US2686441A

US2686441A - Cross-rolling mill and blankconfining shoes for it

Info

Publication number: US2686441A
Application number: US263607A
Authority: US
Inventors: Stephen W Girgosh
Original assignee: Nat Supply Co
Current assignee: National Supply Co
Priority date: 1951-12-27
Filing date: 1951-12-27
Publication date: 1954-08-17
Anticipated expiration: 1971-08-17

Description

g- 17, 9 s. w. GIRGOSH 2,586,441

CROSS-ROLLING MILL AND BLANK-CONFINING SHOES FOR IT Filed Dec. 27, 1951 .5 2 I I a a JNVENTOR. fTfPl/[Al (u Q1/2 05 A r roe/W: rs.

Patented Aug. 17, 1954 CROSS-ROLLING MILL AND BLANK- CONFINING SHOES FOR IT Stephen W. Girgosh, Ambridge, Pa., assignor to The National Supply Company, Pittsburgh, Pa., a corporation of Pennsylvania Application December 27, 1951, Serial No. 263,607

2 Claims. 1

The invention relates to cross-rolling mills of the type that are used for piercing solid blanks or billets which are then used in the manufacture of seamless tubes, and to like cross-rolling mills that are used for elongating, expanding and reducing the wall thickness of previously pierced blanks. Each such mill comprises a pair of rolls having their axes inclined to each other and to the center line of the working pass between them so that a blank that is being pierced or otherwise worked is fed forwardly in a helical fashion by rotating it on its longitudinal axis.

Cross-rolling mills of the type explained are usually provided with upper and lower shoes confining work pieces while they are being cross rolled. Customarily the lower shoe is so positioned in a roll pass that the axis of the billet or other work piece that is being cross rolled lies slightly below the center line of the roll pass, which results in the work piece being forced downwardly against the lower shoe by the roll reaction. Because of this, the lower shoe is subject to greater wear than the upper shoe, and it may become red hot by frictional heat generated by the work piece on the shoe and by heat trans-- fer from the work piece.

In the operation of cross-rolling mills, the rolls are cooled by streams of water that are continuously applied to their working faces. Some of such water is effective for cooling the upper shoe, but little, if any, of it is effective for cooling the lower shoe because the sides of the shoes conform quite closely with the contour of the rolls, and hence the upper shoe prevents water that is applied to the rolls from flowing downwardly on the lower shoe.

The object of this invention is to provide a cross-rolling mill with a pair of shoes, the upper one of which is so notched at its vertical side or sides that a substantial amount of cooling water applied to the rolls can flow downwardly upon the lower shoe for cooling it during the intervals between the cross rolling of billets or other blanks.

The invention is somewhat diagrammatically illustrated in the accompanying drawings, in which Fig. 1 is a plan view of a pair of barreltype cross rolls of a billet-piercing mill, the upper shoe being removed, and the pierced portion of a billet that is being pierced being shown in horizontal central section; and Fig. 2 a perspective view of one of the rolls and a pair of shoes adjacent to it.

Having reference to the drawings, a pair of cross rolls I and 2 having their axes inclined to each other and to the center line of the working pass between them has a pair of upper and lower shoes 3 and 4, respectively, positioned between the rolls above and below the working pass. In Fig. 1 a solid heated billet 5 is shown as being pierced by a mandrel 6 which is held in fixed position in the throat of the roll pass by a mandrel bar I, the tubular pierced portion 8 of the billets being shown in section in a horizontal central plane. The piercing is effected by rotation of rolls I and 2 in the directions indicated by the arrows shown on them. The side of upper shoe 3 is provided with a vertical notch 9 at the throat of the pass, which notch forms with the face of roll I a passage for flow of cooling water applied to the face of the roll. As shown in Fig. 2 during the operation of the mill, roll I is so rotated that it face moves downwardly at the working pass, and a stream of cooling water I0 is continuously applied to its working face.

During a piercing operation, cooling water applied to the rolls cannot reach lower shoe 4 because the metal of the blank that is in contact with the faces of the rolls prevents it from doing so. However, in the interval between each piercing operation, the rotation of roll I towards the pass facilitates the flow of water through the passage formed by the face of the roll and the vertical face of notch 9 to lower shoe 4 for cooling it.

In the practice of this invention, it has been found that the life of lower shoe 4 has been materially increased in comparison with the life of shoes in which no such provision is made for cooling the lower shoe. By way of example, and not of limitation, when conventional unnotched shoes were used in a billet piercing mill in the manufacture of seamless oil well casing of 5 /2" outside diameter from solid billets of 6.60 in diameter, it has been necessary to change the shoes two to three times in each eight hour turn, due to excessive wear on the lower shoe. When using an upper shoe having it side provided with a notch the same as herein illustrated and described, it has been found that in the same piercing mill used for the same piercing operation, the shoes may be used for sixteen hours without changing them, or in other words for two full eight-hour turns. In terms of the number of like billet that were pierced, the mill equipped with conventional shoes could produce from only 250 to about 300 pierced blanks before it was necessary to change the shoes, whereas in the same piercing operation more than one thousand pieces can be pierced by using a notched upper shoe the same as that herein illustrated and described.

According to the provisions of the patent statutes, I have explained the principle and mode of operation of my invention, and have illustrated and described What I now consider to be the best embodiment of it. However, I desire to have it understood that, within the scope of the appended claims, the invention may be practiced otherwise than as illustrated and described.

I claim:

1. In a cross-rolling mill, the combination with a pair of cross-roll having their axes inclined to each other and to the center line or pass between them, and means for supplying cooling water to the upper parts of the rolls, of stationary upper and lower blank-confining shoes between said rolls, one shoe being positioned above and the other below said center line of pass, the upper shoe having its opposite side faces conforming lengthwise to the contour of the roll faces beside it with only slight clearance between the shoe and rolls, whereby the flow of cooling water down between the upper shoe and rolls is obstructed, and a side of the upper shoe being provided with a notch extending from top to bottom of the shoe and forming with the adjacent roll a vertical passage for the flow of a stream of roll-cooling water downwardly onto the lower shoe to cool it.

2. In a cross-rolling mill, the combination with a pair of cross-rolls having their axes inclined to each other and to the center line of pass between them, and means for supplying cooling water to the upper parts of the rolls, of stationary upper and lower blank-confining shoes between said rolls, one shoe being positioned above and the other below said center line of pass, the upper shoe having its opposite side faces conforming lengthwise to the contour of the roll faces beside it with only slight clearance between the shoe and rolls, whereby the flow of cooling water down between the upper shoe and rolls is obstructed, and the side of the upper shoe beside the roll that ha the face moving downwardly at the working pass being provided with a notch extending from top to bottom of the shoe adjacent the throat of the pass, said notch forming with said roll a vertical passage for the flow of a stream of roll-cooling water downwardly onto the lower shoe to cool it.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,943,764 Holloway Jan. 16, 1934 25 1,986,704 Bannister Jan. 1, 1935 2,155,883 Bannister Apr. 25, 1939 2,334,853 Wiley Nov. 23, 1943 FOREIGN PATENTS 0 Number Country Date 602,173 Germany Sept. 3, 1934