US3487791A - Burning bar - Google Patents

Description

EE), WW H. A. mm

BURNING BAR Filed Feb. 21. was

INVENTOR. AMP/1 V A D4144 United States Patent US. Cl. 110-1 3 Claims ABSTRACT OF THE DISCLOSURE A cutting torch having an elongated burnable metal casing containing a plurality of elongated burnable metal rods, at least one of which is mainly aluminum. A coupling on one end of said cutting torch connecting same to a conduit extending from a source of oxygen.

BACKGROUND OF THE INVENTION This invention relates in general to a torch for cutting hard material, such as rock, cast iron and concrete and, more particularly, relates to a cutting torch of the type having a metallic casing filled with metal rods which will gradually burn at a very high temperature when ignited in the presence of substantialy pure oxygen.

A cutting torch of the foregoing type, which is comprised of a steel casing containing a core of steel rods or wires and at least one magnesium or magnesium base alloy wire is disclosed in Patent No. 3,260,076. During operation of this torch, oxygen is passed through the casing .along the spaces between the wires. The magnesium wire is ignited in the presence of the oxygen and in turn supplies a quantity of heat upon ignition suflicient to ignite the steel wires and casing.

There are certain inherent problems and disadvantages in the use of magnesium or magnesium base alloy wire in such a core. For example, magnesium is particularly susceptible to corrosion and will become coated with a layer of a basic carbonate, especially if the magnesium is stored in moist air, even though at ordinary temperatures. This coating impedes proper combustion and, furthermore, since this coating is a noncoherent coating, the magnesium will, in time, become entirely corroded and converted to the basic carbonate. This corrosion and decomposition is accelerated in storage facilities that are above normal temperatures and humidity, which is frequently the case. The problem of corrosion is particularly important in a cutting torch, since the magnesium wires are of a relatively small diameter, thus relatively quickly depleted. Also, since the spaces between the wires are small, they are easily obstructed by corroded metal.

Storage of the magnesium wires in any quantity also may create a degree of fire hazard, since magnesium wires will burn readily in the presence of air, if sufficiently heated, as by an elevated temperature in the storage area. Although the incidence of such magnesium fires may be fairly low, the danger from such a fire is substantial due to the extreme heat produced. A further fire hazard is produced during operation of the cutting torch since the magnesium may continue to burn in the presence of air even after the oxygen has been turned off.

It has been found that the magnesium wire can be replaced with an aluminum rod or wire, thereby overcoming the above-mentioned problems. Aluminum stores very well for long periods of time without adverse effects since a self-protecting oxide coating is produced when the aluminum is in the presence of air. Additionally, no fire hazard is created when aluminum is used, since aluminum will not normally burn when in the presence of ambient atmosphere, even at a relatively elevated temperature. Furthermore, aluminum has been found to be far more 3,487,791 Patented Jan. 6, 1970 stable and far more economical to use than magnesium due to its lower market price. This is of considerable importance where, as here, substantial quantities of the metal are consumed during a very short period of operation of the torch.

Accordingly, it is a primary object of this invention to provide a cutting torch having a combustible metallic casing filled with metal rods, including at least one aluminum rod and a plurality of ferrous metal rods, capable of producing a very high temperature when ignited in the presence of oxygen, said torch being adapted for safe and convenient storage for extended periods of nonuse without danger of fire or loss of effectiveness due to corrosion.

Another object of the invention is to provide a cutting torch which is more economical to make and use than those previously provided.

Other objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings, in which:

FIGURE 1 is a broken side view of an embodiment of the invention.

FIGURE 2 is an enlarged, cross-sectional view taken along the line IIII in FIGURE 1.

FIGURE 3 is a broken, cross-sectional view taken along the line III-Ill in FIGURE 2.

FIGURE 4 shows an exploded view of the coupling partially in section.

For convenience in the following description, the words front and rear, and words of similar import will refer to the left and right ends, respectively, of the torch as illustrated in FIGURE 1. The words inner and outer and derivatives thereof will refer, respectively, to directions toward and away from the geometric center of the device and designated parts thereof.

SUMMARY OF THE INVENTION In general, the objects and purposes of the invention are met by providing a cutting torch comprised of a coupling and an elongated burning member having a plurality of metal rods or wires contained within a fer rous metal casing. At least one of the wires is comprised of aluminum or an aluminum base alloy, and the remaining wires are preferably comprised of a ferrous metal. The coupling serves as a handgrip and as means for connecting the burning member to an oxygen supply conduit.

DETAILED DESCRIPTION The cutting torch of the invention, a preferred embodiment of which is illustrated at 10 in FIGURE 1, is comprised of a burning member or pipe 11 of any desired length which is replaceably fitted into a coupling 12 connected to a source 13 of oxygen.

The burner pipe 11 (FIGURES l and 2) includes a cylindrical casing 16 and a core 17. The cylindrical casing 16 may be comprised of an iron or steel pipe which is open at both ends. Although the casing may be of any desired length, it is preferably about 10 feet in length. The core 17 extends substantially the full length of casing 16 and is comprised of a plurality of fusible metal rods or wires 18, such as iron or steel, and at least one rod or wire 19 of aluminum or an aluminum base alloy. The wires 18 and 19 are tightly packed in casing 16 such that spaces 21 exist therebetween.

