US3409071A

US3409071A - Apparatus for use in withdrawing and guiding a continuous cast strand

Info

Publication number: US3409071A
Application number: US544908A
Authority: US
Inventors: Joseph J Ciochetto
Original assignee: Koppers Co Inc
Current assignee: Raymond Kaiser Engineers Inc
Priority date: 1966-04-25
Filing date: 1966-04-25
Publication date: 1968-11-05
Anticipated expiration: 1985-11-05

Description

Nov. 5, 1968 .1..1 CIOCHETTO 3,409,071

APPARATUS FOR USE IN WITHDRAWING AND GUIDING A CONTINUOUS CAST STRAND 5 Sheets-sheet 1 Filed April 25, 1966 I NVEN TOR.

m n m a Nov. 5, 1968 J. J CIOCHETTO 3,409,071

APPARATUS FOR USE IN WTHDRAWNG AND GUIDING' A CONTINUOUS CAST STRAND Filed April 25, 1966 5 Sheets-Sheet 2 INVENTOR. JasfPH J. c/acf/Ero Nov. 5, 1968 J. J. GIOCHI-:TTC 3,409,071

APPARATUS FOR USE IN WITHDRAWING AND GUIDING A CONTINUOUS CAST STRAND Filed April 25, 1966 3 SheeLS-Shee(l 3 INVENTOR. .M55/H J C/C/ETTO BY gaan cmu/H* gm LA nfiarlze United States Patent O 3,409,071 APPARATUS FOR USE IN WITHDRAWING AND GUIDING A CONTINUOUS CAST STRAND Joseph J. Ciochetto, Allison Pai-k, Pa., assgnor to Koppers Company, Inc., a corporation of Delaware Filed Apr. 25, 1966, Ser. No. 544,908 16 Claims. (Cl. 164-274) ABSTRACT F THE DISCLOSURE A starting lbar in accordance with the disclosure comprises a first member or dummy plug that coacts with the mold and temporarily closes the bottom thereof while the casting being formed in the mold adheres to the first member; a second member or adapter head that is removably connected to the first member, and is adapted to coact with a guide structure or apron disposed beneath the mold so as to receive and support the casting after the same leaves the mold; and a third member or guide head that is removably connected to the second member, and is adapted to conform substantially to the curvature of the guide structure; and a fourth member or flexible band that cooperates with power means to advance and retract the starting -bar apparatus relative to the casting mold.

This invention relates to continuous metal casting and more particularly to an improved apparatus for use in continuous casting.

Before la continuous strand of cast metal can be formed and withdrawn from the usual open-ended flow-through casting lmold, it is necessary to temporarily close the open bottom of the mold in such a manner that the molten metal is retained in the mold long enough to partially solidify and form a skin that retains molten metal in the casting after it is withdrawn from the mold. The usual manner of temporarily closing the bottom ofthe mold is to yinsert the end portion of a tool called a dummy or starting bar into the mold; the end portion of the bar that is inserted into the mold has substantially the size and shape of the bottom of the mold and thereby closes the bottom of the mold. The cast metal entering the rnold partially soldifes in the bottom of the mold and attaches to the inserted end portion of a dummy plug which is usually attached to one end of an elongate starting bar. Thereafter, the starting bar and the casting together are withdrawn continuously from the mold by means of the D usual pinch rolls, or other suitable apparatus.

Heretofore, straight rigid starting bars have been effectively used with a vertical continuous casting machine, but with the advent of the low head or arcuate type of continuous casting machine, the rigid starting bar has not been entirely satisfactory. A starting bar that is most effective for use with an arcuate or low head type of casting machine must be flexible to conform to the radius of curvature of the casting which is continuously withdrawn from this type of machine. Heretofore, various types of flexible starting bars have been proposed for use with the arcuate or low head continuous casting machine, including segmental type starting bars, but such starting bars have not proved to be entirely satisfactory.

3,409,071 Patented Nov. 5, 1968 For a further understanding of the present invention and for advantages and features thereof, reference may be made to the following description taken in conjunction with the accompanying drawings which show, for the purpose of exemplitication, a preferred embodiment of the invention.

In the drawings:

FIG. 1 is an elevational view, partly in section, of a preferred embodiment of apparatus for use in withdrawing a continuous casting from a mold;

FIG. 2 is a plan view of a portion of the apparatus of FIG. 1;

FIG. 3 is a plan view of a portion of the apparatus of FIG. 2;

FIG. 4 is an elevational view of the apparatus of FIG. 3;

FIG. 5 is a view along line V-V of FIG. 4;

FIG. 6 is a detail of construction of a portion of the apparatus; and

FIG. 7 is a schematic elevational view of the apron or continuous cast strand guide structure.

