US2699697A - Mandrel changing apparatus - Google Patents

Description

Jan. 18, 1955 mea Feb 7 1951 J. W. KELSO MANDREI.. CHANGING APPARATUS Jan. 18, 1955 3 Sheets-Sheet 2 Filed Feb. 7, 1951 Jan. 18, 1955 J. w. KELso 2,699,697

MANDREL CHANGING APPARATUS Filed Feb. 7. 1951 3 Sheets-Sheet 3 Inventar: JH/V l1( KELSO,

United States Patent MANDREL CHANGING APPARATUS John W. Kelso, Clairton, Pa., assignor to United States Steel Corporation, a corporation oiNewJersey` Application February 7, 1951, Serial `Nm 209,750

1 Claim. (Cl. 80-1) This invention relates to apparatusfor mechanically handling and changing thepiercing mandrels in seamless tubing4 mills.

ln operating such mills, the piercing mandrel` must be changed after each billet-has been pierced and must be thoroughly cooledbefore-it cany be re-used. It is-,customary to employ three or more mandrels for each mill, one of which is in usewhile the others are cooling. Usually mandrels are changed manually, which is a fiatilguing operation, particularly for larger sizes omanre s.

An object of the present invention is to provide improved apparatus for mechanically handling and chang ing mandrels and which can be installed on existing mills without otherwise altering the mill or mandrel structure.

A further object of the invention is to provide a mandrel handling apparatus which includes mechanical means for gripping a mandrel and cooperating mechanical means for transferring mandrels thus gripped from the guide shoe of a piercing mill to a cooling bosh and from said bosh to the mandrel trough of the mill.

in accomplishing these and other objects of the invention I have provided improved details of structure, a preferred form of which is shown in the accompanying drawings, in which;

Figure l is a top plan view of a portion of a piercing mill which is equipped with a mandrel changing apparatus embodying features of the present invention;

Figure 2 is a side elevational view, with parts broken away, of the mandrel changing apparatus;

Figure 3 is an end elevational view of the mandrel changing apparatus; and

Figure 4 is a vertical sectional view of a cooling bosh for the mandrels.`

The drawing shows a portion of a seamless tubing piercing mill which includes the usual rolls and 12, guide shoe 13, and mandrel trough 14. The mill is shown as equipped with four piercing mandrels M1, M2, M3, and Mr. In operation, a cool mandrel is deposited in mandrel trough 14. The mandrel bar of the mill, moving from right to left but not shown, picks up this mandrel. A hot billet advances through the mill from left to right between rolls 10 and 12, passes over the mandrel and thus is pierced, and moves on into the mandrel trough, from which it subsequently discharges sidewise onto skids 15. ln the meantime the mandrel bar is retracted, leaving the now heated mandrel resting in the guide shoe 13. A cooling bosh 16 is situated beside the mandrel trough on the opposite side from skids and has water sprays 17. The heated mandrel is removed from the guide shoe and placed in the bosh and thus cooled for another piercing. The parts thus far described can be of any standard or desired construction, and therefore are not shown nor described in greater detail.

The apparatus of the present invention includes a verti cal column 19 which is situated adjacent the mandrel trough 14, preferably on the same side asthe cooling bosh 16. This column has a thrust bearing 19 and carries a sleeve 20 which rests on said thrust bearing and is rotatable on a vertical axis. Said sleeve carries a short, radially extending boom 21, which is fixed thereto, as by gussets 22. Boom 21 carries a longer, longitudinally extending boom 23. Preferably a structural member 24 connects the free extremity of boom 23 and the top of sleeve 29 to rigidity these parts. Column 18 is positioned and boom 21 dimensioned so that boom 23 can occupy a position directly over the mandrel trough 14 but also can swing to either side thereof.

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Boom 23 serves as a trackway for a carriage 25, which has wheels 26 riding on anges on said boom` A doubleacting fluid pressure cylinder 27 is fixed to the boom and contains a reciprocable piston and piston rod 28. The free end of said piston rod is connected to carriage 25 at 29 so that application of pressure to cylinder 27 either projects or retracts said carriage along boom 23.

A frame 30 is pivoted to carriage 25 at 31. A doubleacting lluid pressure cylinder 32 is pivoted to said carriage at 33 and contains a reciprocable piston and piston rod 34. The free end of said piston rod is pivoted to frame 30at 35, so that application of pressure to cylinder 32 moves frame30 up or down about its pivot 31.

Frame 39 carries cooperating fixed and movable mandrel engaging jaws 36 and 37 respectively. The latterrjaw is pivoted to the frame at 38 and has an operating lever 39extending from the opposite side of its pivot. Frame 30 has-an overhanging ear 40. A double-acting fluid pressure cylinder 41 is pivoted to said ear at 42 and contains a reciprocable piston and piston rod 43. The free end of said piston rod is pivoted to the free end of the operating lever 39 at 44` so that application of pressure to cylinder 41 opens or closes jan/S36 and 37.

