US2355838A

US2355838A - Electromechanical method of and means for conditioning surfaces of metal bodies

Info

Publication number: US2355838A
Application number: US350590A
Authority: US
Inventors: Lloyd W Young; Eibe W Deck
Original assignee: Linde Air Products Co
Current assignee: Linde Air Products Co
Priority date: 1940-08-03
Filing date: 1940-08-03
Publication date: 1944-08-15
Anticipated expiration: 1961-08-15

Description

1944- L. w. YOUNG ET AL 2,355,838

ELECTROMECHANICAL METHOD OF AND MEANS FOR CONDITIONING SURFACES OF METAL BODIES Filed Aug. 3, 1940 3 Sheets-Sheet l INVENTORS LLOYD w. YOUNG EIBE w. DECK ATTO RN EY Aug. 15, 1944. w YOUNG ET AL 2,355,838 ELECTROMECHANIGAL METHOD OF AND MEANS FOR CONDITIONING SURFACES OF METAL BODIES Filed Aug. 5, 1940 3 Sheets-Sheet 2 INVENTORS LLOYD W. YOUNG BY Q ATTORNEY DECK 5 Sheets-Sheet 5 INVENTORS LLOYD W. YOUNG ATTORNEY EIBE 1 L. W. YOUNG ETAL ELECTRQMECHANICAL METHOD OF AND MEANS FOR CONDITIONING SURFACES OF METAL BODIES Filed Aug 5, 1940 Aug. 15, 1944.

Patented Aug. 15, 1944 UNITED STATES PATENT OFFICE ELECTROMECIIANICAL METHOD OF AND MEANS FOR CONDITIONING SURFACES OF METAL BODIES Lloyd W. Young, Scotch Plains, and Eibe W. Deck,

Plainfleld, N. J assignors to The Linde Air Products Company, a corporation of Ohio Application August 3, 1940, Serial No. 350,590

16 Claims.

mill to form blooms, billets, slabs, bars, etc.-

Also, the working of the metal in any of such rolling steps itself sometimes causes the surface of the body to crack. Thus, frequently the surface defects, such as seams and cracks, are rolled into the body and become concealed by the rolling operation. Further, the rolling operation increases the length of th defects inversely in proportion to the change inarea of cross section of the body being rolled. It is, therefore, desirable to eliminate such surface defects before the metal body is subsequently worked, and the elimination of the surface defects should result in a smooth and regular surface contour so that oxide coated sides will not be folded over on each other, when rolled, to produce objectionable folds within the metal. Heretofore, desurfaclng or deseaming of metal bodies was usually accomplished by either chipping, grinding, planing, or by a thermochemical conditioning process. The last-mentioned process, although being the most rapid, is effective only when conditioning iron and certain iron alloys. Many of the known mechanical methods of deseaming and desurfacing metal bodies require large machines, which, in addition to being expensive, are inflexible and cumbersome, but must be employed for processing those metal bodies which can be neither deseamed nor desurfaced by the thermochemical process.

Therefore, the main objects of this invention are to provid a rapid, flexible, and efficient electromechanical method of and means for surface conditioning hot or cold ferrous and non-ferrous metal bodies; an effective, and economical method of and means for electromechanically surface conditioning, such as desurfacing, deseaming and descaling, either hot or cold work of electrically conductive material; an improved electromechanical Work-surface conditioner having automatic control means for governing the longitudinal speed of the work undergoing treatment in accordance with an efficient operating characteristic thereof; an improved method of and apparatus for desurfacing metal bodies in a rolling mill; and an improved method of and apparatus for deseaming.

In accordance with the invention there is provided electromechanical apparatus for surface conditioning electrically conductive material having an effective width greater than the depth of the removed surfac layer, conveyor means of electrically conductive material for advancing the work with respect to a rotary tool having an annular periphery provided with transverse teeth, and circuit means for connecting a suitable source of electrical energy across the rotary tool and the conveyor mean to effect the desired surface heating.

The improved electromechanical apparatus for surface conditioning work preferably comprises a work surface conditioner including work propelling means for moving work to be surface conditioned along a predetermined path of movement, a substantially stationar surface condltioning means including a rotary tool which is adapted to engage the work surface, and a source of electrical energy connected across the rotary tool and the work to generate localized heat for simultaneously softening and mechanically re" moving a layer of surface metal of predetermined width from the work as it is moved relatively thereto by the work propelling means, and control means adapted automatically to regulate the speed of th work propelling means in accordance with a characteristic, such as the cur. rent or voltage, of the electrical energy supplied across the rotary tool and the work. Thus, the work always moves at a speed which will maintain the maximum metal removing condition per power unit input.

