US3520351A - Starting bar arrangement for continuous casting machine - Google Patents

Description

K. L. RANKIN July 14, 1970 STARTING BAR ARRANGEMENT FOR CONTINUOUS CASTINGMACHINE Filed Feb. 8, 1968 INVENTOR.

KENNETH L. RANK/N BY JLWMM bpdww United States Patent O STARTING BAR ARRANGEMENT FOR CONTINUOUS CASTING MACHINE Kenneth L. Rankin, Pittsburgh, Pa., assignor to Koppers Company, Inc., a corporation of Delaware Filed Feb. 8, 1968, Ser. No. 704,126 Int. Cl. B2211 11/08 US. Cl. 164--274 7 Claims ABSTRACT OF THE DISCLOSURE Apparatus for handling a straight rigid starting bar used with vertical continuous casting machines comprises a set of powered pinch rolls that engage only the starting bar and move it out of a non-magnetic storage caisson and into engagement with strand engaging pinch rolls that move the starting bar in an upward direction to close the bottom of a casting mold. When disconnected from the cast strand the first set of pinch rolls return the starting bar to storage.

A starting bar disengaging arm is rotatably mounted to a flange on the storage caisson and is movable to turn the starting bar to disengage it from the cast strand.

BACKGROUND OF THE INVENTION Continuous metal casting machines of both the vertical cut-off and the horizontal cut-off type utilize some type of dummy or starting bar to initially close the discharge end of the casting mold, and to act as a tool to connect to and withdraw the cast srand from the mold. Usually, the starting bar is a straight, solid, rectangular bar that is provided with an expendable head that connects to the continuous cast strand, when it is initially formed, by means of a quick disconnect device so that the starting bar can be readily and quickly released from the expendable head at a proper moment.

Heretofore, it has been customary to store the starting bar in an open pit of substantial size, set usually below ground level, from which the starting bar is elevated to a position where it closes the bottom of the mold. Within the pit, there is usually an elevating mechanism including a starting bar basket that engages the lower end of the starting bar, and that raises and lowers the starting bar.

Such an arrangement of apparatus to handle a starting bar is a costly facility. Besides the considerable initial investment, it is necessary to provide periodic maintenance to remove slag, tools, water, and other debris that generally accumulates in such an open storage pit.

In contrast to the customary arrangement for handling a starting bar, the present invention greatly simplifies the starting bar handling arrangements that are avallable 1n the prior art, thereby reducing the initial cap1tal investment and also the cost of maintaining the starting bar handling mechanism.

SUMMARY OF THE INVENTION In accordance with the invention, apparatus for handling a starting bar used with casting machines to produce continuous cast strands of metal includes a non-magnetic tubular member axially arranged in a position beneath the mold in which the starting bar is stored when it is not operatively in use. A closure is provided for the tubular member, having an aperture through which the bar freely moves, and an arm surrounding the bar is supported on the closure and is engageable with the bar to disconnect it from the strand at a proper moment. A set of powered pinch rolls, mounted adjacent the closure, engage the only bar to raise and lower it from the starting bar storage tubular member.

For a further understanding of the invention and for 3,520,351 Patented July 14, 1970 features and advantages thereof reference may be made to the drawing which shows for the purpose of exemplification a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWING In the drawing:

FIG. 1 is a schematic elevational view, partly in section, of apparatus in accordance with the invention for handling a starting bar; and

FIG. 2 is a view along line IIII of FIG. 1.

DETAILED DESCRIPTION Referring to FIG. 1, apparatus 11 for handling a starting bar in accordance with the invention is located beneath a conventional type of continuous casting machine wherein molten metal 13 flows from a tundish 15 into a vertical casting mold 17 that is cooled in the usual manner by flowing cooling water into the mold through conduit 19 and out of the mold through conduit 21. The mold 17 is supported in the usual manner upon supporting structure 23 which may be reciprocated vertically in a known manner.

Beneath the mold support structure 23, there is a conventional spray chamber 25, a first set of powered pinch rolls 27, and, just below the first set of pinch rolls, there is a conventional strand-bender mechanism. The strandbender mechanism comprises a fixedly mounted roller 29, which acts as a fulcrum, and a movable roller 31 journaled to an arm 33 that is pivotally connected to a cylinder-piston arrangement 35 by means of which the arm 33 pivots to bring the roller 31 into engagement with the strand, and bends the strand toward the horizontal position.

Below the bender roll arrangement and toward the left, as shown in FIG. 1, there are two spaced apart conventional cast strand chutes or guides 37, 39.

FIG. 1 shows a conventional straight rigid starting bar 41 in the raised operative position, with its upper end inserted into the lower end of the mold 17. The lower end portion of the starting bar 41 is engaged by a second set of powered pinch rolls 43 that are suitably fixedly mounted to a pivotable arm 49 that surrounds the bar 41. The second set of pinch rolls 43 engage only the starting bar 41 and advance it upwardly axially into the mold. Also, they control the withdrawal and the descent of the starting bar after it is disengaged from a cast strand; such a strand 45 is shown in the drawing as being directed by the bender rolls 29, 31 toward a horizontal attitude.

The strand turning arm 49 (FIG. 2) is provided with an opening 51 having a size and shape that is about the same size and shape as the starting bar 41 which freely passes therethrough. The strand turning arm 49 (FIG. 1) is fitted with depending legs 53, 55 that engage and move in slots 57, 59, preferably arcuately shaped, in a twopiece closure 61 for a starting bar storage caisson 63. The strand turning arm 49 is also connected pivotally to a fluid actuated cylinder-piston arrangement 65 that is suitably pivotally mounted as at 66 to structure 68 for moving the arm 49 through a horizontal are in the usual manner, thereby turning the starting bar equally to disconnect it from the strand 45.