The apparatus in FIG. 1 comprises an arcuateguide structure 8 (FIG. 7) disposed beneath a continuous casting mold 10 and a flexible starting bar 11 cooperating with the guide structure 8; the flexible starting bar 11, comprises an adapter head portion 13, a guide head portion 15, a flexible body portion 17, and a key bar member 19 for joining the adapter head portion 13 to the guide head portion 15.

The adapter head portion 13 is generally a parallelepipedon, which is a geometrical solid prism having six faces that are parallelograms. Preferably, the end edges of the head portion 13 are slightly chamfered, as at 21. In the end portions of the head portion 13, there are

keyhole slots

25, 27 that extend transversely of the head portion 13, about as shown in FIG, 1.

Two additional spaced apart

holes

29, 31 are so located in the head portion 13 that their respective axes are generally perpendicular to the plane of the

slots

25, 27, and the axes of the

holes

29, 31 are substantially tangent to the surface of the

keyhole slots

25, 27, about as shown in FIG. 1. Other larger holes 33 are provided in the prism 13 for the purpose of reducing the weight of the adapter head.

It is customary to temporarily close the lbottom of the flow-through continuous casting mold with a dummy plug or other suitable device that is preferably removably connectable to the head of the starting bar. In FIG. 1, a dummy plug 35 is provided with a key bar 37 that is adapted to removably fit in and mate with the keyhole slot 25 in the left-hand end portion of the adapter head 13. The dummy plug 35 may have a suitable connector (not shown), such as the anchor bolt 7 shown in Patent 2,920,359, mounted in the end of the dummy plug that mates with the casting mold. After the molten metal solidifies around the connector, the casting may be withdrawn from the mold -by means of the starter bar. The adapter head 13 may, of course, 'be -readily connected and disconnected to the plug 35 simply by inserting the key bar 37 in the key slot 25.

The guide head 15 also has

keyhole slots

39, 41 in each end, and the double key bar 19 may be used effectively to connect the adapter head 13 to the guide head 15 in the same general manner as the key bar 37 connects the plug 35 to the adapter head 13. Referring to FIGS. 3-5, the guide head 15 comprises a main body portion 43; iirst and second wheel and

axle assemblies

45, 47; and first and

second cover plates

49, 51.

The main body portion 43 is generally a parallelepipedon having substantially the same height as the adapter head 13. The length of the guide head may be made to suit the particular installation, While the width may be slightly less than the width of the adapter head 13 (see FIG. 2). From FIGS. 4 and 5, it will be noticed that the main body portion 43 has, adjacent each end, opposed upper 53, 57 and lower 55, 59 slots or grooves. Axially disposed in the plane of and connecting the slots or

grooves

53, 55 and 57, 59, are spaced apart

cylindrical bores

65, 67 and 61, 63.

In each upper and lower slot or

groove

53, 57 and 55, 59, there is disposed an axle-wheel assembly; conveniently, grooves 53, 55 accommodate rst axle-wheel assemblies 45, while

grooves

57, 59 accommodate second axlewheel assemblies 47. Both of the axle-

wheel assemblies

45, 47 are substantially identical and each comprises a rectangular main axle portion `69 and end axle guide portions 71 that project perpendicularly from the main axle portion 69, as shown in FIG. 5.

Support wheels 73 are mounted to the ends of each axle 69 by bolts 75 threaded into the axles -69 with suitable washers or spacers 77 disposed between the hub of the wheel and the end of the axle. Of course, the wheels 73 may be mounted to the axle l69 in any other suitable manner if preferred.

In each

cylindrical bore

61, 63, 65, 67 there is a nest of concentric compression-type springs; each nest comprising a pair of spaced apart inner 79 and outer 81 springs. It will be noticed, by referring to FIG. 5, that the inner spring 79 is of smaller diameter than the outer spring 81 and in fact the diameter of the wire comprising the inner spring 79 is smaller than the wire comprising the outer spring. It is preferably to use a nest of springs in each bore in 'order to gain the required spring capacity for the intended service.

As may be noticed from FIGS. 3 and 4, t-he first and second cover plates, 49, 51 are secured in respective recesses 83 in the main body portion by means of fasteners 85, such as the socket -head-type of cap screws shown in FIG. 3. The

cover plates

49, 51 fit over the

grooves

57, 59, and 53, 55, and retain the axle-wheel assemblies within their respective grooves.

The guide head 15 is alsoprovided with spaced apart holes 87, 89 (see FIG. 3) that are similar to the

holes

29, 31 in the adapter head 13. In the right-hand end (FIG. 3) of the guide head 15, there is a V-shaped groove 91 extending in a vertical direction (FIG. l) which is for a purpose that will be hereinafter disclosed. The V-shaped groove 91 is located preferably on the longitudinal center line axis of the guide head 15.

