US2809545A

US2809545A - Arrangement for rolling straight bars at high rolling speeds

Info

Publication number: US2809545A
Authority: US
Inventors: Norlindh Sven Erik Malte
Original assignee: Individual
Current assignee: Individual
Priority date: 1952-02-06
Filing date: 1956-11-01
Publication date: 1957-10-15
Anticipated expiration: 1974-10-15
Also published as: BE517421A; FR1187605A; GB743853A

Description

' 1957 s. E. M. NORLINDH 2,309,545

ARRANGEMENT FOR ROLLING STRAIGHT BARS AT HIGH ROLLING SPEEDS Filed NOV. 1. 1956 6 Sheets-Sheet 1 22 h LO LO LO IN V EN TOR.

ISVEN ER/k/7ALTE NORLINDH Oct. 15, 1957 s. E. M. NORLlNDH 2,809,545

ARRANGEMENT FOR ROLLING STRAIGHT BARS AT HIGH ROLLING SPEEDS Filed Nov. 1, 1956 6 Sheets-Sheet 2 FIGJ SVEN ERIK MALTE NORLINDH Oct. 15, 1957 s. E. M. NORLINDH 2,809,545

ARRANGEMENT FOR ROLLING STRAIGHT BARS AT HIGH ROLLING SPEEDS Filed Nov. 1, 1956 e Sheets-Sheet 3 FIG.8

I LJELL'WM 5v EN ER/K MALTE NORL/NDH BY kw 1 wig/Fw Oct. 15, 1957 s. E. M. NORLINDH ARRANGEMENT FOR ROLLING STRAIGHT BARS AT HIGH ROLLING SPEEDS 6 Sheets-Sheet 4 Filed Nov. 1, 1956 wmdmmm mw 3 3 mq om W 2 mm: Q or m mm qm .m an bm mm mm qmimiiqmqmm m o n m A. m m NF NAATIMWP .m N

INVENTOR SvEiv ERIK NALTE NOR L/NDH 1 J 29km Oct. 15, 1957 s. E. M. NORLINDH ARRANGEMENT FOR ROLLING STRAIGHT BARS AT HIGH ROLLING SPEEDS 6 Sheets-Sheet 5 Filed NOV. 1, 1956 I INVENTOR. 5v EN ERIK /7ALTE NORL/NDH BY 4 m, JJ MM Oct. 15, 1957 s. E. M. NORLINDH 2,809,545

ARRANGEMENT FOR ROLLING STRAIGHT BARS AT HIGH ROLLING SPEEDS Filed Nov. 1, 1956 6 Sheets-Sheet 6 FIG.13 FIGJS INVENTOR.

5vE/v ERIK/VALTE NORLINDH BY him/J WWW feet/min.) .designed' to roll down to 9.5 mm. (about diameter,

.up to the; previously cut .bar. -trated in Fig. 12 of .the drawings which'will "be later United States Patent ARRANGEMENT FOR ROLLINGI STRAIGHT BARS AT HIGH ROLLING. SPEEDS Thisinvention relatestoan improved apparatus for :rolling. straight I.bars at'high rolling speeds and in par- ;ticularto an improved means for cutting the rolled bar into lengths and conveying the same via switching chan- :nels and friction-braking guide ch'ann'els-to a-cooling bed.

In'the modern small section mills hitherto used, steel .hasbeen rolled in straight lengths upto a finishing speed :of :about meters/sec. (about 2,000feet/min;), usually with one or two strands. In the'case of two strands as a:rule;a. double runout roller table and-a twin cooling .bed have been used. During the last deca'des,-'however.

-;certain. designs have been developed with --a single cooling zbed,:together with four runout roller tablesplaced in ;four stories. The finishing speed has, hoewver, always been limited to about 10 meters/sec. (about 2,000 The small section -mills have usually "been :and in.certain cases even down to 7 mm.'(about-% diameter. .For smaller sizes, the 'output'becomestoo small. At 9.5 mm. (about %")-diameter, atheoretical outputof tons/hourat -10 m./sec. (about 2,000

ftJmin.) is obtained. At 7 mm. (about %2") diameter,

the output is theoretically as small as 10.8 tons/hour,

and at 5 mm. (about 0.2") diameter, it is only 525 tons/ hour.

