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Publication numberUS2527490 A
Publication typeGrant
Publication dateOct 24, 1950
Filing dateJan 16, 1950
Priority dateJan 31, 1949
Publication numberUS 2527490 A, US 2527490A, US-A-2527490, US2527490 A, US2527490A
InventorsAlbert H Adams
Original AssigneeKwik Arc Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Method of removing portions of metal bodies
US 2527490 A
Abstract  available in
Images(1)
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Claims  available in
Description  (OCR text may contain errors)

Cd. 24, 1950 A. H. ADAMS 2,527,490

METHOD OF REMOVING PORTIONS OF METAL BODIES Original Filed Jan. 31, 1949 IN VEN TOR.

ALBERT H ADAMS M 1mm);

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Patented Oct. 24, 1950 METHOD ,OF REMOVING PORTIONS OF METAL BODIES Albert H. Adams ,.Liina, Ohio, assignor, by direct and mesne assignments, to Kwik-Arc, Inc., Cleveland, Ohio, a corporation of Ohio Original application January 31, 1949, Serial No. 73,735. Divided and this application January 16, 1950, Serial No. 138,853

6 Claims.

This application is a division of my copending patent application Serial No. 73,735 filed Janu ary 31, 1949.

My invention herein relates to methods of removing a portion of a metallic body, oxidizing the molten metal, and blowing away the oxidized metal. 7

One of the uses to whichmy method is particularly adapted is the removal of defects, such as the removal of sand particles, slag, or other foreign material from a ferrous casting, or the removal of other defective portions of a metallic body, such as an iron or steel casting.

Other uses and adaptations will be suggested by the disclosure of the herein, described method and my preferred device, which is suitable for carrying out the method. For, the purpose. of providing a concrete illustration and example .of my method and a suitable device for carrying out my method, the present description refers to the use of the deviceandmethodfor theremoval of defects in metallic bodies, such as the removal of sand and other foreign matter embedded in a ferrous casting.

An object of my invention is to provide an improved method for the rapid efiicient and safe removal of portions of a metal body. V

Another object is the provision of a method for eificiently removing, sand defects and other defects from a body such as a ferrous casting.

Another object is the provision of an improved method for melting a portion of a metallic body with an electric arc and the rapid oxidation of the melted metal. v

Another object is the provision of. a method adapted to electrically melt metal at a desired location, to quickly oxidize the metal at that oation and to remove the molten metal Without injury to the operator of the apparatus.

. .Another object is the provision of an improved method for removing a portion of a metallic body, such as a ferrous casting. 7

Another object isthe provision of an improved method for the removal of defects from a metal body.

Another object is the provision of an improved method for preparing a metal body for the efficient replacement of metal removed in the removal of adefect. I

Another object is the provision of a method which simultaneously removes a defect from a metal body and prepares the metal body for replacement of good metal, such as by the welding of additionalmetal thereto.

Other objects and a filler understanding of the iii invention may be had by referring to the following. description and claims, taken in conjunction with the accompanying drawing, in which:

Figure 1 is a side View of the preferred form of my device;

Figure 2 is a side View of a modified form of my device; r I

Figure 3 is a partial view of the device shown in Figure 2 and looking in the direction of the arrows 33 of Figure 2; and

Figure 4 is a view illustrating the forward end of my device in any of its forms in operating position in relationship to a ferrous casting having a portion removed.

In the form of my device illustrated in Figure 1, there is an elongated supporting frame denoted generally by the reference character II. This frame is comprised generally of an elongated electrode holder 15 in the form of a pipe or cylinder and a conduit. member 23, which are linked or coupled together by a bracket or coupling [2 and a bracket or coupling I3. The assembly of two parallel members, one the electrode holder and the other the conduit for oxygen, held firm- 7 1y together by the brackets l2 and I3 provide the elongated frame member H. Around the holder I5 and between the brackets l2 and I3 is an insulatedcovering M, which provides a handle or gripping member for the supporting frame.

