Patent Publication Number: US-3877673-A

Title: Collapsible pattern for a ladle-lining installation

Description:
[451 Apr. 15,1975  
 United States Patent Bisinella et al.  
 PATENTEUAPR 1 Sms 3,877, S73  
 SHEET 1 g5 5 PATENTEDAPR 1 5 m5 &#39;lllllllllllj PMENTEUAPR 1 5ms SHEET 5 5 COLLAPSIBLE PATTERN FOR A LADLE-LINING INSTALLATION This application is a division of our copending United States patent application Ser. No. 168,689, filed on Aug. 3, 1971 and entitled APPARATUS FOR LIN- ING THE WALLS OF METALLURGICAL VESSELS WITH PREPARED REFRACTORY MATERIAL,  
 now U.S. Pat. No. 3,779,679, granted on Dec. 18,  
  The present invention relates generally to an apparatus for lining a ladle or other cup-shaped metallurgical vessel with a continuous arcuate rim by delivering wads of prepared refractory material into the annular or continuous space which exists between the side wall of the ladle and a conformably shaped pattern which is centered within the ladle. The invention is particularly concerned with a novel collapsible pattern which is adapted for use in the ladle to be lined or relined, has novel facilities for centering it in the ladle at the time it is initially installed in the ladle and, thereafter, leveling it within the ladle in order to bring the axes of the pattern and the ladle into coincidence; has novel facilities for shrinking or contracting it after the refractory lining has been completely introduced in the space around the pattern so as to break the bond between the side surface of the pattern and the inner side surface of the green lining material to the end that the pattern may be readily hoisted from the newly-lined ladle; and also novel facilities The guiding the associated, rotary wad-projecting ramming unit or slinger assembly into an axially centered position above the rim of the ladle and, thereafter, supporting such assembly during ladle-lining operations. A further feature of novelty which is associated with the pattern per se resides in the provision of means for confining the wads of prepared refractory material which is rammed by the slinger assembly into the continuous arcuate space between the pattern and the ladle an&#39;d preventing the same from flowing inwardly over the bottom wall of the ladle. The provision of a novel collapsible pattern such as has briefly been outlined and possessing the stated features of novelty constitutes the principal object of the present invention.  
  Other objects and advantages of the invention will readily suggest themselves from a consideration of the following detailed description.  
  The invention consists in the several novel features which are thereinafter set forth and are more particularly defined by the claims at the conclusion hereof.  
 In the accompanying five sheets of drawings forming FIG. 4 is a vertical sectional view taken on the line 4-4 of FIG. 3;  
  FIG. 5 is a vertical sectional view taken on the line 5-5 of FIG. 3;  
  FIG. 6 is a vertical sectional view taken on the line 6-6 of FIG. 3; I  
  FIG. 7 is an enlarged fragmentary side elevational view of a portion of the structure which is shown in FIGS. 3 and 5, the view disclosing one of a number of spreader jacks which are associated with the pattern shell assembly of the present invention;  
 FIG. 8 is an enlarged fragmentary detail view of the structure which is enclosed in the dotted line circle F8 a part of this specification, one illustrative embodiment of the invention is shown.  
 IN THESE DRAWINGS FIG. 1 is a top plan view, somewhat schematic in its representation, showing a steel mill installation (ladle lining apparatus) which incorporates the collapsible of FIG. 5;  
  FIG. 9 is an enlarged fragmentary detail view of the structure which is enclosed in the dotted linne circle F9 of FIG. 5;  
  FIG. 10 is an enlarged fragmentary detail view of the structure which is enclosed in the dotted line F10 of FIG. S;  
  FIG. 1 1 is a reduced fragmentary horizontal sectional view taken on the line ll-ll of FIG. 6 and showing the details of a gate mechanism which is employed in connection with the invention, the gate proper being illustrated in its closed position;  
  FIG. 12 is a sectional view similar to FIG. 11 but showing the gate proper in its open position;  
  FIG. 13 is a reduced fragmentary horizontal sectional view similar to FIG. 11 but showing the details of another and counterpart gate mechanism which is ernployed in connection with the present invention, the gate proper being shown in its closed position;  
  FIG. 14 is a sectional view similar to FIG. 13 but showing the gate proper in its open position;  
  FIG. 15 is a horizontal view taken through the bottom portion of FIG. 5 and illustrating the nature of the pattern shell centering mechanism which is employed in connection with the invention;  
  FIG. 16 is an enlarged vertical sectional view taken on the line 16-16 of FIG. 15;  
 FIG. 17 is an enlarged vertical sectional view taken on the line 17-17 of FIG. 15;  
  FIG. 18 is an enlarged vertical sectional view taken on the line 18-18 of FIG. 15; and  
  FIG. 19 is an enlarged vertical sectional view taken on the line 19-19 of FIG. 15.  
  Referring now to the drawings in detail and in particular-to FIGS. 1 and 2 wherein a complete steel mill la dle-lining installation or system is illustrated in a somewhat diagrammatic fashion, a metallurgical vessel in the fonn of a pouring ladle for molten steel is designated in its entirety by the reference numeral 10, the ladle being operatively positioned in a ladle pit 12 where the ladle-lining procedure takes place. The upper portion of the ladle 10 is provided with the usual outwardly extending, diametrically opposite supporting trunnions 14 by means of which it is supported when, after lining, it is used in connection with an overhead hoist for actual metal pouring operations. The trunnions 14 are secured in thickened bosses 15. As shown in FIG. 2, the ladle 10 comprises a circular bottom wall 16 and a continuous side wall 18 which terminates in an open or exposed upper rim 20. The latter, in the illustrated form of ladle, is generally oval or elliptical but may under certain circumstances be truly circular. The bosses l5 are formed as integral parts of the upper portion of the side wall 18. The present installation includes a ladle-lining apparatus which is capable of use, without any modification whatsoever, for lining ladles or other metallurgical vessels regardless of whether the same present either circular or elliptical rims. The ladle pit 12 exists by reason of a concrete pit-forming shell 22 which is shown as being positioned in a conformably-shaped opening 24 in the floor or foundation surface 26 of the steel mill. Spaced apart, horizontally extending, channel beams 28 extend along a pair of opposed sides of the pitforming shell 22 and receive thereon the trunion-supporting bosses in ladlesupporting relationship.  
