GB2082490A - Rolling guide for steel U type- sheet piling - Google Patents

Abstract

A roller guide (20) for both grinding and forming steel U type- sheet piling comprises two tandem inner rollers (35) each disposed adjacent the inner surface of a flange of the piling for bending fingers formed at the end of the flange, and two tandem outer rollers (36) each engaging said fingers. Roller gaps (S) between the inner and outer rollers (35,36) are adjustable, shelves 44,52 for supporting a bottom (5) of the fingers are formed on one or both of the inner and outer rollers, and at least the inner rollers each comprises a roller shaft (37) and a roller body (39) incorporating therein a bearing (38) being in contact with the roller shaft. The roller guide is disposed adjacent the delivery of a finishing roll and the piling is advanced by the roll into the roller guide (20) at a low initial speed. <IMAGE>

Description

SPECIFICATION Rolling guide for rolling steel U type-sheet piling and rolling method thereof The present invention relates to a roller guide for hot rolling a steel U-sheet piling and a rolling method thereof, and particularly to improvements in a roller guide used for bending a Larssen type fingers and a rolling method using the roller guide.

In general, steel sheet pilings are widely used for cut-off walls and water leakage prevention in the waterway construction in revers and the revetment works in harbour construction. According to the shapes in cross section, the steel sheet piling is classified into several types including a steel U type-sheet piling, a steel Z type-sheet piling, a steel straight websheet piling, an interlocking steel pipe piling and the like, out of which the steel U typesheet piling is most widely used. Furthermore, according to the shapes of fingers serving as the connections between the sheet pilings, the steel U type-sheet piling is classified into several types, out of which Larssen type one as shown in Fig. 1 is widely used in general.

As shown in Fig. 1, the steel U type-sheet piling 1 having the Larssen type fingers is provided at opposite ends of a web 2 thereof with flanges 3 and formed into a latter 'U' shape in cross section by the provision of the web 2 and flanges 3. The fingers 4 formed at the end of the flange 3 includes a finger bottom 5 bent outwardly and a finger 6 being formed by erecting the end edge portion of the finger bottom 5 and inclining the tip end thereof toward the flange 3. As shown in Fig.

2, the steel U type-sheet piling 1 having the abovedescribed Larssen type fingers 4 is inverted in direction with respect to adjacent steel U type-sheet pilings 1, connected at the fingers 4 to the adjacent steel U type-sheet pilings 1, and driven into the ground, thus being formed into a wall. The steel U typesheet piling 1 having the Larssen type fingers 4 has such characteristic features that the connections between the fingers 4 are not easily releasable, water leakage preventiveness is high, durability is high in use where pull-out and drive-in operations are repeated, the fingers is compact in size and high in sectional performance and the like. Consequently, in order to fully bring out the characteristic features as described above, the result of rolling of the fingers 4 is very important.

As the methods of rolling the steel U typesheet piling 1 having the Larssen type fingers 4, heretofore, there have been two methods including a method of rolling the fingers 4 by use of caliber rolls only and a method of forming the fingers 4 by use of caliber rolls and roller guides in finishing rolling step. As shown in Figs. 3A through 3D, forming of the fingers 4 by use of the caliber rolls only is performed during final four passes in such a manner that (A) firstly the finger 6 is generally formed, (B) secondly, the inner and outer Nall surfaces are formed, (C) thirdly, the finger 6 is intermediately bent, and (D) finally, bending of the finger 6 is finished.With the rolling of the fingers 4 by use of the caliber rolls on y as described above, such disadvantages have been presented that many pass numbers needed for forming the fingers require increased pass numbers. At the end period of the rolling process, two passes needed for bending the finger require longer period o- time, as the steel is formed to longer size of length, and moreover, to provide caliber rolls for forming the finger 4, results in increased costs in manufacture of the caliber rolls. To obviate the abovedescribed disadvantages, there has been adopted a method of forming the fingers by use of a roller guide.

