US2603989A - Continuous rolling mill - Google Patents

Description

y 22, 1952 J. w. SHEPERDSON 2,603,989

CONTINUOUS ROLLING MILL Filed March 5, 194' 3 Sheets-Sheet l & 22 22 j'zz a] 22 g :f A igfgigf; 1' 3' q g INVENTOR.

JOHN W. JHEPE/PDS ON A TTORNEY y 22, 1952 J. w. SHEPERDSON 2,603,989

CONTINUOUS ROLLING MILL Filed March 5, 194' 3 Sheets-Sheet 2 O Il 33 34 Fig. 5 32 Z9 E Fig.7-

- 60 INVENTOR.

JOH W, JHEPERDSON I I BY Zz 22 in the bar;

Patented July 22, 1952 CONTINUOUS ROLLING MILL John W. Sheperdson, Worcester, Mass., assignor to Morgan Construction Company, Worcester, Mass, a corporation of Massachusetts Application March 3, 1947, Serial No. 732,034

3 Claims.

This invention relates to continuous rolling mills, and more particularly to continuous mills arranged for the hot rolling of metal bars and commonly known as merchant mills, although the invention may be applicable in certainrespects to other types of continuous mills.

The usual merchant mill includes a plurality of roll. stands through which the bar travels successively, the spacing and arrangement of the roll stands being such that the bar will extend through several or all of the stands simultaneously. It is customary to form a loop in the bar between certain stands in order to relieve the bar of tension. If the loop is allowed to grow freely a considerable spacemust be provided to accommodate such growth. Accordingly in some instances the size of the loop has been controlled by means of regulating apparatus actuated automatically by the looped bar itself. In general however such prior apparatus has been of a dellcate and flimsy construction likely to be rendered It is a further object of the invention to provide a continuous rolling mill having a series of roll stands with looping tables between successive stands, and control apparatus for regulating the speeds of the roll stands in accordance with variations in the sizes of the adjacent loops, the

control apparatus being of a rugged construction which will be unaffected by mill scale and undamaged by cobbles.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in 1 traveling from one roll stand to the next;

: Fig. 3 is a view similar to Fig. 2, showing the position of the parts after a loop has been formed Fig. 4 is an enlarged section taken approximately on the .line 44 of Fig.2;

Fig. 5 is an enlarged sectiontaken approximately on the line 5'5 of Fig. 3;

Fig. 6 is an enlarged section taken approximately on the line 66 of Fig. 2;

Fig. '7 is an enlarged section taken along approximately 0n the line 1--"! of Fig, 2; and

Fig. 8 is an electrical wiring diagram showing a means for controlling the speed of. one roll stand.

In Fig. 1' there is shown diagrammatically a plurality of roll stands Ill, ll, I2, I3 and I4 arranged in a longitudinal row so that a metal bar may pass through them in succession. These roll stands are driven by electric motors l6, l1, l8, I9 and 20 respectively. As shown, the roll 1 standsare alternately horizontal and vertical, so

that, twistguides are not required. Between each pair of successive roll stands there is provided a substantially horizontal table 22 on which a loop may form in the bar, in order that the bar may be rolled without appreciable tension.

One of these looping tables 22 isshown on a larger scale in Figs. 2 and 4. It will be seen that an upstanding flange 24 isformed on the table along the outer side of the path of the bar 3 as it travels in a direct line from one roll stand I I to the receiving guide 25 of the following roll stand B2. The table is preferably slightly inclined upwardly away from this flange. On the inner side of the path of the bar there is provided a row of guide blocks 26 which are arranged to project upwardly through openings 21 in the table. These blocks 26 are connected to one another beneath the table to form an integral unit or member 29. This member is provided with ears 30 (one only being shown) which are pivotally supported on a horizontal rod 3| (Fig. 4) beneath the flange 24. An arm 32 extends downwardly from the member29', and a link 33 connects this arm to the slidable piston rod 34 of a suitable fluid motor 35. These parts are so constructed and arranged that after the front end of the bar 3 has entered the roll stand l2, the member 29 may be swung downwardly, asshown in Fig. 5, to

permit the bar to move over the topsof the blocks 26 and form a loop on the table 22.