For swinging the boom 23 about therpivot on column 18, the apparatus includes a motor driven winch 45,' (Figure 3) a cable 46 wrapped around said winch and connected to the free end of said boom, a second cable 47 connected to the free end of the boom and extending in the opposite direction, and a counterweight 48 at the end of the latter cable. For guiding cable 46 between the winch and boom, the apparatus includes a hollow vertical column 49 which is situated above the winch and has a sheave 5t) at its upper end. The cable extends up through this column, around sheave 50, and thence to the free end of the boom. Similarly for guiding cable 47 between the boom and counterweight, the apparatus includes a vertical column 51 which has a sheave 52 at its upper end. Cable 47 extends from the free end of the boom, around sheave 52, and down through column 51 to the counterweight. Winch 45 can be rotated in either direction. When it winds cable 46, it swings boom 23 counterclockwise, as viewed in Figure l. When it un* winds cable 46, the pull of the counterweight 48 on cable 47 swings boom 23 clockwise.

Skids 15 carry an inclined mandrel supporting table 53. A retractable stop 54 is pivoted at 55 to the lower part of said table, and when projected retains a mandrel on the table. A double-acting iluid pressure cylinder 56 is pivoted to said table at 57 and contains a reciprocable piston and piston rod 58. The free end of piston rod 58 is pivoted to the lower end of stop 54. Application of pressure to cylinder 56 thus either projects or retracts stop 54. When the stop is retracted, the mandrel retained thereby rolls down into the mandrel trough 14 in a position to be picked up by the mandrel bar of the mill, as already explained. Pierced lengths of tubing travel far enough to the right in the mandrel trough so that table 53 does not interfere with their removal to the skids 15.

In operation, assume that the mill has just pierced a billet and a heated mandrel M1 is resting on the guide shoe 13 and a cooled mandrel M4 on the inclined table 53. Cylinder 27 is operated to retract carriage 25, cylinder 32 to raise the frame 30, cylinder 41 to open the jaws 37 and 38, and winch 45 to swing the boom 23 to a position directly over the mandrel trough 14. Next cylinder 32 is operated to lower the frame 30, and cylinder 27 to project the carriage 25. This operation moves the xed jaw 36 within the mandrel bore. Next cylinder 4l is operated to close the jaws and thus grip the mandrel, cylinder 32 to raise the frame 3l) and the mandrel, cylinder 27 to retract the carriage 25 and the mandrel, and winch 45 to swing the boom 23 counterclockwise. These movements are coordinated to place the mandrel opposite a vacant space in the cooling bosh 16. Next cylinder 32 is operated to lower the frame 30 and the mandrel, cylinder 27 to project the carriage 2S and thus project the mandrel into this vacant space, and cylinder 41 to open the jaws 37 and 36 and release the mandrel.

In the meantime cylinder 56 is operated to retract stop 54 and thus release mandrel M4, which rolls down into the mandrel trough 14. The cylinder then is operated to project the stop so that the table can receive and retain another mandrel. Next the carriage, jaws, frame and winch are operated to grip a cooled mandrel from bosh 16, carry it to a position above table 53 and deposit it on said table.

From the foregoing description it is seen that the apparatus of the present invention affords a simple and reliable means for mechanically handling and changing mandrels in a seamless tubing piercing mill. The apparatus can be installed in conjunction with existing mills without otherwise altering their structure, and it effectively eliminates the need for handling mandrels manually.

While I have shown and described only a preferred embodiment of the invention, it is apparent that modifications may arise. Therefore I do not wish to be limited to the disclosure set forth but only by the scope of the appended claim.

I claim:

An apparatus comprising an upright column, a first horizontal boom extending from and carried by said column for rotation thereabout, a second horizontal boom extending at right angles to and rigidly carried by said first boom at the free end thereof and movable therewith, said second boom being horizontally offset from said column by the length of said rst boom leaving the space beneath said second boom unobstructed, means connected to one of said booms for rotating them about said column,

a carriage movably supported on said second boom, a double-acting uid pressure cylinder and piston on said second boom and connected to said carriage for projecting and retractng the latter with respect to said rst boom, a frame pivoted to said carriage and having a free end adapted to be raised and lowered relative to said carriage, a double-acting uid pressure cylinder and piston connected to said carriage and said frame for raising and lowering the free end of said frame, a pair of mandrel gripping jaws carried by the free end of said frame and being relatively movable on a horizontal axis, and a double-acting uid pressure cylinder and piston connected to said frame and one of said jaws for opening and closing said jaws.

References Cited in the le of this patent UNITED STATES PATENTS 184,168 Nickle Nov. 7, 1876 426,046 McCleane et al Apr. 22, 1890 744,071 Hayward Nov. 17, 1903 1,302,861 Schott May 9, 1919 1,764,736 Lowy June 17, 1930 2,191,143 Hiatt Feb. 20, 1940 2,583,834 Gross Ian. 29, 1952 FOREIGN PATENTS 503,970 France Mar. 29, 1920

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