This method by use of the roller guide rolles a bloom 7 as the blank to provide a steel U type-sheet piling 1 (Refer to Fig. 1) through a break down caliber roll 8, an roughing caliber roll 9 and a finishing caliber roll 10 as shown in Fig. 4. The roller guide 11 is provided adjacent the entering side of the final caliber (Kal. 1) of the finishing caliber roll 10, and caused to carry out bending of the finger 6 of the fingers 4, so that one caliber can be reduced in number and the period of time required for rolling can be decreased.As shown in Fig. 5, the roller guide 11 provided adjacent the entry of the finishing caliber roll 10 has a pair of rollers including an inner roller 1 2 disposed at the inner surface side of the flange 3 of the steel U type-sheet pilinc 1 and an inverted cone-shaped outer roller 1 13 for being engaged with the fingers 4 to bertd the finger 6. These inner and outer rollers 12, and 1 3 are integrally, projectingly providec at vertically opposite ends thereof with roller shafts 1 4 and 15, respectively. An upper bearing box 1 6 for supporting the roller shaft 14 of the inner roller 1 2 is opposed to the web 2 of the steel U type-sheet piling 1.A lower bearing box for supporting the roller shaft 1 5 of the outer roller 1 3 is a fixed gu de 1 7 for supporting the finger bottom 5 of the fingers 4, and, when the fingers 4 slides or this guide 17, the finger 6 is bent by the outer roller 1 3. Rollings by the inner and outer rollings 12, 1 3 as described above ate simultaneously carried out on the fingers at the other end, not shown. In the finishing rolling step provided with the abovedescriblzd roller guide, in conducting passes with the calibers (Kal. 1, Kal. 2 and Kal. 3) of the finishing caliber roll 10, the finger 6 is formed in the fingers 4 as shown in Figs. 6A throu 3h 6D.More specifically. the blank to be rolled, which has been passed through the intermediate caliber roll 9 has its tip end of the flangs 3 deformed at Kal. 3 as shown in Fig. 6A, further deformed to be provided with the inner and outer wall surfaces at Kal. 2 as shown in Fig. 6B. Subsequently, immediately before Kal. 1 being the final pass, the blank is formed with the finger 6 by the inner and outer rollers 1 2, 1 3 of the roller guide 11 as shown in Fig. 6C, and the forming of the fingers 4 is completed at the final Kal. 1 as shown in Fig. 6D.

However, there have been various problems with the rolling by use of the conventional roller guide 11. More specifically, firstly, the guide 1 7 for guiding the fingers 4 is interposed between the inner and outer rollers 1 2 and 1 3 which constitute the roller guide 11.

There have been such problems that this guide 1 7 being fixed, when receiving a vertical component P of the bending force rendered by the outer roller 13, is subjected to friction with the finger bottom 5. As the steel sheet piling passes therethrough, friction increases, particularly, wear is caused to a contacting portion between the roller 1 3 and the finger 6 to a considerable extent, and scratches are caused to the product.Furthermore, the finger bottom 5 is deformed to a shape similar to the worn surface of the guide 1 7. Further, there are presented such disadvantages that the worn guide 1 7 causes the slope of the finger 6 to be not constant and unstabilized, and the friction coefficient is increased, thus the finger does not come out of the roller guide 11.

Secondly, the roller guide 11 has been provided at the inlet side of the final pass (Kal. 1) of the finishing caliber roll 10, and hence, if a plurality of the pair of inner and outer rollers 12, 1 3 are continuously provided to perform bendings at two stages or more, then there occurs such a problem that only the force for conveying the blank by table rollers cannot pass through the roller guide 11, and, unless the blank is forcibly driven into the roller guide 11, the blank does not come out of the guide roller.If the blank is forcibly driven into the roller guide to avoid the not coming out of it, then the roller shafts 14, 1 5 and the bearings tend to be damaged, thus the occurring of the burned surface of the rollers 12, 1 3 caused by a difference between the rotational speed of the rollers 12, 1 3 and the bitten-in speed of the blank.