Extending from the forwardend of the holder I5 is a holder extension l6 secured thereto by the nut ll, so that members l5 and iii in effect form a long holder extending through the frame II and forwardly from the forward end of the frame. A collar member i8 is secured to the forward end of the extension l6 by means of a turn screw shownin the, drawing. There is a socket member l9 integral with the collar l8, which socket H has a cylindrical bore'of inner wall adapted to receive and complementarily hold a cylindrical carbon electrode 26. The angularity of the bore in socket member; is suchthat the upper included angle between electrode 20 and the holder I5 is on the order of '73 degrees, and the included anglebetween thelower end of the electrode 20 and the horizontally disposed holder is on the order of l07 degrees. In other words, a disposition of the socket is such that the carbon electrode 20 and its lower tip or operating end 2 I is inclined away from the operator holding the handle 14 and looking forward toward the electrode. It has been found that an inclination of the electrode actuaily. as shown or within a range of few degrees latitude the preferable angle for the operators manipulation of the device and observation of the result. The lower end or operatingend 2| of the carbon cylindrical electrode 20 is somewhat pointed, like a sharpened pencil, as indicated.

A cable or electrical conductor 22 shown entering the electrode holder at the right-hand end of Figure 1 extends through the holder l and extension 6 to provide electrical connection with the carbon electrode 20 in socket IS. The righthand end of cable 22, shown broken away in the illustration, is adapted to be connected to a source of suitable electrical energy, such as a generator.

A hollow conduit adapted to conduct a gas, such as oxygen, is also carried by the frame and extends through the brackets l2 and I3. This conduit, although made up of several parts, provides through communication for the oxygen or other gas. A pipe 23 of suitable length extends through an opening in the bracket l3 and to its outer or right-hand end there is attached a hose or other conduit 24, shown broken away at the right-hand end in Figure 1. The hose or conduit 24 is adapted to be connected to, and in communication with, a source of oxygen or other gas under pressure. At the forward end of pipe 23 there is a valve assembly 25 in communication with the pipe 23. An operators handle 26 operates the valve 25 so as to open and close the valve 25 upon manipulation of handle 26. Forwardly of the operating valve 25 there is an adjusting valve 21 in communication therewith. A handle 28 on the adjusting valve 27 provides for adjusting the orifice of the adjusting valve 21 to predetermine the amount of oxygen blast which will be produced upon opening the operating valve 25. Forwardly of the adjusting valve 21 there is a union 35, which extends through an opening in bracket l2. Threadably secured to the forward end of the union 35 there is a sleeve or cylinder 32, also in communication with the opening through union 35, valve 21, valve 25, pipe 23 and hose 24.

A tube member 29, the embodiment shown in Figure l, is adapted to move forwardly and rearwardly relative to the conduit formed by the valves and pipe 23, whereby the tube member 29 telescopically fits within the sleeve member 32. The rearward end of the tube member 29 is straight and is denoted by the reference character 33. Portion 33 has formed on its rearward end a piston portion 3|, which closely fits and slides along the inner walls of the sleeve member 32. The piston 3| has an opening therethrough communicating with the interior of portion 33 of the tube member 29, so that the hollow tube member 29 is in communication with the assembled conduit extending through the supporting frame. There is a forward nozzle tip 30 formed upon the most forwardly end of the tube member 29. The forward axial end of tube member 29 and tip portion 3|) is open to atmosphere so that a nozzle for the ejectment of oxygen or other gas is provided, the orifice of the nozzle being in alignment with the axis of the tube member 29 at its forward end. Therefore, with valves 25 and 2'! in an open position, oxygen under pressure entering pipe 23 from the hose 24 goes through the assembly and out through the open orifices of tube member 29 at the forward tip 30. The direction of the blast of oxygen is determined by the disposition of the forward end of the tube member.

The straight portion 33 of tube member 29 extends from the piston 3| to the angularl bent portion of the tube. This straight portion 33 provides a piston stem for the piston 3|. There is a threaded plug 34, threadably secured to the forward end of the sleeve 32 and there is a hole in the plug 34 through which the straight portion 33 of tube member 29 slidably fits so that straight portion 33 may move forwardly and rearwardly through the plug 34. A spring 36 is mounted within the sleeve 32 around the straight portion 33 of the tube member 29. One end of the spring 36 abuts against the inner wall of plug 34 and the other end of spring 36 abuts against the end wall of piston 3|. The bias of spring 36 is such as to resiliently urge the piston 3| rearwardly, that is to the position illustrated in Figure 1, and thus to retract the tube member 29 and tip portion 30 to the rearward position shown in full line in Figure 1. With the adjusting valve 21 in an open position and upon the manipulation of handle 26 to open the valve 25, oxygen under pressure entering the sleeve 32 through the union 35 not only passes through the hollow interior of tube member 29, but also pneumatically forces the piston 3| forwardly, that is toward the left of Figure 1, and thus extends the tube 29 forwardly. The forward position of tube member 29 is shown in broken line in Figure l and the rearward or retracted position of tube member 29 is shown in full line in Figure 1. Therefore, when it is desired to supply a blast of oxygen to the vicinity of the operating end 2| of the carbon electrode 20, the valves are so operated as to cause a flow of oxygen under pressure to flow through the assembled parts from hose 24. The oxygen under pressure will cause the forward end of the tube member 29 to immediately move forward to its extended position and oxygen will be ejected forwardly out of the open end of the tube member 29 and in the direction indicated by the disposition of the forward end of the tube member 29.

