US3534648A - Shears for parting continuously-cast billets - Google Patents

Description

Unite States atent lnventor Appl. No. Filed Patented Assignee Priority Werner Skiera Dusseldorf, Germany 723,462

April 23, 1968 Oct. 20, 1970 Schloemann Aktiengesellschatt Dusseldorf, Germany a company of Germany April 28, 1967 Germany Sch 40,627

SHEARS FOR PARTING CONTlNUOUSLY-CAST BILLETS 5 Claims, 6 Drawing Figs.

US. Cl 83/694 826d 1/06 Field of Search 83/694, 580

[56] References Cited UNITED STATES PATENTS 1,438,888 12/1922 Barton 83/694X 1,798,106 3/1931 Pels 83/694 2,380,898 7/1945 Pimentel 83/694X 2,626,664 1/1953 Regele 83/694X 3,143,025 8/1964 Koester et al 83/694X Primary Examiner-Frank T. Yost Atmrney-Sandoe, Neill, Schottler and Wikstrom ABSTRACT: Shears for parting a continuously-cast metal bil let consist ofa pair of blades mounted to move cooperatively together. The length of the shearing edge of each blade has an indented central portion, shorter than the width of the billet to be sheared, and diverging end portions, the shearing faces of the end portions being reliefground.

:IBPGAN l Patente Get. 26, 1970 3,534,648

Sheet 2 of 2 lOd INVENTOR. WERNER SKIERA ATTORNEYS Patented 0st. 29, 1970 3,534,548

INVENTOR. WERNER SKIERA BY M M ZVM ATTORNEYS SHEARS FOR PARTING CONTINUOUSLY-CAST BILLETS The present invention is a shearing mechanism, consisting of a pair of cooperating shear blades adapted for parting a continuously-cast billet of metal, such as steel, while the billet is at a high temperature.

In continuous-casting it is desired to sever the continuouslycast billet into suitable lengths for subsequent rolling operations while the metal is still hot from the casting operation thereby to reduce or eliminate reheating for the rolling operation.

In a usual arrangement the billet emerging from the continuous casting machine passes to a shearing station where it is severed into predetermined lengths which thus pass through a furnace to the roll train of a rolling mill.

The billets are ordinarily passed through the furnace to reheat them, and/or to permit the heat they already contain to become more uniformly distributed therein, to facilitate the rolling operation.

In a known arrangement the shearing is accomplished with straight edged shear blades. When the billet is at an elevated temperature, however, the straight edged blades flatten and broaden the severed ends of the billets, so that they will not properly be received through the first rolls of the rolling mill. In addition, the billets with broadened ends tend to damage the hearth of the furnace, and to buckle if the distortion prevents the billets from lying flat on the hearth. In practice, to facilitate rolling billets having broadened ends, the ends are trimmed by cutting, and/or the rolls at the entrance of the rolling mill are spaced further apart to receive them.

It has also been proposed to use contoured shearing blades and to arrange them at an angle, 45 for example, for severing the billets diagonally. But these blades arranged in this manner also cause harmful broadening of the severed ends. Moreover, in plants for casting and working several continuously-cast billets closely arranged side by side, there is not enough space to place the angularly arranged shears side by side in a line so that they must be staggered, which increases the overall length of valuable plant space taken up by the shearing station.

It is an object of this invention to provide shears for parting a continuously-cast billet without flattening or otherwise distorting the ends, thereby avoiding possible damage to the furnace and rolling mill, or improper heating or rolling, and also eliminating the added expense and complications involved in trimming the ends and/or rearranging the spacing of the first rolls of the rolling mill.

This is accomplished with shears in accordance with the present invention which have the lengths of their shearing edges formed with an indented central portion, which is shorter than the width of the billet to be parted, and two end portions diverging respectively from the ends of the central portion. Thus, when the pair of blades move cooperatively together to shear the billet, the diverging end portions of the shearing edges, which are the first portions of the shearing edges to engage the billet, make bevelled kerfs in the edges of the billet at the start of the cut. The direction of forces producing these bevelled kerfs being in toward the center of the billet, oppose spreading of the billet initially and thereafter as the central portions of the shearing edges shear through the billet to complete the severing.

For parting billets of a width of 100 mm, for example, particularly clean, distortion-free cuts are obtained when the length of the central portion of each blade is about 80 percent of the billet, and the end portions diverge from the central portions at an angle of about B".