In order to assist in the formation of the loop, the flange 24 is shaped to provide a pocket 31 (Figs. 2 and 6) for the reception of a'yoke 38 which carries an upright idler roller 39 positioned at the outer side of the path of the bar, near the entrance end of the looping table. This yoke 38 is pivotally supported by a vertical pin 40 beneath the table, and'the table is provided with an opening 4| within which the roller. 39 may travel as the'yoke is moved about its pivot. Such move- The invention provides a means whereby the size of the loop in the bar will be controlledautomatically. For this purpose the table22-'is" provided with an opening 58 at the inner side of-the guide blocks 26. Within this opening :there is mounted a group of electrical contact 1blocks'5l;

52, 53, 54, 55 and 56. These blocks are arranged in two rows extending approximately 'at'right angles with the path of travel of the bar, the blocks in one row being staggered with respect to theblocks. in the other row, and they project upwardly slightly above the" top of the table so thatthe looped bare may make Contact with them.

Furthermore, the 1 blocks "in ,each' row slightly overlap the blocks in'the other row, in a direction lengthwise of.,the.rows,in, order that the bar'will alwayslbein contact with at least one block while the loop is under automatic control. 'Asfshown inFig. '7, the upper surfaces ofthe blocks. are

rounded to avoid scratching of the bar. 'The blocks are electrically insulated from one another and from the table ,22', and for this purpose each block is sl'ottedto fit 'overtheflupper portion of an upright plate '58 of electrical insulatingmaterial. ,The 'lower portions of the ,plates are secured to beams .59 'whichzare connected to. the bottomjof the table 22 by" suitable brackets 60.

Conduits 82 are provided ad'j'acent'thebeams' ,59 to enclose wires'leading to theseparatecontact blocks. Depending skirts 6,3,areprovided onvthe blocks to'p'rotect the conduits from damage by cobbles and'to prevent sh'ortfc'ircuits by mill scale which may drop through=the opening'5ll. j'Itv will "be noted that the blocks". are spaced appreciably from one another and from the edge of the opetm so.

In Fig;- 8 there-is shown diagrammatically certain electrical apparatus "whereby the speed ,of the motor- I81 may "be controlled automatically, and it will be understood that'the's'peefds of ,the motors 11; 9 and 20'may"be'controlled' by similar means. Theinormal speed ofeach motor is such, in relation to the speed of the motor driving the preceding roll'stand} that: aloop "willflstart to *fo'rmandto increase in sizefas soonfasthejfront end of 'the' bar enters ther'rolls. The automatic control simply prevents this? loop from growing beyond a predetermined size. "As jshownfthe motor I 8' is ofawell-knownty'rw havingan armature' fiiand a field fifi. ""lfhe armatureiliimay be connected to adirect current. sourcef't'l through a 'switch'fifi. "The field 188 ma be connected to. ,a

' "direct" current source" fisfthroiigh aiswitch "10. Resistance units 12, I3,

4 The coils 88, 8|, 82, 83 and 84 also control normally open switches 88b, 81b, 82b, 83b, and 84b respectively which are connected between the ground at 81 and the respective contact blocks 5!, 52, 53, 54 and 55. As indicated at 88, the bar B is grounded by its contact with the various -rol ls,:tables, and the like.

