US 3253446 A
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Description (OCR text may contain errors)
May 31, 1966 T. SENDZIMIR REVERSE ANGLE PLANETARY MILL Filed June 7, 1963 INVENTOR EM DQSLU ATTORNEYS United States Patent REVERSE ANGLE PLANETARY MILL Tadeusz Sendzimir, 9 Randolph Ave., Waterbury, Conn. Filed June 7, 1963, Ser. No. 286,406 8 Claims. (Cl. 72-234) The present invention relates to the method of and apparatus for producing wide strips of metal or other substances by plastic deformation in the hot or cold state, and particularly to the reduction from so-called slab to strip form. The term slab, when applied to steel, means a semi-finished product after reduction from the ingot on a so-called blooming or slabbing mill, or to a product produced directly by casting. A slab is usually a piece of material of rectangular cross-section whose width is several times its thickness and whose length varies from a few feet to several dozen feet. The slab may also be of continuous length if it is produced by continuous casting. In low-carbon steel, a typical slab would have a cross-section of, say, 6" X 40 and might weigh approximately 18 tons. This slab would serve as a base material for the production of strip which could range anywhere from 40" wide to over 80 wide, or wider, but might be only 0.080 thick. Such a strip usually is collected in coil form.
The invention herein described may be used in conjunction with the mill disclosed in my cop-pending US. application, Serial Number 149,642, filed November 2, 1961. The aforementioned copending application discloses a reduction mill of the class where the work rolls make cyclic contact with the workpiece or slab beingv rolled. In other words, the work rolls do not rotate about fixed axes but rotate about axes which move in a direction parallel to the roll-bite at a speed in excess of the translation speed of the workpiece. In such a mill, means other than the work rolls must be provided to feed the slab between the mill rolls. Planetary mills, such as described e.g. in US. Patent 2,710,550, fall under this class of mills and are used throughout this disclosure as an example. Such planetary mills reduce the thickness of the work piece from slab to strip thickness, but do not substantially change the width of said workpiece. The result is that all inclusions, segregations and other defects in the material are elongated in one direction only; therefore, the thus-produced strip shows less advantageous physical properties in the direction transverse to rolling. It is very desirable that the reduction from slab to strip thickness be accompanied by a certain side spreading of the metal, which correspondingly improves transverse properties. This condition is fulfilled in the rolling process as disclosed hereinafter.
The mill described in aforementioned co-pending application provides for feeding the slab to the planetary mill assembly at an angle other than 90 to the roll axes. One principal result of such angular feeding, is that the strip being delivered from the work rolls is wider than the slab fed to the work rolls. As an example, it has been found that if the slab is fed to the mill rolls at an angle of 30 to the axes of the rolls, the strip delivered from the rolls will be twice as wide as the slab fed to the rolls.
By varying the angle at which the slab is fed to the mill rolls, different widths of strip may be produced from a slab of a particular width. However, the large size of the mills, the means for feeding the slab to the mills, the furnace for heating and maintaining the temperature of the slab and other elements forming part of the rolling system, have heretofore made it impracticable to change the angle at which the slab is fed once the system has been set up. For example, when a continuous slab-casting installation is used and the slab fed directly at a 90 angle to the mill, it would be extremely difficult and impracticable to move the slab-casting installation relative to the mill. It would be equally diflicult to change the angle of the rolling mill since it is usually followed by a cooling table and a coiler, which latter components would also have to be moved along with the mill.
Accordingly, the principal object of this invention is to provide means for changing the angle of feed of slab to a mill without need to alter the position of either the furnace and the means for feeding the original slab or the planetary mill which produces the strip and all the equipment subsequent to it including planishing mill or mills, cooling bed and coilers.
Another object of the invention is to provide an intermediate planetary mill between the main feeding portion of the system and the main rolling portion of the system, such intermediate mill performing a rolling operation and being capable of position adjustment to readily adjust the angle of the slab being fed thereto and the angle of the partially reduced slab being fed to the main mill.
Still another object of the invention is to provide an angularly movable mill in conjunction with a stationary mill to control the ultimate width of rolled strip.
Still other objects and advantages of the invention will in part be obvious and will in part be apparent from the specification.
The invention accordingly comprises the several steps and the relation of one or more of such steps with respect to each of the others, and the apparatus embodying features of construction, combination of elements and arrangement of parts which are adapted to effect such steps, all as exemplified in the following detailed disclosure, and
the scope of the invention will be indicated in the claims;
For a fuller understanding :of the-invention, reference is had to the following description taken in connection with the accompanying drawing, in which:
FIG. 1 is a partial schematic plan view' of a mill system incorporating the instant invention, with an alternate position of the intermediate mill being shown in phantom;
FIG. 2 is a schematic elevational view of a mill system incorporating the instant invention; and
FIG. 3 is a schematic elevational view of alternat means for feeding the slab .to the system.
