US2200259A - Apparatus for conditioning the surfaces of metal bodies - Google Patents

Description

M 14, 1940 J. H. BucKNAM ET AL .200.25

APPARATUS FOR CONDITIONING THE SURFACES 0F METAL BODIES v Filed Feb. 9, 1939 8 Sheets-Sheet 1 INVENTORS Iv/mash. EOCK/VAM Amway 1/ 1/4452 ATTO R N EY J. H. BUCKNAM El AL 2.200.259

Filed Feb. 9. 1939 8 Sheets -Sheet 2 May 14, 1940.

AYPARATUS FOR conmnoume THE sunmcss or META}; aonn'zs J. H. BUCKNAM ET AL May 14, 1940.

APPARATUS FOR conmuoums THE SURFACES 0F METAUBODIES Filed Feb. 9. 1939 v 8 Sheets-Sheet 3 M MW INVENTORS Jfvu-s H BUCK/VAN ALF/e50 [WI/LL52 Aer/we I? KELLER.

ATTORNEY May 14, 1940. v J. H. BUCKNAM ET AL .200.259

APPARATUS FOR CONDITIONING THE SURFACES OF METAL BODIES FiledFab. 9, 1939 8 Sheets-Sheet 4 INVENTO RS Jaw/5.5 Hfiuamwn 'AZFEEO 1/7/4452 ATTORNEY May 141M940.

J. H. BYUCKNAM Er AL 2.200.25 I

APPARATUS FOR counmxoume THE SURFACES OF METAL BODIES Filed Feb. 9. 1939 8 Sheets-Sheet 5 as a5 k-d 59 H as INVENTORS JZMEJ HEWCKA/AM Auesaf/Wusz Aer/we f2 KELLER //4 ATTORNEY J. H. BUCKNAM ET AL 2.200.259

APPARATUS FOR CONDITIONING THE SURFACES 0F METAL BODIES Filed Feb. 9, 1939 8 Sheets-Sheet 6 ATTORNEY Mgy 14, 1940. I J. H. BUCKNAM :1- AL APPARATUS FOR CONDITIONING THE SURFACES METAL BODIES Filed Feb. 9, 1939 8 Shets-Sheet 7 mMN MMMEMM M $61.1. 0 a T3. N HIM W mg w 2 A 144 Y B May 14, 1940. .1. H. BUCKNAM ET AL 200.

APPARATUS FOR CONDITIONING THE SURFACES 0F METAL BODIES I Filed Feb. '9, 1939 8 Sheets-Sheet 8 Q III INVENTORS Jane's bf 506471641? ALF/9E0 J M4452 BY Azrwae M11244? A TORNEY Patented May 14, 1940 UNITED STATES PATENT OFFICE APPARATUS FOR CONDITIONING THE SUB.- t

- FACES F METAL BODIES Application February 9, 1939, Serial No. states 24' Claims.

This invention relates to apparatus for conditioning the surfaces of metal bodies, by applying high temperature localized heat on a zone extending completely across a wide surface of such body and relatively moving the body and the heat applying means to progressivelycondition the entire surface. The invention relates more particularly to an apparatus for'thermo-chemically removing a layer of metal from an upper surface or from an upper surface anda side surface of a semi-finished steel shape such as a billet, bloom or slab, and for eliminating scale from such surfaces.

In the casting of steel ingots and during the hot rolling of steel, defects such as scale, surface cracks, slag inclusions, seams, and the like, appear on and'in. the surfaces of the steel being processed, and in order to reduce the number of rejections of finished products made from the 00 resulting steel shapes, the surface defects are generally removed before or during an intermediate stage of the rolling. Scale is commonly removed by pickling and other defects have been eliminated by chipping away the defective surface metal. Hand-operated blowpipes having suitable nozzles are now also used for thermochemically removing the defective surface metal adjacent each vdefect by effecting a combustion of the steel with oxygen. Lately, machines employing suitable nozzles have come into use for simultaneously conditioning the entire side surfaces of rectangular billets and for simultaneously conditioning the two opposite side faces of such billets when the billets are cold and also while they are at a rolling temperature and are Passing from one rolling operation to another.

The present invention provides a machine for thermally conditioning the top surface of a steel shape such as a billet, bloom or slab, for eliminating scale accretions and more particularly, for thermo-chemically removing a layer of surface metal from the entire top surface or from the top surface and an edge surface of a steel bloom or slab while it is passing from one rolling operation to the next. A blowpipe head producing high temperature heating flames and/or an oxygen stream of relatively great width sufficient to extend substantially across the top surface of a slab is supported above the slab in such a way that the head is movable in a plane transverse to the slab supported on a roll table. The blowpipe head is moved relatively along the surface of the slab from one end edge thereof to the opposite edge. When surface metal is removed, the

head is maintained in contact with the work surface during the movement in order that the surface metal may be uniformly removed and the gas efliciently used. The supporting mechanism is so arranged and constructed that the head is maintained parallel to or in contact with the slab 5 surface irrespective of changes in the'level of the surface and irrespective of the warp or twist 'of the slab. The head may be quickly lowered and raised from the operating position adjacent the work and the entire machine may be moved laterally away from the conveyor line when it is desired to pass slabs along without a surfacing treatment. When an edge surface is to be simultaneously conditioned an auxiliary blowpipe head is provided at one end of the main head and the supporting mechanism is arranged to provide a lateral floatingmovement of the heads to maintain the auxiliary head also in the operating position with respect to the edge of the slab.