The angularity of the forward end of tube member 29, including the tip portion 39, that is, the angularity of the internal bore of the tube member, is such that the upper included angle between the axis of the tube or nozzle and the horizontal disposition of the frame member II is on the order of 53 degrees, and the larger included angle between the axis of the nozzle member and the elongated frame is on the order of 127 degrees. Therefore, the included angle between the axis of the electrode 29 (which is the axis of the cylindrical socket l9) and the axis of the nozzle member at the forward end is on the order of 20 degrees. In practice it is found that an included angle on this order or within a range of a few degrees of this included angle of 20 degrees is preferable from an operating point of view.

The operation of my device and in the carrying out of my improved method the use of the same in removing the sand defects in a casting will be described. In the inspection of a ferrous casting, bits of sand or other foreign material are found embedded in the casting at or near the surface thereof. This is a defect and must be removed and good solid metal reinstated in its place. Preferably, a chalk mark is placed on the casting around the defective area to indicate the portion of the metal to be removed. This chalk mark is readily visible in the light of an electric are through the colored glasses worn by the operator. The operator holding the frame H in his hand and extending the forward end holding the electrode 20 forwardly of him touches the casting at the defective area with the forward tip 2| of the carbon electrode. By having the casting connected to a source of electric power,

as well as the cable 22, so that the casting forms one pole and the electrode 20 the other pole, a flow of current passes between the casting and electrode. The frame II and holder parts l and I6 are held substantially horizontal and parallel to the upper surface of the casting, so that the electrode is inclined downwardly and forwardly. Upon slightly raising the frame to draw the electrode away from the casting while the current is flowing, an electric arc will be set up between the casting and electrode at the defective area. This arc melts the metal in the defective area and thereby forms a pool of molten metal in a crater in the casting.

Figure 4 represents the disposition of the parts with the electrode 20 held at operating position in relationship to the casting so that an arc is struck. In this view, the reference character 44 indicates a part of a metal body, such as an iron or steel casting. A crater or cavity 45 has been formed in the casting 44 by the heat of the arc melting the metal in the defective area. The electric are from the electrode 20 is indicated by the reference character 48. It is to benoted that this are is vertical and extends in a dire-ct line from the lowermost end of electrode 20 to the casting 44. The frame is substantially parallel with the upper surface 46 of the casting 44. At the time that the arc is on and the metal has been melted, the crater 45 is filled with molten metal, the upper surface of the pool of molten metal substantially coinciding with the upper surface of 46 of the casting 44. The stream of oxygen is illustrated by a series of arrows marked by the reference character 41. The greatest concentration of the stream of oxygen and the greatest force of the oxygen blast is in the middle of the stream and closest to the orifice of the nozzle. As the oxygen blast leaves the nozzle, it spreads out to some extent as indicated by the arrows. In Figure 4 both the rrc and oxygen blast are shown for purposes of illustration. In practice, both may be present for a short period but as herein described, the blast of oxygen soon extinguishes the arc.

In Figure 4, the broken lines between holder extension I6 and tube member 29, which lines are marked by reference character 49, indicate a mechanical connection between the electrode holder and the oxygen conduit. This mechanical connection 49 may be the frame and assembly shown in Figure 1, may be the modified form of mechanical connection shown in Figure 2, or may be another mechanical connection within the spirit and intent of my invention, as covered by the appended claims.

