US3658120A - Retractable dummy bar guide - Google Patents

Abstract

A chute is provided below the exit end of a continuous casting mold to guide the dummy bar into the mold. Moving means are provided to move the chute away from the mold assembly after casting starts so that the chute will not be damaged by breakouts.

Description

United States Patent Precht et al.

[ 1 Apr. 25, 1972 RETRACTABLE DUMMY BAR GUIDE Horst Precht, Jamaica, N.Y.; Herbert Fastert, Wyckotf, NJ.

Concast Incorporated, New York, NY.

Apr. 14, 1970 Related [1.8. Application Data Continuation of Ser. No. 662,420, Aug. 22, 1967, abandoned.

Inventors:

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Field of Search References Cited UNlTED STATES PATENTS 8/1967 Foldessy ..l64/l74 3,446,270 5/1969 Michelson 3 ,448,789 6/1969 Gallucci 3,495,651 2/1970 Rokop et al ..l64/282 X FOREIGN PATENTS OR APPLICATIONS 1,280,393 ll/1961 France ..l64/82 Primary Examiner-R. Spencer Annear A!t0rney-Sandoe, Hopgood & Calimafde [57] ABSTRACT A chute is provided below the exit end ofa continuous casting mold to guide the dummy bar into the mold. Moving means are provided to move the chute away from the mold assembly after casting starts so that the chute will not be damaged by breakouts.

3 Claims, 2 Drawing Figures This is a continuation of U.S. Pat. application No. 662,420 filed Aug. 22, 1967, now abandoned.

This invention relates to the art of continuous casting and, more particularly, relates to an improved apparatus for guidance of the dummy bar into the continuous-casting mold.

In continuous casting plants the molten metal is poured into an open-ended water-cooled mold which chills the metal in contact with the mold walls to form a peripheral skin defining the billet or strand. To initiate the casting operation it is necessary temporarily to seal the bottom of the mold in order to contain the molten metal within the mold. This has been done by insertion of a dummy bar into the exit end of the mold. After the mold is filled with molten metal to the desired level the dummy bar is extracted, pulling from the mold the cast strand. The level of the molten metal in the mold is maintained by pouring molten metal into the mold at the same rate as the metal is solidified and extracted from the mold. The strand issuing from the mold encases a molten core within the defining peripheral walls. This strand is passed through water sprays for further cooling of the strand.

In the continuous casting plants known to the art a plurality of rollers are provided just below the continuous casting mold. These rollers have the function of guiding the dummy bar as it is pushed upwardly to seal the exit end of the mold and also provide guidance for the issuing strand. It has been found that the issuing strand can be successfully withdrawn without roller guidance, although in some cases a single pair of rollers located immediately below the mold, as shown in the drawing, may be useful to support the issuing strand and to center it with respect to the mold. In fact, the usual series of rollers may interfere with the flow from some types of water sprays. However, elimination of these rollers has been impossible in curved mold machines due to the required guidance of the dummy bar. Since continuous casting plants must be designed to encounter breakout, the presence of the roller guides below the mold has been of particular disadvantage since they may be damaged by hot metal during a breakout.

It is therefore an object of the present invention to provide an improved apparatus for dummy bar guidance.

In accordance with this object, there is provided in a preferred embodiment of this invention a chute positioned below the exit end of the mold to guide the dummy bar as it is inserted into the exit end of the continuous casting mold. Means are provided to move the chute after casting starts. The chute is moved sufficiently far away from the mold assembly so that it cannot be damaged by hot metal in the event of a breakout. The movement of the chute exposes the issuing strand to the full intensity of water spray nozzles positioned below the mold.

Having briefly described this invention it will be described in greater detail in the following portions of this specification which may best be understood by reference to the accompanying drawing of which:

FIG. 1 is a partially sectioned elevation view in accordance with one embodiment of the present invention, and

FIG. 2 is a partially sectioned elevation view of another embodiment of the present invention.

