US3670804A - Trap door to prevent water from descending into starter bar pit - Google Patents

Abstract

An apparatus for deflecting the flow of water into the casting path of a continuous-casting machine. A trap door is hingedly fixed above a starter bar exit hole in a casting guide mechanism. The trap door is pivoted out of the path of the starter bar to permit the bar access to the bar receiver and is pivoted into position over the access hole to deflect cooling water down the casting guide. The trap door may be made of a marginal frame covered by a thin sheet of readily penetrable material.

Description

United States Patent Hofmann et al.

[54] TRAP DOOR To PREVENT WATER FROM DESCENDING INTO STARTER BAR PIT [72] Inventors: Gottfried Holmann, Brentwood, Allegheny County; James T. Stull, Jackson Township, Butler County, both of Pa.

[73] Assignee: United States Steel Corporation [22] Filed: Sept. 10, 1970 [2]] Appl. No.: 70,973

[521 [1.5. CI. ..l64/274, 164/282 [51] Int. Cl ..B22d 11/08 [58] Field of Search 164/82, 274, 282, 283

[56] References Cited UNITED STATES PATENTS 3,338,297 8/1967 Foldessy 164/274 [1;] 3,670,804 [451 June 20, 1972 3,520,351 7/1970 Rankin ..l64/82 X FOREIGN PATENTS OR APPLICATIONS 982,981 2/ 1965 Great Britain ..164/282 Primary Examiner-R. Spencer Annear Attorney-Ralph H. Dougherty ABSTRACT marginal frame covered by a thin sheet of readily penetrable material.

5 Claim, 3 Drawing Figures TRAP DOOR TO PREVENT WATER FROM DESCENDING INTO STARTER BAR PIT This invention relates to the continuous casting of metals and more particularly, to a novel means for preventing water from descending into a starter bar receiver.

It is customary in the continuous casting of metals to provide an apparatus comprising a vertical tubular mold open at the upper end for receiving molten metal and open at the lower end for the discharge of a metal casting, water sprays located below the mold for directing cooling water against the casting as it descends, guide rolls between the bottom of the mold and the bending means, bending means comprising a plurality of bending rolls for bending the continuously-formed casting into a curved path, a curved-casting guide containing additional guide rolls located beneath the bending rolls, and straightening rolls located at the point at which the curved casting is tangent to the horizontal.

When molten metal is initially poured into the mold, the lower end of the mold is closed by the insertion of a starter bar into the bottom of the mold. If the starter bar is of the rigid type, provision must be made for disconnecting the starter bar from the, casting and moving it from the path of the casting as, or before, the casting commences to bend. One such apparatus is shown in Foldessy US; Pat. No. 3,447,591. In such apparatus a portion of the casting guide is removed to allow the starter bar to pass. Where the bending rolls are spaced from the additional guide rolls in the casting guide, an entry chute is utilized, which chute has a hole to admit passage of a starter bar. The lower end of the starter bar, after passing through such hole, is brought straight downwardly by a suitable means, such as a traveling receptacle. When the tension between the starter bar and the casting is relieved as the leadingedge of the starter bar contacts the receptacle, disconnection of the bar from the casting commences. Starter bar disconnect mechanisms are well known in the art and therefore are neither shown in the drawings nor described herein. After the starter bar parts from the casting, its rate of descent is increased and the bending rolls are actuated to initiate bending of the casting. While the casting is moving through the guide'roll rack, it is desirable to deliver a great flow of cooling water on the casting to maintain a high rate of solidification of the castings liquid core. l-leretofore large quantities of cooling water have accompanied the starter bar into the receiver wherein it is stored.

It is the primary object of the present invention to provide means for diverting as much cooling water as possible from the starter bar receiver to the chute and the curved-casting guide.

It is also an object of the invention to provide means for preventing damage to the continuous-casting equipment when the starter bar path is inadvertently blocked.

7 We have found that by placing a trap door on the inside ofthe chute, we can provide access to the receiver for the starter bar when desired, yet once the starter bar has completely passed through the opening, the door may be closed and all succeeding cooling water will thereupon be diverted to the path of the casting.

In the drawings:

FIG. 1 is a side elevational view of a portion of a continuous-casting machine.

FIG. 2 is a sectional view taken through the chute along line lI--ll of FIG. .1.

FIG. 3 is a plan view of the trap door.

In the continuous-casting process depicted inFlG. 1, a

only in outline. Chute 20 has an opening 25 therethrough directly in the vertical path of the starter bar. Immediately beneath opening 25 is a starter bar passageway 26 having a traveling receptacle (not shown) therein and terminating in a bar storage pit (not shown).