The principal objects of this invention are to provide apparatus for surface conditioning an entire face or two adjoining faces of a ferrous metal body such as a slab or bloom; to provide apparatus for removing a layer of surface metal particularly while such body is at rolling temperature and in transit from one rolling operation to 5 the next; to provide such an apparatus which may be installed to operate in conjunction with an existing conveyor table of a steel mill; to provide a relatively wide gas-delivering device which shall surface condition the entire width of a slab in a single pass; to provide mechanism for movhis the gas delivering device into engagement with the surface or surfaces being treated and for maintaining such gas delivering device in uniform relation to the surfaces across the entire width of the surfaces during the operation irrespective of variations in the level of the surfaces or a warp or twist of the body; and to provide such apparatus for simultaneously surface conditioning the top surface and an adjoining edge surface of a steel slab.

These and other objects and novel features of this invention will become apparent from the following description taken in connection with the accompanying drawings in which:

. Fig. 1 is a perspective view of an exemplary apparatus in position over a slab for thermally or thermo-chemically treating the top surface of the slab according to the invention;

Fig. 2 is an elevational view of the apparatus shown in Fig. 1 with parts broken away to show the counterbalancing mechanism;

Fig. 3 is a plan view of the mechanism shown in Figs. 1, and 2;

Fig. 4 is a fragmentary front view on an enlarge'd scale of the blowpipe head with parts a broken away to show the nozzle devices;

Fig. 5 is a vertical sectional view on an enlarged scale of the left-hand blowpipe head supapparatus according to the invention for condi tioning both the top surface and an edge surface of the slab;

Fig. 11 is a vertical sectional view of the ap-' paratus shown in Fig. 10;

Fig. 12 is an enlarged vertical cross-sectional view of the blowpipe head of the apparatus shown in Fig. 10;

Fig. 13 is a fragmentary view of a horizontal section taken on the line |3--|3 of Fig. 12; and

Fig. 14 is a fragmentary view of a horizontal section taken on the line |4l4 of Fig. 11.

Referring to Fig. 1, the steel body to be surface-treated may, forexample, be a slab shown at S which is supported upon the power-driven rollers 28 of the customary steel mill conveyor table C. The conveyor rolls 28 are supported in bearings in a frame and are connected by gearing to the conveyor table driving motor in the cus-' tomary manner. The blowpipe head for projecting gases against the top surface of the slab S is shown generally at H. The head H extends transversely across the slab and has a width suificient to cover the widest slab to be surface-treated. The head H is supported preferably at each end thereof by lifting devices or jacks which are enclosed within two columns J adjacent each end of the head and depending downwardly from the frame or carriage F between the overhead ways or rails upon which the carriage F runs. The rails R may be supported in any suitable manner, as upon parallel beams 2| which are horizontal and extend transversely of and above the conveyor line or roll table C. The ends of the beams 2| may be supported in any suitable manner, as by the supporting columnsdr walls of a building or by special supporting frames. Also, depending from one end of the carriage F and between the rails R is another column-like housing shown generally at W for enclosing the weights which counterbalance the blowpipe head H.

Referring to Figs. 1, 2, and 3, the carriage or frame F comprises a pair of long side plates 22, parallel and spaced apart by several cross members rigidly secured thereto, preferably by welding. Such cross members include the pair of vertical plates 23 at the left portion of the carriage and similar plates 24 near the right-hand end of the carriage. The plates 23 are spaced apart approximately the same distance as the side plates 22 are spaced, and they depend downwardly below the carriage F to form the inside and outside walls of the left-hand jack column J. The pair of plates 24 similarly form the inside and outside walls of the right-hand column J. Four wheels 25 are employed for supporting the carriage upon the rails R. The wheels 25 are disposed outside of the plates 22 and are mounted at the ends of axles 28 which pass transversely through the plates 22 and through bearlugs 21, securedto the outside surfaces of the plates. One axle 25 is disposed between the plates 23 and the other is disposed between the plates 24. Only the left-hand axle is powerdriven although both axles may be driven "if desired. For moving the carriage transversely of the roll table and along the rails R, a worm-gear 28 secured to the mid-portion of the left hand axle 26 is provided. The'worm-gear 28 meshes with a worm 29 disposed above the axle 26 and mounted on a shaft 38 that is journalled at its left end in a bearing 3| secured to the left plate 23. The other end of the shaft 38 passes through the right-hand plate 23 and a bearing 32 mounted thereon to a speed-reducer 33 which is directly coupled with an electric motor 34. The reducer 33 with motor 34 is supported upon a horizontal plate 35 secured to the side plates 22. For safety reasons and to prevent dirt from settling on the rails R, the wheels 25 are covered by hoods 36 secured to the outside of each side plate 22. The

lower portions of plates 23 that form the inside and outside walls of the left jack housing column J are joined by side plates 31 which have their upper ends also welded to the lower edges of the side plates 22. Side plates 38 similarly form with plates 24 the right-hand jack column J. v 1

The weight-housing W comprises a box formed by four vertical plates two of which are side plates 39 secured against the inside surfaces of I side plates 22 and near the right-hand end thereof. The other two plates 40 are inside and outside wall plates secured between the plates 39. Theweight-housing W is also provided with a bottom 4| firmly secured to the plates 39 and 40. For counterbalancing the major portion of the weight of the head H, two counterweights 42 are employed, although if desired, a single counterweight may be used. The weights 42 move vertically within the housing W and are suspended therein by chains 43 which pass over pulleys 4,4 in the upper portion of the housing W. From the pulleys 44 the chains 43 pass horizontally between plates 22 to two pulleys 45 directly above the head H and spaced apartan equal distance from each side of a vertical center line through the head H. From the pulleys 45 which are secured to cross-brackets 45 secured between side plates 22, the chains depend vertically downward and are connected to the head H.