Referring now to FIGS. 1 and 2, a slab 1 1 may be continuously cast in a vertical position by means of a continuous casting installation 12, thereby permitting continuous operation of the mill. A plurality of rollers 13 are provided to feed and guide slab 11 and bend it from the vertical plane of casting -to the horizontal plane of rolling. Rollers 13 guide and feed the slab to the feed rolls 14 disposed on opposite sides of the slab to feed the slab to the first planetary mill while performing a preliminary rolling operation thereon. Feed rolls 14 may be driven by means of a motor (not shown) through couplings 15. A holding furnace 16 is preferably provided to maintain the slab at the desired rolling temperature. As shown, the holding furnace may be advantageously disposed proximate to the feed rolls to keep the heat loss from the slab at a minimum prior to entry to the mill. The first planetary mill indicated generally at 17 would be a roughing mill to initially roll the slab to slab of greater width and smaller thickness. The planetary mill 17 is indicated schematically as having a pair of back-up rolls 18 and a plurality of planetary work rolls 19 which contact the slab. As shown more especially in FIG. 1, slab '11 is fed to planetary mill 17 at an angle to the direction of rolling, thereby providing for an increase in widthof the strip delivered from the mill. The direction of rolling is indicated by arrow 21 in FIG. 1 and the angle of the slab feed with relation .to the direction of rolling is indicated as a all substantially as disclosed in patent applica- 3 tion 149,642 hereinabove referred to. The rolls of planetary mill 17 would be driven by means of a motor 22 located apart from the main structure of the planetary mill carrying the rolls. Telescopic spindles 23 and fiexible couplings 24 would be provided to drive the mill rolls from the motor.
By way of example, a continuously cast slab having a thickness of 6" and a width of 40 would be reduced to a thickness of about by rolls 14. If the slab is thereupon fed to the work rolls of planetary mill 17 at an angle a of 45 to the direction of rolling, it has been found that its width would be increased to over 56". While the exact thickness of the intermediate slab 25 is not important, it is preferable to make it around 2 /2.
The partially rolled slab 25 would be fed to the main or finishing planetary mill, indicated generally at 26, by means of feed rolls 27 which may preferably contact slab 25 along the edges thereof. Feed rolls 27 would be driven in any suitable manner (no shown). While not mandatory, it has been found preferable to position planetary mill 26 with the axes of the rolls parallel to the axes of the first feed rolls 14 so that the strip 28 being delivered from the mill would be parallel to slab 11 being fed to the first planetary mill. Such a set-up has been found to provide maximumspace utilization of the entire rolling system. Planetary mill 26 would be provided with the usual type of back-up rolls 29 and work rolls 30. The rolls may be driven by any suitable means through couplings 31 as shown in more detail in the co-pending application 149,642.
1f the aforementioned orientation is maintained, the direction of rolling would be indicated by the arrow 34 and the line of feed would make the same angle at, but directed to the left this time, with the direction of rolling. Carrying further the previous example, strip 28 delivered from planetary mill 26 would have its width increased to almost 80 and the thickness reduced to approximately 0.100". A finishing .mill, indicated generally at 35, and comprising suitably driven rolls 36, could be placed in series with planetary mill 26 to further reduce strip 28 to its desired finished size, 0.080, for example. The final strip 37 would then be passed over a cooling table 38 and coiled as at 39.
As can be readily seen, the roughing planetary mill 17 is much narrower than the finishing planetary mill 26. 'It is therefore lighter and can be shifted easier to alter the angle of feed of the slab 11. Thus the angle at which the slab is fed to the roughing planetary mill and also the angle at which the partially rolled slab is fed to the main planetary mill, can be readily adjusted, thereby providing for the rolling of slab of a particular width into strip of any number of desired widths.
In changing the roughing planetary mill 17 to a position to roll strip of a'narrower width than the strip rolled in the foregoing example, planetary mill 17 would be shifted to the position shown in phantom in FIG. 1 as 17 At the phantom position, slab 11 would be 'fed to the roughing planetary mill at an angle 0 to the direction of rolling and the partially rolled slab '25 would also be fed at an angle 0 (this time to the left) to the direction of rolling of planetary mill 26. By utilization of telescopic spindles '23 and flexible couplings .24, drive motor 22 need not be repositioned, thereby pnoviding for minimal movement of machinery to effect the change in feed angle. In shifting the roughing planetary mill, it is necessary that a line drawn between the point of first contact of the planetary rolls 30 with the slab 25 at the vertical plane of symmetry of the mill 26, indicated as 41, and the analogous point of roll-bite at planetary mill 17, indicated as 42, be substantially perpendicular to the axes of the rolls of roughing mill 17, so that the partially rolled slab will be fed .to planetary mill 26 in correct direction to the working rolls. In the phantom position of planetary mill 17, angle 0 is smaller than angle a, thereby providing that the finished strip delivered from the mill will be narrower when the planetary mill is in the phantom position 17 than when planetary mill 17 is in the full line position. Thus, by introducing the roughing planetary mill 17 into the system, substantial controlmay be had over the width of strip being rolled by merely changing the position of the roughing planetary mill without disturbing the remainder of the system. It should be noted that feed rolls 27 must also be repositioned when the roughing planetary mill is repositioned. These feed rolls 27 are therefore preferably mounted directly on the housing of the roughing mill 17 so that they automatically move together with it and stay in correct position in relation to it.