In accordance with the invention, there is provided in a machine for electromechanically conditioning the surface of work, such as an ingot, bloom, billet Or the like, by causing the work to move through a conditioning station in effective electrical contact with an electrode located at said station while an electromotive force is applied across said work and said electrode, apparatus for establishing constant or continuous electrical contact with the work while moving it with respect to the electrode which apparatus comprises motor driven conveyor roll means for supporting and advancing the work longitudinally through the station, lateral way means, such as longitudinal guides or cams, disposed above the roll means, conveyor means carried by the roll means and adapted to pass between the lateral way means, a plurality of inwardly directed fingers mounted on th conveyor means adapted successively to engage opposite sides of the work and assist the roll means in advancing the work through the station, and spring means coacting with the lateral way means and the conveyor means for causing the fingers firmly to grip the work and establish therewith continuous electrical contact.

The machine for electromechanically conditioning the surface of work with a rotating electrode preferably is provided with apparatus for comprises advancing work lengthwise through a surface treating station, and subjecting the surface of the work passing through the station simultaneously to the electrical heat softening effect and mechanical surface layer removing action of a rapidly rotating milling tool having an annular periphery provided with transverse teeth constituting an electrode of opposite polarity to that of the work in circuit relation with a suitable source of electrical energy, the effective width of the tool being substantially greater than the depth of the surface layer removing action thereof. For desurfacing, the effective width of the tool is at least equal to that of a longitudinal face of the work. For deseaming, the effective width of the tool is at least equal to the depth of the resulting groove.

Further, in accordance with the invention, the process of conditioning a work surface includes the step of rapidly rotating the tool in a direction such that it opposes the advance of the work and throws waste material away from the conditioned surface thereof and toward the unconditioned surface of the work, and continuously removing the waste material transversely of the direction of advance of the work.

In another aspect in accordance with the invention, the process of conditioning work comprises hot rolling the work to reduce its cross section, and subjecting at least a portion of the surface of the work to a rotating tool and the flow of an electric current between the work and such tool while the work is substantially at a rolling temperature and moving from one rolling operation to another, the combined surface heating and mechanical surface layer removing effect of the rotating tool acting to treat a longitudinal zone of predetermined width on the surface of the work to condition it for subsequent hot rolling.

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, both as to its organization and method of operation, together with further objects thereof, will best be understood by reference to the specification taken in connection with the accompanying drawings. a

Fig. 1 is a view mainly in end elevation and partly in cross section of a desurfacing machine embodying features of the invention;

Fig.

- the roll stand ii.

2,su,esa

the machine shown in Fig. 1, with parts broken away and shown in section;

Fig. 3 is a fragmentary view in section of a modification;

Figs. 4 and 5 areviews mainly in side and end elevation, respectively, of a deseaming machine embodying features of the invention; and

Fig. 8 is a circuit diagram illustrating one form of automatic control embodying features of the invention.

Referring particularly to Figs. 1 and 2 of the drawings. there is illustrated a desurfacing machine il associated with a rolling mill including a conventional roll stand Ii. The work Win the form of a metal body is shown in the desurfacing machine ll immediately after passing from The desurfacing machine ll preferably comprises a rotary tool I! housed in a protective casing i3 and adapted to be actuated ,or rotated by a motor l4 mounted on a supporting base II. The rotary fool I2 is preferably in the form of a wheel having a peripheral milled surface it (i. e., provided with transverse teeth, as shown) engageable with the surface S of the work W. The wheel I! is provided with impeller blades H for circulating air to cool the tool during operation. If necessary, vents may be provided in the sides of the protective casing II for the entrance and exit of a large quantity of cooling air. If desired. the tool may be cooled, as shown in Fig. 3, by the provision of a channel II on the inner periphery thereof for a cooling liquid L, such as water. Centrifugal force due to the rotation of the tool IIa causes the water to remain within the channel ll, cooling being effected through vaporization. The water may also be circulated in the channel I I by means of a water circulating system including an inlet pipe ll and an outlet scoop or pipe 20 operatively associated with the channel ll.