  In FIGS. 1 and 2 of the drawings, the ladle 10 is shown in its ladle-lining environment, i.e., in associated relationship with the aforementioned ladle-lining apparatus, and in its fully lined condition at the termination of the operation but prior to dismantlement and withdrawal of the hereinafter described liner pattern from the interior of the ladle. Said liner pattern constituted the subject matter of the present invention as hereafter indicated. In FIGS. 1 and 2, the completely installed lining or liner is shown at 30, and it is in the nature of a homogenous monolithic mass which is formed of compacted wads of prepared refractory material and then cured by a tiring operation as well known in the art. The liner 30 is generally of frusto-conical or elliptical configuration and is formed by progressively introducing wads of the lining material into the arcuate space 32 which exists between the inner face of the side wall 18 of the ladle 10 and the outer side face of the aforementioned liner pattern. The latter is designated by the reference numeral 31 and is removably disposed within the ladle 10 is centered relationship. As will be described in detail subsequently, the liner-forrning pattern 34 is of a sectional composite nature and it includes a four-part split pattern wall or shell 36 of a generally frusto-conical or elliptical configuration which is conformable in shape to the frusto-conical or elliptical configuration of the ladle side wall 18 but which is of lesser radial extent so that when the pattern shell is centered within the ladle 10, the aforementioned arcuate space 32 is established. For convenience, such space will hereafter be referred to as an annulus In order to break the bond between the formed refractory liner 30 and the liner or lining-forming pattern 34 after the ladle 10 has been lined, the pattern shell 36 is capable of limited construction. After such contraction of the pattern shell, the pattern 34 as a whole may be hoisted by an overhead hoist or crane (not shown) from its centered relationship within the ladle l0. This liner pattern has associated therewith novel internal means for contracting its shell 36, as well as means whereby the liner pattern as a whole may be hoisted into position within the ladle 10 and removed therefrom. Such means have been omitted from FIGS. 1 and 2 in the interest of clarity but they appear elsewhere in the drawings.  
  The lining material which ultimately is delivered to the annulus 32 for ladle-lining purposes is in the form of a prepared refractory mix which is obtained in packaged form. This material is batch fed by a skip hoist 38 to a conventional mulling apparatus which is illustrated schematically in FIGS. 1 and 2 and is designated in its entirety by the reference numeral 40. The apparatus 40 is of the top feed open rim type and includes a mulling bowl 42 within which there is a rotary, power-driven crosshead having mounted thereon a series of plows which serve to agitate, squeeze, and aerate the refractory mix while at the same time water is predetermined quantity is introduced into the bowl 42. The aforementioned refractory mix consists of granular material to which there has been suitable conditioning substances, the mix as a whole, however, being a dry mix requiring only the additionof, and intimate mixing with, a predetermined percentage of water in order to attain an earth-like consistency which constitutes the required mixture and is suitable for introduction into the annulus 32 which exists between the pattern shell 36 and the side wall 18 of the ladle 10.  
  As will be described in detail subsequently, the refractory lining material which is introduced into the annulus 32 is delivered in the form of small wads which are flung from a slinger assembly 44 which constitutes the principal or effective functional component of a rotary ramming unit 45, the latter being adapted to be positioned in seated relationship on the liner pattern 34 after the latter has been properly installed in the ladle l0. Upon rotation of the ramming unit 45 bodily about the vertical axis of the pattern 34, the slinger assembly travels or orbits in a generally circular or elliptical path, and it is provided with a discharge chute 46 which remains at all times in register with the annulus 32 and discharges the wads of refractory material thereinto. These wads are successively compacted in the annulus which gradually becomes filled with the refractory material. After the annulus has become filled with the refractory material, the ramming unit 45 is hoisted from the liner pattern 34 and, thereafter, the shell 36 of said liner pattern is contracted radially in order to free the same from the formed liner 34. Thereafter, the liner pattern 34 is hoisted from the pit-supported ladle which, in turn, is hoisted from the pit 12 so that a fresh stand-by unlined ladle may be placed in the pit preparatory to a succeeding ladle-lining operation.  
  It is essential for proper filling of the annulus 32 that the slinger assembly 44 deliver its refractory linerforming material to the annulus at a uniform rate so that this material will build up uniformly during filling of the annulus, and thus, result in uniform density of the completed lining. Since the mulling apparatus 40 is of the batch type, it is necessary that the periodic batch discharge from the apparatus 40 be converted into a substantially steady flow of material to the slinger assembly 44. For this purpose, a bucket elevator 50 is positioned to receive the periodic batch discharge from the mulling apparatus 40 and to elevate the same for introduction into a feeder 52 which discharges the material in a mixed condition continuously onto an articulated conveyor assembly 54, the latter leading from the feeder 52 to the slinger assembly 44 of the ramming unit 45. The conveyor assembly 54 is comprised of two independently power-driven conveyors including a material-receiving conveyor 56 and a material-delivery conveyor 58, the former receiving the refractory lining material from the feeder 52 and the latter delivering such material directly to the slinger assembly 44 of the rotating unit 45. The mulling apparatus 40 and its associated skip hoist 38 and the feeder 52 and its associated bucket elevator 50 function to translate the batch feed of the refractory lining material to the mulling apparatus 40 into a continuous flow of such material from the mulling apparatus to the receiving conveyor 56.  
