US3442322A

US3442322A - Flexible dummy bar for continuous casting machines

Info

Publication number: US3442322A
Application number: US578313A
Authority: US
Inventors: Herbert Lemper
Original assignee: Mesta Machine Co
Current assignee: MESTA ENGINEERING COMPANY APARTNERSHIP OF PA
Priority date: 1966-09-09
Filing date: 1966-09-09
Publication date: 1969-05-06
Anticipated expiration: 1986-05-06

Description

H. LEMPER 3,442,322

FLEXIBLE DUMMY BAR FOR CONTINUOUS CASTING MACHINES May 6, 1969 Filed Sept. 9, 1966 Q w WM MN United States Patent U.S. Cl. 164-274 8 Claims ABSTRACT OF THE DISCLOSURE I disclose a flexible dummy bar for continuous casting machines, said dummy bar comprising an elongated flexible band member, a plurality of gauge blocks loosely mounted on said band member, said gauge blocks each being of a thickness equal to that of a continuous body to be cast, said gauge blocks being disposed in a tandem array along the length of said band member and being relatively closely spaced with clearances such as to permit flexure of said band member when said dummy bar is passed through said casting machine, at least some of said gauge blocks being shaped so as to straddle portions of said gauge blocks in a direction longitudinal of said band in order to present a substantially and continuously smooth surface to said casting machine.

The present invention relates to starting bars for continuous casting machines and more particularly to a flexible starting bar which can be utilized with equal facility in starting the strands or continuous bodies to be cast in continuous casting machines wherein the strands are bent through arcuate paths from vertical positions to horizontal positions, and in continuous casting machines wherein the strands being cast are not bent at all.

The advantages of utilizing flexible starting or dummy bars rather than solid bars of soft metal to start the strands of continuous casting machines, have long been appreciated in the continuous casting art. Flexible starting bars have been proposed heretofore for continuous casting machines, for example, the chain type and/ or the segmented type. Known flexible starting bars have, however, been heavy complex units that are very expensive to manufacture and to maintain. Additionally, their weight alone has made them extremely cumbersome and diflicult to handle. Prior flexible starting bars have utilized a relatively large number of component parts which not only add to their Weight but greatly increase the likelihood of expensive breakdowns during use resulting in wasted strands and loss of production time.

I overcome these difliculties of the prior art by providing a novel, flexible dummy bar that is much lighter, simplier and less expensive to manufacture, simplier to repair, and easier to handle than flexible starting bars heretofore known. Moreover, the flexible dummy bar of the present invention is fabricated from relatively few component parts and is arranged for quickly attaching and detaching the dummy bar relative to the ends of the continuous strands.

I provide a flexible dummy bar comprising an elongated flexible band member having a plurality of gauge block elements loosely mounted thereon such that the proponderant proportion of at least one side of the flexible band is covered by the gauge blocks, said gauge blocks desirably being shaped to cover substantially the entire surface of both sides of the flexible band while permitting the bar to flex about a given radius in the case of vertical casting machines, said gauge blocks being relatively closely spaced from one another and arranged on the flexible band such that a constant thickness of the length 3,442,322 Patented May 6, 1969 of the dummy bar is presented to pinch rolls disposed thereacross along the path thereof when passing through said continuous casting machine. In other arrangements the dummy bar is provided with head means for engaging .the molten material strand as it is initially formed in the mold structure of the continuous casting machine, and with tail piece means for engagement by suitable traction or. withdrawal apparatus for drawing the dummy bar through said pinch rolls.

In still other arrangements of the invention I provide detachable dummy bar head means which are secured to the metal strand by embedding within the molten material thereof and held therein when the material solidifies. The gauge blocks of the dummy bar can be closely spaced so that the clearances therebetween are largely eliminated when the dummy bar is bent around its intended radius of curvature, in vertical casting machines. Desirably, I provide a flexible dummy bar which can be substantially square in cross sectional configuration so that the dummy bar can be used for both billet and slab sized strands. It will be understood, of course, that a rec tangular cross sectional configuration can be imparted to the flexible dummy bar pursuant to the teachings of the present invention. The latter arrangement is desirable for use with continuous casting machines which are used only to cast slabs of the same width. Then, desirably, the flexible dummy bar is of the same cross sectional configuration as that of the slabs.