After the arc has been struck and the electrode raisedto substantially the'position shown in Fi ure 4 so that the required amount of metal has been removed to free or obliterate the defect, no

further melting is required. In practice, the distance between the'electrode and casting will depend upon the power of the current being used and the force of the oxygen blast. V The current and the supply of oxygen are correlated to the operation being undertaken. As soon as the required amount of metal has been melted to loosen the defect, that is, to melt the metal around and in the defective area, then the further flow of an arc is no longer necessary. At this time the flow of oxygen is supplied to the nozzle member by manipulating the valve handle so that a blast of oxygen in suitably concentrated form and of sufficient quantity is ejected out through the oriflee of the nozzle. This oxy en blast traverses LII 6. the path of the arc and immediately extinguishes the arc. As seen from the illustration and as noted from the angularity of the several parts, there is a cross-fire between the arc and the stream of oxygen ejected from the nozzle. This cross-fire is such that the oxygen immediately and automatically extinguishes the arc and stops further melting operation. At the same time, the oxygen blast is directed downwardly over the entire pool of melted metal from a position and at an angle whereby the entire pool is instantaneously smothered or covered with oxygen. Substantially all parts of the pool of molten metal are contacted at the same time by the oxygen as the nozzle orifice is substantially over the crater t5 and the force of the oxygen blast and the spreading of the oxygen as it leaves the main stream of the oxygen blast is such that the oxy gen reaches substantially all portions of the pool at once.

The angularity and disposition of the parts is also such that the force of the oxygen blas't'is at an acute angle to the surface of the pool and of the casting, which surface is also substantially p2 allel to the supporting frame of the device. Therefore, the direction of the force of the oxygen blast is to one side so that the force ofthe oxygen tends to blow the oxidized metal out of the crater 45 in a direction that is forwardly and away from the frame. Thus the force of the oxygen is directed away from the operator holding the frame and operating the valve so that the danger of having hot molten metal or oxidized metal blown upon or toward the operator is obviated. The oxidized metal and any molten metal which may not have been completely oxidized is blown away from the operator for his safety and also for giving him a clear view of the crater. After enough oxygen has been ejected, and

usually only a short blast of oxygen isrequired,

there remains a smooth clean crater of regular form and having a smooth polished wall. The condition of the crater after melting and oxidizing, asdescribed, is such that new metal may be immediately welded into the crater to fill it up with new material welded'to the'casting. Thus, not only is the operation simple, efficient and safe, but the device and method producean excellent result in making the casting ready for im'- mediately welding new metal to the casting to fill in the cavity left by the removed metal.

Inasmuch as the forward tip or operating end of the electrode becomes 'quite hot from the arc and whereas it is desired to bring the forward end of the nozzle up quite close to this forward end, any danger of having the nozzle melted or otherwise injured by the electrode and the heat generated is obviated by the automatic retraction of the nozzle memberwhen oxygenis not being ejected. In the form shown in Figure 1, the spring 36 automatically withdraws the tube 29 forming the nozzle rearwardly' when the valve is closed to shut off the flow of oxygen When it is de sired to eject a blast of oxygen at the desired location immediately adjacent the tip of the electrode, then the valve 26 is operated to cause oxygen to flow. The force of the oxygen against the piston 3! causes the nozzle to immediately move to its extended position, shown in broken line in Figure l, and the continued flow of oxygen through the orifice of the nozzle takes place, as illustrated for example in Figure 4. Thus tl is provided automatic means for extendingnnd retracting the nozzle relative position. t

to its operating In Figure 2 there is a modified form of my device in that manual means are provided for extending the nozzle to operating position when the ejectment of oxygen is to take place. In this modified form, the tube member 29 has a long straight portion 31, which slidably engages in a suitable hole in bracket I2, whereby the tube member 29 with its straight portion 31 may move forwardly and rearwardly relative to the bracket I2. The rearward end of straight portion 31 of tube member 29 telescopically fits within a sleeve or cylinder 39 in a close sliding fit, whereby the straight portion 31 of the tube member 29 may move forwardly and rearwardly within the sleeve 39. A flange or abutment 40 is welded or otherwise secured to the tube portion 31 so as to move forwardly and rearwardly therewith. A spring 4| around the tube portion 31 and interposed between the flange 40 and the bracket 12 biases or urges the flange 40 rearwardly to the position shown in Figure 2. Thus, the tube member 29 is biased to the rearward position shown in Figure 2 by the resilient action of the spring 4|. The forward end of spring 4| abuts against abutting surface 38 of the bracket [2 and the rearward end of spring 4| abuts against the flange 40 carried on the tube portion 31, whereby the flange and tube secured thereto are resiliently urged rearwardly. The forward travel of the tube member 29 is limited by the spacing between bracket l2 and flange 40 and the thickness of the compressed spring therebetween.