The exible body portion 17 comprises a metal band 93 that is substantially an elongate flat bar having a rectangular cross section; the width of the band 93 being substantially greater than the thickness thereof. In the embodiment of the invention shown in FIG. l, one end of the band 93 is key-shaped, as at 95, in such a manner that it fits in and cooperates with the keyhole slot 41 (FIG. 4) in the right-hand end of the guide head 15. The key head 95 acts in the same 4manner as the double key 19 and removably connects the main body portion to the guide head 15. The band 93 may be locked in position relative to the guide head 15 by means of a removable locking pin 97 disposed in the hole 89. When locked in position, the band 93 is exibly movable in the plane of the axis of the apron 8 and starter bar 11.

The band 93, at regular intervals along its center line longitudinal axis, is provided with holes 99. Each hole is adapted to freely accommodate the short tubular portion 101 of an assembly 100 (FIG. 6). Each tubular spacer 101 also freely accommodates a pin 103 that extends both above and below the band 93 and is substantially normal to the band. The pin 103 lits rotatably also within upper 105 and lower 107 tubular members that are each welded in the bosom of upper 109 and lower 111 angular members respectivley (FIG. 2). Both the upper end portion of the tubular member 105, and the lower end of the tubular member 107, are pierced transversely, as are the respective upper and lower ends of the pin 103 and the angles 109, 111. In each transverse aperture so for-med, there is disposed a locking pin 113. Thus, each assembly 100, comprising the tubular spacer 101, the pin 103, the upper and lower

tubular members

105, 107, and locking pin 113, is mounted to the band 93 in such a manner that the assembly 100 may move freely, but within prescribed limits, in the linear axial direction of the pin 103, and yet the entire assembly 100 is free to rotate about the vertical axis of the pin 103. In a normal state of rest, the upper portion of the assembly 100 (FIG. 1) rests on the upper surface of the band 93, but the entire assemblage -may move upwardly or downwardly as the band 93 exes while passing through apparatus, such as pinch rolls 135, that are used to drive the starting bar 11 toward and away from the casting mold.

While the assemblies 100 are free to rotate about the vertical axis of the pin 103, it is desirable to limit the amount of axial rotational movement of all of the assemblies 100. Accordingly, stop pins are mounted in the band 93, about where shown in FIG. 2. The stop pins 115 project both above and below the band surfaces and engage the upper and lower angular 4members 109, 111 Irespectively, thereby restricting the rotational movement of the assemblies 100. It is desirable to limit the amount of pivotal movement of all of the assemblies 100 so that they will be in proper alignment (FIG. 2) with the longitudinal axis yof the starter bar. It is also desirable to permit some pivoting of the angle-pin assemblages 100 so as not to cause a binding of them when the band 93 liexes.

It should be noted that the heel of the top and bottom angular members 109, 111 are purposely attened as at V110; the top and bottom angular members 109, nearest the guide head 15, fitting loosely into the groove 91 in the 4right-hand end portion of the guide head 15.

The arrangement of the assemblies 100 and the structure of each assembly has several advantages. First, the upper 109 and lower 111 angle members engage the pinch rolls -along a single line of contact such as is indicated at 112 in FIG. 2. It will be observed that the line of contact 112 crosses the toe portions of the upper 109 (and lower 111) angle members of a rst assembly 100, as well as the heel portion 114 of the upper (and lower) angle members of a second assembly. Thus, the pinch rolls are in contact with at least one successive assembly 100, after initial contact is made with the first assembly. Second, the frictional forces acting between the pinch rolls 135 and the angle members 109, 111, cause the respective assembly 100 in contact with the pinch rolls to pivot about the -axis of the pin 103. Third, the contactual forces, after orienting the assembly 100, also tend to align the starter bar with the longitudinal axis of the supportI or guide structure 8; the longitudinal axis of the guide structure or apron 8 being perpendicular to the axes of the pinch rollers 135.

It will be understood by those skilled in the art that the centering and aligning of the angle members 109, 111 and the band portion 93 is achieved both when the starting bar 11 is being advanced toward the casing mold, and when the starting bar is being withdrawn from the casting mold.

The liexible starting bar of the invention is most conveniently used with the curved supporting and guiding Iapron structure 8 shown in FIGS. 1, 5 and 7. The apron 8 is conveniently made in three

Sections

8a, 8b and 8c, although Vmore or fewer sections may be used if desired, and each of these apron sections subtends an angle-of about 30 at the center of curvature of the apron. That is to say, the center line longitudinal :axis of the apron subtends substantially an arc of 90 of a circle, although the axial arc may be a portion of an ellipse, a parabola `or any other smooth curve if preferred.

