US2289786A - Blowpipe apparatus and process - Google Patents

Description

July 14, 1942. w JONES 2,289,786

BLOWPIPE APPARATUS AND PROCESS Filed Oct. 19, 1940 INVENTOR HOMER W. JONES ATTORNEY July m, I i942 UNITED STATES PATENT .oFFicE BLOWPIPE APPARATUS AND PROCESS Homer W. Jones, Westiield, N. J., assignor to The ldilrlilde Air Products Company, a corporation of Application October 19, 1940, Serial No. 361,821 1 Claims. (01.148-9) This invention relates to.blowpipe' apparatus and process, and particularly to an improved method of and means for inhibiting slag accumulations on the lower edge of a steel body adjacent the kerf resulting from a thermochemical severing operation, e; g., when cutting a ferrous metal body with an oxy-acetylene blowpipe.

- In the course of manufacture of ferrous metal bodies, such as steel products, it is often necessary to cut the steel bodies, such as blooms or billets, into shorter lengths before further processing, because of the excessive length that would be obtained in rolling{ to the finished size without such severing operation. Ordinarily, when steel parts, such as billets, bloom and bars, are severed with a cutting blowpipe prior to such finishing operation, it is necessary that the cut surfaces be free and clean of slag and other oxidic formations, so that all surfaces of the resulting ieces will besmooth, because, in subsequent processing orrolling of the' resulting pieces, all lateralsurfaqes of the pieces must be'smooth, otherwise slag .will be rolled into the piece and produce] a, defective product. However, especially in cutting steel at a relatively high temperature', such as that used in hot rolling, the thermochemical severing operation is accompanied by an accumulation of slag along the lower edges of the work adjacent the kerf, which is very difficult to remove owing to the fact that the slag contains a large percentage of unoxidized metal.

The main objects of this invention are, therefore, to inhibit the accumulation of slag on the underside of work adjacent a thermochemical 'cut by providing an improved method of and means for producing a smooth and slag-free kerf during the severing operation; to provide novel thermochemical apparatus for controlling slag discharged from the kerf at the underside of work during a thermochemical severing operathe depth of the cut varies from the beginning to the end of the severing operation. a

In accordance with the invention, there is provided thermochemical means for preventing slag from adhering to the underside of a ferrous which comprises directing a stream of commer-,

V cially pure oxygengas of suitable velocity against the work surfaces along both sides of the i cut and causing the stream of oxygen to follow the point of emergence of the slag from the kerf as the cutting progresses through the work.

tion; to provide an improved process of controlling slag tending to accumulate on the lower side of a ferrous metal body being thermochemically cut; to provide a blowpipe apparatus capable of a variety of uses in thermochemically treating or conditioning a. metal surface; to provide a novel and emcient blowpipe apparatus for simultaneously severing a metal'body and eliminating slag accumulation along the resulting cut and the edges adjoining the same; and to provide apparatus which enable two blowpipes freely to spread apart or automatically approach each other and constantly keep both at the proper relation to the work, while performing a severing operation in which the thickness of the bar or The blowpipe apparatus preferably comprises, in combination, two blowpipes adapted to perform, a work severing operation, means supporting the blowpipes, and means for moving the blowpipes with respect to work to be severed, and means for causing the two blowpipes to V spread apartfreely and automatically approach each other in constant relation to the work while performing a severing operation in which the thickness of the work or the depth of the cut varie from the beginning to the end of the severing operation.

The novel features which are believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, together with further objects thereof will best be understood by reference to the specification taken in connection with the accompanying drawing.

Fig. 1 is a fragmentary view in side elevation of. apparatus embodying the invention and constructed to perform the improved method; and

Fig. 2 is a fragmentary view in section of the apparatus, taken on line 2-2 of Fig. 1.

Referring to the drawing, the apparatus illus-- trated by way of example comprises a horizontal main supporting arm I which is secured to any suitable propelling means, such as motor-propelled carriage 2 mounted on and movable along a track 3. Depending from the main supporting arm I and rigidly secured thereto isa vertical supporting arm 4. A horizontal blowpipe supporting bar 5 is pivoted to the arm 4 by a pin 6,

to permit vertical displacement of a cutting blowpipe I as it i propelled over the work, such as a steel bar W to be severed. Depending obliquely from the bar are two arms 9, 9 having bearings l0, lll'at their free outer ends, on which are journalled guide rolls H, H for guiding the blowpipe I over the bar W.