After the finishing stand, the bars are cut'by means of a rotary shear into a suitable number of cooling bedlengths. In this way,'the weight of the'billets can bekept high, e. 'g. 150 kgs. (330 lbs.). With regard'to theconsiderably lower output of the smallest sizes .of

.bars, they are very expensive to roll.

at a-higher finishing speed than 10 m./sec. (about.2,000

ft./min.).

The difiiculties inguiding the bars athi'gh speeds onto a cooling bed'of conventional design are due'to the f following facts.

( 1) The uneven surface of the runout roller'table caused by the rollers veryeasily gives the front end of the bar a wrong direction so that the'front'end'turns .upwardswand then into any other direction. This is especially true for the smallest sizes of barssince these areconsiderablymore flexible and tend to take a-wrong direction at their front ends.

(.2) 'The elevating flaps or the sweep-off fiaps'easily give the frontends ofvthebars a wrong direction when they are carried over to the cooling bed.

(3) At'higher speeds, the. brakingperiod and stopping distances. are increased so that the following bar catches described in detaiL This phenomenon is illus- 7 A bar-of carbonlsteellthat runs out freely and is'braked by' the friction caused .by itsown weight against apron :platesof-cast iron or wrought iron, has a coefi'icient of iriction =about 0.3. .At a finishing speed of 5.9 m./ sec. 5 :(l,160 ft.'/min.) and with =0.3, thebrakingperiod is 2 secondsand the stopping distance is 5.9 m..(19.3 ft.). At a finishing speed of.11.7 m./sec. (about 2,300 ft./min.) thebrakingperiod is 4 seconds and the stopping distance .is 23.2 ma (76 ft.). Ifsuch a bar is cut every'four sec- :nonds the previously cut barhas reached the speed zero, :i. .e. it stops at the very instant when the following .cooling .bed length is-.cut. Fig. 12 shows how the two .barsroverlap eachother. When the finishing speed is 20.4 m./sec. (4,000 itlmin.) the braking period is 7-l seconds andithe stopping distance is 71.5 m. .(235 ft). fFig. .12. il1ustrates'how thebars overlap each other :when they-are cut every two, every three, every four and-every fiveseconds.

:As has already been :mentioned in my co-pending illnitedrStates applicationSerial No. 266,419,'filed January 14, 1952, relating to a plant layout for medium section, smallasection, wirerod and strip rolling mills, the bar is cutinto bed lengths just aftervthe finishing sstand ofithe wire rod train. The bars can then slide t throughpipes'toi the coolingbed and the distance between .the;rotary.shear andthe cooling bed is adapted to the speed, .in order that the bars will be friction braked :to-a standstilljust above the cooling bed. The present .invention is .characterized in that the cut-off cooling .bedzlengths. are,.by. means of switching channels, directed .into different elongated guide channels wherein the slide and brake themselves by friction to a standstill at .a point just above the cooling bed and are then transxferredonto the cooling bed.

.Theinvention is illustrated in the accompanying drawings wherein:

.Fig. 1-.is, aschematic side view showing the improved arrangement of switching channels and guide channels ;for leading the cutbarlengths to the cooling bed;

Fig. 2 is a view similar to Fig. 1 but showing the elements in' plan;

Figs. 3-7 are: transverse sections. taken on lines III- 1H, IVIV, -VV,"VIVI and VIIVII, respectively in "Fig. 1;

Fig. 8 is a section showing in detail alower part in Fig. 7;

.Figs.,9 and 10 are views similar to Figs. 1 'and 2 but showing amodified embodiment of.the invention utilizing additional switching channels and two cooling beds instead of one;

Fig. 11 is a schematic'sectional view of the cooling bed, the view being taken on line XI-)G of Fig. 10;

Fig. .12 is a tabulationand chart indicating the move- 'ment of-the bars when .braked by their ownfriction against the .guide channels atdifferent finishing speeds and when'cut into different lengths, and

Figs.-1517.are various views of the revolvable shear -device whichcutsthe continuously running high speed rolled bar'stock into cooling .bed lengths as the first switching channel is shifted between its two delivery positions.

