US2247943A - Cross rolling mill - Google Patents

Description

y 1, 194.1 s. E. DIESCHER ,2 3.

.CRQSS ROLLIxG MILL Filed May 18 1.939 3 SheetS- Sheet 1 ATTORNEYS y 1, 1941- s. E. DIESCHER 7,

CROSS ROLLING MILL Filed May 18, 1939 3 Sheets-Sheet 2 INVENTOR. BY 632 1 HWM A; ATTORNEYS.

July 1, 1941.

. S. E. DIESCHER CROSS ROLLING MILL Filed May 18, 1939 3 Sheets-Sheet 3 JNVENTQIQ.

a ATTORNEYS WK R mwmhll.

Patented July 1, 1941 CROSS ROLLING MILL Samuel n. Diescher, Pittsburgh, Pa., assignor to Dieseher Tube Mills, Inc., Pittsburgh, Pa., a corporation of Delaware Application May 18, 1939, Serial'No. 274,407

'4 Claims.

The invention relates to cross rolling mills for use in the making of seamless tubing, and has particularly to do with cross rolling mills of the type illustrated and described in my-Patent No. 1,870,209.

Millsof this type are equipped with driven guide discs positioned in the pass between a pair of cross rolls and effective to divert longitudinally the peripheral flow of the metal eflected by the cross rolls, to limit the lateral bulging of blanks and to pull the blanks forward in thepass. Due to such action of the guide discs, either in the piercing of blanks, in the elongating of pierced blanks or in the sinking of elongated blanks, much greater elongations of the blanks are respectively attainable than by the use of other types of cross rolling mills.

The cross rolls used in mills of this type have been either of the barrel shape or conical form, and have been rotated by drives on the delivery side oi the mills. It is characteristic of, each of these forms of cross rolls that their working faces sogrlp the metal of blanks that in and of them selves the rolls effect an appreciable retardation of the elongation of the blanks, and therefore the elongating action by the guide discs is lessened.

tubing, so constructed and arranged as to effect increased elongations of blanks and to facilitate accessibility to the working parts of the mill.

The invention is illustrated in the accompanying drawings of which Fig. 1 is a plan view of a cross rolling mill embodying the invention; Fig. 2

an elevation of the right-hand side of the mill as viewed in Fig.1; Fig. 3 a horizontal sectional view through the pass of piercing mill cross rolls, the plane of view being indicated by the line IlIIII, Fig. 2; Fig. 4 a diagrammatic plan view'of the mill in association with auxiliary apparatus for piercing solid blanks; Fig. 5 a view, similar to Fig. '3, through sinking mill cross rolls; and Fig, 6 a diagrammatic plan view of several stands of the mill arranged with auxiliary apparatus for sinking tubes.

The cross rolling mill provided according to my invention is equipped with a pair of cross rolls of the conical type, each of which is a somewhat prolonged frustum of a cone having large and ,smalldiameter portions which preferably difier in r specific contour depending upon whether the 111111 rolling mill, for use in the making oi seamless is used for piercing solid blanks. elongating pierced blanks or sinking formed tubes. Rather than positioning the larger diameter portion of each opposed to the larger diameter portion of the other, as is the prevailing practice, the larger diameter portion of each roll is opposed to the smaller diameter portion of the other, advantages of which are explained hereinafter. longitudinal feed of blanks as they are acted upon by the working faces of the cross rolls in the pass of the mill, the axes of the rolls are vertically inclined to each other and to the pass line between the rolls, and are horizontally inclined to such line. Instead of rotating the cross rolls by drives arranged entirely on the entry or delivery side of the mill. which latter arrangement is the pervailing practice in cross rolling mills of the driven guide disc type, means are provided for driving one of the cross rolls from the entering and the other from the delivery side of the mill, advantages of which will also be explained hereinafter. In the preferred embodiment of the invention the mill is equipped with one or two driven guide discs, which, for reasons presently to be explained, are preferably mounted in-a housing which is positioned entirely at a side of the vertical plane passing through the pass line, the guide discs being positioned in the pass and each being rotatably supported in an overhanging manner at one side only of the pass.

Having reference to the accompanying drawlugs, and particularly to Figs. 1 and 2, each of a pair of the conical cross rolls I and la is at- 5 t-ached to the end ,of a drive shaft 2- mounted'in a housing 3 supported by a base I in such a manner that each may be independently adjusted to and from the pass line. and that lag and lead,