Surrounding the casing II of the rotary tool I2 is a magnetic coil II which is preferably located about midway between the center of the rotary tool I! and the lower peripheral edge thereof. The coil 1i preferably is connected in circuit relation with a suitable source of electrical energy -so that the magnetic lines of force generated thereby will confine the formation of electric arcs between the rotary tool I! and the work surface S within the zone of physical contact between the peripheral surface of the tool and the work. The magnetic coil 2| preferably directs the electric/arcs forwardly against the work W to prevent arcing to the side.

The rotary electrode i2 preferably is revolved in a direction such that it engages the work surface 8 in opposition to the forward movement of travel of the latter. In order to insure positive forward movement of the work while under the mechanical action of the rotary tool II, the work 'W is supported and advanced longitudinally through the treating station by motor driven roll actuating or work propelling means including mils 2:, II and II in line with a roll I which is located between the roll stand ii and the desurfacingmachine ll. Such roll means is preferably driven by an electric motor 20 which is 2 is a view mainly in front elevation of desurfacing machin'e'ill.

Carried by the rolls 22-24 are conveyor belt means preferably comprising a pair of

endless chains

28, 23 which are adapted to be driven in unison by .the motor driven roll 22. Fastened to each of the endless chains 28 is a series of blocks 23 preferably in the form of inwardly directed fingers adapted successively to engage opposite sides of the work W and assist the roll means in advancing the latter through the desurfacing machine It. The surfaces 30 of the blocks or fingers 2-9 which contact the work W have a tooth-like contour providing a good electrical and physical contact when pressed into engagement with the work. Each block 29 is attached to a spring loaded horizontal roller 3| and a supporting roller 32. The rollers 32 are adapted to support the conveyor means in travelling over the relatively stationary tracks 21 while the rollers 3| are adapted to coact with the lateral way means or cams of

tracks

21, 21 and the conveyor means to cause the inwardly directed fingers 29 firmly to grip opposite sides of the work W and establish therewith constant or continuous electrical contact as the work is moved through the treating station. The lateral ways 21 have a tapered approach or guides for receiving the rollers 3| before they reach their horizontal position where they are forced inwardly, as pointed out above.

A preferred electrical system is described in detail below. However, the conveyor means and the rotary tool preferably comprise electrically conducting material connected to a suitable source of electrical energy which is conducted to the rotary tool or milling wheel |2 by any suitable means, and to the work by means of the lateral ways of the tracks or side channels 21, rollers 3|, 32, and the inwardly directed fingers 23 which also assist, as pointed out above, in advancing the work W through the desurfacing machine l longitudinally in the direction of its length. .As shown by Fig. 2, the effective width of the rotary tool or electrode I2 is preferably slightly greater than that of the entire face or surface S of thework W. Thus, the entire face S of the work W may be desurfaced in a single pass in its movement through the desurfacing machine l0.

The desurfacing machine I0 is preferably provided with means for collecting waste 33 thrown rearwardly with respect to the direction of travel of the work W, which collecting means may comprise a continuously driven endless belt 34 provided with a series of cups 35 mounted thereon for collecting the Waste 33 as it is thrown back by the wheel I2 and then conveying the waste alongside of the machine and dumping it into a suitable receptacle. The teeth l6 of the wheel |2 are preferably provided with cleaning means, such as air streams, under high pressure emanating from a series of ports in a delivery pipe 31 disposed in operative relation to the edge of the cutter l2.

In considering the operation of the desurfacing machine shown in Figs; 1 and 2, assuming that the rotary electrode l2 and the stationary way means 21 are connected to a suitable source desurfacing machine Ill. Thus, the work W be- 'face l6 of the tool l2.

nected to the lateral way means 21 and the tool l2. An electric arcing zone is thus established in the area of contact between the successive transverse teeth of the rapidly rotating electrode l2 and the forwardly moving electrode W which heats and thereby softens successive transverse Portions of the work surface S which are thereupon immediately removed by the mechanical action of the teeth comprising the peripheral sur- The depth of the desurfaced zone is compartively slight compared to its width, being preferably only about 1': inch. In this way undesirable surface formation is quickly and eillciently removed from the work between rolling stages while the work is in a hot rolling condition.