The operation of the invention will now be apparent from the above disclosure. The previously heated metal bar B will travel successively through the roll stands [0, I I, l2, l3 and M, with -=a'-reduction in bar cross-sectional area taking place in each stand. Ordinarily the bar will exand close ;the switch 801). Opening the switch connected ,in- *series with" the I field 1 66, 1 but i.

size these units are allQshort-circuited. ,Forthis purpose there," are provided. magnetic contactors having coils 19,80; 8|, 82. "Bland 84 which ,conitrol normally closed switches 19a, 80a, 8461,8211, 83a, and 34a respectively, :these switches being "connected .inishunt with the resistance units 12, 13, 14,15, lfifland ll respectively. 'Ihecoils l9, "88, 8 I, 82, 831; and .84 are connect'ed between a source ..86f..of positive electrical potential-and the respective contact. blocks 5 I, 52. 53,54; 55and. 56.

the loopQ-inthebar has reached a predetermined tend through all of'these roll stands during most of the rolling operation. As the front end of each bar leaves the roll stand I I and reaches the following 'table 2 2, as shown in Fig. 2, it will travel --in a straight path between the flange 24 on one side and the upwardly projecting blocks 26 on the other side, thereupon passing through Fthejguide 25 and entering'the roll stand l2. As soon as'ithis occurs the operator will admit pressure fluid to the fluid motors 35 and 43, thereby lowering the guide blocks 28 (as indicated in 'Fig.

5) and swinging the idler roller 39 to the position shown in" Fig. 3, thereby forming a loop in the bar on the table 22. As the loop starts to' form, the motor 18 will be operating at a relatively low :speed, since the switches [90. to 84a inclusivewill I alljbe closed, thus shunting the resistance units 'lzf'to" 11, inclusive, and producing a relatively "strong field 66, the switches '68 and ill of course being closed. Accordingly the loop will continue toincrease insize and move outwardly across ,the 'table22. u'ntilit makes contact with the blockil and grounds the same. This will establish a circuit from the source 88 through the coil 19 to ground, energizing this coil and opening the switch 19a, therebyrendering the resistance unit 'l2'efiective to reduce the energization of the field {GB-and increasing the speed of the motor 18 slightly. This will reduce the rate of growth or the loop, but ordinarily itwill nevertheless corrtinue "to .grow'until it makes contact with the next block 52, grounding'thisblock and energizing thecoil 80. "Thiswill open the switch a -8fla-will"render the'resistance unit 73 effective to speed up the motor [8 still further, and closing the" switch -80b-willmaintain a circuit through ="the'-'coil 19 even after the loophas moved w'ardly out of contact with the block 5!. If the loop 'stillgcontinues to grow, it will make contact -With-the block 53 and ground the sa'me,'thus "energizing the' coil 8| opening the switch I8la :and closingthe switch8lb. This will-render the resistance unit 14 efiective toflincr'ease thespeed of the motor |8still further and at the sameti-me maintain-a circuit through-the coil 80 even after thef'loop'has moved I outwardly out of-contact with thegblock 52.

I In. a similar .manner,-if the loop nevertheless continues to grow, it willgrounclthe block 54,,then-the block .55, and possibly-eventhe .bl'ock156, which will result in shunting-all the resistance units 1'12 to ll inelusivezand surely-provide sufiicientrspeed-for the-rolls I-2"to reduce the size of the'loop.

. Any appreciable reduction inthe 'size of {the loop will result-in a slowingrdown of the "rolls d2.

'Ihus if theloop moves inwardly out ofcontact withtheblock 56- and into'contact-with the block -55,-the coil 84- will be de-energ'ized," closing switch 84a and opening switch 84b. This will shunt the tresistancezunit 11 and cause a corresponding decrease in the speed io'i themotor l8. -=O"peni-ng the switch 841) will ensure the de-energization of the coil 83 in the event the loop moves inwardly out of contact with the block 55. Thus any variation in the size of the loop will cause a change in the speed of the rolls I2 tending to oppose such variation, and the loop will remain within the size limits determined by the positions of the inner and outer blocks 5| and 56 respectively.

As soon as the rear end of the bar has left the looping table, the operator will restore the guide blocks 26 and the roller 99 to their original positions by means of the motors 35 and 43, in preparation for the arrival of the next bar. The several looping tables 22 may all be similar in construction and mode of operation.