Preferably each of the gauge blocks comprises a pair of similarly shaped elements rigidly fastened to a spacer member, with the spacer being thicker than the flexible band member and loosely mounted in an opening therein so that the gauge blocks are loosely mounted on the flexible band member to obviate interference with the flexure thereof.

I also desirably provide gauge blocks of differing contours and arranged such that the gauge blocks of one con tour alternate with those of another contour to provide a longitudinally overlapping and closely spaced array of gauge blocks along the length of the flexible bar. In one arrangement of this latter feature of the invention the gauge blocks are arranged in tandem array along the length of the flexible bar. Desirably, also, the aforementioned head and tail means are of similar cross sectional configuration relative to the gauge blocks, so that they are, in effect, continuations of the flexible portion of the dummy bar.

During the foregoing description various objects, features and advantages of the invention have been alluded to. These and other objects, features and advantages of the invention 'will be elaborated upon during the following description of presently preferred embodiments of the invention together with presently preferred methods of practicing the same.

In the accompanying drawings, I have shown certain presently preferred embodiments of the invention and have illustrated certain presently preferred methods of practicing the same wherein:

FIGURE 1 is a side elevational view of the flexible dummy bar of the invention as used in a vertical continuous casting machine;

FIGURE 2 is an enlarged top plan view of the flexible dummy bar shown in FIGURE 1 but shown here in its unflexed condition;

FIGURE 3 is a side elevational view of the flexible dummy bar as shown in FIGURE 2; and

FIGURE 4 is a cross sectional view of the flexible dummy bar as shown in FIGURE 3 and taken along reference line IVIV thereof.

Referring now more particularly to the drawings and initially to FIGURE 1, flexible dummy bar 10 is illustrated in connection with a vertical continuous casting machine exemplified schematically by mold structure 12 and 'withdrawal apparatus of which the guide and pinch rolls 14 and 16 form a part. As better shown in FIGURES 2 and 3 of the drawings, the flexible dummy bar includes a flexible band 18 having a plurality of openings 20 therein which in this example are equally and tandemly spaced along the length of the band 18. Preferably, the flexible dummy bar 10 which includes head connector 22 and tail connector 24 is as long as the distance of the path of travel of the strand to be cast from the mold 12.to the cut-off station (not shown) of the continuous casting machine, but is at least as long as the distance from the mold structure 12 to the first pair of pinch rolls 16 of the aforementioned withdrawal equipment.

A

gauge block

26 or 28 is mounted on the flexible band 18 of each of its openings 20, with the result that the

blocks

26, 28 are aranged in a tandem array. Desirably the gauge blocks 26 and 28 each extend substantially across the width of the band 18, and are of H and round configurations, respectively. The gauge blocks 26, 28 are alternated along the length of the flexible bar 18 so as to provide an interfitting or overlapping array of the gauge blocks. That is to say, the longitudinally extending arms 30 of the gauge blocks 26 overlap the adjacent extremities 32 of the gauge blocks 28 in a direction longitudinal of the flexible band 18. This overlapping arrangement prevents the ends or extremities of the individual gauge blocks from being damaged by the pinch rolls 16 as the dummy bar is drawn therethrough. Other configurations of one or both groups of

blocks

26, 28 can obviously be utilized, within the teachings of the present invention.