The head H is moved vertically preferably by motor operated mechanism. To this end, adjacent the left-hand end of the carriage frame F is mounted a motor 41 on a horizontal bracket plate 48 between the side plates 22. The shaft of the motor 41 carries a sprocket 49 which is connected by a chain to drive a sprocket 50 mounted on and adjacent the left-hand end of a horizontal jack shaft 5|. The jack shaft 5| is disposed below the side plates 22 and passes through both jack columns J, being journalled in bearings 52 secured to the outside faces of the plates 23 and the plates 24. The jack shaft 5| is positioned back of the center line of the carriage so as not to interfere with the chains 43. The motor 41 is preferably provided with a magnetic brake 53 so that it can be accurately stopped and locked in the stopping position. To controlthe vertical movement of the heads H, a limit switch mechanism is preferably provided and disposed underneath the motor 41. The limitswitch mechanism may comprise a spur-gear 55 mounted on the end of the jack-shaft n which .ing 8 geam'neshes with a spur-gear "on the end I a shaftill extending from the limit-switch h ussecured to the under side of the pie. J8. The liftlng-jackmechanism is shown in detail in Figs. and 6. Only the left-hand jack is described because the right-hand jack mechanism is similar but opposite handed. This mechanism comprises a .vertical screw 88 which has its lower end joumalledin a footstep bearing 88 supported on the bottom II of the jack'column. At the-upper end of the screw 59 is mounted a worn-wheel .82 which meshes with a worn 88 on the jack shaft 5i. The upper journal of the screw 89 is journalled in a roller bearing 84 that is mounted on a bracket plate 88 secured between the side plates 81, the screw 58 being suspended vertically by the bearing 84. The turning of the screw 59 moves vertically the special nut 88 which is in threaded engagement thereon. In Fig. 6 it will be seen that the nut 88 is provided with two projecting ears 6! which engage the under surface of a plate 68. The plate 88 is secured to the top end of .a box-like portion 88 of the blowpipe head supporting bracket 18. The boxportion 88 surrounds the nut 88, a considerable clearance space being provided between the nut 86 and the inner walls of the'box 69 which are also provided with vertical channels ll into which the ears 81 project in order that the nuts 88 will be prevented from turning with the screw 88. The plate 88 has a hole through it having a diameter larger than the nut 68 so that only the ears. 81 can contact with the plate. This construction provides a loose engagement of thebracket box 88 with the nut 86 so that the bracket 68 can rock laterally with respect to the nut. If it is in the lowermost positiomthe open bottom of the box 89 rests in contact with foursprings 12 secured to the bottom plat ail of the column. v

Means is provided for guiding the vertical movement of the box 88. within the column J. Such means should maintain the box 69 substantially vertical while permitting it to rock later- .ally in the plane of the section of Fig. 5 and while preventing fore and aft displacement or excessive transverse displacement of the head H. To this end, in the present example, a set of four rollers guided by vertical guide channels are provided. One pair of the rollers 14 is guided between vertical, spaced-apart angle irons 18. One leg of each angle 18 is secured to the inside surface of the left-hand plate 23 and the other legs are spaced apart and parallel to form a guide channel for the rollers H which are journalled on two trunnions I5 projecting horizontally leftward from the box 69 and respectively located adjacent the upper and lower ends thereof. A second pair of rollers 18 is provided and mounted on the end portions of a trunnion shaft 11, the axis of which is in perpendicular relation to the trunnions I8 and located substantially midway between the trun-' nions' 15 and adjacent the left-side wall of the box 89, the rollers 18 being located'outside the box 89 and adjacent the front and back walls thereof. The rollers 18 are guided vertically by guide-bars 18 and 19 secured against the inside walls of the front and rear plates 31 of the column J. The guide channel between parallel bars "and 19 is made wider than the diameter of the rollers 16 in order to permit a desired degree of freedom of movement. Brackets 18, for supporting the blowpipe head H, project from the right-hand wall of the box 89 through an opening in the righthand plate 28 of the column J. The opening 88 is vertically long enough to permit movement of the bracket 18 through its full range and, to keep out dust and dirt, the portion of the opening not occupied by the bracket Ill may be enclosed by suitable means such as cover plates 8| having their side edges retained in vertical channels 82 so that the plates mayslide vertically with the bracket. The blowpipe head H is connected to the brackets I8 by means of the water-cooled front plate 83 whose ends are each secured to the end of each bracket ,II, preferably by bolts 88.

As best shown in Figs. 1 and 7, the front plate 83 comprises a rectangular plate having its length dimension horizontal and transverse to the slab and its width dimension vertical. As previously described, the plate 88 is supported at each end by the corresponding jack brackets 10. To effectively cool the plate and overcome the heat radiated from the surface of the work and from the desurfacing reaction, the plate 83 is provided with a chamber 85 for cooling water which is introduced into the chamber near the upper right-hand corner of the plate through pipe 88 and'discharges from the upper-left corner of the plate through a pipe 81.