Ech

arcuate portion

8a, 8b, 8c is similar to the others except that the particular support structure adapted to each may be slightly different. Bascially, each arcuate apron section comprises a'group of upper angle members 119 and a group of lower angle members 121 that are maintained in spaced apartl relation in a first direction (vertical as shown in FIG. 5) by means of tie plates 123, that are welded to the toes of the upper and

lower angles

119, 121. In a second direction, usually horizontal, the interconnected upper and

lower angles

119, 121 are maintained in spaced apart relation by means of tie bolts 125. Each tie bolt includes a bolt member 125, that fits in holes (not shown) in the

angle members

119 and 121, nuts 125b threaded on the projecting threaded end portions of the bolts 125a, and a tubular spacer piece 125C that surrounds the bolt 125a and abuts the angles 121 (FIG. 5) and maintains the upper angles 119 and lower angles 121 the desired distance apart.

There is also provided, as part of the apron structure 8, upper and lower horizontal guide rollers 127, as well as right and left hand vertical guide rollers 129. Each guide roller is suitably journaled in the angles 119, 121 (FIG. 5) for rotation about the respective axes of the rollers. The vertical rollers 129, as shown in FIG. 7, are disposed preferably in the same plane as the horizontal rollers 127, though the respective horizontal and vertical rollers may be disposed in spaced apart planes, if desired. The horizontal rollers 127, especially the bottom horizontal rollers, support the continuous cast strand after it emerges from the mold 10. The side vertical rollers 129, of course, contact and guide the cast strand whenever the strand deviates from the axial path of the apron structure 8. So, too, the upper horizontal rollers 127 contact and guide the cast strand whenever it deviates upwardly from the axial path of the apron structure 8.

Elongate flat bars 131, 133 (FIG. 5) are welded respectively to the underneath side of each top angle member 119 and to the upper surface of each lbottom angle member 121. These fixed elongate fiat bars serve to limit the amount of lateral movement of the guide head 15, as well as the entire starter bar 11 and the cast strand to which the starter bar 11 is connected.

Associated With apron structure 8, and with a continuouscasting machine of which the apron structure is a part, is a set of conventional powered pinch rolls 135 (FIG. l) between which the flexible starting bar 11 operates in the manner to be presently described.

As shown in FIG. 7, each

section

8a, 8b and 8c of the apron is individually supported by structure that connects to adjacent support members, such as the Vertical columns 137 and horizontal guides 139.

The support structure for the

apron sections

8a, 8b, 8c includes

side plate members

141a, 141b, 141e associated with a respective apron section, and

lower support members

143, 145, that are respectively supports for the apron sections `8a and 8b. In each

side plate

141a, 141b and 141e there are a plurality of rectangular openings 147 that provide access to and inspection of the casting and starter bar in operation.

T-he support structures 141:1, 141b, 141e including

lower support members

143 and 145, are mounted on

column structures

149, 151, 153 respectively. Such support structures may, of course, be connected to ground footings or other available structure in a conventional mannerl (not shown). Preferably, the support for each

arcuate apron section

8a, 8b, 8c is individually detachably mounted to its respective column structure by means of bolts and the like, so that each apron section may, when necessary or desirable, be removed to effect repairs to or a replacement of a portion or portions of the apron section.

It will be noticed from FIG. 7 that the sets of horizontal 1,27 and vertical 129 cast strand guide rollers are substantially uniformly widely spaced apart along the arcuate axis of t-he apron structure. Actually, the roller sets are more widely spaced apart than is customary in other types of roller apron structures, and so fewer strand supporting rollers are used in the present invention. The horizontal rollers, and especially the lower rollers of veach set, support not only the cast strand as it moves downwardly from the mold 10 and curves toward the horizontal, but also the band portion 93 of the starting bar 11. The lower angle members 111 of the flexible body portion 17 engage the horizontal rollers 127 as the starter bar is being advanced upwardly toward t-he casting mold 10 and retracted downwardly, by the pinch rolls 135. When the starting bar commences to move downward under the influence of the pinch rolls 135, the upper angle members 109 may bear against the upper rollers 127 of each set of guide rollers. As mentioned previously, the guide bars 131, 133 (FIG. 5) serve to keep the guide head 15 centrally located in the apron structure 8, and so the starting bar 11 is not likely to bear against the vertical side rollers 129. However, the vertical side rollers 129 guide the continuous casting whenever it deviates from the central arcuate path of the apron structure 8.