The electrical arc heating effect may be produced by an alternating or a direct current source of electrical energy. However, if available, direct current is preferred because the anode receives a greater amount of heat than does the cathode. Thus, with the work W as the anode and the milling electrode means |2 as the cathode, highly satisfactory desurfacing results may be obtained. Since alternating current is usually available and is easily transformed to the desired voltage, such a source of electrical energy may be used.

If desired, the desurfacing machine It] may be adapted to desurface simultaneously or successively the longitudinal faces of the work W so that theentire longitudinal periphery of the work may be desurfaced before or between or after successive rolling stages thereof while the work is hot or cold. In any event, it will be clear to those skilled in the art that this invention provides rapid, flexible and efficient means for desurfacing work which comprises an electric are for softening successive portions of the surface of the work and milling means for successively removing said softened portions. As pointed out above, for effective operation it is only necessary that the work be capable of conducting an electric current.

Referring particularly to Figs. 4 and 5 of the drawings, there is illustrated a deseaming machine 40 embodyin features of the invention, which preferably comprises a rotary tool 4| in the form of a milling wheel having an annular periphery provided with tranverse teeth. A housing or shell 42 for the wheel is mounted on a shaft 43 which is connected to an actuating or driving motor 44. The work W is held rigidly on a slidably mounted base 45 for movement longitudinally of the deseaming tool 4|. The work-supporting base 45 is mounted for suitable longitudinal movement on a bed 46 provided with parallel ways 41 which cooperate with corresponding grooves in the bottom surface of the base 45. Means for advancing and retracting the work-supporting base 45 preferably comprise a motor driven pinion 48 journalled to the bed 48 for cooperation with a rack 49 associated with the bottom of the work-supporting base 45 between the ways 41.

The work-clamping means on the work-supporting base 45 preferably comprises a vertical flange 50 extending alon one side of the base 45 and a plurality of links 5| pivoted to the opposite edge of the base; each link 5| being provided with a contact plate 53 for engagement with the work W.

Adjustable means are provided for changing the position of the deseaming tool 4| with respect to the work W, such means preferably comprising an elevator for the motor 44 including a platform 54 provided with depending cylindrical guides 55, 55 which are slidably associated with vertical cylinders 58, 58 in telescoping relation; the cylinders 56 being mounted on the machine bed 51 disposed adjacent the bed 46. Supporting the motor platform 54 is a vertical screw 58 which is secured at its upper end to a block 59 mounted on the platform 54 and cooperates with a nut 60 which is adapted to rotate on a bearing 6| mounted on the bed 51. The nut 60 is turned to raise or lower the screw 58 and the parts supported thereby by an electric motor 6| through a worm gear 62 which meshes with an annular gear 63 secured to the nut 60. Thus, by energizing the motor 6| through suitable switching means (not shown) the deseaming wheel 4| may be quickly adjusted to any desired vertical position with respect to the work W.

The platform 54 is provided with a transverse slide for lateral displacement of a base 13 on which is mounted the motor 44. A screw 64 journalled at one end to a boss 65 on the base B and threaded to an upright 66 on the platform 54 is provided with a knob N for changing the transverse position of the rotary tool 4| with respect to the work W. If desired, the transverse adjusting means may be driven by a motor connected to the screw 64. Surrounding the rotary tool 4i and located between the center and lower peripheral edge thereof is a coil 61 which is connected to a suitable source of electrical energy for creating a magnetic flux to control the electric are formed between the rotating electrode 4i and the surface S of the work W in the operation of the deseaming machine in.

In considering the operation of the deseam ing machine III, assuming that the rotary tool 4i and the work-supporting base 45 are connected to a suitable source of electrical energy, the tool 4| is transversely adjusted with respect to the work by means of the screw 64 until the tool is in line with the seam or other defect to be surface conditioned. The work-carrying base 45 is then operated to move the work longitudinally with respect to the rotary tool 4i which is rotated at high speed by the motor 44 in a direction opposing that of the work W. In this way successive transverse surface portions of the work W are subjected to the heat-softening effect of an electric are effectively extending entirely across at least the width of the area to be deseamed, such heat-softened surface portions immediately thereafter being subjected to the mechanical milling action of the transverse teeth of the rapidly rotating tool 4|. The depth of the resulting groove is generally about ,4 inch but may extend to about Va inch, the width of the groove being comparatively wide, such as about to 1% inches. A metal body deseamed to provide a groove of this character may be readily rolled without the formation of objectionable folds, fins, or burrs.