The blowpipe devices of the head H are more clearly shown in Figs. 4 and '7. They are secured to the front plate 83 by a row of support or frame plates 88 which are secured against the back of the front plate by means of bolts 89. Each frame plate 88 carries an individual'nozzle header 98. of which one or more may be employed to make upthe desired width of blowpipe head H. Nozzle headers similar to the type here employed are shown and described in detail in the copending application, Serial No. 174,335, filed November 13, 1937, by James H. Bucknam, and entitled: Blowpipe apparatus. In the apparatus herein described, a plurality of headers 98 are employed, each having eight nozzles 9|. .Each nozzle 9| produces a central jet of low velocity oxygen surrounded by preheating flames. The headers 98 contain suitable passages for supplying the heating gas mixture-and the cutting oxygen separately to each nozzle. The nozzles 8| project downwardly and forwardly from each header 98 and are clamped or disposed in a transverse row, the

oxygen orifices of the row of nozzles being spaced frame-plate 88 by a pair of ears 92 projectingupwardly from the forward face of the header. Each header is supplied with heating gas mixture by four vertical gas mixers or blowpipes 93 which discharge into the header and are secured at their upper ends to a bracket 94 projecting from the rear of each plate 88. The cutting oxygen is supplied to each header 98 by vertical pipes 95 connecting the header to a transverse oxygen manifold 96. The manifold 98 is supplied with oxygen through a hose'9'l which connects to the discharge side of a solenoidoperated control valve 88. Several such control valves '98 are connected to another transverse oxygen supply manifold 99 supported upon a transverse platform I secured at each end to the columns J. g The main oxygen supply to the manifold 30 is through a conduit MI. The oxygen and the acetylene which'are the gases preferably employed for forming the pre-heating gas mixture are supplied-to the blowpipe 93 by short manifolds I02 and I03 which receive oxygen and acetylene from flexible conduits I04 and I05. Each blowpipe 93 is connected to the oxygen manifold I02 by a tube I08 and each blowpipe is connected to the acetylene manifold I03 by a tube I01.. Suitable control valves I08 and I09 for each tube are provided and are set to deliver the gases in the correct proportion. The manifolds I02 and I03 are supported by a gooseneck bracket IIO secured to the upper edge of the frame plate 88.

The nozzles 3i and blowpipe headers 90 are protected by a wide shoe III having a front wall H2, the upper edge of which is secured to the lower edge of the front plate 83. The bottom wall II3 of this shoe is adapted to ride on the surface of the slab S and is preferably provided with a layer of hard surface metal to protect it from excessive wear. If desired, however, rollers I hereinafter described, may also be attached to the head H for supporting it on the slab surface in order to reduce friction during operation. The nozzles 9| project through openings at the joint between the-front wall and the bottom II3 of the shoe. The back wall II4 of the shoe is secured to the bottom flange of a cross-channel H5 which has its ends firmly secured to the front plate 33 by means of web or bracket plates H6 at each end. The counter-weight chains 03 are connected to the head H by two bolts II 1 secured to the top flange of the cross channel 5. The shoe III is also provided with end walls which together with its front and back walls form a chamber which holds cooling water surrounding the nozzles 9| and the lower portion of the header 90. Such cooling water is supplied to the shoe at the left end thereof by the pipe 01 which is connected between the front plate 33 and the left-end wall of the shoe. The excess water discharges from the shoe through a pipe II8 which conducts the water from the other end wall of the shoe and discharges it beyond the right-hand edge of the slab S. Cooling water is also supplied to each blowpipe header 90 by a flexible tube 9 supplying water to a manifold I from which a tube I2I conducts the water to the blowpipe nozzle header. The water discharges from the cooling chamber of each nozzle header 90 into the water space of the shoe III. To deflect heat and slag from the blowpipe mechanism, a dust shield I22 (see Figs. 2 and 7) is provided which is hung at each end on brackets I23 secured to the front plates 31 of the columns J. The shield I22 thus hangs vertically in front of the plate 83. To limit the movement of the carriage F toward the right, a pair of electric-limit switches I24 and I25 are provided as shown in Fig. '1. The switch I24 is mounted on the underside of the front beam M and is provided with an arm I26 which contacts with a cam I21 secured to the front side of the right-hand column J. The cam I21 has a triangular contacting surface with the ridge thereof upward so that the arm I26 may ride over the ridge. The switch I25 is mounted on the top surface of the lower flange of the beam 2I and is provided with an upwardly extending arm I23 which contacts with a cam I29 secured to the front side 39 of the weight-housing W.

The gases and water are supplied to the maof travel.

chine from a stationary supply point by suitable flexible or jointed connections that supply oxygen to conduits MI and I04, fuel gas such as acetylene to conduit I05, and water to conduits 86 and 0,

the connections being arranged to permit the movement of the machine through a desired range Electrical cables (not shown) similarly connect the motors 34 switches I24, I25, and I30, with a stationary control panel. The limit switch I30 provides an additional control for the motor 41 when lowering the head H. The switch I 30, as shown in Figs. 2 and 3, is secured on a bracket I3I projecting from the rear-side plate 22 and has a'downwardly depending switch arm I32 that engages with a cam projection I33 bolted to the upper chain 43.