A pivot support 59 integral with or carried by the sleeve 39 provides a pivot support for a manually operated lever 43. This lever 43 has a handle portion readily manipulated by the operator and has a cam surface 42 which engages against the rearward surface of the flange 40. The shape of the cam surface 42 is such that upon pressing the handle of lever 43 in a direction to oppose the spring 4|, the flange 40 is moved forwardly to extend the tube member 29. Upon release of the lever 43 by the operator, the action of the spring 4| moves the flange 40 rearwardly and thus retracts the forward end of the tube member 29 to its position shown in full line Figure 2. In the extended or advanced position of the nozzle at the end of the tubed member 29, the nozzle is in the position shown in broken line in Figure 2. Thus, in the form of invention illustrated in Figure 2, there is manual means provided for moving the nozzle member in one direction and automatic means moving it in another direction relative to the operating position of the nozzle. The adjusting valve 21 and the operating valve are similar to those shown in the form shown in Figure 1. By reason of the disposition of the parts in modified form, the pipe 23 in form shown in Figure 2 is somewhat shorter than that illustrated in the form for Figure 1. Similarly, the straight portion of tube member 29 in the form of Figure 2 is somewhat longer than the straight portion 33 of tube member 29 in the form shown in Figure 1.

My invention not only encompasses the automatic and manual means for moving the nozzle relative to the electrode, as illustrated by way of example in Figures 1 and 2, but also encompasses the spacing and angularity of the several parts, particularly at the forward end, as illustrated in Figure 4. Therefore, the mechanical connection indicated by the reference character 49 in Figure 4 not only includes the forms of supporting means illustrated in Figures 1 and 2, but also includes other mechanical arrangements whereby this desired spacing and angularity is obtained.

Although in the preferred form of my invention as heretofore illustrated, it is desired and a considerable advantage to have the nozzle member extendable and retractable, the arrangement that I have shown at the forward end of my device, and particularly the relationship between the socket I9 and nozzle formed by the forward end of the tube member 29 is such that new and surprisingly excellent results are obtainable.

My method of removing defects in large metal bodies,such as ferrous castings,has provided great economy in manhours in the removal of defects and in the replacing of metal removed. It was formerly the custom to use chipping hammers to manually chip out the metal around the defect so as to remove the defective area and to carefully form the wall of the cavity to prepare it for welding. By my method and with the use of my instrument the removal of defects is rapidly accomplished with a minimum of effort and with results which leave the casting or oth r metal body in a proper condition for instantaneous welding of new metal thereto. In actual comparison of the use of my device and the practice of my invention with the devices and methods heretofore used, there is such an astonishing difierence in time, effort and results obtained that the disclosure herein made is of great advantage to industry. The disclosure of my invention in improved apparatus and method is made so that knowledge thereof and protection thereto may be afforded under the provisions of the patent statutes. The present disclosure includes the foregoing description and the description of the device and method set forth in the appended claims which are incorporated herein by reference as a part of this description.

Although the invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and method, and the combination and arrangement of parts and steps may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. The method of removing a portion of a metal body which comprises the steps of: first electrically melting said portion by an electric are between said body and an electrode to provide a crater of melted metal, and next directing a blast of oxygen in a path traversing said are at an acute angle and disposed between said electrode and said body in a direction away from the operator and substantially over said crater to extinguish said are, to smother said melted metal with oxygen to oxidize the same, and to blow the oxidized metal away from the operator, said step of directing a blast of oxygen including the aiming of the axial center of the blast in a path disposed at a distance from said electrode to minimize oxidation of the electrode and the releasing of said blast from a location substantially over said crater and projected downwardly therefrom to said crater.

2. The method of removing a portion of a ferrous body which comprises the steps of: first providing an electric arc to said body to melt said portion, next providing a blast of oxygen, and directing, from a position substantially over the melted metal and intermediat the said are and the operator, said blast of oxygen at an acute angle to the path of said arc, said acute angle f 9 being substantially less than the complementary angle between said blast and the surface of said body, to intercept said are over the melted metal and to smother the melted metal, whereby the arc is extinguished, the melted metal is oxidized, and the oxidized metal is blown away from the operator.

