US1850026A - Rolling of channel sections with wide flanges - Google Patents

Description

March V15. 1932.. J. MEISER 5 ,0

ROLLING OF CHANNEL SECTIONS WITH WIDE FLANGES Filed Jan. 13. 1930 2 Sheets-Sheet 2 l'bventar B vfiwzeb z M Patented Mar. 15, 1932 .J'OS EF MEISER, OF DOBTHURD, GERMANY BOLIJINGDF CHANNEL SECTIONS WITH WIDE FLANGES Application flled'ifanuary is, 1930, Serial No.

relates to method of rolling especially those with wide to provide a desirable im- My invention channel sections, flanges and aims provement. I

In rolling metal sections. by the operation of conducting metal bars through passes comprising pairs of rolls that gradually approximate the form and shape of the finished section. it is necessary for thecentre of gravity of the cross sectional surface of each section (corresponding to the pass for the time being) to lie nearly as possible in a line drawn midway between the axesof the two rolls and parallel therewith. 1

When dealing with" wide-flange channel sections wherein the centre of gravity is situated very near the web of the iron, the fulfillment of the above condition of the rolling art (as is essential for steady running) has heretofore made it necessary to very considerably weaken the roll that acts on the hollow side of the channel, at the part occupied by the flanges. Consequently, either a rapid destruction of the rolls had to be counted upon, or stronger and heavier rolls had to be used.

My invention obviates this disadvantage or necessity for stronger and heavier rolls which are costly, in that, while maintaining the total width of the section always the same, I cause the web of the roughed section, between the flanges, to draw towards the interior of the channel, thus displacing the centre of gravity of the cross section away from'the web and in the direction of the flanges. the web being flattened out only in the final finishing pass. At that stage, however, the weakening of the rolls is not so important, the final pass being situated near thebearings of the rolls.

0 A practicable embodiment of the invention is diagrammatically illustrated in the accompanying drawings, in which1:--

Fig. 1 shows a firstpair of roughing rolls in side elevation; r

Fig. 2 is a similar elevation Iota second pair of roughing rolls 4 gig. 3 shows the pair of finishing rolls;

Fig. 4 shows how the "displacement of the rolling-mill practice.

centre of gravity is efi'ectedfby modifying 420,577, aim in Germany February 25, 1929.

the shape of the roughed sections according to my invention.

It is assumed in the representation that 2. rolled bar must be put through ten passes denoted at 1, 2, 3 et seq. to 10. In the first pass, 1, it is given the cross sectional form A, and thereafter in succession the forms B, C, D by the first pair of rolls R and R then it is given in succession the forms E, F, G by the second pair of rolls R and R and lastly it is given in succession the forms H, J, K between the final pair of rolls R and B In each of Figs. 1 to 3, the central axes of said pairs of rolls (R and'R R and R and R and R are indicated by the dot-and-dash lines aa: aa, while the line of action, midway between said axes and crossed at equal speed by corresponding points of the co-acting pair of rolls, is indicated by 6-6. As already stated, it is necessary in rollingmill practice to have the centre of gravity of the cross sectional surface of each of the several'forms A, B, C et seq. to K coincide apwithout having to weaken the rolls unduly in places, I give the roughed sections forms that progressively approach the shape of the letter M, so that the web of the channel sectionwill be depressed or recessed in the centre like a saddle, this shape being retainedup to the last roughed section J, shown 4 at the pass 9 in Fig. 3.

Fig. 4=- shows what transverse displacement and what saving in the diameter of the rolls I efiect in this manner. The'heavy outline,

obliquely hatched, illustrates the course of the web of a roughed section approximately corresponding tothe form-J in the pass 9,

whilst the adjacent thinner outline shows the penultimate shape obtained in existing thisshape is substantially straight at c; The axis of gravity of this usual shape is indicated by the line H. Now, as the result of my givmg the web the curved form repre- It will be seen that roll.

formative blank in the successive stages ofv I '50 I sented by d e f and, at the same time, drawing the flanges of, the section slightly in towards the centre, as shown, the axis of gravity is displaced from the position H to y--y and the centre of gravity is displaced, by

the distance .2, from the point S to the point S in the direction of the free ends of the flanges. It will be apparent that to maintain the aforesaid condition while employing thev usual shapes of roughed sections with straight web a, the roll R would have to be cut deeper, by said distance 2, in the centre in pass 9, and would therefore be considerably more liable to damage in rolling.

By not pressing the web out flat until the final pass 10, it is unnecessary to recess the roll R more deeply except in this particular portion which is near the bearing of the Consequently, the roll is subjected to less stressing as a whole, and has a lesser tendency to fracture.

Having now particulary' described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is 1. In amethod of producing channel sections of metal with wide flanges by passing a blank or bar of the metal through a succession of forming spaces or passes between oppositely rotated pressure rolls, the improvement which consists in drawing the intermediate or web portion of theforming section inward toward the center of the channel in the successive stages while maintaining the width thereof always the same, so that the centre of gravity of the section will be displaced in the direction of the free ends of its flange portions, and in the final step or pass back-drawing and flattening said web portion while still maintaining the section at the same width.

2. In the process of producing channel sections of metal with wide marginal flanges by passing a blank or bar of the metal through a plurality of successive forming spaces or passes between oppositely rotated press rolls, the improvement which consists 1n drawing the central portion of the formation inwardly toward the center in the mean direction of its sides simultaneously shaping into the flange portions of the finished section without varying the width of the piece-from that originally, so as to displace the centre of gravity of the forming section in said direction or toward. the free ends of its flange portions'during the suc cessive press actlons, and finally back-drawing and flattening out said central portion forming the web of the section while maintaining it still at the original width.

3. The improved' ,.method of producing channel sections of metal with wide marginal flanges, characterized passing a blank or bar of the metal through a progressive succession of forming spaces or passes be,

tween oppositely rotated rolls pressing the same into shape; drawing the central or webforming portion of the graduallyshaped section inwardly toward the center in the mean direction of its simultaneously forming flange portions without varying the width of the section from that of the original blank, so as in the successive stages to displace the sections center of gravity in said direction toward its free ends; and in the final step or pass drawing said central web-forming portion in oposite direction to a flat plane with flange portions at desired angle thereto in the completely formed section, while maintaining the latter still at the same width.

4. A method of rolling'channel sections oi metal having webs and wide flanges which consists in passing the blank through roughing passes and then through a finishing pass between shaping rolls, maintaining in all said roughing passes the metal "to "a constant width and simultaneously in said roughing

Images