Iniorder to reduce friction between the shoe III and the surface of the slab, two or more rollers I34 may preferably be secured to the shoe to the rear of the nozzles as shown in detail in Figs. 8 and 9. Each roller is secured to the middle of an axle I35 having end portions journalled in bearings I36 which are carried by a bracket I31. The bracket I31 has two horizontal ears I38, one

' above each bearing which are bolted to the flange I39 projecting rearwardly from the wall I I4 of the shoe III. The bracket I31 is also provided with a forward cross-connecting member I40 which is secured against the back wall II4 of the shoe. Preferably a roller bracket I31 is secured adjacent each end of the shoe III with the axis of each roller orifices. The periphery of each roller I34 which contacts the work surface from which metal and/or scale has been removed extends to a level very slightly below the bottom II3 of the shoe so that the portion of theweight of the. head H that is not counterbalanced is carried by the rollers I34.

It will be seen that the lifting-jack mechanism supports and guides the head H so that it may freely float in a vertical plane whereby either end of the head may automatically adjust itself to a different level than the opposite end in order that the nozzle orifices may be maintained at a uniform distance above the surface of the slab even though such surface does not lie exactly in a horizontal plane.

I34 parallel to the row of nozzle and 41 and the limit a slab is preferably as follows:

It is assumed that the machine has been moved to the left away from over the conveyor table and that all adjustments have been made. The operator stands at a stationary control table (not shown) so located as to allow him a clear view of the work and may, by actuating electrical remote control mechanism, operate the machine as follows: The slab S is brought into a position with its forward end edge located in alignment with the operating position of the nozzles 9| by operating a positioning switch of the control table to energize the electric motor which drives the roll table. By closing a second switch, the motor 34 is started (its brakes 33 being released) and through worm 30 and wheel 29, turns the lefthand wheels 25 which traverse the carriage along the rails R to the right until the arm I26 makes contact with the cam I21. The raising of the arm I26 closes switch I24 which, through a motor control device, reduces the speed of the motor 34. When the arm I28 engages cam I29, the switch I25 is closed operating another control device which stops the motor and applies the brake 33 to hold the carriage F in a fixed position. This position is determined by the relative positions of the cam I29 and switch I25 and is such that the blowpipe head will be directly over the slab S.

The operator then moves a control handle to a first position which releases the brake 03 and starts the motor 41 which turns thescrew 50 in each jack column J through worm; 02, wheels 63, and jack shaft 5| which is in chain connection with the motor 41. 'rurhih of the screws 58 causes the nuts 66 to feed down and lower the brackets which they carry. The uniform downward movenient of the head H continues until the shoe III or a roller I34 touches the surface of' freely on the surface of the slab. The weight,

of the head is largely counterbalanced by the weights 42 so that the pressure of the shoe III on the surface of the slab is moderate. The actual rotation of the motor 41 is stopped by the action of the limit-switch within the casing 58. An additional control for the downward movement is provided by the limit-switch I80, the downwardly depending arm I32 of which engages cam I33 on the chain 43. I

When the head H rests on the slab with the nozzles very close to the end of the surface entering the machine, the operator turns the control handle to'a second position which energizes electrically-operated valves that turn on the pre- ,heating gas mixture which then issues from the nozzles 9|. If the slab S is at a rolling temperature, the gases immediately ignite; if not, they may be ignited by an electric spark or by other means. In a very short interval of time the heating flames will raise the surface metal on which they impinge to an ignition temperature, whereupon the operator moves his controller to a third position which energizes the electricallyoperated cutting-oxygen valve 00 to open it. The

oxygen issues from the nozzles 9| and immediately combines with the surface metal against which it impinges, converting-a portion of such metal into a molten slag which flows forward on the surface. The great heat generated by the reaction also removes some of the surface metal in the molten state mixed with the molten slag. Simultaneously, with the turning on of the cutting oxygen, the roll table motor starter is ener gized so that the slab is propelled along the roll stop the movement of the slab and also de-v energizesthe electrically-operated gas valves to turn off the gases. The operator however, can anticipate this action by turning the controller handle to a fourth position immediately when the end of the slab reaches the blowpipe head. The fourth position de-energizes the electricallyoperated gas valves and closes them unless they have been de-energized by the action of switch I30. The fourth position also energizes the starter of the motor 41 which then operates the jacks for raising the head H. This-upward movement is stopped by the limit-switch in casing 50 the conveyor line.

which de-energizes motor 41 and applies the brake 53 to hold the head locked in the upward position.

The operator can now move the carriage F to theleft if it is desired to move the dean!- facing machine away from the conveyor table C, or the roll table C may be operated to .position another slab under the head H for a conditioning treatment. In order to condition the other side of the slab, the latter may be run onto a section of the conveyor table, that is provided with a slab manipulator. A suitable slab'manipulator is described in the copending application Serial Noi 174,286, filed November 13, 1937, jointly in the names of W.-C. Weidner and A. M. Keller,

and entitled: Method and apparatus for manipulating slabs and the like. The manipulator turns the slab over, after which it is run backward along the conveyor table until the forward edge of the untreated side is in position under the head H. This side is then conditioned in the manner described. r

The 'machinecan .be quickly adiusted to condition various widths of blooms or slabs. This is done by shutting off those valves I08, I09, and

95' which supply the gases to any nozzles that are not needed or extend beyond the side edges of the slab. It is preferable that'the desurfacing flame or gas streams produced by the head H shall be substantially continuous across its width and only slightly wider than the top surface being treated. This is in order that any fins or other defects at the lateral edges will be removed.