In addition, in accordance with a preferred form of the invention the shearing faces of the end portions of the shearing edge are relief ground; that is, the end portions are bevelled, or sloped, to shear in a plane spaced from the shear plane of the central portions and to displace the sheared material in a direction the reverse of the direction in which material is displaced by the shearing edge of the central portion. The effect of this is that the end portions displace material from the sides of the billet toward the middle just prior to the shearing of the middle, with the result that the billet is sheared without bulging to the sides and without forming stepped cuts across the sheared end faces.

An embodiment of the invention is shown by way of example in the accompanying drawings in which:

FIG. 1 is a side elevation of shearing mechanism, shown schematically and partly broken away, including a pair of cooperatively movable shear blades in accordance with the invention, for parting a continuously-cast billet;

FIG. 2 is a front elevation of the mechanism shown in FIG. 1;

FIG. 3 is a front view oftlie shear blades, illustrated in FIGS. l and 2, showing them in their relative positions after a bevelled kerf has been started in the edges ofa billet;

FIG. 4 is a side view ofthe shear blades shown in FIG. 3; and

FlGS. 5a and 5b are sections respectively along the lines 5a-5a, and Sb-Sb on FlG. 4.

Referring to FIGS. 1 and 2, a pair of cooperating shear blades 10a and 10b embodying the present invention are incorporated in shearing mechanism carried on a frame 12. The frame 12 is provided with wheels 13 riding on lateral guides 14, and is moved laterally by a positioning piston and cylinder device 15 attached to the frame for positioning it laterally between rollers 16 and 17, which are part of a roller table ofa continuous-casting machine (not shown) and which support and convey a continuously-cast billet 18 away from the continuous-casting mold (not shown). As illustrated, the frame 12 is provided with rollers 19 and 20, the roller 19 being in line to guide a continuous billet 18, passing over the roller 16, in between the blades 10a and 10b from one side of the shearing mechanism and the roller 20 being in line to guide parted billet sections 1811 out to the roller 17 at the other side of the mechanism.

The upper shear blade 10a is fixed in a blade support member 21 on the frame 12. The lower shear blade 10b is mounted on a support carriage 22 that is mounted to be vertically movable in a guide 23 on the frame 12 by a piston rod 24 operated by a hydraulic drive cylinder 25 (or other suitable drive mechanism). Adjacent the upper blade 10a, a movable hold down clamp 26 is mounted on the blade support number 21 to be moved up and down, for clamping a billet 18 in position to be sheared, by a piston 27 operated by a drive cylinder 28.

Referring now to FIGS. 3 to 5b, the blades 10a and 10b are each formed with straight, indented central portions, 30a, 30b respectively, and respective end portions 31a, 31b diverging from the ends of the central portions 30a, 30b. As shown, the central portions 30a, 30b are shorter than the width of a billet 18 being sheared so that the end portions 31a, 31b engage the edges of the billet 18 on a slant to form bevelled kerfs therein. As seen in FIGS. 3 and 4, the edge portions 31a, 31b are reverse ground with respect to the shear plane defined by the cooperating edges 32a, 32b of the central portions 30a, 30b of the blades 10a, 10b. Thus, as illustrated in FIGS. 5a and 5b, which show the direction of displacement of material relative to the shearing plane at the time the blades have just engaged and partly entered the billet 18, the end portions 31a of the upper blade 10a and the end portions 31b of the lower blade 10b make bevelled kerfs in the top and bottom edges of the billet 18, as indicated at 33a and 331;. As indicated, the end edges 31a. 31b displace the material of thc billet 18 in directions opposite, respectively, to the directions in which the material is displaced by the central portions 30a, 30b of the shearing edges of the blades 10a and 10b.

lclaim:

1. Shears for parting continuously-cast metal billets comprising a pair of blades mounted to move cooperatively together for shearing a billet placed between them, each of said blades having the length of its shearing edge formed by an indented central portion shorter than the width of said billet and end portions diverging respectively from the ends of the central portion, and the shearing faces of said central portion and of said end portions of the shearing edge being bevelled respectively in opposite directions relative to the plane in which they shear said billet.

2. The shears of claim I in which the shearing faces of said end portions are relief ground relative to the shearing edge of the central portion to shear in a plane spaced from the plane in which the central portion shears.

3. The shears of claim 1 in which said end portions diverge

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