It will be apparent that the invention provides a simple and dependable continuous rolling mill in which bars may be rolled without tension. Loops are formed between successive roll stands, and these loops are controlled by automatically varying the speeds of the roll stands. This automatic control is brought about by engagement of the bar with contact blocks so arranged that the bar itself forms a portion of an electrical control circuit. These blocks are constructed and mounted in a rugged manner, and they are very unlikely to be damaged by cobbles. Any loose scale which may drop from the bar as it travels across the blocks is free to fall through the opening 50 in the table without causing short circuits or other difiiculties. The slight inclination of the table 22, shown in Fig. 5, is helpful in maintaining good electrical contact of the bar with the blocks.

Having thus described my invention, what I claim as new and desire to secure by Letters Paten is:

1. A continuous rolling mill comprising a first and second roll stand through which a metal bar may travel successively and thereby be subjected to successive reductions, a substantially horizontal looping table located between the roll stands, means to drive the roll stands at such relative speeds as to cause a portion of the bar to accumulate between the stands, means to deflect the portion of the bar between the stands in a lateral direction and thereby form a loop in the bar in a substantially horizontal plane on the table, a series of stationary blocks associated with the table and electrically insulated from the table and from one another, the upper surfaces of the blocks being located slightly above the upper surface of the table, the blocks being in position to be engaged successively by the looped bar and thereby be electrically grounded as the loop increases in size and the bar travels over the tops of the blocks, means responsive to the grounding of the successive blocks to alter the speed of one of the roll stands successively in a manner tending to limit the growth of the loop, a guide associated with said table for directing the bar toward the second roll stand, and means retracting the guide to permit said loop to be formed by said deflecting means after the bar has reached the second roll stand.

2. A continuous rolling mill comprising a pair of roll stands through which a metal bar'may travel successively and thereby be subjected to successive reductions, a substantially horizontal looping table located between the roll stands, means to drive the roll stands at such relative speeds as to cause a portion of the bar to accumulate between the stands, means to deflect the portion of the bar between the stands in a lateral direction and thereby form a loop in the bar in 'a substantially horizontal plane on the table, a series of stationary blocks associated with the table and electrically insulated from the table and from one another, the upper surfaces of the blocks being in position to be engaged successively by the looped bar and thereby be electrically grounded as the loop increases in size and the bar travels over the top of the block, and means responsive to the grounding of the successive blocks to alter the speed of one of the roll stands successively in a manner tending to limit the growth of the loop, said table being provided with an opening to receive the blocks, the blocks being spaced from one another and from the edge of the opening so that mill scale may readily drop through the opening.

3. A continuous rolling mill comprising a pair of roll stands through which a metal bar may travel successively and thereby be subjected to successive reductions, a substantially horizontal looping table located between the roll stands, means to drive the roll stands at such relative speeds as to cause a portion of the bar to accumulate between the stands, means to deflect the portion of the bar between the stands in a lateral direction and thereby form a loop in the bar in a substantially horizontal plane on the table, a series of stationary blocks associated with the table and electrically insulated from the table and from one another, the upper surfaces of the blocks being located slightly above the upper surface of the table, the blocks being in position to be engaged successively by the looped bar and thereby be electrically grounded as the loop increases in size and the bar travels over the tops of the blocks, means responsive to the grounding of the successive blocks to alter the speed of one of the roll stands successively in a manner tending to limit the growth of the loop, and a guide located between the direct line of bar travel from one stand to the other and the stationary blocks, the guide providing a barrier to prevent lateral movement of the bar toward the blocks, means being provided whereby the guide may be lowered after the front end of the bar has reached the second bar to allow formation of the loop.

JOHN W. SHEPERDSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,170,153 Henderson Feb. 1, 1916 1,443,223 Knight Jan. 23, 1923 2,193,189 Brooke et al. Mar. 12, 1940 FOREIGN PATENTS Number Country Date 598,311 Germany u, June 8, 1934

Images