Referring to Figs. 10 to-14, inclusive, an alternative machine for surface conditioning both an edge surface as well as the top surface of a slab is shown. This machine is similar in general principles to that illustrated in Figs. 1 to 9, but is differently arranged structurally. The corresponding parts are similarly numbered but have the prefix 2 added to the number.

Instead of being carried onoverhead rails, the carriage F is mounted on wheels 225 which run on cross rails R secured to the floor underneath The columns J extend vertically upward from the carriage frame F and have their opposed inner faces provided with vertical slideways I45. Two slideways I45 are provided on each column J' and the jack screws 259 are disposed between them. The jack screws 259 are secured at their lower ends in footstep bearings on the carriage F, and at their upper ends are connected by beveled gearing within gear housings I46 to the transverse jack shaft I. The jack shaft 25I simultaneously turns both jack screws 259 and is connected to the motor 241 by speed reducing mechanism within a housing I4'I mounted on top of the left-hand jack column J. The slide brackets 269 threadedly engage with the screws 259 andare slidingly secured to the ways. I so that the rotation of the screws 259 will raise or lower the slide brackets 269 simultaneously. Each slide bracket 2% is provided with two arms M8 which extend forwardly and inwardly and are pivotally connected to corner bearings I40 of two horizontally swingable links I50. The links I50 are of the same length and extend rearwardly. The rear corners of links I50 are provided with corner bearings I5I which are pivotally connected to arms I52 that extend forwardly from each end of cross member 958. The cross member I53 is thereby transversely and freely movable horizontally and is urged leftward by suitable meanssuch as, for example, by a spring I04 shown more clearly in Fig. 14. The

spring I54 is secured between the right-hand slide to j bracket 269' and the right-hand link I50 and has its ends supported within a socket I55 in the link I50 and a cup I56 on the bracket 289.

The slab S is .supported during its passage through the machine by a roller 220 that has its axle journalled in bearings I51 mounted on the frame F. The roller 220 is disposed a suflicient distance in front of the head H' in order to avoid interference with the operation thereof. When the carriage F is moved to the right'so that the surface-conditioning. mechanism is away from the operating position,,the slabs S that are passed along the conveyor line are supported by an auxiliary roll 220' which is mounted in bearings I58 on the right-hand portion of the frame F.

The head Hflis supported by the cross member I53 in such amanner that it is freely movable vertically in order that the nozzles 9| may be maintained in constantly uniform relation with the surface irrespective of the local variations in the height of the surface. To this end the transverse shoe I59 is provided at each end thereof with a vertically extending guide I60. The guide I60 .is vertically slidable in a channel formed by the legs of two parallel vertical angles I GI which are secured against .the end wall I62 -of the cross member I53. Endwise motion of the nozzle headers 290 being secured in a row within the walls of the shoe so that the nozzles SI projecting therefrom pass through the openings between the front wall I68 and the bottom wall I69 of the shoe.

For surface conditioning the side edge of the Y slab, an auxiliary blowpipe head III is provided. The auxiliary head is similar in construction to the main head but shorter and comprises a shoe v I12 having similarly arranged walls within which is a single nozzle header having nozzles 9| that pass through openings between the front and bottom walls of the shoe I12. The auxiliary shoe I12 is positioned so that its row of nozzles is vertical and is secured at one end of the main shoe I59 by suitable means such as screws I13 that secure the upper side wall of the shoe I12 to the bottom end of the guide I60 and by a bracket I14 secured between the rear portion of the upper side wallof the shoe I12 and the rear portion of the right-end wall of the shoe I59.

Heating gas mixture is supplied to the nozzle headers 290 by blowpipes 293 which are vertically disposed and braced by the crossbar 294 which has its ends secured to the guides I60. The blowpipe 293 for supplying heating gas mixture to the auxiliary head I'1I is secured against the rear wall I10 of the shoe I 59 and its outlet is connected with the blowpipe header of head I H by a conduit I15. The oxidizing gas is supplied to the nozzle headers by conduits 295 and 295, respectively, which have flexible portions connected to manifolds within a housing I16 on the platform.

I11 formed by the upper portion of the cross member I53. Suitable flexible conduits'flfl connect the gas inlets of the blowpipes 293 and 293 to corresponding manifolds within the housing I16.

heating gases are turned on and ignited and when the surface metal impinged thereby has reached the ignition temperature the. oxidizing gas is turned on and the slab S advanced through the machine. The head H will ride in contact with the surface oiv the work during the operation, the auxiliary head I1I being maintained in contact with the right-hand edge surface of the slab by the actiongf the horizontally swinging links I50 and the spring I54. The head Hf will be free to tilt laterally in the vertical plane in order to follow a twist or warp of the slab. surface and the auxiliary head ill will be maintained constantly in alignment yvith the edge surface. When the slab is turned over, the opposite edge surface will be in position for treatment simultaneously with the surface that was formerly on the bottom.

The invention is not limited to the exact details disclosed and it will be seen that certain features of the invention may be used independently of the others and changes may be made in various features of the apparatus without departing from the essentials of the invention. For example, although the mechanisms herein described in detail are especially adapted for desurfacing steel slabs it is contemplated that the same principles are applicable to mechanism for removing scale from the surfaces of slabs and other shapes. Furthermore, other'types of blowpipes may be employed, for example; a blow-pipe providing a continuous sheet-like gas stream; or a row of blowpipe nozzles each having more than one oxidizing gas ori-' flce; or a row of blowpipe nozzles each having a slot-like oxidizing'gas orifice producing a row of ribbon-like oxidizing gas streams which form, in eifect, a continuous sheet-like stream; or blowpipes providing a single row of separate hightemperature flames directed substantially perpendicularly against the work.