Thirdly, such a construction has been adopted that the rollers 12, 1 3 are integrally formed with the roller shafts 14, 15, respectively, and the bearings are secured to the upper and lower portions of the rollers 1 2, 13, independently of the rollers, so that a product of steel LI type-sheet piling 1 having a small height of the flange 3 cannot be rolled. More specifically, in the case the height of the flange 3 is small, the inner roller 1 2 backs a space sufficient for providing an upper bearing box therein, so that the roller shaft 14 and bearing big enough for bearing he bending force of the finger 6 cannot be used.Furthermore, there are such disadvantages that the inner and outer rollers 12, 1 3 are provided at the upper and lower portions thereof with the bearing boxes, the assembling accuracy tends to be deteriorated and the assembling may require a long period of time.

Now, one of the most important factors in producing the steel U type-sheet piling 1 is to form the fingers 4 capable of being smoothly driven in without being disengaged from the fingers of the adjacent steel U type-sheet piling when the steel sheet pilings are connected to one another. A condition required for preventing the fingers 4 from being disengaged is to have a proper contact length of the finger 6 exceeding the minimum contact length g as shown in Fig. 7, in addition to the fingers having a satisfactory mechanical strength. Furthermore, for the drive-in characteristics, it is necessary that the lock opening width b shown in Fig.8 is flred so that the swing angle 8 of the fingers 4 shown in Fig. 9 is appropriate.The abovedescribed contact length g and swing angle S are related to each other in connection with the opening width b as shown in Fig. 10, and the contact length g is inversely proportional to the swing angle S.

Consequently, it is desirable to freely adjust the opening width b of the fingers 4 depending on the details of the construction work.

However, in the rolling by use of only the abovedescribed caliber rolls, the change of the lock opening width b necessitates to change the shapes of calibers of the rolls, with the result that the changes of the rolls is required, thereby presenting a disadvantage.

The present invention has been developed to obviate the abovedescribed disadvantages of the prior art and has as its object the provision of a roller guide for rolling a steel U type-sheet piling, with which, in rolling a steel U type-sheet piling, no scratches are caused to the finger bottom 5 and finger 6 of the fingers 4, the blank to be rolled is stably driven into the roller guide by the enforced force of the caliber roll without the driving force of the table rollers, further, steel U typesheet pilings having the heights of flange covering a wide range can be rolled and the opening width of the fingers can be freely adjusted, and a method of rolling thereby.

To achieve the abovedescribed object, according to the present invention, the roller guide for bending is provided adjacent the delivery side of the finishing caliber roll, the roller gap formed between the inner and outer rollers is made variable, a brim for supporting the finger bottom of the fingers is provided on either one or both of the inner and outer rollers, at least the inner roller is constituted by a roller shaft and a roller body incorporating therein a bearing, further, the blank to be rolled is advanced by the driving force of the finishing caliber roll, previously driven into the roller guide provided at the delivery side of the finishing caliber roll, and the rolling speed is increased after the forward end of the blank has passed through the roller guide.

The abovementioned features and object of the present invention will become more apparent with reference to the following description, taken in conjunction with the accompanying drawings, wherein like reference numerals denote like elements, and in which: Figure 1 is an end view showing the steel U type-sheet piling having Larssen type fingers; Figure 2 is a block diagram showing the connected state of the steel U type-sheet piling as described above; Figures 3A through 3D are sectional views showing the fingers, respectively, during finishing process by use of only the caliber rolls of the prior art; Figure 4 is a flow sheet of rolling by use of the conventional roller guide; Figure 5 is a sectional view showing the essential portions of the conventional roller guide;; Figures 6A through 6D are sectional views showing the fingers, respectively, during finishing process by use of the roller guide; Figure 7 is a sectional view showing the contact length of the fingers; Figure 8 is a sectional view showing the lock opening width of the fingers; Figure 9 is a sectional view showing the value of rotation of the fingers; Figure 10 is a graphic chart showing the relationship between the contact length and the value of rotation in connection with the opening width of the fingers; Figure 11 is a flow sheet of rolling, showing the positional arrangement of the roller guide in this embodiment; Figure 12 is a sectional view showing the forms of the blank to be rolled in the respective steps; Figure 13 is a partially broken plan view showing the roller guide in this embodiment; Figure 14 is a front view thereof;; Figure 75 is a sectional view taken along the line XV-XV in Fig. 14; Figure 16 is an enlarged view showing the essential portions shown in Fig. 15; Figures 1 7A through 1 7D are sectional views showing the fingers during finishing process in this embodiment; and Figure 18 is a front view showing the essential portion of a modified embodiment.