3. The method of removing a defect from a metal casting which comprises the steps of: first providing an electric are extending to said casting in the vicinity of said defect to provide a pool of melted metal at said defect, and next releasing from a position substantially directly over said pool a stream of oxygen above said pool and sufficient to smother and oxidize the entire pool and directing said stream of oxygen downwardly in a path at an acute angle to the vertical substantially less than the complementary angle between said path and a horizontal plane end toward said pool and toward all portions thereof and also transversely of said are to simultaneously extinguish the arc and at an angle to the surface of said pool to blow out the oxidized metal in one general direction.

4. The method of removing a defect from a ferrous casting which comprises the steps of holding an electrode in advance of the operator and above the defect, first causing an arc to be produced between said electrode and said casting to melt the metal in the vicinity of said defect and to provide a crater of molten metal, next holding an oxygen-emitting nozzle substantially directly over said crater of molten metal to direct a blast of oxygen downwardly over all of said crater to smother and simultaneously oxidize the molten metal, and also directing the main stream of said blast at an angle to the surface of the molten metal in said crater and in a direction away from the operator to blow the oxidized metal out of the crater away from the operator, the said directed blast being along a path that is at an acute angle to the arc and of a magnitude substantially less than the magnitude of the complementary angle between said path and the adjacent surface of said casting.

5. The method of removing a portion of a ferrous metal body which comprises: holding an electrode at a distance from the said body; causing an electric arc to extend directly between said electrode and the surface of said body at the location of the portion to be removed to electrically melt said portion, said are being extended in a line substantially at a right angle to the plane of the said surface; thereafter releasing a blast of oxygen from a position over the melted portion and directing said blast of oxygen toward said melted portion in a line of flow disposed at an acute angle to the line of said are to intercept said are and to extinguish the same, and also disposed at an acute angle to the plane of said surface and to meet said melted portion and oxidize the same and also to blow the oxidized metal from said body in a direction away from the said line of flow, the acute angle of said line of flow to the line of said are being substantially less than th complementary angle between said line of flow and the plane of said surface.

6. A method of removing a portion of a ferrous metal body at a location of its surface, comprising the steps of: causing an electric arc to extend vertically to said surfac to melt the metal of the body at said location; thereafter, and while said are is present, releasing a blast of oxygen at a location over the melted metal and below the upper limit of said are, aiming said blast of oxygen at an acute angle to said surface and across the path of said are in an amount sufficient to extinguish said are and simultaneously toward said body at said location to oxidize said melted metal and to blow the oxidized metal in a direction away from the blast of oxygen aimed at said acute angle, the angle of said blast to the line of said are being substantially less than the complementary angle between said blast and said surface.

ALBERT H. ADAMS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 866,498 Menne Sept. 17, 1907 1,436,557 Wysong Nov. 21, 1922 2,501,954 McKechine et a1. Mar. 28, 1950

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US866498 *Aug 27, 1906Sep 17, 1907Coeln Muesener Bergwerks Actien VerMethod of melting through masses of material.
US1436557 *Sep 28, 1920Nov 21, 1922C V RatcliffProcess of and device for removing rivet heads
US2501954 *Jun 28, 1945Mar 28, 1950Ian C MckechnieElectric arc drill
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US2978569 *Nov 7, 1958Apr 4, 1961Gen Motors CorpMethod and apparatus for forming holes in sheet metal
US3128366 *Aug 28, 1959Apr 7, 1964John R McconnellFabricating of structural steel members or units
US4166209 *Nov 7, 1977Aug 28, 1979Arcair CompanyApparatus for reducing operating noise of the air-carbon arc cutting and gouging process
US4258244 *May 10, 1979Mar 24, 1981Arcair CompanyMethod for reducing operating noise of the air-carbon arc cutting and gouging process
US4485287 *Sep 16, 1982Nov 27, 1984Agency Of Industrial Science & TechnologyMethod of making a hole in a thick-walled metal material
US5021624 *Apr 11, 1988Jun 4, 1991Gene RogersCutting tools for conventional and MIG electric welders
Classifications
U.S. Classification219/70
International ClassificationF23D14/32
Cooperative ClassificationY02E20/344, F23D14/32
European ClassificationF23D14/32