In FIG. 7, the upper end of the apron structure section 8c is disposed adjacent the lower end of another separate apron section 8d that is enclosed within the lower portion of a spray chamber 155. The spray chamber 155 is supported upon a horizontal table 157, and the mold table also supports the continuous casting mold 10.

In operation, the starting bar 11 is first assembled by inserting the key bar portion 37 of the plug 35 into the key slot 25 of the adapter head 13, and then inserting a keeper pin 137 in the hole 29. The keeper pin 137 mates with a groove 165 (FIG. 2) and removably secures the plug 35 to the adapter head 13. When it is necessary or desirable to disconnect the plug 35 from the adapter head, it is only necessary to remove the keeper pin 137, using any suitable available tool. In like manner, the adapter head 13 is removably connected to the guide head by inserting the key bar 19 into the

key slots

27, 39 and then by inserting a keeper pin 167 in each

hole

31 and 87. Then, to complete the starter bar assembly, the key head portion 95, of flexible body portion 19, is inserted in the key slot 41 and another keeper pin (not shown) may be inserted in the hole 89 to removably connect the flexible body portion 17 to the guide head 15.

After assemblying the starter bar 11 in the manner described, t-he plug 35 and adapter head 13 are first inserted between the pinch rolls 135, and the pinch rolls are then rotated in the direction of the arrow A (FIG. 1) drivingly engaging the adapter head 13 and urging the starter bar 11 toward the left, that is, in the direction toward the casting mold 10 (FIG. 7). The Wheels 73 meanwhile will have been positioned, as shown in FIG. 5, to engage and roll upon the

angle frame members

119, 121 of the apron structure 8.

As the starter bar 11 moves toward the left (FIG. 7), under the influence of the pinch rolls 135, the bar 11, and especially the flexible body portion 17, exes and bends in general conformity to the arcuate axis of the

angle members

119, 121 forming the apron structure 8. It will be noted (FIGS. 1 and 7) that the curvature of the apron structure commences at or about opposite the vertical center line of the pinch rolls 135 and sweeps upwards toward the casting mold 10; the axis of the apron structure subtending an angle of about The apron structure to the right (FIG. 1) of the center of the pinch rolls is substantially straight and horizontal preferably.

The pinch rolls first engage the adapter head 11 and then engage the top and

bottom plates

49, 51 of the main body portion of the guide head 15. Thereafter, when the guide head has passed through the pinch rolls, the pinch ro'lls commence engagement, on the transverse line of contact 112 (FIG. 2) with angle-pin assemblies 100,

and, in particular, the heel and leg portions of the upstanding angle members 109, 111. As the pinch rolls continue to advance the starter bar 11 toward the left, the pinch rolls engage successively the heel and leg portions of successive angle members 109, 111, as they advance in the direction of motion of the bar. The pinch rolls 135 urge the starter bar 11 upwardly until the plug portion 35 enters the bottom of the mold the required distance.

As soon as the plug is properly sealed in the mold, the casting may proceed in the normal manner. Molten metal 159 flows from a tundish 161 and solidities around the end portion of the plug 35 that is inserted into the bottom of the mold 10. Thereafter, the casting forms a skin in the mold and the casting may be withdrawn by reversing the direction of rotation of the pinch rolls 135.

The pinch rolls act on the upper 109 and lower 111 angle members along the transverse line of contact 112 (FIG. 2) as mentioned previously, and the flexible body portion 17 is thereby urged into a central axial relation to Iboth the apron structures and the pinch rolls.

The wheels 73 of the guide head 15 maintain rolling frictional contact with the

angle members

119, 121 of the apron structure 8 by means of the

springs

79, 81 and they maintain substantially an axial relation with the apron structure by means of the at lbar guides '131, 133.

It is a feature of the present invention that, while there may be only substantially line contact between the pinch rolls and the heel and legs of the angular members 109, 111, nevertheless, the contactual forces acting between the pinch rolls and the canted ends of the legs of the angles urge the starting bar toward the mold in Such a manner that the starting bar continually tends to center itself with respect to the pinch rolls and the apron structure axis. Likewise, when the pinch rolls are reversed to withdraw the starting bar and casting from the mold, the contactual forces acting between the pinch rolls and the legs of the angles continually urge and maintain the starting bar in a central position with respect to the apron structure and the pinch rolls.

A feature of the present invention is that the angles 109, 111 of each assembly 100 are freely mounted to the band 93 even though the band may flex as required by the general curvature of the apron structure. The anglepin assemblies 100 freely move and oscillate within preselected limits in an unrestrained manner with respect to the band, but yet, the pinch rolls continually urge the starting bar along the axis of the apron toward or away from the mold, as the case may be.