In both desurfacing and deseaming with this equipment, a definite balance preferably should exist between the mechanical work done by the blade and the heating effected by the electrical arc. In considering the basic principle of the automatic control system used in connection with the present apparatus, the extreme conditions under which the apparatus may operate are: first, by the application of sheer mechanical force without the aid of the electric arc; and second, by the use of an electric are without the aid of mechanical force. In the first condition it is obvious that the tool must do the entire job of deseaming or desurfacing by sheer mechanical forces In the second condition the electrical energy employed in the arc will be of no avail since the heat will do nothing but soak into the metal body and no metal will be removed. In the second condition, if mechanical force is employed in addition to the introduction of heat into the body, itmay be readily seen that if the rotating cutter is moved at a very slow linear speed with respect to the work, a large amount or energy will be absorbed in forming an electrical arc, the heat thereby produced soaking into the metal body, but the quantity of metal actually removed beingrelatively small because of the low linear speed of the rotating cutter. This condition obviously will produce very low emciencies. If it be further assumed that the linear speed of the rotating cutter is increased to a point where the mechanical energy employed is at a maximum, a condition is approached which is similar to that obtained by using sheer mechanical force without the aid of an electric arc because the arc is unable to melt the surface of the metal body fast enough eifectively to aid the operation. Furthermore, with such condition, a short circuit will occur in the electrical circuit and heating will take place only by virtue of the I. R. drop through the metal body. This condition also results in very inefllcient operation.

From the foregoing, it is obvious that the most efllcient operating condition exists somewhere between the two operating extremes; that is, at a point where a definite arc will form between the transverse teeth of the cutting tool and the work with the tool operating to supply maximum mechanical force in the removal of metal. The system to control this process, therefore, must be operated from the voltage drop between the cutting tool and the work, and, in turn, operate the forward displacement of the work with respect to the tool so that such voltage drop at all times remains constant to thereby obtain the most efficient operating conditions. For example, one form of automatic control is diagrammatically illustrated by Fig. 6 of the drawings which is applicable to either the desurfacing machine ill or deseaming machine 40 described above. However, for simplicity it will be described in connection with the desurfacing machine lli. Conductors 10, III are connected to any suitable source of electrical energy, such as an alternating current power line, the motor I 4 for driving the rotary tool l2 being connected to the

conductors

10, 10 through suitable switches, not shown. For supplying a large current of low voltage across the surface of the work W and the periphery I6 of therotary tool l2, there is preferably provided a motor-generator set comprising a motor II and a generator 12; the motor ll being connected across the conductors Ill through suitable switching means, not shown. The generator 12 is connected in circuit relation with the tracks 21 and the rotary tool l2 by way of an automatic control unit ll through which is supplied electric energy for driving the motor 26 which operates the work-advancing mechanism through roll 22.

In considering the operation oi the automatic control circuit shown in Fig. 6, assuming that the value of voltage drop between the work W and the tool I2 is used for regulating purposes, the automatic control unit 13 is adjusted so that the speed of the motor 26 is responsive to the value of said ,voltage drop. Thus, should the operating conditions become such that said voltage drop changes, the speed of the driving. motor 26 is automatically changed to a proper value to compensate for such change in the voltage drop, insuring maximum mechanical surface layer removal under the established electrical conditions of the circuit.-

-While this invention is particularly applicable to deseaming and desurfacing ferrous and nonferrous metals and alloys, it will be understood that the invention is also applicable for descaling, surface cleaning and the like, employing an electric arc for heating the surface of the work up to or above a soft state and mechanical means for removing the heated surface metal simultaneously therewith or immediately thereafter. While a circular milling cutter preferably comprises such means, it will be understood that other suitable rotary tools of electrically conductive material may be used.

We are aware that it has been proposed to treat the defective surface metal of billets and the like by electrical arcs which superficially melt the surface and produce a substantially homogeneous surface free from defects, the arcs being produced between longitudinally moving work and a plurality of carbon electrodes arranged in banks which are moved parallel to the surface of the work and transversely to the longitudinal movement thereof. However, such treatment of the defective surface metal is subject to the disadvantage that the surface metal itself is not removed and to avoid oxidation thereof it is necessary to maintain an inert or non-oxidizing atmosphere over the reaction zone.