Detailed description will hereunder be given of an embodiment of the roller guide for rolling a steel U type-sheet piling and a method of rolling thereby according to the present invention with reference to the drawings.

Fig. 11 shows the positional arrangement of the roller guide 20 in this embodiment.

This drawing is a flow sheet of rolling the steel U type-sheet piling, in which, a bloom 21 being rectangular in cross section, which has been heated to about 1250"C in a heating furnace, not shown, is rolled into a steel U type-sheet piling through three reversible mills. More specifically, firstly, the bloom 21 is subjected to 1 -- 3 passes per caliber roll, totalling up to 7 passes by use of three types of calibers (Kal. 10 - 8) formed in a roughing caliber roll 22 while the gap between the rolls is varied. The blank, which has passed through the breakdown caliber roll 22, is rolled by use of four types of calibers (Kal. 7 4) in a roughing caliber roll 23 disposed downstream of the breakdown caliber roll 22, totalling up to 5 passes.Subsequently, the blank is subjected to one pass per caliber by use of three types of calibers (Kal. 3 - 1) formed in a finishing caliber roll 24. A roller guide 20 in this embodiment is provided at the delivery side of Kal. 2 of the finishing caliber roll, and the blank 26, after its fingers 27 have been rolled, is formed into the form of a product 25 by use of Kal. 1. Fig. 12 shows forms rolled by the calibers (Kal. 10 ~ 1) in the abovedescribed caliber rolls 22 24.

As described above, the roller guide 20 is disposed at the delivery side of Kal. 2 of the finishing caliber roll 24 and the construction thereof is shown in Figs. 1 3 through 1 5. The roller guide 20 has a guide box 28 serving as a jacket member, and a guide groove 29 is formed on the undersurface of this guide box 28 in a direction perpendicular to the advancing direction of the blank 26. A rest bar 30 is coupled into this guide groove 29, so that the roller guide 20 as a whole can move by being guided by the rest bar 30 in a direction perpendicular to the advancing direction of the blank 26. Furthermore, a wedge-shaped block 32 is detachably fastened into the guide groove 29 and the guide roller 20 can be fixed by tightening a nut 34 threadably coupled onto a bolt 33 extending through the wedge-shaped block 32.The blank 26 is passed through the interior of this guide box 28 in an inverted letter 'U' shape.

In this guide box 28, a pair of inner and outer rollers 35, 36 are provided in opposed relations to the fingers 27 at opposite ends of the blank, respectively, and further, another pair of inner and outer rollers 35A, 36A similar to the abovedescribed pairs are disposed downstream thereof at opposite sides.

The inner roller 35 includes a roller shaft 37 vertically erected and a roller body 39 incorporating therein a bearing 38 being in rolling contact with the outer peripheral surface of the roller shaft 37, and the roller body 39 is rotatably supported on the roller shaft 37. The roller 37 is projected from the upper and bottom ends of the roller body 39, and the lower end of the roller shaft 37 is supported on a bottom board 41 of a center guide 40 secured to the center of a floor board of the guide box 28. The center guide 40 has a wall member 42 erected from the center of the bottom board 41 between the adjacent inner roller 35 and itself, and secured to the upper end of this wall member 42 is a top retainer 43 opposed to the inner roller 35 from above.

The upper end portion of the roller shaft 37 is supported by the top retainer 43. The roller body 39 constituting the inner roller 35 is brought into rolling contact with the inner surface of the flange 3 of the blank 26 to support a bending force rendered by the outer roller 36, and a shelf 44 is integrally formed on the lower portion of the roller body 39, to thereby support the finger bottom 5 of the blank 26. This shelf 44 has a smooth curved surface contiguous to the roller body 39, and this curved surface forms an inclination a of a predetermined value (' 20 degrees) with a surface contacting the finger bottom 5. The same arrangement as in the inner roller 35 is adopted in the inner roller 35A disposed downstream thereof.