It is also a feature of the invention that, should one or more angle-pin assemblies 100 become damaged or need to be replaced, each assembly may individually be easily removed from the band. This is effected simply by extracting either one of the transverse horizontal pins 113 which will allow the vertical pivot pin 103 to be ref movd from the tubular spacer 101, and the entire assembly 100 from the band. Thereafter, a new assembly 100 may be quickly and easily mounted to the band by reversing the removal steps.

While in a preferred embodiment of the invention, structural angles 109, 111 are used in the assemblies 100, it should be understood that other shaped members may be used if prefer-red. Actually, replacements for the angle members 109, 111 may be arcuate plates, ovalar tubular members, rectangular members, or members having any other shape as long as the contactual forces acting lbetweenl the pinch rolls and the members tend t0 maintain the band 93 in a central axial position with rcspect to the axis of the pinch rolls and the apron structure.

The wheels 73 may move laterally -within prescribed limits established by the adjacent edges of the plates 131, 133 (FIG. 5), and should the adapter head 13 or guide head veer from the aprons central axial path, as the starter bar is being advanced toward or retracted from the mold, the wheels 73 would engage the adjacent edge of the guide bars 131, 133 and be thereby restrained from further lateral movement with respect to the apron structure. Simultaneously, the action of the pinch rolls on the angle members 109, 111 tends to return the guide head to a central axial position,

Although the invention has been described herein with a certain degree of particularity, it is understood that the present disclosure has been made only as an example and that various modifications and changes may be made as followed within the scope of the invention as defined by the appended claims.

What is claimed is:

1. A continuous casting arrangement comprising: p

(a) an open-ended casting mold wherein molten metal owing thereinto from a tundish forms a continuous cast strand;

(b) a spray cham-ber disposed beneath said mold for cooling said cast strand as it emerges from said mold;

(c) a cast strand guide apron disposed beneath said spray chamber, said apron comprising a plurality of adjacent arcuate structures adapted to receive said cast strand and support and guide the same in a direction toward a horizontal attitude;

(d) a starter bar for withdrawing said cast strand from said mold including,

(i) a plug portion for temporarily closing the bottom of said mold and connecting to said cast strand,

(ii) an adapter head removably connected to said plug portion,

(iii) a guide head removably connected to said adapter head and provided with rollers that are resiliently biased into rolling frictional contact with said apron,

(iv) a flexible body portion removably connected to said guide head and supported by said spron, said flexible body portion conforming generally to the shape of said apron; and

(e) powered pinch rollers engageable with said starter 'bar to advance same toward said casting mold and to withdraw both said starter bar and said cast strand from said mold.

2. In apparatus for use in withdrawing a continuous cast strand from a mold, the combination comprising:

(a) a cast strand guide apron including a plurality of adjacent arcuate structures adapted to receive said cast strand and to support and guide the same in a direction toward a horizontal attitude; and

(b) a starter bar for withdrawing said cast strand from said mold including:

(ii) an adapter head removably connected to said plug portion,

(iii) a guide head removably connected to said adapter head and provided with rollers that are resiliently biased into rolling lfrictional contact with said apron structure.

(iv) a flexible body portion removably connected to said guide head and supported by said apron structure, said flexible :body portion conforming generally to the shape of said apron structure.

3. In a starter bar for use with an apron structure in withdrawing a continuous cast strand from a mold, the combination comprising:

(a) an adapter head removably connectable to said cast strand; and

(b) a guide head removably connectable to said adapter head and provided with rollers that are resiliently biased continuously into rolling frictional contact with said apron structure whereby said starter bar and said strand conform substantially to the path defined by the axis of said apron structure.

4. In a starter bar for use with an apron structure in withdrawing a continuous cast strand from a mold, the combination comprising:

(a) a guide head having rollers that are resiliently biased continuously into rolling frictional contact with said apron structure and conforming substantially to the path deined by the axis of said apron structure; and

(b) a flexible body portion removably connectable to said guide head and supported by said apron structure, said exible body portion also conforming generally to the arcuate shape of said apron structure.

5. In a starter bar for use with an apron structure in widthdrawing a continuous cast strand from a mold, the combination comprising:

(b) a guide head having rollers that are resiliently biased into continuous rolling frictional contact with said apron structure, whereby said guide head and said strand follow substantially the path defined by v the axis of said apron structure. l

6. In an elongate starter bar comprising a plurality of interconnected members for use in withdrawing a continuous cast strand from a -mold along the axis of an apron structure, the improvement comprising:

(a) a guide head member flexibly linked to at least one other member and including:

(i) a main body portion having therein apertures adapted to receive cooperative projections on adjacent members -whereby said adjacent members are flexibly linked to said guide head, and

(ii) rollable means resiliently mounted to said main body portion and adapted to engage said apron structure whereby said guide head moves relative to said apron and along the axis thereof.