-With reference now to theembodiment of the invent-ion-illustrated inFigs. .1-8, the referencenumeral 1 indicates the finishing stand, the delivery guides from'the stand 1 arevindicated by numeral 2, and the first switch .ing pipe or channel and which is located between the .delivery guides :2 and a revolving shear device 5,is

indicated by numeral 3. The delivery-end of switch 0 .channel 3 is connected to thepiston of a compressed air operated cylinder 4. and which functions toshiftthe 'deslivery endof switch-channel 3 back and forth between .twn. delivery. positions as shown in Fig. 3 and also-in Theshear devicei'. is 'locatedlbetween thev deliveryend of switch channel'Sandthe inlet. ends of;the pair of switching channels .6 and 7 and functions to cut the. conrtinuously. running bar stock into lengths each time the switching channel '3 isshifted from one delivery position i to' the other. .The:delivery ends of the pair of switchin'gchannelsfi and 7. are eachconnected respectively to

pistons

8, 8 of other compressed air operated cylinders and are reciprocated in alternation. between upper and lower delivery positions: A guide or braking channel is provided for each delivery position of the switchingchannels 6 and 7'." Consequently, as'shown in Fig. 5, the

"guide or;

braking channels

9 and 11 are associated with the two delivery positions of .switching channel 6, and

guide or braking:channels: and .12 are associated with the two'delii/ery positions of switching channel 7..

The construction. and operating sequence for the revolving shear device situated between the delivery end of switching channel 3 and the stationary entrance ends of the next following pair of switching

channels

6 and 7 is illustrated in Figs. 13 to 17. Therevolvingshear device is comprised of a pair of rotary driven disc shears 5 supported on a housing 5a which contains the drive 'mechanism for the shears 5 and housing 5a is supported by a vertically extending shaft 512 in such manner as to enable the housing 5a to be revolved back and forth about the axis of shaft 5b between the two positions. shown respectively 'inFigs. 14 and 16 and Which are 90 apart.

- A' pressure air cylinder 4a is utilized for this purpose and its piston is connected to the shear housing 5a. The axis of shaft 5b coincides with a line passed through the centers of the disc shears 5 and the latter are also thereby revolved back and forth between two cutting positions 90 apart. Fig. 13 shows the positions of the shears 5 and stock S as related to Fig. 14 wherein the switching channel 3 is feeding the stock into switching channel 6, and me similar manner, Fig. 15 shows the positions of the shears 5 and stock S as related to Fig. 16 wherein the switching channel 3 is feeding the stock S into switching channel 7.

With reference to Fig. 14, it is seen that the rolled stock coming through the guides 2 passes through the switching channel 3 and the next switching channel 6 into one of the two

guide channels

9 or 11 associated with the delivery end of switching channel 6. When a cut is to be made, the pressure air cylinder 4 is actuated to thereby shift the delivery end of switch channel 3 r from the position shown in Fig. 14 to the position shown in Fig. 16. This movement causes the stock S to be pushed in the direction indicated by the arrow in Fig. 13 'into the shears 5 where it is gripped by them and cut off. The cut ofi length of stock then passes through channel 9, for example, in sliding contact therewith and 'is gradually braked to a standstill upon reaching the cooling bed 73. Just after the cut is made, the pressure air cylinder 4a then operates to revolve the shears 5 to the position shown in Fig. 16. The following part of the stock then passes by the shears 5 into the entrance end of switching channel 7 and thence through the same into one'of the two

guide channels

10 or 12 associated with the delivery end of switching channel 7.

When the next cut is to be made the pressure air cylinder 4 is again actuated to shift the delivery end of channel 3 from the position shown in Fig. 16 back to theposition shown in Fig. 14 and the stock S is simultaneously pushed in the direction indicated by the arrow in Fig. 15 into the shears 5 where it is gripped and cut 013?. The cut off length of stock then passes through channel 12, for example, and is gradually friction braked to a .standstill as it reaches the cooling bed 73.

The next following portion of the stock to be cut off feeds -through switch channel6 and. into guide channel 11 as air cylinder 8' shifts the delivery end, of switch channel 6 from its upper to its lower position, see Fig. 4, and the next following portion of the stock to be cut ofi feeds through switch channel 7 and into guide channel 10 as air cylinder 8 shifts the delivery end of switch channel 7 from its lower toitsilpper position, see Fig. 4.

The sequence of operations then repeats itself causing successivelycut off lengths to pass through guide and

friction braking channels

9, 12, 11 and 10' to the cooling bed 73.