  The skip hoist 38 (see FIG. 2) embodies a vertically shiftable dump bucket 60 which is slidably mounted on a relatively tall framwork 62 and is adapted to be shifted vertically in opposite directions under the control of a reversible motor Ml at the upper end of the framework 62. In its lowered position, the dump bucket 60 assumes 4the upright position in which it is shown in full lines in FIG. 2, in such upright position the bucket disposed adjacent to the floor or foundation surface 26 where its open rim is conveniently accessible for bucket-loading purposes. As the dump bucket progresses upwardly, it encounters a cam 64 adjacent to the upper portion of the framework 62. As the result of engagement with such cam, the bucket 60 is caused to tilt and empty its contents by gravity into the open upper end of the bowl 42 of the mulling apparatus 40.  
  The mulling apparatus 40 is fixedly mounted on the upper end of a concrete pedestal 66 and in the medial regions of the bowl thereof there is provided a discharge gate 68 which is adapted to be opened near the end of each mulling cycle so that as the apparatus continues to function, the moist lining material becomes discharged onto a horizontally disposed conveyor 70 by means of which it is conducted to the receiving hopper 72 of the bucket elevator 50. The conveyor &#39;.70 is of the belt type and includes driving and driven belt rollers 74 and 76, an endless belt 78, and an electric driving motor M2 which is operatively connected to the driving roller 74 by a belt and pulley arrangement 80.  
  The discharge end of the conveyor 70 overlies the aforementioned receiving hopper 72 which is associated with the bucket elevator 50 and the latter involves in its general organization the usual endless chain and bucket structure 82 which serves to conduct the lining material from the hopper 72 to the upper end of a surrounding, upstanding, rectangular, hollow casing 84 and deposit the same in a discharge chute 86. The latter empties into a receiving hopper 88 which is associated with the feeder 52. The chain and bucket structure 82 is adapted to be driven under the control of an electric motor M3.  
  The feeder 52 is supported on an elevated platform 90 which is mounted on the bucket elevator casing 84 and includes a centrally fed, horizontally disposed, rotatable, material-receiving disk 91. The latter discharges the lining material which is received thereon in peripheral fashion and under the influence of one or more fixed scraper plates 92 which extend in secant fashion over the surface of the rotating disk 91. The peripherally-discharged lining material falls by gravity into a receiving hopper 94 which is associated with the aforementioned material-receiving conveyor 56.  
  For a full understanding of the nature and function of the ramming unit 45 and its associated slinger assembly 44, reference may be had to our aforementioned copending U.S. Pat. application Ser. No. 168,689. It is deemed sufficient for descriptive purposes herein to state that this ramming unit is adapted to be hoisted into a central position in centered relationship over the ladle l0 after the liner pattern 34 has been operatively installed and levelled in the ladle. The details of the liner pattern and its internal mechanism will be set forth in detail subsequently, but for an understanding of the manner in which the ramming unit is introduced into and withdrawn from the ladle 10, into and out of functional cooperation with the linear pattern 34, it is sufficient to state that the ramming unit 45 seats upon a pair of horizontally disposed, coplanar, shelf-like deck plates 502 and 503 (see FIGS. 4 and l1) which extend across the upper region of the liner pattern and are fixedly secured therein. It is to be understood that the disclosure of FIG. 2 of the drawings is largely schematic in its representation and that, therefore, these deck plates 502 and 503 are the only internal functional components of the liner pattern which are illustrated therein, the remaining internal components being omitted in the interests of clarity, especially since they are disclosed in detail in FIGS. 3 to 19, inclusive.  
  Referring now particularly to FIGS. 3 and 4, the ramming unit 45 involves in its general organization an undercarriage 504 which constitutes a base support for the ramming unit as a whole and is adapted to be removably mounted on the deck plates 502 and 503 of the liner pattern 34. This undercarriage 504 is in the form of a framework consisting of structural steel members and including a quadrilaterally arranged series of four radially diverging, horizontally disposed frame legs 506 (see FIG. 3) each of which is comprised of two parallel, spaced apart, structural channel members 508, the channel faces of which oppose each other. Said channel members are maintained in their parallel spaced relationship by means of inner end bars 510, outer end bars 512, and intermediate crossbars 514. The inner ends of the frame legs 506 are disposed in close proximity to one another so that the four legs, considered collectively, establish a symmetrical cross which, when seated on the deck plate 502 substantially spans the rim region of the pattern shell 36 in two directions. The outer end regions of adjacent frame legs 506 are connected together by diagonal braces 516, there being four such struts and each strut consisting of a length of angle iron.  
  The above described undercarriage 504 constitutes a permanent component of the ramming unit 45 and is adapted, along with the entire unit, to be bodily lowered into the pattern shell 34 in order properly to position the slinger assembly 44 and also to support the same in its proper relationship with respect to the annulus 32 for ladlelining purposes. Accordingly, in order to insure proper centering of the undercarriage 504 vertically extending, upwardly tapered, locating brackets 518 are fixedly secured by bolts 520 to the deck plates 502 and 503 in the peripheral region of the pattern shell 36 and each bracket cooperates with a respective frame opening 522 near the outer end of a frame leg 506 in guiding the under carriage to its final home position as it is being lowered into the rim region of the liner pattern 34. The under carriage 504 is adapted to be removably anchored in position on the deck plates 502 and 503 by means of bolts 524 which are threaded into the upper end portions of the locating brackets 518 and serve to secure hold-down plates 526 in a clamped position with respect to the outer ends of the frame legs 506. By removing the bolts 524 and the hold-down plates 526, the undercarriage 504 may be separated from the liner pattern 34 by a hoisting operation. Apertured hoisting lugs 528 are located in circumferentially spaced regions of the undercarriage 504 and are connected to either the struts 516, or the outermost crossbars 514, or both. The ramming unit 45 is shown in dotted outline in FIG. 4 in its permanently supported position on the undercarriage 504 and includes an electric turret motor M6 for rotating the turret, and a gear reduction device 534. The latter is supported on a pair of spaced apart inverted channel members 584 which, in turn, are carried on the channel members 508 of the undercarriage 504. The motor M6 is supported by a base framework from a pair of spaced apart inverted channel members 606 which bridge the distance between adjacent channel members 508.  
