US2084331A - Seamless pipe or tube mill - Google Patents

Description

Je 22, 1937 v s. FlNDLATER 2,084,331

SEAMLESS PIPE O R TUBE MILL Filed Nov. 2l, 1934 6 Sheets-Sheet l bwefdo: Y STEVE/vso/v F/NDLQTEE,

.Pune 22, 1937. s. FlDL-ATI'ER i 1 2,084,331

- SEAMVLESS PIPE OR TUBE MILL Filed Nov. 21, 1934 6 sheets-sheet 2 y STEVENSO/v HNDLQTEE;

`une 22, 1937. s, FINDLATER v 2,084,331

SEAMLESS PIPE OP. TUBE MILL Filed Nov. 2l, 1954 6 Sheets-Sheet 3 lwenfo': STEVE/VSON HNQLQTEE,

June 22, 1937. s F'INDLATER 2,084,331

SEAMLESS PIPE OR TU BE MILL Filed Nov. 21, 1954 e sheets-sheet 41 jwed'o: STEVENSON /F//VDQQT/ffe,

June 22, 1937. s. FINDLATER 2,084,331

SEAMLES'S PIPE OF` TUBE MILL Filed Nov. .21, 1934 e sheets-sheet 5 IJune 22, 1937. s, FINDLATER 2,084,331

SEAMLESS PIPE OP. TUBE MILL Filed NOV. 21, 1934 6 Sheets-Sheet 6 Patented June 22, 1937 iP/MEN ori-loa 2,084,331 sEAmEss faire oa TUBE Mns.

Stevenson Findlater, McKeesport, Pa., assigner to National 4Tube Company, a corporation of New Jersey Application November 21, 1934, Serial No. 754,169

4 Claims.

This invention relates to improvements in seamless pipe or tube mills, and more particularly to means `for automatically compensating for the expansion of the mandrel bar.

In the manufacture of seamless pipes and tubes, considerable difliculty has been encountered in maintaining constant the distance between the surfaces of the various rolls of the mill and the surfaces of the mandrel plug, such as is commonly used in piercing, expanding, elongating, reducing, etc., operations. While this condition can be attributed somewhat to the expansion of the rolls and mandrel plug, it is largely due to the expansion of the mandrel barl supporting the plug in the roll pass. That is to say, as the rolls and mandrel plug of the mill acquire heat from the work-piece being processed they will, of course, expand, causing their surfaces to become closer to one another. As the mandrel bar becomes hotter, acquiring heat from the work-piece being processed, it will increase in length and accordingly move the surfaces of the mandrel plug nearer to the rolls of the mill. This moving together of the various metal working surfaces of the mill causes the wall thickness of the work-piece being processed to vary, due to a more substantial reduction in the wall of the work-piece when the mandrel bar, rolls and mandrel plug are hot than would be the case were they cold.

The temperature of a seamless pipe or tube mill is usually no higher at the end of a long period of operation than it was at the beginning. This is for the reason that the mill is started without cooling water on the rolls and heated billets passed therethrough until the rolls acquire a desired temperature. At this time the rolls are sprayed with Water in order that theftemperature will not rise greatly beyond that desired. In this manner the general temperature of the mill is maintained as desired; but as each highlyv heated billet, or work-piece, moves through it, the temperature of the mill elements is temporarily raised. This temporary rise in temperature causes a correspondingly temporary expan- December 29, 1934, Serial No. 759,804, I have' disclosed apparatus which is inmany respects similar to that disclosed herein. This copending application is, however, concerned with makJ lng a tubular work-piece which is tapered in both inside diameter and wall thickness.

One object of the present invention is to provide novel and automatically actuated means for` compensating to exactness the expansion of the mandrel bar and rolls of the mill, and maintain- -ing constant the distance between the surfaces of the various rolls of the mill and the surfaces of the mandrel plug, resulting in elimination of variations from the desired wall thickness of the work-piece. A

Another object of the invention is to provide novel and automatically actuated mechanism, operating under a heavy thrust, for slowly withdrawing the mandrel bar of a seamless tube mill in exact ratio to the expansion o'f the mandrel bar and of the rolls in the mill, resulting in a constantly maintained distance between the various metal working surfaces, together with automatically actuated mechanism for rapidly returning the mandrel plug to its initial position.