as well as vertical, adjustments may be made asis customary in cross rolling mills. Each drive shaft is driven by a separate motor 5 through suitable reduction gears arranged in a gear box 8. As appears from Fig. 1, the small diameter portion of roll 1 is opposed to the large diameter portion of the roll la, and the small diameter portion of the latter is opposed to the large diameter portion of the former. Furthermore, as there shown, the axis 01' each cross roll is inclined horizontally to the pass line which is indicated by the dot-and-dash line I.- As indicated in Fig. 2, the axes of the cross rolls are vertically inclined to each other and to the pass line through the pass line there is a guide disc housing 10 which supports each of two driven guide discs II and I2, although if desired only one of them maybe used. The shaft of upper guide disc I I is rotatably mounted in a block I3 which is mounted for vertical adjustment on a vertical face of housing I0, block I3 being here shown as provided with a T-head'H whose outstanding ends are mounted in a T-slot bracket I5 attached to Block I3 is supported by an adshaft and mitre pinions 2| and 22 attached, respectively, to shaft 20 and worm shaft I8. In a similar manner, guide disc I2 is mounted in a block 25 which'is mounted for vertical sliding movement inhousing I0 and is adapted to be adjusted by a hand wheel 28 through a drive, shown in Fig. 2, similar to that Just explained with reference to the upper guide disc I I. Each guide disc is driven by a universal coupling shaft 21 which may be connected to a pinion stand 28 (Fig. 4) driven by a motor 29. The driving of I the guide discs may be at the peripheral speeds face of the cross roll at and adjacent to thethroat of the pass. Similarly, a substantial portion of opposed face 3Ia of cross roll Ia slips upon the face of the work piece because such roll face rotates at an increasingly less peripheral speed than does the portion of the roll at and adjacent to the throat'of the pass.- Likewise, there are corresponding slippages between explained in my above mentioned Patent No.

1,870,209, and in thus driving them there are attained the advantages explained in that patent.

At the outside of each. roll housing base 4 there is a shaft 35 which is provided with worms 36 that mesh with worm wheels 33 attached to screws 39 which engage the housing 4. By rotating each shaft 35 the roll housing with which it is associated may be adjusted laterally to and from the pass line, and particularly cross roll I may be moved to such an extent that the guide discs become readily accessible for changing them.

Fig. 3 illustrates to enlarged scale the form of theconical cross rolls and their action upon a solid work piece, as ina piercing mill. The face of each of these cross rolls, instead of being the frustum of one, is the frusta of two cones. Thus, the working face of roll I is formed of two sections, one being an entering section on the largerand the other a delivery section 3I on the smaller diameter portion of the roll. Similarly,

I the working face of roll I a is formed of two sections 30a and 3Ia, the former being'on the larger and the latter on the smaller diameter 1 portion of the roll. The junction of the roll face section forms, as shown in Fig. 3, the throat or narrowest portion of the piercing pass,'in which there is shown a solid blank 32 being pierced over a mandrel 33 held in the pass by a mandrel bar 34.

It is characteristic of the cuts; rolling mill used that have been equipped with guide discs.

This result I believe to be due .0 the increased slippage between the working faces of the cross rolls and the work piece as compared to the 'slippage that attends the action of the other forms of cross rolls that have been used on such mills.

By way of explanation, in all cross rolling mills the metal of a work piece is acted upon helically to rotate and feed it forwardly. With conical rolls, formed and positioned as herein disclosed,

the helical feed of the work piece is substantially that imparted to it at the throat of the pass,

which, as shown, is substantially midway between the ends of the cross rolls. The pitch of this helix, which determines the normal longitudinal feed of blanks, may of course be varied by the setting of the cross rolls in the manner substantial portions of the roll faces 3| and 30a on the delivery side of the pass. 7

The effect of this slippage is two-fold. In the first, place, the natural tendency of the work piece to move forwardly in proportion .to the pitch of itshelical feed is retarded less in the areas of roll contact where slippage occurs than if such areas of the rolls engaged the work piece with no slippage. In the second place, there being less retardation to the flow of the metal of a blank where slippageoccurs, the elongating action of the guide discs upon such metal is not impaired and retarded. In other words, the metal is freer to be fed forwardly by the guide discs at such places as it is not firmly en-' gaged by the working faces of the cross rolls, or in other words at the places where cross roll slippage takes place. Thus, in the operation of this mill greater elongations can be effected than in the operation of the heretofore used cross rolling mills equipped with guide discs. This is particularly advantageous in piercing solid blanks for use in the production of smaller diameter seamless tubing. The increased longitudinal, as compared with the circumferential, flow of the metal of a blank makes it possible to produce from solid billets of a given size smaller diameter pierced blanks than can be produced on other types of piercing mills. This effects either a saving in the entering and that of cross roll Ia on the de-' livery side of the mill.

The guide discs II and I2 are. mounted inhousing I 0 which is positioned entirely on the right-hand side of the pass as viewed in this figure. At the entering side of the mill there is a feed table or trough equipped with a pusher 46, or with such other instrumentality as may be necessary or desirable to enter blanks in a mill depending upon whether it is equipped to pierce solid blanks or to elongate them on a mandrel as shown in my above mentioned Patent No. 1,870,209. On the delivery side of the mill in line with the pass and with feed table 45 there is a receiving table 41 which may be equipped with a mandrel supporting bar 48 for a piercing mill, or with means for extracting a cylindrical mandrel when the mill is used for elongating pierced blanks. For delivering blanks to the mill a transfer table 49 extends from a table 50 to feed table 45 on the side thereof opposite to the drive of cross roll I. Similarly, on the delivery side of the mill thereis a discharged from such table, as for example after.

mandrels or mandrel bars have been removed from elongated tubes or pierced blanks.