On the other hand, similarly to the inner roller 35, the outer roller 36 includes a roller shaft 45 and a roller body 47 incorporating therein a bearing 46, and the roller body 47 is rotatably supported on the roller shaft 45.

The lower end of the roller shaft 45 projected from the undersurface of the roller body 47 is supported by a side guide 48 being of a letter 'U' shape in cross section and secured to the side surface of the guide box 28, while, the upper end of the roller shaft 45 is supported by a top retainer 50 sucured to the upper portion of the side guide 48 opposed to the outer roller 36 from above through a bolt 49.

Further, threadably coupled to the top retainer 50 is a retaining bolt 51, and the upper end of the roller shaft 45 is brought into pressing contact with and fixed to the lower end of this retaining bolt 51. The roller body 47 constituting the outer roller 36 presses the finger 6 of the blank 26 downward to the flange 3, and is formed into an inverted cone-shape to be able to bend the finger. Integrally formed at the lower end of this roller body 47 is a shelf 52 for supporting the finger bottom 5 iri the same fashion as the shelf 44 provided on the roller body 39 of the inner roller 35. This shelf 52 has a smooth curved surface contiguous to the roller body 47, and this curved surface forms an inclination ss of a predetermined value (' 20 degrees) with a surface contacting the finger bottom 5.Furthermore, the outer roller 36A disposed downstream is of the same arrangement as the outer roller 36 disposed upstream thereof except that the roller body 47A is different in shape from the roller body 47. More specifically, the total degrees of bending angle for the finger 6 in the roller guide 20 is normally 45 to 60 degrees, and the shapes of the roller bodies 47 and 47A are determined such that this ratio of bending is divided half-and-half be tween the outer rollers 36 and 36A disposed upstream and downstream, respectively.

The side guide 48 for supporting the outer rollers 36 and 36A is pressed from above and fixed by fixing bolts 53 through the upper surface of the guide box 28, and mounted on the guide box 28 in a manner to be movable in a direction perpendicular to the advancing direction of the blank 26 (Refer to Figs. 1 3 and 14). For the movement in the crosswise direction as described above, there are provided bolts 55 planted in the side guide 48, projecting through the side well of the guide box 28 and threadably coupled thereto with - nuts 54 and pushing bolts 56 threadably coupled to the side wall of the guide box 28 and being in abutting contact with the side wall of the side guide 48.To move this side guide 48, the fixing bolts 53 are loosened the pushing bolts 56 are also loosened, and the nuts 54 threadably coupled to the bolts 55 are further, screwed in, whereby the pulling bolts 55 are withdrawn to the outside to move the side guide 48 outward, so that a roller gap S between the inner and outer rollers 35, 36 can be increased (Refer to Figs. 1 5 and 16). Meanwhile, when the nuts 54 are untightened and the pushing bolts 56 are screwed in, the roller gap S is decreased.

Consequently, the roller gap S is freely adjustable through the operation of the bolts 55 and the pushing bolts 56, so that the opening width b of the fingers 4 of a product 25 can be desirably adjusted.

Furthermore, a lower forward end guide 57 extendedly formed at the delivery side of Kal.

2 of the finishing caliber roll 24 for guiding the web 2 of the blank 26 is secured to the upstream side of the roller guide20 through a pin 58. This lower forward end guide 57 is rotatable around the pin 58 and adapted to be constantly in contact with the caliber roll 24. A top retainer guide 59 is secured to the upper inner wall surface of the guide box 28 in the advancing direction of the blank 26.

The thickness of a liner 60 inserted between an upstream side upper edge portion of the guide box 28 and the top retainer guide 59 is adjusted so that the forward end of the top retainer guide 59 can approach the finishing caliber roll 24.

In the drawing, designated at 61 is an auxiliary support member secured for supporting the guide box 28 in the case the roller guide 20 is long.

Description will now be given of the method of rolling the blank 26 by use of the roller guide 20 with the abovedescribed arrange ment.