A further object is to regulate the relative positions of the mandrel plug to the various metal working rolls, even when the mill is cold, in accordance with the temperature of the workpiece, and thus compensate for differences in resistance to metal displacement caused by introducing metal of varying temperature into the mill.

A still further object is to provide novel apparatus of the class described which can be installed on existing mills with butl little modification and expense.

These and further objects of the invention will appear after referring to the drawings, in which:

Figure 1 is a fragmentary plan of a conventional pipe or tube mill.

Figure 2 is a fragmentary plan of the apparatus of the invention.

Figure 3 is a sectional view on the line III-III of Figure 2.

Figure 4- is a view onthe line ure 3.

Figures 5 and 6 are electrical circuits for operating the various elements of the invention.

Referring to Figure- 1 of the drawings, there is disclosed a conventional seamless pipe or tube mill of the well known Stiefel type, comprising a pair of cone-shaped metal Aworking rolls A between which there is disposed a mandrel plug B.

IV--IV of Fig- In this gure of the drawings one of the cone- .4 is secured to the carriage 3 in any suitable manner as, for example, by a coupling 4* on the extension 3* of a thrust bearing located immediately at the rear thereof.

A support l is pivoted to the frame 2, as at 5*,

r and provided with a horizontauy disposed shaft 3 adjacent the upper surface of the mandrel bar carriage 3. -A pair of links 3. is secured to the shaft t and is adapted, by suitable mechanism, to move the support B above the pivot 3*.

A motor 3 is secured to the frame 2 and provided with the usual motorshaft 3* and coupling III, for connecting theI same to a shaft I I* of a gear reduction mechanism generally indicated at II. The gear reduction II is provided with another shaft Ilb and a coupling I2 for connection .to a shaft I3 which is iournaledin a bearing I4.l

A magneticclutch I3 is disposed adjacent the bearing I4 for clutching-in ashaft I3. A worm ,I1 is mounted on the shaft I3 for rotating a worm gear 24. The worin gear 24 is provided with a suitably journaled elongated sleeve portion 24",

yon which it is mounted. The elongated sleeve portion 24* is internally screw-threaded for engagement with a screw 2t, which is secured to one of the links 3 by a pin 2V. The other end of the shaft I3 is provided with acoupling It to which there is secured a shaft I3on which there is mounted a worm 23. The shaft I3 is secured at its other end to the shaft 23* oi' a motor 23, by means of a coupling 2I.

The worm 23 is adapted to cooperate with a worm gear 23 which is mounted on a suitably Journaled elongated sleeve 23*. 'I'he elongated sleeve 23* is internallyscrew-threaded to receive a screw21, which is secured to the free end of the'other of thelinks 3 by a pin 21..

A magnetic b e 23 is provided for the motor 23. A latch 1 is secured to the horizontal shaft 3 and is adapted to make contact on its outer end with a wear-plate 3'I which is secured to the mandrel bar carriage 3.

,The horizontal shaft 3 and latch 1, which is secured thereto, are adapted to be partially rotated by means ofa rod 1*, which is secured to the shaft 3 at one of its ends in a suitable manner, and to the piston of an air cylinder 1* at its other end.

'A suitable and conventional electrical wiring circuit including a pyrometer device, relays. and preferably also pushbuttons, is provided for the motors 3 and 23, the magnetic clutch device Il and the magnetic brake 23 for the motor 423.

'Ihe rotation of the motor 3 is automatically compensated for diil'erences in theresistance to metal displacement caused by introducing metal of varying temperatures into the rolls. The operation is such that the variations in temperature of the work-piece being processed, as measured by photoelectric, optional radiation or other pyrometer, will be transmitted to the motor 3 in suchmannerastoincreaseorretardtherotation thereof, thereby varying the rate at which the compensator operates.