We are also aware that it has been proposed to deseam blooms, billets, sheet bars and the like, by striking an arc between the metal and an electrode and then moving the electrode along the surface defect top'roduce a single groove having a depth at least equal to that of the defect. Such process, however, must be manually carried out and is subject to the disadvantage that oxides are liable to be included in the metal which is melted in transforming the defect into a groove.

We are also aware that it is old to cut or sever metal by means of a rapidly rotating thin disc and a suitable source of electrical energy connected across the metal being cut and the disc to facilitate the severing operation. Cutting and severing machines operating on this principle are generally known as electric arc saws. However, since the saw itself has an eifective width substantially less than the depth or length of the intended cut or kerf, it is not suitable for conditioning the surface of a metal body in accordance with our invention.

While there have been described what are at present considered to be the preferred embodiments of this invention, it will be obvious to those skilled in the art that various changes and modifications may be made therein without departing from the invention, and it is therefore intended in the appended claims to cover all such changes and modifications as fall within the true spirit and scope of the invention.

What is claimed is:

1. Process of work-surface conditioning, such as descaling, desurfacing and deseaming, which comprises, advancing work in the direction of its length through a surface-conditioning station, and subjecting successive shallow transverse surface portions of the work passing through said station simultaneously to the electric are heatsoftening effect and mechanical cleaning action ofv a rapidly rotating tool having an annular periphery provided with transverse teeth constituting an electrode of opposite polarity to that of said work in circuit relation with a suitable source of electrical energy, the effective workcontact width of said tool being substantially greater than the depth of the cleaning action thereof.

2. Process of work surface conditioning, such as descaling, desurfacing and deseaming metal, which comprises advancing work while hot in the direction of its length through a surface conditioning station, and subjecting successive shallow transverse surface portions of the work passing through said station simultaneously to the electric arc heat-softening effect and mechanical surface layer removing action of a rapidly rotating tool having an annular periphery provided with transverse teeth constituting an electrode of opposite polarity to that of said work in circuit relation with a suitable source of electrical ener y, the effective work-contacting width of said tool being substantially greater than the depth of the surface layer removing action thereof.

3. Process of surface conditioning, such as desurfacing ferrous and non-ferrous metal bodies, such as ingots, billets, blooms and the like, which comprises subjecting to the heat-softening effect of an electric arcing zone successive shallow transverse surface portions extending entirely across at least one face of the body, and then mechanically removing each of said transverse surface portions immediately after it has been subjected to the heat-softening efiect of said electric arcing zone.

4. Process of desurfacing work which comprises, advancing the work in the direction of its length through a desurfacing station, and subjecting the entire width of a longitudinal face of said work passing through said station simultaneously to the electric arc heat-softening effect and mechanical surface layer removing action of a rapidly rotating tool having an annular periphery provided with transverse teeth constituting an electrode of opposite polarity to that of said work, the eifectivewidth of said tool being at least equal to that of said face.

5. Process of surface conditioning, such as deseaming ferrous and non-ferrous metal bodies, such as ingots, billets, blooms and the like, which comprises subjecting to the heat-softening effect of an electric arcing zone successive shallow transverse surface portions extending entirely across at least one seam, and then mechanically removing each of said transverse surface portions imediately after it has been subjected to the heat-softening effect of said electric arcing zone.

6. Process of deseaming work which comprises, advancing the work substantially in the direction of a seam through a deseaming station, and subjecting the work along said seam simultaneously to the electric arc heat-softening effect and mechanical-surface layer removing action of a rapidly rotating tool having an annular periphery provided with transverse teeth constituting an electrode of opposite polarity to that of said work, the effective width of said tool being at least equal to the depth of the resulting surface layer removing action,

'7. A work surface conditioner comprising, in combination work actuating means for moving work to be surface conditioned along a predetermined path of movement, substantially stationary surface conditioning means including a rotary tool, means for actuating the rotary tool, a source of electrical energy connected across said rotary tool and the work for simultaneously electrically softening and mechanically removing a surface layer of predetermined width from the workas it is moved relatively thereto by said work propelling means, and control means adapted automatically to regulate the speed of at least one of the actuating means in accordance with a characteristic of the electrical energy supplied across said rotary tool and the work.