It is contemplated that at least one edge surface of a slab may be thermally conditioned by providing an additional blowpipe head disposed at one end of the main blowpipe head and depending vertically downward therefrom for projecting gas simultaneously against the edge of the slab the added head being urged toward the edge surface to maintain it in operative relation to such surface during the relative movement between the heads and the slab.

We claim:

1. Apparatus for thermo-chemically removing surface metal from a ferrous metal body such as a steel slab comprising a blowpipe head having nozzle means adapted to' project a substantially sheet-like stream of oxidizing gas obliquely against a relatively wide area of-a surface of said slab; a frame for supporting said head; means for supporting said slab in a position for surfacing treatment; means for eflecting relative movement of said head with respect to said slab in a' direction along said surface of and from one edge to the opposite edge of said slab; and mechanism for supporting said head on said frame constructed and arranged to maintain said nozzles in the operating position with respect to said surface by providing both limited perpendicular movement of said head in accordance with 7 changes in the level of said-surface and also limited lateral coming of said Head in response to any lateral twist or warp of the surface encountered during said relative movement.

2. Apparatus for thermo-chemically removing surface metal from a ferrous metal body such as a'steel slab' comprising a blowpipe head having nozzle means adapted to project a substantially sheet-like stream of oxidizing gas obliquely against a relativelywide area of a surface of said slab; a frame for supporting said head; means for supporting said slab in a position for surfacing treatment; means for effecting relative movement of said head" with respect to said slab in a direction along said surface of and from one,edge to the opposite edge of said slab; and m'eachanism for supporting said head on said frame, said mechanism including means for counter-balancing a substantial portion of the weight of said head, and column means on said frame connected to each end 'of said head for sup- I porting the same, said column means being constructed and arranged to co-operate with said head to permit free and independent vertical movement of either end of said head in accordance with thelevel of the adjacent edge of the surface.

' cent edge portion of said surface, a pair of de- 3. Apparatus for thermo-chemically removing surface metal from aferrous metal body such as a steel'slab comprising a blowpipe head having nozzle means adapted to project a substantially sheet-like stream of oxidizing gas obliquely against a relatively wide area of a surface of said slab; a frame for supporting said head; means for supporting said slab in a position for treatment of said surface; means for effecting relative" movement between said head and said slab in a direction lengthwise of said surface and from' vices cooperatively associated with said head and said column means and adapted to move said I head toward and away from said surface, and common means for operating said devices simultaneously.

4. Apparatus for thermo-chemically removing surface metal from a ferrous metal body such as a steel slab comprising a blowpipe head having nozzle means. adapted to project a substantially sheet-like stream of oxidizing gas obliquely against a relative wide area of a surface of said slab; a frame for supporting said head; means for supporting said slab in a-position for treatment of said surface; means for effecting relative movement between said head and said slab in a direction-lengthwise of said surface and from one end edge to the opposite-end edge of said slab; and mechanism for supporting said head on said frame, said mechanism including column means on said frame connected to each end of said head for guiding-the same, said column means being constructed and arranged to,

cooperate with said head to permit free and independent vertical movement of either end of said head in accordance with the level of the adjacent edge portion of said surface, ways transversely disposed with respect to the length dimension of said slab, and means for moving said frame along said ways for positioning said head transversely with respect to said surface.

5. In a machine for thermally conditioning the surface of a metal body such as a steel slab; a relatively'wlde blowpipe head adapted to project gas against the top surface of such body, the width of said head being sufficient to project gas on anarrow transverse zone of said surface extending completely across the surface; a supporting frame; means connected to said frame for vertically guiding each lateral end of said blowpipe head independently of the other; and means on said frame forllfting said head by engaging with and simultaneously raising both ends of said head. 1

6. A machine as claimed in claim 5 in which said guidifig means is constructed and arranged to confine. the movement of said head solely in a plane transversely of said body and normal to said surface.

7. A machine as claimed in claim 5 in which said guiding means is constructed and arranged to confine the movement of said head solely in a plane transversely of said body and normal to said surface, and for providing vertical movement of said head through a relatively large displacement and lateral rotation of said head in said plane between limits.

8. A machine as claimed in claim 5 which includes means for counterbalancing a substantial portion of the weight of said head.

9. A machine as claimed-in'claim 5 in which said lifting means is constructed and arranged to automatically disengage with said head when the head is lowered into contact with said stirface.

10. A machine as claimed in claim'5 in which said frame is supported by a carriage for mov-= ing said frame and said head thereon horizontally with respect to said body.

. 11. A machine for thermally conditioning the surface of a metal body such as a steel slab according to claim 5 including a plurality of rollers secured to the lower portion' of said head for engaging with the surface of said slab to maintain said head substantially parallel to said sur face.

12. A machine-according to claim 5 in which said lifting means are connected to said head by horizontally swingable links whereby said head is freely movable transversely for main taining said head in alignment with an edge of the slab.