In operation, upon the entry of a pipe or tube described. As before stated, the'rate at which the motor operates is controlled through suitable resistance, modied by the action of the pyrometer. gear' reduction 'I I and shaft I 3, through the magn etic clutch I5, is transmitted to the worm I1, coupling I3 and, by means of shaft I3, the worm 23. 'I'he worms I1 and 23 will rotate the worm gears 24 and 23, and their respective sleeves 24* and 26*. The action will cause the screws 2l and 21 to draw the links 3 and attached support 5 backward, or away from the mill, and accordingly permit the same movement of the mandrel bar 4 and the plug B on `theother end thereof. A tendency of the plug, mandrel bar and mandrel bar carriage to move backwardly will, of course, be caused by the action of the work-piece in the mill. This motion will be slowly permitted, as determined by the'suitable.l resistance described, until the work-piece has passed through the mill.

'I'he rotation of the shaft I6, which is transmitted to the shaft I3 by means of the coupling I8, will cause the shaft 23* of the motor 23 to rotate idly, when the motor 3 is energized to withdraw the mandrel bar carriage.

After the work-piece has. passed throughthe mill, the mandrel bar carriage and attached mandrel bar must be quickly returned in order to position the mandrel plug (not shown) in its initial position in the mill, before the next tube or work-pieceds introduced into the rolls A.

The operator attending the device, or a suitable relay, momentarily -energizes the magnetic brake 23 for the motor 23. 'I'his operation at the same time instantaneously deenergizes the magnetic clutch I3 and disengages the motor 3. The motor 23 is then actuated to reverse the direction of rotation of the worms 23 and l1 to rapidly return the support 3 to position preparatory to-rolling the next work-piece. -At the proper and predetermined position, the action of the motor 23 is arrested by' a suitable limit switch, which also applies the brake 23 for the motor 23.

As before stated, the motor 23 will rotate when bar carriage but, upon the return straks of the carriage, when the motor 23 is enerdned, the magnetic clutch Il ,is ,deenergized preventing rotation of the gear reduction, generally indicated at II, and the'motor 3.

Referring to Figures 5 and 6 of the drawings, I have disclosed in s diagram one form of electrical control which'will function to operate the elements of the invention in the manner previously described. In this diagram the numerals 33 and 3I designate suitable power lines carrying normal voltage; such as 220 volts.

In order to satisfactorily control the operation of the motor 3, a wire 33 is connected between the power lines 33 and 3|, and includes a starting switch 34 and a coil 33.` A line 33 connects the line 33, between the power line 3| and the starting switch 34, to the line 33, between the starting switch 34 and the coil 33.

'rms` une n includes a manually opera' stopping switch 33 and a pair of contacts 3l* which are operated by the coil 3l. A line 33 connects thel line 33, between thel contacts 33* and the line 33, with the line 33 between the coil 3l and the power line 3|. This line includes a coil 43 and a pair of contacts 3l", the latter valso ...une

'I'he motion transmitted by the motor 3,l

=the action of the motor 3 withdraws the mandrel 83, and a pair of contacts 80, the latter being.

being operated by the coil 35. A line 4| is connected to the line 36,- between the contacts 35e and the line 33, and to the line 38 between the coil 40 and the contacts 35". This line` 6| has included in its circuit a pair of coils 62 and 43 and -an auxiliary magnetic switch M.

The motor 8 is connected between the power lines 38 and 3| by a line 8 which includes two pairs of contacts, as at 82 and 63a, which are operated by the coils d2 and 83, respectively. This line 66 also includes a pair of contacts d8 between the power line 30 and the motor 8, and a pair of contacts B8 between the contacts d2 and 83 and the power line 3|. The contacts dllB and 30h are operated by the coil iii and likewise the auxiliary contacts dt The photoelectric pyrometer device, which is generally indicated at X, is connected by a line d8 with a series of relays d8, 58, 5|, 52, 53 and 54. These relays form a part of'a field rheostat 55 which eects an automatic speed adjustment for the motor 9. Each of these relays is adjusted to trip at a denite temperature. This eld rheostat is connected between the power lines 38 and 3| by a line 56. This line 56 has included therein, between the power line 30 and the eld rheostat 55, the shunt eld for the motor 9, which is designated at 9a, and a hand-operated rheostat 51.