The two-piece closure 61 comprises an outer annular member 67 that is bolted, as at 69, to a flange 71 fixed to the caisson 63, and that is provided with a groove 73 that accommodates the peripheral portion of a second inner member 75 of the two-piece closure 61. The second inner member 75 also has an aperture 77 in it of substantially the same size and shape as the starting bar 41 which passes freely through the aperture 77.

The caisson 63 is a cylindrical tubular member made preferably of non-magnetic material, that is set in the 3 ground 79 and that may be encased in concrete 81 to insure fixity. The caisson 63 is provided with a siphon tube 79, or similar tube may be connected to a conventional pump apparatus (not shown) to extract liquid from the bottom of the caisson 63. Adjacent the top of the caisson, there may be, if desired, an electrical limit switch that may be connected to a timer mechanism and that may be actuated by the starting bar 41 so that the pinch rolls 43 will stop when the lower end of the starting bar 41 has reached a selected lower level.

In operation the second set of pinch rolls 43 are actuated to raise the starting bar 41 from its initial lowered and stored position (suggested by the dotted outline in the drawing), and advance the starting bar upward along the axis of the mold. The starting bar passes through the first set of powered pinch rolls 27, the spray chamber 25 and into the mold 17 in a conventional manner.

After the starting bar has been sealed in the mold, and after the casting has solidified sufliciently to be withdrawn from the mold, the first set of pinch rolls 27 are actuated to withdraw, or lower, the starting bar and the casting from the mold. After the casting has passed through the first set of pinch rolls, and after the head of the starting bar has descended past the bender roll arrangement, the strand-starting bar disconnect arm 49 is pivoted to rotate the starting bar through an angle to disconnect the starting bar from the casting in the usual manner.

Then, under the influence of the second set of pinch rolls 43 the starting bar 41 descends into the caisson 63 to its stored position, and if a limit switch is used, the pinch rolls stop when the lower end of the starting bar reaches a preselected lower level.

The cast strand 45, in the usual manner, is urged by the bender roll arrangement toward the guide chutes 37, 39 and toward a horizontal attitude.

Between the strand engaging and disconnect apparatus 49, and between the two-piece closure 61, there are a plurality of nozzles 89 that direct jets of air, or other suitable fluid, onto the surface of the starting bar to remove slag and other surface encrustation.

The faying surfaces between the first 67 and second 75 members, and between the second 75 member and the flange 71, are suitably lubricated in a known manner to facilitate rotary movement of the second member 75 when the starting bar is rotated to disconnect it from the cast strand.

The caisson is made of non-magnetic material, such as stainless steel, so that magnetic debris, such as slag, tools and the like may be readily and easily removed from the bottom of the caisson by means of an electric magnet. Also, such an electric magnet may be used to remove a portion of the starting bar itself should a piece break off and fall down into the caisson. Similarly, other magnetic scrap material can also be easily removed from the caisson by means of such a magnet. Water and other fluids, of course, would be removed through the use of the siphon tube, or the pump suction arrangement mentioned hereinbefore.

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 the scope of the invention is defined by what is hereinafter claimed.

What is claimed is:

1. In a vertical continuous metal casting apparatus for producing continuous cast strands of metal, improved apparatus for handling a starting bar comprising:

(a) a non-magnetic tubular member situated below and axially aligned with the mold portion of said casting mechanism;

(b) a closure on said tubular member having an opening therein through which said starting bar freely moves out of said non-magnetic tubular member upwardly toward said mold;

(c) means rotatably mounted to said closure for engaging and twisting said starting bar to disconnect the same from said cast strand; and

(d) means situated adjacent said non-magnetic tubular member and said closure engaging said starting bar for raising said starting bar from said tubular member and advancing said bar toward said mold, and for lowering said starting bar into said tubular member.

2. The invention of claim 1 wherein:

(a) the means for twisting said starting bar comprises and arm engageable with said starting bar and a cylinder-piston arrangement that is connected to said arm and that is actuatable to move said arm about the axis of said bar.

3. The invention of claim 1 wherein:

(a) said means to raise and lower said starting bar is a set of powered pinch rolls.

4. The invention of claim 1 wherein:

(a) said closure is comprised of two members, one of which is stationary with respect to said tubular member and the other of which is movable with said starting bar when said starting bar is rotated by said twisting means.

5. The invention of claim 2 including:

(a) means to remove surface adhering material from said starting bar before it passes through said closure into said non-magnetic tubular member; and

(b) means for removing fluid from said tubular member.

6. In a vertical continuous metal castingapparatus for producing continuous cast strands of metal, improved apparatus for handling a starting bar comprising:

(a) a non-magnetic tubular member situated below and axially aligned with the mold portion of said casting mechanism;

(b) a closure for said tubular member including a first annular member fixed to said closure and a second annular member surrounding said starting bar and rotatably supported and guided by said tubular member and by said first annular member;

(c) an arm engageable with said starting bar for twisting the same to disengage said bar from said cast strand;

(d) a cylinder-piston arrangement connected to said arm and actuatable to move said arm about the axis of said bar to disconnect said bar from said cast strand; and

(e) a set of pinch rolls mounted to said arm engaging said starting bar to elevate the same from said tubular member upwardly toward said mold and to retract and control the descent of said bar into said tubular member after it has been disengaged from said cast strand; and

(f) nozzle means located adjacent said closure for directing jets of fluid against said strand to remove surface encrustations therefrom.

7. The invention set forth in claim 6 including:

(a) means to remove fluid from said tubular member.

References Cited FOREIGN PATENTS 12/ 1952 Austria.

7/ 1962 Great Britain.

I. SPENCER OVERHOLSER, Primary Examiner R. S. ANNEAR, Assistant Examiner US. Cl. XR

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