Y The blowpipe I is secured to one end of the bar 5 by a circumferential clamp 12 so that its nozzle I3 is maintained in fixed position with respect to the axis of rollers l-l. When the nozzle I3 is properly spaced from the work W, forward movement of the main arm I will cause the blowpipe I to traverse the work W while the guide rollers l I maintain the nozzle I3 spaced a substantially constant distance from the curved upper surface of the work W. To counterbalance a portion of the weight of the blowpipe 1 and the guides, a counterweight I4 is secured to the opposite end of the bar 5, thereby reducing the force required to displace the apparatus forwardly during the process of severing the bar W.

A horizontal member I5 is pivoted to the vertical arm 4 by apin- Hi, to carry at one end a blowpipe I! having a nozzle adapted to deliver a low velocity oxygen jet. The purpose of the blowpipe IT, in the illustrated form of the invention, is to prevent slag from clinging to the lateral surfaces along both edges of the cut, so that such slag will not be rolled into these surfaces later, and so that a later and separate operation will not be necessary to scrape or chip the slag accumulations off such lateral surfaces.

Pivoted by a pin H! 'to the member I5 is a carriage comprising a wheel supporting member l9 having two ears 20, 20 extending outwardly therefrom and carrying wheels 2|, 2|. The arrangement is such that forward movement of the barl will, therefore, cause wheels 2| to move forwardly and, by virtue of a counterweight 22 on the opposite end of bar l5, thewheels 2| will follow the curved underside of the work W and at the same time maintain a substantially constant vertical relationship of the blowpipe IT with the cutting nozzle I3. The oxygen jet blowmovement is so controlled that the oxygen stream emanating therefrom is constantly maintained substantially at a fixed angle, preferably tangent, to the curved under surface of the round bar W at the emerging point P of the slag S as the cutting progresses through the work W.

During the cutting operation, both the slag controlling blowpipe l1 and the cutting blowpipe I travel at equal speeds about the work W, the blowpipe ll emitting a stream of low velocity oxygen tangent to the point P from which the slag is leaving kerf K, the arrangement being such that all of the slag S is oxidized and blown free from the base metal, leaving the surfaces Although the apparatus and method of this invention are disclosed for use in severing round stock, the principles of the invention are also applicable in the cutting of stock of other configuration, such as rectangular or square stock.

The blowpipe apparatus may also be used for thermochemical operations other than cutting and slag controlling For example, the blowpipe I! may be used for flame machining or treating an undulating or curved ferrous metal surface by virtue of its novel supporting apparatus which acts to keep the blowpipe at a substantially fixed angle with respect to the work surface as it is moved thereover.

I claim: 1. Blowpipe apparatus comprising,' in combination, a support, a horizontal member pivoted to said support for-tilting movement about a horizontal axis, a blowpipe carriage pivoted to one end of said member for tilting movement about a horizontal axis, said carriage comprising a pair of eccentric wheels adapted to engage the surface of work, such as a round bar of ferrous metal, and follow the contour thereof when said support is moved'horizontally with respect to such work, a counterweight on the other end of said member, and a blowpipe mounted on said carriage for delivering a jet at a substantially fixed angle with respect to the surface of such work by virtue of the Contact of said eccentric wheels therewith in rolling thereon.

'2. An apparatus for cutting cylindrical bars of I ferrous metal comprising, in combination, an oxy-fuel gas cutting blowpipe, means for supporting said cutting blowpipe for causing it to follow theuppersurface of a cylindrical bar while discharging an oxy-fuel gas cutting stream downwardly to form a kerf in said bar, a slag controlling blowpipe having a nozzle for directing a soft oxygen jet at the point of emergence of the slag from such kerf and substantially tangentially to the surface of said bar, means supporting pipe I! is so secured to the carriage l9 and its' said nozzle for causing said soft oxygen jet to follow, the lower surface of said bar in tangential relation thereto, means for propelling said cutting blowpipe and said nozzle in unison transversely of said bar to sever the same while preventing slag from accumulating on the surface of said bar adjacent the cut, said oxygen jet being directed toward and progressively following the point of emergence of slag from the kerf produced by said cutting blowpipe, said nozzle supporting means comprising a support, a horizontal member pivoted to said support .for tilting moveof the work W adjacent the cut smooth and'entirely free of objectionable accumulations of slag and other oxides that may be formed. Such slag accumulations ordinarily cling to .the sides of the kerf K along the underside of the work W merit about a horizontal axis, a nozzle carriage pivoted to one end of said member for tilting movement about a horizontal axis, said carriage comprising a pair of wheels adapted to engage the curved bottom surface of said bar and follow the contourthereof When'said support is moved horizontally with respect to such work, and a counterweight on the other end of said member, said nozzle being mounted on said'carriage for delivering said soft oxygen jet substantially tangentially with respect to the curved bottom surface of such bar by virtue of the rolling engagement of said wheels with said bar.