Because the drives of both cross rolls are not on the delivery side of the mill, rack or table may be positioned, as shown, close to the mill. Among the advantages of this are economy of mill space, manual accessibility to the metal working elements of the mill, and better visibility of the operation of the mill at its delivery side. Furthermore, in the case of a piercing mill, the workman who places mandrel heads on the mandrel bar has much greater freedom of action. These advantages are further enhanced by supporting the guide discs in a housing positioned entirely at the side of the pass opposite to rack 5|, or in other words on the same side of the pass as its cross roll la and its drive.

Mills embodying my invention are particularly useful for sinking or reducing the diameters of tubes in the manner disclosed in my Patent No.

. the other, the axes of the rolls being vertically 1,934,844. However, for this purpose it is preferable to provide the working faces of the cross rolls with curved profiles as generally illustrated in Fig. 5, which shows a pair of conical cross rolls 60 and 50a positioned as explained with reference to Figs. 1 and 2. The outer end of the small diameter portion SI of rolls 60 and 60a is conical in profile, as is also the outer end 62 of the large diameter portion of these rolls. Between these conically profiled ends the profile of the roll faces is curved, as indicated at 63. The purpose of thus curving the central portions of these rolls is to avoid undue concentration of work at one locality on the guide discs, the avoidance of which concentration is desirable in efiective sink- In Fig. 6 there is diagrammatically shown a plan view of three stands of cross roll sinking mills arranged in tandem, although the number of stands may vary. These are equipped with pairs of .conical cross rolls 65, 66 and 61 constructed and arranged according to my present invention and associated with driven guide discs. The stands are so spaced from each other that each tube leaves one before it enters another of the stands. In case the bores of the sunk tubes are not sufficiently smooth after the tubes have passed through the sinking mill, the tubes may be passed through a further cross rolling mill of the type herein disclosed, or of any other suitable type, the tubesfirst being supplied with cylindrical mandrels. On the other hand, e tubes may be passed directly to a sizing mill after passing through the successive stands of sinking mills. As shown in Fig. 6, there is a cross rolling mill equipped with a pair of cross rolls 88, of the type herein disclosed, positioned beyond the sinkingmill cross rolls 61. When a tube has passed through the cross rolls 61, a cylindrical mandrel, taken from the transfer rack 69, is placed within the tube which is then passed through rolls 68. The tube with the mandrel in it may then be moved laterally 'on a rack Illv to a table II on which the mandrel is removed by a stripper l2 and returned to rack 69. The tube may then be transferred to a table 13 from which it may pass through a suitable sizing mill 14 consisting of a plurality of stands of grooved rolls 'of well known construction.

In the foregoing, and in the appended claims,

various positions of the cross rolls and other parts of the mill are described and defined with have its periphery bear reference to vertical and horizontal locations. It

will be understood that these designations are relative and are not limiting."

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

I claim:

1. A cross rolling mill for use in the making of seamless tubing, comprising a pair of conical cross rolls having the larger diameter portion of each opposed to the smaller diameter portion of inclined to each other and to the pass line between them and being horizontally inclined to the pass line, means for driving one of the cross rolls from the entering and the other from the delivery side of the mill, a rotatable guide disc positioned in the pass between the cross rolls to have its periphery bear upon a blank passing through the mill, and means for driving said disc at a peripheral speed materially in excess of the longitudinal feed of the blank effected by the cross rolls, whereby to increase the elongation of the blank.

2. A cross rolling mill for use in the making of seamless tubing, comprising a pair of conical cross rolls having the larger diameter portion of each opposed to the smaller diameter portion of the other, the axes of the rolls being vertically inclined to each other and to the pass line between them and being horizontally inclined to the pass line, means for driving one of the cross rolls from the entering and the other from the delivery side of the mill, a pair of rotatable guide discs positioned in the pass between the cross rolls to have their peripheries bear upona blank passing through the mill, one guide disc being aboveand the other below the pass line, and means for driving said discs at peripheral speeds materially in excess of that of the longitudinal feed of the blank effected by the cross rolls, whereby to increase the elongation of the blank.

3. A cross rolling mill for use in the making of seamless tubing, comprising a pair of conical cross rolls having the larger diameter portion of each opposed to the smaller diameter portion of the other, the axes of the rolls being vertically inclined to each other and to the pass line between them and being horizontally inclined to the pass line, means for driving one of the cross rolls from the entering and the other from the delivery side of the mill, a guide disc housing at a side of a vertical plane through the pass line, a guide disc rotatably mounted in said housing and positiond in the pass between the cross rolls to upon a blank passing through the mill, and means for driving saiddisc at a peripheral speed materially in excess of that of the longitudinal feed of the blank effected by the cross rolls, whereby to increase the elongation of the blank.

4. A cross rolling mill for use in the making plane through the pass line, means for driving one of the cross rolls from the entering and the other from the delivery side of the mill, a pair of guide discs rotatably mounted in said housing and positioned in the pass between the cross rolls to have their peripheries bear upon a blank passing through the mill, one guide disc being 5 whereby to increase the elongation ofthe blank.

SAMUEL E. DIESCHER.

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