The delivery. end portions of guide channels 9-12 are located near the cooling bed, are disposed horizontally one above the other asshown in Fig. 6, and are connected to the horizontally disposed terminal channels 81 as indicated in Figs. 7 and 8.

When a cut-off bar 80, Fig. 8, has stopped in the castiron channel 81, this channel, which is fastened to a tube 82, can be turned counter-clockwise, as shown for the lowermost channel 81 of Fig. 8, so that the cut falls down, for example, into the first cooling bed notch 61. 1

If the rolling speed in the finishing stand 1 is e. g. 20.4 m./sec. (4000 ft./min.), a cooling bed with the length D=8O m. (262 ft.), Fig. 2, and the. shear cuts every third second, the length of the cuts. will be C=6l.2=(200 ft). The stopping distance 'B at p.=0;3

V will be 71.5 m. (235 ft.), which shall be equal to the distance between the'rotary shear 5 and a short length into the cooling bed. In order to avoid that the tail end of the last out of the strand stops at a point considerably different from those ones of the other cuts the distance A from the finishing stand to the rotary shear must be short.

In Figs. 7 and 8 an upper cover 83 is shown for each channel 81 serving as a lid. Hereby the bar' becomes completely enclosed and a frictional drag is imposed upon thecut section until it has stopped. The difiiculties to control the movements of the first end of the bar which are very great, when using open runout roller tables, already at a speed of 11 m./sec. (2200 ftJmin.) arehereby eliminated and it is possible to roll at practically any speed. In order to secure a time margin long enough to let the cuts pass down from the guide channel 81, the length of the cuts must be suflicient or else the cuts have to be distributed into a sufiicient number of pipes and guide channels. See Fig. 12. At 20.4 m./ sec. (4000 ft./min.) and 40.8 m. (134 ft.) cutting-length three channels are filled the whole time and the interval from the time when a cut stops until the next one enters, is only 2.7 seconds with 4 pipes according to Figs. 1 to 8. At 61.2 m. (200 ft.) cutting-length this interval is 5.55 sec., at 81.2 m. (265 ft.) cutting-length 8.5 sec. and at 102 m. (335 ft.) 11.5 sec.

Each channel 81 with its cover 83 is preferably made in short sections with regard to the thermal expansion. The tube 82 has, however, just the same length as the cooling bed and can suitably be cooled with water, and rests on horizontal supports 84, on which the tube 82 can roll, when the bar is tipped on the cooling bed. See Fig. 8, the lower channel. The tubes 82 can suitably be guided by the

chains

90, 91 and 92, when each is operated by the compressed-air cylinder 88, turning the tube by means of the lever 89, thereby to discharge a cut-01f bar 80 from the associated channel 81. When the chain has been stretched, the tube cannot roll any further, and in the other direction the tube stops against the beams 85. The tube can possibly be placed upon supporting rollers or something similar. For guiding the bars towards the coolingbed notch 61 there are the vertical guide beams 86 and the inclined beams 87.

Figs. 9-11 illustrate a different embodiment of the invention and in which twin cooling beds are used'and also two additional sets of switching tubes. In this embodiment, the switching tubes 3 and 6', 7' correspond to the

tubes

3 and 6, 7 of the embodiment shown in Figs.

1-8. However, following the pair of switch tubes 6, 7' are two pairs of switch tubes 9', 10 and 11', 12' and the delivery ends of these tubes are shifted between two delivery positions by compressed air cylinders 14. Following the switch tubes 9'12 are four pairs of switch tubes 1522 and the delivery ends of these tubes are shifted between two delivery positions by compressed air cylinders 23. Following the tubes 1522 are two sets of guide friction braking channels, one set consisting of channels 3i38 leading to one half 72 of the cooling bed, and the other set consisting of channels 4148 leading to the other half 73 of the cooling bed.

Fig. 11 there are also shown auxiliary devices such as runout tables 69, 70 for coarser bars having a finishing speed of below 10 m./sec. (2,000 ft./min.). A footway 71 for workmen is located between the cooling beds 72, 73' and shufile bars 75 are provided to transfer a plurality of the bars to a cold shear roller table 77 for cutting the cold shear 79. Also shown in Fig. 11 is a nch roller device for moving the cut stock longitudiby a compressed air motor 97. The pressure roller clamps the bar close to the feeding roller as long as a light beam to a photoelectric cell 98 is not interrupted by the end i the bar. In this way each bar is drawn longitudinally to a position such that a rotary cold shear 99 can cut e. g. twenty bars at a time into finished lengths.

in conclusion it will now be evident that the present 'nvention makes it possible to roll rod stock at relatively sigh speeds and to cut and deliver lengths of the stock 0 the cooling bed via the multiple switching and fricn braking guide channels in such manner that the cut engths do not overtake each other in the channels and re brought to a standstill at the cooling bed.