3. An apparatus for cutting solid bars of ferrous metal. comprising, in combination, an oxyfuel gas cutting blowpipe, means for supporting said cutting blowpipe for causing it to' follow the upper surface of a solid bar while discharging an having a nozzle for directing a jet at the point of emergence of the slag from such kerf and at an acute angle to the surface of said bar, means cutting medium and a jet of oxidizing gas; and,

- while so advancing said medium and said jet, di-

supporting said nozzle for causing said Jet to fol v the surface of said bar adjacent the cut, said jet being directed toward and progressively following the point of emergence of slag from the kerf produced by said cutting blowpipe, said nozzle supporting means comprising a support, a horizontal member pivoted to said support for tilting movement about a horizontal axis, a nozzlecarriage pivoted to said member for'tilting movement about a horizontal axis, said carriage being adapted to engage the bottom surface of said bar and follow the contour thereof when said support is moved horizontally with respect to such work., said nozzle being mounted on said carriage for delivering said jet at an acute angle with respect to the bottom surface of such bar.

t. An apparatus for cutting solid bars of ferrous metal comprising, in combination, an oxyfuel gas cutting blowpipameans for supporting said cutting blowpipe for causing it to follow the upper surface of a solid barwhile discharging an oxy-fuel gas cutting stream downwardly to form a kerf in said bar, a slag controlling blowpipe having a nozzle for directing a soft oxygen jet at the point of emergence of the slag from such kerf and at an acute angle to the surface of said bar, means supporting said nozzle for causing said soft oxygen jet to follow the lower surface of said bar in substantially fixed angular relation thereto, and means for propelling said cutting blowpipe and said nozzle in unison transversely of said bar to sever the same while preventing slag from accumulating on the surface of said bar adjacent the cut, said oxygen jet being directed toward and progressively following the point of emergence of slag from the kerf produced by said cutting blowpipe, said last-named means comprising means for causing said blowpipe and said nozzle to spread apart freely and automatically approach each other in constant relation to the bar while performing the cutting operation in which the thickness of the bar and the depth of the cut varies from the beginning to v the end of the cutting operation.

5. A process of thermochemically cuttinga a solid ferrous metal bar which comprises simultaneously advancing, along a plane extending transversely of said bar, both a thermochemical recting said cutting medium against successive exterior surface portions of said bar alonga line extending along the outside of the bar from one side of the bar to the other side thereof to form a kerf through said bar, and also directing said jet across exterior surface portions of said bar at the successive points of emergence of the slag from said kerf while the latter is being formed.

6. A process of thermochemically cutting a solid cylindrical bar of ferrous metal which comprises directing a thermochemical cutting medium against successive exterior surface portions of said bar along a semi-circular line extending from a point on one side of said bar to a diametrically, opposite point on the other side of said bar, to form a kerf through said bar; directing a separate jet of oxidizing gas tangentially across the surface of said bar at successive points of emergence of slag from said kerf while the latter is being formed; and simultaneously advancing both said cutting medium and said jet along the plane of said kerf and transversely of said bar while moving such medium and jet apart during the first half of the advance of said medium along said line and moving such medium and Jet toward one another during the second half of the advance of said medium along said line. i

7. Apparatus for thermochemically cutting a solid ferrous metal bar which comprises a blowpipe for delivering a thermochemical cutting medium; pivotally-mounted means for supporting said blowpipe and constructed and arranged to positioned relatively to successive portions of the exterior surface of said bar against which such medium is delivered to form a, kerf through said bar; a nozzle for delivering a jet of oxidizing gas;

pivotally-mounted means for supporting said nozzle and constructed and arranged to engage successive portions of the exterior surface of said bar to maintain said nozzle uniformly positioned so as to direct such jet across exterior surface portions of said bar at the successive points of emergence of the slag from said kerf while the latter is being formed; and mechanism for si- 7 multaneously advancing both of the aforesaid pivotally-mounted'means as well as said blowpipe plane extending transversely of said bar. Y

' HOMER W. JONES.

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