8. In a machine for electromechanically conditioning the surface of work with a rotating electrode, apparatus for controlling the temperature of said rotating electrode comprising, impeller means including said electrode for circulating a temperature controlling fluid through passage means within said electrode by virtue of the rotation thereof, and means acting to limit the quantity of said temperature controlling fluid circulated by said impeller means through said passage means within said electrode. a

9. In a machine for electromechanicall conditioning the surface of work .with a rotating electrode, apparatus for controlling the temperature of said rotating electrode comprising, annular channel means concentric with the axis of rotation of said electrode adapted to contain a liquid by centrifugal force by virtue of the rotation of said electrode, and means eccentric with respect to the axis of rotation of said electrode for circulating a temperature controlling liquid through said channel means while said electrode is rotating.

10. In a machine for electrically conditioning the surface of work, such as an ingot, bloom, billet, or the like, by causing the work to move through a conditioning station in effective electrical contact with a rotating electrode located at said station while an electromotive force is applied across said work and said electrode, apparatus for establishing continuous electrical contact with said work while moving it with respect to said electrode comprising, roll means for supporting and advancing the work longitudinally through said station, lateral way means disposed above said roll means, conveyor. belt means carried by said roll means and adapted to pass between said lateral way means, a plurality of inwardly directed fingers mounted on said conveyor belt means adapted successively to engage opposite sides of the work and assist said roll means in advancing said work through said station, and spring means coacting with said lateral way means and said conveyor belt means for causing said fingers firmly to grip said work and establish therewith continuous-electrical contact.

11. In a machine for electrically treating the surface of work, such as an ingot, bloom, billet, or the like, by causing the work to move through a treating station in effective electrical contact with an electrode located at said station while an electromotive force is applied across said work and said electrode, apparatus for establishingconstant electrical contact with said work while moving it with respect to said electrod comprising roll means for supporting and advancing the work longitudinally through said station, lateral way means disposed adjacent said roll means, conveyor means carried by said roll means and adapted to pass through said lateral way means,'a plurality of inwardly directed fingers mounted on said conveyor means adapted successively to en- 15 gage opposite sides of the work as said work is advanced through said station, and spring means coacting with said lateral way means and said conveyor means for causing said fingers firmly to grip said work and establish therewith constant electrical contact.

12. In a machine for electrically treating the surface of the work, such as an ingot, bloom, billet, or the like, by causing the work to move through a treating station in effective electrical contact with an electrode located at said station while an electromotive force is applied across said work and said electrode, apparatus for establishing constant electrical contact with said work while moving it with respect to said electrode comprising roll means for supporting and advancing the work longitudinally through said station. lateral way means disposed adjacent said roll means, conveyor means carried by said roll means and adapted to pass adjacent said lateral way means, a plurality of contact means mounted on said conveyor means adapted successively to engage opposite sides of the work as said work is moved through said station, and spring means coacting with said lateral way means and said conveyor means for causing said contact means firmly to grip said work and establish therewith constant electrical contact.

13. The process of treating work, such as an ingot, bloom, billet, or the like, which comprises, hot rolling the work to reduce its cross section, and simultaneously subjecting at least a portion of the surface of said work to the mechanical scarflng action of a rotating tool and the archeating action of an electric current flowing between said work and said tool while said work is substantially at a rolling temperature and moving from one rolling operation to another, the arc-heating action of said current and the mechanical scarflng action of said rotating tool combining to desurface a longitudinal zone of pre-, determined width on the surface of said work suitably to condition it for subsequent hot rolling.

14. The method of surface conditioning a metal body, which comprises maintaining between a relatively wide electrode and a surface of said body an electric arcing zone of sufilcient intensity to heat-soften a relatively shallow surface portion of said body, advancing said electric arcing zone along a predetermined path on said surface to heat-soften successive relatively shallow transverse surface portions of said body, and mechanically removingwith said relatively wide electrode each surface portion along said path as such portion is heat-softened in such electric arcing zone.

15. Apparatus for conditioning'a surface of a metal body comprising, in combination, means for propellin said body along a predetermined path; surface conditioning means for simultaneously electrically softening and mechanically removing a layer of metal from said surface as said body is propelled along said path, said sur-- ratus, means for advancing the work through a surface conditioning station; and means for simultaneously subjecting the work passing through said surface conditioning station to an electric heat softening arc and a mechanical surface layer removing action, said means including a rapidly rotating tool having an annular periphery provided with transverse teeth and constituting an electrode of opposite polarity to that of said work, the effective width of said teeth being at least equal to the depth of the resulting surface 5 layer removal.

morn w. YOUNG. EIBE w. m