Referring to Figure 5 of the drawings, it is to be noted that the motor for rotating the usual metal working rolls is diagrammatically shown at 58, being connected by a line 59 between suitable power lines 80 and 8|. While one motor 58 is'illustrated in the drawings and may be employed to drive both of the metal working rolls through the medium of suitable gearing (not shown), the invention also contemplates the driving of each roll with an individual motor..

higher voltage than that furnished through the power lines 30 and 8|; as, for instance, 600 volts. A shunt is included in the line 5d between the power line B8 and the motor 58. A pair of lines 68 and $1 connect the shunt 85 with a load relay $8. The magnetic clutch i5 which is carried on the shaft i8 is connected between the power lines 38 and 3| by a line 18, which has included therein two pairs of contacts, as at 68B and 68h, one on either side of the magnetic clutch. The magnetic brake 28 is connected by a line il with the power Alines 38 and 3| and includes in its circuit two pairs of contacts, as at t5 and 85|. A line i3 is connected to the line 18 between the power line 38, and the contacts 88B, and to the line 1| between the contacts 85 and the magnetic brake 28.' Thisv line 13 includes a pair of contacts 68. A similar line 'B4 is connected to the line 18 between the power line 3i andthe lline 38 and the starting switch 18 with the line 11 betweenthe starting switch 18 and the limit switch 18. This line 8| includes a stopping switch operated by the coil 88.

A line 84 connects the line 8| between the contacts 80B and limit switch i9 with the line 11 between the coil 88 and the power line 3|. The line 84 has included in its circuit a pair of coils 85 and a pair of contacts 80h, the latter being operated by the coil 88. A line 81 is connected to the line 8| between the contacts 88 and the limit switch 19, and to the line 84 between the coils 85 and the contacts 80h. cludes in its circuit a pair of coils 88, 89 and'an auxiliary switch 85e, the latter being operated by the coils 85.

, y The coils 85 of the line 84, in addition to operating the auxiliary magnetic switch 85e, also operate the contacts 85e and 85h in the line 1|.

The motor 23 is connected between the power lines 30 and 3| by a line 98 which has included therein al pair of contacts 88a and 89a which are operated by the coils 88 and 8S, respectively, of the line 81, A pair of contacts are disposed in the line 98 between the motor 22 and the power line 38 as indicated at 85; while asimilar pair of contacts 85d are disposed in the line 90 between the power linev 3| and the contacts 88B and 89a.

A line 8i is connected between the power lines 3@ and 3i and includes the shunt eld for the motor 23, which is designated at 23a, and a handoperated irheostat 93.

The energization of the load relay 88 closes the contacts 68 and 68 in the line 1G, and the contacts 88c and 88d in the lines 13 and 18, re-

spectively.

The limit switch 19 is arranged in such manner as to be opened by the movement of the This line 81 inmandrel bar carriage 3 to its original position in the mill, prior to the processing of a work-piece.

In operation: The operator of the mill closes the starting switch 38 for the motor 8, thus energizing the coil 35 (which is maintained by its contacts 358), thus closing the contacts 35B and 85 and energizing the coil 48 to close the contacts dit? and dill. The closing of these contacts and the contacts of the auxiliary switch M, which they eiect, starts the motor 8 whichwill attain a speed of rotatie-n which is predetermined by the setting of the hand-operated rheostat 51. The closing of the contacts of the auxiliary switch it energides the coils 2 and '43, thus closing the 25 and csa.

contacts As the work-piece (not shown) enters the mill, the power` required bythe motor 58 in driving the metal working rolls passes through the shunt 65. This causes a voltage drop across the shunt, and energizes the load relay 68, which causes the closing of the contacts 68, 58h, 88 and 68d. The closing of these contacts energizes the magnetic clutch i5, and the magnetic brake 28. The

accompanying coupling of the clutch and the releaseof the brake mechanically connects the motor 8, which is running, as previously mentioned. 'I'he motor 8 withdraws the'g mandrel bar carriage 3 of the mill at a speed which' is predetermined by the setting of the hand-operated rnetat t1.

, The photoelectric pyrometer device, which is generally designated at X, is set for a predetere mined temperature indication. and if the temperature of the work-piece as it passes the point upon which it is trained, is either above or below this indication, the relays 49 through 54, inclusive, are individually, and progressively excited and caused to function. The functioning of these relays will include, or delete, sections of the field rheostat 55 to increase, or decrease, the speed of operation of 'the motor 8. It will thus be seen that the rate of withdrawal of the mandrel bar vcarriage 3 is indirect proportion to the temperatue of the work-piece being processed in the mill. That is to say, the size of the pass will remainA constant regardless of variations resulting from expansion of the mandrel plug and rolls, which is, in turn, due to temperature changes. 'I'hese changes in temperature take place upon the entry into the mill of each highly heated work-piece.