The blank 26, which has been threaded between the calibers Kal. 2 of the finishing caliber rolls 24 for rolling, is disposed at the delivery side of the caliber Kal. 2. The number of rotation of the caliber rolls is decreased in advance, and the forward end of the blank 26 is driven into the roller guide 20 at a slow rolling speed. Immediately after the forward end of the blank 26 has gone out of the roller guide 20, the rotational speeds of the caliber rolls 24 are increased to the normal rolling speed, whereby the threading of the blank 26 through the roller guide 20 is effected by the torque of the finishing caliber rolls 24.

Fig. 1 7 shows the forming conditions of fingers in the finishing rolling process including the roller guide 20. In the caliber (Kal. 3) of the finishing caliber rolls 24 through which the blank 26 is initially threaded, the finger 6 is roughly formed as shown in Fig. 17A. In the subsequent caliber (Kal. 2), the blank 26 is further rolled. Immediately after leaving the caliber (Kal. 2), as shown in Fig. 17, the blank 26 thus rolled has its finger 6 bent by means of the roller guide 20 as shown in Fig.

17C. In this case, in the roller guide 20, due to the presence of the shelves 44, 52, the undersurface of the finger bottom 5 is supported, so that occurrence of scratches on the finger bottom 5 can be avoided. Moreover, owing to the inclinations a and ss of the shelves 44, 52, buckling of the finger bottom 5 in ward (shown in Fig. 5) can be avoided because the finger bottom is bulged downward. Furthermore, the roller bodies 39, 47 are separated from the roller shafts 37, 45 to be individually rotatable and no difference in speed occurs between the blank 26 and the roller bodies 39, 47, so that scratches on the surfaces contacting the finger 6 can be prevented from occurring. The blank 26, which has passed through the roller guide 20 as described above, is threaded through the subsequent caliber (Kal. 1) where the finger 6 is formed.In this case, the finger is rolled with a gap Z being formed between the outer surface of the finger 6 and the finishing caliber roller 24, and mainly the flange 3, web 2 and finger bottom 5 are formed.

Further, when bending is carried out by use of the roller guide 20, each roller gap S can be adjusted. By this adjustment of each roller gap S, the opening width b of the fingers 4 can be desirably adjusted within the limit of a gap Z of the final caliber (Kal. 1) in the finishing caliber roll 24. More specifically, each side guide 48 (shown in Fig. 13) is changed its positional relationship with the guide box by the adjustment of the nut 54, bolt 55 and pushing bolt 56, whereby each roller gap S is changed in value, so that each decreased roller gap S can reduce the opening width b. This opening width variation is normally 2 mm, and, in general the roller gap S is changed within the limits of 2 - 6 mm.

Meanwhile, the blank is finally rolled by the final caliber (Kal. 1). In the case the fingers 4 is subjected to finishing rolling, if the gap Z (See Fig. 17D) is present, a change in the opening width with roller results in a change in the opening width of the product. In contrast to the above, in the case the gap Z is not present, if an opening width more than the opening width of the final caliber (Kal. 1) is bended by the guide roll 20, a fingers 4 which has the same opening width as the opening width of the final caliber (Kal. 1) has is rolled by the final caliber. By this arrange ment, the lock opening width b is adjustable in the condition that the gap Z is present in the final caliber (Kal. 1).According to the experiments, when the roller gap S was changed by + 2 mm, the lock opening width b was changed by + 1 mm, whereby the contact length g was adjusted by about 3 mm and the swing angle 8 was adjusted by about 7 degrees.

Fig. 1 8 shows a second embodiment having such an arrangement that, out of the inner and outer rollers 35 and 36, only the inner roller 36 disposed at one side is formed with a shelf 44 and the outer roller 36 opposed thereto is not formed with a shelf. In this case, to allow the blank to pass through a space formed between the inner and outer rollers 35 and 36 in stabilized conditions, it is desirable that the inclination of the shelf 44 is 5 degrees or less.

As has been described hereinabove, according to a roller guide for rolling a steel U typesheet piling and a rolling method thereof, the roller is improved in its shape by forming on the roller with a shelf capable of supporting the finger bottom, so that the blank is protected from scratches and burning surfaces.

Moreover, the roller is constructed such that the roller incorporates therein a bearing which is separately formed from the roller shaft, so that a sheet piling having a flange small in height can be rolled, sheet pilings having flanges in wider height range can be rolled, and the rollers can rotated very smoothly.