  The nature of the liner-forming pattern 34 of the apparatus is disclosed in detail in FIGS. 3 thru 19, inclusive. The disclosure of this pattern in FIGS. 1 and 2 is entirely schematic, there being shown in such figures of the drawings only a simple frusto-conical shell or wall 36 with no facilities for collapsing the same in order to break the bond between the shell and the liner after a ladle-lining operation and preparatory to lifting the pattern from the lined ladle.  
  As best shown in FIGS. 5 and 6, the liner pattern 34 involves in its general organization two superimposed pattern sections in the form of an upper section 800 and a lower section 802. These sections are somewhat similar in their construction and are equipped with similar internal components whereby they are capable of being collapsed and expanded for pattern removal and installation purposes as previously mentioned. The upper pattern section 800 is provided with a split twopart frusto-conical wall consisting of wall parts 804 and 805 (see FIGS. 6 and 11), and the lower pattern section 802 is provided with a split, two-part frusto-conical wall consisting of wall parts 806 and 807 (see FIGS. 6 and 13). The small base rim 808 of the upper frustoconical section 800 is substantially equal in diameter to the large base rim 810 of the lower frusto-conical sec tion 800 is substantially equal in diameter to the large base rim 810 of the lower frusto-conical section 802 in order that the former rim may seat on the latter rim as shown in FIG. 23 when the sections are assembled upon each other within the confines of the ladel 10. When the two pattern sections 800 and 802 are then assembled, the four wall parts 804, 805, 806 and 807 establish the aforementioned composite over-all frustoconical pattern shell 36.  
  It will be understood that the term frusto-conical as employed herein is not necessarily intended to imply the fact that the walls of the upper and lower pattern sections 800 and 802 are in the shape of true cone frustums. In the illustrated form of the liner pattern 34, the rim region of the upper pattern section 800 is elliptical and the major axis of the ellipse is slightly longer than the minor axis. The small base of the lower pattern section may be circular, in which case it will be understood that the herein termed frusto-conical walls will be slightly out-of-round and will progress from an ellipse at the upper end of the liner pattern to a circle at the lower end of the pattern. Therefore, in the remainder of the-specification, and in the appended claims, the terms frusto-conical, and circulan or such terms when coupled with the prefix semi are intended to include the out-of-round condition describedlabove.  
  Considering now only the lower pattern section 802 which includes the wall parts 806 and 807 as indicated in FIG. 7, these two parts are hingedly connected together in clamshell fashion and along a vertical axis by means of a piano-type hinge (see also FIGS. ll and 13). Preferably, but not necessarily, such hinge connection is disposed on the minor axis of the generally elliptical pattern structure. Diametrically across the lower pattern section 802 with respect to the hinge 816 is a gate assembly 818. The latter includes a narrow, full height vertical flap-like section or gate flap 820 which is connected by a piano-type hinge 822 to the distal side margin of the wall part 806 and constitutes a swing-in gate flap which normally lies or coincides with the frusto-conical contour of the wall parts 806 and 807 when the lower pattern section 802 is fully expanded as shown in FIG. 13, but which swings inwardly and assumes the position shown in FIG. 14 in order to permit the wall parts 806 and 807 to move closer together to effect slight contraction of the lower pattern section 802 for pattern removal purposes after the ladle 10 has been fully lined.  
  In order to manipulate the gate 820 between its two extreme positions (closed and open), a manually operable turnbuckle-type expansion and contraction jack 824 is disposed within the confines of the lower pattern section 802 and is connected at its opposite ends to the gate 820 and to a fixed reaction bracket 826 of appreciable radial extent on the distal portion of the wall part 806. The jack 824 constitutes one of a number of similar jacks which are employed in connection with the liner pattern 34 and the nature of these jacks will be made clear presently.  
  Relative movement of the clamshell-like wall parts 806 and 807 of the lower pattern section 802 toward and away from each other to contact or expand said lower pattern section, as previously described, is accomplished under the control of a turnbuckle-type expansion and spreader jack 830, which is similar to the jack 824, the jack 830 being connected at its opposite ends to two fixed reaction brackets 832 and 834 which are associated with the lower pattern section 802 and are disposed on opposite sides of the hinge 816 but adjacent to the distal portions of said wall parts 806 and 807.  
  The lower pattern section 802 of the liner pattern 34 may be provided with a wide variety of internal wall reinforcing components, depending upon the specific size and shape of the section. In theillustrated form of this pattern section, the reinforcing components consist of various radial gusset-like webs 840, vertical angle bars 842, and the like which require no detailed description at this point. The various gusset-like webs 840 serve to support thereon a pair of coplanar deck plates 844 and 846 which are similar to the previously described upper deck plates 502 and 503 and are secured by bolts 847 to and supported on curved or arcuate, longitudinally extending angle bars 848 (see FIG. 9), such angle bars being welded as indicated at 850 to the wall parts 806 and 807. Upstanding, apertured hoisting lugs 851 (see FIG. 6) are welded or otherwise fixedly secured to the deck plates 844 and 846.  
  The lower rim of the lower pattern section 802 is open and has installed therein a centering mechanism, a pattern levelling means, and a shield arrangement, the details of which are shown in FIGS. 15 to 18, inclusive, and the nature of which will be set forth presently.  