13. In a machine for thermally'conditioning the surface of a metal body such as a steel slab; a relatively wide blowpipe head adapted to project gas against the top surface of such body. the width of said head being suflicient to project gas on a narrow transverse zone extending completely across the surface; a supporting frame; vertical guides depending from said frame adjacent both lateral ends of said head; a bracket secured to and extending from each lateral end said nuts when the screws are rotated; each of said brackets having a portion engageable by said nuts upon upward movement of the nuts and disengageaible therefrom upon downward movement of the nuts after said head makes contact with the surface of said body; and means for simultaneously rotating said jack screwsfor raising both ends of said head simultaneously.

14. In a machine for thermally conditioning the surface of a metal body such as a steel slab; a blowpipe device comprising a transverse front member having an edge portion adapted to be positioned adjacent a surface of said slab; a plurality of nozzle headers detachably secured to said front member adjacent to each other in a row along said edge portion of said front member, each of said headers being provided with a row of nozzles and arranged so that the several rows of nozzles are aligned to form a continuous evenly spaced row of nozzle orifices extending along substantially the full width of said blowpipe device; and means for supplying oxidizing gas and fuel gas to said headers.

15. Apparatus according to claim 14 in which said transverse front member is provided with a chamber for cooling fluid and means is provided for passing cooling fluid therethrough.

16. Apparatus according to claim 14 including a wide multiple nozzle shoe having a bottom adapted to engage the surface of the work, said shoe having also a front wall and a ,row' of openings extending from the inside to the outside of said shoe adjacent the corner between the front and bottom walls of the shoe, said nozzles severally extending fro-m the inside of the shoe into said openings so that only the orifice ends of said nozzles are exposed.

17. Apparatus according to claim 14 including a wide multiple nozzle shoe having a bottom adapted to engage the surface of the work, said shoe having also a front wall and a row of openings extending from the inside to the outside of said shoe adjacent the corner between the front and bottom walls of the shoe, said nozzles severally extending from the inside of the shoe into said openings so that only the orifice ends of said nozzles are exposed and said front wall being secured to said front member independently of said nozzle headers.

18. Apparatus according to claim 14 including a wide multiple nozzle shoe having a bottom adapted to engage the surface of the work, said shoe having also a front wall and a row of openings extending from the inside to the outside of said shoe adjacent the corner between the front and bottom walls of the shoe, said noz- Zles severallyextending from the inside-of the shoe into said openings ,so that only the orifice ends of said nozzles are exposed; said shop having also rear and end walls forming with the front and bottom walls, a chamber for cooling fluid, said front member being provided with a chamber for cooling fluid, and means for supplying cooling fluid to both chamberscomprising an inlet to the chamber of said front plate; a connection from the chamber of said front plate to one end of the chamber of said shoe, and an outlet from the other end of the chamber of said shoe.

19. Apparatus according to claim 14 including a supporting frame; means for supporting said body in a position to be operated upon; means for effecting relative motion between said frame and said body longitudinally along a surface thereof; means on said frame for vertically-guiding each end of said front member independentlyof orifices parallel to said surface during such relative movement. x

20. In a machine for thermally conditioning the surface of a metal body such as a steel slab; a relatively wide blowpipe head adapted to proiect gas against a horizontal surface of' such body, the width of said head being sumcient to project the gas on a narrow transverse zone of said surface extending completely across the surface; a supporting frame for said headiemeans for supporting said body in a position to be operated upon; means for efiecting relative motion between said frame and blowpipe head and said body longitudinally along said surface; means on said frame for moving said head away from 15 21. Ina machine for thermally conditioning the surface of a metal body such as a steel slab;

a relatively wide main blowpipe head adapted to project gas against the top surface of such body, the width of said head being suificient to project gas on a narrow transverse zone extending completely across said top surface; an auxiliary blowpipe head disposed at one end of said main blowpipe head and arranged at an angle thereto forprojecting gas on a narrow zone across an edge-surface adjacent to said top surface; a supporting frame; column means on said frame disposed adjacent eachend of said main head; and supporting mechanism connecting said main head and said auxiliary head to said column means, said mechanism being constructed and arranged for providing free and universal movement of said heads'in a plane transverse to said slab for maintaining said main head in uniform alignment across the top surface of the slab and said auxiliary head in uniform relation to the edge surface of the slab irrespective of a twist or warp in the slab and departure from straightness of the edge surface.

22. Apparatus according to claim 21 in which said mechanism comprises a. transverse member; horizontally swingable links connecting each end of said transverse member to said column means; and means for adjustably supporting said main head on said transverse member arranged to provide a limited degree of free movement of said transverse member to a respective bracket member; and means for adjustably supporting said main head on said transverse member ar ranged to provide a limited degree of free movement of said head toward and away from the top surface and lateral canting of said head between limits.

24. Apparatus for thermo-ehemically removing surface metal from a ferrous metal body such as a steel slab comprising a blowpipe head having nozzle means adapted to project a substantially sheet-like stream of oxidizing gas obliquely against a relatively wide area of a surface of said slab; a frame for supporting said head; means for supporting said slab in a position for treatment of said surface; means for effecting relative movement between said head and said slab in a direction lengthwise of said surface and from one end edge to the opposite end edge of said slab; and mechanism for supporting said head on said frame, said mechanism including column" means on said frame connected to each end of said head for guiding the same, said column means being constructed and arranged to cooperate with said head to permit free and independent vertical movement of either end of said head in accordance with the level of the adjacent edge portion of said surface, and means on said frame adapted to move said head toward and away from said surface.

JAIMES H. BUCKNAM. ALFRED J. MILLER.

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