Furthermore, the roller guide is disposed at the delivery side of the finishing caliber roll and the blank is advanced by the torque of the finishing caliber roll, so that the need to provide driving means for the forcible approach run of the blank can be eliminated.

Moreover, such a process is adopted that the blank is driven into the roller guide at a low speed in advance, whereby an impact force of the blank is avoided acting on the roller guide, so that the service life of the roller guide can be extended. In particular, the lock opening width of the fingers can be changed within the limit of the gap of the final caliber of the finishing caliber roll, so that it becomes possible that both the sheet pilings, in which the drive-in characteristics is considered most important, and of the sheet pilings, in which the water leakage preventiveness is considered most important, can be desirably rolled.

It should be apparent to one skilled in the art that the abovedescribed embodiments are merely illustrative of but a few of the many possible specific embodiments of the present invention. Numerous and varied other ar rangements can be readily devised by those skilled in the art without departing from the spirit and scope of the invention.

Claims (8)

1. A roller guide for hot rolling a steel U type-sheet piling, comprising inner rollers each disposed at the side of the inner surface of flanges for bending a Larssen type fingers formed at the forward end of the flange of the steel U type-sheet piling, and outer rollers each engaging said fingers, wherein roller gaps between the inner and outer rollers are made variable.

2. A roller guide for rolling a steel U typesheet piling, comprising inner rollers each disposed at the side of the inner surface of a flange for bending a Larssen type fingers formed at the forward end of the flange of the steel U type-sheet piling, and outer rollers each engaging said fingers, wherein roller gaps between the inner and outer rollers are made variable and a shelf or shelves for supporting a finger bottom of the fingers are formed on one or both of the inner and outer rollers.

3. A roller guide for rolling a steel U types sheet piling, comprising inner rollers each disposed at the side of the inner surface of a flange for bending a Larssen type fingers formed at the end of the flange of the steel U type-sheet piling, and other rollers each engaging said fingers, wherein roller gaps between the inner and outer rollers are made variable, a shelf or shelves for supporting a finger bottom of the fingers are formed on one or both of the inner and outer rollers, and, out of said inner and outer rollers, at least said inner rollers each comprises a roller shaft and a roller body incorporating therein a bearing being in rolling contact with the roller shaft.

4. A roller guide for rolling a steel U typesheet piling as set forth in claim 1, 2 or 3, wherein said inner and outer rollers are disposed upstream and downstream in the direction of flow of a blank, and the ratio of bending of a finger is divided half-and-half between the outer rollers disposed upstream and downstream.

5. A roller guide for rolling a steel U typesheet piling as set forth in claim 1, 2 or 3, wherein a shelf or shelves provided on one or both of said inner and outer rollers for supporting the finger bottom of the fingers each have a smooth curved surface contiguous to the roller body, said curved surface forming an inclination of a predetermined value with a surface contacting the finger bottom.

6. A roller guide for rolling a steel U typesheet piling as set forth in claim 1, 2 or 3, wherein said roller guide for rolling is disposed adjacent the delivery of a finishing caliber roll.

7. A method of rolling a steel U type-sheet piling for bending a fingers by means of a roller guide for rolling comprising inner rolLers each disposed at the side of the inner surface of a flange for bending a Larssen type fingers formed at the forward end of the flange of the steel U type-sheet piling and outer rollers each engaging said fingers, wherein roller gaps between the inner and outer rollers are made variable, a shelf or shelves for supporting a finger bottom of the fingers are formed on one or both of the inner and outer rollers, saidguide roller, in which, out of said inner and outer rollers, at least said inner rollers each comprises a roller shaft and a roller body incorporating therein a bearing being in contact with the roller shaft, is disposed adjacent the delivery of a finishing caliber roll, a blank is advanced by a torque of said finishing caliber roll, the blank is bitten into the roller guide at a low speed in advance, and, immediately after the forward end of the blank has gone out of the roller guide, the rolling speed is increased.

8. A roller guide for hot rolling a steel U type-sheet piling which guide is substantially as hereinbefore described with reference to any of Figs. 11 to 1 8 of the accompanying drawings.