'Ihe power required by the motor, or motors,

\ V5i! which drives the metal working rolls of the approach zero, and in consequence thereof the deenergization of the load relay 58. The ,Ideenergization of this load relay opens the contacts 48", 68h, Sac and 68d, to deenergize the magnetic clutch l5 and the magnetic brake 28. This last operationv uncouples the clutch and applies the brake to stop the motor 9.

,After the operator has removed the work-piece from the mill from the usual discharge trough (not shown) and returns the mandrel bar to the usual position, he operates the starting switch 18 for the motor 23. The operation of the starting switch I8 for the motor 23 energizes the coil 80 (which is maintained by one of its contacts 80.) and closes the contacts 80* and 80h; thus energizing the coils 85. The energization of thel coils 85 closes the contacts 85, 85, 85 and 85d and the contacts of i drel bar carriage 3 to its original position in the mill, which isv predetermined by the location of the limit swith 18, the latter opening when this position is reached. The opening ofthis limit switch deenergizes the coil 88, thus opening the contacts .88* and 88, thereby stopping -the operation of the motor 28 and eiecting. the application of the magnetic brake 28. all by the opening of the various contacts 85,A 85h, 85 and 85, and the contacts of the auxiliary `switch 85, which is caused by the deenergization of the coils 8l.

'Ihe equipment' is now ready for another cycle of operation, which is eiected by the entry of a second work-piece between the rolls of the mill which are driven by the motor 58. 'Ihis effects a second "voltage drop" across the shunt 85, which energizes the load relay 88, thus repeating the operation previously described.

While I have shown and described certain speciilcl embodiments of my invention, it will be un- ,derstood-that I do not wish to be limited exactly thereto, since various modiiications may be made without departing from the scope of my invention, as deiinedf'by the following claims.

I claim:

1. A seamless pipe or tube mill comprising in 'combination at least one power actuated metal -working roll, a roll for coacting with said rst of said mandrel plug is adjusted with respect to said rolls, means responsive to the temperature of said pipe or tube for modifying the. rate of 'speed of said last named means, and means for returning said carriage to its initial position.

2. A seamless pipe or tube mill comprising, in combination, at least one power actuated metal working roll, a roll for` coacting with said ilrst named roll, a movable carriage, a mandrel bar connected to and extending from said movable carriage, a mandrel plug carried on the extended end of said mandrel bar, said mandrel plug being adapted for disposal intermediate said rolls, a support adjacent said carriage, means on said support-for making contact with said carriage, means for moving said support away from said rolls while a pipe or, tube is being acted upon by said rolls and said mandrel plug, said last named means permitting said carriage to likewise move away from said rolls, whereby the position of` said mandrel plug is adjusted with respect to said rolls, means responsive to the temperature of said pipe or tube for modifying the rate of speed of said last named means, and means for returning said support and said carriage `to their initial positions.

3. A seamless pipe or tube mill comprising, inA

combination, at least one power actuated'metal working roll, a roll for coacting with said rst named roll, a mandrel bar, a mandrel plug carried by said mandrel bar, said mandrel plug being adapted for disposal intermediate said rolls, means for withdrawing said mandrel plug from said rolls to maintain a desired relationship between the surfaces of said mandrel plug and said rolls while a pipe or tube is being acted upon thereby, means responsive to the temperature of said pipe or tubefor controlling the speed of operation of said withdrawing means, and-means for returning the withdrawn mandrel plug to its initial position.

`4. A seamless pipe or tube mill comprising,`in combination. at least one power actuated metal working roll,a roll for coacting with said iirst for expansion and-maintain substantially constants soy the distance between the surfaces of said mandrel plug and said rolls while a pipe or tube is being acted upon thereby, means responsive to the temperature of said pipe or tube for controlling the speed of. operation of said withdrawing means, and means for returning the withdrawn mandrel plug to its initial position. L

N FINDLATER.

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