I claim:

1. Guide channel means for delivering cut sections of rolled stock, said out sections travelling slidingly and in contact with the surfaces of said guide channel means thereby to frictionally brake said cut sections to substantially a standstill at the delivery end thereof, said guide channel means including a first switching channel for receiving at the inlet end thereof a continuous length of the rolled stock, means actuating said first switching channel to shift the outlet end thereof between two spaced delivery positions, a pair of switching channels having stationary inlet ends located respectively at the delivery positions of said first switching channel, a revolvable shear device located between the outlet end of said first switching channel and the stationary inlet ends of said pair of switching channels for cutting said continuous length of rolled stock as it emerges from the outlet end of said first switching channel into separate lengths for sliding movement through said pair of switching channels in alternation, means to revolve said shear device about its ads from one cutting position to another, the shearing action being efiected by moving the stock across the shears upon shifting of said first switching channel and said revolvable shear device being revolved alternately as said first switching channel is shifted from one delivery position to the other delivery position, means actuating each of said pair of switching channels to shift the outlet ends thereof in alternation between two spaced delivery positions, and guide channels having their inlet ends located respectively at each of the delivery positions of said pair of switching channels for receiving the separate lengths of rolled stock delivered by said pair of switching channels.

2. Guide channel means for delivering cut sections of rolled stock, said out sections travelling slidingly and in contact with the surfaces of said guide channel means thereby to frictionally brake said out sections to substantially a standstill at the delivery end thereof, said guide channel means'including a first switching channel for receiving at the inlet end thereof a continuous length of the rolled stock, means actuating said first switching channel to shift the outlet end thereof between two spaced delivery positions, a pair of switching channels having stationary inlet ends located respectively at the delivery positions of said first switching channel, a revolvable shear device located between the outlet end of said first switching channel and the stationary inlet ends of said pair of switching channels for cutting said continuous length of rolled stock as it emerges from the outlet end of said first switching channel into separate lengths for sliding movement through said pair of switching channels in alternation, means to revolve said shear device about its axis from one cutting position to another, the shearing action being effected by moving the stock across the shears upon shifting of said first switching channel and said revolvable shear device being revolved alternately as said first switching channel is shifted from one delivery position to the other delivery position, means actuating each of said pair of switching channels to shift the outlet ends thereof in alternation between two spaced delivery positions, guide channels having their inlet ends located respectively at each of the delivery positions of said pair of switching channels for receiving the separate lengths of rolled stock delivered by said pair of switching channels, said separate lengths of rolled stock being ultimately braked to substantially a standstill at the outlet end portions of said guide channels by friction with the surfaces of said guide channels as said separate lengths of rolled stock slide through the same, and means for removing said separate lengths of rolled stock from the outlet end portions of said guide channels.

3. Guide channel means as defined in claim 2 wherein the outlet end of said first switching channel is shifted between two spaced delivery positions in a first plane and wherein the outlet ends of said pair of switching channels are shifted between two spaced delivery positions in a second plane normal to said first plane and wherein said guide channels are longitudinally curved between their inlet ends and their outlet end portions and have their outlet end portions located generally horizontal and each above the other.

4. Guide channel means as defined in claim 2 wherein said means for removing said separate lengths of rolled stock from the outlet end portions of said guide channel comprises a generally horizontal open-topped terminal channel aligned with the outlet end of each said guide channel, a tube individual to and supporting each of said terminal channels, power means for turning each said tube to carry the associated open-topped terminal channel between an upwardly inclined stock-retaining position and a downwardly inclined stock-discharging position and a stationary cover plate for each said open-topped channel positioned to close the same when in the said stock retaining position.

References Cited in the file of this patent UNITED STATES PATENTS 1,407,169 Rosenkrautz Feb. 21, 1922 1,852,237 George Apr. 5, 1932 2,017,378 Statz Oct. 15, 1935