FIG. 3 schematically represents an alternate form of the system if the slab is not fed directly from a continuous casting unit. In such a case, the slab 43 would be fed into the holding furn 'ace 16 by means of a roller table 44, slab 43 being preferably in a preheated condition. The remainder of the system would be as heretofore described.
It should be noted that the system heretofore described can also be utilized to roll strip without increasing the width thereof. In such a case, the continuous casting installation 12 would be shifted laterally so that the slab would 'feed directly into the main planetary mill 26, thereby by-passing roughing planetary mill 17. Shifting the continuous tundish and mould laterally, within the tower structure, is a quick and simple operation on a suitably engineered unit and does not encounter such difficulties as are referred to in column 1, line 55, of the present disclosure where a change of the angular relationship as between the cast slab and the planetary mill is considered.
If it is desired to make the said roughing planetary mill 17 stilllighter in order to improve its shiftabil-ity without materially detracting from its performance it can be simplified by providing only one of the two reducing instrumentalities preferably the lower one, as a regular planetary assembly consisting of a backing roll surrounded by a group of usually 12 to 24 pl-ant'ary work-rolls whereas the other (say the upper) instrumentality may be a simple roll of a diameter preferably, al though not necessarily, similar to the overall diameter of the planetary assembly co-acting with it upon the slab. Said roll may be driven independently of the planetary assembly drive at a peripheral speed superior to but approaching the exit speed of slab 25 or it may be driven from the same source of power :as the said planetary assembly, through suitable gearing.
It will thus be seen that the objects set forth above, among those made apparent from the preceding description, are efiiciently attained and, since certain changes may be made in carrying out the above method and in the construction set forth without departing from the spirit and scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.
It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.
What is claimed is:
1. In a planetary installation for the rolling of flat strip from slab, the provision of a supplementary planetary mill disposed ahead of the main planetary mill and at an angle thereto for feeding slab .to said main mill at that angle substantially in the plane of said feeding, said supplementary mill being disposed to receive slab also at an angle thereto, both of said rangles being of approximately the same magnitude, but opposite in direction.
2. In a system for rolling strip, means for increasing the width of the workpiece during rolling comprising, a first rolling mill, means to feed slab to said first rolling mill at an angle thereto, and a second rolling mill adapted to receive and roll the partially reduced slab from said first mill, said first mill being positioned to feed said partially reduced slab to said second (mill at an angle thereto substantially in the plane of said feeding.
3. The system of claim 2 wherein the line of travel of slab to said first mill is parallel to the line of travel of strip from said second mill.
4. The system of claim 2 wherein the angle of feed of slab to said first mill equals the angle of feed of partially reduced sla'b to said second mill.
5. In a system for rolling strip, means for increasing the width of the workpiece during rolling comprising, a first rolling mill, means to feed slab to said first rolling mill at an angle thereto, :a second rolling mill adapted to receive and roll the partially reduced slab from said first mill, said first mill being positioned to feed said partially reduced slab to said second mill at an angle thereto substantially in the plane of said feeding, and means for changing the position of said first mill with relation to said second mill and said means to feed slab to concurrently change both angles of feeding.
*6. In a system for rolling strip, means for increasing the width or" the workpiece during rolling comprising, a first rolling mill, means to feed slab to said first rolling mill at an angle thereto, a second rolling mill adapted to receive and roll the partially reduced slab from said first mill, said'first mill being positioned to feed the partially reduced slab to said second mill at an angle thereto substantially in the plane of said feeding, the line of travel of strip \from said second mill being parallel to the line of travel of strip to said first mill, said angles of deed to said mills being substantially equal, and means for changing the position of said first m-ill relative to said second mill and said means to feed slab to concurrently change both angles iby equal amounts thereby changing the width of the workpiece rolled by the system.
7. The method of adjusting the width of strip rolled bya system for rolling comprising, feeding slab to a first mill at an angle thereto, positioning the first mill relative to a second mill to feed the partially reduced slab from said first mill to said second mill at an angle thereto substantially in the plane of said feeding, and moving said first mill relative to said second mill to change the angle of feed of the workpiece both to the first mill and to the second mill, thereby changing the Width of strip delivered from the mill system.
'8. In a mill system composed of primary and secondary cyclical rolling instrumentalities and means to feed the workpiece to the instrumentalities, the method of controlling the str-ip width comprising the step of, repositioning the angular position of one of the instrumentalities substantially in the plane of said feeding with respect to the other of the instrumentalities substantially in the plane of said feeding.
References Cited by the Examiner UNITED STATES PATENTS 2,345,765 4/1944 Michel 72--l8 2,505,146 4/1950 Ryan. 2,787,046 4/ 1957 Wagstaff 29-l 8 CHARLES W. LANHAM, Primary Examiner.
C. H. HITTSON, Assistant Examiner.