The coupling 12 (FIGURES 3 and 41', which connects the burner pipe 11 to an oxygen supply conduit 22, is comprised of a cup-shaped housing 23, a cap 24 and a resiliently flexible gripping sleeve 26. The housing 23 has a cylindrical wall 27 and a rear end wall 28 with an internally threaded, central opening 29' therethrough. The

cylindrical wall 27 is externally threaded at 31 for re- The embodiments of the invention in which an ex ception into the internally threaded cap 24, which has-a =--='clusive proper-ty =orprivilege-isclaimed are-definedas forward end wall 32 with a concentric opening 33 therein. The cylindrical gripping sleeve 26 is comprised of a resiliently flexible material and has an external diameter such that it may, when unstressed, easily but snugly slide within the cup-shaped housing 23. The sleeve 26 has fa central bore 34 extending therethrough including a forwardly diverging portion 36. The bore 34 has a diameter which will permit snug but slideable reception of the burner pipe 11. The sleeve 26 also has a pair of rigid metal collars47 and 48, which are mounted on the axially opposite ends of sleeve 26.

, One side of a valve 37. is connected to the housing 23 of coupling 12 by a nipple 38, and the other side of valve 37 is connected to an oxygen supply conduit 22. The valve 37 is provided for controlling the flow of oxygen from the source 13 through the conduit 22.

a The torch 10 is assembled by connecting the cup-shaped housing 23 together with valve 37 to the oxygen supply conduit 22. The sleeve 26 is then inserted into the housing 23 with the diverging portion 36 of bore 34 facing forwardly, and the cap 24 is screwed partway onto the threaded portion 31 of housing 23. The burner pipe 11, with the rods 18 and 19 therein, is inserted through opening 33 in the cap 24 and into the bore 34 of sleeve 26 until pipe 11 abuts the rear end wall 28 of housing 23. The outwardly diverging portion 36 of bore 34 serves to guide pipe 11 during its initial insertion into coupling 12. The cap 24 is then screwed tightly onto housing 23, thereby axially compressing sleeve 26 and causing same to expand radially inwardly and outwardly. Thus, the sleeve 26 grips the burner pipe 11 and the inner surface of wall 27, thereby providing a seal which prevents escape of the oxygen and firmly holds the pipe with respect to the coupling.

The torch 10 may be placed in operation by first opening valve 37 to permit oxygen to pass through coupling 12 and spaces 21 through burner pipe 11. The torch 10 is then ignited by directing an ignited, oxygen acetylene welding torch at the forward open end of the burner pipe 11. The aluminum wire 19 is heated until it ignites, in the presence of the oxygen. The burning aluminum wire 19 then raises the temperature of the iron or steel wires and casing to a temperature sufficient to cause the iron or steel to burn. Thereafter, the torch 10 will continue to burn and consume the aluminum and steel wires and the casing so long as oxygen is supplied. The torch 10 while so burning produces a temperature in the range of 4,500 to 10,000 F. Under normal operating conditions, a burning member 11 of the described construction and 10 feet long will be consumed in from three to six minutes of substantially continuous use.

Although a particular preferred embodiment of the invention has been disclosed above for illustrative purposes, it will be understood that variations or modifications thereof, which come within the scope of the appended claims, are fully contemplated.

follows: .6

1. In a cutting torch including coupling means connectible to an oxygen supply,: a burner pipe comprising: an elongated casing having inner and outer cylindrical surfaces, saidcasing being made'from a ferrous 'metal material which burns in the presence of oxygen and being received into and releasably held by said coupling means; and

a plurality of elongated combustible metal wires, at

least one of said wires being made substantially entirely of aluminum, said wires being of substantially uniform cross-sectional area and having substantially the same length as said casing, said wires being arranged parallel'within said casing so that their surfaces define a plurality of lengthwise passages through which said oxygen can pass from said coupling means, whereby said oxygen supply can move from said coupling means to the opposite end of said casing to effect the burning of said torch.

2. The cutting torch defined in claim 1, wherein said casing and said wires, other than said aluminum were,

are made of steel.

3. The cutting torch as defined in claim 2, wherein said coupling means is comprised of:

a cup-shaped housing including a cylindrical wall and a rear end wall defining a cylindrical chamber, said rear end wall having a coaxial opening therethrough providing communication between the interior of said housing and said oxygen supply, said opening being of lesser diameter than said burner pipe; 3

I a resiliently flexible sleeve having a central bore, said sleeve being coaxially received within said cylindrical chamber and being of greater axial length than said cylindrical chamber; and

a cap member adjustably mounted upon said housing and engageable with said sleeve, said cap member having a central opening through which said pipe is received, whereby said burner pipe is received into said central boreand abuts said rear end wall, adjustment of said cap member toward said end wall causing said sleeve to radially expand and sealingly engage said cylindrical wall and said pipe.

UNITED STATES PATENTS References Cited 1,494,003 5/1924 1116161161. 1,631,290 6/1927 Sheedy etal.

2,286,192 I 6/1942 Aitchison et al. 3,260,076 7/1966 Humberg 431-99 CHARLES J. MYHRE, Primary Examiner US. 01. X.R. 431- 99

Images