  Considering now the upper pattern section 800 of the liner pattern 34, except for its larger over-all mean diameter and a slightly different arrangement of the internal wall-reinforcing components which are associated therewith, this section is similar in its general organization to the lower patten section 802 and, therefore, for descriptive purposes, it is deemed sufficient to designate the corresponding structural reinforcing components, for example, such as the gusset-like webs, the angle bars and the like, as well as the functional components including the gate assembly, the spreader jack for the clamshell-type wall parts 804 and 805, the hinge 802 is open as previously set forth, the lower rim of the upper pattern section 800 is provided with a pair of coplanar base plates 852 and 854 (see FIGS. and 6) which seat respectively upon the deck plates 844 and 846 when the upper pattern section 800 is seated upon the lower pattern section 802. Clamping bolts 856 (see FIGS. 5 andV 9) serve releasably to fasten the thus paired plates together and these bolts constitute the sole means whereby the two pattern sections may be clamped to each other in order to provide a unitary pattern structure.  
  It is to be noted that the deck plates 502 and 503, which are rigidly secured within the upper portion of the upper pattern section 800 and serve to support the undercarriage 504 of the ramming unit 45, define therebetween a generally rectilinear openinng 858 (see FIG. 11), this opening constituting a manhole by means of which a workman may descend below the deck plates 502 and 503. In order to facilitate the workmans descent, a ladder 860 extends between the deck plate 503 and the base plate 854 in the vicinity of this opening and is welded in position therebetween. The deck plates 844 and 846 of the lower pattern section 802 detine therebetween a generally circular opening 862 (see FIG. 13) which constitutes a second manhole whereby a workman may descend below the deck plates 844 and 846, a second ladder 864 being welded to and suspended from the deck plate 846.  
  It will be understood that the hinges 816 and the gate assemblies 818 of the two superimposed pattern sections 800 and 802 are arranged in precise vertical alignment for operation in unison when the liner pattern 34 as a wh&#39;ole is expanded or collapsed.  
  The aforementioned turnbuckle-type jacks 830 (see FIGS. 5 and 6) and the turnbuckle-type jacks 824 (see FIGS. 11 and 13) are, except for size, substantially identical in construction, the spreader jacks for the clamshell pattern sections being larger then the manipulating jacks for the gate assemblies. One of the spreader jacks 830 is shown in detail in FIG. 2l and it includes an elongated turnbuckle sleeve 870 having internal threads which are of opposite pitch and cooperate with a pair of aligned spreader screws 872. The latter are provided at their outer ends with eyelets 873 by means of which they may be pivotally connected by lug Accordingly, and as best shown in FIGS. 5 and 10, the upper rim region of the upper pattern section 800 of the liner pattern 34 is provided with a pair of arcuate hardened steel, chute-guiding rails 882 and 884, each rail being approximately 180 extent. These rails are removably mounted on the upper rim of the upper pattern section 800, the rail 882 resting on the upper edge of the wall part 804 and the rail 884 resting on the upper edge of the wall part 805. Certain adjacent ends of the rails 882 and 884 abut each other along the vertical line of the hinge 800 of the upper pattern section 800. Diametrically across the upper pattern section 800 from the hinge 816, the other pair of adjacent ends and pivot-pin arrangements to the parts which are to be spread apart or drawn together. A ratchet wheel 874 which is affixed to the central region of the sleeve 870 is adapted to be progressively manipulated by means of a spring-biased pawl 876 which is carried between the tines of a fork 878. The latter is pivotally connected to of the rails 882 and 884 abut each other when the upper pattern section is in its expanded condition, the&#39;se latter abutting rail ends being disposed in the vicinity of the uppermost gate assembly 818 and in close proximity to the uppermost gate 820 which, at this time, is closed After opening of said uppermost gate 820 under the control of the associated turnbuckle-type jack 824, subsequent movement of the two clamshell-like wall parts 804 and 805 of the upper pattern section 800 toward each other by way of manipulation of the uppermost turnbuckle-type jack 830 will cause the last mentioned adjacent ends of the rails 882 and 884 to overlap each other as shown in FIG. 3a. This overlaping of the rail ends is initiated by reason of the fact that the meeting edges of said rail ends are bevelled in the same direction.  
  The two arcuate guide rails 882 and 884 are removably mounted on the upper edges of their respective wall parts 802 and 804 by means of an annular series of pilot lugs 890 (see FIGS. 4, 5 and l0) which are secured by bolts 892 to the upper margins of said wall parts on the inner sides thereof` and project upwardly beyond the upper rim of the upper pattern section 800. Spacer plates 894 are interposed between the pilot lugs and the upper margins of the adjacent wall parts in order to attain the necessary inward offset of the pilot lugs 890 for proper downward piloting of the two rails 882 and 884 onto the rim of the upper pattern section 800. The rails thus constitute, in effect, an upper rim extension of the pattern shell.  
  It is to be noted, however, that the downwardly extending pilot lugs 890 are omitted in the vicinity of the uppennost gate flap 820 so that this flap is free of the arcuate guide rail 882 in order that the flap will not be obstructed in -its swinging movement away from the guide rail 882.  
  lt will be understood that the two arcuate chuteguiding rails 882 and 884 are designed for cooperation with a pair of follower rollers 896 which straddle these rails alternately during rotation of the turret 532. The rollers 896 will thus follow the closed or continuous arcuate path (circular or elliptical) which is defined by the upper open rim of the liner pattern 34 and, thus, the lower end of the discharge chute 46 will at all times be maintained in proper register with the annulus which is undergoing ramming.  
  The previously mentioned centering mechanism whereby the liner pattern 34 is caused to become centered within the ladle 10 during initial installation thereof is best illustrated in FIGS. 15 and 16 of the drawings and portions of this mechanism also are shown in FIGS. 2,and 11 to 14, inclusive. This mechanisrh is designated in its entirety by the reference numeral 910 and involves in its general organization a downwardly extending locating pin 912 (see FIG. 16) which is carried by the liner pattern 34, and a centering socket 914 which is established by the provision of a pilot tube 916. The latter is mounted on a spider-like frame structure which is positioned on the bottom wall 16 (see FIG. 2) of the ladle 10 in a manner that will be described in detail hereafter.  