Referring now to FIG. 2, opening 25 is shown covered by a trap door 30. The door 30 comprises a rectangularly-shaped marginal metal frame 31, the opening in the center of which corresponds approximately to the size of opening 25 in chute 20. A thin sheet of easily penetrable material 33, such as aluminum, light gage steel sheet or even wood, is held in position by retaining ring 34 and cap screws 35. Alternatively, door 30 may be a single thin steel plate. The door has a pair of hinges 37 fixed to frame 31 by some means, such as welding. A hinge support 39 is fixed to the side of chute 20. A hinge pin 40, which is rotatable in support 39 is fixed to hinges 37 by keys 41. A hinge pin lever am 43 is fixed t-o hinge pin 40 by means of drift pin 44. A hydraulic lever arm actuating cylinder 46 is pivotally attached atits upper end to a pin 48 joumaled in stationary housing 49 which is fixed to the chute 20. The piston rod 50 of cylinder 46 terminates in rod eye 51 which is pivotally attached to lever arm 43 by pin 52. g

In operation, the door 30 is normally closed at the beginning of a casting operation. As the leading edge of the starter bar approaches chute 20, door 30 is moved to the open position shown in dotted outline in FIG. 2. Cylinder 46 is actuated to extend piston rod 50, which forces lever arm 43 to rotate clockwise about the axis of hinge pin 40. Pin 44 causes pin 40 to rotate with arm 43,and keys 41 cause hinges 37 likewise to move the pin. 40 opening trap door 30. Starter bar 10 passes through hole 25 in chute 20. As the leading end of the bar contacts a traveling receptacle, whereby it is lowered into the receiver, tension in the connection between the casting and starter bar is relieved. At this time the bending roll 14 is actuated to deflect the casting, disconnecting it from the starter bar. When parting is completed, the rate of descent of the starter bar greatly increases. Considerable distance develops between the leading end of the casting and the top of the starter bar. When the starter bar has completely passed through the hole 25, cylinder 46 is actuated to retract piston 50, which forces lever arm 43 to rotate about the axis 'of hinge pin 40. Pin 44 causes pin-40 to rotate with arm 43, and keys 41 cause hinges 37 to likewise move the'pin 40 closing trap door 30. Cooling water will no longer exit through hole 25 into the starter bar receiver but will now continue to flow down the starter bar 10 is positioned in the bottom of a continuous casting mold (not shown) and extends downwardly toward bending roll assembly 12. Casting is initiated, and starter .bar 10 moves downwardly through the bending roll assembly. A bending roll 14 extends downwardly from the assembly and is attached thereto by pivoted arms 16. Water sprays 17, between the mold and the bending roll assembly, direct cooling water on the starter bar and casting. A chute 20 is located in the vertical path of the casting and is so positioned to assist the entry of casting 22 into curved-casting guide 23, shown a guide.

The trap door that includes an aluminum sheet 33 is preferred. If the door is not open when the leading end of the starterbar reaches it, the bar will rupture the aluminum sheet causing no further damage to the equipment and will pass through hole 25 into the starter bar receiver without causing a shutdown of the casting operation. The aluminum sheet is easily replaceable for the next cast.

' It can readily be seen from the foregoing that we have invented a means for diverting maximum quantity of cooling bending means, a receiver for holding said starter bar, and.

means above said bending means for spraying water on said casting, the improvement comprising a trap door of readily penetrable material between said bending means and said receiver which trap door opens to allow said starter bar to pass into said receiver and closes to prevent water from entering said receiver and which trap door may be penetrated by the starter bar causing no further damage to the equipment should the trap door be closed when the starter bar reaches it.

2. Apparatus as described in claim 1 in which said trap door 4. Apparatus as described in claim 2 in which said penetracomprises a marginal metal frame having a sheet of said readil al E Wood- ]y penetrable material rcmovably affixed theret 5. Apparatus as described in claim 2 in which said penetra- 3. Apparatus as described in claim 2 in which said penetrable material is steel ble material is aluminum. 5 w -oid

Claims (5)

1. In a continuous-casing machine including means for bending a casting from a vertical path to a horizontal path, a vertically movable starter bar which is disconnected from the leading end of the casting as said leading end reaches said bending means, a receiver for holding said starter bar, and means above said bending means for spraying water on said casting, the improvement comprising a trap door of readily penetrable material between said bending means and said receiver which trap door opens to allow said starter bar to pass into said receiver and closes to prevent water from entering said receiver and which trap door may be penetrated by the starter bar causing no further damage to the equipment should the trap door be closed when the starter bar reaches it.

2. Apparatus as described in claim 1 in which said trap door comprises a marginal metal frame having a sheet of said readily penetrable material removably affixed thereto.

3. Apparatus as described in claim 2 in which said penetrable material is aluminum.

4. Apparatus as described in claim 2 in which said penetrable material is wood.

5. Apparatus as described in claim 2 in which said penetrable material is steel.

Images