With reference now to FIGURES 2 and 4 of the drawings, it will be seen that each of the gauge blocks is formed from a complementary pair of

gauge block elements

26a, 26b or 28a, 28b. Each such pair of gauge block elements are secured rigidly to opposite sides of an annular spacer 34, which desirably is thicker than the flexible band 18.'The outer diameter moreover of the annular spacer 34 is less than the diameter of the band openings 20 so that the

complementary elements

26a, 26b and 28a, 28b are spaced from the adjacent surfaces of the band 18 in order to provide the necessary clearances for flexure of the band 18. Each of the gauge block elements is provided with a central aperture alignable with the central aperture of its associated spacer 34, and the component parts of each gauge block are rigidly secured by means of a rivet 36.

When thus assembled on the flexible band 18 the gauge blocks 26 and 28 are each loosely and pivotally mounted thereon. However, the pivotal movement of the gauge blocks 26 is limited by clearances 38 between the outer end portions of the arms 30 and the adjacent outer periphery of the gauge blocks 28. The lateral surfaces 40 of the arms 30 as viewed in FIGURE 2 of the drawings are inclined inwardly to an extent sufficient to prevent the arms 30 from overhanging the lateral edges of the band 18 when the gauge blocks 26 are thus pivoted. This pivotal movement of the gauge block 26 is desirable to ensure that the clearances 38 are equal when required, to permit proper flexing of the metal band 18.

At its ends, the flexible band 18 terminates in laterally extending bearing members 42 which are loosely fitted into complementary recesses 44 respectively formed in the tail connector 24 and in link member 46 forming part of the head connector 22. The relatively loose fitting ofjoint 50 so that the remainder of the dummy bar '10 can be quickly removed from the strand and after the latter passes through the pinch rolls 16 and other portions of the withdrawal equipment. In this arrangement the quick-detach joint includes a transverse cylindrical bore 52 formed transversely through the longitudinally extending arms 54 of the link member 46 and a retaining pin 56 secured thereto and having an intermediate flattened portion 58. By moving the detachable head piece 48 of the head connector 22 to a position substantially at right angles to that shown in FIGURE 3 of the drawings the headpiece 48 can be removed from the link member 46 by passing the flattened portions 58 of the pin 56 through a complementary restricted access opening portion 60 of head piece 48. In furtherance of this purpose the inward end-ofthe head piece 48 is rounded as denoted by reference character 62 and the intermediate shouldered portions of the head piece portion are rounded in concave fashion at 64 to permit the aforementioned angular disposition of the head piece 48.

Desirably, the head connector 22 is provided with suitable keying means such as bolt 66 which is threaded into a longitudinally tapped aperture of the head piece 48 in order to ensure retention of the head piece 48 in the adjacent end' of the strand when the latter solidifies. A threaded shaft 68 or the like shown in fragmentary form in FIGURE 3 and forming part of the aforementioned withdrawal equipment,- can be similarly secured to the tail connector 24.

The adjacent or inward end portions of the tail connec: tor 24 and of thelink member 46 are rounded at 70 and 72 respectively for interfitting association with the endmost gauge blocks 26a and 2617 respectively.

Although the flexible dummy bar 10 has been illustrated as square in cross sectional 'configuration, it will be understood-that the" gauge blocks 28 can be formed with elements of larger diameter andthat the elements of the gauge block 26 can be formed with correspondingly larger plan areas in order to impart a rectangular configuration to the flexible dummy bar 10. At the same time the width of'the flexible band 18 can be increased to the extent that the diameter of the gauge block 28 is increased. It will'als o be understood that the thickness of the gauge blocks 26 and 28 can be made correspondingly greater'or lesser to conform the flexible dummy bar 10 to a given thickness of the cast strand with which it is associated; Thus, the gauge blocks 26, 28 are of the same thickness as the strands to be cast, and preferably the widths of the flexible band 18 and of the gauge blocks 26;"28 are'the same as that "of the strands so that the strands are started throughthe casting machine in perfecfaligninent. It should be noted that although the gauge blocks 26,28 are loosely'mount'ed on the flexible band'18, they continuously present a smooth surface of i constant thickness to the pinch rolls 16.