  The pilot tube 916 is carried at the center of a series of quadrilaterally arranged radial arms 918 each of which is of two-part construction and consists of an inner tube section 920 which is square in cross section, and an outer tube section 922 which is telescopically received in the inner section so as to be adjustable outwards and inwards in a radial direction. Longitudinal slots 923 (see FIGS. and 18) in the upper portions of the inner tube sections 920 expose the inner end regions of the associated outer tube sections 922, and upstanding manipulating pins 924 are secured to the inner ends of the inner sections 922 and project upwardly through the slots 923. Vertically extending locking pins 926 (see FIG. 17) which are urged downwards by helical compression springs 928 cooperate with longitudinal series of closely spaced locating holes 930 in the upper outer portions of the inner tube sections 922 in order that the outer tube sections may be secured in any desired radial position with the inner tube sections. A rectangular reinforcing hub plate 932 overlies and is welded to the intersecting inner end regions of the four radial arms 918, the pilot tube 916 projecting upwardly through a hole 934 in the central portion of such plate.  
  The locating pin 912 is provided with a downwardly tapered lower end 936 and, as shown in FIGS. 11 to l5, inclusive, is carried on the central portion of a horizontal generally diametrically extending strut member 938. The latter is of a composite nature and includes two aligned channel members 940 which, at their inner end regions, are welded in back-to-back fashion to a third short channel member 942. The central portions of the horizontal flanges of the channel member 942 are burned out in order to receive the locating pin 913 which is welded in position in the burned out regions. The outer ends of the two aligned channel members 940 are welded to attachment brackets 944 which, in turn, are welded to the walls 806 and 807 of the lower pattern section 802.  
  It is to be noted at this point that, although the radially extending, extensible and contractible arms 918 which are associated with the centering mechanism 910 and normally overlie on the bottom wall 16 of the ladle l0 are referred to herein as radial arms, in the illustrated form of the liner pattern 34, these arms are not truly radial since the point of divergency of these four arms is slightly offset from the geometrical center of said bottom wall 16 as clearly shown in FIG. 15. Similarly, although the horizontally extending strut member 938 which is carried on the lower pattern section 802 of the liner pattern 34 is referred to as being diametrically disposed with respect to such pattern section, actually this strut is slightly offset from a true diameter and it, therefore, lies in a secant plane with respect to the liner pattern 34. These offset arrangements are necessary in order that the strut 938 shall be secured to only one of the two wall parts 806 and 807 so that it may move bodily with the part 807 to which it is attached when the liner pattern 34 as a whole is expanded and contracted as previously described.  
  The previously mentioned pattern leveling means which is carried at the lower end region of the lower pattern section 802 is provided for the purpose of adjusting the liner pattern 34 to a centered position within the ladle 10 at the time it is initially installed within the ladle. This means is comprised of a series of at least three, but preferably four, circumferentially spaced leveling jack assemblies 950, each of which includes an hydraulic jack proper 952 (see FIGS. 15 and 19) embodying a cylinder part 954 and a plunger part 956. The cylinder part of each assembly 950 is supported on a shelf-like bracket 958 which is welded to the inner side of one of the wall parts 806 or 807 as the case may be, and the plunger part projects downwardly and is adapted to seat on a reinforcing plate 960 which is interposed betwen the plunger and the bottom wall 16 of the ladle 10. Flexible hose connections -962 leading to the opposite ends of the cylinder parts 954 enable the various jack assemblies 950 to be individually operated from a remote region such, for example, as the control cabinet 722.  
  Still referring to FIGS. 15 and 19 of the drawings, the previously mentioned shield arrangement whereby the refractory lining material which is flung in wad form into the annulus 32 between the side walls of the ladle 10 and the liner pattern 34 is prevented from flowing or shifting inwardly beneath the pattern during ladlelining operations consists of a pair of generally semicylindrical apron members 970 and 972 of short height, the apron member 970 closely hugging the lower portion of the inside wall surface of the wall part 806 of the lower pattern section 802, and the apron member 972 similarly hugging the lower portion of the inside wall surface of the wall 807. These apron members 970 and 972 are formed of sheet metal stock and are slidable vertically on the wall parts to which they are applied. Suitable notches 974, one of which appears in FIG. 19,  
 are cut in the lower rims of the apron 970 and 972 in order to accommodate the outer ends of the outer tube sections 922 of the arms 918. At such time as ladlelining operations have been completed and the liner pattern 34 is hoisted upwardly from the confines of the lined ladle, the top edge portions of the vaious notches 974 rest on the outer ends of said outer tube sections 922 so that the apron assembly will be lifted bodily with the liner pattern 34.  
  The procedure whereby the liner pattern 34 is initially installed in the pit-mounted ladle 10 will vary, depending upon the size and capacity of the ladle, as well as upon the equipment which is available for installing the pattern. As previously stated, the ladle lining apparatus of our aforementioned copending application Ser. No. 168,689 is primarily designed for use in the lining of large ladles. In a range of capacities extending up to two hundred and fifty tons or larger, depending upon hoisting facilities, it may be found desirable to handle the two split pattern sections 800 and 802, i.e., the upper and the lower sections separately. Ordinarily, a pattern which is designed for use with a small ladle will be handled bodily as a single unit, in which case the upper pattern section 800 and the lower pattern section 802 will be permanently bolted together, utilizing the clamping bolts 856 (see FIG. 9), as previously described for this purpose. After bolting the two pattern sections together, the thus assembled liner pattern 34 may be hoisted by using the upper set of hoisting lugs 851. If successive hoisting operations are resorted to in order to install the liner pattern 34 within the ladle 10, the lower set of hoisting lugs 851 will be employed when initially setting the lower pattern section 802 into the ladle and, thereafter, the upper set of hoisting lugs will be employed for placement of the pattern section 800 on top of the liner pattern section 802. In either instance, prior to placement of the lower pattern section 802 in the ladle, the workman will adjustvthe centering mechanism (see FIG. 15) so that the outer square tube sections 922 of the extensible and contractible radial arms 918 are fully extended into engagement with the ladle side wall 18 while the quadrilateral frame structure which embodies such arm rests on the bottom wall 16 of the ladle. The adjustment of these square outer tube sections will be made so that the centering socket 914 of the pilot tube 916 (see FIGS. l5 and 16) will attain the correct receiving position for reception therein of the center locating pin 912 which is carried by the channel 942 of the lower pattern section 802.  