7. The invention set forth in claim 6 wherein:

(a) said rollable means include wheels journaled in axles that are resiliently mounted in said main body portion.

8. In an elongate starter bar comprising a plurality of interconnected members for use in withdrawing a continuous cast strand from a mold along the axis of an apron structure, the improvement comprising:

(a) a rectangular rst elongate member that is relatively thinner than its Width and is flexibly movable in the vertical longitudinal plane of the axis of said apron structure, said elongate member having therein a plurality of holes;

(b) a short first tubular member freely disposed in each of said holes;

(c) a rod in each short tubular member disposed substantially normal to the rectangular elongate member;

(d) a second and a third tubular member freely mounted to each said rod on opposite sides of said elongate member;

(e) means removably securing said second and third tubular members to said rod; and

(f) second elongate members mounted to each said second and third tubular member and projecting from said rectangular elongate member, each said second elongate member being so shaped and arranged that when said starter bar is urged axially relative to said mold, the forces acting on the outwardly projecting ends of said second elongate members urge said first elongate member into alignlment with the axis of said apron structure.

9. The invention set forth in claim 8 wherein:

CII

(a) said second elongate members are structural angles.

10. A continuous casting arrangement comprising:

, (a) an open-ended casting mold wherein molten metal flowing thereinto from a tundish forms a continuous cast strand;

(b) a spray chamber disposed beneath said mold for cooling said cast strand as it emerges from said mold;

(c) a cast strand guide apron disposed beneath said spray chamber, said apron comprising:

(i) a plurality of arcuate members disposed in spaced relation to each other around a longitudinal arcuate axis substantially coplanar with the axis of said casting mold;

(ii) rst means maintaining said members in a spaced apart relation in one direction;

(iii)` second means maintaining said members in spaced apart relation in another direction;

(iv) means mounted on said arcuate members for engaging said starter bar and guiding the same and said casting substantially along the axis of said support structure; and

(v) a plurality of groups of rollers means mounted on said members for supporting said cast strand;

(d) a starter bar for withdrawing said cast strand from said mold including,

(ii) an adapter head removably connected to said plug portion,

(iii) a guide head removably connected to said adapter head and supported on rollers that are resiliently biased into rolling frictional contact with said apron structure,

(iv) a exible body portion removably connected to said guide head and supported by said apron structure, said iiexible body portion conforming generally to the shape of said apron structure; and

(e) powdered pinch rollers engageable with said starter bar to advance the same toward said casting mold and to withdraw both said starter bar and said cast strand from said mold.

11. In a segmental starter bar for use with an apron structure in withdrawing a continuous cast strand from a mold, the combination comprising:

(a) an adapter head removably connected to said cast strand;

(b) a guide head member iiexibly connected to said adapter head and including:

(i) a main body portion, and

(ii) wheels journaled to axles that are resiliently mounted to said main body portion and adapted to engage said apron structure and move relative thereto along the axis of said apron structure,

(c) a exible body portion removably connectable to said guide head and supported by said apron structure, said flexible body portion conforming generally to the arcuate shape of said apron structure; and

(d) -means flexibly connecting said flexible body portion to said guide head. l

12. In apparatus for use in withdrawing a continuous cast strand from a mold, the combination comprising:

(a) a cast strand guide apron including a plurality of adjacent individual arcuate structures adapted to receive said cast strand and to support and guide the same in a direction toward a horizontal attitude; and

(b) a starter bar for withdrawing said cast strand from said mold including:

(ii) an adapter head=removably connected to said plug portion, t fv v (iii) a guide headremovably connected to said adapter head and supported'ori rollers that are resiliently biased into rolling frictional contact with said apron'y structure,

(iv) a flexible body portion removably connected to said guide head and supported by said apron structure, said exible body portion conforming generally to the shape of said apron structure and including:

(a) an elongate member that is relatively thinner than its Width and that is exibly movable in :the plane of the axis of said apronys'aid elongate member having therein a plurality of holes;

(b) a first tubular member freely disposed Vin each said hole, each tubular member surrounding an elongate rod member disposed substantially normal to said elongate member; and

(c) second and third members removably mounted to each Said rod member and disposed on opposite sides of said elongate member, said second and said third members terminating at substantially equal distances from said elongate member, said second and third members being of such a shape that a plane disposed normal to the longitudinal axis of the elongate member and intersecting at least one of said second and one of said third members also intersects successive second and third members.

