame machining operation encountered in practice.

Although a nozzle has been shown that provides heating flames to heat to an ignition temperature the metal to be removed, it should be understood that such metal can be heated in any other suitablemanner. For example, an electric arc may be employed to preheat the surface metal to an ignition or kindling temperature, or the entire metallicbody can be heated to an ignition temperature.

When employing nozzles that provide heating flames, some economy can be effected by shutting off the supply of combustible gas after a cut has been started. This is possible because it has been found that the oxidized metal or slag, as it is generally termed, has sufficient residual heat to yheat to an ignition temperature successive surface portions subsequently exposed to the action of the oxidizing gas stream. In many instances, however, it is desirable to apply heating flames during an entire flame machining operation so as to remove a greater amount of metal per cubic lfoot of oxidizing gas.

This insures sufficient flaring ofI and such slag blown ahead of the nozzle as the cut is being made, is reduced substantially to a non-adherent granular state.

In practicing the present method of ame machining the plates or other structural shapes are preferably supported in a substantially. horizontal plane, and the grooves or cuts may be produced on one or both sides of a plate. After a plate has once been suitably supported and it is desired to produce a groove or grooves on the under side thereof, such groove or grooves can readily be made by positioning the nozzle at the under side of the plate and moving the same relatively thereto.

Although it has been stated that the abovedescribed nozzles are particularly suitable for producing cuts or grooves along seams formed by adjacent metallic bodies, it is to be understood that they are equally applicable to other flame machining applications where it is desired to remove metal from metallic bodies in the manner described above.

While we have shown particular embodiments of our invention, it will be apparent to those skilled in the art that modications may be made without departing from the spirit and scope of our invention.

We claim:

1. A blowpipe nozzle for flame machining having an oxidizing gas passage extending therethrough terminating in a discharge oriice, said passage having a portion of constant cross sectional area extending back from said oriflc'e with a short end section thereof adjacent the discharge orifice at an abrupt obtuse angle to the remainder of the passage, whereby the oxidizing gas leaving the orifice is caused to expand laterally a desired amount. 2. A blowpipe nozzle for flame machining deep grooves comprising a main body portion and a short end portion at an obtuse angle thereto, the axes of both portions lying in a plane and both portions being substantially symmetrical about their axes and having cross sections Whose Width in the direction perpendicular to said plane is smaller than the corresponding dimension in said plane, said nozzle having an oxidizing gas passage terminating in an end orice and a plurality of combustible gas passages therethrough, all of said passages having an abrupt angular change of direction at the juncture of said main body portion and said end portion.

3. A blowpipe nozzle for flame machining deep grooves comprising a main body portion and a short end portion at an obtuse angle thereto, the axes of both portions lying in a vertical plane and both portions being substantially symmetrical about their axes and having cross sections whose Width in the direction perpendicular to said plane is smaller than the corresponding dimension in said plane, said nozzle having an oxidizing gas passage terminating in an end orifice and a plurality of combustible gas passages therethrough, all of said passages being of circular cross section and having an abrupt angular change of direc' portions being substantially symmetrical about their axes and having cross sections whose width in the direction perpendicular to said plane is smaller than the corresponding dimension in said plane, said nozzle having an oxidizing gas passage terminating in an end oriilce and a plurality of combustible gas passages therethrough, all of said passages having an angular change of direction at the juncture of saidmain body portion and said end portion, said combustible gas passages terminating in two groups of 'heating orifices disposed in rows adjacent the upper and lower sides of said end orice respectively. the outer heating orifices in each row being inclined laterally to the plane so as to direct heating gas toward the sides of the groove.

FRANK C. GEIBG. WILGoT J. JAcoBssoN.

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