  The lower pattern section 802 is then lowered into the ladle and coupling of the locating pin 912 and the pilot tube 916 is effected. As the lower portion of the lower pattern section 802 approaches the ladle bottom wall 16, the apron members 970 and 972 will be brought into engagement with said bottom wall 16, thus arresting further downward movement of these apron members. As the lower pattern section 802 continues to be lowered, the apron sections shift with respect to the wall parts 806 and 807 of the lower pattern section. After the lower pattern section 802 has become fully within the ladle, a workman who has descended into the lower section of the pattern 34 beneath the deck plates 84d and 846 will then retract the square tube sections so that they lie entirely within the confines of the generally cylindrical pattern section wall parts 806 and 807.  
  If the upper pattern section 800 has been bolted to the lower pattern section 802 for hoisting and lowering in unison therewith, the liner pattern 34 as a whole is at this time ready to receive thereon the ramming unit 45. If separate hoisting operations for the two pattern sections are resorted to, the upper pattern section 800 must be applied to the installed. If such is the case, a ramming unit can be installed. lf such is the case, a workman inside the upper pattern section 800 will effect the necessary bolting operation after the latter section has been lowered into the ladle and brought to rest on the lower pattern section 802.  
  With both pattern sections bolted together and the thus assembled liner pattern 34 properly positioned within the ladle l0, the ramming unit 45 will be lowered into position over the upper pattern unit 800 so that the frame openings (see FIG. 17) 522 register with the tapered brackets 518 for guiding the undercarriage 504 of the ramming unit properly into position on the two deck plates 502 and 503. After the undercarriage seats on these deck plates, the hold-down plates 526 are installed as previously described in order fixedly to secure the ramming unit 45 in position on the liner pattern 34. Ramming operations may then take place with the prepared refractory lining material flowing to the orbiting slinger assembly 44 and the latter discharging its wads of conditioned lining material into the annulus 32 as previously described in detail.  
  Upon filling of the annulus 32 with wads of the prepared refractory lining material, feeding operations are discontinued by terminating the rotation of the turret turntable 562. Then, prior to withdrawal of the liner pattern 34 from the lined ladle 10, the undercarriage 504 is released from the deck plates 502 and 503 by removing the hold-down plates 526, after which this undercarriage, as well as the entire ramming unit 45, may be hoisted from the lined ladle by causing the hoisting lugs 528 to be engaged by the lift hooks of an overhead crane or other hoisting mechanism.  
  After a given ladle has been rammed for lining purposes and the annulus 32 which exists between the side walls of the ladle and the liner pattern 34 is filled with densely rammed wads of prepared refractory lining material, the bond between the hardened lining material in the annulus and the outer surface of the side wall or shell 36 of the pattern 34 must be broken before the pattern can be hoisted from the lined ladle. To accomplsh this, a workman who has descended the ladder 860 (see FIGS. 5 and 6) and a workman who has descended the ladder 864 will simultaneously manipulate the tumbuckle-type expansion and contraction jacks 824 in such a manner as to swing the associated gate members 820 inwardly to their open positions as shown in FIG. 17a. Immediately thereafter, these workmen will manipulate the pattern wall spreader jacks 830 in such a manner as to draw the clamshell-like wall parts 804 and 805, and 806 and 807 toward each other land, thus, effect contraction of the entire liner pattern 34 as a unit. During this contraction of the pattern, and as shown in FIG. 3a, the adjacent end regions of the two rails 884 and 886 will assume the overlapped condition in which they are illustrated in this view. With the pattern thus contracted or collapsed, the pattern may then be hoisted from the ladle, utilizing the upper group of apertured hoisting lugs 851 as anchor points for the lifting hooks of an overhead crane or the like.  
  Still mill ladles of the type under consideration vary in their dimensions both as regards the shape of their rims and the shape of their bottom walls. Some ladles have slightly elliptical rims, which is to say that the rims thereof are possessed of major and minor axes which differ by as much as twenty-four inches, depending upon the size and capacity of a particular ladle. Most ladles also have circular bottom walls although a few have elliptical bottom walls. Nearly all ladles have side walls which slant inwardly and downwardly in order to accommodate a transition from the shape of their rims to the shape of their bottom walls. Therefore, strictly speaking, a given ladle cannot be said to be truly frustoconical. Where a given ladle is provided with a truly circular rim, there is a question as to whether in seeking a generic definition, the term elliptical would be applicable to such a rim even though a circle is a special form of ellipse which occurs when the two aces of the ellipse attain equality. Therefore, in order to make it clear that the present invention is intended to cover the lining of all manner of steel mill ladles, whether their rims and bottom walls are elliptical or circular and whether their side walls are truly frusto-conical or deviate slightly from a cone frustum or are cylindrical, it will be understood that the term elliptical is intended to cover a circular shape; that the term frustoconical is intended to cover a structure which gives the general appearance of a cone frustum but which, in reality, deviates therefrom at various levels and in which its slant height may vary at different circumferential surface regions; and that minor departures in shape as, for example, an outstruck pouring lip on the rim of a ladle, shall not nullify a term which is used to designate an over-all contour in the absence of such departure.  