' From the foregoing it will be apparent that novel and eflicient forms of flexible dummy bars have been disclosed herein. The flexible dummy bar of the invention is lighter-and morexsimply constructed than known types and therefore is easier to'manipulate and lessexpensive to fabricate and maintain. Atthe sametime, having relatively few component parts, git'is of a rugged structural design.,Wh;ile Lhave-shoWn certain presently preferred embodiments of theinventionandhave described certain of a thickness equal tothat ofv a continuous body'to be castfseiid"gaugeblocks being disposed. in a tandem array along the length of saidband member and being relatively closely spaced with clearances such as to permit flexure of said band member when said dummy bar is pressed through said casting machine, some of said gauge blocks being shaped so as to straddle portions of adjacent gauge blocks in a direction longitudinal of said band in order to present a substantially and continuously smooth surface to said casting machine.

2. The combination according to claim 1 wherein said some gauge blocks are pivotally mounted on said band member so that uniform clearances between said gauge blocks are maintained during fiexure of said band membet.

3. The combination according to claim 1 wherein said some gauge blocks and the remainder of said gauge blocks are disposed in an alternating array along the length of said band member.

4. A flexible dummy bar for continuous casting machines, said dummy bar comprising an elongated flexible band member, a plurality of gauge blocks loosely mounted on said band member, said gauge blocks each being of a thickness equal to that of a continuous body to be cast, said gauge blocks being disposed in a tandem array along the length of said band member and being relatively closely spaced with clearances such as to permit flexure of said band member when said dummy bar is passed through said casting machine, some of said gauge blocks being shaped so as to overlap portions of adjacent gauge blocks in a direction longitudinal of said band in order to present a substatially and a continuously smooth surface to said casting machine, said some gauge blocks and the remainder of said gauge blocks being disposed in an alternating array along the length of said band member, said remaining gauge blocks being of generally circular configuration having a diameter substantially equal to the width of the band member, and said some gauge blocks having longitudinally'extending arm portions disposed to protrude longitudinally beyond the nearest portions of said remaining gauge blocks.

5. The combination according to claim 4 wherein said some gauge blocks are pivotally mounted on said band member for limited pivotal movement defined by clear ances between said arm portions and the periphery of adjacent ones of said remaining gauge blocks.

6. The combination according to claim 5 wherein said some gauge blocks have a width substantially equal to that of said band member and the outer surfaces of said arm portions are tapered inwardly to obviate their overhanging the adjacent lateral edges of said band member during said limited pivotal movement.

7. The combination according to claim 1 wherein the ends of said band members are loosely secured in head and tail connector respectively, and the inward ends of said head and tail connectors are shaped for overlapping disposition relative to the adjacent endmost ones respec' tively of said gauge blocks.

8. The combination according to claim 1 wherein the ends of said band member are secured in head and tail connectors respectively, the transverse sectional config uration of said head and tail connectors beng substantially similar to adjacent ones of said gauge block's.

References Cited UNITED STATES PATENTS 2,920,359 1/ 1960 Easton et al 164269 3,262,162 7/1966 Lemper 164274 3,324,934 6/1967 Hess et a1 164-274 3,351,125 11/1967 Colombo 164 -274 FOREIGN PATENTS 1,421,502 11/ 1965 France.

J. SPENCER OVERHOLSER, Primary Examiner. R. S. ANNEAR, Assistant Examiner.

US. DEPARTMENT OF COMMERCE PATENT OFFICE Washington, D.C. 20231 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,442,322 May 6, 1969 Herbert Lemper It is certified that error appears in the above identified patent and that said Letters Patent are hereby corrected as shown below:

Column 1, line 24 "said", first occurrence, should read adjacent line 64, "proponderant should read preponderant Column 3 line 18, aranged" should read arranged Column 5, line 2, "pressed" should read passed line 27, "substatially should read substantially Columr 6, line 14, "connector should read connectors line 21, "beng" should read being Signed and sealed this 14th day of April 1970.

(SEAL) Attest:

WILLIAM E. SCHUYLER, JR.

Commissioner of Patents Edward M. Fletcher, J r.

Attesting Officer