13. In a starter bar for use with an apron structure for withdrawing a continuous cast strand from a mold, the combination comprising:

(a) an adapter head removably connected to said cast strand;

(b) a guide head removably connected to said adapter head and supported on rollers that are resiliently biased into rolling frictional contact with said apron structure; and

(c) a flexible body portion removably connected to said guide head and supported by said apron structure whereby said exible body portion conforms generally to the arcuate shape of said apron structure, said flexible body portion including:

(i) an elongate member that is relatively thinner than its width and that is flexibly movable in the plane of the axis of said apron, said elongate member having therein a plurality of holes;

(ii) a first tubular member freely disposed in each said hole, each tubular member surrounding an elongate rod member disposed substantially normal to said elongate member; and

(iii) second and third members removably mounted to each said rod member and disposed on opposite sides of said elongate member, said second and said third .members terminating at substantially equal distances from said elongate member, said second and third members being of such a shape that a plane disposed normal to the longitudinal axis of the elongate member and intersecting at least one of said second and one of said third members also intersects successive second and third members.

14. In a starter bar for use with an apron structure in withdrawing a continuous cast strand from a mold, the combination comprising:

(a) a cast strand guide apron including a plurality of spaced apart groups of arcuate support members, each said group including:

(i) spaced apart angle members located at the corners of a rectangle;

(ii) means connecting and maintaining two adjacent angle members as a group in spaced apart relation inone direction; v

(iii) means connecting and maintaining the groups of connected adjacent angle members in spaced apart relation in another direction; f

(iv) a plurality of first rollers journaled to the connected angle members of each group;

(v) a plurality of second rollers journaledtto and disposed between groups of connected angle members, said first and second rollers having substantially mutually perpendicularaxes;

(vi) guide plates mounted to said angle members for engaging and limiting the lateral movement of said starter bar as the same moves along the Vaxis of said apron toward and away from said mold;

(b) means supporting each said group of arcuate members whereby their axes are substantially in arcuate alignment and coplanar with the axis of said casting mold; and

(c) a guide head member adapted to engage said apron structure including:

(i) a main body portion, and

(ii) wheel means `mounted to axles that are resiliently mounted to said main body portion and adapted to engage said apron structure whereby said guide head moves relative to said apron and along the axis thereof. y

1S. In an elongate starter bar comprising a plurality of interconnected members for use in withdrawing a continuous cast strand from a mold along the axis of an apron structure, the improvement comprising:

(a) a exible body portion flexibly linked to at least one other member and including:

(i) an elongate first member that is flexibly movable in the plane of the axis of said apron structure;

(ii) a plurality of spaced apart second members mounted to said elongate first members and freely movable linearly and rotationally with respect to said elongate rst, member; and with (iii) each spaced apart second member including at least one angle mounted substantially normal to the elongate rst member so that a plane normal to the longitudinal axis of the first member intersects the toe portions of one angle member and intersects the heel portion of an adjacent succeeding angle member.

16. In an elongate starter bar comprising a plurality of interconnected members for use in withdrawing a continuous cast strand from a mold along the axis of an apron structure, the improvement comprising:

(a) an elongate member that is relatively thinner than its width and that is flexibly movable in the plane of the axis of said apron, said elongate member having therein a plurality of holes;

(b) a rst tubular member freely disposed in each said hole, each tubular member surrounding an elongate rod member disposed substantially normal to said elongate member;

(c) a second and a third member removably mounted to each said rod member on opposite sides of said elongate member, said second and said third members terminating at substantially equal distances from said elongate member, said second and third members being of such a shape that a plane disposed normal to the longitudinal axis Vof the elongate member and intersecting at least one of said second and one of said third members also intersects successive second and third members, wherein (i) said second and said third members are angles that are pivotable about the axis of said elongate rod; and

13 14 Y (d) means to limit the pivotal movement of said 3,305,899 2/1'967 Saunders.

angles. 3,324,934 6/ 1967 Hess et al. 164-274 References Cited 3,338,297 8/1967 Foldessy 164-274 UNITED STATES PATENTS 3,351,125 11/1967 COlOmbO 164274 3,358,744 12/ 1967 ROSSi 164-282 5 FOREIGN PATENTS 2,920,359 1/1960 Easton et al. 164-274 X 1 379 352 10/1964 F 3,080,625 s/196s Pearson et a1. 164-274 728 412. /19 5 j fance. 3,157,920 11/1964 Hess 164-282 x f 4 5 Great tmf (,ffgea-l ffg 10 J. SPENCER OVERHOLSER, Primsfy Examiner.

3,262,162 7/ 1966 Lemper 164-274 R. S. AN'NEAR, Assistant Examiner.