  The invention is not to be limited to the exact arrangement of parts shown in the accompanying drawings or described in this specification as various changes in the details of construction may be resorted to without departing from the spirit or scope of the invention. For example, although the present ladle and pattern have been shown as being pit-mounted, it is obvious that, if desired, they may be operatively installed on a ladle carriage which travels on rails and is capable of being lined in situ when brought ot the vicinity of a ramming unit such as the unit 45 at a ramming station. Therefore, only insofar as the invention is particularly pointed out in the accompanying claims is the same to be limited.  
  Having thus described the invention what we claim as new and desire to secure by Letters Patent is:  
  l. A ladle-lining installation comprising a relatively deep ladle having a generally circular bottom wall and an upstanding, upwardly and outwardly sloping side wall terminating in an elliptical upper rim, and an expansible and contractible shell-like, generally frustoconical, separable, two-section pattern positioned with its small end region facing downwards, centered within said ladle, and having an outer composite shell which, when fully expanded, is conformable in shape to that of the ladle side wall and, in combination with such side wall, defines an annulus which is adapted to be rammed with refractory lining material and which, when so rammed, produces a lining for said ladle side wall, said pattern embodying an upper frusto-conical pattern section and a similar lower frusto-conical pattern section, each pattern section being comprised of two semi frusto-conical wall parts hingedly connected together in clamshell fashion along a substantially vertical hinge line, and in addition a relatively narrow gate flap, said wall parts being approximately equal in arcuate extent and having linearly straight substantially vertical distal side edges which, when the pattern is fully expanded, assume slightly spaced apart substantially parallel positions, said gate flap being of full section height and being interposed between said distal side edges of the wall parts, thus completing the frusto-conical configuration of the pattern section, said gate flap having one of its side edge regions hingedly connected to the distal side edge of one of said wall parts and having its other side edge region disposed in coextensive sealing engagement with the distal side edge of the other wall part, thus closing the gap between the distal side edges of the two wall parts, a first spreader-type jack effectively connected at its opposite ends to said one side edge region of said gate flap and to a medial region of the one wall part and effective when contracted to swing the gate flap inwardly of the pattern section, and a second spreader-type jack effectively connected at its opposite ends to the distal end regions of said wall parts and effective when contracted to draw said spaced apart distal side edges of the wall parts toward each other after said gate flap is swung inwardly to thus decrease the over-all dimension of the pattern section by a slight distance, the hinge line for the two pattern sections being vertically aligned, the lower small end region of the upper pattern section being of the same size and configuration as the upper large end region of the lower pattern section and mating with the latter, a circular base plate extending across the lower small end region of &#39;the upper pattern section, said base plate being divided along a substantially diametric line into two coplanar sections which move bodily with the respective wall parts of said upper pattern section, a circular deck plate extending across the upper large end region of the lower pattern section, said plate being divided along a substantially diametric line into two coplanar sections which move bodily with the respective wall parts of such lower pattern section, and means releasably securing said deck and base plates together to maintain the upper pattern section seated on the lower pattern section, said deck and base plates being formed with registering central openings therethrough for access bodily to the interior of the pattern.  
  2. A ladle-lining installation comprising a relatively deep ladle having a generally circular bottom wall and an upstanding, upwardly and outwardly sloping side wall terminating in an elliptical upper rim, and an expensible and contractible shell-like, generally frustoconical, separable, two section pattern positioned with its small end region facing downwards, centered within said ladle, and embodying an outer composite shell which, when fully expanded, is conformable in shape to that of the ladle side wall and, in combination with such side wall, defines an annulus which is adapted to be rammed with refractory lining material and which, when so rammed, produces a lining for said ladle side wall, said pattern being comprised of an upper pattern section and a similar lower pattern section, each pattern section being comprised of two generally semi frusto-conical wall parts hingedly connected together in clamshell fashion along a substantially vertical hinge line, and, in addition, a relatively narrow gate flap of substantially the same height as the wall parts, interposed between the dital side edges of said wall parts, having one of its side edge regions hingedly connected to the digital side edge of one of said wall parts and having its other side edge region disposed in coextensive sealing engagement with the distal side edge of the other wall part in order to close the gap between the distal edges of the two wall parts when the pattern section is in its expanded position, a spreader jack assembly extending internally acros each pattern section in secant fashion and connected at its ends to the wall parts respectively, a divided base plate extending across the lower small end region of said upper pattern section, a divided deck plate extending across the upper large end region of said lower pattern section, means for releasably securing said base plate to the deck plate, and at least three circumferentially spaced levelling jacks fixedly mounted on the lowr rim region of the outer composite shell of the pattern and designed for engagement with the bottom of the ladle, the hinge line for the two pattern parts being vertically aligned.  
  3. A ladle-lining installation as set forth in claim 2 and wherein said levelling jacks are of the hydraulic type and include cylinders fixedly mounted on the lower end region of the wall parts of the lower pattern section, and plungers extensible from the cylinders and engageable with the bottom wall of the ladle.  
  4. A ladle-lining installation as set forth in claim 2 including, additionally, a generally semicylindrical apron section slidable vertically on the lower edge region of each wall part of the lower pattern section, the apron sections constituting, in effect, downward extensions of the wall parts on which they are slidable for preventing inward flow of rammed refractory lining material beneath the pattern during the annulus ramming operation.  
  S. A ladle-lining installation as set forth in claim 4 and including, additionally, interengaging centering means on the lower end region of said pattern and said bottom wall of the ladle for aligning said lower end and bottom wall in coaxial relationship.  
  6. A ladle-lining installation as set forth in claim 5 and wherein said interengaging centering means comprises a spider-like frame structure positioned on the bottom wall of the ladle and including a hub from tive length thereof.