In FIG. 1 there is shown a continuous casting mold having an open-ended mold cavity 12 extending therethrough. The mold cavity, defined by the water-cooled walls of the mold, is curved. As is conventional the mold is oscillated on a curved path to cast a curved strand. Below the exit end of the mold there is provided a chute 14 having a curved chute face 16 to match the curvature of the strand receiving guidance arrangement positioned below the chute in conventional manner. The chute is mounted on pin 18 which serves as a pivot. A hydraulic ram 20, having an actuating rod 22 coupled to the chute by the pin and bushing coupling 24 is provided to move the chute from the operating position shown to a second position illustrated in dotted outline.

In operation the chute is positioned in the operative position to guide the dummy1 bar 26 as it is moved u wardly into sealing engagement wit the exit end of the mol After the filling of the mold with molten metal and initiation of casting by withdrawal of the dummy bar with the strand affixed thereto, the chute is moved to the inoperative position by actuation of hydraulic cylinder 20. The movement of the chute to the retracted position ensures that the chute will not be damaged by a breakout. The strand travels the short distance (approximately 4 to 6 feet) unsupported where the strand now receives the full application of the water spray from the spray nozzles positioned along the strand path in conventional manner.

In FIG. 2, there is shown a curved mold 10 with a chute 28 positioned below the mold. The chute is provided with a frame member 30 having a slot 32 therein. A stationary pin 34, which may be mounted on a portion of the frame (not shown) of the casting apparatus, engages the slot 32. The chute is also provided with a rearwardly extending frame member 36 having a slot 37 slidably receiving another stationary pin 38, which also may be mounted on the frame of the casting apparatus. The pins 34 and 38 thus support and guide the chute 28 for generally horizontal movement. The frame member 36 is coupled to the actuating rod 40 of a hydraulic or a pneumatic ram 42. Operation of the ram 42 moves the chute from the operative position shown in solid outline to a retracted position shown in dotted outline as indicated by arrow 44.

Thus, in both embodiments, the roller apron immediately below the mold can be eliminated.

This invention may be variously modified and embodied within the scope of the subjoined claims.

What is claimed is:

I. In a continuous casting plant having a continuous casting mold for casting a curved strand, the improvement comprising a chute having an open chute face curved to match the path of the lower surface of the cast strand and adapted to guide the end of a dummy bar into the exit end of the mold, said chute having an operable position immediately below said casting mold and in the path of the lower surface of the cast strand, and means for moving said chute from said operable position to an inoperative position retracted from the path of the lower surface of the issuing strand.

2. The improvement in accordance with claim 1 in which said chute is pivoted at one end thereof, and in which said retraction means comprises a ram having an actuating rod coupled to said chute at a position separated from said pivoted end, said ram being operable to move said chute from the operative position to the retracted position.

3. The improvement in accordance with claim 1 in which said chute includes a frame member extending forwardly therefrom, said frame member being provided with a slot, said chute being provided with a rearwardly extending frame member, a second slot in said rearwardly extending frame member, and pins engaging said slots for guiding the movement of said chute to a first position in which said chute face guides a dummy bar into the exit end of the mold and then to a second position away from the path of a cast strand from the mold, and in which said moving means comprise a ram having an actuating rod, said actuating rod being coupled to said rearwardly extending frame member.

Claims (3)

1. In a continuous casting plant having a continuous casting mold for casting a curved strand, the improvement comprising a chute having an open chute face curved to match the path of the lower surface of the cast strand and adapted to guide the end of a dummy bar into the exit end of the mold, said chute having an operable position immediately below said casting mold and in the path of the lower surface of the cast strand, and means for moving said chute from said operable position to an inoperative position retracted from the path of the lower surface of the issuing strand.

2. The improvement in accordance with claim 1 in which said chute is pivoted at one end thereof, and in which said retraction means comprises a ram having an actuating rod coupled to said chute at a position separated from said pivoted end, said ram being operable to move said chute from the operative position to the retracted position.

3. The improvement in accordance with claim 1 in which said chute includes a frame member extending forwardly therefrom, said frame member being provided with a slot, said chute being provided with a rearwardly extending frame member, a second slot in said rearwardly extending frame member, and pins engaging said slots for guiding the movement of sAid chute to a first position in which said chute face guides a dummy bar into the exit end of the mold and then to a second position away from the path of a cast strand from the mold, and in which said moving means comprise a ram having an actuating rod, said actuating rod being coupled to said rearwardly extending frame member.

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